JP2014042921A - Laser working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser working method capable of peeling a portion of a working object into a desired shape by the irradiation of a laser beam.SOLUTION: Prior to the step of peeling a peel-planned part 10 from a working object 1 by the irradiation of a laser beam L1, a crack 8 is formed along a reference line BL specifying the peel-planned part 10. Thus, at the step of peeling the peel-planned part 10, the peel-planned part 10 can be peeled along that crack 8. By controlling the modes of the reference line BL and the crack 8, therefore, the peel-planned part 10 can be peeled into a desired shape.

Description

  The present invention relates to a laser processing method for peeling a part of an object to be processed by laser light irradiation.

  As a conventional technique in the above technical field, for example, a U-shaped groove processing method described in Patent Document 1 is known. In this U-shaped groove processing method, the heated portion is peeled off from the vicinity of the boundary with the non-heated portion by thermal expansion of the heated portion by scanning the surface of the glass substrate with a laser beam and rapidly heating the glass substrate, A groove having a U-shaped cross section is formed on the surface of the glass substrate.

Republished patent WO2009 / 0500938

  As described above, according to the method described in Patent Document 1, a part of a processing target such as a glass substrate can be peeled off by laser light irradiation. However, in the method described in Patent Document 1, the cross-sectional shape of the groove formed by peeling a part from the workpiece is limited to a U-shape, or the width of the peeled part varies. Therefore, there is a problem that a desired shape cannot be processed.

  This invention is made | formed in view of such a situation, and makes it a subject to provide the laser processing method which can peel a part of workpiece into a desired shape by irradiation of a laser beam.

  In order to solve the above-described problem, a laser processing method according to the present invention includes a step of preparing a workpiece including a portion to be peeled, and a reference line that defines the portion to be peeled after preparing the workpiece. A step of forming a crack in the workpiece, and a step of peeling the portion to be peeled from the workpiece by irradiating the portion to be peeled with the first laser light after forming the crack in the workpiece. It is characterized by providing.

  In this laser processing method, a crack is formed along a reference line that defines the part to be peeled prior to the step of peeling the part to be peeled from the workpiece by irradiation with the first laser beam. If it does in this way, in the process of peeling a peeling scheduled part, peeling of the scheduled peeling part can be produced along the crack. Therefore, according to this laser processing method, it is possible to peel the part to be peeled into a desired shape by controlling the reference line and the mode of the crack.

  In the laser processing method according to the present invention, in the step of forming the crack, the second laser light is processed along the reference line in a state where the condensing point of the second laser light is located inside the processing object. By irradiating the object, a crack can be formed at least inside the object to be processed along the reference line. In this case, for example, a crack can be suitably formed along the reference line even on a workpiece made of a material that is difficult to form a crack on the surface by a method such as scribing.

  In the laser processing method according to the present invention, the part to be peeled includes the surface of the object to be processed, and a plurality of reference lines are set along the surface of the object to be processed. In the step of forming a crack in the workpiece along each of the reference lines and peeling off the part to be peeled, by irradiating the part to be peeled along the plurality of reference lines with the first laser light The part to be peeled can be peeled from the workpiece. In this case, the surface of the workpiece can be smoothed by peeling off the part to be peeled including the surface of the workpiece and exposing the smooth surface of the workpiece.

  In the laser processing method according to the present invention, the part to be peeled includes the edge of the object to be processed, and the reference line is set on the surface and the side surface forming the edge of the object to be processed. In the step of peeling, the part to be peeled can be peeled off by irradiating the part to be peeled along the edge of the object to be peeled with the first laser beam, and the workpiece can be chamfered. In this case, the workpiece can be chamfered by peeling off the part to be peeled including the edge of the workpiece. In particular, as described above, it is possible to cause peeling of a portion to be peeled along the crack, and therefore it is possible to perform chamfering into a desired shape by controlling the reference line and the mode of the crack.

  In the laser processing method according to the present invention, in the step of forming cracks, a plurality of rows of cracks can be formed so that the chamfered shape of the workpiece is formed of a plurality of surfaces extending along the reference line. If it does in this way, the chamfering shape of a processed object can be made into the shape constituted from a plurality of surfaces.

  In the laser processing method according to the present invention, the crack can be continuously formed along the reference line in the step of forming the crack. In this case, peeling of the part to be peeled can be caused to surely follow the reference line and the crack.

  In the laser processing method according to the present invention, the crack can be intermittently formed along the reference line in the step of forming the crack. In this case, the amount of crack formation can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the laser processing method which can peel a part of workpiece into a desired shape by irradiation of a laser beam can be provided.

It is a perspective view of the processing target object in the laser processing method concerning a 1st embodiment. It is a figure which shows the principal part of the process of forming a crack in a workpiece. It is a figure which shows the principal part of the process of forming a crack in a workpiece. It is a figure which shows the principal part of the process of forming a crack in a workpiece. It is a figure which shows the principal part of the process of peeling a peeling plan part from a process target object. It is a figure which shows the principal part of the process of peeling a peeling plan part from a process target object. It is a figure for demonstrating the modification of the laser processing method which concerns on 1st Embodiment. It is a figure for demonstrating the modification of the laser processing method which concerns on 1st Embodiment. It is a figure which shows the modification of the crack in this embodiment. It is a figure which shows the modification of the crack in this embodiment. It is a perspective view of the processing target object in the laser processing method concerning a 2nd embodiment. It is a figure which shows the process of forming a crack in a workpiece. It is a figure which shows the process of peeling a peeling plan part from a process target object. It is a perspective view of the processing target object in the laser processing method concerning a 3rd embodiment. It is a figure which shows the principal part of the process of forming a crack in a workpiece. It is a figure which shows the principal part of the process of forming a crack in a workpiece. It is a figure which shows the process of peeling a peeling plan part from a process target object. It is a figure for demonstrating the modification of the laser processing method which concerns on 3rd Embodiment. It is a figure for demonstrating the modification of the laser processing method which concerns on 3rd Embodiment. It is a figure for demonstrating the modification of the laser processing method which concerns on this embodiment.

Hereinafter, a laser processing method according to an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. In the laser processing method described below, a part of an object to be processed is peeled off by laser light irradiation.
[First Embodiment]

  First, the laser processing method according to the first embodiment of the present invention will be described. In this laser processing method, first, a processing object 1 is prepared as shown in FIG. The workpiece 1 is made of, for example, glass (including tempered glass), SiC, silicon, sapphire, or the like. The workpiece 1 has a rectangular plate shape. The workpiece 1 has a front surface 3, a back surface 4 opposite to the front surface 3, and a side surface 6 that connects the front surface 3 and the back surface 4 to each other. The workpiece 1 includes a part to be peeled 10. The part 10 to be peeled is defined by a pair of reference lines BL set on the surface 3 of the workpiece 1.

  The reference line BL is a virtual line extending from one end of the workpiece 1 to the other end so as to be parallel to each other with a predetermined interval. Therefore, the part 10 to be peeled is set in a stripe shape extending at a constant width from one end to the other end of the workpiece 1 so as to include a part of the surface 3 of the workpiece 1. Later, the planned peeling portion 10 is irradiated with laser light to peel (remove) the peeling scheduled portion 10 from the workpiece 1 and a groove is formed on the surface 3 of the workpiece 1 as shown in FIG. 11 is formed.

  In the subsequent process, a crack (initial crack) is formed in the workpiece 1 along the reference line BL. This process will be described in detail. 2-4 is a figure which shows the principal part of the process of forming a crack in a workpiece. 2B is a partial sectional view taken along line II-II in FIG. 2A, and FIG. 3B is taken along line III-III in FIG. FIG. 4B is a partial cross-sectional view taken along line IV-IV in FIG.

  In this step, first, as shown in FIG. 2, a laser beam (second laser beam) L2 is irradiated along one reference line BL. More specifically, along the one reference line BL in a state where the surface 3 of the workpiece 1 is the incident surface of the laser beam L2 and the condensing point P of the laser beam L2 is located inside the workpiece 1. By moving the condensing point P relatively (in the direction of the arrow A2), the laser beam L2 is irradiated (scanned) to the workpiece 1 along the reference line BL. Thereby, as shown in FIG. 3, the modified region 7 is formed inside the workpiece 1 along one reference line BL.

  The laser beam L2 passes through the workpiece 1 and is particularly absorbed in the vicinity of the condensing point P inside the workpiece 1, whereby a modified region 7 is formed in the workpiece 1. The modified region 7 includes a region where the density, refractive index, mechanical strength, and other physical properties are different from the surroundings. The reforming region 7 means, for example, a melting processing region (a region including at least one of a region once re-solidified after melting, a region in a molten state, and a region in the middle of re-solidifying from a molten state). ), A crack region, a dielectric breakdown region, a refractive index change region, and the like, and there are regions where these are mixed.

  Furthermore, the modified region 7 includes a region where the density of the modified region 7 in the material of the workpiece 1 is changed compared to the density of the non-modified region, and a region where lattice defects are formed (these are the Collectively referred to as the high-density transition region). In addition, the melt-processed region, the refractive index changing region, the region where the density of the modified region 7 is changed compared to the density of the non-modified region, and the region where lattice defects are formed are further included in these regions. In some cases, cracks (cracks, microcracks, etc.) are included in the interface between the quality region 7 and the non-modified region. The included crack may be formed over the entire modified region 7, or only in a part or in a plurality of parts.

  When the laser beam L2 is a pulsed laser beam, the modified region 7 is configured as a set of modified spots formed by one pulse shot (that is, one pulse laser irradiation: laser shot). Further, the modified region 7 may include a plurality of cracks extending from the modified spot. Examples of the modified spot include a crack spot, a melting treatment spot, a refractive index change spot, or a mixture of at least two of them.

Here, the irradiation conditions of the laser beam L2 can be set as follows, for example.
Wavelength: 532nm
Energy: 18μJ
Pulse width: 500ps
Scanning speed: 500mm / s

  As a result, the modified region 7 is formed inside the workpiece 1 as described above, and a crack 8 is generated from the modified region 7. The crack 8 is continuously formed from one end of the workpiece 1 to the other end along the reference line BL. Further, the crack 8 reaches the surface 3 of the workpiece 1. Then, the modified region 7 and the crack 8 are formed along the reference line BL as shown in FIG. 4 by irradiating the laser beam L2 along the other reference line BL in the same procedure.

  In the subsequent process, the part 10 to be peeled is peeled from the workpiece 1 by irradiating the part 10 to be peeled with laser light. This process will be described in detail. FIG. 5 is a diagram illustrating a main part of a process of peeling a part to be peeled from a workpiece. 5B is a partial cross-sectional view taken along line V-V in FIG. 5A, and FIG. 6B is taken along line VI-VI in FIG. 6A. FIG.

  In this step, first, as shown in FIG. 5, the surface 3 of the workpiece 1 is used as the incident surface of the laser beam (first laser beam) L1, and the beam spot SP of the laser beam L1 is positioned at the portion 10 to be peeled off. In this state, the beam spot SP is relatively moved along the reference line BL (in the direction of the arrow A1), so that the laser beam is applied to the part 10 to be peeled along the reference line BL from one end to the other end of the workpiece 1. Irradiate (scan) light L1.

  As a result, as shown in FIG. 6, with the movement of the beam spot SP of the laser beam L1 (that is, along with the scanning of the laser beam L1), the separation target portion 10 is turned up from the workpiece 1. Is peeled off. At this time, since the crack 8 is formed along the reference line BL in the workpiece 1, the peeling of the part to be peeled 10 is defined by the crack 8, and along the crack 8 (along the reference line BL). ) It will progress. As a result, as shown in FIG. 1B, the part to be peeled 10 is peeled from the workpiece 1 along the reference line BL, and the striped grooves 11 are formed on the surface 3 of the part 10 to be peeled. Is formed.

Note that the part to be peeled 10 is peeled continuously in the moving direction of the beam spot SP (scanning direction of the laser light L1) depending on the shearing force generated by the irradiation of the laser light L1 and the shearing force generated by the heating. It is considered that a crack is generated in the workpiece 1 and then the surface 3 of the workpiece 1 is contracted by natural air cooling. The irradiation conditions of the laser beam L1 for causing such peeling can be set as follows, for example. As a light source of the laser light L1, for example, a CO ₂ laser or the like can be used.
Beam spot diameter φ: 1.0 mm
Output: 100W
Scanning speed: 1000mm / s

  As described above, in the laser processing method according to the present embodiment, prior to the step of peeling the planned peeling portion 10 from the workpiece 1 by irradiation with the laser beam L1, the reference line BL defining the planned peeling portion 10 is used. A crack 8 is formed along. If it does in this way, in the process of peeling the peeling scheduled part 10, peeling of the scheduled peeling part 10 can be produced along the crack 8. FIG. Therefore, according to this laser processing method, by controlling the reference line BL and the crack 8 to a desired mode (position, shape, etc.), for example, a portion to be peeled into a desired shape, such as improving the linearity of the processed shape. 10 can be peeled off.

  As described above, the shapes of the reference line BL and the crack 8 can be arbitrarily set according to a desired processing shape. For example, as shown in FIG. 7 (a), the reference line BL is set in a rectangular shape inside a predetermined distance from the outer peripheral portion of the workpiece 1, and along the reference line BL (in the direction of the arrow A2). Ii) The crack 8 can be formed by irradiating the laser beam L2. In this case, as shown in FIG. 7B, the planned peeling portion 10 is irradiated by irradiating the rectangular peeling planned portion 10 defined by the reference line BL and the crack 8 with the laser beam L1. It peels and the rectangular groove | channel 11 can be formed in the surface 3 of the workpiece 1 as FIG.7 (c) shows.

  Similarly, the reference line BL can be set in an annular shape to form an annular crack 8, but for example, as shown in FIG. When the planned separation portion 10 defined by the reference line BL is wider than the diameter of the beam spot SP of the laser beam L1, a plurality of separation portions 10 (here, as shown in FIG. 8B) are used. Then, the crack 8 can be formed so as to be divided into two regions 10a. If it does in this way, each of the some area | region 10a can be irradiated and peeled off with the laser beam L1, and the whole peeling scheduled part 10 can be peeled.

  Moreover, the crack 8 is not limited to what was mentioned above, The following are included. That is, the crack 8 does not need to reach the surface 3 of the workpiece 1 as shown in FIG. In this case, the crack 8 reaches the surface 3 of the workpiece 1 due to the irradiation with the laser beam L1, and the peeling scheduled portion 10 can be peeled off. As described above, the crack 8 only needs to be formed at least inside the workpiece 1.

  Moreover, the crack 8 may be formed so that it may incline with respect to the direction perpendicular | vertical to the surface 3 and the back surface 4 of the workpiece 1 as FIG.9 (b) shows. In this case, the to-be-peeled portion 10 having a trapezoidal cross section is peeled, and a groove having a trapezoidal cross section is formed in the workpiece 1. Moreover, the crack 8 is not limited to what arises from the modification | reformation area | region 7 as mentioned above. That is, the crack 8 may be formed without the formation of the modified region 7 by irradiation with a predetermined laser beam, or as shown in FIG. It may be a scribe groove formed on the surface 3 of the workpiece 1 by scribe or the like.

Further, as shown in FIG. 9D, the crack 8 can be formed such that the outer shape of the cross-sectional shape of the part to be peeled 10 to be peeled is formed by a straight line and a curved line. Furthermore, the cracks 8 are not limited to those formed continuously along the reference line BL, and may be formed intermittently along the reference line BL as shown in FIG. . About the modification of the above crack 8, it can apply similarly also in the following embodiment.
[Second Embodiment]

  Subsequently, a laser processing method according to the second embodiment of the present invention will be described. In this laser processing method, first, a processing object 1A is prepared as shown in FIG. The workpiece 1A is made of, for example, glass (including tempered glass), SiC, silicon, sapphire, or the like. The processing object 1A includes a part 10A to be peeled. The part to be peeled 10A is defined by a plurality of (here, five) reference lines BL.

  The reference line BL is a virtual line extending from one end of the workpiece 1A to the other end so as to be parallel to each other at a predetermined interval, and along the surface 3 of the workpiece 1A (over the entire surface 3). It is arranged. Accordingly, the part to be peeled 10A is set so as to include the entire surface 3 of the workpiece 1 as a set of striped regions 10a defined by the pair of reference lines BL. In the subsequent process, as shown in FIG. 11B, the separation target portion 10A is irradiated with a laser beam to peel (remove) the separation target portion 10A from the processing target 1A, and the processing target 1A. The processed surface 3A is exposed.

  In the subsequent process, as in the first embodiment, the laser beam L2 is irradiated along each of the reference lines BL, so that the workpiece is processed along each of the reference lines BL as shown in FIG. A modified region 7 is formed inside 1A, and a crack 8 is generated from the modified region 7. Thereby, the crack 8 from the inside of the workpiece 1A to the surface 3 of the workpiece 1A is continuously formed along one of the reference lines BL from one end to the other end of the workpiece 1A. Note that FIG. 12B is a cross-sectional view taken along line XII-XII in FIG.

