Browse Prior Art Database

Automated Pin Attachment by Welding

IP.com Disclosure Number: IPCOM000062368D
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Gesell, J: AUTHOR [+3]

Abstract

Input/output (I/O) pins are welded to I/O pads on ceramic semiconductor chip carriers by an automated process. Pins are preformed, e.g., by punching a metal tape. During welding to chip carriers, the pins remain attached to selvage strips which are perforated to allow accurate, automatic feeding in alignment with chip carriers. Roller electrodes are in contact with pin material over I/O pads on chip carriers and pulses of welding current are programmed to result in multiple, overlapping welds of pin material to pad material. An example is given wherein pins are welded to one edge of each of two sets of chip carriers in a continuous process.

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Automated Pin Attachment by Welding

Input/output (I/O) pins are welded to I/O pads on ceramic semiconductor chip carriers by an automated process. Pins are preformed, e.g., by punching a metal tape. During welding to chip carriers, the pins remain attached to selvage strips which are perforated to allow accurate, automatic feeding in alignment with chip carriers. Roller electrodes are in contact with pin material over I/O pads on chip carriers and pulses of welding current are programmed to result in multiple, overlapping welds of pin material to pad material. An example is given wherein pins are welded to one edge of each of two sets of chip carriers in a continuous process. Referring to the figure, two sets of chip carriers 2 are preheated (150 to 250 degrees Celsius) and continuously fed with the pads of the carriers 6 in alignment with punched and preformed metal tape 4 under a set of roller welding electrodes 8. The metal tape 4 is punched to create the pins to be welded to the chip carrier pads 6. Holes 10 are provided in the selvage of the metal tape 4 for accurate positioning and movement of the tape relative to the chip carriers. The punched metal tape 4 is formed into an appropriate shape, such as that shown in Sec. A-A End View, to provide wide tolerance in roller positioning and of punched tape width dimensions, and to allow large thermal expansion excursions of the metal tape without creating stress at the weld points. Welding current pulses are prog...