Flexible copper clad laminate

Abstract

Provides a flexible copper clad laminate, which includes a polyimide substrate; a nickel-copper alloy layer; and a copper layer. The nickel-copper alloy layer is formed on at least one side of the polyimide substrate by electroless plating and comprises at least nickel, copper and phosphorus. A content of the copper is more than 30 wt % of the nickel-copper alloy layer, a content of the phosphorus is less than 5 wt % of the nickel-copper alloy layer, and a corrosion potential of the nickel-copper alloy layer in a 0.02 vol % sulfuric acid solution is greater than −20 mV. The copper layer is formed on a side of the nickel-copper alloy layer away from the polyimide substrate and combined with the nickel-copper alloy layer to form a metal conductive layer. In addition, the aforementioned flexible copper clad laminate has electrochemical corrosion resistance and sufficient peel strength, facilitating the production of flexible printed circuit boards.

What is claimed is: 
     
         1 . A flexible copper clad laminate, comprising:
 a polyimide substrate;   a nickel-copper alloy layer, formed on at least one side of the polyimide substrate by electroless plating and comprising nickel, copper and phosphorus, wherein a content of the copper is more than 30 wt % and less than 80 wt % of the nickel-copper alloy layer, a content of the phosphorus is less than 5 wt % of the nickel-copper alloy layer, and a corrosion potential of the nickel-copper alloy layer in a 0.02 vol % sulfuric acid solution is greater than −20 mV; and   a copper layer formed on a side of the nickel-copper alloy layer away from the polyimide substrate and combined with the nickel-copper alloy layer to form a metal conductive layer.   
     
     
         2 . The flexible copper clad laminate of  claim 1 , wherein the nickel-copper alloy layer is a single-layer plating. 
     
     
         3 . The flexible copper clad laminate of  claim 1 , wherein the nickel-copper alloy layer further comprises at least one selected from the group consisting of iron, cobalt, molybdenum, tungsten, tin, chromium and zinc. 
     
     
         4 . The flexible copper clad laminate of  claim 1 , wherein the copper layer is formed on the nickel-copper alloy layer by electroplating, and a thickness of the copper layer is 0.2˜20 μm. 
     
     
         5 . The flexible copper clad laminate of  claim 2 , wherein the copper layer is formed on the nickel-copper alloy layer by electroplating, and a thickness of the copper layer is 0.2˜20 μm. 
     
     
         6 . The flexible copper clad laminate of  claim 3 , wherein the copper layer is formed on the nickel-copper alloy layer by electroplating, and a thickness of the copper layer is 0.2˜20 μm. 
     
     
         7 . The flexible copper clad laminate of  claim 1 , wherein a peel strength between the metal conductive layer and the polyimide substrate is greater than or equal to 0.7 kgf/cm. 
     
     
         8 . The flexible copper clad laminate of  claim 2 , wherein a peel strength between the metal conductive layer and the polyimide substrate is greater than or equal to 0.7 kgf/cm. 
     
     
         9 . The flexible copper clad laminate of  claim 3 , wherein a peel strength between the metal conductive layer and the polyimide substrate is greater than or equal to 0.7 kgf/cm. 
     
     
         10 . The flexible copper clad laminate of  claim 4 , wherein a peel strength between the metal conductive layer and the polyimide substrate is greater than or equal to 0.7 kgf/cm. 
     
     
         11 . The flexible copper clad laminate of  claim 5 , wherein a peel strength between the metal conductive layer and the polyimide substrate is greater than or equal to 0.7 kgf/cm. 
     
     
         12 . The flexible copper clad laminate of  claim 6 , wherein a peel strength between the metal conductive layer and the polyimide substrate is greater than or equal to 0.7 kgf/cm.