MECHANICAL FAILURES IN Pb-FREE PROCESSING: SELECTED MITIGATION TECHNIQUES FOR PAD CRATER DEFECTSAuthors: Brian Gray, P. Eng., John McMahon, P. Eng.
Company: Celestica Inc.
Date Published: 10/24/2010 Conference: SMTA International
Multiple pad crater mitigation paths are currently being pursued, which include changes to resin formulations and determination of working process strain limits. Initial determination of working strain limits for ball grid arrays (BGAs) has been completed at multiple strain rates and pad crater was found to be the predominant failure mode . The pad crater occurred in the area of highest strain, the BGA package corners. Investigation of pad crater mitigation through changes to footprint design including larger solder masked defined (SMD) pads at BGA corners is investigated.
Key words: pad crater, spherical bend test, mechanical failure mode, process strain, solder mask defined (SMD) non-solder mask defined (NSMD), ball grid array (BGA)
Members download articles for free:
Not a member yet?
What else do you get when you join SMTA? Read about all of the benefits that go along with membership.
Notice: Sharing of articles is restricted to just your immediate work group. Downloaded papers should not be stored on an external network or shared on the internet.