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US4632852A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for electroless copper plating

Assignee: Hitachi Ltd
•
Filing: 1985-06-18
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Granted: 1986-12-30
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Expires: 2005-06-18
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Abstract

Abstract In a process for electroless copper plating in an electroless copper plating solution containing a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH-adjusting agent, a plating film having distinguished mechanical properties can be obtained by adding at least one of soluble inorganic silicon compounds and soluble inorganic germanium compounds and conducting the electroless copper plating by injecting an oxygen-containing gas into the plating solution or by adding an oxidizing agent to the plating solution or by both injection or the oxygen-containing gas and addition of the oxidizing agent thereto. The stability of the electroless copper plating solution can be maintained better thereby and substantially thick plating is possible.

Inventors

  • 👤 Haruo Akahoshi
  • 👤 Kanji Murakami
  • 👤 Mineo Kawamoto
  • 👤 Motoyo Wajima
  • 👤 Rituji Toba
  • 👤 Shoji Kawakubo
  • 👤 Akio Tadokoro

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 15:35
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/38; H; H05; H05K; H05K3/00; H05K3/10; H05K3/18; H05K3/181; H05K3/187; C23C18/40

Claims Analysis

Total Claims: 33
Claim 1
Independent Claim 97 words
A process for electroless copper plating in an electroless copper plating solution containing a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH-adjusting agent, which comprises adding at least one of soluble inorganic silicon compounds and soluble inorganic germanium compounds as an additive to the electroless copper plating solution and conducting electroless copper plating by injecting an oxygen-containing gas into the plating solution or by adding an oxidizing agent to the plating solution or by both injection of the oxygen-containing gas and addition of the oxidizing agent.
Claim 2
Dependent Claim 97 words
A process for electroless copper plating in an electroless copper plating solution containing a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH-adjusting agent, which comprises adding at least one of soluble inorganic silicon compounds and soluble inorganic germanium compounds as an additive to the electroless copper plating solution and conducting electroless copper plating by injecting an oxygen-containing gas into the plating solution or by adding an oxidizing agent to the plating solution or by both injection of the oxygen-containing gas and addition of the oxidizing agent.
Claim 3
Dependent Claim 28 words
A process according to claim 1, where the additive is added in an amount of 10 mg/l to 1 g/l in terms of silicon atom or germanium atom.
Claim 4
Dependent Claim 37 words
A process according to claim 1, wherein the soluble inorganic silicon compound is at least one of water glass, sodium metasilicate, sodium orthosilicate, sodium silicate, potassium silicate, lithium silicate, sodium polysilicate, silicon dioxide, and a silicon-containing gas.
Claim 5
Dependent Claim 32 words
A process according to claim 1, wherein the soluble inorganic germanium compound is at least one of sodium germanate, potassium germanate, lithium germanate, germanium dioxide, germanium chloride, germanium sulfate, and germanium nitrate.
Claim 6
Dependent Claim 12 words
A process according to claim 1, wherein the oxygen-containing gas is air.
Claim 7
Dependent Claim 29 words
A process according to claim 5, wherein the air is injected into the plating solution in a rate of at least 0.01 l/min per liter of the plating solution.
Claim 8
Dependent Claim 29 words
A process according to claim 6, wherein the air is injected into the plating solution at a rate of 1 to 5 l/min per liter of the plating solution.
Claim 9
Dependent Claim 16 words
A process according to claim 1, wherein the oxidizing agent is hydrogen peroxide or a persulfate.
Claim 10
Dependent Claim 17 words
A process according to claim 8, wherein the persulfate is potassium persulfate, sodium persulfate or ammonium persulfate.
Claim 11
Dependent Claim 24 words
A process according to claim 1, wherein the oxidizing agent is added to the plating solution in an amount of at least 0.5 g/l.
Claim 12
Dependent Claim 22 words
A process according to claim 1, wherein the electroless copper plating is carried out at a temperature of at least 40° C.
Claim 13
Dependent Claim 16 words
A process according to claim 1, wherein the complexing agent has a chemical structure of >N--C--C--N<.
Claim 14
Dependent Claim 22 words
A process according to claim 12, wherein the complexing agent is ethylenediaminetetracetic acid, N-hydroxyethylethylenediaminetriacetic acid, 1,2-diaminopropanetetracetic acid, diethylenetriaminepentacetic acid or cyclohexanediaminetetracetic acid.
Claim 15
Dependent Claim 75 words
A process for electroless copper plating in an electroless copper plating solution containing a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH-adjusting agent, which comprises adding at least one additive selected from the group consisting of a soluble inorganic silicon compound and a soluble inorganic germanium compound to the plating solution, introducing an oxidizing medium into the plating solution and conducting electroless copper plating.
Claim 16
Dependent Claim 75 words
A process for electroless copper plating in an electroless copper plating solution containing a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH-adjusting agent, which comprises adding at least one additive selected from the group consisting of a soluble inorganic silicon compound and a soluble inorganic germanium compound to the plating solution, introducing an oxidizing medium into the plating solution and conducting electroless copper plating.
Claim 17
Dependent Claim 14 words
A process according to claim 14, wherein the oxidizing medium is an oxygen-containing gas.
Claim 18
Dependent Claim 17 words
A process according to claim 15, wherein the oxygen-containing gas is introduced while conducting electroless copper plating.
Claim 19
Dependent Claim 25 words
A process according to claim 15, wherein the oxidizing medium is an oxidizing agent selected from the group consisting of hydrogen peroxide and a persulfate.
Claim 20
Dependent Claim 23 words
A process according to claim 17, wherein the persulfate is selected from the group consisting of potassium persulfate, sodium persulfate and ammonium persulfate.
Claim 21
Dependent Claim 24 words
A process according to claim 17, wherein the oxidizing agent is added to the plating solution in an amount of at least 0.5 g/l.
Claim 22
Dependent Claim 22 words
A process according to claim 14, wherein the electroless copper plating is carried out at a temperature of at least 40° C.
Claim 23
Dependent Claim 16 words
A process according to claim 14, wherein the complexing agent has a chemical structure of >N--C--C--N<.
Claim 24
Dependent Claim 28 words
A process according to claim 21, wherein the complexing agent is selected from the group consisting of ethylenediaminetetracetic acid, N-hydroxyethylethylenediaminetriacetic acid, 1,2-diaminopropanetetracetic acid, diethylenetriaminepentacetic acid and cyclohexanediaminetetracetic acid.
Claim 25
Dependent Claim 28 words
A process according to claim 14, wherein the additive is added in an amount of 10 mg/l to 1 g/l in terms of silicon atom or germanium atom.
Claim 26
Dependent Claim 43 words
A process according to claim 14, wherein the additive is at least one soluble inorganuc silicon compound selected from the group consisting of water glass, sodium metasilicate, sodium orthosilicate, sodium silicate, potassium silicate, lithium silicate, sodium polysilicate, silicon dioxide, and a silicon-containing gas.
Claim 27
Dependent Claim 38 words
A process according to claim 14, wherein the additive is at least one soluble inorganic germanium compound selected from the group consisting of sodium germanate, potassium germanate, lithium germanate, germanium dioxide, germanium chloride, germanium sulfate, and germanium nitrate.
Claim 28
Dependent Claim 12 words
A process according to claim 15, wherein the oxygen-containing gas is air.
Claim 29
Dependent Claim 34 words
A process according to claim 26, wherein the air is injected into the plating solution while conducting electroless copper plating at a rate of at least 0.01 l/min per liter of the plating solution.
Claim 30
Dependent Claim 34 words
A process according to claim 26, wherein the air is injected into the plating solution while conducting electroless copper plating at a rate of 1 to 5 l/min per liter of the plating solution.
Claim 31
Dependent Claim 71 words
A process according to claim 14, wherein the additive is at least one soluble inorganic silicon compound selected from the group consisting of water glass, sodium metasilicate, sodium orthosilicate, sodium silicate, potassium silicate, lithium silicate, sodium polysilicate, silicon dioxide, and silicon-containing gas and at least one soluble inorganic germanium compound selected from the group consisting of sodium germanate, potassium germanate, lithium germanate, germanium dioxide, germanium chloride, germanium sulfate, and germanium nitrate.
Claim 32
Dependent Claim 18 words
A process according to claim 17, wherein the oxidizing agent is introduced prior to conducting electroless copper plating.
Claim 33
Dependent Claim 30 words
A process according to claim 14, wherein the oxidizing medium is both an oxygen-containing gas and an oxidizing agent selected from the group consisting of hydrogen peroxide and a persulfate.

References Cited (Backward Citations)

US2938805A Cited
US3915717A Cited
US4152467A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-12-29 1990-06-30 1990-12-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-12-29 1994-06-30 1994-12-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-12-29 1998-06-30 1998-12-30 $7700.00 Window Closed / Lapsed

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