JPH07243052A - Electroless composite planting device - Google Patents

Abstract

PURPOSE:To easily and uniformly disperse grains in a plating tank to suppress a run away reacton by forming the plating device with a first tank contg. an electroless nickel plating soln. and a second tank contg. a heating medium, covering the periphery of the first tank and heating the plating soln. indirectly. CONSTITUTION:A composite plating bath, in which grains are dispersed in an electroless nickel plating soln. to conduct plating by chemical reduction, is used to apply electroless nickel composite plating to a material to be plated. At this time, the composite plating bath consists of an inner tank 2 contg. a plating soln. and an outer tank 1 covering the periphery of the tank 2 and contg. a heating medium to indirectly heat the plating soln. in the tank 2. The outside of the outer tank 1 is supported by struts 3, the tank 2 has a conical bottom 4 at an incliniation of >=45 deg., and a plating soln. circulating pipe 5 is fixed to the tip of the bottom 4. As a result, the plating film forming rate is accurately controlled without complicating the device structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroless composite plating device, and more specifically, it can be applied to an electroless nickel composite plating device, and can also be applied to a surface modification technique for various parts. In particular, without complicating the device structure,
Dispersed particles can be easily and uniformly dispersed in the plating tank to prevent changes in the eutectoid amount of dispersed particles in the plating film, and to suppress reaction runaway of the plating solution while increasing the plating film formation rate. The present invention relates to an electroless composite plating device that can be accurately controlled.

[0002]

2. Description of the Related Art In a conventional electroless nickel composite plating apparatus, it is a fundamentally important problem to uniformly disperse dispersed particles in a plating tank, and it becomes a big problem in plating. Among them, there is so-called reaction runaway in which nickel precipitation explosively proceeds with dispersed particles in the plating solution as nuclei due to local heating of the plating solution or the like. This reaction runaway is likely to occur at a portion where dispersed particles are likely to stay, particularly at the bottom, other than when locally heated.

Therefore, as a conventional technique for solving the problem that dispersed particles are likely to be generated at the bottom of the plating tank, an electroless composite plating apparatus reported in, for example, Japanese Patent Application Laid-Open No. 5-263261 is known. Here, in an electroless composite plating apparatus in which a fluid supply pipe is arranged in the lower part of the plating tank and a blowout hole is formed in the supply pipe so as to face the bottom surface of the plating tank, the fluid supply pipe is plated by a creeping means. Since it is configured to move along the bottom surface of the plating solution, there is an advantage that it is possible to prevent the plating liquid from being jetted toward the bottom surface of the plating tank of the fluid supply pipe to prevent fine particles from being deposited on the bottom surface of the plating.

[0004]

However, in the conventional electroless composite plating apparatus reported in the above-mentioned Japanese Patent Laid-Open No. 5-263261, a drive mechanism for moving the fluid supply pipe must be provided. In addition to the complexity of the device structure, the electroless composite plating requires 9 plating baths.
Since the temperature becomes high near 0 ° C., there is a problem that the evaporated plating solution and the dispersed particles that have spattered easily adhere to the driving part to cause corrosion and wear, which easily causes a device failure.

Furthermore, since the dispersed state of the dispersed particles in the plating tank is not uniform at the top and bottom of the plating tank only by jetting the plating liquid from the blow-out hole of the fluid supply pipe and stirring it, If the dispersed state of dispersed particles is not uniform in the plating tank, when processing a large amount of the object to be plated, the co-deposition amount of dispersed particles in the plating film changes due to the difference in the position in the plating tank. There was a problem that it was easy to do.

Therefore, the present invention makes it possible to easily disperse the dispersed particles uniformly in the plating tank without complicating the structure of the apparatus, thereby making it difficult to cause a change in the co-deposition amount of the dispersed particles in the plating film. In addition, it is an object of the present invention to provide an electroless composite plating apparatus capable of accurately controlling the plating film formation rate while suppressing reaction runaway of the plating solution.

[0007]

The invention according to claim 1 is
An electroless composite plating apparatus for applying electroless nickel composite plating to a material to be plated using a composite plating bath in which dispersed particles are dispersed in an electroless nickel plating solution for plating by chemical reduction A first tank for containing a plating solution, and a second tank for covering the periphery of the first tank and for indirectly heating the plating solution in the first tank.
It is characterized in that it is configured from the tank of.

According to a second aspect of the invention, in the first aspect of the invention, the first tank is made of stainless steel, and the inner surface of the first tank is mirror-polished. It is a feature. The invention according to claim 3 is
In the invention described in claim 1, the bottom shape of the first tank is a ship bottom shape having a tapered slope of 45 ° or more or a conical shape.

