JPH0452292A - Method and device for producing gold plating - Google Patents

Abstract

PURPOSE:To obtain an excellent gold plating with good adhesion and with the ruggedenesses practically unrecognized by dipping a surface to be plated in a plating soln. in parallel with the soln. surface and agitating the soln. in the opposite direction to the rotation of the surface to be plated. CONSTITUTION:A material 1 is fixed to a holder 2 as a gold plating device and dipped in a gold plating soln. 9 in parallel with the soln. surface, the holder 2 is rotated by a motor 5 through a rotating shaft 3, and an anode 6 is connected to a power source and erected in the soln. 9 in a gold plating bath 7. A thermocouple 10 is set to control the temp. of the soln. 9, and the temp. is measured and kept constant. The soln. is agitated by a rotary stirrer 8, which is rotated in the opposite direction to the rotation of the holder 2. Consequently, the surface of the material 1 is always placed below the surface of the soln. 9 irrespective of the vaporization of the soln., and the plating rate and quality are kept uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention [Field of Industrial Application] The present invention relates to a method for producing gold plating used as an electrode or a protective film, and an apparatus therefor.

[Conventional technology]

Conventionally, this type of gold plating is carried out by stirring the gold plating solution 9 while keeping it at a constant temperature, as shown in FIG. A common method is to position the (At this time,
(A positive potential is applied to the solution.) The current value to be passed during plating is determined by the area of the object to be plated submerged in the plating solution, taking into consideration the properties of the plating solution. by this,
The area of the surface to be plated and the current value that are submerged in water are very important in plating because they determine the state of the plating (surface and lightness) and the plating speed.

The gold plating solution 9 is kept at 45 to 55°C with the surface of the hot plate 11 at 70°C. The best liquid temperature is 48.6°C. As a result, the water in the gold plating solution evaporates, resulting in a phenomenon in which the liquid level drops at a rate of about 15 mm/hr. If this happens, the surface of the object to be plated that is flooded with water will be lowered, and the area and current value settings will change compared to the initial values. To prevent this, ion-exchanged water was replenished as needed, or the plating solution tank was made larger (increasing the amount of plating solution). However, these methods
(The former) lowers the concentration of the plating solution, and (the latter) increases the running cost.〇 [Problem to be solved by the invention] In response to these problems, the present invention reduces the concentration of the plating solution. To provide a method for manufacturing gold plating and an apparatus for the same, which maintains a constant plating area with a small amount of plating solution without lowering the surface area.

Structure of the Invention [Means for Solving the Problems] The present invention improves the method of positioning the surface of the object to be plated (negative potential surface) perpendicular to the flow direction of the liquid, and It is characterized by performing plating while positioning the surface of the object to be plated (negative potential surface) in parallel and rotating it in the opposite direction to the direction in which the plating solution is stirred. At this time, the rotation speed of the object to be plated is set to one-tenth or less of the plating solution stirring speed in consideration of the stirring effect.

That is, the present invention has the following features: 1. In gold plating, in which the surface of a dielectric object is plated by keeping the plating solution at a constant temperature and applying an electric charge to the solution, the surface to be plated is positioned parallel to the surface of the plating solution. A gold plating method characterized by plating by submerging the object in water and performing plating while rotating the object to be plated and stirring the plating solution in opposite directions.

2. The plating solution is kept at a constant temperature, the plating solution is stirred, and the plated object is placed in a gold plating device with a positive electrode surface perpendicular to the flow direction of the plating solution. This gold plating apparatus is characterized in that the object is placed parallel to the surface of the plating solution, and the object is plated with gold while rotating the object to be plated and stirring the plating solution in opposite directions.

[Effect]

By using this gold plating manufacturing method and apparatus, the surface of the object 1 to be plated immersed in the gold plating solution 9 can always be located below the liquid level, as shown in FIG.
Therefore, the amount of evaporation of the liquid can be kept constant regardless of the amount of evaporation, so the speed and quality of plating can be kept constant.

〔Example〕

FIG. 3 is a cross-sectional view of a gold plating apparatus in which the object to be plated is positioned parallel to the surface of the plating solution, and the object to be plated is plated with gold while rotating the object and stirring the plating solution in opposite directions.

Neutronex 3, which is gold nitrite as a gold plating solution
09 was used. As the plated object 1 of the sample to be plated with gold, a glass slide measuring 50 mm x 30 mm was used, the surface (one side) of which was deposited with Cr--Au. Alternatively, it may be a dielectric material based on electroless nickel. The holder part 2 that fixes the sample to be plated 1 has a shape as shown in FIG. An electrode 4 was built into the holder part 2 as shown in FIG. 2 at the claw part of the holder part 2 so that a current could flow through the surface. Using these materials, gold plating was performed using a gold plating apparatus as shown in FIG.

In FIG. 3, as a gold plating device, an object 1 to be plated is attached to a holder part 2, the holder part 2 is rotated via a holder rotation shaft 3 connected to a motor rotation part 5, and a gold plating tank 7 is connected to a power supply. Take the electrode, stand the positive electrode part 6 vertically in the gold plating solution, insert a thermocouple to measure the temperature in order to control the temperature of the gold plating solution 9, and turn the rotating star 9.
This is a gold plating device that stirs the gold plating solution using -8.

The rotating directions of the rotary stirrer 8 and the holder part 2 are opposite to each other. The positive electrode section 6 is a Ti--Pt expander, and has a Ti base plated with platinum of 2 .mu.m. The rotation speed of the holder part 2 of the sample to be plated is 30
I kept it at RPM. In addition, the optimal condition for the current applied to the positive electrode 6 and the plated object 1, which is the sample surface, is 3.7 mA/
Taking into consideration the loss of the C intestine 2 and the claw portion of the holder part 2, it was set to 55 Oboro A. The plating time was 100 minutes.

The Au layer on the surface of the plated film thus prepared was etched by about 2 μm using an ECR etching apparatus, and the film thickness was measured to be 16.2 μm (excluding the thickness of the base electrode portion). The surface condition after etching was so good that no unevenness could be seen under 200x magnification.

C0 Effects of the Invention [Effects of the Invention] As described above, by immersing the surface to be plated in water parallel to the level of the plating solution, and rotating the direction of rotation of the surface to be plated and the direction of stirring the plating solution in the opposite direction, The surface condition and adhesion of the gold plating were examined, and the gold plating was so good that no irregularities could be observed, and the yield was improved by more than 30%.

[Brief explanation of the drawing]

FIGS. 1(a), (b), and (c) show external views of the object to be plated used in the embodiments of the present invention mounted on a part of the holder, and FIG. 1(a) shows the object to be plated attached to the holder. Fig. 1(b) is a top view of Fig. 1(a), and Fig. 1(b) is a front view of the external appearance attached to the
c) is a bottom view of FIG. 1(a). FIG. 2 is a partially enlarged front view showing the structure of the claw portion of the object holder. FIG. 3 shows a schematic sectional view of the plating apparatus used in the embodiment of the present invention. FIG. 4 shows a schematic cross-sectional view of a conventional gold plating apparatus. DESCRIPTION OF SYMBOLS 1... Non-plated item, 2... Part of holder, 3... Holder rotating shaft, 4... Electrode, 5... Part of rotating motor, 6... Positive electrode part, 7...・Gold plating tank, 8...
- Rotating stirrer, 9... Gold plating solution, 10... Thermocouple, 11... Hot plate.

Claims (1)

[Claims] 1. In gold plating, in which the surface of a dielectric object is plated by keeping the plating solution at a constant temperature and applying an electric charge to the solution, the surface to be plated is positioned parallel to the level of the plating solution. A gold plating method characterized by plating while rotating the object to be plated and stirring the plating solution in opposite directions. 2. The plating solution is kept at a constant temperature, the plating solution is agitated, and the object to be plated is plated in a gold plating device with a positive electrode surface perpendicular to the direction of flow of the plating solution. A gold plating device that is located parallel to the liquid surface and performs gold plating while rotating the object to be plated and stirring the plating solution in opposite directions.