Title :
Narrowing the gap in flip chips
Author :
Gektin, Vadim ; Bar-Cohen, Avram
Author_Institution :
Appl. Mater., Santa Clara, LA, USA
fDate :
5/1/1998 12:00:00 AM
Abstract :
Due to the high I/O density, low-cost assembly, and low package profile, DCA is the technology of choice in many current applications. However, DCA configurations are vulnerable to thermally induced strains and the resulting solder-joint fatigue, which, in turn, leads to reduced reliability. In recent years it has been found possible to obtain dramatically higher (5-10X) reliability and to operate successfully with much larger chip sizes, under comparable operating conditions and with identical solders, by underfilling a chip. Underfilling is done by filling the gap between the chip and substrate with epoxy, which also surrounds the solder joints. Underfilling between the chip and substrate reduces solder-joint deformation and shear strain
Keywords :
finite element analysis; flip-chip devices; integrated circuit packaging; integrated circuit reliability; soldering; thermal stresses; DCA; I/O density; chip sizes; epoxy; flip chips; low-cost assembly; operating conditions; package profile; reliability; shear strain; solder-joint fatigue; thermally induced strains; underfilling; Capacitive sensors; Circuits; Electronic packaging thermal management; Flip chip; Lead; Organic materials; Silicon; Temperature dependence; Thermal expansion; Thermal stresses;
Journal_Title :
Circuits and Devices Magazine, IEEE
