Summary

Strain gage measurement is a reliable method of finding and resolving excessive strains on a PCB, and should be implemented in the fixture preventive maintenance routine. Strain gage tests must be conducted after every modification that can affect the strain in the fixture. Such modifications include probe changes and pressure finger or stopper modifications.

BGA fractures can be induced not only in in-circuit test fixtures, but also during board assembly, testing, system integration, packaging and shipping. We suggest consulting the IPC JEDEC-9704 document (3) for specific guidelines on strain gage testing.

Our FDS simulation tool, used jointly with our strain analysis equipment, has allowed us to develop new and very efficient fixturing methods. Significantly reducing the deformation zones on PCBs and potential fractures in the production environment, our methods are constantly evolving to always meet our clients' needs.

For more information, please feel free to contact our Customer Service Department at This email address is being protected from spambots. You need JavaScript enabled to view it..

Author

Marco Deblois
President Rematek Inc.
Montreal, Quebec, Canada

References

1. PREDICTING BRITTLE FRACTURE FAILURES by P. Borgesen, B. Sykes, Surface Mount Technology, October 2005

2. FLEXURAL STRENGHT OF BGA SOLDER JOINTS WITH ENIG SUBSTRATE FINISH USING 4-POINT BEND TEST by A. Bansal, S. Yoon, V. Mahadev, Altera Corporation, January 2005

3. IPC/JEDEC-9704, PRINTED WIRING BOARD STRAIN GAGE TEST GUIDELINE, Developed by the JEDEC Reliability Test Methods for Packaged Devices Committee (JC-14.1) and the SMT Attachment Reliability Test Methods Task Group (6-10d) of the Product Reliability Committee (6-10) of IPC, June 2005