Browse Prior Art Database

Metallic Sacrificial Foil for Manufacturing Copper Bondable Surface Products

IP.com Disclosure Number: IPCOM000109265D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 37K

Publishing Venue

IBM

Related People

Bauer, F: AUTHOR

Abstract

Disclosed are metallic sacrificial foils which are used as a mechanical protection layer and an etch barrier to manufacture circuit boards.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Metallic Sacrificial Foil for Manufacturing Copper Bondable Surface Products

       Disclosed are metallic sacrificial foils which are used
as a mechanical protection layer and an etch barrier to manufacture
circuit boards.

      Normally, a polyester film (such as NELTAPE*) is bonded to the
surface of the copper-bondable surface (CBS) composite prior to the
drilling, the first vapor blasting, the chemical hole cleaning, and
the second vapor blasting step.  This film must be resistant to
temperatures of about 200oC.  Upon completion of these critical
steps, the foil is removed from the surface.

      After lift-off of the foil, the remaining adhesive has to be
removed from the surface by chemical and/or physical steps to prevent
a reduction in reliability in the succeeding process steps.  In
addition, the higher baking temperatures of subsequent CBS processes
require a higher heat resistance than that of polyester or equivalent
polymers.

      In the process described here, the polyester foil is replaced
by an Al/Cu foil which is laminated to the surface prior to the
critical steps as indicated.  This metallic foil is sufficiently
heat-resistant and as it can be laminated, there is no removal of
adhesive.  As a result, the process is shortened and its reliability
is increased.
*  Trademark of dp Dielectric Polymers, Inc.