JP3180579B2 - Method and apparatus for correcting cutting position of dicing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dicing apparatus,
In particular, the present invention relates to a cutting position correction method and apparatus for correcting displacement of a cutting position of a blade due to thermal expansion of a spindle or the like.

[0002]

2. Description of the Related Art A dicing apparatus cuts and feeds a wafer table on which a wafer is placed in an X direction, and feeds a wafer, which is mounted on a spindle and rotates at high speed, in a Y direction by a blade indexing device. The streets between the chips formed in a lattice on the surface are cut with a blade. In this cutting, it is required that the blade is properly positioned and cut along the street. However, the cutting position of the blade is displaced by about several μm to 10 μm due to thermal expansion of the spindle due to heat from the spindle motor or a temperature change in the cutting area. As a result, the cutting position of the blade in the Y direction is displaced from the normal cutting position, which causes a cutting defect.

For this reason, in the case of the conventional dicing apparatus, when checking whether or not the cutting position is displaced by using an alignment microscope provided integrally with the blade indexing apparatus, the wafer is cut by the blade. This was performed, and the deviation between the actual cutting line and the reference line of the microscope was observed, and the blade position was corrected by the deviation.

[0004]

However, in the case of the conventional dicing apparatus, there is a disadvantage that it is not known whether or not the cutting position of the blade has a displacement until the actual cutting is performed. Further, conventionally, there has been a disadvantage that the displacement cannot be automatically corrected because the displacement itself of the blade cannot be automatically measured.

The present invention has been made in view of such circumstances, and it is possible to detect the displacement of the cutting position without cutting the wafer and to automatically measure the displacement itself, so that the displacement is automatically corrected. It is an object of the present invention to provide a dicing apparatus that can perform the dicing.

[0006]

According to the present invention, in order to achieve the above object, a wafer table on which a wafer is positioned and mounted in the X and Y directions is cut and fed in the X direction, and is mounted on a spindle and rotated. In a cutting position correcting method of a dicing apparatus, a blade to be indexed and fed in a Y direction based on a scale by a blade indexing apparatus, and a street between chips formed in a lattice on the wafer surface is cut by the blade. Setting a reference point on the wafer table coordinates, and integrally setting a measurement point on the blade indexing device in the vicinity of the blade indexed and fed based on the scale reference, and setting the reference point and the measurement point And the distance from the measurement point to the blade is measured. The correspondence between the measurement point and the blade on the wafer table coordinates and on the scale is obtained from the measured positional relationship, and the amount of change in the measured distance is used as correction data to calculate the feed amount of the blade indexing device. It is characterized by correction.

In order to achieve the above object, the present invention provides a wafer table for cutting and feeding a wafer positioned and mounted in the X and Y directions in the X direction, and a blade mounted on a spindle and rotating on a scale. A blade indexing device that performs indexing and feeding in the Y direction based on the wafer table and a control mechanism that controls respective feed amounts of the blade indexing device, and is formed in a lattice shape on the wafer surface. In a dicing machine that cuts a street between chips with the blade, a reference point provided at a place other than the place where the wafer is placed on the wafer table, or a place integrated with the wafer table, A non-contact type sensor which is provided integrally with the blade indexing device near the blade and measures the distance to the blade. And a measuring means for measuring a positional relationship of the sensor in the Y direction with the reference point, and outputs a change amount of the distance measured by the sensor to the control mechanism as correction data, and the control mechanism The feed amount of the blade indexing device is corrected.

[0008]

According to the present invention, the reference point is set on a place other than the place where the wafer on the wafer table is placed, or on a place integrated with the wafer table, that is, on the wafer table coordinates which are not concealed by the placement of the wafer. Provide. Then, a measuring means measures a positional relationship between a reference point and a sensor integrally provided in a blade indexing device for indexing and feeding based on a scale near the blade. Thereby, a correspondence relationship is formed between the wafer table coordinates and the scale, so that the measurement point position of the sensor on the wafer table coordinates is determined, and
The measurement point position of the sensor on the scale corresponding to the position is determined.

On the other hand, in parallel with the measurement by the measuring means, the sensor measures the distance from the measurement point of the sensor to the blade. Thus, the amount of displacement of the blade from its normal position due to elongation of the spindle or the like can be detected from the amount of change in the measured distance measured by the sensor. Then, by performing the measurement with the measuring device and the measurement with the sensor, it is possible to obtain the blade position on the wafer table coordinates and the blade position on the scale corresponding to the position. Thereby, the amount of displacement of the blade on the wafer table coordinates, that is, the amount of change in the measurement distance with the sensor,
It can be regarded as the amount of displacement on the scale. Therefore, if the amount of change detected by the sensor is output to the control mechanism as correction data and the feed amount of the blade indexing device is corrected by the control mechanism by the amount of change on the scale, the displacement of the blade displaced due to elongation of the spindle or the like is obtained. The cutting position can be corrected to a regular cutting position.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a cutting position correcting apparatus for a dicing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. As shown in FIG. 1, the wafer table 10 has X
The wafer 12 is supported on a wafer table base 13 having a cutting feed mechanism in the direction and a θ indexing mechanism in the rotation direction, and the wafer 12 is positioned and mounted on the wafer table 10 by the wafer table coordinates. That is, the streets 16 (see FIGS. 2 and 3) between the chips 14 formed in a lattice on the surface of the wafer 12 correspond to the wafer table 1.
It is positioned so as to be in the X and Y directions of the coordinates of 0. In the vicinity of the wafer table 10, a blade 18 for cutting the wafer 12 along the street 16 is attached to the tip of a spindle 20 rotating at high speed, and the spindle 20 is provided with a Y-axis indexing feed mechanism in the Y direction and an X-axis feed mechanism.
Z in the Z direction orthogonal to the Y plane (the direction orthogonal to FIG. 1)
It is supported by a spindle outer cylinder 24 of a blade indexing device 22 having an axis indexing feed mechanism. The cutting feed mechanism, the .theta. Indexing mechanism, the Y-axis indexing feeding mechanism, and the Z-axis indexing feeding mechanism are respectively connected to control mechanisms (not shown) via signal lines.

A linear scale 26 (for example, a moire fringe scale) is fixedly arranged in the Y direction in the vicinity of the blade indexing device 22.
A reader 28 that reads the linear scale 26
Is attached. The value read by the reader 28 is
Output to the control mechanism. Thereby, the blade 18
Can be precisely indexed and fed in the Y direction in units of about 0.1 μm. A blade cover 30 covering the blade 18 is integrally supported by the blade indexing device 22 around the blade 18. Further, a microscope 32 for alignment is provided integrally with the blade indexing device 22, and an imaging device 33 is connected to the microscope 32. The reference line 34 of the microscope 32 and the blade 1
The cutting line 8 is set to coincide with the blade 18 when there is no displacement.

Next, the operation of the cutting position correcting device of the dicing device of the present invention configured as described above will be described. In order to cut the wafer 12 with the blade 18, first, while observing the wafer 12 placed on the wafer table 10 with the microscope 32, alignment is performed in the θ direction and the Y direction. To the cutting position. The cutting depth into the wafer 12 is determined by indexing in the Z-axis direction, but is not described in detail here because it is not the gist of the invention. Next, the street 16 of the first line is cut by cutting and feeding the wafer table 10 in the X direction. Subsequently, the blades 18 are indexed and fed based on the scale 26 by the pitch in the Y direction (ΔP... See FIG. 2) corresponding to the distance between the streets 16, and then the wafer table 10 is cut and fed in the X direction. The second line street 16 is cut. Similarly, the streets 16 of the wafer 12 are cut one after another.

However, the position of the blade 18 is several μm to 1 μm due to the thermal expansion of the spindle 20 and the temperature change in the cutting area.
It shows a displacement of about 0 μm. As a result, the blade 18 is not positioned at the proper cutting position on the street 16 and causes a cutting defect. Therefore, in the cutting position correcting apparatus of the dicing apparatus according to the present invention, as shown in FIG. 1, the table center of the wafer table 10 is used as the coordinate origin of the wafer table coordinates, and is integrated with the wafer table 10 (by the cutting feed mechanism). (Moved in conjunction with the wafer table 10), and is not hidden even when the wafer 12 is mounted.
_The reference point 36 was provided on _P. A sensor 38 for measuring the distance to the blade 18 is provided in the blade cover 30, and a measuring device 40 for measuring the positional relationship between the measurement point of the sensor 38 and the reference point 36 in the Y direction with an accuracy of 1 μm or less. Provided. The measurement results of the sensor 38 and the measuring device 40 are output to the control mechanism via a signal cable. here,
As the sensor 38 to be used, the laser light emitted from the sensor is reflected by a blade, so that the sensor 3 is used.
A non-contact laser length measuring device that measures the distance from the measurement point 8 to the blade 18 can be used. In addition, the measuring device 40 can obtain a DC output voltage in the same manner as a differential transformer in accordance with the relative displacement between the magnet and the detection head.
A magnesensor device that can be obtained with an accuracy of m or less can be used. A magnet is mounted on the reference point 36, and a detection head for detecting the magnet is provided on the blade cover 30.

The displacement of the blade 18 is corrected as follows. That is, the reference point 36 and the sensor 38
Is measured by the measuring device 40 in the Y direction. As a result, a correspondence is formed between the coordinates of the wafer table 10 and the scale 26.
0 together with the measurement point position Y ₁ of the sensor 38 on the coordinates are determined, the measurement point position y ₁ of the sensor 38 on the scale 26 corresponding to the measurement point position Y ₁ is determined. Therefore, even if the spindle outer cylinder 24 of the blade indexing device 22 is extended by heat or the like, the wafer table 1
The measurement point position Y ₁ of the sensor 38 on the zero coordinate and the measurement point position y ₁ of the sensor 38 on the scale 26
Is not changed, the correction of the spindle outer cylinder 24 supporting the spindle 20 is automatically performed. In the measurement by the measuring device 40, for example,
As shown in FIG. 4, when the measurement points of the sensor 38 and the measurement device are provided on the blade cover 30 so as to be spaced apart in the Y direction, the separation distance ( ΔH) is measured (calibrated), and the positional relationship between the reference point 36 and the sensor 38 is determined in consideration of the distance (ΔH).

On the other hand, in parallel with the measurement by the measuring device 40,
The sensor 38 measures the distance from the measurement point of the sensor 38 to the blade 18. Accordingly, when the blade 18 is not displaced, the distance between the blade 18 and the measurement point of the sensor 38 is constant. 38 can be taken as the amount of change in the distance measured. Also, the measurement in the measuring device 40, by performing measurement at the sensor 38, it is possible to obtain the blade position Y ₂ on the wafer table 10 coordinates, at on the scale 26 corresponding to the blade position Y ₂ it can be obtained blade position y _2. Thus, the displacement of the blade 18 on the coordinates of the wafer table 10 can be regarded as the displacement on the scale 26. Therefore, sensor 3
8 is output to the control mechanism as correction data, and is output to the control mechanism on the scale 26 by the scale corresponding to the displacement (when the scale 26 is a moire fringe scale, the moire fringe corresponding to the displacement is used). If the feed amount of the blade indexing device 22 is corrected by the control mechanism only by the number of times of light and dark is read by the reader 28), the cutting position of the blade 18 displaced due to elongation of the spindle 20 or the like can be corrected to the normal cutting position. it can.

For example, as shown in FIG.
If the distance between the blade 18 and the measurement point of the sensor 38 in a state where there is no displacement is defined as a reference distance L, and the spindle 20 thermally expands and the blade 18 is displaced toward the sensor 38, the displacement amount (ΔL ) Is the reference distance (L)-
It is calculated as the measurement distance (T). Then, it is possible to obtain with that blade position on the wafer table coordinate of time can be obtained as Y _3, the blade position on scale 26 corresponding to the blade position Y ₃ as y _3. Therefore, the blade indexing device 22 is moved in the direction in which the blade 18 moves away from the sensor 38 by the blade displacement amount (ΔL) from the blade position y ₃ on the scale 26.
Is corrected, the blade 18 is corrected to the normal cutting position.

As described above, in the cutting position correcting device of the dicing device of the present invention, when the blade 18 is displaced,
The displacement of the blade 18 can be corrected on the basis of the wafer table coordinates. As a result, the wafer 18 is moved by the blade 18 as in the case where the displacement is corrected on the basis of the conventional microscope.
Eliminates the need for cutting. Also, a sensor 38 provided integrally with the reference point 36 and the blade indexing device 22 is provided.
Is measured by the measuring device 40 so that the displacement amount of the blade 18 can be grasped as the displacement amount on the scale 26. Accordingly, the displacement of the blade 18 can be controlled as it is in the feed amount of the blade indexing device 22, so that the displacement of the blade 18 can be automatically corrected in real time.

In the embodiment, the coordinate origin is set at the center of the wafer table. However, the present invention is not limited to this. If the Y coordinate of the reference point 36 is known on the coordinates of the wafer table. Good.

[0019]

As described above, according to the cutting position correcting apparatus for a dicing apparatus according to the present invention, once the blade position is correctly positioned at the cutting position when the dicing apparatus is started up, the blade position can be changed thereafter. By measuring the distance to the blade with the sensor, the displacement of the blade can be continuously detected, and the displacement of the blade itself can be detected.

Therefore, it is possible to detect the displacement of the cutting position without cutting the wafer as in the related art and to automatically correct the displacement of the blade in real time.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a cutting position correction device of a dicing device according to the present invention.

FIG. 2 is an explanatory diagram illustrating streets between chips formed on a wafer surface.

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is an explanatory view for explaining the principle of the cutting position correcting device of the dicing device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Wafer table 12 ... Wafer 13 ... Wafer table base 16 ... Street of wafer 18 ... Blade 20 ... Spindle 22 ... Blade indexing device 24 ... Spindle outer cylinder 26 ... Scale 28 ... Scale reader 30 ... Blade cover 32 ... Microscope 36 Reference point 38 Sensor 40 Measurement device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/301 B24B 27/06

Claims (2)

(57) [Claims] 1. A wafer table on which a wafer is positioned and mounted in the X and Y directions is cut and fed in the X direction, and a rotating blade attached to a spindle is divided in a Y direction based on a scale by a blade indexing device. Send it out,
In a cutting position correction method of a dicing apparatus for cutting a street between chips formed in a lattice shape on the wafer surface with the blade, a reference point is set on the wafer table coordinates, and the index is determined based on the scale reference. A measurement point is set integrally with the blade indexing device in the vicinity of the blade to be fed, and a distance between the measurement point and the blade is measured while measuring a positional relationship between the reference point and the measurement point in the Y direction. Measure and obtain the correspondence between the measurement point and the blade on the wafer table coordinates and on the scale from the measured positional relationship, and use the blade index as the correction data with the measured distance change as correction data. Cutting position of dicing machine characterized by correcting the feed amount of the machine Correction method. 2. A wafer table for cutting and feeding a wafer placed and positioned in the X and Y directions in the X direction, and a blade indexing and feeding a rotating blade attached to a spindle in the Y direction based on a scale. A dicing device having a control mechanism for controlling the respective feed amounts of the wafer table and the blade indexing device, and cutting the streets between chips formed in a lattice on the wafer surface with the blade. In, a reference point provided in a place other than the place where the wafer is placed on the wafer table, or in a place integral with the wafer table, and integrally with the blade indexing device near the blade A non-contact type sensor provided for measuring a distance to the blade, the reference point and the sensor Measuring means for measuring the positional relationship in the Y direction, and outputting the amount of change in the distance measured by the sensor to the control mechanism as correction data, and controlling the feed amount of the blade indexing device by the control mechanism. A cutting position correction device for a dicing device, wherein the correction is performed.