Browse Prior Art Database

Fabricated of Plated Stripline and Keeper

IP.com Disclosure Number: IPCOM000093797D
Original Publication Date: 1966-Feb-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

McNichol, JJ: AUTHOR

Abstract

In fabricating magnetic film memories it frequently is desirable to provide each word stripline with an individual keeper strip secured to it. This technique enables the word strips and their keepers to be formed by a single plating and etching process.

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Fabricated of Plated Stripline and Keeper

In fabricating magnetic film memories it frequently is desirable to provide each word stripline with an individual keeper strip secured to it. This technique enables the word strips and their keepers to be formed by a single plating and etching process.

To practice this method a commercially available copper-coated sheet of flexible insulating material such as MYLAR is exposed on one side to an etchant. The fatter uniformly reduces the thickness of the copper layer until there is just sufficient copper left to provide a good conductive path for small, direct currents. A copper layer not greater than 0.1 mil thick is preferred.

The etched copper layer then is coated with a suitable photoresist. This is removed in the desired areas by photoetching techniques for selectively exposing the copper in the desired word line pattern. Those copper areas which are free of photoresist then are electroplated with permalloy to the desired thickness thus forming the magnetic keeper strips. At this stage of the process the article appears in cross-section as shown in the extreme left-hand view above.

The next step is to etch out the remaining photoresist between the keeper strips, as indicated in the center drawing. The final step * Trademark of E. I. du Pont de Nemours & Co. consists of removing the copper in the areas between the keeper strips. Thus, there are formed the individual word strips plated with their permalloy keeper strips...