Low melting pads for instant electrical connections

Abstract

The present invention discloses a pad for establishing instant electrical connection (PIEC) for in-line ion measurement device. The PIEC pad employs low-melting-point conductive materials, such as gallium or indium, as the attaching contact materials. The melting points of these materials can be below 160.degree. C. The vapor pressures of these materials are generally lower than 10.sup.-5 mm Hg in the temperature range between 100-300.degree. C. A PIEC pad is formed on a heavily doped semiconductor substrate covered with a metal layer. A layer of low-melting-point low-vapor-pressure material, e.g., gallium or indium, is then formed on the bottom of the heavily doped substrate. By heating a measuring device, the temperature is raised and the bottom low-melting attaching layer is melted and a good electric contact is established between the PIEC pad and the device for measurement A bonding wire is also formed on top of the metal layer. The bonding wire is electrically connected to a test or measuring electrode for current-voltage (I-V), capacitance-voltage (C-V) or other types of in-line testing or qualification measurements.

Dependencies are inferred from the claim text.