to test more of the dies 108 at once once the circuits in all the dies 108 are tested the test chuck 32 is moved in an x direction so that each one of the substrates 56 a c is aligned with a respective one of the slots 50 d f as shown in fig1 the test chuck 32 is then moved in a direction 108 so that the substrates 56 a c are located in the slots 50 d f respectively the vacuum on the test chuck is then released so that the substrates 56 a c are released from the test chuck 32 the test chuck 32 is then dropped so that the substrates 56 a c drop into supports of the slots 50 d f as shown in fig1 and 18 the substrate removal apparatus 42 includes a retracting tool 110 a conveyor system 112 and a removal cassette 114 the retracting tool 110 is first used to move the substrate 56 a onto the conveyor system 112 the conveyor system then moves the substrate 56 a into the removal cassette 114 while the substrate 56 a is moved into the removal cassette 114 another substrate 56 d.