JPS58130300A - Control device for electroplating - Google Patents

Abstract

PURPOSE:To apply electroplating of high quality in good yields and with high productivity, by using two control circuits for total currents in changing such as changing of passes, sizes, and line speeds, and controlling total currents continuously. CONSTITUTION:The reference current signal of a control circuit 20 for total current is inputted through a timing change-over circuit 10 to current control amplifiers 8-1-8-n of respective passes, by which the currents of plating power sources 4-1-4-n are controlled. Control circuits 20, 30 for total currents operate the reference signals of the total currents to provide prescribed plating thickness and output the reference signal of the electric power 1/n said signal to each pass. When the detecting means for an optimum current range in the circuit 20 emits commands for pass changing, etc. to a timing device 50, the device 50 outputs a tracking start command to a tracking device 40. According to the command from the device 40, the circuit 10 changes over the device 20 to the device 30 so as to avoid interruption in the control of the total currents.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Technical Field The present invention relates to an electroplating control device for continuously electroplating zinc, tin, nickel, aluminum, etc. onto a metal strip.

b. Prior Art It is known that metal strips (hereinafter referred to as metal strips) can be plated by passing an electrolytic solution through the metal surface C: the metal to be plated by applying an electric current. The industrial application of this principle to continuous production equipment is called a plating processing line (hereinafter referred to as a line).

In order to perform electroplating, these lines are arranged so that a plurality of plating tanks IA to IE are arranged in succession as shown in Fig. 1, and the metal strip 3 passes through them. . The details of the plating tanks IA to IE, which are installed in series, are shown in Figure 2 (2).The metal strip 3 enters the plating tank 11 through five rolls, passes through the sinking roll 6, and goes to the next roll 5B. Proceed. Roll 5 A * 5 B is connected to the member side of the plating power sources 4A to 4D. From C2, the metal strip 3 has a negative 4 position, and the plating material is connected to the positive side of the plating power sources 4A to 4D. By connecting as 2p, it becomes possible to apply a positive potential and plate the metal strip 3.The upper side of the metal strip 3 (=two electrodes).

Plating the upper surface of the metal strip between 2B and the metal strip 3, and electrodes 2C and 21) on the lower side of the metal strip 3.
The lower surface of the metal strip can be plated between the metal strip 3 and the metal strip 3. However, metal strip 3 and electrodes 2A-2
D must be filled in electrolyte 1'.

Each plating tank has a similar structure, but in one plating tank, plating on one side (
Since the plating (on the top side or the bottom side) is performed at two places, each plating power supply unit is referred to as a pass. That is, in FIG. 2, there are two passes for upper plating and 42 passes for lower plating.

When plating the metal strip 3 with the above configuration,
The following relationship holds true.

t 1. == / X W X 〒Song (2) v=
L 4... (3) (2) , (From formula 31, P: Plating adhesion amount I? + All 7 columns V; Line speed l; Plating length T; Time to pass through the plating length W: Metal strip width (plate width) In other words, the amount of plating deposited P is proportional to the upper or lower full-path current ■!The fastening coefficient, α, and the line speed V (
=//T). The plating coefficient α is the electrolyte concentration,
Plating effect rate, plating current density, electrical efficiency, etc. (depends on performance, but most of them are determined by electrolyte concentration.

If the current is not applied evenly to two paths, uneven plating will occur, so the amount of plating is 1; ,
It allows current to flow evenly.

In the conventional electroplating control device, it is necessary to control the entire current, so as shown in the control Kl system diagram in FIG.
(-Metting 1: Control is performed by comparing with the required total current-carrying path current. In other words, the total current reference signal is given from the reference device 6, and the total current control amplifier 7 controls the current from 1st path to nth path. A comparison operation is performed with the sum of the current detection signals of each path, and the result is given as a current reference signal for each path.Current control amplifier 8
−1 to g−n are compared with the current detection signal of its own path, and the current deviation signal is controlled to be zero (the second plating power supply 4 is controlled. Therefore, the plating current 1fπ-current control amplifier 8-1-8 The plating current is passed through each path according to the input C = given current reference signal, i.e. the output amount of the total current control amplifier 7. Since the output of the total current control amplifier 7 is given by the participating paths n C = 2, Each path (2 is l/n of total current
Outputs the current reference signal.

When the current value of one of the current paths changes due to some reason, if you want to continuously process the amount of plating deposited at a constant value, then from equation (4) (2), by changing the current flowing through all paths, the current flow will be Current is supplied to compensate for the changed current in paths other than the changed path. This is generally referred to as total current control.

In addition, in order to obtain good plating, there is an optimum current density determined by the plating material and the material to be plated (-), and good plating cannot be obtained even if the current density is exceeded or decreased.

However, the line speed is not always constant,
In addition, there are no lines that process only the same metal strip width (hereinafter referred to as plate width) and the same amount of plating,
If necessary, use formula (4) to energize all paths! When the upper limit of the optimum current is exceeded, a new C-pass is applied, and conversely, when the optimum current falls below the lower limit, some of the current-carrying paths are cut off. This work is called path switching.

In addition, if the amount of adhesion of the next material differs or if the width of the plate changes, a new all-pass current standard must be determined and a current commensurate with that must be applied. This operation is called resizing.

If the pass current is changed or the pass size is changed, the plating thickness on the metal strip 3 will change before the change is completed, making it difficult to obtain the desired plating thickness.
There are cases where the gauge becomes partially off-gauge. Among such cases, cases in which the plating thickness is less than a predetermined thickness are referred to as failure of adhesion resistance. However, if the material loses its adhesion resistance, it will not be able to be used as a product).

Generally, more plating is applied than the predetermined adhesion resistance.
Although the deposition resistance is avoided, the amount of deposition resistance increases, which is uneconomical when plating expensive metals.

Furthermore, when changing the size or changing the pass, the predetermined plating thickness changes depending on the line speed V and the board width W, as is clear from equation (4), so if you try to maintain the plating thickness, the size Change, line speed V until end of pass change
must be kept constant, and when changing sizes, the line speed must be kept constant and at the same time, total current control must be interrupted and manual operation must be performed. This requires complicated operations for the operator, and if this is done incorrectly, the amount of plating deposited will be off, leading to a decline in quality, slowness, and roughness, resulting in serious problems. ,it is obvious.

d. Purpose of the Invention The present invention has been made in view of the above-mentioned circumstances C and 2, and it is possible to track the processed material without interrupting the total current control in response to changes such as path change, size change, speed change, etc. The purpose of the present invention is to provide an electroplating control device that continuously performs total current control, has good quality and yield, and is highly productive.

e. Structure of the Invention Invention I: An embodiment showing the structure of an electroplating control device according to the present invention is shown in the control system diagram in FIG. Kinkei strip 3 is
Plating is performed by the electric power C2 supplied by the plating electric current 11 [4-1 to 4-n] between the rolls 5-1 to 5-n and the electrodes 2-1 to 2-n. The plating power supplies 4-1 to 4-n are magnetically controlled by current control amplifiers IB8-1 to f3-n of each path.

Current control amplifiers 8-1 to g-n are connected to total current control circuits (1), (2), 20 via timing switching circuit 10.
．． One of 30 current reference signals is input. The total current control circuits (1), (2), 20.30 calculate a total current reference signal for the metal strip 3 so that a predetermined plating thickness is obtained, Output a signal to each path.

Further, a path change command is issued to the timing device 50 from an optimal current range detection means (not shown) provided inside the total current control circuit (1), 20, and the timing device 50 outputs a tracking start command to the tracking device 40. . According to the command from the tracking device 40, the timing switching circuit 10 and the total current control calculation circuit (1), (
2), 20, and 30 perform the control operations described in the next section.

f. Effect of invention The operation of each device in the above configuration will be explained below.

Figure 7M5 is a diagram showing the energization state of each path when the number of paths is added. Figure 5(a) shows I from the Na3 path to the 5th bus.
・Indicates a state in which two currents (each path) are energized. The total current at this time is I,X3.

Now, the current flow value Io of each path is the upper limit of the optimal current density (=
Suppose that it becomes necessary to introduce a new bus.

The number of new paths must be determined such that the current density of each path is maintained at or above the lower limit of the optimum current density.

FIG. 5(b) shows a pattern in which it is necessary to input two buses as new paths. That is, from FIG. 5(a), tIi5
It is necessary to maintain a good plating state by changing the number of passes and current flow as shown in FIG.

