Patent US4314299A successfully refreshed from Google Patents.
Patent US3046622A successfully refreshed from Google Patents.
US4997516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving adherence of copper foil to resinous substrates
Assignee: Park Aerospace Corp
•
Filing: 1989-11-29
•
Granted: 1991-03-05
•
Expires: 2009-11-29
Abstract
Abstract The present invention comprises an improvement in the surface treatment of copper surfaces. It produces a strong and stable bond, resistant to chemical attack and to thermal and mechanical stresses between said copper foil surfaces and adjacent surfaces of resinous layers. It is especially useful in multilayer printed circuit fabrication and in the treatment of copper circuit lines and areas which are disconnected from each other, that is, which do not have electrically conductive continuity. In a method according to the invention, an oxidized cooper surface is reduced in the presence of a polymer addition agent, and the partially reduced surface is then exposed to a nonoxidizing reagent. The result is a reticulated metallic copper microstructure capable of forming a strong adhesive bond with a resinous substrate, and having a high resistance to thermal, mechanical, and chemical (e.g. acid) stress.
Inventors
- 👤 Edward Adler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:02
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/382; H05K3/385; C; C23; C23C; C23C22/00; C23C22/05; C23C22/60; C23C22/63; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2203/00; H05K2203/03; H05K2203/0307; H05K2203/0315; H05K2203/07; H05K2203/0703; H05K2203/0723; H05K2203/11; H05K2203/1157; H05K3/46; H05K3/4611
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
61 words
A method of treating an oxidized copper surface comprising: reducing said oxidized copper surface in alkaline solution with a reducing agent if the presence of a polymer addition agent, exposing said reduced surface to a nonoxidizing reagent which dissolves hydrous cuprous oxide and does not substantially dissolve metallic copper, and rinsing said surface at least once and thereafter drying said surface.
Claim 2
Independent Claim
61 words
A method of treating an oxidized copper surface comprising: reducing said oxidized copper surface in alkaline solution with a reducing agent if the presence of a polymer addition agent, exposing said reduced surface to a nonoxidizing reagent which dissolves hydrous cuprous oxide and does not substantially dissolve metallic copper, and rinsing said surface at least once and thereafter drying said surface.
Claim 3
Dependent Claim
22 words
A method according to claim 1, wherein said reducing agent is sodium hydrosulfite and said alkaline solution is a sodium hydroxide solution.
Claim 4
Dependent Claim
30 words
A method according to claim 1, wherein said polymer addition agent is a high molecular weight material selected from the group consisting of glue, gelatin, gum arabica, dextrin, and polyacrylate.
Claim 5
Dependent Claim
19 words
A method according to claim 1, wherein said non-oxidizing reagent comprises a source of chloride ions in acid solution.
Claim 6
Dependent Claim
21 words
A method according to claim 1, wherein said reducing, step is performed at a temperature ranging from 35° to 50° C.
Claim 7
Dependent Claim
30 words
A method according to claim 1, wherein said non-oxidizing reagent is selected from the group consisting of dilute hydrochloric acid and a mixture of dilute hydrochloric acid and sodium chloride.
Claim 8
Dependent Claim
57 words
A method according to claim 1, wherein the reducing agent is from 5 to 100 g/l of sodium hydrosulfite, the alkaline solution contains from 5 to 200 g/l of sodium hydroxide, the addition agent is from 50 to 250 g/l of gelatin, and the nonoxidizing reagent is 100 g/l of sodium chloride in 0.1 normal hydrochloric acid.
Claim 9
Dependent Claim
54 words
A method according to claim 7, wherein said reducing step is performed for about 2 to 3 minutes at a temperature of 38° to 42° C., using 25 g/l of sodium hydrosulfite, 20 g/l of sodium hydroxide, and 125 g/l of gelatin, and said exposing step is performed for about 10 to 30 seconds.
Claim 10
Dependent Claim
17 words
A method according to claim 1 wherein said reduced surface is washed prior to said exposing step.
