2000 Volume 12 Issue 12 Pages 788-793
A practical method for predicting gold-wire deformation during the transfer molding process of semiconductor devices has been developed. In this study, a QFP (Quad Flat Package) having 160 wires was used. The deformed configuration and maximum deformed values were measured for different configurations of the gold wires. Horizontal, dimensionless, and deformed configurations of gold wires could be characterized by elastic straight beams under the conditions of end supports and center load. By combining the results of this study with those of a previous report on the BGA (Ball Grid Array) package, we were able to establish a relationship between the parameter λ and the resin velocity component perpendicular to the center of each wire, resin flow time at the center of each wire, apparent resin viscosity in the mold cavity, gold wire dimensions such as loop height, actual length and diameter, and Young's modulus for the gold wire. The relationship between λ and the maximum horizontal displacement, δmax was described by a combination of a straight line from the origin of the coordinate axes leading to a saturation curve. For the linear region, an empirical equation model to estimate δmax was obtained.
