JPH0361394A - Electroplating device - Google Patents

Abstract

PURPOSE:To form a uniformly plated layer in a range over the whole surface of metal without generating a gas pit by traveling a cathode with a metallic plate fitted to the rear surface thereof in the upper part of an anode and ejecting an electrolyte to the metallic plate from the upper face of the anode and performing electroplating. CONSTITUTION:A metallic plate 15 is fitted to the rear surface of a cathode 10 and fixed with the fixtures 16a by an air cylinder 16. The electrolyte circulating pumps 7 are operated to sent the electrolyte 6a in a tank 6 into the anodes 8 from the feed ports 3a. The electrolyte 6a is ejected from the slit holes 8b provided on the upper faces of the anodes 8 and circulated between an upper step part 4a and a lower step part 4b. In this state, a motor 14 is operated to drive a traveling chain 12 and the cathode 10 is traveled along a guide shaft 9 at the prescribed velocity. Therefore the electrolyte 6a ejected from the slits 8b is jetted on the metallic plate 15 and electroplating is performed by conducting electricity between the anodes 8 and the cathode 10. At this time, the ejected electrolyte 6a is controlled by regulating the valves 7a. Thereby a plated layer uniform in film thickness and surface roughness is formed in a range over the whole surface of the metallic plate 15 and generation of a gas pit is prevented.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an electrolytic plating apparatus for producing electrolytic copper foil, and more specifically, an electrolytic plating apparatus that produces uniform film thickness and surface roughness and produces fewer gas pits. The present invention relates to an electrolytic plating device with a new structure that is effective for producing copper foil.

(Prior art) Copper-clad laminates, which are the material for printed circuit boards, are manufactured using various methods. One of these methods is the transfer method. This transfer method uses a polished surface of a metal plate. Electrolytic plating is applied to form a W4 foil layer of a predetermined thickness, the surface of the copper TRS layer is roughened if necessary, and an insulating base material is crimped onto this to bond the copper foil layer and the insulating base material. This method involves separating only the metal plate and leaving the copper foil layer on the insulating base material side.

Regarding electrolytic plating in this case, high-speed plating methods in which electrolytic plating is performed at high current density have recently been adopted for the purpose of achieving high productivity.

In this method, a metal plate on which copper foil is to be formed is used as a cathode, an insoluble anode is placed at a predetermined distance from the metal plate, and with both fixed, a predetermined flow rate is applied to the gap between the two electrodes. Electrolytic plating progresses by forcing the electrolyte to continue flowing. At this time, the current density is appropriately selected depending on the flow rate of the electrolytic solution, that is, the speed at which the electrolytic solution contacts the surface of the metal plate.

(Problems to be Solved by the Invention) However, in the case of electrolytic plating performed in the manner described above, the following problems occur.

That is, first, gas is generated in the gap between the two electrodes during electrolytic plating, but the gas concentration in the electrolyte at this time is diluted by the new electrolyte supplied at the electrolyte supply port side, and becomes low. However, on the electrolytic solution outlet side, the gas generated on the upstream side also collects, so the gas concentration becomes high. As a result, the surface of the copper foil layer on the electrolyte supply port side of the gap between the two electrodes becomes dense, and conversely, the plating surface becomes rough on the electrolyte outlet side. Therefore, the film thickness and surface roughness of the formed copper foil are not uniform over the entire surface and vary. Moreover, many gas pits are generated in the copper foil formed on the electrolyte outlet side.

The above-mentioned tendency becomes more noticeable as the current density increases.

When such W4 foil is transferred to an insulating base material, the adhesive strength between the tRfIg and the insulating base material in the resulting copper-clad laminate varies depending on the location, and the reliability of the product is significantly reduced. do.

Further, in the case of the above-described method, the shapes of the opposing surfaces of the cathode and the anode are required to be the same.

If the shape and size of the opposing surface of the anode is smaller than that of the cathode (metal plate), not only will it be impossible to perform electrolytic plating over the entire surface of the cathode, but the gas generated will not escape. This is because the condition deteriorates, leading to an increase in gas focus.

The present invention solves the above-mentioned problems and improves film thickness.

The purpose of the present invention is to provide an electrolytic plating apparatus capable of forming a copper foil on the surface of a metal plate that has uniform surface roughness over the entire surface and does not generate gas pits.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention includes an electrolyte tank for storing an electrolyte, an electrolyte circulation pump connected to the electrolyte tank, and an electrolyte circulation pump. A box-shaped anode is connected to the box-shaped anode and has at least one slit hole formed in its upper surface; Each cathode is disposed facing the hole at a predetermined distance, and while the cathode is running, the electrolyte in the electrolyte tank is spouted out from the slit hole on the upper surface of the anode by a circulation pump, and the electrolyte is discharged from the cathode. An electrolytic plating apparatus is provided which performs electrolytic plating by spraying onto the lower surface, and the entire apparatus is separated into two parts, an upper part and a lower part, by a partition plate having an electrolyte inlet and an electrolyte outlet. an electrolytic solution tank that stores the electrolytic solution flowing out from the electrolytic solution outlet; and an electrolytic solution tank that is connected to the electrolytic solution tank and liquid-tightly connected to the electrolytic solution inlet. an anode having a box-like shape, in which an electrolyte WI ring pump is disposed, the upper part is liquid-tightly connected to the electrolyte inlet, and at least one slit hole is formed in the upper surface of the anode; and a cathode that is suspended from a cathode traveling device installed above the upper part, and whose lower surface faces the slit hole in the upper surface of the anode at a predetermined interval, and which runs on the cathode. There is provided an electrolytic plating apparatus characterized in that electrolytic plating is performed by spraying the electrolytic solution onto the lower surface of the cathode by spouting the electrolytic solution from a slit hole on the upper surface of the anode while the electrolytic solution is sprayed onto the lower surface of the cathode.

(Function) In the device of the present invention, the electrolytic solution fed into the anode of the box-shaped body by the electrolyte circulation pump is ejected from the slit hole on the top surface of the anode at a predetermined flow rate. Then, the cathode runs at a predetermined speed across the spouting electrolyte, and in the process, the electrolyte is sprayed in a film onto the lower surface of the cathode, that is, the surface of the metal plate set there. Therefore, the moving metal plate is electrolytically plated one after another while its surface is in contact with a fresh, steady flow of electrolyte, and the generated gas is carried away by the electrolyte that flows away from the metal plate surface without being retained. Since it is quickly removed from the electrolytically plated surface, the thickness of the copper foil formed and the surface roughness are uniform over the entire surface.
Furthermore, gas bits no longer occur.

(Example) Below, one example of the device of the present invention will be described in more detail based on the accompanying drawings.

FIG. 1 is an overall configuration diagram of the embodiment device.

In FIG. 1, the apparatus has four frames 2a, 2b, 2c, and 2d erected on the ground 1, and a partition plate 3 is disposed in the middle of each frame.
It is divided into two sections: a lower section 4b and a lower section 4b.

The partition plate 3 is formed with electrolyte inlets 3a, 3a and an electrolyte outlet 3b, and above the partition plate is an electrolyte inlet 3a which has a planar shape and is similar to the partition plate.
, 3a, and an upper tank 5 having a through hole communicating with the electrolyte outlet 3b is disposed. Note that, without providing the upper tank 5, the upper stage portion 4a may be formed as a tank with an upper opening by surrounding each frame with a plate and using the partition plate 3 as a bottom plate.

An electrolyte tank 6 is arranged in the lower part 4b, and the upper part 4
The electrolytic solution a flows in from the electrolytic solution outlet 3b described above and can be stored therein.

Further, an electrolyte circulation pump 7°7 is arranged in the lower part 4b, one end of the pump is connected to the electrolyte tank 6, and the other end is liquid-tightly connected to the electrolyte inlet 3a of the partition plate 3. By operating the electrolyte circulation pump 7, the electrolyte 6a in the electrolyte tank 6 can be circulated between the lower section 4b and the upper section 4a. The piping connecting the electrolyte circulation pump 7 and the electrolyte inlet 3a has a flow rate Sl1.
A control valve 7a and a flow meter 7b are attached, so that the flow rate and flow rate of the electrolytic solution 6a spouted from the electrolytic solution tank 6 to the upper stage 4a can be controlled at 1 lil'f.

In the tank 5 of the upper part 4a, there are electrolyte inlet ports 3a, 3.
An anode 8.8 is disposed in fluid-tight connection with a, and this is connected to the pole . As shown in the perspective view of FIG. 2, the anode 8 has a box-like shape as a whole, and the upper surface 8a has a
A slit hole 8b extending in a direction perpendicular to the running direction of the cathode, which will be described later, is formed. The length of this slit hole 8b is determined based on the width of the metal plate (the length in the direction orthogonal to the running direction), which will be described later.

Frames 2a and 2b, frames 2c and 2d (not shown)
A guide shaft 9.9 is installed between them, and a cathode 10 is suspended from this guide shaft 9. That is,
The cathode 10 is an electrically insulating support 11. which is provided with bearing sliding parts 11a, lla that slide on the guide shaft 9.
11 and is supported by the guide shaft 9. Further, a traveling chain 12 is attached to both ends of the cathode 10, and this traveling chain 12 forms a loop with sprockets 13a, 13b, 13c, and 13d attached to the upper part of the frame. It is integrated with. Therefore, by operating the motor 14 to drive the traveling chain 12, the cathode 10 can travel in the direction of the arrow p. Conductors 10a, 10a are attached to the cathode IO, and these are connected to the 0 pole.

The lower surface of the cathode 10 faces the upper surface 8a of the anode 8 at a predetermined distance, and a metal plate 15 on which the W4 foil is to be formed can be detachably attached to the lower surface. There is. That is, air cylinders 16, 16 are attached to both end sides of the shade 8iilo, and the metal plate i5 is removably attached using fixtures 16a, 16a which are moved up and down by these air cylinders 16.

Next, the operation of this device will be explained.

First, a metal plate 15 made of a predetermined material 1 whose surface has been polished is attached to the lower surface of the cathode 10, and is fixed to the cathode 10 by operating the air cylinder 16 and tightening it with the fixture 16a. Next, the electrolyte circulation pump 7 is operated to drain the electrolyte 6 in the electrolyte tank 6.
a into the anode 8 from the electrolyte inlet 3a. The introduced electrolyte is passed through the slit hole 8b of the anode top surface 8a.
As illustrated in FIG. 2, the upper stage part 4a and the lower stage part 4
It circulates between b.

In this state, the motor 14 is operated at a predetermined rotation speed to drive the traveling chain 12, and the cathode 10, that is, the metal plate 15 is driven.
is made to travel along the guide shaft 9 at a predetermined speed.

Immediately before the electrolyte ejected from the slit hole 8b hits the metal plate 15, electricity is applied between the anode 8 and the cathode 10 to start electrolytic plating.

At this time, flow 11! ! Adjust the flow rate of the electrolyte ejected from the slit hole 8b by adjusting the ff valve 7a so that the contact speed of the electrolyte on the surface of the traveling metal plate 15 is at a predetermined level, and the current is adjusted accordingly. Set density.

The flow rate of the electrolyte from the slit hole 8b is determined by the amount of the electrolyte 6a supplied from the electrolyte circulation pump 7, the width of the slit hole 8b,
Since these values are determined by the length, etc., these values may be appropriately selected in relation to the above-mentioned liquid contact speed.

For example, a copper plating solution is used as the electrolytic solution, and the gap between the metal plate 15 and the anode top surface 8a is set to 3 to 20 mm.

The running speed of the cathode 10 (metal plate 15) is 0.5 to 2 m/s.
Under conditions where the flow rate of the electrolytic solution from the slit hole 8b is 0.1~10m7sec, even if the flow density is set to 20~100A/da'', the surface of the metal plate 15 will not reach the surface of the metal plate 15. The formed copper foil has an excellent surface condition with a variation in thickness of ±2.5% or less, a surface roughness of 0.1 to 2 μm or less, and the number of gas pins generated is O pieces/10 cd. In the conventional method, the thickness variation is on the order of ±5%, the surface roughness is on the order of 0.1 to 10 tIm, and 10 ctl to 5 pieces/dm.

(Effects of the Invention) As is clear from the above explanation, according to the apparatus of the present invention, the metal plate to be plated is run while being sprayed with electrolyte at a predetermined flow rate, so that the surface of the metal plate is always kept fresh. A steady flow of electrolyte is formed, and the generated gas is quickly removed together with the electrolyte, resulting in a uniform film thickness and surface roughness over the entire surface of the metal plate. A plating layer without gas pits is formed.

Furthermore, in the case of this apparatus, electrolytic plating can be performed by simply adjusting the length of the slit hole to the width of the metal plate to be processed and the path, so that the overall shape of the anode can be made smaller.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of an embodiment of the device of the present invention, and Fig. 2 is a perspective view of an example of an anode. , 3a...electrolyte inlet, 3b...
... Electrolyte outlet, 4a... Upper part, 4b... Lower part, 5... Upper tank, 6... Electrolyte tank, 6a
... Electrolyte, 7... Electrolyte circulation pump, 7a...
Flow N control valve, 7b...flow meter, 8...anode, 8
a...Anode top surface, 8b...Slit hole, 9...Guide shaft, 10...Cathode, 10a...Conductor,
11...Support body, lla...Bearing sliding part, 1
2... Traveling chain, 13a. L3b, 13c, 13d... Sprocket, 14...
- Motor, 15...Metal plate, 16...Air cylinder, 16a...Metal plate fixture.

Claims (2)

[Claims] (1) An electrolyte tank that stores an electrolyte, an electrolyte circulation pump that is connected to the electrolyte tank, and a box that is connected to the electrolyte circulation pump and has at least one slit hole formed on its top surface. an anode of the body, and a cathode suspended from a cathode traveling device installed above the anode, the lower surface of which faces the slit hole of the anode surface at a predetermined distance, and the cathode An electrolytic plating apparatus characterized in that while running the anode, the electrolytic solution in the electrolytic solution tank is spouted out from a slit hole on the upper surface of the anode by a circulation pump, and is sprayed onto the lower surface of the cathode to perform electrolytic plating. (2) The entire device is divided into two chambers, an upper part and a lower part, by a partition plate having an electrolyte inlet and an electrolyte outlet. An electrolyte tank for storing a liquid, and an electrolyte circulation pump connected to the electrolyte tank and liquid-tightly connected to the electrolyte inlet are provided in the upper part, and the electrolyte inlet is connected to the electrolyte inlet. a box-shaped anode, which is fluid-tightly connected to the box-shaped anode and has at least one slit hole formed in its upper surface;
A cathode is suspended from a cathode traveling device installed on the upper part of the upper part, and the lower surface thereof faces the slit hole in the upper surface of the anode at a predetermined interval. An electrolytic plating apparatus characterized in that electrolytic plating is performed by spraying the electrolytic solution onto the lower surface of the cathode by spouting the electrolytic solution from a slit hole on the upper surface of the anode.