Patent US5451720A successfully refreshed from Google Patents.
US5451720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit board thermal relief pattern having improved electrical and EMI characteristics
Assignee: Dell USA LP
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Filing: 1994-03-23
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Granted: 1995-09-19
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Expires: 2014-03-23
Abstract
Abstract A circuit board having a thermal relief pattern for isolating heat generated during soldering of components thereon. The circuit board comprises (1) a substantially planar insulating substrate, the substrate having a via therethrough and (2) a substantially planar conductive layer located over the substrate, the via passing through the layer, the layer having a thermal relief pattern comprising a plurality of apertures located about the via, the plurality of apertures cooperating to restrict heat flow across the thermal relief pattern, each of the plurality of apertures having a boundary with the conductive layer free of discontinuities to inhibit edge effect electromagnetic resonance, the plurality of apertures defining a plurality of corresponding conductive bands in the conductive layer and between the plurality of apertures, the conductive bands cooperating to provide a predetermined minimum level of electrical conduction across the thermal relief pattern.
Inventors
- 👤 H. Scott Estes
- 👤 David Staggs
- 👤 Deepak Swamy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:37
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/11; H05K1/115; H05K1/116; H05K1/0201; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3447; H05K2201/00; H05K2201/06; H05K2201/062; H05K2201/09; H05K2201/09209; H05K2201/0929; H05K2201/09309; H05K2201/09372; H05K2201/09454; H05K2201/09654; H05K2201/0969; H05K3/40; H05K3/42; H05K3/429
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
122 words
A circuit board, comprising: a substantially planar insulating substrate, said substrate having a via therethrough; and a substantially planar conductive layer located over said substrate, said via passing through said layer, said layer having a thermal relief pattern comprising a plurality of apertures located about said via, said plurality of apertures cooperating to restrict heat flow across said thermal relief pattern, each of said plurality of apertures having a boundary with said conductive layer free of discontinuities to inhibit edge effect electromagnetic resonance, said plurality of apertures defining a plurality of corresponding conductive bands in said conductive layer and between said plurality of apertures, said conductive bands cooperating to provide a predetermined minimum level of electrical conduction across said thermal relief pattern.
Claim 2
Dependent Claim
122 words
A circuit board, comprising: a substantially planar insulating substrate, said substrate having a via therethrough; and a substantially planar conductive layer located over said substrate, said via passing through said layer, said layer having a thermal relief pattern comprising a plurality of apertures located about said via, said plurality of apertures cooperating to restrict heat flow across said thermal relief pattern, each of said plurality of apertures having a boundary with said conductive layer free of discontinuities to inhibit edge effect electromagnetic resonance, said plurality of apertures defining a plurality of corresponding conductive bands in said conductive layer and between said plurality of apertures, said conductive bands cooperating to provide a predetermined minimum level of electrical conduction across said thermal relief pattern.
Claim 3
Dependent Claim
18 words
The circuit board as recited in claim 1 wherein each of said plurality of apertures are substantially ovoid.
Claim 4
Dependent Claim
18 words
The circuit board as recited in claim 1 wherein each of said plurality of apertures are substantially circular.
Claim 5
Dependent Claim
21 words
The circuit board as recited in claim 1 wherein said via is adapted to receive a lead of an electronic component.
Claim 6
Dependent Claim
17 words
The circuit board as recited in claim 1 wherein said via is adapted to receive molten solder.
Claim 7
Dependent Claim
20 words
The circuit board as recited in claim 1 further comprising a conductive coating over an inner surface of said via.
Claim 8
Dependent Claim
20 words
The circuit board as recited in claim 1 wherein said conductive layer is adapted to carry radio frequency electric current.
Claim 9
Dependent Claim
20 words
The circuit board as recited in claim 1 wherein said conductive layer provides an electrical ground for said circuit board.
Claim 10
Dependent Claim
25 words
The circuit board as recited in claim 1 wherein said plurality of apertures are located in a ring surrounding and substantially centered on said via.
Claim 11
Dependent Claim
17 words
The circuit board as recited in claim 1 wherein said conductive layer is composed of copper metal.
Claim 12
Dependent Claim
156 words
A circuit board, comprising: a substantially planar insulating substrate, said substrate having a via therethrough, said via adapted to receive a lead of an electronic component and molten solder to create a solder joint; and a substantially planar conductive layer located over said substrate and adapted to carry radio frequency electric current, said via passing through said layer, said layer having a thermal relief pattern comprising a plurality of apertures located in a ring surrounding and substantially centered on said via, said plurality of apertures cooperating to restrict heat flow across said thermal relief pattern, each of said plurality of apertures having a boundary with said conductive layer free of discontinuities to inhibit edge effect electromagnetic resonance, said plurality of apertures defining a plurality of corresponding conductive bands in said conductive layer and between said plurality of apertures, said conductive bands cooperating to provide a predetermined minimum level of electrical conduction across said thermal relief pattern.
Claim 13
Dependent Claim
156 words
A circuit board, comprising: a substantially planar insulating substrate, said substrate having a via therethrough, said via adapted to receive a lead of an electronic component and molten solder to create a solder joint; and a substantially planar conductive layer located over said substrate and adapted to carry radio frequency electric current, said via passing through said layer, said layer having a thermal relief pattern comprising a plurality of apertures located in a ring surrounding and substantially centered on said via, said plurality of apertures cooperating to restrict heat flow across said thermal relief pattern, each of said plurality of apertures having a boundary with said conductive layer free of discontinuities to inhibit edge effect electromagnetic resonance, said plurality of apertures defining a plurality of corresponding conductive bands in said conductive layer and between said plurality of apertures, said conductive bands cooperating to provide a predetermined minimum level of electrical conduction across said thermal relief pattern.
Claim 14
Dependent Claim
18 words
The circuit board as recited in claim 11 wherein each of said plurality of apertures are substantially ovoid.
Claim 15
Dependent Claim
18 words
The circuit board as recited in claim 11 wherein each of said plurality of apertures are substantially circular.
Claim 16
Dependent Claim
20 words
The circuit board as recited in claim 11 further comprising a conductive coating over an inner surface of said via.
Claim 17
Dependent Claim
20 words
The circuit board as recited in claim 11 wherein said conductive layer provides an electrical ground for said circuit board.
Claim 18
Dependent Claim
16 words
The circuit board as recited in claim 11 wherein said thermal relief pattern comprises five apertures.
Claim 19
Dependent Claim
17 words
The circuit board as recited in claim 11 wherein said conductive layer is composed of copper metal.
Claim 20
Dependent Claim
20 words
The circuit board as recited in claim 11 wherein said conductive layer is an intermediate layer in said circuit board.
Claim 21
Dependent Claim
19 words
The circuit board as recited in claim 11 wherein said plurality of apertures are etched in said conductive layer.
Claim 22
Dependent Claim
30 words
The circuit board as recited in claim 11 further comprising a plurality of alternating substrate and conductive layers forming a plurality of spaced-apart conductive patterns for communication of electrical signals.
References Cited (Backward Citations)
US5326937A
Cited
US5264664A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-09-18 | 1999-03-20 | 1999-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-09-18 | 2003-03-20 | 2003-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-09-18 | 2007-03-20 | 2007-09-19 | $7700.00 | Window Closed / Lapsed |