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Formed-In-Place Solder Preform Process

IP.com Disclosure Number: IPCOM000034313D
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Emmerick, AJ: AUTHOR [+4]

Abstract

Herein shown and described is an improved solder preform process providing in-place solder preforming. Known tinning processes of micro-circuit module pins using preformed solder components involve placing a drop of soldering flux at each tinning site, precisely placing a solder ball at each site and then reflowing the solder in a furnace. Also, ring-shaped solder preforms have been used, the preforms being placed over a pin and reflowed. These processes have a number of limitations, including the need for precise placement, difficulties in making and handling preforms, and the like. This process eliminates such limitations. As shown in Fig. 1, a solder ball 1 is placed on the top of a lower punch 3 in a lower die 5. (Image Omitted) Fig.

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Formed-In-Place Solder Preform Process

Herein shown and described is an improved solder preform process providing in-place solder preforming. Known tinning processes of micro-circuit module pins using preformed solder components involve placing a drop of soldering flux at each tinning site, precisely placing a solder ball at each site and then reflowing the solder in a furnace. Also, ring-shaped solder preforms have been used, the preforms being placed over a pin and reflowed. These processes have a number of limitations, including the need for precise placement, difficulties in making and handling preforms, and the like. This process eliminates such limitations. As shown in Fig. 1, a solder ball 1 is placed on the top of a lower punch 3 in a lower die 5.

(Image Omitted)

Fig. 2 shows the solder ball 1 flattened by the pressure of an upper punch 7 in an upper die 9, acting in opposition to the lower punch 3 and lower die 5. The flattened ball is positioned on the upper die 9. Fig. 3 shows the module 11 positioned under the upper die 9 with the center line of a pin 13 in lower die 5 congruent with the center line of the upper die 9. Fig. 4 shows the upper die 9 and its contents lowered to the ceramic substrate 11. Fig. 5 shows the upper punch 7 and upper die 9 exerting pressure on the flattened solder ball 1, reforming the ball around the pin head. Fig. 6 shows the upper punch 7 and the upper die 9 raised to clear the preformed solder at the pin head. Fig. 7 shows...