JPS5980768A - Apparatus for automatically filtering electroless plating solution - Google Patents

Abstract

PURPOSE:To improve the filtering capacity and to stabilize the on-line analysis of the components in a plating soln. by installing ultrafiltration units in a path for the plating soln. and a means of analyzing a filtrate freed of fine particles and of returning a plating soln. prepared by adding a replenisher to the filtrate to the plating vessel. CONSTITUTION:A plating soln. fed from a regenerating vessel 2b to a holdup tank 3 is passed through a cooling vessel 3a, freed of coarse matter by filtration with a filter 20, and fed to a prefilter 4. Most of the filtered plating soln. is returned to the tank 3, and part of the filtrate is fed to ultrafiltration units 5. Most of the plating soln. contg. fine-grained additives is returned to the tank 3, and the filtrate is fed to a relay tank 30. The filtrate is circulated through a component analyzer 6, and the analytic signal is fed to an automatic supplier to supply the required amount of a replenisher to the vessel 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic filtration device for electroless plating solution, and specifically improves the filtration capacity and durability of an ultrafiltration device, and improves the filtration ability of an ultrafiltration device, and improves the durability of the plating solution during electroless plating work. Regarding an automatic filtration device for electroless plating solution that enables online component analysis to be continued for a long period of time and improves workability ◇ Electroless plating is different from electrolytic plating. This is a plating method in which a plating material is precipitated by a reducing agent contained in a plating solution to form a plating layer on the surface of a gold ingot.It is particularly effective in preventing scratch corrosion of automobile transformer Z-shaped parts, clutch parts, etc. It is applied to the surface treatment of mechanical parts that are subjected to high-speed heavy loads that are prone to sliding, and can significantly improve their self-lubricating properties, wear resistance, and corrosion resistance. The reason why such a large characteristic is exhibited is that particulate additives such as ceramics or metals such as oxides, carbides, carbides, and borides are dispersed and precipitated in the plating material. This fine particle additive is a round fine particle with a diameter of about 1 μm, and provides high self-lubricating properties and wear resistance to the overlaid plating layer.

In order to perform such electroless plating in a stable state over a long period of time, it is necessary to maintain the various components of the plating solution at constant concentrations.

Therefore, in the past, the plating solution was sampled at regular intervals using a beaker, etc., the components were analyzed by chemical analysis using a titration method or gravimetric method, and the pi (pi) value was measured using a pH meter. The plating solution was regenerated by replenishing the plating solution.In other words, with normal colorimetric analyzers that apply the transmission method, fine particles get in the way and analysis is impossible, so in the past, the components of the sample were analyzed from the plating solution tank. Therefore, there was a time lag in the analytical data, and the properties of the plating solution could not always be grasped with high precision and quickly.

The present invention has been made to eliminate the drawbacks of the prior art described above, and its purpose is to provide a plating solution containing particulate additives such as oxides, carbides, supports, borides, gold stripes, etc. In a deplating device that performs electroless plating on objects to be plated, an ultrafiltration device is placed in the plating solution passageway that sends the plating solution from the plating solution tank to the component analyzer. The fine particles contained in the liquid are removed and only the filtrate is sent to the component analyzer, and the plating containing the filtrate analyzed by the nuclear component analyzer and the fine particles removed by the ultrafiltration device is To improve the efficiency of plating solution management and electroless plating work by returning the plating solution to the plating solution tank and performing online component analysis of the plating solution to eliminate the time lag of analysis data. Out. Another purpose of the trench is to place a self-purifying pre-filter in the plating solution passage that sends the plating solution from the plating solution tank to the ultrafiltration device. In addition, it removes coarse particles and foreign substances from the smooth plating solution, prevents particles from accumulating on the module membrane of the ultrafiltration device, and improves the filtration of the ultrafiltration device. By improving the capacity and making stable component analysis of the plating solution online, we also made it possible to filter the plating solution while washing the pre-filter with the plating solution, and at the same time, we were able to improve the filtration capacity of the pre-filter by itself. The goal is to make it possible to recover through purification. Another objective is to provide a two-chamber water-jacketed hold-up tank with a plating solution cooling function in the submerged plating passage that sends plating solution from the plating solution tank to the pre-filter. The pumped plating solution is cooled and sent to the ultrafiltration device to improve the durability of the ultrafiltration device, and the filtrate that has been analyzed by the component analyzer is quickly returned to the plating solution tank. The objective is to improve work efficiency.

In short, the present invention (% invention) provides an electroless plating apparatus that performs electroless plating on an object to be plated using a plating solution containing particulate additives such as oxides, expanded substances, nitrides, borides, and metals. , a plating solution tank containing the plating solution, a component analyzer to which the plating solution in the plating solution tank is circulated and supplied, and a plating solution passageway between the component analyzer and the plating solution tank. a self-purifying pre-filter disposed in a plating solution passage between the ultrafiltration device and the plating solution tank; The plating tank sent from the tank is filtered in advance, and further separated into a plating solution containing particulate additives and a filtrate in the ultrafiltration device, and the filtrate is supplied to the component analyzer to analyze the components of the filtrate. The plating solution is analyzed and an automatic replenishment device is instructed to return the plating solution to the plating solution tank together with the plating solution containing the particulate additive, and the component analysis of the plating solution is performed online. This is a characteristic feature. In addition, the present invention (second
The present invention is an electroless plating apparatus that performs electroless plating on an object to be plated using a plating solution containing particulate additives such as oxides, carbides, nitrides, borides, and metals.
A plating solution tank containing the plating solution, a component analyzer to which the plating solution in the plating solution tank is circulated, and a plating solution passageway between the component analyzer and the plating solution tank. a self-purifying prefilter disposed in a plating solution passage between the ultrafiltration device and the plating solution tank; A two-chamber water jacketed hold-up tank having a cooling function for the plating solution is disposed in the plating solution passageway between the plating solution passages, and the plating solution sent from the plating solution tank is cooled by the hold-up tank.
The plating solution is filtered in advance using the self-purifying prefilter, further separated into a plating solution containing particulate additives and a filtrate using the ultrafiltration device, and the filtrate is supplied to the component analyzer to analyze the filtrate. Analyze the components, instruct the automatic replenishment solution replenishment device to operate, send it to the hold-up tank together with the plating solution containing the particulate additive, and return it to the plating solution tank, and analyze the components of the plating solution. It is characterized by being configured to be online.

The present invention will be explained below based on embodiments shown in the drawings. The automatic filtration device 1 for electroless plating solution according to the present invention includes a plating solution 41Ii12, a hold-up tank 3 with a two-chamber water jacket, a self-purifying play filter 4, an ultrafiltration device 5, and a plating solution 41Ii12. and a component analyzer 6 including a replenishment metering pump control device.

The plating solution M2 contains a plating solution for electroless plating, and is used for applying electroless plating to the object to be plated.
! It consists of a tub 2a and a Niyuyu 2b for regenerating the plating solution, and the bottom of both tubs is equipped with a pump 10 and a valve 11.
connected via.

Matameri 1! There is an overflow connection to the regeneration tank 2b at the top of the side wall of 2a! (not shown) is provided,
The plating solution is constantly circulated between both tanks. Further, the bottom of the regeneration tank 2b is connected to the hold-up tank 3 via the pulp 12.13.

The hold-up tank 3 includes a cooling tank 3a for cooling the plating solution sent from the regeneration tank 2b, and an overflow tank for storing the filtrate after analysis in the component analyzer 6 and overflow liquid from the hold-up tank 3. A cooling pipe 15 is arranged in the cooling tank 3a. The cooling water Waa is connected to the prefilter 4 via a pressurized circulation pump 16 and a valve 17. In this plating@liquid supply path, the precipitate is discharged to the drain 19 via the pulp 18, and the coarse matter contained in the plating solution is removed by the coarse matter filter 2, which has a built-in mesh filter.
0 and cooling tank 3 adapted to be filtered by 0
An overflow passage (not shown) to the outside is provided at the upper part of the side wall of a, through which excess cooling water can overflow.

The pre-filter 4 has a built-in filter cloth 22 made of stainless steel (100 psi 8+L) or Saran, which is formed into a corrugated shape and held between a pair of support frames 21 made of a corrosion-resistant material, such as stainless steel. A small ultrasonic transducer 23 (28 kHz, 100 W or less) is attached to the bottom surface of the pre-filter 4 as a means to improve the ultrasonic efficiency as required. Most of the plating solution pumped into the pre-filter 4 is returned to the hold-up tank 3 via the valve 24.The plating solution filtered through the pre-filter 4 is also transferred to the ultra module. Pressure control valve 25
The precipitates accumulated on the prefilter 4 are sent to the ultrafiltration device 5 through the pulp 2.
6 and is discharged to a drain 27.

Of the plating liquid sent to the ultrafiltration device [5], most of the plating liquid containing particulate additives is returned to the bold-up tank 3 via the ultramodule pressure control valve 28. Only the filtered filtrate is placed in front of the component analyzer 60 and sent to the filtrate relay tank 30 (7c). In FIG. 1, 31 and 32 are pressure gauges, and 33 is a flow meter.

The component analyzer 6 analyzes the components of the filtrate that is circulated and supplied from the filtrate relay tank 3o using a colorimeter (not shown), and sends No. 48 of this analysis result to an automatic replenishing liquid replenishing device (not shown). Then, the required amount of replenishment liquid is pumped into the regeneration tank 2b. A switching cock 35 is disposed in the plating solution passage between the filtrate relay tank 30 and the hold-up tank 3, and a button can be pressed to temporarily store the filtrate in the storage tank 36 as needed via the switching cock. ing.

The plating solution sent from the regeneration tank 2b to the hold-up tank 3 is cooled by a cold box 3a, then filtered in advance by a pre-filter 4, and further filtered by an ultrafiltration device 5.
It is separated into a plating solution containing particulate additives and a filtrate.
The filtrate is supplied to a component analyzer 6, the components of the filtrate are analyzed, and an operation instruction is given to the replenishment liquid supply device 1.
Since it contains particulate additives, it is returned to the hold-up tank 3 together with the plating solution, and is further returned to the regeneration tank 2b of the plating solution tank 2, so that component analysis of the plating solution can be carried out online. .

The present invention is constructed as described above, and its operation will be explained below. Plating sent from the regeneration tank 2b to the hold-up tank 3? The temperature of the plating solution 1& is about 85°C, but as the plating solution passes through the cooling pipe 15 of the cooling tank 3a, the temperature of the plating solution decreases to about 40°C.
The coarse particles of the plating solution are filtered by the coarse filter 20, and the pressurized circulation pump 16 sends the plating solution to the pre-filter 4 where it is filtered. and is returned to the hold-up tank 3.The mulch liquid filtered by the filter cloth 22 is sent to the ultrafiltration device 5 via the ultramodule pressure control valve 25. It is automatically cleaned by the turbulent flow generated when the cutting liquid collides with the support frame 21 formed in a corrugated shape.In addition, the self-cleaning effect of the filter cloth 22 is enhanced by the ultrasonic irradiation of the vibrator 23. When it is particularly desired to clean the inside of the prefilter 4, the reverse situation is performed by opening the pulp 40 and pouring the plating solution (the filtrate stored in the storage tank 36) or pure water from above the filter cloth 22.

Of the plating solution pumped into the ultrafiltration table 5, most of the plating solution containing particulate additives is returned to the hold-up tank 3 via the ultramodule pressure control valve 28. Only the filtered filtrate is sent to the liquid reading relay tank 30.

The emu sent to the ultrafiltration device 5 in this way,
Since it is cooled by the cooling tank 3a of the bold-up tank 3, the ultra-Na filtration device 5 does not need to use materials with particularly high heat resistance on both sides, and even inexpensive materials can be used.

In addition, since the plating solution containing particulate additives is filtered by the smooth pre-filter 4, there is no possibility that particulates will accumulate on the modifier and i-le membranes of the ultrafiltration fc station 5, and the The filtration capacity of the outer filtration device 5 is improved. That is, conventionally 3
Although the ultrafiltration device 5 was cleaned every hour, the ultrafiltration device f5 according to the present invention does not lose its filtration ability even after being used continuously for more than 100 hours, and the filtrate is stably supplied to the filtrate relay tank 30. can.

In addition, although four ultrafiltration devices [5] are provided in the example, in the unlikely event that particulates were deposited on one of the four module membranes during operation, the filtration performance became impossible. This is to ensure that the amount of filtrate supplied to the component analyzer 6 is always stabilized by immediately removing one of the tubes and operating the remaining three tubes, and the number of tubes is not necessarily limited to four. The filtrate sent to the filtrate relay tank 30 is circulated and supplied to the component analyzer 6, and the components of the filtrate are analyzed by a colorimeter. A signal of this analysis result is sent to the automatic replenishment device, and the required amount of replenishment liquid is sent to the regeneration Pa2b.

In this way, only the filtrate from which the fine particles contained in the plating solution have been removed is sent to the component analyzer II6, and the component analysis of the plating solution can be performed online, eliminating the time lag of analysis data as in the past. This eliminates this problem and greatly improves the accuracy of plating solution management and workability.

