Sample analysis method and sample analyzer

Abstract

To analyze the internal state of a sample with high accuracy.SOLUTION: A load acting upon a cutting-edge in a direction X is measured while cutting a sample in the direction X in a first X-direction cutting step following a first Z-direction cutting step. The load acting upon the cutting-edge in the direction X is measured while cutting the sample in the direction X in a second X-direction cutting step following a second Z-direction cutting step. The first round of the second Z-direction cutting step involves cutting the sample to a position downward in the direction Z from the cutting position in the first X-direction cutting step. The second and subsequent rounds of the second Z-direction cutting step involves cutting the sample to a position downward in the direction Z from the cutting position of the second X-direction cutting step carried out immediately before. The internal state of the sample is analyzed on the basis of the load in the direction X measured in the first and second X-direction cutting steps.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a sample analysis method and a sample analysis apparatus for analyzing the internal state of a sample.

Background Art

[0002] In a lithium battery, when the component distribution inside the electrode becomes non-uniform, the performance deteriorates. Patent Document 1 discloses a method of analyzing the internal state of an electrode using a cutting device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, there has been a demand for analyzing the internal state of a sample with higher precision.

[0005] An object of the present invention is to provide a sample analysis method and a sample analysis apparatus capable of analyzing the internal state of a sample with high precision.

Means for Solving the Problems

[0006] In order to achieve the above object, a sample analysis method according to the present invention is a sample analysis method for analyzing the internal state of a sample using a cutting device. The cutting device includes a cutting edge, a sample stage for fixing the sample, and a drive unit for relatively moving the cutting edge and the sample stage. The cutting edge and the sample stage are relatively movable in the X direction and the Y direction parallel to the surface of the sample and perpendicular to each other, and in the Z direction perpendicular to the surface of the sample.

[0007] The sample analysis method according to the present invention includes a first Z-direction cutting step, a first X-direction cutting step, a second Z-direction cutting step, and a second X-direction cutting step. In the first Z-direction cutting step, the cutting edge is relatively moved downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage, thereby cutting the surface of the sample. In the first X-direction cutting step, following the first Z-direction cutting step, the cutting edge is relatively moved forward in the X direction with respect to the sample stage, thereby cutting the sample while measuring the load in the X direction applied to the cutting edge. In the second Z-direction cutting step, after the first X-direction cutting step, the cutting edge is relatively moved downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage, thereby cutting the sample. In the second X-direction cutting step, following the second Z-direction cutting step, the cutting edge is relatively moved forward in the X direction with respect to the sample stage, thereby cutting the sample while measuring the load in the X direction applied to the cutting edge.

[0008] The second Z-direction cutting step and the second X-direction cutting step are each performed at least once. The first second Z-direction cutting step cuts the sample to a position below the cutting position of the first X-direction cutting step in the Z direction. The second Z-direction cutting step and subsequent steps cut the sample to a position below the cutting position of the immediately preceding second X-direction cutting step in the Z direction.

[0009] The sample analysis method according to the present invention further includes an analysis step of analyzing the internal state of the sample based on the load in the X direction measured in the first X-direction cutting step and the second X-direction cutting step.

[0010] According to the sample analysis method according to the present invention described above, while moving the cutting edge in the X direction with respect to the sample in the first and second X-direction cutting steps and performing cutting, in order to measure the load in the X direction applied to the cutting edge, the load in the X direction at different depths (Z-direction positions) in the sample can be obtained with high precision. Therefore, using the measured value of the load in the X direction, the internal state of the sample can be analyzed three-dimensionally with high precision.

[0011] In the sample analysis method according to the present invention, in each of the first X-direction cutting step and the second X-direction cutting step, the cutting ranges in the X direction and the Y direction may include the same region. By doing so, using the measured value of the load in the X direction, the state of a specific three-dimensional region inside the sample can be analyzed with high precision.

[0012] In the sample analysis method according to the present invention, when the second Z-direction cutting step is performed once, the second Z-direction cutting step starts from the cutting surface of the first Z-direction cutting step or the first X-direction cutting step. When the second Z-direction cutting step is performed two or more times, the later second Z-direction cutting step may start from the cutting surface of the immediately preceding second Z-direction cutting step or the second X-direction cutting step. By doing so, compared with the case of starting cutting from the sample surface in each second Z-direction cutting step, the cutting distance is shortened, so that the time required for analysis can be significantly reduced.

[0013] In the sample analysis method according to the present invention, the analysis step may include a first analysis step of obtaining an average value of the load in the X direction measured in the same specific section in the X direction in the first X-direction cutting step and the second X-direction cutting step, and a second analysis step of analyzing the internal state of the sample by comparing the average values of the load in the X direction obtained in the first analysis step with each other. By doing so, using the average value of the load in the X direction at different depths (Z-direction positions) in the sample, the internal state of the sample can be analyzed with higher precision.

[0014] In the sample analysis method according to the present invention, the sample may be an electrode for a battery. By doing so, the internal state of the battery electrode can be analyzed three-dimensionally with high precision.

[0015] The sample analysis apparatus according to the present invention is a sample analysis apparatus for analyzing the internal state of a sample, and includes a cutting blade, a sample stage for fixing the sample, a driving unit for relatively moving the cutting blade and the sample stage, a control unit for controlling the driving of the driving means, and an analysis unit for analyzing the internal state of the sample. The cutting blade and the sample stage are relatively movable in the X direction and the Y direction parallel to the surface of the sample and perpendicular to each other, and in the Z direction perpendicular to the surface of the sample.

[0016] A first command, a second command, a third command, and a fourth command are programmed in the control unit. The first command causes the cutting blade to relatively move downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage, thereby performing a first Z-direction cutting step of cutting from the surface of the sample. The second command causes the cutting blade to relatively move forward in the X direction with respect to the sample stage following the first Z-direction cutting step, thereby performing a first X-direction cutting step of measuring the load in the X direction applied to the cutting blade while cutting the sample. The third command causes the cutting blade to relatively move downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage after the first X-direction cutting step, thereby performing at least one second Z-direction cutting step of cutting the sample. The fourth command causes the cutting blade to relatively move forward in the X direction with respect to the sample stage following the second Z-direction cutting step, thereby performing at least one second X-direction cutting step of measuring the load in the X direction applied to the cutting blade while cutting the sample.

[0017] The third command includes a command to cut the sample to a position below the cutting position in the Z direction from the cutting position in the first X-direction cutting step in the first second Z-direction cutting step, and to cut the sample to a position below the cutting position in the Z direction from the cutting position in the second X-direction cutting step immediately preceding in the second and subsequent second Z-direction cutting steps.

[0018] The analysis unit analyzes the internal state of the sample based on the load in the X direction measured in the first X-direction cutting step and the second X-direction cutting step.

[0019] According to the sample analysis apparatus according to the present invention described above, while moving the cutting edge in the X direction with respect to the sample and performing cutting in the first and second X-direction cutting steps, the load in the X direction applied to the cutting edge is measured. Therefore, the load in the X direction at different depths (Z-direction positions) in the sample can be obtained with high accuracy. Accordingly, using the measured values of the load in the X direction, the internal state of the sample can be analyzed three-dimensionally with high accuracy.

Effect of the Invention

[0020] According to the present invention, it is possible to provide a sample analysis method and a sample analysis apparatus capable of analyzing the internal state of a sample with high accuracy.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0022] (Embodiment) Hereinafter, a sample analysis method according to an embodiment and a sample analysis apparatus capable of implementing the sample analysis method will be described with reference to the drawings.

[0023] <Sample analysis apparatus> FIG. 1 is a cross-sectional configuration diagram of the sample analysis apparatus of the present embodiment, and FIG. 2 is a perspective view of a part of the sample analysis apparatus of the present embodiment.

[0024] As shown in FIGS. 1 and 2, the sample analysis apparatus 1 of the present embodiment includes a cutting blade 2, a sample stage 4 for fixing a sample 3, driving means 12, 18, 31 for relatively moving the cutting blade 2 and the sample stage 4, and a control unit 40 for controlling the driving of the driving means 12, 18, 31.

[0025] The cutting blade 2 and the sample stage 4 are relatively movable in the X direction and the Y direction parallel to the surface of the sample 3 and perpendicular to each other, and in the Z direction perpendicular to the surface of the sample 3. FIG. 3 is a diagram for explaining the relative movement direction of the cutting blade 2 with respect to the sample stage 4. In the present embodiment, with respect to the sample stage 4, the cutting blade 2 is relatively movable along the three-axis directions shown in FIG. 3, that is, in the X direction which is the cutting direction of the cutting blade 2, the Y direction perpendicular to the X direction (the width direction of the cutting blade 2), and the Z direction perpendicular to the surface of the sample 3. Incidentally, the forward and backward directions in the X direction are referred to as “+X direction” and “−X direction” respectively, and the downward and upward directions in the Z direction are referred to as “+Z direction” and “−Z direction” respectively.

[0026] The cutting blade 2 is supported by a cutting blade support portion 11 held by the main body portion 10. The cutting blade 2 can be moved in the X direction (the direction in which the cutting line extends) together with the main body portion 10 and the cutting blade support portion 11 by a driving means (X-direction movement motor) 12 provided on the opposite side of the cutting blade 2 across the main body portion 10. The X-direction movement motor 12 is provided on the main body support portion 30 via a support base 14. The main body portion 10 is provided on the X-direction guide shaft 17 on the main body support portion 30 with the X-direction sliding member 16 interposed therebetween so as to be movable in the X direction on the main body support portion 30. The X-direction movement motor 12 moves the main body portion 10 in the X direction together with the X-direction sliding member 16 through an X-direction threaded rod 13. An X-direction displacement meter 15 for measuring the X-direction displacement (X-direction movement distance) of the cutting blade 2 is provided on the X-direction guide shaft 17. As the X-direction displacement meter 15, for example, a laser displacement meter, a micrometer, etc. are used.

[0027] The cutting blade 2 can be moved in the Z direction (the direction perpendicular to the surface of the sample 3) together with the cutting blade support portion 11 by a driving means (Z-direction movement motor) 18 provided above the cutting blade support portion 11. The Z-direction movement motor 18 is supported by the main body portion 10 via a connecting portion 19. The Z-direction movement motor 18 moves a nut 21 provided on the side surface of the main body portion 10 in the Z direction through a Z-direction threaded rod 20, and the nut 21 moves the cutting blade 2 in the Z direction together with the cutting blade support portion 11. A Z-direction displacement meter 22 for measuring the Z-direction displacement of the nut 21, that is, the Z-direction displacement (Z-direction movement distance) of the cutting blade 2 is provided on the main body portion 10. As the Z-direction displacement meter 22, for example, a contact displacement meter such as a scale method, a micrometer, etc. are used. The nut 21 is provided on the Z-direction guide shaft 23 on the side surface of the main body portion 10 with the Z-direction sliding member 24 interposed therebetween so as to be movable in the Z direction on the side surface of the main body portion 10. A Z-direction pressure detector 25 for measuring the pressure (Z-direction pressure) applied in the Z direction from the cutting blade 2 to the sample 3 is provided on the cutting blade support portion 11.

[0028] The sample stage 4 is provided on the main body support portion 30 while sandwiching, in order from above, a sliding member 26 for X-direction pressure detection, a guide shaft 35 for X-direction pressure detection, an X-direction inclination adjustment means 36, a Y-direction inclination adjustment means 37, an XY-direction position adjustment member 38, a sliding member 27 for Y-direction, and a guide shaft 28 for Y-direction. Further, the sliding member 26 for X-direction pressure detection is a member for transmitting the load applied from the cutting edge 2 during cutting to the X-direction pressure detector 29, and slides along the guide shaft 35 for X-direction pressure detection according to the load applied from the cutting edge 2. The X-direction inclination adjustment means 36 is a member for rotating the sample fixing surface of the sample stage 4 in the X-direction (the rotation axis is along the Y-direction), and specifically, a micrometer can be used. The Y-direction inclination adjustment means 37 is a member for rotating the sample fixing surface of the sample stage 4 in the Y-direction (the rotation axis is along the X-direction), and specifically, a micrometer can be used. The XY-direction position adjustment member 38 is a member for manually moving the sample stage 4 and setting it at the cutting start position before the automatic cutting starts. The sample stage 4, together with the sliding member 26 for X-direction pressure detection, the guide shaft 35 for X-direction pressure detection, the X-direction inclination adjustment means 36, the Y-direction inclination adjustment means 37, and the XY-direction position adjustment member 38, is provided on the guide shaft 28 for Y-direction on the main body support portion 30 so as to be movable in the Y-direction on the main body support portion 30 while sandwiching the sliding member 27 for Y-direction. On the guide shaft 35 for X-direction pressure detection, an X-direction pressure detector 29 for measuring the pressure (X-direction pressure) applied in the X-direction from the cutting edge 2 to the sample 3 is provided.

[0029] The sample stage 4 is movable in the Y-direction by a drive means (Y-direction movement motor) 31 disposed on one side in the Y-direction of the sliding member 27 for Y-direction. The Y-direction movement motor 31 moves the sample stage 4 in the Y-direction together with the sliding member 27 for Y-direction through a Y-direction threaded rod 32.

[0030] In the sample analyzer 1 of the present embodiment, the driving of the X-direction movement motor 12, the Z-direction movement motor 18, and the Y-direction movement motor 31 is automatically controlled by a control unit 40 including a computer such as a personal computer. The control unit 40 reads information detected by the X-direction displacement meter 15, the X-direction pressure detector 29, the Z-direction displacement meter 22, and the Z-direction pressure detector 25 through the input interface 41, and based on the information, controls the driving of the X-direction movement motor 12 and the Z-direction movement motor 18 through the first output interface 42 and controls the driving of the Y-direction movement motor 31 through the second output interface 43.

[0031] For the Y-direction displacement (Y-direction movement distance) of the cutting blade 2, the control unit 40 may use the movement distance of the drive command to the Y-direction movement motor 31, or alternatively, a Y-direction displacement meter for measuring the Y-direction movement distance may be provided and the information detected by the displacement meter may be used. Also, for the X-direction displacement (X-direction movement distance) of the cutting blade 2, instead of the information detected by the X-direction displacement meter 15, the control unit 40 may use the movement distance of the drive command to the X-direction movement motor 12, and for the Z-direction displacement (Z-direction movement distance) of the cutting blade 2, instead of the information detected by the Z-direction displacement meter 22, the control unit 40 may use the movement distance of the drive command to the Z-direction movement motor 18. However, when cutting the sample 3, since there may be a displacement in the movement distance due to the reaction force received by the cutting blade 2 from the sample 3, etc., in order to cut the sample 3 accurately, for the X-direction movement distance and the Z-direction movement distance, it is better to perform the cutting while precisely monitoring the actual movement distance with a displacement meter.

[0032] In the control unit 40, each function is implemented by a computer executing a program. The computer includes, as main hardware components, a processor that operates according to the program, a memory that stores data necessary for the execution of the program, and the like. The type of the processor is not limited as long as it can realize functions by executing the program. For example, it may be composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or LSI (large scale integration). The program and data are recorded on a non-transitory recording medium such as a ROM readable by the computer, an optical disk, or a hard disk drive. The program and data may be stored in advance in the recording medium, or may be supplied to the recording medium via a wide area communication network including the Internet or the like.

[0033] In the control unit 40, a first command, a second command, a third command, and a fourth command are programmed. The first command causes the cutting blade 2 to perform a first Z-direction cutting process of cutting from the surface of the sample 3 by relatively moving the cutting blade 2 downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage 4. The second command causes the cutting blade 2 to perform a first X-direction cutting process of measuring the X-direction load applied to the cutting blade 2 while cutting the sample 3 by relatively moving the cutting blade 2 forward in the X direction with respect to the sample stage 4 following the first Z-direction cutting process. The third command causes the cutting blade 2 to perform at least one second Z-direction cutting process of cutting the sample 3 by relatively moving the cutting blade 2 downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage 4 after the first X-direction cutting process. The fourth command causes the cutting blade 2 to perform at least one second X-direction cutting process of measuring the X-direction load applied to the cutting blade 2 while cutting the sample 3 by relatively moving the cutting blade 2 forward in the X direction with respect to the sample stage 4 following the second Z-direction cutting process.

[0034] Further, the third command includes a command to cut the sample 3 to a position below the cutting position in the Z direction than the cutting position in the first X-direction cutting process in the first second Z-direction cutting process, and to cut the sample 3 to a position below the cutting position in the Z direction than the cutting position in the second X-direction cutting process immediately preceding in the second and subsequent second Z-direction cutting processes.

[0035] The sample analyzer 1 of the present embodiment analyzes the internal state of the sample 3. Specifically, in the sample analyzer 1 shown in FIGS. 1 and 2, the control unit 40 includes an analysis unit that analyzes the internal state of the sample 3 based on the load in the X direction measured in the first and second X-direction cutting processes. However, the present invention is not limited to this, and the analysis unit may be provided separately from the control unit 40. For example, the analysis unit may be configured by another computer connected to the control unit 40 via a network. The sample analyzer 1 excluding the analysis unit is a cutting device that cuts the sample 3.

[0036] Also, in the sample analyzer 1 shown in FIGS. 1 and 2, as drive means for relatively moving the cutting edge 2 and the sample stage 4, an X-direction moving motor 12 that moves the cutting edge 2 in the X direction, a Z-direction moving motor 18 that moves the cutting edge 2 in the Z direction, and a Y-direction moving motor 31 that moves the sample stage 4 in the Y direction are used. However, as long as the cutting edge 2 and the sample stage 4 are relatively movable in at least three axial directions of the X direction, the Y direction, and the Z direction, either the cutting edge 2 or the sample stage 4 may move.

[0037] <Sample analysis method> Hereinafter, the sample analysis method of the present embodiment using the sample analyzer 1 shown in FIGS. 1 and 2 will be described.

[0038] In the sample analysis method of this embodiment, first, a step (A) of fixing the sample 3 on the sample stage 4 is performed. For example, the sample stage 4 is composed of a box-shaped body having a sample suction part (suction hole) on the upper surface on which the sample 3 is placed, and a suction pipe (not shown) is connected to the side part of the box-shaped body, and the suction pipe may be connected to a vacuum pump (not shown). Thus, by operating the vacuum pump, the sample 3 can be suctioned downward on the sample stage 4, and the sample 3 can be fixed to the sample stage 4. Instead of such a fixing method, the sample 3 may be fixed on the sample stage 4 by a chemical fixing method using an adhesive, hot melt, etc., or a physical fixing method using bolts, etc. However, in terms of fixing accuracy and ease of operation, the above-described suction fixing is preferable.

[0039] Next, a step (B) of measuring the inclination of the surface of the sample 3 is performed. Step (B) can be implemented as an inclination measuring means using, for example, a stylus that contacts the surface of the sample 3 and a Z-direction displacement meter 22 and a Z-direction pressure detector 25 in the sample analyzer 1. Specifically, a stylus is attached to the cutting edge support part 11 instead of the cutting edge 2, and while the stylus is in contact with the sample 3, the stylus is moved while applying a constant load using the Z-direction pressure detector 25, and the displacement of the stylus is continuously detected using the Z-direction displacement meter 22. Thus, since the height information of the surface of the sample 3 can be obtained, the inclination of the surface of the sample 3 can be measured. Also, at a plurality of locations on the surface of the sample 3, the stylus may be pressed against the surface of the sample 3 to a certain height position using the Z-direction displacement meter 22, and the load received by the stylus at that time may be detected by the Z-direction pressure detector 25. Thus, since the loads received at a certain height position can be compared at a plurality of points, the inclination of the surface of the sample 3 can be measured.

[0040] When measuring the inclination, it is preferable to move the pressure element in at least two directions, i.e., the X direction and the Y direction, to perform the inclination measurement. To further improve the inclination measurement accuracy, it is more preferable to move the pressure element in three directions, i.e., the X direction, the Y direction, and the diagonal direction (for example, the direction intersecting the X direction at 45°), to perform the inclination measurement. The tip shape of the pressure element used for the inclination measurement preferably has a curved surface so as not to damage the sample 3 when it comes into contact with the sample 3. To further improve the inclination measurement accuracy, the tip shape of the pressure element is more preferably spherical.

[0041] Next, a step (C) of adjusting the inclination of the surface of the sample 3 is performed. For example, an X-direction inclination adjustment means 36 (a micrometer for rotating the sample fixing surface of the sample stage 4 in the X direction, with the rotation axis along the Y direction) and a Y-direction inclination adjustment means 37 (a micrometer for rotating the sample fixing surface of the sample stage 4 in the Y direction, with the rotation axis along the X direction) are used to adjust the angle of the sample 3. Alternatively, instead of the micrometer, an inclination adjustment means such as an actuator may be used. After performing the step (C), the inclination measurement of the step (B) may be performed again to confirm that the surface of the sample 3 has approached horizontal.

[0042] After performing the above steps (A), (B), and (C), a cutting operation (the first Z-direction cutting step, the first X-direction cutting step, the second Z-direction cutting step, and the second X-direction cutting step) by the cutting edge 2 of the sample analyzer 1 (cutting device) is started. When starting the cutting operation, the operator may preset various cutting conditions such as the number of cutting times in the control unit 40 so that the cutting operation is automatically performed.

[0043] As the cutting conditions, the range of the three-dimensional region to be analyzed in the sample 3 may be set, for example, to 5 μm to 1000 μm in the Z direction and 500 μm to 20000 μm in the X direction. In the Y direction, it may be set to 0.05 mm to 4.0 mm according to the width of the cutting edge 2.

[0044] As the conditions for the first and second Z-direction cutting processes, for example, the +Z-direction cutting distance may be set to 1 μm to 100 μm, and the +Z-direction cutting speed may be set to 0.1 μm / s to 50 μm / s. Since the +Z-direction cutting distance is the difference between the measurement depth of the previous X-direction load and the measurement depth of the subsequent X-direction load, when the +Z-direction cutting distance is reduced, the analysis accuracy increases, while when the +Z-direction cutting distance is increased, the measurement time is shortened. Therefore, the +Z-direction cutting distance may be set considering the balance between the two. The +Z-direction cutting distance may be different in each Z-direction cutting process. For example, after initially cutting with a large +Z-direction cutting distance, the +Z-direction cutting distance may be reduced to finely analyze a predetermined Z-direction range. Also, when cutting in the +Z direction and +X direction in the first and second Z-direction cutting processes, for example, the +X-direction cutting distance may be set to 500 μm to 20,000 μm, and the +X-direction cutting speed may be set to 1 μm / s to 1000 μm / s.

[0045] As the conditions for the first and second X-direction cutting processes, for example, the +X-direction cutting distance may be set to 500 μm to 20,000 μm, and the +X-direction cutting speed may be set to 1 μm / s to 1000 μm / s. Here, according to the setting of the +X-direction cutting distance in the first and second X-direction cutting processes, the X-direction setting of the "range of the three-dimensional region to be analyzed in Sample 3" described above is performed.

[0046] The load cell used for measuring the X-direction load applied to the cutting edge 2 in the first and second X-direction cutting processes may be selected according to the load (horizontal load Fh) to be measured. For example, if the horizontal load Fh is 0.1 N or less, a load cell with a rated capacity of 5 N may be selected; if the horizontal load Fh is more than 0.1 N and less than 20 N, a load cell with a rated capacity of 20 N may be selected; if the horizontal load Fh is 20 N or more, a load cell with a rated capacity of 100 N may be selected. Since the smaller the rated capacity of the load cell, the better the resolution, for normal sample analysis, a load cell with a rated capacity of 20 N may be selected; for the analysis of electrodes of lithium-ion batteries, etc., a load cell with a rated capacity of 5 N may be selected; for the analysis of metals, a load cell with a rated capacity of 100 N may be selected.

[0047] [First Z-direction cutting process] In the first Z-direction cutting process, the control unit 40 drives the X-direction movement motor 12 and the Z-direction movement motor 18 to move the cutting edge 2 in the +Z direction (downward in the Z direction) or in the +Z direction and the +X direction (forward in the X direction), thereby starting cutting from the surface of the sample 3.

[0048] Specifically, when the sample stage 4 on which the sample 3 is fixed is set at the cutting start position, the cutting edge 2 and the sample 3 are separated in the Z direction. First, the control unit 40 drives the Z-direction movement motor 18 to move the cutting edge 2 downward in the Z direction and bring the cutting edge 2 into contact with the cutting start position on the surface of the sample 3. This contact operation may be performed manually by providing, for example, a mechanism for arbitrarily moving the cutting edge 2 in the Z direction. Also, for the contact confirmation between the sample 3 and the cutting edge 2, for example, the contact between the sample 3 and the cutting edge 2 may be confirmed using a Z-direction pressure detector 25, or the distance between the sample 3 and the cutting edge 2 may be visually confirmed by the operator while photographing the sample 3 and the cutting edge 2 with a video camera or the like and enlarging and displaying it on a personal computer or the like.

[0049] Subsequently, the control unit 40 drives the X-direction movement motor 12 and the Z-direction movement motor 18 to move the cutting edge 2 in the +Z direction (or in the +Z direction and the +X direction) until the cutting edge 2 reaches the set position (+Z-direction cutting distance and +X-direction cutting distance). At this time, the X-direction pressure detector 29 and the Z-direction pressure detector 25 may be used to detect the X-direction pressure and the Z-direction pressure of the cutting edge 2. By doing so, since the cutting situation can be monitored, it is possible to know whether there is a variation from the set value of the cutting operation due to the influence caused by the hardness of the sample 3 or the like. If an unacceptable variation occurs, the cutting operation may be interrupted and steps (B) and (C) may be performed again.

[0050] [First X-direction Cutting Process] Following the first Z-direction cutting process, in the first X-direction cutting process, the control unit 40 drives only the X-direction movement motor 12 to move the cutting edge 2 in the +X direction until the cutting edge 2 reaches the set position (+X-direction cutting distance), thereby measuring the X-direction load applied to the cutting edge 2 while cutting the sample 3. For measuring the X-direction load, an X-direction pressure detector 29 may be used. At this time, the cutting operation is performed without displacing the cutting edge 2 in the Z direction, but due to the inclination of the surface of the sample 3, the movement accuracy of the cutting edge 2, etc., a Z-direction inclination within ±2°, preferably within ±1° with respect to the X direction in the cutting direction is allowed. Note that in the first X-direction cutting process, it is not necessary to cut to the +X-direction end of the sample 3.

[0051] In this embodiment, after the first X-direction cutting process, the control unit 40 may drive the Z-direction movement motor 18 to move the cutting edge 2 in the -Z direction (upward in the Z direction). By doing so, when the first X-direction cutting process is completed and the cutting edge 2 is moved in the -X direction (backward in the X direction) to the start position of the second Z-direction cutting process described later, it is possible to prevent the cutting edge 2 from contacting the cut surface of the sample 3 formed in the first X-direction cutting process. At this time, the control unit 40 may drive the X-direction movement motor 12 together with the Z-direction movement motor 18 to move the cutting edge 2 in the -Z direction and the +X direction, thereby separating a section from the sample 3.

[0052] Subsequently, the control unit 40 drives the X-direction movement motor 12 to move the cutting edge 2 in the -X direction until the cutting edge 2 returns to the start position of the second Z-direction cutting process. Here, in order to shorten the cutting time, the return speed of the cutting edge 2 in the -X direction may be made larger than the movement speed (+X-direction cutting speed) of the cutting edge 2 in the first X-direction cutting process. Also, when returning the cutting edge 2 to the start position of the second Z-direction cutting process, the return movement speed may be reduced immediately before the start position, that is, immediately before the stop position of the cutting edge 2. By doing so, it is possible to prevent displacement of the position of the cutting edge 2 that occurs when suddenly stopping from the state where the cutting edge 2 is moved in the -X direction at high speed.

[0053] [Second Z-direction cutting process] In the second Z-direction cutting process, the control unit 40 drives the X-direction movement motor 12 and the Z-direction movement motor 18 to move the cutting edge 2 in the +Z direction, or in the +Z direction and the +X direction until the cutting edge 2 reaches the set position (+Z-direction cutting distance and +X-direction cutting distance), thereby cutting the sample 3. At this time, the X-direction pressure detector 29 and the Z-direction pressure detector 25 may be used to detect the X-direction pressure and the Z-direction pressure of the cutting edge 2. By doing so, since the cutting situation can be monitored, it is possible to know whether there is a variation from the set value of the cutting operation due to the influence caused by the hardness of the sample 3 or the like. If an unacceptable variation occurs, the cutting operation may be interrupted and steps (B) and (C) may be performed again.

[0054] In addition, when the cutting edge 2 and the sample 3 are separated in the Z direction at the start of the second Z-direction cutting process, the control unit 40 needs to drive the Z-direction movement motor 18 to move the cutting edge 2 in the +Z direction to bring the cutting edge 2 into contact with the sample 3. This contact operation may be performed manually by providing, for example, a mechanism for arbitrarily moving the cutting edge 2 in the Z direction. Also, for the contact confirmation between the sample 3 and the cutting edge 2, for example, the contact between the sample 3 and the cutting edge 2 may be confirmed using the Z-direction pressure detector 25, or the distance between the sample 3 and the cutting edge 2 may be visually confirmed by the operator while photographing the sample 3 and the cutting edge 2 with a video camera or the like and magnifying and displaying it on a personal computer or the like.

[0055] [Second X-direction cutting process] Following the second Z-direction cutting process, in the second X-direction cutting process, the control unit 40 drives only the X-direction movement motor 12 to move the cutting edge 2 in the +X direction until the cutting edge 2 reaches the set position (+X-direction cutting distance), thereby cutting the sample 3 while measuring the X-direction load applied to the cutting edge 2. The X-direction pressure detector 29 may be used for the X-direction load measurement. At this time, the cutting operation is performed without displacing the cutting edge 2 in the Z direction, but due to the inclination of the surface of the sample 3 or the movement accuracy of the cutting edge 2, etc., a Z-direction inclination within ±2°, preferably within ±1° with respect to the X direction of the cutting direction is allowed. In addition, in the second X-direction cutting process, it is not necessary to cut to the +X-direction end of the sample 3.

[0056] In this embodiment, after the second X-direction cutting process, the control unit 40 may drive the Z-direction moving motor 18 to move the cutting edge 2 in the -Z direction (upward in the Z direction). By doing so, when the second X-direction cutting process is completed and the cutting edge 2 is moved in the -X direction to the start position of the next second Z-direction cutting process, it is possible to prevent the cutting edge 2 from contacting the cutting surface of the sample 3 formed in the second X-direction cutting process. At this time, the control unit 40 may drive the X-direction moving motor 12 together with the Z-direction moving motor 18 to move the cutting edge 2 in the -Z direction and the +X direction, thereby separating the slice from the sample 3.

[0057] Subsequently, the control unit 40 drives the X-direction moving motor 12 to move the cutting edge 2 in the -X direction until the cutting edge 2 returns to the start position of the next second Z-direction cutting process. Here, in order to shorten the cutting time, the return speed of the cutting edge 2 in the -X direction may be made larger than the moving speed of the cutting edge 2 in the +X direction (cutting speed in the +X direction) in the second X-direction cutting process. Also, when returning the cutting edge 2 to the start position of the next second Z-direction cutting process, the return speed may be decreased immediately before the start position, that is, immediately before the stop position of the cutting edge 2. By doing so, it is possible to prevent the displacement of the cutting edge 2 that occurs when the cutting edge 2 is suddenly stopped from a state where it is moved in the -X direction at high speed.

[0058] The combined process of the second Z-direction cutting process and the second X-direction cutting process is performed one or more times. The number of times of performing the second Z-direction cutting process and the second X-direction cutting process is set according to the type of the sample 3. For example, in the case of an electrode for a battery, it may be performed 2 to 3 times.

[0059] When the second Z-direction cutting process is performed once, the second Z-direction cutting process starts from the cutting surface of the first Z-direction cutting process or the first X-direction cutting process. When the second Z-direction cutting process is performed two or more times, the subsequently performed second Z-direction cutting process may start from the cutting surface of the immediately preceding second Z-direction cutting process or the second X-direction cutting process. In other words, the first second Z-direction cutting process starts from the cutting surface of the first Z-direction cutting process or the first X-direction cutting process, and the second and subsequent second Z-direction cutting processes start from the cutting surface of the immediately preceding second Z-direction cutting process or the second X-direction cutting process. By doing so, compared with the case of starting cutting from the sample surface in each second Z-direction cutting process, the cutting distance is shortened, so that the time required for analysis can be significantly reduced. Note that the cutting surfaces of the first and second Z-direction cutting processes are cutting surfaces (inclined surfaces) formed when the cutting blade 2 is moved in the +Z direction and the +X direction to cut the sample 3 in the first and second Z-direction cutting processes.

[0060] In each of the first X-direction cutting process and the second X-direction cutting process, the cutting ranges in the X direction and the Y direction may include the same region. By doing so, the state of a specific three-dimensional region inside the sample 3 can be analyzed with high accuracy using the X-direction load measurement value.

[0061] [Analysis process] After the cutting operations (the first Z-direction cutting process, the first X-direction cutting process, the second Z-direction cutting process, and the second X-direction cutting process) of the cutting blade 2 of the sample analyzer 1 (cutting device) are completed, an analysis process is performed to analyze the internal state of the sample 3 based on the X-direction loads measured in the first and second X-direction cutting processes. By comparing the X-direction loads (horizontal loads) applied to the cutting blade 2 at different depths (Z-direction positions) in the sample 3, the uniformity inside the sample 3 can be evaluated, and the Z-direction layer state of the sample 3, such as the adhesion degree, can be evaluated based on the absolute value of the horizontal load. Therefore, for example, electrodes such as lithium-ion batteries and all-solid-state batteries, specifically, the analysis of the active material layer on the electrode becomes possible. Note that since the active material of the all-solid-state battery deteriorates due to moisture in the air, the load measurement is performed in an inert atmosphere such as a glove box.

[0062] The analysis process may include a first analysis process of obtaining the average value of the load in the X direction measured in the same specific section in the X direction in the first and second X-direction cutting processes, and a second analysis process of analyzing the internal state of sample 3 by comparing the average values of the load in the X direction obtained in the first analysis process with each other. The specific section may be set in advance before the start of cutting, or a range where the variation of the load in the X direction (horizontal load) is small may be set as the specific section after the end of load measurement. When setting the specific section after the end of load measurement, the specific section may be determined based on the result of plotting the horizontal load against the measurement time or the moving distance.

[0063] <Analysis Example> Hereinafter, an example of a sample analysis method using the sample analyzer 1 of the present embodiment will be described with reference to FIGS. 4 to 6.

[0064] As shown in FIG. 4, in this example, after performing the first Z-direction cutting process and the first X-direction cutting process, a combination of the second Z-direction cutting process and the second X-direction cutting process is performed three times. In FIG. 4, "the first time" represents the first Z-direction cutting process, "the second time" represents the first second Z-direction cutting process, "the third time" represents the second second Z-direction cutting process, and "the fourth time" represents the third second Z-direction cutting process. In the first and second Z-direction cutting processes, the cutting edge 2 is moved in the +Z direction by the same distance (depth of cut), and in the third second Z-direction cutting process, the cutting edge 2 reaches the final reach depth of the sample 3. The first second Z-direction cutting process starts from the cutting surface of the first X-direction cutting process, the second second Z-direction cutting process starts from the cutting surface of the first second X-direction cutting process, and the third second Z-direction cutting process starts from the cutting surface of the second second X-direction cutting process.

[0065] As shown in FIGS. 4 and 5, in this example, in the first and second X-direction cutting processes, the cutting ranges in the X direction and the Y direction include the same region (specific region) R.

[0066] FIG. 6 shows the load in the X direction (horizontal load Fh) measured in the sample analysis method shown in FIG. 4. In FIG. 6, "the first time" represents the change of the horizontal load Fh measured in the first X-direction cutting process with respect to the measurement time, "the second time" represents the change of the horizontal load Fh measured in the second X-direction cutting process of the first time with respect to the measurement time, "the third time" represents the change of the horizontal load Fh measured in the second X-direction cutting process of the second time with respect to the measurement time, and "the fourth time" represents the change of the horizontal load Fh measured in the second X-direction cutting process of the third time with respect to the measurement time.

[0067] In this example, based on the results shown in FIG. 6, a specific section R is set, the average values of the horizontal load Fh measured in the specific section R in the first and second X-direction cutting processes are obtained, and the internal state of sample 3 is analyzed by comparing these average values with each other.

[0068] <Features of the Embodiment> As described above, according to the sample analysis method of the present embodiment, while moving the cutting edge 2 in the X direction with respect to sample 3 in the first and second X-direction cutting processes to perform cutting, the load in the X direction applied to the cutting edge 2 is measured. Therefore, the load in the X direction at different depths (Z-direction positions) in sample 3 can be obtained with high precision. Accordingly, the internal state of sample 3 can be analyzed three-dimensionally and with high precision using the measured value of the load in the X direction.

[0069] In the sample analysis method of the present embodiment, in each of the first X-direction cutting process and the second X-direction cutting process, the cutting ranges in the X direction and the Y direction may include the same area. In this way, the state of a specific three-dimensional area inside sample 3 can be analyzed with high precision using the measured value of the load in the X direction.

[0070] In the sample analysis method of this embodiment, when the second Z-direction cutting process is performed once, the second Z-direction cutting process starts from the cutting surface of the first Z-direction cutting process or the first X-direction cutting process. When the second Z-direction cutting process is performed two or more times, the later second Z-direction cutting process may start from the cutting surface of the immediately preceding second Z-direction cutting process or the second X-direction cutting process. By doing so, compared with the case of starting cutting from the surface of the sample 3 in each second Z-direction cutting process, the cutting distance is shortened, so that the time required for analysis can be significantly reduced.

[0071] In the sample analysis method of this embodiment, the analysis process may include a first analysis process of obtaining the average value of the X-direction loads measured in the same specific section in the X-direction in the first X-direction cutting process and the second X-direction cutting process, and a second analysis process of analyzing the internal state of the sample 3 by comparing the average values of the X-direction loads obtained in the first analysis process with each other. By doing so, the internal state of the sample 3 can be analyzed with higher accuracy using the average values of the X-direction loads at different depths (Z-direction positions) in the sample 3.

[0072] In the sample analysis method of this embodiment, the sample 3 may be an electrode for a battery. By doing so, the internal state of the electrode for a battery can be analyzed three-dimensionally with high accuracy.

[0073] According to the sample analysis apparatus 1 of this embodiment, while moving the cutting blade 2 in the X-direction with respect to the sample 3 and performing cutting in the first and second X-direction cutting processes, the X-direction load applied to the cutting blade 2 is measured, so that the X-direction loads at different depths (Z-direction positions) in the sample 3 can be obtained with high accuracy. Therefore, using the measured values of the X-direction loads, the internal state of the sample 3 can be analyzed three-dimensionally with high accuracy.

