US3791340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of depositing a metal pattern on a surface
Assignee: AT&T Inc
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Filing: 1972-05-15
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Granted: 1974-02-12
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Expires: 1992-05-15
Abstract
Abstract A method of depositing a metal pattern on a surface of a substrate is disclosed. A surface of the substrate is sensitized with a photosensitive palladium sensitizer. The sensitized surface is exposed to a source of ultraviolet radiation to delineate an unexposed pattern corresponding to the desired metal pattern. The selectively ultraviolet radiation-exposed surface is then immersed in a suitable electroless metal deposition solution wherein an electroless metal is catalytically reduced on the delineated unexposed pattern.
Inventors
- 👤 A Ferrara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:14
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/58; G03C1/00; G03C1/50; H; H05; H05K; H05K3/00; H05K3/10; H05K3/18; H05K3/181; H05K3/182; H05K3/185
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
72 words
In a method of selectively depositing a metal pattern on a surface of a substrate, which comprises: a. coating the surface with a colloidal palladium species which upon exposure to a source of ultraviolet radiation is rendered incapable of participating in an electroless metal deposition catalysis; and b. selectively exposing said coated surface to a source of ultraviolet radiation to delineate an unexposed coated surface pattern corresponding to the metal pattern desired.
Claim 2
Dependent Claim
53 words
dissolving said palladium salt in said medium to produce a salt solution; b1. producing a colloidal solution by forming a colloidal, solid phase in said salt solution, said colloidal, solid phase comprising insoluble hydrous oxide particles of palladium, said particles having dimensions ranging from 10A to 10,000A, including at least the sub-steps of:
Claim 3
Dependent Claim
42 words
maintaining the pH of said salt solution at a value which prevents a spontaneous precipitate; and p1 b. exposing said colloidal solution to a source of ultraviolet radiation to form a second palladium species incapable of participating in an electroless metal catalysis.
Claim 4
Dependent Claim
28 words
The method as defined in claim 2 which further comprises: exposing said unexposed coated surface pattern to an electroless metal deposition solution to deposit an electroless metal thereon.
Claim 5
Dependent Claim
19 words
The method as defined in claim 3 which further comprises: electrochemically depositing a metal deposit on said electroless metal.
Claim 6
Independent Claim
165 words
A method of selectively depositing a metal pattern on a surface of a substrate, which comprises: a. coating the surface with a stable aqueous colloidal solution, formed by a hydrolysis and nucleation reaction, comprising insoluble hydrous oxide particles of palladium, said particles having a size within the range of 10A to 10,000A and said hydrolysis reaction including at least (1) dissolution of a salt of palladium in an aqueous medium and (2) maintenance of the pH of said aqueous medium at a point where no flocculate results; b. exposing selected portions of said coated surface to a source of ultraviolet radiation to render palladium species contained on said selected portions incapable of being reduced to catalytic palladium metal, said selected portions conforming to a negative of the pattern; and c. immersing said selectively exposed surface in an electroless metal plating bath to sequentialLy (1) form catalytic palladium metal and (2) reduce an electroless metal thereon, said reduction being catalyzed by said formed catalytic palladium metal.
Claim 7
Dependent Claim
56 words
In a method of rendering a first ionic palladium species, capable of being reduced to catalytic palladium, incapable of participating in an electroless metal deposition catalysis, which comprises: exposing a colloidal solution comprising said first species to a source of ultraviolet radiation to form a second palladium species incapable of being reduced to catalytic palladium metal.
Claim 8
Dependent Claim
17 words
A palladium species incapable of being reduced to catalytic palladium produced by the method of claim 6.
Claim 9
Independent Claim
50 words
A method of rendering a first ionic species, capable of being reduced to catalytic palladium, incapable of participating in an electroless metal catalysis, which comprises: a. preparing a stable aqueous colloidal solution, comprising the first species, by: a1. forming an aqueous solution of a palladium salt, including the sub-steps of:
Claim 10
Independent Claim
139 words
A method of producing an electrical circuit pattern on a non-conductive substrate, which comprises: a. coating the substrate with a photosensitive colloidal palladium species, which is initially capable of being reduced to catalytic palladium metal but which upon exposure to ultraviolet radiation is rendered incapable of such reduction; b. selectively exposing said coated substrate to a source of ultraviolet radiation to generate a first surface pattern conforming to the electrical circuit pattern, and a second surface pattern, said first surface pattern comprising palladium species thereon capable of reduction to catalytic palladium metal, said second surface pattern comprising palladium species thereon incapable of reduction to catalytic palladium metal; and c. immersing said selectively exposed substrate in an electroless plating bath, catalyzed by catalytic palladium metal, to deposit electroless metal on said first surface pattern to produce the electrical circuit pattern.
Claim 11
Dependent Claim
20 words
The method as defined in claim 9 which comprises the additional step of electroplating metal onto said electrical circuit pattern.
Claim 12
Dependent Claim
21 words
The method as defined in claim 10 which comprises the additional step of removing the substrate from said electroplated circuit pattern.
References Cited (Backward Citations)
US3562005A
Cited
US3657003A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |