RF probing of custom ASIC's

Abstract

Production testing of custom RF ASIC's is limited to a few seconds of testing devices at wafer and again at package. Recent trends towards the use of low cost highly integrated RF ASICS have clearly demonstrated the need for cost effective solutions for production wafer level testing. Wafer testing is generally limited to tests that provide the most information about functionality. When the products have high frequency functionality, the cost of the wafer probe cards increases dramatically. Solutions such as membrane probes, and coaxial ground-signal probes are expensive, but absolutely necessary for high frequency applications. If the device operation is not at too high a frequency, a standard wire tip probe card can be used to provide results that are sufficient to determine whether a device is functional. In this paper we explore the limits of low cost standard wire and shielded wire probe cards. Detailed discussion of the parasitics associated with the wire and shielded probes are discussed. Simulations and measurement results for a low cost probe card are examined. A rough estimate of the usefulness of the card versus frequency is provided.