Patent US3610752A successfully refreshed from Google Patents.
US3610752A
Expired / Lapsed
US
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Preparing printed circuit boards by refracted rays
Assignee: United States Atomic Energy Commission
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Filing: 1970-01-15
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Granted: 1971-10-05
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Expires: 1990-01-15
Abstract
Abstract An improved process for preparing printed circuit boards in which only the conductor surrounding the circuitry is removed. A refractor is utilized in preparing the circuit board negative to obtain exposure of the film only in the regions directly adjacent the lines representing the circuitry.
Inventors
- 👤 Frederick C Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:06
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70058; G03F1/00; G03F7/70216; G03F7/7035; G03F7/70483; G03F7/7055; G03F7/70583; H; H05; H05K; H05K3/00; H05K3/0002; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/0929; H05K2201/09363; H05K2203/00; H05K2203/05; H05K2203/0548; H05K2203/056
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
165 words
A method of preparing a printed circuit board in which the board coated with a conductor material is photoetched to remove conductor material in the regions immediately surrounding the lines of circuitry, the improvement in preparing the negative for such photoetching comprising the steps of: a. preparing a first negative showing the circuit diagram to be imprinted on said circuit board; b. preparing a positive transparency from said first negative of the circuit diagram; c. directing a beam of light through both said first negative and said transparency to a sheet of unexposed film, said first negative and transparency arranged to block all light to said unexposed film; and d. refracting the light from said first negative before reaching said transparency to displace the rays of light causing said film to become exposed only in the regions immediately surrounding each of the circuit lines of said circuit diagram, said film upon developing to be used as the aforesaid negative to prepare said printed circuit board.
Claim 2
Independent Claim
165 words
A method of preparing a printed circuit board in which the board coated with a conductor material is photoetched to remove conductor material in the regions immediately surrounding the lines of circuitry, the improvement in preparing the negative for such photoetching comprising the steps of: a. preparing a first negative showing the circuit diagram to be imprinted on said circuit board; b. preparing a positive transparency from said first negative of the circuit diagram; c. directing a beam of light through both said first negative and said transparency to a sheet of unexposed film, said first negative and transparency arranged to block all light to said unexposed film; and d. refracting the light from said first negative before reaching said transparency to displace the rays of light causing said film to become exposed only in the regions immediately surrounding each of the circuit lines of said circuit diagram, said film upon developing to be used as the aforesaid negative to prepare said printed circuit board.
Claim 3
Dependent Claim
26 words
The method of claim 1 in which refracting of said light is accomplished by mounting refracting means and tilting same reversibly to obtain the aforesaid displacement.
Claim 4
Dependent Claim
35 words
The method of claim 2 in which said refracting means is a flat transparent element tiltably mounted on at least one axis perpendicular to the normal extending from the source of light to said negative.
Claim 5
Dependent Claim
17 words
The method of claim 2 in which said refracting means is a segment of a circular cylinder.
Claim 6
Dependent Claim
17 words
The method of claim 2 in which said refracting means is a segment of a hollow sphere.
References Cited (Backward Citations)
US2014513A
Cited
US3204544A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-04 | 1975-04-05 | 1975-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-04 | 1979-04-05 | 1979-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-04 | 1983-04-05 | 1983-10-05 | $7700.00 | Window Closed / Lapsed |