Since the present invention is configured and operates as described above, it is possible to perform electroless plating on an object to be plated using a plating solution containing particulate additives such as oxides, carbides, nitrides, borides, and metals. In the electroless plating equipment designed for this purpose, an ultrafiltration device is placed in the plating solution passage that sends the plating solution from the plating solution tank to the component analyzer. At the same time, the filtrate analyzed by the component analyzer and the plating solution containing particulates removed by the ultrafiltration device return to the plating solution tank, where the component analysis of the plating solution is carried out. By going online, the time lag in analysis data is eliminated, and the accuracy of plating solution management and maintenance and workability are greatly improved.

In addition, a self-saponifying pre-filter is installed in the liquid passageway to send the plating solution from the plating solution tank to the ultrafiltration device, so before the plating solution is sent to the ultrafiltration device. In addition, the fine particles previously contained in the plating solution are removed by the weir, preventing the fine particles from adhering and accumulating on the module membrane of the ultrafiltration device, improving the filtration capacity of the ultrafiltration device, and allowing for stable component analysis of the plating solution. The self-purifying pre-filter filters the plating solution while being washed with the plating solution, which has the effect of maintaining good filtration ability of the pre-filter. A two-chamber water jacketed hold-up tank is installed in the plating solution passage that sends the plating solution from the plating solution tank to the pre-filter, so the plating solution sent from the plating solution tank is cooled and ultrafiltrated. The durability of the ultrafiltration device sent to the device is greatly improved, and the filtrate analyzed by the component analyzer can be quickly returned to the plating solution tank, which has the effect of greatly improving work efficiency.

[Brief explanation of drawings]

The drawings relate to the embodiment of this @ Ming. Figure 1 is a block diagram of an automatic filtration device for electroless plating solution, Figure 2 is a front view of a self-floating pre-filter, and Figure 3 is a self-purifying pre-filter. FIG. 4 is an enlarged vertical sectional view of section A in FIG. 2. 1 is an automatic filtration device for electroless plating solution, 2 is a plating solution tank,
3 is a hold-up tank with a two-chamber water jacket, 4 is a self-purifying pre-filter, 5 is an ultraviolet & filtration device, and 6 is a component analyzer.0 Patent applicant: Hino Motors Co., Ltd. Agent, Patent attorney 1) Kazuo

Claims (1)

[Scope of Claims] 1. In an electroless plating apparatus for electroless plating of a particulate additive such as oxide, carbide, nitride, boride, metal, etc. onto an object to be plated using a neck plating solution, plating solution between several types of plates containing plating solution, a component analyzer to which the plating solution in the plating solution tank is circulated, and the component analyzer or the plating solution tank described in j. The self-purifying type includes an ultrafiltration device disposed in the passage, and a self-purifying prefilter disposed in the plating liquid passage between the ultrafiltration device and the front d-pinning liquid tank. The plating solution sent from the plating solution tank is filtered in advance using a pre-filter, and the ultrafiltration device separates the plating solution containing particulate additives into a plating solution and a filtrate, and the filtrate is separated from the components described above. The filtrate is supplied to an analyzer, the components of the filtrate are analyzed, the automatic replenishment fluid replenishment device is instructed to operate, and the particulate additive is returned to the plating solution tank along with the filtrate, and the components of the plating solution are An automatic filtration device for electroless plating solution, characterized in that it is configured to conduct analysis online. 2. In an electroless plating apparatus that performs electroless plating on an object to be plated using a plating solution containing particulate additives such as oxides, carbides, nitrides, borides, metals, etc., a plating solution containing the plating solution is used. a component analyzer to which the plating solution in the plating solution tank is circulated and supplied; an ultrafiltration device disposed in a plating solution passage between the component analyzer and the plating solution tank; a self-purifying pre-filter disposed in a plating solution passage between the outer filtration device and the plating solution tank, and a plating solution passage between the self-purifying pre-filter and the plating solution tank; ni-)'f! A two-chamber water jacketed hold-up tank with a liquid cooling function is provided, and the hold-up tank cools the plating solution sent from the plating solution tank, and the plating solution is transferred to the self-purifying type. The filtrate is pre-filtered using a pre-filter, and further separated into a plating solution containing particulate additives and a filtrate using the ultrafiltration device, and the filtrate is supplied to the component analyzer to analyze the components of the filtrate and automatically replenish the replenishment solution. The system is configured to instruct a replenishment device to operate, send the plating solution containing the particulate additive to the hold-up tank, and return it to the plating solution tank, and perform online component analysis of the plating solution. An automatic filtration device for electroless plating solution featuring: