Copper Foil for Printed Circuit Board and Copper Clad Laminate for Printed Circuit Board

Abstract

A copper foil for a printed circuit board is provided. The copper foil includes a layer including nickel, zinc, a compound of nickel and that of zinc (hereinafter referred to as a “nickel zinc layer”) on a roughened surface of a copper foil and a chromate film layer on the nickel zinc layer. The zinc add-on weight per unit area of the nickel zinc layer is 180 μg/dm 2 or more and 3500 μg/dm 2 or less, and the nickel weight ratio in the nickel zinc layer {nickel add-on weight/(nickel add-on weight+zinc add-on weight)} is 0.38 or more and 0.7 or less. This surface treatment technology of a copper foil is able to effectively prevent the circuit corrosion phenomenon in cases of laminating a copper foil on a resin base material and using a sulfuric acid hydrogen peroxide etching solution to perform soft etching to the circuit.

1 . A copper foil for a printed circuit board comprising a nickel-zinc layer including nickel, zinc, at least one of an oxide and a hydroxide of nickel, and at least one of an oxide and a hydroxide of zinc on a roughened surface of a copper foil, and a chromate film layer on the nickel-zinc layer, wherein a zinc add-on weight of the nickel-zinc layer per unit area of the copper foil is 180 μg/dm 2  or more and 3500 μg/dm 2  or less, and a nickel weight ratio in the nickel-zinc layer {nickel add-on weight per unit area/(nickel add-on weight per unit area+zinc add-on weight per unit area)} is 0.38 or more and 0.7 or less. 
     
     
         2 . The copper foil for a printed circuit board according to  claim 1 , wherein the {nickel add-on weight per unit area/(nickel add-on weight per unit area+zinc add-on weight per unit area)} is 0.4 or more and 0.55 or less. 
     
     
         3 . The copper foil for a printed circuit board according to  claim 2 , wherein a chromium add-on weight of the chromate film layer per unit area of the copper foil is 30 μg/dm 2  or more and 100 μg/dm 2  or less. 
     
     
         4 . The copper foil for a printed circuit board according to  claim 3 , further comprising a silane coupling agent layer on the chromate film layer. 
     
     
         5 . The copper foil for a printed circuit board according to  claim 4 , wherein the copper foil is an electrolytic copper foil, and the roughened surface is a rough face obtained during electrolytic plating, a face obtained by additionally performing roughening treatment to the rough face, or a face obtained by performing roughening treatment on a gloss surface of an electrolytic copper foil. 
     
     
         6 . The copper foil for a printed circuit board according to  claim 4 , wherein the copper foil is a rolled copper foil and the roughened surface is a face obtained by performing roughening treatment to the rolled copper foil. 
     
     
         7 . A copper clad laminate for a printed circuit board produced by laminating the copper foil for a printed circuit board according to  claim 4 , and a resin for a printed circuit board. 
     
     
         8 . A copper foil for a printed circuit board according to  claim 1 , wherein chromium add-on weight of the chromate film layer per unit area of the copper foil is 30 μg/dm 2  or more and 100 μg/dm 2  or less. 
     
     
         9 . A copper foil for a printed circuit board according to  claim 1 , further comprising a silane coupling agent layer on the chromate film layer. 
     
     
         10 . A copper foil for a printed circuit board according to  claim 1 , wherein the copper foil is an electrolytic copper foil, and the roughened surface is a rough face obtained during electrolytic plating, a face obtained by additionally performing roughening treatment to the rough face, or a face obtained by performing roughening treatment on a gloss surface of an electrolytic copper foil. 
     
     
         11 . A copper foil for a printed circuit board according to  claim 1 , wherein the copper foil is a rolled copper foil and the roughened surface is a face obtained by performing roughening treatment to the rolled copper foil. 
     
     
         12 . A copper clad laminate for a printed circuit board produced by laminating the copper foil for a printed circuit board according to  claim 1 , and a resin for a printed circuit board.