Patent ID: 8248089

Claim:
An apparatus for testing an electrical property of a semiconductor device, comprising: a substrate support unit; a tester head above the substrate support unit, the tester head including a base; a probe card connected to the base of the tester head; a temperature control unit within the base of the tester head, the temperature control unit being configured to control temperature of the probe card by heat transfer with the probe card, the temperature control unit including: a thermoelectric module configured to change a heat flow direction according to a power flow direction, the thermoelectric module being within the base of the head tester to exchange heat with the probe card, a plate on the thermoelectric module configured to radiate or absorb heat according to a change of the heat flow direction of the thermoelectric module; a power supply, a temperature detector within the base, the temperature detector being configured to detect the temperature of the probe card and to generate a corresponding detection signal, a controller configured to generate a control signal corresponding to the detection signal of the temperature detector and to apply the generated control signal to the power supply to change a power flow direction of the power supply, and a housing, the thermoelectric module, the plate, and the temperature detector being inside the housing; and an elastic member between the base of the tester head and the housing, the elastic member being configured to apply an elastic force to push down the housing.