JPS61163299A - Alloy plating device - Google Patents

Abstract

PURPOSE:To provide the title device capable of keeping the composition of a plating bath and of a deposited alloy layer at a fixed value for many hours by connecting each metallic anode corresponding to the composition of the alloy and an insoluble anode respectively to each rectifier, and connecting the terminals of the negative electrodes collectively to the cathode of a material to be plated. CONSTITUTION:A plating bath 2 contg. plural kinds of metallic ions constituting the alloy components is charged into a plating tank 1, and a material 3 to be plated used as the cathode, metallic anodes 4 and 5 consisting of the plural kinds of metals, and an insoluble anode 6 are dipped into the plating bath 2. In such an alloy plating device, the anodes 4, 5, and 6 are connected respec tively to the anodic output terminals of constant current regulation type rectifiers 7, 8, and 9, and the terminals on the cathode side are connected collec tively to the cathode 3. An overall regulator 10 is further provided, and the share rate of the electric current is set by a potentiometer 11. Consequently, the cathode current efficiency to the alloy components is made higher than the anode current efficiency, and the concns. of the alloy components in the plating bath 2 can be kept constant at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electroplating apparatus for forming an alloy plating layer on the surface of a broken metal object using a plating bath containing a plurality of metal components.

(Prior art) An object to be plated is immersed in a plating bath containing multiple metal components,
Forming an alloy plating layer by electroplating has already been put into practical use. In the alloy plating layer obtained by plating, it is most important that the plurality of metal components forming the alloy are always kept constant. For this purpose, it is an absolutely necessary condition to always maintain a constant concentration of each of the plurality of metal components in the plating bath.

Conventionally, one method has been to frequently analyze the alloy plating layer and replenish the decrease in individual metal components in the form of metal salts. However, this method not only requires a great deal of labor for analysis, but also because the replenishing form is a metal salt and not a pure metal, anions as counterions accumulate in the bath each time it is replenished. There is a drawback that the stability of the plating bath is affected as a result of disturbing the pH value, electrical conductivity, etc. of the bath.

Another method is to use each of the plurality of metals forming the alloy as independent anodes, connect the positive electrodes of separate DC power sources to the independent anodes, and connect the negative electrodes of each DC power source together. There is a method in which an alloy layer of a constant composition is formed on the object to be plated by connecting it to the object to be plated and adjusting the current of each DC power source. In this method, the metal components are supplied from the anode in the form of metal ions, so there is no problem with the accumulation of anions in the bath, but the amount of elution of each metal at the anode, that is, the anode current efficiency Since the amount of precipitation at the cathode, that is, the cathode current efficiency, does not necessarily match, the concentration of each metal component in the bath will eventually exceed the allowable range, which will interfere with normal plating operations. This results in

(Problems to be Solved by the Invention) Two series: In the conventional alloy plating method, it is impossible to maintain the composition of the plating bath constant for a long period of time, resulting in failure. The components of the alloy layer deposited on wave metal products have been examined over a long period of time.
There was a problem that it was not possible to maintain a constant level.

(One Step to Solve the Problems) The present invention has been completed in order to eliminate such problems.

The present invention is applicable to most metals.1. This method was developed by focusing on the fact that the cathode current efficiency is lower than the anode current efficiency during electrolysis of the plating bath. Suspend a plurality of anodes and an insoluble anode, connect the positive output terminals of each separate DC power supply to the anodes, respectively, and connect the negative output terminal of each separate DC power supply with -. ]Connected to the recording cathode,
The purpose is to maintain the concentration of metal components in the bath at a constant level by dissolving the metal components, which have decreased due to precipitation at the cathode, from the anode of each component. .

(Example) The present invention will now be explained in detail with reference to illustrated embodiments.

In Figure 1, (11 is the plating tank, (2) is the A ion and B
a plating bath containing two metal components of ions; (3) an object to be plated that is immersed in the bath to deposit an alloy layer containing metals A and B; (4) an anode made of metal A; ,(5
) is an anode made of metal B, and (6) is an insoluble anode made of an insoluble material such as platinum or graphite. (7), (8),
(9) are all constant current output rectifiers with an M rectification output,
The positive electrode output 1 of the secondary rectifier is the anode (4), (
5) and (6), and the negative output terminals are collectively connected to the object to be plated (3). Note that the filter, heat exchanger, etc. normally attached to the plating tank are not shown. The current of the anode (5) of metal B is I8
, the current of the rectifier (9), that is, the current of the insoluble anode (6), is 1
8, the current (2) flowing to the breaking metal, that is, the cathode, is naturally T=IA-quantity 1111-T.

It is.

The cathode current I depends on the surface area of the object to be plated (3) and the plating bath (2).
), but as mentioned above, for most metals, the cathode current efficiency is lower than the anode current efficiency, so the cathode current 1 is the sum of both dissolving anode currents (IA-1'lB)
Must be bigger.

That is, I>T, +I□ Therefore ■. 〉○, so no current must be passed through the insoluble anode (6).

At this point, A deposits on the object to be plated (3) due to the cathode current I,
Since the amount of each metal B is proportional to I, in order to keep the ion concentration of each metal in the bath (2) constant, it is necessary to re-anode (4).
), (5), it is necessary to make the amounts of both metals A and B dissolved in the anode proportional to I, resulting in T and -KBT.

Therefore, IH= l (Ia + r = (1-KA-KB)T - KNI (KN= l KA KB),
All three anode currents have values proportional to the cathode current ■.

Now, the proportional constants KA and KB are the types of anode metals A and B, and the bath (
It is determined empirically from the composition of 2).

When passing the cathode current (■) corresponding to the surface area of the object to be plated (3), the currents of the rectifiers (7), (8), and (9) are adjusted to K, respectively.
By setting AI, KBl, and KN■, the ion concentrations of both metals A and B in the bath (2) can be kept constant regardless of the progress of the plating process, and the ion concentration of the metals A and B in the bath (2) can be kept constant regardless of the progress of the plating process, and the ion concentration of the metals A and B in the bath (2) can be kept constant regardless of the progress of the plating process. 1
11j It is also possible to always keep the metal component ratio constant.

In the present invention, 'C' is one or two rectifiers (7), (8), (9).
) A common general regulator (10) is installed in +J, and one setter (11) belonging to the general regulator (10) is operated to set the cathode type / I! iδl
(If you set the lit value of +21 to the desired 4ff I,
Depending on the function of the comprehensive adjustment device 00), the output current of the king dai is automatically adjusted to 1. , l, K, and 1 are set. An example of the above general regulator will be explained below with reference to FIG.

In Figure 2, parts equivalent to those in Figure 1 are given equivalent symbols, and (
I3) is a constant voltage DC power supply, TIO is the constant voltage DC power supply 0
3) is a potentiometer connected to 3), which is a setting device for setting the cathode current 2 in FIG. 041,0
51 and (I6) are both potentiometers connected in parallel between the potentiometer (Iυ partial pressure sliding terminal 07) and the common terminal θ8).

311M potentiometer partial pressure sliding end 7-(1
9), (20), and (21) are people's constant current rectifier hfE (
7), (8), and (9) are connected to proportional control analog input terminals.

Now, the output voltage of the potentiometer θυ, that is, the voltage between the partial pressure sliding terminal (17) and the 21mm terminal (18), is V.
s and the proportional control inputs to the constant current rectifiers (7), (8), and (9) are the potentiometers (141,051
, (16), C8■5, Cl1V1, CIIV, respectively.
, (CAcB, ON are proportional constants). Rectifier (
The output currents of 7), (8), and (9) are respectively I n = k CA V 5 1, - k CB V s (k constant number) IN - k
CNV3, and naturally [A-1-11I+IN=1, so 1, = KAI I n ''' K B1 1 ++ - K N 1.The proportionality constant I (KB, KN, respectively, is the potentiometer (14) , (15), (It goes without saying that it is possible to set any value from !1 depending on the position of 10. Also, it is clear that the cathode current ■ can be adjusted depending on the potentiometer (II). be.

