Versatility and flexibility from low outgassing silicones

Silicone materials have unique characteristics allowing use in a broad range of applications and preservation of mechanical properties when exposed to extreme conditions. These mechanical properties absorb stresses incurred during thermal cycling as well as remain stable at temperatures up to 300°C for short intervals. The aerospace industry has utilized silicone adhesives and coatings for over fifty years because of these unique properties. Miniaturization of electronic packages has led to using thinner and more fragile materials. This, in combination with the use of lead-free solder with solder reflow temperatures up to 260°C, can cause high shear stress during heating and cooling that can damage a device. Subsequently, there is growing interest in silicone adhesives and encapsulants for terrestrial electronic packaging applications. A major concern surrounding use of silicones is the volatile component observed to outgas when silicones are exposed to high temperatures and low pressures (vacuum) for extended periods of time. These volatile components may contaminate sensitive surrounding surfaces and equipment making adhesion or soldering difficult in an upstream process. In extreme cases, such as in Micro Electro Mechanical Systems (MEMS) devices, volatiles can cause catastrophic failures with the device operation itself.