Browse Prior Art Database

Additive Plating Method

IP.com Disclosure Number: IPCOM000093747D
Original Publication Date: 1966-Feb-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Piggin, BP: AUTHOR

Abstract

When printed circuits are manufactured by an additive type-process by contact plating through a mask having the circuit configuration the anode is also covered by a mask having roughly the same configuration. Such arrangement maintains an approximately uniform ratio of exposed anode to exposed cathode area.

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

Additive Plating Method

When printed circuits are manufactured by an additive type-process by contact plating through a mask having the circuit configuration the anode is also covered by a mask having roughly the same configuration. Such arrangement maintains an approximately uniform ratio of exposed anode to exposed cathode area.

Tank 1 contains electrolyte such as an acid copper sulfate solution. Copper anode 2 is immersed in the electrolyte and connected to the positive of a DC power supply. The negative is connected to metallized surface 3 of flexible insulating substrate 4 metallized with evaporated copper which acts as a cathode. Between anode 2 and cathode 3 is disposed porous plate 5 on either side of which are masks 6 and 7. Mask 6 has openings in the desired circuit configuration and is adjacent cathode 3. Mask 7 has larger openings in approximately the same configuration and is adjacent anode 2. By a suitable selection of shapes of the openings in mask 7, the ratio of exposed anode 2 area to exposed cathode 3 area is made approximately uniform.

In use electrolyte is caused to move through porous plate 5 and the openings in masks 6 and 7. This causes plating on surface 3 when DC power is applied. Despite varying areas to be plated in different regions on surface 3 approximately uniform thickness plating is achieved.

1

Page 2 of 2

2

[This page contains 1 picture or other non-text object]