3
)5×I! ≧ Lower limit of optimal current density ・・・・・・(6)
FIG. 6 is a flowchart of the tiling device 50.

When the optimum current range detection means provided inside the total current control calculation circuit (1) 20 detects the condition of the above-mentioned equation (5), from the energization state shown in FIG. 5 (Jl), the above-mentioned equation (6) Determine the rounded energization pattern (Figure 5(b)) that satisfies the conditions, and add a new current reference signal to the total current control calculation circuit (2) 30! ! is set, and the timing device 50I outputs the 1-nip pass change necessary command 51. The path change necessary command 5
1, the modified last used pattern shown in FIG. 5(b) is stored in the pattern storage means 53, and at the same time, the retrieval means 54 searches for the pass number on the most upstream side of the stored pattern. Enter the searched path number 55 into the tracking group [40].

FIG. 7 is a flowchart of the tracking device 140.

When the tracking group [40 receives the search path number 55, it issues a tracking start command 41, starts tracking, and at the same time changes the current reference signal Emma from the total current control circuit (2) 30 by the switching operation of the timing switching circuit 10. In response, one bus starts energizing as shown in FIG. 5(C).

With the start of tracking, when the point at the entrance C2 of the first path reaches the entrance of the second path, the 1 bus passage timing output signal 43 is generated, and the total current control 1 is performed by the switching operation of the timing switching circuit 10. )==II! Circuit (2) Current reference signal I from 30! In response to this, the 2-pass starts energizing as shown in FIG. 5(d).

Thereafter, the passing timing output signal 43 is issued sequentially as 3 passes, 4 passes, and 5 passes, and the switching operation of the timing switching circuit 10 causes the total current control IF1 circuit (1) 20 to change the total current Control 11 = 11 circuits (2) 30
Figure 5(e) shows the current reference signals I and I switching from
<0. (2) (D) The energizing current is sequentially switched as shown in Fig. 4.
1C: Connected and measured by the signal from the nine-pulse transmitter 60.

J! provides a detailed flowchart of the timing switching circuit 10. It is shown in Figure 8. When the above-mentioned pass number increase necessary command 51 or size change necessary command 52 is input to the timing switching circuit 10, it outputs the control start command 11 for total current control four paths (2) 20, and changes the number of paths from 1 bus to 5 passes. Based on the input signal of the passing tining output 43, the total current control circuit (2) outputs the built-in command 12 for performing total current control in 30 groups. (Metal) Each time IJ knob 3 passes one bus, the above built-in command 1 is executed.
2, both C and two total current control W circuits (1) output an exclusion command 13 to exclude from the total current control in 20 groups.

The nine inclusion commands 12 and exclusion commands 13 that are output are input to the total current control (b) paths (1), (2) 20, 301-.

The total current control circuits (1), (2) 20, and 30 are shown in FIG. When operating in the pattern shown in FIG. 5(a), the total current control circuit (1) 20 controls (
4) A total 1J1R standard (1) 21 that satisfies the formula is calculated, and is inputted to the total current control amplifier 23 via the correction circuit 22, and its output signal is used in the use path selection switchers 24-1 to 24.
-n, the current control amplifiers 8-1 to 8-n of each path
l is given as a current reference signal. In the energized state shown in Fig. 5(a), -3, Na41 N1 (not shown)
A current reference signal is given to the current control amplifier of each path of 5, and a feedback signal to the total current control amplifier 1) 23 is also
Na3+ N114. As it is returned from each path of 5 (
- A path selection switch (not shown) operates.

When attempting to change the size from the state shown in FIG. 5(a) to the pattern shown in FIG. 5(b), the necessary command 51 in FIG. )3
1, a control start command 11 for the total current control circuit (2) 30 is output from the timing switching circuit 10. Total current reference (2) 31 is equation (4).

A value that satisfies equation (6) is calculated and shown in FIG. 5(b).

Engineering! The current reference signal of 1 is outputted through the correction circuit 32 and the total current control amplifier 33, but the use path selection switch 34 is -1, and outputs a current reference signal to the current control amplifier 8-1 of the N1111 path. At this time, the current reference signal! ! is the value required to energize all paths (in Fig. 5), but since only the Na1 path is initially applied, the correction circuit 32 is configured to perform total NIL control of total current x 1/(number of final paths applied). The total current reference signal is corrected. This state is the energized state shown in FIG. 5(c)H.

