DocumentCode :
1742485
Title :
Current underfills for CSP and BGA
Author :
Doba, Takahisa
Author_Institution :
Loctite Res., Dev. & Eng. Pacific, Loctite (Japan) Corp., Yokohama, Japan
fYear :
2000
fDate :
2000
Firstpage :
240
Lastpage :
242
Abstract :
Chip scale packages (CSP) and ball grid arrays (BGA) are now major package types. In the introduction of CSP/BGA to the market, package reliability was one of the main issues and underfill was required to improve board level reliability (BLR). Flip chip underfill was utilized in applications, but it was relatively slow, required a high temperature cure and had to be kept in a freezer. This paper describes the concepts, development and performance of underfills for CSP/BGA, which the authors have developed recently. The concept of the new underfill for CSP/BGA was fast, low temperature curing with sufficient reliability, and that can be kept in a refrigerator for convenience in handling. Reworkable and nonreworkable underfills were discussed. Reworkability of the underfill is a general requirement in the market for replacement of defective CSP/BGA devices due to the many devices present on multilayer printed wiring boards in current integrated assemblies. One approach to reworkable materials is thermal degradation of the chemical linkages. A few examples, which were found in the current developmental work, are described in terms of degradation and reworkability
Keywords :
ball grid arrays; bonds (chemical); chip scale packaging; circuit reliability; encapsulation; heat treatment; integrated circuit interconnections; maintenance engineering; materials handling; BGA; CSP; ball grid arrays; board level reliability; chemical linkages; chip scale packages; defective BGA replacement; defective CSP replacement; flip chip underfill; freezer storage; handling; high temperature cure; low temperature curing; multilayer printed wiring boards; nonreworkable underfills; package reliability; package type; refrigerator storage; reliability; reworkability; reworkable materials; reworkable underfills; thermal degradation; underfill; underfills; Assembly; Chip scale packaging; Curing; Electronics packaging; Flip chip; Nonhomogeneous media; Refrigeration; Temperature; Thermal degradation; Wiring;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electronic Materials and Packaging, 2000. (EMAP 2000). International Symposium on
Conference_Location :
Hong Kong
Print_ISBN :
0-7803-6654-9
Type :
conf
DOI :
10.1109/EMAP.2000.904161
Filename :
904161
Link To Document :
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