Change search
Refine search result
12 1 - 50 of 67
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Abramson, Nils
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Article may have left false impression that light-in-flight method is new2008In: Laser Focus World, ISSN 1043-8092, Vol. 44, no 4, p. 10-10Article in journal (Other academic)
  • 2.
    Abramson, Nils
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    FEMTOSECOND IMAGING Motion picture of short pulses2011In: Nature Photonics, ISSN 1749-4885, E-ISSN 1749-4893, Vol. 5, no 7, p. 389-390Article in journal (Refereed)
  • 3.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Appearance of Objects at Relativistic Velocities, a Holographic Approach2010In: SEARCH FOR FUNDAMENTAL THEORY / [ed] Amoroso RL, Rowlands P, Jeffers S, MELVILLE, NY: AMER INST PHYSICS , 2010, Vol. 1316, p. 118-124Conference paper (Refereed)
    Abstract [en]

    A diagram borrowed from holographic interferometry has been applied to visualize phenomena in Special Relativity. It displays how a sphere of observation is by velocity elongated into an ellipsoid of observation and produces graphically all the well accepted equations of Einsteins Special Relativity. The Lorentz contraction, however, is explained as an elongation of the measuring rod, the meter, which by definition is based on either a specific number of wavelengths or the velocity of light multiplied by time. The diagram displays the total apparent object distortions including not only the Lorentz contraction but also larger apparent contractions and elongations caused by the classic Doppler Effect. The reasons of these deformations are the delays caused by variations in distance from observer to different parts of the moving object. In this paper we do not discuss the meaning of apparent, as compared to real, deformation.

  • 4.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Holodiagram: elliptic visualizing interferometry, relativity, and light-in-flight2014In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 53, no 11, p. 2398-2404Article in journal (Refereed)
    Abstract [en]

    In holographic interferometry, there is usually a static distance separating the point of illumination and the point of observation. In Special Relativity, this separation is dynamic and is caused by the velocity of the observer. The corrections needed to compensate for these separations are similar in the two fields. We use the ellipsoids of the holodiagram for measurement and in a graphic way to explain and evaluate optical resolution, gated viewing, radar, holography, three-dimensional interferometry, Special Relativity, and light-in-flight recordings. Lorentz contraction together with time dilation is explained as the result of the eccentricity of the measuring ellipsoid, caused by its velocity. The extremely thin ellipsoid of the very first light appears as a beam aimed directly at the observer, which might explain the wave or ray duality of light and entanglement. Finally, we introduce the concept of ellipsoids of observation.

  • 5.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    INSTANT RANDOM INFORMATION2010In: SEARCH FOR FUNDAMENTAL THEORY / [ed] Amoroso RL, Rowlands P, Jeffers S, MELVILLE, NY: AMER INST PHYSICS , 2010, Vol. 1316, p. 113-117Conference paper (Refereed)
    Abstract [en]

    Information is carried by matter or by energy and thus Einstein stated that "no information can travel faster than light." He also was very critical to the "Spooky action at distance" as described in Quantum Physics. However, many verified experiments have proven that the "Spooky actions" not only work at distance but also that they travel at a velocity faster than light, probably at infinite velocity. Examples are Young's fringes at low light levels or entanglements. My explanation is that this information is without energy. In the following I will refer to this spooky information as exformation, where "ex-" refers to existence, the information is not transported in any way, it simply exists. Thus Einstein might have been wrong when he stated that no information can travel faster than light. But he was is right in that no detectable information can travel faster than light. Phenomena connected to entanglement appear at first to be exceptions, but in those cases the information can not be reconstructed until energy is later sent in the form of correlation using ordinary information at the velocity of light. In entanglement we see that even if the exformation can not be detected directly because its luck of energy it still can influence what happens at random, bemuse in Quantum Physics there is by definition no energy difference between two states that happen randomly.

  • 6.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Optical resolution and the duality of light2008In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 47, no 19, p. D1-D5Article in journal (Refereed)
    Abstract [en]

    For 15 years, lensless microscopes have been constructed based on the use of holography, a digital CCD detector, and a computer for image reconstruction by use of, e.g., Fourier transformation. Thus, no lens is involved and therefore the conventional resolution limit of half the wavelength no longer applies. Instead of being limited by the wavelength, the resolution is in this case limited by how exact one can measure the phases of the light. It is remarkable that the interference-limited resolution is approximately 0.01X, whereas the diffraction-limited resolution is only of the order of 0.5X. It is my hope that by combining these two techniques it will be possible to increase the magnification in optical systems by at least an order of magnitude. The calculations at so indicate that information does not necessarily decrease with distance.

  • 7. Arino, I.
    et al.
    Kleist, U.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Rigdahl, M.
    On the relation between surface texture and gloss of injection-molded pigmented plastics2005In: Polymer Engineering and Science, ISSN 0032-3888, E-ISSN 1548-2634, Vol. 45, no 10, p. 1343-1356Article in journal (Refereed)
    Abstract [en]

    The relation between the surface topography of injection-molded plastic objects with deliberately imposed textures and their gloss, measured by means of a conventional glossmeter at incident angles of 20 degrees, 60 degrees and 85 degrees, was investigated. A modification of the general scalar Kirchhoff approximation, which accounts for geometrical features of the glossmeter, is used to describe the experimental gloss values of the textured surfaces. The agreement between the measured and the calculated values for incidence angles of 20 degrees and 60 degrees confirms the usefulness of the approach, though several of the textured surfaces used here are too rough for the Kirchhoff theory to be strictly valid. A poorer agreement, however, was noted at higher incidence angles (85 degrees in this case). For very smooth surfaces (without any texture), the classical Bennett-Porteus theory could in many cases describe the gloss level with sufficient accuracy. The influence on the measured gloss of the polymer material (in terms of its refractive index) and the color of the injection-molded object is also discussed. Light beige specimens in three different polymeric materials (acrylonitrile-butadiene-styrene, acrylonitrile-butadiene-styrene/polycarbonate blend, and polypropylene) as well as three acrylonitrile-butadiene-styrene products with different colors were used. The refractive index of the polymer had no major influence on the measured gloss. The gloss level increased slightly with increasing lightness of the specimens, which can be associated with an increased contribution from the bulk scattering. However, the surface texture governed most of the gloss variations.

  • 8.
    Daemi, Bita
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Image analysis for precision metrology: Verifacition of micro machining systems and aerodynamic surfaces2014Licentiate thesis, comprehensive summary (Other academic)
  • 9.
    Daemi, Bita
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Ekberg, Peter
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Performance Evaluation of Micro Milling Installations2013In: Proceedings of the 10th International Conference on Multi-Material Micro Manufacture / [ed] Azcárate, S.; Dimov S., Singapore: Research Publishing Services, 2013, p. 213-216Conference paper (Refereed)
    Abstract [en]

    Micro manufacturing has developed into many areas over the past decade. Several manufacturing technologies are available but the precision and accuracy of the techniques are still difficult to get access to. Typically the capability information of micro milling equipment is based on specifications given by the machine deliverers. The specified high accuracy is likely to be altered in practice because of environmental conditions and operator skills. So in practice the absolute performances of micro milling/machining equipment may be far off from their listed specifications. When forming the EUMINAfab infrastructure consortium it was decided that independent high precision verification testsshould be made on different installations to help the micro-manufacturers to get the real capability information of their equipment and be able to improve performance to a higher EUMINAfab level. In this study a comprehensive verification test was designed and carried out by using an ultra-precision metrology method for 2D measurements in order to establish more knowledge about the capabilities of micro milling equipment. The measurement results show the machine’s X,Y positioning accuracy, pseudo-repeatability, reproducibility and axis straightness of two different micro milling installations.

  • 10.
    Daemi, Bita
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Optical measurement of waviness on specular surfaces by Fringe Reflection Technique, FRT2012In: Proceedings of the 12th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2012, euspen , 2012, Vol. 1, p. 117-120Conference paper (Refereed)
    Abstract [en]

    The need for accurate measurements of long range low amplitude topographic structure of specular (glossy) surfaces has been increased in automotive and aircraft industries. Optical measurement techniques are the most successful techniques to measure different surface structures with high resolution and high accuracy and at high speed. However, for glossy, specular surfaces many commercial techniques based on surface scattering fail. Fringe Reflection Technique (FRT), mimicking the human observation process of specular surfaces, is then a robust and suitable solution for measuring these surfaces. In our research we are interested in measuring waviness in the micron range over cm long spatial wavelengths. The artefact investigated is a flat casted and painted composite surface. By using a simple and non-expensive FRT-setup, combined with image analysis algorithms high resolution data were obtained. The results match well with reference data obtained by a Coherix interferometer with height measures of some ten micrometers over waviness having a lateral structure of several cm.

  • 11.
    Daemi, Bita
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Performance Evaluation of Laser Micro-Machining Installations2013In: Proceedings of the 10th International Conference on Multi-Material Micro Manufacture / [ed] Azcárate, S.; Dimov S., Singapore: Research Publishing Services, 2013, p. 114-117Conference paper (Refereed)
    Abstract [en]

    Laser micro-machining is a growing field for micro manufacturing in many different materials. To obtain a better understanding of the accuracy of laser micro-machining equipment, moreover machine’s specification, a precise verification test is needed to measure the absolute performance of the machine. Available capability information is usually based on specifications given for the machine installations by machine deliverers. But in practice the absolute performances of some of the micro laser machines are way far off from their specifications. When forming the EUMINAfab infrastructure consortium it was decided that independent high precision verification tests should be made on different installations to help the micro-manufacturers to get the real capability information of their equipment and be able to improve performance to a higher EUMINAfab level. In this study a comprehensive verification test was designed and carried out by using an ultra-precision metrology method in order to establish more knowledge about the capabilities of the laser micro-machining equipment. The measurement results show the machine’s X,Y position accuracy, pseudo-repeatability and reproducibility of three different laser micro-machining installations.

  • 12.
    Dimov, Stefan S.
    et al.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Bramley, Alan N.
    Department of Mechanical Engineering. Universitv of Bath. Bath BA2 7AY. UK.
    Eberhardt, Wolfgang
    Hahn-Schickard-lnstitutf for Microassembly Technology HSG-IMAT, Stuttgart,Germany.
    Engel, Ulf
    Chair of Manufacturing Technology, University of Erlangen-Nuremberg, D-91058, Erlangen, Germany.
    Fillon, Bertrand
    French Atomic Energy Commission, (CEA), Laboratory of Innovation for New Energy Technologies and Nanomaterials (LITEN), 38054 Grenoble, France.
    Johander, Per
    SWEREA IVF Industrial Research and Development Corporation, Argongatan 30, S431 53 Mölndal, Sweden.
    Jung, Erik
    Fraunhofer lnstitute for Reliability and Microintegration, IZM, Berlin Division, Germany.
    Kirby, Paul B.
    Nanotechnology Group, School of lndustrial and Manufacturing Science, Cranfield University, UK.
    Matthews, Christopher.W.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Richter, Martin
    Fraunhofer Institute for Reliability and Microintegration, IZM, Munich Division, Germany.
    Ritzhaupt-Kleissl, Hans-Joachim
    Forschungszentrum Karlsruhe, lnstitute for Materials Research 111, 76021 Karlsruhe, Germany.
    Schoth, Andreas
    IMTEK, University of Freiburg, Georges-Koehler-Allee 103, EG-79110, Freiburg, Germany.
    Velten, Thomas
    Fraunhofer lnstitute for Biomedical Engineering, IBMT, 66386 St. Ingbert, Germany.
    Wenzel, Christian
    Fraunhofer lnstitute for Production Technology, IPT, Steinbachstrasse 17, 52074 Aachen, Germany.
    4M Network of Excellence: Progress Report 2004-20062007In: 4M 2007: Proceedings of the 3rd International Conference on Multi-Material Micro Manufacture / [ed] Stefan Dimov, Wolfgang Menz and Yuli Toshev, Dunbeath: Whittles Publishing, 2007, p. xvii-xxxiConference paper (Refereed)
    Abstract [en]

    The 4M Network of Excellence started on 1st October 2004. It is a consortium of 30 academic and research organisations that came together to form the network under the European Commission's 6th Framework Research Programme. The Network has developed a knowledge community in Micro- and Nano- Technology (MNT) for the batch-manufacture of microcomponents and devices in a variety of materials for future microsystems products, particularly in non-silicon materials. This paper gives an overview of the structure, operation and activity of the network since its inception, illustrating the network's progress towards its goals.

  • 13.
    Dimov, Stefan S.
    et al.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Matthews, Christopher.W.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Brousseau, Emmanuel
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Bigot, Samuel
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    de Grave, Arnaud
    Department of Mechanical Engineering, Technical University of Denmark, Denmark.
    Fillon, Bertrand
    French Atomic Energy Commission, (CEA), Laboratory of Innovation for New Energy Technologies and Nanomaterials (LITEN), 38054 Grenoble, France.
    Weinzierl, Martin
    Fraunhofer Institute for Production Technology, IPT, Steinbachstrasse 17, 52074 Aachen, Germany.
    Engel, Ulf
    Chair of Manufacturing Technology, University of Erlangen-Nuremberg, D-91058, Erlangen, Germany.
    Johander, Per
    SWEREA IVF Industrial Research and Development Corporation, Argongatan 30, S431 53 Mölndal, Sweden.
    Jung, Erik
    Fraunhofer lnstitute for Reliability and Microintegration, IZM, Berlin Division, Germany.
    Kirby, Paul B.
    Nanotechnology Group, School of lndustrial and Manufacturing Science, Cranfield University, UK.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Richter, Martin
    Fraunhofer Institute for Reliability and Microintegration, IZM, Munich Division, Germany.
    Schoth, Andreas
    IMTEK, University of Freiburg, Georges-Koehler-Allee 103, EG-79110, Freiburg, Germany.
    4M Network of Excellence, Progress report 20092009In: 4M/ICOMM 2009: The Global Conference on Micro Manufacture / [ed] Volke Saile, Kornel Ehmann, Stefan Dimov, 2009Conference paper (Refereed)
    Abstract [en]

    This paper gives a brief overview of the activities of the 4M Network of Excellence during the last nine months of its funded period. The 4M Divisions summarise their activity and outline their plans to continue to working together in future. Finally a summary of achievements during the whole lifetime of the Network is given

  • 14.
    Dimov, Stefan S.
    et al.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Matthews, Christopher.W.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Brousseau, Emmanuel
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Bigot, Samuel
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    de Grave, Arnaud
    Department of Mechanical Engineering, Technical University of Denmark, Denmark.
    Hansen, Hans N.
    Department of Mechanical Engineering, Technical University of Denmark, Denmark.
    Bissacco, Giuliano
    Department of Mechanical Engineering, Technical University of Denmark, Denmark.
    Tosello, Guido
    Department of Mechanical Engineering, Technical University of Denmark, Denmark.
    Fillon, Bertrand
    French Atomic Energy Commission, (CEA), Laboratory of Innovation for New Energy Technologies and Nanomaterials (LITEN), 38054 Grenoble, France.
    Bolt, Pieter
    TNO Science and Industry, 5600 HE Eindhoven, The Netherlands.
    Engel, Ulf
    Chair of Manufacturing Technology, University of Erlangen-Nuremberg, D-91058, Erlangen, Germany.
    Johander, Per
    SWEREA IVF Industrial Research and Development Corporation, Argongatan 30, S431 53 Mölndal, Sweden.
    Jung, Erik
    Fraunhofer lnstitute for Reliability and Microintegration, IZM, Berlin Division, Germany.
    Kirby, Paul B.
    Nanotechnology Group, School of lndustrial and Manufacturing Science, Cranfield University, UK.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Richter, Martin
    Fraunhofer Institute for Reliability and Microintegration, IZM, Munich Division, Germany.
    Ritzhaupt-Kleissl, Hans-Joachim
    Forschungszentrum Karlsruhe, lnstitute for Materials Research 111, 76021 Karlsruhe, Germany.
    Schoth, Andreas
    IMTEK, University of Freiburg, Georges-Koehler-Allee 103, EG-79110, Freiburg, Germany.
    Wenzel, Christian
    Fraunhofer lnstitute for Production Technology, IPT, Steinbachstrasse 17, 52074 Aachen, Germany.
    Matovic, J.
    OISAS, Technical University, A 1040, Vienna, Austria.
    4M Network of Excellence, Progress Report 2006-20082008In: 4M 2008: Proceeding of the 4th International Conference on Multi-Material Micro Manufacture / [ed] S. Dimov and W. Menz, Dunbeath: Whittles Publishing, 2008, p. xv-xxxiConference paper (Refereed)
    Abstract [en]

    This report follows on from last year's "Progress Report 2004-2006" and gives an update on the continuing activities, such as the 4M Network cross-divisional projects and annual conference, as well as a description of the new activities in its third and forth year, such as the first 4M Summer School and Book Series. Finally, as the end of the funded lifetime of the network approaches the steps being taken to set up a 4M Association, which aims to create the organizational infrastructure to support the 4M Knowledge Community established in the last five years, are described.

