High-performance tape package

Abstract

A high-pincount, high-power TAB (tape automated bonding) to board VLSI chip package is described. The package consists of a protective ceramic clamshell enclosing a TAB chip with 332 leads at 125 mu m ILB (inner lead bond) pitch extending uninterrupted through the ceramic enclosure to the 0.3-mm pitch OLB (outer lead bond) zone configured for reflow soldering. The package body is clamped to the printed wiring board substrate by a spring-loaded heatsink providing good thermal conductance through a low-pressure separable interface. A 70-mm single site slide carrier tape format is employed to facilitate package assembly from ILB, die attach, clamshell bonding, through test and burn-in, and finally excise and leadform for OLB. A number of rigorous tests were used to qualify the package for use in the VAX4000/300.<>