Patent EP0213762A2 successfully refreshed from Google Patents.
EP0213762A2
Expired / Lapsed
EP
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Electromagnetic shielding material and method of manufacture
Assignee: Chomerics Inc
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Filing: 1986-08-01
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Granted: —
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Expires: 2006-08-01
Abstract
Abstract Aluminum silicon alloys are used as cores for highly conductive metal coated particles to be incorporated in resins for use as electromagnetic interference shielding. High temperature processing conditions are used after coating of the particles to improve internal and external corrosion resistance of gaskets and filled resins into which the particles are incorporated for shielding use.
Inventors
- 👤 Wen-Shian Vincent Tzeng
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 18:14
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0073; H05K9/0081; H05K9/0083; B; B22; B22F; B22F1/00; B22F1/17; B29; B29C; B29C70/00; B29C70/88; B29C70/882; H01; H01B; H01B1/00; H01B1/02; H01B1/20; H01B1/22; H01P; H01P1/00; H01P1/04; H01P1/042; H05K9/0007; H05K9/0015; B29K; B29K2995/00; B29K2995/0003; B29K2995/0005; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12049; Y10T428/12493; Y10T428/12674; Y10T428/12708; Y10T428/12715; Y10T428/12722; Y10T428/12736; Y10T428/12743; Y10T428/1275
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
74 words
An electrically conductive particle for use as a conductive filler in a resin matrix suitable for electromagnetic shielding use, said particle comprising an inner core of an aluminum silicon alloy having from 5 to 20 percent by weight of silicon, an intermediate layer of a metal selected from the group consisting of mercury, palladium, copper, chromium, platinum, gold, nickel, tin, zinc and mixtures thereof, and an outer layer of a highly electrically conductive metal.
Claim 2
Dependent Claim
74 words
An electrically conductive particle for use as a conductive filler in a resin matrix suitable for electromagnetic shielding use, said particle comprising an inner core of an aluminum silicon alloy having from 5 to 20 percent by weight of silicon, an intermediate layer of a metal selected from the group consisting of mercury, palladium, copper, chromium, platinum, gold, nickel, tin, zinc and mixtures thereof, and an outer layer of a highly electrically conductive metal.
Claim 3
Dependent Claim
18 words
A particle in accordance with claim 1 and further comprising said aluminum silicon alloy being an eutectic alloy.
Claim 4
Dependent Claim
36 words
An electrically conductive particle in accordance with claim 1 and further comprising said last mentioned highly electrically conductive metal being silver in an amount of from 4 percent to 25 percent by weight of said particle.
Claim 5
Dependent Claim
25 words
An electrically conductive particle in accordance with claim 1 wherein said intermediate layer comprises from 0.1 percent to 5 percent by weight of said particle.
Claim 6
Dependent Claim
15 words
An electrically conductive particle in accordance with claim 4 wherein said intermediate layer is zinc.
Claim 7
Dependent Claim
15 words
An electrically conductive particle in accordance with claim 3 wherein said intermediate layer is tin.
Claim 8
Dependent Claim
15 words
An electrically conductive particle in accordance with claim 1 wherein said intermediate layer is zinc.
Claim 9
Dependent Claim
72 words
An electromagnetic energy shielding material having a volume resistivity to be effective as an electromagnetic energy shield, said material comprising resin matrix loaded with electrically conductive particles, said particles comprising an aluminum silicon alloy core having a first layer of a material selected from the group consisting of mercury, palladium, copper, chromium, platinum, gold, nickel, tin and zinc, and an outer layer of a highly electrically conductive metal overlying said first layer.
Claim 10
Dependent Claim
72 words
An electromagnetic energy shielding material having a volume resistivity to be effective as an electromagnetic energy shield, said material comprising resin matrix loaded with electrically conductive particles, said particles comprising an aluminum silicon alloy core having a first layer of a material selected from the group consisting of mercury, palladium, copper, chromium, platinum, gold, nickel, tin and zinc, and an outer layer of a highly electrically conductive metal overlying said first layer.
Claim 11
Dependent Claim
36 words
The shielding material in accordance with claim 8 whereas said particles have an intermediate layer of a metal selected from the group consisting of mercury, palatium, copper, chromium, platinum, gold, nickel, tin zinc and mixtures thereof.
Claim 12
Dependent Claim
13 words
Shielding material in accordance with claim 9 whereas said intermediate layer is zinc.
Claim 13
Dependent Claim
14 words
A shielding material in accordance with claim 9 wherein said intermediate layer is tin.
Claim 14
Dependent Claim
14 words
A shielding material in accordance with claim 9 whereas said intermedite layer is nickel.
Claim 15
Dependent Claim
14 words
A shielding material in accordance with claim 8 whereas said outer layer is silver.
Claim 16
Dependent Claim
31 words
A shielding material in accordance with claim 13 wherein said outer layer is silver in an amount of from about 4 percent to about 25 percent by weight of said particle.
Claim 17
Dependent Claim
37 words
A shielding material in accordance with claim 8 wherein said aluminum silicon alloy has from about 70 to about 95 percent by weight of aluminum and from about 5 to about 20 percent by weight of silicon.
Claim 18
Dependent Claim
29 words
A shielding material in accordance with claim 15 wherein said silicon is present in an amount of from 9 to 14 percent and said alloy is an eutectic alloy.
