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Process For Making Thin Metallic Films

IP.com Disclosure Number: IPCOM000098303D
Original Publication Date: 1960-Jul-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Eggenberger, JS: AUTHOR

Abstract

A method of making thin metallic film capable of nondestructive read out interrogation consists of electroplating a nickel iron alloy onto a substrate for a period of at least ten seconds, and preferably ten minutes, at a current density of 60-120 milliamperes per square inch.

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Process For Making Thin Metallic Films

A method of making thin metallic film capable of nondestructive read out interrogation consists of electroplating a nickel iron alloy onto a substrate for a period of at least ten seconds, and preferably ten minutes, at a current density of 60-120 milliamperes per square inch.

An interrogation alloy film 10 is plated onto a substrate 11 having a conducting surface. A storage film 12 is plated over the film 10. Film 10 is of low coercive force whereas film 12 exhibits a relatively high coercive force.

A suitable plating bath is as follows:

218 grams/liter NiSO(4). 6H(2)O

3.4 grams/liter FeSO(4). 7H(2)O

25.0 grams/liter H(3)BO(3)

0.41 grams/liter sodium lauryl sulfate

0.84 grams/liter saccharin

The anode may be nickel and the cathode a substrate of glass covered with a thin conducting layer of copper. The plating bath is preferably maintained without stirring. The current density should be 60 to 120 milliamperes per square inch at
1.1 to 1.3 volts. Within this range, the two film layers are formed, the interrogation layer 10 being richer in iron (84% Ni-16% Fe) with a coercive force, Hc, of 0.4 oersteds. The storage layer 12 has less iron (89% Ni-11% Fe) with a coercive force of about ten oersteds.

Plating for at least ten seconds is required for the second layer to form. After ten minutes of plating, a film having an interrogation layer about 400 A degrees thick and a storage layer about 3000 A degrees thick is produced.

The...