  • 15.
    Ekberg, Lars Peter
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Development of ultra-precision tools for metrology and lithography of large area photomasks and high definition displays2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Large area flat displays are nowadays considered being a commodity. After the era of bulky CRT TV technology, LCD and OLED have taken over as the most prevalent technologies for high quality image display devices. An important factor underlying the success of these technologies has been the development of high performance photomask writers in combination with a precise photomask process. Photomask manufacturing can be regarded as an art, highly dependent on qualified and skilled workers in a few companies located in Asia. The manufacturing yield in the photomask process depends to a great extent on several steps of measurements and inspections. Metrology, which is the focus of this thesis, is the science of measurement and is a prerequisite for maintaining high quality in all manufacturing processes. The details and challenges of performing critical measurements over large area photomasks of square meter sizes will be discussed. In particular the development of methods and algorithms related to the metrology system MMS15000, the world standard for large area photomask metrology today, will be presented.

    The most important quality of a metrology system is repeatability. Achieving good repeatability requires a stable environment, carefully selected materials, sophisticated mechanical solutions, precise optics and capable software. Attributes of the air including humidity, CO2 level, pressure and turbulence are other factors that can impact repeatability and accuracy if not handled properly. Besides the former qualities, there is also the behavior of the photomask itself that needs to be carefully handled in order to achieve a good correspondence to the Cartesian coordinate system. An uncertainty specification below 100 nm (3σ) over an area measured in square meters cannot be fulfilled unless special care is taken to compensate for gravity-induced errors from the photomask itself when it is resting on the metrology tool stage. Calibration is therefore a considerable challenge over these large areas. A novel method for self-calibration will be presented and discussed in the thesis. This is a general method that has proven to be highly robust even in cases when the self-calibration problem is close to being underdetermined.

    A random sampling method based on massive averaging in the time domain will be presented as the solution for achieving precise spatial measurements of the photomask patterns. This method has been used for detection of the position of chrome or glass edges on the photomask with a repeatability of 1.5 nm (3σ), using a measurement time of 250 ms. The method has also been used for verification of large area measurement repeatability of approximately 10 nm (3σ) when measuring several hundred measurement marks covering an area of 0.8 x 0.8 m2.

    The measurement of linewidths, referred to in the photomask industry as critical dimension (CD) measurements, is another important task for the MMS15000 system. A threshold-based inverse convolution method will be presented that enhances resolution down to 0.5 µm without requiring a change to the numerical aperture of the system.

    As already mentioned, metrology is very important for maintaining high quality in a manufacturing environment. In the mask manufacturing industry in particular, the cost of poor quality (CoPQ) is extremely high. Besides the high materials cost, there are also the stringent requirements placed on CD and mask overlay, along with the need for zero defects that make the photomask industry unique. This topic is discussed further, and is shown to be a strong motivation for the development of the ultra-precision metrology built into the MMS15000 system.

  • 16.
    Ekberg, Peter
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Development of a state-of-the-art nm-measurement system for square meter sized lithography masks2012In: Proceedings of the 12th euspen International Conference 2012, 2012, p. 57-62Conference paper (Refereed)
    Abstract [en]

    The demands and solutions for ultra-precision metrology in the manufacturing of lithography masks for the display industry are indeed challenging. Specification demands to be overcome are a measurement repeatability of 10 nm (3 σ) and an absolute accuracy of better than 100 nm (3 σ) on a scale of more than 1.5 m in the X and Y directions. The design of a measurement system that meets these requirements calls for careful selections of materials such as metal, ceramic composites, quartz or glass as they at this precision level are highly affected by the surrounding temperature. Also the fact that the refractive index of air in the interferometers measuring absolute distances is affected by temperature, pressure, humidity and CO2 content make the reference measurements really challenging [1].

    As in many other areas in the industry high quality metrology is the key for success in developing high accuracy production tools. This paper will therefore start by introducing the metrology requirements of mask making for display screens and end with the state-of-the-art results we have achieved.

  • 17.
    Ekberg, Peter
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Metrology: a forgotten added value maker that eliminates cost of poor qualityand supports a sustainable zero defect production2012In: The 5th International Swedish Production Symposium, 2012Conference paper (Refereed)
    Abstract [en]

    The purpose of this paper is to highlight the importance of metrology in the industrial production process.

    Different kinds of processes, like mass production of parts and the very special photo mask process will be

    discussed. It will be shown how much impact metrology has on the added value of the product in the latter

    process. Proper inspection planning with feedbacks from the process at certain points is very important for

    both keeping up the yield and also keeping the process stable. In the example presented about the photo

    mask process bad inspection planning will have extreme consequences. Another aspect that will be

    discussed is the problem when metrology tools or production tools do not fulfil their intended specifications.

    In many cases the user is completely dependent on the tools without any chance to verify their performance.

    This will of course lead to poor quality. Solutions to these kinds of problems generate additional costs in

    investments but will in the long run pay off since quality can be assured.

  • 18.
    Ekberg, Peter
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Ultra precision metrology: the key for mask lithography and manufacturing of high definition displays2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Metrology is the science of measurement. It is also a prerequisite for maintaining a high quality in all manufacturing processes. In this thesis we will present the demands and solutions for ultra-precision metrology in the manufacturing of lithography masks for the TV-display industry. The extreme challenge that needs to be overcome is a measurement uncertainty of 10 nm on an absolute scale of more that 2 meters in X and Y. Materials such as metal, ceramic composites, quartz or glass are highly affected by the surrounding temperature when tolerances are specified at nanometer levels. Also the fact that the refractive index of air in the interferometers measuring absolute distances is affected by temperature, pressure, humidity and CO2 contents makes the reference measurements really challenging. This goes hand in hand with the ability of how to design a mask writer, a pattern generator with a performance good enough for writing masks for the display industry with sub-micron accuracy over areas of square meters.

     As in many other areas in the industry high quality metrology is the key for success in developing high accuracy production tools. The aim of this thesis is therefore to discuss the metrology requirements of mask making for display screens. Defects that cause stripes in the image of a display, the so called “Mura” effect, are extremely difficult to measure as they are caused by spatially systematic errors in the mask writing process in the range of 10-20 nm. These errors may spatially extend in several hundreds of mm and are superposed by random noise with significantly higher amplitude compared to the 10-20 nm.

     A novel method for measuring chromium patterns on glass substrates will also be presented in this thesis. This method will be compared to methods based on CCD and CMOS images. Different methods have been implementedin the Micronic MMS1500 large area measuring machine, which is the metrology tool used by the mask industry, for verifying the masks made by the Micronic mask writers. Using alternative methods in the same system has been very efficient for handling different measurement situations. Some of  the discussed methods are also used by the writers for calibration purposes.

     

  • 19.
    Ekberg, Peter
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics. Micronic Mydata AB,Täby, Sweden .
    Z-correction, a method for achieving ultra-high absolute pattern placement accuracy of large area photomasks2013In: Proceedings of the 13th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2013, euspen , 2013, Vol. 2, p. 253-256Conference paper (Other academic)
    Abstract [en]

    Photomasks are used in the production of LCD, OLED and other kinds of displays. For TV displays these photomasks, made of quartz glass with a Cr pattern, may have sizes up to 1.62 × 1.78 m2 and a thickness up to 16 mm. The absolute placement accuracy, i.e. ×,Y position of a pi×el or line in the mask pattern needs to be better than 150 nm (3s). The demand for higher resolution displays has led to tighter flatness requirements of the photomask, to secure that the chrome pattern is always in best focus. In contrast to small area semiconductor masks with dimensions up to 300 × 300 mm2and three point supports, the large area photomasks have to rest on a large stage in the mask writer. It is then unavoidable that distortions will be induced due to the fact that the glass backside or stage surface is not perfectly flat. If not corrected for, these distortions in Z direction can easily generate geometrical errors in the ×,Y plane corresponding to pattern displacements of several hundred nanometers. To avoid these ×,Y errors we have developed a technique called Z-correction. It is a function developed for correcting the mask pattern placement prior to the writing process in the pattern generator or in a verification measurement in the MMS15000 metrology tool [1]. This is the first time this method is used for improving the accuracy of photo masks. It is based on height measurements of the quartz glass when it is resting on the stage during the temperature stabilizing time. Without using Z-correction it is very challenging to achieve an absolute uncertainty better than ∼200 nm (3s) over an area of 0.8 × 0.8 m2. With Z-correction it is possible to enhance this number to < 100 nm (3s). In the MMS15000 metrology tool the performance is even better, ∼50 nm (3s) over a 0.8 × 0.8 m2 stage area when using Z-correction in the self-calibration process. [2] [3].