Claim 11
Dependent Claim
23 words
A method according to claim 1, wherein said rinsing step is performed at least twice, using a passivating chromate solution at least once.
Claim 12
Dependent Claim
29 words
A method according to claim 10, wherein said passivating chromate solution is a mixture of about 0.5 g/l. CrO 3 and about 0.5 g/l. Na 2 CrO 4 .
Claim 13
Dependent Claim
58 words
A method according to claim 8, wherein said reduced surface is washed with water prior to said exposing step, and wherein said rinsing step is performed at least twice, using a passivating chromate solution at least once, said chromate solution comprising a mixture of about 0.5 g/l. CrO 3 and about 0.5 g/l. Na 2 CrO 4 .
Claim 14
Independent Claim
109 words
A method of treating an oxidized copper surface comprising: reducing said oxidized copper surface with sodium hydrosulfite in the presence of sodium hydroxide and a polymer addition agent selected from the group consisting of glue, gelatin, gum arabica, dextrin, and polyacrylate, washing said reduced surface, exposing said reduced surface to a nonoxidizing reagent selected from the group consisting of dilute hydrochloric acid and a mixture of dilute hydrochloric acid and sodium chloride, and; rinsing said surface at least twice, using a passivating chromate solution at least once, said chromate solution comprising a mixture of about 0.5 g/l. CrO3 and about 0.5 g/l. Na 2 CrO4, and drying said surface.
Claim 15
Independent Claim
109 words
A method of treating an oxidized copper surface comprising: reducing said oxidized copper surface with sodium hydrosulfite in the presence of sodium hydroxide and a polymer addition agent selected from the group consisting of glue, gelatin, gum arabica, dextrin, and polyacrylate, washing said reduced surface, exposing said reduced surface to a nonoxidizing reagent selected from the group consisting of dilute hydrochloric acid and a mixture of dilute hydrochloric acid and sodium chloride, and; rinsing said surface at least twice, using a passivating chromate solution at least once, said chromate solution comprising a mixture of about 0.5 g/l. CrO3 and about 0.5 g/l. Na 2 CrO4, and drying said surface.
Claim 16
Independent Claim
74 words
A method of treating an oxidized copper surface comprising: reducing said oxidized copper surface in alkaline solution with a reducing agent in the presence of a polymer addition agent, exposing said reduced surface to a nonoxidizing reagent which dissolves hydrous cuprous oxide and does not substantially dissolve metallic copper, rinsing said surface at least once and thereafter drying said surface, and depositing a superimposed metallic layer over at least a portion of said surface.
Claim 17
Independent Claim
74 words
A method of treating an oxidized copper surface comprising: reducing said oxidized copper surface in alkaline solution with a reducing agent in the presence of a polymer addition agent, exposing said reduced surface to a nonoxidizing reagent which dissolves hydrous cuprous oxide and does not substantially dissolve metallic copper, rinsing said surface at least once and thereafter drying said surface, and depositing a superimposed metallic layer over at least a portion of said surface.
Claim 18
Dependent Claim
21 words
A method according to claim 14, wherein said metal is selected from the group consisting of copper, nickel, lead, and tin.
Claim 19
Dependent Claim
58 words
A method according to claim 14, wherein said surface is bonded to a resinous laminate, and said surface and laminate are provided with a plurality of through-holes joining said surface to a second surface, and wherein said superimposed metallic layer is deposited over at least the portion of said surface proximate to and in contact with said through-holes.
References Cited (Backward Citations)
US3198672A
Cited
US3990926A
Cited
US3936548A
Cited
JPS56153797A
Cited
US4394419A
Cited
US4503112A
Cited
US4715116A
Cited
US4781991A
Cited
US4549940A
Cited
US4642161A
Cited
US4774122A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-04 | 1994-09-03 | 1995-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-04 | 1998-09-03 | 1999-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-04 | 2002-09-03 | 2003-03-05 | $7700.00 | Window Closed / Lapsed |