KR101892576B1 - Calibration method for a plurality of 3 dimensional laser scanners and laser processing apparatus - Google Patents

Abstract

Disclosed is a method for calibrating multiple three-dimensional laser scanners. The method for calibrating multiple three-dimensional laser scanners includes the following steps: arranging a calibration plate at a reference height; enabling the three-dimensional laser scanners to individually execute a first test marking operation with a first target pattern on the calibration plate; measuring first errors between the first target pattern and the actual pattern formed on the calibration plate by the test marking operation and calibrating the plane setting of each one of the three-dimensional laser scanners based on the first errors; adjusting the height of the calibration plate; enabling the three-dimensional laser scanners to individually execute a second test marking operation with a predetermined second pattern on the calibration plate at the adjusted height while taking the height change of the calibration plate into account; and measuring second errors between the second target pattern and the actual pattern formed on the calibration plate by the second test marking operation and calibrating the vertical direction setting and plane setting of each one of the three-dimensional laser scanners based on the second errors.

Description

Technical Field [0001] The present invention relates to a calibration method for a plurality of three-dimensional laser scanners and a laser processing apparatus using the same,

The present invention relates to a method of calibrating a plurality of three-dimensional laser scanners and a laser processing apparatus using the same.

Many chips are formed on the wafer in the manufacturing process of the semiconductor device. Characters and / or numbers are displayed on the surface of each chip to distinguish these chips by production lot. A laser marking apparatus using a laser beam for this purpose is used. Conventionally, a lot number is marked on each chip after dicing. However, since the development of advanced technology has enabled miniaturization and weight reduction of an integrated circuit (IC), it has become possible to increase work efficiency and increase productivity, And then dicing was performed.

Recently, as the wafer size becomes larger, the thickness of the wafer becomes thinner and a large number of chips are formed on the wafer, warpage phenomenon of the wafer in which the wafer is bent in a certain direction is caused by the weight of the wafer and other workpieces . Such a warp phenomenon occurs as the wafer size increases, the thickness decreases, and the shrinkage increases as the coating material cures. When the deviation of the height of the processed surface of the wafer due to the warpage phenomenon is larger than the depth of focus of the laser beam when marking is performed on the individual chips on the wafer, the beam density of the laser output The size of the laser beam may be changed to lower the marking quality, the line width may become uneven, and the marking position may be wrong.

According to an aspect of the present invention, there is provided a calibration method for calibrating a plurality of three-dimensional laser scanners for improving a processing speed and a processing accuracy, and a laser processing apparatus therefor.

A calibration method for calibrating a plurality of three-dimensional laser scanners according to an aspect of the present invention includes:

Disposing a calibration plate at a reference height;

Each of the plurality of three-dimensional laser scanners performing a first test marking with a first target pattern on the calibration plate;

Measuring a first error between an actual pattern actually formed on the calibration plate and the first target pattern by the first test marking and correcting a plane setting of each of the plurality of three- dimensional laser scanners based on the first error ;

Adjusting a height of the calibration plate;

Taking into account variations in the height of the calibration plate, each of the plurality of three-dimensional laser scanners performing a second test marking with a predetermined second target pattern on a calibration plate of the changed height; And

Measuring a second error between an actual pattern actually formed on the calibration plate and the second target pattern by the second test marking and comparing the plane setting of each of the plurality of three- And correcting the setting according to the vertical direction.

In one embodiment, the plurality of three-dimensional laser scanners include a first three-dimensional laser scanner and a second three-dimensional laser scanner, wherein in the performing the first test marking, The first target pattern of the laser scanner and the first target pattern of the second three-dimensional laser scanner may have the same shape.

In one embodiment, in the step of performing the first test marking, the first three-dimensional laser scanner and the second three-dimensional laser scanner can irradiate to the same target position.

In one embodiment, in performing the second test marking, the second target pattern of the first three-dimensional laser scanner and the second target pattern of the second three-dimensional laser scanner may have the same shape Lt; / RTI >

In one embodiment, in the step of performing the second test marking, the first three-dimensional laser scanner and the second three-dimensional laser scanner can irradiate to the same target position.

In one embodiment, adjusting the height of the calibration plate may include increasing the height of the calibration plate and reducing the height of the calibration plate.

In one embodiment, the height adjustment of the calibration plate may be less than +/- 5 mm.

