JPH05295555A - Device for automatically controlling plating solution - Google Patents

Abstract

PURPOSE:To precisely control the concns. of the components constituting a plating soln. without delay at all times and to automatically control the plating soln. capable of being used even for a high-speed plating. CONSTITUTION:The various components of a plating soln. 3 are analyzed by an analyzer 11, and the replenishing rate of various replenishing agents from a replenishing pump 7 is controlled by this device so that the results of analysis are controlled to the target concn. set by an input unit 15. A fuzzy inference is conducted by a controller 20 with the rate of change in the concns. of the components per unit time and the deviation between the concn. and the target concn. as the input information to obtain the corrected replenishing rate of the various replenishing agents and the replenishing rate of the respective replenishing agents is feedback-controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic plating solution control apparatus for automatically controlling the concentrations of various components of a plating solution to predetermined concentrations.

[0002]

2. Description of the Related Art Conventionally, as a device for automatically controlling the concentration of a plating solution, the concentration of a desired component in the plating solution is automatically analyzed, and the concentration of the desired component in the plating solution is determined based on the analysis result. When it is detected that the concentration is below, a device that automatically replenishes the required amount of replenisher to bring the concentration back to the specified concentration, and the amount of plating solution components consumed per unit time is calculated from the surface area of the plated material during plating. There is known a device (Japanese Patent Laid-Open No. 61-199069) or the like for supplying the consumed amount and continuously analyzing the components of the plating solution to adjust the supplied amount according to the density of the concentration.

[0003]

However, in the former device, after the plating solution is sampled, the concentrations of the components of interest in the plating solution are analyzed, and the results of the analysis show that the concentration has dropped below a predetermined concentration. Therefore, there is a time lag from the sampling of the plating solution to the addition of the replenisher because the replenisher is added in the required amount. Therefore, the concentration of the required component in the plating solution at the time of adding the replenishing agent may be significantly different from the concentration of the required component in the plating solution at the time of sampling, and even if the replenishing agent is added, the concentration of the required component is There is a problem that the density is not adjusted to a predetermined level. And these problems, strictly control the concentration of the plating solution to the narrowest possible range,
This is a great obstacle to making the physical properties of the plating film and the plating rate uniform.

On the other hand, in the latter device, the plating film deposition amount per unit time calculated from the surface area of the object to be plated under a constant plating solution composition and plating conditions,
Since the consumption amount of the required component in the plating solution per unit time is calculated and the required component is replenished to the plating solution in an amount according to the consumption amount, there is no time lag as in the former device. However, when the concentration of the plating solution is maintained at a predetermined control concentration and it is not necessary to adjust the amount of the replenisher, it is possible to control the concentration of the required component to a certain degree.

However, even in this apparatus, it is necessary to analyze the concentrations of the required components in order to confirm whether or not the plating solution concentration is maintained at a predetermined control concentration, and the plating solution concentration is maintained at a predetermined control concentration. If it is confirmed that the replenishing agent has not been supplied, it is necessary to control the supply of the replenishing agent, decrease the replenishing amount of the replenishing agent, increase the replenishing amount of the replenishing agent, and control to add another replenishing agent. Therefore, in performing such control, after all, similarly to the former device, a time lag occurs from the analysis of the plating solution to the addition of the replenisher, and the plating solution concentration cannot be maintained within a predetermined narrow range.
There arises a problem that the physical properties of the plating film and the plating rate cannot be made uniform.

Further, this apparatus is effective only under a certain plating solution composition and plating conditions. If the surface area of the object to be plated, the plating conditions, etc. are different, the control law must be changed each time. However, there is a problem that management is troublesome. Furthermore, each of the above-mentioned conventional devices assumes a case where the plating speed is slow, such as about 20 hours. In this case, the change in the concentration of each component is small and the replenishment amount accompanying it is small, so it is effective to some extent. However, it cannot be used in high-speed plating, for example, in which the plating time is about 2 hours, because the plating reaction is fast and the concentration change is large. That is, in the above conventional apparatus, it is impossible to grasp the state at the moment when the concentration is measured, such as whether the concentration is rising, falling, or leveling (in the past, the plating time is as long as 20 hours and the plating speed is slow, so the concentration change is small). It was almost flat)
Therefore, it is impossible to accurately control the concentration.

