Wafer inspection apparatus
A wafer inspection apparatus includes a probe card, a chuck top, and a vacuum mechanism for evacuating a surrounding space surrounded by the chuck top and the probe card to a set pressure. The vacuum mechanism includes an electropneumatic regulator having a proportional control valve, a pressure sensor, and a valve control unit to control the proportional control valve such that a pressure measured by the pressure sensor becomes close to or equal to a set pressure; and a gas channel network switched between first mode in which a second port of the proportional control valve is connected to the surrounding space via the pressure sensor and second mode in which the second port of the proportional control valve is connected to the surrounding space and the pressure sensor is connected to the surrounding space in parallel with the proportional control valve.
TOKYO ELECTRON LIMITED
G
G01R
inventional
Hiroshi
Yamada