According to a fourth aspect of the present invention, in the above-mentioned first aspect of the invention, an ultrasonic transducer is attached to the bottom surface of the first tank. The invention according to claim 5 is the same as the invention according to claim 1,
A plating solution circulation pipe for leading out the plating solution is attached to the top of the bottom surface of the first tank, and a plating solution circulation pump is installed midway on the upstream side of the plating solution circulation pipe. And a plating solution discharge port provided in the plating solution circulation pipe.

The invention according to claim 6 is characterized in that, in the invention according to claim 5, the plating liquid circulating pump comprises a low pulsation type pump. The invention according to claim 7 is the invention according to claim 1, wherein the bottom portion of the first tank is 2 mm or more and 20 m or more from the bottom portion.
Install the air pipe in a floating position within the range of m or less,
It is characterized in that a plurality of air ejection ports are provided in the air pipe at positions where air is ejected in a direction perpendicular to the bottom surface of the first tank.

The invention of claim 8 is characterized in that, in the invention of claim 7, the air flow rate is in a range of 8 Nl / min or more and 50 Nl / min or less per 1 m ^{2 of} floor area. . According to a ninth aspect of the invention, in the first aspect of the invention, the first tank is used as an anode and the electrode in the plating solution is used as a cathode to apply a voltage. It is a thing.

According to a tenth aspect of the invention, in the above-mentioned fifth aspect of the invention, a trap for nickel precipitation particles is installed in the plating solution circulation system. The invention according to claim 11 is the invention according to claim 10 characterized in that the trap comprises a filter having a mesh of 0.05 mm or more and 0.1 mm or less.

According to a twelfth aspect of the present invention, in the above-mentioned first aspect of the invention, the temperature of the plating liquid in the first tank is adjusted by PID temperature adjustment which is a combination of proportional, integral and differential operations. It is characterized in that a temperature adjusting means is provided. According to a thirteenth aspect of the present invention, in the above-described first aspect of the invention, the plating liquid level in the first tank is always constant according to the evaporation amount of water in the plating liquid in the first tank. It is characterized in that water supply means for replenishing water is installed in the first tank so as to maintain the height.

According to a fourteenth aspect of the present invention, in the above first aspect of the invention, the first tank in the first tank is responsive to a change amount of pH in the plating solution in the first tank. It is characterized in that a pH adjusting agent adding means for adding a pH adjusting agent is installed in the first tank so that the plating solution pH in the tank is always kept at a constant value. According to a fifteenth aspect of the present invention, in the above first aspect of the invention, the nickel ion concentration in the first tank is always set according to the amount of change in the nickel ion concentration in the plating solution in the first tank. It is characterized in that a nickel ion replenishing liquid replenishing means for replenishing the nickel ion replenishing liquid is installed in the first tank so as to maintain a constant value.

According to a sixteenth aspect of the present invention, in the above-mentioned first aspect of the invention, the object to be plated is dipped at an arbitrary angle with respect to the liquid surface of the plating liquid in the first tank. And, the plated material is 5 r. p. m. Above 100 r. p. m.
It is characterized in that a rotation means for rotating at a rotation speed within the following range is installed.

[0016]

According to the first aspect of the invention, the tank structure of the plating apparatus is provided with a first tank for containing the plating solution, and a surrounding of the first tank, and the plating solution in the first tank is indirectly supplied. Since it is composed of the second tank for containing the heating medium for heating to the first tank, it is possible to indirectly heat the plating solution in the first tank by directly heating the heating medium contained in the second tank. Therefore, reaction runaway of the plating solution due to local heating can be prevented.

In the invention according to claim 2, the first tank is made of stainless steel, and the inner surface of the first tank is
Since it is configured to be mirror-polished, it can be made rust-resistant by using stainless steel, and nickel can be prevented from depositing on the wall surface by mirror-forming the first tank wall surface. . In the invention according to claim 3, since the bottom shape of the first tank is configured to be a ship bottom shape having a tapered slope of 45 ° or more or a conical shape, dispersed particles can be obtained by forming the slope of 45 ° or more. Can be prevented from accumulating at the bottom of the first tank and causing the plating solution to run out of reaction. In addition, the bottom shape is
It is preferable to process a large object to be plated, and the conical shape is preferable to process a small object to be plated.

According to the fourth aspect of the present invention, since the ultrasonic vibrator is attached to the bottom portion of the first tank, the bottom portion of the tank is vibrated ultrasonically.
It is possible to prevent the dispersed particles from staying at the bottom of the first tank and the reaction runaway of the plating solution, and at the same time, to disperse the dispersed particles uniformly in the plating solution in the first tank. Claim 5
In the invention described above, a plating solution circulation pipe for leading out the plating solution is attached to the apex portion of the bottom surface of the first tank, and a plating solution circulation pump is installed midway on the upstream side of the plating solution circulation pipe. Since the plating solution discharge port provided in the plating solution circulation pipe is attached to the top of the tank of No. 1, it is possible to circulate the plating solution by pulling it from the bottom with the plating solution circulation pump and pouring it from the top. Therefore, the dispersed particles can be uniformly dispersed in the plating solution in the first tank.