Claim 19
Dependent Claim
33 words
A shielding material in accordance with claim 16 comprising from about 80 to about 50 percent by volume of resin and from about 20 to about 50 percent by volume of said particles.
Claim 20
Dependent Claim
67 words
A shielding material in accordance with claim 17 wherein said particles have an average particle size of from about 20 to 75 microns, said intermediate layer is present in an amount of from 0.2 to about 10 percent by weight of said particle and said electrically conductive outer layer is present in an amount of from about 4 to about 25 percent by weight of said particle.
Claim 21
Independent Claim
53 words
A method of forming electrically conductive particles for use as a conductive filler in a resin matrix for electromagnetic shielding use said method comprising, heating an aluminum silicon alloy core silver plated particle for from about 2 to about 8 hours at a temperature range from about 150° C to about 300° C.
Claim 22
Independent Claim
53 words
A method of forming electrically conductive particles for use as a conductive filler in a resin matrix for electromagnetic shielding use said method comprising, heating an aluminum silicon alloy core silver plated particle for from about 2 to about 8 hours at a temperature range from about 150° C to about 300° C.
Claim 23
Dependent Claim
23 words
A method in accordance with the method of claim 19 wherein said particles are heated at a pressure of less than 1 Torr.
Claim 24
Dependent Claim
20 words
A method in accordance with the method of claim 19 wherein said electrically conductive particles are heated under non-oxidizing conditions.
Claim 25
Dependent Claim
52 words
A method in accordance with the method of claim 19 and further comprising further treating said particles at a temperature of from about 300° C to about 600° C in a non-oxidizing atmosphere for a time period at least sufficient to reach desired temperature to enhance corrosion resistant properties of said particles.
Claim 26
Dependent Claim
49 words
A method in accordance with the method of claim 19 and further comprising treating said particles at a temperature of from about 300° C to about 600° C at a pressure of less than 1 Torr for at least one hour to enhance corrosion resistant properties of said particles.
Claim 27
Independent Claim
83 words
A method of treating particles to improve corrosion resistance properties of said particles both internally and externally when they are mixed with a resin matrix to form a shielding material, said particles being aluminum core particles having a layer of an electrically conductive material, said method comprising treating said particles at a temperature of from about 300°C to about 600°C for a time period at least sufficient to reach a temperature within the desired range to enhance corrosion resistant properties of said particles.
Claim 28
Independent Claim
83 words
A method of treating particles to improve corrosion resistance properties of said particles both internally and externally when they are mixed with a resin matrix to form a shielding material, said particles being aluminum core particles having a layer of an electrically conductive material, said method comprising treating said particles at a temperature of from about 300°C to about 600°C for a time period at least sufficient to reach a temperature within the desired range to enhance corrosion resistant properties of said particles.
Claim 29
Dependent Claim
20 words
A method in accordance with the method of claim 23 wherein said heating is carried out in a non-oxidizing atmosphere.
Claim 30
Dependent Claim
37 words
A method in accordance with the method of claim 24 wherein said heating is carried out under vacuum conditions of less than 1 Torr for at least one hour to enhance corrosion resistant properties of said particles.
Claim 31
Dependent Claim
42 words
A method in accordance with the method of claim 25 wherein said particles comprise an aluminum silicon core having an intermediate layer of a metal selected from the group consisting of mercury, platium, copper, chromium, gold, nickel, tin, zinc and mixtures thereof.
Claim 32
Dependent Claim
42 words
A method in accordance with the method of claim 26 wherein said particles comprise an aluminum silicon core having an intermediate layer of a metal selected from the group consisting of mercury, platium, copper, chromium, gold, nickel, tin, zinc and mixtures thereof.
Claim 33
Dependent Claim
24 words
A method in accordance with the method of claim 27 wherein an outer layer over said intermediate layer comprises a highly electrically conductive metal.
Claim 34
Dependent Claim
24 words
A method in accordance with the method of claim 28 wherein an outer layer over said intermediate layer comprises a highly electrically conductive metal.
Claim 35
Dependent Claim
16 words
A method in accordance with the method of claim 26 wherein said pressure is 10⁻² Torr.
Claim 36
Dependent Claim
18 words
A method in accordance with the method of claim 29 wherein said outer layer is a noble metal.
Claim 37
Dependent Claim
40 words
A method in accordance with the method of claim 32 wherein said intermediate layer comprises from 0.2 to 10 percent by weight of said particles and said outer layer comprises from 4 to 25 percent by weight of said particles.
Claim 38
Independent Claim
66 words
A method of treating aluminum silicon core particles having an outer layer of electrically conductive metals to improve corrosion resistant properties of said particle both internally and externally, when they are mixed with a resin matrix to form an EMI shielding material, said method comprising heating said particles to cause phase transformation of the aluminum silicon core causing spheriodization of originally dendritic precipitates in the core.
Claim 39
Independent Claim
66 words
A method of treating aluminum silicon core particles having an outer layer of electrically conductive metals to improve corrosion resistant properties of said particle both internally and externally, when they are mixed with a resin matrix to form an EMI shielding material, said method comprising heating said particles to cause phase transformation of the aluminum silicon core causing spheriodization of originally dendritic precipitates in the core.
References Cited (Backward Citations)
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