The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 16, 1993
Filed:
May. 20, 1991
John M Rush, Mountain View, CA (US);
Torben Ulander, Sunnyvale, CA (US);
Michael T Verdon, San Jose, CA (US);
Fortrend Engineering Corporation, Sunnyvale, CA (US);
Abstract
The present invention is a rotary, 3-stage wafer transfer machine. The transfer machine utilizes a pneumatically powered lift mechanism to raise wafers from a boat to a retaining area. If the next operation for the wafer is a single density operation (twenty-five wafers per boat), the wafers are the simply transferred to another boat for further processing. If the next operation for the wafers requires double density (fifty wafers per boat), a second set of wafers is lifted to the retaining area, where they are interspersed with the first set to create a double density set of fifth wafers. This set is then transferred to the appropriate boat (generally a quartz boat) for further processing. All components that could generate particulate contamination are sealed off from the transfer area. Extra duty materials are used for the components of the machine to provide unique reproducibility and eliminate much of the required maintenance as compared to the prior art. Lack of contamination and superior reproducibility allow increased yield in the manufacturing process.