JPH03285097A - Anode for electroplating and electroplating method - Google Patents

Abstract

PURPOSE:To build up a plated layer having uniform thickness at a low cost by parallel aligning a plurality of wire bodies or fine rods and also allowing the tips thereof to coincide with the shape of a body to be plated and thereby forming an anode for electroplating and allowing plating liquid to flow out from the intervals of the wire bodies. CONSTITUTION:An anodic body 10 for electroplating is formed by parallel aligning a plurality of wire bodies 11a, fine rods 11b or fine tubes 11c and bundled by an outflow device 12 of plating liquid. The tips 13 of the wire bodies 11a and the fine rods 11b, etc., are arranged in the reverse shape of a body 2 to be plated. Voltage is impressed between the body 2 to be plated and the anodic body 10 for electroplating and current is allowed to flow. A plated layer is built up on the body 2 to be plated. Furthermore plating liquid is allowed to flow toward the body 2 to be plated from the intervals of the wire bodies 11a, the fine rods 11b or the fine tubes 11c. The body 2 to be plated is rotated in accordance with necessity. Thereby the uniformly plated layer is formed on the body 2 to be plated.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to an anode used in electroplating or electroforming, and an electroplating method using the same. A uniform plating layer can be applied even when the plating layer has the following properties. The present invention also relates to an electroplating method suitable particularly when the object to be plated is axially symmetrical.

``Prior Art'' An anode used in electroplating is a plate or bar made of carbon or metal, or a basket in which a metal ball or chip is placed.

However, since these anodes have different shapes from the object to be plated, the current density differs in each part of the object to be plated, and therefore the thickness of the plating layer in each part of the object to be plated becomes non-uniform. Therefore, when uniformity of plating thickness is required, auxiliary electrodes are used in areas where the current density is low to make the thickness of the plating layer uniform in each part of the object to be plated.

FIG. 14 shows an example in which a plate-shaped body made of metal is used as an anode.

In FIG. 14, a plate-shaped anode 1 is installed facing the object to be plated 2, and an auxiliary electrode 33 is arranged at a portion where the distance between the plate-shaped anode 1 and the object to be plated 2 is long. In this state, a plate anode! Electroplating is performed by passing a current between the auxiliary electrode 3.3 and the object to be plated 2.

In addition, when performing electroforming, which is a type of electroplating, if a precise shape is required, if the object to be plated is a male type, the anode is a female type, and this female anode is the inverse of the male type. It is manufactured by processing into a shape, and electroforming is performed with the female anode facing the object to be plated.

"Problems to be Solved by the Invention" However, when using the plate-shaped, rod-shaped, or basket-shaped anodes, it is difficult to control the current density in each part of the object to be plated, and even if an auxiliary electrode is used, it is difficult to control the current density in each part of the object to be plated. It is difficult to determine the shape and size of the auxiliary electrode, and it is difficult to obtain a plated layer of uniform thickness. Furthermore, when using a female anode that is an inverted version of the object to be plated, the production cost is high because the female anode is manufactured by mechanical cutting, electrical discharge machining, or the like.

Furthermore, since this female anode is manufactured in accordance with the shape of each plated body, there is a problem in that an expensive female anode must be manufactured each time.

The present invention has been made in view of the above circumstances, and provides an anode for electroplating that can apply a plating layer of uniform thickness to an object to be plated and that is low in manufacturing cost. It is an object of the present invention to provide a method for efficiently applying a plating layer of uniform thickness to an object to be plated by using an anode.

"Means for Solving the Problems" The present invention comprises a plurality of wire bodies, a plurality of thin rods or thin tubes arranged in parallel and bundled, the tips of which are arranged along the surface shape of the object to be plated. An anode for electroplating, and this anode for electroplating, characterized in that:
The compact, thin rod or tube is made of an insoluble material, and the insoluble material is Ti.

gr, Nb, Ta, and their alloys, and the vicinity of the tip of this insoluble material is coated with a noble metal or a conductive oxide thereof;
and an insulating oxide film is formed on the exposed surface of these alloys, and the electroplating anode and the object to be plated are placed facing each other, and the electroplating anode is Provides an electroplating method in which an electroplating solution flows out from between wire bodies or thin rods toward a body to be plated,
Particularly in the above-mentioned plating method, when the object to be plated is axially symmetrical, the problem is solved by rotating the object to be plated about the axis of rotation with the axis of symmetry as the rotation axis.

"Function" According to the electroplating anode of the present invention, a plurality of wire bodies, a plurality of thin rods or thin tubes are arranged in parallel and bundled,
Since these tips are arranged and fixed along the surface shape of the object to be plated, the distance between the anode and each part of the object to be plated can be kept constant without the need to provide an auxiliary electrode.
A uniform plating film can be formed on the object to be plated.

In addition, if the anode for electrical welding is made of an insoluble material,
Since the electrodes do not wear out, they can be used repeatedly and multiple products can be plated efficiently and with high precision. Furthermore, insoluble materials include i' i , Z rNb, 'l'a, and alloys thereof as core materials, and Pt and Pt are added only near the tip of the core material.
In an anode composed of noble metals such as Ir and FTU, or conductive oxides thereof, and an insulating oxide layer formed on the part of the core material directly exposed to the outer surface, it is possible to Since the current flows only through the opposing anode portions, the current distribution becomes more uniform, and a more uniform plating film can be formed on the object to be plated.

In addition, since this electroplating anode is made of a plurality of wire bodies or a plurality of thin rods arranged in parallel and bundled,
Since it has a large surface area, a large current can be passed through it, so the plating speed can be increased. Furthermore, since it is easy to manufacture, the manufacturing cost is also low.

Further, according to the electroplating method of the present invention, the object to be plated is placed opposite to the anode for electroplating, and the electroplating solution is directed toward the object to be plated from between the wires or thin rods of the anode for electroplating. Because of the outflow, the number of ions passing per unit time per unit area increases, allowing a high current to flow between the electroplating anode and the object to be plated, and high-speed plating is possible.

Furthermore, in the above plating method, if the object to be plated is axially symmetrical, by rotating the object to be plated around the axis of rotation with the axis of symmetry as the rotation axis, uniform plating can be achieved using a simple device on the circumferential surface of the rotating object. A thick plating layer can be formed.

"Example 1" Hereinafter, the electroplating anode and electroplating method of the present invention will be described in detail with reference to the drawings.

1 to 8 are diagrams for explaining an electroplating anode and an electroplating method according to a first embodiment of the present invention.

FIG. 1 shows an example of an anode body 10 for electroplating according to the present invention. This thing has multiple wire bodies lla, thin rods 11
b or thin tubes 11c are arranged in parallel and bundled by a plating solution outflow device 12. The wire body 11a, thin rod 11b or thin tube 11c can be made of the same metal as the plating layer to be formed, but suitable materials include flu, Ir, Rh, PL and alloys thereof. Insoluble metals and insoluble materials such as carbon and graphite. Ti from the viewpoint of conductivity and cost.

Preferably, the core material is Zr, Nb, Ta, or an alloy thereof, and the core material is coated with the above-mentioned insoluble metal or a conductive oxide thereof. In addition, this coating with insoluble metal is applied only to the vicinity of the tip of the wire, thin rod, or thin tube that is the core material, and the insulating oxide consisting of the core material component is applied only to the area where the core material is directly exposed to the surface. More preferably, a layer is formed.

In the anode having such a configuration, current flows out only from the anode portion facing the object to be plated, so that the current distribution can be made more uniform, and a more uniform plating can be formed on the object to be plated. An insulating oxide layer can be formed on the surface of an electrode by immersing the electrode in a plating solution and performing electrolysis using the electrode as an anode. It is better to electrolyze to form an oxide film with higher corrosion resistance, insulation, and uniformity. This insulating oxide film has a thickness of submicron class, so there is no dimensional change in shape and it has sufficient insulation properties. It has the advantage that no jigs or the like are required, and no special equipment or configuration is required.

The cross-sectional shape of the wire, thin rod or thin tube can be various shapes such as a polygon. A circular shape is preferred because it is easy to bundle, there is always a space between the wires when bundled, and it is easy to handle. The diameter of this circle is difficult to determine due to the shape and size of the plated body, but considering workability and plating accuracy, it is 0. Otori~
5. (1+5rillffi is preferable.The thin tube has the advantage that the plating solution can also flow inside the tube.

The ends 13 of these wire bodies 11a, thin rods 11b, or thin tubes 11c are arranged in an inverted shape of the plating body 2 shown in FIG. 2, and are fixed by a plating solution outflow device 12.

As shown in FIG. 3, this plating solution outflow device 12 has a support plate 14 and a fixing plate I5 arranged in parallel, each of which is provided with a support member 16 and an insertion hole I7. The support members 16... are made of rubber or the like, and the support members 16... have wire bodies 11a, thin rods 11, etc.
Fixing holes 16a... are formed in which the thin tubes 11c and 11c can slide and have a size that allows them to be fixed. The wire body 11a, the thin rod 11b, or the thin tube 11c is inserted through the insertion holes 17 of the support plate 14 and the fixing plate 15, and the fixing holes 16a of the support member so that they are parallel to each other, and then the fixing holes 16a, 16a... are fixed.

