JPH02298290A - Iron-nickel alloy plating bath - Google Patents

Abstract

PURPOSE:To obtain an Fe-Ni alloy plating bath having easily controllable physical properties and a long service life by adding malate and tartrate as complexing agents to an aq. soln. contg. Ni and Fe ions, a reducing agent, a pH buffer, a pH adjusting agent and a surfactant. CONSTITUTION:Malate and tartrate as complexing agents for Ni and Fe ions are added to an aq. soln. contg. Ni and Fe ions, a pH buffer, a pH adjusting agent for these metal ions and a surfactant. The concn. of the malate added is about 0.10-1.0mol/l, preferably about 0.30-0.70mol/l and that of the tartrate is about 0.10-1.0mol/l, preferably about 0.20-0.6mol/l. An Fe-Ni alloy plating bath having stable magnetic characteristics and suitability to plating over a long period of time and giving a high quality plating film is obtd.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to bath stabilization of permalloy plating solutions used for magnetic recording.

[Conventional technology]

High-performance soft magnetic materials have been used for magnetic recording thin film heads, perpendicular magnetic recording media, and the like. Commonly used soft magnetic materials include permalloy films made by electroplating, permalloy films made by sputtering, sendust films, amorphous Go-Zr alloys, and permalloy films made by vapor deposition. It is used. Its characteristics include low internal stress, high saturation magnetic flux density, low coercive force, low anisotropic magnetic field, and close to ideal hysteresis curve. The plating method is often selected when a certain thickness of the soft magnetic material is required or when mass production is required. [Issues to be Solved by the Invention i11 However, the iron-nickel alloy plating bath of the prior art lacks bath stability of the plating solution itself, and has many problems such as precipitation and deterioration of magnetic properties. The present invention is intended to solve these problems, and its purpose is to provide a plating bath whose physical properties can be easily controlled and whose liquid life is long. [Means for Solving the Problems] The present invention provides a plating bath containing a complexing agent for metal ions in an aqueous solution containing nickel ions, iron ions, a PH buffer for these metal ions, a PH adjuster, and a surfactant. It is characterized by the simultaneous addition of malate and tartrate, which have an effective complexing ability for nickel and iron ions. In the present invention, the malate concentration used is 0.10 mo
ff/J2 to 1.0 moI2/n, tartrate salt concentration is 0.
With 10 moI2/I2 to 1.0 m0I2/J2, the desired malate concentration is 0.30 mo! /f2~0.7m
o12/12, tartaric salt concentration is 0.20mo (2/2~
It is 0.6moff/9. This means that if the complexing agent concentration is too low, the stability aimed at by the present invention will be lacking, and if malate is 0.7 moJ/2 or more, supersaturation will occur, and tartrate will be 0.6 moJ/! If it is 2 or higher, it will be difficult to dissolve in the bath. [Function 1] From the above, the free ions in the plating bath are appropriately adjusted, the composition of the plating film is kept constant, and precipitation due to oxidation of iron ions can be prevented, thereby greatly improving the life of the solution. Hereinafter, the characteristics of the electroplating bath according to the present invention will be explained as comparative examples and,
This will be explained using an example. [Comparative Example] An fA plate was degreased, washed with water, immersed in acid, and washed with water, and an iron-nickel alloy magnetic film was formed thereon using the following plating bath composition and plating conditions. (Plating bath composition) Nickel sulfate 1.15 mo (2/42 Nickel chloride 0.10 mol/A boric acid
0.24 mail/12 ferrous sulfate
0.054 mo! l/9゜Saccharin
0.50 g/A/sodium uryl sulfate 0.20 g/9° (plating conditions) Current density: 0.4 Adm” Bath temperature: 35°C PH: 60 minutes under conditions of 2.6 or higher A plating film of Sum was obtained by plating. When this film was magnetically measured using a VSM measuring machine, the coercive force was 0.50e and the saturation magnetic flux density was 8000G. Regarding the stability of the plating bath, the following The confirmation was carried out as follows. After pre-treating the copper plate (50 x 50 x 2 mm),
Plating was performed for 60 minutes and plating was repeated one after another. This is 1
The holding force was measured twice. The results are shown in FIG. 1, and it can be seen that the holding force gradually increases. Furthermore, when the plating bath was observed after the first work was completed, a brown precipitate was observed at the bottom of the bath. this is,
This is due to the oxidation of iron ions, which is thought to be the cause of the increase in retention. In addition, in the case of water bath No. 1, it was confirmed that when the temperature was above 40°C, iron ion oxidation rapidly progressed and magnetic properties were lost. The above results revealed that the magnetic properties were unstable and the bath life was extremely short. [Example 1] An iron-nickel alloy magnetic film was formed in the same manner as in the comparative example using a plating bath having the following composition. (Plating bath composition) Nickel sulfate 1.15 mail/12 Nickel chloride 0.10 moβ/I2 Boric acid 0.24 mo12/(1 Ferrous sulfate 0.054 mail/12 Sodium malate 0.50 mof2/12 Tartaric acid Sodium 0.20 mol/f2 saccharin
0.50 g/Flood Sodium Ulauryl Sulfate 0.20 g/E/The magnetic properties of the first plating film were examined in the same manner as in the comparative example, and the coercive force was 0.40 e and the saturation magnetic flux density was 8500 G. Regarding the stability of the plating bath, as shown in FIG. 2, the holding force showed a very stable history. Thereafter, plating was carried out once every - day, and this process was repeated for - months. The results were good, showing stable holding power,
No sediment was found in the bathtub. Furthermore, the bath remained stable even though the temperature was raised to 80° C. with an ice bath composition of 1. The above results confirmed that the magnetic properties are extremely stable and the liquid life is extremely long. [Example 2] The nickel-iron alloy plating bath of the present invention was investigated as a decorative and anticorrosive plating. (Plating bath composition) Nickel sulfate 0.40 moI2/! Nickel monochloride 0.25 moi9 Boric acid
0.75 moβ/ε ferrous sulfate
0.035 mo12/(2 Sodium malate 0.50 mo12/1 Sodium tartrate 0
．． 20 mo12/(1 saccharin 0.
50 g/I2 Sodium lauryl sulfate 0
120 g/12 (plating conditions) Current density: 0.4 Adm Bath temperature: 35°C PH: 2.6 A brass watch case was pretreated and plated to a thickness of 5 μm under the above plating conditions. As a result, this alloy plating had excellent gloss and smoothness, and a high decorative effect was obtained.In addition, the iron content in the plating film was approximately 25%, which was useful for reducing the cost of anode metal, and the plating film was spreadable. [Effects of the Invention] As described above, the nickel-iron alloy plating bath of the present invention provides stable magnetic properties over a long period of time. It became possible to obtain plating properties and a high-quality plating film.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the change in the number of plating times and the holding force of the plating bath used in the comparative example. FIG. 2 is a diagram showing changes in the number of times of plating and the holding force in the plating bath used in Examples. that's all

Claims (1)

[Claims] Iron, characterized in that an aqueous solution containing nickel ions, iron ions, a PH buffer for these metal ions, a PH adjuster, and a surfactant contains malate and tartrate as complexing agents for the metal ions. Nickel alloy plating bath.