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Ball Grid Array and Column Grid Array Module Solder Stencil Template

IP.com Disclosure Number: IPCOM000112877D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Isaacs, PD: AUTHOR [+3]

Abstract

Disclosed is a Ball Grid Array (BGA) and Column Grid Array (CGA) template that is a specially designed spacer which is used in the solder paste screening during BGA or CGA rework or selective attach to support the solder paste stencil and define the solder paste volume printed.

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Ball Grid Array and Column Grid Array Module Solder Stencil Template

      Disclosed is a Ball Grid Array (BGA) and Column Grid Array
(CGA) template that is a specially designed spacer which is used in
the solder paste screening during BGA or CGA rework or selective
attach to support the solder paste stencil and define the solder
paste volume printed.

The BGA or CGA module solder stencil template has the following
features:

o   It supports the solder paste stencil to prevent sagging of the
    stencil to allow for more consistent screening of solder paste.

o   The template thickness supports the stencil in such a way that
    the solder volume that is actually screened correlates to the
    solder volume that would be screened with a much thicker stencil
    without the corresponding problem of plugging the stencil
    openings that are associated with a thicker stencil.

o   The thickness of and opening in the stencil and the thickness of
    the template are optimized to provide the proper solder paste
    volume.  Too much solder paste causes shorts and too little
    solder paste volume will cause either opens or solder joints that
    will fail in a short time in field use conditions.

o   The template provides support such that the volume of solder
    paste deposited has a much tighter volume distribution and the
    solder paste deposit is better defined.

o   The ratio of the template opening and remaining web between ho...