The general regulator 00) is not limited to the configuration shown in FIG. 2, but can be configured as desired.

FIG. 3 shows another embodiment of the general regulator 00).
Parts equivalent to those in FIG. 1 are given equivalent symbols. Qυ is a microprocessor, 031 and Qo are ROM and R, respectively.
AMX (251 is input capo-1, 061, (271,,
Q8) is an analog output port, and both are connected to the pass line and constitute a micro:1 computer system.I291 is a keyboard, CI[ll is a setting input signal, and each input port ( 251.The ROM (23) stores the proportionality constant C9, CB% (”/ll, input from the keyboard (291) in the RA
A program has been written to write to M, read the data of setting input signal 00), multiply CA, CB, and CN respectively, and output to the analog output port (2G+, (2 power, I). 26), (2η, (
The outputs of 28) are connected to constant current rectifiers (7), (8), and (9), respectively.
) is supplied as a proportional control analog input. Therefore, if the data of the setting input signal is V(d)S, the output currents of the rectifiers (7), (8), and (9) are respectively IA=kCAV, -KAI IH=kC, Vs=KBI IN= kCNVS=KN1. Constant of proportionality ■ (Ini 6 and KN are respectively keyboard F
It goes without saying that the cathode current I can be set to any value by inputting it from I291.
It is clear that it can be adjusted by the data of 0).

If a digital switch is used as the setting input signal 00), the cathode current I can be adjusted by operating the digital switch, but it is also possible to input data corresponding to the surface area of the object to be coated and add a calculation function. By doing so, automatic plating treatment at constant current density becomes possible.

(Effects) According to the present invention, a separate constant current regulating rectifier is assigned to each of the anodes of a plurality of metals of the alloy components, and the current corresponding to the difference between the anode current efficiency and the cathode current efficiency is insoluble. It is supplied from a constant current adjustable rectifier separate from the anode, and the sharing ratio of each anode current can be arbitrarily selected, so it is possible to replenish from the anode an amount commensurate with the amount of precipitation at the cathode for each metal component. Therefore, the concentration of each metal ion in the bath 1 can be kept constant at all times, and the composition of the alloy deposited on the cathode can be kept constant at all times. However, since the sum of the output currents of each rectifier, that is, the cathode current, can be adjusted with a single setting device while keeping the sharing ratio of each anode current constant, the current can be adjusted even when the surface area of the plated object is different. Adjustment is also extremely easy.

It should be noted that although the explanation has been given below with reference to binary alloys, it is clear that the present invention can be easily implemented for ternary or higher alloys.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the alloy plating apparatus of the present invention.
88! Figures I and M3 show different embodiments of the general regulator of Figure 1, respectively. 1... plating tank, 2... bath, 3... object to be plated 4.5
... Different types of metal anodes, 6... Insoluble anodes 7.8.9... Constant current adjustable rectifier 10... Comprehensive regulator 11... Potentiometer (for adjusting cathode current) 13
...Constant voltage DC power supply 14.15.16...Potentiometer (for setting current sharing ratio) 22...Microprocessor 25...Input boat 2G, 27.2B...Analog output boat 29...
Keyboard paper 2 diagram procedure amendment form (voluntary)

Claims (1)

[Claims] a plating bath containing multiple types of metal ions forming alloy components;
The object to be plated is immersed in the bath, the anode and the insoluble anode made of each of the plurality of metals, the positive terminals are connected to the anodes respectively, and the negative terminals are collectively connected to the object to be plated. An alloy plating device comprising a plurality of constant current adjustable rectifiers, one regulator that adjusts the sum of output currents of the plurality of rectifiers, and separate regulators that set the current share of each rectifier. .