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Electrical interconnections between adjacent circuit board layers of a multi-layer circuit board

Assignee: 3M Co
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Filing: 1993-06-08
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Granted: 1995-03-28
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Expires: 2013-06-08
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Abstract

Abstract A multi-layer circuit board includes electrical interconnections between adjacent circuit board layers of the multi-layer board. A via hole is provided through a circuit board layer. The via hole is filled with a via metal. The via metal is plated with a low melting point metal. An adhesive film is deposited over the circuit board layer. Adjacent layers of the multi-layer circuit board are stacked and aligned together. The layers are laminated under heat and pressure. The low melting point metal provides an electrical interconnection between adjacent layers.

Inventors

  • 👤 Joel A. Gerber
  • 👤 Peter A. Gits

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 11:59
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4611; H05K3/4614; H05K3/4617; H10; H10W; H10W99/00; H10W70/00; H10W70/60; H10W70/611; H10W90/00; H10W90/401; H05K2201/00; H05K2201/01; H05K2201/0183; H05K2201/0195; H05K2201/03; H05K2201/0302; H05K2201/0305; H05K2201/0332; H05K2201/0388; H05K2201/0394; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/09563; H05K2203/00; H05K2203/11; H05K2203/1189; H05K3/40; H05K3/4038; H05K3/42; H05K3/423; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126; Y10T29/49155; Y10T29/49165

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 177 words
A multi-layer interconnect, comprising: a first circuit board layer having a first side and a second side, the first circuit board layer including a via hole extending through the first circuit board layer from the first side to the second side; a trace metal layer deposited on the first side of the first circuit board layer; conductive via metal carried in the via hole of the first circuit board layer, the conductive via material in electrical contact with the trace metal and forming a crown exterior to the via hole on the second side of the first circuit board layer; a second circuit board layer having a first side; an adhesive between the first side of the first circuit board layer and the first side of the second circuit board layer; and an electrical contact on the first side of the second circuit board layer, the electrical contact generally aligned with the via hole and the conductive via material, wherein the conductive via material provides an electrical conduction path between the trace metal and the electrical contact.
Claim 2
Dependent Claim 177 words
A multi-layer interconnect, comprising: a first circuit board layer having a first side and a second side, the first circuit board layer including a via hole extending through the first circuit board layer from the first side to the second side; a trace metal layer deposited on the first side of the first circuit board layer; conductive via metal carried in the via hole of the first circuit board layer, the conductive via material in electrical contact with the trace metal and forming a crown exterior to the via hole on the second side of the first circuit board layer; a second circuit board layer having a first side; an adhesive between the first side of the first circuit board layer and the first side of the second circuit board layer; and an electrical contact on the first side of the second circuit board layer, the electrical contact generally aligned with the via hole and the conductive via material, wherein the conductive via material provides an electrical conduction path between the trace metal and the electrical contact.
Claim 3
Dependent Claim 21 words
The multi-layer interconnect of claim 1 wherein a layer of low melting point metal overlies the crown of the via metal.
Claim 4
Dependent Claim 15 words
The multi-layer interconnect of claim 2 wherein the low melting point metal comprises immersion tin.
Claim 5
Dependent Claim 15 words
The method of claim 1 wherein the low melting point metal layer comprises electroplated tin.
Claim 6
Dependent Claim 17 words
The multi-layer interconnect of claim 1 wherein the first and second circuit board layers comprise polymeric film.
Claim 7
Dependent Claim 13 words
The multi-layer interconnect of claim 1 wherein the trace metal layer comprises copper.
Claim 8
Dependent Claim 13 words
The multi-layer interconnect of claim 1 wherein the conductive via metal includes copper.
Claim 9
Dependent Claim 17 words
The multi-layer interconnect of claim 1 wherein a conductive adhesive overlies the crown of the via metal.
Claim 10
Dependent Claim 23 words
The multi-layer interconnect of claim 1 including at least a third circuit board layer laminated to the first and second circuit board layers.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-03-27 1998-09-26 1999-03-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-03-27 2002-09-26 2003-03-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-03-27 2006-09-26 2007-03-28 $7700.00 Window Closed / Lapsed

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