GB1052646A - - Google Patents

Abstract

1,052,646. Coating with metals. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 22, 1965 [March 23, 1964], No.12001/65. Heading C7F. An aqueous solution for electrolessly depositing a Ni-Fe-P alloy, having a pH greater than 8, comprises Ni, Fe, hypophosphite and hydroxyl ions and Na K tartrate or other complexing agent. The solution may also contain divalent Co, Mo and Cr ions; surfactants e.g. Na lauryl sulphate; exatants, e.g. succinic acid, adipic anions or alkali fluorides; stabilizers e.g. thiourea, Na ethylxanthate or PbSO 4 and pH regulators e.g. boric acid or disodium phosphate. Ni and Fe salts may be sulphates, chlorides, acetates, sulphates and ferrous ammonium sulphate. Hypophosphite ions may be from hypophosphorous acid or its Na and K salts. Hydroxyl ions may be from Na, K, Li or NH4 hydroxide. Complexing agents may contain primary, secondary or tertiary amino, imino, carboxy or hydroxy groups and are preferably Rochelle or Seignette salt, NH 4 Cl and related polyamines and N-carboxymethyl derivatives. The substrate may be mechanically cleaned and degreased and if copper cleaned with HCl and activated in Pd Cl 2 before immersing in a constant temperature bath covered with xylene to prevent oxidation. Plating may take place in a magnetic field provided by a Helmhotz coil. Substrates include Cu, Ni, Co, Fe, Al, Zn, Pt, Pd, Mn, Cr, Mo, W, Ti, Sb, Ag, brass and carbon. The coated substrate may be a thin film storage device as described in Specification 1,052,647.