Patent US5137618A successfully refreshed from Google Patents.
US5137618A
Expired / Lapsed
US
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Methods for manufacture of multilayer circuit boards
Assignee: Vencore Services and Solutions Inc
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Filing: 1991-06-07
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Granted: 1992-08-11
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Expires: 2011-06-07
Abstract
Abstract The invention is for the formation of multilayer circuit boards where layers are formed sequentially using selective plating techniques and imaging of dielectric materials to achieve fine line resolution and interconnections between circuits. The invention permits the sequential formation of multilayers of higher density using imaging techniques. The method may also be used in single-sided and double-sided circuit board fabrication and for inner layers used in multilayer circuit boards.
Inventors
- 👤 James M. Burnett
- 👤 Richard J. Mathisen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:06
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/10; H05K3/18; H05K3/181; H05K3/182; H05K3/184; H05K3/46; H05K3/4644; H05K3/4661; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/09563; H05K2203/00; H05K2203/05; H05K2203/0562; H05K2203/0565; H05K3/0011; H05K3/0017; H05K3/0023; H05K3/0026; H05K3/0032; H05K3/465
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
155 words
A process for the formation of a circuit board having two or more layers of circuitry, said process comprising the steps of applying a permanent dielectric coating over a substrate, said permanent dielectric coating having imaged openings defining interconnections, selectively plating metal into said imaged openings to form interconnections, applying a sacrificial coating over the layer comprising the permanent dielectric coating and metallized interconnections, said sacrificial coating having imaged openings defining a circuit pattern, catalyzing surfaces of underlying material where bared and the surfaces of said sacrificial coating with an electroless plating catalyst, replacing said sacrificial coating with a second coating having imaged openings corresponding to those formed in the sacrificial coating, and electrolessly plating metal into said openings for interconnections in said dielectric coating and onto catalyzed surfaces, whereby, when plated, there is formed a second circuit in electrical contact with said first substrate, and whereby areas between circuit lines are free of catalyst.
Claim 2
Dependent Claim
155 words
A process for the formation of a circuit board having two or more layers of circuitry, said process comprising the steps of applying a permanent dielectric coating over a substrate, said permanent dielectric coating having imaged openings defining interconnections, selectively plating metal into said imaged openings to form interconnections, applying a sacrificial coating over the layer comprising the permanent dielectric coating and metallized interconnections, said sacrificial coating having imaged openings defining a circuit pattern, catalyzing surfaces of underlying material where bared and the surfaces of said sacrificial coating with an electroless plating catalyst, replacing said sacrificial coating with a second coating having imaged openings corresponding to those formed in the sacrificial coating, and electrolessly plating metal into said openings for interconnections in said dielectric coating and onto catalyzed surfaces, whereby, when plated, there is formed a second circuit in electrical contact with said first substrate, and whereby areas between circuit lines are free of catalyst.
Claim 3
Dependent Claim
12 words
The process of claim 1 where the substrate is a circuit board.
Claim 4
Dependent Claim
17 words
The process of claim 1 where the substrate is a ground plane over a non conducting substrate.
Claim 5
Dependent Claim
12 words
The process of claim 3 where interconnections are formed by electrolytic deposition.
Claim 6
Dependent Claim
17 words
The process of claim 4 including a step of activating underlying copper prior to electrolytic metal deposition.
Claim 7
Dependent Claim
12 words
The process of claim 1 where interconnections are formed by electroless deposition.
Claim 8
Dependent Claim
15 words
The process of claim 1 where said sacrificial coating is applied as a dry film.
Claim 9
Dependent Claim
16 words
The process of claim 1 where said sacrificial coating is applied as a liquid coating composition.
Claim 10
Dependent Claim
15 words
The process of claim 1 where said sacrificial coating is chemically resistant to catalysis chemicals.
Claim 11
Dependent Claim
15 words
The process of claim 14 where said sacrificial coating is developable in weak base solution.
Claim 12
Dependent Claim
14 words
The process of claim 1 where said sacrificial coating is developable in solvent solution.
Claim 13
Dependent Claim
14 words
The process of claim 1 where said sacrificial coating is strippable in base solution.
Claim 14
Dependent Claim
14 words
The process of claim 1 where said sacrificial coating is strippable in solvent solution.
Claim 15
Dependent Claim
15 words
The process of claim 1 where said electroless plating catalyst is a colloidal metal catalyst.
Claim 16
Dependent Claim
14 words
The process of claim 14 where said colloidal metal catalyst is a palladium catalyst.
Claim 17
Dependent Claim
14 words
The process of claim 1 where said second coating is a second permanent dielectric.
Claim 18
Dependent Claim
14 words
The process of claim 1 where said second coating is a second sacrificial coating.
Claim 19
Dependent Claim
16 words
The process of claim 17 where said second sacrificial coating is replaced with a permanent dielectric.
Claim 20
Dependent Claim
21 words
The process of claims 1 or 16 where said permanent dielectric coating has a dielectric constant that does not exceed 4.5.
Claim 21
Dependent Claim
13 words
The process of claim 19 where said dielectric constant does not exceed 3.5.
Claim 22
Dependent Claim
11 words
The process of claim 1 where said deposited metal is copper.
Claim 23
Dependent Claim
34 words
The process of claims 1 or 16 where said permanent dielectric is selected from the group consisting of epoxies, polyamines, polyimides, cyanate esters, benzocyclobutene, acetylene terminated biphenols and liquid crystalline polymers, or mixtures thereof.
Claim 24
Dependent Claim
13 words
The process of claim 22 where said permanent dielectric contains a reinforcing agent.
Claim 25
Dependent Claim
21 words
The process of claim 23 where said reinforcing agent is selected from the group consisting of glass, quartz, polyaramid and polyamide.
Claim 26
Dependent Claim
29 words
The process of claim 1 where imaged openings in said dielectric coatings are formed by exposure of the same to actinic radiation followed by development in a liquid developer.
Claim 27
Dependent Claim
29 words
The process of claim 1 where imaged openings in said sacrificial coating are formed by exposure of the same to actinic radiation followed by development in a liquid developer.
Claim 28
Dependent Claim
29 words
The process of claim 1 where imaged openings in said second coating are formed by exposure of the same to actinic radiation followed by development in a liquid developer.
Claim 29
Dependent Claim
17 words
The process of claim 1 where imaged openings in said dielectric coatings are formed by laser ablation.
Claim 30
Dependent Claim
17 words
The process of claim 1 where imaged openings in said sacrificial coating are formed by laser ablation.
Claim 31
Dependent Claim
17 words
The process of claim 1 where imaged openings in said second coating are formed by laser ablation.
Claim 32
Dependent Claim
11 words
An article of manufacture formed by the process of claim 1.
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) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |