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US5117069A Expired / Lapsed US ⏱️ 0.0 years remaining

Circuit board fabrication

Assignee: Computervision Corp
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Filing: 1990-09-28
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Granted: 1992-05-26
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Expires: 2010-09-28
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Abstract

Abstract A high density multi-level printed wiring board having inter-level electrical connections made by via interconnect holes which are drilled or punched through only those layers of the wiring board that separate the two layers containing the conductors which are to be connected and said holes being filled with a low-resistance silver-filled conductive epoxy.

Inventors

  • 👤 Leo M. Higgins, III

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 10:50
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4611; H05K3/4614; H05K3/4617; H05K1/00; H05K1/02; H05K1/11; H05K1/111; H05K1/112; H05K1/113; H05K3/40; H05K3/4038; H05K3/4053; H05K3/4069; H05K2201/00; H05K2201/01; H05K2201/0183; H05K2201/0195; H05K2201/03; H05K2201/0302; H05K2201/0305; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/096; H05K2203/00; H05K2203/14; H05K2203/1453; H05K3/22; H05K3/28; H05K3/4007; Y; Y10; Y10S; Y10S428/00; Y10S428/901

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 185 words
A printed circuit apparatus comprising a plurality of separate circuit board layers, each board layer comprising a laminate layer having conductive runs thereon and a pre-preg insulating layer; means securing the board layers in a sandwiched array; means defining a continuous interconnecting hole in at least two adjacently disposed circuit board layers between at least two conductive runs on separate laminate circuit board layers; and a curable electrically conductive adhesive disposed within said interconnecting hole providing an electrically conductive bridge between said at least two conductive runs, the interconnecting hole as well as the electrically conductive bridge passing only between said at least two conductive runs, wherein one of said at least two conductive runs is disposed on a first of said plurality of circuit board players, having at least one additional layer above it, and the other of said at least two conductive runs is disposed on a second of said plurality of circuit board layers, having at least one additional layer below it, wherein there are no other interconnecting holes on the plurality of circuit board layers in alignment with said interconnecting hole.
Claim 2
Dependent Claim 185 words
A printed circuit apparatus comprising a plurality of separate circuit board layers, each board layer comprising a laminate layer having conductive runs thereon and a pre-preg insulating layer; means securing the board layers in a sandwiched array; means defining a continuous interconnecting hole in at least two adjacently disposed circuit board layers between at least two conductive runs on separate laminate circuit board layers; and a curable electrically conductive adhesive disposed within said interconnecting hole providing an electrically conductive bridge between said at least two conductive runs, the interconnecting hole as well as the electrically conductive bridge passing only between said at least two conductive runs, wherein one of said at least two conductive runs is disposed on a first of said plurality of circuit board players, having at least one additional layer above it, and the other of said at least two conductive runs is disposed on a second of said plurality of circuit board layers, having at least one additional layer below it, wherein there are no other interconnecting holes on the plurality of circuit board layers in alignment with said interconnecting hole.
Claim 3
Dependent Claim 34 words
A printed circuit apparatus as set forth in claim 1 wherein at least some of said circuit board layers each are comprised of a laminate layer having the conductive run formed thereon by etching.
Claim 4
Dependent Claim 31 words
A printed circuit apparatus as set forth in claim 2 wherein said at least some of said circuit board layers each are also comprised of a fiberglass reinforced polymer pre-preg layer.
Claim 5
Dependent Claim 24 words
A printed circuit apparatus as set forth in claim 1 wherein said adhesive comprises an epoxy paste with fine electrically conductive particles suspended therein.
Claim 6
Dependent Claim 24 words
A printed circuit apparatus as set forth in claim 4 wherein said particles represent on the order of 80% by weight of the adhesive.
Claim 7
Dependent Claim 23 words
A printed circuit apparatus as set forth in claim 4 wherein said particles are selected from a group consisting of silver and copper.
Claim 8
Dependent Claim 22 words
A printed circuit apparatus as set forth in claim 1 wherein said hole has a diameter in the range of 1-18 mm.
Claim 9
Dependent Claim 18 words
A printed circuit apparatus as set forth in claim 1 wherein said interconnecting hole is a blind hole.

References Cited (Backward Citations)

US4383363A Cited
US4851615A Cited
US4650923A Cited
US4685033A Cited
US4679122A Cited
US4672152A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-05-26 1995-11-25 1996-05-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-05-26 1999-11-25 2000-05-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-05-26 2003-11-25 2004-05-26 $7700.00 Window Closed / Lapsed

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