Strain Measurement

Introduction

During PCB test, probe pins are pressed against the workpiece by the fixture to establish electrical contact. Strain measurement is used to verify that this pressure does not cause excessive warpage or stress to the PCB or mounted components.

Details

Strain gauges are attached to designated measurement points on the workpiece or PCB using specialized adhesive. Strain is then measured during fixture pressing and pin contact to confirm that values remain within the specified limits.
If strain exceeds the allowable range, adjustments are made to hold‑down points or fixture components to prevent excessive deformation.

A fixture that has undergone this measurement and adjustment process will keep strain within specification even when testing boards with mounted components.
Measurement points should ideally be placed near components that are more susceptible to strain.