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US4556587A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for electro-magnetic interference shielding

Assignee: Shipley Co Inc
•
Filing: 1983-12-19
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Granted: 1985-12-03
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Expires: 2003-12-19
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Abstract

Abstract A process for metal plating plastic or elastomeric materials which produces a coating of high conductivity which does not reduce over time is disclosed in this application to provide electro-magnetic interference shielding for said materials. This process uses either a particular special plating bath containing stabilizer additions with any surface preparation technique, or a certain specific surface preparation technique along with the use of a standard plating bath or the special stabilized plating bath to obtain metal coatings with the desired properties.

Inventors

  • 👤 Chris Tsiamis
  • 👤 John E. McCaskie

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 14:11
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/20; C23C18/22; C23C18/28

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 123 words
A process for EMI Shielding of plastic or elastomeric materials which comprises: (a) gas-etching the surface of said material by exposure to an atmosphere containing gaseous sulfur trioxide; (b) controlling the gas-etching reaction to a point where the surface will accept a deposit of an activating colloidal metal; (c) activating the etched surface by immersion into a solution containing a colloidal metal catalyst; and (d) plating the substrate with an electroless metal plating bath that contains an organic compound having a thiocarbonyl group in combination with a complexing agent capable of and in a sufficient amount to provide a metal coating which will provide a surface resistivity of less than about 1 ohm/square both initially and after aging for at least one month.
Claim 2
Dependent Claim 123 words
A process for EMI Shielding of plastic or elastomeric materials which comprises: (a) gas-etching the surface of said material by exposure to an atmosphere containing gaseous sulfur trioxide; (b) controlling the gas-etching reaction to a point where the surface will accept a deposit of an activating colloidal metal; (c) activating the etched surface by immersion into a solution containing a colloidal metal catalyst; and (d) plating the substrate with an electroless metal plating bath that contains an organic compound having a thiocarbonyl group in combination with a complexing agent capable of and in a sufficient amount to provide a metal coating which will provide a surface resistivity of less than about 1 ohm/square both initially and after aging for at least one month.
Claim 3
Dependent Claim 25 words
The process according to claim 1 wherein said atmosphere contains a sufficient amount of water vapor to improve the adhesion and/or coverage of the etching.
Claim 4
Dependent Claim 22 words
The process according to claim 1 wherein said activating step comprises immersing the etched material into a solution containing a metal colloid.
Claim 5
Dependent Claim 20 words
The process according to claim 3 wherein said metal colloid is a noble metal colloid or a transition metal colloid.
Claim 6
Dependent Claim 20 words
The process according to claim 4 wherein said noble metal colloid is a colloid of palladium, platinum, silver, or gold.
Claim 7
Dependent Claim 20 words
The process according to claim 4 wherein said transition metal colloid is a colloid of copper, nickel, cobalt, or iron.
Claim 8
Dependent Claim 57 words
The process according to claim 1 which comprises (b) treating the etched surface with a conditioning agent comprising a non-ionic surfactant to improve the surface for activation with a catalytic metal colloid, (c) depositing said activating colloid from a colloidal metal solution, and (d) plating a metal coating upon the activated surface from an electroless metal bath.
Claim 9
Dependent Claim 18 words
The process according to claim 7 in which the surface is cleaned with an alkaline solution after conditioning.
Claim 10
Dependent Claim 17 words
The process according to claim 8 in which the conditioning agent contains the alkaline or acid cleaner.
Claim 11
Dependent Claim 13 words
The process according to claim 16 in which the surface is subsequently neutralized.
Claim 12
Dependent Claim 16 words
The process according to claim 9 in which the surface is subsequently treated with an acid.
Claim 13
Dependent Claim 22 words
The process according to claim 7 in which the surfactant is a polyoxyalkylene or an adduct thereof or an alkyl phenol ethoxalate.
Claim 14
Dependent Claim 13 words
The process according to claim 1 wherein the electroless metal plating is nickel.

References Cited (Backward Citations)

US3983267A Cited
US4201825A Cited
US4308301A Cited
US4336028A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-12-02 1989-06-03 1989-12-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-12-02 1993-06-03 1993-12-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-12-02 1997-06-03 1997-12-03 $7700.00 Window Closed / Lapsed

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