According to the sixth aspect of the invention, since the plating liquid circulating pump is constituted by a low pulsation type pump, an abnormal flow is not generated in the plating liquid in the first tank. Therefore, it is possible to prevent the amount of eutectoid from varying depending on the location during the plating film formation. That is, the dispersion ratio of the dispersed particles in the plating film can be prevented from varying due to the difference in the position of the object to be plated in the first tank.

In the invention according to claim 7, an air pipe is installed on the bottom surface of the first tank at a position floated within a range of 2 mm or more and 20 mm or less from the bottom surface, and the bottom surface of the first tank is provided. On the other hand, because the air pipe is configured to have a plurality of air outlets at the positions where air is ejected vertically, a sufficient amount of air is ejected from the installed air pipe to the bottom of the first tank. As a result, the dispersed particles can be prevented from accumulating at the bottom and the plating solution from running out of reaction, and at the same time, the dispersed particles can be uniformly diffused in the plating solution in the first tank. In addition, if the air pipe is installed at a position closer than 2 mm from the bottom surface, it is not preferable because the mouth of the plating solution circulation pipe provided at the bottom is easily closed, and if the air pipe is installed at a position more than 20 mm away from the bottom surface. However, it is not preferable because it is difficult to eject a sufficient amount of air to the bottom face portion, and in consideration of the above points, the installation position of the air pipe is preferably within the range of 2 mm or more and 20 mm or less from the bottom face portion as described above.

According to the invention of claim 8, the air flow rate is set to be in the range of 8 Nl / min or more and 50 Nl / min or less per 1 m ^{2 of} floor area. Therefore, a sufficient amount of air can be supplied from the installed air pipe. Since it can be ejected to the bottom surface of the first tank, it is possible to prevent the dispersed particles from staying at the bottom and causing the plating solution to run into a reaction runaway.
The dispersed particles can be uniformly dispersed in the plating solution in the tank. It should be noted that if the air flow rate is less than 8 Nl / m ² , it is not preferable because it is difficult to eject a sufficient amount of air to the bottom surface portion, and if the air flow rate is greater than 8 Nl / cm ² , bubbling becomes severe and the liquid It is not preferable because it is easy to scatter and promotes liquid leakage and rust on the device part due to the scattered liquid.
The range of Nl / min or more and 50 N / l or less is preferable.

In the ninth aspect of the invention, since the first tank is used as an anode and the electrode in the plating solution is used as a cathode to apply a voltage, the first tank is used as an anode. It is possible to prevent nickel from depositing in the first tank. According to the tenth aspect of the present invention, since the trap for nickel deposition particles is installed in the plating solution circulation system, a trap dedicated to nickel deposition particles is installed in the plating solution circulation system to deposit nickel deposition. In the same way that only particles can be taken into the trap, ordinary dispersed particles can be passed through, so that nickel deposition particles grow in the plating solution in the first tank, and the plating solution runs out of control. Can be prevented.

According to the eleventh aspect of the present invention, since the trap is composed of a filter having a mesh of 0.05 mm or more and 0.1 mm or less, it is possible to pass ordinary dispersed particles but not nickel precipitation particles. Therefore, the plating solution can be circulated smoothly. If the mesh is smaller than 0.05 mm,
The dispersed particles are easily trapped, which is not preferable, and when the mesh is larger than 1 mm, the nickel precipitation particles are not trapped and easily flow, which is not preferable.

According to the twelfth aspect of the present invention, the PID temperature adjusting means is provided for adjusting the temperature of the plating liquid in the first tank by PID temperature adjustment which is a combination of proportional, integral and differential operations. Since it is configured, the variation in the temperature of the plating solution can be kept as small as possible, so that the plating film forming rate can be kept constant. According to a thirteenth aspect of the invention, according to the amount of evaporation of water in the plating liquid in the first tank, the plating liquid surface in the first tank is always kept at a constant height, Since the water supply means for replenishing water is installed in the first tank, the plating liquid level in the first tank can be kept constant without lowering the temperature of the plating liquid, so that it is always stable. It is possible to obtain the same plating film forming speed.

According to the fourteenth aspect of the present invention, the plating solution pH in the first tank is always kept at a constant value in accordance with the amount of change in the pH of the plating solution in the first tank. Since the pH adjusting agent adding means for adding the pH adjusting agent is installed in the first tank, the pH of the plating solution can be maintained at a constant value without lowering the temperature of the plating solution. It is possible to always obtain a stable plating film formation rate.