In one embodiment, the machining error range of the plurality of three-dimensional laser scanners that have been calibrated may be less than 15 占 퐉.

In one embodiment, each of the plurality of three-dimensional laser scanners includes first to third deflecting units for deflecting an incident laser beam in a first direction and a second direction orthogonal to each other and along a thickness direction of the object, . ≪ / RTI >

According to an aspect of the present invention,

A work table on which an object to be processed is mounted;

A measuring device for measuring a three-dimensional shape of the object to be processed;

The plurality of three-dimensional laser scanners calibrated according to the calibration method; And

And a processor for controlling the plurality of three-dimensional laser scanners based on data measured by the measuring device,

The processing errors of the plurality of three-dimensional laser scanners may be 15 占 퐉 or less.

In one embodiment, the object to be processed may be a wafer having a diameter of 300 mm or more.

In one embodiment, each of the plurality of three-dimensional laser scanners includes first to third deflecting units for deflecting an incident laser beam in a first direction and a second direction orthogonal to each other and along a thickness direction of the object, . ≪ / RTI >

The calibration method for calibrating a plurality of three-dimensional laser scanners according to the embodiment of the present invention and the laser processing apparatus therefor can improve both the processing speed and the processing accuracy for the object to be processed.

1 is a block diagram of a laser processing apparatus according to an embodiment of the present invention,
2 is a schematic diagram illustrating the operation of the laser processing apparatus according to one embodiment of the present invention.
3 is a schematic diagram of a plurality of three-dimensional laser scanners in accordance with an embodiment of the present invention.
4 is a flowchart of a method of processing a laser processing apparatus according to an embodiment of the present invention.
5 is a schematic view of a measurement method of a measurement apparatus according to an embodiment of the present invention.
6A is a two-dimensional machining plan view of a wafer according to an embodiment of the present invention. FIG. 6B is a three-dimensional shaped perspective view of a measured wafer mapping a two-dimensional machining image in accordance with an embodiment of the present invention. FIG.
7 is a flowchart showing a method of calibrating a plurality of three-dimensional laser scanners according to the embodiment,
Figure 8 is a flow chart illustrating one embodiment of Figure 7,
FIG. 9 is a flowchart showing one embodiment of FIG.
10A to 10C are diagrams for conceptually explaining a calibration method of a plurality of three-dimensional laser scanners.
11 is a schematic view illustrating a laser processing apparatus according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements, and the size and thickness of each element may be exaggerated for clarity of explanation.

Terms including ordinals such as " first, " " second, " and the like can be used to describe various elements, but the elements are not limited by terms. Terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term " and / or " includes any combination of a plurality of related items or any of a plurality of related items.

Fig. 1 is a block diagram of a laser machining apparatus 1 according to an embodiment of the present invention, and Fig. 2 is a schematic view for explaining the operation of the laser machining apparatus 1 according to an embodiment of the present invention. 3 is a schematic diagram of a plurality of three-dimensional laser scanners 31, 32 according to an embodiment of the present invention.

1 and 2, a laser machining apparatus 1 according to an embodiment of the present invention includes a first laser beam L1 emitted from a first laser emitting portion 11 and a second laser emitting portion 12 The second laser beam L2 emitted from the work table 70 is focused on one object to be processed mounted on the work table 70 to perform processing operations such as marking, etching, exposure, punching, and scribing have. A laser machining apparatus 1 capable of performing a marking process by condensing a first laser beam L1 and a second laser beam L2 (L2) on a wafer W as an object to be processed will be described below .

The laser processing apparatus 1 according to one embodiment includes a first laser emitting portion 11 capable of emitting a first laser beam L1, a second laser emitting portion 11 capable of deflecting the first laser beam L1 in a specific direction, A second laser output unit 12 capable of outputting the second laser beam L2, and a second three-dimensional laser scanner 31 capable of deflecting the second laser beam L2 in a specific direction, A laser scanner 32, a measurement device 40 capable of measuring the three-dimensional shape of the wafer W, a memory 50, a processor 60 and a user interface 90. [

Each of the first laser emitting portion 11 and the second laser emitting portion 12 is a device capable of emitting the first and second laser beams L1 and L2. As an example, the first laser emitting portion 11 and the second laser emitting portion 12 can perform a marking operation by irradiating a laser beam to semiconductor chips provided on a wafer W to be processed. The laser system including the first laser emitting unit 11 includes a laser oscillator (not shown) in which a laser beam is generated, a reflection mirror (not shown) capable of forming a path for guiding the laser beam emitted from the laser oscillator to the wafer side ). At this time, the wafer W may be provided in the form of a film-like disk, and may be supported in a contact or non-contact manner with a wafer chuck (not shown) as a seating part on which the wafer W can be placed. Further, the wafer chuck (not shown) may be formed so that the size of the accommodating portion for accommodating the wafer W is deformed so as to support the wafer W of various sizes.

