JPH0512437B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an electrodeposition coating device, particularly an electrodeposition coating device that effectively deposits an electrodeposited film and improves the uniformity of the electrodeposited film. be.

This electrodeposition coating apparatus forms an electrodeposition composition film on a plate-shaped object to be coated, particularly a printed wiring board.

(Prior Art) Conventionally, in the production of printed wiring boards, the main surface of the object to be coated and the opposite electrode were in a parallel relationship as a method of forming an electrodeposited composition film. In addition, a large distance between the electrodes had to be maintained in order to obtain a good finish of the coating film.

Therefore, in order to increase production capacity, there is no choice but to increase the number of electrodeposition baths or increase the capacity of the baths, which is extremely uneconomical as the amount of expensive electrodeposition liquid increases per unit area of the printed wiring board.

In addition, since the electrodeposition liquid uses 100% of the solid content in the electrodeposition liquid by a turnover method that replenishes the consumed electrodeposition resin composition, etc., the amount of liquid per unit area of the substrate decreases during one turnover time. The more there are, the longer it will be. In addition, when the production capacity is increased, the amount of electrodeposition liquid increases, making it difficult to manage the liquid, and the equipment costs are also considerable. Furthermore, 1
The longer the turnover time, the more the electrodeposition solution deteriorates, making it impossible to obtain a good coating film.

If the deterioration of the electrodeposition solution progresses in this manner, a situation arises in which the entire electrodeposition solution must be discarded. In particular, when a photosensitive electrodeposition liquid is used, the electrodeposition liquid deteriorates more rapidly and this problem becomes even more serious.

(Problems to be solved by the invention) The present invention has been made in view of the above-mentioned circumstances, and the problems to be solved are as follows: The amount of electrodeposition liquid is large.

Therefore, one turnover becomes longer and the deterioration of the electrodeposition liquid progresses.

Therefore, there is a very high possibility that all of the electrodeposition liquid will be discarded.

It is.

The purpose of the present invention is to eliminate and improve the problems of the prior art described above, simplify the process, improve work efficiency, and reduce manufacturing costs in an electrodeposition coating device. It is.

(Means for Solving the Problems) The present invention has been made to solve the problems of the prior art and achieve the above objects.

The method taken by the present invention to solve these problems is to immerse a plate-shaped object to be coated in an electrodeposition liquid in which an electrodepositable resin composition is dispersed, and then energize the electrodeposition liquid and the object to be coated. In an electrodeposition coating device that forms a coating film on the surface of an object to be coated, a) the objects to be coated are arranged in the electrodeposition bath so that the main surfaces of the objects to be coated are arranged in parallel, and b The electrodes are arranged in a position perpendicular to the main surface of the object to be coated.

An electrodeposition coating device characterized by: ”.

The present invention will be explained in detail using drawings corresponding to embodiments.

As shown in FIG. 1, the electrodeposition bath 1 is formed into a box shape with an open top, and an overflow tank 2 is formed on the side of the electrodeposition bath 1. The electrodeposition bath stores an electrodeposition liquid 3 in which a photosensitive resin composition is dispersed, and an electrode plate 4 serving as a counter electrode to the object to be coated 5 is disposed along the inner wall. Furthermore, in order to uniformly stir the liquid in the tank, one or more systems of electrodeposition liquid blow-off nozzles and nozzles with arbitrary diameters are installed depending on the location in the bath to keep the liquid composition uniform. be able to. In addition, the electrode plate 4 has a fin (fourth
(Fig.) can also be attached.

Furthermore, a swinging device (not shown) is installed so that the object to be coated can be moved in all directions, such as front, back, left, right, up and down, and the inner surface of the hole and uneven surface can be more uniformly moved so that it can be moved only in the required direction at any time. A coating can be obtained. In addition, by using a jig such as a rack basket so that the main surfaces of the object 5 to be coated are all parallel,
Transportation becomes easy. Alternatively, if a special jig is not used, it may be simply fixed to a rocking device, for example. (The fixing method is not shown.) A DC rectifier 6 is installed beside the electrodeposition bath 1, and the electrode plate 4 is connected to the negative electrode side of the rectifier via a cable 7a.
A power supply hanger 8 is connected to the anode side via a cable 7b.

Next, one method of using the device of the present invention will be explained.

The object to be coated 5 that has been automatically or manually transferred from pretreatment is immersed in the electrodeposition liquid 3 and connected to the power supply hanger 8 . Next, turn on the DC rectifier 6 and connect the cable 7b and the power supply hanger 8 from the anode.
Electricity is applied to the object 5 to be coated via the energizer to form a coating film on the object 5 to be coated.

(Actions of the Invention) The present invention, configured as described above, has the following effects.

In the apparatus according to the present invention, since the main surface of the object to be coated is parallel and the counter electrode is arranged perpendicular to the main surface of the object to be coated, a large number of objects to be coated can be electrodeposited at once. The amount of electrodeposition solution can be reduced compared to conventional methods. As a result, the cycle of the solid content (resin content) of the electrodeposition liquid becomes faster, the time for one turnover is shortened, a good quality electrodeposition liquid can always be used, the finish of the coating film is good, and the functionality is also remarkable. Improved.

Regarding the circulation of the electrodeposition solution, we made it possible to uniformly stir the object to be coated while it was immersed in the electrodeposition bath, and the voltage application method also changed the distance between the electrode and the object to be coated without increasing the size of the electrodeposition bath. The distance between coated objects can be set to an effective size, and there is no variation in film thickness, and uniformity is maintained, and the finish of the coating film is also good.

(Example) The present invention will be described below with reference to the drawings.

Example 1 As shown in FIG. 1, an electrodeposition bath 1 is formed into a box shape with an open top, and an overflow tank 2 is formed on the side of the electrodeposition bath 1. An electrodeposition liquid 3 in which a photosensitive resin composition is dispersed is stored in the electrodeposition bath, and an electrode plate 4 serving as a counter electrode to the object to be coated 5 is disposed along the inner wall. This plate 4
It has a flat plate shape and is installed on the entire two sides and the entire bottom surface of the electrodeposition bath 1 so as to be perpendicular to the object 5 to be coated. The condition of the object to be coated 5 when entering the tank is the second condition.
It looks like Figures a to c. The blowing nozzle 6 of the circulation system is arranged with respect to the object 5 to be coated, as shown in FIG.

As a result of electrodeposition by constant voltage method under the above conditions,
The surface finish of each object to be coated was good and the film thickness was uniform.

Example 2 The difference from Example 1 is that a fin-shaped electrode structure is used, and the electrode structure is shown in FIG. Electrodeposition was carried out in the same manner as in Example 1 except for the electrode structure. As a result, stable electrodeposition was possible even at high current density, and the surface finish of the coating film was good and the uniform film thickness was short. Obtained in time.

Example 3 The difference from Examples 1 and 2 is the electrode structure, in which the entire inner surface of the electrodeposited bath is used as an electrode, and a billet plate 9 is provided as shown in FIG. As a result of performing electrodeposition in the same way, even when a large amount of liquid is stirred, fluctuations in current and voltage are small, stable high-speed electrodeposition is possible, and the surface finish of the coating film is good and the film thickness is uniform. Ta.

(Effects of the Invention) As detailed above, in the present invention, as exemplified in the above embodiments, the electrodeposition coating apparatus of the present invention has the following features:
In an electrodeposition coating device in which a plate-shaped object to be coated is immersed in an electrodeposition liquid in which an electrodepositable resin composition is dispersed, and electricity is applied between the electrodeposition liquid and the object to be coated to form a coating film on the surface of the object to be coated. a. The objects to be coated are arranged in the electrodeposition bath so that the main surfaces of the objects to be coated are arranged parallel to each other, and b. It is characterized by the fact that it can stably coat a large number of objects at the same time, which simplifies the process and improves work efficiency.It is an electrodeposition coating that is inexpensive to manufacture and has no quality problems. It provides: That is, in the electrodeposition coating apparatus according to the present invention, the main surfaces of the object to be coated are arranged in parallel, and the electrode serving as the opposite electrode is disposed in a perpendicular relation to the main surface of the object to be coated. When immersed in an electrodeposition bath, the amount of electrodeposition liquid per unit area of the object to be coated is small. As a result, the time for one turnover is short, and the amount of electrodeposition liquid is small relative to the production capacity, making it very economical and very easy to manage the liquid. Furthermore, since one turnover is short, there is no deterioration of the electrodeposition solution and a good solid content can be used, so the performance and appearance of the formed coating are good, and since deterioration does not progress, all the electrodeposition solution can be discarded. This situation no longer arises. Further, although the coating method of the embodiment of the present invention is a constant voltage method, a constant current method can also be applied, or a constant voltage method + constant current method is also possible.

Furthermore, although the embodiment of the present invention is an anionic electrodeposition method, it can also be applied to a cationic electrodeposition method.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a schematic configuration of an electrodeposition coating apparatus of the present invention, and FIGS. 2 a to 2 c are a plan view, a longitudinal sectional view, and 3 is a side sectional view, and FIG.
The figure is a sectional view showing a schematic configuration of another electrodeposition coating apparatus according to the present invention, FIG. 5 is a sectional view showing a schematic configuration of still another electrodeposition coating apparatus according to the present invention, and FIG.
-c are a plan view, a longitudinal cross-sectional view, and a side cross-sectional view showing the schematic structure of a conventional electrodeposition coating apparatus, respectively. Explanation of symbols, 1...electrodeposition bath, 2...overflow tank, 3...electrodeposition liquid, 4...electrode, 5...object to be coated, 6...blowout nozzle, 7...power supply cable, 8... ...Power supply hanger, 9...Bill board.

Claims (1)

[Claims] 1. A plate-shaped object to be coated is immersed in an electrodeposition liquid in which an electrodepositable resin composition is dispersed, and electricity is applied to the electrodeposition liquid and the object to be coated to form a coating film on the surface of the object to be coated. In the electrodeposition coating apparatus, a) the objects to be coated are arranged in the electrodeposition bath so that the main surfaces of the objects to be coated are arranged in parallel, and b, the electrode serving as the opposite electrode is arranged perpendicularly to the main surface of the object to be coated. An electrodeposition coating device characterized in that it is arranged in a position where: 2. The electrodeposition coating apparatus according to claim 1, wherein the electrode serving as a counter electrode to the object to be coated has a fin shape protruding toward the object to be coated. 3. The apparatus according to claim 1 or 2, further comprising a swinging device that swings in one or more directions such as front and back, left and right, and up and down directions while the object to be coated is energized. Electrodeposition coating equipment. 4. Claims characterized in that it has one or more systems of blowing nozzles for liquid reflux, etc. for stirring the electrodeposition liquid, and the diameter of the liquid blowing nozzle is arbitrary depending on the location in the bathtub. The electrodeposition coating apparatus according to any one of items 1 to 3. 5. The electrodeposition coating apparatus according to any one of claims 1 to 4, wherein the object to be coated is transported and electrodeposited using a jig such as a rack basket.