Browse Prior Art Database

Semiconductor Transportation Sensing Alignment Technique

IP.com Disclosure Number: IPCOM000088609D
Original Publication Date: 1977-Jul-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Bertelsen, BI: AUTHOR [+3]

Abstract

Previously, in the automatic transportation of semiconductor wafers and storage associated with said conveyance provided wafer alignment using either mechanical reference bands or stored data directing stepping motors. Said alignment techniques are utilized to inject or eject wafers to or from carriers using the well-known mechanical tongue technique.

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Semiconductor Transportation Sensing Alignment Technique

Previously, in the automatic transportation of semiconductor wafers and storage associated with said conveyance provided wafer alignment using either mechanical reference bands or stored data directing stepping motors. Said alignment techniques are utilized to inject or eject wafers to or from carriers using the well-known mechanical tongue technique.

An improved method is illustrated conceptually in Fig. 1, wherein a light source 1 is focused or directed to a pair of light collectors 2A and 2B. The item being positioned, e.g., a semiconductor wafer, interferes with the beam, causing a variation in the rate of light collected by 2A and 2B as a function of the position of the light-splitting device 3. The light from the collectors is fed into a comparator 4 whereby the amount of light flowing into each collector is measured and transformed into electrical energy, the utilization of which correction to the vertical position of the light-splitting device 3 can be made.

Fig. 2 is an elevation view of a specific embodiment illustrating a semiconductor carrier 5 and a wafer 6 having been removed from the carrier onto an air track transportation device 7 prior to which the wafer was positioned utilizing the light-splitting technique. The light collectors are illustrated at 8. Fig. 3 is a top view showing the illustration of Fig. 2 wherein like reference numerals designate like elements, except that a light emitter...