DEVICE FOR PROLONGING LIFETIME OF ELECTROLESS NICKEL-PLATING LIQUID

摘要

PROBLEM TO BE SOLVED: To provide a device for prolonging the lifetime of an electroless nickel-plating liquid capable of reducing the amount of a waste liquid and reducing losses of raw material components by increasing the use frequency of continuous circulation of an electroless Ni plating liquid.;SOLUTION: A first negative ion exchange membrane 4 which permeates hypophosphite ions, phosphite ions, and SO₄^2- but does not permeate organic acid ions, and a first positive ion exchange membrane 5 which permeates Na+ but does not permeate Ni²⁺ are alternately arranged in a first electrodialysis unit 1 connected to a Ni plating liquid tank 21. A second negative ion exchange membrane 14 which permeates hypophosphite ions and organic acid ions but does not permeate phosphate ions and SO₄^2- and a second positive ion exchange membrane which permeates H⁺ but does not permeate Ni²⁺ are alternately arranged in a second electrodialysis unit 11 connected to its first concentration chamber 7. A second concentration chamber 17 is connected to the Ni plating liquid tank 21.;COPYRIGHT: (C)2008,JPO&INPIT