Browse Prior Art Database

Conformal Plastic Sheet Coating for Protection & Holding of Components

IP.com Disclosure Number: IPCOM000108851D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 60K

Publishing Venue

IBM

Related People

Smith, T: AUTHOR [+2]

Abstract

Disclosed is a means of protecting and holding electronic components onto printed circuit boards. This is accomplished by means of a semi-flexible non-electrically conductive plastic or fabric film coated on one surface with a heat- or ultraviolet- activated adhesive. This film is positioned directly over the already placed components on a circuit board assembly. Both the film and the circuit board are exposed to a relatively high differential pressure of air or other gaseous containment fluid in such a manner as to cause the film to act as flexible diaphragm which conforms tightly onto the surface of the components and the printed circuit substrate.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 67% of the total text.

Conformal Plastic Sheet Coating for Protection & Holding of Components

      Disclosed is a means of protecting and holding electronic
components onto printed circuit boards.  This is accomplished by
means of a semi-flexible non-electrically conductive plastic or
fabric film coated on one surface with a heat- or ultraviolet-
activated adhesive.  This film is positioned directly over the
already placed components on a circuit board assembly.  Both the film
and the circuit board are exposed to a relatively high differential
pressure of air or other gaseous containment fluid in such a manner
as to cause the film to act as flexible diaphragm which conforms
tightly onto the surface of the components and the printed circuit
substrate.  Thus, the components are protected from the outside
environment by this plastic film which is then kept in place by
activating the adhesive layer which is held by pressure differential
intimately in contact with the components and the surface of the
card.  The application of the heat or UV source to activate the
adhesive layer can also be useful for softening the adhesive layer to
enhance conformance around the irregular contours of the assembled
card surface.  The second, or backside, of the card is then covered
in a manner similar to the method described above.  The materials
selected for the film and adhesive should also be selected to cause
shrinkage after the adhesive has been activated and bonded to the
component and card surfaces....