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Low Toxicity Seeding Recipe for the Self Induced Repair Process

IP.com Disclosure Number: IPCOM000108836D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Chen, CJ: AUTHOR

Abstract

Disclosed is a low-toxicity recipe for the laser seeding process for making engineering changes and repair circuit opens using the self-induced repair (SIR) method (1).

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Low Toxicity Seeding Recipe for the Self Induced Repair Process

       Disclosed is a low-toxicity recipe for the laser seeding
process for making engineering changes and repair circuit opens using
the self-induced repair (SIR) method (1).

      Using the SIR method, together with a laser solid-film direct-
writing step, high-quality customized interconnects can be generated,
and circuit opens can be repaired (1-4).  The best material for the
laser seeding process is found to be palladium acetate, with
chloroform as solvent (4,5).  Typically, the spraying solution is
made by dissolving 1 gram palladium acetate in 10 ml of 4:1 mixture
of chloroform and methonol.  After laser seeding, the unreacted
palladium acetate is rinsed off using chloroform (4).  Because
chloroform is a suspect carcinogen, it  is difficult to use in
manufacturing.

      This article describes a low-toxicity recipe for spraying and
rinsing using acetone as solvent.  Acetone is a widely used solvent,
not a carcinogen.  Because palladium acetate is a low-toxicity
material, and a small laser is adequate (for example, 200 mW
air-cooled argon ion laser), the entire seeding process is safe and
easy to handle.

      A proven embodiment of this process is as follows:
1.   Dissolve 1 gram of palladium acetate in 50 ml acetone. To
accelerate dissolution, ultrasonic stirring is recommended. The
solution, with a very dark brown color, is nearly saturate.
2.   Spray the solution on to the substrate. At the beginning of
spraying, small droplets of palladium acetate form on the substrate.
Those droplets are glass-like solid.  Co...