JPH09241884A - Nickel-phosphorus alloy electroplating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the content of P in Ni-P alloy plating constant in a wide current density range by regulating the current density in the cathode to a specified range and executing elecctrolysis while vibration is applied to a plating soln. SOLUTION: In Ni-P alloy electroplating, the cathode current density applied to the cathode is regulated to the range of 0.1 to 20A/dm<2> , preferably, to the range of 1 to 10A/dm<2> . Plating is executed while ultrasonic and/or low frequency vibration is applied to a plating soln. It is preferable that high frequency vibration of 27kHz frequency or low frequency vibration of 20 to 40Hz frequency is applied thereto. At the time of applying the vibration, the content of P in the Ni-P alloy plating is not influenced by the cathode current density, and the content of P in the Ni-P alloy plating is kept constant in a wide current density range. The vibration to be applied is controlled so as to regulate the vibrating width of the content of P in the Ni-P alloy plating to >=3wt.%. As the plating soln., a electroless Ni-P plating waste fluid is used, and the waste fluid is effectively utilized.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to P on various substrates.
The present invention relates to a method for forming a Ni-P alloy film having a small fluctuation in content by electroplating.

2. Description of the Related Art Conventionally, when high corrosion resistance or high hardness is required as the performance of the surface of a substrate, a chemical Ni-P or electric Ni-P alloy plating film has been adopted to relax the internal stress of the film. It is known as a known technique that the addition of a polysaccharide or the like is effective for the purpose. However,
The P content of the electric Ni-P alloy plating is determined by the bath composition, bath temperature,
Even if the plating conditions such as the pH of the bath are kept constant, there is a problem in that it will change significantly depending on the cathode current density.
On the other hand, in recent years, waste liquid treatment of chemical Ni-P plating containing a large amount of phosphite has become a problem. Therefore, chemical Ni-P
As a method for treating and reusing waste liquid, Japanese Patent Publication No.
JP-A-7-126855, JP-A6-1
Although the electrodialysis method, the photocatalytic oxidation method, the precipitation removal method of phosphite, etc. as described in JP-A-36549, JP-A-5-247660 and JP-A-7-267616 are proposed, In any case, it is not a method of directly reusing the waste liquid of the chemical Ni-P plating.

[0002]

DISCLOSURE OF THE INVENTION The present invention provides a plating method in which a Ni-P alloy electroplating film having a small fluctuation of P content can be efficiently obtained and a waste liquid of chemical Ni-P plating can be effectively used. The purpose is to

The present invention has been made based on the finding that the above-mentioned problems can be efficiently solved by setting the cathode current density applied to the cathode to a specific range and electrolyzing in a vibrating state. Of. That is, the present invention is
In the i-P alloy electroplating method, the cathode current density applied to the cathode is set in the range of 0.1 to 20 A / dm ² , and the electrolysis is performed in a state where vibration is applied to the Ni-P alloy electroplating method. I will provide a.

[0003]

BEST MODE FOR CARRYING OUT THE INVENTION The plating method of the present invention includes, for example,
Cathode current density is 0.1 to 20 A / dm ² , preferably 1 to
In the range of 10 A / dm ² , it is preferable that the cathode current density is substantially constant from the start to the end of plating, but it can be changed. The Ni-P alloy plating solution is preferably an aqueous solution having a Ni salt as a Ni supply source, a phosphorous acid or a phosphite salt as a P supply source as basic components, and a pH of 0.5 to 2.0. A more preferable pH is 1.0 to 1.5. Specifically, as P source, hypophosphorous acid, phosphorous acid or their sodium salts, potassium salts, chemical Ni
-P plating waste liquid etc. are mentioned. The amount used of them is preferably 5 to 100 g / l as a whole, and more preferably 10 to 60 g / l.

Examples of the Ni salt include nickel sulfate, nickel chloride, nickel sulfamate, nickel carbonate and the like. The usage amount of them is 100 to 450 as a whole.
g / l is preferred. Furthermore, boric acid as another additive,
Phosphoric acid, sulfuric acid, hydrochloric acid, aqueous ammonia, etc. may be added. In the present invention, an electroless Ni-P plating waste liquid can be used as the plating liquid. As such waste liquid,
For example, Ni 1 to 20 g / l, sodium phosphite 30
~ 1000g / l, sodium hypophosphite 5-100g
/ L, 10 to 100 g / l of an organic acid or the like, and the balance being water. The plating solution temperature is preferably 40 to 90 ° C, and more preferably kept constant in the range of 50 to 70 ° C. The present invention is characterized in that electrolysis is performed in a state where vibration is applied. Specifically, it is preferable to perform plating while applying ultrasonic waves and / or low frequency vibration to the plating solution. The vibration is preferably applied continuously from the start to the end of plating, but may be applied intermittently. As a device for applying such ultrasonic waves and / or low frequency vibrations to the plating solution, a commercially available one may be used,
For example, Clean Rex S series manufactured by Sansha Electric Co., Ltd.
And an agitator manufactured by Nippon Techno Co., Ltd.
By using these, ultrasonic waves with a frequency of 27 kHz, etc.
It is good to give a low frequency vibration such as 40 Hz.

In the present invention, ultrasonic waves and / or low frequency waves are used so that the fluctuation range of the P content in the Ni-P alloy plating film is within 3.0% by weight when the cathode current density changes. It is preferable to apply vibration to the plating solution, and it is more preferable that the fluctuation range of the P content is within 2.0% by weight. In the present invention, various substrates can be used as the substrate on which the Ni—P alloy plating film can be formed, and specific examples include iron, copper or alloys thereof. In the present invention, this substrate is used as a cathode, an insoluble conductive material such as Ni or platinum is used as an anode, and the Ni content is 80 to 99.9.
It is possible to form a Ni-P alloy plating film having a weight% and a P content of 0.1 to 20% by weight. The substrate is preferably subjected to known alkali degreasing and acid-activity pretreatment before the electroplating of the present invention. The thickness of the Ni-P alloy plating film formed by the method of the present invention can be arbitrary, but it is preferably 5 to 20 µ, and more preferably 10 to 15 µ.

[0006]

According to the present invention, by applying ultrasonic vibration or low frequency vibration to the plating solution during the plating treatment,
In the electric Ni-P alloy plating, it is possible to prevent the P content from being affected by the cathode current density, and it is possible to obtain a Ni-P alloy plating having a constant P content in a wide current density range. At the same time, chemical Ni- is used as a P source for electric Ni-P alloy plating.
Since the P plating waste liquid can be used, it is possible to dispose of the chemical Ni-P plating waste liquid. Next, the present invention will be described by way of examples.

[0007]

【Example】

Example 1 SPCC-SD steel sheets were plated with a plating solution having the following bath composition (pH: 0.6, bath temperature: 70 ° C.) to give 0.1, 1, 5, 1
Plating of 10 μm was performed at each cathode current density of 0 and 20 A / dm ² . At this time, from the start of plating to the end
Using Sanja Denki Seisakusho Clean Rex 300, frequency 2
Ultrasonic vibration was applied under the condition of 7 kHz. Plating bath composition Nickel sulfate: 300 g / l Nickel chloride: 80 g / l Phosphorous acid: 30 g / l 85% -Phosphoric acid: 40 ml / l Water balance

Example 2 Plating was performed in the same manner as in Example 1 except that a plating solution having the following bath composition (pH: 1.3, bath temperature: 65 ° C.) was used. Plating bath composition Nickel sulfate: 260 g / l Nickel chloride: 60 g / l Phosphorous acid: 30 g / l Water balance

Example 3 Plating was performed in the same manner as in Example 1 except that a plating solution having the following bath composition (pH: 1.3, bath temperature: 65 ° C.) was used. Plating bath composition Nickel sulfate: 260 g / l Nickel chloride: 60 g / l * Chemical Ni-P waste liquid: 200 ml / l (approx. 30 g / l as phosphorous acid) 89% -Sulfuric acid: 50 ml / l Water balance * Dip-so The following bath composition is used after using NP-17177 7-Turn Co., Ltd. _{Ni: 5.4 g / l Na 2} HPO 3 · 5H 2 O: 260 g / l pH: 5.1

Example 4 Plating was performed in the same manner as in Example 1 except that a plating solution having the following bath composition (pH: 1.0, bath temperature: 70 ° C.) was used. Plating bath composition Nickel sulfamate: 300 g / l Phosphorous acid: 40 g / l Sulfamic acid: 20 g / l Water balance Comparative Examples 1 to 4 Comparative Examples 1 to 4 are the same as above except that ultrasonic vibration is not applied. Plating was performed in the same manner as in Examples 1 to 4. The P content in the films formed in the above Examples and Comparative Examples was measured by a fluorescent X-ray analyzer (JSX-60, JEOL Ltd.).
It was measured according to 1). Table 1 shows the measurement results.

[0011]

[Table 1] Table 1: P content measurement result (unit: weight per unit)
Cent) Negative pole Example Comparison Comparative current density 1 2 3 4 1 2 3 4 0.1A / dm ² 12.8 12.6 11.8 12.1 12.3 12.2 11.4 11.4 1A / dm ² 12.7 12.5 11.8 12.1 12.3 12.1 11.2 11.4 5A / dm ² 12.3 12.0 11.2 11.6 11.2 11.3 10.1 10.7 10A / dm ² 11.8 11.6 10.7 11.0 8.5 9.1 8.5 8.2 20A / dm ² 11.2 11.0 10.3 10.6 6.2 6.4 5.8 6.0 Swing range 1.6 1.6 1.5 1.5 6.1 5.8 5.4 5.4 It can be seen that the P content of the electric Ni-P alloy plating obtained by the plating method according to the invention is constant.

Claims (4)

[Claims] 1. A Ni-P alloy electroplating method, comprising:
A Ni-P alloy electroplating method, characterized in that the cathode current density applied to the cathode is set in the range of 0.1 to 20 A / dm ² and the electrolysis is performed under vibration. 2. The electroplating method according to claim 1, wherein the vibration is applied by ultrasonic waves and / or low frequencies. 3. N formed by fluctuation of cathode current density
The electroplating method according to claim 1, wherein the fluctuation range of the P content in the i-P alloy plating film is within 3.0% by weight. 4. The electroplating method according to claim 1, wherein an electroless Ni-P plating waste liquid is used as the plating liquid.