Thickness measuring device, ceramic green sheet manufacturing device, and ceramic green sheet manufacturing method

Abstract

The invention provides a thickness measuring device capable of measuring the thickness of a coating film functional sheet formed on a carrying sheet with high precision, and also provides a ceramic green sheet manufacturing device and a ceramic green sheet manufacturing method using the thickness measuring device. A thickness measurement device (1) for measuring the thickness of a coating film (20) formed on a carrier sheet (10) being conveyed includes: a first measurement unit (1A) for acquiring thickness information of the carrier sheet (10) before the coating film (20) is formed and acquiring a first position by irradiation with light; a second measurement unit (1B) that acquires thickness information of the mounting sheet (10) and the coating film (20) after the coating film (20) is formed by irradiation with radiation, and acquires a second position; and a calculation processing unit that calculates the thickness of the coating film on the basis of the thickness information of the mounting sheet at the first position and the thickness information at the second position.

Description

Technical Field

[0001] The present invention relates to a thickness measuring device for measuring the thickness of a functional sheet arranged on a mounting sheet. Background Art

[0002] In the past, when manufacturing laminated ceramic electronic components such as laminated ceramic capacitors, it was particularly important to control the thickness of the ceramic green sheet. Generally, the ceramic green sheet is formed by applying a ceramic slurry to a given thickness on a carrier sheet, but in the process of applying the ceramic slurry, it is necessary to control the amount of ceramic slurry applied while measuring the thickness of the coating film, so as to adjust it to a given thickness.

[0003] In addition, in the past, when measuring the thickness of a ceramic green sheet formed on a carrier sheet, a method was generally adopted in which a non-contact thickness measuring device that would not damage the ceramic green sheet was used to measure the total value of the thickness of the ceramic green sheet and the thickness of the carrier sheet as the film thickness value, and the thickness of the ceramic green sheet measured in advance was subtracted from the film thickness value to calculate the thickness of the ceramic green sheet.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 59-99339

[0007] However, in reality, in such a measurement method using a non-contact thickness measuring device, errors due to positional deviation during measurement etc. occur, and it is not easy to measure the sheet thickness with high accuracy.

[0008] In addition, a coating amount measuring device is disclosed, in which two detectors, a thickness detector using X-rays and a thickness detector using β-rays, are arranged as an integrated type parallel to the flow direction of the carrier sheet, and the coating amount is measured by calculation using the difference in their respective radiation absorption coefficients (for example, Patent Document 1).

[0009] However, in such a measuring device using radiation, the thickness of the carrier sheet is prone to measurement errors due to the deviation of the radiation dose. When the measuring object is a functional sheet, high-precision measurement is required, wherein the functional sheet is a sheet intended to be used as a sheet having a specific function, such as a coating film. Summary of the invention

[0010] Problem that the invention aims to solve

[0011] An object of the present invention is to provide a thickness measuring device capable of measuring the thickness of a functional sheet formed on a mounting sheet with high accuracy, and also to provide a ceramic green sheet manufacturing device and a manufacturing method using the thickness measuring device.

[0012] Technical solutions to solve problems

[0013] The inventors of the present invention have discovered that the thickness of a coating film can be measured with high precision in the following manner, and have finally completed the present invention, namely, comprising: a first measuring section for obtaining thickness information of a carrier sheet before the coating film is formed by irradiating light; and a second measuring section for obtaining thickness information of the carrier sheet and the coating film after the coating film is formed by irradiating radiation, and performing calculation processing on the thickness information from the first measuring section and the thickness information from the second measuring section.

[0014] That is, the present invention is a thickness measuring device for measuring the thickness of a coating film formed on a conveyed carrier sheet, wherein:

[0015] The thickness measuring device comprises:

[0016] a first measuring unit that acquires thickness information of the carrier sheet before the coating film is formed by irradiating light, and acquires a first position, the first position being a position where the thickness information of the carrier sheet is acquired;

[0017] a second measuring unit that obtains thickness information of the carrier sheet and the coating film after the coating film is formed by irradiating radiation, and obtains a second position, the second position being a position where the thickness information of the carrier sheet and the coating film is obtained; and

[0018] The calculation processing unit calculates the thickness of the coating film based on the thickness information of the mounting sheet at the first position and the thickness information at the second position within a predetermined range relative to the first position.

[0019] Effects of the Invention

[0020] According to the present invention, it is possible to provide a thickness measuring device capable of measuring the thickness of a functional sheet formed on a mounting sheet with high accuracy, and also to provide a ceramic green sheet manufacturing device and a ceramic green sheet manufacturing method using the thickness measuring device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a diagram showing the structure of the thickness measuring device of the present invention.

[0022] Figure 2 This is a diagram showing a ceramic green sheet manufacturing apparatus using the thickness measuring apparatus of the present invention.

[0023] Figure 3 This is a schematic perspective view of a multilayer ceramic capacitor.

[0024] Figure 4 yes Figure 3 A cross-sectional view of the multilayer ceramic capacitor taken along line IV-IV is shown.

[0025] Description of Reference Numerals

[0026] 1: Thickness measuring device (thickness measuring unit);

[0027] 1A: 1st measurement part;

[0028] 1B: 2nd measurement part;

[0029] 10: mounting sheet;

[0030] 11: Control unit;

[0031] 11A: 1st control unit;

[0032] 11B: 2nd control unit;

[0033] 20: coating film;

[0034] 21: Ceramic green sheet (functional sheet);

[0035] 30: coating film forming part (composite sheet forming part);

[0036] 40: A manufacturing device for ceramic green sheets (a manufacturing device for composite sheets);

[0037] 41: unwinding roller (transport control unit);

[0038] 42: winding roller (transport control unit);

[0039] 43a: 1st tension adjustment roller;

[0040] 43b: second tension adjustment roller;

[0041] 44a: 1st fixed roller;

[0042] 44b: second fixed roller;

[0043] 44c: 3rd fixed roller;

[0044] 44d: 4th fixed roller;

[0045] 50: Multilayer ceramic capacitor;

[0046] 51: laminate;

[0047] 52: dielectric layer;

[0048] 53: internal electrode;

[0049] 54: external electrode;

[0050] 54a: sintering layer;

[0051] 54b: plating layer;

[0052] A: Point A (1st position);

[0053] B: Point B (second position);

[0054] T: Transport direction. DETAILED DESCRIPTION

[0055] The following describes an embodiment of the thickness measuring device of the present invention, but the present invention is not limited thereto. In addition, in order to explain the content of the invention, the drawings are sometimes simplified and drawn schematically, and sometimes the drawn components or the ratio of the size between the components are inconsistent with the components or the ratio of the size between the components described in the specification. In addition, regarding the components described in the specification, there are cases where they are omitted in the drawings, or the number of components is omitted and drawn, etc.

[0056] Figure 1 FIG. 1 is a diagram showing a simplified structure of a thickness measuring device according to an embodiment of the present invention. Figure 2 This is a diagram for explaining a ceramic green sheet manufacturing apparatus using a thickness measuring apparatus.

[0057] (Thickness measuring device)

[0058] The thickness measuring device 1 measures the thickness of the functional sheet arranged on the carrier sheet 10 being conveyed. For example, the ceramic green sheet used in manufacturing the laminated ceramic capacitor is formed by coating the ceramic slurry on the carrier sheet 10. By using the thickness measuring device 1, the thickness of the coating film 20 of the ceramic slurry or the ceramic green sheet 21 formed by drying the coating film of the ceramic slurry can be measured. In addition, the coating film 20 of the ceramic slurry and the ceramic green sheet 21 are both sheets with specific functions that are intended to be used as dielectric layers of laminated ceramic capacitors, and are examples of functional sheets. In addition, since the coating film 20 or the ceramic green sheet 21 is arranged on the carrier sheet 10 by coating, coating is an example of arrangement.

[0059] exist Figure 21, a ceramic green sheet manufacturing apparatus 40 is shown as an example of the structure of an apparatus for manufacturing ceramic green sheets in a continuous production method and having a thickness measuring device 1. The ceramic green sheet manufacturing apparatus 40 includes a feed roll 41, a winding roll 42, a first dancer roll 43a, a second dancer roll 43b, a first fixed roll 44a, a second fixed roll 44b, a third fixed roll 44c, a fourth fixed roll 44d, a thickness measuring device 1 having a first measuring section 1A and a second measuring section 1B, and a coating film forming section 30.

[0060] The ceramic green sheet manufacturing device 40 is a device that applies a ceramic slurry to a carrier sheet 10 unwound from a supply roll 41, and winds up a ceramic green sheet 21 formed by drying the applied ceramic slurry together with the carrier sheet 10 by a winding roll 42. The carrier sheet 10 is conveyed from the supply roll 41 toward the winding roll 42. The direction in which the carrier sheet 10 is conveyed is referred to as a conveying direction T.

[0061] The ceramic green sheet manufacturing apparatus 40 is an apparatus capable of applying a ceramic slurry having an appropriate film thickness using a thickness measuring device 1 including a first measuring unit 1A and a second measuring unit 1B.

[0062] In the manufacturing apparatus 40 of ceramic green sheets, the carrier sheet 10 is a sheet material for supporting the ceramic green sheet 21 formed by applying ceramic slurry and drying it, and is unwound from an unwinding roller 41. The unwound carrier sheet 10 goes to the first measuring section 1A via the first fixed roller 44a, the first dancer roller 43a, and the second fixed roller 44b arranged in sequence from the conveying starting point toward the conveying destination in the conveying direction T.

[0063] The unwinding roller 41, the first fixed roller 44a, the first tension adjustment roller 43a and the second fixed roller 44b for conveying the carrier sheet 10 each have a roller shaft (not shown), and the roller shaft has a rotation axis. Each roller shaft is a linear rod-shaped member, and is arranged parallel to each other. The unwinding roller 41, the first fixed roller 44a, the first tension adjustment roller 43a and the second fixed roller 44b respectively rotate around the rotation axis of the roller shaft. Therefore, the direction roughly orthogonal to the direction of the axis of each roller shaft becomes the conveying direction T. In this way, the conveyed carrier sheet 10 can be stably sent toward the first measuring part 1A.

[0064] In addition, the first dancer roller 43a is disposed between the first fixed roller 44a and the second fixed roller 44b, and the tension applied to the mounting sheet 10 is adjusted by adjusting the vertical position of the first dancer roller 43a and the load applied to the first dancer roller 43a. The operation of the first measuring unit 1A will be described later.

[0065] The coating film forming section 30 is arranged downstream of the first measuring section 1A in the conveying direction T. The coating film forming section 30 has a coating section equipped with a coating device such as a die coater, and applies the ceramic slurry to the surface of the carrier sheet 10 with a given thickness. Regarding the method of applying the ceramic slurry, a roller die coater, a pressure reduction die coater, a roll-off die coater, a slit coater, a curtain coater, a pull-up coater, a knife coater, a casting coater, a reverse roll coater, a blade coater, a screen printing method, etc. can be used according to the thickness of the ceramic raw sheet to be formed. The coating film forming section 30 has a coating section not shown in the figure and a drying section not shown in the figure. The coating section applies the ceramic slurry to the carrier sheet 10. The drying section dries the ceramic slurry applied to the surface of the carrier sheet 10. As the heat source of the drying means in the drying section, hot air, electric heat, microwaves, infrared rays, far infrared rays and the like can be used alone or in combination, and hot air drying and far infrared drying are preferably used alone or in combination.

[0066] The mounting sheet 10 coated with the ceramic slurry by the coating film forming section 30 is dried in the drying section of the coating film forming section 30 , thereby forming the ceramic green sheet 21 .

[0067] Figure 2 The coating film forming section 30 shown includes a coating section for applying ceramic slurry and a drying section that is continuous with the coating section and is used to dry the ceramic slurry. The coating film forming section 30 is composed of the coating section and the drying section. However, it is not limited to such a structure. For example, the coating section and the drying section may be separately arranged, and equipment for performing other processes may be arranged between the coating section and the drying section. In addition, the coating film forming section 30 only needs to have a coating section, and may not have a drying section.

