JPH06238155A - Method and device for supplying slurry - Google Patents

Abstract

PURPOSE:To apply slurry with uniform thickness on a carrier film by supplying the slurry to a slurry tank so as to keep the liq. level of the slurry at a fixed level. CONSTITUTION:A slurry tank 19 is connected to the slurry tank through the liq. feed pipe 15 through which the slurry passes freely, and the liq. level of the slurry tank 19 is kept at a fixed level, so that the liq. level of the slurry tank connected to the slurry tank 19 through the liq. feed pipe 15 is kept at a fixed level. In order to keep the liq. level of the slurry in the slurry tank 19 at a fixed level, the slurry tank 19 is vertically moved by a lift 18 to adjust the liq. level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies a slurry with a uniform thickness on a carrier film in order to manufacture a ceramic green sheet by applying the slurry with a uniform thickness on a carrier film. The present invention relates to a slurry supply method and apparatus for supplying a slurry having a uniform and constant flow rate per hour in the width direction to a coating section.

[0002]

2. Description of the Related Art For example, in the case of producing a green sheet as a base material for an insulating circuit board or an electronic element, a ceramic powder having a uniform thickness is formed on a carrier film made of polyethylene terephthalate film or the like with a resin binder, a dispersant and water. The green sheet is manufactured by applying a slurry mixed and dispersed in a solvent such as an organic solvent and drying the slurry.

Here, a conventional slurry supplying apparatus for supplying the slurry for applying the slurry onto the carrier film is, for example, as shown in FIG. That is, the ceramic powder is water together with the resin binder and the dispersant,
Slurry 12 mixed and dispersed in a solvent such as an organic solvent
Is stored in the slurry tank 9, and this slurry 12
Is supplied to the slurry reservoir 1 through the liquid feed pipe 5 by opening the solenoid valve 10 and operating the pump 7.

An example of the slurry reservoir is shown in FIG. 3, and the outer shape of the slurry reservoir 1 is a substantially rectangular parallelepiped shape. The slurry reservoir 1 has a rectifying portion 3 standing upright at the center of the bottom thereof, and the tip of the rectifying portion 3 is a downward slope. The ceramic slurry is stored in the slurry reservoir 1 before and after the rectifying portion 3. A coating portion (not shown in FIG. 1) side is connected to the tip of the slurry reservoir 1 via a joint 14, and in this coating portion, the slurry 2 supplied from the slurry reservoir 1 side is deposited on the carrier film. It is applied with a uniform thickness. Then, by drying this slurry, a ceramic green sheet is completed on the carrier film 6.

Using this slurry supply device, in order to supply a uniform slurry to the coating part side and form a ceramic green sheet of a uniform thickness on the carrier film, the slurry is fed from the slurry reservoir 1. The flow rate of the slurry 2 needs to be always constant. Therefore, in the conventional slurry supply device, the liquid level sensor 8 for detecting the liquid level of the slurry 2 is provided in the slurry reservoir 1 so that the liquid level of the slurry reservoir 1 becomes constant with respect to a predetermined reference height. The opening / closing of the solenoid valve 10 is controlled.

In this case, a certain amount of the slurry 2 is sent to the slurry reservoir 1 each time the solenoid valve 10 is opened and the pump 7 is operated, and at other times, the slurry 2 is not supplied to the slurry reservoir 1. Therefore, the supply of the slurry 2 to the slurry reservoir 1 is, so to speak, intermittently performed. Therefore, a turbulence of the flow is generated inside the slurry reservoir 1, and the turbulence of the flow changes the flow rate of the slurry supplied to the coating unit side, and the thickness of the slurry film applied on the carrier film is changed. It becomes non-uniform and the surface becomes streaky or uneven in some places.

Therefore, the ceramic slurry pressure-fed from the pump is separately stored before and before the rectifying section 3 of the slurry reservoir 1. As a result, the momentum of the ceramic slurry supplied by the pump 7 is attenuated by the rectifying unit 3, and the slurry is gently supplied from the liquid reservoir portion ahead of the rectifying unit 3 to the coating unit side at a constant flow rate. In this way, the pump 7 and the solenoid valve 1
When the ceramic slurry 2 is pressure-fed using 0 and 0, the opening and closing timing of the solenoid valve 10 is appropriately adjusted, and the pulsation of the ceramic slurry is reduced by the rectifying section 3 in the slurry reservoir 1, so that the liquid level 43 is almost constant. Can be constant.

[0008]

However, in reality, even if it is attempted to suppress the influence of the pulsation of the flow of the slurry 2 by using the rectifying section 3 as described above, the effect cannot be completely suppressed, and the down slope 4 side The ceramic slurry 2 flowing into the pulsation slightly pulsates. Therefore, the flow of the slurry 2 supplied from the slurry reservoir 1 is not uniform, and the slurry applied on the carrier film on the coating portion side also pulsates, causing unevenness in the thickness of the green sheet formed on the carrier film. Will end up. That is, the unevenness of the thickness of the slurry film applied on the carrier film 6 was not eliminated, and streaks and irregularities were generated on the surface of the finished green sheet.

Therefore, in the present invention, in view of the above problems in the prior art, the ceramic slurry is supplied to the slurry reservoir in a uniform flow without using a pump for generating pulsation which is the root cause of the unevenness. It is therefore an object of the present invention to provide a slurry supply method and apparatus capable of applying a slurry having a uniform thickness to a carrier film.

[0010]

That is, in order to achieve the above-mentioned object, in the present invention, an appropriate amount of the slurry 2 is supplied from the slurry tank 19 to the slurry reservoir 1, and further to the coating portion at the tip of the slurry reservoir 1. In the slurry supply method for supplying the slurry 2 having a uniform and constant flow rate every hour in the width direction, the slurry tank 19 and the slurry reservoir 1 are connected by the liquid feed pipe 15 through which the slurry 2 can flow. Provided is a slurry supply method characterized in that the liquid level of the slurry 2 is maintained constant.

Further, in the present invention, the slurry 2 to be supplied is supplied.
A slurry reservoir 1 for storing the slurry 2 for supplying the slurry 2 to the slurry reservoir 1; and a slurry supply means for supplying the slurry 2 from the slurry reservoir 19 to the slurry reservoir 1 In the slurry supply device in which the coating part is arranged at the end of 1, the slurry tank 19 and the slurry reservoir 1 are connected by a liquid feed pipe 15 through which the slurry 2 can flow, and the slurry tank 19
Is provided on a lift table 17 which is lifted and lowered by a lift 18. A slurry supply device is provided.

[0012]

According to the slurry supply method of the present invention, the slurry tank 19 can be arranged at a position relatively higher than the slurry reservoir 1. Then, the slurry 2 stored in the slurry tank 19 is continuously supplied to the slurry reservoir 1. The slurry 2 thus sent to the slurry reservoir 1 flows into the slurry reservoir 1 without causing any disturbance in the slurry stored in the slurry reservoir 1. Further, by keeping the height of the liquid surface 43 constant, a uniform amount of slurry can be flowed out from the slurry reservoir 1. Therefore, the slurry having a constant thickness can be applied on the carrier film in the coating portion ahead of that, and a ceramic green sheet having a uniform thickness is formed.

Further, according to the slurry supply device of the present invention, the slurry tank 19 is placed at an appropriate height by the lift 18 to continuously supply the slurry from the slurry tank 19 to the slurry reservoir 1, The height of 43 can be kept constant. Further, since pulsation does not occur in the slurry flow at this time, the flow is not disturbed in the slurry reservoir 1. This makes it possible to easily and surely carry out the above-mentioned slurry supply method.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 and FIG. 2 show the external appearance of the slurry supply device according to the first embodiment of the present invention.
The slurry reservoir 1 used in this embodiment has basically the same configuration as the slurry reservoir shown in FIG. 3, and the same portions are designated by the same reference numerals.

That is, the slurry reservoir 1 has a substantially rectangular parallelepiped shape as a whole, and has a vertically rectifying portion 3 at the center of the bottom thereof, and the bottom portion in front of the rectifying portion 3 is a horizontal horizontal portion 31. The tip of the straightening section 3 is a downward slope 4 continuous from the top of the straightening section 3. The ceramic slurry is formed on the horizontal portion 31 by the rectifying portion 3 and the wall portion 11 facing the rectifying portion 3.
And the first liquid reservoir 41 surrounded by both side wall portions 16, the down slope 4 and the wall portion 11 and both side wall portions 16 facing the down slope 4.
It is separately stored in the second liquid reservoir 42 surrounded by.

A coating portion (not shown in FIGS. 1 and 2) for coating the carrier film with the slurry to form a ceramic green sheet is connected to the tip of the second liquid reservoir 42. The ceramic slurry flowing out from the second liquid reservoir 42 is applied on the carrier film at this coating part.

FIG. 4 shows an example in which a coating portion by a doctor blade method is directly installed at the tip of the slurry reservoir 1. That is, here, the doctor blade 33 is installed in place of the wall portion 12, and below that, that is, below the tip edge of the downward slope 4,
A long carrier film 6 made of polyethylene terephthalate or the like is passed in a direction orthogonal to the leading edge, and is guided by a feed roller 20 at a constant speed in an arrow direction, that is, in a direction orthogonal to the leading edge of the downward slope 4, Be driven.

On the other hand, FIG. 5 shows the slurry reservoir 1
This is an example in which a coating portion by the reverse roll coating method is installed at the tip of the. That is, here, instead of the wall portion 12, rolls 34 and 35 for reverse roll coating are provided below the leading edge of the descending slope 4 in a direction orthogonal to the leading edge, and the carrier film 6 is passed therethrough. It The carrier film 6 is guided and run by the feed roller 20 at a constant speed. In FIG. 5, reference numeral 36 is a blade for scraping off the slurry 2 from the reverse roll coating 35.

A slurry tank 1 containing a slurry 2 in which ceramic powder is dispersed in a solvent together with a resin binder and the like.
6 is provided, and a liquid feed pipe 15 is connected to the slurry tank 16 and the slurry reservoir 11. This liquid delivery pipe 13 is not equipped with a pump or a solenoid valve, and the slurry 2
Can be freely distributed. A drain cock 21 is provided at the bottom of the slurry tank 16 so that the slurry 2 in the slurry tank 19 can be discarded from the drain cock 21.

The slurry tank 19 is installed on a lift table 17 that is lifted and lowered by a lift 18, and is lifted and lowered by the lift 18. A motor 24 for raising and lowering the lift 18 is controlled by a controller 23, which is provided in the slurry reservoir 11 and operates by receiving a signal from a liquid level sensor 22 for measuring the liquid level of the slurry 2. . As the liquid level sensor 22, for example, a capacitance sensor or a float sensor can be used.

Next, a method of supplying the slurry to the coating portion by the slurry supplying device and applying the slurry 2 on the carrier film there will be described. The slurry 2 supplied to the slurry reservoir 1 from the slurry tank 19 shown in FIG.
Of the slurry in the vicinity of the liquid surface 43 that exceeds the straightening portion 3 and flows over the straightening portion 3 and flows out to the second liquid reservoir portion 42 along the descending slope 4 thereof. The liquid is stored in the second liquid reservoir 42. Then, this second liquid reservoir 4
Slurry 2 stored in No. 2 is supplied to a coating section ahead of it through joint 14, and is applied on a carrier film there.

