Electrolytic copper coating, method of manufacturing the same, and copper electrolyte for manufacturing electrolytic copper coating

Abstract

An object of the present invention is to provide an electrolytic copper coating that exhibits a bendability and flexibility equal to or better than those of rolled copper foil after the heat history in a circuit board fabrication process, especially after a heat history equivalent to the heat history applied when bonding with a polyimide film. The present invention provides an electrolytic copper coating and a method of manufacturing the same wherein, when performing heat treatment so that the LMP value shown in Equation 1 becomes 9000 or more, the result becomes a crystal distribution of crystal grains, having a maximum length of crystal grains after heat treatment of 10 μm or more, of 70% or more: LMP=( T +273)*(20+Log t )  Equation 1 where, 20 is a material constant of copper, T is temperature (° C.), and t is time (hr).

1 . An electrolytic copper coating produced by electrolytic deposition, wherein, when performing heat treatment so that the LMP (Larson-Miller parameter) value shown in Equation 1 becomes 9000 or more, the result becomes a crystal distribution of crystal grains, having a maximum length of crystal grains after heat treatment of 10 μm or more, of 70% or more:
   LMP=( T+ 273)*(20+Log  t )  Equation 1
 
 where, 20 is a material constant of copper, T is temperature (° C.), and t is time (hr). 
 
     
     
         2 . The electrolytic copper coating according to  claim 1 , wherein when the electrolytic copper coating is heat treated to give an LMP value of 9000 or more, the 0.2% proof stress of the electrolytic copper coating is less than 10 kN/cm 2 , and the Young's modulus is less than 2000 kN/cm 2 . 
     
     
         3 . The electrolytic copper coating according to  claim 1 , wherein when the electrolytic copper coating is heat treated to give an LMP value of 9000 or more, the Vickers hardness of the electrolytic copper coating is less than 60 Hv. 
     
     
         4 . The electrolytic copper coating according to any one of  claims 1  to  3 , wherein the electrolytic copper coating, in SIMS (secondary ion mass spectrometry) analysis in the copper coating depth direction, in terms of the strength ratio with the copper (Cu), has a content of chlorine (Cl) of less than 0.5%, a content of nitrogen (N) of less than 0.005%, and a content of sulfur (S) of less than 0.005%. 
     
     
         5 . The electrolytic copper coating according to any one of  claims 1  to  4 , wherein a roughness of at least one surface of the electrolytic copper coating is less than 0.30 μm in terms of Ra and less than 2.0 μm in terms of Rz. 
     
     
         6 . A method of manufacturing an electrolytic copper coating produced by electrolytic deposition using a copper electrolyte, wherein, when performing heat treatment so that the LMP value shown in Equation 1 becomes 9000 or more, the result becomes a crystal distribution of crystal grains, having a maximum length of crystal grains after heat treatment of 10 μm or more, of 70% or more.
   LMP=( T+ 273)*(20+Log  t )  Equation 1
 
 where, 20 is a material constant of copper, T is temperature (° C.), and t is time (hr). 
 
     
     
         7 . The method of manufacturing the electrolytic copper coating according to  claim 6 , wherein the copper electrolyte contains at least one type of reaction product of at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound, at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds, or a combination of at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound and at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds with a heterocyclic compound which has two nitrogen atoms. 
     
     
         8 . The method of manufacturing the electrolytic copper coating according to  claim 6  or  7 , wherein the copper electrolyte contains at least one type of reaction product of at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound, at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds, or a combination of at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound and at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds with a heterocyclic compound which has two nitrogen atoms and contains at least one type of brightener. 
     
     
         9 . The method of manufacturing the electrolytic copper coating according to any one of  claims 6  to  8 , wherein the heterocyclic compound which has two nitrogen atoms is a heterocyclic aromatic compound which has two nitrogen atoms. 
     
     
         10 . A copper electrolyte for manufacturing an electrolytic copper coating, containing at least one type of reaction product of a di- or poly-halogenated chain saturated aliphatic hydrocarbon compound or a di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds with a heterocyclic compound which has two nitrogen atoms and contains at least one type of brightener. 
     
     
         11 . A copper electrolyte for manufacturing an electrolytic copper coating, containing at least one type of reaction product of at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound, at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds, or a combination of at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound and at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds with a heterocyclic compound which has two nitrogen atoms. 
     
     
         12 . A copper electrolyte for manufacturing an electrolytic copper coating, containing at least one type of reaction product of at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound, at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds, or a combination of at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound and at least one type of di- or poly-halogenated chain saturated aliphatic hydrocarbon compound which has one or more ether bonds with a heterocyclic compound which has two nitrogen atoms and contains at least one type of brightener.