[0068] When the objects to be measured by the second measuring section 1B are the ceramic green sheet 21 and the mounting sheet 10 formed by drying the coating film of the ceramic slurry, the thickness of the ceramic green sheet 21 can be calculated by the thickness measuring device 1. On the other hand, when the objects to be measured by the second measuring section 1B are the coating film of the ceramic slurry before drying and the mounting sheet 10, the thickness of the coating film of the ceramic slurry can be calculated by the thickness measuring device 1. The operation of the second measuring section 1B will be described later.

[0069] As described above, the thickness of the coating film 20 that can be calculated by the thickness measuring device 1 includes the thickness of the coating film of the ceramic slurry or the thickness of the ceramic green sheet 21 formed by drying the coating film of the ceramic slurry.

[0070] In the following embodiments, the coating film 20 may be described mainly with reference to the case of the ceramic green sheet 21 formed by drying a coating film of a ceramic slurry, but the present invention is not limited thereto.

[0071] The carrier sheet 10 moves in the conveyance direction T together with the formed ceramic green sheet 21 , and is taken up by the take-up roller 42 via the third fixing roller 44 c , the second dancer roller 43 b , and the fourth fixing roller 44 d arranged in this order in the conveyance direction T.

[0072] The third fixed roller 44c, the second tension adjustment roller 43b, the fourth fixed roller 44d and the winding roller 42 each have a roller shaft (not shown), and the roller shaft has a rotation axis. Each roller shaft is a linear rod-shaped member, and is arranged parallel to each other. The third fixed roller 44c, the second tension adjustment roller 43b, the fourth fixed roller 44d and the winding roller 42 each rotate around the rotation axis of the roller shaft. In addition, the axis center of the roller shaft of the third fixed roller 44c, the second tension adjustment roller 43b, the fourth fixed roller 44d and the winding roller 42 is arranged approximately parallel to the axis center of the roller shaft of the unwinding roller 41, the first fixed roller 44a, the first tension adjustment roller 43a and the second fixed roller 44b. Therefore, the conveying direction T is also a direction substantially orthogonal to the direction of the axis of the roller shafts of the third fixed roller 44c, the second dancer roller 43b, the fourth fixed roller 44d, and the winding roller 42. The carrier sheet 10 is arranged parallel to a plane formed by the direction of the axis of the roller shafts and the conveying direction T. Thus, the carrier sheet 10 can be stably wound up by the winding roller 42.

[0073] The second dancer roller 43b is disposed between the third fixed roller 44c and the fourth fixed roller 44d in the conveying direction T, and the tension applied to the carrier sheet 10 is adjusted by adjusting the vertical position of the second dancer roller 43b and the load applied to the second dancer roller 43b.

[0074] The rotation speed of the unwinding roller 41 and the winding roller 42 can be changed. If the rotation speed of the unwinding roller 41 and the winding roller 42 is changed, the conveying speed of the carrier sheet 10 is changed. The unwinding roller 41 and the winding roller 42 function as a conveying control unit that changes the conveying speed of the carrier sheet 10.

[0075] The manufacturing device 40 for ceramic green sheets can include a thickness measuring device 1 and a coating film forming unit 30, so that in the coating film forming unit 30, the supply amount of the ceramic slurry can be controlled based on the thickness data of the coating film 20 (i.e., the coating film of the ceramic slurry or the ceramic green sheet 21 formed by drying the coating film of the ceramic slurry) measured by the thickness measuring device 1, while the ceramic slurry is coated on the carrier sheet 10 and the ceramic green sheet 21 is formed.

[0076] In this way, the ceramic green sheet manufacturing device 40 can be configured to feed back data on the thickness of the applied ceramic slurry or the thickness of the ceramic green sheet 21 formed by drying the coating film of the ceramic slurry to the coating film forming unit 30, thereby quickly controlling the supply amount of the ceramic slurry, thereby being able to continuously and reliably manufacture ceramic green sheets 21 with uniform thickness.

[0077] The first measuring section 1A of the thickness measuring device 1 measures the thickness of the mounting sheet 10 before the ceramic slurry is applied. The second measuring section 1B of the thickness measuring device 1 measures the thickness of the coating film 20 and the ceramic green sheet 21 (i.e., the thickness of the ceramic green sheet 21 formed by drying the coating film of the ceramic slurry and the mounting sheet 10 added together). As described above, the first measuring section 1A is arranged upstream of the coating film forming section 30 in the conveying direction T, and the second measuring section 1B is arranged downstream of the coating film forming section 30 in the conveying direction T.

[0078] In addition, in the conveying direction T, the direction from the second fixed roller 44b to the third fixed roller 44c is parallel to the horizontal direction, and the mounting sheet 10 is arranged parallel to the horizontal plane. The first measuring section 1A, the coating film forming section 30, and the second measuring section 1B are arranged in a straight line when viewed from the side. However, the first measuring section 1A, the coating film forming section 30, and the second measuring section 1B may not be arranged in a straight line. It is sufficient to arrange the first measuring section 1A, the coating film forming section 30, and the second measuring section 1B in sequence from the conveying starting point to the conveying destination in the conveying direction T.

[0079] The first measuring section 1A disposed upstream (rear side) in the conveying direction T of the carrier sheet 10 includes an irradiation head for irradiating light and a light receiving head for receiving transmitted light or reflected light. The second measuring section 1B disposed downstream (front side) in the conveying direction T of the carrier sheet 10 includes an irradiation head for irradiating radiation radiated by causing electron beams emitted from the cathode to collide with the anode, and a measuring head for detecting the amount of radiation transmitted (absorbed).

[0080] In the first measuring section 1A, when receiving transmitted light, the light irradiating head and the light receiving head are arranged at opposite positions with the carrier sheet 10 sandwiched therebetween. In the interferometry method for receiving reflected light, the light irradiating head and the light receiving head are arranged on the same side of the carrier sheet 10.

[0081] In the second measuring section 1B, in order to measure the amount of radiation transmitted (absorbed) , a radiation irradiation head and a measurement head are provided at positions facing each other with the ceramic green sheet 21 sandwiching the mounted sheet 10 .

