Patent ID: 6169409
Filing Date: 2001-01-02
Classification: G01R

Abstract:
A method of testing electrical characteristics of an object to be tested, at a predetermined low temperature in a prober which includes: a prober chamber; a main chuck on which the object is placed in the prober chamber; a probe card with probes for testing the electrical characteristics of the object as brought into contact with electrical pads of the object placed on the main chuck; a ring-like member, fixed to an upper portion of the prober chamber, for detachably supporting the probe card; a plate provided for said ring-like member at a position outward of the probe card, said plate creating a space defined by said ring-like member between the probe card and said plate itself; and a dry gas supplying mechanism for supplying a dry gas, which does not condense at the predetermined low temperature, to the space so that gas in the space is replaced with the dry gas; said method comprising the steps of: (a) supplying the dry gas, which does not condense at the predetermined low temperature at which the object is tested, from the dry gas supplying mechanism to the prober chamber; (b) replacing the gas in the space with said dry gas by the dry gas supplying mechanism; (c) cooling the object to be tested to the predetermined low temperature; and (d) testing the electric characteristics of the object at the low temperature.