JPS6033383A - Method and apparatus for high speed plating - Google Patents

Abstract

PURPOSE:To obtain a predetermined plating film within a short time by increasing electrolytic current density, by forcibly supplying and recirculating a plating solution to a plating chamber which has an insoluble anode lining formed to the inner wall thereof and filled with an article to be plated. CONSTITUTION:A plating solution with a constant concn. is forcibly recirculated to a plating chamber 2 filled with an article 1 to be plated at a constant flow amount and the aforementioned article 1 to be plated is connected to the cathode side of a DC power source 8 through air cylinder rods 17, 18 to perform plating at high current density. The aformentioned plating chamber 2 is formed of a non-conductive cylinder 15 and a pair of the air cylinder rods 17, 18. The article 1 to be plated is grasped by said rods 17, 18 and an insoluble anode lining 16 is formed to the inner wall of the cylinder 15 and a seal apparatus 20 and access opening 21, 22 of the plating solution are provided. By this mechanism, electrolysis is performed at high current density and a predetermined plating film is obtained within a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for continuous electroplating of hard metals such as chromium and nickel.

[Prior art]

In the conventional electroplating method, an electrode installed in a stationary plating bath is used as one pole, and the object to be plated, which is mounted on a rack and immersed in the bath, is used as the other pole and a current r is passed through it. This is done by depositing the desired metal film on the object to be plated.However, since the metal deposition rate is slow, it takes a long time to obtain a metal plating film with a constant thickness of 7cm, and the current efficiency is poor. There is a difference between this and the fact that it is difficult to increase production efficiency.

Also, since plating takes a long time, as the production scale expands, the plating tank is large and a large number of products are to be plated at once. Become. Therefore, as the size of the device increases, operating costs also tend to increase.

Furthermore, there is a lot of loss due to removal of plating solution that adheres to racks and objects to be plated, and as the equipment becomes larger, especially in the case of chrome plating, the cost of recovery equipment to prevent pollution also increases.

(Object of the Invention) The present invention aims to solve the above problems and provide a plating method suitable for obtaining plated products at high speed, and a miniaturized apparatus.

[Structure of the invention]

Since the supply of metal ions to the cathode (object to be plated) during electroplating is mainly through diffusion movement, the present inventors decided to flow the plating bath to reduce the thickness of the diffusion film around the cathode. The present invention was completed based on the idea that it is possible to increase the current density without reducing the stain fluidity, that is, to increase the critical current density.

That is, the high-speed plating method of the present invention is characterized by forcibly supplying and circulating a plating solution at a constant concentration and a constant flow into a closed system loaded with objects to be plated.

Furthermore, the apparatus of the present invention includes a non-conductive cylinder whose inner wall is lined with an insoluble anode, a sealing device such as a rubber ring is provided, and a hole is provided for forced entry and exit of the plating solution, and the cylinder is coated with plating. A pair of air cylinder ronds and K are inserted while holding the object.
The reason for this is that a sealed plating chamber ((a) is constructed, and the object to be plated is connected to the negative electrode side of the DC wire via the air cylinder ring.

[For production]

During electroplating, when the 1h flow efficiency is equal, the time required to obtain a plated film of a constant thickness is shorter when the current density (current intensity/intensity + 1. surface area) is larger. And in general, what is the #-'i current density at the temperature of the plating bath? z (!” 'i) (The AL efficiency also improves, but when the current density reaches a single shift (limited current 6i1L @ service), hydrogen ions are discharged at the same time as the electric current is discharged.j) The lightning efficiency decreases. Therefore, in conventional chromium plating, the plating bath is operated at a temperature of 45 to 55°C, a current density of 30 to 70 A/dn, and a current efficiency of 15 to 2.
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However, in the method of the present invention, a high current efficiency can be maintained by reducing the thickness of the diffusion layer through the stirring effect of the plating solution and increasing the limiting current density. A plated film can be obtained.

FIG. 1 shows the process quotient of the method of the present invention, in which the object to be plated L is inserted and set into a non-conductive cylindrical body in the direction of the arrow while holding both ends with two air cylinders (not shown). It will be called plating room 2.

The valve 3 is opened, the valves 4 and 5 are closed, and the plating solution is pumped into the plating chamber 2 from the plating solution storage tank 7 using the pump 6. At the same time, several Kiα flow rectifiers were tightened/
The ζ′ needle passes a current through it to damage the electroplating.

At the specified time, close bulb 3 after plating photon, and close bulb 4.
is opened and the pump 9 sends cleaning water from the cleaning water tank 10 to the plating chamber 2, and after cleaning the object 1 to be plated, the impurity removal tank 1
Collect at 1. The impurity 91 removal tank 11 is equipped with a filtration device to remove dust and iron hydroxide mixed in the plating solution, and the pump 12 sends it to the aeration concentrator 13 in an amount corresponding to the amount of washing water. After the water is evaporated and the water balance is balanced, the impurities are removed and the liquid is returned to the auxiliary phase 7, where it roughly overflows into the plating solution storage phase 7. The plating solution storage tank 7 is used for plating.
Since a certain amount of a metal compound, such as chromic acid, is supplied at regular intervals, the plating solution can always be kept at a constant value.

After cleaning the object 1 to be plated in this manner, open the valve 5 to release pressure from the air supply pipe 14. Then, blow off the washing water that has accumulated in the plating chamber for the plating object and close the valves 4 and 5. Once the above steps have been completed, operate the air cylinder and cover '4:! The AI is taken out of the metal plate 2 and taken out as a plated product.

Next, the present invention will be described in further detail with reference to examples.

(Example) Fig. 2 shows a front view of the Kineisuj device, showing a 15 #i cylinder made of synthetic resin with an inner diameter of about 30 mm and a length of about 800 mm, with a ring-shaped insoluble kg m 16 is embedded in the insoluble anode 16. For example, a titanium lath plated with platinum is used as the insoluble anode 16.
It is connected to t miry. 17.18 represents the air cylinder's rond part, which has a diameter of 20 truns and a length of 400 ra, which is used as a piston rod from the left and right.
Hold n plating object 1 with threaded part 19 and move it 7 times ＼ cylinder 1
The cylinder 1 is guided by the rubber ring 20 into the middle part of the cylinder 1.
The gap between 5 and 5 is sealed to form plating 1; H4. In addition, the rod portions 17 and 18 are connected to the negative electrode side of the I-VTE rectifier 8 at two points a and b on the part protruding from the cylinder 15, so that when direct current is passed, the object 1 itself is becomes the cathode. Note that 21.22 represents the entire hole drilled in the wall of the station 15, where g with υ enters and exits in the direction of the arrow.

The composition of the plating solution is, for example, CrO3200~25Or,'
l XH2SO41,0~2.5 flt, Na2S
#6 chromium silicofluoride plating solution with iF62.5~7.5 flt is maintained at 50°C to 60°C, 2~
It is supplied to the above plating chamber at a flow rate of 64/J'rIin per day. And Lunotsu @ current about 1000 ~ 20
00A1 (current density; 500-1000 A/drr
? ) and turn on the power.

In contrast, in the conventional method, as shown in Figure 8:43, the inner y1
0 to 20n? A chromium plating solution with the same composition as above is delivered to Nometsuki Haku 23, and approximately 200 objects 1 to be plated are placed in Rank 24.
It is arranged vertically and horizontally throughout.

And the rack 24 is a negative electric power supply of DC power for $1! A gold cathode is connected to V/J1 with one plating, while an insoluble anode 25 is disposed adjacent to the object 1 to be plated. Plating current is 2500~5UOUA1 current densely 1'i 1
00A/dty? It is. In this way the thickness is 20-3
Compare the results of the plating process to obtain a plated film of 0μ.Method of the present invention Conventional method Current efficiency 60% 20% Deposition rate 60-10μ/min 0.6-1μ/min Plating time 15-30 sec/0.5~'1 hour/piece 1iM Plating solution volume 100~2001 10~20n? (Emission ψ
As mentioned above, according to Akira Honkan's method and apparatus, the deposition rate is 100 times higher than that of the conventional method, and the production rate is about 10 times higher, and the current efficiency is also doubled. do. In addition, since the concentration of the plating solution is continuously adjusted outside the plating chamber, there is no need to keep a large amount of plating solution like in conventional plating machines, and the entire device is shaped like a box for transportation and movement. is also easy. Since the entire equipment is designed as a streamlined system, wastewater treatment costs are reduced, and along with the above-mentioned increase in productivity, the operating cost is reduced to just 1 JJ.

[Brief explanation of drawings]

Fig. 1 shows the process outline of the method of the present invention, Fig. 2 shows a side view of the present invention, and Fig. 31 shows a diagram of the prior art.・Object to be plated 2-・Plating chamber 3.4.5° pump 6・Pump 7・Plating solution storage 8・・
・Direct a rectifier 9...Pump 10...Washing floor mizuyu 11°...Impurity removal tank 12...Pump 13...
Aeration concentrator 15...Cylinder J6°/Insoluble pigeon 4I!
, 17, 18...Rod part 19...Threaded part 2o・
...Rubber ring 21.22...Hole 23...Messa times 24...Rack 25...Infusible Yang 1mm (and 1 other person)

Claims (2)

[Claims] (1) A high-speed plating method characterized by forcibly supplying and circulating plating liquid at a constant hardness and constant flow rate to the sealed thread loaded with the object to be plated. (2) A non-conductive cylinder whose inner wall is lined with an insoluble @electrode, a sealing device such as a rubber ring is provided, and a hole is provided to force the plating solution in and out, and the object to be plated is held between the cylinder. Shitama\
A sealed plating chamber is formed by the pair of inserted air cylinder rods, and the object to be plated is placed in the above air chamber.