The first three-dimensional laser scanner 31 is a device for deflecting the first laser beam L1 in a specific direction. The second three-dimensional laser scanner 32 is a device for deflecting the second laser beam L2 in a specific direction.

Referring to FIG. 3, each of the first three-dimensional laser scanner 31 and the second three-dimensional laser scanner 32 according to the embodiment of the present invention includes first and second laser beams L1 A second deflection unit 320 for deflecting in the Y direction, and a third deflection unit 330 for deflecting in the Z direction. . According to one embodiment, the first deflection unit 310 includes an X-deflection mirror 311 and an X-deflection motor 312, and the second deflection unit 320 includes a Y-deflection mirror 321 and a Y- - deflection motor 322 and the third deflection unit 330 may include a Z-deflection mirror 331 and a Z-deflection motor 332. The Z-

3, the laser beams L1 and L2 emitted from the first laser emitting portion 11 are incident on the Z-deflecting mirror 331, the X-deflecting mirror 311, Deflecting mirror 321 and the Y-deflecting mirror 321, respectively. However, the present invention is not limited thereto. The first laser beam L1 emitted from the first laser emitting unit 11 may be arranged in a manner of arranging a plurality of deflection mirrors, for example, Z-deflection mirror 331, X Deflecting mirror 311 and Y-deflecting mirror 321 according to the arrangement manner of the Z-deflecting mirror 311 and the Y-deflecting mirror 321, May be incident in order. At this time, the X-deflection motor 312, the Y-deflection motor 322, and the Z-deflection motor 332 are connected to the X-deflection mirror 311, the Y- deflection mirror 321, The first laser beam L1 can be deflected in the X direction, the Y direction, and the Z direction, respectively. In the same manner, the second laser beam L2 can be deflected in the X direction, the Y direction, and the Z direction.

As described above, the first and second laser beams L2 and L2 are applied to desired positions of the wafer W to be processed as the first and second laser beams L1 and L2 are deflected in the X direction, L1 may be examined. In addition, a separate condenser lens (not shown) may be disposed between the first and second three-dimensional laser scanners 31 and 32 and the wafer W. [ At this time, the condenser lens (not shown) may be, for example, an F-theta-telecentric lens having an F-setter function in which the position of the imaging point is linearly determined according to the incident angle. However, the present disclosure is not limited to this. When a large-area wafer W having a diameter of 300 mm or more is to be machined by the first laser beam L1, for example, A separate condenser lens (not shown) may not be disposed between the first and second three-dimensional laser scanners 31 and 32 and the wafer W.

Referring again to Fig. 1, the measuring apparatus 40 is a device capable of measuring a three-dimensional shape of a workpiece, for example, a wafer W. The measuring apparatus 40 includes a line measuring unit 410 capable of measuring the one-direction machining line of the wafer W and a measuring unit 410 for measuring the shape of the wafer W along the thickness direction of the wafer W, And a driving unit 430 for moving the depth measuring unit 420 and the line measuring unit 410 and the depth measuring unit 420. [

As an example, the line measuring section 410 is a device capable of measuring an image of a processing line with respect to one direction of the wafer W. For example, the line measuring unit 410 may be a CCD camera, and the line measuring unit 410 may scan the processing line in one of the X direction and the Y direction.

The depth measuring unit 420 is a device capable of measuring the curvature of the wafer W along the Z direction of the wafer W. The depth measuring unit 420 may be a depth sensor such as a TOF sensor Or a method of directly measuring the deformed degree of bending of the wafer W or a method of directly measuring the depth sensor and the degree of bend can be implemented. As an example, the depth measuring unit 420 can measure the shape bending of the wafer W along the processing line measured by the line measuring unit 410. [

The driving unit 430 is a driving unit capable of moving the line measuring unit 410 and the depth measuring unit 420. For example, when the line measuring unit 410 scans the machining line in the X direction, the driving unit 430 can move the depth measuring unit 420 in the X direction. When the line measuring unit 410 moves in the Y direction and scans another machining line in the X direction, the driving unit 430 can move the line measuring unit 410 and the depth measuring unit 420 in the Y direction . The line measuring unit 410 and the depth measuring unit 420 are described as devices capable of measuring the three-dimensional shape of the object to be processed, for example, the wafer W. However, And any device capable of measuring the three-dimensional shape of the wafer W may be used as the measuring device 40. Fig.

The memory 50 may store a program for the operation of the laser machining apparatus 1, data required therefor, and mathematical operation algorithms for optical image analysis or pattern damage degree evaluation, and the like. As an example, the memory 50 may store a two-dimensional processed image or the like for a predetermined wafer W. [ In addition, the memory 50 may store map data or map history data according to a two-dimensional processed image of the wafer W and a three-dimensional image of the measured wafer W, or the like. The memory 50 is a typical storage medium such as a hard disk drive (HDD), a read only memory (ROM), a random access memory (RAM), a flash memory, and a memory Card).

The processor 60 may be hardware that controls the overall function and operation of the laser machining apparatus 1. As an example, the processor 60 may calculate the offset of the processed image for the actual wafer W shape by mapping the three-dimensional curve of the wafer W to the two-dimensional processed image of the wafer W stored in the memory 50 And can determine the actual machining path for the wafer W. The processor 60 may also control the measuring device 40 or control the first laser emitting portion 11 and the second laser emitting portion 12 depending on the mode of use. The processor 60 can also control the first three-dimensional laser scanner 31 and the second three-dimensional laser scanner 32 based on the data measured by the measuring device 40. [ The processor 60 may also process the image signal to display the actual machining path for the wafer W. [

The processor 60 may be implemented in the form of a single microprocessor module or in a combination of two or more microprocessor modules. That is, the implementation of the processor 60 is not limited by any one.

The user interface 90 includes an input for receiving an input for manipulating the mode of use of the laser machining apparatus 1 and an input unit for inputting a three dimensional shape of the wafer W measured by the measuring apparatus 40, And an output unit capable of outputting information about a two-dimensional processing image or an actual processing path of the complemented wafer W by mapping a two-dimensional processing image to the wafer W with respect to the three-dimensional shape of the wafer W .

The user interface 90 may include a button, a keypad, a switch, a dial or a touch interface for operating a mode of use of the laser machining apparatus 1. [ The user interface 90 may include a display unit for displaying an image, and may be implemented as a touch screen. The display unit may include a display panel, such as an LCD panel, an OLED panel, and the like.

4 is a flowchart of a processing method of the laser processing apparatus 1 according to an embodiment of the present invention. 5 is a schematic view of a measurement method of a measurement apparatus according to an embodiment of the present invention. 6A is a two-dimensional machining plan view of a wafer according to an embodiment of the present invention. FIG. 6B is a three-dimensional shaped perspective view of a measured wafer mapping a two-dimensional machining image in accordance with an embodiment of the present invention. FIG.

Referring to FIG. 4, a measuring apparatus 40 provided in the laser processing apparatus 1 according to an embodiment of the present invention can acquire an actual image of a three-dimensional shape of the wafer W. FIG. 5, when the line measuring unit 410 and the depth measuring unit 420 are provided in the measuring apparatus 40, the line measuring unit 410 may measure the depth of the wafer W, To obtain an image of the processing line of the wafer W in one direction, for example, the X direction. At this time, the depth measuring unit 420 can measure the shape bending of the wafer W with respect to the processing line. Thereafter, the line measuring unit 410 and the depth measuring unit 420 can be moved along the Y direction, and the image of the processing line of the wafer W in the X direction and the contour curve of the processing line of the wafer W Can be repeatedly measured. The sensing information on the image and the contour curvature of the processing line of the wafer W measured by the line measuring unit 410 and the depth measuring unit 420 may be transmitted to the processor 60. [ The processor 60 may form a three-dimensional shaped image for the real wafer W as shown in FIG. 6B based on the transmitted sensing information.

Referring again to FIG. 4, a two-dimensional processed image of the wafer W previously stored in the three-dimensional image of the wafer W measured by the measuring device 40 can be mapped. (S220) As an example, the memory 50 may store a two-dimensional machining image for the wafer W as shown in Fig. 6A and may be stored in the three-dimensional image of the wafer W by the processor 60 A two-dimensional processed image for the wafer W can be mapped. The mapping between the processed image and the actual image of the wafer W can be performed by aligning the processed image and the actual image of the wafer W, that is, the overlap degree between the processed image and the actual image.

When a two-dimensional machining image is mapped to a three-dimensional image of the wafer W measured by the measuring device 40, an offset of the machining image with respect to the actual image can be determined. (S230) As an example, there may be an error between the processed image and the actual image. Such an error may be caused by the warpage of the wafer or the shape error of the wafer itself due to the use of the large area wafer W have. A test may be performed on the superimposition of the processed image and the actual image to determine the offset according to the difference between the processed image and the actual image. As an example, a superimposed degree of a processed image and an actual image may be calculated by applying a model such as a linear model predictive control (LMPC) to the superimposed image region. 6A and 6B to compare the positional values between the two-dimensional processed image and the measured actual image to eliminate the error of the overlapping degree according to the above-described calculation result of the overlapping degree, And the offset value of the machining position with respect to the Z direction according to the shape bending of the wafer W can be extracted.

Processing can be performed on the wafer according to the processed image whose offset is complementary using the extracted offset value. (S240) As an example, the processor 60 can acquire a corrected machining image using the extracted offset value, and the first three-dimensional laser scanner 31, according to the machining position extracted from the corrected machining image, The first to third deflection units 310. 320 and 330 provided in each of the first and second three-dimensional laser scanners 32 and 32 respectively move the first and second laser beams L 1 and L 2 in the X direction, Lt; / RTI > Accordingly, an error due to warpage in the Z direction, which may be generated when the wafer W itself has a shape error in the Z direction or a wafer W having a large area, for example, a wafer W having a diameter of 300 mm or more, Can be compensated.

Further, in the case of adjusting the offsets in the X direction, the Y direction, and the Z direction with respect to the entire area, it is possible to perform the laser marking process on the wafer W in a single laser marking process for the entire area, Processing can be performed. Therefore, according to the laser processing method according to the embodiment of the present invention, it is possible not only to reduce the error in the process of dividing the large area wafer W, but also to achieve the entire process more quickly.

The laser machining apparatus 1 according to the embodiment of the present invention includes a plurality of laser emitting units 11 and 12 and a plurality of laser emitting units 11 and 12 for determining the directions of the plurality of laser beams L1 and L2 emitted therefrom, By including the two-dimensional laser scanners 31 and 32, the machining accuracy and the machining speed can be improved at the same time. In other words, the plurality of three-dimensional laser scanners 31 and 32 of the laser machining apparatus 1 according to the embodiment are provided with a plurality of laser beams L1 and L2 aligned three-dimensionally on a common area of a single object to be processed By performing irradiation and processing, both the processing accuracy and the processing speed can be improved.

When a single object is subjected to laser processing by a single three-dimensional laser scanner, errors due to warping in the Z direction can be compensated. Therefore, compared with a two-dimensional laser scanner, for example, a galvanometer scanner , The machining accuracy is improved. However, unlike a galvano scanner, since a single three-dimensional laser scanner further includes a step of deflecting in the Z-axis direction, the processing speed can be slower than the processing speed of the two-dimensional laser scanner.

However, since the laser processing apparatus 1 according to the embodiment includes a plurality of three-dimensional laser scanners 31 and 32 for one object to be processed, the processing speed can be increased by the number of the three-dimensional laser scanners, It is possible to compensate the weakness of the 3D laser scanner.

Further, since the laser processing apparatus 1 according to the embodiment includes a plurality of three-dimensional laser scanners 31 and 32, even if one of the three-dimensional laser scanners is not operated due to various causes such as a failure, Laser processing can also be performed using a laser scanner.

However, when a single object to be processed is processed by using a plurality of three-dimensional laser scanners 31 and 32, and particularly when fine laser processing such as wafer W processing is required, a plurality of three-dimensional laser scanners 31, 32 need to be matched with each other. This is because the actual laser machining by the plurality of three-dimensional laser scanners 31 and 32 may appear unintentionally because the angles at which the plurality of three-dimensional laser scanners 31 and 32 see the object are different from each other . Accordingly, it is necessary to make the settings of the plurality of three-dimensional laser scanners 31, 32 coincide with each other so that the three-dimensional laser scanners 31, 32 recognize the predetermined positions of the object to be processed at the same position, have.

To this end, a laser machining apparatus 1 including a plurality of three-dimensional laser scanners 31, 32 different from the embodiment is provided with a plurality of three-dimensional laser scanners 31, 32 A calibration step may be applied to match the settings.

If the laser machining apparatus 1 does not undergo such a calibration step, since the settings of the plurality of three-dimensional laser scanners 31 and 32 are different from each other, the same three-dimensional laser scanners 31 and 32 The position where the laser beams L1 and L2 are actually irradiated may be different from each other even if the laser beams L1 and L2 are irradiated toward the position. The errors caused by the plurality of three-dimensional laser scanners 31 and 32 may be larger than the errors caused by the plurality of two-dimensional laser scanners.

Hereinafter, a method of calibrating a plurality of three-dimensional laser scanners 31 and 32 will be described.

FIG. 7 is a flowchart showing a calibration method of a plurality of three-dimensional laser scanners 31 and 32 according to the embodiment, FIG. 8 is a flowchart showing one embodiment of FIG. 7, Fig. Figs. 10A to 10C are diagrams for conceptually explaining a calibration method of a plurality of three-dimensional laser scanners 31 and 32. Fig.

Referring to FIGS. 7, 10A and 10B, a calibration plate CP is disposed below the plurality of three-dimensional laser scanners 31 and 32 to have a reference height (S110). The calibration plate CP can be supported by a jig (not shown) movable in the direction of the optical axis.

The calibration plate CP is a plate for calibration and has a flat shape. The calibration plate CP may include iron, but the material is not limited thereto, and may be variously modified if it is a metal.

Next, each of the plurality of three-dimensional laser scanners 31 and 32 on the calibration plate CP performs a first test marking with a predetermined first target pattern T1 (S120).

The actual patterns R11 and R12 actually formed on the calibration plate CP by the first test marking may be different in position or shape from the first target pattern T1. In other words, the target pattern T1 to be formed by the first test marking and the actually formed actual patterns R11 and R12 may differ in at least one of the position and the shape.

The measuring apparatus 40 measures a first error between the actual pattern R11, R12 and the first target pattern T1.

Based on the measured first error, the XY plane setting of each of the plurality of three-dimensional laser scanners 31 and 32 can be corrected (S130). For example, the settings of the first deflection unit 310 and the second deflection unit 320 of the plurality of three-dimensional laser scanners 31 and 32 can be corrected. In this way, the plurality of three-dimensional laser scanners 31, 32 can have the same setting for the calibration plate CP of the reference height.

8, 10A and 10B, for example, a first three-dimensional laser scanner 31 performs a first test marking with a first target pattern T1 on a calibration plate CP, Dimensional laser scanner 32 performs a first test marking with the first target pattern T1 on the calibration plate CP (S1201, S1202).

The first test marking of the first three-dimensional laser scanner 31 and the first test marking of the second three-dimensional laser scanner 32 can proceed at the same time. However, the first test marking sequence of the first and second three-dimensional laser scanners 31 and 32 is not necessarily limited thereto, and may be sequentially performed.

The first target pattern T1 of the first three-dimensional laser scanner 31 and the first target pattern T1 of the second three-dimensional laser scanner 32 may have the same shape.

The target position irradiated on the calibration plate CP by the first three-dimensional laser scanner 31 and the target position irradiated on the calibration plate CP by the second three-dimensional laser scanner 32 are made equal to each other . In other words, the first three-dimensional laser scanner 31 and the second three-dimensional laser scanner 32 can be set to perform the first test marking toward the same position.

If the target position is set differently, it becomes difficult to exclude the influence such as the deviation that may be caused by the area between the target positions. For example, the first three-dimensional laser scanner 31 forms a first target pattern T 1 at a position of the calibration plate CP, and the second three-dimensional laser scanner 32 forms a calibration target It is difficult to exclude the influence of the bending deviation generated between the one position and the other position of the calibration plate CP when the first target pattern T1 is formed at a position different from the one position of the calibration plate CP.

On the other hand, when the target positions are set to be equal to each other as in the embodiment, it is possible to eliminate deviations or the like that may be included when the target positions are different, Calibration becomes possible.

The measuring device 40 is configured to measure a first error between the actual pattern R11 by the first three-dimensional laser scanner 31 and the first target pattern T1 and a real error by the second three- A first error between the pattern R12 and the first target pattern T1 is measured.

Based on the measured first error, the XY plane settings of the first and second three-dimensional laser scanners 31 and 32 can be corrected (S1301, S1302)). For example, the settings of the first deflection unit 310 and the second deflection unit 320 of the first and second three-dimensional laser scanners 31 and 32 can be corrected.

Next, calibration is performed to align the settings of the plurality of three-dimensional laser scanners 31 and 32 along the Z-axis direction perpendicular to the XY plane.

Referring again to FIGS. 7 and 10A, after the plane setting of each of the plurality of three-dimensional laser scanners 31 and 32 is corrected, the height of the calibration plate CP is adjusted (S140). As a result, the calibration plates CP1 and CP2 have different heights from the reference height.

The height of the calibration plate CP can be adjusted in consideration of the height deviation of the object to be processed. For example, when the height deviation of the wafer W to be processed is ± 5 mm or less, the height adjustment of the calibration plate CP may be ± 5 mm or less. The height adjustment error of the calibration plate (CP) may be less than or equal to +/- 10 mu m.

7, 10A and 10C, in consideration of the height variation of the calibration plates CP1 and CP2, a plurality of three-dimensional laser scanners 31 and 32 are provided on a calibration plate CP1 of a changed height, The second test marking is performed with the second target pattern T2 (S150).

As the height of the calibration plates CP1 and CP2 is adjusted, the distance between the plurality of three-dimensional laser scanners 31 and 32 and the calibration plates CP1 and CP2 becomes different. The plurality of three-dimensional laser scanners 31 and 32 perform the second test marking with the second target pattern T2 in consideration of a change in distance from the calibration plates CP1 and CP2.

The actual patterns R21 and R22 actually formed on the calibration plate CP1 by the second test marking may be different in position or shape from the second target pattern T2. The measuring apparatus 40 can measure a second error between the actual patterns R21 and R22 and the second target pattern T2.

Based on the measured second error, the setting along the direction perpendicular to the plane of each of the plurality of three-dimensional laser scanners 31 and 32 can be corrected (S160). For example, the settings of the third deflection unit 330 of the plurality of three-dimensional laser scanners 31 and 32 can be corrected. In this way, the plurality of three-dimensional laser scanners 31, 32 can have the same setting for the calibration plate CP1 of the adjusted height.

8, 10A and 10C, for example, a first three-dimensional laser scanner 31 performs a second test marking on a second target pattern T2 on a calibration plate CP1, 2 three-dimensional laser scanner 32 performs a second test marking on the calibration plate CP1 with the second target pattern T2. The second target pattern T2 of the first three-dimensional laser scanner 31 and the second target pattern T2 of the second three-dimensional laser scanner 32 may have the same shape.

The target position irradiated on the calibration plate CP1 by the first three-dimensional laser scanner 31 and the target position irradiated on the calibration plate CP1 by the second three-dimensional laser scanner 32 are set to be equal to each other .

9 and 10A, the step of adjusting the height of the calibration plate CP may be performed a plurality of times. For example, the step of adjusting the height of the calibration plate CP may be two times.

The step of adjusting the height of the calibration plate CP includes a step S141 of increasing the height of the calibration plate CP so as to be larger than the reference height and a step S142 of reducing the height of the calibration plate CP so as to be smaller than the reference height ).

In the step S141 of increasing the height of the calibration plate CP1 so that the height of the calibration plate CP1 is larger than the reference height, the height can be increased in a range of 5 mm or less from the reference height.

In the step S142 of reducing the height of the calibration plate CP2 so that the height of the calibration plate CP2 is smaller than the reference height, the height can be reduced in the range of 5 mm or less from the reference height.

