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Forming Through Hole Conductor Lines

IP.com Disclosure Number: IPCOM000094126D
Original Publication Date: 1966-Jun-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Rashleigh, C: AUTHOR

Abstract

This method forms conductive lines in holes through printed circuit boards. The method concerns additive methods for depositing connections or windings between opposite faces of single ply or laminated circuit packages or magnetic core matrix structures. This method includes the following steps:

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Forming Through Hole Conductor Lines

This method forms conductive lines in holes through printed circuit boards. The method concerns additive methods for depositing connections or windings between opposite faces of single ply or laminated circuit packages or magnetic core matrix structures. This method includes the following steps:

1) Drilling or punching or molding in shape hole 21 in board 20 which can be made of phenolic composition, epoxy paper or glass, ceramic and the like.

2) Cleaning board 20 and coating it with an adhesive which is allowed to dry.

3) Inserting partitioned plug 28 formed with notches and grooves 29, to fill opening 21. Such occurs except for wall spaces exposed by grooves 29. Plug 28 fits snugly into the adhesive or instead bites into it. The adhesive is scraped off where the arcuate shape matches the shape of the hole.

4) Dipping board 20 in a chemical copper solution which forms a very thin layer of copper on all exposed surfaces.

5) Depositing a thicker electroplated copper layer on all the surfaces rendered conductive by the first thin layer of copper.

6) Screening or photoprinting a resist on the copper face to expose desired land areas and conductor lines.

7) Coating the exposed areas with an acid resistant material such as tin-lead or electroplated precious metal.

8) Removing the resist coating, and etching away of the underlying copper to leave a desired circuit pattern 22...25 or core winding on one or both faces of board 20 thro...