US3742597A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making a coated printed circuit board
Assignee: Hadco Printed Circuits Inc
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Filing: 1971-03-17
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Granted: 1973-07-03
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Expires: 1991-03-17
Abstract
Abstract A printed circuit board includes a circuit portion and a contact portion. Solder coats copper in and adjacent each of a plurality of holes in the circuit portion. An insulating overlay covers the circuit portion except at the solder-coated portions. To construct this board, holes are drilled through a copper clad, laminated plastic sheet. Then resist is applied to all portions of the board except adjacent the holes. Two successive plating processes deposit copper and solder to the board at the holes to produce solder-coated pads at each hole and a soldercoated, copper plating through each hole. The next process step includes depositing a second resist to selected areas of both board portions before etching the board to form contacts and circuits. After plating the contacts, the board is finished by applying a plastic resin overlay to the entire circuit portion except at the pad areas.
Inventors
- 👤 D Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:14
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3473; H05K3/22; H05K3/24; H05K3/243; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/09654; H05K2201/09736; H05K2203/00; H05K2203/04; H05K2203/043; H05K3/02; H05K3/06; H05K3/061; H05K3/28; H05K3/40; H05K3/42; H05K3/425; H05K3/427
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
134 words
A process for making a printed circuit board comprising the following steps, performed in the order hereafter recited: A. providing an insulating substrate clad on at least one side with a conductive foil and having holes extending through said substrate and said foil; B. selectively plating solder onto the clad substrate so that substantially only the walls of said holes and regions of said foil immediately adjacent said holes are solder coated; C. then selectively etching said foil to form conductors extending from said regions, at least one of said conductors terminating in a contact finger portion, said etching not affecting said solder or said regions of said foil; and D. forming an insulating overlay on the entire surface of said clad substrate except on the solder coated areas and said contact finger portion.
Claim 2
Dependent Claim
134 words
A process for making a printed circuit board comprising the following steps, performed in the order hereafter recited: A. providing an insulating substrate clad on at least one side with a conductive foil and having holes extending through said substrate and said foil; B. selectively plating solder onto the clad substrate so that substantially only the walls of said holes and regions of said foil immediately adjacent said holes are solder coated; C. then selectively etching said foil to form conductors extending from said regions, at least one of said conductors terminating in a contact finger portion, said etching not affecting said solder or said regions of said foil; and D. forming an insulating overlay on the entire surface of said clad substrate except on the solder coated areas and said contact finger portion.
Claim 3
Dependent Claim
50 words
A process as recited in claim 1 wherein said solder plating step includes: A. depositing resist on said foil at all areas except areas corresponding to said regions, and B. plating copper on the walls of said holes and in said regions, said solder being plated onto the plated copper.
Claim 4
Dependent Claim
23 words
A process as recited in claim 2 wherein said copper and solder plating steps include electroplating and the resist is an electroplating resist.
Claim 5
Dependent Claim
80 words
A process as recited in claim 1 wherein said solder plating step uses screening steps comprising: A. forming a first screen with opaque portions corresponding to said regions, B. forming a copper flash on all exposed board surfaces, C. depositing an electroplating resist onto the board through the first screen after the first screen and board are in registration, D. electroplating copper onto said foil and the walls of the holes, and E. electroplating solder onto the plated copper surfaces.
Claim 6
Dependent Claim
32 words
A process as recited in claim 1 wherein said overlay forming step comprises A. depositing a heat-hardenable plastic epoxy resin into selected portions of the board, and B. heat hardening the plastic.
Claim 7
Dependent Claim
52 words
A process as recited in claim 4 wherein said overlay forming step includes the steps of A. forming a second screen with opaque portions corresponding to said regions, B. depositing a heat hardenable plastic epoxy resin through the second screen to selected portions of the board, and C. heat hardening the resin.
Claim 8
Dependent Claim
24 words
A process as recited in claim 1 additionally comprising the step of heating the board to the solder melting temperature after forming the overlay.
Claim 9
Dependent Claim
32 words
A process as recited in claim 1 additionally comprising the step of plating copper onto the board adjacent to and through the holes, said copper plating step preceding said solder plating step.
Claim 10
Dependent Claim
48 words
A process as recited in claim 8 wherein said copper plating step includes A. electrolessly depositing a copper flash on said board, B. depositing an electroplating resist to said board except at areas adjacent and through said holes, and C. electroplating copper onto exposed areas of said board.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |