Laser processing method and laser processing device

Abstract

To provide a laser processing method and a laser processing device that can improve throughput when laser ablation processing a workpiece.SOLUTION: A laser processing method includes a protective film detection step of measuring a protective film applied to a workpiece placed on a processing table to obtain data relating to the protective film, a positioning step of determining the position of the workpiece, and a processing step of laser processing a processing line on the workpiece, and the positioning step uses the data relating to the protective film obtained in the protective film detection step to detect at least a part of the position of the workpiece.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laser processing method and a laser processing apparatus. [Background technology]

[0002] For example, a laser processing method is known in which a wafer on which a device layer is formed is cut by laser ablation. With this laser processing method, melted debris may be generated during laser ablation of the wafer, which may adhere to the device layer. To address this issue, a protective film is formed on the surface of the wafer before laser ablation of the wafer. By washing away the protective film after laser ablation, the debris can be removed along with the protective film. This prevents debris from adhering to the device layer.

[0003] Here, the protective film is applied to the surface of the wafer by spin coating or the like while the wafer is placed on a coating table, for example. The protective film may have areas of coating defects, incomplete coating, or an abnormal film thickness. In such cases, the defective coating or incomplete coating causes debris to adhere directly to the device layer at those areas, resulting in wafer defects. Furthermore, if the film thickness is too thick, the protective film may impede the transmission of laser light, leading to processing defects. If the film thickness is too thin, similar to the defective coating or incomplete coating, debris may adhere directly to the device layer at those areas, resulting in wafer defects. Therefore, in order to improve the yield when laser ablation processing wafers, it is important to inspect the protective film for any coating defects, incomplete coating, or abnormal film thickness before processing the wafer.

[0004] That is, after the protective film is applied to the wafer placed on the coating table, the protective film is observed and the coating status is inspected. If the inspection results show that there are no coating defects, incomplete coating, or abnormal film thickness of the protective film, the wafer is transported from the coating table and placed on the processing table. An alignment microscope is used to observe a wafer placed on a processing table at low magnification, and rough alignment is performed to roughly position the wafer. After rough alignment is performed, an alignment microscope is used to observe the wafer at high magnification, and fine alignment is performed to precisely position the wafer. After fine alignment is performed, the processing lines on the wafer are cut by laser ablation processing (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-178427 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in conventional laser processing methods, the protective film is inspected while the wafer is placed on the coating table, and after inspection, the wafer is transported and placed on the processing table, where rough alignment and fine alignment are performed. In other words, in conventional laser processing methods, the protective film inspection and wafer alignment are performed as separate inspection processes. As a result, laser ablation processing of the wafer (i.e., the workpiece) takes a long time, and there is room for improvement in terms of throughput.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a laser processing method and a laser processing apparatus that can improve throughput when laser ablation processing a workpiece. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following means. <1> A laser processing method according to one aspect of the present invention includes a protective film detection step of measuring a protective film applied to a workpiece placed on a processing table to obtain data related to the protective film, a positioning step of determining the position of the workpiece, and a processing step of laser processing a processing line of the workpiece, wherein the positioning step uses the data related to the protective film obtained in the protective film detection step to detect at least a portion of the position of the workpiece. <2> the above <1> In the laser processing method described above, the positioning step includes a contour measurement step, a rough alignment step, and a fine alignment step, and data regarding the protective film may be used in at least one of the contour measurement step, the rough alignment step, and the fine alignment step. <3> the above <1> or <2> In the laser processing method described in the above, the data related to the protective film may include at least one of two-dimensional image data, one-dimensional image data, intensity data, and spectrum data of the protective film. <4> the above <1> ~ <3> In the laser processing method described in any one of the above, at least a portion of the data regarding the protective film acquired in the protective film detection process may be used in at least one of the outer shape measurement process, the rough alignment process, and the fine alignment process.

[0009] <5> A laser processing apparatus according to one embodiment of the present invention is a laser processing apparatus comprising: a protective film detection unit that measures a protective film applied to a workpiece placed on a processing table and acquires data related to the protective film; a positioning unit that determines the position of the workpiece; and a processing unit that laser processes the processing line of the workpiece, wherein the positioning unit uses the data related to the protective film acquired by the protective film detection unit to detect at least part of the position of the workpiece. <6> the above <5> In the laser processing apparatus described in , the positioning unit may include an alignment microscope. [Effects of the Invention]

[0010] According to the present invention, it is possible to improve the throughput when laser ablation processing a workpiece. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a conceptual diagram showing a laser processing device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a conceptual diagram showing a protective film detection unit in the embodiment. [Figure 3] 10 is a plan view showing an example of image data of a wafer acquired by a protective film detection unit in the embodiment. FIG. [Figure 4] 10A and 10B are conceptual diagrams illustrating an example of inspecting a protective film using ultraviolet light irradiated from an irradiation unit in the embodiment. [Figure 5] 10 is a plan view illustrating an example of performing wafer outer shape measurement and rough alignment based on image data acquired by a protective film detection unit in the embodiment. FIG. [Figure 6] 10 is a plan view illustrating an example of performing fine alignment of a wafer based on image data acquired by a protective film detection unit according to an embodiment of the present invention. FIG. [Figure 7] 3 is a flowchart illustrating a laser processing method according to an embodiment. [Figure 8] 10 is a flowchart illustrating a laser processing method according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a laser processing method and a laser processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. Note that in the following embodiments, when the number, numerical value, amount, range, etc. of components are mentioned, unless otherwise specified or when they are clearly limited to a specific number in principle, they are not limited to that specific number and may be more or less than the specific number.

[0013] Furthermore, when referring to the shape or positional relationship of components, etc., it includes things that are substantially similar or approximate to those shapes, etc., unless otherwise specified or when it is clearly considered otherwise in principle.

[0014] In addition, the drawings may exaggerate characteristic parts to make the features easier to understand, and the dimensional proportions of the components may not be the same as in reality. In addition, in cross-sectional views, hatching of some components may be omitted to make the cross-sectional structure of the components easier to understand.

[0015] <Laser processing equipment> FIG. 1 is a conceptual diagram showing a laser processing apparatus according to one embodiment of the present invention. FIG. 2 is a conceptual diagram showing a protective film detection unit. The laser processing apparatus 1 is, for example, an apparatus that cuts processing lines (streets) on a workpiece W by laser ablation processing (laser processing). In this embodiment, the workpiece W will be described as a "wafer W." The wafer W has a device layer DL (semiconductor circuit pattern) formed on the surface of a wafer body Wb. Note that the workpiece W is not limited to a wafer.

[0016] 1, the laser processing apparatus 1 includes a protective film detection unit 2, a positioning unit 3, a control unit 4, and a processing unit 5. The laser processing apparatus 1 performs protective film detection, positioning, and processing of the wafer W on a processing table 11. Therefore, as shown in FIG. 1, the protective film detection unit 2, the positioning unit 3, and the processing unit 5 are disposed above the processing table 11.

[0017] [Protection film detection section] 2, the protective film detection unit 2 places, for example, a wafer W having a protective film Pf applied over the entire surface (i.e., device layer DL) on the processing table 11. As shown in FIG. 2, the protective film detection unit 2 includes a light source 21, a detector 22, condenser lenses 24 and 29, filters 25 and 28, and a dichroic mirror 26. The protective film detection unit 2 guides ultraviolet light 23 emitted from the light source 21 to the wafer W via the condenser lens 24, the filter 25, and the dichroic mirror 26. The protective film detection unit 2 guides reflected light 27 reflected by the wafer W to the detector 22 via the dichroic mirror 26, the filter 28, and the condenser lens 29 to measure the protective film Pf.

