1. Field of the Invention
This invention relates to a probe device using a probe card.
2. Description of the Related Art
In a conventional semiconductor device manufacturing process, the electrical characteristics of a plurality of semiconductor chips as semi-finished products formed on a wafer are examined, thereby sorting them into good and bad ones, and hence enhancing the productivity. Probe devices have been used to examine the electrical characteristics of semiconductor chips formed on a wafer. The probe device has a wafer-holding table movable in X, Y, and Z directions and adapted to hold a semiconductor wafer with the use of a vacuum chuck or the like. A probe card incorporated in the probe device having a probe corresponding to each electrode pad of the chip is arranged above the wafer-holding table, and the table is moved in the Z direction, thereby contacting the probe with the electrode pad, and performing characteristic examination by a tester or the like on the basis of signals supplied through the probe.
In recent years, to perform the process of manufacturing semiconductor devices in a more clean atmosphere, each step of the process has been automated in an unmanned system. Accordingly, the probe device has also been automated by employing e.g. an automatic loader which can automatically load a wafer from a wafer carrier onto a wafer-holding table, and unload the wafer from the table.
However, in the above probe device, each electrode pad must be aligned with a corresponding one of the probes of a probe card, with high accuracy to a degree of several microns--several tens of microns. Further, to contact the probe with the electrode pad, the tip of the probe is adapted to slide on the surface of the electrode pad by so-called over driving (during sliding, the probe cuts the oxide film formed on the surface, thereby obtaining a reliable electrical contact). Thus, it is difficult in the conventional device to automatically perform the alignment. This being so, for example, at least at the time of exchange of probe cards, the track of the probes of a new probe card must be marked on a dummy wafer, and then the new probe card adjusted manually with reference to the track so as to align its probes with the electrode pads of the dummy wafer. Manual alignment, however, cannot be performed with high efficiency or with high accuracy.