Patent US5167992A successfully refreshed from Google Patents.
US5167992A
Expired / Lapsed
US
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Selective electroless plating process for metal conductors
Assignee: Microelectronics and Computer Technology Corp
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Filing: 1991-03-11
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Granted: 1992-12-01
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Expires: 2011-03-11
Abstract
Abstract A method for electrolessly plating an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate. The method includes removing carbonized film from the dielectric surface by applying a plasma discharge, acid treating the metal conductor by dipping the substrate in a first acid solution in order to clean the surface of the metal conductor, activating the metal conductor to allow electroless plating thereon by dipping the substrate in a metal activator solution, deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a second acid solution, and plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution so that the overcoat metal plates on and coats the metal conductor without plating on the dielectric surface.
Inventors
- 👤 Charles W. C. Lin
- 👤 Ian Y. K. Yee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:19
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/244; C; C23; C23C; C23C18/00; C23C18/16; C23C18/1601; C23C18/1603; C23C18/1607; C23C18/1608; C23C18/1633; C23C18/1635; C23C18/18; C23C18/1851; C23C18/1872; C23C18/1886; C23C18/1889; C23C18/20; C23C18/2006; C23C18/2046; C23C18/2073; C23C18/208; C23C18/31; C23C18/32; C23C18/42; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0347; H05K2201/07; H05K2201/0753; H05K2201/0761; H05K2203/00; H05K2203/03; H05K2203/0392; H05K2203/09; H05K2203/095
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
102 words
A method for electrolessly plating an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate, comprising the following steps in the sequence set forth: activating the metal conductor to allow electroless plating thereon by dipping the substrate in an activator solution; deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a deactivator acid solution; and plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution, wherein the overcoat metal plates on the metal conductor without plating on the dielectric surface.
Claim 2
Independent Claim
102 words
A method for electrolessly plating an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate, comprising the following steps in the sequence set forth: activating the metal conductor to allow electroless plating thereon by dipping the substrate in an activator solution; deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a deactivator acid solution; and plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution, wherein the overcoat metal plates on the metal conductor without plating on the dielectric surface.
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein the activator solution is a compound that contains palladium, gold, or platinum.
Claim 4
Dependent Claim
12 words
The method of claim 1, wherein the deactivator acid solution is aqueous.
Claim 5
Dependent Claim
12 words
The method of claim 1, wherein the deactivator acid solution is non-aqueous.
Claim 6
Dependent Claim
13 words
The method of claim 1, wherein the deactivator acid solution is hydrochloric acid.
Claim 7
Dependent Claim
13 words
The method of claim 1, wherein the deactivator acid is a carboxyl acid.
Claim 8
Dependent Claim
27 words
The method of claim 6, wherein the carboxyl acid is selected from the group consisting of acetic acid, formic acid, citric acid, propionic acid, and mixtures thereof.
Claim 9
Dependent Claim
17 words
The method of claim 1, wherein the deactivator acid solution is an alcohol-based, ketone-based, or ether-based solution.
Claim 10
Dependent Claim
27 words
The method of claim 1, wherein the deactivator acid solution is based on liquid selected from the group consisting of ethanol, methanol, propanol, acetone, and ethyl ether.
Claim 11
Dependent Claim
23 words
The method of claim 1, wherein the overcoat metal is selected from the group consisting of nickel, cobalt, nickel alloys, and cobalt alloys.
Claim 12
Dependent Claim
22 words
The method of claim 1, wherein the overcoat metal is selected from the group consisting of nickel, cobalt, nickel/phosphorus, nickel/boron, and nickel/cobalt.
Claim 13
Dependent Claim
20 words
The method of claim 1, wherein the overcoat metal is selected from the group consisting of platinum, silver, and gold.
Claim 14
Dependent Claim
17 words
The method of claim 1, wherein the dielectric is a polymer, a ceramic, or a silicon compound.
Claim 15
Dependent Claim
10 words
The method of claim 1, wherein the dielectric is polyimide.
Claim 16
Dependent Claim
10 words
The method of claim 1 wherein the dielectric is plastic.
Claim 17
Dependent Claim
20 words
The method of claim 1, wherein the conductor metal is selected from the group consisting of copper, aluminum, and tungsten.
Claim 18
Dependent Claim
42 words
The method of claim 1, wherein the conductor metal is copper, the dielectric is a polymer or a plastic, the activator solution contains palladium, the deactivator acid solution removes palladium ions trapped on the dielectric surface, and the overcoat metal contains nickel.
Claim 19
Independent Claim
108 words
A method for selectively depositing an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate, comprising the following steps in the sequence set forth: removing carbonized film from the dielectric surface; activating the metal conductor to allow electroless plating thereon by dipping the substrate in a metal activator solution; deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a deactivator acid solution; and plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution, wherein the overcoat metal coats the metal conductor without plating the dielectric surface.
Claim 20
Independent Claim
108 words
A method for selectively depositing an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate, comprising the following steps in the sequence set forth: removing carbonized film from the dielectric surface; activating the metal conductor to allow electroless plating thereon by dipping the substrate in a metal activator solution; deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a deactivator acid solution; and plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution, wherein the overcoat metal coats the metal conductor without plating the dielectric surface.
