Interference mitigation through conductive thermoplastic composite materials

• US 20030175454A1
• Filed: 03/12/2003
• Published: 09/18/2003
• Est. Priority Date: 11/20/2000
• Status: Active Grant

• Current Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Original Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Inventors: Peng, Hong, Lichtenstein, P. R.
• Granted Patent: US 6,866,908 B2
• Time in Patent Office: Days
• US Class Current: 428/35.7
• CPC Class Codes: H01L 23/3737 Organic materials with or without a thermoconductive filler
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H05K 9/0029 made from non-conductive materials intermixed with electro-conductive particles H05K9/0031 takes precedence
• CPC Class Codes: H05K 9/003 made from non-conductive materials comprising an electro-conductive coating H05K9/0031 takes precedence
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1355 Elemental metal containing [e.g., substrate, foil, film, coating, etc.]

Abstract

An electromagnetic radiation interference mitigation shield is provided for an electronic circuit component. The shield includes a body formed from an electrically and thermally conductive composite material characterized by a volume resistivity ranging from about 0.1 to about 1,000 ohm-cm and a thermal conductivity ranging from about 10×10⁻⁴-cal.-cm./sec.-cm.²-° C. to about 30×10⁻⁴-cal.-cm./sec.-cm.²-° C.

Claims

1. An electromagnetic radiation interference mitigation shield for an electronic circuit component mounted on a circuit board, comprising:

a body formed from an electrically and thermally conductive composite material including a plastic/polymer and conductive particles, said body being positionable on the circuit board over the electronic circuit component, and said material being characterized by a volume resistivity ranging from about 0.1 to about 1,000 ohm-cm and a thermal conductivity ranging from about 10×

10<sup>−

4</sup>-cal.-cm./sec.-cm.²-°

C. to about 30×

10<sup>−

4</sup>-cal.-cm./sec.-cm.²-°

C.

2. The shield of claim 1 wherein said plastic/polymer is selected from a group consisting of acrylonitrile butadiene styrene, polycarbonate, propylene, nylon, styrene acrylonitrile, polysulfone, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyimides, polyester thermoplastic elastomer, acrylic, polyvinyl chloride, styrenics, cured polyester and epoxy resins, rubber, silicone RTV and any thermoplastic, thermoset, or room temperature curing plastics or mixtures thereof.

3. The shield of claim 1 wherein said conductive particles are selected from a group consisting of conductive doping chemicals, metal-coated/plated carbon/glass/plastic fibers, metal-coated carbon/glass/plastic particles, conductive metal fibers, conductive metal particles, metallic salts and any mixtures thereof.

4. The shield of claim 3, wherein said conductive particles are provided in concentrations ranging from about 5% to about 50% by weight.

5. The shield of claim 3, wherein said conductive particle metals are selected from a group consisting of nickel, copper, iron, silver, gold, tin, zinc, lead, aluminum, brass, bronze, stainless steel, other electrically conductive metals and any mixtures thereof.

6. The shield of claim 1, wherein said body includes walls defining a cavity, the electronic circuit component to be shielded being received within said cavity when said body is positioned on the circuit board over the component.

7. The shield of claim 6, wherein said walls are within 0.5 inches or less but are not physically touching the electronic circuit component.

8. An electromagnetic radiation interference mitigation shield for an electronic circuit component mounted on a circuit board, comprising:

a body of electrically and thermally conductive composite material, said body being positionable on the circuit board over the electronic component, and said material being formed from a plastic/polymer and conductive particles, said plastic/polymer being selected from a group consisting of acrylonitrile butadiene styrene, polycarbonate, propylene, nylon, styrene acrylonitrile, polysulfone, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyimides, polyester thermoplastic elastomer, acrylic, polyvinyl chloride, styrenics, cured polyester and epoxy resins, rubber, silicone RTV and any thermoplastic, thermoset, or room temperature curing plastics or mixtures thereof, and said conductive particles being selected from a group consisting of conductive doping chemicals, metal-coated/plated carbon/glass/plastic fibers, metal-coated carbon/glass/plastic particles, conductive metal fibers, conductive metal particles, metallic salts and any mixtures thereof wherein said conductive particles are provided at concentrations ranging from about 5% to about 50% by weight, said body being characterized by a volume resistivity ranging from about 0.1 to about 1,000 ohm-cm and a thermal conductivity ranging from about 10×

10<sup>−

4</sup>-cal.-cm./sec.-cm.²-°

C. to about 30×

10⁴-cal.-cm./sec.-cm.²-°

C.

9. A method of shielding an electronic circuit component mounted on a circuit board, comprising:

positioning on the circuit board over the electronic circuit component a separate body of electrically and thermally conductive composite material formed from a plastic/polymer and conductive particles characterized by a volume resistivity ranging from about 0.1 to about 1,000 ohm-cm and a thermal conductivity ranging from about 10×

10<sup>−

4</sup>-cal.-cm./sec.-cm.²-°

C. to about 30×

10<sup>−

4</sup>-cal.-cm./sec.-cm.²-°

C. so that the walls of said body forming a cavity therein are positioned within about 0.5 inches of the electronic circuit component.

10. An electromagnetic radiation interference mitigation shield for an electronic circuit component, comprising:

a body formed from an electrically and thermally conductive composite material including a plastic/polymer and conductive particles, said body being characterized by a volume resistivity ranging from about 0.1 to 1,000 ohm-cm and a thermal conductivity ranging from 10×

10<sup>−

4</sup>-cal.-cm./sec.-cm.²-°

C. to 30×

10<sup>−

4</sup>-cal.-cm./sec.-cm.²-°

C.

11. The shield of claim 10 wherein said [body includes a] plastic/polymer is selected from a group consisting of acrylonitrile butadiene styrene, polycarbonate, propylene, nylon, styrene acrylonitrile, polysulfone, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyimides, polyester thermoplastic elastomer, acrylic, polyvinyl chloride, styrenics, cured polyester and epoxy resins, rubber, silicone RTV and any thermoplastic, thermoset, or room temperature curing plastics or mixtures thereof.

12. The shield of claim 10 wherein said conductive particles are selected from a group consisting of conductive doping chemicals, metal-coated/plated carbon/glass/plastic fibers, metal-coated carbon/glass/plastic particles, conductive metal fibers, conductive metal particles, metallic salts and any mixtures thereof.

13. The shield of claim 12, wherein said conductive particles are provided in concentrations ranging from about 5% to about 50% by weight.

14. The shield of claim 12, wherein said conductive particle metals are selected from a group consisting of nickel, copper, iron, silver, gold, tin, zinc, lead, aluminum, brass, bronze, stainless steel, other electrically conductive metals and any mixtures thereof.

15. The shield of claim 10, wherein said body includes a cavity for receiving the electronic circuit component to be shielded.

16. The shield of claim 15, wherein said walls are within 0.5 inches or less from the electronic circuit component.