Strain Gauge Analysis

Similar to finite element analysis, rather than using computer generated models, the actual circuit board and test fixture are used in measuring the circuit board’s strain during the test cycle. Small sensors called "tri-directional rosettes" are mounted to the circuit board around strain sensitive components. The measurements taken from the rosettes' are recorded with a scanner.

Test results can highlight the risk of:

• Fractured solder joints
• Lifted pads or traces
• Cracked components
• Delamination of the PCB

Extra measure of attention

The fixture and circuit board are used for the strain gage test resulting in actual "live" measurements of the UUT's flexing during the test cycle. During strain gage testing the fixture gets a detailed inspection and is fine tuned to keep strain at the lowest possible levels.

When should extra testing be performed?

• High concentrations of probes under BGA's or fragile components
• The UUT is thinner than 0.062"
• The UUT larger than 200in²
• Fixture has > 2200 probes
• Extra high spring force probes are utilized
• If a component has a strict warranty policy

A fully detailed Strain Gage report is submitted to the customer comparing test results to the industry standard IPC/JEDEC 9704.