Laser devices and laser irradiation methods

Abstract

A laser device and a laser irradiation method are provided. The laser device according to an embodiment includes a laser source, a laser deflector, an objective lens, an image capturing device, and a corrector. The laser source provides a laser beam to a processing object; the laser deflector deflects the laser beam supplied from the laser source; the objective lens focuses the scattered light incident on the processing object and then scattered by the laser beam; the image capturing device captures an image of the scattered light focused in the objective lens; and the corrector corrects the position of the laser beam using the captured image.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2020-0122320, filed with the Korean Intellectual Property Office on September 22, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to laser devices including beam calibrators and methods for irradiating lasers using the laser devices. More specifically, this disclosure relates to laser devices including beam calibrators capable of improving the accuracy of laser irradiation positions. Background Technology

[0004] Generally, when processing is performed using a laser device, the alignment mark is located on the front of the object being irradiated by the laser, and the position of the laser beam of the laser device is corrected by using the position of the alignment mark on the front.

[0005] Various disclosures exist regarding methods for correcting the laser beam of such laser devices.

[0006] U.S. Patent 6,501,061 discloses a method for determining scanner coordinates to precisely position a focused laser beam. The focused laser beam sweeps across a region of interest (e.g., an opening) on ​​the working surface of a laser scanner. The position of the focused laser beam is detected by a photodetector at predetermined time intervals or spatial intervals, or when the focused laser beam passes through an opening in the working surface. The detected position of the focused laser beam is used to generate a relationship between the actual beam position and the data-based scanner position. The data regarding the relationship between the actual beam position and the scanner position can be used to determine whether the focused laser beam is located at the center of the opening corresponding to the desired position, or to determine the precise position coordinates of the beam.

[0007] US Patent Publication US 2010 / 0292947 discloses a method for performing a scanning head calibration process using guide marks. Calibration marks are formed on an object using a laser, captured by a camera, and the positional error between the guide marks and the calibration marks is measured and corrected. In this method, the object is damaged with a laser during the calibration operation to form the calibration marks, and calibration can only be performed when the calibration marks and guide marks are in the same plane.

[0008] European Patent EP 1666185 relates to a laser processing machine and method having an image acquisition and processing apparatus, and according to this patent, laser calibration processing can be performed using a pattern of an object (e.g., a microchip circuit pattern or a display pixel structure) without using a calibration substrate with special alignment marks. However, this is also difficult to apply when the laser is used to perform the processing on the side of the object rather than on the front surface where the pattern of the object itself is formed.

[0009] The information disclosed in this background section is intended only to enhance the understanding of the background of the described technology, and therefore may contain information that does not constitute prior art known to those skilled in the art in this country. Summary of the Invention

[0010] The implementation has been dedicated to providing a laser device including a beam calibrator and a laser irradiation method using the laser device, wherein the beam calibrator performs processing on a surface different from the surface where the alignment mark is located, thereby improving the accuracy of the laser irradiation position even when the alignment mark is located on a surface different from the surface where the processing is performed.

[0011] It is obvious that the purpose of the implementation is not limited to the above-described purpose, and various extensions can be made without departing from the spirit and scope of the implementation.

[0012] The laser device according to the embodiment includes a laser source, a laser deflector, an objective lens, an image capture device, and a corrector. The laser source provides a laser beam to the object being processed. The laser deflector deflects the laser beam supplied from the laser source. The objective lens focuses the scattered light incident on the object being processed and then scattered. The image capture device captures an image of the scattered light focused in the objective lens. The corrector corrects the position of the laser beam by using the captured image.

[0013] The corrector may include memory and a calculator.

[0014] The object being processed may include a first surface and a second surface perpendicular to each other. The object being processed includes a plurality of alignment marks arranged on the first surface, and a laser beam is irradiated onto the second surface of the object being processed.

[0015] The area of ​​the second surface may be smaller than the area of ​​the first surface, and the multiple alignment marks may be multiple pixels formed in the first surface.

[0016] The objective lens can be arranged to face the second surface.

[0017] Objective lenses can have a numerical aperture of less than 1.

[0018] The objective lens can have a numerical aperture of 0.65.

[0019] The image capturing device can be arranged to face the first surface.

[0020] The image capturing device can capture images with multiple alignment marks.

[0021] The laser irradiation method according to the embodiment includes: supplying a laser beam having a first intensity to a processing object; irradiating the processing object's surface with the laser beam by scanning the supplied laser beam; capturing a first image of the scattered light of the laser beam incident on and then scattered on the surface of the processing object and a second image of an alignment mark of the processing object; calculating a positional error of the laser beam using the captured first and second images; and correcting the calculated positional error.

[0022] Laser irradiation methods may also include: focusing the scattered light of a laser beam using an objective lens.

[0023] Image capture may include capturing a first image of the focused, scattered light.

[0024] Calculating the positional error of the laser beam may include: a first error calculation for calculating the positional difference between the captured first image and the second image.

[0025] The first error calculation can be to calculate the error of the laser beam in the first direction or the error of the laser beam in the second direction perpendicular to the first direction.

[0026] The calculation of the laser beam position error may also include a second error calculation to determine the position difference by comparing the captured first image with a reference image stored in the corrector.

[0027] The second error calculation can be performed by calculating the error of the laser beam in a third direction perpendicular to the first and second directions.

[0028] Calibration may include controlling the position of the laser beam.

[0029] A laser scanner can be used to control the position of the laser beam.

[0030] The laser irradiation method may further include: supplying a laser beam with a second intensity to the object to be processed after calibration, wherein the second intensity may be higher than the first intensity.

[0031] The initial intensity of the laser beam can be 0.01 J / cm. 2 Up to 0.1 J / cm 2 Furthermore, the second intensity of the laser beam can be 1 J / cm. 2 Or larger.

[0032] According to the laser device including a beam calibrator and the laser irradiation method using the laser device according to the embodiment, even when the alignment mark is arranged on a surface different from the surface on which the process is performed, the accuracy of the position of the laser irradiation is improved, and correspondingly, the accuracy of the laser irradiation process can be improved.

[0033] Obviously, the effects of the implementation method are not limited to those described above, and various extensions can be made without departing from the spirit and scope of the implementation method. Attached Figure Description

[0034] Figure 1 This is a block diagram of a laser device according to an embodiment.

[0035] Figure 2 The processing object according to the implementation method is shown.

[0036] Figure 3 This is a schematic diagram of a laser device according to an embodiment.

[0037] Figure 4 This is a flowchart showing the laser irradiation method of the laser device according to an embodiment.

[0038] Figure 5 and Figure 6 yes Figure 3 A magnified view of a portion of it.

[0039] Figure 7A and Figure 7B Provided for describing the operation of the objective lens according to the embodiments.

[0040] Figure 8 The first operation of the beam calibrator of the laser device according to an embodiment is shown.

[0041] Figure 9 Examples of images and results from an image measuring device according to an embodiment are shown.

[0042] Figure 10 The second operation of the beam calibrator of the laser device according to the embodiment is shown.

[0043] Figure 11 An example of an image according to an embodiment is shown.

[0044] Figure 12 An example of an image according to an embodiment is shown.

[0045] Figure 13 An example of the results of an image measuring device according to an embodiment is shown. Detailed Implementation

[0046] In the following description, the invention will be given more fully with reference to the accompanying drawings, which illustrate embodiments of the invention. As those skilled in the art will appreciate, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention.

[0047] The accompanying drawings and descriptions are to be considered illustrative in nature, not restrictive. Throughout the specification, similar reference numerals refer to similar elements.

[0048] In the accompanying drawings, the dimensions and thicknesses of each element are arbitrarily shown for ease of description, and the invention is not necessarily limited to those shown in the drawings. In the drawings, the thicknesses of layers, films, panels, regions, etc., are exaggerated for clarity. Additionally, in the drawings, the thicknesses of some layers and regions are exaggerated for better understanding and ease of description.

[0049] It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, the element can be directly on the other element, or an intermediary element may also be present. Conversely, when an element is referred to as being "directly" on another element, no intermediary element is present. Furthermore, throughout the specification, the phrase "on" the target element will be understood as being located above or below the target element, and not necessarily as being located "on the upper side" based on a direction opposite to the direction of gravity.

[0050] Furthermore, unless there is an explicit description to the contrary, the wording “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of the stated element without excluding any other elements.

[0051] Furthermore, throughout the instruction manual, the phrase "on a plane" means viewing the target portion from the top, and the phrase "on a section" means viewing the section formed by vertically cutting the target portion from the side.

[0052] Throughout this specification, “connection” means not only when two or more constituent elements are directly connected, but also when two or more constituent elements are indirectly connected through another constituent element, or when there is a physical or electrical connection, and “connection” can include situations where the substantially constituent parts are connected to each other even though they are referred to by different names depending on their location or function.

[0053] Reference Figure 1 , Figure 2 and Figure 3 The laser device 100 according to the embodiments will now be described. Figure 1 This is a block diagram of the laser device 100 according to the embodiment. Figure 2The processing object 200 according to the embodiment is shown, and Figure 3 This is a schematic diagram of the laser device 100 according to an embodiment.

[0054] Reference Figure 1 According to the embodiment, the laser device 100 includes a laser source 1 that provides a laser beam 2 to a processing object 200, and a beam calibrator 20 that calibrates the laser beam 2. The beam calibrator 20 includes a laser deflector 3, an objective lens 4, an image capture device 6, and a corrector 7. The corrector 7 includes a memory 7a and a calculator 7b.

[0055] Reference Figure 2 The processing object 200 will now be described. The processing object 200 includes a first surface f1 and a second surface f2 perpendicular to the first surface f1. The first surface f1 is a plane formed by intersecting a first direction X with a second direction Y, and may be the top or bottom surface of the processing object 200. The second surface f2 is a plane formed by intersecting the second direction Y with a third direction Z perpendicular to both the first and second directions X and Y, and may be a side surface of the processing object 200. In this example, the area of ​​the first surface f1 may be larger than the area of ​​the second surface f2. The processing object 200 includes a plurality of alignment marks 5 formed in the first surface f1. The plurality of alignment marks 5 may be a plurality of pixels formed in the first surface f1.

[0056] The laser beam processing can be performed on the second surface f2 instead of on the first surface f1 where the plurality of alignment marks 5 are formed. For example, the object being processed 200 can be a substrate with a plurality of pixels, and the plurality of pixels can be formed in the first surface f1. In order to form a display device with a large area, a plurality of substrates with a plurality of pixels can be connected to each other to create a large display device, and in this case, signal lines for signal transmission must be formed in the side surfaces where the plurality of substrates are connected to each other (i.e., in the second surface f2).

[0057] As previously mentioned, when laser irradiation is performed on the second surface f2 of the processed object 200 to form signal lines, it is necessary to determine whether the laser is accurately irradiated to the expected position in order to calibrate the laser irradiation position. However, since the alignment mark 5 is not located on the second surface f2 being processed, it is difficult to perform a general calibration method.

[0058] Now, will be with Figure 1 Refer to together Figure 3 This describes a beam calibrator 20 for calibrating a laser beam from a laser device 100 according to an embodiment that irradiates a side surface (i.e., a second surface f2 without alignment marks 5) of a processed object 200.

[0059] As previously described, the beam calibrator 20 includes a laser deflector 3, an objective lens 4, an image capture device 6, and a calibrator 7.

[0060] Laser source 1 supplies a laser beam with a desired intensity within a desired time period, and laser deflector 3 deflects the laser beam supplied from laser source 1 and irradiates the deflected laser beam in a direction perpendicular to the second surface f2 of the object being processed 200.

[0061] Objective lens 4 is positioned facing the second surface f2 of the object being processed 200, and focuses the scattered light scattered at the second surface f2 of the object being processed 200.

[0062] The image capturing device 6 captures a first image E1 (not shown) formed by scattered light scattered at the second surface f2 by using light focused by the objective lens 4, and captures a second image E2 (not shown) formed on the first surface f1 of the processing object 200 by using light focused by the objective lens 4.

[0063] The calculator 7b of the calibrator 7 determines whether the first image E1 and the second image E2 captured by the image capture device 6 match each other to calculate the error in the second direction Y, and calculates the error in the third direction Z by comparing the data stored in the memory 7a. As previously described, the position to be irradiated by the laser beam is moved to calibrate the calculated errors in the second direction Y and the third direction Z.

[0064] Next, will be with Figure 1 , Figure 2 and Figure 3 Refer to together Figure 4 , Figure 5 , Figure 6 , Figure 7A , Figure 7B , Figure 8 and Figure 9 The first operation of the beam calibrator 20 of the laser device 100 according to the embodiment will be described.

[0065] Figure 4 This is a flowchart showing the laser irradiation method of the laser device 100 according to the embodiment. Figure 5 and Figure 6 yes Figure 3 A magnified image of a portion. Figure 7A and Figure 7B Provided for describing the operation of objective lens 4 according to the embodiment, Figure 8 The first operation of the beam calibrator 20 of the laser device 100 according to an embodiment is shown, and Figure 9 Examples of images and results from an image measuring device according to an embodiment are shown.

[0066] Reference Figure 3 and Figure 4 As described above, the laser irradiation method according to the embodiment includes the step of supplying a laser beam having a first intensity to the object to be processed 200 using a laser source 1 (S100). The first intensity of the laser beam may be less than the intensity of the laser beam actually used in the processing. For example, the first intensity of the laser beam may be less than or equal to 0.1 J / cm. 2 As described above, in the laser irradiation method, a relatively weak first intensity laser beam is irradiated during the beam calibration operation of the beam calibrator 20, so that the beam calibration operation can be performed without damaging the object being processed 200.

[0067] Next, the laser irradiation method according to the embodiment includes the following steps (S200): while deflecting the laser beam supplied from the laser source 1 to be perpendicular to the second surface f2 of the object to be processed 200 by using a laser deflector 3, the laser beam is irradiated while scanning in a direction parallel to the second direction Y and the third direction Z.

[0068] Next, the laser irradiation method according to the embodiment includes: such as Figure 5 As shown, the step (S300) of focusing the scattered light S scattered from the second surface f2 of the processed object 200 using the objective lens 4, and as shown... Figure 6 As shown, the step (S400) involves capturing a first image E1 formed by scattered light S scattered from the second surface f2 using the image capturing device 6 and capturing a second image E2 formed on the first surface f1 of the processing object 200 using light focused by the objective lens 4. In the capture of the first image E1 and the second image E2 (S400), the first image E1 and the second image E2 can be captured in one frame.

[0069] will with Figure 5 and Figure 6 Refer to together Figure 7A and Figure 7B This will be described in detail.

[0070] As previously described, in the captured image (S400), not only can a second image E2 of a plurality of alignment marks 5 formed in the first surface f1 of the processed object 200 be captured, but also a first image E1 of a laser beam that is vertically irradiated onto the second surface f2 of the processed object 200 can be captured.

[0071] That is, the image capture device 6 simultaneously captures a second image E2 of multiple alignment marks 5 arranged in the first surface f1 of the processing object 200 and a first image E1 formed by scattered light S scattered from the second surface f2 perpendicular to the first surface f1 of the processing object 200. In this case, the image capture device 6 is able to capture the first image E1 and the second image E2 in one frame.

[0072] like Figure 5 and Figure 6 As shown, since the image capturing device 6 is located on the first surface f1 of the processing object 200, it is possible to capture the second image E2 of the plurality of alignment marks 5 arranged in the first surface f1 of the processing object 200. However, it is difficult to directly capture the scattered light S scattered from the second surface f2 of the processing object 200, and therefore the scattered light S is captured by a step (S300) of focusing the scattered light S scattered from the second surface f2 of the processing object 200 using the objective lens 4.

[0073] like Figure 5 As shown, the objective lens 4 can be positioned facing the second surface f2 of the object being processed 200 irradiated by the laser beam. The laser beam irradiating the second surface f2 of the object being processed 200 is scattered at the second surface f2, and the scattered light S can be focused in the objective lens 4. The first image E1 formed by the scattered light S focused in the objective lens 4 is captured by the image capturing device 6.

