CN117020449A

CN117020449A - Laser processing device and laser processing method

Info

Publication number: CN117020449A
Application number: CN202311243325.8A
Authority: CN
Inventors: 坂本刚志; 是松克洋
Original assignee: Hamamatsu Photonics KK
Current assignee: Hamamatsu Photonics KK
Priority date: 2018-10-30
Filing date: 2019-10-30
Publication date: 2023-11-10
Also published as: TW202400339A; WO2020090902A1; JP2022173224A; JP7293475B2

Abstract

The laser processing device is provided with: the device comprises a supporting part, an irradiation part, a moving mechanism, a control part and an imaging part. The control unit performs a 1 st pretreatment of irradiating the object with laser light along a processing line having a plurality of parallel lines arranged in parallel to form a modified region in the object. The image pickup unit obtains a 1 st image, and the 1 st image shows a processing state in which a modified region is formed along a processing line having a plurality of parallel lines by the 1 st preprocessing.

Description

Laser processing device and laser processing method

The present application is a divisional application of patent application with application date of 2019, 10 month and 30 date, application number of 201980071652.5 and the name of laser processing device and laser processing method.

Technical Field

One embodiment of the present application relates to a laser processing apparatus and a laser processing method.

Background

Patent document 1 describes a laser processing apparatus including: a holding mechanism for holding the workpiece, and a laser irradiation mechanism for irradiating the workpiece held by the holding mechanism with laser light. In the laser processing apparatus described in patent document 1, a laser irradiation mechanism having a condenser lens is fixed to a base, and movement of a workpiece in a direction perpendicular to an optical axis of the condenser lens is performed by a holding mechanism.

[ Prior Art literature ]

[ patent literature ]

[ patent document 1] Japanese patent No. 5456510

Disclosure of Invention

[ problem to be solved by the invention ]

However, in the laser processing apparatus as described above, a modified region may be formed along a virtual surface inside the object by irradiating the object with laser light. In this case, a part of the object is peeled off with the modified region extending over the virtual plane as a boundary. In such a peeling process, it may be difficult to peel the object according to processing conditions when the object is irradiated with laser light, for example.

Accordingly, an aspect of the present invention is to provide a laser processing apparatus and a laser processing method capable of reliably peeling an object.

[ means of solving the problems ]

A laser processing apparatus according to an aspect of the present invention irradiates an object with laser light to form a modified region along a virtual plane in the object, the laser processing apparatus including: a support section for supporting an object; an irradiation unit for irradiating the object supported by the support unit with laser light; a moving mechanism for moving at least one of the support portion and the irradiation portion so as to move the position of the converging point of the laser light along the virtual plane; a control unit for controlling the support unit, the irradiation unit, and the movement mechanism; and an imaging unit that images the object from a direction along the incidence direction of the laser beam, wherein the control unit performs a 1 st pretreatment in which the object is irradiated with the laser beam along a processing line having a plurality of parallel lines arranged side by side to form a modified region in the object, and the imaging unit acquires a 1 st image in which the 1 st image shows a processing state in which the modified region is formed along the processing line having the plurality of parallel lines by the 1 st pretreatment.

The inventors of the present invention found that there was a correlation between the peeling of the object and the processing state in the case where the modified region was formed along the processing line having a plurality of parallel lines, as a result of repeated diligent studies. In the laser processing apparatus according to one aspect of the present invention, the 1 st image is obtained, and the 1 st image is in a processing state in which the modified region is formed along the processing line having a plurality of parallel lines. From this 1 st image, the processing conditions can be determined so that the object can be peeled off. Therefore, the object can be peeled off surely.

In the laser processing apparatus according to one aspect of the present invention, the control unit may perform a 2 nd pretreatment in which the object is irradiated with laser light along one processing line to form a modified region in the object, and the imaging unit may acquire a 2 nd image in which the 2 nd image is in a processing state in which the modified region is formed along one processing line by the 2 nd pretreatment.

The inventors of the present invention have found that there is a correlation between the peeling of the object and the processing state in the case where the modified region is formed along one line of processing line as a result of further repeated diligent research. Thus, the laser processing apparatus according to one aspect of the present invention acquires the 2 nd image, and the 2 nd image is in a processing state in which the modified region is formed along one processing line. From this 2 nd image, the processing conditions can be determined so that the object can be peeled off. Therefore, the object can be peeled off surely.

In the laser processing apparatus according to one aspect of the present invention, the control unit may determine the processing state represented by the 2 nd image, and change the processing condition of the 2 nd pretreatment according to the determination result. In this case, the processing conditions of the 2 nd pretreatment may be automatically changed in accordance with the 2 nd image.

In the laser processing apparatus according to one aspect of the present invention, the control unit may determine whether or not the processing state represented by the 2 nd image is a 1 st cutting (sliding) state, and when the processing condition of the 2 nd pretreatment is changed, the 1 st cutting state is a state in which cracks extending from a plurality of modified spots included in the modified region are stretched in a direction along one processing line. It was found that if the processing state in which the modified region was formed along one processing line was not the 1 st cut state, the object was difficult to peel off. In one aspect of the present invention, when the processing state shown in the 2 nd image is not the 1 st cutting state, the processing condition of the 2 nd pretreatment is changed. In this way, the processing conditions can be determined so that the object can be peeled off.

In the laser processing apparatus according to one aspect of the present invention, the control unit may determine the processing state represented by the 1 st image, and change the processing condition of the 1 st pretreatment according to the determination result. In this case, the processing conditions of the 1 st pretreatment may be automatically changed according to the 1 st image.

In the laser processing apparatus according to one aspect of the present invention, the 1 st pretreatment may be a processing line having a plurality of parallel lines arranged side by side, the object is irradiated with laser light under the 1 st processing condition to form a modified region in the object, the image pickup unit obtains, as the 1 st image, an image showing a processing state after the 1 st predetermined amount of laser processing, the control unit determines whether or not the 1 st predetermined amount of processing state after the 1 st laser processing performed in the 1 st pretreatment is a 2 nd cutting state based on the 1 st image, and when the processing state is not the 2 nd cutting state, the 1 st processing condition is changed, and the 2 nd cutting state is a state in which cracks extending from a plurality of modified points included in the modified region are stretched in a direction along the parallel lines and a direction intersecting the parallel lines and are connected.

It has been found that when forming the modified region along the processing line having a plurality of parallel lines, the object can be peeled off reliably by performing the laser processing such that the processing state after the laser processing of the 1 st predetermined amount becomes the 2 nd cutting state. In one embodiment of the present invention, it is determined from the 1 st image whether the machining state after the 1 st predetermined amount of laser machining is the 2 nd cutting state, and if the machining state is not the 2 nd cutting state, the 1 st machining condition is changed. Thus, the 1 st processing condition under which the object can be peeled off can be determined.

In the laser processing apparatus according to one aspect of the present invention, the 1 st pretreatment is to irradiate the object with laser light under the 2 nd processing condition along the processing line having the plurality of parallel lines arranged side by side to form the modified region in the object, and the imaging unit obtains, as the 1 st image: the control unit determines whether the 1 st prescribed amount of the processed state after laser processing performed by the 1 st pretreatment is a 2 nd cut state based on the 1 st image which is an image of the processed state after laser processing which is a 1 st prescribed amount, changes the 2 nd processing condition when the 1 st prescribed amount of the processed state after laser processing is the 2 nd cut state, determines whether the 2 nd processed state after laser processing performed by the 1 st pretreatment is the 2 nd cut state based on the 1 st image which is an image of the processed state after laser processing which is a 2 nd prescribed amount, and extends the plurality of cracks extending from the modified spots in parallel in the parallel direction and the intersecting direction in the parallel direction when the 1 st prescribed amount of the processed state after laser processing is the 2 nd cut state.

It has been found that when forming the modified region along the processing line having a plurality of parallel lines, if the laser processing is performed so that the processing state after the laser processing of the 2 nd predetermined amount becomes the 2 nd cutting state, the object can be peeled while suppressing an increase in the tact time. In one embodiment of the present invention, it is determined from the 1 st image whether or not the machining state after the 1 st predetermined amount of laser machining is the 2 nd cutting state, and when the machining state is the 2 nd cutting state, the 2 nd machining condition is changed. Whether the machining state after the laser machining of the 2 nd predetermined amount is the 2 nd cutting state is determined based on the 1 st image, and when the machining state is not the 2 nd cutting state, the 2 nd machining condition is changed. Thus, the 2 nd processing condition capable of peeling the object while suppressing an increase in the tact time can be determined.

In the laser processing apparatus according to one aspect of the present invention, the object may be a wafer for condition determination or a wafer for a semiconductor device. When the target object is a wafer for condition determination, a processing line may be set at any one of the entire regions of the wafer, and the processing condition may be determined. When the object is a wafer for a semiconductor device, the processing conditions can be determined by setting a processing line in an outer edge region of the wafer, which has little influence on the peeling quality. The condition determining wafer is, for example, a wafer for operation (practie) which does not eventually become a semiconductor device (product). The wafer for a semiconductor device is, for example, a wafer for production (production) of a semiconductor device.

In the laser processing method according to one aspect of the present invention, a modified region is formed along a virtual surface inside an object by irradiating the object with laser light, and the laser processing method includes a 1 st pre-step of forming the modified region in the object by irradiating the object with laser light along a processing line having a plurality of parallel lines arranged side by side, and a 1 st image capturing step of obtaining a 1 st image, wherein the 1 st image is a processing state in which the modified region is formed along the processing line having the plurality of parallel lines by the 1 st pre-step.

In this laser processing method, a 1 st image is obtained, and the 1 st image is a processed state in which a modified region is formed along a processing line having a plurality of parallel lines in the 1 st step. From the 1 st image obtained, the processing conditions can be determined so as to be in a processing state in which the object can be peeled off. Therefore, the object can be peeled off surely.

[ Effect of the invention ]

According to one aspect of the present invention, a laser processing apparatus and a laser processing method capable of reliably peeling an object can be provided.

Drawings

Fig. 1 is a perspective view of a laser processing apparatus according to an embodiment.

Fig. 2 is a front view of a part of the laser processing apparatus shown in fig. 1.

Fig. 3 is a front view of a laser processing head of the laser processing apparatus shown in fig. 1.

Fig. 4 is a side view of the laser processing head shown in fig. 3.

Fig. 5 is a block diagram of an optical system of the laser processing head shown in fig. 3.

Fig. 6 is a block diagram of an optical system of a laser processing head according to a modification.

Fig. 7 is a front view of a part of a laser processing apparatus according to a modification.

Fig. 8 is a perspective view of a laser processing apparatus according to a modification.

Fig. 9 is a plan view showing a schematic configuration of the laser processing apparatus according to embodiment 1.

Fig. 10 (a) is a plan view showing an example of the object, and fig. 10 (b) is a side view of the object shown in fig. 10 (a).

Fig. 11 (a) is a side view of an object for explaining a method of manufacturing a semiconductor device using the laser processing apparatus of embodiment 1, and fig. 11 (b) is a side view of a subsequent object shown in fig. 11 (a).

Fig. 12 (a) is a side view showing the subsequent object of fig. 11 (b), fig. 12 (b) is a plan view showing the subsequent object of fig. 12 (a), and fig. 12 (c) is a side view of the object shown in fig. 12 (b).

Fig. 13 (a) is a side view showing the subsequent object of fig. 12 (b), and fig. 13 (b) is a side view showing the subsequent object of fig. 13 (a).

Fig. 14 (a) is a plan view showing an object to be peeled according to embodiment 1, and fig. 14 (b) is a side view showing an enlarged portion within a broken line frame of fig. 14 (a).

Fig. 15 is a plan view for explaining a plurality of modified spots formed by the peeling process in embodiment 1.

Fig. 16 (a) shows an image showing a state of cutting privacy (stealth), and fig. 16 (b) shows an image showing a state of cutting half-cut (half-cut).

Fig. 17 (a) shows another image showing a state of cutting intimacy, and fig. 17 (b) shows another image showing a state of cutting half-cut.

Fig. 18 (a) shows an image of the 1 st predetermined amount of the laser beam after machining, that is, the cut-and-full state, and fig. 18 (b) shows an image of the 2 nd predetermined amount of the laser beam after machining, that is, the cut-and-full state.

Fig. 19 is a flowchart showing the peeling process according to embodiment 1.

Fig. 20 (a) is a plan view of the object of the peeling process according to embodiment 1, and fig. 20 (b) is a plan view of the subsequent object shown in fig. 20 (a).

Fig. 21 (a) is a plan view showing the subsequent object of fig. 20 (b), and fig. 21 (b) is a plan view showing the subsequent object of fig. 21 (a).

Fig. 22 is a plan view of an object for explaining a crack extending from the modified region.

Fig. 23 is a view showing the observation result of the crack in the object of fig. 22.

Fig. 24 (a) is a plan view of an object to be peeled in the modification of embodiment 1, and fig. 24 (b) is a plan view of an object to be peeled in the subsequent step of fig. 24 (a).

Fig. 25 is a diagram showing an example of a setting screen of the GUI.

Fig. 26 is a diagram showing another example of a setting screen of the GUI.

Fig. 27 is a diagram showing an example of the manager mode of the setting screen of the GUI.

FIG. 28 is a graph showing experimental results of examining the optimum pulse energy for the peeling process.

Fig. 29 (a) is a plan view for explaining the object of the peeling process according to embodiment 2, and fig. 29 (b) is a plan view showing the subsequent object of fig. 29 (a).

Fig. 30 is a flowchart showing the peeling process according to embodiment 2.

Fig. 31 is a flowchart showing a peeling process according to a modification of embodiment 2.

FIG. 32 is a flowchart showing the stripping process according to embodiment 3.

FIG. 33 is a flowchart showing an example of processing for determining the half-cut processing conditions in the peeling processing according to embodiment 4.

FIG. 34 is a flowchart showing an example of processing for determining the 1 st processing condition in the peeling processing of embodiment 4.

FIG. 35 is a flowchart showing an example of processing for determining the 2 nd processing condition in the peeling processing of embodiment 4.

Fig. 36 (a) is a side view of an object for explaining a method of manufacturing a semiconductor device according to a modification, and fig. 36 (b) is a side view of an object subsequent to fig. 36 (a).

Fig. 37 (a) is a side view of an object for explaining a method of manufacturing a semiconductor device according to another modification, and fig. 37 (b) is a side view of an object subsequent to fig. 37 (a).

Fig. 38 (a) is a side view of an object for explaining a method of manufacturing a semiconductor device according to another modification, and fig. 38 (b) is a side view of an object subsequent to fig. 38 (a).

Fig. 39 is a plan view of an object to be peeled as a modification.

Fig. 40 is a plan view of a laser processing apparatus according to a modification.

Fig. 41 is a plan view showing an example of the object, and fig. 41 (b) is a side view of the object shown in fig. 41 (a).

Fig. 42 is a plan view of a laser processing apparatus for explaining a method of manufacturing a semiconductor device using the laser processing apparatus of the modification.

Fig. 43 (a) is a side view of an object for explaining a method of manufacturing a semiconductor device using the laser processing apparatus of the modification example, and fig. 43 (b) is a side view of a subsequent object showing fig. 43 (a).

Fig. 44 (a) is a side view showing the subsequent object of fig. 43 (b), fig. 44 (b) is a plan view showing the subsequent object of fig. 44 (a), and fig. 44 (c) is a side view showing the object of fig. 44 (b).

Fig. 45 is a plan view of a laser processing apparatus for explaining a method of manufacturing a semiconductor device using the laser processing apparatus of the modification.

Fig. 46 is a side view of a part of a laser processing apparatus for explaining a method of manufacturing a semiconductor device using the laser processing apparatus of the modification.

Fig. 47 is a side view showing a peripheral edge portion of the subsequent object of fig. 44 (b) and (c).

Fig. 48 (a) is a side view showing the subsequent object of fig. 47, and fig. 48 (b) is a side view showing the subsequent object of fig. 48 (a).

Fig. 49 (a) is a sectional view showing a peripheral portion of the object, and fig. 49 (b) is a sectional view showing an enlarged portion of fig. 49 (a).

Fig. 50 is a side view of a part of a laser processing apparatus for explaining a method of manufacturing a semiconductor device using the laser processing apparatus of the modification.

Detailed Description

Hereinafter, embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding portions are denoted by the same reference numerals, and redundant description thereof is omitted.

First, basic structure, operation, effects, and modifications of the laser processing apparatus will be described.

[ Structure of laser processing apparatus ]

As shown in fig. 1, the laser processing apparatus 1 includes: a plurality of moving mechanisms 5,6, a pair of laser processing heads 10a,10b of the supporting parts 7, 1, a light source unit 8, and a control part 9. Hereinafter, the 1 st direction is referred to as an X direction, the 2 nd direction perpendicular to the 1 st direction is referred to as a Y direction, and the 3 rd direction perpendicular to the 1 st and 2 nd directions is referred to as a Z direction. In the present embodiment, the X direction and the Y direction are horizontal directions, and the Z direction is vertical direction.

The moving mechanism 5 includes: a fixed part 51, a moving part 53, and a mounting part 55. The fixing portion 51 is attached to the apparatus frame 1a. The moving portion 53 is mounted on a rail provided in the fixed portion 51 so as to be movable in the Y direction. The mounting portion 55 is mounted on a rail provided in the moving portion 53 so as to be movable in the X direction.

The moving mechanism 6 includes: the fixed parts 61, the moving parts 63,64 of the 1 pair, and the mounting parts 65,66 of the 1 pair. The fixing portion 61 is attached to the apparatus frame 1a. The pair 1 of moving parts 63,64 are mounted on rails provided on the fixed part 61, respectively, and can move in the Y direction independently of each other. The mounting portion 65 is mounted on a rail provided in the moving portion 63 so as to be movable in the Z direction. The mounting portion 66 is mounted on a rail provided in the moving portion 64 so as to be movable in the Z direction. That is, the mounting portions 65,66 of the pair of device frames 1a,1 are movable in the respective directions of the Y direction and the Z direction. The moving parts 63,64 constitute the 1 st and 2 nd horizontal moving mechanisms (horizontal moving mechanisms), respectively. The mounting portions 65,66 constitute the 1 st and 2 nd vertical movement mechanisms (vertical movement mechanisms), respectively.

The support portion 7 is attached to a rotation shaft provided in the attachment portion 55 of the moving mechanism 5, and is rotatable about an axis parallel to the Z direction as a center line. That is, the support portion 7 is movable in each of the X direction and the Y direction, and is rotatable about an axis parallel to the Z direction as a center line. The support 7 supports the object 100. The object 100 is, for example, a wafer.

As shown in fig. 1 and 2, the laser processing head 10A is attached to the attachment portion 65 of the moving mechanism 6. The laser processing head 10A irradiates the object 100 supported by the support 7 with laser light L1 (also referred to as "1 st laser light L1") in a state of being opposed to the support 7 in the Z direction. The laser processing head 10B is attached to the attachment portion 66 of the moving mechanism 6. The laser processing head 10B irradiates the object 100 supported by the support 7 with laser light L2 (also referred to as "2 nd laser light L2") in a state of being opposed to the support 7 in the Z direction. The laser processing heads 10a,10b constitute irradiation sections.

The light source unit 8 has 1 pair of light sources 81,82. The light source 81 outputs laser light L1. The laser beam L1 is emitted from the emission portion 81a of the light source 81, and is guided to the laser processing head 10A by the optical fiber 2. The light source 82 outputs laser light L2. The laser beam L2 is emitted from the emission portion 82a of the light source 82, and is guided to the laser processing head 10B by the other optical fiber 2.

The control unit 9 controls the respective units (the support unit 7, the plurality of moving mechanisms 5,6, and 1 pair of laser processing heads 10a,10b, the light source unit 8, and the like) of the laser processing apparatus 1. The control unit 9 is configured as a computer device including a processor, a memory, a storage, a communication device, and the like. In the control unit 9, software (program) read by a memory or the like is executed by a processor, and reading and writing of data in the memory and the storage, and communication by a communication device are controlled by the processor. Thus, the control unit 9 can realize various functions.

Next, an example of processing using the laser processing apparatus 1 configured as described above will be described. An example of this processing is to form a modified region inside the object 100 along a plurality of lines (lines) set in a lattice shape in order to cut the object 100 (wafer) into a plurality of chips (chips).

First, in order to make the support portion 7 for supporting the object 100 face the 1 pair of laser processing heads 10a,10b in the Z direction, the moving mechanism 5 moves the support portion 7 in each of the X direction and the Y direction. Next, in order to make the plurality of lines extending in one direction in the object 100 extend in the X direction, the moving mechanism 5 rotates the support 7 about an axis parallel to the Z direction as a center line.

Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction so that the converging point (a part of the converging region) of the laser light L1 is located on a line extending in one direction. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Y direction so that the converging point of the laser light L2 is located on the other line extending in the one direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction so that the converging point of the laser light L1 is located inside the object 100. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Z direction so that the converging point of the laser light L2 is located inside the object 100.

