Electrolytic plating equipment and electrolytic plating method

Abstract

An electrolytic plating equipment includes: a plating tank for holding plating solution; and a separate tank apart from the plating tank, for holding the plating solution circulating between the plating tank and the separate tank. The separate tank contains a first space and a second space located downstream from the first space. The plating solution in the first space in an amount exceeding a specific height flows from the first space into the second space, and the plating solution falls through air in the second space.

What is claimed is: 
     
         1 . An electrolytic plating equipment comprising:
 a plating tank for holding plating solution; and   a separate tank apart from the plating tank, for holding the plating solution circulating between the plating tank and the separate tank, wherein   the separate tank has therein a first space and a second space located downstream from the first space, and has a structure in which the plating solution in the first space in an amount exceeding a specific height flows from the first space into the second space, and the plating solution falls through air in the second space.   
     
     
         2 . The electrolytic plating equipment according to  claim 1 , wherein the separate tank has a partition extending vertically so as to divide the separate tank into the first space and the second space, and has a structure in which the plating solution in the first space overflows an upper edge located at the specific height on the partition to flow into the second space. 
     
     
         3 . The electrolytic plating equipment according to  claim 1 , wherein
 the separate tank has a partition extending vertically so as to divide the separate tank into the first space and the second space,   the partition has a through hole located at the specific height, and   the separate tank has a structure in which the plating solution in the first space passes through the through hole to flow into the second space.   
     
     
         4 . The electrolytic plating equipment according to  claim 2 , wherein the upper edge of the partition has a extending portion extending towards the second space, and the extending portion has an end separated from the side surface of the partition. 
     
     
         5 . The electrolytic plating equipment according to  claim 4 , wherein the extending portion has a lateral part extending laterally towards the second space and a lower part extending downwards from a lateral end of the lateral part, and the end of the extending portion is a lower end of the lower part, the lower end is separated from the side surface of the partition. 
     
     
         6 . The electrolytic plating equipment according to  claim 1 , further comprising a source pipe for sending the plating solution from the plating tank to the separate tank, wherein the source pipe has a supply port for supplying the plating solution to the first space, and the supply port is located below the specific height. 
     
     
         7 . The electrolytic plating equipment according to  claim 6 , wherein the plating solution is discharged from the supply port towards the inner side of the separate tank. 
     
     
         8 . The electrolytic plating equipment according to  claim 1 , further comprising a source pipe for sending the plating solution from the plating tank to the separate tank, wherein
 the separate tank has a first partition extending vertically so as to divide the separate tank into the first space and the second space and a second partition extending vertically so as to divide the interior of the first space into a settling space for settling metal particles in the plating solution and a supply space located upstream from the settling space for holding the plating solution supplied from the supply port of the source pipe.   
     
     
         9 . The electrolytic plating equipment according to  claim 8 , wherein the second partition has a plurality of communicating holes provided below the specific height for communicating between the settling space and the supply space. 
     
     
         10 . The electrolytic plating equipment according to  claim 8 , wherein the upper edge of the second partition is located at or below the specific height. 
     
     
         11 . The electrolytic plating equipment according to  claim 1 , further comprising:
 a return pipe for returning the plating solution from the separate tank to the plating tank; and   a re-supply pipe for returning the plating solution discharged from the separate tank to the first space.   
     
     
         12 . The electrolytic plating equipment according to  claim 1 , further comprising a mechanical agitator provided in a space downstream from the first space. 
     
     
         13 . The electrolytic plating equipment according to  claim 1 , wherein
 the plating tank has: a tank body for holding the plating solution; and an overflow tank provided integrally with the tank body in which the plating solution from the tank body overflows the upper edge of the side wall of the tank body to flow into the overflow tank, and the overflow tank has an upstream space and a downstream space located downstream from the upstream space, and the plating solution falls through air to flow from the upstream space into the downstream space.   
     
     
         14 . The electrolytic plating equipment according to  claim 13 , wherein the upper edge of the tank body has a extending portion extending towards the overflow tank, and the extending portion has an end that is separated from the side surface of the tank body. 
     
     
         15 . The electrolytic plating equipment according to  claim 1 , wherein a drop through which the plating solution falls through air in the second space is 10 cm or more. 
     
     
         16 . The electrolytic plating equipment according to  claim 1 , wherein the plating solution is used for copper plating, and contains a sulfur-containing organic compound as a brightener. 
     
     
         17 . An electrolytic plating method using an electrolytic plating equipment including: a plating tank for holding plating solution; and a separate tank apart from the plating tank, for holding the plating solution circulating between the plating tank and the separate tank, wherein
 the separate tank has therein a first space and a second space located downstream from the first space, and   the electrolytic plating method comprises:   retaining the plating solution up to a specific height in the first space so that metal particles in the plating solution settle to the bottom of the first space; and   making the plating solution in the first space in an amount exceeding the specific height flow into the second space so that the plating solution is made to fall through air in the second space to thereby adjust the dissolved oxygen concentration of the plating solution.   
     
     
         18 . The electrolytic plating method according to  claim 17 , wherein the plating solution is used for copper plating, and contains a sulfur-containing organic compound as a brightener.