Browse Prior Art Database

Selective Nickel-Plating for the Additive Plating Process

IP.com Disclosure Number: IPCOM000113333D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Bauer, F: AUTHOR

Abstract

This article describes the use of a metal-free seeding process for the pattern plating technique when structuring highly complex printed circuit boards.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 79% of the total text.

Selective Nickel-Plating for the Additive Plating Process

      This article describes the use of a metal-free seeding process
for the pattern plating technique when structuring highly complex
printed circuit boards.

      Known methods, i.e., manufacturing copper structures by
electroplating followed by subtractive etching, are limited by the
increasing integration density of semiconductor components.  Thus,
leakage problems as well as problems concerning the adhesion between
the copper and the laminate arise.

      The new process described below overcomes these problems by
combining a direct plating process, using SO3 to fumigate the epoxy
surfaces and to activate the boreholes, and an additive plating
process by means of which nickel (and subsequently copper) is
selectively plated only at the desired positions of the pattern and
the through holes.

      Proposed process - The printed circuit board is manufactured
conventionally using FR4/glass and UV-blocker as starting materials.
Before placing the through holes the copper foil (typically 1 oz) is
etched away.  The surface of the epoxy is generated by the Copper
Bondable Surface (CBS) foil.  After the SO3 activation the board is
laminated with a photoresist, exposed and developed.

      Subsequently, nickel is plated into the through holes and the
developed pattern by the so called direct surface plating process.
The subsequent copper-plating is defined by the electrical
specifications of the...