Patent US4085285A successfully refreshed from Google Patents.
US4085285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing printed circuit boards
Assignee: US Philips Corp
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Filing: 1976-08-06
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Granted: 1978-04-18
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Expires: 1996-08-06
Abstract
Abstract Manufacture of photosensitive material by a dispersion of particles of semiconducting metal oxide having a charge sign opposite to that of the substrate in the dispersion agent, which dispersion is provided on the substrate surface and adhered thereto. In a similar manner walls of a hole for electrical through-connections are made photosensitive as a pretreatment for metal-plating.
Inventors
- 👤 Gerardus Johannes Meinardus Lippits
- 👤 Petrus Johannes Janssen
- 👤 Henricus Antonius Debruijn
- 👤 Johannes VAN Ruler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:07
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/705; H; H05; H05K; H05K3/00; H05K3/10; H05K3/105; H05K3/106; H05K3/40; H05K3/42; H05K3/422; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; H05K1/0373; H05K2201/00; H05K2201/02; H05K2201/0203; H05K2201/0206; H05K2201/0236; H05K2203/00; H05K2203/07; H05K2203/0703; H05K2203/0716; H05K2203/11; H05K2203/1105
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
223 words
A method of forming completely metallized holes in printed circuit boards, said method comprising providing the desired holes in a substrate, contacting the walls of said substrate with an aqueous dispersion of TiO 2 particles, the charge sign of said TiO 2 particles in the dispersion being opposite to that at the walls of said holes while in contact with said dispersion, rinsing away any excess of said dispersion from the walls of said holes, subjecting the thus treated walls to a thermal treatment at a temperature of more than 50° C but less than the softening temperature or decomposition temperature of the material of said walls, the resultant walls being coated with a layer of TiO 2 particles one grain thick, treating the resultant TiO 2 coated walls of said holes with a solution of a metal salt capable of being reduced to metal nuclei by TiO 2 particles when exposed to actinic light, exposing the walls of said holes to actinic light thereby causing the walls of said holes to be coated with a metal nuclei layer and then subjecting said metal nuclei layer to the action of a solution of a metal compound capable of being chemically deposited on said metal nuclei layer in its metallic state to thereby increase the amount of metal on the walls of said holes.
Claim 2
Independent Claim
223 words
A method of forming completely metallized holes in printed circuit boards, said method comprising providing the desired holes in a substrate, contacting the walls of said substrate with an aqueous dispersion of TiO 2 particles, the charge sign of said TiO 2 particles in the dispersion being opposite to that at the walls of said holes while in contact with said dispersion, rinsing away any excess of said dispersion from the walls of said holes, subjecting the thus treated walls to a thermal treatment at a temperature of more than 50° C but less than the softening temperature or decomposition temperature of the material of said walls, the resultant walls being coated with a layer of TiO 2 particles one grain thick, treating the resultant TiO 2 coated walls of said holes with a solution of a metal salt capable of being reduced to metal nuclei by TiO 2 particles when exposed to actinic light, exposing the walls of said holes to actinic light thereby causing the walls of said holes to be coated with a metal nuclei layer and then subjecting said metal nuclei layer to the action of a solution of a metal compound capable of being chemically deposited on said metal nuclei layer in its metallic state to thereby increase the amount of metal on the walls of said holes.
Claim 3
Dependent Claim
24 words
The method of claim 2 wherein the substrate is provided with a filler having a charge sign opposite that of the TiO 2 particles.
Claim 4
Dependent Claim
51 words
The method of claim 2 wherein the substrate is an epoxy sheet material reinforced with glass fibers coated with a monograin coating of TiO 2 particles of a particle size of less than 0.5 μ and the dispersion of TiO 2 particles employed has a pH of between 1 and 6.
Claim 5
Dependent Claim
16 words
The method of claim 3 wherein the pH of the dispersion is between 2 and 4.
Claim 6
Dependent Claim
49 words
The method of claim 4 wherein the holes are drilled after a pattern has been formed on the substrate and then the walls of the holes are treated with the aqueous dispersion of the TiO 2 particles, exposed to actinic light, provided with metal nuclei and then metal plated.
Claim 7
Dependent Claim
14 words
A printed circuit board having plated-through holes manufactured by the method of claim 1.
References Cited (Backward Citations)
US3485658A
Cited
US3380823A
Cited
GB1209963A
Cited
US3616294A
Cited
US3627576A
Cited
US3674485A
Cited
US3758304A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-17 | 1981-10-17 | 1982-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-17 | 1985-10-17 | 1986-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-17 | 1989-10-17 | 1990-04-18 | $7700.00 | Window Closed / Lapsed |