Total ball shear/zone shear #
Total Ball Shear (TBS), also called zone shear, testing consists of a wide shear tool used to shear multiple rows of solder balls in a single stroke. The test is applied prior to second level attachment to the printed wiring board of the BGA. The shear speed used must be constant throughout the complete shear stroke. Typically the speed is set between 5 to 50 mm/s.
Compared to the more common low speed solder ball shear testing, which is performed on one single solder ball, TBS testing does not provide any relevant force measurement data, but it does provide a visually inspected outcome of the metallurgical joint between the solder ball and BGA pad metallization. As hundreds of solder balls are tested in one time, the very scarce brittle fractures on a single solder ball become visible for inspection.
Therefore TBS testing offers a fast, low cost and easy solution for obtaining substantial statistical information on the brittle versus ductile fracturing of lead-free solder balls. Although it replaces the more time consuming high speed shear testing for in-line BGA production process control, it cannot provide the relevant measurement metrics like high speed shear testing would in a research environment.
Standards #
- JEDEC standard JESD22-B117
Test features #
- Fast, destructive, inline testing of lead-free BGA’s
- Hundreds of solder balls tested simultaneously
- Brittle fracture outcome by visual inspection
- Test speed from 5 mm/s to 50 mm/s
- Stress testing of BGA modules