Next, the light source 81 is caused to output the laser beam L1 and the laser processing head 10A is caused to irradiate the object 100 with the laser beam L1, and the light source 82 is caused to output the laser beam L2 and the laser processing head 10B is caused to irradiate the object 100 with the laser beam L2. At the same time, the moving mechanism 5 moves the support 7 in the X direction so that the converging point of the laser beam L1 is moved relatively along one line extending in one direction and the converging point of the laser beam L2 is moved relatively along the other line extending in one direction. In this way, the laser processing apparatus 1 forms a modified region inside the object 100 along each of the plurality of lines extending in the direction of the object 100.

Next, in order to make the plurality of lines extending in the other direction orthogonal to the one direction of the object 100 extend in the X direction, the moving mechanism 5 rotates the support portion 7 around the axis parallel to the Z direction as the center line.

Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction so that the converging point of the laser light L1 is located on one line extending in the other direction. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Y direction so that the converging point of the laser light L2 is located on the other line extending in the other direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction so that the converging point of the laser light L1 is located inside the object 100. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Z direction so that the converging point of the laser light L2 is located inside the object 100.

Next, the light source 81 is caused to output the laser beam L1 and the laser processing head 10A is caused to irradiate the object 100 with the laser beam L1, and the light source 82 is caused to output the laser beam L2 and the laser processing head 10B is caused to irradiate the object 100 with the laser beam L2. At the same time, the moving mechanism 5 moves the support 7 in the X direction so that the converging point of the laser beam L1 is moved relatively along one line extending in the other direction and the converging point of the laser beam L2 is moved relatively along the other line extending in the other direction. In this way, the laser processing apparatus 1 forms a modified region inside the object 100 along each of the plurality of lines extending in the other direction orthogonal to the one direction in the object 100.

In the above-described processing example, the light source 81 outputs the laser beam L1 having the permeability to the object 100 by, for example, a pulse oscillation method, and the light source 82 outputs the laser beam L2 having the permeability to the object 100 by, for example, a pulse oscillation method. When such laser light is condensed in the object 100, the laser light is particularly absorbed in a portion corresponding to the condensed point of the laser light, and a modified region is formed in the object 100. The modified region is a region having physical properties such as density, refractive index, and mechanical strength different from those of the surrounding non-modified region. Examples of the modified region include: a melt processing region, a fracture region, an insulation breakdown region, a refractive index change region, and the like.

When the laser beam output by the pulse oscillation method irradiates the object 100 and the converging point of the laser beam is relatively moved along the line set in the object 100, a plurality of modified spots are formed so as to be aligned in 1 line along the line. The 1 modified dot was formed by 1 pulse of laser irradiation. The modified region of 1 row is a set of a plurality of modified spots arranged in 1 row. The adjacent modified spots may be connected to each other or separated from each other depending on the relative movement speed of the laser beam converging spot with respect to the object 100 and the repetition frequency of the laser beam. The shape of the set line is not limited to a lattice shape, and may be a ring shape, a linear shape, a curved shape, or a combination of at least one of them.

[ Structure of laser processing head ]

As shown in fig. 3 and 4, the laser processing head 10A includes: a housing 11, an incidence part 12, an adjustment part 13, and a light condensing part 14.

The housing 11 has: wall parts 1 and 2, wall parts 23 and 4, wall parts 21 and 22, wall parts 5 and 25, and wall parts 6 and 26. The 1 st wall portion 21 and the 2 nd wall portion 22 are opposed to each other in the X direction. The 3 rd wall portion 23 and the 4 th wall portion 24 are opposed to each other in the Y direction. The 5 th wall portion 25 and the 6 th wall portion 26 are opposed to each other in the Z direction.

The distance between the 3 rd wall portion 23 and the 4 th wall portion 24 is smaller than the distance between the 1 st wall portion 21 and the 2 nd wall portion 22. The distance between the 1 st wall portion 21 and the 2 nd wall portion 22 is smaller than the distance between the 5 th wall portion 25 and the 6 th wall portion 26. The distance between the 1 st wall portion 21 and the 2 nd wall portion 22 may be equal to the distance between the 5 th wall portion 25 and the 6 th wall portion 26, or may be larger than the distance between the 5 th wall portion 25 and the 6 th wall portion 26.

In the laser processing head 10A, the 1 st wall portion 21 is located on the opposite side of the fixed portion 61 of the moving mechanism 6, and the 2 nd wall portion 22 is located on the fixed portion 61 side. The 3 rd wall portion 23 is located on the mounting portion 65 side of the moving mechanism 6, and the 4 th wall portion 24 is located on the opposite side of the mounting portion 65, that is, on the laser processing head 10B side (see fig. 2). The 5 th wall portion 25 is located on the opposite side from the support portion 7, and the 6 th wall portion 26 is located on the support portion 7 side.

The housing 11 is configured such that the housing 11 is mounted to the mounting portion 65 in a state where the 3 rd wall portion 23 is disposed on the mounting portion 65 side of the moving mechanism 6. Specifically, the following is described. The mounting portion 65 has a bottom plate 65a and a mounting plate 65b. The bottom plate 65a is attached to a rail provided in the moving portion 63 (see fig. 2). The mounting plate 65B is provided upright on an end portion of the bottom plate 65a on the laser processing head 10B side (see fig. 2). In a state where the 3 rd wall portion 23 is in contact with the mounting plate 65b, the bolts 28 are screwed to the mounting plate 65b via the mount 27, whereby the housing 11 is mounted to the mounting portion 65. The mount 27 is provided in each of the 1 st wall portion 21 and the 2 nd wall portion 22. The housing 11 is detachable from the mounting portion 65.

The incident portion 12 is attached to the 5 th wall portion 25. The incidence part 12 makes the laser light L1 enter the housing 11. The incident portion 12 is located on the 2 nd wall portion 22 side (one wall portion side) in the X direction and on the 4 th wall portion 24 side in the Y direction. That is, the distance between the incident portion 12 and the 2 nd wall portion 22 in the X direction is smaller than the distance between the incident portion 12 and the 1 st wall portion 21 in the X direction; the distance between the incident portion 12 and the 4 th wall portion 24 in the Y direction is smaller than the distance between the incident portion 12 and the 3 rd wall portion 23 in the X direction.

The incident portion 12 is configured to allow the connection end portion 2a of the optical fiber 2 to be connectable. A collimator lens for collimating the laser light L1 emitted from the emission end of the optical fiber is provided at the connection end portion 2a of the optical fiber 2, but an isolator for suppressing the return light is not provided. The isolator is provided on the way of the optical fiber on the light source 81 side of the connection end portion 2 a. Thus, the connection end portion 2a can be reduced in size, and the incidence portion 12 can be reduced in size. In addition, a spacer may be provided at the connection end 2a of the optical fiber 2.

The adjusting portion 13 is disposed in the housing 11. The adjustment unit 13 is for adjusting the laser light L1 incident from the incidence unit 12. Each structure of the adjusting unit 13 is mounted on an optical seat 29 provided in the housing 11. The optical mount 29 is attached to the housing 11 so as to divide the region inside the housing 11 into a region on the 3 rd wall portion 23 side and a region on the 4 th wall portion 24 side. The optical mount 29 is integral with the housing 11. Each structure of the adjustment unit 13 is attached to the optical seat 29 on the 4 th wall portion 24 side. The respective structures of the adjustment unit 13 will be described in detail later.

The light condensing portion 14 is disposed on the 6 th wall portion 26. Specifically, the light collecting portion 14 is disposed in the 6 th wall portion 26 in a state of being inserted into a hole 26a formed in the 6 th wall portion 26 (see fig. 5). The condensing unit 14 condenses the laser light L1 adjusted by the adjusting unit 13 and emits the condensed laser light L to the outside of the housing 11. The light condensing unit 14 is located on the 2 nd wall 22 side (one wall side) in the X direction and on the 4 th wall 24 side in the Y direction. That is, the distance between the light condensing portion 14 and the 2 nd wall portion 22 in the X direction is smaller than the distance between the light condensing portion 14 and the 1 st wall portion 21 in the X direction, and the distance between the light condensing portion 14 and the 4 th wall portion 24 in the Y direction is smaller than the distance between the light condensing portion 14 and the 3 rd wall portion 23 in the X direction.

As shown in fig. 5, the adjustment unit 13 includes: an attenuator 31, a beam expander 32, a mirror 33. The attenuator 31, beam expander 32, and mirror 33 of the incident unit 12 and the adjustment unit 13 are arranged on a straight line (1 st straight line) A1 extending in the Z direction. The attenuator 31 and the beam expander 32 are disposed between the incident portion 12 and the reflecting mirror 33 on the straight line A1. The attenuator 31 is for adjusting the power of the laser light L1 incident from the incident portion 12. The beam expander 32 expands the aperture of the laser beam L1 whose power is adjusted by the attenuator 31. The mirror 33 reflects the laser beam L1 having the diameter enlarged by the beam expander 32.

The adjusting unit 13 further includes: a reflective spatial light modulator 34, and an imaging optical system 35. The reflective spatial light modulator 34 and the imaging optical system 35 of the adjusting unit 13, and the condensing unit 14 are disposed on a straight line (the 2 nd straight line) A2 extending along the Z direction. The reflective spatial light modulator 34 modulates the laser light L1 reflected by the mirror 33. The reflective spatial light modulator 34 is a spatial light modulator (SLM: spatial Light Modulator) such as a reflective liquid crystal (LCOS: liquid Crystal on Silicon). The imaging optical system 35 is configured to: a double-sided telecentric optical system that places the reflective surface 34a of the reflective spatial light modulator 34 and the entrance pupil surface 14a of the condenser 14 in imaging relationship. The imaging optical system 35 is composed of 3 or more lenses.

The straight lines A1 and A2 are located on a plane perpendicular to the Y direction. The straight line A1 is located on the 2 nd wall 22 side (one wall side) with respect to the straight line A2. In the laser processing head 10A, the laser light L1 enters the housing 11 from the entrance portion 12, travels on the straight line A1, is reflected by the reflecting mirror 33 and the reflective spatial light modulator 34 in this order, travels on the straight line A2, and is emitted from the light collecting portion 14 to the outside of the housing 11. The order of arrangement of the attenuator 31 and the beam expander 32 may be reversed. Further, the attenuator 31 may be disposed between the reflecting mirror 33 and the reflective spatial light modulator 34. The adjustment unit 13 may also include other optical components (e.g., a deflection mirror (polarization mirror) disposed in front of the beam expander 32).

The laser processing head 10A further includes: a dichroic mirror 15, a measuring unit 16, an observation unit 17, a driving unit 18, and a circuit unit 19.

The dichroic mirror 15 is disposed between the imaging optical system 35 and the light condensing unit 14 on the straight line A2. That is, the dichroic mirror 15 is disposed between the adjusting portion 13 and the light condensing portion 14 in the housing 11. The dichroic mirror 15 is attached to the optical mount 29 on the 4 th wall 24 side. The dichroic mirror 15 transmits the laser light L1. The dichroic mirror 15 is, for example, of a cubic type or a 2-plate type arranged in a skewed relationship from the viewpoint of suppressing astigmatism.

The measurement unit 16 is disposed on the 1 st wall 21 side (opposite to the one wall side) with respect to the adjustment unit 13 in the housing 11. The measurement unit 16 is attached to the optical seat 29 on the 4 th wall 24 side. The measuring unit 16 outputs the measuring light L10 for measuring the distance between the surface of the object 100 (for example, the surface on the incident side of the laser beam L1) and the light collecting unit 14, and detects the measuring light L10 reflected by the surface of the object 100 via the light collecting unit 14. That is, the measurement light L10 output from the measurement unit 16 is irradiated onto the surface of the object 100 via the light collecting unit 14, and the measurement light L10 reflected by the surface of the object 100 is detected by the measurement unit 16 via the light collecting unit 14.

More specifically, the measurement light L10 output from the measurement unit 16 is reflected by the beam splitter 20 and the dichroic mirror 15, which are mounted on the optical mount 29 on the 4 th wall portion 24 side in this order, and is output from the light condensing unit 14 to the outside of the housing 11. The measurement light L10 reflected by the surface of the object 100 is incident into the case 11 from the light collecting unit 14, reflected by the dichroic mirror 15 and the beam splitter 20 in this order, and incident on the measurement unit 16 to be detected by the measurement unit 16.

The observation portion 17 is disposed on the 1 st wall portion 21 side (opposite to the one wall portion side) with respect to the adjustment portion 13 in the housing 11. The observation portion 17 is attached to the optical seat 29 on the 4 th wall portion 24 side. The observation unit 17 outputs observation light L20 for observing the surface of the object 100 (for example, the surface on the side on which the laser light L1 is incident), and detects the observation light L20 reflected by the surface of the object 100 via the light-condensing unit 14. That is, the observation light L20 output from the observation unit 17 is irradiated onto the surface of the object 100 via the light collecting unit 14, and the observation light L20 reflected by the surface of the object 100 is detected by the observation unit 17 via the light collecting unit 14.

More specifically, the observation light L20 output from the observation unit 17 is reflected by the dichroic mirror 15 through the beam splitter 20, and is emitted from the light condensing unit 14 to the outside of the housing 11. The observation light L20 reflected by the surface of the object 100 is incident into the case 11 from the light collecting unit 14, reflected by the dichroic mirror 15, transmitted through the beam splitter 20, incident into the observation unit 17, and detected by the observation unit 17. The wavelengths of the laser light L1, the measuring light L10, and the observation light L20 are different from each other (at least the center wavelengths are shifted from each other).

The driving unit 18 is attached to the optical seat 29 on the 4 th wall 24 side. The driving unit 18 moves the light collecting unit 14 disposed in the 6 th wall 26 in the Z direction by, for example, driving force of a piezoelectric element.

The circuit portion 19 is disposed on the 3 rd wall portion 23 side with respect to the optical seat 29 in the housing 11. That is, the circuit portion 19 is disposed on the 3 rd wall portion 23 side with respect to the adjusting portion 13, the measuring portion 16, and the observing portion 17 in the housing 11. The circuit portion 19 is, for example, a plurality of circuit boards. The circuit unit 19 processes the signal output from the measurement unit 16 and the signal input to the reflective spatial light modulator 34. The circuit unit 19 controls the driving unit 18 based on the signal output from the measuring unit 16. As an example, the circuit unit 19 controls the driving unit 18 so that the distance between the surface of the object 100 and the light collecting unit 14 is kept constant (that is, so that the distance between the surface of the object 100 and the light collecting point of the laser beam L1 is kept constant) based on the signal output from the measuring unit 16. The housing 11 is provided with a connector (not shown) for connecting wires for electrically connecting the circuit unit 19 to the control unit 9 (see fig. 1) and the like.

The laser processing head 10B includes, in the same manner as the laser processing head 10A: the device includes a case 11, an incidence unit 12, an adjustment unit 13, a light-collecting unit 14, a dichroic mirror 15, a measurement unit 16, an observation unit 17, a driving unit 18, and a circuit unit 19. However, each structure of the laser processing head 10B is arranged so as to have a plane-symmetrical relationship with each structure of the laser processing head 10A with respect to a virtual plane passing through the midpoint between the 1 pair of mounting portions 65,66 and perpendicular to the Y direction, as shown in fig. 2.

For example, the housing 11 of the laser processing head 10A (1 st housing) is attached to the attachment portion 65 such that the 4 th wall portion 24 is located on the laser processing head 10B side with respect to the 3 rd wall portion 23 and the 6 th wall portion 26 is located on the support portion 7 side with respect to the 5 th wall portion 25. In contrast, the housing 11 of the laser processing head 10B (the 2 nd housing) is attached to the attachment portion 66 such that the 4 th wall portion 24 is located on the laser processing head 10A side with respect to the 3 rd wall portion 23 and the 6 th wall portion 26 is located on the support portion 7 side with respect to the 5 th wall portion 25.

The housing 11 of the laser processing head 10B is configured such that the housing 11 is mounted on the mounting portion 66 in a state in which the 3 rd wall portion 23 is disposed on the mounting portion 66 side. Specifically, the following is described. The mounting portion 66 has: a bottom plate 66a, and a mounting plate 66b. The bottom plate 66a is attached to a rail provided in the moving portion 63. The mounting plate 66b is provided upright at an end portion of the bottom plate 66a on the laser processing head 10A side. The housing 11 of the laser processing head 10B is attached to the attachment portion 66 in a state where the 3 rd wall portion 23 is in contact with the attachment plate 66B. The housing 11 of the laser processing head 10B is detachable from the mounting portion 66.

[ action and Effect ]

In the laser processing head 10A, since the light source for outputting the laser light L1 is not provided in the housing 11, the housing 11 can be miniaturized. In the case 11, the distance between the 3 rd wall portion 23 and the 4 th wall portion 24 is smaller than the distance between the 1 st wall portion 21 and the 2 nd wall portion 22, and the light condensing portion 14 arranged in the 6 th wall portion 26 is located closer to the 4 th wall portion 24 in the Y direction. In this way, when the housing 11 is moved in the direction perpendicular to the optical axis of the light collecting portion 14, for example, even if another structure (for example, the laser processing head 10B) is present on the 4 th wall portion 24 side, the light collecting portion 14 can be brought close to the other structure. In this way, the laser processing head 10A is adapted to move the light converging portion 14 in a direction perpendicular to the optical axis thereof.

In the laser processing head 10A, the incident portion 12 is provided on the 5 th wall portion 25, and is located on the 4 th wall portion 24 side in the Y direction. In this way, other structures (for example, the circuit portion 19) and the like can be disposed in the region on the 3 rd wall portion 23 side with respect to the adjustment portion 13 in the region inside the housing 11, and this region can be effectively utilized.

In the laser processing head 10A, the light collecting portion 14 is located on the 2 nd wall portion 22 side in the X direction. In this way, when the housing 11 is moved in the direction perpendicular to the optical axis of the light collecting portion 14, for example, even if another structure exists on the 2 nd wall portion 22 side, the light collecting portion 14 can be brought close to the other structure.

In the laser processing head 10A, the incident portion 12 is provided on the 5 th wall portion 25, and is located on the 2 nd wall portion 22 side in the X direction. As described above, other structures (for example, the measuring unit 16 and the observation unit 17) and the like can be disposed in the region on the 1 st wall portion 21 side of the adjustment unit 13 in the region inside the housing 11, and this region can be effectively used.

In the laser processing head 10A, the measuring unit 16 and the observation unit 17 are disposed in a region on the 1 st wall 21 side with respect to the adjustment unit 13 in a region within the housing 11; the circuit portion 19 is disposed on the 3 rd wall portion 23 side with respect to the adjustment portion 13 in the region inside the housing 11; the dichroic mirror 15 is disposed between the adjusting portion 13 and the light condensing portion 14 in the case 11. In this way, the area within the housing 11 can be effectively utilized. Further, in the laser processing apparatus 1, processing can be performed based on the measurement result of the distance between the surface of the object 100 and the light converging portion 14. In the laser processing apparatus 1, processing according to the observation result of the surface of the object 100 can be performed.

In the laser processing head 10A, the circuit unit 19 controls the driving unit 18 based on the signal output from the measuring unit 16. In this way, the position of the converging point of the laser beam L1 can be adjusted based on the measurement result of the distance between the surface of the object 100 and the converging portion 14.

In the laser processing head 10A, the incident portion 12, the attenuator 31, the beam expander 32, and the mirror 33 of the adjusting portion 13 are disposed on a straight line A1 extending in the Z direction, and the reflective spatial light modulator 34, the imaging optical system 35, the light collecting portion 14, and the light collecting portion 14 of the adjusting portion 13 are disposed on a straight line A2 extending in the Z direction. In this way, the adjustment section 13 including the attenuator 31, the beam expander 32, the reflective spatial light modulator 34, and the imaging optical system 35 can be made compact (compact).

In the laser processing head 10A, the straight line A1 is located on the 2 nd wall 22 side with respect to the straight line A2. In this way, in the case where another optical system (for example, the measuring unit 16 and the observation unit 17) using the light collecting unit 14 is configured in the region on the 1 st wall 21 side with respect to the adjusting unit 13 in the region inside the housing 11, the degree of freedom in the configuration of the other optical system can be improved.

The above operation and effects can be similarly exhibited by the laser processing head 10B.

In the laser processing apparatus 1, the light converging portion 14 of the laser processing head 10A is located on the laser processing head 10B side in the housing 11 of the laser processing head 10A, and the light converging portion 14 of the laser processing head 10B is located on the laser processing head 10A side in the housing 11 of the laser processing head 10B. In this way, when the 1 pair of laser processing heads 10A,10B are moved in the Y direction, the light converging portion 14 of the laser processing head 10A and the light converging portion 14 of the laser processing head 10B can be brought close to each other. In this way, according to the laser processing apparatus 1, the object 100 can be processed efficiently.

The mounting portions 65,66 of the pair of laser processing apparatuses 1,1 are moved in the Y direction and the Z direction, respectively. Thus, the object 100 can be processed more efficiently.

In the laser processing apparatus 1, the support portion 7 is moved in each of the X direction and the Y direction, and rotates about an axis parallel to the Z direction as a center line. Thus, the object 100 can be processed more efficiently.

Modification example

For example, as shown in fig. 6, the incident portion 12, the adjustment portion 13, and the light-collecting portion 14 may be arranged on a straight line a extending in the Z direction. In this way, the adjustment unit 13 can be made compact. In this case, the adjustment unit 13 may not include the reflective spatial light modulator 34 and the imaging optical system 35. The adjusting section 13 may have an attenuator 31 and a beam expander 32. In this way, the adjusting section 13 having the attenuator 31 and the beam expander 32 can be made compact. The order of the attenuator 31 and the beam expander 32 may be reversed.

The case 11 may be configured such that at least 1 of the 1 st wall portion 21, the 2 nd wall portion 22, the 3 rd wall portion 23, and the 5 th wall portion 25 is disposed on the mounting portion 65 (or the mounting portion 66) side of the laser processing apparatus 1, and the case 11 is mounted on the mounting portion 65 (or the mounting portion 66). The light collecting portion 14 may be located on the 4 th wall portion 24 side at least in the Y direction. In this way, when the housing 11 is moved in the Y direction, for example, even if another structure exists on the 4 th wall portion 24 side, the light condensing portion 14 can be brought close to the other structure. In the case where the housing 11 is moved in the Z direction, the light condensing unit 14 may be brought close to the object 100, for example.

The light collecting portion 14 is also reliably located on the 1 st wall portion 21 side in the X direction. In this way, when the housing 11 is moved in the direction perpendicular to the optical axis of the light collecting portion 14, even if another structure exists on the 1 st wall portion 21 side, for example, the light collecting portion 14 can be brought close to the other structure. In this case, the incident portion 12 may be located on the 1 st wall portion 21 side in the X direction. In this way, other structures (for example, the measuring unit 16 and the observation unit 17) and the like can be disposed in the region on the 2 nd wall portion 22 side of the adjustment unit 13 in the region within the housing 11, and this region can be effectively utilized.

At least 1 of the light guide of the laser beam L1 from the emission portion 81a of the light source unit 8 to the incidence portion 12 of the laser processing head 10A and the light guide of the laser beam L2 from the emission portion 82a of the light source unit 8 to the incidence portion 12 of the laser processing head 10B may be implemented by a reflecting mirror. Fig. 7 is a front view of a part of the laser processing apparatus 1 in which the laser light L1 is guided by a mirror. In the configuration shown in fig. 7, the mirror 3 for reflecting the laser light L1 is attached to the moving part 63 of the moving mechanism 6 so as to face the outgoing part 81a of the light source unit 8 in the Y direction and face the incident part 12 of the laser processing head 10A in the Z direction.

In the configuration shown in fig. 7, even if the moving portion 63 of the moving mechanism 6 is moved in the Y direction, the mirror 3 can be maintained in a state of being opposed to the emission portion 81a of the light source unit 8 in the Y direction. Further, even if the mounting portion 65 of the moving mechanism 6 is moved in the Z direction, the mirror 3 can be maintained in a state of being opposed to the incident portion 12 of the laser processing head 10A in the Z direction. Therefore, the laser light L1 emitted from the emission portion 81a of the light source unit 8 can be surely made incident on the incident portion 12 of the laser processing head 10A regardless of the position of the laser processing head 10A. Further, a light source such as a high-power long-short pulse laser which is difficult to guide light through the optical fiber 2 can be used.

In the configuration shown in fig. 7, the mirror 3 may be attached to the moving portion 63 of the moving mechanism 6 so that at least 1 of the angle adjustment and the position adjustment can be performed. In this way, the laser light L1 emitted from the emission portion 81a of the light source unit 8 can be more surely incident on the incident portion 12 of the laser processing head 10A.

The light source unit 8 may have 1 light source. In this case, the light source unit 8 is constituted as long as: a part of the laser light output from 1 light source may be emitted from the emission portion 81a, and the other part of the laser light may be emitted from the emission portion 82 b.

The laser processing apparatus 1 may also include 1 laser processing head 10A. Even in the case of the laser processing apparatus 1 including 1 laser processing head 10A, when the housing 11 is moved in the Y direction perpendicular to the optical axis of the light collecting portion 14, the light collecting portion 14 can be brought close to another structure even if the other structure exists on the 4 th wall portion 24 side, for example. As described above, according to the laser processing apparatus 1 including the 1 laser processing head 10A, the object 100 can be processed efficiently. In the laser processing apparatus 1 including 1 laser processing head 10A, if the mounting portion 65 is moved in the Z direction, the object 100 can be processed more efficiently. In the laser processing apparatus 1 including 1 laser processing head 10A, if the support 7 is moved in the X direction and rotated about the axis parallel to the Z direction as the center line, the object 100 can be processed more efficiently.

The laser processing apparatus 1 may include 3 or more laser processing heads. Fig. 8 is a perspective view of the laser processing apparatus 1 including 2 pairs of laser processing heads. The laser processing apparatus 1 shown in fig. 8 includes: a plurality of moving mechanisms 200,300,400, supporting portions 7, 1 pair of laser processing heads 10a,10b, 1 pair of laser processing heads 10c,10d, and a light source unit (not shown).

The moving mechanism 200 moves the support portion 7 in each of the X direction, the Y direction, and the Z direction, and rotates the support portion 7 about an axis parallel to the Z direction as a center line.

The moving mechanism 300 has: the fixing portions 301 and 1 pair of mounting portions (1 st mounting portion and 2 nd mounting portion) 305 and 306. The fixing portion 301 is attached to a device frame (not shown). The mounting portions 305 and 306 of 1 pair are mounted on rails provided on the fixing portion 301, respectively, and are movable in the Y direction independently of each other.

The moving mechanism 400 includes: fixing portions 401, 1 pair of mounting portions (1 st mounting portion, 2 nd mounting portion) 405,406. The fixing portion 401 is attached to a device frame (not shown). The mounting portions 405 and 406 of 1 pair are mounted on rails provided on the fixing portion 401, respectively, and are movable in the X direction independently of each other. The rail of the fixing portion 401 is arranged to intersect the rail of the fixing portion 301 in a three-dimensional manner.

The laser processing head 10A is attached to the attachment portion 305 of the moving mechanism 300. The laser processing head 10A irradiates the object 100 supported by the support 7 with laser light while facing the support 7 in the Z direction. The laser beam emitted from the laser processing head 10A is guided from a light source unit (not shown) through the optical fiber 2. The laser processing head 10B is attached to the attachment portion 306 of the moving mechanism 300. The laser processing head 10B irradiates the object 100 supported by the support 7 with laser light while facing the support 7 in the Z direction. The laser beam emitted from the laser processing head 10B is guided from a light source unit (not shown) through the optical fiber 2.

The laser processing head 10C is attached to the attachment portion 405 of the moving mechanism 400. The laser processing head 10C irradiates the object 100 supported by the support 7 with laser light in a state of being opposed to the support 7 in the Z direction. The laser beam emitted from the laser processing head 10C is guided from a light source unit (not shown) through the optical fiber 2. The laser processing head 10D is attached to the attachment portion 406 of the moving mechanism 400. The laser processing head 10D irradiates the object 100 supported by the support 7 with laser light while facing the support 7 in the Z direction. The laser beam emitted from the laser processing head 10D is guided from a light source unit (not shown) through the optical fiber 2.

The configuration of the pair 1 of laser processing heads 10a,10b of the laser processing apparatus 1 shown in fig. 8 is the same as the configuration of the pair 1 of laser processing heads 10a,10b of the laser processing apparatus 1 shown in fig. 1. The configuration of the pair 1 of laser processing heads 10c,10d of the laser processing apparatus 1 shown in fig. 8 is the same as the configuration of the pair 1 of laser processing heads 10a,10b in the case where the pair 1 of laser processing heads 10a,10b of the laser processing apparatus 1 shown in fig. 1 is rotated 90 ° about the axis parallel to the Z direction as the center line.

For example, the housing (1 st housing) 11 of the laser processing head 10C is attached to the attachment portion 65 such that the 4 th wall portion 24 is located on the laser processing head 10D side with respect to the 3 rd wall portion 23 and the 6 th wall portion 26 is located on the support portion 7 side with respect to the 5 th wall portion 25. The light converging portion 14 of the laser processing head 10C is located on the 4 th wall portion 24 side (i.e., the laser processing head 10D side) in the Y direction.

The housing 11 of the laser processing head 10D (the 2 nd housing) is attached to the attachment portion 66 such that the 4 th wall portion 24 is located on the laser processing head 10C side with respect to the 3 rd wall portion 23 and the 6 th wall portion 26 is located on the support portion 7 side with respect to the 5 th wall portion 25. The light converging portion 14 of the laser processing head 10D is located on the 4 th wall portion 24 side (i.e., the laser processing head 10C side) in the Y direction.

With the above configuration, in the laser processing apparatus 1 shown in fig. 8, when the laser processing heads 10A and 10B of 1 pair are moved in the Y direction, the light converging portion 14 of the laser processing head 10A and the light converging portion 14 of the laser processing head 10B can be brought close to each other. When the 1 pair of laser processing heads 10C,10D are moved in the X direction, the light converging portion 14 of the laser processing head 10C and the light converging portion 14 of the laser processing head 10D can be brought close to each other.

The laser processing head and the laser processing apparatus are not limited to the one for forming the modified region in the object 100, and may be one for performing other laser processing.

Next, embodiments will be described. Hereinafter, the description repeated with the above embodiment will be omitted. Embodiments 1 to 3 are reference embodiments.

[ embodiment 1 ]

The laser processing apparatus 101 shown in fig. 9 irradiates the object 100 with laser light so that the converging point (at least a part of the converging region) is aligned, thereby forming a modified region in the object 100. The laser processing apparatus 101 performs trimming processing and peeling processing on the object 100 to obtain (manufacture) a semiconductor device. The trimming process is a process for removing unnecessary portions of the object 100. The peeling process is a process for peeling a part of the object 100.

The object 100 is a semiconductor wafer formed in a disk shape, for example. The object is not particularly limited, and may be formed of various materials and may have various shapes. A functional element (not shown) is formed on the surface 100a of the object 100. The functional elements are, for example: a light receiving element such as a photodiode, a light emitting element such as a laser diode, a circuit element such as a memory, and the like.

As shown in fig. 10 (a) and 10 (b), an effective region R and a removed region E are set in the object 100. The effective region R is a portion corresponding to the semiconductor device to be obtained. For example, the effective region R is a disk-shaped portion including a central portion when the object 100 is viewed from the thickness direction. The removed region E is a region outside the effective region R in the object 100. The removed region E is an outer edge portion of the object 100 other than the effective region R. For example, the removed region E is a circular ring-shaped portion surrounding the effective region R. The removed area E includes a peripheral edge portion (a slope portion of the outer edge) when the object 100 is viewed from the thickness direction.

A virtual plane M1, which is a predetermined surface to be peeled, is set on the object 100. The virtual plane M1 is a plane on which the modified region is to be formed. The virtual plane M1 is a plane facing the laser light incident surface of the object 100, that is, the back surface 100 b. The virtual plane M1 is a plane parallel to the back surface 100b, and is, for example, circular. The virtual plane M1 is a virtual area, and is not limited to a plane, but may be a curved surface or a 3-dimensional surface. The effective region R, the removal region E, and the virtual plane M1 can be set by the control unit 9. The effective region R, the removed region E, and the virtual plane M1 may also be assigned coordinates.

A line M3 as a trimming target line is set in the object 100. The line M3 is a line predetermined to form the modified region. Line M3 extends annularly inside the outer edge of object 100. The line M3 extends in a circular ring shape. The line M3 is a portion of the object 100 on the opposite side of the virtual plane M1 from the laser light incident surface, and is set at the boundary between the effective region R and the removed region E. The setting of the line M3 can be performed by the control unit 9. The line M3 is a virtual line, but may be an actually drawn line. Line M3 may also be assigned coordinates.

As shown in fig. 9, the laser processing apparatus 101 includes: stage 107, laser processing head 10A, 1 st Z axis rail 106A, Y axis rail 108, image pickup section 110, GUI (graphical user interface Graphical User Interface) 111, and control section 9. The stage 107 is a support portion for placing the object 100. The stage 107 is configured in the same manner as the support portion 7 (see fig. 1). In the stage 107 of the present embodiment, the object 100 is placed in a state where the back surface 100b of the object 100 is on the laser light incident surface side, that is, the upper side (a state where the front surface 100a is on the stage 107 side, that is, the lower side). The stage 107 has: a rotation axis C provided at the center thereof. The rotation axis C is an axis extending along the Z direction. The stage 107 is rotatable about a rotation axis C. The stage 107 is driven to rotate by a driving force of a known driving device such as a motor.

The laser processing head 10A irradiates the object 100 mounted on the stage 107 with the 1 st laser beam L1 (see fig. 11 a) in the Z direction, and forms a modified region in the object 100. The laser processing head 10A is mounted on the 1 st Z-axis rail 106A and the Y-axis rail 108. The laser processing head 10A is linearly movable in the Z direction along the 1 st Z-axis rail 106A by a driving force of a known driving device such as a motor. The laser processing head 10A is linearly movable in the Y direction along the Y axis rail 108 by a driving force of a known driving device such as a motor. The laser processing head 10A constitutes an irradiation section.

The laser processing head 10A includes the reflective spatial light modulator 34 described above. The laser processing head 10A is provided with a distance measuring sensor 36. The distance measuring sensor 36 emits a distance measuring laser beam to the laser light incident surface of the object 100, and detects the distance measuring light reflected by the laser light incident surface, thereby acquiring displacement data of the laser light incident surface of the object 100. As the distance measuring sensor 36, when it is a sensor that is not coaxial with the 1 st laser light L1, a sensor of a triangle distance measuring system, a laser confocal system, a white confocal system, a spectroscopic interference system, an astigmatic system, or the like can be used. When the distance measuring sensor 36 is a sensor coaxial with the 1 st laser light L1, a sensor of an astigmatic system or the like can be used. The circuit 19 (see fig. 3) of the laser processing head 10A drives the driving unit 18 (see fig. 5) so that the light converging unit 14 tracks the laser light incident surface based on the displacement data acquired by the distance measuring sensor 36. As a result, the condensing unit 14 is moved in the Z direction based on the displacement data so that the distance between the laser light incident surface of the object 100 and the 1 st laser light L1, i.e., the 1 st condensing point, is kept constant.

The 1 st Z-axis track 106A is a track extending along the Z-direction. The 1 st Z-axis rail 106A is attached to the laser processing head 10A via the attachment portion 65. The 1 st Z-axis track 106A moves the laser processing head 10A in the Z direction in order to move the 1 st focal point of the 1 st laser beam L1 in the Z direction (the direction intersecting the virtual plane M1). The 1 st Z-axis track 106A corresponds to the moving mechanism 6 (see fig. 1) or the moving mechanism 300 (see fig. 8).

The Y-axis rail 108 is a rail extending along the Y-direction. Y-axis track 108 is mounted to Z-axis track 106A. The Y-axis rail 108 moves the laser processing head 10A in the Y direction so that the 1 st focal point of the 1 st laser beam L1 moves in the Y direction (in the direction along the virtual plane M1). The Y-axis rail 108 is a rail corresponding to the moving mechanism 6 (see fig. 1) or the moving mechanism 300 (see fig. 8).

The imaging unit 110 images the object 100 from a direction along the incident direction of the 1 st laser beam L1. The image pickup section 110 includes an alignment camera AC and an image pickup unit IR. The alignment camera AC and the imaging unit IR are mounted on the mounting portion 65 together with the laser processing head 10A. The alignment camera AC is, for example, a light-capturing device pattern or the like that penetrates the object 100. The image thus obtained is used as an alignment of the irradiation position of the 1 st laser light L1 to the object 100.

The imaging unit IR photographs the object 100 by light transmitted through the object 100. For example, when the object 100 is a wafer containing silicon, near infrared light is used in the imaging unit IR. The imaging unit IR includes: a light source, an objective lens, and a light detection unit. The light source outputs light having penetrability to the object 100. The light source is composed of, for example, a halogen lamp and a filter, and outputs light in the near infrared region, for example. The light output from the light source is guided by an optical system such as a mirror, and is irradiated to the object 100 through the objective lens.

The objective lens passes light reflected by the surface opposite to the laser light incident surface of the object 100. That is, the objective lens passes light propagating (penetrating) through the object 100. The Numerical Aperture (NA) of the objective lens is, for example, 0.45 or more. The objective lens has a correction ring. The correction ring corrects aberration generated by light in the object 100 by adjusting the distance between a plurality of lenses constituting the objective lens, for example. The light detection unit detects light passing through the objective lens. The light detection unit is constituted by an InGaAs camera, for example, and detects light in the near infrared region. The imaging unit IR can image at least one of a modified region formed in the object 100 and a crack extending from the modified region. That is, in the laser processing apparatus 101, the processing state of the laser processing can be checked without damage by using the imaging unit IR. The imaging unit IR is configured to: and a processing state monitoring unit for monitoring (internally monitoring) the processing state of the laser processing in the object 100.

The GUI111 displays various information. GUI111 includes, for example, a touch panel display. Various settings concerning the processing conditions are input to the GUI111 by an operation such as a touch by a user. The GUI111 is an input unit configured to receive an input from a user.

The control unit 9 is configured as a computer device including a processor, a memory, a storage, a communication device, and the like. In the control unit 9, software (program) read by a memory or the like is executed by a processor, and reading and writing of data in the memory and the storage, and communication by a communication device are controlled by the processor. The control unit 9 controls each unit of the laser processing apparatus 101, thereby realizing various functions.

The control unit 9 controls at least the stage 107, the laser processing head 10A, the moving mechanism 6 (see fig. 1), or the moving mechanism 300 (see fig. 1). The control unit 9 controls: rotation of the stage 107, irradiation of the 1 st laser beam L1 from the laser processing head 10A, and movement of the 1 st focal point of the 1 st laser beam L1. The control unit 9 can perform various controls based on rotation information (hereinafter also referred to as "θ information") concerning the rotation amount of the stage 107. The θ information may be obtained based on the driving amount of a driving device that rotates the stage 107, or may be obtained by another sensor or the like. The θ information can be obtained by various known techniques. The θ information here includes: the rotation angle is based on the state when the object 100 is positioned in the 0 ° direction.

The control unit 9 controls the start and stop of the irradiation of the 1 st laser beam L1 of the laser processing head 10A based on the θ information while rotating the stage 107 and positioning the 1 st focal point at a position along the line M3 (the peripheral edge of the effective region R) of the object 100, thereby performing the trimming process for forming the modified region along the peripheral edge of the effective region R. The trimming process is a process of the control unit 9 that realizes trimming processing. The trimming process of the present embodiment irradiates the 1 st laser beam L1 along the line M3 on the opposite side of the laser light incident surface from the virtual plane M1 inside the object 100 before the peeling process (1 st processing process described later) to form a modified region.

The control unit 9 irradiates the 1 st laser beam L1 from the laser processing head 10A while rotating the stage 107, and controls the movement of the 1 st focal point in the Y direction, thereby performing a lift-off process for forming a modified region along the virtual plane M1 inside the object 100. The peeling process is a process of the control unit 9 for realizing the peeling process. The control unit 9 controls the display of the GUI 111. The trimming process and the peeling process are performed according to various settings input from the GUI 111.

The formation of the modified region and the switching of the stop thereof can be realized as follows. For example, in the laser processing head 10A, the start and stop (ON/OFF) of the irradiation (output) of the 1 st laser beam L1 are switched, whereby the formation of the modified region and the stop of the formation can be switched. Specifically, when the laser oscillator is constituted by a solid-state laser, the start and stop of the irradiation of the 1 st laser beam L1 can be switched at high speed by switching ON/OFF of a Q-switch (AOM (acousto-optic modulator), EOM (electro-optic modulator), or the like) provided in the resonator. When the laser oscillator is constituted by a fiber laser, the start and stop of the irradiation of the 1 st laser light L1 can be switched at high speed by switching ON/OFF of the output of the semiconductor laser constituting the seed laser light (seed laser) and the amplifier laser light (excitation laser light). When the external tuning element is used in the laser oscillator, the ON/OFF of the irradiation of the 1 st laser light L1 can be switched at high speed by switching the ON/OFF of the external tuning element (AOM, EOM, etc.) provided outside the resonator.

