Laser processing method and laser processing apparatus

Abstract

Properly verify the processing quality of the groove formed by laser irradiation. The laser processing method includes: a processing step, forming a groove on the surface of the workpiece by irradiating the surface of the workpiece with a laser; a cleaning step, removing debris accumulated around the groove during its formation by cleaning; and a kerf inspection step, after the cleaning step, acquiring a post-cleaning image as an image of the groove's perimeter, and verifying the groove processing quality, including the location where the groove was formed, based on the post-cleaning image.

Description

Technical Field

[0001] The disclosed technologies involve laser processing methods and laser processing equipment. Background Technology

[0002] As a technology related to confirming the processing quality (cut inspection) of grooves formed on a workpiece, the following technologies are known. Patent Document 1 describes a processing apparatus comprising: a coordinate data acquisition step for acquiring multiple three-dimensional coordinate data representing the shape of a processing groove formed along the processing feed direction; a projection data generation step for generating two-dimensional projection data of the processing groove projecting the three-dimensional coordinate data onto a two-dimensional plane perpendicular to the processing feed direction; and a cross-sectional profile calculation step for calculating the cross-sectional profile of the processing groove based on the two-dimensional projection data.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2024-114382 Laser grooving is a process that creates grooves on the surface of a workpiece, such as a semiconductor wafer, by irradiating it with a laser. The quality of the grooves formed on the workpiece is then assessed, a process known as kerf inspection. Kerf inspection is performed using an image of the area surrounding the groove. In laser grooving, debris containing molten material scattered by the laser accumulates around the groove. If kerf inspection is performed before cleaning away this debris, the edges of the groove may become unclear in the image used for kerf inspection, making the process difficult. Summary of the Invention

[0004] The disclosed technology was developed in view of the aforementioned problems, with the aim of properly verifying the processing quality of grooves formed by laser irradiation.

[0005] The disclosed technology involves a laser processing method comprising: a processing step in which a groove is formed on the surface of a workpiece by irradiating the surface of the workpiece with a laser; a cleaning step in which debris accumulated around the groove during its formation is removed by cleaning; and a kerf inspection step in which, after the cleaning step, a post-cleaning image is acquired as an image of the periphery of the groove, and the processing quality of the groove, including the location where the groove was formed, is confirmed based on the post-cleaning image.

[0006] Based on the confirmation result of the groove formation position in the cut inspection process, processing conditions including conditions related to the groove formation position can be set in the next processing process.

[0007] An alarm can be issued if the processing quality of the groove, as confirmed during the kerf inspection process, does not meet the specified standards.

[0008] The cleaning process and the kerf inspection process can be performed after all the grooves that should be formed on the surface of the workpiece are formed in the processing step. Based on the confirmation result of the processing quality of the grooves in the kerf inspection process, the processing conditions in the processing step to be performed on the next workpiece are set.

[0009] The laser processing method may further include a step of determining the appropriateness of the cleaning process based on a comparison between a pre-cleaning image and a post-cleaning image, which is an image of the periphery of the tank acquired prior to the cleaning process.

[0010] The laser processing method may further include: a step of forming a protective film on the surface of the workpiece before the processing step, and removing the protective film together with the debris during the cleaning step.

[0011] The laser processing method may further include: after the cleaning process, a process of obtaining a post-cleaning cross-sectional profile, wherein the post-cleaning cross-sectional profile is the cross-sectional profile of the periphery of the groove of the workpiece after the protective film has been removed.

[0012] The laser processing method may further include: a step of obtaining a pre-cleaning cross-sectional profile of the periphery of the groove of the workpiece having the protective film, prior to the cleaning step; and a step of estimating the thickness of the protective film based on the pre-cleaning cross-sectional profile and the post-cleaning cross-sectional profile.

[0013] The disclosed technology involves a laser processing apparatus comprising: a processing unit that forms a groove on the surface of a workpiece by irradiating the workpiece with a laser; a cleaning unit that removes debris accumulated around the groove as a result of its formation by cleaning; and a kerf inspection unit that, after removing the debris, acquires a post-cleaning image of the groove's periphery, and, based on the post-cleaning image, confirms the processing quality of the groove, including the location where the groove was formed.

[0014] Invention Effects Based on the publicly available technology, the processing quality of the grooves formed by laser irradiation can be reliably confirmed. Attached Figure Description

[0015] Figure 1 This is a process flow diagram illustrating an example of a laser processing method according to an embodiment of the disclosed technology.

[0016] Figure 2A This is a cross-sectional view showing an example of the structure of the workpiece involved in an embodiment of the disclosed technology.

[0017] Figure 2BThis is a cross-sectional view illustrating an example of a laser processing method according to an embodiment of the disclosed technology.

[0018] Figure 2C This is a cross-sectional view illustrating an example of a laser processing method according to an embodiment of the disclosed technology.

[0019] Figure 2D This is a cross-sectional view illustrating an example of a laser processing method according to an embodiment of the disclosed technology.

[0020] Figure 3A This is a diagram illustrating an example of a cleaned image according to an embodiment of the disclosed technology.

[0021] Figure 3B This is a diagram illustrating an example of a pre-cleaning image according to an embodiment of the disclosed technology.

[0022] Figure 4 This is a diagram illustrating an example of a method for confirming the formation position of a groove in a kerf inspection process according to an embodiment of the disclosed technology.

[0023] Figure 5 This is a diagram illustrating an example of the functional structure of a laser processing apparatus according to an embodiment of the disclosed technology.

[0024] Figure 6 This is a process flow diagram illustrating one example of the laser processing method involved in the comparative example.

[0025] Figure 7 It is a cross-sectional view showing a workpiece with grooves formed.

[0026] Figure 8 This is a process flow diagram illustrating an example of a laser processing method according to other embodiments of the disclosed technology.

[0027] Figure 9 This is a process flow diagram illustrating an example of a laser processing method according to other embodiments of the disclosed technology.

[0028] Figure 10 This is a process flow diagram illustrating an example of a laser processing method according to other embodiments of the disclosed technology.

[0029] Figure 11A It is a diagram schematically illustrating the cross-sectional profile before cleaning involved in an embodiment of the disclosed technology.

[0030] Figure 11B It is a diagram schematically illustrating the cross-sectional profile after cleaning according to an embodiment of the disclosed technology.

[0031] Figure 11C It is a diagram schematically illustrating the cross-sectional profile after cleaning according to an embodiment of the disclosed technology.

[0032] Explanation of reference numerals in the attached figures 10: The object being processed; 13: Protective film; 14: Trough; 15: Debris; 20: Image after cleaning; 21: Image before cleaning; 30: Laser processing equipment; 31: Protective film forming section; 32: Processing Department; 33: Cleaning and Processing Department; 34: Cutting Inspection and Treatment Department; 35: Processing condition setting unit; 40: Clean the cross-sectional profile before cleaning; 41: Cross-sectional profile after cleaning. Detailed Implementation

[0033] Hereinafter, an example of an embodiment of the disclosed technology will be described with reference to the accompanying drawings. Furthermore, the same reference numerals will be used for the same or equivalent constituent elements and parts in each drawing, and repeated descriptions will be omitted.

[0034] [First Implementation Method] Figure 1 This is a process flow diagram illustrating an example of a laser processing method according to the first embodiment of the disclosed technology. The laser processing method according to this embodiment includes steps P1 to P7 as described below. The laser processing method according to this embodiment is applicable to the case of forming grooves on the surface of a workpiece by laser cutting.

[0035] Figure 2A This is a cross-sectional view showing an example of the structure of the workpiece 10. The workpiece 10 is, for example, a semiconductor wafer, having a silicon substrate 11 and a wiring layer 12 containing an insulator disposed on the silicon substrate 11. The material and structure of the workpiece 10 are not particularly limited. The workpiece 10 may, for example, have one or more layers containing any one of metal, resin, glass, semiconductor, or insulator.

[0036] In process P1 (protective film formation process), a protective film 13 is formed on the surface of the workpiece 10. Figure 2BIn laser grooving, debris containing molten material scattered by laser irradiation adheres to the surface of the workpiece. This debris is difficult to remove by washing with pure water alone, and, for example, when it adheres to electrodes, becomes a major cause of poor electrical properties. To avoid this problem, a water-soluble protective film is formed on the surface of the workpiece before laser grooving, and the debris accumulates on the protective film 13. The protective film 13 is removed along with the debris during the cleaning process after laser grooving. The protective film 13 may, for example, contain polyvinyl alcohol and poly(N-vinylacetamide). The protective film 13 can be formed, for example, by spin coating.

