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US4684055A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of selectively soldering the underside of a substrate having leads

Assignee: Intersil Corp
•
Filing: 1985-09-09
•
Granted: 1987-08-04
•
Expires: 2005-09-09
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Abstract

Abstract A method for soldering the underside of a substrate between leads. A paste of solder emulsified in a flux material is printed onto a carrier and film. The paste is adhered to the film by drying or reflowing before being placed onto the substrate between the projecting leads. The substrate and film are then heated. The molten solder having an affinity for plated surface areas of the substrate and no affinity for the polyimide film transfers and self-aligns to the plated surfaces of the substrate. The method allows selective soldering of the underside surface of a substrate having leads without soldering these leads, or selective soldering of some plated areas of a substrate while leaving other plated areas free of solder.

Inventors

  • 👤 Scott D. Baer
  • 👤 Thomas P. Glenn

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 12:13
CPC Classifications
B; B23; B23K; B23K3/00; B23K3/06; B23K35/00; B23K35/02; B23K35/0222; H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3485; H05K2201/00; H05K2201/10; H05K2201/10227; H05K2201/10424; H05K2201/10613; H05K2201/10954; H05K2201/10984; H05K2203/00; H05K2203/01; H05K2203/0147; H05K2203/0156; H05K2203/03; H05K2203/0338

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 81 words
The method of applying solder to metallic areas of a substrate comprising: placing a solder carrier having solder paste adhered to said carrier on one surface onto a substrate surface in predetermined areas having metallic and non-metallic areas, wherein said solder paste surface of said carrier faces said substrate surface and said paste areas substantially coincide with said metallic areas; heating said solder carrier and substrate to transfer said solder to said metallic areas; and remove said carrier from said substrate.
Claim 2
Independent Claim 81 words
The method of applying solder to metallic areas of a substrate comprising: placing a solder carrier having solder paste adhered to said carrier on one surface onto a substrate surface in predetermined areas having metallic and non-metallic areas, wherein said solder paste surface of said carrier faces said substrate surface and said paste areas substantially coincide with said metallic areas; heating said solder carrier and substrate to transfer said solder to said metallic areas; and remove said carrier from said substrate.
Claim 3
Dependent Claim 18 words
The method of claim 1, wherein said solder paste is a suspension of solder in a flux material.
Claim 4
Dependent Claim 19 words
The method of claim 2, including depositing said solder paste onto said solder carrier and drying said paste thereon.
Claim 5
Dependent Claim 19 words
The method of claim 2, including depositing said solder paste onto said solder carrier and reflowing said paste thereon.
Claim 6
Dependent Claim 12 words
The method of claim 1, wherein said solder carrier is a film.
Claim 7
Dependent Claim 10 words
The method of claim 5, wherein said film is polyimide.
Claim 8
Dependent Claim 14 words
The method of claim 5, wherein said solder paste is printed onto said film.
Claim 9
Dependent Claim 19 words
The method of claim 7, wherein said solder printing matches the metallic areas to be soldered of said substrate.
Claim 10
Dependent Claim 11 words
The method of claim 1, wherein said substrate surface has leads.
Claim 11
Dependent Claim 29 words
The method of claim 9, wherein said film is placed entirely in between the leads and wherein said film has a width less than the distance between said leads.

References Cited (Backward Citations)

US3726007A Cited
US3950200A Cited
US4327124A Cited
US4304640A Cited
US4332341A Cited
US4339784A Cited
US4442966A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-08-03 1991-02-02 1991-08-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-08-03 1995-02-02 1995-08-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-08-03 1999-02-02 1999-08-04 $7700.00 Window Closed / Lapsed

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