Browse Prior Art Database

Laser Excitation for Passivation Decal Transfer

IP.com Disclosure Number: IPCOM000120700D
Original Publication Date: 1991-May-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 49K

Publishing Venue

IBM

Related People

Brofman, PJ: AUTHOR [+5]

Abstract

Engineering change (EC) schemes and line repairs for high density packages may require metal wire adds and deletes within close proximity to solder interconnections. To ensure that metal adds are both electrically and physically isolated from the solder interconnection, local passivation of the adds may be required. In addition, metal line laser deletes are opens in metal that could be potentially shunted (no longer electrically isolated) by contamination. In such cases, local passivation can be used to ensure laser deletes in metal lines remain clean and electrically open. (Image Omitted)

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 94% of the total text.

Laser Excitation for Passivation Decal Transfer

      Engineering change (EC) schemes and line repairs for high
density packages may require metal wire adds and deletes within close
proximity to solder interconnections.  To ensure that metal adds are
both electrically and physically isolated from the solder
interconnection, local passivation of the adds may be required.  In
addition, metal line laser deletes are opens in metal that could be
potentially shunted (no longer electrically isolated) by
contamination.  In such cases, local passivation can be used to
ensure laser deletes in metal lines remain clean and electrically
open.

                            (Image Omitted)

      A possible technique for achieving local passivation is to
build polymeric decal structures on polymeric carrier films.  The
decal "island" structures can be built by photolithographic
techniques such that controlled volumes and dimensions of passivating
polymer can be transferred locally.  The decals would then be aligned
over the area to be passivated and laser energy of the right power
and wavelength could be used to ablate the decal from the carrier
film onto the substrate.  Essentially, the laser is providing the
energy to release and transfer the decal from the carrier film onto
the substrate.  A possible requirement of this technique is the use
of a release layer situated between the decal structure and the
carrier which would facilitate the decal re...