Browse Prior Art Database

Protection of Polyimide Surfaces through Removable Polymeric Coating

IP.com Disclosure Number: IPCOM000103841D
Original Publication Date: 1993-Feb-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Feger, C: AUTHOR [+4]

Abstract

Disclosed is a polymeric covering to protect ceramic substrates covered with polyimide during the process of attaching engineering change (EC) wires. During this attachment the polyimide surface is often damaged, because the tweezers used to hold and push the wires around slip and gouge the polyimide. This is particularly harmful when the area of the C4 pads is damaged. A material is proposed to cover the C4 pads, and a device to apply this material automatically. Furthermore, a device applying such coatings to polyimide surfaces with low degrees of metallization is disclosed.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 58% of the total text.

Protection of Polyimide Surfaces through Removable Polymeric Coating

      Disclosed is a polymeric covering to protect ceramic substrates
covered with polyimide during the process of attaching engineering
change (EC) wires.  During this attachment the polyimide surface is
often damaged, because the tweezers used to hold and push the wires
around slip and gouge the polyimide.  This is particularly harmful
when the area of the C4 pads is damaged.  A material is proposed to
cover the C4 pads, and a device to apply this material automatically.
Furthermore, a device applying such coatings to polyimide surfaces
with low degrees of metallization is disclosed.

      Ordinary gelatin has a higher hardness than polyimide, and can
be used as a tough coating which protects the polyimide from
scratches.  The gelatin is commercially available in sheet form or as
powder, from which thin films (50 - 100 micron) are easily prepared.
Such films adhere well to a polyimide surface wetted with water or a
mixture of water and ethylene glycol (up to 10%), or a dilute
solution of gelatin in one of the aforementioned liquids.  If the
polyimide surface is highly metallized, the last method is preferred.

      To protect the C4 areas, chip-sized gelatin films are attached,
using one of the above-mentioned methods.  If water alone is used to
attach the gelatine, the gelatine has to be wet also on the top
surface with water.  The substrate is dried at moderate temperatures
(50 C)....