JPH0626787B2 - Tilt detection method for cutting device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting the inclination of a workpiece (object to be cut) in a cutting device, for example, a crystal in a crystal cutting device for slicing a semiconductor single crystal ingot to cut a wafer. The present invention relates to a technique effectively applied to a horizontal tilt and vertical tilt detection device.

[Prior Art] As a cutting device for cutting a wafer from a crystal ingot,
There is a wire saw that reciprocates a wire coated with an abrasive and slices it. In the conventional wire saw, the correction of the inclination θ ₁ (hereinafter referred to as runout) in the left-right direction of the crystal fixed on the gonio table with respect to the horizontal plane is performed by applying a thin oil film such as paste to the end surface of the work (crystal body) 1. For example, as shown in FIG. 5 (A), the wire 2 is brought into contact with the end face, the trace of the wire remaining on the oil film is visually detected, and it is detected that the wire 2 is tilted. This is done by adjusting the gonio table so that the No. 2 uniformly contacts the entire oil film on the end face. Further, the inclination θ ₂ of the work 1 on the gonio table 3 in the front-back direction with respect to the horizontal plane (hereinafter,
As shown in FIG. 6, the probe 15a of the micrometer 15 is brought into contact with the end face of the work 1 and moved vertically as shown in FIG. 6, and the inclination θ ₂ is calculated from the movement amount l and the measured value δ of the micrometer. = Tan δ / l.

[Problems to be Solved by the Invention] In the above-described conventional inclination detection method, repetitive work is indispensable to obtain high accuracy, and skill of the operator is also required. Moreover, since the tilts in the left-right direction and the front-rear direction, that is, the shake and the tilt must be detected separately and by different methods, there is a problem that the work time required for detecting and correcting the tilt becomes long.

The present invention has been made in view of the problems as described above, and the purpose thereof is, in a cutting device for a rod-shaped work, it is possible to detect the deflection and tilt of the reference plane simultaneously and with high precision. An object of the present invention is to provide an inclination detection device that does not require it and can be performed in a short time.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a cutting wire in which two sets of photoelectric switches, each of which includes a light transmitter and a light receiver, are arranged so that their detection optical axes are parallel to each other. And a pair of micrometers are arranged such that an imaginary line connecting the probe tips is parallel to the plane including the two detection optical axes.

[Operation] According to the above-mentioned means, the pair of micrometer is moved in the vertical direction relative to the work to measure the position of the end face of the work, so that the shake and tilt of the end face can be simultaneously measured. This eliminates the need to separately measure runout and tilt as in the past, and eliminates the need to repeat the measurement, and also displays the tilt quantitatively on the display unit to accurately and quickly cut the object to be cut without skill. The above-described object of being able to detect the inclination of the reference plane can be achieved.

[Embodiment] FIGS. 1 to 3 show an embodiment of an inclination detecting device when the present invention is applied to a wire saw for cutting a semiconductor crystal ingot.

A mounting plate 12 is fixed to the tip of a horizontal support plate 11 that supports the entire tilt detection device so as to hang downward, and a photoelectric switch 13 including a light projector 13a and a light receiver 13b is provided on the back surface of the mounting plate 12. Two sets are provided. The two sets of photoelectric switches 13 have light-emitters and light-receivers 13a and 13b so that their detection optical axes are oriented in the vertical direction.
Are fixed by brackets 14, respectively.

Further, an opening 12a is formed in the center of the mounting plate 12, and a pair of electric micrometers 15 and 15 are mounted on the mounting plate 12 so as to be located in the opening 12a and to allow the detection probe 15a to project forward. It is installed. The detection signal of the micrometer 15 is supplied to the indicator 4 (see FIG. 4), and the moving amount of each probe is displayed in analog.

In the pair of electric micrometers 15 and 15, an imaginary line connecting the tips of the detection probes 15a and 15a is
The two sets of photoelectric switches 13 are positioned so as to be parallel to the surface including the detection optical axis.

On the other hand, as shown in FIG. 3, the support plate 11 that supports the detection device is fixed at its base end side to the linear movement stage 17 by an aruggle bracket 16, and the linear movement stage 17 is slidably mounted on the rotary stage 18. It is placed.
The rotary stage 18 is rotatably mounted on a magnet base 19 having an electromagnetic chuck.

The translation stage 17 can be moved in the extending direction of the support plate 11 by turning the adjustment knob 17a, and the rotary stage 18 can be adjusted in angle by grasping the fixed knob 18a and turning it around the vertical axis. Is configured.

Next, a method of correcting the position of the work in the wire saw to which the tilt detecting device 10 is applied will be described with reference to FIG.

First, using an appropriate calibration jig (not shown), position the line connecting the tips of the probes 15a, 15a of the electric micrometer so that they are parallel to the plane including the detection optical axes of the two photoelectric switches 13. Do. Then, the instruction of the indicator 4 of the micrometer at this time is set to "0". Then, the support plate 1 on which the detection device 10 is mounted
1 is set on the mounting base 9 of the wire saw.

Next, the cutting wire 2 is brought close to the detection device, and the position of the support plate 11 is adjusted by using the rotary stage 18 and the linear movement stage 17 so that the two photoelectric switches 13 detect the wire 2 at the same time. To do. In this case, the two lamps corresponding to the signal of the photoelectric switch 13 can be turned on, and the stage 1
It suffices to move 7 and 18 and fix the stage at a position where they are turned on at the same time. by this,
The line connecting the tips of the probes 15a of the pair of electric micrometers 15 is completely parallel to the cutting wire 2.

