STRUCTURE AND PROCESS FOR REDUCING DIE CORNER AND EDGE STRESSES IN MICROELECTRONIC PACKAGES

摘要

A MICROELECTRONIC DIE IS ALIGNED WITH A PACKAGE SUBSTRATE AND ATTACHED TO IT USING SOLDER BALLS (350). A SPECIALLY SHAPED HEAT SPREADER, PREFERABLY WITH A COEFFICIENT OF THERMAL EXPANSION (CIE) SIMILAR TO THAT OF SILICON, IS ATTACHED TO THE BACK SIDE OF THE DIE USING A HEAT-CONDUCTING ADHESIVE. AN EPOXY-BASED MATERIAL IS FLOWED INTO THE GAP (360) BETWEEN THE DIE (330). THE SUBSTRATE (310), AND THE HEAT SPREADER VIA A THROUGH-HOLE IN EITHER THE SUBSTRATE OR THE HEAD SPREADER (300; 320) USING A DISPENSE PROCESS OR A TRANSFER MOLDING PROCESS. BY POSITIONING THE HEAT SPREADER TO ABOUT THE DIE CORNERS AND OR EDGES, THE STRESSES ON THE DIE ARE SUBSTANTIALLY REDUCED OR ELIMINATED. FIGS 3 & 7