Author_Institution :
VLSI Technology Inc., San Jose, CA, USA
Abstract :
The continuous miniaturization of computers necessitates the use of new high pin count plastic packages such as TQFP (thin quad flat pack). These new package types, with 1.4-, 1.0-, or 0.8-mm plastic package body thickness, have very limited space for bond wire, specifically in the loop height dimension. This restriction imposes a challenge to the traditional wire bond technology, especially when long wire is needed for small die. The author reviews the constraints a thin plastic package imposes on wire bonding, and presents a statistical design of an experiment based on a response surface methodology to characterize wire loop profile control. Based on the regression equations generated, a mathematical model is established to guide the development of a predetermined loop profile suitable for thin plastic package assembly. The effects of major bonding parameters, such as wire length, kink-height, reverse loop, loop factor, bonding speeds, and wire tension, and their interactions on loop profile are analyzed
Keywords :
lead bonding; surface mount technology; SMD; SMT; TQFP; bond wire; bonding parameters; bonding speeds; high-pincount; kink-height; loop factor; mathematical model; microassembly; package assembly; plastic packages; regression equations; response surface methodology; reverse loop; statistical design; surface-mount; thin quad flat pack; wire bond technology; wire length; wire loop profile control; wire tension; Assembly; Bonding; Electronics packaging; Microassembly; Microcomputers; Plastic packaging; Response surface methodology; Semiconductor device packaging; Space technology; Wire;
