Browse Prior Art Database

Solder Ball Reflow

IP.com Disclosure Number: IPCOM000037737D
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Emerick, AJ: AUTHOR [+4]

Abstract

Solder balls can be positioned with wider tolerance and reflowed with improved assurance by placing the balls at respective fluxed locations on a substrate, superpositioning a plate fixture and inverting the assembly during furnace reflow.

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Solder Ball Reflow

Solder balls can be positioned with wider tolerance and reflowed with improved assurance by placing the balls at respective fluxed locations on a substrate, superpositioning a plate fixture and inverting the assembly during furnace reflow.

In FIG. 1, ceramic circuit substrate 1 has a plurality of metal pads 2 with respective pins 3, of which only one is shown. A spot of flux 4 and a solder ball 5 are placed adjacent each pin and solder pad. Thereafter, fixture plate 6 of FIG. 2 (to which solder does not adhere during the subsequent reflow) is placed on the substrate. The fixture has opening 7 at the chip mounting position 8 and locator pins 9 to center substrate 1. The assembly is then inverted and passed through a reflow furnace. The solder balls are restrained in motion and tend to flatten thus forming a larger diameter to reach respective pads and pins.

Disclosed anonymously.

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