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.
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Besuchen Sie unseren Stand #330 und unser PDC „Wafer-to-Wafer and Die-to-Wafer Hybrid Bonding for Advanced Interconnects“ von Dr. Viorel Dragoi am 27. Mai und hören Sie sich auch unsere Vorträge „Advanced FO PLP Digital Lithography Patterning Development for AI Devices“ & „Wafer-to-Wafer Bonding With Saddle-Shaped Wafers“ von Dr. Ksenija Varga und Anton Alexeev am 29. Mai an. Wir freuen uns auch darauf, Sie bei der Poster Session am 29. Mai zu treffen, wo Urban Peter „IR Laser Debonding for Silicon Based Temporary Carrier Systems Enabling 2.5D and 3D Chiplet Integration Processes“ präsentieren wird.
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