Tokyo Electron Limited

Tokyo Electron Yamanashi Limited

Noboru Tozawa

Kazuhito Yokomori

Hisashi Nakajima

A prober for a semiconductor wafer includes a main body having an interface section connected to probe needles, a test head detachably attached to the interface section, and a manipulator for moving the test head. The manipulator includes X-, Y-, Z-, .theta.X-, .theta.Y-, and .theta.Z-positioning mechanisms for positioning the test head in six directions. The Z-positioning mechanism consists of an elevator which is installed on a base and drives a slide frame. A fall preventing mechanism is provided adjacent to the elevator. The fall preventing mechanism includes a nut of a ball thread provided on the slide frame, and a shaft of the ball thread which is engaged with the nut. A brake shoe is provided at the lower end of the shaft. A brake seat is provided on the base and faces the lower surface of the brake shoe. A ball pushed by a spring is in point-contact with the center of the lower surface of the brake shoe, so that a small gap is formed between the brake shoe and the brake seat. When a thrust load exceeding a bias force of the spring is applied to the shaft by the test head due to a breakdown of the elevator, the shaft moves down together with the slide frame by the small gap. Accordingly, the brake shoe is brought into contact with the brake seat, thereby preventing the shaft from rotating relative to the nut, so that the slide frame is prevented from moving down any more.

Growing community of inventors

Nirasaki, Japan

Noboru Tozawa