6-Joyce-Board Test Workshop 2005.pdf

Intro to Strain testing• As BGA package size and ball pitch have decreased, second-level interconnect failure due to manufacturing over-flexurehas become an increasing concern, especially whencombined with the metallurgical changes for lead freemanufacturing.• Data suggests typical manufacturing processes may exceedstrain limits in one or more of these areas: Board Assembly,ICT, Functional Test and System Assembly• In Circuit Testing (ICT) has shown to induce the higheststrain.• Strain gage measurement is a common and effective way ofmonitoring board flexure, and Intel® is now establishingstrain limits for our BGA products.• Intel’s® BFI (Board Flex Initiative) is a set of tools that hasbeen carefully designed to correlate laboratory experimentaldata to the real world factory.3