Patent US2934074A successfully refreshed from Google Patents.
US4064290A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for coating plated through hole surfaces
Assignee: Individual
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Filing: 1973-08-06
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Granted: 1977-12-20
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Expires: 1993-08-06
Abstract
Abstract A system is disclosed for coating the interior surfaces of plated through holes in printed circuit boards by flowing a minimal volume of a low viscosity fluid carrying resist solids through holes in a board. After coating, the liquid phase of the fluid is evaporated, leaving a protective solid coating adhered to the walls of the plated through holes. The system enables positive imaging of the printed circuit boards preparatory to etching.
Inventors
- 👤 Julius Alex Ebel
- 👤 Ernest H. Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:24
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/0094; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/09581; H05K2201/0959; H05K2203/00; H05K2203/02; H05K2203/0278; H05K2203/15; H05K2203/1518; H05K3/02; H05K3/06; H05K3/061; H05K3/40; H05K3/42; H05K3/425; H05K3/427
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
93 words
A method of coating the walls of holes through a printed circuit board to provide a resist coating on such walls comprising the steps of: providing a fluid having a characteristic for adhering to said walls and curable to a solid coating; flowing a stream of said fluid through said holes, which stream completely fills said holes and whereby flow is in sufficient quantity to purge air and impurity particles from said holes; and ceasing said stream of said fluid and curing such fluid as adheres to said walls to provide a coating.
Claim 2
Independent Claim
93 words
A method of coating the walls of holes through a printed circuit board to provide a resist coating on such walls comprising the steps of: providing a fluid having a characteristic for adhering to said walls and curable to a solid coating; flowing a stream of said fluid through said holes, which stream completely fills said holes and whereby flow is in sufficient quantity to purge air and impurity particles from said holes; and ceasing said stream of said fluid and curing such fluid as adheres to said walls to provide a coating.
Claim 3
Dependent Claim
26 words
A method according to claim 1 further including the step of wiping the plant surfaces of said printed circuit board prior to curing of fluid thereon.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein said fluid has a viscosity between about 20 and about 50 centipoises.
Claim 5
Dependent Claim
12 words
A method according to claim 1 wherein said walls comprise metallic surfaces.
Claim 6
Dependent Claim
28 words
A method according to claim 1 wherein said printed circuit board is maintained generally vertical to provide said holes horizontal during a further step of curing said fluid.
Claim 7
Dependent Claim
26 words
A method according to claim 1 wherein at least a quantity of fluid equal to three times the volume of said holes flows through said holes.
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) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |