| 31. |
- Antelius, Mikael, et al.
(author)
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Hermetic integration of liquids using high-speed stud bump bonding for cavity sealing at the wafer level
- 2012
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In: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 22:4, s. 045021-
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Journal article (peer-reviewed)abstract
- This paper reports a novel room-temperature hermetic liquid sealing process where the access ports of liquid-filled cavities are sealed with wire-bonded stud bumps. This process enables liquids to be integrated at the fabrication stage. Evaluation cavities were manufactured and used to investigate the mechanical and hermetic properties of the seals. Measurements on the successfully sealed structures show a helium leak rate of better than 10 (10) mbarL s (1), in addition to a zero liquid loss over two months during storage near boiling temperature. The bond strength of the plugs was similar to standard wire bonds on flat surfaces.
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| 32. |
- Antelius, Mikael, et al.
(author)
-
Room-temperature wafer-level vacuum sealing by compression of high-speed wire bonded gold bumps
- 2011
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In: Proceedings IEEE International Conference on Solid-State Sensors, Actuators, and Microsystems (Transducers). - : IEEE. ; , s. 1360-1363
-
Conference paper (other academic/artistic)abstract
- This paper reports experimental results of a novel room temperature vacuum sealing process based on compressing wire bonded gold “bumps”, causing a material flow into the access ports of vacuum-cavities. The leak rate out of manufactured cavities was measured over 5 days and evaluated to less than the detection limit, 6×10-12 mbarL/s, per sealed port. The cavities have been sealed at a vacuum level below 10 mbar. The method enables sealing of vacuum cavities at room temperature using standard commercial tools and processes.
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| 33. |
- Antelius, Mikael, et al.
(author)
-
Small footprint wafer-level vacuum packaging using compressible gold sealing rings
- 2011
-
In: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 21:8, s. 085011-
-
Journal article (peer-reviewed)abstract
- A novel low-temperature wafer-level vacuum packaging process is presented. The process uses plastically deformed gold rings as sealing structures in combination with flux-free soldering to provide the bond force for a sealing wafer. This process enables the separation of the sealing and the bonding functions both spatially on the wafer and temporally in different process steps, which results in reduced areas for the sealing rings and prevents outgassing from the solder process in the cavity. This enables space savings and yields improvements. We show the experimental result of the hermetic sealing. The leak rate into the packages is determined, by measuring the package lid deformation over 10 months, to be lower than 3.5 x 10(-13) mbar l s(-1), which is suitable for most MEMS packages. The pressure inside the produced packages is measured to be lower than 10 mbar.
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| 34. |
- Antelius, Mikael, et al.
(author)
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Wafer-Level Vacuum Sealing by Coining of Wire Bonded Gold Bumps
- 2013
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In: Journal of microelectromechanical systems. - 1057-7157 .- 1941-0158. ; 22:6, s. 1347-1353
-
Journal article (peer-reviewed)abstract
- This paper reports on the investigation of a novel room-temperature vacuum sealing method based on compressing wire bonded gold bumps which are placed to partially overlap the access ports into the cavity. The bump compression, which is done under vacuum, causes a material flow into the access ports, thereby hermetically sealing a vacuum inside the cavities. The sealed cavity pressure was measured by residual gas analysis to 8x10(-4) mbar two weeks after sealing. The residual gas content was found to be mainly argon, which indicates the source as outgassing inside the cavity and no measurable external leak. The seals are found to be mechanically robust and easily implemented by the use of standard commercial tools and processes.
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| 35. |
- Antfolk, Christian, et al.
(author)
-
Sensory feedback from a prosthetic hand based on air-mediated pressure from the hand to the forearm skin.
- 2012
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In: Journal of rehabilitation medicine : official journal of the UEMS European Board of Physical and Rehabilitation Medicine. - : Medical Journals Sweden AB. - 1651-2081. ; 44:8, s. 702-707
-
Journal article (peer-reviewed)abstract
- Objective: Lack of sensory feedback is a drawback in today's hand prostheses. We present here a non-invasive simple sensory feedback system, which provides the user of a prosthetic hand with sensory feedback on the arm stump. It is mediated by air in a closed loop system connecting silicone pads on the prosthetic hand with pads on the amputation stump. The silicone pads in a "tactile display" on the amputation stump expand when their corresponding sensor-bulb in the prosthesis is touched, evoking an experience of "real touch". Methods: Twelve trans-radial amputees and 20 healthy non-amputees participated in the study. We investigated the capacity of the system to mediate detection of touch, discrimination between different levels of pressure and, on the amputees also, the ability to locate touch. Results: The results showed a median touch threshold of 80 and 60 g in amputees and non-amputees, respectively, and 90% and 80% correct answers, respectively, in discrimination between 2 levels of pressure. The amputees located touch (3 sites) correctly in 96% of trials. Conclusion: This simple sensory feedback system has the potential to restore sensory feedback in hand amputees and thus it could be a useful tool to enhance prosthesis use.
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| 36. |
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| 37. |
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| 38. |
- Asiatici, Mikhail, et al.
(author)
-
Capacitive inertial sensing at high temperatures of up to 400 degrees C
- 2016
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In: Sensors and Actuators A-Physical. - : Elsevier. - 0924-4247 .- 1873-3069. ; 238, s. 361-368
-
Journal article (peer-reviewed)abstract
- High-temperature-resistant inertial sensors are increasingly requested in a variety of fields such as aerospace, automotive and energy. Capacitive detection is especially suitable for sensing at high temperatures due to its low intrinsic temperature dependence. In this paper, we present high-temperature measurements utilizing a capacitive accelerometer, thereby proving the feasibility of capacitive detection at temperatures of up to 400 degrees C. We describe the observed characteristics as the temperature is increased and propose an explanation of the physical mechanisms causing the temperature dependence of the sensor, which mainly involve the temperature dependence of the Young's modulus and of the viscosity and the pressure of the gas inside the sensor cavity. Therefore a static electromechanical model and a dynamic model that takes into account squeeze film damping were developed.
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| 39. |
- Asiatici, Mikhail, et al.
(author)
-
Through Silicon Vias With Invar Metal Conductor for High-Temperature Applications
- 2017
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In: Journal of microelectromechanical systems. - : IEEE Press. - 1057-7157 .- 1941-0158. ; 26:1, s. 158-168
-
Journal article (peer-reviewed)abstract
- Through silicon vias (TSVs) are key enablers of 3-D integration technologies which, by vertically stacking andinterconnecting multiple chips, achieve higher performances,lower power, and a smaller footprint. Copper is the mostcommonly used conductor to fill TSVs; however, copper hasa high thermal expansion mismatch in relation to the siliconsubstrate. This mismatch results in a large accumulation ofthermomechanical stress when TSVs are exposed to high temperaturesand/or temperature cycles, potentially resulting in devicefailure. In this paper, we demonstrate 300 μm long, 7:1 aspectratio TSVs with Invar as a conductive material. The entireTSV structure can withstand at least 100 thermal cycles from −50 °C to 190 °C and at least 1 h at 365 °C, limited bythe experimental setup. This is possible thanks to matchingcoefficients of thermal expansion of the Invar via conductor andof silicon substrate. This results in thermomechanical stressesthat are one order of magnitude smaller compared to copperTSV structures with identical geometries, according to finiteelement modeling. Our TSV structures are thus a promisingapproach enabling 2.5-D and 3-D integration platforms for hightemperatureand harsh-environment applications.
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| 40. |
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