Corrosion-resistant, form-in-place EMI shielding gasket
AssigneeParker-Hannifin Corporation
InventorJohn P. Kalinoski
Life of this patent
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Abstract
An electrically-conductive, corrosion-resistant EMI shielding gasket having an EMI shielding effectiveness of at least about 80 dB at between about 10 MHz and 10 GHz. The gasket is formed-in-place on a surface of a substrate as applied to such surface in a form-stable bead of a fluent polymeric reaction system and cured thereon under substantially atmospheric pressure. The reaction system has a strip volume resistivity of from about 500-1000 m.OMEGA.-cm and is admixture of: (a) an elastomeric resin binder component; and (b) an electrically-conductive filler component of nickel-coated graphite particles. The substrate surface may be that of a housing or other enclosure for electronic components.
Claims36
A one-part, fluent polymeric reaction system which may be applied as a form-stable bead to a surface of a substrate and cured by thermal-addition thereon under substantially atmospheric pressure to form a corrosion-resistant, electrically-conductive, elastomeric EMI shielding gasket having an EMI shielding effectiveness of at least about 80 dB substantially over a frequency range of between about 10 MHz and about 10 GHz, said reaction system having a strip volume resistivity of from about 500-1000 m.OMEGA.-cm and comprising an admixture of:
- (a) a silicone resin binder component including a first functional group;
- (b) a cross-linking agent component including a second functional group reactive with said first functional group of said binder component;
- (c) a metallic catalyst component effective to catalyze the reaction of said first and second functional groups;
- and
- (d) an electrically-conductive filler component comprising nickel-coated graphite particles.
An electrically-conductive, corrosion-resistant EMI shielding gasket having an EMI shielding effectiveness of at least about 80 dB substantially over a frequency range of between about 10 MHz and about 10 GHz which is formed-in-place on a surface of a substrate as applied to said surface in a form-stable bead of a fluent polymeric reaction system and cured thereon under substantially atmospheric pressure, said reaction system having a strip volume resistivity of from about 500-1000 m.OMEGA.-cm and comprising an admixture of:
- (a) an elastomeric resin binder component;
- and
- (b) an electrically-conductive filler component comprising nickel-coated graphite particles.
A method of forming an electrically-conductive, corrosion-resistant elastomeric EMI shielding gasket in situ on a surface of a substrate, said gasket having an EMI shielding effectiveness of at least about 80 substantially over a frequency range of between about 10 MHz and about 10 GHz, and said method comprising the steps of:
- (a) providing a fluent, polymeric reaction mixture having a strip volume resistivity of from about 500-1000 m.OMEGA.-cm and comprising:
- (i) an elastomeric resin binder component;
- and
- (ii) an electrically-conductive filler component comprising nickel-coated graphite particles;
- (b) applying a bead of said reaction mixture to the surface of the substrate;
- and
- (c) curing said reaction mixture under substantially atmospheric pressure to form said gasket on the surface of the substrate.
Dependencies are inferred from the claim text.