  • 20.
    Ekberg, Peter
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics. Micronic Laser Systems, Stockholm, Sweden.
    Stiblert, Lars
    Micronic Laser Systems, Stockholm, Sweden.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    A Large-area ultra-precision 2D geometrical measurement technique based on statistical random phase detection2012In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 23, no 3Article in journal (Refereed)
    Abstract [en]

    The manufacturing of high-quality chrome masks used in the display industry for the manufacturing of liquid crystals, organic light emission diodes and other display devices would not be possible without high-precision large-area metrology. In contrast to the semiconductor industry where 6' masks are most common, the quartz glass masks for the manufacturing of large area TVs can have sizes of up to 1.6 x 1.8 m(2). Besides the large area, there are demands of sub-micrometer accuracy in 'registration', i.e. absolute dimensional measurements and nanometer requirements for 'overlay', i.e. repeatability. The technique for making such precise measurements on large masks is one of the most challenging tasks in dimensional metrology today. This paper presents a new approach to two-dimensional (2D) ultra-precision measurements based on random sampling. The technique was recently presented for ultra-precise one-dimensional (1D) measurement. The 1D method relies on timing the scanning of a focused laser beam 200 mu m in the Y-direction from an interferometrically determined reference position. This microsweep is controlled by an acousto-optical deflector. By letting the microsweep scan from random X-positions, we can build XY-recordings through a time-to-space conversion that gives very precise maps of the feature edges of the masks. The method differs a lot from ordinary image processing methods using CCD or CMOS sensors for capturing images in the spatial domain. We use events grabbed by a single detector in the time domain in both the X-and Y-directions. After a simple scaling, we get precise and repeatable spatial information. Thanks to the extremely linear microsweep and its precise power control, spatial and intensity distortions, common in ordinary image processing systems using 2D optics and 2D sensors, can be practically eliminated. Our 2D method has proved to give a standard deviation in repeatability of less than 4 nm (1 sigma) in both the X-and Y-directions over an area of approximately 0.8 x 0.8 m(2). Only feature edges are recorded, so all irrelevant information in areas containing constant intensity are filtered out already by the hardware. This relaxes the demands and complexity of the data channel dramatically compared to conventional imaging systems.

  • 21.
    Ekberg, Peter
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Stiblert, Lars
    Micronic Laser Systems, Stockholm, Sweden.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    A new general approach for solving the self-calibration problem on large area 2D ultra-precision coordinate measurement machines2014In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 25, no 5, p. 055001-Article in journal (Refereed)
    Abstract [en]

    The manufacturing of flat panel displays requires a number of photomasks for the placement of pixel patterns and supporting transistor arrays. For large area photomasks, dedicated ultra-precision writers have been developed for the production of these chromium patterns on glass or quartz plates. The dimensional tolerances in X and Y for absolute pattern placement on these plates, with areas measured in square meters, are in the range of 200-300 nm (3 sigma). To verify these photomasks, 2D ultra-precision coordinate measurement machines are used having even tighter tolerance requirements. This paper will present how the world standard metrology tool used for verifying large masks, the Micronic Mydata MMS15000, is calibrated without any other references than the wavelength of the interferometers in an extremely well-controlled temperature environment. This process is called self-calibration and is the only way to calibrate the metrology tool, as no square-meter-sized large area 2D traceable artifact is available. The only parameter that cannot be found using self-calibration is the absolute length scale. To make the MMS15000 traceable, a 1D reference rod, calibrated at a national metrology lab, is used. The reference plates used in the calibration of the MMS15000 may have sizes up to 1 m(2) and a weight of 50 kg. Therefore, standard methods for self-calibration on a small scale with exact placements cannot be used in the large area case. A new, more general method had to be developed for the purpose of calibrating the MMS15000. Using this method, it is possible to calibrate the measurement tool down to an uncertainty level of <90 nm (3 sigma) over an area of (0.8 x 0.8) m(2). The method used, which is based on the concept of iteration, does not introduce any more noise than the random noise introduced by the measurements, resulting in the lowest possible noise level that can be achieved by any self-calibration method.

  • 22.
    Ekberg, Peter
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Stiblert, Lars
    Micronic Laser Systems, Stockholm, Sweden.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Ultra-precision geometrical measurement technique based on a statistical random phase clock combined with acoustic-optical deflection2010In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 21, no 12, p. 125103-Article in journal (Refereed)
    Abstract [en]

    Mask writers and large area measurements systems are key systems for production of large liquid crystal displays (LCD) and image devices. With position tolerances in the sub-mu m range over square meter sized masks, the metrology challenges are indeed demanding. Most systems used for this type of measurement rely on a microscope camera imaging system, provided with a charge coupled device, a complementary metal-oxide-semiconductor sensor or a time delay and integration sensor to transform the optical image to a digital gray-level image. From this image, processing algorithms are used to extract information such as location of edges. The drawback of this technique is the vast amount of data captured but never used. This paper presents a new approach for ultra-high-precision lateral measurement at nm-levels of chrome/glass patterns separated by centimeters, so called registration marks, on masks used for the LCD manufacturing. Registration specifications demand a positioning accuracy <200 nm and critical dimensions, i.e. chrome line widths, which need to be accurate in the 80 nm range. This accuracy has to be achieved on glass masks of 2.4 x 1.6 m(2) size. Our new measurement method is based on nm-precise lateral scanning of a focused laser beam combined with statistical random phase sampling of the reflected signal. The precise scanning is based on an extremely accurate time measuring device controlling an acousto optic deflector crystal. The method has been successfully applied in measuring the 4 mu m pitch of reference gratings at standard deviations sigma of 0.5 nm and registration marks separated by several cm at standard deviations of 23 nm.

  • 23.
    Ekberg, Peter
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Stiblert, Lars
    Micronic Laser Systems, Stockholm, Sweden.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Z-correction, a method for achieving ultraprecise self-calibration on large area coordinate measurement machines for photomasks2014In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 25, no 5, p. 055002-Article in journal (Refereed)
    Abstract [en]

    High-quality photomasks are a prerequisite for the production of flat panel TVs, tablets and other kinds of high-resolution displays. During the past years, the resolution demand has become more and more accelerated, and today, the high-definition standard HD, 1920 x 1080 pixels(2), is well established, and already the next-generation so-called ultra-high-definition UHD or 4K display is entering the market. Highly advanced mask writers are used to produce the photomasks needed for the production of such displays. The dimensional tolerance in X and Y on absolute pattern placement on these photomasks, with sizes of square meters, has been in the range of 200-300 nm (3 sigma), but is now on the way to be <150 nm (3 sigma). To verify these photomasks, 2D ultra-precision coordinate measurement machines are used with even tighter tolerance requirements. The metrology tool MMS15000 is today the world standard tool used for the verification of large area photomasks. This paper will present a method called Z-correction that has been developed for the purpose of improving the absolute X, Y placement accuracy of features on the photomask in the writing process. However, Z-correction is also a prerequisite for achieving X and Y uncertainty levels <90 nm (3 sigma) in the self-calibration process of the MMS15000 stage area of 1.4 x 1.5 m(2). When talking of uncertainty specifications below 200 nm (3 sigma) of such a large area, the calibration object used, here an 8-16 mmthick quartz plate of size approximately a square meter, cannot be treated as a rigid body. The reason for this is that the absolute shape of the plate will be affected by gravity and will therefore not be the same at different places on the measurement machine stage when it is used in the self-calibration process. This mechanical deformation will stretch or compress the top surface (i.e. the image side) of the plate where the pattern resides, and therefore spatially deform the mask pattern in the X- and Y-directions. Errors due to this deformation can easily be several hundred nanometers. When Z-correction is used in the writer, it is also possible to relax the flatness demand of the photomask backside, leading to reduced manufacturing costs of the plates.

  • 24.
    Ekberg, Peter
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics. Micronic Mydata AB, Sweden .
    Von Sydow, A.
    Past and future challenges from a display mask writer perspective2012In: Photomask and Next-Generation Lithography Mask Technology XIX, SPIE - International Society for Optical Engineering, 2012, Vol. 8441, p. 84410N-Conference paper (Refereed)
    Abstract [en]

    Since its breakthrough, the liquid crystal technology has continued to gain momentum and the LCD is today the dominating display type used in desktop monitors, television sets, mobile phones as well as other mobile devices. To improve production efficiency and enable larger screen sizes, the LCD industry has step by step increased the size of the mother glass used in the LCD manufacturing process. Initially the mother glass was only around 0.1 m 2 large, but with each generation the size has increased and with generation 10 the area reaches close to 10 m2. The increase in mother glass size has in turn led to an increase in the size of the photomasks used - currently the largest masks are around 1.6 &amp;times; 1.8 meters. A key mask performance criterion is the absence of "mura" - small systematic errors captured only by the very sensitive human eye. To eliminate such systematic errors, special techniques have been developed by Micronic Mydata. Some mura suppressing techniques are described in this paper. Today, the race towards larger glass sizes has come to a halt and a new race - towards higher resolution and better image quality - is ongoing. The display mask is therefore going through a change that resembles what the semiconductor mask went through some time ago: OPC features are introduced, CD requirements are increasing sharply and multi tone masks (MTMs) are widely used. Supporting this development, Micronic Mydata has introduced a number of compensation methods in the writer, such as Z-correction, CD map and distortion control. In addition, Micronic Mydata MMS15000, the world's most precise large area metrology tool, has played an important role in improving mask placement quality and is briefly described in this paper. Furthermore, proposed specifications and system architecture concept for a new generation mask writers - able to fulfill future image quality requirements - is presented in this paper. This new system would use an AOD/AOM writing engine and be capable of resolving 0.6 micron features.

