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US5136120A Expired / Lapsed US ⏱️ 0.0 years remaining

Technique for reducing electromagnetic interference

Assignee: Nokia Bell Labs
•
Filing: 1990-12-12
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Granted: 1992-08-04
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Expires: 2010-12-12
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Abstract

Abstract At least one pair of areas on a circuit pack or substrate is allocated for the placement of electromagnetic interference (EMI) absorbing material, e.g., split ferrite cores. All or a portion of the conductor paths for the circuit are routed between pairs of the allocated areas. After the circuit pack is developed and tested, if EMI suppression is required, the EMI-absorbing material extends around the conductors passing between the pairs of allocated areas using holes formed through the allocated pairs of areas. Such holes are formed prior to circuit assembly or, alternatively, are formed only as needed after circuit testing. A clip is used to secure the EMI-absorbing material to the circuit pack. Advantageously, the insertion and securement of the EMI-absorbing material does not require any soldering or special manufacturing tools or fixtures. Accordingly, it can be readily provided in any manufacturing process.

Inventors

  • 👤 Adam B. Craft
  • 👤 Gabor P. Torok

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 16:17
CPC Classifications
G; G01; G01R; G01R1/00; G01R1/02; G01R1/18; H; H05; H05K; H05K1/00; H05K1/02; H05K1/0213; H05K1/0216; H05K1/023; H05K1/0233; H05K1/18; H05K1/182; H05K2201/00; H05K2201/08; H05K2201/083; H05K2201/086; H05K3/00; H05K3/30; H05K3/301

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 140 words
A circuit pack including a circuit board having a least one conductive path formed thereon and at least one pair of holes passing therethrough, said board having two sides; electromagnetic interference absorbing material having first and second parts, each of said parts being receivable by a predetermined pair of holes and each part extending from a different one of said two sides; and a clip for retaining said two parts in contact with one another, said clip including first and second components for respectively receiving said first and second parts, said first and second components being disposed adjacent to a different one of said sides; and mating means disposed on each of said components for interlocking with one another, said mating means also capable of uncoupling from one another so that said parts can be removed from said circuit board.
Claim 2
Dependent Claim 140 words
A circuit pack including a circuit board having a least one conductive path formed thereon and at least one pair of holes passing therethrough, said board having two sides; electromagnetic interference absorbing material having first and second parts, each of said parts being receivable by a predetermined pair of holes and each part extending from a different one of said two sides; and a clip for retaining said two parts in contact with one another, said clip including first and second components for respectively receiving said first and second parts, said first and second components being disposed adjacent to a different one of said sides; and mating means disposed on each of said components for interlocking with one another, said mating means also capable of uncoupling from one another so that said parts can be removed from said circuit board.
Claim 3
Dependent Claim 11 words
The circuit pack of claim 1 wherein said material is ferrite.
Claim 4
Dependent Claim 15 words
The circuit pack of claim 1 wherein said material is formed as a split core.
Claim 5
Dependent Claim 24 words
The circuit pack of claim 1 wherein said first and second components each include a cavity for respectively receiving said first and second part.
Claim 6
Dependent Claim 26 words
The circuit pack of claim 1 wherein said clip further includes means in said first component for biasing the received first part against the second part.
Claim 7
Dependent Claim 28 words
The circuit pack of claim 1 wherein said clip further includes means in said first component for biasing said second component against a side of said circuit board.

References Cited (Backward Citations)

US4899019A Cited
JPH0253698A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-08-04 1996-02-03 1996-08-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-08-04 2000-02-03 2000-08-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-08-04 2004-02-03 2004-08-04 $7700.00 Window Closed / Lapsed

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