According to a fifteenth aspect of the invention, according to the amount of change in the nickel ion concentration in the plating liquid in the first tank,
Since the nickel ion replenishing solution replenishing means for replenishing the nickel ion replenishing solution is installed in the first tank so that the nickel ion concentration in the first tank is always kept at a constant value, Since the nickel ion concentration in the plating solution can be maintained at a constant value without lowering the temperature of the plating solution, it is possible to always obtain a stable plating film formation rate.

According to the sixteenth aspect of the present invention, the object to be plated is immersed at an arbitrary angle with respect to the liquid surface of the plating liquid in the first tank, and the object to be plated is 5 r. p. m.
Above 100 r. p. m. Since the rotation means for rotating at the number of rotations within the following range is installed, the dispersion ratio of the dispersed particles in the plating film can be appropriately changed, and the eutectoid amount can be changed depending on the location during the plating film formation. It can be prevented from scattering. The number of lines is 5r. p.
m. If it is smaller than this, it is not preferable because the object to be plated is hard to rotate and only one side can be plated, which makes uniform plating difficult, and the rotation speed is 100 r. p. m. When the value is made larger, the number of revolutions is too high, the dispersed particles are easily repelled from the object to be plated, and it becomes difficult for the dispersed particles to enter the plating film, which is not preferable. Further, by appropriately inclining the material to be plated with respect to the liquid surface, it is possible to change how the dispersed particles enter the plating film.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a plan view and a cross-sectional schematic view showing the structure of a plating tank of an electroless composite plating apparatus according to an embodiment of the present invention. In FIGS. 1 and 2, 1 is an outer tank, 2 is an inner tank disposed inside the outer tank 1, and 3 is an outer tank 1.
Is a pillar that supports.

The tank structure of this embodiment is such that the inner tank 2 for containing the plating solution and the inner tank 2 that covers the inside of the inner tank 2 are covered.
It is composed of an outer tank 1 for containing a heat medium for indirectly heating the inner plating solution. The bottom part 4 of the inner tank 2 is
It has a conical shape having an inclined surface inclined at 45 ° or more, and a plating liquid circulation pipe 5 is attached to the tip of the bottom portion 4.

Next, FIGS. 3 to 5 are views showing an air jet pipe installed in the inner tank 2 shown in FIGS. As shown in FIG. 3, the air jetting pipe 6 has a bottom 4
It is installed at a floating position within a range of up to 20 mm, and is installed in multiple stages along the bottom part 4. Next, FIG. 4 is a diagram showing the air ejection holes 7 provided in the air ejection pipe 6 shown in FIG.
As shown in FIG. 4, a plurality of air ejection holes 7 are formed in the air ejection pipe 6 at equal intervals. Next, FIG. 5 is a view showing how air is blown out vertically from the air ejection holes 7 shown in FIG. 4 to the bottom portion 4 of the inner tank 2. As shown in FIG. 5, the air ejection pipe 6 is arranged so that air is ejected from the air ejection hole 7 perpendicularly to the bottom portion 4 of the inner tank 2. At this time, the air flow rate is set to be in the range of 8 Nl / min or more and 50 Nl / min or less per 1 m ² of floor area so that the dispersed particles settled in the bottom portion 4 of the inner tank 2 can be blown up and uniformly dispersed.

Next, FIG. 6 is a diagram showing the structure of a composite plating apparatus according to an embodiment of the present invention. The plating solution is used for the inner tank 2
Pipe 5 for plating liquid circulation attached to the apex of the bottom 4 of the
And flows into the lower part of the nickel precipitation particle trap 8 through the plating solution circulation pipe 5. At this time, the nickel precipitation particle trap 8 is installed in the plating solution circulation pipe 5 in the plating solution circulation system. A filter 9 having a 0.1 mm mesh is installed in an intermediate portion of the nickel precipitation particle trap 8. For this reason, nickel deposited particles having a diameter larger than that of ordinary dispersed particles cannot pass through the filter 9 and accumulate at the bottom of the nickel deposited particle trap 8. The plating solution derived from the upper part of the nickel precipitation particle trap 8 is lifted with the help of a plating solution circulation pump 10 installed in the middle of the plating solution circulation pipe 5 in the plating solution circulation system, and then plated. A plating solution discharge port 5a is installed in the upper part of the inner tank 2 so as to be poured from the upper part of the apparatus. At this time, the plating liquid circulating pump 10 is of a low pulsation type so that the discharged plating liquid does not cause an abnormal flow in the inner tank 2 as much as possible. Furthermore, in electroless composite plating, the temperature of the plating solution is 90
In some cases, the particles to be dispersed may have a high hardness, and therefore the inner tank 2 and the plating solution circulation pump 10 have heat resistance, acid resistance, and wear resistance. For example, stainless steel is preferable. The inner tank 2 is formed by polishing the inner surface into a mirror surface.

As described above, the plating solution temperature is high, and when the plating process is performed, nickel ions in the plating solution are consumed and reduced, and the pH also changes.
A nickel ion replenisher is replenished and a pH adjuster is added. In this case, there is no problem if the plating liquid surface, nickel ion concentration and pH are constantly monitored by a sensor and automatically replenished, but since dispersed particles in the plating liquid adversely affect the sensor, it is difficult to make a device, and It will be very expensive.

However, in the plating apparatus for mass production, the same plated object is always plated by the same amount in most cases, so that the amount of the above-mentioned replenishment product consumed in one plating process and in a fixed time is limited. You can roughly understand. Therefore, in order to keep the plating liquid level in the inner tank 2 at a constant height at the upper part of the plating apparatus, the inner plating liquid surface in the inner tank 2 is always kept at a constant height in accordance with the evaporation amount of the water in the plating liquid in the inner tank 2. Depending on the amount of change in the nickel ion concentration in the plating solution in the inner tank 2 and the water supply tank 11 for replenishing the water inside, the nickel ion concentration in the inner tank 2 is always maintained at a constant value. The nickel ion replenisher tank 12 for replenishing the nickel ion replenisher into the tank 2 and the plating solution pH in the inner tank 2 is always constant according to the amount of change in pH in the inner tank 2 A pH adjusting liquid tank 13 for adding a pH adjusting liquid so as to maintain the value of
Is installed and the valve 14 is adjusted so that an amount corresponding to the consumption amount of each liquid can be supplied. In this method, since each liquid can be replenished little by little, the plating liquid temperature can be constantly maintained at a constant temperature without being lowered, and the nickel ion temperature and pH in the plating liquid are also always constant values. be able to.

In the present embodiment, a case has been described in which the three tanks 11 to 13 each of which the liquid is separated are independently configured. It may be composed of two tanks, that is, a tank in which the above are combined and a tank for the nickel ion replenisher. In practice, it is preferable to dilute the water with a pH adjuster, which makes it difficult to form a complex such as nickel hydroxide and prevents the plating solution from being adversely affected.

Next, a weak potential difference of about 1.5 V is applied between the bottom portion 4 of the inner tank 2 and the plating solution so that the bottom portion 4 of the inner tank 2 serves as an anode and the plating solution side serves as a cathode. To do. This can prevent nickel ions from accumulating in the inner tank 2 and precipitating nickel. The bottom portion 4 of the inner tank 2 has a bottom portion 4 provided on the ultrasonic vibration generator 15.
The ultrasonic vibrator 16 provided for the ultrasonic vibration generator 15 is attached to the bottom 4
The whole is designed to vibrate ultrasonically. Due to the ultrasonic vibration of the ultrasonic vibrator 16, the dispersed particles settled on the bottom 4 rise again without staying as they are and are dispersed in the inner tank 2.

Next, the space between the outer tank 1 and the inner tank 2 is filled with a heat medium such as ethylene glycol, and the temperature of the plating solution in the inner tank 2 is indirectly increased by heating this with a heater or the like. Raise. If a simple ON-OFF mechanism such as a thermostat is adopted for the temperature control in this case, the temperature overshoot becomes large and the film forming rate changes greatly. Therefore, in the temperature control system, a proportional operation (P operation) that outputs a control output whose magnitude is proportional to the deviation, and an integral operation that changes the output so that the deviation is automatically zero if there is a deviation ( I operation) and a PID temperature controller 1 that employs a PID operation that combines a differential operation (D operation) that gives an output proportional to the change rate of the deviation.
7 is used. Accordingly, even if the temperature is raised in a short time, overshoot does not occur and the temperature change can be suppressed within ± 0.5 ° C., so that the film forming rate can be kept constant.

Next, FIG. 7 is a view showing a holding state of the object to be plated 20 during the plating film formation of one embodiment according to the present invention. By immersing the object to be plated 20 at the time of depositing the plating film at an arbitrary angle with respect to the liquid surface of the plating solution, the dispersion ratio of the dispersed particles in the plating film can be appropriately changed. Further, at this time, the number of collisions with dispersed particles is changed by changing the number of revolutions of the object to be plated 20 during the plating film formation,
Similarly to the above, the dispersion ratio of the dispersed particles in the plating film can be appropriately changed. Therefore, a desired dispersion ratio can be obtained by using these two. In FIG. 7, 21 is a DC power supply and 22 is a cathode electrode.

When the plating film is formed, the number of revolutions of the object 20 to be plated is 5 r.s. p. m. If it is too low, the dispersion ratio of the dispersed particles in the plated film varies depending on the location. In addition, the number of revolutions of the plated object 20 is 100 r. p. m. If it is set too high, the object to be plated 20 flicks the dispersed particles and the dispersion ratio is extremely lowered. Therefore, when these are taken into consideration, the number of revolutions of the object 20 to be plated is 5 to 100 rpm.
p. m. It is good to set it in the range.

As described above, in this embodiment (claim 1), the plating structure of the plating apparatus is such that the plating bath in the plating tank is an inner tank 2 in which the plating solution is placed and the inner tank 2 is covered. Since it is composed of the outer tank 1 for containing the heat medium for indirectly heating the liquid, the plating liquid in the inner tank 2 is indirectly heated by directly heating the heat medium contained in the outer tank 1. Since it can be heated, reaction runaway of the plating solution due to local heating can be prevented.

In this embodiment (claim 2), the inner tank 2 is
Since it is made of stainless steel, and its inner surface is mirror-polished, it is possible to prevent rust and prevent nickel from depositing on the inner wall surface of the tank 2. In this embodiment (Claim 3), the bottom shape of the inner tank 2 is configured to be a conical shape having a taper slope of 45 ° or more. Therefore, the dispersed particles are accumulated at the bottom of the inner tank 2. It is possible to prevent the plating solution from running out of reaction and to efficiently process a small object to be plated.

In the present embodiment (claim 4), since the ultrasonic vibrator is attached to the bottom portion of the inner tank 2, the bottom portion of the inner tank 2 is ultrasonically vibrated to disperse. It is possible to prevent particles from accumulating at the bottom of the inner tank 2 and causing the plating solution to run out of reaction.
The dispersed particles can be uniformly dispersed in the plating solution inside.

In this embodiment (claim 5), a plating liquid circulation pipe 5 for leading out the plating liquid is attached to the top of the bottom surface of the inner tank 2, and the plating liquid circulation pipe 5 is provided with a plating liquid in the middle of the upstream side thereof. Since the liquid circulation pump 10 is installed, and the plating liquid discharge port 5a provided in the plating liquid circulation pipe 5 is attached to the upper part of the inner tank 2, the plating liquid is pumped by the plating liquid circulation pump 10. Since it can be circulated by pulling out from the bottom and pouring from the top, the dispersed particles can be uniformly diffused in the plating liquid in the inner tank 2.

In this embodiment (claim 6), the plating liquid circulating pump 10 is constituted by a low pulsation type pump, so that an abnormal flow is not generated in the plating liquid in the inner tank 2. Therefore, it is possible to prevent the amount of eutectoid from varying depending on the place during the plating film formation. That is, it is possible to prevent the dispersion ratio of the dispersed particles in the plated film from varying due to the difference in the position of the object to be plated in the inner tank 2.

In this embodiment (Claim 7), the air jet pipe 6 is installed on the bottom surface of the inner tank 2 at a position floating within a range of 2 to 20 mm from the bottom surface, and the bottom surface of the inner tank 2 is set. Since a plurality of air ejection holes 7 are provided in the air ejection pipe 6 at a position where air is ejected in the vertical direction, a sufficient amount of air is supplied from the installed air ejection pipe 6 to the inside. Since it can be ejected to the bottom of the tank 2, the dispersed particles can be prevented from accumulating at the bottom and the plating solution from running out of reaction, and at the same time, the dispersed particles can be dispersed in the plating solution inside the tank 2. It can be diffused uniformly.
It should be noted that if the air jetting pipe 6 is installed at a position closer than 2 mm from the bottom part, the opening of the plating liquid circulation pipe 5 provided at the bottom part is likely to be blocked, which is not preferable, and at a position more than 20 mm away from the bottom part. When the air jet pipe 6 is installed, it is difficult to jet a sufficient amount of air to the bottom surface portion, which is not preferable. Considering the above points, the installation position of the air jet pipe 6 is 2 mm or more from the bottom as described above.
A position within the range of 0 mm or less is preferable.

In this embodiment (claim 8), the air flow rate is
Since the floor area is configured to be in the range of 8 Nl / min or more and 50 Nl / min or less per 1 m ^2, it is possible to eject a sufficient amount of air from the installed air ejection pipe 6 to the bottom surface of the inner tank 2. Therefore, it is possible to prevent the dispersed particles from staying at the bottom and the reaction of the plating solution to run away, and at the same time, it is possible to uniformly disperse the dispersed particles in the plating solution in the inner tank 2. If the air flow rate is less than 8 Nl / m ² , it is not preferable because it is difficult to eject a sufficient amount of air on the bottom surface, and the air flow rate is 50 Nl / cm 2.
^If it is larger than ² , bubbling becomes severe and the liquid is likely to be scattered, which is not preferable because it promotes liquid leakage and rust of the device part due to the scattered liquid. Considering these, the air flow rate is 8 Nl / m ² or more 50 Nl
It is preferably in the range of / cm ² or less.

In this embodiment (claim 9), the inner tank 2 is used as an anode, and the electrode in the plating solution is used as a cathode to apply a voltage. Therefore, the inner tank 2 is used as an anode. Therefore, nickel can be prevented from depositing in the inner tank 2. In the present embodiment (claim 10), since the nickel depositing particle trap 8 is installed in the plating solution circulation system, it is possible to take only nickel depositing particles into the trap 8. Since the dispersed particles can be passed through, it is possible to prevent nickel precipitation particles from growing in the plating solution in the inner tank 2 and causing reaction runaway of the plating solution.

In the present embodiment (claim 11), since the nickel precipitation particle trap 8 is constituted by a filter having a 0.1 mm mesh, ordinary dispersed particles are passed but nickel precipitation particles are not passed. Therefore, the plating solution can be circulated smoothly. A mesh smaller than 0.05 mm is not preferable because dispersed particles are easily trapped, and a mesh larger than 1 mm is not preferable because nickel precipitation particles are not trapped and easily flow.

The present embodiment (claim 12) is provided with a PID temperature controller 17 for adjusting the temperature of the plating liquid in the inner tank 2 by PID temperature adjustment which is a combination of proportional, integral and differential operations. With this configuration, the variation in the temperature of the plating solution can be kept as small as possible, so that the plating film formation rate can be kept constant. This embodiment (claim 13)
Depending on the amount of evaporation of water in the plating liquid in the inner tank 2,
Since the water tank 11 for replenishing water is installed in the inner tank 2 so that the plating liquid surface in the inner tank 2 is always kept at a constant height, the temperature of the plating solution is lowered. Since the surface of the plating liquid in the inner tank 2 can be kept constant without the need for a stable plating film formation rate.

In this embodiment (claim 14), the plating solution pH in the inner tank 2 is always kept at a constant value in accordance with the amount of change in the pH of the plating solution in the inner tank 2. Since the pH adjusting liquid tank 13 for adding the pH adjusting agent is installed in the inner tank 2, the pH of the plating liquid can be maintained at a constant value without lowering the temperature of the plating liquid.
It is possible to always obtain a stable plating film formation rate.

In this embodiment (claim 15), the nickel ion concentration in the inner tank 2 is always kept at a constant value in accordance with the amount of change in the nickel ion concentration in the plating solution in the inner tank 2. In addition, since the nickel ion replenishing liquid tank 12 for replenishing the nickel ion replenishing liquid is installed in the inner tank 2, the nickel ion concentration in the plating liquid is kept constant without lowering the temperature of the plating liquid. Therefore, it is possible to always obtain a stable plating film formation rate.

In this embodiment (claim 16), the material to be plated is
The plating solution in the inner tank 2 is immersed at an arbitrary angle with respect to the surface of the plating solution, and the object to be plated is 5 to 100 r.p.m. p. m. Since the rotation means for rotating at a rotation speed within the range is installed, the dispersion ratio of the dispersed particles in the plated film can be appropriately changed by tilting the object to be plated at an arbitrary angle, and It is possible to prevent the amount of eutectoid from varying depending on the location during the plating film formation. The number of lines is 5
r. p. m. If it is smaller than this, it is not preferable because the object to be plated is hard to rotate and only one side can be plated, which makes uniform plating difficult, and the rotation speed is 100 r. p. m. When the value is made larger, the number of revolutions is too high, the dispersed particles are easily repelled from the object to be plated, and it becomes difficult for the dispersed particles to enter the plating film, which is not preferable.

In the above embodiment, the case in which the shape of the bottom 4 of the inner tank 2 is a circular tank having a conical shape has been described, but the present invention is not limited to this.
For example, as shown in FIGS. 8 to 10, the shape of the bottom portion 4 of the inner tank 2 may be a rectangular tank having a ship bottom shape. In this case, the same effect as that of the above embodiment can be obtained, and it is large. The material to be plated can be efficiently processed.

[0053]

According to the present invention, the dispersed particles can be easily and uniformly dispersed in the plating tank without complicating the structure of the apparatus, and the change in the co-deposition amount of the dispersed particles in the plating film is less likely to occur. In addition to the effect, it is possible to suppress the reaction runaway of the plating solution and accurately control the plating film formation rate.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of a plating tank of an electroless composite plating apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of the plating tank shown in FIG.

FIG. 3 is a view showing an air ejection pipe installed in the inner tank shown in FIGS.

FIG. 4 is a diagram showing air ejection holes provided in the air ejection pipe shown in FIG.

FIG. 5 is a diagram showing a state in which air is blown out vertically from an air ejection hole shown in FIG. 4 to an inner tank bottom.

FIG. 6 is a diagram showing a configuration of an electroless composite plating apparatus according to an embodiment of the present invention.

