US4963291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Insulating electromagnetic shielding resin composition
Assignee: World Properties Inc
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Filing: 1989-05-10
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Granted: 1990-10-16
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Expires: 2009-05-10
Abstract
Abstract Filler blends of electroconductive particles with electrically non-conductive particles are provided which are useful in making electromagnetic shielding resins for encapsulating electronic devices.
Inventors
- 👤 Robert M. Bercaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:02
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0073; H05K9/0081; H05K9/0083; C; C08; C08K; C08K3/00; C08K3/01; C08K3/013; C08K3/18; C08K3/34; H01; H01B; H01B1/00; H01B1/20; H01B1/22; H01B1/24; H10; H10W; H10W42/00; H10W42/20; H10W42/281; H10W42/287; H10W74/00; H10W74/40; H10W74/47; H10W74/473
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
55 words
A filler blend for making electromagnetic shielding resins which comprises, (a) 8-55 percent by volume of electroconductive particles of spherical crosssectional dimensions ranging from 0.5-50 microns having a resistivity less than 1×10 2 ohms, and (b) electrically non-conductive particles of spherical cross-sectional dimensions ranging from 0.005-2 microns having a resistivity greater than 1×10 8 ohms.
Claim 2
Dependent Claim
55 words
A filler blend for making electromagnetic shielding resins which comprises, (a) 8-55 percent by volume of electroconductive particles of spherical crosssectional dimensions ranging from 0.5-50 microns having a resistivity less than 1×10 2 ohms, and (b) electrically non-conductive particles of spherical cross-sectional dimensions ranging from 0.005-2 microns having a resistivity greater than 1×10 8 ohms.
Claim 3
Dependent Claim
31 words
A filler blend of claim 1 which comprises (a) 14-55 percent by volume of electroconductive particles wherein the volume ratio of said non-conductive particles to said electroconductive particles ranges from 0.25-0.72.
Claim 4
Dependent Claim
29 words
A blend of claim 1 wherein said electroconductive particles are selected from the group consisting of iron, iron alloys, copper, aluminum, silver and electromagnetic oxides of iron and chromium.
Claim 5
Dependent Claim
49 words
A blend of claim 1 wherein said electrically non-conductive particles are selected from the group consisting of silica, mica, quartz, glass, calcium silicate, aluminum silicate, zirconium silicate, alumina, titanium dioxide, barium titanate, calcium carbonate, calcium sulfate, ferric oxide, lithium aluminum sulfate, magnesium silicate, zirconium oxide and insoluble resin beads.
Claim 6
Dependent Claim
18 words
A blend of claim 1 wherein said electroconductive particles are carbonyl iron and said non-conductive particles are silica.
Claim 7
Dependent Claim
25 words
A blend of claim 5 wherein said particles of iron ranges from 2 to 15 microns and said silica ranges from 0.005-1 microns in cross-section
Claim 8
Dependent Claim
17 words
A blend of claim 6 wherein the volume ratio of silica to carbonyl iron ranges from 0.3-0.4.
Claim 9
Dependent Claim
54 words
A molding composition comprising a uniform mixture of a filler blend of claim 1 with an electrically non-conductive binder resin selected from the group consisting of thermoplastic and thermosetting polymers having a volume resistivity of at least 1×10 10 ohms-centimeters wherein the volume of said filler in said resin is 30-80 percent by weight.
Claim 10
Dependent Claim
26 words
A composition of claim 8 wherein said binder resin is selected from the group consisting of polyepoxides, polyamides, polyimides, polyesters, polyethersulfone, polyetherether ketone, and blends thereof.
Claim 11
Dependent Claim
22 words
An electromagnetic inductor having an effective amount of the protective electronic shielding resin coating of a cured molding composition of claim 8.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |