JP2002086424A - Apparatus for molding ceramic green sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold a green sheet with a uniform thickness over the whole face even when there exists unevenness on the thickness of a carrier film. SOLUTION: In a doctor blade type apparatus for molding a ceramic green sheet, the bottom face of a doctor blade or the top face of a guide part of a slurry coating part provided with the doctor blade and the guide part facing to the doctor blade and supporting the carrier film from the bottom side is made to be an elastic beam structure and the elastic beam has a plurality of load acting parts in the longitudinal direction and the load acting parts are connected with an actuator whose output is controlled based on a command from a controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus for molding a ceramic green sheet used for a ceramic laminated component or a ceramic laminated substrate with a good thickness.

[0002]

2. Description of the Related Art As a method for producing a ceramic green sheet, a doctor blade method of applying a slurry onto a carrier film through a doctor blade and drying the slurry to obtain a ceramic green sheet is well known. Many techniques for accurately manufacturing ceramic green sheets have been disclosed. For example, Japanese Patent Application Laid-Open No. 62-92806 discloses a molding apparatus for molding a slurry, a first measuring device for measuring the thickness of a wet green sheet in a non-contact manner in the vicinity of the molding apparatus, and a drying apparatus for drying the wet green sheet. A drying device to be used, a second measuring device for measuring the thickness of the green sheet dried by the drying device, and a driving unit for moving the carrier film at a constant speed; 2 Based on the thickness measurement result by the measuring device, calculate the shrinkage ratio after electrically drying, calculate the thickness of the wet green sheet with respect to the set thickness, and monitor the thickness with the first measuring device, So that the thickness of the green sheet is the calculated thickness
There is disclosed a manufacturing method in which a gap between the molding device and the carrier film is made variable.

[0003]

The ceramic green sheets (hereinafter abbreviated as green sheets) are required to be formed with a thickness accuracy on the order of microns on the downsizing and higher precision of ceramic laminated parts and the like. I have. The known example is intended to automatically correct the thickness change of the dried green sheet due to the viscosity and density of the slurry, and to mass-produce the green sheet with good thickness accuracy, and to measure the length of the green sheet in the longitudinal direction. This is an effective technique for improving thickness variations. However, in order to form a highly accurate green sheet having a thickness variation of several microns or less over the entire surface, it is necessary to improve the thickness variation not only in the longitudinal direction but also in the width direction. The conventional technology including the above cannot cope.

The inventor has found that variations in the width direction are greatly affected by variations in the thickness of the carrier film. The thickness variation of the carrier film is in the range of several microns, which was not considered as a problem in the past.However, in order to form a green sheet with high thickness accuracy, it is necessary to take measures as one of the factors. It came out. Accordingly, an object of the present invention is to provide a molding apparatus capable of molding a green sheet having a uniform thickness over the entire surface even if the thickness of the carrier film varies.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a doctor blade type ceramic green sheet forming apparatus.
The lower surface of the doctor blade or the upper surface of the guide portion of the slurry coating portion having a doctor blade and a guide portion that supports the carrier film from below facing the doctor blade has an elastic beam structure, and the elastic beam has a plurality of loads in the longitudinal direction. An actuator having an action section, wherein an actuator whose output is controlled based on a command from the control device is connected to the load action section. By controlling the outputs of the plurality of actuators, the elastic beam can be brought into various uneven states, and the gap amount in the width direction can be finely adjusted. Further, the present invention provides a slurry thickness measuring device installed between the slurry coating unit and the slurry drying device, which can measure a plurality of data in a slurry width direction, and a plurality of data from the slurry thickness measuring device, A control device that calculates a control amount of each actuator based on the thickness variation and outputs an operation amount to a driving unit of each actuator may be provided. Further, the present invention provides a carrier film thickness measuring device installed between the slurry coating unit and the carrier film unwinding unit, which can measure a plurality of data in a carrier film width direction, and a plurality of data from the carrier film thickness measuring device. May be input, a control device that calculates a control amount of each actuator based on a variation in the thickness of the carrier film, and outputs an operation amount to a driving unit of each actuator.

Further, in the above invention, a position control means for vertically moving a doctor blade or a guide portion, and a green sheet thickness provided between a slurry drying device and a carrier film winding portion for measuring a plurality of data in a green sheet width direction. And a controller for receiving the data from the green sheet thickness measuring device, calculating a shrinkage ratio of the slurry based on the data from the slurry thickness measuring device, A target slurry thickness is calculated based on the thickness, a position control amount of a doctor blade or a guide portion that eliminates a deviation between the target slurry thickness and the measured slurry thickness is calculated and output to the position control means. Can be

[0007]

(Embodiment 1) Hereinafter, a description will be given with reference to the drawings. FIG. 1 shows a configuration example of a green sheet forming apparatus according to the present invention. The carrier film 2 is unwound at a constant speed from the unwinding unit 3, and the slurry 5 is applied to the upper surface in the coating unit 1, which is a feature of the present invention, and passes through the drying device 6 so that the slurry 5 becomes In the formed state, it is wound by the winding unit 4. A slurry thickness measuring device 40 is provided on the upper surface of the carrier film 2 between the coating unit 1 and the drying device 6, and a green sheet thickness measuring device 41 is provided on the upper surface of the carrier film 2 having exited the drying device 6.

The coating section 1 includes a doctor blade 11 which forms one surface of a tank having a slurry reservoir and which is orthogonal to a carrier film feeding direction, and a carrier film 2 which is installed below the doctor blade 11 so as to face the doctor blade 11. And a guide portion 12 for supporting the same. FIG.
2 shows a schematic configuration of the doctor blade 11. Both ends of the doctor blade 11 in the longitudinal direction are connected to positioning members 12 (12a, 12b) arranged to be vertically movable by pins 13 (13a, 13b). The positioning member 12 is connected to a nut of a ball screw 15 that is rotated by a servomotor 14 and can be electrically controlled. Therefore, by controlling the servo motor 14, the doctor blade 11 can be vertically controlled, and the gap between the knife edge 16 at the tip of the doctor blade and the upper surface of the carrier film 2 can be adjusted with high precision. By independently controlling the left and right servomotors 14a and 14b, the doctor blade 11 can be tilted to finely adjust the gap amount so that the left and right are different.

The doctor blade 11 is a plate-like member, and has left and right bases 17 each having a hole into which the pin 13 is fitted.
And three beams formed so as to connect the base portions by performing groove processing on a portion sandwiched between the base portions. The uppermost beam is a rigid beam 18 having high bending rigidity, and a plurality of (9 in FIG. 2) air cylinders 19 are attached along the upper longitudinal direction of the rigid beam 18. Below the rigid beam 18, the rigid beam 18
Two elastic beams 20, 21 having a lower bending rigidity (several tenths to several tenths) than the rigid beam 18 provided in parallel to
A plurality (nine in FIG. 2) of thrust transmitting members 22 vertically connected to the upper and lower elastic beams are formed. Air cylinder 1
Numeral 9 arranges the thrust transmitting member 22 so that the axis thereof substantially coincides with the axial center, and connects the rod to the upper elastic beam 20. The upper elastic beam 20 is made as thin as possible in the vertical direction to reduce the bending rigidity so that the output of the air cylinder 19 is effectively transmitted to the thrust transmitting member 22 immediately below. The thrust transmitting member 22 and the upper and lower elastic beams 20 and 21 are connected by an elastic hinge 26. The knife edge 16 is formed below the lower elastic beam 21. The knife edge 16 is thin and low in height so that it can be integrally deformed with the lower elastic beam 21.

As described above, the pushing / pulling force from the air cylinder 19 acts on the lower elastic beam 21 via the upper elastic beam 20 and the thrust transmitting member 22 to deflect the knife edge 16. The lower elastic beam 21 has a high torsional rigidity because a plurality of thrust transmitting members 22 are connected between the upper and lower elastic beams 20, 21. Deforms only vertically. Therefore, by controlling the output directions and thrusts from the plurality of air cylinders 19 and bending the lower elastic beam 21 at multiple points to form various irregularities, the lower surface height of the knife edge 16 can be finely adjusted. it can.