  Subsequently, the part to be peeled 10A is peeled from the workpiece 1A by irradiating the part 10A to be peeled with the laser beam L1. More specifically, as shown in FIG. 13 (a), the surface 3 of the workpiece 1A is used as the incident surface of the laser beam L1, and the laser beam L1 is applied to one region 10a of the planned separation portion 10A. The beam spot SP is positioned. In this state, the beam spot SP is relatively moved along the reference line BL (in the direction of the arrow A1) to irradiate (scan) the region 10a with the laser beam L1. Thereby, as shown in FIG. 13B, the region 10a is peeled from the workpiece 1A.

  By repeating the same procedure for the other regions 10a, all the regions 10a are peeled off, and the entire portion to be peeled 10A is peeled as shown in FIG. 11B. Thereby, the whole surface 3 of the workpiece 1A is peeled off, and the machining surface 3A of the workpiece 1A is exposed.

As described above, according to the laser processing method according to the present embodiment, the smooth processed surface 3A of the workpiece 1 is formed by peeling off the planned peeling portion 10A including the entire surface 3 of the workpiece 1A. The surface of the workpiece 1A can be smoothed by exposing it.
[Third Embodiment]

  Subsequently, a laser processing method according to the third embodiment of the present invention will be described. In this laser processing method, first, a processing object 1B is prepared as shown in FIG. The workpiece 1B is made of, for example, glass (including tempered glass), SiC, silicon, sapphire, or the like. The processing target 1B includes a part to be peeled 10B. The planned peeling portion 10B is defined by a pair of reference lines BL.

  The reference line BL is set on each of the surface 3 and the side surface 6 of the workpiece 1B that forms the edge 12 of the workpiece 1B. Each of the reference lines BL extends from one end of the workpiece 1B to the other end. Therefore, the part 10B to be peeled extends from one end of the workpiece 1B to the other end so as to include the edge 12 of the workpiece 1B. Later, as shown in FIG. 14 (b), the part 10B to be peeled is irradiated with laser light to peel (remove) the part 10B (and the edge 12) to be peeled from the object 1B. Chamfer the object 1B.

  In subsequent steps, as shown in FIGS. 15 and 16, the modified region 7 is formed inside the workpiece 1 by irradiating the laser beam L <b> 2 along the reference line BL. More specifically, first, as shown in FIG. 15, the condensing point P of the laser light L2 is positioned inside the processing object 1B with the surface 3 of the processing object 1B as the incident surface of the laser light L2. In the state, the processing object 1B is irradiated (scanned) with the laser beam L2 along the reference line BL by relatively moving the condensing point P along the reference line BL (in the direction of the arrow A2).

  As a result, as shown in FIG. 16, a row of modified regions 7 are formed along the reference line BL. Here, since the modified region 7 includes the cracks as described above, in this step, a row of cracks is formed along the reference line BL. 15B is a partial cross-sectional view taken along line XV-XV in FIG. 15A, and FIG. 16B is a line XVI-XVI in FIG. It is a fragmentary sectional view along line.

  Subsequently, as shown in FIG. 17, the laser beam L1 is irradiated to the planned peeling portion 10B to peel the planned peeling portion 10B from the workpiece 1B. More specifically, as shown in FIG. 17A, the surface 3 of the workpiece 1B is used as the incident surface of the laser light L1, and at least a part of the beam spot SP of the laser light L1 is formed on the part to be peeled 10B. In the positioned state, the beam spot SP is relatively moved along the reference line BL (in the direction of the arrow A1) to irradiate (scan) the laser beam L1 along the edge 12 to the separation scheduled portion 10B.

  Thereby, as shown in FIG. 17B and FIG. 14B, the part to be peeled 10B including the edge 12 of the workpiece 1B is peeled from the workpiece 1B, and the workpiece 1B Perform chamfering. Thereafter, if necessary, the entire chamfering of the workpiece 1B can be performed by repeating the same procedure for the part to be peeled including other edges of the part to be peeled 10B.

In addition, the irradiation conditions of the laser beam L1 here can be set as follows, for example.
Beam spot diameter: 0.34mm
Output: 100W
Scanning speed: 300mm / s

  As described above, according to the laser processing method according to the present embodiment, it is possible to perform chamfering of the workpiece 1B. In particular, since the separation of the part 10B to be separated is defined by the modified region 7 (a crack included in the modified region 7), the processing object 1B is controlled by controlling the formation position of the modified region 7. It is possible to control the chamfering shape (for example, depth).

