Browse Prior Art Database

Solder-Levelling Device

IP.com Disclosure Number: IPCOM000061673D
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Funari, J: AUTHOR [+2]

Abstract

The regulation of solder volume for the soldering of recessed pins to substrates is difficult to achieve due to surface tension that tends to "ball-up" the solder. In those situations where chips are mounted directly above pin heads, the pin heads are recessed, and the solder must not protrude above the substrate. Because inadequate solder makes a weak joint, a device that ensures sufficient solder and also that the solder does not protrude above the substrate, thereby interfering with the chip, is provided. A titanium plate 1 (Fig. 1) is heated by a heater cartridge 2 which has a negative wetting angle with solder and which is not alloyed or wetted by it. The plate 1 is placed in contact with pinned substrate 3 having recessed pins 4. Fig.

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Solder-Levelling Device

The regulation of solder volume for the soldering of recessed pins to substrates is difficult to achieve due to surface tension that tends to "ball-up" the solder. In those situations where chips are mounted directly above pin heads, the pin heads are recessed, and the solder must not protrude above the substrate. Because inadequate solder makes a weak joint, a device that ensures sufficient solder and also that the solder does not protrude above the substrate, thereby interfering with the chip, is provided. A titanium plate 1 (Fig. 1) is heated by a heater cartridge 2 which has a negative wetting angle with solder and which is not alloyed or wetted by it. The plate 1 is placed in contact with pinned substrate 3 having recessed pins 4. Fig. 2, a cross-sectional view of recessed pin 4, shows pin 4 recessed in hole 5 and solder 6 having height above the substrate. The application of heated titanium plate 1 melts and reflows solder 6, eliminating solder protrusion and permitting mounting of chips on the substrate.

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