Optimal dimension of PQFP by using Taguchi method

This paper addresses the use of finite element techniques and Taguchi metho d to optimize package design for plastic quad flat packages (PQFP) with and without a heat slug assembled. Warpage in both types of PQFPs during the c uring process of temperature changing from 175 degrees C to room temperatur e was simulated by using three-dimensional finite element models. Taguchi m ethod was applied to both models to isolate the major control factors that minimize package warpage. Results of this analysis suggest that PQFPs witho ut heat slug should keep the thickness of both mold compound and die pad as smaller as possible. For PQFPs with heat slug assembled, it was found that larger Young's modulus of heat slug material and smaller Values of tempera ture coefficient of expansions of mold compound, die pad, and die attachmen t would yield the least warpage. (C) 2000 Elsevier Science Ltd. All rights reserved.