IPC IPC/JEDEC-9706

Abstract

This document establishes metrology guidelines to electrically and reliably detect solder joint opens on Flip-Chip Ball Grid Array (FCBGA) SMT board assemblies during the mechanical shock or drop event. In-situ metrology can monitor not only FCBGA assembly with daisy-chain components but can also monitor product components with power or ground planes or equivalent daisychain test structures. In addition, the metrology is capable of providing ball-level resolution provided appropriate test structures are designed into the test package and board. The metrology was validated for thermal solutions with compression load. Although the initial focus of this metrology is specific to FCBGA assemblies in mechanical shock or drop testing, the same approach can eventually be extended to other stress tests (e.g. vibration, mechanical bend, and temperature cycle) and/or components (including other BGAs, sockets assemblies and TH/SMT leaded/leadless assemblies) depending on evolution and adoption of the guidelines (title and scope could be updated based on the outcome from future planned studies). This metrology may not be capable of detecting partial solder ball cracks, since resistance does not significantly change until the solder crack is close to 100%. Finally, the detection of pad cratering failures will be possible through use of this metrology, provided there is a complete trace crack. <br><strong>Purpose</strong> This document provides: Description of concept behind efficient in-situ electrical metrology to reliably detect FCBGA assembly solder joint opens during mechanical shock or drop test </span><ul> <li>Guidelines for special daisy-chain test structure to standardize test board design for ball-level electrical monitoring of FCBGA joints</li> <li>Minimum requirements to establish the metrology in the lab for execution</li> <li>Definition for in-situ electrical open detection criteria</li> <li>Guidelines for electrical and FA data analysis</li></ul><br>