The fixed plate +5 further has a liquid outlet 18°18...
・is formed. A plating solution supply port 20A is provided in the side wall 19 of the plating solution outflow device 12, and is connected to a plating solution supply pipe 20.

An example of the electroplating anode body 10 shown in FIG. 1 can be manufactured by the following method.

(1) First, as shown in FIG. 4, an object to be plated 2 and a plurality of wire bodies 11a, thin rods 11b or thin tubes ItC arranged in parallel and bundled by the plating solution outflow device 12 are prepared. The tips +3 of these reduced bodies 11a1, thin rods 11b, or thin tubes 11c are arranged in advance in a straight line parallel to the plating solution outflow device 12.

■Next, as shown in Fig. 5, the body 2 to be plated is
1a, press against the tip 13 of the thin rod 11b or thin tube 11c.

■ Next, gradually push the body 2 to be plated in the direction of the arrow in FIG. The tips 13 of the parts 11b are moved to a position where the object 2 to be plated is arranged in an inverted shape.

■Next, move the body 2 to be plated in the direction shown by the arrow in FIG. 6 to remove the wire 11a, thin rod 11b or thin tube! Remove the body 2 to be attached without moving the tip 13 of 1c.

Next, as shown in FIG. 7, the electroplating anode 10 and the object 2 to be plated are placed facing each other in a plating tank 2 made of rubber-lined steel plate, reinforced plastic, etc., and the distance between the two electrodes is set to about several 11. Place them close together. These arrangement methods are such that when the body 2 to be plated is moved parallel to the anode body IO for electroplating in the direction of the anode body 10 for electroplating, the shape of the body 2 to be plated is a deformed part of the anode body IO for electroplating. 1
It is designed to fit into the shape of 0A.

Next, the plating bath 21 is filled with the plating bath 22 . As the plating bath 22 used here, the N of the plating layer to be applied is
Selected according to category. In addition, the wire body 11a or the thin rod 1
When the material of 1b is an insoluble metal, it is necessary to replenish the plating bath 22 with the metal used to form the plating layer. For example, in the case of electrolytic nickel plating, 1iN+
Nickel ions can be replenished by adding nickel carbonate corresponding to the ions to the plating bath 22.

Furthermore, as this plating bath 22, diamond, CBN, S
A solid image such as iC, hBN, etc. is added to the plating bath 22.
It may be dispersed inside.

In order to apply a plating layer to the object 2 to be plated using the apparatus configured as described above, the object 2 to be plated is connected to the cathode, the anode is connected to the anode body 10 for electroplating, and the object 2 and the object 2 to be electroplated are connected to the cathode. This is carried out by applying a voltage between the plating anode bodies 10 and causing a current to flow.

In order to further increase the efficiency of forming the plating layer, the plating solution in the plating bath 22 is caused to flow out from between the wire 11a, the thin rod 11b, or the thin tube 11c toward the object to be plated 2 in the direction of the arrow in the figure. An example of a method for doing this is to pump the plating bath 22 from the liquid suction port 23 through the pipe 24 with the pump 25, and then use the pump 25 to pump the plating bath 22 through the pipe 2o to the plating solution in the plating solution outflow device chamber 2. It is ejected from the supply port 2OA. The plating bath 22 in the plating solution outflow device 12 that is sprayed by hand is a plating solution flow system shown in FIG. 1! Liquid outlet I8 of the fixed plate 15 of 12...
・Flows out toward the object 2 to be plated.

Furthermore, if the shape of the object 2 to be plated is axially symmetrical as shown in FIG.
If plating is performed using the above method while rotating, a more uniform plating layer can be formed on the object 2 to be plated.

"Embodiment 2" FIGS. 9 to 13 are diagrams for explaining an electroplating anode and an electroplating method according to a second embodiment of the present invention.

FIG. 9 shows an example of the structure of the wire body 11a, thin rod 11b, or thin tube 11c constituting the electroplating anode 10A of the present invention.

The wire body 11a, the thin rod 11b, or the thin tube 11c consists of a core material 40, an insulating oxide film 4I, and a noble metal or noble metal oxide coating 42 formed on one end of the core material 40. An insulated lead wire 44 is bonded to the core material 40, and the bonded portion is covered with an insulating resin coating 43.

In the case of the thin tube 11c, joining can be easily performed by inserting the lead wire 44 into the thin tube 11c and caulking it. Further, in the case of the thin tube 11c, it is preferable to connect the lead wire 44 with both ends open so that the plating solution can also flow into the thin tube Ilc.

Furthermore, if a part of the outer surface and the entire inner surface of the capillary tube 11c are coated with a noble metal or noble metal oxide coating 42, the area where current can flow out increases, and the current flows out only from the vicinity of the opening at the tip of the capillary tube iIc. Control of current distribution is easier. In this case, the outer surface of the thin tube lie does not necessarily need to be coated with a noble metal.

FIG. 1O is a side view of an anode assembly in which a plurality of anodes shown in FIG. 9 are stacked and bundled one by one using a tightening jig (not shown).

FIG. 11 is a cutaway view of the A-A' cross section shown in FIG. , It can be used as a liquid passage hole during plating.

FIG. 12 shows the space 45 that exists between adjacent anodes for forcing the plating solution and the thin tube 1 when the anode is the thin tube 11c.
1c, this electroplating anode 10A is a wire body 11a.
..., thin rods 11b... or thin tubes +1c... are bundled and supported by a plating solution outflow device I2, and this plating solution outflow device 12 includes a support body 47 made of Plus Deck, a fixing plate 46, rubber, etc. It is composed of an elastic body 50 and a liquid suction pipe 48, and is configured so that an insulated lead wire 44 can be taken out from the plating solution outflow device 12.

FIG. 13 is a partially cutaway view of the BB' cross section in FIG. 12.

The method of assembling the entire electroplating anode + OA is shown in FIG. 13.

The anode to which the lead wires shown in FIG. Place the fourth elastic body 53 in a predetermined position, place the fixing plate 46 on top of it, apply force in the direction shown by the arrow in FIG.
When the tightening force between 1c reaches a predetermined value, tighten with the screw 54.
The fixing plate 46 and the support body 47 are connected and fixed.

Thereafter, as in Example 1, wire IIa...
・By pressing the tips of the thin rods 11b... or thin tubes +1c... and moving each of the wire bodies 11a, thin rods 1"lb, or thin tubes 11c one by one following the shape of the object to be plated, The shape of the body to be plated is copied to complete the shape of the anode body.

The method of performing electroplating using the electroplating anode body 10A obtained in this manner is the same as the method of performing plating using the electroplating anode 10 shown in Example Day 1.

"Experimental Example" As Experimental Example 1, a groove-shaped object [not shown in Figure 15] was used as the object to be plated.
Using an L-roll 60, the outer circumference 61 of the grooved roll was plated, and the side surface 62 was insulated masked. In addition, the dimension between QC in Situation 5 is 15am, and the dimension between QC and 90 is 55m5.
+, OA distance is 801m'? 'be.

After forming the electroplating anode body 10A shown in FIG. 12, it is pressed against the tip of the round bar-shaped wire body 11a, and the inverted shape of the grooved roll 60 is copied. The final anode shape (+01) shown was created.

After degreasing and cleaning the grooved C1-roll 60, the grooved roll 60 is immersed in a plating bath, and then the tip of the electroplating anode +011 is placed at a distance of 2ig from the object to be plated.
Ni plating was performed for 1 hour at a total current of 25 A while rotating the liquid-plated body at a speed of 20 r, p, - around the shaft center.

The following sulfamic acid Ni plating was used as the Ni plating solution.

Ni sulfamate 450f#! Boric acid 309/Q Anti-pitting agent Small amount Brightener Small amount pH 4.0 Temperature 50°C Also, replenish Ni carbonate paste in an amount corresponding to the electrolytic consumption of Ni ions in the plating solution to maintain a constant Ni ion concentration in the solution. We aimed to

As the electrode material, insoluble materials and shapes shown in Table 1 were used.

The amount of plating solution circulated through the liquid outflow device was set to 5Q1 minute.

After plating, the plating thickness of the outer peripheral part 61 of the grooved roll 60 was measured at positions A, B, and C shown in FIG. 15, and the plating thickness ratios B/A and C/A are shown in Table 1. Ta.

As Experimental Examples 2 to 4, actual test example 1 was carried out using the anode shown in Table 1.
An example of actual testing on a plated object with the same shape! Electric Ni plating was performed under the same plating conditions as in Example 1, and the plating thickness was measured in the same manner as in Experimental Example 1. The results are shown in Table 1.

In addition, as a comparative example, electrolytic Ni plating was performed on an object to be plated having the same shape as in Experimental Example 1 using a platinum-plated titanium plate as an anode under the same conditions as in Experimental Example 1.

The size of the liquid immersion part of the platinum-plated titanium plate was 160 m long and 150 m5+ wide, and the installation distance from the plated plate was 300 m to make the current distribution as uniform as possible.

