US6219239B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
EMI reduction device and assembly
Assignee: Hewlett Packard Enterprise Development LP
•
Filing: 1999-05-26
•
Granted: 2001-04-17
•
Expires: 2019-05-26
Abstract
Abstract An EMI reduction device is coupled between a printed circuit board (PCB) assembly and a heat sink. The PCB assembly includes a processor core that is the source of unintentional electromagnetic interference (EMI). The EMI reduction device is attached to a heat sink which is positioned over the processor core such that it capacitively couples emissions from the processor core to a grounding plane resident in the PCB assembly, thereby reducing the unintentional EMI. Simultaneously, the EMI reduction device is able to maintain thermal contact with the heat sink.
Inventors
- 👤 Hans T. Mellberg
- 👤 Bertram Kim Cheong Chan
- 👤 Susannah Gardner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:44
CPC Classifications
H; H05; H05K; H05K7/00; H05K7/14; H05K7/1422; H05K7/1427; H05K7/1429; H05K7/1431; H05K9/00; H05K9/0007; H05K9/002
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
133 words
An electronic assembly, comprising: a circuit board having a top surface and a bottom surface, the circuit board including an electronic device mounted on the top surface thereof; a thermal dissipation device positioned over the top surface of the circuit board and thermally contacting the electronic device; and an Electromagnetic Interference (EMI) reduction device interposed between the circuit board and the thermal dissipation device, the EMI reduction device having top surface and a bottom surface, the EMI reduction device including a plurality of mounting tabs projecting from the top surface thereof and a plurality of spring fingers projecting from the bottom surface thereof, wherein the EMI reduction device is attached to the thermal dissipation device via the mounting tabs, and wherein the EMI reduction device contacts the circuit board via the spring fingers.
Claim 2
Dependent Claim
133 words
An electronic assembly, comprising: a circuit board having a top surface and a bottom surface, the circuit board including an electronic device mounted on the top surface thereof; a thermal dissipation device positioned over the top surface of the circuit board and thermally contacting the electronic device; and an Electromagnetic Interference (EMI) reduction device interposed between the circuit board and the thermal dissipation device, the EMI reduction device having top surface and a bottom surface, the EMI reduction device including a plurality of mounting tabs projecting from the top surface thereof and a plurality of spring fingers projecting from the bottom surface thereof, wherein the EMI reduction device is attached to the thermal dissipation device via the mounting tabs, and wherein the EMI reduction device contacts the circuit board via the spring fingers.
Claim 3
Dependent Claim
20 words
The assembly of claim 1 , wherein the mounting tabs project from an outer periphery of the EMI reduction device.
Claim 4
Dependent Claim
36 words
The assembly of claim 1 , wherein the spring fingers contact the circuit board at contact points that surround the electronic device, and wherein the EMI reduction device has no physical contact with the electronic device.
Claim 5
Dependent Claim
47 words
The assembly of claim 1 , wherein the EMI reduction device has an aperture defined therein, the aperture communicating with the top surface and the bottom surface of the EMI reduction device, wherein the thermal dissipation device maintains thermal contact with the electronic device through the aperture.
Claim 6
Dependent Claim
16 words
The assembly of claim 4 , wherein the spring fingers are disposed laterally of the aperture.
Claim 7
Dependent Claim
47 words
The assembly of claim 1 , wherein the thermal dissipation device has a top surface and a bottom surface, and wherein the thermal dissipation device includes a thermal compound disposed on the bottom surface thereof, the thermal compound of the thermal dissipation device contacting the electronic device.
Claim 8
Dependent Claim
33 words
The assembly of claim 1 , wherein the EMI reduction device includes a dielectric layer disposed on the bottom surface thereof, the dielectric layer of the EMI reduction device contacting the circuit board.
Claim 9
Dependent Claim
29 words
The assembly of claim 1 , further comprising: at least one retention clip passing through the EMI reduction device and securing the thermal dissipation device to the circuit board.
Claim 10
Dependent Claim
13 words
The assembly of claim 1 , wherein the electronic device is a processor.
