TY  - JOUR
AB  - Plastic ball grid arrays (PBGAs) have been gaining increasing industry acceptance
as potentially the lowest cost packages for high pin count applications. The main factors for their
success include the inherent low cost of plastic packages, the high yields achievable with existing
assembly equipment, the density advantages of an area array and, in many cases, superior electrical
performance. The reliability of these packages with respect to solder joint fatigue has been extensively
studied; however, little has been published on their reliability with respect to
moisture‐related failure mechanisms during assembly, such as popcorning. In this
study, two types of plastic ball grid array packages, a 225‐lead full matrix array and a
256‐lead perimeter array, which were preconditioned by baking at 125°C for 24 hours
followed by exposure to 85°C and 30% relative humidity for 168 hours, were then
subjected to three passes of simulated infra‐red reflow at 1°C/s and
0.67°C/s. Subsequent examination using scanning acoustic microscopy and environmental
scanning electron microscopy revealed considerable delamination and cracking in both package types
reflowed at the higher ramp rate. This damage originated in the die attach and propagated along the
weakest interfaces in the package. At the lower ramp rate, a much smaller amount of delamination was
observed. This suggests that there is a critical ramp rate below which popcorn cracking can be
inhibited.
VL  - 14
IS  - 1
SN  - 1356-5362
DO  - 10.1108/13565369710800439
UR  - https://doi.org/10.1108/13565369710800439
AU  - McCluskey P.
AU  - Munamarty R.
AU  - Pecht M.
PY  - 1997
Y1  - 1997/01/01
TI  - Popcorning in PBGA Packages During IR Reflow Soldering
T2  - Microelectronics International
PB  - MCB UP Ltd
SP  - 20
EP  - 23
Y2  - 2024/04/26
ER  -