JPS5848659A - Method and apparatus for measuring electroless plating speed - Google Patents

Abstract

PURPOSE:To measure the plating speed by immersing a sample strip of a metal with catalytic activity to electroless plating in a plating soln. at a constant speed for a fixed time to subject the strip to electroless plating and by carrying out anodic stripping while immersing the strip in an electrolytic soln. at the constant speed. CONSTITUTION:A sample strip 2 of a metal with catalytic activity to electroless plating is driven at a constant speed with a rubber roller 6 through auxiliary rollers 7, 8 and a guide roller 5 and immersed in a plating soln. 4 in a plating tank 1 through a guide roller 3 to subject the strip 2 to electroless plating. The strip 2 plated in the tank 1 for a fixed time is immersed in an electrolytic cell 9 by a fixed area and electrolyzed as an anode at a constant voltage applied between the anode and a cathode 11. In the cell 9 the metal deposited in the tank 1 is electrolyzed. The electrolytic current is measured with an ammeter 13, and by utilizing the face that the current corresponds to the plating speed, the plating speed is measured. The surface of the sample strip is a metal belonging to the 5 or 6 period of theIB or VIII group or an alloy thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for measuring the plating rate of electroless plating.

S [Deplating involves containing metal salts and reducing agents in the plating solution,
A catalytically active metal film is formed by utilizing the autocatalytic reaction of a reducing agent. Industrially, electroless nickel plating using hypophosphite as a reducing agent and electroless copper plating using formaldehyde as a reducing agent have been put into practical use and are widely used for forming circuits on printed circuit boards. .

In electroless plating, the plating rate, that is, the formation rate of the plated metal film, is determined by the pH 9 reducing agent of the plating solution.

1 per 1 liter of annihilated salts, trace amounts of additives, etc. and reaction products.
Since the plating temperature fluctuates, managing the plating solution is much more difficult than with electroplating, making it difficult to maintain a constant quality of the product.

This L length M arises from the fact that there is no way to easily and quickly measure the electroless plating speed continuously with high precision. It was rare.

However, in the past, the following method was usually used to measure the rate of electroless plating.

In other words, electroless plating is carried out on a specimen of a certain area for one hour, and the speed is calculated from the 1i child of the precipitation exchange rate, or the thickness of the electrolytic film is calculated by measuring the thickness of the deposited gold nugget on the specimen at regular intervals. With this method, the constantly changing plating speed is averaged and measured, making it extremely difficult to measure the speed continuously. .

An object of the present invention is to provide a method and apparatus for continuously measuring the electroless plating rate, which has been difficult with the prior art.

In the present invention, #:t, in order to visually measure the electroless plating rate, a plating specimen made of a metal that is catalytically active for electroless plating is immersed in a plating solution for a certain period of time at a speed of one foot to perform electroless plating. After that, the test specimen was immersed in the electrolytic solution at a speed of 1 foot and subjected to Anor F strobbing. Taking advantage of the fact that the metal deposited on the specimen is proportional to the electrolytic current,
This is to know the plating speed.

Next, the present invention will be explained in detail. FIG. 1 shows the basic configuration of the present invention, which is a plating tank.

The plating electrode 2 is made of a metal that is catalytically active for electroless plating, and is made of wires such as P, , P, , A, foils of these metals, wires and foils plated with these metals, or thin films of these metals. It is also possible to use any material formed by vapor deposition or the like on a conductor.

The clamping electrode 2 formed in an annular shape grips the guide a-ra 3.
guide roller 5 while immersing a certain area in plating solution 4. It is driven at a constant speed by a rotary rubber roller 6 which is rotated at a constant speed by a rotary motor. 7.8 is an auxiliary guide that smoothes the movement of the mating t-pole 2.

After being plated for one hour in plating tank 1, the plating was 1JL.
Electrode 2Ia, 'In the electrolytic tank 9, one foot area is immersed in the electrolyte 10, the plating electrode 2 is used as the anode, and the cathode 11 is
Electrolyzes at a constant voltage. 12 is a power source that applies a voltage between the positive and negative electrodes, 13 is an ammeter that measures the electrolytic current, and 14 is a recording needle.

