Automatic wafer loading and pre-alignment system

US3972424A · kind A · utility

Assignee

• Computervision Corporation · US

Inventors

• Kenneth L. Levy · Stevenson, US
• David Corbin · San Jose, US
• Alan J. Fleming · Poughquag, US
• David Friedman · Austin, US
• Gilbert G. Fryklund · Winchester, US
• Vance A. Parker · Princeton, US
• Gerd Schliemann · Sunnyvale, US

Key dates

• Filing date: Aug 14, 1975
• Grant date: Aug 3, 1976
• Expiry date: Aug 14, 1995

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B65H2301/42256
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

An automatic wafer loading and pre-alignment system for integrated circuit wafer-mask Aligners. A belt feed track system is employed to transport wafers from a "send" wafer storage carrier to a wafer pre-alignment station. The wafer is machanically pre-aligned with respect to the wafer chuck of the Aligner by means of a roller arm and flat-finder system. After completion of the pre-alignment process, the Aligner turntable is rotated to carry the pre-aligned wafer and chuck to the home position of the turntable and at the same time position another chuck at the pre-alignment station. If the new chuck at the pre-alignment station contains a wafer, the wafer is transported from the chuck to a "receive" wafer storage carrier by means of a belt return track system. The feed and return wafer belt track systems have a common portion between the pre-alignment station and the respective "send" and "receive" wafer storage carriers. Photosensors are used to detect the presence or absence of wafers at critical locations in the loading system and at the pre-alignment station.