Claim 11
Dependent Claim
101 words
An Electromagnetic Interference (EMI) reduction device capable of reducing electromagnetic emissions emanating from an electronic device of a circuit board, the EMI reduction device comprising: a frame having a top surface and a bottom surface; a plurality of mounting tabs projecting from the top surface of the frame, the mounting tabs adapted to couple the EMI reduction device to a thermal dissipation device; and a plurality of spring fingers projecting from the bottom surface of the frame, the spring fingers adapted to contact the circuit board at points surrounding the electronic device and position the frame relative to the circuit board.
Claim 12
Dependent Claim
101 words
An Electromagnetic Interference (EMI) reduction device capable of reducing electromagnetic emissions emanating from an electronic device of a circuit board, the EMI reduction device comprising: a frame having a top surface and a bottom surface; a plurality of mounting tabs projecting from the top surface of the frame, the mounting tabs adapted to couple the EMI reduction device to a thermal dissipation device; and a plurality of spring fingers projecting from the bottom surface of the frame, the spring fingers adapted to contact the circuit board at points surrounding the electronic device and position the frame relative to the circuit board.
Claim 13
Dependent Claim
38 words
The device of claim 10 , wherein the frame has an aperture defined therein, the aperture communicating with the top surface and the bottom surface of the frame, wherein the aperture is adapted to surround the electronic device.
Claim 14
Dependent Claim
16 words
The device of claim 11 , wherein the spring fingers are disposed laterally of the aperture.
Claim 15
Dependent Claim
18 words
The device of claim 10 , wherein the mounting tabs project from an outer periphery of the frame.
Claim 16
Dependent Claim
16 words
The device of claim 10 , wherein the bottom surface of the frame is non-electrically conductive.
Claim 17
Dependent Claim
16 words
The device of claim 10 , wherein the top surface of the frame is electrically conductive.
Claim 18
Independent Claim
123 words
A method of reducing Electromagnetic Interference (EMI) emissions emanating from and dissipating heat generated by an electronic device mounted on a circuit board, the method comprising the steps of: providing an EMI reduction device having a top surface and a bottom surface and having an aperture defined therein, the aperture communicating with the top surface and the bottom surface; attaching the EMI reduction device to a thermal dissipation device with a plurality of mounting tabs projecting from the top surface of the EMI reduction device; contacting the circuit board with a plurality of spring fingers projecting from the bottom surface of the EMI reduction device; and contacting the electronic device with the thermal dissipation device through the aperture of the EMI reduction device.
Claim 19
Independent Claim
123 words
A method of reducing Electromagnetic Interference (EMI) emissions emanating from and dissipating heat generated by an electronic device mounted on a circuit board, the method comprising the steps of: providing an EMI reduction device having a top surface and a bottom surface and having an aperture defined therein, the aperture communicating with the top surface and the bottom surface; attaching the EMI reduction device to a thermal dissipation device with a plurality of mounting tabs projecting from the top surface of the EMI reduction device; contacting the circuit board with a plurality of spring fingers projecting from the bottom surface of the EMI reduction device; and contacting the electronic device with the thermal dissipation device through the aperture of the EMI reduction device.
Claim 20
Dependent Claim
24 words
The method of claim 16 , further comprising the step of: surrounding an outer periphery of the electronic device with the EMI reduction device.
Claim 21
Dependent Claim
32 words
The method of claim 16 , further comprising the step of: securing the thermal dissipation device to the circuit board with at least one retention clip passing through the EMI reduction device.
Claim 22
Dependent Claim
26 words
The method of claim 16 , wherein the step of contacting the circuit board includes contacting the circuit board at contact points surrounding the electronic device.
Claim 23
Dependent Claim
23 words
The method of claim 16 , wherein the step of contacting the circuit board includes contacting a ground plane of the circuit board.
References Cited (Backward Citations)
US5136120A
Cited
US5053924A
Cited
US5278351A
Cited
US5311408A
Cited
US5241453A
Cited
US5357404A
Cited
US5428508A
Cited
US5566052A
Cited
US5740013A
Cited
US5880930A
Cited
US6053771A
Cited
US6043983A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-04-16 | 2004-10-16 | 2005-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-04-16 | 2008-10-16 | 2009-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-04-16 | 2012-10-16 | 2013-04-17 | $7700.00 | Window Closed / Lapsed |