9, after the height of the calibration plate CP is increased, the second test marking is performed by the plurality of three-dimensional laser scanners 31 and 32, and then the Z-axis setting is corrected (S1501, S1502, S1601, S1602). After the height of the calibration plate CP is reduced, the second test marking is performed by the plurality of three-dimensional laser scanners 31 and 32, and then the Z-axis setting is corrected (S1501, S1502, S1601, S1602 ).

Although the step S141 for increasing the height of the calibration plate CP is performed before the step S142 for reducing the height of the calibration plate CP in FIG. 9, the present invention is not limited to this and the order may be changed.

The laser machining apparatus 1 including a plurality of three-dimensional laser scanners 31 and 32 that have undergone the above-described calibration steps may have a machining error of 15 mu m or less.

Although two laser scanners 31 and 32 are illustrated as examples of the three-dimensional laser scanners 31 and 32 in the above-described embodiment, the present invention is not limited to this, and a plurality of three-dimensional laser scanners 31, 32, , And of course, may be three or more. Accordingly, three or more laser beams L1, L2, L3 can be irradiated onto one wafer W at the same time.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined by the appended claims.

One … Laser processing equipment
11 ... The first laser-
12 ... The second laser-
31 ... The first three-dimensional laser scanner
32 ... The second three-dimensional laser scanner
40 ... Measuring device
50 ... Memory
60 ... Processor
70 ... Work table
90 ... User interface
CP ... Calibration plate
T1, T2 ... Target pattern
R11, R12, R21, R22 ... Actual pattern

Claims (12)

Disposing a calibration plate having a flat shape at a reference height;
Each of the plurality of three-dimensional laser scanners performing a first test marking with a first target pattern on the calibration plate;
Measuring a first error between an actual pattern actually formed on the calibration plate and the first target pattern by the first test marking and correcting a plane setting of each of the plurality of three- dimensional laser scanners based on the first error ;
Adjusting a height of the calibration plate;
Performing a second test marking with a predetermined second target pattern on the calibration plate at a changed height, each of the plurality of three-dimensional laser scanners taking into account the height change of the calibration plate; And
Measuring a second error between an actual pattern actually formed on the calibration plate and the second target pattern by the second test marking and comparing the plane setting of each of the plurality of three- And calibrating a setting along a vertical direction of the three-dimensional laser scanner. The method according to claim 1,
Wherein the plurality of three-dimensional laser scanners include a first three-dimensional laser scanner and a second three-dimensional laser scanner,
The first target pattern of the first three-dimensional laser scanner and the first target pattern of the second three-dimensional laser scanner have a plurality of third Dimensional laser scanner. 3. The method of claim 2,
Wherein the step of performing the first test marking irradiates the first three-dimensional laser scanner and the second three-dimensional laser scanner at the same target positions. 3. The method of claim 2,
In the step of performing the second test marking, the second target pattern of the first three-dimensional laser scanner and the second target pattern of the second three-dimensional laser scanner have a plurality of three Dimensional laser scanner. 5. The method of claim 4,
Wherein the step of performing the second test marking irradiates the first three-dimensional laser scanner and the second three-dimensional laser scanner at the same target position with each other. The method according to claim 1,
Wherein adjusting the height of the calibration plate includes increasing the height of the calibration plate and reducing the height of the calibration plate. The method according to claim 1,
Wherein the height adjustment of the calibration plate is +/- 5 mm or less. The method according to claim 1,
Wherein a plurality of three-dimensional laser scanners that have been calibrated have a machining error range of 15 m or less. The method according to claim 1,
Wherein each of the plurality of three-dimensional laser scanners comprises:
And a first to a third deflecting unit for deflecting the incident laser beam in a first direction, a second direction and a thickness direction of the object, respectively, which are orthogonal to each other. A work table on which an object to be processed is mounted;
A measuring device for measuring a three-dimensional shape of the object to be processed;
A plurality of three-dimensional laser scanners calibrated according to any one of claims 1 to 7; And
And a processor for controlling the plurality of three-dimensional laser scanners based on data measured by the measuring device,
Wherein a machining error of the plurality of three-dimensional laser scanners is 15 占 퐉 or less. 11. The method of claim 10,
Wherein the object to be processed is a wafer having a diameter of 300 mm or more. 11. The method of claim 10,
Wherein each of the plurality of three-dimensional laser scanners comprises:
And first to third deflection units for deflecting the incident laser beam respectively in a first direction, a second direction, and a thickness direction of the object perpendicular to each other.

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