Composite wire probes for testing integrated circuits

Abstract

An electrical probe of an aspect includes a high yield strength wire core. The high yield strength wire core includes predominantly one or more materials selected from tungsten, tungsten-copper alloy, tungsten-nickel alloy, beryllium-copper alloy, molybdenum, stainless steel, and combinations thereof. The high mechanical strength wire core has a yield strength of at least 1 gigapascal (GPa) at temperature of 250° C. The electrical probe also includes a low electrical resistivity layer concentrically around the high yield strength wire core. The concentric layer includes predominantly one or more materials selected from silver, gold, copper, and combinations thereof. The low electrical resistivity layer has an electrical resistivity of no more than 2×10Ohm-meters. The electrical probe has an outer cross-sectional dimension of the electrical probe that is no more than 50 micrometers. Between 60 to 85% of the outer cross-sectional dimension is provided by the high mechanical strength wire core. Between 10 to 30% of the outer cross-sectional dimension is provided by the low electrical resistivity layer.