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Laser Seeding Followed by Laser Plating for Circuitization And Repair

IP.com Disclosure Number: IPCOM000120379D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Vigliotti, DR: AUTHOR [+2]

Abstract

This article describes a technique which uses only laser seeding and laser plating to repair an open copper circuit. The open circuit is first seeded with palladium-acetate dissolved in a solvent such as chloroform. The solution, when applied to the region of the open circuit dries rapidly in air without any application of heat to the substrate [1]. After drying, the region to be repaired is pyrolyzed selectively with a focussed laser, generally an argon laser with tens of milliwatts of incident power for typical microcircuit opens. Other lasers can also be used. The unreacted Pd-acetate is now removed in any one of a number of organic solvents. At this stage, the circuit is electrically connected but of relatively high resistance.

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Laser Seeding Followed by Laser Plating for Circuitization And Repair

      This article describes a technique which uses only laser
seeding and laser plating to repair an open copper circuit. The open
circuit is first seeded with palladium-acetate dissolved in a solvent
such as chloroform.  The solution, when applied to the region of the
open circuit dries rapidly in air without any application of heat to
the substrate [1]. After drying, the region to be repaired is
pyrolyzed selectively with a focussed laser, generally an argon laser
with tens of milliwatts of incident power for typical microcircuit
opens.  Other lasers can also be used.  The unreacted Pd-acetate is
now removed in any one of a number of organic solvents.  At this
stage, the circuit is electrically connected but of relatively high
resistance. The repair is completed by using an acid copper sulfate
solution or an electroless solution in combination with the same
laser to plate-up the seed layer with copper via thermally induced
exchange plating [2].  Here, the laser is scanned back and forth
along the seeded region, causing copper to deposit.  To assure a
minimum amount of circuit dissolution which occurs simultaneously in
order to maintain charge conservation, small amounts of bulk copper
can be placed in close proximity to the region of the repair site in
those cases where the circuit under repair contains very little
copper.  Alternatively, electroless solution can be used in place of
copper sulfate and the seed layer built-up selectively again by
scanning the laser in the region of the break.  In either case, no
extenal EMF is applied...