|EPSI INC. - Electronics Packaging Solutions International Inc.
P.O. Box 1522, Montclair, NJ 07042 USA, tel. & fax: +1 (973)746-3796
|ABSTRACT (PAPER GIVEN AT 2010 SMTA INTERNATIONAL CONFERENCE, OCT. 26, 2010, ORLANDO, FL):
Saito, T., Tamai, N. (Hirose Electric, Japan), Kikuchi, T. (Hirose Electric, USA), Ramakrishna, G. (Cisco Systems), Chu,
Q., Sethuraman, S. (Jabil), Shea, C. (Shea Engineering Services) and Clech, J-P. (EPSI Inc.),
"Long-Term Reliability Assessment Of A New Lead-Free Area Array Connector System"
BGA mezzanine connectors are essential elements of today’s Telecom and Datacom systems because they provide distinct advantages to system
designers and manufacturers. To developers, they offer design flexibility and cost reduction opportunities. To assemblers, they often eliminate
the expensive wave soldering process, thus improving operational efficiency and profitability.
Area array connectors have proven their long-term performance in Tin-Lead solder systems, but the mandatory switch to Lead-free alloys has
forced requalification programs that include assembly process and reliability testing. Before any new connector can be designed or adopted,
concerns about SMT process windows, reliable X-ray inspection and rework, and BGA joint reliability must be defined and assessed.
A new BGA connector system that is designed to improve both assembly and reliability has been developed. This paper describes the connector’
s design features that address processing concerns and increase long-term reliability. It reviews the results of tests that assessed the system’s
performance in accelerated thermal cycling.
Accelerated thermal cycling (0-100°C) of over 72,000 solder joints produced six confirmed failures between 7,700 and 10,000 cycles, indicating
a level of performance that far exceeds typical BGA packages. Weibull and dye & pry analyses showed that the connectors’ individual blocks
function independently of each other during thermal cycling, presumably contributing to their surprisingly high long-term performance. The
predicted life of the connectors when subjected to daily thermal cycles of 25 – 60°C is 30 years.
Key words: BGA connector, Area Array connector, Reliability, Lead-Free
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