Browse Prior Art Database

Precision Wafer Orientation and Transfer System

IP.com Disclosure Number: IPCOM000080783D
Original Publication Date: 1974-Feb-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Jorgenson, RR: AUTHOR [+2]

Abstract

Wafers are precisely and rapidly oriented on a pedestal at work stations which are provided for resist contact or projection printing, wafer identification, wafer dicing, and testing, using a wafer orientation system which includes directional air bearings and a rotating capstan.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 2

Precision Wafer Orientation and Transfer System

Wafers are precisely and rapidly oriented on a pedestal at work stations which are provided for resist contact or projection printing, wafer identification, wafer dicing, and testing, using a wafer orientation system which includes directional air bearings and a rotating capstan.

Referring to Figs. 1 and 2, wafer 8 is conveyed by input air slide 1 having directional air jets 7 which provide an air stream Q(S), such that wafer 8 does not make contact with notch locating pin 4 while arriving at orientation station 10. At station 10, wafer 8 is acted upon by orientation flow jets 2 in pedestal 11 having lift component Q(L) and drag component Q(D) (Fig. 2), which drive wafer 8 against high-speed rotating capstan 5 and fixed notch locating pin 4.

As shown, the net driving force Q(V) associated with orientation flow jets 2 is directed at alpha = 45 degrees between locating pin 4 and capstan 5, which are located at an angle of 90 degrees relative to one another.

Capstan 5 contains a resiliant tracking surface with a high coefficient of friction (e.g., urethane rubber) and diameter suitable for high-speed wafer orientation. The combined effects of circumferential drive force F(T) of capstan 5 and the resultant flow vector force Q(V) of flow jets 2, causes wafer 8 to rotate until wafer notch 3 seeks and engages notch locating pin 4. Upon engagement, capstan 5 idles at wafer flat 12 and the presence of notch 3 at pin 4 is sensed by detectors 9A and 9B.

The sensing of the engagement of notch 3 with pin 4 causes nesting arms 6A and 6B to engage wafer 8, thereby disengaging wafer 8 from capstan 5 and imparting the final registration...