For example, in the case of the doctor blade method, as shown in FIG. 4, at the tip of the second liquid reservoir 42,
The ceramic slurry is directly applied onto the carrier film 6 fed at a constant speed. Further, in the case of the reverse roll coating method, as shown in FIG.
The ceramic slurry is once applied onto the coating roll 35 at the bottom of the, and then the ceramic slurry on the coating roll 35 is transferred and applied onto the carrier film 6 fed at a constant speed. In any case, since the carrier film 6 is continuously fed in the direction of the arrow by the feed roller, the slurry 2 flowing out from the tip edge of the descending slope 4 is applied thereon, and the slurry is dried, A film-shaped ceramic green sheet is formed.

As the slurry is coated on the carrier film, the amount of the slurry 2 in the slurry reservoir 1 decreases and the liquid level decreases. Then, the liquid level sensor 8 detects this, and the controller 23 shown in FIG. 1 drives the motor 24 of the lift 18 to raise the slurry tank 19 on the lift table 18. As a result, the slurry 2 is continuously fed from the slurry tank 19 to the slurry reservoir 1 through the liquid delivery pipe 15 without pulsation. In addition, the rotation of the motor is controlled by a command from the controller 23 so as not to raise the lift 17 abruptly. As a result, the slurry 2 having a constant thickness can be applied on the carrier film 6.

In the slurry supply method according to the present invention, even if the lift 17 as in the slurry supply apparatus according to the above-described embodiment is not used, a proper amount of the slurry 12 is added to the slurry tank 19 while the liquid of the slurry 12 is added. It is also possible to carry out by keeping the position constant.

[0025]

As is apparent from the above description, according to the slurry supply method and apparatus of the present invention, the slurry 2 flowing into the slurry reservoir 1 does not disturb the flow of the slurry in the slurry reservoir 1. . Therefore, the slurry reservoir 1
The flow of the slurry 2 flowing from the coating section to the coating section can be made uniform, and the uniformity of the slurry film such as the green sheet formed in the coating section can be improved.

[Brief description of drawings]

FIG. 1 is a partially longitudinal side view showing an entire structure of a slurry supply device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the slurry supply device according to the embodiment.

FIG. 3 is a partially longitudinal side view showing a conventional example of a slurry supply device.

FIG. 4 is an enlarged cross-sectional view of a main part of a slurry supply device that is another embodiment of the present invention.

FIG. 5 is an enlarged cross-sectional view of a main part of a slurry supply device that is still another embodiment of the present invention.

[Explanation of symbols]

 1 Slurry Reservoir 2 Slurry 3 Rectifier 4 Downward Slope 6 Carrier Film 8 Liquid Level Sensor 17 Lift 18 Elevator 19 Slurry Tank 20 Feed Roller 23 Controller 24 Lift Motor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B65G 53/30 D 7612-3F

Claims (2)

[Reference number] 0040725-01 [Claims] 1. A proper amount of slurry (2) is supplied from a slurry tank (19) to a slurry reservoir (1), and the coating portion at the tip of the slurry reservoir (1) is uniform in the width direction and constant every hour. In a slurry supply method for supplying a flow rate of a slurry (2), a liquid feed pipe (1) in which a slurry (2) can freely flow through a slurry tank (19) and a slurry reservoir (1).
A method for supplying slurry, characterized in that the liquid level of the slurry (2) in the slurry tank (19) is maintained constant by connecting with the slurry in (5). 2. A slurry reservoir (1) for storing the supplied slurry (2), a slurry tank (19) for storing the slurry (2) to be supplied to the slurry reservoir (1), and this slurry tank (19). ) To the slurry reservoir (1) for supplying the slurry (2) to the slurry reservoir (1), and the slurry reservoir (1) is provided with a coating section. Slurry reservoir (1)
And the slurry (2) are connected by a liquid feed pipe (15) through which the slurry (2) can flow, and a slurry tank (19) is installed on a lift table (17) which is lifted and lowered by a lift (18). Characteristic slurry supply device.