Robust titanate-modified encapsulants for high voltage potting application of multi-chip module

High voltage gated diode crosspoint (GDX) devices (operational at 375 V) in AT&T´s No. 5ESS, require exceptional protection. Heat curable silicone elastomer appears to be the ideal material for this application. The material formulation includes small amounts of a silane coupling agent which increases material adhesion to the potted hybrid integrated circuit (HIC) structure. However, residual silicone couple agent tends to defuse to outer casings thereby contaminating leads and preventing further lead attach assembly. Titanate modified silicone elastomer was developed which prevents silane coupling agent contamination and also further improves adhesion within the potted structure. This paper begins with a FT-IR GC/MS analyses of the contaminant problem, followed with a chemical application towards the final solution to achieving a robust potted GDX HIC. Furthermore, laser ionization mass spectra analysis (LIMA) was used to elucidate the additional titanate interaction with the potting compound