Browse Prior Art Database

Flush Printed Circuits

IP.com Disclosure Number: IPCOM000098875D
Original Publication Date: 1958-Aug-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Miles, ED: AUTHOR

Abstract

Flush printed circuits may be fabricated in a manner such that the circuitry will not become distorted during the flushing operation. The individual elements comprising the circuitry are not separated until after the composite circuitry is embedded in an insulating base.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Flush Printed Circuits

Flush printed circuits may be fabricated in a manner such that the circuitry will not become distorted during the flushing operation. The individual elements comprising the circuitry are not separated until after the composite circuitry is embedded in an insulating base.

A photosensitive emulsion resistive to an etching solution is applied to a sheet of copper or other suitable metal and then exposed to a light source through a negative of the circuit desired. Upon development, the area between the circuitry is exposed metal. The area of the copper not covered by the resistive emulsion is etched to a predetermined depth as shown above, whereby the individual circuit elements remain unseparated. The resistive emulsion is removed and the copper sheet is then placed upon an uncured phenolic board with the circuitry contacting the same. Pressure applied to the copper sheet embeds the circuit elements into the phenolic board. The copper sheet is then ground or etched until the circuit elements are separated and flush or coplanar with the surface of the board. The phenolic board is then cured.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]