EMI Shielding Coating / Plating

Ecoplate Tech Bulletin  

 CHO-Shield 2056 Tech Bulletin

There are many secondary operation technologies used to shield thermoplastic housings.

• Conductive paints
• Electroless plating selective & non-selective
• Sputtered vacuum metalization
• Thermal spray

We can have any of these applied to the housing either through in-house application or our authorized suppliers. The primary factors to consider when choosing a secondary EMI coating are:

• Shielding effectiveness
• Environmental resistance
• Part geometry
• Part production volume

Applied material cost must be balanced with performance to find the best solution. The following table shows a relative ranking of the technologies.

EMI Material Application - Relative Cost and Effectiveness
  Filler Binder Shielding
Effectiveness
200 MHz
to 18 GHz
Humidity
Resistance
Maximum
Operating
Temperature
Solvent
Resistance
Abrasion
Resistance
Masking
Tooling Cost
Batch
Set Up
Costs
Applied
Cost
Paint Ni Acrylic * * * * * $$ $ $
Ag/Cu Acrylic *** * * * * $$ $ $$
Cu Urethane *** ***** ***** ***** *** $$ $ $$$$$
Ag Urethane **** ***** ***** ***** *** $$ $ $$$$$
Ag Epoxy **** ***** ***** ***** ***** $$ $ $$$$$
Vacuum Metalization Al N/A * * *** *** ** $$$$ $$$$$ $
Selective Plating Ni/Cu N/A *** * *** *** ** $$ $$ $$
Non-Selective Plating Ni/Cu N/A *** * *** *** ** $ $$ $
Thermal Arc Spray Sn/Zn N/A ***** ***** ***** ***** ***** $$$$$ $ $$

 

Legend
Lowest
Highest
Effectiveness
*
*****
Cost
$
$$$$$

 

Chomerics in-house selection of paints contains all commonly used filler and paint binders. They range from 50 dB controlled environment Ni/Acrylic to >90dB aerospace grade Ag/Epoxy systems. If we do not make the needed paint we will obtain it and apply it for you. We have in house painting abilities ranging from manual spray to robotic paint lines. These are complemented by an authorized paint spray supplier allowing us to provide the best solution.

Metalization by sputtering or plating are done by our authorized supplier base. Sputtered aluminum is a good solution in low shielding applications where volume supports a higher tooling cost and the batch process. Plated nickel over copper can be done selectively or non-selectively for internal noncosmetic parts. Ni/Cu provides excellent shielding, however it is not recommended for high humidity uncontrolled environments.

Thermal spray of tin-zinc by Parker Chomerics ECOPLATE® process provides high shielding with excellent resistance to harsh environments.

There is no single solution and all solutions vary in cost. Since Parker Chomerics is unique in offering all technologies, let our design engineers assist you in making the best choice for shielding your plastic housing at the lowest total cost of ownership.

NOTICE: The information contained herein is to the best of our knowledge true and accurate. However, since the varied conditions of potential use are beyond our control, all recommendations or suggestions are presented without guarantee or responsibility on our part and users should make their own tests to determine the suitability of our products in any specific situation. This product is sold without warranty either expressed or implied, of fitness for a particular purpose or otherwise, except that this product shall be of standard quality, and except to the extent otherwise stated Chomerics’ invoice, quotation, or order acknowledgement. We disclaim any and liability incurred in connection with the use of information contained herein, or otherwise. All risks of such are assumed by the user. Furthermore, nothing contained herein shall be construed as a recommendation to use any process or to manufacture or to use any product in conflict with existing or future patents covering any product or material or its use.