The present invention has been made in view of the above problems, and provides an automatic plating solution management apparatus capable of always accurately controlling the concentrations of various components constituting the plating solution without a response delay and applicable to high-speed plating. The purpose is to

[0008]

Means for Solving the Problems That is, the present invention made to achieve the above-mentioned object is, as illustrated in FIG. 1, various types of plating solutions consumed by plating in a plating tank containing a plating solution. Replenishing means for replenishing each component as a replenishing agent, plating condition inputting means for inputting the target concentration of each replenishing agent in the plating solution and the plating condition of the material to be plated, and the plating condition inputting means. Control amount calculating means for calculating the replenishing speed or the replenishing amount of each replenishing agent replenished by the replenishing means based on the target concentration of each replenishing agent in the plating solution and the plating condition of the material to be plated, and the control amount calculation Automatic management device for plating solution, comprising: replenishment control means for controlling the replenishment rate or the replenishment rate of each replenisher from the replenishment means to the plating tank according to the replenishment rate or the replenishment rate calculated by the means. To The concentration of the plating solution in the plating tank, based on the analysis result by the concentration analysis means for analyzing each of the replenisher and the plating solution concentration analysis means, the change amount of each replenisher concentration per unit time, A concentration change amount calculating means for calculating, a deviation between the concentration of each replenisher analyzed by the concentration analyzing means and a target concentration, and a change amount of each replenisher concentration calculated by the concentration change amount calculating means, A storage means that stores in advance a fuzzy rule representing a relationship between the replenishment speed of each replenisher or a correction amount of the replenishment amount, and a deviation between the concentration of each replenisher analyzed by the concentration analysis means and a target concentration, And the amount of change of each replenisher concentration calculated by the concentration change amount calculation means as input information, and using the fuzzy rule stored in the storage means, the replenishment speed of each replenisher or the correction amount of the replenishment amount. Fuzzy reasoning about Correction amount setting means for setting the correction rate of the replenishing speed or the replenishing amount of each replenishing agent, and the replenishing speed or the replenishing amount calculated by the control amount calculating means is corrected by the set correction amount. An automatic plating liquid management device is characterized in that: a control amount updating means for changing a replenishing speed or a replenishing amount of each replenishing agent controlled by the replenishing controlling means.

[0009]

In the automatic plating solution management apparatus of the present invention having the above-described structure, the control amount calculation means first sets the target concentration of each replenisher in the plating solution input from the plating condition input means and the plating target. Based on the plating condition of the material, the replenishing means calculates the replenishing speed or the replenishing rate of each replenishing agent to be replenished to the plating tank, and the replenishment controlling means performs the plating from the replenishing means in accordance with the calculated replenishing speed or the replenishing rate. The replenishment speed or the replenishment amount of each replenisher to the tank is controlled.

Further, in the present invention, the concentration analysis means analyzes the concentration of the plating solution in the plating tank for each replenishment agent, and the concentration change amount calculation means calculates the unit of each replenishment agent concentration based on the analysis result. Calculate the amount of change over time. Then, the correction amount setting means uses the deviation between the concentration of each replenisher analyzed by the concentration analysis means and the target concentration, and the amount of change in each replenisher concentration calculated by the concentration change amount calculation means as input information, Using the fuzzy rules stored in the storage means, the correction rate of the replenishment speed or the replenishment amount of each replenisher is set, and the control amount updating means
The replenishment speed or the replenishment amount calculated by the control amount calculation means is corrected by the set correction amount to change the replenishment speed or the replenishment amount of each replenisher controlled by the replenishment control means.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 2 is a schematic configuration diagram showing the overall configuration of an automatic plating solution management apparatus of an embodiment to which the present invention is applied.

As shown in FIG. 2, the automatic management apparatus of this embodiment is a plating apparatus that performs plating with the electroless copper plating solution 3 contained in the plating tank 1, and the plating consumed by the plating in the plating solution 3 is performed. Liquid component, copper (C
u), sodium hydroxide (NaOH), formalin (H
CHO) concentration control, and a replenisher tank 5 containing these plating solution components as replenishers, and replenishers Cu, NaOH, HCH contained in the replenisher tank 5.
Replenishment pump 7 for individually replenishing O to plating tank 1, pumping pump 9 for sampling plating solution 3 in plating tank 1, Cu concentration and NaOH in plating solution 3 sampled by pumping pump 9 Analyzer 11 for analyzing the concentration and HCHO concentration, and the replenisher Cu in the plating solution 3,
The input device 15 for setting the plating conditions such as the target concentration of NaOH and HCHO and the surface area of the material to be plated 13, and the replenishment pump 7 based on the plating conditions set by the input device 15 and the analysis result by the analysis device 11. The control device 20 controls the replenishment rate of each replenishing agent Cu, NaOH, and HCHO. The analysis device 11 is
In addition to the concentrations of the above replenishers in the plating solution 3, the measurement temperature and Ph of the plating solution 3 can be measured.

Next, the control device 20, as shown in FIG.
The CPU 20a, the ROM 20b, the RAM 20c and the like are mainly configured as a well-known microcomputer, and Cu output from the analyzer 11 is used as an input / output interface.
Concentration, NaOH concentration, HCHO concentration, measurement temperature and Ph
Analysis result input unit 20d for inputting a signal indicating the replenishment agent, replenishment agents Cu, NaOH, and HCHO set by the input device 15.
Plating concentration input section 20e for inputting a signal representing the target concentration of the target material and the surface area of the material 13 to be plated, each replenisher Cu, NaO
A replenishment command output unit 20f that outputs a control signal for controlling the replenishment speed of H and HCHO to the replenishment pump 7 is provided.