  • 25.
    Ferri, Carlo
    et al.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Brousseau, Emmanuel
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Dimov, Stefan S.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Repeatability analysis of two methods for height measurements in the micrometer range2006In: 4M 2006 Second International Conference on Multi-Material Micro Manufacture / [ed] Wolfgang Menz, Stefan Dimov and Bertrand Fillon, Amsterdam: Elsevier, 2006, p. 165-168Conference paper (Refereed)
    Abstract [en]

    A precision study of two height measuring methods is carried out. The first method is based on a White Light Interferometer (WLI) and the second on a Co-ordinate Measuring Machine (CMM) equipped with an optical probe. The height measurements considered are in the range [150; 250] μm. Point and interval estimates of repeatability are reported in the paper. This study presents experimental evidence that, under repeatability conditions, the precision of the WLI method is about five times higher than that of the optical CMM method. Furthermore, the precision of WLI is constant over the investigated height range whereas a dependency of the CMM precision on the nominal dimensions is identified. For both methods a linear relationship is detected between the random error and the sequence in which the measurements are taken.

  • 26.
    Hyll, Caroline
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Infrared Emittance of Paper: Method Development, Measurements and Application2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Thermography is a non-destructive technique which uses infrared radiation to obtain the temperature distribution of an object. The technique is increasingly used in the pulp and paper industry. To convert the detected infrared radiation to a temperature, the emittance of the material must be known. For several influencing parameters the emittance of paper and board has not previously been studied in detail. This is partly due to the lack of emittance measurement methods that allow for studying the influence of these parameters.

    An angle-resolved goniometric method for measuring the infrared emittance of a material was developed in this thesis. The method is based on the reference emitter methodology, and uses commercial infrared cameras to determine the emittance. The method was applied to study the dependence on wavelength range, temperature, observation angle, moisture ratio, sample composition, and sample structure of the emittance of paper and board samples. It was found that the emittance varied significantly with wavelength range, observation angle and moisture ratio. The emittance was significantly higher in the LWIR (Long-Wavelength Infrared) range than in the MWIR (Mid-Wavelength Infrared) range. The emittance was approximately constant up to an observation angle of 60° in the MWIR range and 70° in the LWIR range, respectively. After that it started to decrease. The emittance of moist samples was significantly higher than that of dry samples. The influence of moisture ratio on the emittance could be estimated based on the moisture ratio of the sample, and the emittance of pure water and dry material, respectively.

    The applicability of measured emittance values was demonstrated in an investigation of the mechanical properties of sack paper samples. An infrared camera was applied to monitor the generation of heat during a tensile test of a paper sample. It was found that the observed increase in thermal energy at the time of rupture corresponded well to the value of the elastic energy stored in the sample just prior to rupture. The measured emittance value provided an increased accuracy in the thermal energy calculation based on the infrared images.

  • 27.
    Hyll, Caroline
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Vomhoff, Hannes
    Innventia AB.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    A method for measurement of the directional emittance of paper in the infrared wavelength range2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 5, p. 958-967Article in journal (Refereed)
    Abstract [en]

    A method for measuring the directional emittance of paper and board samples was developed. The available literature showed that the influence of temperature and observation angle on the emittance of dry and moist paper had not been investigated in detail. Methods adapted for such investigations were not available. In the developed method, the emittance of a sample is determined by comparing its infrared radiation with the radiation emitted from a reference surface with known emittance. In order to investigate the influence of the wavelength range, two cameras, operating in the mid-wavelength and long-wavelength infrared range, respectively, were used. The method allows for the adjustment of the directional emission angle in a range from 0° down to 80°, and variation of the sample temperature between 30°C and 100°C. A study was performed to evaluate the method. Here, the directional emittance of handsheets made from thermo-mechanical pulp was measured at different wavelength ranges, sample temperatures and emission angles. The obtained emittance values and trends were in agreement with previous experimental work and theoretical predictions. The emittance of the samples was also measured using Fourier-Transform Infrared spectroscopy. Given the methodological differences between the two measurement approaches, the results were in good agreement.

  • 28.
    Hyll, Caroline
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Vomhoff, Hannes
    Innventia AB.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Directional emittance of dry and moist paper2012Report (Other academic)
  • 29.
    Hyll, Caroline
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Vomhoff, Hannes
    Innventia AB.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Directional emittance of dry and moist paper2014In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 29, no 2, p. 294-303Article in journal (Refereed)
    Abstract [en]

    The directional emittance of dry and moist paper and board samples was measured in two wavelength ranges; the mid-wavelength infrared (MWIR) range and the long-wavelength infrared (LWIR) range. The influence of pulp type, pulp drying, pulp refining, fibre orientation, additives, coating, and observation angle on the emittance of dry paper was examined. The influence of sample moisture and observation angle on the emittance of moist samples was also investigated. The emittance in the LWIR range was higher than the MWIR emittance. The emittance varied with pulp type, especially for TMP, which had a significantly lower emittance compared to the samples made of chemical pulp. The impact of different properties, such as pulp type, refining or coating, was much smaller in the LWIR range than in the MWIR range. Observation angle was found to significantly impact the emittance at angles larger than 60 degrees from the normal direction in the MWIR range, and angles larger than 70 degrees in the LWIR range. The emittance increased with increasing moisture ratio. This increase was most pronounced at low absolute moisture ratios, where an addition of an already small amount of water could impart a large change in emittance. It was found that the emittance and sample moisture could be correlated well using a linear combination of the emittance of dry paper and pure water.

  • 30.
    Hyll, Caroline
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Vomhoff, Hannes
    Innventia AB.
    Nygårds, Mikael
    Innventia AB.
    Analysis of the plastic and elastic energy during the deformation and rupture of a paper sample using thermography2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 2, p. 329-334Article in journal (Refereed)
    Abstract [en]

    Thermography has been used to quantitatively analyze the plastic and elastic energy during deformation of paper. Sack paper samples were subjected to uniaxial tensile testing until rupture occurred. The temperature of the sample was simultaneously recorded with an infrared camera. The mechanical energy invested in the deformation was determined based on the force and deformation data. The thermal energy that accumulated in the sample during testing was estimated using the temperature measurements. Here, special attention was put on using the correct emittance values for the sack paper by measuring it with a new method. When comparing exerted mechanical energy with released thermal energy up to the time of sample rupture, about 40% to 60% of the mechanical energy could be detected as thermal energy. The lacking share of heat was most likely lost due to cooling of the sample during the experiments, as a lower share of detected mechanical energy was obtained for longer experiments. When comparing the increase in thermal energy during rupture to the elastic energy stored in the sample, an agreement of better than 90% was found.

  • 31.
    Hyll, Kari
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics. Innventia, Sweden.
    Image-based quantitative infrared analysis and microparticle characterisation for pulp and paper applications2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Measurements of process variations and particle morphology are widely employed in the pulp and paper industry. Two techniques with high potential, infrared thermography and microparticle characterisation, are mainly used qualitatively. Quantitative thermography requires knowledge of the emittance, a material property which has not been measured under many process-relevant conditions. Quantitative characterisation of microparticles, e.g. pulp fines and mineral fillers, requires the analysis of a large number of particles, which can be accomplished using flow microscopes. Flow microscopes for pulp analysis have had insufficient spatial resolution to resolve fines and fillers. Additionally, there has been a lack of methods which can differentiate between fines and fillers in a mixed suspension.

    State-of-the-art instruments for particle image analysis were evaluated and compared to laser diffractometry, a measurement method based on scattering by diffraction. Laser diffractometry was found to be highly sensitive to the complex refractive index of the particles, and especially to its change due to moisture absorption. A high-resolution imaging flow cytometer and a high-resolution fibre analyser were found to be complementary for characterisation of pure fines and fines/filler mixtures, and superior to laser diffractometry. A method for differentiating between fines and fillers in a suspension based on their autofluorescence and side-scattering was proposed and qualitatively evaluated.

