구리계 리드프레임/EMC 계면의 접착력 측정

Abstract

Copper-based leadframe sheets were oxidized in hot alkaline solutions to form brown and black oxide layers on the surface, molded with the epoxy molding compound (EMC), and machined to form sandwiched double cantilever beam (SDCB) and sandwiched Brazil-nut (SBN) specimens. The two types of specimens were designed to measure the adhesion strength of the leadframe/EMC interfaces under quasi-Mode I (G_(IC)) and mixed Mode loadings (G_c), respectively. Results showed that both oxide layers enhanced G_(IC) to the level of ∼80 J/㎡ at two minutes of the oxidation time. G_c increased parabolically with phase angle when the sign of phase angle was positive. For both cases, interface crack began to kink into EMC when G_c was ∼150 J/㎡.