Browse Prior Art Database

Automatic Semiconductor Positioning System

IP.com Disclosure Number: IPCOM000076731D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Eisenstadt, BM: AUTHOR [+2]

Abstract

This system features the use of a photodiode array to scan a semiconductor chip and to align a stud mounted on a positioning table with the chip. The photodiode array 2 is fixedly mounted via a stand 8 to an X-Y-theta positioning table 6. Illumination means 7, which provides illumination to the sensors and to the semiconductor chip 3, is also attached to stand 8. Chip 3 is held in place by chip holder 9 which moves up and down as required for bonding of the chip to the stud. Illustrated on the chip are raised solder balls which are used to determine the chip position and orientation. The heating column 5 holds the chip stud 4. Displacement transducers, not shown, are connected to four-point locator slides at the heating column, to give the position data of the stud relative to positioning table 6.

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Automatic Semiconductor Positioning System

This system features the use of a photodiode array to scan a semiconductor chip and to align a stud mounted on a positioning table with the chip. The photodiode array 2 is fixedly mounted via a stand 8 to an X-Y-theta positioning table 6. Illumination means 7, which provides illumination to the sensors and to the semiconductor chip 3, is also attached to stand 8. Chip 3 is held in place by chip holder 9 which moves up and down as required for bonding of the chip to the stud. Illustrated on the chip are raised solder balls which are used to determine the chip position and orientation. The heating column 5 holds the chip stud 4. Displacement transducers, not shown, are connected to four-point locator slides at the heating column, to give the position data of the stud relative to positioning table 6. The data on the position of chip 3 is obtained from the photodiode array, the outputs of which are sampled at selected times by multiplexor 10, fed to threshold circuit 12 and into the process controller 20 via photodiode array interface circuit 14. The position of the mounting stud 4 is fed through the process controller 20 via A/D converter 16. Data from the chip and stud is used to compute position information in the process controller, thereby allowing the alignment of the stud under the chip for subsequent bonding.

Fig. 2 illustrates the relationship of photodiode array 2 to the solder balls on chip 3. The array is linear,...