a reusable burn - in / test fixture for testing unsingulated dice on a semiconductor wafer consisting of two halves . the first half of the test fixture is a wafer cavity plate for receiving the wafer , and the second half establishes electrical communication between the wafer and electrical testing equipment . a rigid substrate has conductors thereon which establish electrical contact with the wafer . the test fixture need not be opened until the burn - in and electrical testing are completed . after bum - in stress and electrical testing , it is possible to establish interconnection between the single die or separate and package dice into discrete parts , arrays or clusters , either as singulated parts or as arrays .