[0037] In process P2 (processing process), a groove 14 is formed on the surface of the workpiece 10 covered by the protective film 13. Figure 2C The groove 14 is formed by irradiating the surface of the workpiece 10, which has a protective film 13, with a laser. The groove 14 is formed, for example, at a depth from the surface of the protective film 13 through the wiring layer 12 to the silicon substrate 11. The workpiece 10 has multiple lines (cut tracks) from which the groove 14 is formed. In step P2 (processing step), the groove 14 is formed on all lines.

[0038] Debris 15, including molten material scattered by laser irradiation, accumulates on the surface of the protective film 13 at the periphery of the tank 14. The surface of the workpiece 10 is covered by the protective film 13, thereby preventing the debris 15 from directly contacting the surface of the workpiece 10.

[0039] In process P3 (cleaning process), the protective film 13 formed on the surface of the workpiece 10 is removed. Figure 2D Since the protective film 13 is water-soluble, it can be removed by washing with pure water. The debris 15 generated by laser grooving is removed together with the protective film 13.

[0040] In step P4 (cutting inspection step), a cutting inspection is performed to confirm the processing quality of the groove 14 formed in step P2 (processing step). During the cutting inspection, a post-cleaning image of the periphery of the groove 14, the object to be processed, is obtained after step P3 (cleaning step). The cutting inspection is performed based on the post-cleaning image. Figure 3A This is a diagram showing an example of image 20 after cleaning. Figure 3A A groove 14 formed along the dicing path of a semiconductor wafer 10, which is the object of processing, is shown. Confirming the processing quality of the groove 14 includes confirming the formation location of the groove 14 determined based on the post-cleaning image 20.

[0041] In step P5, it is determined whether the processing of all workpieces 10 has been completed in steps P1 to P4. If all workpieces 10 have been processed, this routine ends. If none of the workpieces 10 have been processed, the process is transferred to step P6. In step P6, the workpiece 10 is changed. That is, the next workpiece 10 is selected as the processing object.

[0042] In process P7 (processing condition setting process), based on the confirmation result of the formation position of the groove 14 in process P4 (cutting inspection process), the processing conditions in process P2 (processing process) to be performed on the next processing object 10 selected in process P6 are set. The processing conditions include conditions related to the formation position of the groove 14.

[0043] Figure 4 This diagram illustrates an example of how the formation position of the groove 14 in process P4 (cutting inspection process) is confirmed. The formation position of the groove 14 is confirmed based on the post-cleaning image 20. The edge of the groove 14, formed by laser irradiation, is meandering due to edge chipping. In confirming the formation position of the groove 14, the midpoint between the inner edges E1 and E2 of the groove 14 is determined as the center position C1 of the groove 14. Furthermore, the distance between the center position C1 of the groove 14 and the center position C2 in the groove width direction (Y direction) of the post-cleaning image 20 is used to derive an offset ΔY as an appropriate position from the formation position of the groove 14.

[0044] In step P7 (processing condition setting step), based on the offset ΔY derived in step P4 (cutting inspection step), the processing conditions related to the formation position of the groove 14 for the next workpiece 10 are set. Specifically, the parameters specifying the formation position of the groove 14 are corrected so that the offset ΔY of the formation position of the groove 14 formed in the next workpiece 10 is zero. Then, the process returns to step P1, and the next workpiece 10 is processed using steps P1 to P4.

[0045] Furthermore, the chipping condition can also be confirmed in process P4 (cutting inspection process). Specifically, the distance between the outer edges E3 and E4 of groove 14 can be derived as an index C indicating the chipping condition. Additionally, the width of groove 14 can also be confirmed in process P4 (cutting inspection process). Specifically, the distance between the inner edges E1 and E2 of groove 14 can be derived as the width W of groove 14. In process P7 (processing condition setting process), laser irradiation conditions such as laser power, pulse width, and pulse interval can be set based on the chipping condition or the width of groove 14 confirmed in process P4 (cutting inspection process).

[0046] Figure 5This is a diagram illustrating an example of the functional structure of a laser processing apparatus 30 performing the aforementioned processes P1 to P7. The laser processing apparatus 30 includes a protective film forming section 31, a processing section 32, a cleaning section 33, a kerf inspection section 34, and a processing condition setting section 35.