The ROM 20b stores a control program for executing the above-mentioned replenishment speed control, as well as data such as fuzzy rules and membership functions, which will be described later, necessary for executing this control program. Then, when the various plating conditions are input via the input device 15 by the operation of the CPU 20a, the control device 20 stores the various plating conditions in the RAM 20c, and thereafter, the analysis device 11
Each time the concentration of the replenishing agent Cu, NaOH, HCHO is given from, the amount of change in the replenishing agent concentration is calculated and stored in the RAM 20c.
H2, HCHO concentration, amount of change in replenisher concentration, ROM2
Based on the fuzzy rule and membership function in 0b, the replenishment rate of each replenishment agent Cu, NaOH, HCHO is calculated, and a control signal according to the calculation result is sent to the replenishment pump 7, and the replenishment pump 7 calculates it. Each of the replenishers Cu, NaOH, and HCHO is replenished to the plating tank 1 at the replenishment rate.

Hereinafter, the replenishment speed control process executed by the CPU 20a will be described with reference to the flowchart shown in FIG. It should be noted that this replenishment speed control process is performed by replenishing the replenishment agents Cu, NaOH, HCHO from the input device 15.
The description will be made assuming that the plating conditions such as the target concentration and the surface area of the material to be plated 13 are input and the plating conditions are stored in the RAM 20a in advance.

As shown in the figure, when this process is started,
First, in step 110, the material to be plated 13 is placed in the plating tank 1.
It is determined whether or not is input. If the material 13 to be plated has been placed in the plating tank 1, it is determined in the following step 120 whether or not the material 13 to be plated is currently being placed. For example, the process proceeds to step 130, and based on the target concentrations of the replenishers Cu, NaOH, and HCHO stored in the RAM 20a and the surface area (plating load) of the plated material 13, the replenishers Cu during plating, The initial value of the replenishment rate of NaOH and HCHO is calculated. Then, in the following step 140, the replenishment speed command corresponding to this calculation result is output to the replenishment pump 7, and the process proceeds to step 110 again.

On the other hand, when it is judged in step 120 that it is not immediately after the material 13 to be plated is put in, that is,
If the material 13 to be plated has already been plated,
In step 150, the concentrations of the replenishers Cu, NaOH, and HCHO analyzed by the analyzer 11 are read, and in the subsequent step 160, the replenisher C read this time is read.
Based on the concentrations of u, NaOH, and HCHO and the concentrations of the replenisher Cu, NaOH, and HCHO read last time, each replenisher Cu,
The amount of change in the concentration of NaOH or HCHO per unit time is calculated.

Then, the process proceeds to the following step 170, and the calculated amount of change in concentration of each replenishing agent Cu, NaOH, HCHO and each replenishing agent Cu, NaOH, HC read this time.
From the HO concentration and the target concentrations of the replenishers Cu, NaOH, and HCHO, fuzzy inferences are made on the correction amounts of the replenishment rates of the replenishers Cu, NaOH, and HCHO, and the replenishers Cu, N
Update the supply rate of aOH and HCHO,
Then, the replenishment speed command corresponding to the updated replenishment speed is output to the replenishment pump 7, and the process proceeds to step 110 again.

Next, when it is judged in the above step 110 that the material to be plated 13 is not being put into the plating tank 1, it is determined that the step is to proceed to step 180.
At present, it is determined whether or not the material to be plated 13 has just been taken out of the plating tank 1. And now, the plated material 1
Immediately after the removal of No. 3, the process proceeds to step 190, and the target concentrations of the replenishing agents Cu, NaOH, and HCHO stored in the replenishing agent RAM 20a are reduced in order to reduce the replenishing rate of the replenishing agents Cu, NaOH, and HCHO. And plated material 13
Based on the surface area of each, the replenisher Cu, NaO at the time of building bath
The initial values of the replenishment speeds of H and HCHO are calculated, the process proceeds to the subsequent step 140, and the replenishment speed command corresponding to this calculation result is output to the replenishment pump 7, and then step 110 is executed again.
Move to.

On the other hand, if it is determined in step 180 that the material to be plated 13 is not immediately removed from the plating tank 1, the process proceeds to step 200 and the analyzer 1
The concentration of each replenishing agent Cu, NaOH, and HCHO analyzed in 1 is read, and in the following step 210, the change amount per unit time of the concentration of each replenishing agent Cu, NaOH, and HCHO is calculated as in step 150 above. To do. Then, in the following step 220, as in the case of the above step 170, the correction amounts of the replenishing speeds of the replenishing agents Cu, NaOH, and HCHO are fuzzy inferred to determine the replenishing agents Cu, NaOH, and HCHO.
Update the replenishment speed of and move to the following step 140,
A replenishment speed command corresponding to the updated replenishment speed is output to the replenishment pump 7, and the process proceeds to step 110 again.

As described above, in the present embodiment, the respective replenishment agents Cu are respectively added at the time of plating when the material 13 to be plated is placed in the plating tank 1 and at the time of the construction bath when the material 13 to be plated is taken out of the plating tank 1. , NaOH and HCHO are fuzzy inferred for the correction amount of the replenishment rate, and the replenishment rate is updated.

Then, the fuzzy inference procedure executed in steps 170 and 220, and the membership function and fuzzy rule used in executing the fuzzy inference will be described in detail. First, FIG. 5, FIG. 6 and FIG. 7 respectively show the membership functions for the replenishers Cu, NaOH and HCOH used in this fuzzy reasoning. In addition, the horizontal axis of each membership function shown in each figure corresponds to each value shown in the figure, and the vertical axis shows "the degree of certainty" according to the value.
(Hereinafter referred to as “confidence level”).

FIG. 5A is a characteristic diagram showing a membership function relating to the concentration of the replenishing agent Cu. This C
The fuzzy set of u concentration is “very small (NL)”, “small (NM)”, “slightly small (NS)”, “same as target concentration (ZR)”, and “slightly large” with respect to the Cu target concentration. (PS) ”,“ large (PM) ”, and“ significantly large (PL) ”are divided into seven stages of fuzzy sets, and each membership function forms a membership function related to the Cu concentration.

Next, FIG. 5B is a characteristic diagram showing a membership function relating to the amount of change in the concentration of the replenishing agent Cu.
The fuzzy set of the Cu concentration change amount is “very small (NL)”, “slightly small (NS)”, “no change (Z
R) ”,“ Slightly large (PS) ”,“ Very large (P)
L) ”is divided into five stages of fuzzy sets, and each membership function forms a membership function regarding the Cu concentration change amount.

FIG. 5 (c) is a characteristic diagram showing the membership function relating to the current replenishment rate of the replenishment agent Cu. The fuzzy set of the Cu current replenishment rate is "small (N)" or "large ( P) ”is divided by a two-stage fuzzy set, and C is determined by each membership function.
u Currently forming a membership function for replenishment rate.

Further, FIG. 5D is a characteristic diagram showing a membership function relating to the replenishment rate of the replenishment agent Cu,
This fuzzy set of Cu replenishment rate is “remarkably reduced (NL)”, “reduced (NM)”, “slightly reduced (NS)”, “current state maintained (ZR)” with respect to the current replenishment rate. , "Slightly increase (PS)", "Increase (P)
M) ”,“ Significantly increase (PL) ”, and are divided into sets of 7 sizes, and Cu is defined by each membership function.
It forms a membership function related to replenishment speed.

Next, FIG. 6A is a characteristic diagram showing a membership function relating to the concentration of the replenishing agent NaOH, and this fuzzy set of NaOH concentration is similar to the above-mentioned fuzzy set of Cu concentration with respect to the target NaOH concentration. “Small (NL)”, “Small (NM)”, “Slightly small (NS)”, “Same as target concentration (ZR)”, “Slightly large (PS)”, “Large (PM)”, It is segmented by a 7-step fuzzy set of “pretty large (PL)”.

FIG. 6 (b) is a characteristic diagram showing a membership function relating to the amount of change in the concentration of the replenishing agent NaOH, and this fuzzy set of the amount of change in the NaOH concentration is similar to the fuzzy set of the amount of change in the Cu concentration. "It's quite small (N
L) ”,“ Slightly small (NS) ”,“ No change (Z
R) ”,“ Slightly large (PS) ”,“ Very large (P)
L) ”is divided into five stages of fuzzy sets.

FIG. 6 (c) is a characteristic diagram showing a membership function relating to the current replenishment rate of the replenisher NaOH, and the fuzzy set of this NaOH current replenishment rate is C
u Like the fuzzy set of the current supply speed, it is divided into two stages of fuzzy sets of “small (N)” and “large (P)”.

Further, FIG. 6 (d) is a characteristic diagram showing the membership function relating to the replenishment rate of the replenishing agent NaOH, and this fuzzy set of NaOH replenishment rate is the same as the current replenishment rate as the fuzzy set of Cu replenishment rate. For speed,
Replenishment speed is "remarkably reduced (NL)" and "reduced (N
M) ”,“ Slightly reduce (NS) ”,“ Maintain current status (Z)
R) ”,“ Slightly increase (PS) ”,“ Increase (P)
M) ”and“ significantly increase (PL) ”.

Next, FIG. 7A is a characteristic diagram showing a membership function relating to the concentration of the replenisher HCHO,
This fuzzy set of HCHO concentration is the above Cu concentration, N
Similar to the fuzzy set of aOH, “substantially small (NL)”, “small (NM)”, and
"Slightly small (NS)", "Same as target concentration (Z
R) ”,“ Slightly large (PS) ”,“ Large (P)
M) ”and“ quite large (PL) ”are classified into seven stages of fuzzy sets.

FIG. 7B is a characteristic diagram showing a membership function relating to the amount of change in the concentration of the replenisher HCHO. The fuzzy set of the amount of change in HCHO concentration is the fuzzy set of the amount of change in Cu and the fuzzy set of NaOH. Similarly, it is classified by a five-step fuzzy set of “pretty small (NL)”, “slightly small (NS)”, “no change (ZR)”, “slightly large (PS)” and “pretty large (PL)”. ing.

FIG. 7 (c) is a characteristic diagram showing the membership function relating to the current replenishment rate of the replenisher HCHO, and the fuzzy set of the HCHO current replenishment rate is C
u Like the current supply speed and the fuzzy set of NaOH, it is divided into two stages of fuzzy sets of “small (N)” and “large (P)”.

Further, FIG. 7D is a characteristic diagram showing a membership function relating to the replenishment rate of the replenishing agent HCHO. The fuzzy set of the HCHO replenishment rate is the same as the fuzzy set of the Cu replenishment rate and the NaOH replenishment rate. , The supply speed is reduced considerably compared to the current supply speed (N
L) ”,“ Reduce (NM) ”,“ Slightly reduce (N
S) ”,“ Maintain current status (ZR) ”,“ Slightly increase (P
S) ”,“ Increase (PM) ”,“ Increase significantly (P)
L) ”is divided into a set of 7 sizes.

Next, the fuzzy rule at the time of plating used in the above step 170 is the concentration of the replenishers Cu, NaOH and HCOH set as described above, the amount of change in concentration, the current replenishment rate, and the replenishment rate. [Table 1] to [Table 3] are set based on the membership function regarding the above, and the fuzzy rule at the time of bathing used in the above step 220 is based on the above membership functions. Are set as shown in [Table 4] to [Table 6].

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

[Table 5]

[0041]

[Table 6]

[Table 1] to [Table 3] and [Table 4]
[Table 6] shows each replenishment agent C at the time of plating and at the time of bathing, respectively.
A fuzzy rule table relating to the replenishment agent replenishment speed, which is a conditional expression of the replenishment agent concentration and the variation amount of the replenishment agent set for each of u, NaOH, and HCOH, is shown. It is intended to use the membership function for the current replenishment rates of the replenishers Cu, NaOH, HCHO under certain combination conditions with agent changes.

That is, for example, the fuzzy rules shown in Table 1 are: (1) If the Cu concentration is considerably smaller than the target concentration (NL). The amount of change in Cu concentration has increased considerably (P
L). Then, the Cu replenishment rate is maintained as it is (ZR).

(2) If the Cu concentration is much smaller than the target concentration (NL). The Cu concentration change amount is slightly increasing (PL). If so, increase the Cu replenishment rate (P
M). (3) If the Cu concentration is much smaller than the target concentration (NL).

The amount of change in Cu concentration is zero (ZR).
Then, the Cu replenishment rate is considerably increased (PL). (4) If the Cu concentration is much smaller than the target concentration (NL). The amount of change in Cu concentration is slightly reduced (N
S).

Then, the Cu replenishment rate is considerably increased (PL). (5) If the Cu concentration is much smaller than the target concentration (NL). The amount of change in Cu concentration has decreased considerably (N
L). If so, the Cu replenishment rate is considerably increased (P
L).

(6) If the Cu concentration is lower than the target concentration (NM). The amount of change in Cu concentration has increased considerably (PL). If so, reduce the Cu replenishment rate slightly (N
S). (7) If the Cu concentration is smaller than the target concentration (N
M).

The Cu concentration change amount is slightly increased (P
L). Then, the Cu replenishment rate is maintained as it is (ZR). (8) If the Cu concentration is smaller than the target concentration (N
M). The amount of change in Cu concentration is zero (ZR).

Then, the Cu replenishment rate is slightly increased (P
S). (9) If the Cu concentration is smaller than the target concentration (N
M). The amount of change in Cu concentration is slightly reduced (NS).
If so, increase the Cu replenishment rate (PM).

(10) If the Cu concentration is smaller than the target concentration (NM). The amount of change in Cu concentration is considerably reduced (NL). If so, increase the Cu replenishment rate (PM). (11) If the Cu concentration is slightly lower than the target concentration (N
S).

The amount of change in Cu concentration has increased considerably (PL). If so, reduce the Cu replenishment rate (NM). (12) If the Cu concentration is slightly lower than the target concentration (N
S). The Cu concentration change amount is slightly increasing (PL).

Then, the Cu replenishment rate is maintained as it is (Z
R). (13) If the Cu concentration is slightly lower than the target concentration (N
S). The amount of change in Cu concentration is zero (ZR). Then, the Cu replenishment rate is maintained as it is (ZR).

(14) If the Cu concentration is slightly lower than the target concentration (NS). The amount of change in Cu concentration is slightly reduced (NS). If so, increase the Cu replenishment rate slightly (P
S). (15) If the Cu concentration is slightly lower than the target concentration (N
S).

The amount of change in Cu concentration is considerably reduced (NL). If so, increase the Cu replenishment rate (PM). (16) If the Cu concentration is the same as the target concentration (ZR). C
The amount of change in u concentration has increased considerably (PL).

Then, the Cu replenishment rate is reduced (N
M). (17) If the Cu concentration is the same as the target concentration (ZR). C
The u concentration change amount is slightly increased (PL). Then,
Cu replenishment speed is slightly reduced (NS).

(18) If the Cu concentration is the same as the target concentration (ZR). The amount of change in Cu concentration is zero (ZR). Then, the Cu replenishment rate is maintained as it is (ZR). (19) If the Cu concentration is the same as the target concentration (ZR).

The amount of change in Cu concentration is slightly decreased (N
S). Then, the Cu replenishment rate is slightly increased (PS). (20) If the Cu concentration is the same as the target concentration (ZR). C
The amount of change in u concentration has decreased considerably (NL).

If so, increase the Cu replenishment rate (P
M). (21) If the Cu concentration is the same as the target concentration (ZR). C
The amount of change in u concentration has decreased considerably (NL). NaO
H Current replenishment speed is low (N).

HCHO current replenishment rate is small (N).
If so, increase the Cu replenishment rate (PS). (22) If the Cu concentration is slightly higher than the target concentration (P
S). Then, the Cu replenishment rate is slightly reduced (NS).

(23) If the Cu concentration is higher than the target concentration (PM). If so, reduce the Cu replenishment rate (N
M). (24) If the Cu concentration is considerably higher than the target concentration (PL). If so, reduce the Cu replenishment rate considerably (N
L).

The fuzzy rule is summarized in the table. As in the rules (20) and (21) above, the Cu concentration is the same as the target concentration (ZR), and the amount of change in Cu concentration is considerably reduced. If (NL), the membership functions of the NaOH current replenishment rate and the HCHO current replenishment rate are further used.

This is because, for example, since the Cu replenishing agent is alkaline, when it is replenished, the alkalinity becomes strong and it is necessary to reduce the NaOH replenishing amount.
This is because the concentrations of u, NaOH, and HCHO affect each other, and according to the above rule, each replenisher Cu, NaOH,
The HCHO replenishment speed can be controlled comprehensively and optimally.

The fuzzy rules shown in [Table 2] to [Table 6] are basically set in the same manner as described above.
The fuzzy rules described as "NS / PS" and "PM / PS" in [Table 2] and the fuzzy rules described as "PM / PS" in [Table 3] are set as follows, respectively. There is.・ “NS / PS” in [Table 2] (a) If the NaOH concentration is the same as the target concentration (Z
R).

The amount of change in the NaOH concentration is slightly reduced (NS). Cu current replenishment rate is small (N). Then, the NaOH replenishment rate is slightly reduced (NS). (b) If the NaOH concentration is the same as the target concentration (Z
R).

The amount of change in NaOH concentration is slightly reduced (NS). Cu current replenishment rate is high (P). Then, increase the NaOH replenishment rate slightly (PS). -[PM / PS] in [Table 2] (c) If the NaOH concentration is the same as the target concentration (Z
R).

The amount of change in the NaOH concentration is considerably reduced (NL). If so, increase the NaOH replenishment rate (P
M). (d) If the NaOH concentration is the same as the target concentration (Z
R). The amount of change in NaOH concentration has decreased considerably (N
L).

The current Cu supply rate is small (N). HC
HO current replenishment speed is low (N). Then, NaOH
Increase the replenishment speed slightly (PS).・ "PM / PS" in [Table 3] (e) If the HCHO concentration is the same as the target concentration (Z
R).

The amount of change in HCHO concentration is considerably reduced (NL). If so, increase the HCHO replenishment speed (P
M). (f) If the HCHO concentration is the same as the target concentration (Z
R). The amount of change in HCHO concentration has decreased considerably (N
L).

The current Cu supply rate is small (N). Na
OH current replenishment rate is low (N). Then HCHO
Increase the replenishment speed slightly (PS). Further, in [Table 4] to [Table 6], the fuzzy rule described as "abnormal" is
Under each condition, the current supply rate of each of the replenishers Cu, NaOH, and HCHO is maintained, and it is displayed on a display device (not shown) that "pump abnormality, plating abnormality may occur", and [Table 4]. ~ In [Table 6], the fuzzy rule described as "stop" indicates that each supplement C
It indicates that the supply of u, NaOH and HCHO is stopped.

Next, according to the fuzzy rules shown in [Table 1] to [Table 6] and the membership function shown in FIG. 5 to FIG. Will be described with reference to the flowchart shown in FIG. The fuzzy inference shown in FIG. 8 is executed for each replenisher Cu, NaOH, HCHO.