[0074] Reference Figure 7A As shown in Equation 1, the amount of scattered light I(θ) scattered at the second surface f2 of the processed object 200 can be estimated by Lambert's cosine law.

[0075] Equation 1

[0076] I(θ) = I0cos(θ)

[0077] In addition, the amount of scattered light sensed by the image sensor of the imaging system including objective lens 4 is changed according to the numerical aperture NA of objective lens 4, and the numerical aperture NA is calculated as given in Equation 2.

[0078] Equation 2

[0079] NA = tan(α)

[0080] For example, the amount I of scattered light incident on the image sensor through objective lens 4 with numerical aperture NA. camera It can be calculated using Equation 3.

[0081] Equation 3

[0082]

[0083] Here, φ is the azimuth angle relative to the direction of the incident laser beam. When the numerical aperture NA of the objective lens 4 of the imaging system is not too high (e.g., when the numerical aperture NA is less than 1 or NA << 1), the intensity of the scattered light incident on the image sensor (i.e., the amount of scattered light I) can be calculated as shown in Equation 4. camera ).

[0084] Equation 4

[0085] I camera ≈I0NA 3

[0086] As shown in Equation 4, in order to sense a large amount of scattered light at the second surface f2, which is the side surface of the processing object 200, it is desirable to have a numerical aperture NA that is less than 1 but as large as possible. For example, it is preferred that the numerical aperture is greater than about 0.1.

[0087] Figure 7B An example of an image captured by an image sensor when the numerical aperture of objective lens 4 is 0.65 is shown. Figure 7B The image shows a laser beam irradiating an area of ​​approximately 8 μm with a power of approximately 10 mW and a pulse frequency of approximately 1 MHz. This corresponds to approximately 0.02 J / cm². 2 Energy density.

[0088] exist Figure 7B In the image, the bright spot at the center corresponds to the position of the laser beam illuminating the side surface of the object being processed 200.

[0089] As previously described, by using an objective lens 4 with a numerical aperture greater than about 0.1, an image formed by scattered light caused by the scattering of a laser beam irradiating the side surface of the object being processed 200 can be captured.

[0090] As previously described, by using the image capture device 6, a first image E1 (not shown) formed by scattered light from a second surface f2 perpendicular to the first surface f1 of the object being processed 200 and a second image E2 (not shown) located on the first surface f1 of the object being processed 200 are captured by using light focused by the objective lens 4. In this case, the first image E1 and the second image E2 can be captured by the image capture device 6 in one frame.

[0091] After the step of capturing the first image E1 and the second image E2 (S400), the laser irradiation method according to the embodiment includes: Figure 8 The step shown is (S500) in which the corrector 7 uses the first image E1 and the second image E2 to calculate the error in the horizontal direction (i.e., the first direction X and the second direction Y).

[0092] The calculator 7b of the corrector 7 calculates the differences dx_correction and dy_correction between the positions dx and dy according to the first image E1 and the positions dx_ref and dy_ref according to the second image E2 using the first image E1 and the second image E2 captured by the image capture device 6. The position differences are calculated as given in equations 5a and 5b.

[0093] dx_correction = dx_ref - dx<Equation 5a>

[0094] dy_correction=dy_ref-dy<Equation 5b>

[0095] As described above, the laser irradiation method according to the embodiment includes: a first correction (S600) for correcting the laser beam irradiation position in the first direction X and the second direction Y by using calculated position differences (dx_correction and dy_correction).

[0096] Next, refer to Figure 9 The program interface of the corrector 7 used in the first correction (S600) is described.

[0097] exist Figure 9 In the first interface (a), an example of a first image E1 (laser beam) and a second image E2 (reference image) is shown.

[0098] exist Figure 9 In the second interface (b), based on one of the multiple alignment marks 5, the center of one of the alignment marks 5 in the fixed area (the area marked by the quadrilateral in (a)) is displayed as 0.

[0099] exist Figure 9 In the third interface (c), the intensity of the laser beam is plotted as a curve by using the first image E1 of the laser beam detected according to the position, while the position of the laser beam is moved by 2 μm relative to an alignment mark 5.

[0100] Reference Figure 9 The intensity of the laser beam varies within a range of approximately 1 μm or less, and the portion with the maximum intensity of the laser beam is the location where the laser beam is irradiated. Correspondingly, the position of the laser beam can be adjusted to the center of alignment mark 5. Accordingly, the position of the laser beam can be corrected within a range of 1 μm or less.

[0101] Next, will be with Figure 1 , Figure 2 , Figure 3 and Figure 4 Refer to together Figure 10 , Figure 11 , Figure 12 and Figure 13 The second operation of the beam calibrator 20 of the laser device 100 according to the embodiment will be described. Figure 10 The second operation of the beam calibrator 20 of the laser device 100 according to the embodiment is shown. Figure 11 An example of an image according to an embodiment is shown. Figure 12 An example of an image according to an embodiment is shown, and Figure 13 An example of the results of an image measuring device according to an embodiment is shown.

[0102] The first operation of the beam calibrator 20 of the laser device 100 is to calibrate the position of the laser beam in the horizontal direction (first direction X and second direction Y), and the second operation of the beam calibrator 20 of the laser device 100 is to calibrate the position of the laser beam 2 in the vertical direction (third direction Z).

[0103] Return to reference Figure 4 The laser irradiation method according to the embodiment includes the step of determining the error in the third direction Z by using a first image E1 using a corrector 7 (S700).

[0104] First, in the step of irradiating the laser beam (S200), the laser beam irradiated from the laser source 1 can be irradiated by using the laser deflector 3 while continuously changing its position along the third direction Z.

[0105] As previously described, the first image E1 formed by the scattered light of the laser beam that is continuously changing position along the third direction Z is captured by the steps of focusing the scattered light (S300) and capturing the focused scattered light (S400).

[0106] In the step (S700) of determining the error in the third direction Z, the captured first image E1 is compared with the image data stored in the memory 7a of the corrector 7, and accordingly, the error in the third direction Z is calculated by the calculator 7b of the corrector 7.

[0107] This will refer to Figure 10 , Figure 11 and Figure 12 Provide a detailed description.

[0108] Reference Figure 10 In the step of irradiating the laser beam (S200), the position of the laser beam irradiated while continuously changing position along the third direction Z will be described. For example... Figure 10As shown, the laser beam can be scanned and irradiated while changing position from the reference position Z0 of the second surface f2 of the processed object along the upward direction Z+ and the downward direction Z-.

[0109] The reference position Z0 is the position to be processed, and it can be the position for focusing with objective lens 4.

[0110] Figure 11 An image showing the image data stored in the memory 7a of the corrector 7 is displayed. (Refer to...) Figure 11 At the reference position Z0, the spot size of the first image E1 of the laser beam is small, which means that the laser beam is focused at an accurate position. Furthermore, when deflected upwards (Z+) from the reference position Z0 and downwards (Z-), the laser beam image has a semi-circular shape with opposite directions. As previously described, by comparing the image data stored in the memory 7a of the calibrator 7 with the actually measured first image E1 of the laser beam, it is possible to determine how much the laser beam has deflected from the reference position Z0 along the third direction Z.

[0111] Figure 12 An example is shown where a laser beam (0 μm) is irradiated at a reference position Z0 using an objective lens 4 having a numerical aperture of approximately 0.65, and a first image E1 is captured at a position (+10 μm) deflected approximately 10 μm upwards from the reference position Z0 in the Z+ direction, and at a position (-10 μm) deflected approximately 10 μm downwards from the reference position Z0 in the Z- direction. Figure 12 The image shows a laser beam irradiated with a laser power of approximately 10 mW and a laser pulse of approximately 1 MHz onto a region of approximately 8 μm. This corresponds to approximately 0.02 J / cm². 2 Energy density.

[0112] Reference Figure 12 , and reference Figure 11 The situation described is similar, with the laser beam (0 μm) illuminating the reference position Z0 having an image focused in a narrow region, and the laser beam illuminating the position deflected upwards by about 10 μm from the reference position Z0 and the laser beam illuminating the position deflected downwards by about -10 μm from the reference position Z0 having images of semi-circular shapes with opposite directions.

[0113] exist Figure 13 In this context, the spot size of the first image E1 of the laser beam, illuminated while scanning along the third direction Z, is measured. (Refer to...) Figure 13 The position where the spot size of the first image E1 is the smallest (i.e., the position where it is deflected by about 8 μm) is the position where the laser beam is most focused, and this is the position where the actual processing will be performed.

[0114] In the step (S700) of determining the error in the third direction Z in the laser irradiation method according to the embodiment, the image data stored in the memory 7a of the calibrator 7 is compared with the first image E1 of the actually measured laser beam to calculate how much the laser beam has deflected from the reference position along the third direction Z. The laser irradiation method according to the embodiment includes a step (S800) of correcting a second position error of the laser beam in the third direction Z by using the value calculated in the step (S700) of determining the error in the third direction Z.

[0115] In the steps of correcting the first position error (S600) and correcting the second position error (S800), the position of the irradiating laser beam or the position of the object being processed 200 can be changed. The position of the irradiating laser beam can be changed to the desired position using a laser scanner. For example, the laser scanner can be a galvanometer or a polygon scanner, and may include at least two reflectors.

[0116] The laser irradiation method according to the embodiment includes: after correcting the position of the laser beam irradiating the second surface f2 of the object to be processed 200 by a step of correcting a first position error (S600) and a step of correcting a second position error (S800), irradiating a laser beam of a second intensity required for actual processing (S900). The second intensity of the laser beam used in the actual laser processing is approximately 1 J / cm². 2 Or larger.

[0117] As described above, according to the laser irradiation method of the embodiment, after irradiating a second surface f2 perpendicular to a first surface f1 on which a plurality of alignment marks 5 are formed among a plurality of surfaces of the object to be processed 200 with a relatively weak first intensity laser beam, a first image E1 formed by the laser beam and a second image E2 on the plurality of alignment marks 5 are captured, and a step of correcting a first position error in the first direction X and the second direction Y (S600) and a step of correcting a second position error in the third direction Z (S800) are performed based on the captured image, and then a laser beam with a second intensity required for actual processing is irradiated so that even on the side surface of the object to be processed 200 where the alignment marks 5 are not formed, the laser beam can irradiate the correct position.

[0118] While this disclosure has been described in conjunction with embodiments currently considered practical, it is to be understood that the invention is not limited to the disclosed embodiments. Rather, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A laser device comprising: a laser source that supplies a laser beam to a processing object; a laser deflector that deflects the laser beam supplied from the laser source; an objective lens that focuses scattered light of the laser beam that is incident on the processing object and then scattered; an image capturing device that captures an image of the scattered light focused in the objective lens; and a corrector that corrects a position of the laser beam by using the captured image; wherein the processing object includes a first surface and a second surface perpendicular to the first surface, the processing object includes a plurality of alignment marks arranged on the first surface, and the laser beam is irradiated to the second surface of the processing object. The corrector includes a memory and a calculator.

2. The laser device of claim 1, wherein, An area of the second surface is smaller than an area of the first surface, and 3. The laser device of claim 1, wherein, the plurality of alignment marks are a plurality of pixels formed in the first surface. The objective lens is arranged to face the second surface of the processing object.

4. The laser device of claim 1, wherein, The objective lens has a numerical aperture of less than 1.

5. The laser device of claim 4, wherein, The objective lens has a numerical aperture of 0.

65.

6. The laser device of claim 5, wherein, The image capturing device is arranged to face the first surface of the processing object.

7. The laser device of claim 1, wherein, The image capturing device captures an image of the plurality of alignment marks.

8. The laser device of claim 1, wherein, 9. A laser irradiation method comprising the steps of: supplying a laser beam having a first intensity to a processing object; irradiating the laser beam to a plurality of positions of a surface of the processing object by scanning the supplied laser beam; capturing a first image of scattered light of the laser beam that is incident on the surface of the processing object and then scattered and a second image of an alignment mark of the processing object; calculating a position error of the laser beam by using the captured first image and the captured second image; and correcting the calculated position error; wherein the processing object includes a first surface and a second surface perpendicular to the first surface, the processing object includes a plurality of alignment marks arranged on the first surface, and the laser beam is irradiated to the second surface of the processing object. ​

Images