[0082] (Slide Plate)

[0083] The ceramic raw sheet 21 is formed by drying a ceramic slurry applied to the surface of a sheet-like or film-like carrier sheet 10 selected from a material such as PP, PET or PEN. The material of the carrier sheet is not particularly limited, and a resin sheet is preferably widely used. In addition, the carrier sheet is preferably light-transmissive. In order to efficiently manufacture a stacked ceramic capacitor, a stacked sheet in which a plurality of sheets having different physical properties are stacked can be used. In addition, in order to efficiently peel the ceramic raw sheet formed on the carrier sheet 10 from the carrier sheet 10, a sheet called a release layer can be provided on the surface of the carrier sheet 10 coated with the ceramic slurry.

[0084] The mounting sheet 10 has a width dimension of about 100 to 1000 mm and a thickness dimension of about 0.01 to 1.0 mm. The mounting sheet is sometimes also referred to as a mounting film.

[0085] The carrier sheet 10 is prepared in a state where a PET sheet or a PET film is wound around a pay-out roll 41, for example. Then, in the ceramic green sheet manufacturing device 40, the carrier sheet 10 is coated with a ceramic slurry by the coating film forming unit 30 while being conveyed from the pay-out roll 41 to the take-up roll 42, and is taken up by the take-up roll 42 together with the formed ceramic green sheet 21.

[0086] (1st measurement section)

[0087] The first measurement unit 1A is disposed upstream of the coating film forming unit 30 in the conveyance direction T of the mounting sheet 10 .

[0088] The first measuring unit 1A is preferably a non-contact type using, for example, spectral interferometry. In the spectral interferometry, the first measuring unit 1A irradiates light to the mounting sheet 10 before the coating film 20 is formed, and receives light reflected by the mounting sheet 10.

[0089] Therefore, the first measurement unit 1A includes an irradiating head for irradiating light and a light receiving head for receiving reflected light, and the light irradiating head and the light receiving head are arranged on the same side of the surface of the mounting sheet 10 .

[0090] The so-called spectral interference method mentioned here is a method for obtaining film thickness based on the following principle. That is, if the carrier sheet 10 before applying the ceramic slurry is irradiated with light, the first reflected light and the second reflected light are generated. The first reflected light is the light reflected from the surface of the carrier sheet 10 and the boundary surface of the atmosphere with different refractive indices, and the second reflected light is the light incident from the surface of the carrier sheet 10, which is transmitted through the inside of the carrier sheet 10 and reflected from the back of the carrier sheet 10 and the boundary surface of the atmosphere with different refractive indices. The light sources of these two reflected lights are the same, and interference caused by multiple lights with different optical path lengths is generated. Due to the interference of light, if the phases are the same, they are mutually enhanced, and if the phases are opposite to each other, they are mutually weakened. The interference light is spectrally split, and the obtained spectral waveform pattern is Fourier transformed, etc., so that the optical distance can be obtained. In the case of obtaining the film thickness of the carrier sheet 10 itself, the value of the thickness of the carrier sheet 10 is obtained by calculating it using the refractive index corresponding to the material structure of the carrier sheet 10.

[0091] When obtaining the thickness information of the carrier sheet 10 by the spectral interference method, visible light, laser, super luminescent diode (SLD) light, etc. can be used as the irradiation light. It is particularly preferred to use coherent light with a wavelength of 400 to 900 nm generated by an SLD (Super Luminescent Diode) light source.

[0092] The first measuring unit 1A converts the received light into an electrical signal. The received light varies according to the thickness of the carrier sheet 10, so the electrical signal obtained by converting the received light contains information related to the thickness. Here, the information related to the thickness is referred to as thickness information. The first measuring unit 1A obtains the measurement position of the carrier sheet 10 and the thickness information at the measurement position.

[0093] The first measuring unit 1A acquires the thickness information of the mounting sheet 10 before the coating film is formed by the optical interference type measuring method, so that the measurement error can be relatively small and the thickness information of the mounting sheet 10 can be obtained with high accuracy.

[0094] The first measuring section 1A is arranged at a given distance in the vertical direction from the surface of the carrier sheet 10, and irradiates light from a plurality of light sources arranged at fixed intervals along the width direction of the carrier sheet 10 orthogonal to the conveying direction T. The width direction of the carrier sheet 10 orthogonal to the conveying direction T is parallel to the axial direction of the roller. For example, the light source is a light source that utilizes amplification based on stimulated emission, more specifically, a laser light source.

[0095] Figure 1 1 is a diagram showing an example of the thickness measuring device 1 , and shows a state of the thickness measuring device 1 when viewed from the upper surface of the mounting sheet 10 on which the ceramic slurry is applied by the coating film forming unit 30 .

[0096] The first measuring section 1A is arranged upstream of the coating film forming section 30 in the conveying direction T of the carrier sheet 10. A plurality of first measuring sections 1A are arranged in the width direction of the carrier sheet 10, and as the carrier sheet 10 moves in the conveying direction T, the first measuring sections 1A can measure the thickness of the entire surface of the carrier sheet 10.

[0097] The first measuring section 1A includes a plurality of light sources arranged at a given interval along the width direction of the carrier sheet 10 orthogonal to the conveying direction T. The interval between the light sources can be set to 10 to 250 mm. The positions of the light sources in the first measuring section 1A and the interval between the light sources are not limited to Figure 1 .exist Figure 1 In FIG. 1 , an embodiment in which nine light sources are configured is shown, but the number of light sources is not limited thereto. Figure 1 In the embodiment, the plurality of light sources are arranged parallel to the width direction of the mounting sheet 10 which is perpendicular to the conveying direction T, but may be arranged parallel to the width direction of the mounting sheet 10 .

[0098] In the spectroscopic interference method, the irradiation head for irradiating light and the light receiving head for receiving reflected light are arranged on the same side of the mounting sheet 10, so the light receiving head can be arranged from Figure 1 The light irradiated by the light source shown in the figure becomes reflected light and is reflected from the mounting sheet 10. Therefore, when a plurality of light sources are arranged, a plurality of light receiving heads can be arranged so as to correspond to the respective light sources.

[0099] The first measuring unit 1A intermittently measures the thickness of the mounting sheet 10 moving in the conveying direction T at predetermined intervals. Figure 1 In FIG. 1 , each measurement point is indicated by a dot, and as the mounting sheet 10 moves in the conveyance direction T, the measurement points on the mounting sheet 10 are indicated by a dotted line.

[0100] By adjusting the given interval, the number of measurement points can be increased or decreased.

[0101] like Figure 2 As shown, the first control unit 11A is located upstream of the coating film forming unit 30 in the conveyance direction T in which the mounting sheet 10 is conveyed, and is arranged below the first measurement unit 1A with the mounting sheet 10 interposed therebetween.

[0102] The first control unit 11A controls the intensity and interval of light emitted from the light source of the first measurement unit 1A. The first control unit 11A may be provided with support rollers for supporting the carrier sheet 10 moving in the conveying direction T and maintaining the carrier sheet 10 horizontally.

[0103] The first control unit 11A that controls the intensity and the interval of the light irradiated from the light source of the first measurement unit 1A is not limited to being arranged below the mounting sheet 10, but may be arranged above the mounting sheet 10. Furthermore, it is not limited to being arranged upstream of the coating film forming unit 30, but may be arranged downstream of the coating film forming unit 30.

[0104] As will be described later, the thickness information measured by the first measuring unit 1A is averaged and used for data at a plurality of consecutive measurement points. Figure 1 , a state where 15 measurement points are used for averaging is shown, and the 15 measurement points are schematically enlarged and shown. A measurement point located in the center among a plurality of measurement points for calculating the average value is recorded as, for example, point A. The position of point A is set as the first position.

[0105] In addition, the number of measurement points to be averaged can be appropriately set according to the measurement conditions.

[0106] Regarding the thickness information measured by the first measuring unit 1A, Figure 1 As shown in FIG. 1 , the data of a plurality of consecutive measurement points are averaged and used. Figure 1 , a state where 15 measurement points are used for averaging is shown, and the 15 measurement points are schematically enlarged and shown. Usually, the number of measurement points for averaging is 1 to 100, but it may be appropriately set according to the measurement conditions.

[0107] Among the plurality of measurement points used for calculating the average value, a measurement point located in the center is recorded as, for example, point A (first position).

[0108] Furthermore, since the plurality of measurement points used for calculating the average value are sequentially moved, a part of the measurement values ​​used for deriving the average value at the previous measurement point is also used in the average value at the next measurement point.

[0109] The information of the measurement position and thickness thus acquired is sent from the first measurement unit 1A to the calculation processing unit. The size of the measurement point is generally 10 to 20 mm in diameter, but is not limited thereto.

[0110] The first measuring unit 1A irradiates light from a plurality of light sources arranged along the width direction of the mounting sheet 10 orthogonal to the conveying direction T to acquire thickness information of the mounting sheet 10 . However, defects of the mounting sheet 10 may also be detected by using a spectroscopic interferometer.

[0111] (Second measurement section)

[0112] The second measuring section 1B is arranged downstream of the coating film forming section 30 in the conveying direction T of the carrier sheet 10. The second measuring section 1B irradiates the coating film 20 and the carrier sheet 10 (i.e., the coating film of the ceramic slurry or the ceramic raw sheet 21 formed by drying the coating film of the ceramic slurry and the carrier sheet 10) with radiation, and detects the radiation transmitted through the coating film 20 and the carrier sheet 10. The second measuring section 1B converts the detected radiation into an electrical signal. The detected amount of radiation varies depending on the thickness of the coating film 20 and the carrier sheet 10, so the electrical signal obtained by converting the detected radiation contains information related to the thickness. Therefore, the second measuring section 1B obtains the measurement position of the coating film 20 and the carrier sheet 10 and the thickness information at the measurement position.

[0113] Regarding the thickness information measured by the second measuring unit 1B, Figure 1 As shown in FIG. 1 , the data of a plurality of obliquely continuous measurement points are averaged and used. Figure 1 , a state in which the number of measurement points for averaging is set to 7 is shown, and the 7 measurement points are schematically enlarged and shown.

[0114] Normally, the number of average measurement points is 1 to 100, but may be appropriately set according to measurement conditions.

[0115] A measurement point located in the center among a plurality of measurement points used for calculating the average value is recorded as, for example, point B. The position of point B is set as the second position.

[0116] Furthermore, since the plurality of measurement points used for calculating the average value are sequentially moved, a part of the measurement values ​​used for deriving the average value at the previous measurement point is also used in the average value at the next measurement point.

[0117] The distance between point B (second position) and a specific point A (first position) among the multiple points A (first position) obtained by the first measuring unit 1A is selected so as to be within a given range. The selection of point B can be achieved by changing the conveying speed of the carrier sheet 10. The conveying speed of the carrier sheet 10 can be achieved by controlling the rotation speed of the unwinding roller 41 and the winding roller 42 as the conveying control unit. The speeds of the unwinding roller 41 and the winding roller 42 are controlled so that the position deviation from the specific point A is reduced. As a result, point B is selected in a state where the position deviation from the specific point A is reduced. Point B is selected so that it becomes within a given range relative to the specific point A, thereby corresponding to the specific point A. In addition, the given range is within 200 μm, and more preferably within 15 μm.

[0118] The second measuring section 1B performs measurements intermittently at predetermined intervals while reciprocating along the width direction of the carrier sheet 10 orthogonal to the conveying direction T. The carrier sheet 10 moves in the conveying direction T, so that Figure 1As shown by the dotted line, the second measuring section 1B performs measurement in a zigzag manner on the mounting sheet 10. As described above, the measurement position of the second measuring section 1B is controlled by the rotation speeds of the unwinding roller 41 and the winding roller 42 as the transport control section.

[0119] The second measurement unit 1B is provided so as to be reciprocatingly movable relative to the mounting sheet 10 on a plane parallel to the surface of the mounting sheet 10 so as to have a component in a direction orthogonal to the conveyance direction T of the mounting sheet 10 .

[0120] The reciprocating movement of the second measuring section 1B in the width direction of the carrier sheet 10 orthogonal to the conveying direction T can be performed by using a motor, cylinder, linear motor or the like as a driving source and by various direct-acting mechanisms such as ball screws, racks and pinions, timing belts, guides or the like.

[0121] The unwinding roller 41, the first fixed roller 44a, the first tension adjustment roller 43a, the second fixed roller 44b, the third fixed roller 44c, the second tension adjustment roller 43b, the fourth fixed roller 44d and the winding roller 42 for conveying the carrier sheet 10 all have an axis, which is configured to be parallel to the width direction of the carrier sheet 10 that is orthogonal to the conveying direction T of the carrier sheet 10, and the reciprocating movement of the second measuring part 1B in the width direction of the carrier sheet 10 that is orthogonal to the conveying direction T becomes parallel to the axis center of the above-mentioned rollers.

[0122] The second measuring unit 1B can irradiate radiation and measure the thickness of the mounting sheet 10 and the ceramic green sheet 21 based on the transmittance of the radiation or the absorption coefficient of the irradiated object. X-rays or β-rays can be used as radiation, and these radiations can be combined to perform measurement using the difference in absorption coefficient.

[0123] The selection can be made according to specific conditions such as the material constituting the mounting sheet 10 and the ceramic green sheet 21, the thickness of the object to be irradiated with radiation, etc. Here, as the radiation irradiated by the second measuring unit 1B, it is preferable to use X-rays which are electromagnetic waves having a wavelength of 1 pm or more and 10 nm or less.

[0124] like Figure 2 As shown, the second control unit 11B is located downstream of the coating film forming unit 30 in the conveyance direction T in which the mounting sheet 10 is conveyed, and is arranged below the second measurement unit 1B with the mounting sheet 10 interposed therebetween.

[0125] The second control unit 11B controls Figure 1The operation of the second measuring unit 1B that reciprocates in the width direction of the carrier sheet 10 orthogonal to the conveying direction T and the interval of the radiation irradiated intermittently by the second measuring unit 1B are controlled. In addition, a measuring head that detects the amount of radiation transmitted (absorbed) can be arranged in the second control unit 11B, and control is performed for sending the electrical signal obtained by converting the detected radiation to the calculation processing unit.

[0126] The second control unit 11B may be provided with support rollers for supporting the mounting sheet 10 moving in the conveyance direction T and maintaining the mounting sheet 10 in a horizontal state.

[0127] The second control unit 11B for controlling the operation of the second measuring unit 1B that reciprocates in the width direction of the mounting sheet 10 and the interval of the radiation rays intermittently irradiated by the second measuring unit 1B is not limited to being arranged below the mounting sheet 10, but may be arranged above the measuring unit of the second measuring unit 1B and the mounting sheet 10. Furthermore, it is not limited to being arranged downstream of the coating film forming unit 30, but may be arranged upstream of the coating film forming unit 30.

[0128] The information of the measurement position and thickness measured by the second measuring unit 1B is sent to the calculation processing unit.

[0129] (Calculation Processing Unit)

[0130] The calculation processing unit calculates the thickness of the coating film 20 at a given position of the mounting sheet 10 using the thickness information corresponding to the position information measured by the first measuring unit 1A and the thickness information corresponding to the position information measured by the second measuring unit 1B. A specific calculation method is described below.

[0131] In the calculation processing unit, the thickness of the coating film 20 (i.e., the coating film of the ceramic slurry or the ceramic green sheet 21 formed by drying the coating film of the ceramic slurry) is calculated based on the thickness information of the specific point A (the first position) sent from the first measuring unit 1A and the thickness information of the point B (the second position) corresponding to the specific point A sent from the second measuring unit 1B. As described above, the unwinding roller 41 and the winding roller 42 as the conveying control unit are controlled so that the position deviation between the first position and the second position in the conveying direction is reduced. The distance between the point A and the point B falls within a given range, and the thickness information of the point A and the thickness information of the point B can be treated as the thickness of the same position.

[0132] The first position is thickness information of the mounting sheet 10 , and the second position is thickness information of the mounting sheet 10 and the ceramic green sheet 21 . Therefore, the thickness of the ceramic green sheet 21 can be calculated by subtracting the thickness information at the first position from the thickness information at the second position.

[0133] In addition, the positional deviation between the first measurement position and the second measurement position may be reduced without using the unwinding roller 41 and the winding roller 42 as the transport control unit.

[0134] The calculation processing unit has the position information of all the points A sent from the first measuring unit 1A and the position information of the points B sent from the second measuring unit 1B. The calculation processing unit can select the point B having the smallest position information deviation from the position information of the specific point A. The calculation processing unit can also calculate the thickness of the ceramic green sheet 21 by subtracting the thickness information of the specific point A from the thickness information of the point B having the smallest position information deviation from the position information of the specific point A.

[0135] The calculation processing unit constituting the thickness measuring device 1 calculates the thickness of the coating film 20 (i.e., the coating film of the ceramic slurry or the ceramic green sheet 21 formed by drying the coating film of the ceramic slurry) based on the thickness information from the first measuring unit 1A and the second measuring unit 1B, and can send the calculated data of the thickness of the ceramic green sheet 21 to the supply amount control unit to control the supply amount of the ceramic slurry, thereby adjusting the coating amount of the ceramic slurry applied to the carrier sheet 10 in the coating film forming unit 30. In addition, the calculation processing unit and the supply amount control unit of the thickness measuring device 1 can also be assembled into the coating film forming unit 30, so that the coating amount of the ceramic slurry can be controlled using the calculated data of the thickness of the ceramic green sheet 21.

[0136] (Manufacturing of ceramic green sheets)

[0137] The ceramic slurry for producing the ceramic green sheet 21 can be obtained by preparing ceramic particles containing Ba, Ca, Ti, etc., a binder, an organic solvent, etc., and wet mixing them. The binder and solvent contained in the ceramic slurry can use known binders and solvents.

[0138] The ceramic slurry is transferred from the storage tank to the coating film forming unit 30 by a pump. The coating film forming unit 30 includes a coating unit for applying the ceramic slurry. In addition, a drying unit for drying the applied ceramic slurry may be provided.

[0139] The coating film forming unit 30 applies ceramic slurry onto the carrier sheet 10 by a die coater, a gravure coater, or the like. In particular, when the carrier sheet 10 is composed of a plurality of layers with a release layer as the top layer, the ceramic slurry is applied onto the release layer and dried to form a ceramic raw sheet 21.

[0140] The thickness of the applied ceramic slurry is 0.1 to 50 μm. The applied ceramic slurry is dried by evaporating the solvent contained in the ceramic slurry with far infrared rays, a heater, etc., to form a ceramic green sheet. The drying temperature is 30 to 100°C.

[0141] The manufacturing device 40 of ceramic green sheets can include a thickness measuring device 1 and a coating film forming unit 30. The coating film forming unit 30 is configured to perform film thickness feedback control for controlling the supply amount of ceramic slurry based on the data of the thickness of the coating film 20 (i.e., the coating film of the ceramic slurry or the ceramic green sheet 21 formed by drying the coating film of the ceramic slurry) measured by the thickness measuring device 1, and to coat the supplied ceramic slurry on the carrier sheet 10 while controlling the supply amount, thereby forming the ceramic green sheet 21. As the supply amount control unit for realizing the film thickness feedback control, for example, an electromagnetic valve can be configured, and further, an electromagnetic type, ultrasonic type, or other flow meter can be configured.

[0142] The ceramic green sheet manufacturing device 40 is configured to feed back data on the thickness of the applied ceramic slurry or the accurate thickness of the sheet measured after the ceramic green sheet 21 is formed to the coating film forming unit 30, thereby quickly controlling the supply amount of the ceramic slurry, thereby being able to continuously and reliably manufacture ceramic green sheets 21 with uniform thickness.

[0143] (Manufacturing of Multilayer Ceramic Capacitors)

[0144] Next, an example of a method for manufacturing a multilayer ceramic capacitor will be described.

[0145] Figure 3 This is a perspective view of the appearance of a multilayer ceramic capacitor. Figure 4 yes Figure 3 A cross-sectional view of the multilayer ceramic capacitor taken along line IV-IV is shown.

[0146] First, ceramic green sheets 21 manufactured by a ceramic green sheet manufacturing apparatus 40 and conductive paste for internal electrodes are prepared. The conductive paste for internal electrodes contains a binder and a solvent, and a known organic binder and organic solvent can be used. The conductive paste for internal electrodes forms internal electrodes 53 .

[0147] Next, a conductive paste for internal electrodes is printed in a predetermined pattern on the ceramic green sheet by, for example, screen printing, gravure printing, etc., thereby forming an internal electrode pattern.

[0148] Next, a predetermined number of ceramic green sheets for outer layers without internal electrode patterns are stacked, ceramic green sheets with internal electrodes are sequentially stacked thereon, and a predetermined number of ceramic green sheets for outer layers are stacked thereon, thereby manufacturing a laminated sheet. The ceramic green sheets form the dielectric layer 52 constituting the laminated ceramic capacitor 50.

[0149] The obtained laminated sheets are pressed in the stacking direction by isostatic pressing or the like, thereby making a laminated block. Next, the laminated block is cut into a given size to cut out laminated small pieces. At this time, the corners and ridges of the laminated small pieces can also be rounded by roller grinding or the like.

[0150] Furthermore, the stacked small pieces are fired to produce the stacked body 51. The firing temperature at this time depends on the materials of the dielectric and the internal electrodes, but is preferably 900°C or higher and 1300°C or lower.

[0151] Conductive paste for external electrodes is applied to both end surfaces of the obtained laminate 51 and fired to form a fired layer 54a of the external electrode 54. The firing temperature at this time is preferably 700° C. to 900° C. Then, a plating layer 54b is applied to the surface of the fired layer as needed.

[0152] Through the above steps, a multilayer ceramic capacitor is manufactured.

[0153] In the embodiment of the present invention, a method is shown in which the functional sheet is a coating film of a ceramic slurry or a ceramic green sheet 21 formed by drying a coating film of a ceramic slurry. However, the functional sheet is not limited to such a coating film of a ceramic slurry or a ceramic green sheet. The functional sheet can be any sheet of material that can be arranged on the carrier sheet 10. Depending on the material of the functional sheet arranged on the carrier sheet 10, any one of X-rays and beta rays can be used. When using X-rays, the optimal wavelength can be selected according to the properties of the material arranged on the carrier sheet 10. When using beta rays, the optimal radiation source can be used according to the properties of the material arranged on the carrier sheet, for example, 85 Kr, 147 Pm, 204 Ti, 90 Sr, etc. Although coating is shown as an example of arrangement, the present invention is not limited to coating. The functional sheet may be arranged on the mounting sheet 10 by bonding, vapor deposition, blowing, or the like.

[0154] Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and can be implemented in various forms within the scope of the present invention. The present invention includes the following combinations.

[0155] <1>

[0156] A thickness measuring device measures the thickness of a coating film formed on a conveyed carrier sheet, wherein:

[0157] The thickness measuring device comprises:

[0158] a first measuring unit that acquires thickness information of the carrier sheet before the coating film is formed by irradiating light, and acquires a first position, the first position being a position where the thickness information of the carrier sheet is acquired;

[0159] a second measuring unit that obtains thickness information of the carrier sheet and the coating film after the coating film is formed by irradiating radiation, and obtains a second position, the second position being a position where the thickness information of the carrier sheet and the coating film is obtained; and

[0160] The calculation processing unit calculates the thickness of the coating film based on the thickness information of the mounting sheet at the first position and the thickness information at the second position within a predetermined range relative to the first position.

[0161] <2>

[0162] A thickness measuring device, comprising:

[0163] The transport part transports the mounting sheet in the transport direction;

[0164] a composite sheet forming unit that forms a composite sheet in which a functional sheet is arranged on the carrier sheet; and

[0165] The thickness measuring unit measures the thickness of the object being transported.

[0166] in,

[0167] The thickness measuring unit comprises:

[0168] a first measuring unit for acquiring thickness information of the carrier sheet before the functional sheet is arranged by irradiating light;

[0169] a second measuring unit for acquiring thickness information of the composite sheet after the functional sheet is arranged by irradiating radiation;

[0170] a transport control unit that controls the transport unit so that a positional deviation in the transport direction between a first position of the mounting sheet irradiated with the light by the first measuring unit and a second position of the mounting sheet irradiated with the radiation by the second measuring unit is reduced; and

[0171] The calculation processing unit calculates the thickness of the functional sheet based on the thickness information of the mounting sheet at the first position and the thickness information of the composite sheet at the second position.

[0172] <3>

[0173] according to <1> or <2> The thickness measuring device, wherein:

[0174] The first measuring part is arranged at a given distance in a vertical direction from the surface of the carrier sheet being transported, and the second measuring part is arranged to be able to move back and forth relative to the carrier sheet on a plane parallel to the surface of the carrier sheet so as to have a component in a direction orthogonal to the transport direction of the carrier sheet.

[0175] <4>

[0176] according to <1> to <3> The thickness measuring device described in any one of claims , wherein:

[0177] The first measuring unit performs interference measurement.

[0178] <5>

[0179] according to <1> to <4> The thickness measuring device described in any one of claims , wherein:

[0180] The first measuring unit performs reflection-type interferometry measurement.

[0181] <6>

[0182] according to <1> to <5> The thickness measuring device described in any one of claims , wherein:

[0183] The first measuring unit irradiates light from a plurality of light sources arranged at regular intervals along a width direction of the mounting sheet that is perpendicular to the conveying direction.

[0184] <7>

[0185] according to <1> to <6> The thickness measuring device described in any one of claims , wherein:

[0186] The second measuring unit irradiates X-rays or beta rays as radiation.

[0187] <8>

[0188] A device for manufacturing a ceramic green sheet, comprising:

[0189] <1> The thickness measuring device; and

[0190] The coating film forming unit controls the coating amount based on the thickness of the coating film measured by the thickness measuring device,

[0191] The coating film is a coating film of a ceramic slurry or a ceramic green sheet formed by drying the coating film of the ceramic slurry,

[0192] A ceramic slurry is applied onto the carrier sheet to form a ceramic green sheet.

[0193] <9>

[0194] A method for manufacturing a ceramic green sheet, using <1> The thickness measuring device, wherein:

[0195] The coating film is a coating film of a ceramic slurry or a ceramic green sheet formed by drying the coating film of the ceramic slurry,

[0196] The coating film forming section forms a ceramic green sheet by coating the ceramic slurry on the mounting sheet while controlling the coating amount based on the thickness of the coating film of the ceramic slurry or the ceramic green sheet calculated by the thickness measuring device.

Claims

1. A thickness measuring device for measuring the thickness of a coating film formed on a conveyed carrier sheet, wherein: The thickness measuring device comprises: a first measuring unit that acquires thickness information of the carrier sheet before the coating film is formed by irradiating light, and acquires a first position, the first position being a position where the thickness information of the carrier sheet is acquired; a second measuring unit that obtains thickness information of the carrier sheet and the coating film after the coating film is formed by irradiating radiation, and obtains a second position, the second position being a position where the thickness information of the carrier sheet and the coating film is obtained; as well as The calculation processing unit calculates the thickness of the coating film based on the thickness information of the mounting sheet at the first position and the thickness information at the second position within a predetermined range relative to the first position.

2. A thickness measuring device, comprising: The transport part transports the mounting sheet in the transport direction; a composite sheet forming unit that forms a composite sheet in which a functional sheet is arranged on the carrier sheet; and The thickness measuring unit measures the thickness of the object being transported. in, The thickness measuring unit comprises: a first measuring unit for acquiring thickness information of the carrier sheet before the functional sheet is arranged by irradiating light; a second measuring unit for acquiring thickness information of the composite sheet after the functional sheet is arranged by irradiating radiation; a transport control unit that controls the transport unit so that a positional deviation in the transport direction between a first position of the mounting sheet irradiated with the light by the first measuring unit and a second position of the mounting sheet irradiated with the radiation by the second measuring unit is reduced; as well as The calculation processing unit calculates the thickness of the functional sheet based on the thickness information of the mounting sheet at the first position and the thickness information of the composite sheet at the second position.

3. The thickness measuring device according to claim 1 or 2, wherein: The first measuring part is arranged at a given distance in a vertical direction from the surface of the carrier sheet being transported, and the second measuring part is arranged to be able to move back and forth relative to the carrier sheet on a plane parallel to the surface of the carrier sheet so as to have a component in a direction orthogonal to the transport direction of the carrier sheet.

4. The thickness measuring device according to any one of claims 1 to 3, wherein: The first measuring unit performs interference measurement.

5. The thickness measuring device according to any one of claims 1 to 4, wherein: The first measuring unit performs reflection-type interferometry measurement.

6. The thickness measuring device according to any one of claims 1 to 5, wherein: The first measuring unit irradiates light from a plurality of light sources arranged at regular intervals along a width direction of the mounting sheet that is perpendicular to the conveying direction.

7. The thickness measuring device according to any one of claims 1 to 6, wherein: The second measuring unit irradiates X-rays or beta rays as radiation.

8. A device for manufacturing a ceramic green sheet, comprising: The thickness measuring device according to claim 1; and The coating film forming unit controls the coating amount based on the thickness of the coating film measured by the thickness measuring device, The coating film is a coating film of a ceramic slurry or a ceramic green sheet formed by drying the coating film of the ceramic slurry, A ceramic slurry is applied onto the carrier sheet to form a ceramic green sheet.

9. A method for manufacturing a ceramic green sheet, using the thickness measuring device according to claim 1, wherein: The coating film is a coating film of a ceramic slurry or a ceramic green sheet formed by drying the coating film of the ceramic slurry, The coating film forming section forms a ceramic green sheet by coating the ceramic slurry on the mounting sheet while controlling the coating amount based on the thickness of the coating film of the ceramic slurry or the ceramic green sheet calculated by the thickness measuring device.

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