[0047] The protective film forming unit 31 performs the processing in step P1 (protective film forming step). That is, the protective film forming unit 31 forms a protective film 13 on the surface of the workpiece 10. The protective film forming unit 31 may also include, for example, a spin coater (not shown) for forming the protective film 13 by spin coating.

[0048] The processing unit 32 performs the processing in step P2 (processing step). That is, the processing unit 32 forms a groove 14 on the surface of the workpiece 10. The processing unit 32 may also include, for example, a laser optical system (not shown) that forms the groove 14 by irradiating the surface of the workpiece 10 with a laser.

[0049] The cleaning process unit 33 performs the processing in step P3 (cleaning process). That is, the cleaning process unit 33 removes the protective film 13 formed on the surface of the workpiece 10 by cleaning. The cleaning process unit 33 may also include, for example, a cleaning device (not shown) that cleans by supplying pure water to the surface of the workpiece 10.

[0050] The kerf inspection processing unit 34 performs the processing in step P4 (kerf inspection step). Specifically, the kerf inspection processing unit 34 acquires a post-cleaning image, which is a top view of the periphery of the cleaned groove 14, and based on the post-cleaning image, confirms the machining quality of the groove 14, including the formation position of the groove 14. Based on the post-cleaning image, the kerf inspection processing unit 34 outputs a confirmation result of the machining quality of the groove 14, including an offset ΔY from the appropriate position of the groove 14. The kerf inspection processing unit 34 may also include a camera that captures the post-cleaning image and a computer (not shown) that analyzes the post-cleaning image to output the confirmation result of the formation position of the groove 14.

[0051] The processing condition setting unit 35 performs the processing in step P7 (processing condition setting step). That is, the processing condition setting unit 35 sets processing conditions related to the formation position of the groove 14 based on the confirmation result of the groove 14 formation position output from the kerf inspection processing unit 34. The processing condition setting unit 35 may also include a computer (not shown) that outputs processing conditions based on the confirmation result of the groove 14 formation position.

[0052] Figure 6This is a process flow diagram illustrating an example of the laser processing method involved in the comparative example. The laser processing method involved in the comparative example includes steps P11 to P19 as described below. In step P11, a protective film 13 is formed on the surface of the workpiece 10. In step P12, a groove 14 is formed on the surface of the workpiece 10 by laser cutting. Here, the groove 14 is formed for a portion of the multiple lines (cutting paths) from which the groove 14 is to be formed. In step P13, the processing quality of the groove 14 is checked (cutting inspection). In step P14, it is determined whether all lines corresponding to the groove 14 have been processed (grooving). If there are lines that have not been processed (grooving), the workpiece lines are changed in step P15. In step P16, based on the cutting inspection results derived in step P13, the processing conditions for the new workpiece lines are set. Afterward, the process returns to step P11. After all lines have been processed (grooving), the protective film 13 formed on the surface of the workpiece 10 is removed in step P17. In step P18, it is determined whether all workpieces 10 have been processed. If there are workpieces 10 that have not been processed, in step P19, the workpiece is changed, and the new workpiece is processed in steps P11 to P17.

[0053] According to the laser processing method involved in the comparative example, the cleaning process (process P17) is performed after all lines have been formed with grooves 14 and the processing quality (cutting inspection) of each groove 14 has been confirmed. That is, the confirmation of the processing quality (cutting inspection) of the groove 14 is based on a top view image of the periphery of the groove 14 before the cleaning process (process P17) is performed, i.e., an image before cleaning.

[0054] Figure 3B This is a diagram showing an example of image 21 before cleaning. In image 21 before cleaning, sometimes the edges of groove 14 become unclear due to the accumulation of debris generated by laser grooving around the periphery, making it difficult to confirm the processing quality of groove 14 (kerf inspection). That is, according to the laser processing method involved in the comparative example, it is sometimes difficult to properly confirm the processing quality of groove 14 (kerf inspection).

