JP2003527477A - Regular chemical replenishment system - Google Patents

Abstract

  (57) [Summary] A method for controlling the components of a chemical bath includes the following steps. Determining a replenishment condition for the chemical bath, defining a unit of the replenishment condition, establishing a pacing coefficient corresponding to the replenishment capacity of the replenishment medium per unit replenishment condition, Defining a replenishment limit corresponding to a defined unit of replenishment conditions and a pacing factor product. In response to replenishment conditions such as elapsed time, amp-hours (or charge), number of product loads, product surface area, transmission rate per hour, etc., a continuous replenishment rate for a given component of the chemical bath is determined. You. This method replenishes the ingredients as they are actually consumed. It also prevents reductions (or increases if by-products are poured) and time delays associated with detection and correction. This system allows the operator to set the replenishment delivery calculation. Once these settings are established, the system automatically adjusts the replenishment rate based on the replenishment conditions by plating bath analysis.

Description

Detailed Description of the Invention

TECHNICAL FIELD The present invention generally relates to a given concentration or equilibrium (bala) of a chemical constituent in a chemical bath.
nce system, more particularly, a historical replenishment r that changes in response to chemical analysis of chemical baths.
ate), a system for replenishing chemical components.

BACKGROUND OF THE INVENTION Known devices and methods for maintaining a predetermined concentration or equilibrium of chemical constituents of a chemical bath include feed-forward control and feed-backward control. Apply a system that uses both. Feedback control depends on sensor inputs for component concentration, plating efficiency, current output from the rectifier, drag-out rate, plating solution volume and level, temperature, and plating thickness.

Feedforward control relies on predictive models. Changes in the composition of the plating bath due to anodic and cathodic reactions before and after electroplating are quantitatively modeled as a function of current-time. In addition, the change through scoop is also modeled as a function of current-time. These are combined to obtain the overall system model. Often, a mass balance or mass balance equation is used in the model to calculate the make-up as a function of current-time to make up for the weight loss and maintain a constant bath composition.

The known device utilizes a microprocessor to compare the sensor signal obtained by the feedback control sensor against the set points obtained by the predictive model and the control / tolerance limits. If the value exceeds the control / tolerance limit, the system (1) recommends the addition of additional replenisher and (2) defers the approaching feed forward addition for a determined period of amp-hours. And / or (3) assist the user in returning the bath parameters to within the user's desired range through the display screen for cause analysis.

Known systems are complex and not very accurate. There is a need for a system that is effective in adjusting the historical trends in make-up additions and does not rely on adjusting the predictive model to carry out make-up.

DISCLOSURE OF THE INVENTION In its first aspect, the invention takes the form of a method of controlling the constituents of a chemical bath. This method aspect of the invention includes the following steps. That is, the rate of continued replenishment of a given component of a chemical bath.
) First, determining the replenishment conditions for the chemical bath second, adjusting the continuous replenishment rate of certain components of the chemical bath according to the replenishment conditions,
including.

The continuous replenishment rate in the first determining step is based on the historical replenishment rate. In one embodiment of the present invention, the second step of determining the replenishment condition includes the step of monitoring the elapsed time. In another embodiment, the second step of determining the replenishment conditions comprises monitoring the consumption of electrical energy, for example by a chemical bath, monitoring the number of products to be plated in the plating bath, and And / or monitoring the surface area of the product to be plated in a plating bath. In a further embodiment of the invention, the step of first determining the continuous replenishment rate comprises the following steps. That is, it includes a step of first setting the amount of the replenishing medium, and a step of thirdly determining a replenishment frequency corresponding to a settling rate of the set amount of the replenishing medium in the chemical bath with respect to the replenishment condition. . This embodiment may further include the following further steps. That is, it includes a step of defining a unit of the supply condition and a step of counting the units for which the supply condition has elapsed.

[0008] In this embodiment, there is further provided the step of defining a replenishment limit value corresponding to the product in defined units of replenishment conditions and in a predetermined number of units of replenishment conditions. The step of adjusting the continuous replenishment rate includes comparing the counted number of units of the replenishment condition with a predetermined number of units of the replenishment condition. Additionally, adjusting the continuous replenishment rate includes determining the rate of adjustment of the continuous replenishment rate.

According to a further method aspect of the invention there is provided a method of controlling the contents of a chemical bath, the method comprising the steps of: That is, the step of determining the replenishment condition for the chemical bath, the step of defining the unit of the replenishment condition, and the pacing coefficient (pacing coefficient) corresponding to the replenishment volume of the replenishment medium per unit replenishment condition.
setting a factor (constant interval coefficient), and defining a replenishment limit value corresponding to a defined number of replenishment conditions of defined units and pacing factor products.

In one embodiment of this further aspect of the invention, an additional step of counting elapsed units of replenishment conditions is provided. Another embodiment includes performing a replenishment of the chemical bath when the replenishment limit is reached,
Testing the chemical bath to determine the contents of the chemical bath, and adjusting the replenishment rate of the chemical bath in performing the chemical bath replenishment. The step of adjusting the replenishment amount of the chemical bath is executed according to the relationship of the following equation. P _F '= P _F × [1+ (RA / T) × A] This is described in more detail below. This embodiment may include adjusting the replenishment of the chemical bath and includes the additional step of changing the replenishment limit. In a still further embodiment of the present invention, the step of adjusting the chemical bath replenishment rate comprises:
It includes the further step of varying the make-up capacity of the make-up medium per unit make-up condition.

Replenishment An aspect of the replenisher of the present invention is a combination of software, computer / controller hardware, and chemical preparation hardware that, at the same time, can: -Receive commands and send responses or status to the host computer. -Receive commands and send responses or status to the user's keyboard and display terminal. -Start, monitor and stop the delivery of multiple chemicals separately to multiple destinations.

Some parameters that are monitored or tracked by the system are:・ Chemical flow rate ・ Chemical usage (cumulative) ・ Chemical inventory status (no problem, low stock, empty) ・ Pump status (actuated, stopped, unusable) ・ Pump calibration factor )

In order to get an accurate and variable confirmed delivery, use: -The flow rate is limited to the approximate predetermined value.・ Volume flow rate is a paddle wheel flow sensor in the flow path.
Measured by summing the pulses from. -When the planned capacity is delivered, the flow is stopped by the shutoff valve.

The advantages of this method are: 1) By limiting the flow rate, the flow sensor is kept linear and, more importantly, the capacity per unit pulse range is reproducible, which results in a high degree of accuracy. To ensure. 2) By summing the pulses and stopping at the desired total number of pulses (or volume),
A variable and predetermined amount may be delivered, thus the system is considerably simpler than a variable flow system. 3) The delivered volume can be confirmed rather than assumed, for example by using a flow sensor instead of a volumetric metering pump.

In combination with the flow limiting methods shown below (FIGS. 16 and 17), the above are less expensive than other mechanical methods of delivering variable capacity. The feedstock is fed at a constant pressure to a limiting needle valve or orifice by the use of a pneumatic pump that delivers a constant pressure. This method offers the advantages of low cost and mechanical simplicity. When the pump is used in the range of 1-10% of its flow capacity, this method achieves the highest accuracy, which is an important feature. The chemical flow rate is monitored during delivery. Very low or stopped flow rates are used to detect and provide an alarm indication of empty chemical supply conditions. This is used in place of the "empty" supply level detector, which may or may not be actually useful for the pump. In addition, the flow rate, cumulative amount delivered from the start of delivery, and total delivered from de-setting or feedstock replenishment are recorded during delivery.

Pacing replenishment The replenishment system of the present invention involves replenishment at a rate proportional to a certain event, hereinafter referred to as replenishment condition. Suitable events that make up replenishment conditions include elapsed time, amp-hour (or charge),
Number of product loads, product surface area, delivery rate per hour (line
speed), etc. are included. Since the process constituents are actually consumed, the method of the present invention replenishes the processing constituents. It also prevents depletion (or buildup if pouring by-products) and associated time delays for detection and correction.

[0017]   As mentioned above, precision supply is an important aspect of the system of the present invention.   In each example, replenishment is automatically started under the following replenishment conditions.   -Based on analysis results.   -Based on amp-minutes.   -Based on manufacturing.   -Based on processing time.   -Based on elapsed time.   -Based on the worker's request.

In one embodiment, the system is based on the analysis results for each parameter / chemical and the accumulation of amp-minutes (or other replenishment conditions listed above). Allows you to set up a refueling delivery calculation. Once these settings are established, the system automatically adjusts the replenishment rate based on amp-minutes, depending on the plating bath analysis results.

Because of this functional tuning feature, which is functional, a communication link is provided between the plating components and the controller of the system of the present invention. This link informs the system of ampere-minutes (current amount) by means of the plating cell / bath so that replenishment can be initiated, for example, based on the amp-minute set point.

More specifically, replenishment of the chemical bath proceeds at a predetermined rate that may be based on bath history experience during a particular operation. Alternatively, the existing replenishment rate for a given system effect may be predetermined based on experience with similar or related chemical systems. According to one embodiment of the invention, the replenishment rate is determined by the pacing signal at the trip point (
It is performed in small batches or aliquots of user-defined capacity at a frequency controlled by the time required to reach the trip point). Trip points are paced units, for example 10.0 amp-minutes,
Or 3 a predetermined total of product loads. The capacity delivered after reaching the trip point is defined by the following relation, and corresponds to the capacity delivered when the real time constant interval unit is equal to or exceeds the trip point of this constant interval unit or thereafter. . Replenishment capacity = P _F × P P _F is a pacing coefficient, which is a unit of accumulated replenishment capacity per fixed interval unit. P is a unit of fixed intervals in which replenishment conditions are accumulated.

This fixed interval unit is continuously accumulated in real time. Also, chemical bath samples are taken periodically to determine if the replenishment rate is adequate to maintain the desired equilibrium of chemical components. In situations where the sampling results indicate that excess water is added or poured, or replenishment is delayed or inaccurate, the chemical bath may be abnormally diluted in the following situations: A single delivery of make-up material is increased. Alternatively, the replenishment capacity is maintained the same, but subsequent replenishment occurs immediately by essentially maintaining a fixed, but low, but accumulated constant interval unit.

In a further embodiment of the invention, the replenishment rate, or pacing factor, is adjusted in response to intermittent quantitative analysis. That is, the feedstock ratio is replenished in proportion to the accumulated signal or pacing factor. Since the device of the present invention is capable of performing accurate intermittent quantitative analysis of the contents of chemical baths, the results of this type of analysis are intermittent to match the accumulated pacing factor to the rate of replenishment. Is used for. In an embodiment where the present invention is utilized in a metal surface treating chemical bath, the time interval for adjusting or tuning the ratio depends on the degree to which the treatment is dynamic and its predictability.
It ranges from 0 minutes to several hours.

In a very advantageous embodiment of the invention, the tuning is carried out immediately after the respective analysis result is obtained. The adjustment or tuning is performed according to the following formula: P _F '= P _F × [1+ ( _RA / T) + A] P _F is the current pacing factor, in units of replenishment capacity per unit of interval . P _F 'is the new pacing factor. R is the replenishment amount calculated from the current quantitative analysis result. This calculation is usually stoichiometric. T is the total fixed interval replenishment amount from the previous analysis result. This excludes any amount replenished for analysis or other reasons as required by the operator. A is a fractional adjustment rate, which is in the range of 0 <A ≦ 1. The pacing factor is adjusted by a quick control method. Processes that require fast response and have high analytical certainty utilize settings near 1.0. Processes that are less dynamic or have lower analytical certainty utilize lower settings below 0.5.

Compared to standard PID (Proportion, Integral, Derivative) control, the method of the present invention uses the total amount required to return to the process control set point after each analysis. Integration error (constant steady-state deviation (offset))
Recover from. In order to avoid subsequent overshoot and correction after reaching the set point, and in order to achieve a quick recovery, the integration error is deliberately noted only by refueling at regular intervals. Not done.

The overshoot is corrected by pausing refueling at regular intervals until the overshoot (without sending out) is bypassed which equals the calculated capacity that caused the overrun. The tuning equation is used as usual, and of course the R term is negative. As with the integral error, this avoids subsequent negative excesses and corrections after reaching the set point in order to achieve a quick recovery.

In one particular illustrated embodiment of the invention, the practice of the invention comprises: 1. Pacing signal conditioning for converting or amplifying the pacing signal into the receivable range. 2. Conversion of the signal to digital form. 3. 3. Signal integration to generate a sum of inputs over time; Comparison of the integrated signal with a trip point that initiates a small dose of medication. 5. Sends the current supply amount and cancels the setting of signal integration to zero.

[0027]   Chemical concentration control (further examples)   tuning   According to a further embodiment of the invention, the tuning is based on:

When the analysis result is obtained, the amount of change in the analytical measurement value from the immediately preceding analysis is calculated. If averaging of the results is valid, this same formula applies, but the current measurement is replaced by the average of the current n measurement and the previous n measurement, and the previous measurement is
It is replaced by the average of the previous n measurements and the previous n measurements. Change in analytical measurement value = current measurement value-previous measurement value

Next, the degree of lack of supply (−) or the degree of excessive delivery (+) due to no change in measurement is calculated. Other non-constant replenishment contributions are also considered by the following equation. Fixed interval replenishment amount error = amount of change in analytical measurement value x analytical replenishment coefficient-total replenishment amount from non-constant intervals since the last analysis Here, the "analytical replenishment coefficient" is used to convert the analysis result into the replenishment amount. Is a multiplier that is It is the liters replenishment (liters r) per gram / liter below the target value.
eplenishment), expressed in replenishment units per analytical unit. "Total non-periodic replenishment volume since last analysis" includes all replenishment volumes that are not based on time or amp-minutes, such as replenishment according to the results of the previous analysis or manual replenishment. . Then the new supply factor is calculated according to the following equation: New coefficient = previous coefficient−previous coefficient × (tuning rate / 100) × constant interval replenishment amount error / total non-constant replenishment amount from the previous analysis where “tuning rate of tuning” is It is a tuning ratio expressed as 0 to 100%. A typical operating value is 20.0. It depends on analysis error, analysis frequency, and rate of process change. That is, the user sets it in proportion to the change rate, the analysis error, and the analysis frequency.

When the coefficients go to zero, another equation derived for the two factor tuning method has the advantage of not being “stuck”. It is, first of all, a calculation for the "ideal factor", which is the factor when all measurements and data are perfectly accurate. Total chemical consumption = -Amount of change in analytical measurement value x Analytical replenishment coefficient + Total replenishment quantity from previous analysis Ideal coefficient = Total chemical consumption / Cumulative pacing unit from previous analysis or ideal coefficient = ( -Amount of change in analysis measurement value * Analytical replenishment coefficient + Total replenishment amount from previous analysis) / Cumulative pacing unit from previous analysis New coefficient = previous coefficient x (1-synchronization rate / 100) + ideal coefficient x (Synchronization rate / 1
00)

It should be noted that these equations omit tuning if the “cumulative pacing units from previous analysis” is zero.

