US3208921A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making printed circuit boards
Assignee: Unisys Corp
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Filing: 1962-01-02
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Granted: 1965-09-28
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Expires: 1982-01-02
Abstract
No abstract record available.
Inventors
- 👤 Clarence E Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:28
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/10; H05K3/108; H05K3/40; H05K3/42; H05K3/425; H05K3/428; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0347; H05K2203/00; H05K2203/05; H05K2203/0502; H05K2203/0542; H05K2203/07; H05K2203/0703; H05K2203/0723; H05K2203/13; H05K2203/1377; H05K2203/1388
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
194 words
A METHOD FOR PRODUCING PRINTED CIRCUITS MOUNTED ON THE OPPOSITE FACES OF A CONDUCTIVELY CLAD INSULATING BOARD HAVING ELECTRICAL CONNECTIONS THROUGH THE BOARD BETWEEN PREDETERMINED POINTS ON SAID CIRCUITS, SAID METHOD COMPRISING THE STEPS OF: COATING SAID OPPOSITE FACES OF SAID BOARD WITH A PHOTOGRAPHIC RESIST, SELECTIVELY EXPOSING PREDETERMINED AREAS OF SAID RESIST AT WHICH CIRCUIT CONDUCTORS ARE TO BE FORMED SO THAT EXPOSED AREAS SURROUND UNEXPOSED RESIST LOCATIONS AT WHICH HOLES ARE TO BE CUT THROUGH SAID BOARD, THE UNEXPOSED RESIST LOCATIONS ON ONE FACE OF SAID BOARD BEING IN REGISTRATION WITH RESPECTIVE UNEXPOSED RESIST LOCATIONS ON THE OTHER FACE OF SAID BOARD, REMOVING THE UNEXPOSED RESIST AND THE CONDUCTIVE CLADDING LYING BENEATH SAID UNEXPOSED RESIST, COVERING SAID OPPOSITE FACES OF SAID BOARD WITH A LAYER OF CONDUCTIVE MATERIAL, SAID LAYER OF CONDUCTIVE MATERIAL BEING THIN RELATIVE TO THE THICKNESS OF SAID CONDUCTIVE CLADDING, COVERING SAID LAYER OF CONDUCTIVE MATERIAL WITH A LAYER OF RESIST MATERIAL, CUTTING HOLES THROUGH SAID BOARD AT SIAD UNEXPOSED RESIST LOCATIONS, ELECTROPLATING CONDUCTIVE LININGS ON THE INTERIOR SURFACES OF SAID BAORD SURROUNDING SAID HOLES, AND REMOVING SAID LAYER OF RESIST MATERIA L AND SAID LAYER OF CONDUCTIVE MATERIAL.
Claim 2
Independent Claim
194 words
A METHOD FOR PRODUCING PRINTED CIRCUITS MOUNTED ON THE OPPOSITE FACES OF A CONDUCTIVELY CLAD INSULATING BOARD HAVING ELECTRICAL CONNECTIONS THROUGH THE BOARD BETWEEN PREDETERMINED POINTS ON SAID CIRCUITS, SAID METHOD COMPRISING THE STEPS OF: COATING SAID OPPOSITE FACES OF SAID BOARD WITH A PHOTOGRAPHIC RESIST, SELECTIVELY EXPOSING PREDETERMINED AREAS OF SAID RESIST AT WHICH CIRCUIT CONDUCTORS ARE TO BE FORMED SO THAT EXPOSED AREAS SURROUND UNEXPOSED RESIST LOCATIONS AT WHICH HOLES ARE TO BE CUT THROUGH SAID BOARD, THE UNEXPOSED RESIST LOCATIONS ON ONE FACE OF SAID BOARD BEING IN REGISTRATION WITH RESPECTIVE UNEXPOSED RESIST LOCATIONS ON THE OTHER FACE OF SAID BOARD, REMOVING THE UNEXPOSED RESIST AND THE CONDUCTIVE CLADDING LYING BENEATH SAID UNEXPOSED RESIST, COVERING SAID OPPOSITE FACES OF SAID BOARD WITH A LAYER OF CONDUCTIVE MATERIAL, SAID LAYER OF CONDUCTIVE MATERIAL BEING THIN RELATIVE TO THE THICKNESS OF SAID CONDUCTIVE CLADDING, COVERING SAID LAYER OF CONDUCTIVE MATERIAL WITH A LAYER OF RESIST MATERIAL, CUTTING HOLES THROUGH SAID BOARD AT SIAD UNEXPOSED RESIST LOCATIONS, ELECTROPLATING CONDUCTIVE LININGS ON THE INTERIOR SURFACES OF SAID BAORD SURROUNDING SAID HOLES, AND REMOVING SAID LAYER OF RESIST MATERIA L AND SAID LAYER OF CONDUCTIVE MATERIAL.
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) | 1968-09-27 | 1969-03-29 | 1969-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-27 | 1973-03-29 | 1973-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-27 | 1977-03-29 | 1977-09-28 | $7700.00 | Window Closed / Lapsed |