Decal With Power/Ground Plane Partitioned by Thermal Coefficient of Expansion
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-29
In the electronic packaging of semiconductor chips having controlled- collapse chip connector (C-4) pads to provide electrical connection to printed circuit cards, thermal expansion constraints are important because mounting the chip to an assembly must be done in a manner such that the thermal strains experienced during the usage of the device do not excessively fatigue the C-4 solder column and shorten its life. Also, mounting the chip carrier assembly must be done so that thermal strains do not shorten the life of the card-carrier connection, i.e., pins or solder joints. The use of a flexible chip carrier comprised of a thin polyimide film can flex to accommodate the thermal strain and provide long chip and joint life.