Alternatively, the formation of the modified region and the switching between the stop thereof may be realized as follows. For example, the optical path of the 1 st laser beam L1 is opened and closed by controlling a mechanical mechanism such as a shutter (shutter), whereby the formation of the modified region and the stop of the formation are switched. The 1 st laser beam L1 may be switched to CW light (continuous wave) to stop the formation of the modified region. The liquid crystal layer of the reflective spatial light modulator 34 may also display: the formation of the modified region is stopped by forming the condensed state of the 1 st laser beam L1 into a pattern that cannot be modified (for example, a pear-shaped pattern that scatters laser light). The power adjustment unit such as an attenuator may be controlled to reduce the power of the 1 st laser beam L1 so that the modified region cannot be formed, thereby stopping the formation of the modified region. The formation of the modified region may be stopped by switching the polarization direction. The 1 st laser beam L1 may be scattered (scattered) in a direction other than the optical axis and cut (cut), thereby stopping the formation of the modified region.

Next, an example of a method of manufacturing (acquiring) a semiconductor device by performing trimming processing and peeling processing on the object 100 using the laser processing apparatus 101 will be described. The manufacturing method described below is reusable (reusable) in terms of the removed portion (portion of the object 100 that is not used as a semiconductor device) removed from the object 100 by the trimming process and the peeling process.

First, the object 100 is placed on the stage 107 with the back surface 100b being on the laser light incident surface side. The surface 100a of the object 100 on which the functional element is mounted is protected by an adhesive support substrate or tape (tape material).

Next, trimming processing is performed. Specifically, as shown in fig. 11 (a), the 1 st laser beam L1 of the laser processing head 10A is irradiated while the stage 107 is rotated at a constant rotational speed in a state where the 1 st focal point P1 is located on the line M3 of the object 100. The irradiation of the 1 st laser beam L1 is repeated while changing the position of the 1 st focal point P1 in the Z direction. That is, as shown in fig. 10 (b) and 11 (b), before the peeling process, the modified region 43 is formed along the line M3 at a portion of the object 100 on the opposite side of the laser light incident surface from the virtual plane M1.

The peeling process is then performed. Specifically, as shown in fig. 12 (a), the 1 st laser beam L1 is irradiated from the laser processing head 10A while the stage 107 is rotated at a constant rotation speed, and the laser processing head 10A is moved along the Y-axis rail 108 so that the 1 st converging point P1 moves in the Y-direction from the outer edge side to the inner side of the virtual plane M1. As shown in fig. 12 b and 12C, a modified region 4 extending in a spiral shape (involute curve) centered on the position of the rotation axis C (see fig. 9) is formed along the virtual plane M1 in the object 100. The modified region 4 includes a plurality of modified spots. As shown in fig. 13 (a), a part of the object 100 is peeled off at the boundary between the modified region 4 extending over the virtual plane M1 and the crack extending from the modified point of the modified region 4. At the same time, the removal region E is removed by taking the modified region 43 along the line M3 and the crack extending from the modified point of the modified region 43 as boundaries.

The peeling of the object 100 and the removal of the removal region E may be performed by using, for example, an adsorbent. The object 100 may be peeled off on the stage 107 or may be moved to a peeling-dedicated area. The object 100 may be peeled off by air blowing (air blow) or an adhesive tape. When the object 100 cannot be peeled off by the external stress alone, the modified regions 4 and 43 can be selectively etched by an etching solution (KOH, TMAH, or the like) that reacts with the object 100. Thus, the object 100 can be easily peeled off. The stage 107 is rotated at a constant rotational speed, but the rotational speed may be changed. For example, the rotational speed of the stage 107 may be changed so that the pitch (pitch) of the modified spots included in the modified region 4 is constant.

Next, as shown in fig. 13 (b), the peeled surface 100h of the object 100 is ground by finish machining or by polishing with a polishing material such as a grindstone. When the object 100 is peeled off by etching, the polishing can be simplified. As a result of the above, the semiconductor device 100k is obtained.

Next, the peeling process according to the present embodiment will be described in more detail.

As shown in fig. 14 (a), a line (processing line) M11 is set in the object 100 to be peeled. The line M11 is a line predetermined to form the modified region 4. The line M11 extends in a spiral manner from the peripheral edge side toward the inner side in the object 100. In other words, the line M11 extends in a spiral shape (involute curve) centered on the position of the rotation axis C (see fig. 9) of the stage 107. The line M11 has a plurality of processing lines of parallel lines M11a arranged in parallel. For example, a peripheral portion of the spiral is formed into 1 parallel line M11a. The line M11 is a virtual line, but may be an actually drawn line. Line M11 may also be assigned coordinates.

As shown in fig. 14 a and 14 b, the object 100 has a slope portion (peripheral edge portion) BB having a side surface intersecting the laser light incident surface, that is, the back surface 100 b. The chamfer portion BB is, for example, a chamfer surface for improving strength. The inclined surface portion BB is formed by forming the angle of the peripheral edge of the object 100 into a curved surface (R-surface). The inclined surface portion BB is, for example, a portion of the object 100 between the peripheral edge and the inside of 200 to 300 μm.

An alignment object 100n is provided on the object 100. For example, the alignment object 100n has a certain relationship in the θ direction (the rotation direction of the stage 107 about the rotation axis C) with respect to the position of the object 100 in the 0 ° direction. The position in the 0 ° direction is the position of the object 100 serving as the reference in the θ direction. For example, the alignment object 100n is a notch (notch) formed on the peripheral edge side of the object 100. The alignment object 100n is not particularly limited, and may be an orientation flat (orientation flat) of the object 100 or a pattern of a functional element.

The control unit 9 performs 1 st processing for irradiating the 1 st laser beam L1 under 1 st processing conditions on the bevel peripheral portion (1 st portion) 100X including the bevel portion BB. After the 1 st processing, the control unit 9 performs the 2 nd processing of irradiating the 1 st laser beam L1 with a 2 nd processing condition different from the 1 st processing condition on the inner peripheral portion (2 nd portion) 100Y of the object 100 on the inner side than the inclined surface peripheral portion 100X. The 1 st processing step and the 2 nd processing step are included in the peeling step. The sizes of the inclined surface peripheral portion 100X and the inner peripheral portion 100Y of the object can be input via the GUI 111.

In the 1 st processing and the 2 nd processing, as shown in fig. 15, the 1 st laser beam L1 is branched so that a plurality of modified spots SA aligned in a row along an oblique direction C2 oblique to an orthogonal direction (processing proceeding direction) orthogonal to the extending direction C1 of the line M11 are formed on the virtual plane M1. The branching of the 1 st laser beam L1 can be realized by, for example, a reflective spatial light modulator 34 (see fig. 5).

In the example shown in the figure, the 1 st laser light L1 is branched by 4 to form 4 modified spots SA. Regarding the adjacent pair of modified points SA among the 4 modified points SA after branching, the interval in the extending direction C1 of the line M11 is the branching pitch BPx, and the interval in the orthogonal direction of the extending direction C1 is the branching pitch BPy. Regarding the pair of modified spots SA formed by irradiation of the 1 st laser light L1 of 2 continuous pulses, the interval in the extending direction C1 is the pulse pitch PP. The angle between the extending direction C1 and the inclining direction C2 is the branching angle α.

In the 1 st processing and the 2 nd processing, the 1 st laser beam L1 is irradiated to the object 100, and the position of the 1 st converging point P1 is moved from the peripheral edge toward the inner side along the spiral line M11 with respect to the object 100, whereby the modified region 4 is formed along the line M11. That is, in the 1 st and 2 nd processing steps, the region of the object 100 where the modified region 4 is formed is shifted in the 1 st direction from the peripheral edge toward the inside.

The 1 st processing condition and the 2 nd processing condition are conditions for forming the modified region 4 by irradiating the 1 st laser beam L1 along one processing line, so that a processing state (hereinafter also simply referred to as "processing state") inside the object 100 is a cut half-cut state (1 st cut state) described below. The 1 st processing condition and the 2 nd processing condition are conditions for forming the modified region 4 by irradiating the 1 st laser beam L1 along a processing line M11 having a plurality of parallel lines arranged in parallel, and are conditions for bringing the processing state into a cutting complete cutting state (2 nd cutting state) described later.

The 1 st processing condition is a condition for changing the processing state after the laser processing of the 1 st predetermined amount to the cutting complete cutting state. The 2 nd processing condition is a condition for setting the processing state after the laser processing of the 2 nd predetermined amount more than the 1 st predetermined amount to the cutting complete cutting state. Specific parameters of the 1 st processing condition and the 2 nd processing condition include: the 1 st laser L1 has a branch number, a branch pitch BPy, BPx, pulse energy, a pulse pitch, a pulse width, a processing speed, and the like. The machining condition for setting the machining state to the half-cut state is a machining condition in which parameters are appropriately set according to known techniques so that the machining state is set to the half-cut state. The machining condition for bringing the machining state into the cut-through state is a machining condition in which parameters are appropriately set according to known techniques so that the machining state is brought into the cut-through state. For example, in the 1 st processing condition, the number of branches is 4, the branch pitch BPy is 20 μm, the branch pitch BPx is 30 μm, the pulse energy is 16.73. Mu.J, the processing speed is 800mm/s, the pulse pitch is 10 μm, and the pulse width is 700ns. For example, the processing condition 2 is the same as the processing condition 1 except that the branching pitch BPy is 30 μm.

The processing state found in the peeling processing will be described below.

Fig. 16 (a) and 17 (a) are images showing a cut hidden state. Fig. 16 (b) and 17 (b) are images showing the cut half-cut state. Fig. 18 (a) is an image showing a processing state after the laser processing of the 1 st predetermined amount, that is, a cut-and-fully-cut state. Fig. 18 (b) is an image showing a processing state after the laser processing of the 2 nd predetermined amount, that is, a cut-and-fully-cut state.

Fig. 16 (a) to 18 (b) are images of the position of the virtual plane M1 imaged by the imaging unit IR from the laser light incident surface. Fig. 16 a and 16 b show a processing state in which the 1 st laser beam L1 is irradiated along one processing line (parallel line) to form the modified region 4. Fig. 17 (a) to 18 (b) show a processing state in which the 1 st laser beam L1 is irradiated along a plurality of processing lines to form the modified region 4. The processing line is set to extend straight in the left-right direction in the drawing. As shown in fig. 16 (a) to 18 (b), the machining state is changed in 3 stages according to the pulse energy, the branching pitch, and the like.

As shown in fig. 16 (a) and 17 (a), the cut hidden (SST) state means: the modified spots (scratches) SA contained in the modified region 4 are not extended or connected to each other. The cleavage hidden state is a state in which only the modified spots SA are observed. In the cut hidden state, since the crack is not stretched, even if the number of processing lines is increased, the state cannot be changed to the cut complete cut state.

