Thermal and viscoelastic characterization of transfer-molded epoxy encapsulant during simulated post-mold cure

Abstract

This paper describes the characterization of epoxy mold compound by subjecting transfer-molded encapsulants to a temperature programme simulating post-mold cure using thermomechanical analysis and dynamic mechanical analysis. The real-time change in dimension and viscoelastic properties of the epoxy encapsulant during an experimental post-mold cure process is measured. Results show evidence of residual cure shrinkage and flexural storage modulus growth occuring during experimental post-mold cure; sharp initially but stabilize subsequently. A minimum post-mold cure duration is recommended in order to ensure optimum dimensional and mechanical stability of the epoxy encapsulant.