FIG. 7 is a diagram showing a holding state of an object to be plated at the time of forming a plated film according to one embodiment of the present invention.

FIG. 8 is a plan view showing a configuration of a plating tank applicable to the present invention.

FIG. 9 is a front view showing the configuration of the plating tank shown in FIG.

FIG. 10 is a side view showing the configuration of the plating tank shown in FIG.

[Explanation of symbols]

 1 Outer Tank 2 Inner Tank 3 Support 4 Bottom 5 Plating Liquid Circulation Pipe 5a Outlet 6 Air Jet Pipe 7 Air Jet Hole 8 Nickel Precipitate Particle Trap 9 Filter 10 Plating Liquid Circulation Pump 11 Water Tank 12 Nickel Ion Replenisher tank 13 pH adjusting tank 14 Valve 15 Ultrasonic vibration generator 16 Ultrasonic vibrator 17 PID temperature controller 20 Plated object 21 DC power source 22 Cathode electrode

Claims (16)

[Claims] 1. An electroless composite plating apparatus for applying electroless nickel composite plating to a material to be plated by using a composite plating bath in which dispersed particles are dispersed in an electroless nickel plating solution for plating by chemical reduction. In, a tank structure of the plating apparatus, a first tank for containing a plating solution, and a heating medium for covering the periphery of the first tank and indirectly heating the plating solution in the first tank An electroless composite plating apparatus characterized by comprising a second tank for containing 2. The electroless composite plating apparatus according to claim 1, wherein the first tank is made of stainless steel, and the inner surface of the first tank is mirror-polished. 3. The electroless composite plating apparatus according to claim 1, wherein the bottom shape of the first tank is a ship bottom shape having a tapered slope of 45 ° or more or a conical shape. 4. The electroless composite plating apparatus according to claim 1, wherein an ultrasonic vibrator is attached to the bottom portion of the first tank. 5. A plating solution circulation pipe for leading out the plating solution is attached to an apex portion of the bottom surface of the first tank, and a plating solution circulation pump is installed midway on the upstream side of the plating solution circulation pipe. 2. The electroless composite plating apparatus according to claim 1, wherein a plating solution discharge port provided in the plating solution circulation pipe is attached to the upper part of the tank 1. 6. The electroless composite plating apparatus according to claim 5, wherein the plating solution circulating pump comprises a low pulsation type pump. 7. The bottom portion of the first tank is provided with 2 from the bottom portion.
An air pipe is installed at a position that floats within a range of 20 mm or more and 20 mm or less, and a plurality of air ejection ports is provided in the air pipe at a position where air is ejected in a direction perpendicular to the bottom surface of the first tank. The electroless composite plating apparatus according to claim 1, wherein: 8. The air flow rate is 8 N per 1 m ^{2 of} floor area.
The electroless composite plating apparatus according to claim 7, wherein the range is 1 / min or more and 50 Nl / min or less. 9. The electroless composite plating apparatus according to claim 1, wherein the first tank is used as an anode and the electrode in the plating solution is used as a cathode to apply a voltage. 10. A trap for nickel precipitation particles is installed in the plating solution circulation system.
The electroless composite plating apparatus described. 11. The trap has a diameter of 0.05 mm or more and a value of 0.
The electroless composite plating apparatus according to claim 10, wherein the electroless composite plating apparatus comprises a filter having a mesh of 1 mm or less. 12. The temperature control of the plating liquid in the first tank is performed by:
2. The electroless composite plating apparatus according to claim 1, further comprising PID temperature adjusting means for adjusting PID temperature by combining proportional, integral and differential operations. 13. The inside of the first tank so that the plating surface of the inside of the first tank is always kept at a constant height in accordance with the evaporation amount of water in the plating solution inside the first tank. The electroless composite plating apparatus according to claim 1, wherein a water supply means for supplying water is installed in the apparatus. 14. The pH of the plating solution in the first tank in the first tank is always maintained at a constant value in accordance with the amount of change in pH in the plating solution in the first tank. PH in the first tank
The electroless composite plating apparatus according to claim 1, further comprising a pH adjusting agent adding means for adding an adjusting agent. 15. The first tank so that the nickel ion concentration in the first tank is always kept at a constant value in accordance with the amount of change in the nickel ion concentration in the plating solution in the first tank. 2. The electroless composite plating apparatus according to claim 1, further comprising nickel-ion replenisher replenishing means for replenishing the nickel-ion replenisher. 16. The material to be plated is immersed by inclining it at an arbitrary angle with respect to the liquid surface of the plating liquid in the first tank, and the material to be plated is 5 r. p. m. Above 100 r. p. m. The electroless composite plating apparatus according to claim 1, further comprising rotating means for rotating at a rotational speed within the following range.