1. |
- Brinkfeldt, Klas, et al.
(author)
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Thermo-mechanical simulations and measurements on high temperature interconnections
- 2011
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In: 12th Int. Conf. on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2011. - 9781457701078
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Conference paper (peer-reviewed)abstract
- In order to place sensors or electronics in very high temperature environments, new materials and methods for interconnection are required. A comparative study between different electrical interconnection methods for very high operation temperatures (500 °C - 800 °C) is presented. Thermo-mechanical simulations and characterization of samples of the interconnection types during high temperature exposure are presented. The results of the thermo-mechanical simulations showed that stresses are low in a connection system based on liquid interconnection. This system, however, proved to be difficult to realize due to problems with oxides and sealing of the metallic liquid. Modeling of an interconnection based purely on mechanical pressure without any solder or metallic bond showed high stress. This was also confirmed during high temperature exposure where the connection failed. High stress was also predicted for an interconnection based on nano-Ag paste. The high temperature tests, however, showed promising results at 800 °C for over 100 hours. © 2011 IEEE.
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2. |
- Brinkfeldt, Klas, et al.
(author)
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High temperature packaging for SiC power transistors
- 2012
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In: Proceedings - 2012 45th International Symposium on Microelectronics, IMAPS 2012. ; , s. 1124-1130
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Conference paper (peer-reviewed)abstract
- Power transistors based on silicon carbide (SiC) are now commercially available. They have a higher efficiency and higher voltage blocking capabilities than conventional silicon devices. The wide-band gap and chemical inertness of SiC makes it suitable to high temperature operation. However, there is a need for new packaging for power transistors that can operate in higher temperatures. We have developed a package based on ceramics and silver for high temperature operation of SiC power transistors. Three types of SiC devices from different manufacturers are packaged and tested in room temperature. Though the devices were still functional after the packaging process, their performance seem to have degraded. This could be a result of the high temperature packaging process and the measurement setup. FEM simulations are also performed to investigate the thermo-mechanical behavior of the package. The target operating temperature of the package is 400°C. Modeling show stress concentrations at the corners of the device chip and suggests that this stress is decreased if the substrate metallization is changed from copper to silver.
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3. |
- Brinkfeldt, Klas, et al.
(author)
-
Simulations of a high temperature pressure sensor packaging and interconnection
- 2012
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In: EuroSimE 2012. - 9781467315128
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Conference paper (peer-reviewed)abstract
- Modeling and thermal cycling of a high temperature pressure sensor packaging is presented. The packaging is based on the green-state milling of alumina to the desired geometry and conduits for the electrical conductors, followed by sintering of the ceramics with the electrical conductors inside. The electrical interconnections are based on silver. For short term operation, the package can be exposed to temperatures close to the melting temperature of silver (961°C). It has shown operational in temperature cycling above 600°C for more than 1800 hours. Modeling of the package show that the stress in the electrical interconnections are close to the yield stress of silver at 20°C. The stress free temperature in the modeling was set to 850°C. Temperature induced stress and strains in the packaging and a fatigue simulation are performed. The package is generic and can be converted to fit most geometries and high temperature applications. © 2012 IEEE.
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4. |
- Dimov, Stefan S., et al.
(author)
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4M Network of Excellence : Progress Report 2004-2006
- 2007
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In: 4M 2007. - Dunbeath : Whittles Publishing. - 9781904445531 - 9781420070040 ; , s. xvii-xxxi
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Conference paper (peer-reviewed)abstract
- 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.
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5. |
- Dimov, Stefan S., et al.
(author)
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4M Network of Excellence, Progress Report 2006-2008
- 2008
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In: 4M 2008. - Dunbeath : Whittles Publishing. - 9781904445760 ; , s. xv-xxxi
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Conference paper (peer-reviewed)abstract
- 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.
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6. |
- Dimov, Stefan S., et al.
(author)
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4M Network of Excellence, Progress report 2009
- 2009
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In: 4M/ICOMM 2009. ; , s. s.1-9
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Conference paper (peer-reviewed)abstract
- 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
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7. |
- Edwards, M.J., et al.
(author)
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Pressure and temperature dependence of GaN/AlGaN high electron mobility transistor based sensors on a sapphire membrane
- 2012
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In: Physica Status Solidi (C) Current Topics in Solid State Physics. - : Wiley. - 1862-6351. ; 9, s. 960-963
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Journal article (peer-reviewed)abstract
- This paper reports a high pressure sensor based on a GaN/AlGaN High Electron Mobility Transistor (HEMT) that uses its 375 mm thick sapphire substrate to provide a robust base and enables device operation up to at least 60 bar (6 MPa). Transduction of changes in ambient pressure occurs via piezoelectric and pyroelectric effects on the channel conductance. The HEMTs were strategically placed along an 8 mm 2 GaN/AlGaN/GaN/sapphire chip; where the central 4 mm diameter behaves as a pressure sensitive 'drumskin'. The location of peak response lies in the HEMT at the geometric centre of the drumskin, demonstrated by the change in I DS when the pressure was increased from 0 to 60 bar. The response of six strategically placed HEMTs along the chip's surface, were compared to a finite element model to predict sensor behaviour. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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8. |
- Edwards, Michael, et al.
(author)
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Modelling and optimisation of a sapphire/GaN-based diaphragm structure for pressure sensing in harsh environments
- 2010
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In: Conference Proceedings - The 8th International Conference on Advanced Semiconductor Devices and Microsystems, ASDAM 2010. - 9781424485758 ; , s. 127-130
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Conference paper (peer-reviewed)abstract
- GaN is a potential sensor material for harsh environments due to its piezoelectric and mechanical properties. In this paper an 8mm diameter sensor structure is proposed based on a GaN / AlGaN / sapphire HEMT wafer. The discs will be glass-bonded to an alumina package, creating a 'drumskin' type sensor that is sensitive to pressure changes. The electromechanical behaviour of the sensor is studied in an attempt to optimise the design of a pressure sensor (HEMT position and sapphire thickness) for operation in the range of 10 - 50 bar (5 MPa) and above 300°C. ©2010 IEEE.
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9. |
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10. |
- Johander, Per, et al.
(author)
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Layer Manufacturing as a Generic Tool for Microsystem Integration
- 2007
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In: 4M 2007, Third International Conference on Multi-Material Micro Manufacture. - 1904445535 - 9781904445531 - 1420070045 - 9781420070040
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Conference paper (peer-reviewed)abstract
- Nearly every microsystem application requires specific packaging solutions. In this paper we suggest a newapproach to use layer manufacturing as a generic tool for microsystem integration. Three different methods to produce3D electrical interconnects are presented. Ink jet printing is used for the ceramic layer manufacturing process, as well asfor the printing of silver for circuit patterns. The technique is demonstrated for an Inertial Measurement Unit(IMU)platform. A four-sided pyramid was manufactured with layer manufacturing in ceramics and four gyroscopes weremounted on the sides of the pyramid. A demonstrator with three light diodes was also manufactured to demonstrate thepossibility to produce 3D electrical interconnects in the volume of the pyramid.
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