Therefore, one of the gonio table 3 and the linear movement stage 17 is moved to approach each other, and the probe 15a is brought into contact with the end surface of the work 1. Then, the deflection direction of the work is confirmed by the indication value of the indicator 4 at that time, and the deflection direction angle of the goniometer table 3 is adjusted so that the difference between the indication values of the two indicators 4 becomes zero.

Then, while the probe 15a is kept in contact with the end surface of the work 1, the goniometer table 3 is moved up and down, the tilt direction of the end surface is confirmed by looking at the indicator 4, and the difference between the indicated values of the two indicators 4 is continuous. Then, adjust the tilt of the gonio table in the direction of tilt so that it becomes zero.

According to the above method, since the shake and tilt of the work can be performed by one detection device, the tilt of the work can be corrected in a shorter time than the conventional method in which the shake and the tilt are detected and corrected by separate detection methods. Can be done. Further, in the detection device of the above-mentioned embodiment, since the degree of the shake of the work can be quantitatively displayed by the indicator, an oil film is formed on the end face of the work, and a cutting wire is brought into contact with the oil film to detect the shake as in the conventional method. Therefore, it is not necessary to require the skill of the operator or to perform the detection repeatedly to bring the shake close to zero. Therefore, the accuracy of correcting the inclination of the work is also improved.

Table 1 shows the experimental results of the correction error when the inclination of the work is corrected by applying the conventional method and the detection device of the above-mentioned embodiment to the work set on the wire saw. A wire having a diameter of 160 μm was used in the experiment.

From Table 1, it can be seen that the use of the detection apparatus of the present embodiment significantly improves the error in the deflection direction of the work, as compared with the conventional method.

In the above embodiment, the tilt detecting device is configured by combining the photoelectric switch and the electric micrometer, but a sensor such as a displacement gauge or a roughness meter is used instead of the electric micrometer, and the photoelectric switch is combined with the sensor. Alternatively, the tilt detection device may be configured.

Further, in the embodiment, the measured value of the electric micrometer is analog-displayed by the indicator, but it goes without saying that it may be displayed by a digital display.

Further, in the above embodiment, the tilt of the work is detected by using two electric micrometers and moving them relatively, but the measurement may be performed using three electric micrometers. .

[Effects of the Invention] As described above, the present invention has a pair of photoelectric switches for detecting the position of the cutting blade at two points, a position sensor for measuring the reference surface of the object to be cut at two or more points, Display means for displaying the measured value by the position sensor is provided, and the line connecting the tips of the detectors of the position sensor is positioned so as to maintain a predetermined positional relationship with the surface including the two detection optical axes of the photoelectric switch. In a state where the position of the cutting blade is aligned with the surface including the two detection optical axes of the photoelectric switch, the end face of the object to be cut is brought into contact with the detector of the position sensor,
Since the tilt of the end surface of the workpiece is detected based on the signal measurement from the position sensor at that time, it is not necessary to separately measure the shake and tilt of the work, and it is not necessary to repeat the measurement and the display Since the inclination is quantitatively displayed, there is an effect that the inclination of the reference plane of the object to be cut can be detected accurately in a short time without requiring skill.

The present invention is not limited to a cutting device that uses a wire saw as a cutting blade, and can be applied to a band saw and a workpiece inclination detection device in a cutting device that uses a disk-shaped blade. Further, the work to be cut is not limited to the semiconductor crystal body, and can be applied to an apparatus for cutting by moving a cutting blade in parallel or at a predetermined angle with respect to a reference plane provided on the work.

[Brief description of drawings]

FIG. 1 is a perspective view of a back portion showing an embodiment of a work inclination detecting apparatus according to the present invention, FIG. 2 is a perspective view of the inclination detecting apparatus seen from the front side, and FIG. FIG. 4 is a front view showing a method of attaching to a cutting device, FIG. 4 is a perspective view for explaining a tilt detecting method using a work tilt detecting device according to the present invention, and FIGS. 5 (A) and 5 (B) are conventional. FIGS. 6 (A) and 6 (B) are plan views showing a method for detecting the shake of a work by the conventional method, and FIGS. 1 ... Object to be cut (workpiece), 2 ... Cutting blade (wire),
10 ... Tilt detection device, 13 ... Photoelectric switch, 15 ...
... distance sensor (electrical micrometer), 15a ... detector (probe).

Claims (1)

[Claims] 1. A pair of photoelectric switches for detecting the position of a cutting blade at two points, a position sensor having two or more detectors for measuring a reference surface of an object to be cut at two or more points, Providing display means for displaying the measured value by the position sensor,
With the line connecting the tips of the detectors of the position sensor positioned so as to maintain a predetermined positional relationship with the surface including the two detection optical axes of the photoelectric switch, the two detection optical axes of the photoelectric switch are After aligning the position of the cutting blade with the surface containing, the end surface of the object to be cut is brought into contact with the detector of the position sensor, and the end surface of the object to be cut based on the measurement signal from the position sensor at that time. A tilt detecting method in a cutting device, wherein the tilt is detected.