[0018] FIG. 3 is a plan view showing an example of image data of a wafer acquired by a protective film detection unit in the embodiment. As shown in FIGS. 2 and 3, the protective film detection unit 2 acquires inspection image data 30 based on the measured protective film Pf with the wafer W placed on the processing table 11. The image data 30 is a high-resolution two-dimensional image of the entire wafer W (i.e., the entire protective film Pf) associated with the absolute position coordinates of the processing table 11. The protective film detection unit 2 transmits the acquired image data 30 to the control unit 4 (see FIG. 1). The image data 30 acquired by the protective film detection unit 2 may be image data of the entire wafer W or image data of a portion of the wafer W.

[0019] Examples of the detector 22 of the protective film detection unit 2 include an area sensor camera, a line sensor camera, a photomultiplier tube, and a spectrometer. The area sensor camera acquires two-dimensional image data of the entire wafer W (the entire protective film). The two-dimensional image data can be used as image data 30 for inspecting the protective film Pf.

[0020] The line sensor camera acquires one-dimensional image data of the entire wafer W (the entire protective film Pf). The one-dimensional image data acquired by the line sensor camera is associated with position information. Therefore, by combining multiple one-dimensional image data and converting the position information into two-dimensional image data, it can be used as image data 30 for inspecting the protective film Pf.

[0021] The photomultiplier tube acquires intensity data of the entire wafer W (the entire protective film Pf). The intensity data acquired by the photomultiplier tube is associated with position information. Therefore, by combining multiple intensity data and converting them into two-dimensional image data based on the position information, the data can be used as image data 30 for inspecting the protective film Pf.

[0022] The spectrometer acquires spectral data of the entire wafer (the entire protective film Pf). The spectral data acquired by the spectrometer is associated with position information. Therefore, by combining multiple spectral data and converting them into two-dimensional image data based on the position information, the data can be used as image data 30 for inspecting the protective film Pf.

[0023] FIG. 4 is a conceptual diagram illustrating an example of inspecting a protective film with ultraviolet light irradiated from an irradiating unit in the embodiment. 4, when the ultraviolet light 23 reaches the surface of the wafer W, the ultraviolet light 23 is reflected by the surface of the wafer W. On the other hand, when the ultraviolet light 23 reaches the protective film Pf, an additive contained in the protective film Pf generates fluorescence 23A in response to the ultraviolet light 23. The ultraviolet light reflected from the wafer W and the fluorescence 23A emitted from the protective film Pf are included in image data 30 (see FIG. 3) acquired by the detector 22.

[0024] The protective film detection unit 2 inspects the protective film Pf for any coating defects, incomplete coating, or film thickness abnormalities based on the acquired image data 30 of the entire wafer W. Note that, although an example of inspecting the protective film Pf based on the fluorescence 23A emitted from the protective film Pf will be described in this embodiment, the protective film may also be inspected using other inspection methods. The protective film detection unit 2 transmits the acquired image data 30 of the entire wafer W and the inspection results to the control unit 4 (see FIG. 1). If the protective film Pf has no coating defects, no coating insufficiencies, or abnormal film thickness and is properly applied, the control unit 4 transmits the image data 30 of the entire wafer W to the positioning unit 3 (see FIG. 1).

[0025] The protective film detection unit 2 may acquire position information and intensity information of the protective film Pf, in addition to the image data 30. The protective film detection unit 2 may acquire, for example, at least one of two-dimensional image data, one-dimensional image data, intensity data, and spectral data of the protective film Pf. Therefore, the data related to the protective film may include at least one of position information and intensity information, specifically at least one of two-dimensional image data, one-dimensional image data, intensity data, and spectral data.

[0026] [Positioning part] FIG. 5 is a plan view illustrating an example in which wafer outer shape measurement and rough alignment are performed based on image data acquired by the protective film detection unit. As shown in FIGS. 1 and 5, if the protective film Pf (see FIG. 2) is free of coating defects, incomplete coating, or film thickness abnormalities, the alignment unit 3 performs outline measurement (SRS) to determine the center position O1 and size (shape) of the wafer W based on image data 30 of the entire wafer W. In alignment, the image data of the entire wafer W may be used, or only a portion of the image data of the entire wafer W may be used. Therefore, when there is no need to distinguish between the image data 30 and the image data of the entire wafer W, the image data 30 may refer to the image data of the entire wafer W and the image data of a portion of the wafer W. Specifically, the alignment unit 3 detects three points 32-34 on the outer periphery (edge) 31 in the image data 30, and determines the outer shape (i.e., size) and the center position O1 of the wafer W from the detected three points 32-34. Note that a point 35 on the outer periphery 31 may also be detected for confirmation. At this time, the center position O1 of the wafer W roughly coincides with the center position O2 (see FIG. 2) of the processing table 11 when the wafer W is placed on the processing table 11.

[0027] Next, the alignment unit 3 performs rough alignment based on the image data 30, determining the θ position and Y position from the streets (processing lines) 37 and alignment pattern 38 (see FIG. 3) of the wafer W. The alignment pattern 38 is part of the layout of the wafer on which devices are mounted. That is, the alignment unit 3 detects the streets 37 and alignment pattern 38 based on the registered patterns for rough alignment in the image data 30. The alignment unit 3 determines the θ position based on the center position O1 of the wafer W and the Y position of the wafer W in the Y direction from the detected streets 37 and alignment pattern 38. The θ position and Y position are determined, for example, by detecting the streets 37 and alignment pattern 38. The rough alignment roughly determines the θ position and Y position of the wafer W.

[0028] FIG. 6 is a plan view illustrating an example in which fine alignment of a wafer is performed based on image data acquired by a protective film detection unit. The positioning unit 3 roughly aligns the wafer W to a rough position, and then performs fine alignment based on the image data 30. That is, the positioning unit 3 detects alignment patterns 38 formed on the wafer W based on the image data 30 and precisely positions the wafer W. The alignment patterns 38 detected by fine alignment are finer than the alignment patterns 38 detected by rough alignment. By performing fine alignment, the positioning unit 3 detects processing lines 37 on the wafer W for each processing axis. More specifically, the positioning unit 3 detects the arrangement of the alignment patterns 38 on the wafer W based on registered patterns 39 for detecting the alignment patterns 38 in the image data 30, and precisely positions the wafer W. The positioning unit 3 detects the processing lines 37 on the wafer W by performing fine alignment. For example, the registered pattern 39 in FIG. 6 is a pattern for detecting processing lines 37 extending in the X direction. A different registered pattern may be used to detect processing lines 37 extending in the Y direction. In this way, the position of the wafer W is determined.

[0029] The reason why alignment is divided into rough alignment and fine alignment is as follows. For example, if only fine alignment is performed and the layout of alignment pattern 38 is to be detected from the beginning based on a model of registered pattern 39, highly accurate detection is required, which takes a long time. Therefore, before fine alignment, the wafer W is roughly positioned by rough alignment. After rough positioning is performed by rough alignment, the alignment pattern 38, whose rough position has been determined, is detected by fine alignment based on registered pattern 39. This allows the alignment pattern 38 to be detected in a short time. Therefore, the wafer W can be precisely aligned by fine alignment in a short time.

[0030] The positioning unit 3 may use the position information and the intensity information for at least a part of the detection of the position of the wafer W (for example, at least one of the outline measurement step, the rough alignment step, and the fine alignment step). In particular, two-dimensional image data, one-dimensional image data, intensity data, or spectrum data may be used.

[0031] [Control Unit] After the positioning unit 3 detects the processing line 37 of the wafer W for each processing axis by fine alignment, the control unit 4 operates the processing unit 5. The processing unit 5 moves the processing table 11 (see FIG. 2) in the Y-axis direction. By moving the processing table 11 in the Y-axis direction, the wafer W is aligned in the Y-axis direction with respect to the laser irradiation unit (not shown) of the processing unit 5.

[0032] [Processing department] After aligning the wafer W in the Y-axis direction, the processing unit 5 moves the wafer W in the X-axis direction and emits a laser beam from the laser irradiation unit of the processing unit 5. The oscillated laser beam is focused and irradiated onto the processing line 37, thereby cutting the processing line 37 by laser ablation processing.

[0033] <Laser processing method> Next, a laser processing method for performing laser ablation processing on the wafer W using the laser processing apparatus 1 will be described with reference to FIGS. FIG. 7 is a flowchart illustrating the laser processing method. 1 to 3 and 7, in step S10, the entire wafer W (i.e., the entire protective film Pf) is acquired as image data 30 by the protective film detection unit 2 (protective film detection step). The image data 30 is associated with the absolute position coordinates of the processing table 11 (see FIG. 4). After acquiring the image data 30, in step S11, the protective film detection unit 2 inspects the protective film Pf (see FIG. 2) based on the image data 30 to determine whether there is any coating defect, incomplete coating, or film thickness abnormality.

[0034] In step S12, it is determined whether the protective film Pf has any coating defects, incomplete coating, or film thickness abnormalities. If the protective film Pf has any coating defects, incomplete coating, or film thickness abnormalities, in other words, if the quality of the protective film is poor, the protective film Pf is recoated, for example, on the wafer W (step S17). On the other hand, if the protective film Pf has no coating defects, incomplete coating, or film thickness abnormalities in the protective film Pf and has been applied appropriately in step S12, in other words, if the quality of the protective film is good, the process proceeds to step S13.

[0035] 1, 5, and 7, in step S13, the alignment unit 3 performs outline measurement (SRS) to detect the center position O1 and size (shape) of the wafer based on the image data 30 acquired by the protective film detection unit 2. Specifically, three points 32 to 34 on the outer periphery 31 are detected in the image data 30, and the outline (i.e., size) of the wafer W and the center position O1 of the wafer W are detected from the detected three points 32 to 34 (alignment step).

[0036] After measuring the outer shape of the wafer, in step S14, rough alignment is performed by the positioning unit 3. That is, the streets 37 and alignment patterns 38 are detected based on the image data 30. From the detected streets 37 and alignment patterns 38, the θ position based on the center position O1 of the wafer W and the Y position of the wafer W in the Y direction are determined. By performing rough alignment, the wafer W is roughly positioned (positioning step).

[0037] After the wafer W is roughly positioned by rough alignment, in step S15, fine alignment is performed by the positioning unit 3. That is, by performing fine alignment based on the image data 30, the processing line 37 of the wafer W is detected for each processing axis, and the wafer W is precisely positioned (positioning step).

[0038] After detecting the processing line 37 of the wafer W by fine alignment, the processing unit 5 is operated to move the processing table 11 in the Y-axis direction. By moving the processing table 11 in the Y-axis direction, the wafer W is aligned in the Y-axis direction with respect to the laser irradiation unit (not shown) of the processing unit 5.

[0039] After the wafer W is aligned in the Y-axis direction, in step S16, the wafer W is moved in the X-axis direction, and a laser beam is emitted from the laser irradiation unit of the processing unit 5. The oscillated laser beam is focused and irradiated onto the processing line 37, thereby cutting the processing line 37 by laser ablation processing (processing step).

[0040] In the laser processing method according to this embodiment, image data 30 is acquired by the protective film detection unit 2, and outer shape measurement, rough alignment, and fine alignment of the wafer W are performed based on the acquired image data 30. That is, the positioning step includes an outer shape measurement step, a rough alignment step, and a fine alignment step, and image data is used in the outer shape measurement step, the rough alignment step, and the fine alignment step.

[0041] According to the laser processing method and laser processing apparatus 1 described above, as shown in FIGS. 1 to 3, the protective film detection step is performed by the protective film detection unit 2, thereby acquiring image data 30 of the wafer W placed on the processing table 11. The processing line 37 of the wafer W is detected based on the acquired image data 30. Specifically, in the positioning step performed by the positioning unit 3, the image data 30 is used when detecting the processing line 37 from the outer shape measurement, rough alignment, and fine alignment of the wafer W. Therefore, when detecting the processing line 37 of the wafer W, measurement using an alignment microscope (low-magnification microscope or high-magnification microscope) can be omitted, and the detection of the processing line 37 can be speeded up.

[0042] Here, the processing line 37 of the wafer W is detected while the wafer W is placed on the processing table 11. The processing table 11 is a table on which the wafer W is placed when laser ablation processing is performed. Therefore, during laser ablation processing of the wafer W, the processing line of another wafer cannot be detected by the processing table 11. For this reason, increasing the speed of detection of the processing line 37 directly leads to an improvement in the throughput of the entire processing of the wafer W. As a result, by using the image data 30 when detecting the processing line 37, it is possible to improve the throughput when laser ablation processing the wafer W.

[0043] In the embodiment, an example has been described in which the image data 30 is used to perform the contour measurement, rough alignment, and fine alignment in detecting the processing line 37, but this is not limiting. As another example, the image data 30 may be used in at least part of the contour measurement, rough alignment, and fine alignment in detecting the processing line 37. This will be described in detail as a modified example below.

[0044] <Modification> Next, a modified example of the embodiment will be described. Note that the same reference numerals and step numbers will be used to designate the same or similar content as in the embodiment, and detailed description thereof will be omitted. 1, a laser processing apparatus 50 of the modified example includes a positioning unit 51. The positioning unit 51 includes an alignment microscope (not shown). The alignment microscope includes a low-magnification microscope and a high-magnification microscope (both not shown). The low-magnification microscope observes the device layer DL to detect the outline and processing lines 37 (both see FIG. 3) of the wafer W when performing outline measurement and rough alignment. The high-magnification microscope measures (observes) the protective film Pf to detect the processing lines 37 and alignment patterns 38 of the wafer W when performing fine alignment.

[0045] The positioning unit 51 performs outline measurement and rough alignment based on the wafer W and protective film Pf measured with a low-magnification microscope. The positioning unit 51 performs fine alignment based on the wafer W and protective film Pf measured with a high-magnification microscope.

[0046] Next, a laser processing method for performing laser ablation processing on a wafer W using the laser processing apparatus 50 of the modified example will be described with reference to FIGS. FIG. 8 is a flowchart illustrating a laser processing method according to a modified example. 1, 2, and 8, if the protective film Pf is properly applied without any coating defects, incomplete coating, or film thickness abnormalities in the protective film Pf in step S12, the process proceeds to step S20. In step S20, it is determined whether or not the image data 30 acquired by the protective film detection unit 2 will be used for contour measurement. If it is determined that the image data 30 will be used, the process proceeds to step S13. On the other hand, if it is determined that the image data 30 will not be used in step S20, the wafer W is measured with a low-magnification microscope in step S21. After measuring the wafer W with the low-magnification microscope, contour measurement is performed based on the measurement image from the low-magnification microscope in step S13.

[0047] After the outer shape measurement is performed, in step S22, it is determined whether or not the image data 30 acquired by the protective film detection unit 2 will be used for rough alignment. If it is determined that the image data 30 will be used, the process proceeds to step S14. On the other hand, if it is determined in step S22 that the image data 30 will not be used, in step S23, the wafer W is measured with a low-magnification microscope. After measuring the wafer W with the low-magnification microscope, in step S14, rough alignment is performed based on the measurement image from the low-magnification microscope. By performing rough alignment, the wafer W is roughly positioned.

[0048] After performing the rough alignment, in step S24, it is determined whether or not the image data 30 acquired by the protective film detection unit 2 will be used for fine alignment. If it is determined that the image data 30 will be used, the process proceeds to step S15. On the other hand, if it is determined in step S24 that the image data 30 will not be used, in step S25, the wafer W is measured with a high-magnification microscope. After measuring the wafer W with the high-magnification microscope, in step S15, fine alignment is performed based on the measurement image from the high-magnification microscope. By performing fine alignment, the processing line 37 of the wafer W is detected for each processing axis, and the wafer W is precisely positioned. After the processing line 37 of the wafer W is detected by fine alignment, in step S16, the processing line 37 is cut by laser ablation processing in the processing unit 5.

[0049] According to the modified laser processing method and laser processing apparatus 50 described above, a low-magnification microscope and a high-magnification microscope are provided as alignment microscopes in the positioning unit 51. Therefore, for example, when the protective film Pf is not properly applied to the wafer W or when the processing line 37 (see FIG. 3) is to be detected manually, the processing line 37 can be detected using the alignment microscopes.

[0050] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0051] For example, in the above embodiment, the protective film detection unit 2 is described as having the configuration shown in FIG. 2 (coaxial epi-illumination). However, instead of coaxial epi-illumination, a ring illumination or other illumination may be used. For example, when a ring illumination is used, a condenser lens may be coaxially disposed in the central space of the ring illumination that emits ultraviolet light, and the fluorescence emitted by the ultraviolet light irradiated from the ring illumination may be received by a detector disposed opposite the protective film with the condenser lens interposed therebetween. Alternatively, ultraviolet light may be irradiated obliquely onto the protective film, and the light reflected by the protective film may be received by a combination of a condenser lens and a detector at the position of specular reflection. In this case, instead of receiving specularly reflected light, a configuration in which the light is received by a combination of a condenser lens and a detector disposed perpendicular to the position of irradiation of the ultraviolet light and facing the protective film may be considered.

[0052] In addition, in the modified example, an example in which the alignment microscope is equipped with a low-magnification microscope and a high-magnification microscope has been described, but, for example, the alignment microscope may be equipped with either a low-magnification microscope or a high-magnification microscope. Also, a microscope with variable magnification may be used as the low-magnification microscope and the high-magnification microscope.

[0053] In addition, the components in this embodiment can be replaced with well-known components as appropriate, without departing from the spirit of the present invention. [Explanation of symbols]

[0054] 1. Laser processing equipment 2 Protective film detection unit 3 Positioning part 4. Control section 5 Processing section 11 Processing table 21 Light source 22 Detector 23 Ultraviolet light 23A Fluorescence 24 Condenser lens 25 filters 26 Dichroic Mirror 27 Reflected light 28 filters 29 Condenser Lens 30 Image data 31 Outer edge 37 Street (processing line) Patterns 38 and 39 50 Laser processing equipment 51 Positioning part

Claims

1. a protective film detection step of measuring a protective film applied to a workpiece placed on a processing table and acquiring data related to the protective film; a positioning step of determining the position of the workpiece; A laser processing method including a processing step of laser processing a processing line of the workpiece, The positioning step uses data relating to the protective film acquired in the protective film detection step for at least a part of the detection of the position of the workpiece.

2. 2. The laser processing method according to claim 1, wherein the positioning step includes a contour measurement step, a rough alignment step, and a fine alignment step, and data related to the protective film is used in at least one of the contour measurement step, the rough alignment step, and the fine alignment step.

3. 3. The laser processing method according to claim 1, wherein the data relating to the protective film includes at least one of two-dimensional image data, one-dimensional image data, intensity data, and spectrum data of the protective film.

4. 3. The laser processing method according to claim 1, wherein at least a part of the data relating to the protective film acquired in the protective film detection step is used for at least a part of the detection of the position of the workpiece.

5. a protective film detection unit that measures a protective film applied to a workpiece placed on a processing table and acquires data related to the protective film; a positioning unit for determining the position of the workpiece; A laser processing apparatus comprising: a processing unit that laser processes a processing line of the workpiece; The positioning unit uses the data about the protective film acquired by the protective film detection unit to detect at least a part of the position of the workpiece.

6. The laser processing device according to claim 5 , wherein the positioning unit includes an alignment microscope.

Images