Browse Prior Art Database

Surface Carbonization by Microwave Treatment

IP.com Disclosure Number: IPCOM000119359D
Original Publication Date: 1991-Jan-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 73K

Publishing Venue

IBM

Related People

Angelopoulos, M: AUTHOR [+3]

Abstract

Disclosed is a process for the rapid and efficient production of a conducting polymer surface which is suitable for shielding applica tions.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Surface Carbonization by Microwave Treatment

      Disclosed is a process for the rapid and efficient
production of a conducting polymer surface which is suitable for
shielding applica tions.

      Polymeric materials are desirable for electronic enclosures due
to their ease of manufacture, design freedom, lightweight, mechanical
and non-corrosive properties and cost savings.  However, to meet FCC
regulations for the emission of RF noise and to prevent external RF
signals from affecting the performance of the electronic components,
the plastic enclosures must be shielded against Electromagnetic
Interference (EMI).  In addition, shielding is also required for the
prevention of electrostatic discharge (ESD) within the electronic
components since this could cause severe damage to the devices.

      The usual shielding approach is to (i) apply a conducting
coating such as a highly loaded metal paint which is expensive to
apply; (ii) fill the polymer with a conducting material, either metal
or carbon powder; or (iii) carbonize the polymeric material directly.
Coatings have the disadvantage that the adhesion between the coating
and the polymeric substrate must withstand harsh treatment, including
temperature, humidity and mechanical wearing, e.g., scratching and
rubbing.  Filling the polymer has the disadvantage that usually high
levels of loading are necessary to meet the shielding demands.  This
high loading may degrade the properties of the plastic material, such
as the impact resistance.

      Carbonization has the disadvantage that the polymeric material
is embrittled in the process, thus comprising some of the mechanical
properties that the material was selected for.  However, if only the
surface of the polymer is carboniz...