As shown in FIG. 8, first, in step 300, a fuzzy rule used for fuzzy inference is selected depending on whether it is currently plating or bathing. That is, whether to use the rules for plating shown in [Table 1] to [Table 3] or the rules for bathing shown in [Table 4] to [Table 6] for fuzzy inference Select.

Next, at step 310, replenishers Cu, N
The deviation between the target concentration of aOH and HCHO and the actual concentration of the replenisher Cu, NaOH, and HCHO analyzed by the analyzer 11 is obtained, and the concentration deviation and the change amount of the replenisher concentration obtained in step 160 or step 210 Based on, and the confidence factor for each of these input variables is obtained from each of the membership functions.

Next, at step 320, it is selected which of the above fuzzy rules the fuzzy set to which the above variables belong, and the concentration deviations of the replenishing agents Cu, NaOH and HCHO for each of the applicable fuzzy rules. And the confidence of the change amount of the replenisher concentration are compared, and the smallest confidence is set as the minimum confidence. In this case, if it is necessary to see the current replenishment speed of the replenishment agents Cu, NaOH, and HCHO in the fuzzy rule selected by the concentration deviation of the replenishment agents Cu, NaOH, and HCHO and the change amount of the replenishment agent concentration, The certainty factor is also obtained for the fuzzy set, and the minimum certainty factor is set.

Then, in the following step 330, the weighting process based on the minimum certainty factor is applied to the membership function concerning the replenishment rate of each replenishing agent Cu, NaOH, HCHO, and in the next step 340, the weighting process is performed for each fuzzy rule. The membership function relating to the replenishment rate of the replenished replenishers Cu, NaOH, and HCHO is represented by each replenisher C.
All of u, NaOH, and HCHO are overlaid to create a membership function for a new replenishment rate by union.

Finally, in step 350, the centroid value G of the new membership function created in step 340 is calculated, and the centroid value G is used as the replenishing agent Cu, NaOH,
Determined as a correction value for the HCHO replenishment speed. Next, a specific example of the above fuzzy inference will be described with reference to FIG. In FIG. 9, 1.9 [g / l] is set as the target value of Cu concentration (target concentration), and the Cu concentration (CU) analyzed by the analyzer 11 is 1.73 [g / l]. ,
Cu concentration variation (CUCV) is -0.03 [g / l ・ m
in], an inference example of a Cu replenishment rate correction value (CUPV) at the time of plating is shown.

As shown in FIG. 9, the Cu concentration (CU) is
2 "small (NM)" and "somewhat small (NS)"
Cu concentration change amount (CUCV)
Is "slightly decreased (NS)" and "is zero (Z
R) ”. Therefore, the above-mentioned four rules (8), (9), (13) and (14) are selected as the fuzzy rules including these sets.

As for the certainty factor of the fuzzy set NM of Cu concentration, the deviation between the Cu concentration and the Cu target concentration is 0.17 [g
/ L], the value is 0.76, and the certainty factor of the fuzzy set NS having the same Cu concentration is 0.24. On the other hand, C
Since the Cu concentration change amount is −0.03 [g / l · min], the certainty factor of the fuzzy set NS of the u concentration change amount is
0.7, which is also the fuzzy set Z of the Cu concentration change amount
The confidence of R is 0.3.

Therefore, the above rules (8), (9), (13), (14)
Has a minimum confidence of 0.7, 0.9, 0.24, 0.24
Therefore, the membership function regarding the weighted Cu replenishment rate is obtained for each of the rules (8), (9), (13), and (14). Then, by adding all these membership functions, a new membership function relating to the Cu replenishment rate is created, the center of gravity G is calculated for this membership function, and the correction value C of the Cu replenishment rate is calculated.
UPV is determined.

As described above, in this embodiment, the correction amounts of the replenishment rates of the replenishers Cu, NaOH, and HCHO are set to the difference between each component concentration in the plating solution and the target concentration, and the unit time of each component concentration. Per change, and each replenisher Cu, NaO
The current replenishment rates of H and HCHO are obtained by fuzzy inference, and the replenishment rates of the replenishers Cu, NaOH, and HCHO are controlled.

Therefore, the replenishers Cu and N in the plating solution are
Depending on the concentration changes of aOH and HCHO, each replenisher Cu,
The replenishment rates of NaOH and HCHO can always be optimally controlled, and the plating solution can be well managed even when high-speed plating is performed.

Further, in this embodiment, in fuzzy inference of the replenishment rate correction value of a certain replenisher, the current replenishment rate of another replenisher is also taken into consideration, so that the plating solution should be managed comprehensively. You can That is, when each replenishment agent influences each other, conventionally, the addition of each replenishment agent is adjusted based on the empirical know-how of a skilled person, but in the present embodiment, such a skilled person is used by the fuzzy rule. It is possible to manage the plating solution, including the empirical know-how.

In this embodiment, a triangular or trapezoidal membership function is used as the membership function.
The form of such a membership function may be a form that conforms to the control specifications, and may be any form such as a bell type as long as no contradiction occurs in the fuzzy operation.

The fuzzy rule used in this embodiment is an example, and by adding an input variable,
More optimal plating solution management can be performed. For example, in the above embodiment, the temperature of the plating solution and the P of the plating solution are
About h etc., it was not taken in as an input variable,
By taking these as input variables and adding new fuzzy rules and membership functions, the plating solution can be controlled more optimally.

Further, in the present embodiment, the plating apparatus for performing electroless copper plating has been described, but the present invention can be applied to other plating apparatuses having different plating solution components to optimally control the component concentration of the plating solution. It becomes possible to do. Further, in the present embodiment, in the device for constantly supplying the replenishment material,
Although the case of controlling the replenishment speed has been described, the present invention is also applied to a device that periodically replenishes replenishment material and the replenishment amount at the time of replenishment is controlled, and the same effect as above is obtained. Can be obtained.

[0085]

As described above, in the automatic plating solution management apparatus of the present invention, the replenishment speed or the correction amount of the replenishment amount of each replenisher in the plating solution is set to the replenisher in the plating solution. Obtained by fuzzy reasoning using the input information as the difference from the target concentration and the amount of change in each replenisher concentration per unit time,
The replenishment speed or the replenishment amount of each replenishment agent is controlled. Therefore, the replenishment speed or the replenishment amount of each replenisher can always be optimally controlled according to the change in the concentration of each replenisher in the plating solution, and even when high-speed plating is performed, the control of the plating solution is performed. Can be satisfactorily performed.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a configuration of an entire plating liquid automatic management apparatus according to an embodiment.

3 is a block diagram illustrating an internal configuration of the control device 20 and a flow of various signals input to and output from the control device 20. FIG.

FIG. 4 is a flowchart showing a replenishment speed control process executed by the CPU 20a.

FIG. 5 is a graph showing a membership function regarding a replenisher Cu stored in a ROM 20b.

FIG. 6: Replenisher NaO stored in ROM 20b
It is a graph showing the membership function regarding H.

FIG. 7: Replenisher HCH stored in ROM 20b
It is a graph showing the membership function regarding O.

FIG. 8 is a flowchart showing a processing procedure for performing fuzzy inference on the correction value of the replenishment speed of each replenisher in steps 170 and 220 of FIG.

9 is an explanatory diagram illustrating a specific example of the fuzzy inference procedure illustrated in FIG.

[Explanation of symbols]

1 ... Plating tank 3 ... Plating solution 5 ... Replenisher tank 7
Replenishment pump 9 ... Pumping pump 11 ... Analysis device 13 ... Plated material 15 ... Input device 20 ... Control device 20a ... CPU
20b ... ROM 20c ... RAM 20d ... Analysis result input section 20e
… Plating condition input section 20f… Replenishment command output section

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Fumio Kojima 1-1, Showa-cho, Kariya City, Aichi Prefecture Nihon Denso Co., Ltd. (72) Inventor Nobumasa Ishida 1-1-Chome, Showa Town, Kariya City, Aichi Prefecture Within the corporation

Claims (1)

[Claims] 1. A replenishing means for replenishing a plating bath containing a plating solution with various components in the plating solution consumed by the plating as replenishing agents, and a target concentration of each of the replenishing agents in the plating solution and a plating target. The plating condition input means for inputting the plating conditions of the material, and the above-mentioned replenishing means replenishing based on the target concentration of each replenisher in the plating solution input from the plating condition input means and the plating conditions of the material to be plated. Control amount calculating means for calculating the replenishing speed or the replenishing amount of each replenishing agent, and each replenishing from the replenishing means to the plating tank according to the replenishing speed or the replenishing amount calculated by the control amount calculating means. A replenishment control means for controlling a replenishment speed or a replenishment amount of the agent, and a concentration analysis means for analyzing the concentration of the plating solution in the plating tank for each replenisher, Based on the analysis result by the plating solution concentration analysis means, a concentration change amount calculation means for calculating the change amount of each replenisher concentration per unit time, and the concentration of each replenisher analyzed by the concentration analysis means and the target concentration And a change amount of each replenisher concentration calculated by the concentration change amount calculating means and a replenishment speed or a correction amount of the replenishment amount of each replenisher, which is stored in advance as a fuzzy rule. Means, the deviation between the concentration of each replenishment agent analyzed by the concentration analysis means and the target concentration, and the change amount of each replenishment agent concentration calculated by the concentration change amount calculation means as input information, and the storage A fuzzy rule stored in the means is used to make a fuzzy inference regarding the correction amount of the replenishing speed or the replenishing amount of each replenishing agent, and the replenishing speed or the correction amount of the replenishing amount of each replenishing agent is set. When, Control amount updating means for correcting the replenishing speed or the replenishing amount calculated by the control amount calculating means by the set correction amount, and changing the replenishing speed or the replenishing amount of each replenisher controlled by the replenishment controlling means. An automatic plating solution management device characterized by being provided with.