The plating thickness was measured in the same manner as in Experimental Example 1, and the results are shown in Table 1.

(Blank below) In addition, as Experimental Example 5, we will show the limits of how much healthy plating can be obtained with the configuration of Experimental Example 4, with and without operating the plating solution outflow device to eject the plating solution from the anode body. When calculating the current, if the value of no plating solution is ejected is 1, the plating limit current is doubled when the plating solution is ejected at 2 g/min, and is 5 g/min.
It increased by 4 times in 20 g/min and IO times at 20 g/min.

"Effects of the Invention" As explained above, the electroplating anode of the present invention has a plurality of wire bodies or a plurality of thin rods arranged in parallel and bundled, and the tips of these wires align with the surface shape of the object to be plated. Since the anodes are arranged along the , the distance between the anode and each part of the object to be plated can be kept constant without providing an auxiliary electrode, and a uniform plating film can be formed on the object to be plated. Furthermore, since it has a large surface area, a large current can be passed through it, so the plating speed can be increased. Furthermore, since it is easy to manufacture, the manufacturing cost is low.

In addition, in the electroplating method of the present invention, an electroplating anode and an object to be plated are arranged to face each other, and the electroplating solution flows out between the wires or thin rods of the electroplating anode toward the object to be plated. Therefore, a high current can be passed between the electroplating anode and the object to be plated, and high-speed plating is possible.

Furthermore, in the above plating method, if the object to be plated is axially symmetrical, if the object to be plated is rotated around the axis of rotation, a plating layer with a more even thickness can be formed. can do.

Furthermore, according to the electroplating anode and electroplating method of the present invention, the more complex the shape of the object to be plated, the greater the difference in uniformity between the plated layer and the conventional method.

Furthermore, when the plating bath contains solids, the solids are more uniformly dispersed in the plating layer applied by the method of the present invention than by conventional stirring.

[Brief explanation of drawings]

FIG. 1 is a side view showing a first embodiment of the electroplating anode of the present invention, FIG. 2 is a sectional view showing an object to be plated, and FIG. 3 is a plating solution of the first embodiment of the electroplating anode. 4 to 6 are side views of a tank showing the method for producing an electroplating anode of the present invention, and FIG. 7 is a diagram showing an apparatus for explaining the electroplating method of the present invention. Sectional side view,
Figure 8 is a sectional view showing an example of an axially symmetrical plated object, Figure 9
The figure is a side view showing an example of the structure of a wire, a thin rod, or a thin tube constituting an electroplating anode according to a second embodiment of the present invention.
Figure 0 is a side view of the anode assembly made by stacking and bundling a plurality of wire bodies, thin rods, or thin tubes shown in Figure 9, and Figure 11 is a cross section taken in the direction of the /l-A' arrow shown in Figure 1O. Figure 12 is a side view of the entire electroplating anode when the plating solution is forced to flow into the space existing between adjacent thin tubes and inside the thin tubes, and Figure 13 is B-13 in Figure 12. 14 is a sectional view showing a conventional electroplating method n using an anode; FIG. 15 is a side view showing a grooved roll that is the object to be plated; FIG. 16 and FIG. I7 is a side view showing a second embodiment of the electroplating anode of the present invention. ... object to be plated, 0, IOA ... anode for electroplating, Ia, I lb, l Ic ... wire body, thin rod or thin tube 2 ... plating bath, 0 ... axis of symmetry (rotation shaft).

Claims (6)

[Claims] (1) For electroplating, in which a plurality of wire bodies, a plurality of thin rods, or thin tubes are arranged in parallel and bundled, and the tips of these are arranged along the surface shape of the object to be plated. anode. (2) The electroplating anode according to claim 1 and the object to be plated are arranged to face each other, and the electroplating solution is caused to flow out between the wires or thin rods of the electroplating anode toward the object to be plated. An electroplating method characterized by: (3) Claim 2 characterized in that the axially symmetrical object to be plated is rotated around the axis of rotation with its axis of symmetry as the axis of rotation.
Electroplating method described. (4) In the electroplating anode according to claim 1, a wire body,
An anode for electroplating, characterized in that the thin rod or tube is made of an insoluble material. (5) In the electroplating anode according to claim 4, the insoluble material is made of Ti, Zr, Nb, Ta, and alloys thereof, and the vicinity of the tip of the insoluble material is coated with a noble metal or a conductive oxide thereof. An anode for electroplating characterized by: (6) In the anode for electroplating according to claim 4, the insoluble material is made of Ti, Zr, Nb, Ta, and alloys thereof, and an insulating oxide film is formed on the portion where the insoluble material is exposed on the surface. An anode for electroplating characterized by: