US4842946A
Expired / Lapsed
US
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Method for treating a polyimide surface to improve the adhesion of metal deposited thereon, and articles produced thereby
Assignee: General Electric Co
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Filing: 1987-09-28
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Granted: 1989-06-27
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Expires: 2007-09-28
Abstract
Abstract A method for treating a polyimide surface is disclosed, in which an adhesion-promoting compound such as thiourea contacts the surface prior to the electroless plating of metal thereon. Articles formed by such a method are also disclosed.
Inventors
- 👤 Donald F. Foust
- 👤 William V. Dumas
- 👤 Edward J. Lamby
- 👤 Bradley R. Karas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:01
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/20; C23C18/22; C23C18/26; H; H05; H05K; H05K3/00; H05K3/38; H05K3/389; Y; Y10; Y10S; Y10S205/00; Y10S205/924; Y10S205/926; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678; Y10T428/31681; Y10T428/31725
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
216 words
A method for improving adhesion of a metallization layer on a polyimide surface which comprises the steps of: treatment of the surface with an adhesion-promoting organic double bond-containing compound selected from the group consisting of ##STR5## and salts or hydrates thereof; wherein each X is independently oxygen or sulfur; R 1 and R 2 independently selected from the group consisting of hydrogen, alkyl groups containing about 1 to about 15 carbon atoms, aromatic groups containing about 6 to about 20 atoms, and alkoxy groups containing about 1 to about 10 carbon atoms; R 3 and R 4 are independently selected from the group consisting of R 1 , S - NH 2 , NHR 1 , NHNH 2 and R 1 CO--; R 5 is selected from the group consisting of R 1 , NHR 1 , and S - ; R 6 and R 7 are each independently hydrogen or an alkyl group containing about 1 to 10 carbon atoms; Y is selected from the group consisting of NH, NHNH, --S--S--, alkylene groups containing from 1 to about 10 carbon atoms, and arylene groups containing about 1 to about 20 carbon atoms; and n is 1 or 2; electroless deposition of the metallization layer on the treated surface; and heating of the resulting metallized article.
Claim 2
Independent Claim
216 words
A method for improving adhesion of a metallization layer on a polyimide surface which comprises the steps of: treatment of the surface with an adhesion-promoting organic double bond-containing compound selected from the group consisting of ##STR5## and salts or hydrates thereof; wherein each X is independently oxygen or sulfur; R 1 and R 2 independently selected from the group consisting of hydrogen, alkyl groups containing about 1 to about 15 carbon atoms, aromatic groups containing about 6 to about 20 atoms, and alkoxy groups containing about 1 to about 10 carbon atoms; R 3 and R 4 are independently selected from the group consisting of R 1 , S - NH 2 , NHR 1 , NHNH 2 and R 1 CO--; R 5 is selected from the group consisting of R 1 , NHR 1 , and S - ; R 6 and R 7 are each independently hydrogen or an alkyl group containing about 1 to 10 carbon atoms; Y is selected from the group consisting of NH, NHNH, --S--S--, alkylene groups containing from 1 to about 10 carbon atoms, and arylene groups containing about 1 to about 20 carbon atoms; and n is 1 or 2; electroless deposition of the metallization layer on the treated surface; and heating of the resulting metallized article.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein the metal of the metallization layer is copper.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein R 1 and R 2 are independently selected from the group consisting of hydrogen, lower alkyl groups, lower alkoxy groups, and benzene.
Claim 5
Dependent Claim
61 words
The method of claim 3 wherein R 3 and R 4 are independently selected from the group consisting of lower alkyl groups, NH 2 , NHNH 2 , lower alkylamine groups and CH 3 CO--; R 5 is NHCH 3 or NHCH 2 CH 3 ; and R 6 and R 7 are each independently hydrogen or a lower alkyl group.
Claim 6
Dependent Claim
30 words
The method of claim 4 wherein the adhesion-promoting compound is selected from the group consisting of thiosemicarbazide hydrochloride, 2,4-dithiobiuret, semicarbazide hydrochloride, acetylthiourea, thiourea, acetamide, urea, N,N-dimethylacetamide, thioacetamide, and thiocyanuric acid.
Claim 7
Dependent Claim
11 words
The method of claim 5 wherein the adhesion-promoting compound is thiourea.
Claim 8
Dependent Claim
31 words
The method of claim 1 wherein the adhesion-promoting compound is incorporated into a non-aggressive liquid at a concentration in the range of about 0.1% by weight to about 50% by weight.
Claim 9
Dependent Claim
21 words
The method of claim 7 wherein the liquid containing the adhesion promoter is maintained at a pH less than about 4.5.
Claim 10
Dependent Claim
23 words
The method of claim 7 wherein the liquid containing the adhesion promoter is maintained at a pH of about 6.5 to about 7.5.
Claim 11
Dependent Claim
25 words
The method of claim 7 wherein thiourea as the adhesion promoter is dissolved in water at about 1% by weight to about 20% by weight.
Claim 12
Dependent Claim
40 words
The method of claim 10 wherein the solution of water and thiourea is maintained at a temperature of about 65° C. to about 85° C. and a pH of about 0 to about 11.0 during treatment of the polyimide surface.
Claim 13
Dependent Claim
13 words
The method of claim 11 wherein the pH is less than about 4.5.
Claim 14
Dependent Claim
50 words
The method of claim 1 further comprising the step of preparing the polyimide surface for treatment with the adhesion-promoting organic compound by mild etching, washing with a basic solution, and then treatment with a composition consisting essentially of a mild etching compound and either an alcohol, water, or mixtures thereof.
Claim 15
Dependent Claim
68 words
The method of claim 13 wherein the mild etching compound is selected from the group consisting of concentrated sulfuric acid, dimethylformamide, and N-methyl-2-pyrrolidone; and the basic solution comprises a compound selected from the group consisting of sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, and mixtures thereof, each of which may be dissolved in a solvent selected from the group consisting of water, methanol, ethanol, ethylene glycol, and mixtures thereof.
Claim 16
Dependent Claim
11 words
The method of claim 14 wherein the polyimide contains a filler.
Claim 17
Dependent Claim
47 words
The method of claim 1 wherein the polyimide surface having the metallization layer thereon is heat-treated at a temperature of from about 60° C. to about 170° C. for about 5 minutes to about 120 minutes prior to the deposition of more of the metal by electroplating.
Claim 18
Dependent Claim
33 words
The method of claim 16 wherein the polyimide surface is heat-treated after electroplating, at a temperature of from about 25° C. to about 170° C. for about 15 minutes to about 48 hours.
Claim 19
Dependent Claim
43 words
The method of claim 1 wherein the heating of the article is performed after the deposition of more of the metal by electroplating, at a temperature of from about 25° C. to about 170° C. for about 15 minutes to about 48 hours.
Claim 20
Dependent Claim
28 words
The article produced by treating a polyimide surface according to the method of claim 1, characterized by an adhesive strength of at least about 5.0 pounds per inch.
Claim 21
Dependent Claim
14 words
The article of claim 19 wherein the metal of the metallization layer is copper.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |