Low thermal expansion adhesives and encapsulants for cryogenic and high power density electronic and photonic device assembly and packaging

摘要

Filled composite compositions can be used as encapsulants, underfill materials, and potting materials in electronic and optical packages that are subjected to a wide temperature range. The composites contain a matrix and a filler composition. In a preferred embodiment, the matrix is an organic material. The filler composition contains particles of a material that have a negative coefficient of thermal expansion. The filler composition contains particles having a wide range of sizes. Furthermore, the particles exhibit a non-normal, for example, log normal or power-law, particle distribution. The non-normal size distribution of the particles enables the filler composition to be formulated at high levels into organic matrices, resulting in composites that have very low coefficient of thermal expansion to match those of the semiconductor materials in the electronic package or optical components in an optical assembly.