Two factor tuning When two different factors such as ampere-min and time to reduce the solution are to be considered, they are usually reduced at the same time and in different ratios. ,
Must be determined by algebra. The equation is most easily solved without the "tuning speed" term. These will be added subsequently. Change in analysis measurement value due to constant interval replenishment amount error 1 = analysis replenishment coefficient-total replenishment amount from the previous analysis + change in analysis measurement value due to total replenishment amount 11 at constant intervals = constant interval unit 1 x Ideal Pacing Coefficient 1 Here, “constant interval unit 1” is the sum of recorded constant interval units from the last analysis, such as amp-minutes. The "ideal pacing coefficient 1" is a practical but unknown conversion coefficient for converting a fixed interval unit into a replenishment amount. This gives: Fixed interval replenishment amount error 1 = constant interval unit 1 × ideal pacing coefficient 1 × analysis replenishment coefficient−total replenishment amount from previous analysis + constant interval replenishment amount 1 1 constant interval replenishment amount error 2 = constant interval unit 2 × ideal Pacing factor 2 x Analytical replenishment coefficient-Total replenishment amount from previous analysis + Total constant interval replenishment amount 2 Total constant interval replenishment amount error = Change in analytical measurement value x Analytical replenishment factor-Total replenishment amount from previous analysis Total + constant interval supply amount total 1 + constant interval supply amount total 2 or total constant interval supply amount error = constant interval supply amount error 1 + constant interval supply amount error 2 To shorten the formula, A = total constant interval supply amount error B = Analytical replenishment coefficient E1 = Constant interval unit 1 E2 = Constant interval unit 2 X1 = Ideal pacing coefficient 1 X2 = Ideal pacing coefficient 2 C = Total replenishment amount from previous analysis D1 = Constant interval replenishment amount 1 D = Supply amount of fixed interval replenishment 2 F = Amount of change in analytical measurement value O = Analysis replenishment coefficient Error of replenishment amount of constant interval 1 = E1 × X1-C + D1 Error of replenishment amount of constant interval 2 = E2 × X2-C + D2 Error of replenishment amount of constant interval = Fixed interval replenishment amount error 1 + constant interval replenishment amount error 2, total constant interval replenishment amount error = F × G−C + D1 + D2 Then, the following formula is given. F * G-C + D1 + D2 = E1 * X1-C + D1 + E2 * X2-C + D2 X1 is rearranged as follows. X1 = (F * G-C + D1 + D2 + C-D1-E2 * X2 + C-D2) / E1 The following is a summary. X1 = (F × G + C−E2 × X2) / E1 or ideal pacing coefficient 1 = (change amount of analysis measurement value × analysis replenishment coefficient + total replenishment amount from immediately preceding analysis−constant interval unit 2 × ideal pacing coefficient) 2) / pacing unit 1 ideal pacing coefficient 2 = (change amount of analysis measurement value × analysis replenishment coefficient + total replenishment amount from previous analysis−constant interval unit 1 × ideal pacing coefficient 1) / pacing unit 2

Since these are two equations with two unknowns, we use two sets of data: first, the current and previous set of data, second, the previous one. And using the previous two sets of data must be solved. Matrix algebra is sufficient for this. The above equations can be simplified if constant terms are combined. X1 = K / E1-X2 * E2 / E1 and X2 = K / E2-X1 * E1 / E2 Here, K = F * G + C

Visual Basic User Interface
rface) A visual basic user interface (management program) should include the following features. 1. A text box for entering the tuning rate for each coefficient. This is a percentage expressed as 0-100. This default value is 100.0 and should only be set to a lower value if the rate of consumption proportional to the pacing factor is inconsistent. 2. A check box for selecting whether to delay replenishment at regular intervals so that the target value can be restored when the concentration is high. The default value for this box is its own value. 3. For use in calculating replenishment adjustments and delay capacities, the previous measurements (
A text box for entering numbers from 0 to 10). The default value is 2, which is set higher if more analysis error needs to be eliminated. The text box heading is, for example, "Use mean of current and previous results"
Should be.

Level Control Level control of chemical process solutions is challenging due to the variety of conditions encountered. Conventionally, there are many level detection methods, each having a strong part and a weak part. Surface bubbles, for example, are not a problem for most radio frequency (RF) level sensors, but are considered liquids for ultrasonic or acoustic sensors. However, the RF sensor will not work if it is lightly coated or has a low conductivity solution.

Durability (or reliability) is also a problem. The electronics associated with most sensors inherently have a limited operating temperature range above which the sensor may break. Another example is that maintenance becomes problematic if the solution coats or crystallizes on the surface. Finally, space constraints often limit where sensors can be placed. It is usually the sensor tip (or electronics package) that causes these space problems. For example, on open tanks, hoists are commonly used to move the material being processed in and out of the tank. This "material flow" limits the available space for installing equipment above the liquid level in the tank.

The system utilizes pneumatic level sensing techniques to solve or prevent the above-mentioned problems. (See FIGS. 16 and 17) In general, this technique uses: 1) a pressure-regulated air or gas source, 2) a precision orifice or needle valve for limiting the gas flow rate, 3) a pressure switch or sensor for detecting the pressure in the pipe, 4) a solution immersed in a terminal A conduit made of a material that is internal to the pressure of the liquid at a certain depth and is inert to the processing solution.

