Plated through-holes in a printed circuit board
First Claim
1. A process for electroplating a metallic layer on a side wall of a hold formed in a conductor clad board to produce a plated through-hole in a printed circuit board, comprising the steps of:
- coating the side wall of the hole with an excess of fluid ink having predetermined electrically conductive properties and predetermined surface tension and wetting characteristics,removing excess ink from the hole,the predetermined surface tension characteristics of the ink pulling the remaining ink into a relatively thin smooth and uniform film of fluid ink remaining in the hole upon removal of the excess ink,the predetermined wetting characteristics of the ink adhering the film substantially uniformly over the whole surface of the side wall of the hole,changing the ink in the film from a fluid to a substantial solid, andelectroplating a metallic layer on the solid film of ink on the side wall.
3 Assignments
0 Petitions
Accused Products
Abstract
A process of forming plates through-holes in a printed circuit board involves placing a film of fluid ink having electrically conductive properties on a side wall of the hole, curing the film to a solid and electroplating a layer of metal on the conductive ink film. The conductive ink preferably is a composition including conductive particles such as carbon and silver flakes. The ink also preferably includes a thermosetting or radiation curable binder and a thinner. The film of ink is cured before the layer of metal is electroplated thereon. The plated through-hole is protected from the etchant when the conductors are etched by placing a radiation curable putty material into the hole, curing it, and then depositing a layer of resist on top of the cured putty and a conductive sheet clad to the substrate of the circuit board.
101 Citations
14 Claims
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1. A process for electroplating a metallic layer on a side wall of a hold formed in a conductor clad board to produce a plated through-hole in a printed circuit board, comprising the steps of:
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coating the side wall of the hole with an excess of fluid ink having predetermined electrically conductive properties and predetermined surface tension and wetting characteristics, removing excess ink from the hole, the predetermined surface tension characteristics of the ink pulling the remaining ink into a relatively thin smooth and uniform film of fluid ink remaining in the hole upon removal of the excess ink, the predetermined wetting characteristics of the ink adhering the film substantially uniformly over the whole surface of the side wall of the hole, changing the ink in the film from a fluid to a substantial solid, and electroplating a metallic layer on the solid film of ink on the side wall. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 14)
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12. A process for electroplating a metallic layer on a side wall of a hole formed in a conductor clad board to produce a plated through-hole in a printed circuit board, comprising the steps of:
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coating the side wall of the hole with a predetermined fluid ink having electrically conductive properties, removing any excess ink to leave a film of fluid ink adhering to the side wall of the hole, changing the ink in the film from a fluid to a substantial solid, electroplating a metallic layer on the solid film of ink on the side wall, filling holes with a radiation curable putty after the layer of metal has been electroplated on the side wall of the hole, and curing the putty by exposing it to radiation to create a hole plug. - View Dependent Claims (13)
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Specification