公开(公告)号：US3702263A

公开(公告)日：1972-11-07

申请号：US3702263D

申请日：1970-02-20

Applicant: IBM

Inventor： HALL DAVID W ,  LINDHOLM JOHN A ,  ROMANKIW LUBOMYR T ,  SCHMECKENBECHER AINOLD F

IPC: C23C18/36 ,  C23C18/50 ,  H01F41/24 ,  H01F10/00

CPC classification number: H01F41/24 ,  C23C18/36 ,  C23C18/50 ,  Y10S428/928 ,  Y10S428/936 ,  Y10T428/12979

Abstract: A PROCESS FOR ELECTROLESSLY PLATING SUBSTRATES WITH THIN FILMS OF MAGNETIC MATERIAL WHICH IS CARRIED OUT IN A TEMPERATURE RANGE WHICH INCLUDES ROOM TEMPERATURE. THE PROCESS INCLUDES THE IMMERSION OF SUBSTRATE IN AN AQUEOUS SOLUTION WHICH CONTAINS IRON IONS AND AT LEAST ANOTHER METAL ION SUCH AS NICKEL, WHICH UPON DEPOSITION FORM THE MAGNETIC MATERIAL. A REDUCING AGENT SUCH AS SODIUM HYPOPHOSPHITE IS PROVIDED IN THE BATH IN AN AMOUNT SUFFICIENT TO CAUSE DEPOSITION OF THE METALS IN SMALL GRAIN SIZES. SUFFICIENT HYDROXYL IONS ARE ALSO PROVIDED TO MAINTAIN THE BATH IN CONDITIONS WHICH RANGE FROM SLIGHTLY ACIDIC TO HIGHLY ALKALINE. THE BATH IS THEN MAINTAINED IN A TEMPERATURE RANGE WHICH INCLUDES ROOM TEMPERATURE OVER WHICH RANGE THIN FILMS HAVING A CHARACTERISTIC SILVERY FINISH INDICATIVE OF SMALL GRAIN SIZE ARE PRODUCED. THE PROCESS ALSO INCLUDES THE STEP OF AGING A FERROUS BATH FOR A PERIOD OF TIME SUFFICIENT TO CONVERT THE FERROUS IONS TO STABILIZE THE BATH. THE ABOVE-MENTIONED CONSTITUENTS AND OTHER COMPLEXING AND BUFFERING AGENTS WHICH PREVENT THE PRECIPITATION OF THE METALS FROM SOLUTION ARE PRESENT IN THE SOLUTION IN SELECTED CONCENTRATIONS WHICH PERMIT THE PLATING OF SMALL GRAIN SIZE MAGNETIC FILMS AT LOW TEMPERATURE.