JP3584273B2 - Film thickness measurement method - Google Patents

Description

[0001]
【Technical field】
The present invention relates to a film thickness measuring and monitoring apparatus capable of measuring the thickness of a film on a coated sheet formed by laminating a film on the surface of a foil-like substrate, such as a sheet electrode for a battery. About.
[0002]
[Prior art]
For example, a sheet electrode for a battery is formed as a cover sheet in which a film made of an active material is laminated on a surface of a foil-shaped base material made of a metal. In the case of a covering sheet such as a battery sheet, various properties are affected by the thickness of the laminated film, and it is important to accurately measure and monitor the thickness.
[0003]
2. Description of the Related Art Conventionally, various types of devices for measuring the film thickness of a coating sheet, such as a device that measures offline, a device that measures online, a contact type, and a non-contact type, have been proposed.
[0004]
[Problem to be solved]
However, the conventional film thickness measurement monitor has the following problems, and it is difficult to accurately and efficiently measure the film thickness of the coated sheet.
For example, Japanese Patent No. 2628516 discloses a contact-type thickness measuring device that measures the thickness of a film-shaped resin sheet off-line. This measuring device has problems in that when the base material is a thin metal foil, it cannot be held and the thickness cannot be measured, and in that it cannot be continuously measured online.
[0005]
Japanese Patent Publication No. 8-30647 proposes an apparatus for measuring the thickness of a film-shaped resin sheet online by using both laser and eddy current. This device is excellent in that it can measure the thickness in a non-contact state, but cannot measure it when the substrate is metal.
[0006]
It is also conceivable to measure the film thickness by optical means using the light receiving distance characteristics of the optical fiber probe. However, when the color of the film is not constant, accurate measurement is difficult, so that it cannot be used, for example, for measuring the thickness of the active material of the battery sheet electrode.
There is also a method of measuring a specific interval by using the directivity of a semiconductor laser beam. However, in addition to the above-described problem of being affected by the color, shape, gloss, and the like of the film, there is a problem that the size of the apparatus is increased. However, there is also a problem that it is difficult to go online if the vibration and the ambient atmosphere temperature are not sufficiently controlled.
[0007]
The present invention has been made in view of the problems of the conventional apparatus, and can measure and monitor the film thickness of the coated sheet accurately and efficiently regardless of the types of the substrate and the film. An object of the present invention is to provide a method for measuring a film thickness.
[0008]
[Means for solving the problem]
The present invention relates to a coated sheet having a coated portion formed by laminating a film made of an active material for a battery electrode on the surface of a metal foil as a sheet-shaped substrate , and a blank portion where the substrate is exposed. A coating thickness measuring method for measuring the thickness of the coating in the above,
A cylindrical reference roll having a roll surface for contacting the back surface of the covering sheet;
A covering portion measuring device for measuring the thickness of the covering portion in the covering sheet in contact with the reference roll, a margin measuring device for measuring the thickness of the margin portion,
A calculating unit for calculating the thickness of the film based on the measured values of the covering portion measuring device and the margin measuring device,
Each of the covering portion measuring device and the blank portion measuring device measures a shaft portion provided so as to be able to advance and retreat in a direction perpendicular to the roll surface of the reference roll and a displacement of the shaft portion in the advance and retreat direction. a displacement detector for a device comprising a and contact terminals spherical rotatably provided on the tip of the shaft portion used,
The contact terminals in the covering portion measuring device is brought into contact with the covering portion sandwiching the covering portion between the reference roll to measure its thickness A, whereas, the contact in the blank portion measuring device The terminal is brought into contact with the margin, the margin is sandwiched between the reference roll and the thickness B is measured, and the thickness C of the film is calculated by (AB) in the arithmetic unit. per to calculate and obtain,
The covering sheet is advanced along the reference roll, and the contact terminals of the covering section measuring instrument are reciprocated in the width direction within the range of the covering section, and the trajectory of the contact terminals in the covering section measuring instrument is determined. A method for measuring a film thickness characterized by forming a zigzag shape .
[0009]
It is most remarkable in the present invention that the above-mentioned apparatus is characterized in that both the covering portion measuring device and the blank portion measuring device are provided with shafts provided so as to be able to advance and retreat in a direction perpendicular to the roll surface of the reference roll. Part, a displacement detection part for measuring the displacement of the shaft part in the retreating direction, and a spherical contact terminal rotatably provided at the tip of the shaft part . In obtaining the thickness C, the covering sheet is advanced along the reference roll, and the contact terminals of the covering section measuring device are reciprocated in the width direction within the range of the covering section. Is to make the locus of the contact terminal in zigzag .
[0010]
As the reference roll, a cylindrical roll having almost no shaft runout is used. The interior can be hollow.
The shaft runout refers to a position change amount of an arbitrary point when the reference roll is rotated around the reference axis, and is preferably 3/1000 mm or less. When the shaft runout exceeding 3/1000 mm occurs in the reference roll, there is a problem that the reference point at the time of thickness measurement becomes unstable, and accurate thickness measurement cannot be performed.
[0011]
Further, the reference roll has a welding structure in order to have a hollow structure or the like. Therefore, it is mounted on an unbalance measuring / correcting machine (balancing machine), and adjustment is performed by adding mass in a light direction. The unbalance value in this case is preferably 20 g or less. If it exceeds 20 g, there is a problem that it causes vibration and noise.
[0012]
In the above reference roll, the cylindricity defined as the deviation of the cylindrical portion from the geometrical cylindrical surface and the circularity defined as the deviation of the circular portion from the geometric circle are: In any case, it is preferable that the thickness be 3/1000 mm or less. Even when these values exceed 3/1000 mm, there is a problem that the thickness measurement reference point becomes unstable and accurate thickness measurement cannot be performed.
[0013]
Further, it is preferable that the surface of the reference roll is subjected to, for example, hard chrome plating to improve hardness (abrasion resistance). Thereby, the stability of the reference point of the thickness measurement can be further improved.
[0014]
In addition, the contact area of the covering sheet with the reference roll needs to be in close contact, so it is preferable to increase the contact area. In particular, when viewed from the cross section of the reference roll, it is preferable that both are brought into contact with each other at a half or more (center angle of 180 ° (degree) or more) of the arc. Thereby, the air caught between the reference roll and the covering sheet can be reduced, and the thickness measurement accuracy can be improved.
Further, it is preferable to provide a tension control device for applying tension to the covering sheet before and after the reference roll. As the tension control device, for example, there is a dancer roll (see the embodiment).
[0015]
As described above, the covering portion measuring device and the blank portion measuring device have the shaft portion, the displacement detecting portion, and the spherical contact terminal rotatably provided at the tip of the shaft portion. The shaft portion is provided so as to be able to advance and retreat in a direction perpendicular to the roll surface of the reference roll, that is, in a radial direction of a circular cross section of the reference roll.
[0016]
Further, the displacement of the shaft portion in the forward / backward direction is detected by the displacement detecting section. The configuration of the displacement detection unit can be various configurations such as a configuration using a differential transformer, a mechanical configuration, and the like.
Further, the displacement detection units are all electrically connected to the calculation unit.
[0017]
The spherical contact terminal is rotatably provided at the tip of the shaft. As a method of holding the contact terminal, for example, there is a method of holding the contact terminal rotatably in an arbitrary direction like a ball at the tip of a ballpoint pen of a writing utensil. When only one rotation direction of the contact terminal is required, a rotation shaft that can obtain a desired rotation direction can be provided and held on the rotation shaft.
[0018]
In addition, it is possible to adopt a configuration in which one of the covering portion measuring devices is moved left and right to measure while changing the measuring position in the width direction. Alternatively, a plurality of covering portion measuring devices may be used, arranged side by side, and the thickness at each position may be measured. In any case, the thickness of the coating can be measured not only at one point but also in a wide range, and variation in the film thickness in the width direction can be obtained.
[0019]
Next, the operation of the present invention will be described.
The film thickness measuring and monitoring device of the present example measures the thickness of the covering portion and the margin portion of the covering sheet in a contact state by using the covering portion measuring device and the margin measuring device. In this measurement, for example, by setting the state in which the contact terminal is brought into contact with the reference roll in advance as a zero (0) point, the displacement amount when the measured portion is clamped is directly used as the thickness A or B. can do.
Therefore, the thickness measurement by the above-mentioned covering portion measuring device and margin measuring device can be easily and accurately performed irrespective of the material, color, etc. of the substrate and the film of the covering sheet as the object to be measured.
[0020]
Further, a spherical contact terminal rotatably provided at the tip of each of the measuring instruments is provided. Therefore, the covering sheet with which the contact terminals have been brought into contact can be moved. That is, it is possible to continuously measure and monitor the thickness A of the covering portion and the thickness B of the margin portion continuously online while advancing the covering sheet in contact with the reference roll sequentially according to the rotation of the reference roll. it can.
[0021]
In addition, point contact can be realized and traversed left and right while the covering sheet is running, so that the contact point can be constantly changed. Therefore, it is possible to prevent wear powder such as a soft active material from adhering to a specific portion. Therefore, the influence of abrasion powder such as an active material constituting the covering sheet or the like can be reduced, and the measurement accuracy can be improved.
[0022]
Also, the thickness C of the film can be calculated by the arithmetic unit using the thickness data A and B to calculate AB, so that even if there is unevenness in thickness in the length direction of the material. The thickness of the coating can be determined very easily and accurately.
[0023]
As described above, according to the present invention, it is possible to provide a film thickness measurement monitor device that can measure the film thickness of a coated sheet accurately and efficiently without being largely influenced by the types of the substrate and the film. it can.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
A film thickness measurement monitoring device according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 6A, the coating thickness measuring and monitoring device 1 of the present embodiment includes a coating portion 820 formed by laminating an active material as a coating 82 on the surface of a metal foil as a sheet-like base material 81. This is an apparatus for measuring the thickness C of the coating 82 in the battery sheet electrode as the covering sheet 8 having the blank portion 810 where the base material 81 is exposed. In addition, as shown in FIG. 6B, the cover portions 820 may be provided on both surfaces of the base material 81 in some cases.
[0025]
As shown in FIG. 1, the coating thickness measurement monitor device 1 includes a cylindrical reference roll 2 for bringing the back surface of the covering sheet 8 into contact with the roll surface 20, and a covering portion of the covering sheet 8 contacting the reference roll 2. Based on the measured values of the covering portion measuring device 3 for measuring the thickness of the margin 820, the margin measuring device 4 for measuring the thickness of the margin 810, and the covering portion measuring device 3 and the margin measuring device 4. And a calculation unit 5 for calculating the thickness of the film.
[0026]
As shown in FIGS. 1 and 3, each of the covering portion measuring device 3 and the blank portion measuring device 4 includes a shaft portion 31 provided so as to be able to advance and retreat in a direction perpendicular to the roll surface 20 of the reference roll 2. It has a displacement detector 32 for measuring the displacement of the shaft 31 in the above-mentioned forward and backward directions, and a spherical contact terminal 33 rotatably provided at the tip of the shaft 31.
[0027]
As shown in FIG. 1, the covering portion measuring device 3 makes the contact terminal 33 contact the covering portion 820, clamps the covering portion 820 between the reference roll 2, and measures the thickness A thereof. On the other hand, the margin measuring device 4 makes the contact terminal 33 abut on the margin 810, clamps the margin 810 with the reference roll 2, and measures the thickness B thereof. The thickness C of the film 82 is calculated by calculating (AB) in the calculation unit 5.
[0028]
The details are described below.
As shown in FIGS. 1 and 2, the film thickness measuring and monitoring device 1 of this example is a device incorporated in a sheet electrode production line as a covering sheet 8, and a dancer roll 191 is provided on the entrance side of the reference roll 2. Is provided with a fixing roll 192 on the output side, and the film thickness of the covering sheet 8 sent along these is measured. That is, as shown in FIG. 2, the covering sheet 8 first contacts the dancer roll 191 and changes its direction to the upper reference roll 2, and further changes its direction along the reference roll 2 to lower the fixed roll. The direction is changed along 192 to be sent to the next step.
[0029]
The dancer roll 191 is provided to move up and down in order to keep the tension applied to the covering sheet 8 constant.
The three rolls 2, 191, 192 were arranged such that the contact state of the covering sheet 8 with the reference roll 2 was in an arc of about 180 ° at the central angle α of the reference roll cross section.
[0030]
As shown in FIG. 1, the reference roll 2 has a roll surface 20 wider than the entire width of the covering sheet 8, and has a support neck 21 at both ends. The roll surface 20 is hard chrome-plated to a thickness of about 50 μm and finished with high hardness. The reference roll 2 is hollow and has a shaft runout of 3/1000 mm or less, an unbalance value of 20 g or less, and a cylindricity and a roundness of 3/1000 mm or less.
[0031]
As shown in FIG. 1, the reference roll 2 is rotatably supported via bearings 13 in bearings 12 provided on a pair of left and right housings 11. A measuring device support member 15 is provided above the housing 11 via a bracket 14. The measuring device support member 15 is provided with the covering portion measuring device 3 and the margin measuring device 4.
[0032]
As shown in FIG. 1, the margin measuring device 4 is fixed at a position where it contacts the margin 810 of the covering sheet 8. Further, the covering portion measuring device 3 is movably fixed to the measuring device support member 15 via the moving device 16 so as to be able to move left and right on the covering portion 820 of the covering portion measuring device 8.
Further, as shown in FIGS. 1 and 2, the covering portion measuring device 3 and the blank portion measuring device 4 have their shaft portions 31 arranged perpendicular to the roll surface 20 of the reference roll 2 as described above.
[0033]
Next, the structures of the covering portion measuring device 3 and the blank portion measuring device 4 will be described with reference to FIGS.
The covering portion measuring device 3 has a substantially spherical housing 30, and the shaft portion 31 is held by bearings 35 and 36 provided above and below the housing 30 so as to be vertically movable. The shaft portion 31 is provided with a guide pin 319 for stabilizing the vertical movement thereof, and this is engaged with a guide groove 309 provided in the housing 30.
[0034]
The shaft portion 31 and the housing 30 have spring engaging portions 318 and 308, respectively, and a spring 307 for urging the shaft portion 31 downward is provided between these. The spring 307 affects the contact force (contact load) of the covering portion measuring device 3 and the margin measuring device 4 on the covering portion 820 and the margin portion 810. In this example, the contact force of the covering part measuring device 3 was set to be 1 N or less, and the contact force of the margin measuring device 4 was set to about 5 N.
[0035]
In the vicinity of the center of the housing 30, a displacement detecting section (core section) 32 for measuring the displacement of the shaft section 31 in the reciprocating direction (vertical direction) is provided.
As shown in FIGS. 4 and 5, the displacement detection unit 32 includes an iron core 322 fixed to the shaft 31 via a support member 321 having a U-shaped cross section so as to surround the shaft 31 and the housing 30. It comprises a fixed coil portion 323.
[0036]
The core 322 is finished by covering the core with glass. The coil section 323 is composed of a primary coil for excitation connected to an AC power supply and two secondary coils arranged so as to sandwich the primary coil, and the whole is covered with glass and finished.
The displacement detection unit 32 is configured to measure a displacement amount as a digital output from a voltage change detected from the secondary coil by a relative movement of the iron core 322 and the coil 323. This measurement principle is based on the application of a differential transformer.
[0037]
Further, as shown in FIG. 3, the spherical contact terminal 33 provided at the tip of the shaft portion 31 is rotatably held by a tip support 335 having a structure like a tip of a ballpoint pen. The contact terminal 33 is fixed by screwing the screw portion 336 of the tip support 335 into the tip hole 316 of the shaft portion 31.
The spherical contact terminal 33 used had a diameter of 2 mm with chrome plating applied to the surface of a steel material. This can be changed to a ceramic material of high hardness such as alumina from the point of abrasion resistance.
[0038]
In addition, as shown in FIG. 1, the covering portion measuring device 3 and the blank portion measuring device 4 are electrically connected to the calculating portion 5. The arithmetic unit 5 has a built-in AD converter, is configured to convert analog data into digital data, calculate the film thickness C by the above (A-B), and display this on the monitor 55. ing.
[0039]
The covering sheet 8 of this example is a sheet electrode for a battery as described above, and includes a base material 81 made of aluminum or copper metal foil having a thickness of 0.01 to 0.03 mm and a width of 150 to 600 mm; An active material comprising positive and negative electrodes having a thickness of about 0.05 to 0.2 mm and a width of 130 to 580 mm provided on the surface. The margins are provided on both left and right sides, each having a width of 10 mm. This coating sheet 8 forms the coating 82 by applying a paste-like active material to a base material 81 and drying it in a previous step of the coating thickness measurement monitoring device 1.
[0040]
Next, when actually measuring the film thickness of the coating sheet 8 using the film thickness measurement monitor device 1, as shown in FIGS. The contact terminal 33 of the covering portion measuring device 3 is brought into contact with the covering portion 820 to sandwich the covering portion 820 between the reference roll 2 and the contact portion of the margin measuring device 4 with respect to the margin portion 810. The margin portion 810 is sandwiched between the reference roll 2 and the reference roll 2.
[0041]
Then, the covering sheet 8 is advanced at a constant speed along the reference roll 2 and the covering portion measuring device 3 is reciprocated in the width direction within the range of the covering portion 820. Accordingly, the trajectory 88 of the contact terminal 33 of the covering portion measuring device 3 has a zigzag shape, and the thickness of the covering portion 820 can be measured over a wide range in the width direction.
The coating thickness A and the margin thickness B measured by the coating measuring device 3 and the blank measuring device 4 are sequentially transmitted to the calculating portion 5 as described above, and the calculation of (A−B) is performed. Thereby, the thickness C of the film 82 can be continuously measured.
[0042]
As described above, the film thickness measuring and monitoring device 1 of the present embodiment measures the above thicknesses A and B in a contact state using the covering portion measuring device 3 and the margin measuring device 4, and uses this to measure the film thickness. The thickness C can be obtained by calculation. Therefore, it is possible to easily and accurately measure and monitor the thickness of the coating regardless of the base material of the coating sheet and the material and color of the coating. Therefore, even if the covering sheet 8 is a sheet electrode for a battery of any material as in this example, the thickness of the film 82 made of the active material can be accurately measured.
[0043]
Further, the contact terminals 33 of the covering portion measuring device 3 and the margin measuring device 4 are spherical bodies rotatably provided as described above. Therefore, the covering portion measuring device 3 and the blank portion measuring device 4 can be relatively moved while being in contact with the covering sheet 8, and the thickness measurement monitor can be continuously performed online.
[0044]
Further, in this example, the thickness measurement monitor can be performed while reciprocating the covering portion measuring device 3 right and left. Therefore, the variation in the film thickness in the width direction can be measured, and the accuracy of the film thickness management can be improved.
[0045]
Therefore, according to the present embodiment, there is provided a film thickness measuring and monitoring apparatus 1 which can measure the film thickness of the covering sheet 8 accurately and efficiently without being largely influenced by the types of the base material 81 and the film 82. be able to.
[0046]
Embodiment 2
In this example, the film thickness measurement monitor device 1 of the first embodiment is provided with a film defect determination function.
That is, as shown in FIG. 7, a target value C ₀ , upper limit value CU, and lower limit value CL of the film thickness C are determined in advance. Then, when calculating the film thickness C, the calculation unit 5 determines whether the thickness C exceeds the upper limit value CU or the lower limit value CL, and if so, issues an alarm. It is configured in.
Others are the same as the first embodiment.
[0047]
In this case, it is possible to recognize that there is a defect in the film due to the large variation in the film thickness C, and it is possible to easily recognize defective products.
Otherwise, the same operation and effect as those of the first embodiment can be obtained.
[0048]
Embodiment 3
In this example, as shown in FIG. 8, a type in which three sets of covering portion measuring devices 301 to 303 are fixed at equal intervals in the width direction instead of the covering portion measuring device 3 which can move left and right in the first embodiment. Is a film thickness measurement monitor device. Each of the covering section measuring devices 301 to 303 is electrically connected to the arithmetic section 5. The coating measuring instrument 301 arranged on the left shows the thickness of the left coating, the coating measuring instrument 302 arranged in the center shows the thickness of the central coating, and the coating measuring instrument 303 arranged on the right shows the thickness of the right coating. It is configured to monitor each of the measurements. Others are the same as the first embodiment.
