JP5413655B2 - Film thickness measuring device - Google Patents

Description

  The present invention relates to an apparatus for measuring a film thickness of a coating film formed by applying a coating liquid in the length direction of a belt-shaped substrate, and a method for measuring the film thickness.

  As an apparatus for measuring the thickness of a coating film formed on a belt-like substrate, there is an apparatus described in, for example, Japanese Patent Application Laid-Open No. 2002-257506 (Patent Document 1). This publication describes a non-contact film thickness measuring device that measures the coating film thickness applied on a metal plate. A laser displacement meter is used as a non-contact film thickness measuring device for measuring the coating film thickness, and has a structure for measuring the film thickness while moving in the width direction of the metal plate. The apparatus disclosed in the publication has a structure for measuring the coating film thickness formed on the metal plate while conveying the metal plate by the rotation of the metal roller.

JP 2002-257506 A

  By the way, for example, in the case of manufacturing a lithium ion secondary battery, an electrode active material is applied to a belt-shaped substrate to form a coating film. At this time, in order to increase the yield, it is required to form a coating film with good accuracy such as the position of the coating film, the width of the coating film, and the thickness of the coating film on the belt-like substrate. The inventor measures the position of the coating film formed on the belt-shaped substrate, the width of the coating film, the thickness of the coating film, and the like, and feedback-controls the coating apparatus based on the measurement result, thereby It is considered to form a coating film with high accuracy such as the position of the coating film, the width of the coating film, and the thickness of the coating film on the material. For this purpose, it is premised that the position of the coating film formed on the belt-shaped substrate, the width of the coating film, the thickness of the coating film, and the like can be measured with high accuracy. In particular, when forming a coating film on a belt-like substrate, it is preferable to continuously apply the belt-like substrate while being conveyed by a roller from the viewpoint of productivity. And in this coating aspect, it is preferable that it can carry out also about the measurement of said coating film, without stopping a coating process.

  However, in an existing apparatus such as Patent Document 1, it is difficult to accurately measure the film thickness of the coating film formed on the belt-like substrate while the belt-like substrate is conveyed by a roller. Specifically, when the belt-like substrate is transported at a high speed or when the tension applied to the belt-like substrate is small, air is caught between the belt-like substrate and the roller, and the belt-like substrate becomes a roller. Elevated from the outer surface is likely to occur. As a result of such air entrainment, an air layer is locally generated between the belt-shaped substrate and the roller, and the surface of the belt-shaped substrate becomes uneven (the height from the outer surface of the roller to the surface of the substrate varies depending on the location) Therefore, there was a problem that the film thickness of the coating film formed on the substrate surface could not be measured with high accuracy.

  The present invention has been made in view of such a point, and its main purpose is to measure the film thickness of the coating film without being affected by the occurrence of air entrainment between the belt-like substrate and the roller. It is providing the film thickness measuring method which can be performed. Moreover, the other object of this invention is to provide the film thickness measuring apparatus which can implement | achieve such a film thickness measuring method of a coating film preferably.

  The method provided by the present invention is a method for measuring the film thickness of a coating film formed in the length direction of a base material by supplying a coating liquid from a coating portion to a belt-like base material conveyed on a roller. is there. In this method, the thickness X1 from the outer surface of the roller to the surface of the base material is measured by a first thickness sensor at a position upstream of the coating portion with respect to the transport direction of the base material. Including. Further, the method includes measuring the thickness X2 from the outer surface of the roller to the surface of the coating film with a second thickness sensor at a position downstream of the coating portion with respect to the transport direction of the substrate. And calculating the film thickness of the said coating film formed in the said strip | belt-shaped base material from the difference of the thickness X1 measured with the said 1st thickness sensor and the thickness X2 measured with the said 2nd thickness sensor is included. .

  According to this film thickness measuring method, the thickness X1 from the outer surface of the roller to the surface of the substrate is measured at a position upstream of the coating portion, and the outer surface of the roller is positioned downstream of the coating portion. The thickness X2 from the surface to the surface of the coating film is measured, and the film thickness of the coating film formed on the strip substrate is calculated from the difference between the obtained thickness X1 and thickness X2. Even when air is caught in between and the belt-like substrate is lifted from the outer surface of the roller, the film thickness of the coating film can be measured without being affected by the influence.

  In a preferable aspect of the method disclosed herein, the coating part is configured to be able to form a plurality of rows of coating films in the length direction of the belt-like substrate. And the said 1st thickness sensor and the 2nd thickness sensor are provided with two or more corresponding to each of the said several rows of coating film. In this case, since the film thicknesses of the plurality of rows of coating films can be measured in parallel, the measurement time can be shortened compared to the case where the film thicknesses of the plurality of rows of coating films are measured using a single thickness sensor.