[0055] On the other hand, according to the laser processing method involved in the implementation of the disclosed technology, the processing quality of the groove 14 (kerf inspection) is confirmed based on... Figure 3A The cleaning process was demonstrated in image 20. In image 20, the debris 15 was removed along with the protective film 13, resulting in a clear edge on the groove 14, allowing for proper confirmation of the groove 14's processing quality (cutting inspection). Furthermore, by adjusting the laser irradiation conditions when forming the groove 14 on the workpiece 10, such as... Figure 7As shown, the protective film 13 retracts, exposing the edge of the groove 14. In this case, even in the pre-cleaning image, the edge of the groove 14 is clearly visible. Therefore, in this situation, the superiority of confirming the processing quality (cutting inspection) of the groove 14 based on the post-cleaning image is reduced. On the other hand, the retraction of the protective film 13 may adversely affect the processing quality of the groove 14, and therefore is preferable to avoid. In recent years, laser irradiation conditions that make it difficult for the protective film 13 to retract have been discovered and applied. In the case where the protective film 13 is not easy to retract, since the edge of the groove 14 becomes unclear in the pre-cleaning image, the laser processing method involved in this embodiment, which confirms the processing quality (cutting inspection) of the groove 14 based on the post-cleaning image, is effective.

[0056] [Second Implementation] Figure 8 This is a process flow diagram illustrating an example of a laser processing method according to the second embodiment of the disclosed technology. The laser processing method according to the second embodiment differs from the laser processing method according to the first embodiment in that it includes steps P4A and P4B.

[0057] Process P4A is performed after process P4 (kerf inspection process). In process P4A, it is determined whether the machining quality of the groove 14 confirmed in process P4 (kerf inspection process) meets the prescribed standards. For example, in process P4A, it can also be determined whether the offset ΔY from the appropriate position of the groove 14 derived in process P4 (kerf inspection process) is greater than the reference value. If it is determined that the machining quality of the groove 14 meets the prescribed standards, the process proceeds to process P5; if it is determined that the machining quality of the groove 14 does not meet the prescribed standards, the process proceeds to process P4B. The processing of process P4A is performed, for example, by a computer installed in the laser processing apparatus 30.

[0058] In process P4B, the laser processing unit 30 issues an alarm. The alarm can be issued, for example, by displaying a warning message on a monitor attached to the laser processing unit 30, emitting an audible sound, or illuminating a light. After the alarm is issued, processing proceeds to process P5.

[0059] As described above, the laser processing method according to the second embodiment of the disclosed technology issues an alarm when the processing quality of the groove 14 formed on the workpiece 10 does not meet the specified standard. Therefore, the operator can respond by changing the processing conditions for the next workpiece 10, and can maintain the processing quality of the groove 14.

[0060] [Third Implementation Method] Figure 9This is a process flow diagram illustrating an example of a laser processing method according to the third embodiment of the disclosed technology. The laser processing method according to the third embodiment differs from the laser processing method according to the first embodiment described above in that it includes steps P2A, P4C, and P4D.

[0061] Process P2A is performed after process P2 (processing process). In process P2A, the workpiece 10 (see reference) that was to be processed before process P3 (cleaning process) is obtained. Figure 2C The image before cleaning is a top view of the periphery of groove 14.

[0062] Process P4C is performed after process P4 (cutting inspection process). In process P4C, the pre-cleaning image 21 (reference image) obtained in process P2A is processed. Figure 3B ) and the post-cleaning image 20 obtained in process P4 (cutting inspection process) (refer to Figure 3A The images are compared, and based on the comparison results, it is determined whether the cleaning in process P3 (cleaning process) is appropriate.

[0063] In the image 21 before cleaning, the edges of the groove 14 become unclear due to debris accumulated around it. If the cleaning in step P3 (cleaning step) is proper, the edges of the groove 14 become clear in the image after cleaning because the debris is almost completely removed. Therefore, if, for example, the difference between the image before and after cleaning is above a predetermined threshold, it can be determined that the cleaning in step P3 (cleaning step) is proper. Alternatively, if the difference between the image before and after cleaning is less than a predetermined threshold, it can be determined that the cleaning in step P3 (cleaning step) is improper. If the cleaning in step P3 (cleaning step) is determined to be proper, the process proceeds to step P5; if the cleaning in step P3 (cleaning step) is determined to be improper, the process proceeds to step P4D. The processing in step P4C is performed, for example, by a computer installed in the laser processing apparatus 30.

[0064] In process P4D, the laser processing unit 30 issues an alarm. The alarm can be issued, for example, by displaying a warning message on a monitor attached to the laser processing unit 30, emitting an audible sound, or illuminating a light. After the alarm is issued, processing proceeds to process P5.

[0065] As described above, according to the laser processing method of the third embodiment of the disclosed technology, the appropriateness of process P3 (cleaning process) is determined based on the pre-cleaning image and the post-cleaning image, and an alarm is issued if the cleaning in the cleaning process is determined to be inappropriate. Therefore, the operator can change the cleaning conditions in process P3 (cleaning process) performed on the next workpiece 10. Furthermore, if the cleaning in the cleaning process is determined to be inappropriate, the laser processing apparatus 30 can also control the re-implementation of process P3 (cleaning process) on the workpiece 10.

[0066] [Fourth Implementation Method] Figure 10 This is a process flow diagram illustrating an example of a laser processing method according to the fourth embodiment of the disclosed technology. The laser processing method according to the fourth embodiment differs from the laser processing method of the first embodiment described above in that it includes steps P2B, P3A, P3B, P3C, and P3D.

[0067] Process P2B is performed after process P2 (machining process). In process P2B, a cross-sectional profile representing the cross-sectional shape of the groove 14 formed in process P2 (machining process) is obtained. The cross-sectional profile is information depicting the shape of the workpiece 10 in a cross-section parallel to both the width and depth directions of the groove 14 formed in the workpiece 10.

[0068] The cross-sectional profile can be obtained, for example, by acquiring three-dimensional coordinate data representing the shape of the groove 14 using a white light interferometer, generating projection data that projects the three-dimensional coordinate data onto a two-dimensional plane, and performing noise reduction and statistical processing on the two-dimensional projection data. As a technique for deriving the cross-sectional profile based on the three-dimensional coordinate data representing the groove shape acquired using a white light interferometer, the technique described in Japanese Patent Application Publication No. 2024-114382 can be applied, for example. In addition to a white light interferometer, a laser microscope can also be used as the shape measurement unit employing an optical method for acquiring the cross-sectional profile.

[0069] The cross-sectional profile obtained in process P2B will be referred to as the "pre-cleaning cross-sectional profile". This is based on the workpiece 10 (referring to the image) being irradiated with the protective film 13. Figure 2C The reflected light on the surface of the surface is used to obtain the profile of the cross section before cleaning.

[0070] Figure 11A This is a schematic diagram showing the cross-sectional profile 40 before cleaning. In the cross-sectional profile 40 before cleaning, a relatively flat line drawn around the groove 14 delineates the surface of the protective film 13. Therefore, in the cross-sectional profile 40 before cleaning, the height position of the relatively flat line drawn around the groove 14 can be determined as the surface position H1 of the protective film 13.

[0071] Process P3A is performed after process P3 (cleaning process). In process P3A, a cross-sectional profile representing the cross-sectional shape of the periphery of the cleaned tank 14 is obtained. The cross-sectional profile obtained in process P3A will be referred to as the "cleaned cross-sectional profile" below. This is based on the workpiece 10 (refer to) being irradiated with the protective film 13 removed. Figure 2D The profile of the cross section after cleaning is obtained by reflecting light from the surface of the surface.

[0072] Figure 11B This is a schematic diagram showing the cross-sectional profile 41 after cleaning. In the cross-sectional profile 41 after cleaning, a relatively flat line drawn around the groove 14 delineates the surface of the wiring layer 12. Therefore, in the cross-sectional profile 41 after cleaning, the height position of the relatively flat line drawn around the groove 14 can be determined as the surface position H2 of the wiring layer 12.

[0073] In process P3B, the thickness of the protective film 13 is estimated based on the pre-cleaning cross-sectional profile obtained in process P2B and the post-cleaning cross-sectional profile obtained in process 3A. Specifically, as follows... Figure 11C As shown, the distance between the surface position H1 of the protective film 13, determined by the cross-sectional profile before cleaning, and the surface position H2 of the wiring layer 12, determined by the cross-sectional profile after cleaning, is estimated as the thickness T of the protective film 13.

[0074] In process P3C, it is determined whether the thickness T of the protective film 13 estimated in process P3B is within the specified range. If it is determined that the estimated thickness T of the protective film 13 is within the specified range, the process proceeds to process P4; if it is determined that the estimated thickness T of the protective film 13 is not within the specified range, the process proceeds to process P3D. The processing of processes P3B and P3C is performed, for example, by a computer installed in the laser processing apparatus 30.

