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US4303798A Expired / Lapsed US ⏱️ 0.0 years remaining

Heat shock resistant printed circuit board assemblies

Assignee: AMP-AKZO Corp A CORP OF
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Filing: 1979-04-27
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Granted: 1981-12-01
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Expires: 1999-04-27
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Abstract

Abstract The heat shock resistance of plated through holes in printed circuit assemblies is significantly increased by using as the through hole plating a special multi-layered arrangement comprising at least two layers of an electrically conductive metal in combination with at least one intermediate layer of a different electrically conductive metal. In preferred embodiments, the through hole plating comprises at least two layers of a stressed metal together with at least one intermediate layer of a metal having a stress in counteraction to that of one or more of the other metal layers. These through hole platings are capable of exposure to conditions of heat shock, such as encountered during high temperature soldering, without developing cracks resulting in breaks in the conducting pathways and failures.

Inventors

  • 👤 Milan Paunovic

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 15:12
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/244; H05K3/40; H05K3/42; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0341; H05K3/02; H05K3/06; H05K3/061; H05K3/062; H05K3/425; H05K3/426; H05K3/427; H05K3/428; Y; Y10; Y10S; Y10S428/00; Y10S428/901

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 78 words
In a method of printed circuit board manufacture, the improvement for increasing the heat shock resistance of the through hole plating comprising using as said plating at least two layers of an internally stressed electrically conductive metal, each such layer having a thickness of from about 2.5 to about 35 microns, in combination with at least one intermediate layer of a different electrically conductive metal having an internal stress in counteraction to that of said other metal layers.
Claim 2
Dependent Claim 78 words
In a method of printed circuit board manufacture, the improvement for increasing the heat shock resistance of the through hole plating comprising using as said plating at least two layers of an internally stressed electrically conductive metal, each such layer having a thickness of from about 2.5 to about 35 microns, in combination with at least one intermediate layer of a different electrically conductive metal having an internal stress in counteraction to that of said other metal layers.
Claim 3
Dependent Claim 23 words
The method of claim 1 in which the metal of the through hole plating is selected from among copper, nickel, gold and tin.
Claim 4
Dependent Claim 61 words
In a method of printed circuit board manufacture, the improvement for increasing the heat shock resistance of the through hole plating comprising using as said plating a three-layered arrangement in which the first and third layers each consist of copper and the intermediate layer consists of nickel, each such layer having a thickness of from about 2.5 to about 35 microns.
Claim 5
Dependent Claim 61 words
In a method of printed circuit board manufacture, the improvement for increasing the heat shock resistance of the through hole plating comprising using as said plating a three-layered arrangement in which the first and third layers each consist of copper and the intermediate layer consists of nickel, each such layer having a thickness of from about 2.5 to about 35 microns.
Claim 6
Dependent Claim 20 words
The method of claim 3 in which the copper layers are compressive stressed and the nickel layer is tensile stressed.
Claim 7
Dependent Claim 72 words
In a printed circuit board having a multiplicity of through holes, a through hole plating having increased heat shock resistance comprising at least two layers of an internally stressed electrically conductive metal, each said layer having a thickness of from about 2.5 to about 35 microns, in combination with at least one intermediate layer of another electrically conductive metal having an internal stress in counteraction to that of said other metal layers.
Claim 8
Dependent Claim 72 words
In a printed circuit board having a multiplicity of through holes, a through hole plating having increased heat shock resistance comprising at least two layers of an internally stressed electrically conductive metal, each said layer having a thickness of from about 2.5 to about 35 microns, in combination with at least one intermediate layer of another electrically conductive metal having an internal stress in counteraction to that of said other metal layers.
Claim 9
Dependent Claim 25 words
The printed circuit board of claim 5 in which the metal of the through hole plating is selected from among copper, nickel, gold and tin.
Claim 10
Dependent Claim 49 words
A printed circuit board having improved resistance to heat shock in which the through hole plating comprising a three-layered arrangement consisting of a first and third layers of copper and an intermediate layer of nickel, each such layer having a thickness of from about 2.5 to about 35 microns.
Claim 11
Dependent Claim 49 words
A printed circuit board having improved resistance to heat shock in which the through hole plating comprising a three-layered arrangement consisting of a first and third layers of copper and an intermediate layer of nickel, each such layer having a thickness of from about 2.5 to about 35 microns.
Claim 12
Dependent Claim 22 words
The printed circuit board of claim 7 in which the copper layers are compressive stressed and the nickel layer is tensile stressed.
Claim 13
Dependent Claim 83 words
A printed circuit board assembly comprising (a) an insulating base having a plurality of through holes defining interconnecting points; (b) a printed circuit pattern on one or both sides of the insulating base; and (c) a plating on the walls of the through holes comprising a first and third layers consisting of copper and an intermediate layer consisting of nickel, each of said first and third copper layers and said nickel layer having a thickness of from about 2.5 to about 35 microns.
Claim 14
Dependent Claim 83 words
A printed circuit board assembly comprising (a) an insulating base having a plurality of through holes defining interconnecting points; (b) a printed circuit pattern on one or both sides of the insulating base; and (c) a plating on the walls of the through holes comprising a first and third layers consisting of copper and an intermediate layer consisting of nickel, each of said first and third copper layers and said nickel layer having a thickness of from about 2.5 to about 35 microns.

References Cited (Backward Citations)

US3514538A Cited
US3959523A Cited
US4047290A Cited
US4104111A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-11-30 1985-06-01 1985-12-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-11-30 1989-06-01 1989-12-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-11-30 1993-06-01 1993-12-01 $7700.00 Window Closed / Lapsed

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