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Method to Control Solder Volume And Bridging On Printed Circuit Surface Patterns And Preserve Processing Freedom

IP.com Disclosure Number: IPCOM000100413D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 3 page(s) / 80K

Publishing Venue

IBM

Related People

Senger, RC: AUTHOR [+2]

Abstract

This article describes several alternative geometries and patterns to achieve solder volume (thickness) and bridging control during wave or molten solder processing, and also to allow freedom of solder processing direction for printed circuit boards and the line having surface mounted technology (SMT) land patterns.

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This is the abbreviated version, containing approximately 55% of the total text.

Method to Control Solder Volume And Bridging On Printed Circuit Surface Patterns And Preserve Processing Freedom

       This article describes several alternative geometries and
patterns to achieve solder volume (thickness) and bridging control
during wave or molten solder processing, and also to allow freedom of
solder processing direction for printed circuit boards and the line
having surface mounted technology (SMT) land patterns.

      It features the di-section of long rectangular lands into
smaller square or circular geometrical elements of the same width as
the original land to control solder thickness and bridging, and the
placement of these elements into a desirable pattern to eliminate
processing directional dependency.

      For a wave soldering process, it can be shown that solder
thickness on surface mount lands is controlled by the geometry of the
lands, and in particular, that solder thickness of round and square
lands is a function of the diameter or edge dimension of the land.
Also, it can be shown that on a rectangular land, the solder volume
is controlled predominantly by the smaller (width) dimension of the
rectangle.

      Bridging between lands is a function of the length of the land
and the spacing between lands, (more bridging with longer, closer
spaced lands).  In addition to the above, long narrow lands are more
susceptible to bridging if they are wave solder processed in the
parallel direction rather than the orthogonal direct...