Copper foil for high frequency circuit, method of production and apparatus for production of same, and high frequency circuit using copper foil

Abstract

A copper foil reducing transmission loss at a high frequency and excellent in bond strength with a resin substrate, including at least a granular layer and a columnar layer in its thickness direction, the columnar layer being formed on at least one surface of the granular layer forming the copper foil or the granular layer being formed on at least one surface of the columnar layer forming the copper foil, the relation of the thickness A of the granular layer and the thickness B of the columnar layer in the copper foil being preferably A/(A+B)=40 to 99%, a method of production and apparatus for production for the same, and a high frequency circuit using the same.

1 . A copper foil for a high frequency circuit comprising at least one granular layer and columnar layer in a thickness direction.  
     
     
         2 . A copper foil for a high frequency circuit comprising a granular layer forming the copper foil and a columnar layer formed on at least one surface of the same.  
     
     
         3 . A copper foil for a high frequency circuit comprising a columnar layer forming the copper foil and a granular layer formed on at least one surface of the same.  
     
     
         4 . A copper foil for a high frequency circuit as set forth in  claim 2 , wherein the relation between a thickness A of the granular layer forming the copper foil and the thickness B of the columnar layer is A/(A+B)=40 to 99%.  
     
     
         5 . A copper foil for a high frequency circuit as set forth in  claim 3 , wherein the relation between a thickness B of the columnar layer forming the copper foil and the thickness A of the granular layer is A/(A+B)=40 to 99%.  
     
     
         6 . A copper foil for a high frequency circuit as set forth in  claim 1 , wherein at least one surface is roughened.  
     
     
         7 . A copper foil for a high frequency circuit as set forth in  claim 2 , wherein at least one surface is roughened.  
     
     
         8 . A copper foil for a high frequency circuit as set forth in  claim 3 , wherein at least one surface is roughened.  
     
     
         9 . A copper foil for a high frequency circuit as set forth in  claim 4 , wherein at least one surface is roughened.  
     
     
         10 . A copper foil for a high frequency circuit as set forth in  claim 5 , wherein at least one surface is roughened.  
     
     
         11 . A copper foil for a high frequency circuit as set forth in any one of  claims 1  to  10 , wherein at least one surface is subjected to at least one of treating by nickel plating, zinc plating, chrome plating, alloys of the same, chromate treatment, organic rust-prevention treatment, and silane coupling agent treatment.  
     
     
         12 . A method of production of a copper foil for a high frequency circuit comprising immersing and rotating a foil-making drum in an electrolytic tank to form a granular layer on the surface of said foil-making drum, then plating a columnar layer on at least one surface of the same.  
     
     
         13 . A method of production of a copper foil for a high frequency circuit comprised of immersing and rotating a foil-making drum in an electrolytic tank to form a columnar layer on the surface of said foil-making drum, then plating a granular layer on at least one surface of the same.  
     
     
         14 . An apparatus for production for a copper film for a high frequency circuit working a method of production as set forth in  claim 12  or  13  comprising immersing and rotating a foil-making drum in an electrolytic tank for making a granular layer and columnar layer and continuously electrodepositing a granular layer and columnar layer on the foil-making drum.  
     
     
         15 . A high frequency circuit fabricated using a copper foil as set forth in any one of  claims 1  to  10 .  
     
     
         16 . A high frequency circuit fabricated using a copper foil as set forth in  claim 11 .  
     
     
         17 . A high frequency circuit fabricated using a copper foil produced by a method of production as set forth in  claim 12  or  13 .  
     
     
         18 . A high frequency circuit fabricated using a copper foil produced by an apparatus for production as set forth in  claim 14.