US Patent 11670555 PCM metal shielding for wafer testing

Method and devices to reduce integrated circuit fabrication process yield loss due to undesired interactions between PCMs and the wafer test probes during wafer sorting tests are disclosed. The described methods entail the use of a properly patterned metal layer on the PCM dies adjacent to the product dies under test. Such patterned metal layers shield traces of the wafer probes from the circuits of the PCM dies. Various exemplary metal layer patterns are also presented.