disclosed is a sculpted probe pad and a gray scale etching process for making arrays of such probe pads on a thin flexible interposer for testing the electrical integrity of microelectronic devices at terminal metallurgy . also used in the etching process is a novel fixture for holding the substrate and a novel mask for 1 - step photolithographic exposure . the result of the invention is an array of test probes of preselected uniform topography , which make ohmic contact at all points to be tested simultaneously and nondestructively .