In this apparatus, the plating rate is determined by utilizing the fact that the deposited in the plating bath 1 is electrolytically eluted in the electrolytic bath 9, and the electrolytic current at this time corresponds to the plating rate.

As the plating electrode, it is desirable to use a metal that is catalytically active for electroless plating and is insoluble as an anode.
P t e P d # A% I is suitable for 0% selected from the 5th and 6th phase metal females of the group.

Also, it is not necessary that the plating electrode be annular, and the effects of the present invention will not be impaired as long as it can always move in one direction at a constant speed. but.

To continuously measure the sew rate over a long period of time, it is advantageous to periodically utilize short embedding electrodes.

However, the essence of the present invention is not to form the plating electrode into an annular shape; for example, as shown in Figure 1g2, a linear electrode may be used as the tape plate 7'C.

That is, by winding the fc-plated electrode 15 around the tape, or winding the electrode from the wheel 16 onto the wheel 17 that rotates at a constant speed, electroless plating is applied in the metal plate 18, and then in the electrolytic bath 19. No need to electrolyze. Electrolytic cell 19
And Peng cathode 20 has one voltage dragon @21! The electrolytic electrolyte fi is measured by the ammeter 22 and recorded by the recorder 25, thereby automatically controlling the plating speed.

Furthermore, the present invention allows not to directly plate the plating electrode with the plating paddle. In other words, as shown in Figure 5,
A small plating chamber 24 is provided in the side leg #eit of the plating speed, and a plating solution is introduced into the plating tank from an external plating tank using a pump or the like, and after plating the plating electrode 25, the plating solution is applied to the cathode 27 in the electrolytic chamber 26. A voltage is applied to the power source 28, and the electrolytic current is measured with a current meter 11E and recorded with a recorder 30. 31 indicates a driving device.

Example 1 The present invention was implemented and as an example, the speed of electroless copper plating was automatically measured by constructing the apparatus shown in Fig. 4. The plating electrode 32 consists of a plating chamber, a plating chamber, a measurement system, and a plating electrode 32.
There is one in which both ends of a 51 mφ platinum wire are welded to form an annular shape. The drive mechanism for moving the plating electrode 32 in one direction at a constant speed is attached to the rotating shaft of a D-C servo motor, and the plating electrode 15t' is pressed by a rubber roller 33 and an auxiliary roller 34 made of brass, and the auxiliary rubber roller 55 valve to rotate the plating electrode 32. In this embodiment, the voltage of the servo motor is adjusted, and the feeding speed of the plating electrode 32 is set to 5IIEI per minute.

In the plating 36 for copper plating the plating electrode 32, a pump 58 constantly circulates a plating solution from a large plating tank 37 for plating the plating products.

The height of the plating solution was always kept constant by overflow. The plating electrode 32 moves while being copper-plated in the plating chamber 36, and the part where the plating electrode 32 enters the plating chamber 36 is made of silicone rubber 39 having a hole of α511 mφ to prevent the plating solution from leaking.

Next, the electrolytic chamber 40 dissolves the copper deposited on the plating electrode.
The electrolytic solution is circulated through the tank 41L and the pump 42, and the liquid level is raised to a certain level above the overflow, as in the plating chamber, and placed at the outlet of the plating electrode 32. If the silicone rubber 43 has a hole of 5Mφ, liquid leakage was prevented. In this electrolytic chamber 40, the plating electrode was immersed for 5m, and
In order to dissolve the copper deposited on the plating electrode, a voltage of L α1v was applied to the power supply 45 to the copper cathode 44 having a plating electrode, and the current I was measured with the ammeter 46 and recorded on the recorder 47.

The electroless steel plating solution to be measured in this example had a primary composition 'Ik' as shown below.

As the electrolytic solution, the solution described in Section 1 below was used. Of course, the present invention is not only effective for those with a % foot fluid composition such as baldness and baldness, but these are only examples.

Further, the feeding speed, shape, electrolytic voltage, etc. of the plating electrode 32 are not limited to this example.

(Inatsu Electroless Steel Plating Solution/(B) Electrolyte Solution The electroless copper plating solution described above varies in plating measurement in the range of 1 to 4 μm/n depending on the concentration of the main component.

According to the apparatus of this example, there is a proportional relationship between the plating speed and the ps current, and the plating speed can be measured as a change in current value of 1 to 4 mA. The relationship is as shown in Figure 5, and it is also clear that by recording the current, it is possible to directly record changes in plating speed over time.

Example 2 Using an apparatus having the same configuration as in Example 1, the speed of electroless nickel plating was measured. Since the speed of electroless nickel plating (Fi) and electroless copper plating (L) is high, the plating electrode made of (151111φ Japanese gold wire) was 5 tons at a speed of 5 (to) 7 minutes.
Immerse it in the SM plating solution! After applying KEL plating to π, it was immersed in an electrolytic solution for 151 m and electrolyzed at α4V using a KEL plate with an area of 2 gaJ as a cathode.

Electroless nickel plating solution used in this example.

The electrolyte solution is as follows.

(c) The effect of the present invention was investigated using an apparatus and solution that splashes electrolyte (on electroless nickel plating solution).
As shown in the figure, a good linear relationship between plating speed and electrolytic current was obtained, and it was found that the speed of electroless nickel plating can be automatically measured as a current value.

Example & Using the same equipment and solution as Example 1, the plating electrode feeding speed [
was changed to 1.2 and 5.10 m/min, copper plating was applied, and the electrolysis voltage in the electrolytic chamber was set to α05. α1. α5゜1.0,1.
5,2. The plating speed was measured by changing the OV, and a good linear relationship was established between the plating speed and the electrolytic current, just as in Example 1, indicating that the plating speed could be measured automatically.

Although the embodiments have been explained in detail above, the present invention is characterized in that the plating speed can be determined from the electrolytic current when a metal specimen electrolessly plated under certain conditions is subjected to anodic electrolysis under certain conditions. Since the plating speed can be automatically measured using a simple method, the effect of facilitating the management of plating solutions and plating products is extremely large.

[Brief explanation of drawings]

Figures 1 to 4 are diagrams showing the apparatus of the present invention; Figure 5;
Figure 6 shows experimental data. 1... Plating tank 2... Plating electrode 4... Plating solution 6... Rubber roller 9... Electrolytic bath 11,... Cathode 12... Power supply 13... Current needle 0゜A11" 80. ￫＼ ′-￥ / concave size 2 wa 1 -73 figure f 4 figure 5 figure ya l figure

Claims (1)

[Claims] 1. Electroless plating is applied to a catalytically active plating specimen while moving it at a constant speed in an electroless plating solution, and then the plated specimen is immersed in the electrolytic solution for a moment. A method for measuring electroless plating speed, characterized by performing anode stripping while moving at a high speed, and continuously calculating the plating speed from the electrolytic current at this time. The surface of the catalytically active surface plating sample for zs electroplating is characterized in that its surface is made of any metal of Group 1B, 5.6 of 81, or an alloy of these metals. Range 1. ! The method for measuring electroless plating speed described in J. (5) A catalytically active plating specimen for electroless plating, a plating bath for applying electroless plating to this plated specimen, an electrolytic bath for anodically stripping the plated metal deposited on this plating specimen, and the aforementioned plating specimen. An electroless plating speed measuring device comprising: a drive device that moves to the top of a plating tank; and an anoto stripping/yping current measuring section. 4. The claim that the surface of the plated specimen that is catalytically active for electroless plating is one of metals 5 and 6 of Group 1B and Group 8, or an alloy of these metals. 3. The electroless plating rate measuring device according to item 3.