Better Thermal, Mechanical and Dielectric Properties of Cured Polyimides Using Low Pressure Vacuum Cure Processing

In this paper, to meet the demand placed on Polyimide materials in Fan Out Wafer and Panel Level Processing applicable to Heterogeneous Integration, thermal, mechanical, and dielectric properties were studied for different types of Polyimide and Poly-Benz-Oxazole (PBO) materials, such as HD-4100, HD-8820 and HD7110, as a function of different process parameters, under atmospheric and vacuum process conditions. Vacuum cure results in higher thermal stability with lower outgassing in HD-4100 and HD-8820 films. Vacuum cure of HD-4100 and HD-7110 appears to increase the dielectric strength, but no similar trend is seen for HD-8820. These results are consistent with the assumption that cure under vacuum reduces the amount of volatile and volatilizable material remaining in the film after the cure process.