DocumentCode :
2959421
Title :
A process and reliability analysis of no flow underfill materials for high throughput flip chip processing
Author :
Smith, Brian A. ; Thorpe, Ryan ; Baldwin, Daniel F.
Author_Institution :
Center for Board Assembly Res., Georgia Inst. of Technol., Atlanta, GA, USA
fYear :
2000
fDate :
2000
Firstpage :
178
Lastpage :
190
Abstract :
Development of new material systems will increase flip chip market growth provided they reduce manufacturing time and enhance reliability. Among these new materials are no flow underfills. Properly formulated, these underfills can significantly decrease manufacturing cost by eliminating the fluxing process, the underfill flow process, and the underfill cure process. This work evaluates the reliability of no-flow underfill materials and performs a critical failure mode analysis of flip chip structures using no flow underfills. Six test vehicles and four reliability tests were used to evaluate and analyze the reliability performance of several commercial no flow underfill materials. Different test vehicles were used to evaluate the effect of varying chip size, interconnect density, pad surface finish metallization, and solder mask opening design. Accelerated reliability tests performed included liquid/liquid thermal shock (LLTS), air/air thermal cycling (AATC), moisture sensitivity preconditioning, and temperature humidity aging (TH). Materials tested in this work demonstrated the ability to survive 1000 cycles in LLTS and AATC without failure, 1000 hours of TH and level three preconditioning. A number of unique failure modes are identified, including bulk underfill cracking, fillet cracking, solder interconnect fatigue cracking and underfill interfacial delamination
Keywords :
ageing; delamination; encapsulation; failure analysis; fatigue cracks; flip-chip devices; humidity; integrated circuit interconnections; integrated circuit metallisation; integrated circuit packaging; integrated circuit reliability; microassembling; soldering; surface treatment; thermal shock; thermal stresses; 1000 hr; accelerated reliability tests; air/air thermal cycling test; bulk underfill cracking; chip size; critical failure mode analysis; failure modes; fillet cracking; flip chip market growth; flip chip material systems; flip chip processing; flip chip structures; fluxing process; interconnect density; liquid/liquid thermal shock test; manufacturing cost; manufacturing time; moisture sensitivity preconditioning; no flow underfill materials; no flow underfills; no-flow underfill materials reliability; pad surface finish metallization; process analysis; reliability; reliability analysis; reliability performance; reliability tests; solder interconnect fatigue cracking; solder mask opening design; temperature humidity aging; test vehicles; throughput; underfill cure process; underfill flow process; underfill interfacial delamination; Costs; Failure analysis; Flip chip; Manufacturing processes; Materials reliability; Materials testing; Performance analysis; Performance evaluation; Surface finishing; Vehicles;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electronics Manufacturing Technology Symposium, 2000. Twenty-Sixth IEEE/CPMT International
Conference_Location :
Santa Clara, CA
ISSN :
1089-8190
Print_ISBN :
0-7803-6482-1
Type :
conf
DOI :
10.1109/IEMT.2000.910727
Filename :
910727
Link To Document :
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