US4127438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adhesion promoter for additively plated printed circuit boards
Assignee: International Business Machines Corp
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Filing: 1977-11-07
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Granted: 1978-11-28
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Expires: 1997-11-07
Abstract
Abstract Subsequent to the additive plating of copper circuitry on a substrate and prior to further steps such as lamination to form a multilayer printed circuit board, a sequence of etching and cleaning steps are used to improve the lamination strength of the additively plated copper. The circuitized substrate is dipped in an etchant bath and then baked at an elevated temperature for 2-4 hours. Following this the circuitized substrate is washed with an organic cleaner, water rinsed and air dried. Thereafter a chlorite oxide layer is added to the circuitized substrate and it is ready for further processing.
Inventors
- 👤 Thomas C. Babcock
- 👤 Theron LaR. Ellis
- 👤 Henry C. Majka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:25
CPC Classifications
C; C23; C23G; C23G5/00; C23G5/02; H; H05; H05K; H05K3/00; H05K3/38; H05K3/382; H05K3/383; H05K3/385; H05K2203/00; H05K2203/03; H05K2203/0315; H05K2203/0392; H05K2203/11; H05K2203/1105; H05K3/46; H05K3/4611
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
81 words
A method for treating a circuitized substrate wherein the circuitized substrate is made by additively plating copper on the substrate, to prepare the circuitized substrate for oxidation and subsequent lamination into a multilayer printed circuit board, comprising the steps of: dipping the circuitized substrate in an etching bath; baking the circuitized substrate at a temperature between 135° C. and 170° C.; cleaning the surface of said circuitized substrate with an organic cleaner; rinsing said circuitized substrate; and drying said circuitized substrate.
Claim 2
Independent Claim
81 words
A method for treating a circuitized substrate wherein the circuitized substrate is made by additively plating copper on the substrate, to prepare the circuitized substrate for oxidation and subsequent lamination into a multilayer printed circuit board, comprising the steps of: dipping the circuitized substrate in an etching bath; baking the circuitized substrate at a temperature between 135° C. and 170° C.; cleaning the surface of said circuitized substrate with an organic cleaner; rinsing said circuitized substrate; and drying said circuitized substrate.
Claim 3
Dependent Claim
17 words
The invention according to claim 1 wherein said circuitized substrate is baked for 2 to 4 hours.
Claim 4
Dependent Claim
24 words
The invention according to claim 1 wherein said etching solution is chosen from the group consisting of cupric chloride, ferric chloride and sodium persulfate.
Claim 5
Dependent Claim
27 words
The invention according to claim 1 wherein said etching bath is a solution comprising between 30 grams per liter and 120 grams per liter of sodium persulfate.
Claim 6
Dependent Claim
25 words
The invention according to claim 4 wherein said circuitized substrate is dipped in said etching bath for a time between 1 minute and 15 seconds.
Claim 7
Dependent Claim
27 words
The invention according to claim 1 wherein said organic cleaner comprises about 15% potassium hydroxide, about 15% propylene glycol, about 55% methyl carbitol and the remainder water.
Claim 8
Dependent Claim
24 words
The invention according to claim 6 wherein said circuitized substrate is cleaned by dipping in said organic cleaner for 2 minutes ± 10 seconds.
Claim 9
Dependent Claim
29 words
The invention according to claim 1 wherein said organic cleaner comprises about 40% methylene chloride, about 35% wetting agents and the remainder a combination of oxalic acid and methanol.
Claim 10
Dependent Claim
21 words
The invention according to claim 8 wherein said circuitized substrate is cleaned by dipping in said organic cleaner for 2-5 minutes.
Claim 11
Dependent Claim
60 words
The invention according to claim 1 wherein the step of rinsing said circuitized substrate comprises: subjecting said circuitized substrate to 2 consecutive hot water rinses, each lasting about 30 seconds; dipping said circuitized substrate in a 25% hydrochloric acid solution for about 30 second; and, rinsing said circuitized substrate in 2 consecutive distilled water baths, each lasting about 1 minute.
Claim 12
Independent Claim
101 words
A method for treating a circuitized substrate, wherein said circuitized substrate is made by additively plating copper on the substrate, to prepare the circuitized substrate for oxidation and subsequent lamination into a multilayer printed circuit board, comprising the steps of: dipping the circuitized substrate in an etching solution consisting of 30-120 grams per liter of sodium persulfate for a time of 1 minute to 15 seconds; baking the circuitized substrate for about 2 hours at a temperature of 135° C. ± 5° C.; cleaning the surface of said circuitized substrate with an organic cleaner; and, rinsing and drying said circuitized substrate.
Claim 13
Independent Claim
101 words
A method for treating a circuitized substrate, wherein said circuitized substrate is made by additively plating copper on the substrate, to prepare the circuitized substrate for oxidation and subsequent lamination into a multilayer printed circuit board, comprising the steps of: dipping the circuitized substrate in an etching solution consisting of 30-120 grams per liter of sodium persulfate for a time of 1 minute to 15 seconds; baking the circuitized substrate for about 2 hours at a temperature of 135° C. ± 5° C.; cleaning the surface of said circuitized substrate with an organic cleaner; and, rinsing and drying said circuitized substrate.
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) | 1981-11-27 | 1982-05-29 | 1982-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-27 | 1986-05-29 | 1986-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-27 | 1990-05-29 | 1990-11-28 | $7700.00 | Window Closed / Lapsed |