JP3365608B2 - Nickel ion replenishment method and apparatus for plating - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating nickel ion replenishing method and apparatus capable of efficiently replenishing nickel ions to a plated portion.

[0002]

2. Description of the Related Art According to Japanese Unexamined Patent Publication (Kokai) No. 8-246199, an ion replenishing section is provided in a passage between a plating apparatus for plating and a plating solution tank, and at least one of the replenishing sections is a soluble pair consisting of a plating substance. Proposal of a method to supply the plating substance to the plating treatment part by supplying electricity to each electrode while flowing the plating liquid between the electrodes of the replenishment part, eluting the plating substance from the electrode into the plating liquid Has been done.

[0003]

Conventionally, in the ion replenishment portion, ions are eluted on the anode side, but the plating solution is deposited on the cathode side because the plating solution is also in contact with the cathode side. Also, although ions are replenished on the anode side,
On the cathode, the plating in which the same amount of ions are consumed is deposited, so that the amount of ions in the plating solution does not increase.
If the ions eluted from the anode do not reach the cathode,
It is often thought that ions can be replenished, but since ions also exist in the vicinity of the cathode and are attracted to the cathode to be deposited, it is not possible to replenish ions to the plating treatment section simply by flowing the electrolytic solution. In order to replenish the ions, it is necessary to suppress the precipitation at the cathode, but in the past, ions were simply eluted in the replenishment section and the plating solution was flowed to the plating treatment section to perform plating. Was bad.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a nickel ion replenishing method and apparatus for plating that can be efficiently performed to replenish nickel ions to a plating treatment section.

The above-mentioned purpose is to coat an object to be plated in the plating treatment section.
Plating, nickel plating with plating solution
A device that replenishes ions, separate from the plating process section
Provide a plating solution tank to replenish nickel ions, and
PH for detecting the pH value in the plating solution tank
Nickel ion replenishment depending on the measuring instrument and the value of the pH measuring instrument
Plating nickel io provided with a control device to control the amount
Thus it is achieved down supply device.

Further, the above object is to subject the object to be plated to a plating treatment.
Plating on the processing part and the plating solution together with the plating solution on the plating part.
It is a method of replenishing nickel ions,
Separately, a plating bath for replenishing nickel ions is installed.
In the nickel-plated nickel ion replenishing device for digit plating,
PH measurement to detect the pH value in the plating bath in the plating bath
A pH meter is provided and nickel ion is replenished according to the value of the pH meter.
Thus it is achieved nickel ions replenishing plating method of controlling the amount.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A nickel ion replenishing method and apparatus for plating according to an embodiment of the present invention will be described below. The present invention is a nickel ion replenishment method characterized in that nickel ions are eluted in the nickel plating solution by performing electrolysis with nickel as an anode in the nickel plating solution. Cathode current density (A / dm ² ) ÷ Voltage (V) value is 10 or less and cathode current density is 20 A / dm
^Under the condition of ² or more, the method of causing plating burn on the cathode and suppressing nickel deposition on the cathode is adopted. That is, according to the present invention, nickel is used as an anode for plating at a high current density, so that a phenomenon called plating burn is usually caused on the cathode to suppress nickel deposition on the cathode.

[0007] In general, when the nickel ion concentration near the cathode decreases in the plating burn, water in the plating solution is electrolyzed to generate hydrogen, the pH near the cathode interface locally rises, and the nickel ion becomes an oxide. It is a phenomenon that it becomes a hydroxide or a hydroxide and forms a black product which is discolored. When the plating burns, hydrogen gas is generated and nickel deposition on the cathode (so-called plating) is suppressed, and nickel eluted from the anode increases the nickel ion concentration in the plating solution.

A nickel ion replenishing device capable of increasing the nickel ion concentration in the plating solution will be described below with reference to the drawings. FIG. 1 is a schematic view of a plating apparatus A of the present invention. As shown in the figure, this is an apparatus in which an anode 11 is arranged in a cylinder 10 hole of an engine, which is an object to be plated, and electrolytic plating is performed while flowing a plating solution between them.

In the plating processing section A of the plating apparatus, an electrode plate 7 on the anode side is arranged so as to be sandwiched between an upper insulating plate 6 and a lower insulating plate 8 on the lower frame 1a. An electrode plate 9 on the cathode side is arranged between the cylinder 10 and the cylinder 10. Further, an upper jig 13 is arranged above the cylinder 10 with a packing 12 interposed therebetween. At the center of each of these members, a hole having the same diameter as the inside diameter of the cylinder 10 is bored, and these holes and the centers thereof are all arranged on the same axis. Frame 1
An air cylinder 15 is provided on the upper frame 1b, and by operating the air cylinder 15, the pressing rod 15a expands and contracts in the vertical direction. In the cylinder 10, the upper jig 13 is pressed and fixed on the lower frame 1a by the pressing force of the pressing rod 15a.

The electrolytic solution is pressure-fed by the pump 4 from the plating solution tank 2, flows into the plating processing section from the solution inflow section 5 arranged in the lower frame 1a, passes through the inner hole of the cylinder 10, and then passes through the upper jig 13. It is discharged to the plating solution tank 2 through the solution outflow portion 14 arranged on the side of the. An anode 11 supported by an electrode supporting portion 7a of the electrode plate 7 is provided in the cylinder 10, and is supported and fixed so as to be located at the center of the passage of the plating solution. The connection with the DC power supply 3 is such that the cylinder 10 side is − and the anode 11 side is +. In this way, even when plating is performed at a high current density when the plating solution is flowed only on the inner surface of the cylinder,
Since the ions can be replenished quickly, plating burns will not occur, but the ion consumption in the plating solution is fast, so an ion replenishment device is required.

Next, the nickel ion replenishing device B of the plating apparatus according to the present invention will be described. FIG. 2 is an enlarged view of the plating bath 2 of FIG. A nickel anode 16 and a cathode 17 are provided in the plating solution tank 2, and these electrode portions are connected to a power source 18 by lead wires. The plating solution is supplied from the pump 4 shown in FIG.
Is supplied to the plating processing section in which the cylinder 10 holes are plated, and then returned from the plating processing section to the plating solution tank 2 through the pipe 20 connected to the solution outflow section 14. The anode 16 needs to have a large surface area for promoting dissolution, and it is preferable to use nickel pellets by putting them in a basket made of titanium or the like. The cathode 17 has a smaller surface area than the anode 16 in order to increase the current density. In the device, if the amount of current is the same, the amount of nickel that elutes from the anode is the same, but if the surface area of the cathode is small, the cathode current density will be large, and plating burns will occur easily, and the ion replenishment efficiency will increase. is there.

When the nickel ions in the plating solution decrease, the pH of the plating solution decreases. Therefore, the pH meter 21 is immersed in the plating solution, and the controller 22 controls the amount of electricity supplied from the power source 18 by the difference between the value of the pH meter 21 and the pH value before plating (initial value) to adjust the nickel ion supply amount. To do. As a result, the change in nickel ion concentration can be detected in real time, and the nickel ion plating portion can be quickly replenished. Examples of the nickel plating solution include a nickel sulfamate bath, a nickel sulfate bath, and a dispersion plating bath in which particles of ceramics thereof are dispersed. The anode 11 in the plating treatment part may be a soluble anode using nickel or an insoluble anode such as titanium, platinum or carbon.

FIG. 3 shows a modification of the plating apparatus. In this plating apparatus, the plating processing section A is the same as that in FIG.
The nickel ion replenishing device D for plating is different in that a plating replenishing tank 23 is provided separately from the plating solution tank 2, and the electrode parts 16 and 17 are arranged in the replenishing tank 23. Supply tank 2
The plating solution generated in 3 is pumped to the plating solution tank 2 by the pump 24 to replenish the nickel ions, and the plating solution is discharged to the replenishment tank 23 via the drain valve 25 of the plating solution tank 2. The advantage of providing the replenishment tank 23 in addition to the plating solution tank 2 is to replenish it to the plating solution tank 2 if a nickel ion is produced in advance if a nickel ion-generated plating solution is prepared in advance. This enables quick replenishment to the plating process part.

FIG. 4 shows another modification of the nickel-ion replenishing device for plating. This ion replenishing device E transfers a part or all of the plating solution to the intermediate tank 26 by opening the valve 25 while the nickel ion concentration of the plating solution in the plating solution tank 2 is lowered to a certain extent, and the electrode parts 16 and 17 are provided. In the replenishment tank 23 in which the nickel ion is generated in advance, the plating solution is pumped by the pump 24 to the plating solution tank 2, and then the valve 27 is opened to transfer the plating solution in the intermediate tank 26 to the replenishment tank 23. This is an example of supply. FIG. 5 shows another modification of the nickel-ion replenishing device F for plating. This is a modified example in which two plating replenishment tanks 28 and 29 are provided in the plating solution tank 2, and plating solutions containing nickel ions eluted in the replenishment tanks 28 and 29 are plated alternately. Liquid tank 2
It is a method of supplying to. The plating solution discharged from the plating solution tank 2 is introduced into one of the replenishment tanks 28 and 29 by the three-way valve 30, and the nickel ion-supplemented plating solution is pumped through the three-way valve 31 by the pump 32 or 33. Is a replenishing device that supplies the plating solution to the plating bath 2. By this method, more stable nickel ions can be supplied to the plating treatment part. In addition, three or more supply tanks are provided,
There is no problem even if it can be switched.

The nickel anode used in the plating solution tank or the replenishing tank of the nickel ion replenishing device has good solubility,
It is preferable to use one that is depolarized (prevents polarization) with sulfur or nickel oxide. Other nickel anodes have low activity and are easily passivated, and are not suitable as anodes for supplementing nickel ions. Nickel anodes containing sulfur or nickel oxide have a small amount of nickel sulfide or nickel oxide in the nickel crystal grains or in some grain boundaries,
Ni and Ni ₃ S ₂ or Ni in a nickel plating solution,
It creates a local cell with NiO, prevents passivation of the anode and promotes dissolution of nickel at the anode. In order to replenish nickel ions efficiently and quickly, it is necessary to use these nickels.

[0016]

EXAMPLES Examples of the present invention will be described below. The electrolytic conditions were as follows, and the plating treatment was performed using the nickel ion replenishing device for plating shown in FIG. Plating solution: Nickel sulfamate 535 ml / l Boric acid 45 g / l Saccharin soda 3.2 g / l Hypophosphorous acid 1.5 g / l Temperature: 57 ° C. pH: 4.2 Cathode as a result of current-carrying conditions and plating treatment Table 1 shows the presence or absence of plating burns.

[0017]

[Table 1]

From Table 1, it was found that plating burns occurred when the current density was 20 A / dm ² or more and the value of current density / voltage was 10 or less. For example, current density 8
Under the conditions of 7.3 Adm ² and 10 V, plating burns occurred at the cathode, the nickel deposition efficiency at the cathode was 30%, and the ion concentration in the plating solution increased. On the other hand, under normal conditions where plating burns do not occur, the deposition efficiency of the cathode is as high as 99%,
The ion concentration in the liquid did not rise.

Although the embodiment of the present invention has been described above, it is needless to say that the present invention is not limited to this and various modifications can be made based on the technical idea of the present invention.

[0020]

As described above, according to the present invention, nickel is used as an anode in the plating solution in the plating solution, the cathode current density is 20 A / dm ² or more, and the cathode current density / voltage Electrolysis is performed under the condition that the value is 10 or less and nickel oxide is generated at the cathode to suppress nickel deposition. Therefore, it is possible to suppress the precipitation of nickel on the cathode by dissolving nickel under conditions that are usually referred to as poor plating, and it is possible to efficiently supply nickel ions to the plating treatment part. Further, by making the surface area of the cathode smaller than the surface area of the anode, it is possible to cause plating burn on the cathode, and it is easy to cause plating burn even with a small current, which leads to energy saving.

