Effects of Multilayer Structures Made of Epoxy Compounds with Different Filler Contents on Thermo-Mechanical Stresses in 3D packages

Three-dimensional integration technologies allow combining components and substrates for various purposes, made of different materials, within a single heterogeneous assembly. This approach allows electronic designers to reduce the weight and dimensions of products, while maintaining the functional parameters. However, the combination of different materials in one package leads to the appearance of thermo-mechanical stresses, which not only during operation, but also during the manufacture of the device. This article shows that it is possible to reduce the effect of thermo-mechanical stresses on a product by increasing the plasticity of the sealed compound, as well as by uniformly distributing stresses over the volume of the assembly. The latter option can be implemented using layers of the amount of composite material, in which the filler is in the range from 50% to 80% when the CTE (coefficient of thermal expansion) changes from 35 to 7.5 ppm per Celsius degree.