When the doctor blade 11 having the above structure is used, a double doctor blade system is preferably used so that the slurry in the slurry pool does not leak from the groove 23 beside the thrust transmitting member 22. That is, the doctor blade (not shown) on the upstream side has a general solid plate shape, and is disposed so that the slurry passing through the lower surface of the doctor blade does not cross the lower elastic beam 21 of the doctor blade 11. The head of the slurry supplied to the doctor blade 11 becomes constant, and this is more effective for forming a green sheet having a small thickness variation.

The slurry thickness measuring device 40 and the green sheet thickness measuring device 41 include a capacitance type or laser type sensor 4.
5 can be used. By connecting the sensor 45 to the moving mechanism via an arm so that the carrier film 2 can be traversed, the thickness information of the applied slurry and the green sheet at an arbitrary position in the width direction is measured by one sensor, It can be output to the control device 60. Control device 6
Numeral 0 is electrically connected to the servo motor 14 installed in the coating section 1 and the drive control means 61 and 62 of the air cylinder 19 to control the position of the servo motor 14 and the output of the air cylinder 19. Can be. The measuring devices 40 and 41 may have a configuration in which a number of sensors 45 are arranged at the same position as the air cylinder in the width direction of the carrier film 2.

Next, the operation of the coating section 1 will be described.
In forming the green sheet 7, first, the slurry 5 is formed under predetermined initial conditions with respect to the target green sheet thickness.
Is started. The slurry thickness measuring device 40 measures the slurry thickness at the same width direction position where the air cylinder 19 is disposed while reciprocating in the carrier film width direction at a predetermined speed, and outputs the same to the control device 60. The green sheet thickness measuring device 41 is, like the slurry thickness measuring device 20,
While reciprocating in the width direction of the carrier film at a predetermined speed, the thickness of the green sheet at the position where the air cylinder is disposed is measured and output to the control device 60. The control device 60 includes a slurry thickness measuring device 40 and a green sheet thickness measuring device 41.
The shrinkage ratio is calculated based on the thickness data from As the thickness data at this time, it is preferable to use the average value of the thickness data at each point in the width direction, and use the data before and after drying the same slurry.

On the basis of the target green sheet thickness T0 previously input to the control device 60 and the calculated shrinkage ratio,
The target slurry thickness t0 at the time of application is calculated. Control device 6
0 is the measured slurry thickness t1 and the target slurry thickness t0
The control amount is calculated based on a preset control algorithm such as PI control, and the operation amount is output to the servo motor driving means 61 so as to eliminate the deviation of the servo motor 14.
Moves the doctor blade 11 in the vertical direction to adjust the gap. That is, the target green sheet thickness T0
To control the amount of macroscopic gap to achieve.

However, each slurry thickness t1a in the width direction,
t1b,... are not always the same due to the influence of, for example, thickness variations of the carrier film 2. Control device 6
0 is the slurry thickness t1a in the width direction of the carrier film,
.. are individually compared with the target slurry thickness t0, and the output of the air cylinder 19 is adjusted to displace the lower surface of the doctor blade 11 so as to eliminate the difference. The relationship between the deformation of the doctor blade 11 and the output of each air cylinder 19 is obtained in advance for the doctor blade to be used, is stored in a database in the control device, and the pressure control amount of each air cylinder is calculated based on this. An operation amount is output to each electropneumatic regulator 62 which is a drive control unit. In this way, the thickness variation over the entire surface of the green sheet can be improved by correcting the microscopic thickness variation in the slurry width direction immediately after the application with almost no delay.

(Embodiment 2) In Embodiment 1 described above, the thickness of the applied slurry in the width direction is detected and feedback control is performed.
The thickness variation of the carrier film 2 before slurry application is detected, and the slurry is applied by controlling the displacement of the lower surface of the doctor blade 11 by the variation to control the gap to fall within a predetermined variation range. In this embodiment, a carrier film thickness measurement 42 is provided between the coating unit 1 and the unwinding unit 3 having the above-described configuration. The carrier film thickness measuring device 42 includes a capacitance type or laser type sensor 45 capable of measuring the carrier film thickness, and a slurry thickness measuring device 40.
As in the case of (1), the carrier film 2 may be connected to the moving mechanism via an arm so that the carrier film 2 can be traversed, or a large number may be provided.

In the control, the thickness of the carrier film at the position of the air cylinder in the width direction of the carrier film 2 is measured and output to the control device 60 in the same manner as when the data is collected by the slurry thickness measuring device 40. The control device 60 calculates the pressure control amount of the air cylinder 19 so that the gap amount corresponds to the carrier film thickness variation, and outputs the operation amount to the electropneumatic regulator of each air cylinder. The second embodiment may be implemented in combination with the first embodiment.

As described above, the beam section is formed on the doctor blade 11 of the coating section 1 and the knife edge 16 is bent, but the beam section having the same structure is provided not on the doctor blade 11 side but on the guide section 12 side. A gap may be adjusted by forming a portion, arranging an air cylinder, and lifting the carrier film from below. In this case, the doctor blade may be in the form of a solid plate or pipe, or may be of a single doctor blade type. In this case, the macroscopic overall adjustment mechanism of the gap may be provided on the doctor blade side or on the guide section side. Note that a piezoelectric element, a linear motor, or the like can also be used as an actuator that applies a load to the lower elastic beam.

[0019]

As described above, according to the present invention, the gap variation in the width direction of the carrier film can be detected, and the local gap in the width direction can be adjusted with almost no delay. Green sheets can be manufactured. Further, the gap between the doctor blade and the carrier film can be adjusted as a whole in consideration of the degree of shrinkage of the slurry.

[Brief description of the drawings]

FIG. 1 shows a ceramic green sheet forming apparatus according to the present invention.

FIG. 2 is a structural view of a doctor blade for explaining the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Coating part, 2 ... Carrier film, 3 ... Unwinding part, 4 ... Winding part, 5 ... Slurry, 6 ... Drying device,
7 ... green sheet, 11 ... doctor blade, 14
... Servo motor 16 Knife edge 17 Doctor blade base 18 Rigid beam 19 Air cylinder 20 Upper elastic beam 21 Lower elastic beam 22
... thrust transmitting member, 26 ... elastic hinge, 40 ... slurry thickness measuring device, 41 ... green sheet thickness measuring device, 42
... Carrier film thickness measuring instrument, 60 ... Control unit, 61
... Servo motor drive means 61 ... Electro-pneumatic regulator

Claims (4)

[Claims] 1. A doctor blade-type ceramic green sheet forming apparatus, comprising: a doctor blade lower surface or a guide portion of a slurry coating portion having a doctor blade and a guide portion facing the doctor blade and supporting a carrier film from below. The upper surface has an elastic beam structure, and the elastic beam has a plurality of load acting portions in the longitudinal direction, and an actuator whose output is controlled based on a command from a control device is connected to the load acting portion. Ceramic green sheet molding equipment. 2. A slurry thickness measuring device installed between a slurry coating unit and a slurry drying device and capable of measuring a plurality of data in a slurry width direction, and a plurality of data from the slurry thickness measuring device are inputted. 2. The ceramic green sheet forming apparatus according to claim 1, further comprising: a control unit that calculates a control amount of each actuator based on the thickness variation and outputs an operation amount to a driving unit of each actuator. 3. A carrier film thickness measuring instrument installed between the slurry coating section and the carrier film unwinding section, which can measure a plurality of data in a carrier film width direction, and a plurality of data from the carrier film thickness measuring instrument. 3. The ceramic green sheet molding according to claim 1, further comprising: a controller that inputs a control value, calculates a control amount of each actuator based on a variation in the thickness of the carrier film, and outputs an operation amount to a driving unit of each actuator. apparatus. 4. A ceramic green sheet forming apparatus according to claim 1, wherein said ceramic green sheet forming apparatus is provided between said slurry drying apparatus and said carrier film winding section, said position controlling means being capable of moving a doctor blade or a guide section up and down. A green sheet thickness measuring device capable of measuring a plurality of data in the width direction of the green sheet, wherein the control unit receives data from the green sheet thickness measuring device and receives data from the slurry thickness measuring device. Calculate the slurry shrinkage rate based on the target, calculate the target slurry thickness based on the target green sheet thickness, and position the doctor blade or guide to eliminate the deviation between the target slurry thickness and the measured slurry thickness. A ceramic green sheet forming apparatus for calculating a control amount and outputting the calculated control amount to the position control means.