JP4242522B2 - Laser processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser processing apparatus that processes an object using laser light, and more particularly to a laser processing apparatus that processes a disk-shaped object such as a wafer.
[0002]
[Prior art]
4A and 4B are plan views showing an example of a conventional laser processing apparatus. As shown in FIGS. 4A and 4B, the conventional laser processing apparatus is provided above the wafer 20 and a fixing mechanism 31 provided below the wafer 20 and fixing the lower surface of the wafer 20 by vacuum suction or the like. A position measuring device 32 that measures the position and eccentricity of the wafer 20 (the amount of positional deviation between the rotation center R0 of the fixing mechanism 31 and the center W0 of the wafer 20) is provided. Among these, the fixing mechanism 31 is connected to an XYZθ axis drive mechanism (not shown), and is driven in each of the X, Y, Z, and θ directions. Further, the position measuring device 32 has a plurality of transmission sensors 33 arranged corresponding to the outer peripheral edge of the wafer 20 after completion of positioning.
[0003]
In such a conventional laser processing apparatus, first, as shown in FIG. 4A, after the lower surface of the wafer 20 is fixed on the fixing mechanism 31, the wafer 20 is attached to each transmission sensor 33 of the position measuring device 32. The fixing mechanism 31 is moved in the X and Y directions by an XYZθ axis driving mechanism (not shown) so as to cover the measurement region.
[0004]
Next, as shown in FIG. 4A, the position measuring device 32 rotates the wafer 20 fixed on the fixing mechanism 31 clockwise (θ direction) by an XYZθ axis driving mechanism (not shown). The amount of eccentricity of the wafer 20 is measured.
[0005]
Thereafter, as shown in FIG. 4B, the rotation center R0 of the fixing mechanism 31 and the center W0 of the wafer 20 are made to coincide with each other based on the eccentricity measured in this way. Specifically, after moving the fixing mechanism 31 downward (Z direction) away from the lower surface of the wafer 20, the fixing mechanism 31 is moved in the X and Y directions to rotate the rotation center R 0 of the fixing mechanism 31 and the wafer 20. Match the center W0. Thereafter, the fixing mechanism 31 is moved upward (Z direction) to fix the lower surface of the wafer 20, and then the fixing mechanism 31 is moved in the X and Y directions to position the wafer 20 with respect to the X and Y directions.
[0006]
Then, as shown in FIG. 4B, the wafer is fixed by the position measuring device 32 while rotating the wafer 20 fixed on the fixing mechanism 31 clockwise (θ direction) by an XYZθ axis driving mechanism (not shown). The notch-shaped orientation flag 20a provided on the outer peripheral edge 20 is detected, and the wafer 20 is positioned with respect to the θ direction so that the orientation flag 20a is at a predetermined position in the circumferential direction (the lowermost part in the drawing in FIG. 4B).
[0007]
Finally, a laser beam emitted from a laser device (not shown) is guided to the wafer 20 positioned in the X, Y, and θ directions in this way, and the laser beam is directed to a predetermined processing position on the wafer 20. To start laser processing.
[0008]
At this time, since the wafer 20 is always positioned at the same position in the X, Y, and θ directions, the laser beam irradiation position (processing position T) is set in advance as shown in FIG. The position can be determined based only on position information (for example, position information on the wafer 20 with reference to the orientation flag 20a ((X2, Y2) in FIG. 3B)).
[0009]
[Problems to be solved by the invention]
As described above, in the conventional laser processing apparatus, the wafer 20 is always kept at the same position in the X, Y, and θ directions by the XYZθ axis drive mechanism (not shown) that can be driven in the X, Y, Z, and θ directions. Positioning and laser processing are performed based on preset processing position information.
[0010]
However, the above-described conventional laser processing apparatus requires a drive mechanism having a plurality of drive shafts as a drive mechanism for driving the fixing mechanism 31, which causes a problem that the structure of the apparatus is complicated and the cost is increased. Further, since it is necessary to change the position of the transmission sensor 33 in accordance with the shape and dimensions of the wafer 20, there is a problem that costs increase. Furthermore, in order to align the rotation center R0 of the fixing mechanism 31 and the center W0 of the wafer 20, it is necessary to move the fixing mechanism 31 in the vertical direction (Z direction) (the wafer 20 is moved by the fixing mechanism 31). There is a problem that time (tact time) is prolonged.
[0011]
The present invention has been made in consideration of such points, and an object thereof is to provide a laser processing apparatus capable of simplifying the structure of the apparatus and performing efficient laser processing simply and inexpensively.
[0012]
[Means for Solving the Problems]
The present invention provides, as a reference example , a laser processing apparatus that processes an object using laser light emitted from a laser apparatus, a fixing mechanism that fixes the object, a predetermined point on the fixing mechanism, and a position on the object. A position measuring device that measures the amount of positional deviation from a fixed point, an irradiation position adjusting mechanism that adjusts the irradiation position of the laser beam emitted from the laser device to the object, and a laser at a predetermined processing position on the object A control device that controls the irradiation position adjustment mechanism based on preset processing position information so that light is irradiated, and the control device is based on the positional deviation amount obtained by the position measurement device. Provided is a laser processing apparatus that controls the irradiation position adjusting mechanism while correcting the processing position information.
[0013]
The present invention provides, as a solution , a laser processing apparatus that processes a disk-shaped object with laser light emitted from a laser apparatus, a fixing mechanism that fixes the disk-shaped object, and the fixing mechanism that fixes the disk-shaped object. A rotary drive mechanism for rotating a disk-shaped object, the rotary drive mechanism for positioning the disk-shaped object at a predetermined position in a circumferential direction during processing of the disk-shaped object; A position measuring device that measures the amount of misalignment between the center of rotation of the fixing mechanism and the center of the disk-shaped object while the fixing mechanism is rotated, and the disk-like shape of the laser light emitted from the laser device An irradiation position adjusting mechanism that adjusts an irradiation position with respect to the object, and the irradiation position based on preset processing position information so that a predetermined processing position on the disk-shaped object is irradiated with laser light. A control device for controlling the adjustment mechanism, wherein the control device controls the irradiation position adjustment mechanism while correcting the processing position information based on the positional deviation amount obtained by the position measurement device. Provided is a laser processing apparatus.
[0014]
In the above-described solving means , the position measuring device measures a circumferential position of the disk-shaped object by using a reference position mark provided on the disk-shaped object, and the rotational drive mechanism is configured to move the position of the position measurement device. It is preferable to position the disk-shaped object at a predetermined position in the circumferential direction based on the circumferential position measured by the measuring device. The reference position mark is preferably an orientation flag provided on the disk-shaped object. Furthermore, it is preferable that the irradiation position adjusting mechanism is a beam scanner mechanism that deflects laser light emitted from the laser device.
[0015]
According to the reference example of the present invention, the position measuring device measures the amount of positional deviation between the predetermined point on the fixing mechanism and the predetermined point on the object, and controls the irradiation position adjusting mechanism in consideration of the amount of positional deviation. Since the irradiation position of the laser beam is adjusted, the structure of the drive mechanism that drives the fixing mechanism and the position measuring device can be simplified, and thus efficient laser processing can be performed simply and inexpensively. be able to.
[0016]
According to the solution means of the present invention, the position measuring device measures the amount of misalignment between the center of rotation of the fixing mechanism and the center of the disk-shaped object, and controls the irradiation position adjusting mechanism while considering the amount of misalignment. Since the irradiation position of the laser beam is adjusted, the structure of the drive mechanism that drives the fixing mechanism and the position measuring device can be simplified, and thus efficient laser processing can be performed simply and inexpensively. be able to.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views for explaining an embodiment of a laser processing apparatus according to the present invention. In the present embodiment, a case where a wafer (disk-shaped object) is processed using laser light will be described as an example.
[0018]
As shown in FIG. 1, the laser processing apparatus 10 includes a fixing mechanism 11 that is provided below the wafer 20 and fixes the lower surface of the wafer 20 by vacuum suction or the like. A θ axis drive mechanism (rotation drive mechanism) 12 that can be driven in the θ direction is connected to the fixing mechanism 11 so that the wafer 20 fixed on the fixing mechanism 11 can be rotated in the plane of the wafer 20. It has become.
[0019]
The laser processing apparatus 10 also includes a laser apparatus 13 that emits laser light, and a beam scanner mechanism (irradiation position adjusting mechanism) that deflects the laser light emitted from the laser apparatus 13 and adjusts the irradiation position of the laser light on the wafer 20. 14).
[0020]
Further, the laser processing apparatus 10 includes a position measuring device 15 above the wafer 20, and the eccentric amount of the wafer 20 (the center of rotation of the fixing mechanism 11) while the fixing mechanism 11 is rotated by the θ-axis driving mechanism 12. The positional deviation amount between R0 and the center W0 of the wafer 20) and the position of a notch-shaped orientation flag (reference position mark) 20a provided on the outer peripheral edge of the wafer 20 can be measured. As the position measuring device 15, a linear sensor, a CCD (Charge Coupled Device), or the like can be used.
[0021]
Here, a control device 16 is connected to the beam scanner mechanism 14 and the position measuring device 15, so that a laser beam is irradiated to a predetermined processing position on the wafer 20 when the wafer 20 is processed. Can be controlled. Specifically, the control device 16 uses preset processing position information (for example, position information on the wafer 20 with reference to the orientation flag 20a) and the eccentric amount of the wafer 20 obtained by the position measurement device 15. Based on this, the beam scanner mechanism 14 is controlled. During the processing of the wafer 20, the wafer 20 is positioned at a predetermined position in the circumferential direction by the θ-axis drive mechanism 12 based on the circumferential position measured by the position measuring device 15.
[0022]
Next, the operation of the present embodiment having such a configuration will be described with reference to FIGS. Here, FIGS. 2A and 2B are views for explaining a positioning method of the wafer 20 in the laser processing apparatus 10, and FIGS. 3A and 3B are eccentric amounts of the wafer 20 in the laser processing apparatus 10. FIG. It is a figure which shows the relationship between an actual processing position, comparing with the case of the conventional laser processing apparatus.
[0023]
First, as shown in FIG. 2A, the lower surface of the wafer 20 is fixed on the fixing mechanism 11.
[0024]
Next, as shown in FIG. 2 (a), the wafer 20 fixed on the fixing mechanism 11 is rotated clockwise (θ direction) by the θ-axis driving mechanism 12 and the wafer 20 is eccentric by the position measuring device 15. The quantity and the position of the orientation flag 20a are measured.
[0025]
After that, as shown in FIG. 2B, the wafer 20 fixed on the fixing mechanism 11 is rotated clockwise (θ direction) by the θ-axis drive mechanism 12, and the orientation flag 20a is moved to a predetermined position in the circumferential direction (FIG. 2). In FIG. 2B, the wafer 20 is positioned with respect to the θ direction so as to be near the bottom of the drawing. Here, the wafer 20 is positioned so that the straight line connecting the rotation center WO of the wafer 20 and the orientation flag 20a is parallel to the straight line connecting the rotation center R0 of the fixing mechanism 11 and the processing coordinate origin O.
[0026]
Finally, the laser beam emitted from the laser device 13 (see FIG. 1) is guided to the wafer 20 positioned in the θ direction in this way via the beam scanner mechanism 14 (see FIG. 1), and the wafer 20 Laser processing is started by irradiating the predetermined processing position above with laser light.
[0027]
At this time, since the wafer 20 is positioned only in the θ direction, as shown in FIG. 3A, the wafer 20 is positioned in a different position each time in the X and Y directions. For this reason, in the present embodiment, as shown in FIG. 3A, the irradiation position (processing position T) of the laser beam is set with reference to preset processing position information (for example, the orientation flag 20a on the wafer 20). It is determined based on the set position information (vector NT)) and the amount of eccentricity (vector ON) of the wafer 20 obtained by the position measuring device 15.
[0028]
Specifically, the position information set with reference to the orientation flag 20a on the wafer 20 is (X2, Y2) (= vector NT), and the eccentricity of the wafer 20 after being positioned in the θ direction is (X1, If Y1) (= vector ON), the actual machining position (X, Y) (= vector OT) is
(X, Y) = (X2 + X1, Y2 + Y1)
Can be obtained as
[0029]
As described above, according to the present embodiment, the position measuring device 15 measures the amount of eccentricity of the wafer 20 (the amount of positional deviation between the rotation center R0 of the fixing mechanism 31 and the center W0 of the wafer 20) and considers the amount of eccentricity. However, since the beam scanner mechanism 14 is controlled to adjust the irradiation position of the laser beam, the drive mechanism for driving the fixing mechanism 11 does not need to use drive shafts in the X, Y, and Z directions, and the apparatus The cost can be reduced by simplifying the structure. Further, since the position measuring device 15 only needs to measure mainly the amount of eccentricity of the wafer 20, it is not necessary to change the position measuring device in accordance with the shape and dimensions of the wafer 20, and the cost can be reduced. Furthermore, since it is not necessary to change the wafer 20 by the fixing mechanism 11, work time (tact time) can be shortened. For this reason, it is possible to simplify the structure of the apparatus and perform efficient laser processing simply and inexpensively.
[0030]
In the above-described embodiment, the notch-shaped orientation flag is used as the reference position mark, but the orientation flag is not limited to the notch-shaped form. In addition to the orientation flag, a dedicated mark or the like may be provided on the surface of the wafer 20 separately.
[0031]
In the above-described embodiment, the case of processing a wafer that is a disk-shaped object is described as an example. However, the present invention is not limited to this, and an object having an arbitrary shape such as a rectangle is described. Similarly, the present invention can also be applied. In this case, the positional deviation amount between the predetermined point on the fixing mechanism and the predetermined point on the object may be measured, and the preset processing position information may be corrected based on the positional deviation amount. . In this case, since there is no need to obtain the amount of eccentricity of the object, there is an advantage that it is not necessary to provide a θ-axis drive mechanism.
[0032]
【The invention's effect】
As described above, according to the present invention, it is possible to simplify the structure of the drive mechanism that drives the fixing mechanism and the position measuring device, and therefore, efficient laser processing can be performed easily and inexpensively.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of a laser processing apparatus according to the present invention.
2 is a view for explaining a wafer (disk-shaped object) positioning method in the laser processing apparatus shown in FIG. 1; FIG.
3 is a diagram showing a relationship between the amount of wafer eccentricity and an actual processing position in the laser processing apparatus shown in FIG. 1 in comparison with a conventional laser processing apparatus.
FIG. 4 is a view for explaining a method of positioning a wafer (disk-shaped object) in a conventional laser processing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Laser processing apparatus 11 Fixing mechanism 12 (theta) axis drive mechanism (rotation drive drive)
13 Laser device 14 Beam scanner mechanism (irradiation position adjustment mechanism)
15 Position Measuring Device 16 Control Device 20 Wafer (Disk Object)
20a Orientation flag (reference position mark)

Claims (4)

In a laser processing apparatus that processes a disk-shaped object with laser light emitted from a laser apparatus,
A fixing mechanism for fixing the disk-shaped object;
A rotation driving mechanism for rotating the disk-shaped object fixed by the fixing mechanism, wherein the disk-shaped object is positioned at a predetermined position in the circumferential direction when the disk-shaped object is processed. When,
A position measuring device that measures the amount of positional deviation between the center of rotation of the fixing mechanism and the center of the disk-shaped object in a state where the fixing mechanism is rotated by the rotation driving mechanism;
An irradiation position adjusting mechanism for adjusting an irradiation position of the laser beam emitted from the laser device to the disk-shaped object;
A control device for controlling the irradiation position adjusting mechanism based on preset processing position information so that a predetermined processing position on the disk-shaped object is irradiated with laser light;
The laser processing device, wherein the control device controls the irradiation position adjusting mechanism while correcting the processing position information based on the positional deviation amount obtained by the position measuring device. The position measuring device measures a circumferential position of the disk-shaped object by a reference position mark provided on the disk-shaped object, and the rotational drive mechanism is measured in the circumferential direction measured by the position measuring device. the laser processing apparatus according to claim 1, wherein the positioning the disk-like object at a predetermined position in the circumferential direction based on the position. The laser processing apparatus according to claim 2, wherein the reference position mark is an orientation flag provided on the disk-shaped object. The irradiation position adjusting mechanism is a laser machining apparatus according to any one of claims 1 to 3, characterized in that a beam scanner mechanism for deflecting the laser beam emitted from the laser device.

Images