    Furthermore, a method for measuring the directional and integrated emittance of paper was developed and its accuracy was determined. Measurements on a wide range of samples showed that the emittance of fibre-based materials vary significantly with wavelength, pulp type, observation angle, and moisture content. By applying measured quantitative values of the emittance, the thermal energy emitted by sack paper samples during mechanical deformation could be quantitatively calculated. The increase in thermal energy at the time of rupture was found to correlate well with the elastic share of the mechanical energy that was stored in the sample during its elongation.

    In summary, the results of this work have facilitated the use of quantitative microparticle analysis and infrared thermography for pulp and paper applications. 

  • 32.
    Hyll, Kari
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics. Innventia AB, SE-11428 Stockholm, Sweden.
    Size and shape characterization of fines and fillers: a review2015In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 30, no 3, p. 466-487Article in journal (Refereed)
    Abstract [en]

    Many properties of fines and fillers are dependent on their size and shape. This review is on the literature on size and shape characterization of fines and fillers. It takes into account measurement techniques of particle width, length, equivalent diameter, area, and shape/morphology. The advantages and limitations of different methods are discussed. Measurement of other particles properties, e.g., optical, chemical or rheological, were not included in the review. Size and shape characterization methods can be roughly divided into gravimetric and non-gravimetric methods. Gravimetric measurements methods account for all particles in the sample, but give only indicative size and shape information. Non-gravimetric methods usually give more direct size and shape information, but only account for particles larger than the resolution of the instrument. Additionally, measuring both larger and smaller particles simultaneously is rarely possible. An implication is that current analysers fail to measure a larger share of the sample, for example fibrils, which have a high impact on product properties. Of the reviewed measurement techniques, flow microscopy had the highest potential. Based on instruments found in other application areas, possible developments for flow microscopes include multiwavelength illumination and sensors, fluorescent staining, and hydrodynamic focusing.

  • 33.
    Hyll, Kari
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics. Innventia AB, Sweden.
    Björk, E.
    Vomhoff, H.
    Flow imaging characterisation of morphological changes of chemical pulp due to refining2016In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, no 3, p. 411-421Article in journal (Refereed)
    Abstract [en]

    The influence of the refining process on the morphological changes of a chemical softwood pulp was investigated. The Voith LR40 industrial-like laboratory low consistency refiner was used, where the pulp was refined with five refining segments with differences in bar widths, groove widths, and cutting angles. The refined pulp was characterized with a fibre analyser with a spatial resolution of approximately 4 &mu;m/pixel and a wide size range. The fines fraction of the refined pulp was also characterized with an imaging flow cytometer with a spatial resolution of 0.33 &mu;m/pixel and a narrower size range. The fibre analyser measurements showed that the mean length, width, and aspect ratio of the fines decreased monotonically with accumulated refining energy. The imaging flow cytometer with its higher spatial resolution showed little change in fines morphology with accumulated refining energy. The morphology of the fines was more dependent on the applied specific refining energy than the design of the refining segment. However, a segment with much finer grooves and bars, initially designed for hardwood, gave significantly less fibre shortening, fines generation, external fibrillation, kink, and fines that were more fibrillar, compared to the other segments.Grant: The authors of this work would like to thank Prof. Lars Mattsson, Thomas Grahn, and Eva Ålander for fruitful discussions. The discussions with Lorentzen & Wettre were of great assistance. The financial support of the Swedish Energy Agency and the Önnesjöstiftelsen to the PhD project, and of the Fibre and Stock Design research programme to this evaluation study is gratefully acknowledged.

  • 34.
    Kari, Hyll
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics. Innventia, Sweden.
    Björk, Elisabeth
    Mid Sweden University; Innventia.
    Vomhoff, Hannes
    Innventia, Sweden.
    Characterization of morphological changes of chemical pulp fibres and fines due to refiningManuscript (preprint) (Other academic)
    Abstract [en]

    The influence of the refining process on the morphological changes of a chemical softwood pulp was investigated. An industrial-like laboratory refiner was used, where the pulp was refined with five refining segments with differences in bar widths, groove widths, and cutting angles. The refined pulp was characterized with a fibre analyser with a spatial resolution of approximately 4 µm/pixel and a wide size range. The fines fraction of the refined pulp was also characterized with an imaging flow cytometer with a spatial resolution of 0.33 µm/pixel and a narrower size range.

    The fibre analyser measurements showed that the mean length, width, and aspect ratio of the fines decreased monotonically with accumulated refining energy. The imaging flow cytometer with its higher spatial resolution showed little change in fines morphology with accumulated refining energy.

    The morphology of the fines was more dependent on the applied specific refining energy than the design of the refining segment. However, a segment with much finer grooves and bars, initially designed for hardwood, gave significantly less fibre shortening, fines generation, external fibrillation, kink, and fines that were more fibrillar, compared to the other segments. 

  • 35.
    Kari, Hyll
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics. Innventia AB.
    Farahani, Farnaz
    Innventia AB, Sweden .
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Optical methods for fines and filler size characterization: Evaluation and comparison2016Report (Other academic)
    Abstract [en]

    The pulp fines and mineral fillers in the fine fraction of a papermaking stock influence process conditions and sheet properties. The influence is largely dependent on the size and shape of the particles. Quantitative characterization of the size and shape of fines and fillers would aid in process control and prediction of product properties.  Thus, the aim of the study was to evaluate and compare optical instruments which can be used to quantitatively characterize the fine fraction of a papermaking stock. The compared instruments were the Mastersizer2000 from Malvern, based on diffraction scattering of a laser beam, the ImageStream from Amnis, and the Fiber Tester and Fiber Tester Plus from ABB Lorentzen & Wettre. The last three instruments are all based on imaging of the particles and have spatial resolutions ranging from 0.33 µm to about 10 µm per pixel.

    All instruments overestimated the size of calibration spheres with known sizes. In several cases, calibration particles that were smaller than the spatial resolution of the instrument were detected. In these cases, the relative measurement error was large, likely due to positioning and quantization errors. It is also suggested that the oversizing was partly due to dissimilar optical properties of the calibration particles, compared to the typical sample, and that better calibration materials for fines need to be developed.

    For the image-based instruments, the relative share of fines and filler particles increased with as the size of the measured particles decreased. Thus, with higher spatial resolution, more particles were detected. However, the shape of the particle size distribution depended on the resolution and the field-of-view. The ImageStream resolved single PCC particles, which has not previously been done using flow microscopy. Due to its limited field-of-view, the ImageStream could not measure the largest fines, which were detected by the Fiber Tester and Fiber Tester Plus. While the Fiber Tester Plus did not resolve single PCC particles, it detected, due to its higher resolution, a higher share of smaller particles than the Fiber Tester. Overall, the ImageStream and the Fiber Tester Plus were found to be complementary.

    The diffraction-based method struggled to measure small fines. It is proposed that small fines diffracted light insufficiently to be detected by the instrument. The obtained result was also highly sensitive to the choice of refractive index; a fact that some of the previous users apparently were not aware of.

    In summary, image-based methods were found to perform better than the diffraction-based method when measuring on fines and mixtures of fines and fillers, while the highest resolution image-based instrument and the diffraction-based method were best when measuring on pure fillers.

  • 36.
    Kirillin, Mikhail
    et al.
    Institute of Applied Physics RAS.
    Su, Rong
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Sergeeva, Ekaterina
    Laboratory of Biophotonics, Institute of Applied Physics RAS.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Myllylä, Risto
    Monte Carlo simulation in optical coherence tomography for quality inspection of materials2013Conference paper (Refereed)
    Abstract [en]

    Quality inspection of materials is one of modern applications of optical coherence tomography (OCT) featuring non-invasiveness and high speed required for in-production control of such materials as paper and alumina ceramics. Some of materials to be controlled are characterized by high scattering which can introduce distortions to the obtained OCT images, therefore additional interpretation can be required in order to evaluate material quality. In order to understand formation of OCT images of highly scattering materials samples and evaluate OCT potential for their quality inspection Monte Carlo simulations could be employed. This paper discusses application of Monte Carlo technique for simulation of OCT inspection of paper and alumina ceramics samples. Implementation of Monte Carlo simulation allows to evaluate the effect of OCT setup parameters and material properties on formation of the OCT-images. Multilayer models of paper and alumina ceramics structures are involved in the study.

  • 37.
    Li, Yujiang
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Computer Systems for Design and Manufacturing.
    Su, Rong
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Hedlind, Mikael
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Computer Systems for Design and Manufacturing.
    Ekberg, Peter
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Kjellberg, Torsten
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Computer Systems for Design and Manufacturing.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Model based in-process monitoring with optical coherence tomography2012In: Procedia CIRP: 1st CIRP Global Web Conference: Interdisciplinary Research in Production Engineering (CIRPE2012),, Elsevier, 2012, p. 70-73Conference paper (Refereed)
    Abstract [en]

    The demands on in-process 3D monitoring in ceramic micromanufacturing industry require a high-precision, non-destructive, rapid and automated inspection technique for measuring the thickness of component layer, determining the shape and dimensions of the embedded 3D structures, and detecting the de-bonding, cracks, warping and deformation. One of the promising metrology techniques is optical coherence tomography (OCT). With the dedicated image processing algorithm and the industrial product data exchange standard, the model-based integration of OCT as a new metrology tool is demonstrated. As a generic standard for any product or manufacturing information, ISO 10303 STEP AP242 is employed for the measured data model. Unambiguous data representation is achieved by integrating additional modelling constraints. The proposed framework allows fully using the technical advantages of OCT to in-process 3D monitoring.

  • 38.
    Lindqvist, Richard
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Geometrical and dimensional Measurement Planning: - a systematic and holistic approach2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In order to ensure final product quality on machined components, manufacturing enterprises must measure and inspect the geometrical and dimensional characteristics of components before they go into higher-value assemblies. Commonly, the geometrical and dimensional measurement and inspection occurs every time at machine tool set-up, when a line is restarted or if the production process is changed. Production metrology and results from production measurements is used as input data for statistical process control and monitoring of production processes. The purpose of our research has been to firstly perform a state of the art analysis in the area of measurement planning applied in the automotive and aerospace industry. The output from the state of the art study has then been used to identify future trends and needs including a gap analysis. Then we used the analysis to explore and develop a model and methodology for measurement and controllability planning.   In this licentiate thesis we have explored the area of GMCP (Geometrical and dimensional Measurement and Controllability Planning). As a major result in this thesis a state of the art survey on GMCP is presented. Based on the state of the art study a theory and model framework for GMCP has been explored and a methodology and tool called QAM (Quality Assurance Matrix) is highlighted in this thesis. In the end of the thesis we present and discuss the present research results we have accomplished and in the final chapter we draw conclusions and outline the continued research within the SIMET-GICP project.

  • 39.
    Lindqvist, Richard
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Horst, John
    National Institute of Standards and Technology (NIST), Gaithersburg, USA.
    Brown, Robert
    Mitutoyo America Corporation, USA.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Equipp - Exchange of quality measurement process plans2010In: 10th International Symposium on Measurement and Quality Control 2010, ISMQC 2010, 2010, p. 212-215Conference paper (Refereed)
    Abstract [en]

    Quality is a pillar for success in every enterprise, and the absolute prerequisite for quality is measurement, but if measurement is actually going to improve quality, a process plan for performing the measurement must be properly defined. Increasingly, measurement process planning is performed semi-automatically in software, and since every software vendor has their own format for measurement process plans, this situation leads to interoperability costs. The eQuiPP (exchange of Quality Measurement Process Plans) specification is proposed as a standard which will reduce interoperability costs. The actual cost resulting from the lack of standardization is most likely enormous even though this cost is difficult to quantify. Standards like eQuiPP, properly defined and implemented, eliminate costs such as: • Information translation • Information quality degradation • Reduced perception of quality • Lack of freedom to choose best-in-class • Restraints on corporate or technical agility • Higher fees due to reduced competition • Reduced product and process innovation • Increased training and license fees • Unnecessary software development • Information access fees (e.g., PMI with CAD) • Information integrity and validation testing • Product delays and lost opportunities • High dependence on vendor viability • Excess support staff and equipment The primary scope of this new proposed standard is currently limited to an XML (eXtensible Markup Language) Schema quality measurement plan export format (XSD, extensible schema definition) for variable and attribute inspection plan processing.

  • 40.
    Lindqvist, Richard
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Karlsson, Karl-Johan
    Volvo Construction Equipment, Eskilstuna, Sweden.
    Hedman, Stefan
    Volvo Construction Equipment, Eskilstuna, Sweden.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Geometry assurance and quality control planning by QAM2010In: 10th International Symposium on Measurement and Quality Control 2010, ISMQC 2010, 2010, p. 196-199Conference paper (Refereed)
    Abstract [en]

    The purpose of this paper is to present research results within the field of GMCP (Geometrical and dimensional Measurement and Controllability Planning) applied for complex products. GMCP is a prerequisite activity in modern manufacturing of complex products and components. It is attaining high interest and priority among the manufacturing industry management and this is due to the increased demands and focus on environmental sustainability, cost reduction, quality work and the aim towards zero defects in manufacturing. The necessity of a systematic, holistic and integrated engineering QAM (Quality Assurance Matrix) methodology tool is being presented and discussed. The QAM tool and model was originally an idea derived from Volvo CE in Eskilstuna and was initiated through an ISO 9000 quality revision requirement. The current ongoing SIMET (Swedish Industrial Metrology Forum) research has further developed the ideas and underlying theory with new principles and rules embedded in the model and matrix. The current solution has been developed and implemented in a Microsoft Excel application. However, the long term sustainable and rational solution will preferably be implemented in a database design environment.

  • 41.
    Lindqvist, Richard
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Lundgren, Magnus
    Hedman, Stefan
    Volvo Construction Equipment, Eskilstuna, Sweden.
    Lindahl, Peter
    Vångell, Tomas
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    An information-model approach for systematic and holistic geometrical inspection and control planning (GICP)2009In: Journal of the CMSC, ISSN 2328-6067, Vol. 4, no 2, p. 20-26Article in journal (Refereed)
  • 42.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Experiences and challenges in Multi Material Micro Metrology2007In: The second International Conference on Micro-Manufacturing, ICOMM-2007 / [ed] T.Kurfess and J. Ziegert, Clemson: Clemson University Digital Press, 2007, p. ICOMM2007-Conference paper (Refereed)
    Abstract [en]

    The Microsystems Technology manufacturing is expanding into other materials than the silicon. Polymers, metals and ceramics manufactured with micron feature sizes put new demands on metrology systems and a better education of instrument operators. In particular 3D-structured polymers require special care with regard to measurement forces for contacting probes of e.g. coordinate measuring machines. Ceramics tend to scatter light from the bulk, which can introduce off-sets from the true surface position in e.g. optical triangulation systems. Engineered metals tend to have comparatively rough surfaces compared to silicon and this imposes problems when a dimension of a micro feature is to be measured, as the roughness may introduce large local variations in measured size of a particular item. One of the most critical problems is associated with the high aspect ratio features present in micro systems manufacturing. This paper will high-light some examples of etrology problems found within the European 4M Multi Material Micro Manufacturing Network, discuss them, show new surprising results of optical profiling on high aspect ratio features and discuss possible solutions to get around some of the obstacles.

  • 43.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Metrology of 3D microstructures: a demanding task with surprising results2007In: / [ed] Manfred Geiger, Ulf Engel, Erlangen: University of Erlangen-Nuremberg , 2007Conference paper (Other academic)
  • 44.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Metrology of micro-components – a real challenge for the future2006In: Proceedings of the 5th International Seminar on Intelligent Computation in Manufacturing Engineering (CIRP ISME ’06) / [ed] R. Teti, CIRP , 2006, p. 547-552Conference paper (Refereed)
    Abstract [en]

    Micro manufacturing is steadily advancing from research labs to spin off companies. Products formerly manufactured by thin film technology using semiconductor processes are being replaced by more efficient full 3D micro manufacturing techniques. Materials have expanded to polymers, metals and ceramics. From being wafer based structures of tens of microns in width and a thickness of up to a micron, feature sizes are now a few microns wide and hundreds of microns deep. This puts very high demands on the geometrical dimensional and roughness measurement tools of the future. This paper gives a review of current metrology tools available for dimensional and surface characterization, and their limitations. It will also present the requirements of future instruments and discuss potential techniques to solve these issues.

  • 45.
    Mattsson, Lars
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    The Challenge of Dimensional Metrology on High Aspect Ratio Micro Structures2007Conference paper (Refereed)
    Abstract [en]

    The 4M-Multi Material Micro Manufacture Network of Excellence initiative is concentrating its efforts on non-silicon materials, i.e. metals, polymers and ceramics. For metrology of micro-components this material choice has a big impact on the possibility of making accurate measurements, although vision based metrology problems are already very obvious in high aspect ratio MEMS manufacturing[3]. This paper will report some specific findings related to the measurement of high aspect ratio microstructures of polymers and metals.

  • 46.
    Mattsson, Lars
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Bolt, Pieter
    TNO Science and Industry, 5600 HE Eindhoven, The Netherlands.
    Azcarate, Sabino
    Tekniker Technological Center, 20600 Eibar, Spain.
    Brousseau, Emmanuel
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Fillon, Bertrand
    French Atomic Energy Commission, (CEA), Laboratory of Innovation for New Energy Technologies and Nanomaterials (LITEN), 38054 Grenoble, France.
    Fowler, C.
    Science and Technology Facilities Council, Rutherford Appleton Laboratory (RAL), Technology – Central Microstructure Facility, Harewell Science and lnnovation Campus, Didcot, Oxfordshire, OX11 OQX, UK.
    Gelink, E.
    TNO Science and Industry, 5600 HE Eindhoven, The Netherlands.
    Griffiths, C.
    Manufacturing Engineering Centre, Cardiff University, Cardiff CF24 3AA, UK.
    Kahn Malek, Chantal
    FEMTO-ST Institute, CNRS UMR 6174, LPMO Department, 25044 Besancon Cedex, France.
    Marson, S.
    School of Applied Sciences, Cranfield University, Cranfield, Beds, MK43 OAL, UK.
    Retolaza, Aritz
    Tekniker Technological Center, 20600 Eibar, Spain.
    Schneider, A.
    Science and Technology Facilities Council, Rutherford Appleton Laboratory (RAL), Technology – Central Microstructure Facility, Harewell Science and lnnovation Campus, Didcot, Oxfordshire, OX11 OQX, UK.
    Schoth, Andreas
    IMTEK, University of Freiburg, Georges-Koehler-Allee 103, EG-79110, Freiburg, Germany.
    Témun, Attila
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Tiquet, P.
    French Atomic Energy Commission, (CEA), Laboratory of Innovation for New Energy Technologies and Nanomaterials (LITEN), 38054 Grenoble, France.
    Tosello, Guido
    Department of Mechanical Engineering, Technical University of Denmark, Denmark.
    How reliable are surface roughness measurements of micro-features?: Experiences of a Round Robin test within nine 4M laboratories2008In: 4M 2008: Proceedings of the 4th International Conference on Multi-Material Micro Manufacture / [ed] S. Dimov and W. Menz, Dunbeath: Whittles Publishing, 2008, p. 139-142Conference paper (Refereed)
    Abstract [en]

    Surface roughness of tiny micro machined features is not easy to verify. The statistical variation of the surface itself can be the limiting factor that hampers tolerance verification. In this paper we have studied this effect and we also test the performance of 10 different surface profilers over a very well specified surface area. For this area 6 profilers yielded the same result within a standard deviation window of ±6%. For other areas, on top of narrow bars and in narrow and deep channels, a much larger spread in the Round Robin results were found.

  • 47.
    Mattsson, Lars
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Schulze, Volker
    Institut für Produktionstechnik und Institut für Werkstoffkunde, Karlsruhe Institute of Technology, Karlsruhe, Germany .
    Schneider, Johannes
    Institut für Angewandte Materialien, Karlsruhe Institute of Technology, Karlsruhe, Germany .
    Quality assurance and metrology2009In: Ceramic Processing in Microtechnology / [ed] H-J Ritzhaupt-Kleissl, P. Johander, Dunbeath: Whittles Publishing, 2009, p. 305-325Chapter in book (Other academic)
    Abstract [en]

    The cost effective large scale production of reliable micro systems for mechanical and tribological applications requires a customized quality assurance. Equipment and procedures established for the characterization of materials and components on the macro scale very often cannot be successfully applied on the micro scale. Therefore in recent years customized techniques were developed for dimensional control, surface topography and roughness characterization as well as for microstructural analysis, mechanical and tribological testing. This chapter overviews the state-of-the-art of research and technological developments on these fields and thereby responds on the necessary fundamentals of metrology, the constraints of the used equipment and technologies as well as the particular problems arising from characterization of micro components made of ceramic materials.

  • 48.
    Olin, Pontus
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Hyll, Caroline
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Ovaskainen, Louise
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Ruda, Marcus
    Schmidt, Oskar
    Turner, Charlotta
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Development of a Semicontinuous Spray Process for the Production of Superhydrophobic Coatings from Supercritical Carbon Dioxide Solutions2015In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 54, no 3, p. 1059-1067Article in journal (Refereed)
    Abstract [en]

    Superhydrophobic surfaces have been fabricated in a continuous spray process, where an alkyl ketene dimer (AKD) wax is dissolved in supercritical carbon dioxide (scCO(2)) and sprayed onto the substrate. The mass of extracted AKD from scCO2 has been investigated as well as the pressure, temperature, and flow of CO2 at the steady-state spray conditions. Several different substrates such as glass, aluminum, paper, poly(ethylene terephthalate) (PET), and polytetrafluoroethylene (PTFE) have been successfully coated, and the superhydrophobic properties have been evaluated by measurement of water contact angle, water drop friction, scanning electron microscopy (SEM), and surface topography. The most efficient spray process, considering surface properties and mass of extracted AKD, is obtained at the lowest temperature investigated, 67 degrees C, and the highest pressure evaluated in this study, 25 MPa. We also show that the influence of preexpansion conditions (p, T) on the surface temperature at the selected spray distance (3 cm) is negligible by measurement with an infrared camera during spraying.

  • 49.
    Su, Rong
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Assessment of optical coherence tomography for metrology applications in high-scattering ceramic materials2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Large-scale and cost-effective manufacturing of ceramic micro devices based on tape stacking requires the development of inspection systems to perform high-resolution in-process quality control of embedded manufactured cavities, metal structures and defects.

    In this work, alumina ceramic samples are evaluated by optical coherence tomography (OCT) operating at 1.3μm wavelength and some dimensional data are obtained by dedicated image processing and segmentation. Layer thicknesses can be measured and laser-machined channels can be verified embedded at around 100μm depth. Moreover, detection of internal defects is enabled.

    Monte Carlo ray tracing simulations are employed to analyze the abilities of OCT in imaging of the embedded channels. The light scattering mechanism is studied for the alumina ceramics, and different scattering origins and models are discussed. The scattering parameters required as input data for simulations are evaluated from the integrating sphere measurements of collimated and diffuse transmittance spectra using a reconstruction algorithm based on refined diffusion approximation approach.

     

  • 50.
    Su, Rong
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Improved inspection and micrometrology of embedded structures in multi-layered ceramics: Development of optical coherence tomographic methods and tools2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Roll-to-roll manufacturing of micro components based on advanced printing, structuring and lamination of ceramic tapes is rapidly progressing. This large-scale and cost-effective manufacturing process of ceramic micro devices is however prone to hide defects within the visually opaque tape stacks. To achieve a sustainable manufacturing with zero defects in the future, there is an urgent need for reliable inspection systems. The systems to be developed have to perform high-resolution in-process quality control at high speed. Optical coherence tomography (OCT) is a promising technology for detailed in-depth inspection and metrology. Combined with infrared screening of larger areas it can solve the inspection demands in the roll-to-roll ceramic tape processes. In this thesis state-of-art commercial and laboratory OCT systems, operating at the central wavelength of 1.3 µm and 1.7 µm respectively, are evaluated for detecting microchannels, metal prints, defects and delaminations embedded in alumina and zirconia ceramic layers at hundreds of micrometers beneath surfaces.

    The effect of surface roughness induced scattering and scattering by pores on the probing radiation, is analyzed by experimentally captured and theoretically simulated OCT images of the ceramic samples, while varying surface roughnesses and operating wavelengths. By extending the Monte Carlo simulations of the OCT response to the mid-infrared the optimal operating wavelength is found to be 4 µm for alumina and 2 µm for zirconia. At these wavelengths we predict a sufficient probing depth of about 1 mm and we demonstrate and discuss the effect of rough surfaces on the detectability of embedded boundaries.

    For high-precision measurement a new and automated 3D image processing algorithm for analysis of volumetric OCT data is developed. We show its capability by measuring the geometric dimensions of embedded structures in ceramic layers, extracting features with irregular shapes and detecting geometric deformations. The method demonstrates its suitability for industrial applications by rapid inspection of manufactured samples with high accuracy and robustness.

    The new inspection methods we demonstrate are finally analyzed in the context of measurement uncertainty, both in the axial and lateral cases, and reveal that scattering in the sample indeed affects the lateral measurement uncertainty. Two types of image artefacts are found to be present in OCT images due to multiple reflections between neighboring boundaries and inhomogeneity of refractive index. A wavefront aberration is found in the OCT system with a scanning scheme of two galvo mirrors, and it can be corrected using our image processing algorithm.

12 1 - 50 of 67
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf