JP3510940B2 - Cut surface inspection method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection of a deviation angle of a cut surface of a plate-shaped single crystal sample (for example, an AT cut plate of quartz) by X-ray diffraction measurement, and the sample according to the deviation angle. The present invention relates to a method and an apparatus for inspecting a cut surface for selecting.

[0002]

2. Description of the Related Art An AT cut plate made of quartz is specified so that a predetermined crystal lattice plane is inclined at a predetermined angle with respect to the cut plane. Explaining the “cut surface”, the outer surface of the cut plate cut into a plate shape is composed of a flat surface and a back surface (there is no distinction between front and back) and side edges connecting them, but And the back side is called "cut side". The tilt angle formed by the cut surface and the crystal lattice surface becomes important as a factor that determines the characteristics of the crystal unit.

In an actual cut plate, the above-mentioned value of the tilt angle slightly deviates from the reference tilt angle due to a cutting error. It is desired that this error be within the range of about 15 seconds. However, the accuracy of the cutting angle of the AT cut plate is usually only about 1 minute. Therefore, in order to obtain an AT-cut plate in which the variation of the deviation with respect to the reference tilt angle (hereinafter referred to as deviation angle) is set within 15 seconds, the deviation angle of the cut AT-cut plate is measured by X-ray diffraction measurement. It is necessary to select the AT cut plate by classifying the deviation angle in 15 second intervals after the inspection. By doing so, it is possible to obtain several groups of AT-cut plates whose variation in deviation angle is within the range of 15 seconds even if the precision of the cutting angle is poor. Each of these groups is effectively used according to the purpose.

As a conventional cut surface inspection device, an X-ray diffractometer is used to automatically inspect the deviation angle of an AT cut plate of quartz, and the deviation angle is automatically classified by a predetermined step width. There is one that selects AT cut boards. This type of cut surface inspection apparatus is described in Japanese Patent Laid-Open No. 4-252943.

The above-mentioned conventional cut surface inspection apparatus first measures the inclination angle of the crystal lattice plane with respect to the cut surface of the standard sample, and adopts this as the standard reference inclination angle. That is, the origin for measuring the tilt angle of the crystal lattice plane is determined by performing X-ray diffraction measurement on this standard sample. With respect to the sample to be measured, the deviation angle from this origin is measured, and the sample is classified according to the deviation angle.

[0006]

In the cut surface inspection apparatus, a large number of cut plates can be continuously and automatically inspected.
The continuous measurement may take a long time. For example, taking the case of continuously measuring 10,000 cut plates in one measurement lot, assuming that the processing speed is 1,000 sheets per hour, it takes 10 hours to complete the measurement of this lot.
It is known that when the X-ray diffraction measurement is performed for such a long time, an error with time in angle measurement occurs.
For example, when the ambient temperature of the X-ray diffraction measurement device changes, the degree of thermal expansion of the sine bar mechanism used as the drive mechanism of the goniometer changes and an angle measurement error occurs. Further, even if the position of the X-ray focal point moves due to a change in ambient temperature, an angle measurement error occurs. When such an angle measurement error occurs, the accuracy of the deviation angle measurement of the cut plate decreases, and the deviation angle is the same between the cut plate measured at the beginning of the measurement lot and the cut plate measured at the end. Even if it is selected as belonging to the classification range, the deviation angle may not be within the expected variation range.

The present invention has been made to solve the above-mentioned problems, and an object thereof is a method and apparatus for inspecting a cut surface in which the accuracy of selecting deviation angles does not deteriorate even when continuous measurement is performed for a long time. To provide.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a standard sample is placed in a standby state on a standard sample mounting table, a predetermined number of samples to be measured or a predetermined time is measured, and then the standard sample is used to measure a standard reference inclination angle. Is being remeasured. This gives X
Even if an angle measurement error occurs due to a change over time in the line diffraction measurement unit, this error can be corrected every predetermined time. Further, even if there is an error in the origin adjustment by the standard sample for some reason, the error can be recovered by adjusting the origin every predetermined time. Further, when the result of the origin adjustment for each predetermined time is considerably different from the origins so far, it is possible to automatically stop the subsequent measurement, assuming that some abnormality has occurred.

[0009]

1 is a plan view showing the construction of an embodiment of the cut surface inspection apparatus of the present invention. This cut surface inspection device is a device for inspecting and selecting the deviation angle of the cut surface of the AT cut plate of quartz. This apparatus is roughly divided into a sample alignment section 12 that aligns the samples 10, a sample supply robot 16 that supplies the sample to the sample stage 14, and an X-ray diffraction measurement section 18 that measures the deviation angle of the cut surface of the sample. Between the standard sample placing table 15 for waiting the standard sample, the sample selecting and storing section 22 for selecting and storing the sample according to the deviation angle, and the sample table 14, the standard sample placing table 15, and the sample selecting and storing section 22. And a sample transfer robot 24 for transferring the sample. Of these, the sample alignment unit 12 and the sample supply robot 16
And constitute a sample supply section, and the sample transport robot 24 and the sample selection storage section 22 constitute a sample discharge section. In addition,
The sample transport robot 24 constitutes a sample transfer unit for a functional part for transferring a sample between the sample table 14 and the standard sample mounting table 15, and the sample selection storage section 2 is connected to the sample table 14 from the sample table 14.
The functional portion for sorting and transporting the sample in 2 constitutes a part of the sample discharging part.

The sample aligning section 12 functions to align roughly square samples (AT cut plates) by utilizing vibration, and includes a loading tray 26, a circular vibrating bowl 28, and a linear aligning table 30. Has become. An optical attitude determination device that detects a sample that does not face a predetermined direction and removes it is provided in the middle of the alignment table 30.

FIG. 3 shows the configuration of the attitude determination device. First,
Explaining the shape of the sample 10, it has a square shape with one side of 10 mm and a thickness of 0.1 to 0.4 mm.
C1.5 chamfers 32 are formed at two adjacent apexes. The sample 10 is extruded from the vibrating bowl onto the alignment table with one sides of the squares in contact with each other. However, the direction in which the positions of the two chamfers 32 face is different. Therefore, there is a posture determination device in order to allow only the sample 32 having the correct posture to pass from the sample 10 having the different directions. The attitude determination device includes three pairs of photoelectric detection units, and three light emitting units 3
4a, 34b, 34c and three light receiving parts 36a, 36
b and 36c. The position of the chamfer 32 is detected based on the detection results of the three light receiving portions of these photoelectric detection units, and the quality of the posture of the sample 10 is determined. Figure 4
If the state of the sample 10 shown in is a correct posture,
At this time, the light receiving units 36a and 36b detect light, and the light receiving unit 36c does not detect light. If the detection result is any other combination, it means that the sample 10 is not in the correct posture. Also, if all the photodetectors detect light,
The sample 10 does not exist. When it is detected that the sample 10 is not in the correct posture, the sample 10 is removed from the alignment table by compressed air and is returned to the vibrating bowl.

Returning to FIG. 1, the sample supply robot 16 is
Samples at the tip of the alignment table 30 are supplied to the sample table 14 one by one. The sample supply robot 16 includes a rotatable horizontal arm 38. Below the tip of the arm 38 is a suction pad capable of sucking a sample by the action of vacuum suction. One side of the sample on the sample table 14 is pressed against the reference surface,
Accurately oriented.

The X-ray diffraction measuring unit 18 is a stationary X-ray tube 4.
0 and a stationary X-ray detector 42. Figure 4
(A) is a front view of an X-ray diffraction measurement unit. The X-rays 44 emitted from the X-ray tube 40 hit one cut surface (lower surface) of the sample 10 on the sample table 14. X-ray 46 diffracted here is X
It is detected by the line detector 42. The sample table 14 is formed with three protrusions 48 (which are well shown in FIG. 2).
The sample 10 rests on these protrusions 48. Sample table 14
A groove 50 (see FIG. 2) for ensuring passage of X-rays is provided in the center of the
See also) is formed. As shown in FIG. 4 (b),
An air hole 52 is opened in the sample table 14, and the air hole 5
2 is connected to a negative pressure source, and the sample 10 is held on the sample table 14 by the action of negative pressure.

FIG. 5 is an enlarged front view of the vicinity of the sample 10. The sample 10 shown in this figure is an AT cut plate of quartz, and the crystal lattice plane 54 of (0, 1, -1, 1) is 3 ° with respect to the cut plane 56 so that the crystal lattice plane 54 becomes left downward in the figure.
It is inclined. The incident X-ray 44 is incident on the cut surface 56 at an angle of 16 ° 20 '. At this time, the diffracted X-ray 46 is 26 ° 4 with respect to the incident X-ray 44.
Diffract at an angle of 0 ', and the X-ray detector 42 is arranged in this direction. The rotation center line 58 of the sample table is the cut surface 56.
It is aligned so that it is above it and extends perpendicular to the page. The sample stage and the sample 10 on it can be rotated about this rotation center line 58 in a minute angular range, and by finding the angular position of the sample stage when the detected X-ray intensity is maximum. The deviation angle of how much the crystal lattice plane 54 deviates from the predetermined reference tilt angle (3 °) can be obtained. When adjusting the origin of the X-ray diffraction measurement unit, a standard sample having a predetermined reference inclination angle is used, and the sample stage is rotated so that the diffracted X-ray from the standard sample can be detected. The position is the origin. Based on the tilt angle of this standard sample,
The error of the tilt angle of the measurement sample is measured, and this becomes the deviation angle.

Returning to FIG. 1, the sample transfer robot 24 is
Sample base 14, standard sample mounting base 15, and sample selection storage 22
The sample can be transferred between and. This sample transport robot 24
Has an arm 62 movable along the X movement guide 60. Below the tip of the arm 62 is a vacuum suction pad.

The sample sorting / accommodating section 22 is provided with nine sample inlets 64 and nine corresponding storage boxes 66. The input port 64 is connected to the corresponding storage box 66 via a dedicated shooter. The nine storage boxes correspond to nine types of classification ranges of the deviation angle of the cut surface.

In this embodiment, the above nine storage boxes are
The following Table 1 is set in 15 second increments according to the deviation angle of the cut surface of the sample.
It is classified as shown in.

[Table 1] First storage box-less than 52.5 seconds 2nd storage box-52.5 seconds or more-less than 37.5 seconds Third storage box −37.5 seconds or more −22.5 seconds or less 4th storage box -22.5 seconds or more-less than 7.5 seconds Fifth storage box -7.5 seconds or more +7.5 seconds or less 6th storage box +7.5 seconds or more +22.5 seconds or less 7th storage box +22.5 seconds or more +37.5 seconds or less Eighth storage box +37.5 seconds or more +52.5 seconds or less 9th storage box + 52.5 seconds or more

FIG. 2 is a perspective view showing the peripheral structure of the standard sample mounting table. The sample table 14 and the standard sample mounting table 15 are fixed on a base 68, and the base 68 is fixed to a goniometer 70. The goniometer 70 can rotate around a rotation center line 72. The standard sample mounting table 15 is arranged next to the sample table 14, and like the sample table 14, the standard sample can be adsorbed and supported on the three protrusions 49 by the action of negative pressure. The standard sample 11 is transferred between the sample table 14 and the standard sample mounting table 15 by the suction pad 74 of the sample transport robot 24.
Transported by.

Next, a method of using the standard sample mounting table 15 will be described. In order to start the measurement with this cut surface inspection apparatus, first, a standard sample is used to measure a diffracted X-ray from a predetermined crystal lattice plane, and the rotation angle of the goniometer at that time is set as the origin of the goniometer. That is, first, in FIG.
Place the standard sample 11 on the sample stand 14 of
By irradiating the cut surface (lower surface) of No. 1 with X-rays and rotating the goniometer 70, an angular position where diffracted X-rays can be detected is searched for. This angular position is the origin of the goniometer angle measurement. In practice, this standard sample is used to perform measurements a plurality of times and the average value is calculated to be the angle measurement origin.

As the standard sample 11, a sample which matches a predetermined reference inclination angle (for example, 3 °) as much as possible or an arbitrary sample is used. In the latter case,
The numerical value of the tilt angle of the crystal lattice plane itself has little meaning,
Ultimately, the main purpose is to obtain a group of cut plates in which the “variation” of the deviation angle is within a certain range.

As the first method for automatically supplying the standard sample 11 to the sample table 14, the standard sample 11 is held in advance on the standard sample mounting table 15, and the standard sample 11 is sampled using the suction pad 74. The method of transferring to the table 14 and FIG.
There is a method in which a standard sample is placed on the tip of the alignment table 30 and the standard sample is supplied to the sample table 14 using the sample supply robot 16, and either method may be adopted.
Alternatively, only at the very beginning, the operator may place the standard sample directly on the sample table 14.

In FIG. 2, when the origin of the goniometer is determined using the standard sample 11, the standard sample 11 is transferred to the standard sample mounting table 15 using the suction pad 74. Then, in the next step, the sample to be measured is sent to the sample table 14 by the sample supplying robot 16, so that the deviation angle from the standard reference inclination angle of the sample to be measured is successively measured. Meanwhile, the standard sample 11 is mounted on the standard sample mounting table 15
Waiting on

Next, an example of the overall operation of this cut surface inspection apparatus will be described. In FIG. 1, first, the standard sample mounting table 1
Put a standard sample on 5. When the cut surface inspection device is started, the suction pad at the tip of the arm 62 of the sample transport robot 24 picks up the standard sample from the standard sample mounting table 15 and mounts it on the sample table 14. Then, X-ray diffraction measurement is performed on the cut surface of the standard sample, and the rotation angle of the goniometer when the diffracted X-ray can be detected is used as the angle measurement origin. This established the standard reference tilt angle. Then, the sample transport robot 24 is used to transfer the standard sample from the sample base 14 to the standard sample mounting base 15.

Next, a large number of samples 10 are placed in the input tray 26 of the sample alignment section 12. The sample falls from the vibrating input tray 26 into the vibrating bowl 28, and is aligned along the outer circumference of the vibrating bowl 28 while rotating clockwise in response to the vibration of the vibrating bowl 28. The aligned samples are pushed out to the alignment table 30, but of these samples, those having an inappropriate posture are eliminated by the posture determination unit. The sample at the tip of the alignment table 30 is adsorbed on the adsorption pad of the arm 38 of the sample supply robot 16 and placed on the sample table 14. When the deviation angle of one cut surface (lower surface) of the sample is measured by the X-ray diffraction measurement unit 18, the sample is adsorbed by the adsorption pad of the arm 62 of the sample transport robot 24 and sent to the sample selection storage unit 22. . Then, the sample is dropped to the corresponding sample inlet 64 according to the measured deviation angle.

After the deviation angle measurement is performed on 1000 samples, the sample supply robot 16 suspends the sample supply to the sample stage 14 temporarily. Then, the sample transport robot 24 picks up the standard sample from the standard sample mounting table 15 and mounts it on the sample table 14. Then, the X-ray diffraction measurement is performed again on the cut surface of the standard sample, and the rotation angle of the goniometer when the diffracted X-ray is detected is set as a new angle measurement origin. As a result, even if an angle measurement error due to a change over time occurs, the angle measurement error is eliminated by setting a new angle measurement origin. Then, after transferring the standard sample from the sample table 14 to the standard sample mounting table 15 again, the measurement and selection of the deviation angle of the sample to be measured is restarted. In this way, every time 1000 samples are inspected, the angle measurement origin is readjusted using the same standard sample. It should be noted that the angle measurement origin may be readjusted every time a fixed time (for example, one hour) elapses regardless of the number of inspection sheets.