[0049]
In this case, since the film thickness at three points can be constantly measured and monitored, the thickness variation of the film can be measured more accurately.
FIG. 9 shows an example in which the film thickness C is displayed on the monitor 55. In the drawing, the film thicknesses on the left, center, and right sides are indicated by symbols L, C, and R, respectively. As can be seen from the figure, it is possible to constantly monitor the thickness of the coating at the three points in the coating portion 820.
Otherwise, the same operation and effect as those of the first embodiment can be obtained.
Further, the film thickness measurement monitor device may be attached to a coating machine or the like, and may be used for control of feeding back the measured value for adjusting the coating gap or the like.
[0050]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a film thickness measurement monitor device that can measure the film thickness of a coated sheet accurately and efficiently without being largely influenced by the types of the substrate and the film. it can.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of a film thickness measurement monitor device according to a first embodiment.
FIG. 2 is an explanatory view showing a roll arrangement of a film thickness measurement monitor device in the first embodiment.
FIG. 3 is an explanatory diagram showing a structure of a covering portion measuring device (margin portion measuring device) in the first embodiment.
FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, showing a displacement detection unit of the covering part measuring device in the first embodiment.
FIG. 5 is an explanatory diagram viewed from B in FIG. 4 illustrating a displacement detection unit of the covering unit measuring device in the first embodiment.
FIG. 6 is an explanatory diagram showing a configuration of a covering sheet according to the first embodiment.
FIG. 7 is an explanatory diagram showing a target value C0, an upper limit value CU, and a lower limit value CL of a film thickness C in a film defect determination function according to the second embodiment.
FIG. 8 is an explanatory diagram showing a configuration of a film thickness measurement monitor device according to a third embodiment.
FIG. 9 is an explanatory diagram showing a film thickness measurement monitor result chart in the third embodiment.
[Explanation of symbols]
1. . . Monitor for measuring film thickness,
2. . . Reference roll,
20. . . Roll surface,
3. . . Coating measuring instrument,
31. . . Shaft,
32. . . Displacement detector,
33. . . Contact terminal,
4. . . Margin measuring instrument,
5. . . Arithmetic unit,
8. . . Cover sheet,
81. . . Base material,
82. . . Film,
810. . . Margins,
820. . . Covering part,

Claims (1)

The above-mentioned coating in a coated sheet having a coating formed by laminating a coating made of an active material for a battery electrode on the surface of a metal foil as a sheet-shaped base, and a blank portion where the base is exposed. Film thickness measuring method for measuring the thickness of
A cylindrical reference roll having a roll surface for contacting the back surface of the covering sheet;
A covering portion measuring device for measuring the thickness of the covering portion of the covering sheet in contact with the reference roll, a margin measuring device for measuring the thickness of the margin portion,
A calculating unit for calculating the thickness of the film based on the measured values of the covering part measuring device and the margin measuring device,
Each of the covering portion measuring device and the blank portion measuring device is configured to measure a shaft portion provided so as to be able to advance and retreat in a direction perpendicular to the roll surface of the reference roll, and to measure a displacement of the shaft portion in the advance and retreat direction. a displacement detector for a device comprising a and contact terminals spherical rotatably provided on the tip of the shaft portion used,
The contact terminals in the covering portion measuring device is brought into contact with the covering portion sandwiching the covering portion between the reference roll to measure its thickness A, whereas, the contact in the blank portion measuring device The terminal is brought into contact with the margin, and the margin is sandwiched between the reference roll and the thickness B. The thickness B of the film is measured. per to calculate and obtain,
The covering sheet is advanced along the reference roll, and the contact terminal of the covering section measuring instrument is reciprocated in the width direction within the range of the covering section, and the trajectory of the contact terminal of the covering section measuring instrument is determined. A film thickness measuring method characterized by forming a zigzag shape .

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