Browse Prior Art Database

Solder-Height Variation Reduction by Calendaring

IP.com Disclosure Number: IPCOM000100969D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Fry, BM: AUTHOR [+4]

Abstract

The disclosed concept provides a fast and economical way to reduce variations in solder height on printed circuit SMC pads when solder is predeposited using the immersion wave solder process (*).

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Solder-Height Variation Reduction by Calendaring

       The disclosed concept provides a fast and economical way
to reduce variations in solder height on printed circuit SMC pads
when solder is predeposited using the immersion wave solder process
(*).

      As shown in Fig. 1, significant height variation exists in
solder thickness from pad to pad.  Solder joint opens are caused by
such variations since all component leads do not contact the solder
during the reflow process. See Fig. 2.

      The calendaring process shown in Fig. 3 eliminates this
variation and provides a uniform surface for component placement.
The described method also allows processing of cards of various
thicknesses with simple adjustment of the calendaring rollers.

      Reference
(*)  J. R. Getten and R. C. Senger, "Immersion Wave Soldering
Process," IBM J. Res. Devlop. 26, 379 (May 1982).