Metal to glass anodic bonding for microsystems packaging

In this communication, we report on metal to glass anodic bonding for Microsystems packaging. Bonded Pyrex-Foturan/Metal double stack and Silicon/Pyrex/Metal triple stack were investigated for applications in the sensor encapsulation field. Anodic bonding of metals, sheets of Invar, Kovar, Alloy 42 and Titanium, and thin films of Titanium, to Ion-containing glasses with two different thermal expansion coefficients, Pyrex and Foturan, was evaluated in terms of samples preparation, bonding parameters, and bonding characteristics. Selected metals anodically bonded to glass exhibited levels of residual stress, strength and tightness that make this technique suitable for packaging Microsystems, silicon piezoresistive sensors and micro-fluidic systems, among others.