Next, when the tracking point reaches the first bus passing position (second, the timing switching circuit 10 outputs the total current section from the timing switching circuit 10 from the passing signal 43 + 2 for each pass in FIG. 7). is output, and at the same time a command 12 for assembling the total current control circuit (2) into the group is output. Since it is not used, the exclusion command 13 is irrelevant.

When the installation command 12 is output, the -2 path is installed by the use path selection switch (not shown) and the correction circuit 3
2, total current control is performed using a total current reference signal of total current x 2/(number of final pass throwers).

At this time, the current feedback is N1111 path, m
2 bus is returned to the total current control amplifier 33. This state is shown in #I5 diagram (d).

Next, when the tracking point passes the second pass, the total current control circuit (2) 30 incorporates the Na3 pass.
Total current of (number of final passes input) [* Control is performed, total current control circuit (1) 20 is 13 passes removed, total current calculated by (number of passes before switching - 1) / (number of passes before switching) Switch to control. At this time, the feedback amount of the total current control amplifier 33 is the path of Nal+Na2, Na3,
The feedback amount of the total current control amplification 1!23 is N1
4. It becomes a pass of Na5.

This shaped nail is shown in FIG. 5(e).

Thereafter, proceed to the Na5 pass with C2 in the same way, and when the final pass is input, shift the position of total current control circuit (2) 30 to the standby state of total current control circuit (1) 20, The operation of the total current control circuit (2) 30 ends. The total current control after this point is controlled by the total current control circuit (1) 20 shown in FIG.

In the above explanation, the example of path switching is ζ2 and ζ9, and the total current control is shown as an example of two groups, but three or more groups may be used. In this case, you can expect better fine-grained control and an increase in line speed.

The descent is suitable for faster lines.

g Effects of the Invention As explained above, according to the electroplating control device of the present invention, it is possible to perform pass change and size change without interrupting total current control, and it is possible to perform pass change and size change without interrupting total current control. Even if the line speed is not kept constant, the plating resistance can be maintained at a predetermined value, and an electroplating control device with good quality and yield and improved productivity can be provided. I can do it.

[Brief explanation of drawings]

Fig. 1 is a diagram of the plating tank arrangement, Fig. #I2 is a detailed diagram of the plating cypress, Fig. 3 is a conventional control system diagram, Fig. 4 is a control system diagram according to the present invention, and Fig. 5 is a diagram of the energization state of each path. , FIG. 6 is a flow chart of the timing device [50], and FIG. 7 is a flowchart of the timing device [50].
8 is a flowchart of the timing switching circuit 1o, and FIG. 9 is a detailed diagram of the total current control circuit 20.30. 1.1A~IE...Plating tank 2A~2D, 2-1~2-n-electrode (plating material) 3...
・Metal strip 4A to 4D, 4-1.4-n-plating power supply 5A * 5
B e 5-1 + 5-n +++ Roll 6...Sinking roll 7.23.33...Total current control amplifier 8-1 to 8-
n... Current control amplifier 10... Timing switching circuit 20.30... Total current control circuit 40... Tracking device 50... Tie determining device 60... Pulse oscillator 61... Meter Roll for #j (7317) Agent Patent Attorney Noriyuki Chika (
(1 person) Figure 1 Figure 2 Figure 3 37 Nogsuuuuuuuuuuuuuuu-ηha0suuuuuu Figure 4 Figure 5 / 234. S □7gusN. (b) -m--"]-1 "t-Jl-" 1L-Jl-
2==2] 1r(9)-]]T Figure 6

Claims (1)

[Claims] In an electroplating control device in which a plurality of plating tanks are arranged in succession and a metal strip that moves continuously within the plurality of plating tanks is continuously plated in a plurality of passes, the plurality of buses 1
: a tracking device which is equipped with respective current control devices and detects and monitors the amount of movement of the metal strip; A second total current control circuit is provided, and the current reference signal of each of the current control devices is controlled by the first total current control circuit according to a command from the tracking device.
An electroplating control device characterized in that a timing switching circuit is provided for switching from the total current control circuit to the output signal of the second total current control circuit so that the total current control is performed continuously without interruption.