The orifice restricts the flow of air to the right (downstream) of the orifice to the pressure head of the liquid above the outlet of the bubbling tube. Restrict. The change in level is detected by the change in gas pressure required to balance the gas and liquid at the tube outlet. After the level rises, the gas pressure increases until the gas pressure equals the outlet liquid pressure, after which the gas is evacuated (bubbled) and equilibrated.

In some embodiments of the present invention, the following are used: 1. Low pressure gas, eg, 2 psi or less, to supply the system. This limits the maximum possible pressure and thus prevents damage to the low pressure switch or sensor if the tube outlet is blocked. 2. For example, a thin orifice with a diameter of 0.008 to 0.020 inches. This slows the gas flow and allows it to be subjected to a pressure equal to the immersed head height. It is also sufficient to keep the inside of the tube uncoated with chemicals,
Therefore, an increase in pressure is prevented. This is especially beneficial in solution, otherwise the solution will dry and set at the air-liquid interface. Although the present invention is not limited to these orifice sizes, our choice of these sizes worked well in a viable embodiment. 3. Oversized conduit. By using a conduit that is much larger than needed, for example, _ inch diameter instead of _ inch diameter, all measurable pressure drops due to air flow are eliminated. This allows the pressure sensor and associated equipment to be located remotely from the solution, in a safe, convenient, and / or centralized location. In practical embodiments of the invention, spacings of up to 100 feet were utilized without loss of performance. 4. For example, up to 1/2 inch diameter, and even up to 1 inch diameter, the tubes or pipe sections that come into contact with the solution can be made larger, which makes clogging of the outlet, such as with dry matter, less likely. Become. In the actual example, clogging of the outlet did not matter, but this technique
It can be effective in some solutions. 5. Where an inert, more expensive material is required in contact with the solution, before introducing the solution, from a conduit of standard material, such as nylon, polyurethane, or polyethylene, a Teflon® Such a connection may be provided to replace the conduit of inert material. This also has the advantage of providing a convenient way to replace the submerged tube or pipe section if it becomes damaged or dirty. 6. By using two level sensors that are immersed at known fixed vertical distances apart, the pressure readings are compensated for changes in solution density before converting them into levels or volumes. May be done. Of course, this method only applies to continuous analog level detection,
It does not apply to discrete point level switching.

The software used in conjunction with this level measurement method accomplishes the following: 1. "Debauncing" of tank wave movements. The level is not constant and is actually corrugated, as the tank solution being measured is subject to agitation, either intentionally or by workflow. To give consistent and valid measurements throughout, the software uses this "noise"
Eliminates switch-type level detection. However, the way to do this is not only to create a large hysteresis (or deadband) in the switch, and thus to reduce the accuracy, but also to "high" and "low" (on and Sum the readings (of off),
To average. Therefore, if during the 5/2 period (five second period) a sum of 8 high and 2 low measurements is obtained, the level is switched to the switching range.
vel) is calculated as 80%. This integer value is used to achieve precise control within a narrow range. For example, the programmer may set the replenishment to start at 70% and end at 80%. 2. A further improvement on this technique was to use a weighted average, with the most recent measurements having the most weight. This simplified formula is as follows. New average level = (((100−W) × previous average level) + (W × current level measurement value)) / 100 where the current level measurement value is 0 or 1, and “W” is It is a weight given to the latest measured value. A typical range of "W" is 5-20, and how much wave motion buffering is desired (how low "W") is to respond to tank level changes (low "W"). "W"), This weighting technique is applicable to both discontinuous and analog sensors. 3. In this way, wave motion can be used to ascertain the functionality of the level sensor of interest. Any measurement in the range 0-100% (not including 0% and 100%) confirms that the switch corresponds to a level change such as due to wave motion. By initiating filling when the level is in the switching range, which is the standard operating mode, slight agitation of the tank can be used to verify the functionality of the sensor. 4. If desired, a user-configurable control to reduce switching and filling valve cycling also allows automatic overfilling, thus extending machine life. 5. Where two level sensors are used, each is also used to verify proper operation of the other. When installed at different levels, the lower sensor is used as the processing or target level and the higher sensor is used as the alert or warning level. When so arranged, if the sensor in the lower position measures any less than 100%, the only valid measurement of the sensor in the higher position is 0%. The sensor in the higher position can make further measurements only if the sensor in the lower position reads 100%. This outside situation is reported to the operator as an error and is interlocked with software that prevents dangerous or overfilling operations. The signal from one is used to start filling the device or emptying the device, and the signal from the other is used to stop them in a factory with two sensors. It is common. Therefore, the second sensor cannot be used to back up the first sensor, because the second sensor must be used for level control operation. A third sensor is required for protection or interlock. 6. As a further protection against failures, stop filling if the level does not rise to a measurable range within a preset time, 2) if the target value is not reached within a (longer) preset time However, a software timer is used to alert the operator. Automated filling will continue until an unacceptable operator-initiated de-setting occurs.
Alternatively, automatic filling cannot be done until the level is returned to the target value by some external means. 7. This creates a fail-safe design, which means that sensor failure does not cause further disaster. False readings of the high sensor will deactivate the filling. False readings of the low position sensor will lead to filling attempt timeouts. (The fill time limit is set to be less than the time required to fill the tank from the sensor to the rim.)

Specific Copper Plating Embodiments In the particular illustrated embodiment of the present invention specifically adapted to copper plating environments, the system is for manual analysis and replenishment of chemicals associated with control parameters of a copper plating bath. Is designed to eliminate the need for. The system of the present invention also provides automatic sensor calibration, and internal system diagnostics maintain a high degree of reliability, repeatability, and throughput. In addition, effective troubleshooting is possible, reducing the need for maintenance.

In this example, an automated analyzer is provided for copper sulfate, sulfuric acid, hydrochloric acid, and two organic reagents / additives. In a very advantageous embodiment, the analyzer is equipped with a titrametric procedure.
ure) is automated to give a sharp and clear end point in about 5-7 minutes. The overall cycle time, including the time spent for sampling, purging, sample preparation, duplicate analysis, cleanup, and trend checking is about 20-3.
0 minutes.

More specifically, this embodiment of the invention accomplishes the automated chemical analysis and automated chemical replenishment set forth below. Automated chemical analysis Automated chemical replenishment Copper Sulfate Copper Sulfate Sulfate Chloride Hydrochloric acid Additive # 1 Organic Reagent Additive # 2 Organic Reagent

The analyzer of the present invention also automates cyclic voltammetric stripping for the analysis of organic components and provides an indication of all organic contaminants in the plating solution. If selected to be performed in a particular tank, these analyzes are programmed to be performed at the same time as the analysis of inorganic components. Within the scope of the method (titration or CV or CPVS) analysis will occur one after the other.

Housing In a very advantageous embodiment, the system of the invention has a transparent front part,
It is housed in a flame-retardant polypropylene cabinet with hinged (locked) doors. This system uses a pH electrode, a redox potential electrode, a chloride ion specific electrode, and a cyclic voltammetry stripping unit to automate the required analytical operations. The cabinet is equipped with leak detection and secondary containment and is designed to accept chemical samples from up to three pressurized sampling lines.

The cabinet also includes a display screen for monitoring various activities active in the local control unit (LCU), a CPU shelf, a pull-out keyboard fixed to the drawer, a printer stand, and It also houses a management system with electrical panels. In a practical embodiment, the general size of this cabinet is 48
Inches x height 72 inches x depth 24 inches. In this example, the analyzer is connected to the management system through an RS-422 data transfer device. An LCU is a combination of software, computer or controller hardware, signal processing modules, sensors, and actuators. It is used to monitor, control, and report various physical parameters including temperature, level, conductivity, pH, voltage, current, pressure, flow, and other parameters that can be measured by the sensor. It is used where continuous monitoring and immediate control response are required. It also aggregates continuous sensor measurements during a particular time interval into maximum, average and minimum values and reports them to the monitoring computer (or management system) described above. This method improves local monitoring and control response and reduces the computational and communication load on the monitoring computer.

Chemical Replenisher Solution Reservoir and Processing Unit Device The chemical replenishment, storage and processing unit device is made of flame retardant polypropylene and, in the particular illustrated embodiment of the invention, five “NOW- Designed to accept PAK '4 liter containers. This unit device includes: Replenisher for chemical replenisher and level control (× 2) Replenishment pump module Flow sensor and multipoint header (header) and valve Sampling pump for analyzer Indicator lamp Audible alarm Secondary containment Leak detection Safety stop Equipment Vibration suppression equipment Analyzer Waste collection

The packaging method is designed to create a dust chamber type environment. Practical examples of current designs are ST-93, CE "Essential" and UL.
Comply with UL electrical standards.

In another embodiment, a chemical replenishment, storage, and processing unit device made of flame retardant polypropylene can optionally be designed to accept five “NOW-PAK” 200 liter containers. To accommodate these requirements, the system includes: -Management PC controller with GEM / SEC host communication output-Automatic chemical analyzer; -Online CVS unit with integrated modification-Chemical replenisher controller with custom made Now-Pak 200 liter replenishment system-Tower Local control unit with interlock control and monitoring functions, as well as tower light and audible alarm control functions.

Certain problems may arise in the copper sulphate plating embodiments of the present invention that should be addressed and / or corrected. These problems and their respective corrections are as follows.

[Table 1]

BEST MODE FOR CARRYING OUT THE INVENTION An understanding of the present invention will be obtained by reading the following detailed description together with the accompanying drawings.
It will be easier.

FIG. 1 is a process flow chart of a particular illustrated embodiment of the invention for copper plating operations and chemical control. As shown here, the system has a chemical s
From the taging organic addition tank) 12, a plater (plat
er; gloss machine) is included. The carbon treatment tank 14 is a new solution filling tank (f
resh solution make up tank) 16 with a new solution and a plating collection tank (plat
ing collection tank 17). The carbon treatment tank 14 supplies the treated solution to a post treatment chemical holding tank 18 which delivers the solution to the chemical organics addition stage tank 12.

FIG. 2 illustrates a 200 liter “NOW PAK” automated dosing system 20. In this embodiment, a CuSO ₄ tank 22, a H ₂ SO ₄ tank 23, an HCl tank 24, and organic additive tanks 25 and 26 are provided. The tank is contained within a housing 27 with a spill drain 28. A pair of valves 29 for communicating with the tank are shown in the figure.

FIG. 3 is a simplified plan view of a management facility 30 using an RS232 / 422 data exchange path (not shown) in the amp-minute embodiment.

