Electronics tester

A tester apparatus comprising:

• a wafer chuck;
• a tray for releasably holding a wafer the tray being releasably positioned on the wafer chuck, the wafer chuck having a vacuum passage therethrough, the tray having a plurality of vacuum openings therethrough, each vacuum opening connecting a rear side of the wafer to the vacuum passage in the wafer chuck so that, when a vacuum is applied to the vacuum passage, the vacuum secures the rear side of the wafer to the tray;
• a contactor board;
• contactor contacts mounted to the contactor board, each contactor contact having a surface positioned to make contact with a respective front wafer terminal on a front side of the wafer;
• and
• an electric tester connected to the contactor contacts, such that, in use, current conducts through the front side wafer contacts and the contactor contacts between the electric tester and a circuit in the wafer to test the circuit.

A method of testing a wafer comprising:

• holding a wafer in a tray;
• positioning the tray on a chuck;
• applying a vacuum to a vacuum passage though the wafer chuck, the tray having a plurality of vacuum openings therethrough, each vacuum opening connecting a rear side of the wafer to the vacuum passage in the wafer chuck so that the vacuum secures the rear side of the wafer to the tray;
• moving a contactor board and the tray relatively towards one another so that surfaces of contactor contacts mounted to the contactor board make contact with respective front wafer contacts on a front side of the wafer;
• conducting current through the front side wafer contacts and the contactor contacts between an electric tester and a circuit in the wafer to test the circuit;
• and
• removing the wafer from the tray.