Claim 21
Dependent Claim
16 words
The method of claim 18, wherein the carbonized film is removed by a wet chemical etchant.
Claim 22
Dependent Claim
14 words
The method of claim 19, wherein the wet chemical etchant is a non-aqueous solvent.
Claim 23
Dependent Claim
11 words
The method of claim 20, wherein the nonaqueous solvent is hydrazine.
Claim 24
Dependent Claim
15 words
The method of claim 18, wherein the wet chemical etchant is an aqueous alkaline solution.
Claim 25
Dependent Claim
12 words
The method of claim 22, wherein the aqueous alkaline solution in NaOH.
Claim 26
Dependent Claim
16 words
The method of claim 18, wherein the carbonized film is removed by applying a plasma discharge.
Claim 27
Dependent Claim
13 words
The method of claim 24, wherein the plasma discharge includes an oxygen/argon gas.
Claim 28
Dependent Claim
14 words
The method of claim 24, wherein the plasma discharge includes an oxygen/helium/SF 6 gas.
Claim 29
Dependent Claim
47 words
The method of claim 26, wherein the plasma discharge includes an oxygen/helium/SF 6 gas in the proportions of about 50/10/10, a pressure of about 100 to millitorr, a RF power of about 100 to 400 watts, and the plasma discharge occurs for about 30 to 120 seconds.
Claim 30
Dependent Claim
44 words
The method of claim 18, further comprising acid treating the metal conductor, between the steps of removing the carbonized film and activating the metal conductor, by dipping the substrate in a first acid solution, in order to clean the surface of the metal conductor.
Claim 31
Dependent Claim
20 words
The method of claim 18, wherein the conductor metal is selected from the group consisting of copper, aluminum, and tungsten.
Claim 32
Dependent Claim
14 words
The method of claim 18, wherein the dielectric is a polymer or a plastic.
Claim 33
Independent Claim
141 words
A method for electrolessly plating an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate, comprising the following steps in the sequence set forth: removing carbonized film from the dielectric surface by applying a plasma discharge; acid treating the metal conductor by dipping the substrate in a first acid solution in order to clean the surface of the metal conductor; activating the metal conductor to allow electroless plating thereon by dipping the substrate in a metal activator solution; deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a second acid solution; and plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution, wherein the overcoat metal plates on and coats the metal conductor without plating on the dielectric surface.
Claim 34
Independent Claim
141 words
A method for electrolessly plating an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate, comprising the following steps in the sequence set forth: removing carbonized film from the dielectric surface by applying a plasma discharge; acid treating the metal conductor by dipping the substrate in a first acid solution in order to clean the surface of the metal conductor; activating the metal conductor to allow electroless plating thereon by dipping the substrate in a metal activator solution; deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a second acid solution; and plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution, wherein the overcoat metal plates on and coats the metal conductor without plating on the dielectric surface.
Claim 35
Dependent Claim
12 words
The method of claim 31, wherein the first acid solution is inorganic.
Claim 36
Dependent Claim
26 words
The method of claim 32, wherein the first acid solution is selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, and mixtures thereof.
Claim 37
Dependent Claim
12 words
The method of claim 31, wherein the first acid solution is organic.
Claim 38
Dependent Claim
14 words
The method of claim 34, wherein the first acid solution is a carboxyl acid.
Claim 39
Dependent Claim
28 words
The method of claim 35, wherein the carboxyl acid is selected from the group consisting of formic acid, acetic acid, propionic acid, citric acid, and a mixture thereof.
Claim 40
Dependent Claim
15 words
The method of claim 31, wherein the first and second acid solutions are hydrochloric acid.
Claim 41
Dependent Claim
20 words
The method of claim 31, further comprising rinsing the first acid solution off the substrate before activating the metal conductor.
Claim 42
Dependent Claim
20 words
The method of claim 31, further comprising rinsing the second acid solution off the substrate before plating the overcoat metal.
Claim 43
Dependent Claim
23 words
The method of claim 31, wherein the overcoat metal is selected from the group consisting of nickel, cobalt, nickel alloys, and cobalt alloys.
Claim 44
Dependent Claim
18 words
The method of claim 31, wherein the activator solution is a compound that contains palladium, gold, or platinum.
Claim 45
Dependent Claim
14 words
The method of claim 31, wherein the dielectric is a polymer or a plastic.
Claim 46
Dependent Claim
20 words
The method of claim 31, wherein the conductor metal is selected from the group consisting of copper, aluminum, and tungsten
Claim 47
Dependent Claim
42 words
The method of claim 31, wherein the conductor metal is copper, the dielectric is a polymer or a plastic, the activator solution contains palladium, the second acid solution removes palladium ions trapped on the dielectric surface, and the overcoat metal contains nickel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-12-01 | 1996-06-01 | 1996-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-01 | 2000-06-01 | 2000-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-01 | 2004-06-01 | 2004-12-01 | $7700.00 | Window Closed / Lapsed |