FIG. 4 is a simplified illustration of the mixing and filtering device 40. The mixing of the metal hydroxide, the acid waste, and the activator is performed in the mixing tank 41. The acid waste can include acidic Cu, CuCl, persulfate, Na persulfate, and acidic hydrogen peroxide. The metal hydroxides from the wastewater and activator that are mixed and applied to the first pH adjuster 43 and the second pH adjuster 44 respectively are received in the mixing tank 41. The pH adjusted material is then placed in a clarifier in tank 46, followed by a thickener 47. Next, the distillate from the mixing tank 41 is filtered by a filter press 4
Can be multiplied by 8.

FIG. 5 is a simplified plan view of the appearance of the replenishment system 50 constructed according to the present invention. The replenishment material is received in the replenishment connection 51. Electromechanical devices (not shown in this figure), such as solenoids, pumps, etc., are included within the refueling system area 53, and electrical power and compressed air are received from the inlet 55. The power is converted to low voltage to activate the internal components of the system in area 56.

FIG. 6 is a plan view of an actual embodiment of the 200 liter refueling system 60. In this embodiment, each of the plurality of 200 liter drums 62 is provided with an associated pump 63. The processing status can be viewed through the view window 64. Control by the operator is performed through the operator's keyboard 66, which in this embodiment of the invention is a high voltage station.
It is installed at 67.

FIG. 7 is a diagram of a main system status computer display screen 70 of the management system of the present invention. This figure shows various parts of the line status display screen.

FIG. 8 is a diagram of a computer display screen 80 of the management system of the present invention showing a parameter status display screen 80 for retaining post-treated inorganic chemicals.

FIG. 9 is a diagram of a computer display screen 90 of the management system of the present invention showing a further parameter status display screen showing the chemical organics addition stage.

FIG. 10 is a diagram of a computer display screen of the management system of the present invention showing a further parameter status display screen 100 of the plater.

FIG. 11 is a diagram of a computer display screen of the management system of the present invention showing an inflow chemical test display screen 110.

FIG. 12 is a diagram of a computer display screen of the management system of the present invention showing an analyzer control system display screen 120.

FIG. 13 is a diagram of a computer display screen of the management system of the present invention showing a display screen showing the supply of copper sulfate to the plater.

FIG. 14 is a diagram of a computer display screen of the management system of the present invention showing a feedstock display screen 140.

FIG. 15 is a computer display screen of the management system of the present invention showing a copper sulfate setting display screen 150.

FIG. 16 is a simplified illustration of a device 160 for obtaining an accurate delivery capacity. The air pump 161 receives a constant pressure supply air at the suction port 162 and also receives a chemical feedstock required to be delivered at the feedstock inlet 163. The output from the air pump 163 is sent to the needle valve 164. In some embodiments of the invention, the needle valve may be replaced with an orifice (not shown) of a given size. The flow rate of the chemical at the outlet of the needle valve can be monitored by the flow meter 166 and controlled by the shutoff valve 167. This device produces a highly controlled flow rate of delivered chemicals.

FIG. 17 shows an apparatus 17 for achieving an accurate measurement of the level of liquid material in a chemical bath.
0 is shown in a simplified form. During operation, the pressure of the pressurized gas passing through the orifice 171 is monitored by the pressure gauge 173. Pressurized gas is released at an outlet 174 immersed in a chemical bath 176. The pressure measurement with manometer 173 constitutes an accurate measure of the level of the chemical bath. Therefore, a simple and inexpensive level monitor is provided.

Although the present invention has been described with respect to certain specific embodiments and uses, those of skill in the art will recognize that
Additional embodiments may be generated in view of this teaching without departing from the scope of the claimed invention or departing from the spirit of the claimed invention. Therefore, it should be understood that the drawings and the specification disclosed herein are presented to facilitate the understanding of the present invention and should not be construed as limiting the scope thereof. .

[Brief description of drawings]

FIG. 1 is a process flow chart of a particular illustrated embodiment of the present invention for copper plating operations and chemical control.

[Fig. 2]   Figure 2 illustrates a 200 liter "NOW PAK" automated dosing system.

FIG. 3 is a simplified plan view of a management facility using an RS232 / 422 data exchange path in an amp-minute embodiment.

[Figure 4]   1 is a simplified illustration of a mixing and filtering device.

[Figure 5]   It is the top view which simplified the external appearance of the supply system comprised by this invention.

[Figure 6]   FIG. 7 is a plan view of an actual embodiment of a 200 liter replenishment system.

FIG. 7 is a diagram of a computer display screen of the management system of the present invention showing a line status display screen.

FIG. 8 is a computer display screen of the management system of the present invention showing a parameter status display screen for post-treatment inorganic chemical retention.

FIG. 9 is a computer display screen of the management system of the present invention showing a further parameter status display screen showing the chemical organics addition stage.

FIG. 10 is a computer display screen of the management system of the present invention showing a further parameter status display screen of the plater.

FIG. 11 is a computer display screen of the management system of the present invention showing an inflow chemical test display screen.

FIG. 12 is a computer display screen of the management system of the present invention showing an analyzer control system display screen.

