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Phosphite Bath For Magnetic Electrodeposition

IP.com Disclosure Number: IPCOM000096760D
Original Publication Date: 1963-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Sanborn, MA: AUTHOR [+2]

Abstract

In the substitution of sodium phosphite for sodium hypophosphite in baths for magnetic electrodeposition, greater stability and control of bath characteristics are achieved.

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Phosphite Bath For Magnetic Electrodeposition

In the substitution of sodium phosphite for sodium hypophosphite in baths for magnetic electrodeposition, greater stability and control of bath characteristics are achieved.

A typical formulation in which sodium phosphite is used is:

NiCl(2) - 6H(2)O 50 gm/l

CoCl(2) -6H(2)O 20 gm/l

NH(4)Cl or (NH(4)) HC(6)H(5)O(7) 25 gm/l

Na(2)HPO(3) - 5H(2)O 2.5 gm/l

In this formulation, the pH is kept in the range of 4.0 to 4.5, current at 5 amps per square foot and plating time approximately 5 minutes for a 15 to 20 microinch deposit. Magnetically, the deposit has a coercivity of 320 to 400 oersteds, a remanence of about 500 gauss and a squareness of 0.75.

The coercivity of the magnetic deposit can be controlled by changing the pH of the solution. Since pH is easy to control through automatic devices, the formulation lends itself to large scale automatic processing where stability of control can be maintained.

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