JPH1112785A - Electroplating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the film thickness distribution and film quality of a plating film uniform on a large-area substrate by adopting the constitution to arrange an anode between a substrate to be plated and a discharge/suction mechanism and integral this discharge/suction mechanism with the anode. SOLUTION: The substrate 4 to be plated is so formed that the substrate can be oscillated vertically or laterally on the same plane inclusive of its surface by an oscillating device, etc., and simultaneously this substrate itself acts as a cathode at the time of electroplating. The meshed anode 6 is integrated with the plating liquid discharge/suction mechanism 5 as a unit. This unit is so supported as to move vertically along rails 7 disposed in parallel with the surface of the substrate 4 to be plated. A discharge side pipe 8 and a suction side pipe 9 are connected by Tygon tubing to the discharge/suction mechanism 5. The substrate 4 to be plated and the anode 6 are held in a parallel state by such constitution, by which the application of a uniform voltage and current on the substrate 4 to be plated is made possible and the uniform plating of the large area is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anode which is moved in parallel with a surface of a substrate to be plated when manufacturing an electronic circuit board, and a direction substantially perpendicular to the surface of the substrate to be plated. The present invention relates to an electroplating apparatus having a discharge and suction mechanism for discharging and sucking a plating solution from the apparatus.

[0002]

2. Description of the Related Art Various techniques have been proposed as techniques for manufacturing printed electronic circuit boards. For example,
The substrate to be plated is shaken in the plating tank, or bubbles are generated from the bottom of the plating tank, and the liquid is circulated to perform more uniform plating on the substrate to be plated (printed wiring board). The method has been widely used since ancient times. Further, as a high-speed plating method, there has been proposed a method in which a plating solution is jetted, ejected onto a surface of a substrate to be plated, and plated (Japanese Patent Publication No. 57-6 / 1982).
0788 or JP-B-58-759).

In addition, it is difficult to perform uniform plating including the inside of a through-hole on a printed circuit board by a conventional method. In recent years, a plating solution has been jetted and injected onto a substrate to be plated. At the same time, there has been proposed a method of applying a oscillating power to a substrate or operating an anode to increase the contact of a plating solution with a through hole to perform plating.

[0004] To give a few examples, a plating apparatus for through holes which has a suction mechanism at the bottom of a plating tank and a discharge mechanism at the top of the plating tank and swings a substrate to be plated (Japanese Patent Publication No.
No. 1-47918), a through-hole plating apparatus in which the discharge mechanism itself reciprocates (Japanese Patent Publication No. 57-390).
No. 79), a through-hole plating apparatus equipped with an anode that moves in synchronization with a plating solution spray tube (Japanese Patent Publication No. Sho.
No. 8-21840) has been proposed.

[0005]

However, in the conventional oscillating system, the substrate to be plated is moved at a slow speed (about 1 m / min), so that agitation having an effect of suppressing hydrogen generation during plating is realized. However, this does not solve the problem of the concentration gradient of metal ions formed on the outermost surface of the substrate to be plated.

[0006] In the case of through-hole plating by a jet of a plating solution, the circulation of the solution to the through-holes is effective, but a wiring pattern having a line width of several tens of microns or less can be formed.
In the case of plating by the additive method, the input power is concentrated on the edge of the wiring, the edge grows abnormally, and the cross section often becomes a so-called M-shape. As described above, when the cross section has an M-shape, as the wiring width becomes narrower, a compressive stress is generated inside the wire, and the wiring peels off from the substrate to be plated after manufacturing. Therefore, it is desired that the cross section of the wiring shape be trapezoidal or rectangular.

In addition, it is necessary to take into account not only stress generated from the shape but also stress derived from the composition structure of the plating film itself. That is, in order to reduce the stress of the plating film, a soft plating film (for example, Vickers hardness: about Hv = 50) may be used. Therefore, as described above, in order to easily form wiring having a trapezoidal or rectangular cross section by plating, and to suppress the composition structure of the plating film itself, the plating method itself has been changed. It is necessary to.

On the other hand, in the above-mentioned conventional example, if the substrate to be plated has a size of about 100 mm square, the plating film thickness and the composition structure can be sufficiently uniformized. For example, in the case of a substrate of 400 mm square or more, it is very difficult to apply uniform plating to the entire substrate. That is, in the conventional plating by swinging the substrate, in the case of a large area, the current density in the central portion of the substrate is reduced. Therefore, the film thickness in the central portion of the substrate is inevitably reduced. ).

Further, even in a through-hole plating apparatus using a jet or a plating apparatus having a jet port on the same surface as an anode electrode, when a plated wiring pattern is to be formed over a large area, it is difficult to form a wiring pattern. The shape may have an irregular shape such as an M-shape having peeling stress, or a variation in film thickness distribution may be formed on the substrate to be plated.

This is a problem when wiring to a large area such as a wiring technology for a flat panel display such as a wall-mounted television in the future. It is essential to obtain a plating film.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide an electroplating apparatus which achieves a uniform film thickness distribution and film quality on a large-area substrate. To be.

[0012]

In order to achieve the above-mentioned object, according to the present invention, there is provided an anode which is moved parallel to a surface of a substrate to be plated, and an anode which is substantially perpendicular to the surface of the substrate to be plated. In the electroplating apparatus including a discharge suction mechanism that discharges a plating solution from the apparatus, the anode is disposed between the substrate to be plated and the discharge suction mechanism, and the discharge suction mechanism is It is characterized in that it is integrated with the anode.

[0013] In this case, it is preferable that the discharge ports and the suction ports of the discharge / suction mechanism are alternately arranged in the moving direction of the anode. The anode may have a mesh shape, and a part of the plating solution discharged from the discharge and suction mechanism may be configured to pass through the mesh of the anode. Further, the substrate to be plated is
It is a glass substrate having a metal component adhered to its surface or a part thereof, and a wiring pattern is formed by plating on a portion of the metal component on the substrate.

With this configuration, it is possible to perform wiring pattern plating of a large area, which cannot be obtained by conventional through-hole plating. In addition, by placing the anode (anode electrode) between the substrate and the discharge / suction mechanism, the distance between the substrate and the electrode can be shortened, and a high current density can be realized. Can be large. Also, in the case of conventional jet plating, it was common to install the anode away from the substrate, but using an anode movable method, and
Since the discharge / suction mechanism has a mechanism integrated with the anode, the substrate to be plated and the electrodes are in a parallel state, so that a uniform voltage and current can be given to the substrate to be plated, and a large area can be obtained. Uniform plating becomes possible.

Also, by using the electroplating apparatus of the present invention, pattern wiring can be performed on a glass substrate, and a glass wiring substrate having wiring formed on an inorganic substrate can be manufactured. Moreover, conventional jet plating is effective as through-hole plating or high-speed plating, but as described above, it has an irregular shape, large stress, and poor adhesion to form a pattern on a large-area substrate. Although there were problems such as bad, by using the electroplating apparatus of the present invention, a uniform wiring with good wiring cross-sectional shape, plating film composition, plating film thickness distribution on the metal component adhered on the glass substrate Plating becomes possible.

Further, in the electroplating apparatus of the present invention, since a part of the plating solution discharged from the discharge and suction mechanism passes through the mesh anode, the plating solution discharged from the discharge port is applied to the mesh of the mesh electrode. It passes through and is ejected to the substrate to be plated, but since the arrangement area of the discharge ports is formed wider than the width of the anode at this time, the jet flows in a region slightly wider than the anode width where plating is formed. Hit the substrate. In other words, in this state, the discharge and suction mechanism moves with the movement of the anode, and is constantly plated (the width of the anode).
On both sides of the substrate, the high state of the metal ions is maintained, the injection becomes possible, and the uniform plating becomes possible. In addition, by using a mesh anode, the anode can be installed between the substrate to be plated and the discharge / suction mechanism and can be close to the substrate to be plated. And the margin of plating conditions can be increased.

At this time, in a preferred embodiment, if the diameter of the mesh is too small, the liquid resistance increases, so that the mesh is desirably 1004 or more as a lath type symbol. Thereby, the uniformity of the plating film and the wiring cross section of the plating wiring can be formed in a preferable shape without stress.

[0018]

FIG. 1 shows a vertical electroplating apparatus for providing wiring on a glass substrate according to an embodiment of the present invention. The electroplating apparatus has a double structure composed of an inner tank 1 and an outer tank 2. In practice, the plating solution 3 is pushed out from the bottom of the inner tank 1, and the overflowed amount is transferred to the outer tank 2. It is a mechanism that flows in.

The substrate 4 to be plated can be swung up and down or left and right on the same plane including the surface of the substrate to be plated by, for example, a swinging device (not shown). It is configured to be a cathode itself during electroplating. In FIG. 1, reference numeral 5 denotes a plating solution discharge / suction mechanism, and a mesh-shaped anode 6 is integrated with the plating solution discharge / suction mechanism 5 (hereinafter, referred to as an anode-equipped discharge / suction mechanism unit). The discharge / suction mechanism unit with the anode is provided with a rail 7 provided in parallel with the substrate surface.
The discharge side pipe 8 and the suction side pipe 9 are connected to the discharge and suction mechanism 5 by a Tygon tube (not shown). Further, a pump 10 for circulating the plating solution from the suction side pipe 9 to the discharge side pipe 8 is provided outside.

In order to circulate the plating solution in the outer tank 2 to the inner tank 1, the bottom of each of the outer tank 2 and the inner tank 1 is
Pipes 13 and 14 are connected and these are pump 1
2 and a filter 11 connected in series with each other. Then, the overflowing plating solution is cleaned by the filter 11 and the pump 12 works.
It is returned to the inner tank 1.

Next, a description will be given of a discharge / suction mechanism unit with an anode, which is a main part of the present invention. FIG. 2 is an external perspective view of the discharge and suction mechanism unit with anode. In the drawing, reference numeral 20 denotes a plating liquid discharge port, 21 denotes a plating liquid suction port, and the anodes 6 are arranged in parallel on the front of the unit housing 126 at predetermined intervals. Discharge port 20 and suction port 21
Are arranged side by side in a row, and the rows of the unit housings are arranged alternately with respect to the moving direction of the anode 6 (that is, the moving direction of the unit up and down along the rail 7). The anodes 6 are arranged on the front, and the surfaces of the anodes 6 are opposed to each other so as to cover some of the rows.

Thus, the plating solution discharged from the discharge port 20 of the discharge / suction mechanism unit with an anode is injected directly or through the mesh opening of the mesh anode 22 to the front of the substrate 4 to be plated. . At this time, the mesh of the mesh-shaped anode 6 becomes a passage resistance, and reduces the discharge flow velocity. When the mesh functions like a shielding plate (baffle plate), an opening of an appropriate size may be provided in the mesh anode 22 at a location facing the discharge port.

FIG. 3 is a schematic cross-sectional view of the internal water pipe of the discharge / inhalation mechanism unit with the anode. In this figure, reference numeral 24 denotes the arrangement of the discharge system and reference numeral 25 denotes the arrangement of the suction system.
These are stored in the unit housing 26 and communicate with the respective discharge ports 20 and the suction ports 1. And it is connected to the pipes 8 and 9 and circulates for injection. It should be noted that in this embodiment, the positive and negative water pressures of each discharge port 20 and suction port 21 are made uniform,
The purpose is to make the flow rate of the discharged plating solution as uniform as possible.

[0024]

【Example】

(Embodiment 1) Next, a case where plating is specifically performed by the electroplating apparatus of the present invention will be described. This embodiment describes a case where copper wiring is provided on a glass substrate. First, a blue glass substrate is washed with an acid and an alkali, and palladium (hereinafter referred to as Pd) is applied to the substrate by 0.1 μm by electroless plating. Thereafter, wiring was patterned on the substrate by photolithography. The line width of the pattern at this time was 50 μm.

This patterning method is as follows. A positive resist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is spin-coated on the substrate with Pd, and after exposure and development, etching is performed with a mixed acid (a mixed solution of nitric acid, hydrochloric acid, and acetic acid). The resist was peeled off, and a Pd wiring pattern was formed on the glass substrate. Next, after performing an activation treatment of Pd with an acid / alkali, it was installed in the electroplating apparatus of the present invention shown in FIG. 1 (in the inner tank 1). The plating solution is a copper nitrate solution (copper sulfate: 50 g / liter, sulfuric acid: 1)
(90 g / liter) and plating was performed at 3 A / dm ² . At this time, the moving speed of the discharge / suction mechanism unit with the anode was 3 cm / sec. As a result, 30
The film thickness distribution in a 0 mm square substrate is 5 μm ± 0.4 μm
The cross-sectional shape to be formed was also trapezoidal, and the plating film had high adhesion (low stress) to the substrate.

(Embodiment 2) The discharge / suction mechanism unit with an anode according to the present invention in this embodiment is not a mechanism that can move up and down in parallel to a vertically laid substrate as in Embodiment 1, It is arranged parallel to the ground, and the discharge and suction mechanism unit with the anode is installed below the substrate, and when discharging the plating solution, it is blown up upward, but this is installed parallel to the substrate. If so, there is no change in its functions and effects. In the present embodiment, such a horizontal method allows horizontal transfer when transferring a substrate, and makes a plating line, which is structurally effective during integrated production from cleaning of the substrate to final drying of the substrate. Can be demonstrated.

(Embodiment 3) In the discharge / suction mechanism unit with an anode according to the present invention in this embodiment, the substrate is installed in parallel with the ground, however, contrary to the embodiment 2, the substrate is disposed above the substrate. When the plating solution is discharged, it is blown downward. Such a horizontal method enables horizontal transfer when transferring a substrate, as in the second embodiment, forms a plating line, and performs structural production during integrated production from cleaning of the substrate to final drying of the substrate. Can be effective.

[0028]

As described above, according to the present invention,
Electroplating comprising: an anode that is moved in parallel with the surface of the substrate to be plated; and a discharge and suction mechanism that discharges and sucks a plating solution from a direction substantially perpendicular to the surface of the substrate to be plated. In the apparatus, the anode is disposed between the substrate to be plated and the discharge / suction mechanism, and
The discharge / suction mechanism is integrated with the anode.

Therefore, the wiring pattern formed by plating can be configured to have a uniform film quality, a uniform film thickness, a low film stress, and a sufficient adhesion to the substrate while having a large area. For this reason, for example, a wiring pattern can be easily formed on a glass substrate, and a large-sized wiring substrate made of an inorganic material such as glass can be provided for a wall-mounted television or the like.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an electroplating apparatus showing an embodiment of the present invention.

FIG. 2 is a perspective view of the liquid discharge / inhalation mechanism unit with anode.

FIG. 3 is a schematic diagram of a cross section of a water distribution pipe provided inside a unit housing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner tank 2 Outer tank 3 Plating solution 4 Substrate to be plated 5 Plating solution discharge / suction mechanism 6 Mesh anode 7 Rail 8 Discharge side pipe 9 Suction side pipe 10 Pump 11 Filter 12 Pump 13 Piping 14 Piping 21 Plating liquid discharge port 22 Plating solution inlet 24 Discharge system water pipe 25 Suction system water pipe 26 Unit housing

Claims (4)

[Claims] An anode which is operated to move in parallel with the surface of the substrate to be plated, and a discharge and suction mechanism which discharges and sucks a plating solution from a direction substantially perpendicular to the surface of the substrate to be plated. Wherein the anode is disposed between the substrate to be plated and the discharge and suction mechanism, and the discharge and suction mechanism is integrated with the anode. Plating equipment. 2. The electroplating apparatus according to claim 1, wherein the discharge port and the suction port of the discharge / suction mechanism are alternately arranged in the moving direction of the anode. 3. The method according to claim 1, wherein the anode has a mesh shape, and a part of the plating solution discharged from the discharge suction mechanism is configured to pass through the mesh of the anode. The electroplating apparatus according to claim 1. 4. The substrate to be plated is a glass substrate having a metal component adhered to the surface or a part thereof,
The electroplating apparatus according to any one of claims 1 to 3, wherein a wiring pattern is formed by plating on a portion of the metal component on the substrate.