| abstract |
An improved semiconductor unit package is disclosed. This package is implemented by a semiconductor device (1) having an electrode pad (2), a substrate (6) having a terminal electrode (5), a bump electrode (3) formed on the electrode pad (2), a conductive adhesion layer (4) with flexibility, and an encapsulating layer (7) formed by curing a composition the viscosity and thixotropy index of which are below 100 Pa.s and below 1.1, respectively. Such a composition essentially consists of (A) a resin binder that contains, for example, a polyepoxide, an acid anhydride, and a rheology modifier and (B) a filler. The rheology modifier is one capable of impeding interaction between a free acid contained in the acid anhydride and a polar group at the surface of the filler. An encapsulant with improved flowability is used, so that the encapsulant readily flows and spreads to fill a gap between the semiconductor device (1) and the substrate (6) with no air bubbles. This achieves semiconductor unit packages with high reliability and productivity. |