  Note that, in the laser processing method according to the present embodiment, the form of the modified region 7 that defines the peeling of the part to be peeled 10B is not limited to that described above. For example, as shown in FIG. 18, the modified region 7 may be formed along each of the pair of reference lines BL. In this case, two rows of modified regions 7 and cracks 8 are formed. FIG. 18B is a partial cross-sectional view taken along line XVIII-XVIII in FIG.

  As a result, as shown in FIG. 19A, the chamfered shape F of the workpiece 1B is defined by each of the two rows of cracks 8, so that the two extending along the reference line BL are two. It will be formed from the surface. As described above, in this laser processing method, a plurality of rows of modified regions 7 are formed on the processing target 1B so that the chamfered shape of the processing target 1B is constituted by a plurality of arbitrary surfaces extending along the reference line BL. And cracks 8 can be formed. In addition, the extending direction in the plane perpendicular to the reference line BL (in the drawing in the drawing) of each surface forming the chamfered shape F corresponds to the extending direction of the crack 8 in the plane orthogonal to the reference line BL. ing.

  In the laser processing method according to the present embodiment, as shown in FIG. 19B, the side surface 6 closer to the formation position of the modified region 7 than the surface 3 is used as the incident surface of the laser light L2. It may be used. Thus, in this laser processing method, an arbitrary surface can be used as the incident surface of the laser beam L2 in accordance with the form of the modified region 7 formed.

  The above embodiment describes one embodiment of the laser processing method according to the present invention. Therefore, the laser processing method according to the present invention is not limited to the above-described one. The laser processing method according to the present invention can be arbitrarily modified as described above without departing from the scope of the claims recited in the claims.

  For example, as shown in FIG. 20, when the surface 3 of the workpiece is curved three-dimensionally, the laser beam in the thickness direction of the workpiece in the step of forming the crack 8 in the above embodiment. While changing the position of the condensing point P of L2 according to the displacement of the surface 3 (that is, keeping the distance from the surface 3 of the condensing point P in the thickness direction of the workpiece) constant, the laser beam L2 By irradiating the workpiece, a crack 8 can be formed at a certain position from the surface 3 in the thickness direction of the workpiece.

  DESCRIPTION OF SYMBOLS 1,1A, 1B ... Workpiece, 3 ... Surface, 6 ... Side face, 8 ... Crack, 10, 10A, 10B ... Planned peeling part, 12 ... Edge, L1 ... Laser beam (first laser beam), L2 ... Laser beam (second laser beam), P ... Condensing point, F ... Chamfered shape, BL ... Base line.

Claims (7)

A step of preparing a workpiece including a portion to be peeled,
After preparing the workpiece, forming a crack in the workpiece along a reference line defining the part to be peeled;
After forming the crack in the workpiece, peeling the part to be peeled from the workpiece by irradiating the part to be peeled with a first laser beam;
A laser processing method comprising:   In the step of forming the crack, the processing object is irradiated with the second laser light along the reference line in a state in which a condensing point of the second laser light is positioned inside the processing object. The laser processing method according to claim 1, wherein the crack is formed at least inside the processing object along the reference line. The part to be peeled includes a surface of the workpiece,
A plurality of the reference lines are set along the surface of the workpiece,
In the step of forming the crack, the crack is formed in the workpiece along each of the plurality of reference lines,
In the step of peeling the part to be peeled, the part to be peeled is peeled from the workpiece by irradiating the part to be peeled with the first laser light along each of the plurality of reference lines. The laser processing method according to claim 1 or 2, characterized by the above-mentioned. The part to be peeled includes an edge of the workpiece,
The reference line is set on the surface and the side surface forming the edge of the workpiece,
In the step of peeling the part to be peeled, the part to be peeled is peeled by irradiating the part to be peeled along the edge of the workpiece with the first laser light, and the workpiece The laser processing method according to claim 1, wherein chamfering is performed.   5. The plurality of rows of the cracks are formed so that the chamfered shape of the workpiece is formed of a plurality of surfaces extending along the reference line in the step of forming the cracks. The laser processing method as described in.   The laser processing method according to claim 1, wherein, in the step of forming the crack, the crack is continuously formed along the reference line.   The laser processing method according to claim 1, wherein in the step of forming the crack, the crack is intermittently formed along the reference line.

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