Browse Prior Art Database

Laser Modification of Epoxy-Glass Composites for Selective Palladium Seeding

IP.com Disclosure Number: IPCOM000102849D
Original Publication Date: 1990-Feb-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 63K

Publishing Venue

IBM

Related People

Burns, FC: AUTHOR [+3]

Abstract

Disclosed is a method for selectively seeding epoxy-glass composites with Pd+2 ions and subsequent electroless copper deposition. An excimer laser is used to ablate the epoxy and create a layer of carboxyl groups on the exposed glass cloth. The laser-created carboxyl groups will complex the Pd+2 ions, which, in turn, act as a seed for growth of copper from an electrolysis copper bath.

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Laser Modification of Epoxy-Glass Composites for Selective Palladium Seeding

      Disclosed is a method for selectively seeding epoxy-glass
composites with Pd+2 ions and subsequent electroless copper
deposition.  An excimer laser is used to ablate the epoxy and create
a layer of carboxyl groups on the exposed glass cloth.  The
laser-created carboxyl groups will complex the Pd+2 ions, which, in
turn, act as a seed for growth of copper from an electrolysis copper
bath.

      When using electrolysis copper plating techniques to create
circuit lines for printed circuit (PC) boards the standard procedure
is roughly as follows.  The entire PC board is seeded with a catalyst
which promotes deposition of copper. A layer of photoresist is
applied to the seeded PC board. The photoresist is exposed and
developed to define a circuit pattern in the photoresist.  Copper
circuit lines are grown on the PC board by placing it in an
electroless copper bath for an appropriate length of time.  An
alternative method for seeding PC boards and growing copper lines is
described below.  The method of this disclosure does not involve the
use of photoresists.

      The epoxy-glass composite (PC board) is placed in an
appropriate fixture and exposed to an excimer laser beam of
sufficient fluence (energy/cm2) to ablate the epoxy.  After the epoxy
is completely ablated the glass cloth is exposed to the laser beam.
A chemical species, most likely a form of carboxyl (-CO2) group, is
...