Browse Prior Art Database

Method to Improve Copper-Plated Line Adhesion to Fluoropolymer Laminates

IP.com Disclosure Number: IPCOM000103486D
Original Publication Date: 1990-Dec-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 1 page(s) / 52K

Publishing Venue

IBM

Related People

Ellis, TL: AUTHOR [+3]

Abstract

Disclosed is a process for improving the adhesion of copper lines to a fluoropolymer laminate by modifying the polymer surface with chromium at high temperature and pressure.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 72% of the total text.

Method to Improve Copper-Plated Line Adhesion to Fluoropolymer Laminates

      Disclosed is a process for improving the adhesion of copper
lines to a fluoropolymer laminate by modifying the polymer surface
with chromium at high temperature and pressure.

      It is well known that adhesion of copper to fluoropolymers is
poor and that the surface of the polymer must be modified to improve
the polymer/metal adhesion.  A thin layer of chromium applied to the
polymer under lamination conditions markedly improves the adhesion of
electrolytic copper lines.  Laminates are formed by using 7 oz.
copper as a carrier, upon which the fluoropolymer is placed.  The top
laminate layer consists of a sacrificial smooth copper-Invar-copper
(CIC) layer to which a thin film (400 Ao) of chromium is sputtered.
The chromium side of the CIC is placed in contact with the
fluoropolymer.  The laminate is made at 730oF at 1600 psi.  The CIC
is later etched away, leaving a thin film of chromium on the polymer
surface.  Next, 400 Ao of chromium is sputtered onto the modified
laminate surface, followed by 3000 Ao of sputtered copper, which is
used as a seed layer.  Then, 1.5 mils of electrolytic copper is
deposited.  The laminate is then subjected to a typical photoresist
process to produce lines suitable for peel testing.

      The peel strength of copper lines electrolytically deposited to
the modified, seeded fluoropolymer surface may be increased more than
300% over the peel str...