Patent ID: 7119432
Filing Date: 2006-10-10
Classification: H01L

Abstract:
1. A semiconductor package comprising: a packaging substrate; a semiconductor die having a top surface and a bottom surface having its bottom surface mounted on the substrate using solder balls; a heatspreader mounted at the top surface of the package; and a multi-layer heat transfer element arranged between the semiconductor die and the heat spreader to enable thermal communication between the die and the heat spreader wherein the multi-layer heat transfer element includes: a core spacer plate having a top surface and a bottom surface wherein the core spacer is arranged solely between the die and the heatspreader; a first layer of thermally conductive reflowable material formed ante top surface of the core and directly above the die configured to attach the core to the heatspreader, wherein the reflowable materials comprises a solder from the group consisting of silver containing solders, tin containing solders, lead containing solders, silicon titanium containing solders, tin silver containing solders, and tin bismuth containing solders; and a second layer of thermally conductive reflowable material formed on the bottom surface of the core to attach the core to the top surface of the die, wherein the reflowable materials comprises a solder selected from the group consisting of silver containing solders, tin containing solders, lead containing solders, silicon titanium containing solders, tin silver containing solders, and tin bismuth containing solders.