Patent ID: 7535244

Claim:
An apparatus comprising: a first substrate comprising a plurality of drive circuits configured to supply test signals to a semiconductor device, first signal transmission lines electrically connected to the drive circuits and configured to transmit the test signals from the drive circuits, and a plurality of first signal transmission terminals electrically connected to the first signal transmission lines, the first substrate having a first opening at an inner periphery thereof for projecting light on the semiconductor device; and a second substrate electrically connected to the first substrate and detachable from the first substrate, said second substrate comprising second signal transmission lines and a plurality of second signal transmission terminals electrically connected to the second signal transmission lines, wherein the first signal transmission terminals are electrically connected to the second signal transmission lines and the second signal transmission terminals are electrically connected to the first signal transmission lines, the second substrate having a second opening at an inner periphery thereof for projecting light on the semiconductor device, the second opening being concentric to the first opening of the first substrate.