JP2004186510A - Bubble removing device for viscous fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bubble removing device for viscous fluid which can reliably remove bubbles in a resist agent, etc. and can perform a quick bubble removing work. <P>SOLUTION: The bubble removing device for viscous fluid is used in a cycling resist agent supply mechanism, etc. in a resist agent applicator, and has a viscous fluid storage vessel, a supply port for a viscous fluid formed above the viscous fluid storage vessel, and a cylinder having a ceiling fitted in the viscous fluid storage vessel. The cylinder is formed in a tapered shape which enlarges its diameter toward downward, and then the viscous fluid is released from the supply port. While the viscous fluid flows down on an outer wall of the cylinder, bubbles included in the viscous fluid are removed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous fluid bubble removing apparatus used in a circulating resist solution supply mechanism in a resist solution applying apparatus, and more particularly to a viscous fluid bubble removing apparatus capable of removing bubbles reliably and efficiently. It is intended to provide a removing device.
[0002]
2. Description of the Related Art As one example of this type of viscous fluid bubble removing device, there is a viscous fluid bubble removing device used in a circulating resist solution supply mechanism in a resist solution application device such as a printed circuit board.
[0003] That is, in the resist liquid application step in the printed circuit board manufacturing process, it is necessary to uniformly apply the resist liquid to the printed circuit board. For this reason, for example, roll coating or curtain coating is performed. When applying the resist solution, a circulating resist solution supply mechanism of supplying the resist solution onto the printed circuit board, collecting and reusing the used resist solution is incorporated in the line of the resist solution applying process. . The reason is that the resist is a very expensive material, and it is desired to reduce the consumption.
In the conventional circulation type resist solution supply mechanism, the resist solution is retained in a resist solution storage tank having a plurality of partitions, and the resist solution overflows from each partition or flows from the lower portion of the partition to remove bubbles. A device for removing bubbles of the viscous fluid to be removed is provided.
[0005]
However, in the above-described viscous fluid bubble removing apparatus of the mere overflow and bottom water type, the effect of removing bubbles due to the viscosity of the resist solution is low, and the coated printed circuit board is not so effective. There was a risk that defects such as pinholes would occur in the resist liquid layer on the surface of the resist.
Therefore, the applicant first deposits a resist liquid storage tank, a supply port of a recovered resist liquid formed on the upper side wall of the resist liquid storage tank, and a resist liquid discharged from a supply nozzle of a hopper, respectively. Thereafter, an apparatus for removing bubbles of a resist solution having a partition for overflowing and a resist solution storage tank into a plurality of spaces, and having a partition having countless pores for allowing the resist solution to pass therethrough was proposed (see JP-A-2002-55460). .
However, even in the resist liquid bubble removing apparatus having a partition having a myriad of pores through which the resist liquid passes as described above, there is a problem that bubbles do not quickly rise to the liquid surface from the pores of the partition. However, such a type of resist liquid bubble removing apparatus has a disadvantage that it is difficult to improve the speed of removing bubbles.
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems, to reliably remove bubbles in a resist solution, and to perform a rapid bubble removal operation. To provide an air bubble removing device.
[0009]
That is, a viscous fluid bubble removing device according to the present invention is a viscous fluid bubble removing device used in a circulating resist solution supply mechanism or the like in a resist solution applying device. A fluid storage tank, a supply port for the viscous fluid formed in the upper part of the viscous fluid storage tank, and a tubular body having a top plate attached in the viscous fluid storage tank; After forming a tapered shape whose diameter increases toward the end, the viscous fluid is discharged from the supply port, and while the viscous fluid flows down the outer wall of the cylindrical body, bubbles contained in the viscous fluid are removed. It is characterized by having done.
In the viscous fluid bubble removing apparatus according to the present invention, the cylindrical body is provided with a concave portion in its top plate for allowing the viscous fluid to flow toward the outer wall side of the cylindrical body while storing the viscous fluid. Is also a feature.
According to the viscous fluid bubble removing apparatus of the present invention, the resist liquid is caused to flow down in a film form on the surface of the cylindrical body whose diameter is enlarged in a tapered shape. In combination with this, the bubbles in the resist solution can be efficiently removed, and the bubbles in the resist solution can be surely removed, so that a more economical viscous fluid bubble remover can be provided. Was.
Further, according to the viscous fluid bubble removing apparatus of the present invention, the viscous fluid storage tank can be made compact because of its simple structure, and the viscous fluid storage tank can be easily disassembled and cleaned. I can do it.
[0013]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment in which the present invention is applied to a viscous fluid bubble removing device attached to a circulation type resist solution supply mechanism used in a resist solution applying device for a printed circuit board will be described below. This will be specifically described.
FIG. 1 is a schematic sectional view showing one embodiment of a viscous fluid bubble removing apparatus according to the present invention, and FIG. 2 is an explanatory view showing a state in which bubbles are removed while a viscous fluid flows down an outer wall of a cylindrical body. FIG.
The apparatus for removing bubbles of a viscous fluid according to the present invention is used in a circulating resist solution supply mechanism (not shown) in a resist solution applying apparatus. A resist solution storage tank 11 is provided. The resist liquid storage tank 11 has a supply port 13 for a recovered resist liquid (viscous fluid) 12 formed at an upper portion thereof, supplies the resist liquid 12 onto a printed circuit board, and collects the used resist liquid 12. It is put into the resist solution storage tank 11 through the supply port 13 and reused.
The supply port 13 is provided with a supply pipe 14 for a diluting liquid of the resist liquid 12, and a nozzle 15 for supplying a fresh resist liquid is provided in the vicinity thereof. It is desirable to control the open / close valve of the supply nozzle 15 so that the new resist solution is automatically replenished when the liquid level of the resist solution 12 in the resist solution storage tank 11 reaches a predetermined level. .
In this manner, in the resist solution storage tank 11, the resist solution 12 collected from the supply port 13 and reused, and the resist solution 12 replenished as needed are stored appropriately.
A cylindrical body 17 having a top plate 18 is mounted on the resist solution storage tank 11 formed of a dish-shaped container disposed in a housing 16. The cylindrical body 17 is formed in a tapered shape such that the diameter of the outer wall increases downward. The top plate portion 18 is provided with a concave portion 19 that stores the resist solution 12 and allows the resist solution 12 to overflow toward the outer wall of the cylindrical body 17. In the figure, reference numeral 22 denotes a discharge port provided at the bottom of the resist solution storage tank 11, and reference numeral 23 denotes a discharge pump.
The operation of removing bubbles will be described with reference to FIG. 2. When the resist solution 12 first flows from the concave portion 19 of the top plate portion 18 toward the outer wall of the cylindrical body 17, bubbles 21 contained in the resist solution 12 are contained therein. Can be moved to the surface of the resist solution 12 and removed. Thereafter, the resist liquid 12 flows down the outer wall of the cylindrical body 17 which is tapered so as to spread out. At this time, since the resist liquid 12 flows obliquely in a film form, the bubbles 21 in the resist liquid 12 Quickly move to the resist film surface. The resist solution 12 flowing down to the resist solution storage tank 11 is made thinner by surface tension while moving along the outer wall of the cylindrical body 17, and the bubbles 21 are removed from the resist solution 12. The air bubbles 21 are caused to emerge on the resist film surface more quickly by the action. The flow velocity that produces such an action of removing the bubbles 21 can be appropriately determined in consideration of the viscosity of the resist solution 12, the diameter and height of the cylindrical body 17, and other conditions.
When the resist liquid storage tank 11 receives the resist liquid 12 flowing down the outer wall of the cylindrical body 17, the resist liquid 12 flows down the outer wall of the cylindrical body 17 which is tapered so as to spread out. Therefore, there is no possibility that the bubbles 21 may be involved.
In the viscous fluid bubble removing apparatus having the above-described structure, the resist liquid 12 flows down the wall of the cylindrical body 17 from the top plate 18 of the cylindrical body 17 and is stored in the resist liquid storage tank 11. . Thereafter, the resist solution is supplied from a discharge port 22 provided at the bottom of the resist solution storage tank 11 to a piping system of a circulation type resist solution supply mechanism, and is supplied to a resist solution application step. The obtained resist solution coating layer was able to obtain a very high quality printed board without generating pinholes or the like due to bubbles in the coating film.
[0022]
According to the apparatus for removing bubbles of a viscous fluid of the present invention, since the resist solution is caused to flow down on the surface of the cylindrical body in a film form, the bubbles in the resist solution are combined with the thin film thickness and the surface tension. Can be efficiently removed, and the bubbles in the resist solution can be reliably removed, so that a more economical viscous fluid bubble removing device can be provided.
Further, according to the viscous fluid bubble removing apparatus of the present invention, the viscous fluid storage tank can be made compact because of its simple structure, and the viscous fluid storage tank can be easily disassembled and cleaned. I can do it.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing one embodiment of a viscous fluid bubble removing device according to the present invention.
FIG. 2 is an explanatory view showing a state in which bubbles are removed while a viscous fluid flows down an outer wall of a cylindrical body.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Resist liquid storage tank 12 Resist liquid 13 Supply port 14 Diluent supply pipe 15 Resist liquid supply nozzle 16 Table 17 Cylindrical body 18 Top plate 19 Depression 21 Bubbles 22 Discharge port 23 Discharge pump

Claims (2)

A viscous fluid bubble removing device used in a circulation type resist solution supply mechanism or the like in a resist solution application device, comprising: a viscous fluid storage tank; a viscous fluid supply port formed in an upper part of the viscous fluid storage tank; A cylindrical body having a top plate portion mounted in the fluid storage tank, and forming the cylindrical body in a tapered shape whose diameter increases downward, and discharging the viscous fluid from the supply port. And removing bubbles contained in the viscous fluid while the viscous fluid flows down the outer wall of the cylindrical body. 2. The device for removing bubbles of a viscous fluid according to claim 1, wherein the cylindrical body is provided with a concave portion for allowing the viscous fluid to flow toward the outer wall side of the cylindrical body while storing the viscous fluid in a top plate portion thereof.

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