Eutectic bonding, also called eutectic soldering, is where the combination of two or more metals allow direct transformation from solid to liquid state or vice versa at specific temperature without passing two-phase equilibrium. The eutectic temperature is much lower than the melting temperature of the materials that are involved in the bonding process. Eutectic bonding is ideal for high-vacuum applications as this process has very low outgassing.
Eutectic wafer bonding is widely used in the MEMS industry for hermetic sealing, pressure or vacuum encapsulation as it allows highly reliable wafer-level processing for devices with the smallest form factors. The most common metals/alloys that are used in eutectic bonding are Al-Ge, Au-Sn and Au-In. However, there are many other material combinations available that can produce a eutectic bonding system. Additionally, the ability of silicon to alloy with metals like Au can also be the basis for eutectic bonding. All eutectic bonds must go through a liquid phase and thus are less sensitive to surface flatness irregularities, scratches and particles, thereby facilitating high volume manufacturing. Bonding temperature, time and pressure are the most important parameters for eutectic bonding where high bond strength can be achieved with low processing temperature and minimum resultant stress. Eutectic bonding can additionally enable hermetic sealing and electrical interconnections in a single process. Compared to other intermediate layers, such as adhesives or glass-frit, eutectic bonding also promotes better out-gassing and hermeticity.
Visit our booth #330 and our PDC "Wafer-to-Wafer and Die-to-Wafer Hybrid Bonding for Advanced Interconnects" held by Process Technology Manager Tobias Wernicke on 27th of May and listen as well to our talks “Advanced FO PLP Digital Lithography Patterning Development for AI Devices” & “Wafer-to-Wafer Bonding With Saddle-Shaped Wafers” held by Business Development Manager Dr. Ksenija Varga and Anton Alexeev on 29th of May. We are also looking forward to meet you at the poster session on 29th of May where Supervisor Process Technology Peter Urban will present “IR Laser Debonding for Silicon Based Temporary Carrier Systems Enabling 2.5D and 3D Chiplet Integration Processes”
Listen to our Keynote "The role of wafer bonding in next generation interconnect scaling" held by Corporate Technology Development & IP Director Markus Wimplinger
Listen to our talks on Wednesday June 18th in Session 15:
"Investigation of influence of structure geometry on resist coverage for spray coating" held by Johanna Rimböck, Technology Development and
"Utilizing Inkjet Coating and Nanoimprinting for Complex 3D Patterns with Gradual Height Increase and Minimal Residual Layer" held by Business Development Manager Thomas Achleitner.
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