FIG. 13 is a computer display screen of the management system of the present invention showing a display screen showing the supply of copper sulfate to the plater.

FIG. 14 is a computer display screen of the management system of the present invention showing a feedstock display screen.

FIG. 15 is a computer display screen of the management system of the present invention showing a copper sulfate setting display screen.

FIG. 16   1 is a simplified illustration of a device for obtaining an accurate delivery capacity.

FIG. 17 is a simplified diagram of an apparatus that accomplishes accurate measurement of liquid material levels in a chemical bath.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, SD, SL, SZ, UG, ZW), E A (AM, AZ, BY, KG, KZ, MD, RU, TJ , TM), AL, AM, AT, AU, AZ, BA, BB , BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, G H, GM, HR, HU, ID, IL, IN, IS, JP , KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, M W, MX, NO, NZ, PL, PT, RO, RU, SD , SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZW

Claims (21)

[Claims] 1. A method of controlling components of a chemical bath, which comprises first determining a continuous replenishment rate of predetermined components of the chemical bath, and second determining replenishment conditions for the chemical bath. And the step of adjusting the continuous replenishment rate of the predetermined components of the chemical bath according to the replenishment conditions,
Control method consisting of. 2. The method of claim 1, wherein in the first determining step, the continuous replenishment rate is based on a historical replenishment rate. 3. The method of claim 1, wherein in the second determining step, the replenishment condition comprises the step of monitoring elapsed time. 4. The method of claim 1, wherein in the second determining step, the replenishment condition comprises the step of monitoring the consumption of electrical energy by the chemical bath. 5. The chemical bath is a plating bath, and in the second determining step,
The method of claim 1 wherein the replenishment conditions comprise the step of monitoring the number of products to be plated in the plating bath. 6. The chemical bath is a plating bath, and in the second determining step,
The method of claim 1 wherein the replenishment conditions comprise the step of monitoring the surface area of the product to be plated in the plating bath. 7. The continuous replenishment rate in the first determining step comprises first setting the amount of replenishment medium, and, with respect to replenishment conditions, the rate at which the set amount of replenishment medium precipitates in the chemical bath. 3. The method according to claim 1, further comprising the step of thirdly determining a replenishment frequency corresponding to. 8. A step of defining a unit of supply condition,   The stage of counting the units that have passed the supply condition, The method of claim 7, further comprising: 9. The method of claim 8, further comprising the step of defining a make-up limit value corresponding to a defined unit of make-up condition and a product of a predetermined number of make-up unit. 10. The method of claim 9, wherein the step of adjusting the continuous replenishment rate comprises comparing the counted number of replenishment condition units to a predetermined number of replenishment condition units. 11. The method of claim 10, wherein the step of adjusting the continuous replenishment rate comprises the step of determining the rate of adjustment of the continuous replenishment rate. 12. A method of controlling chemical bath components, the steps of determining replenishment conditions for a chemical bath, defining units of replenishment conditions, and replenishment of replenishment medium per unit replenishment conditions. A control method comprising the steps of setting a pacing factor corresponding to the capacity, and defining a predetermined number of defined units of replenishment conditions and a replenishment limit value corresponding to the product of the pacing factor. 13. The method of claim 12, further comprising the step of counting elapsed units of replenishment conditions. 14. The method of claim 13, further comprising the step of performing replenishment of the chemical bath when the replenishment limit is reached. 15. The method of claim 14, further comprising the step of testing the chemical bath to determine the content of the chemical bath. 16. The method of claim 15, further comprising the step of adjusting the replenishment rate of the chemical bath in the step of performing the replenishment of the chemical bath. 17. The present invention wherein the step of adjusting the replenishment amount of the chemical bath is: P _F '= P _F × [1+ (R _A / T) × A] P _F = unit of replenishment capacity per unit of fixed interval Pacing coefficient, P _F '= new pacing coefficient, R = replenishment amount calculated from the current quantitative analysis result, T = total constant interval replenishment amount from the previous analysis result, A = partial adjustment rate, 0 <A ≦ 1 17. The method of claim 16, implemented according to the relationship of the equation: 18. The method of claim 16, wherein adjusting the replenishment rate of the chemical bath comprises the further step of varying the replenishment volume of the replenishment medium per unit replenishment condition. 19. The method of claim 16 wherein adjusting the replenishment of the chemical bath comprises the further step of varying the replenishment limit. 20. A method of adjusting the replenishment rate of a determined component of a chemical composition, the previous analytical measurement being proportional to the determined component of the chemical composition (referred to as the "previous measurement"). And the current analytical measurement value (“current measurement value”) proportional to the determined components of the chemical composition.
The second step is to determine the change amount of the analytical measurement value by the formula: change amount of analytical measurement value = current measurement value-previous measurement value, and constant interval replenishment amount error = analytical measurement A method of calculating a replenishment amount error by the formula of change amount of value × analytical replenishment coefficient−total replenishment amount which is not constant interval from the immediately preceding analysis. 21. A new replenishment coefficient is calculated by the following formula: new coefficient = previous coefficient−previous coefficient × (tuning rate / 100) × fixed interval replenishment amount error / total non-constant replenishment amount from the previous analysis. 21. The method of claim 20, wherein steps are further provided.