Design of  Test Probes

Spring-loaded Test Probes (GKS) normally consist of 3 individual components. All components must be manufactured with the type of precision, which is demanded by the micro-electronics industry.

The Plunger with the contacting zone is available in a large choice of tip-styles. It must provide the smallest possible contact resistance between the Test Probe and test point, to ensure that measurement results are not distorted. The most common plunger materials are Steel and CuBe – both of which are hardened. For very passive tip-styles brass is also used.

The Spring provides the necessary contact pressure and this even after several hundred thousand strokes (testing cycles). The specified spring-forces are reached with the recommended working stroke and are subject to a tolerance range of +/- 10-15%; this being due to the parameter restrictions when designing and manufacturing springs for such small components.

For easy measurement of the spring forces, common spring-force measuring gauges are used.

The Barrel accommodates the plunger and the spring. The actual measurement signal flows via the barrel to the Receptacle. To improve the smooth movement, after gold-plating the barrel is treated with a very thin organic protective layer.