[0074] (Other embodiments) Although the embodiments have been described above, it will be understood that various changes in form and detail can be made without departing from the spirit and scope of the claims. Also, the above embodiments may be combined or replaced as appropriate as long as the functions of the object of the present disclosure are not impaired. Further, the descriptions such as "first", "second",... described above are used to distinguish the phrases to which these descriptions are given, and do not limit even the number or order of the phrases.

Explanation of Reference Numerals

[0075] 1 Sample analyzer 2 Cutting blade 3 Sample 4 Sample stage 10 Main body part 11 Cutting blade support part 12 Driving means (X-direction movement motor) 13 X-direction screw rod 14 Support base 15 X-direction displacement gauge 16 X-direction sliding member 17 X-direction guide shaft 18 Driving means (Z-direction movement motor) 19 Connecting part 20 Z-direction screw rod 21 Nut 22 Z-direction displacement gauge 23 Z-direction guide shaft 24 Z-direction sliding member 25 Z-direction pressure detector 26 X-direction pressure detection sliding member 27 Y-direction sliding member 28 Y-direction guide shaft 29 X-direction pressure detector 30 Main body support part 31 Driving means (Y-direction movement motor) 32 Y-direction screw rod 35 X-direction pressure detection guide shaft 36 X-direction tilt adjustment means 37 Y-direction tilt adjustment means 38 XY-direction position adjustment member 40 Control part 41 Input Interface 42 First Output Interface 43 Second Output Interface

Claims

1. A sample analysis method for analyzing the internal state of a sample using a cutting device, wherein the cutting device includes a cutting edge, a sample stage for fixing the sample, and a driving unit for relatively moving the cutting edge and the sample stage, and the cutting edge and the sample stage are relatively movable in each of an X direction and a Y direction that are parallel to the surface of the sample and perpendicular to each other, and a Z direction that is perpendicular to the surface of the sample, the sample analysis method including a first Z-direction cutting step of cutting the sample from the surface of the sample by relatively moving the cutting edge downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage; a first X-direction cutting step of measuring a load in the X direction applied to the cutting edge while cutting the sample by relatively moving the cutting edge forward in the X direction with respect to the sample stage following the first Z-direction cutting step; a second Z-direction cutting step of cutting the sample by relatively moving the cutting edge downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage after the first X-direction cutting step; a second X-direction cutting step of measuring a load in the X direction applied to the cutting edge while cutting the sample by relatively moving the cutting edge forward in the X direction with respect to the sample stage following the second Z-direction cutting step, wherein the second Z-direction cutting step and the second X-direction cutting step are each performed at least once, the first second Z-direction cutting step cuts the sample to a position below the cutting position of the first X-direction cutting step in the Z direction, the second and subsequent second Z-direction cutting steps cut the sample to a position below the cutting position of the immediately preceding second X-direction cutting step in the Z direction, and the sample analysis method further includes an analysis step of analyzing the internal state of the sample based on the loads in the X direction measured in the first X-direction cutting step and the second X-direction cutting step, a sample analysis method.

2. In each of the first X-direction cutting step and the second X-direction cutting step, a cutting range in the X direction and the Y direction includes the same region, the sample analysis method according to Claim 1.

3. When the second Z-direction cutting process is performed once, the second Z-direction cutting process starts from the cutting surface of the first Z-direction cutting process or the first X-direction cutting process. When the second Z-direction cutting process is performed two or more times, the subsequent second Z-direction cutting process starts from the cutting surface of the immediately preceding second Z-direction cutting process or the second X-direction cutting process. The sample analysis method according to claim 1 or 2.

4. The analysis process includes: a first analysis process of obtaining an average value of the load in the X direction measured in the same specific section in the X direction in the first X-direction cutting process and the second X-direction cutting process; a second analysis process of analyzing the internal state of the sample by comparing the average values of the load in the X direction obtained in the first analysis process. The sample analysis method according to claim 1 or 2.

5. The sample is an electrode for a battery. The sample analysis method according to claim 1 or 2.

6. A sample analysis device for analyzing the internal state of a sample, comprising: a cutting edge; a sample stage for fixing the sample; a driving unit for relatively moving the cutting edge and the sample stage; a control unit for controlling the driving of the driving means; an analysis unit for analyzing the internal state of the sample. The cutting edge and the sample stage are relatively movable in the X direction and the Y direction parallel to the surface of the sample and perpendicular to each other, and in the Z direction perpendicular to the surface of the sample. To the control unit: a first command for causing the cutting edge to be relatively moved downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage to perform a first Z-direction cutting process of cutting the sample from the surface of the sample; a second command for, following the first Z-direction cutting process, causing the cutting edge to be relatively moved forward in the X direction with respect to the sample stage to perform a first X-direction cutting process of measuring the load in the X direction applied to the cutting edge while cutting the sample; a third command for, after the first X-direction cutting process, causing the cutting edge to be relatively moved downward in the Z direction or downward in the Z direction and forward in the X direction with respect to the sample stage to perform at least one second Z-direction cutting process of cutting the sample. Following the second Z-direction cutting step, by relatively moving the cutting edge forward in the X direction with respect to the sample stage, while cutting the sample, a fourth command for performing at least once a second X-direction cutting step of measuring the load in the X direction applied to the cutting edge is programmed, In the first second Z-direction cutting step, the third command includes a command to cut the sample to a position below the cutting position of the first X-direction cutting step in the Z direction, and in the second and subsequent second Z-direction cutting steps, to cut the sample to a position below the cutting position of the immediately preceding second X-direction cutting step in the Z direction. Based on the loads in the X direction measured in the first X-direction cutting step and the second X-direction cutting step, the analysis unit analyzes the internal state of the sample. Sample analysis apparatus.

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