Browse Prior Art Database

Hot-Air Solder-Levelling Fixture for Flexible Circuit

IP.com Disclosure Number: IPCOM000101331D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Cox, AR: AUTHOR

Abstract

This article describes a design for a hot-air solder-leveling process fixture to hold parts to be soldered to flexible circuits. It produces good controlled solder heights in the low micron range from 10-60 microns for tab assembly sites.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 67% of the total text.

Hot-Air Solder-Levelling Fixture for Flexible Circuit

       This article describes a design for a hot-air
solder-leveling process fixture to hold parts to be soldered to
flexible circuits.  It produces good controlled solder heights in the
low micron range from 10-60 microns for tab assembly sites.

      The hot-air solder-leveling process used to solder parts to
flex circuits, requires a fixture to which the part is first attached
before it can be processed.  The fixture supports the circuit as it
is lowered into the molten solder and then it is withdrawn back
through the high pressure, hot-air knives.  All the existing types of
fixtures are either window frames, solid plates or mesh barriers,
which fail to give good controlled solder height.  The parts have
either been too thin to provide good solder joints at the tab or too
thick which causes a low yield due to shorting when the thermode
later reflows the joints.  Thick solder also requires extensive
rework to remove shorts on both tab and all other exposed solder
sites.

      Shown in Fig. 1 is a design comprising a profiled solid plate 1
with a flex circuit 2 positioned in front of it with a flow of hot
air 5 directed at the face of flex circuit 2.  Plate 1 is profiled to
suit the circuit hole pattern on the flex circuit 2 with low areas 3
and high areas 4.  Low areas 3 are positioned behind areas on flex
circuit 2 requiring controlled solder thickness by allowing solder to
be blown out of all th...