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Repair and Circuitization of Wiring on Aluminum Nitride Substrates

IP.com Disclosure Number: IPCOM000106911D
Original Publication Date: 1992-Jan-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Dreyfus, RW: AUTHOR [+3]

Abstract

It is becoming evermore important to produce circuits on boards and modules with high thermal conductivity so that heat produced by increased circuit density can be dissipated as efficiently as possible.

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This is the abbreviated version, containing approximately 52% of the total text.

Repair and Circuitization of Wiring on Aluminum Nitride Substrates

       It is becoming evermore important to produce circuits on
boards and modules with high thermal conductivity so that heat
produced by increased circuit density can be dissipated as
efficiently as possible.

      It has been shown that aluminum nitride ceramic, A1N, is very
suitable for use as a substrate material, due especially to its high
thermal conductivity.  It has been shown (1) that AlN can be made
locally conducting by exposure to several pulses of excimer (UV)
laser light from the lasing action of ArF, KrF, XeCl or XeF gas
mixtures. (1) also shows that the laser exposed regions will plate up
with electroless copper to produce copper lines with the high
electrical conductivity required for microelectronic circuits.  A
disadvantage of this technique is that electroless copper is slow and
generally will also plate up onto any pre-existing copper circuits
unless such circuits are masked off or some means is used to
accelerate the plating locally at the laser-exposed regions.

      This article proposes using part of the basic idea of (1) in a
repair scheme for "open" copper circuits on an AlN substrate.
Initial electrical conduction across the gap region of the open
circuit is achieved with the excimer laser.  The repair is now
completed using AC plating with copper sulfate, a technique called
self-induced repair (SIR) (2).  Probes (preferably copper) are used
to make electrical contact with the line under repair, such that the
laser-expos...