The present invention is not limited to the above embodiment, but the following modifications are possible. (1) When classifying the deviation angle of the sample, it is possible to classify by any angle step instead of the above 15 second step. (2) The posture determination device for the sample is not limited to the optical posture determination device shown in FIG. 3, and a posture determination method utilizing optical rotation, a posture determination method utilizing low-precision X-ray diffraction measurement, etc. Other means may be used. (3) The mechanism for transporting the sample is not limited to the suction pad as described above, and other transport means may be used. (4) The present invention is applicable not only to an AT cut plate of quartz but also to any cut plate in which a predetermined crystal lattice plane is inclined with respect to the cut surface.

[0027]

According to the present invention, the standard reference tilt angle is measured again using the standard sample after the measurement of the predetermined number of samples or the predetermined period of time. Even if an angular error occurs, this error can be corrected every predetermined time. Further, even if there is an error in the origin adjustment by the standard sample for some reason, the error can be recovered by adjusting the origin every predetermined time. Further, when the result of the origin adjustment for each predetermined time is considerably different from the origins so far, it is possible to automatically stop the subsequent measurement, assuming that some abnormality has occurred.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of an embodiment of a cut surface inspection apparatus of the present invention.

FIG. 2 is a perspective view showing a peripheral structure of a standard sample mounting table.

FIG. 3 is a perspective view of a main part of a posture determination device.

FIG. 4 is a front view of an X-ray diffraction measurement section and a front sectional view of a sample table.

FIG. 5 is an enlarged front view of the vicinity of the sample.

[Explanation of symbols]

10 samples 11 standard samples 12 Sample alignment section 14 sample table 15 Standard sample holder 16 Sample feeding robot 18 X-ray diffraction measurement section 22 Sample selection storage 24 Sample transfer robot 40 X-ray tube 42 X-ray detector 64 sample inlet 66 Storage Box

Claims (3)

(57) [Claims] 1. A cut surface inspection apparatus having the following configuration. (A) A sample supply unit that supplies a sample, which is cut into a plate shape so that a predetermined crystal lattice plane has a predetermined reference inclination angle with respect to the cut plane, in a predetermined direction to the sample stage. (B) By irradiating the sample with X-rays from an X-ray source and detecting the diffracted X-rays from the sample with an X-ray detector, the deviation angle from the reference inclination angle of the cut surface of the sample can be determined. X-ray diffraction measurement unit to measure. (C) A standard sample mounting table for holding the standard sample on standby. (D) A sample transfer section for transferring the standard sample between the sample table and the standard sample mounting table. (E) A sample discharging section for selecting a sample whose deviation angle has been measured according to the deviation angle. 2. The cut surface inspection apparatus according to claim 1, wherein the standard sample mounting table and the sample table are fixed to the same goniometer. 3. A cut surface inspection method comprising the following steps. (A) A step of aligning a standard sample cut in a plate shape so that a predetermined crystal lattice plane has a predetermined reference inclination angle with respect to the cut surface in a predetermined direction and supplying the sample to the sample stage. (B) The cut surface of the standard sample is irradiated with X-rays, and the diffracted X-rays from the cut surface are detected to measure the tilt angle of the crystal lattice plane with respect to the cut surface. Stage to be adopted as a standard inclination angle. (C) A step of picking up the standard sample from the sample table and transferring it to the standard sample mounting table. (D) A step of aligning a sample to be measured cut in a plate shape such that a predetermined crystal lattice plane has a predetermined reference inclination angle with respect to the cut surface in a predetermined direction and supplying the sample to the sample stage. (E) A step of irradiating the cut surface of the sample to be measured with X-rays and detecting diffracted X-rays from the cut surface to measure a deviation angle from the standard reference inclination angle of the cut surface. (F) A step of selecting the sample to be measured whose deviation angle is measured according to the deviation angle. (G) After the deviation angle of the sample to be measured is measured for a predetermined number of times or for a predetermined time, the standard sample placed on the standard sample mounting table is transferred to the sample table, and the crystal lattice of the cut surface of the standard sample is measured. Remeasure the tilt angle of the surface and use this tilt angle as the new standard reference tilt angle. (H) A step of repeating the steps (C) to (G).