Claims
- 1. A method for the formation of a circuit board having two or more layers of circuitry, said method comprising the steps of applying a permanent dielectric coating over a first circuit layer having imaged openings defining interconnections, catalyzing the surface of the permanent dielectric coating and the imaged openings by contact with an electroless plating catalyst, applying a coating over said catalyzed permanent dielectric coating, said coating having imaged openings defining a circuit pattern, and electrolessly plating metal into said openings for interconnections and circuitry whereby, when plated, there is formed a second circuit in electrical contact with said first circuit.
- 2. The method of claim 1 where the electroless plating catalyst is a colloidal metal catalyst applied to a particulate free surface.
- 3. The method of claim 2 where the imaged openings are formed by exposure through a mask and wet development.
- 4. The method of claim 2 where the imaged openings are formed by laser ablation.
- 5. The method of claim 2 where the colloidal metal catalyst is a palladium catalyst.
- 6. The method of claim 2 where the permanent dielectric coating has a dielectric constant that does not exceed 4.5.
- 7. The method of claim 6 where the dielectric constant does not exceed 3.5.
- 8. The method of claim 2 where the deposited metal is copper.
- 9. The method of claim 2 where the permanent dielectric is a member selected from the group of epoxies and polyamines.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of copending application(s) Ser. No. 07/462,607 filed on Jan. 9, 1990 now U.S. Pat. No. 5,246,817 which application is a continuation-in-part of U.S. patent application Ser. No. 07/054,102, filed May 20, 1987 now U.S. Pat. No. 4,902,610 which latter application is a continuation of U.S. patent application Ser. No. 06/761,843, filed Aug. 2, 1985 now abandoned.
US Referenced Citations (11)
Continuations (2)
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Date |
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Parent |
462607 |
Jan 1990 |
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Parent |
761843 |
Aug 1985 |
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Continuation in Parts (1)
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Number |
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54102 |
May 1987 |
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