Method of Controlling Transient Temperature Differential of Integrated Circuits and Substrates
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-27
A technique is described whereby the transient temperature difference between integrated circuit chips and their mounting substrates is controlled. Two methods are described aimed at reducing mechanical stress caused by different coefficients of expansion of the materials which make up large-scale integrated (LSI) and very large-scale integrated (VLSI) circuits on semiconductor materials. Especially, the problem caused by "chips" which are essentially the size of a silicon wafer "wafer scale integration" is addressed. Typically, when power is turned on LSI/VLSI circuits, a transient temperature difference occurs between the circuit chips and the substrate, such that mechanical stress will occur. This stress limits the size of chips and/or restricts the placement of contacts on the substrate.