Composition of INGUN Test Probes

Base Materials

The choice of the base materials is dependent on the demands put on each individual component.

Brass is sometimes used for passive tip-styles and for machined barrels. The high percentage of copper makes it an ideal electrical conductor. Brass, however, is too soft for aggressive tip-styles.

Steel is used for practically all aggressive tip-styles. It provides a high level of hardness and sharpness of the points and the flanks. This ensures good durability and reliable contacting.

BeCu (Beryllium-Copper) provides a good combination and compromise between brass and steel: The high percentage of copper makes it an ideal electrical conductor and the small percentage of Beryllium allows the base material to be hardened (up to 435 HV). This then ensures good durability and optimizes the aggressiveness of the plunger tip.

New-Silver (NiAg) and Bronze are mainly used for Receptacles and the Barrels of the Test Probes. These materials have a high tensile strength, which is ideal for the long-term life of Test Probes. Furthermore, these materials provide a good elasticity of the crimps on the Receptacles.

Spring Steel of the highest possible quality is used for the manufacturing of the springs. For high and low temperature ranges, certain high-alloyed spring steels (i.e. stainless steel) are used.

Plating Materials

Hard-gold, chem. Nickel and Rhodium are used. The choice of plating materials is made according to functional features.

Hard-gold: best chemical resistance, Hardness 150-200 HV. Especially good against oxidation.

Rhodium: extremely good resistance to wear, Hardness 600-1000 HV; very brittle. Usage when special demands in regard to durability of the plunger tip are required. Because of the brittleness, this plating material is not suitable for aggressive tip-styles in conjunction with high spring forces.

Chem. Nickel: very good chem. resistance, Hardness 400-600 HV. Important because of the true depositing, i.e. without build up on points and edges (so-called "dogbone" effect). Very suitable as durable layer for plungers. Because of the relatively high ductility. This plating material is ideal for aggressive tip-styles.

Aurun: this gold-alloy plating type was developed especially for Test Probes and has a very good chem. resistance. Hardness 300-350 HV. Usage for aggressive tip-styles for testing unwashed PC-Boards.

All plating materials guarantee the best contacting reliability due to the very low specific resistance values.