In addition to the plating solution tank, a replenishment tank is further provided,
Since the electrode portion is provided on the side of the replenishing tank, if the nickel ions are replenished to the replenishing tank, the nickel ions can be quickly replenished to the plating solution tank even when the nickel ion concentration is reduced on the plating solution tank side. Since the pH measuring device for detecting the pH value is provided in the plating solution tank, a quick response for achieving a desired plating treatment environment becomes possible. When the object to be plated is a cylinder, by introducing the plating solution in the plating solution tank into one end of the cylinder hole, nickel ions can be stably supplied to the cylinder hole, and efficient plating can be performed. .

[Brief description of drawings]

FIG. 1 is a schematic diagram of a plating treatment part and a nickel ion supply device for plating according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a nickel ion replenishing device for plating according to an embodiment of the present invention.

FIG. 3 is a schematic view of a plating treatment part and a nickel ion supply device for plating according to a modification of the present invention.

FIG. 4 is a schematic view of a nickel ion replenishing device according to a modification of the present invention.

FIG. 5 is a schematic view of a nickel ion replenishing device according to another modification of the present invention.

[Explanation of symbols]

2 plating bath 10 cylinders 16 Anode 17 cathode 18 power 21 pH meter 23, 28, 29 Supply tank A, C plating equipment B, D, E, F Ion replenishing device

Continuation of the front page (72) Inventor, Yoichi Kamisaki, 300, Takatsuka-cho, Hamamatsu City, Shizuoka Prefecture Suzuki Stock Company (56) References A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C25D 21/14 C25D 3/12 C25D 7/00 C25D 7/04

Claims (6)

(57) [Claims] 1. An object to be plated is plated in a plating treatment section,
Nickel ions are supplemented to the plating treatment part together with the plating solution.
It is a device that supplies nickel nickel separately from the plating part.
The plating solution tank for replenishing the ON is provided,
A pH measuring device for detecting the pH value in the plating solution tank,
The nickel ion supply amount is controlled by the value of the pH measuring device.
Nickel ion replenishment equipment for plating with a control device
Place 2. The plating solution tank in which the plating solution is stored,
By providing an electrode part consisting of an anode and a cathode, nickel ions
Nickel ion supplement for plating produced by elution from the anode
In the feeder, the surface area of the cathode is
And the anode is depolarized.
The plating plating according to claim 1, characterized in that
A shell ion replenishing device. 3. The object to be plated is a cylinder, and the plating is
Introduce the plating solution from the solution tank into one end of the cylinder hole and
After plating, return the plating solution from the opening on the other end to the plating solution tank.
The nickel plating solution in the plating process area while circulating the plating solution.
The method according to claim 1, wherein the ON is replenished and the cylinder hole is plated.
Or a nickel ion replenishing device for plating according to claim 2.
Place 4. An object to be plated is plated in a plating treatment section,
Nickel ions are supplemented to the plating treatment part together with the plating solution.
It is a method of supplying nickel nickel separately from the plating treatment part.
A plating nick provided with a plating solution tank for supplying ON
Plating on the above plating bath in the Kell ion replenishing device
A pH measuring device for detecting the pH value in the liquid tank is provided.
It is necessary to control the amount of nickel ion replenishment by the value of the measuring instrument.
Mushroom nickel ion replenishment method. 5. The plating solution tank in which the plating solution is stored,
By providing an electrode part consisting of an anode and a cathode, nickel ions
Nickel ion supplement for plating produced by elution from the anode
In the feeder, the surface area of the cathode is
And the anode is depolarized.
Of the above-mentioned electrode, depending on the value of the pH measuring device.
The plating according to claim 4, wherein the amount is controlled.
Nickel ion replenishment method. 6. The object to be plated is a cylinder, and the plating is
Introduce the plating solution from the solution tank into one end of the cylinder hole and
After plating, return the plating solution from the opening on the other end to the plating solution tank.
The nickel plating solution in the plating process area while circulating the plating solution.
5. Replenishing ON and plating the cylinder hole.
Or a method for supplying nickel ions for plating according to claim 5
Law.