[0075] In process P3D, the laser processing unit 30 issues an alarm. The alarm can be issued, for example, by displaying a warning message on a monitor attached to the laser processing unit 30, emitting an audible sound, or illuminating a light. After the alarm is issued, processing proceeds to process P4.

[0076] As described above, in the laser processing method according to the fourth embodiment of the disclosed technology, the thickness of the protective film 13 is estimated based on the cross-sectional profile before and after cleaning, and an alarm is issued if the estimated thickness of the protective film 13 is not within the specified range. This allows the operator to respond by changing the thickness setting of the protective film 13 for the next workpiece 10 being processed.

[0077] Furthermore, if the estimated thickness T of the protective film 13 is not within the specified range, the computer installed in the laser processing apparatus 30 can perform a process to change the thickness setting of the protective film 13 in the next workpiece 10 to be processed. In this case, the thickness setting of the protective film 13 is changed so that the estimated thickness T of the protective film 13 matches the target value.

[0078] In the first to fourth embodiments described above, a method of cleaning and cutting inspection is illustrated after all lines on the workpiece 10 to which grooves 14 should be formed have been grooved 14. However, the disclosed technology is not limited to this method. It is also possible to perform cleaning and cutting inspection after forming grooves 14 on a portion of the lines on the workpiece 10 to which grooves 14 should be formed, then to form a protective film on the workpiece 10 again, and to perform cleaning and cutting inspection on the remaining portion of the lines after forming grooves 14, and so on in a cyclical process.

Claims

1. A laser processing method, comprising: The processing step involves irradiating the surface of the workpiece with a laser to form grooves on the surface of the workpiece. The cleaning process removes debris that accumulates around the periphery of the tank as it is formed. and The seam inspection process involves acquiring a post-cleaning image, which serves as an image of the periphery of the groove, after the cleaning process. Based on the post-cleaning image, the processing quality of the groove is confirmed, including the formation position of the groove.

2. The laser processing method according to claim 1, wherein, Based on the confirmation result of the groove formation position in the kerf inspection process, the processing conditions in the next processing step are set, including conditions related to the groove formation position.

3. The laser processing method according to claim 1, wherein, An alarm is issued if the processing quality of the groove, as confirmed during the kerf inspection process, does not meet the specified standards.

4. The laser processing method according to claim 1, wherein, After all the grooves that should be formed on the surface of the workpiece are formed in the processing step, the cleaning step and the cut inspection step are performed. Based on the confirmation result of the processing quality of the groove in the kerf inspection process, the processing conditions in the processing process to be performed on the next processing object are set.

5. The laser processing method according to claim 1, wherein, The laser processing method further includes a step of determining the appropriateness of the cleaning process based on a comparison between a pre-cleaning image (which is an image of the periphery of the tank acquired before the cleaning process) and a post-cleaning image.

6. The laser processing method according to claim 1, wherein, The laser processing method further includes a step of forming a protective film on the surface of the workpiece before the processing step. In the cleaning process, the protective film is removed along with the debris.

7. The laser processing method according to claim 6, wherein, The laser processing method further includes: after the cleaning process, a process of obtaining the cross-sectional profile after cleaning, wherein the cross-sectional profile after cleaning is the cross-sectional profile of the periphery of the groove of the processing object after the protective film has been removed.

8. The laser processing method according to claim 7, wherein, The laser processing method further includes: Prior to the cleaning process, a process for obtaining a pre-cleaning cross-sectional profile, wherein the pre-cleaning cross-sectional profile is the cross-sectional profile of the periphery of the groove of the workpiece having the protective film; and The process of estimating the thickness of the protective film based on the cross-sectional profile before cleaning and the cross-sectional profile after cleaning.

9. A laser processing apparatus, comprising: The processing unit forms grooves on the surface of the workpiece by irradiating the surface of the workpiece with a laser. The cleaning process removes debris that accumulates around the periphery of the tank as it is formed by cleaning. and The kerf inspection and processing unit, after removing the debris, acquires a post-cleaning image of the periphery of the groove, and confirms the processing quality of the groove based on the post-cleaning image, the processing quality of the groove including the formation position of the groove.

Images