Patent ID: 8124519

Claim:
A method of bonding a plurality of semiconductor dies to a substrate, each of the dies susceptible to curling when subject to an elevated temperature; the method comprising the steps of: providing a semiconductor die having a center and a plurality of side edges; providing a substrate; applying to the substrate a layer of the solder paste; wherein the layer of solder paste comprises a plurality of beads, wherein the volume of each bead is selected based on the magnitude of a gap between the substrate and die at the point of application for a temperature substantially equal to the reflow temperature of the solder paste; wherein the volume of said beads increases from the center of the die to the plurality of side edges; and heating the substrate with solder paste and semiconductor die to the melting temperature of the solder paste to couple the die to the substrate; wherein the semiconductor die comprises an upper layer and a lower layer proximal to the substrate; wherein the semiconductor die curls above 160 degrees Celsius due to thermal expansion mismatch of the upper layer and lower layer.