  In a preferred aspect of the method disclosed herein, the thickness of the same part as the measurement part measured by the first thickness sensor is measured by the second thickness sensor among the belt-like base material conveyed on the roller. taking measurement. Since the entrainment of air between the belt-shaped substrate and the roller occurs locally, the thickness of the air layer may vary depending on the measurement location of the belt-shaped substrate. Therefore, if the measurement location of the first thickness sensor and the second thickness sensor is shifted, the thickness of the air layer at different positions is measured by both sensors, and even if the two are subtracted, the thickness of the air layer may not be properly eliminated. is there. According to the above method, since the measurement locations of the first thickness sensor and the second thickness sensor are matched, the thickness of the air layer corresponding to the measurement location can be appropriately excluded.

  In a preferred aspect of the method disclosed herein, the first thickness sensor and the second thickness sensor are scanned in the width direction of the band-shaped substrate, and the band-shaped substrate is scanned along the width direction of the band-shaped substrate. The film thickness distribution of the coating film formed on the material is measured. Thereby, the distribution of the film thickness of the coating film formed on the band-shaped substrate, that is, the position of the coating film with respect to the band-shaped substrate, the width of the coating film, and the thickness of the coating film are measured in the width direction of the band-shaped substrate. be able to. According to the present invention, since it is not affected by air entrainment, such a film thickness distribution in the width direction can be accurately measured.

  In a preferred aspect of the method disclosed herein, the position of the end in the width direction of the belt-shaped substrate conveyed by the roller is detected. And the thickness distribution of the said coating film formed in the said strip | belt-shaped base material is measured along the width direction of the said strip | belt-shaped base material on the basis of the position of the detected width direction edge part of the strip | belt-shaped base material. According to this method, for example, even when the position of the belt-like substrate is shifted during conveyance due to a phenomenon such as meandering, the film thickness distribution in the width direction can be measured without being affected by the influence. That is, according to the above method, the film thickness distribution of the coating film can be accurately measured without being influenced by meandering in addition to air entrainment.

  Moreover, this invention provides the coating-film thickness measuring apparatus which can preferably implement | achieve the measuring method of the said coating-film thickness. This apparatus measures the film thickness of a coating film formed by applying a coating liquid to a belt-like substrate. The apparatus supplies a coating liquid in the length direction of the base material by supplying a coating liquid to the roller that transports the belt-shaped base material in the length direction of the base material and the belt-shaped base material transported on the roller. A coating part to be formed and a first part which is provided at a position upstream of the coating part with respect to the transport direction of the base material and measures a thickness X1 from the outer surface of the roller to the surface of the base material A thickness sensor, and a second thickness sensor that is provided at a position downstream of the coating portion with respect to the transport direction of the substrate and that measures a thickness X2 from the outer surface of the roller to the surface of the coating film. Is provided. And it is comprised so that the film thickness of the coating film formed in the said strip | belt-shaped base material can be calculated from the difference of the thickness measured with the said 1st thickness sensor, and the thickness measured with the said 2nd thickness sensor. Yes. According to this measuring apparatus, the film thickness measuring method of the coating film can be preferably realized.

  In a preferable aspect of the apparatus disclosed herein, the first thickness sensor and the second thickness sensor are scanned in the width direction of the band-shaped base material, and along the width direction of the band-shaped base material, It is comprised so that the film thickness distribution of the coating film formed in can be measured. Thereby, the film thickness distribution of the coating film can be accurately measured in the width direction.

  In a preferred aspect of the apparatus disclosed herein, a position sensor is provided that detects the position of the end in the width direction of the belt-shaped substrate conveyed by the roller. Then, the film thickness distribution of the coating film formed on the belt-like substrate can be measured along the width direction of the belt-like substrate with reference to the position of the widthwise end portion of the belt-like substrate detected by the position sensor. It is configured as follows. According to this configuration, even when the position of the belt-like substrate is shifted during conveyance due to meandering or the like, the film thickness distribution in the width direction can be measured without being affected by the influence.

  In a preferable aspect of the apparatus disclosed herein, the coating unit is configured to be able to form a plurality of rows of coating films in the length direction of the belt-like substrate. And the said 1st thickness sensor and the 2nd thickness sensor are provided with two or more corresponding to each of several rows of coating films. In this case, since the film thicknesses of the plurality of rows of coating films can be measured in parallel, the measurement time can be shortened compared to the case where the film thicknesses of the plurality of rows of coating films are measured using a single thickness sensor.

The side view which shows typically the film thickness measuring apparatus which concerns on one Embodiment of this invention. The perspective view which shows typically the coating part which concerns on one Embodiment of this invention. The perspective view which shows typically the film thickness measuring apparatus which concerns on one Embodiment of this invention. The figure for demonstrating the film thickness measuring method which concerns on one Embodiment of this invention. The figure for demonstrating the film thickness measuring method which concerns on one Embodiment of this invention. The figure for demonstrating the film thickness measuring method which concerns on one Embodiment of this invention. The figure for demonstrating the film thickness measuring method which concerns on one Embodiment of this invention. The top view which shows the intermediate body which manufactures a strip | belt-shaped electrode.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field. Moreover, in the following drawings, the same code | symbol is attached | subjected and demonstrated to the member and site | part which show | plays the same effect | action. In addition, the following embodiment only illustrates one embodiment of the present invention, and the present invention is not limited to the following embodiment.

<First Embodiment>
As shown in FIG. 1, the film thickness measuring apparatus 100 according to this embodiment measures the film thickness of a coating film 12 formed by applying a coating liquid in the length direction of the belt-like substrate 10. This film thickness measuring apparatus 100 supplies the coating liquid 44 to the roller 30 that conveys the belt-like substrate in the length direction of the substrate, and the belt-like substrate that is conveyed on the roller. The coating part 40 that forms the coating film 12 in the direction, and two thickness sensors (first thickness sensor 50) provided at positions upstream and downstream of the coating part 40 with respect to the substrate transport direction 90. And a second thickness sensor 60).

  The roller 30 is a device that conveys the belt-like substrate 10. In this embodiment, the belt-like base material 10 is laid over a plurality of rollers 30 and 32 in order, and tension is applied to the belt-like base material 10. A drive device (not shown) for rotating the roller is attached to some of the rollers. The film thickness measuring apparatus 100 conveys the belt-like substrate 10 in the substrate conveyance direction 90 by rotating the roller 30.

  The coating part 40 is an apparatus which forms the coating film 12 in the length direction of the strip | belt-shaped base material 10, as shown in FIG. In this embodiment, the coating unit 40 supplies a die 42 having a discharge port for discharging a coating liquid 44 obtained by pasting a material for forming the coating film 12, and supplies the coating liquid 44 to the die 42 at a predetermined pressure. And a coating liquid supply unit 46. In this embodiment, the coating film 12 is formed while the belt-like substrate 10 is traveling in the substrate conveyance direction 90. That is, while the belt-like substrate 10 is conveyed by the rotation of the roll 30, the gap (coating gap) between the roll 30 and the die 42 is passed, and the coating liquid 44 is applied to the belt-like substrate 10 from the die 42. Thereby, the coating film 12 is formed in the length direction of the belt-like substrate 10.

As shown in FIG. 1, the first thickness sensor 50 is provided at a position upstream of the coating unit 40 with respect to the substrate transport direction 90. The first thickness sensor 50 is upstream of the coating liquid supply position A0 and downstream of the position A1 where the base material 10 is first wound on the roll 30 (immediately after the base material 10 is wound on the roller 30). It only has to be arranged on the side. At that position, the first thickness sensor 50 measures the thickness X1 from the outer surface 30a of the roller 30 to the surface 10a of the substrate 10 (see I in FIG. 1). In addition, I surrounded by a circle in FIG. 1 is a cross-sectional view of a main part in which a measurement point by the first thickness sensor 50 is enlarged.
For the first thickness sensor 50, for example, a commercially available general laser displacement meter (for example, Keyence Corporation) is used. In this case, as shown in FIG. 3, the laser displacement meter (first thickness sensor) 50 is a belt-like substrate conveyed on the roller 30 on the upstream side of the coating liquid supply position (below the roller 30 in FIG. 3). 10 so as to face 10. Then, the surface of the substrate 10 conveyed on the roller 30 is irradiated with laser light, and the distance from a predetermined reference position to the surface of the substrate 10 is measured. In this case, the surface of the substrate 10 from the outer surface of the roller 30 based on the distance from the obtained reference position to the surface of the substrate 10 and the distance from the preset reference position to the outer surface of the roller 30. The thickness X1 up to can be measured.

Moreover, the 2nd thickness sensor 60 is provided in the position of the downstream rather than the coating part 40 with respect to the conveyance direction 90 of a base material, as shown in FIG. The second thickness sensor 60 is disposed downstream of the coating liquid supply position A0 and upstream of the position A2 where the base material 10 is separated from the roller 30 (immediately before the base material 10 is separated from the roller 30). It only has to be. At that position, the second thickness sensor 60 measures the thickness X2 from the outer surface 30a of the roller 30 to the surface 12a of the coating film 12 (see II in FIG. 1). In addition, II surrounded by a circle in FIG. 1 is an enlarged cross-sectional view of a main part measured by the second thickness sensor 60.
For the second thickness sensor 60, for example, a general laser displacement meter that is commercially available is used, similarly to the first thickness sensor 50. In this case, as shown in FIG. 3, the laser displacement meter (second thickness sensor) 60 is a belt-like substrate that is conveyed on the roller 30 on the downstream side of the coating liquid supply position (above the roller 30 in FIG. 3). 10 so as to face 10. And the laser beam is irradiated to the surface of the coating film 12 formed in the strip | belt-shaped base material 10, and the distance from the predetermined reference position to the surface of the coating film 12 is measured. In this case, the surface of the coating film 12 from the outer surface of the roller 30 based on the distance from the obtained reference position to the surface of the coating film 12 and the distance from the preset reference position to the outer surface of the roller 30. The thickness X2 up to can be measured.

  The film thickness measuring apparatus 100 determines the film thickness of the coating film 12 formed on the belt-like substrate 10 from the difference between the thickness X1 measured by the first thickness sensor 50 and the thickness X2 measured by the second thickness sensor 60. It is configured to be able to calculate. In this embodiment, as shown in FIG. 3, calculation for calculating the film thickness of the coating film 12 from the difference between the thickness X <b> 1 measured by the first thickness sensor 50 and the thickness X <b> 2 measured by the second thickness sensor 60. A portion 54 is provided. Measurement data of the thickness X 1 measured by the first thickness sensor 5 is sent from the first thickness sensor 50 to the calculation unit 54. The calculation unit 54 stores the measurement value of the thickness X1 sent from the first thickness sensor 50 in the storage unit 56. Further, the measurement value of the thickness X <b> 2 measured by the second thickness sensor 60 is sent from the second thickness sensor 60 to the calculation unit 54. The calculation unit 54 stores the measurement value of the thickness X2 sent from the second thickness sensor 60 in the storage unit 56. In the calculation unit 54, the film of the coating film 12 is calculated from the difference (subtraction) between the measurement value of the thickness X 1 of the first thickness sensor 50 and the measurement value of the thickness X 2 of the second thickness sensor 60 stored in the storage unit 56. Calculate the thickness.

  Here, the air 70 may be caught between the belt-like substrate 10 and the roller 30, and a part of the belt-like substrate 10 may be lifted from the outer surface 30 a of the roller. When the conveyance speed of the belt-like substrate 10 due to the rotation of the roller 30 is high (for example, when the conveyance speed of the belt-like substrate exceeds 50 m / min), or when the tension applied to the belt-like substrate 10 is small, the above Air entrainment is particularly likely to occur. As a result of such air entrainment, an air layer 70 is locally generated between the belt-like base material 10 and the roller 30, and the surface of the belt-like base material 10 becomes uneven (the height from the outer surface 30a of the roller to the base material surface 10a is high). Therefore, in the conventional mode in which the first and second thickness sensors 50 and 60 are not used, there is a problem that the film thickness of the coating film 12 formed on the belt-like substrate 10 cannot be measured accurately. It was.

  In contrast, in the present embodiment, as shown in FIG. 1, the thickness X1 from the outer surface 30a of the roller to the surface 10a of the base material is measured at a position upstream of the coating unit 40, and the coating unit 40 is measured. The thickness X2 from the outer surface 30a of the roller to the surface 12a of the coating film is measured at a position downstream of the roller, and the film of the coating film 12 formed on the belt-like substrate from the difference between the obtained thickness X1 and thickness X2 Since the thickness is calculated, for example, even when the air 70 is caught between the belt-like base material 10 and the roller 30 and the belt-like base material 10 is lifted from the outer surface 30a of the roller, it is not affected by this, and the coating film 12 The film thickness can be measured.

  4 and FIG. 5 in addition, as schematically shown in FIG. 4, when the conveyance speed of the belt-like substrate 10 is increased, air is caught between the belt-like substrate 10 and the roller 30. An air layer 70 is formed between the belt-like substrate 10 and the roller 30. The first thickness sensor 50 measures the thickness X1 from the outer surface 30a of the roller to the substrate surface 10a before the coating shown in FIG. Therefore, the obtained thickness X1 includes not only the thickness d1 of the base material 10 but also the thickness d2 of the air layer 70. On the other hand, the second thickness sensor 60 measures the thickness X2 from the outer surface 30a of the roller to the coating surface 12a after the coating of FIG. Therefore, the obtained thickness X2 includes not only the thicknesses d1 and d3 of the base material 10 and the coating film 12, but also the thickness d2 of the air layer 70.

  That is, the first thickness sensor 50 measures “the thickness d1 of the substrate 10 + the thickness d2 of the air layer 70”, and the second thickness sensor 60 measures “the thickness d1 of the substrate 10 + the thickness d2 + of the air layer 70 + the thickness of the coating film 12”. d3 "is measured. Therefore, when the measurement value of the first thickness sensor 50 is subtracted from the measurement value of the second thickness sensor 60, only the “film thickness d3 of the coating film 12” formed on the substrate 10 is calculated. The “thickness d2 of the air layer 70” caught between the rollers 30 is excluded. Thus, even when air is caught between the belt-like substrate 10 and the roller 30, the film thickness of the coating film 12 can be measured without being affected by the influence. If this method is used, the film thickness can be accurately controlled even in high-speed coating, so that the yield can be improved while increasing the productivity. Thereby, waste can be reduced and waste of resources can be omitted, and material costs and product costs can be reduced.

  In the technology disclosed herein, the second thickness sensor 60 measures the thickness of the same location as the measurement location measured by the first thickness sensor 50 in the belt-like substrate 10 conveyed on the roller 30. Configured to get. That is, the first thickness sensor 50 and the second thickness sensor 60 measure the thickness of the same portion of the belt-like substrate 10 conveyed on the roller 30. Since the entrainment of air between the belt-shaped substrate and the roller occurs locally, the thickness of the air layer may vary depending on the measurement location of the belt-shaped substrate. Therefore, if the measurement location of the 1st thickness sensor 50 and the 2nd thickness sensor 60 shift | deviates, the thickness of the air layer of a different position is measured with both sensors, and even if it subtracts both, the thickness of an air layer cannot be excluded appropriately. There is a case. On the other hand, in this embodiment, since the measurement location of the 1st thickness sensor 50 and the 2nd thickness sensor 60 is made to correspond, the thickness of the air layer 70 corresponding to a measurement location can be excluded appropriately.

  In this case, in order to appropriately exclude the thickness of the air layer 70 corresponding to the measurement location, the substrate 10 is conveyed from the measurement position by the first thickness sensor 50 to the measurement position by the second thickness sensor 60. In addition, it is preferable that the position and thickness of the air layer 70 do not substantially change (that is, air does not escape or swell during the period from the first thickness sensor 50 to the second thickness sensor 60). In the technique disclosed herein, as shown in FIG. 1, the first thickness sensor 50 is arranged to avoid immediately after the base material 10 is wound around the roller 30. For example, it is preferable that the first thickness sensor 50 is disposed at an appropriate distance from the position A1 where the substrate 10 is first wound around the roller 30 (however, upstream of the coating liquid supply position A0). In this way, the first thickness sensor 50 is disposed so as to avoid immediately after the base material 10 is wound around the roller 30, so that the base material 10 is conveyed from the measurement position by the first thickness sensor 50 to the measurement position by the second thickness sensor 60. In the meantime, the position and thickness of the air layer 70 are hardly changed. Therefore, the thickness of the air layer 70 caught between the belt-like base material 10 and the roller 30 can be more appropriately excluded.

  Further, as shown in FIG. 1, the second thickness sensor 60 is disposed so as to avoid a position immediately before the base material 10 is separated from the roller 30. For example, it is preferable that the second thickness sensor 60 is disposed at an appropriate distance from the position A2 where the base material 10 is separated from the roller 30 (however, downstream of the coating liquid supply position A0). Thus, the base material 10 is transported from the measurement position by the first thickness sensor 50 to the measurement position by the second thickness sensor 60 by arranging the second thickness sensor 60 so as to avoid immediately before the base material 10 is separated from the roller 30. In the meantime, the position and thickness of the air layer 70 are hardly changed. Therefore, the thickness of the air layer 70 caught between the belt-like base material 10 and the roller 30 can be more appropriately excluded.

  In addition, the 1st and 2nd thickness sensors 50 and 60 should just be a sensor which can detect the thickness from the outer surface 30a of a roller to the base-material surface 10a and the coating-film surface 12a. For this reason, various changes can be made to the specific configurations of the first and second thickness sensors 50 and 60. In this embodiment, an optical sensor using laser light is exemplified, but the present invention is not limited to this, and various sensors may be applied as long as the surface shape of the belt-like substrate 10 and the coating film 12 can be measured. be able to.

<Second Embodiment>
This embodiment is different from the first embodiment described above in that the coating films 12 and 16 are formed not only on one side of the belt-like substrate 10 but also on both surfaces of the belt-like substrate 10. That is, as shown in FIG. 6, the coating film 16 is formed in advance on the back surface of the belt-like substrate 10 conveyed on the roller 30. This coating film 16 may be, for example, a coating film formed by applying a coating liquid in the length direction of the belt-like substrate 10 using the apparatus 100 of the first embodiment described above. In this case, the gap between the belt-like substrate 10 and the roller 30 is increased by the thickness of the coating film 16 formed on the back surface of the belt-like substrate 10, so that air is easily caught between the belt-like substrate 10 and the roller 30. Moreover, when the film thickness of the coating film 16 formed on the back surface of the belt-shaped substrate 10 is non-uniform (when the thickness of the coating film 16 is uneven depending on the location), the surface of the substrate 10 is uneven. Therefore (because the height from the outer surface of the roller to the surface of the substrate varies depending on the location), it becomes more difficult to accurately measure the film thickness of the coating film 12 formed on the surface of the substrate 10.

  Even in such a case, if the film thickness measuring apparatus 100 of this embodiment is used, the film thickness of the coating film 12 can be measured accurately. That is, the first thickness sensor 50 measures the thickness X1 from the outer surface 30a of the roller to the base material surface 10a before coating in FIG. 16 thickness d4 "is obtained. Further, the second thickness sensor 60 measures the thickness X2 from the outer surface 30a of the roller to the coating film surface 12a after the coating of FIG. 7, and “the thickness d1 of the substrate 10 + the thickness d2 + of the air layer 70 + the coating film”. 16 thickness d4 + thickness d3 of coating film 12 ”is obtained. Therefore, when the measurement value of the first thickness sensor 50 is subtracted from the measurement value of the second thickness sensor 60, only the “film thickness d3 of the coating film 12” formed on the substrate 10 is calculated. The “thickness d2 of the air layer 70” caught between the rollers 30 and the “thickness d4 of the coating film 16” formed on the back surface of the belt-like substrate 10 are excluded. In this way, even when air is entrained between the belt-like substrate 10 and the roller 30, or even when the thickness of the coating film 16 formed on the back surface of the belt-like substrate 10 is uneven, the influence is exerted. Without being received, the film thickness of the coating film 12 can be measured.

  Hereinafter, other features of the first and second embodiments will be further described.

As shown in FIG. 3, the first thickness sensor 50 and the second thickness sensor 60 are scanned in the width direction of the band-shaped substrate 10, and are formed on the band-shaped substrate 10 along the width direction of the band-shaped substrate 10. It is comprised so that the film thickness distribution of the coating film 12 can be measured.
In this embodiment, the first thickness sensor 50 and the second thickness sensor 60 are respectively attached to scanning mechanisms 52 and 62 that are arranged in parallel to the width direction of the belt-like substrate 10. And each scanning mechanism 52 and 62 is driven, and the surface shape of the width direction of the strip | belt-shaped base material 10 is measured, moving the thickness sensors 50 and 60 to the width direction of the strip | belt-shaped base material 10. FIG. Thereby, about distribution of the film thickness of the coating film 12 formed in the strip | belt-shaped base material 10, ie, the position of the coating film 12 with respect to a strip | belt-shaped base material, the width | variety of the coating film 12, and the thickness of the coating film 12 Can be measured in the width direction. In the film thickness measuring apparatus 100 of this embodiment, since it is not influenced by air entrainment, such a film thickness distribution in the width direction can be accurately measured.

Further, as shown in FIG. 3, the film thickness measuring apparatus 100 includes a position sensor 80 that detects the position of the end in the width direction of the belt-like substrate 10 conveyed by the roller 30.
In this embodiment, the position sensor 80 is composed of an optical sensor. The position sensor 80 includes a light projecting unit 82 and a light receiving unit 84 disposed so as to face each other vertically with respect to a position where the end 14 in the width direction of the belt-shaped substrate 10 conveyed by the roller 30 is inserted. I have. The position sensor 80 detects the position of the end 14 in the width direction of the belt-like substrate 10. That is, part of the laser light emitted from the light projecting unit 82 is blocked by the belt-shaped substrate 10. Then, a part of the laser light irradiated to the outside of the end portion 14 in the width direction of the belt-like substrate 10 reaches the light receiving portion 84. The light receiving unit 84 can detect the region where the laser light has reached and the region where the laser light is blocked by the belt-shaped substrate 10. Thereby, the position of the width direction edge part 14 of the strip | belt-shaped base material 10 is detectable.

The film thickness measuring device 100 is formed on the band-shaped substrate 10 along the width direction of the band-shaped substrate 10 with the position of the end 14 in the width direction of the band-shaped substrate 10 detected by the position sensor 80 as a reference. The film thickness distribution of the coated film 12 can be measured.
In this embodiment, the correction unit 86 corrects the measurement values measured by the first and second thickness sensors 50 and 60 with reference to the position of the width direction end portion 14 of the belt-like substrate 10 detected by the position sensor 80. It has. A detection result of the position of the end 14 in the width direction of the belt-like substrate 10 detected by the position sensor 80 is sent from the light receiving unit 84 of the position sensor 80 to the correction unit 86. The correction unit 86 stores the detection result of the position of the end 14 in the width direction of the belt-shaped substrate 10 sent from the position sensor 80 in the storage unit 56.

  In the correction unit 86, the first and second thickness sensors stored in the storage unit 56 with reference to the detection result of the position in the width direction end portion 14 of the band-shaped substrate 10 of the position sensor 80 stored in the storage unit 56. The measurement results of 50 and 60 are corrected. That is, the measurement results of the first and second thickness sensors 50 and 60 are shifted in the width direction by a considerable amount when the position of the belt-like substrate 10 is shifted with respect to the scanning mechanisms 52 and 62. The belt-like substrate 10 may be displaced with respect to the roller 30, and such an event occurs. In this embodiment, the position sensor 80 always detects the position of the end 14 in the width direction of the belt-like substrate 10. The correction unit 86 always uses the position of the end 14 in the width direction of the strip-shaped substrate 10 detected by the position sensor 80 as a reference, and the film for the strip-shaped substrate 10 obtained by the first and second thickness sensors 50, 60. The measurement result of the thickness distribution (the position of the coating film 12 with respect to the belt-shaped substrate, the width of the coating film 12, the thickness of the coating film 12) is corrected.

  Thereby, even if the belt-like substrate 10 is displaced with respect to the roller 30, the displacement can be detected by the position sensor 80. And the measurement result of the film thickness distribution of the strip | belt-shaped base material 10 obtained with the thickness sensors 50 and 60 can always be correct | amended on the basis of the width direction edge part 14 of the strip | belt-shaped base material 10. FIG. Thereby, the film thickness distribution (the position of the coating film 12, the width of the coating film 12, the thickness of the coating film 12) with respect to the band-shaped substrate 10 is accurately determined with reference to the width direction end portion 14 of the band-shaped substrate 10. Can be measured. For this reason, for example, even when the position of the belt-like substrate 10 is shifted with respect to the roller 30 due to a phenomenon such as meandering, the film thickness distribution in the width direction can be measured without being affected by the influence. That is, in the film thickness measuring apparatus 100 of this embodiment, the film thickness distribution of the coating film 12 can be accurately measured without being affected by air entrainment or meandering.

  In addition, the thickness distribution of the coating film 12 that the coating unit 40 forms on the belt-like substrate 10 is controlled by feeding back the corrected film thickness distribution data thus obtained to the coating unit 40. be able to. For example, based on the film thickness distribution obtained by the first and second thickness sensors 50, 60, the position of the coating film, the width of the coating film, and the thickness of the coating film formed on the belt-shaped substrate by the coating unit 40 are determined. A control unit (not shown) for controlling each can be provided. Data on the film thickness distribution of the coating film 12 obtained by the first and second thickness sensors 50 and 60 is sent to the control unit. The control unit appropriately operates the actuator 48 (see FIG. 2) of the coating unit 40 based on the data on the film thickness distribution of the coating film 12, and the coating film 12 formed on the belt-like substrate 10 is applied. The position and orientation of each die 42 are controlled so that the position of the film 12, the width of the coating film 12, and the thickness of the coating film 12 are formed with high accuracy. In the film thickness measuring apparatus 100 of this embodiment, the film thickness distribution of the coating film 12 can be accurately measured by eliminating the influence of air entrainment and meandering. Therefore, the position of the coating film 12, the width of the coating film 12, and the thickness of the coating film 12 are accurately formed with respect to the belt-like substrate 10 by feeding back the data of the film thickness distribution to the coating unit 40. Can do.

  The film thickness measuring apparatus 100 described above can be applied to a process of forming a coating film of an electrode active material on a strip electrode, which is a constituent element of a wound electrode body of a battery such as a lithium ion secondary battery. At this time, the film thickness distribution of the coating film 12 formed on the belt-shaped substrate can be measured with high accuracy by using the above-described film thickness measuring apparatus.

  For example, as shown in FIG. 8, three rows of coating films 12 are formed at a predetermined interval in the length direction on one strip-shaped base material 10, and the central portion of the coating film 12 and a space between the coating films 12 are formed. Each is formed with a slit (the position where the slit is formed is indicated by a chain line in FIG. 8). And the strip | belt-shaped base material 10 is cut | disconnected by the said slit, and six strip | belt-shaped electrodes are manufactured, respectively. In such a case, according to the film thickness measuring apparatus described above, the film thickness distribution of the coating film 12 formed on the belt-like substrate 10 can be measured with high accuracy. Further, by feeding back the obtained film thickness distribution data to the coating portion, the position of the coating film 12, the width of the coating film 12, and the thickness of the coating film 12 are accurately formed with respect to the belt-like substrate 10. The yield can be improved only by appropriately providing a cutting margin for forming the slits A to E. As a result, waste can be reduced, material costs, material usage efficiency, etc. can be improved very efficiently, and product costs can be reduced.

  As shown in FIG. 8, when forming a plurality of rows of coating films 12 in the length direction of the strip-shaped substrate 10 from the coating portion 40, the first thickness sensor 50 and the second thickness sensor 60 are arranged in a plurality of rows. It is desirable that a plurality of coating films 12 are provided corresponding to each of the coating films 12. For example, in the example of FIG. 3, the first and second thickness sensors 50 and 60 are arranged in a number corresponding to the three rows of the coating films 12 (three units). In this case, since the film thicknesses of the three rows of the coating films 12 can be measured in parallel, the measurement time can be shortened compared to the case where the film thicknesses of the three rows of the coating films are measured using a single thickness sensor. That is, when measuring the film thickness distribution of the coating film 12 in three rows using a single thickness sensor, it is necessary to move the sensor over the entire width of the belt-like substrate 10, so The time will be longer. On the other hand, in the configuration of FIG. 3, the film thicknesses of the three rows of coating films 12 can be simultaneously measured in parallel, so that the measurement cycle time can be shortened. Thereby, the number of measurement samples per roll of the belt-shaped substrate can be increased, and more accurate measurement can be performed. Note that the zigzag line drawn on the base material 10 in FIG. 3 represents the scanning locus of the second thickness sensor 60.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible.

DESCRIPTION OF SYMBOLS 10 Belt-like base material 10a Base material surface 12 Coating film 12a Coating film surface 14 Width direction edge part 16 of strip-like base material 30 Coating film 30 formed on the back surface of the strip-like base material Coating unit 42 Die 44 Coating liquid 46 Coating liquid supply unit 48 Actuator 50 First thickness sensor 52 Scanning mechanism 54 Calculation unit 56 Storage unit 60 Second thickness sensor 62 Scanning mechanism 70 Air layer 80 Position sensor 82 Light projecting unit 84 Light receiving unit 86 Correction unit 90 Substrate transport direction 100 Film thickness measuring device

Claims (10)

A film thickness measuring device that measures the film thickness of a coating film formed by applying a coating liquid in the length direction of the belt-shaped substrate,
A roller for conveying the belt-like substrate in the length direction of the substrate;
A coating unit that forms a coating film in the length direction of the substrate by supplying a coating liquid to the belt-shaped substrate conveyed on the roller;
The upstream side of the coating unit with respect to the transport direction of the base material, and the downstream side of the position where the base material is first wound around the roller, the outer surface of the roller A first thickness sensor that measures a thickness X1 up to the surface of the substrate;
The downstream side of the coating unit with respect to the transport direction of the base material and the upstream side of the position where the base material is separated from the roller, the outer surface of the roller A second thickness sensor for measuring the thickness X2 to the surface,
It is comprised so that the film thickness of the said coating film formed in the said strip | belt-shaped base material can be calculated from the difference of the thickness X1 measured with the said 1st thickness sensor, and the thickness X2 measured with the said 2nd thickness sensor. A film thickness measuring device. The coating part is configured so as to be able to form a plurality of rows of coating films in the width direction of the belt-shaped substrate,
2. The film thickness measuring device according to claim 1, wherein a plurality of the first thickness sensors and the second thickness sensors are provided corresponding to each of the plurality of rows of coating films.   The said 2nd thickness sensor is comprised so that the thickness of the same location as the measurement location measured with the said 1st thickness sensor among the strip | belt-shaped base materials conveyed on the said roller can be measured. Or the film thickness measuring apparatus of 2.   The first thickness sensor and the second thickness sensor are scanned in the width direction of the band-shaped substrate, and the film thickness distribution of the coating film formed on the band-shaped substrate is measured along the width direction of the band-shaped substrate. The film thickness measuring device according to any one of claims 1 to 3, wherein the film thickness measuring device is configured to be able to measure. A position sensor for detecting the position of the end in the width direction of the belt-shaped substrate conveyed by the roller;
The first thickness sensor and the second thickness sensor are arranged on the belt-like substrate along the width direction of the belt-like substrate with reference to the position of the widthwise end portion of the belt-like substrate detected by the position sensor. The film thickness measuring apparatus according to claim 4, configured to measure a film thickness distribution of the formed coating film. A film thickness measuring method for measuring the film thickness of a coating film formed in the length direction of the substrate by supplying a coating liquid from a coating portion to a belt-shaped substrate conveyed on a roller,
The base material from the outer surface of the roller at a position upstream of the coating portion with respect to the transport direction of the base material and downstream of the position where the base material is first wound around the roller. Measuring the thickness X1 up to the surface of the first thickness sensor;
From the outer surface of the roller to the surface of the coating film at a position downstream of the coating portion and upstream of the position where the substrate is separated from the roller with respect to the transport direction of the substrate. Measuring a thickness X2 of the second thickness sensor with a second thickness sensor; and
Calculating the film thickness of the coating film formed on the band-shaped substrate from the difference between the thickness X1 measured by the first thickness sensor and the thickness X2 measured by the second thickness sensor;
A method for measuring a film thickness. The coating part is configured so as to be able to form a plurality of rows of coating films in the width direction of the belt-shaped substrate,
The film thickness measuring method according to claim 6, wherein a plurality of the first thickness sensors and the second thickness sensors are provided corresponding to each of the plurality of rows of coating films.   The thickness measurement of Claim 6 or 7 which measures the thickness of the same location as the measurement location measured with the said 1st thickness sensor among the strip | belt-shaped base materials conveyed on the said roller with the said 2nd thickness sensor. Method.   The first thickness sensor and the second thickness sensor are scanned in the width direction of the band-shaped substrate, and the film thickness distribution of the coating film formed on the band-shaped substrate is measured along the width direction of the band-shaped substrate. The film thickness measuring method according to claim 6, wherein the film thickness is measured. Detecting the position of the end in the width direction of the belt-shaped substrate conveyed by the roller,
The film thickness distribution of the coating film formed on the band-shaped substrate is measured along the width direction of the band-shaped substrate with reference to the detected position of the end in the width direction of the band-shaped substrate. 10. The method for measuring a film thickness according to 9.

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