Plating apparatus

Abstract

A plating apparatus includes a plating bath storing a plating solution and plating targets, and an injector in the plating bath. The injector includes a first injection port to inject the plating solution. The plating targets included in the plating solution are stirred by the plating solution injected from the injector. A mesh portion is provided at the first injection port. The mesh portion is defined by at least two stacked meshes. The mesh portion includes a central portion and a circumferential portion provided outside the central portion when viewed in a planar direction. The circumferential portion is defined by one layer of the mesh or a plurality of layers of the mesh. The central portion is defined by a plurality of layers of the mesh. A number of layers of the mesh in the central portion is greater than that of the circumferential portion.

What is claimed is: 
     
         1 . A plating apparatus comprising:
 a plating bath in which a plating solution including plating targets is stored; and   an injector provided in the plating bath, the injector including a first injection port to inject the plating solution; wherein   the plating targets included in the plating solution are stirred by the plating solution injected from the injector;   a mesh portion is provided at the first injection port of the injector;   the mesh portion is defined by at least two stacked meshes, the mesh portion includes a central portion and a circumferential portion provided outside the central portion when viewed in a planar direction;   the circumferential portion includes one layer of mesh or a plurality of layers of mesh;   the central portion is made of a plurality of layers of mesh; and   a number of layers of the mesh in the central portion is greater than a number of layers of the mesh in the circumferential portion.   
     
     
         2 . The plating apparatus according to  claim 1 , wherein a metal pipe having a cylindrical shape and including a hollow portion is provided directly above the injector. 
     
     
         3 . The plating apparatus according to  claim 1 , wherein
 the number of layers of the mesh in the circumferential portion is one; and   the number of layers of the mesh in the central portion is two.   
     
     
         4 . The plating apparatus according to  claim 1 , wherein in the mesh portion, a mesh opening of the central portion is smaller than a mesh opening of the circumferential portion when viewed in the planar direction. 
     
     
         5 . The plating apparatus according to  claim 1 , wherein the central portion has a circular shape when viewed in the planar direction. 
     
     
         6 . The plating apparatus according to  claim 1 , wherein the central portion has a polygonal shape when viewed in the planar direction. 
     
     
         7 . The plating apparatus according to  claim 6 , wherein the central portion has a quadrangular shape when viewed in the planar direction. 
     
     
         8 . The plating apparatus according to  claim 1 , wherein
 the injector has an inner cylindrical shape including a bottom surface and an inner wall, with the first injection port provided in an upper end thereof;   a second injection port is provided in the bottom surface, an opening area of the second injection port is smaller than an opening area of the first injection port; and   the plating solution is injected into the injector from the second injection port.   
     
     
         9 . The plating apparatus according to  claim 1 , comprising:
 a metal pipe having a cylindrical shape and including a hollow portion, the metal pipe defining and functioning as a first electrode;   a partition wall pipe made of an electrically insulating material, the partition wall pipe having a cylindrical shape and including a hollow portion, the partition wall pipe being provided with a plurality of holes through which the plating solution passes but through which the plating targets do not pass; and   a second electrode; wherein   the metal pipe, the partition wall pipe, and the second electrode are each accommodated in the plating bath;   the metal pipe is located inside the hollow portion of the partition wall pipe, and a plating forming portion is provided between an inside of the partition wall pipe and an outside of the metal pipe;   the second electrode is located outside of the partition wall pipe;   the injector is provided below the metal pipe;   the plating targets are moved upward through the hollow portion of the metal pipe with an upward flow of the plating solution injected from the injector;   the plating targets are discharged to an outside from an upper end of the hollow portion of the metal pipe and stirred in the plating solution;   the plating targets subsequently fall downward through the plating forming portion; and   while the plating targets fall downward, the plating targets each are plated by application of a current between the metal pipe defining and functioning as the first electrode and the second electrode.   
     
     
         10 . The plating apparatus according to  claim 9 , wherein
 the first electrode is a cathode electrode; and   the second electrode is an anode electrode.   
     
     
         11 . The plating apparatus according to  claim 2 , wherein two rod-shaped electrically-conductive support portions are integrally provided with an upper portion of the metal pipe. 
     
     
         12 . The plating apparatus according to  claim 9 , wherein the second electrode has a cylindrical shape. 
     
     
         13 . The plating apparatus according to  claim 9 , wherein the metal pipe, the partition wall pipe, and second electrode are arranged concentrically with aligned central axes. 
     
     
         14 . The plating apparatus according to  claim 1 , wherein the mesh portion includes an electrically insulating material. 
     
     
         15 . The plating apparatus according to  claim 8 , further comprising a circulation line connected between a liquid suction port located in the plating bath and the second injection port.