Safe, effective hydrogen fuel cells are one of the contenders for the next shift in mobile power technology. One of the solutions to the inherent risks of high pressure hydrogen fuel cells is an outer low pressure container with an inner high pressure containers containing a micro-electromechanical systems (MEMS) valve which regulating the pressure. These MEMS valves consist of several etched Si-chips stacked and bonded, which shall withstand the pressure and temperature range in the high pressure fuel cell as well as the embrittlement caused by the hydrogen gas. Hydrogen embrittlement is a phenomena where materials, mostly metals, lose their ductility due to diffusion of hydrogen atoms into their grain boundaries. A suitable method for stacking the chips is needed and thus a literature study was conducted. Several chip-to-chip bonding methods were investigated in the purpose of finding the most suitable methods tolerating temperatures between -40 to 85°C, pressure up to 1000 bar, hermetically sealing, withstanding hydrogen embrittlement and still bond with particulate contaminations caused by testing each chip. The method found to be best fitting for the purpose was anodic bonding with an alkali glass. Alternatively anodic bonding with a ceramic glass system could be considered if technique from alkali glass is adaptable.
Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-531298 |
Date | January 2024 |
Creators | Shankan, Tala, Wahab Abdul, Oranos, Hamidi, Mustafa, Al-Chaabawi, Ahmad, Rengård, Wilhelm |
Publisher | Uppsala universitet, Institutionen för materialvetenskap |
Source Sets | DiVA Archive at Upsalla University |
Language | English |
Detected Language | English |
Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
Format | application/pdf |
Rights | info:eu-repo/semantics/openAccess |
Relation | MATVET-K ; 24008, MATVET-Q ; 24001 |
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