Browse Prior Art Database

Polyimide Underlay for Flat Film Memory Plates

IP.com Disclosure Number: IPCOM000092472D
Original Publication Date: 1966-Nov-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Gendron, MF: AUTHOR [+4]

Abstract

Vastly superior results are achieved by the use of a thin film of polyimide material such as Pyre-M. L.* as the dielectric underlay for flat film memory plates.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Polyimide Underlay for Flat Film Memory Plates

Vastly superior results are achieved by the use of a thin film of polyimide material such as Pyre-M. L.* as the dielectric underlay for flat film memory plates.

Normally, a flat film memory plate comprises a highly polished silver-copper or copper substrate 3'' x 3'' x .080''. Upon this is successively vacuum deposited a 100A thick film of chromium, a 1-2 micron thick film of silicon monoxide, and a 600-800 Angstroms thick film of nickel-iron-copper which is subsequently etched into thousands of bits.

By forming the dielectric underlay of polyimide material rather than silicon monoxide, the following advantages are derived. The polyimide can be applied to rough surfaces, eliminating some polishing operations and the need for a chromium underlay. Application of the polyimide can be by pouring, spinning, spraying or screening and need not be under vacuum resulting in a considerable savings of time. Finally, the polyimide film possesses superior dielectric and thermal expansion characteristics, being stable at ambient temperature and pressure as well as under vacuum at the curing temperature of the nickel-iron- copper film. *Trademark of E. I. du Pont de Nemours & Co.

1