JP2003112097A - Dip coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a deviation of thickness of coating films and to prevent particlar impurities from sticking to the surface of a coating article such as a copper clad laminate, in a dip coating apparatus for forming the coating films by dipping the article into the coating liquid in a tank. SOLUTION: An opening edge 6 is formed at the top end of the tank. This opening edge has a uniform height over the entire circumference of the tank and the coating liquid overflows uniformly over the entire circumference. A receiving groove 7 is also formed over the entire circumference to receive the overflowed coating liquid. The coating liquid is circulated by a pump 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dip coating apparatus for introducing a coating solution into a tank, immersing an object to be coated in the coating solution in the tank, and forming a coating film on the surface of the object.

[0002]

2. Description of the Related Art For example, in the process of manufacturing an electronic circuit board, a copper clad laminate is immersed in a photosensitive resist solution in a tank to form a coating film on the surface of the copper clad laminate. The ones described in JP-A-8-51268 and JP-A-10-256703 are used.

In the apparatus of the publication, as shown in FIG. 3, a nozzle head 1 is provided in a tank 2, and in the tank 2, the nozzle head 1 is arranged above an inclined bottom plate 3. Further, the pump 4 is connected to the filter 5 and the nozzle head 1, the photosensitive resist liquid is sent by the pump 4, the filter 5 filters it, and after the filtering, the photosensitive resist liquid is sent to the nozzle head 1 and the tank Introduced in 2. Then, the copper clad laminate is immersed in the photosensitive resist solution of the tank 2, and after immersion, the copper clad laminate is placed in the tank 2.
Is pulled up from the liquid surface of. Therefore, the coating film is formed on the surface of the copper clad laminate.

With respect to the structure of the tank 2 of the publication, the tank 2 is of a square type and has a square opening upper end. Further, on one side of the upper end of the rectangular opening, the opening edge 6 is formed lower than the opening edges of the other sides, the receiving groove 7 is formed outside the opening edge 6, and the photosensitive resist liquid is stored in the tank 2. Was introduced into the opening edge and overflowed from the opening edge 6,
The receiving groove 7 receives the overflowed photosensitive resist solution. Further, the receiving groove 7 is connected to the valve 8 and the pump 4, and the photosensitive resist liquid passes through the valve 8 and
Circulate to pump 4.

[0005]

In this case, in order to form the coating film accurately and prevent the film thickness from deviating, in particular, when the copper clad laminate is pulled up from the liquid surface of the tank 2, It is necessary to keep the liquid level of the tank 2 mirror-like,
When the photosensitive resist liquid overflows from the opening edge 6 on one side of the upper end of the opening of the tank 2, the photosensitive resist liquid flows in one direction along the liquid surface of the tank 2,
Cannot maintain the liquid surface of the mirror surface. Therefore, normally, the pump 4 is temporarily stopped, the liquid level of the tank 2 is kept in a mirror state, and the copper clad laminate is pulled up from the liquid level of the tank 2.

However, because the photosensitive resist solution was flowing in one direction along the liquid surface of the tank 2, the tank 2
Even if the pump 4 is temporarily stopped, the photosensitive resist liquid remains in the portion where the eddy occurs even if the pump 4 is temporarily stopped.
Then, there is a problem in that it affects the coating film on the surface of the copper-clad laminate, causing a deviation in the film thickness. Further, when the pump 4 is temporarily stopped, the photosensitive resist liquid does not overflow from the opening edge 6 and the particulate impurities cannot be discharged from the liquid surface of the tank 2. Therefore, when the copper-clad laminate is pulled up from the liquid surface of the tank 2, there is also a problem that particulate impurities adhere to the surface of the copper-clad laminate.
Before the next immersion of the copper-clad laminate, the pump 4 must be driven again to introduce the photosensitive resist solution into the tank 2 and overflow it from the opening edge 6, resulting in poor efficiency.

In addition, in the metal etching process, the stainless plate is often immersed in the photosensitive resist solution in the tank 2 to form a coating film on the surface of the stainless plate. The silicon wafer may be immersed in the photosensitive resist solution in the tank 2 to form a coating film on the surface of the silicon wafer. The lens or glass substrate may be dipped in the resin liquid in the tank 2 to form a coating film on the surface of the lens or glass substrate. However, the same applies to the problem of deviation in the thickness of the coating film, the problem of particulate impurities, and the problem of efficiency.

Therefore, according to the present invention, a coating solution such as a photosensitive resist solution is introduced into a tank, an object to be coated such as a copper clad laminate is immersed in the tank coating solution, and a coating film is formed on the surface of the object. In the dip coating device to form,
The purpose is to prevent deviation in the thickness of the coating film, to prevent particulate impurities from adhering to the surface of the object, and to improve efficiency.

[0009]

According to the present invention, the coating liquid is sent by the pump and introduced into the tank. Furthermore, an opening edge is formed at the upper end of the opening of the tank,
The opening edge has a uniform height over the entire circumference of the tank. Therefore, the coating liquid overflows uniformly over the entire circumference of the tank. Further, outside the opening edge, a receiving groove is formed around the entire circumference of the tank, receives the overflowing coating liquid, and the coating liquid circulates to the pump.

When the object is dipped in the coating solution, it is preferable to form the coating film by immersing the object in a state where the coating solution overflows without stopping the pump.

Further, in a preferred embodiment, the nozzle head is provided in the tank, and the coating liquid is sent to the nozzle head. The nozzle head has a downward ejection port, and the coating liquid is ejected from the ejection port and introduced into the tank.

Further, a nozzle head and a punching plate are provided in the tank, the punching plate is arranged above the nozzle in the tank, the coating liquid is sent to the nozzle head, introduced into the tank, and passes through the punching plate. Then, it rises and the coating liquid is rectified by the punching plate.

Further, a pump is connected to the bubble floating chamber,
The nozzle head communicates with the bubble levitation chamber, and in the bubble levitation chamber, the coating liquid floats and is removed, and then the coating liquid is sent to the nozzle head and introduced into the tank.

[0014]

Embodiments of the present invention will be described below.

FIG. 1 shows a dip coating apparatus according to the present invention, in which a nozzle head 1 is provided in a tank 2 and is arranged above an inclined bottom plate 13 as in the apparatus shown in FIG. The photosensitive resist solution is sent by the pump 4, and is filtered by the filter 5,
After filtration, the photosensitive resist solution is sent to the nozzle head 1,
Introducing into the tank 2 is also similar to the device of FIG. Then, a plurality of copper-clad laminates 9 are hung on the holding jig 10, and the arm 11 is moved by the servomotor and the ball screw.
Is lowered, the copper clad laminate 9 is dipped in the photosensitive resist solution in the tank 2, and after the immersion, the arm 11 is raised by the servomotor and the ball screw, and the copper clad laminate 9 is pulled up from the liquid surface of the tank 2. . Therefore, the coating film is formed on the surface of the copper clad laminate 9.

In the case of this apparatus, as shown in FIG. 2, the tank 2 is of a square type and has a rectangular opening upper end, and the opening edge 6 is formed at the opening upper end of the tank 2. Three
The device is similar to the above device, but the opening edge 6 has a uniform height over the entire circumference of the tank 2. Therefore, the photosensitive resist liquid overflows uniformly over the entire circumference of the tank 2. Further, outside the opening edge 6, a receiving groove 7 is formed over the entire circumference of the tank 2 to receive the overflowed photosensitive resist solution. The receiving groove 7 has an inclined bottom surface that is inclined in a certain direction, and the photosensitive resist liquid flows along the inclined bottom surface of the receiving groove 7 and is collected in the collecting portion 12 of the receiving groove 7. Further, the recovery portion 12 is connected to the valve 8 and the pump 4, and the photosensitive resist solution circulates through the valve 8 and the pump 4 as in the apparatus of FIG.

Therefore, regarding the liquid surface of the tank 2 of this apparatus, the photosensitive resist liquid overflows uniformly over the entire circumference of the tank 2, and therefore, even if the pump 4 is not stopped temporarily, Is kept specular.
There is no eddy on the liquid surface of the tank 2. Therefore, in this apparatus, when the copper-clad laminate 9 is immersed in the photosensitive resist solution, the pump 4 is not stopped, and the copper-clad laminate 9 is immersed in a state where the photosensitive resist solution overflows to form a coating film. To be done. As a result, there is no deviation in the thickness of the coating film. The photosensitive resist liquid overflows uniformly over the entire circumference of the tank 2, and accordingly, the particulate impurities can be discharged from the liquid surface of the tank 2, and the particulate impurities adhere to the surface of the copper clad laminate 9. Nor. There is no need to temporarily stop the pump 4 and drive it again, and the efficiency is high.

Further, in this embodiment, the nozzle head 1
Has a plurality of ejection ports, and the photosensitive resist solution is ejected from the ejection port of the nozzle head 1 and introduced into the tank 2. The spout is downward. Therefore, the photosensitive resist solution is jetted downward and introduced into the tank 2, and thereafter, the photosensitive resist solution smoothly rises, and turbulent flow does not occur in the photosensitive resist solution in the tank 2. Further, a punching plate 13 is provided in the tank 2 and
Inside the punching plate 13 is the nozzle head 1.
The photosensitive resist liquid passes through the punching plate 15 and rises. Therefore, the punching plate 13 is preferable because the photosensitive resist liquid is rectified.

Further, in this embodiment, the pump 4 is connected to the filter 5 and the bubble floating chamber 14, and first,
The photosensitive resist liquid is introduced into the bubble floating chamber 14. Further, the nozzle head 1 communicates with the bubble floating chamber 14, and in the bubble floating chamber 14, the bubbles float and are removed from the photosensitive resist liquid, and then the photosensitive resist liquid is sent to the nozzle head 1. It is introduced into the tank 2. For bubbles floating from the photosensitive resist liquid, the bubble floating chamber 14 is connected to the valve 15 and the recovery portion 12 of the receiving groove 7, and the valve 15 is always slightly opened.
Therefore, the air bubbles are discharged together with a small amount of liquid, pass through the valve 15, and escape to the recovery portion 12 of the receiving groove 7. Therefore, air bubbles are not introduced into the tank 2.

It is also possible to use a stainless plate or a silicon wafer as an object to be coated, and immerse this in the photosensitive resist solution in the tank 2 to form a coating film on the surface of the stainless plate or the silicon wafer. It is also possible to use a resin liquid as a coating liquid, use a lens or a glass substrate as an object to be coated, and immerse the lens or glass substrate in the resin liquid of the tank 2 to form a coating film on the surface of the lens or the glass substrate. .

[0021]

As described above, according to the present invention, there is no deviation in the thickness of the coating film, and no particulate impurities adhere to the surface of the object. It is highly efficient and can achieve the intended purpose without the need to temporarily stop and restart the pump.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

2 is a perspective view of the device of FIG. 1. FIG.

FIG. 3 is a perspective view of a conventional dip coating device.

[Explanation of symbols]

1 nozzle 2 tanks 4 pumps 6 opening edge 7 Receiving 9 Copper clad laminate 13 punching plate 14 Bubble floating chamber

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Claims (5)

[Claims] 1. A dip coating apparatus for introducing a coating solution into a tank, immersing an object to be coated in the coating solution in the tank, and forming a coating film on the surface of the object, the coating solution comprising: A pump introduced into the tank, an opening edge formed at the upper end of the opening of the tank, having a uniform height over the entire circumference of the tank, and allowing the coating solution to overflow uniformly over the entire circumference of the tank, and the opening. A dip coating device, which is formed around the entire circumference of the tank on the outer side of the rim, and which comprises a receiving groove for receiving the overflowed coating liquid and circulating the same to the pump. 2. When the object is immersed in the coating liquid,
The apparatus according to claim 1, wherein the object is immersed in a state where the coating liquid overflows without stopping the pump to form the coating film. 3. A nozzle head having a downward ejection port is provided in the tank, and the coating liquid is sent to the nozzle head, ejected from the ejection port, and introduced into the tank. The device according to claim 1 or 2. 4. A nozzle head and a punching plate are provided in the tank, the punching plate is arranged above the nozzle head in the tank, and the coating liquid is sent to the nozzle head and introduced into the tank. , Pass through the punching plate, raise,
The apparatus according to claim 1, wherein the punching plate is configured to straighten the coating liquid. 5. A nozzle head is provided in the tank, the pump is connected to the bubble levitation chamber, the nozzle head is communicated with the bubble levitation chamber, and the bubbles are floated from the coating liquid in the bubble levitation chamber. 3. The apparatus according to claim 1 or 2, wherein the coating solution is removed, and then the coating solution is sent to the nozzle head and introduced into the tank.