As shown in fig. 16 b and 17 b, the half cut (SHC) state means: the cracks extending from the plurality of modified spots SA included in the modified region 4 extend in the direction along the processing line. In the image, in the cut-and-half state, the modified spots SA and spots (stains) along the processing line were confirmed. The number of processing lines is changed to the full cut state by increasing the number of processing lines so that the processing state is the half cut state, but the number of processing lines changed to the full cut state is changed according to the processing conditions. In order to generate a complete cut state, a half cut state is indispensable as a processing state in the case of forming the modified region 4 by irradiating the 1 st laser beam L1 along one processing line.

The cut-to-full-cut (SFC) state refers to: the cracks extending from the plurality of modified spots SA included in the modified region 4 extend in the directions along the plurality of processing lines and in the directions intersecting the processing lines, and are connected to each other. The cut-off state refers to: the cracks extending from the modified spots SA extend vertically and horizontally on the image and are connected across a plurality of processing lines. As shown in fig. 18 (a) and 18 (b), the cut-through state is a state where the modified point SA on the image cannot be confirmed (a state where a space or a gap formed by the crack is confirmed). In the completely cut state, since the cracks are generated across the plurality of processing lines, the modified region 4 cannot be formed by irradiating the 1 st laser beam L1 along one processing line.

The cut-to-full state includes: the 1 st cut-off complete state and the 2 nd cut-off complete state. The 1 st cut complete cut state is a cut complete cut state generated after the 1 st prescribed amount of laser processing (see fig. 18 (a)). The 2 nd cut complete cut state is a cut complete cut state generated after the laser processing of the 2 nd predetermined amount which is larger than the 1 st predetermined amount (refer to fig. 18 (a)).

The 1 st predetermined amount of laser processing is, for example, a case where the 1 st laser light L1 is irradiated along a plurality of parallel lines of less than 100 lines to form the modified region 4. The laser processing of the 1 st predetermined amount is, for example, a case where the width in the index (index) direction of the region forming the modified region 4 in the object 100 is less than 12 mm. The index direction is a direction perpendicular to the extending direction of the processing line when viewed from the laser light incident surface. The laser processing of the 2 nd predetermined amount is, for example, a case of irradiating the 1 st laser beam L1 along 100 or more processing lines to form the modified region 4. The laser processing of the 2 nd predetermined amount is, for example, a case where the width in the index direction of the region forming the modified region 4 in the object 100 is 12mm or more. The 1 st and 2 nd predetermined amounts are not particularly limited, and may be various parameters. The 1 st and 2 nd predetermined amounts may be, for example, processing time. The 1 st and 2 nd predetermined amounts may be combinations of a plurality of parameter amounts.

Although fig. 16 (a) to 18 (b) are images captured by the imaging unit IR, the same images as those in fig. 16 (a) to 18 (b) can be obtained even when the images are captured by a normal IR camera. As a result of fig. 16 (a) to 18 (b), the shape, size, and the like of the object 100 are not particularly limited, and the same result as in fig. 16 (a) to 18 (b) can be obtained even if the object 100 is a hole wafer (hole wafer) or a small wafer. The results in fig. 16 (a) to 18 (b) are results of performing only laser processing (the results are performed on the premise of not applying stress). Even when the modified region 4 is formed by irradiating the 1 st laser beam L1 along a plurality of processing lines less than 100, the object 100 may be subjected to stress to be in a completely cut state.

The control unit 9 sets the 1 st processing condition and the 2 nd processing condition according to an input from the user via the GUI 111. The display and input of the GUI111 will be described later. The control unit 9 displays the imaging result of the imaging means IR, that is, the processing state of the inside of the object 100, on the GUI 111.

The imaging unit IR monitors: whether or not the processing state in the case of forming the modified region 4 along the spiral line M11 is a cut half-cut state. The imaging unit IR monitors whether or not the processing state after the laser processing of the 1 st predetermined amount is the cut-through state (i.e., whether or not the processing state is the 1 st cut-through state) in the 1 st processing. The imaging unit IR monitors whether or not the processing state after the laser processing of the 2 nd predetermined amount is the cut-through state (i.e., whether or not the processing state is the 2 nd cut-through state) in the 2 nd processing. The monitoring of the state includes: the function of monitoring the state is realized and/or information (such as an acquired image) capable of distinguishing the state is acquired.

The control unit 9 determines from the monitoring result of the imaging unit IR that: whether the processing state after the laser processing of the 1 st prescribed amount in the 1 st processing treatment is the 2 nd cutting complete cutting state or not, and whether the processing state after the laser processing of the 2 nd prescribed amount in the 2 nd processing treatment is the 2 nd cutting complete cutting state or not. The processing state can be determined by using various known image processing methods. The determination of the machining state may be performed by using a previously trained pattern (AI) obtained by deep learning (deep learning). The other determinations by the control unit 9 are the same.

Next, the peeling process will be described in detail with reference to the flowchart of fig. 19.

The peeling process according to the present embodiment is to peel the object 100 by performing the 2 nd process after the crack reaches the inclined surface portion BB by the 1 st process. Specifically, the control unit 9 controls each unit of the laser processing apparatus 101 to execute the following processes.

First, the stage 107 is rotated and the laser processing head 10A is moved along the Y-axis rail 108 and the 1 st Z-axis rail 106A so that the alignment camera AC is positioned directly above the alignment target 100n of the object 100 and the alignment camera AC is focused on the alignment target 100 n. Shooting is performed by aiming at the camera AC. Based on the captured image of the alignment camera AC, the position of the object 100 in the 0-degree direction is acquired. Further, the diameter of the object 100 is obtained from the captured image of the alignment camera AC. The diameter of the object 100 may be set by an input from a user.

Next, as shown in fig. 9 and 20 (a), the stage 107 is rotated to position the object 100 in the 0-degree direction. The laser processing head 10A is moved along the Y-axis rail 108 so that the 1 st focal point P1 is located at a predetermined position for start of separation in the Y-direction. The laser processing head 10A is moved along the 1 st Z-axis track 106A so that the 1 st focal point P1 is located on the virtual plane M1 in the Z direction. For example, the predetermined position for start of peeling is a predetermined position farther than the object 100.

Next, the rotation of the stage 107 is started. Tracking by the back surface 100b of the distance measuring sensor is started. Before the start of tracking by the distance measuring sensor, it was confirmed in advance that the position of the 1 st focal point P1 was within the distance measuring range of the distance measuring sensor. When the rotation speed of the stage 107 becomes constant (constant speed), the irradiation of the 1 st laser beam L1 by the laser processing head 10A is started.

While irradiating the 1 st laser beam L1 on the inclined surface peripheral portion 100X under the 1 st processing condition, the 1 st converging point P1 is moved along the Y-axis rail 108 so as to move toward the inner peripheral side in the Y-direction (step S1, 1 st processing step). In step S1, the region of the object 100 in which the modified region 4 is formed is shifted in the 1 st direction E1 from the peripheral edge toward the inside. In step S1, laser processing is performed with the index direction set to the 1 st direction E1. In step S1, the 1 st focal point P1 is moved along the spiral line M11 from the peripheral edge to the inner side to form the modified region 4. In the above step S1, the irradiation of the 1 st laser beam L1 may be started when the optical axis of the 1 st laser beam L1 is still located outside the object 100 or when it is located at the inclined surface peripheral portion 100X.

After the 1 st machining step of the 1 st predetermined amount, the rotation of the stage 107, the irradiation of the 1 st laser beam L1, and the like are stopped, and the 1 st machining step is stopped. Based on the imaging result of the imaging means IR, it is determined whether or not the processing state after the processing of the 1 st predetermined amount is the cut-off state (step S2). When the result of step S2 is Yes, the rotation of the stage 107, the irradiation of the 1 st laser beam L1, and the like are restarted, and the 1 st processing step is restarted (step S3). In this way, the modified region 4 is formed along the spiral line M11 at the inclined surface peripheral portion 100X, and the machined state is brought into the cut-and-fully-cut state (see fig. 20 b).

Next, as shown in fig. 9 and 21 (a), while the stage 107 is rotated, the 1 st laser beam L1 is irradiated to the inner peripheral portion 100Y under the 2 nd processing condition, and the laser processing head 10A is moved along the Y-axis rail 108 so that the 1 st focal point P1 moves toward the inner peripheral side in the Y-direction (step S4, 2 nd processing step). In step S4, laser processing is performed with the index direction set to the 1 st direction E1. In step S4, the 1 st focal point P1 is moved along the spiral line M11 from the peripheral edge to the inner side to form the modified region 4.

After the 2 nd machining step of the 2 nd predetermined amount, the rotation of the stage 107, the irradiation of the 1 st laser beam L1, and the like are stopped, and the 2 nd machining step is stopped. Based on the imaging result of the imaging means IR, it is determined whether or not the processing state after the processing of the 2 nd predetermined amount is the cut-through state (step S5). If yes in step S5, the rotation of the stage 107, the irradiation of the 1 st laser beam L1, and the like are restarted, and the 2 nd processing step is restarted (step S6). In this way, the modified region 4 is formed along the spiral line M11 in the inner peripheral portion 100Y, and the machined state is set to the cut-complete state (see fig. 21 (b)).

By the above operation, the modified region 4 is formed along the line M11 over the entire virtual plane M1, and the processing is completed (step S7). Based on the imaging result of the imaging means IR, it is determined whether the processing state after the completion of the processing is a completely cut state of the cut over the entire area of the virtual plane M1 (step S8). When the above step S8 is yes, the process is normally ended when the peeling process has been normally completed. On the other hand, if the step S2 is No (No), the step S5 is No, or the step S8 is No, it is determined that an error (error) has occurred in the machining state, and for example, the error in the machining state is notified via the GUI111 (step S9). For example, after step S9, the 1 st processing condition and the 2 nd processing condition are reset by another process (for example, the process of embodiment 4 described later).

When the width of the slope peripheral portion 100X in the index direction is 35mm or less, warpage (warp) of the slope portion BB may occur during the processing of the 2 nd step. When the width of the slope peripheral portion 100X in the index direction is larger than 35mm, warpage of the slope portion BB may occur during the 1 st processing.

Fig. 22 is a plan view of the object 100 for illustrating the crack extending from the modified region 4 formed along the virtual plane M1. Fig. 23 shows the observation result of the crack in the object 100 of fig. 22. Fig. 22 shows a state in which the object 100 is observed from the laser light incident surface. In the experiment, in the object 100, the modified region 4 was formed along a plurality of linear processing lines provided side by side in the outer peripheral portion 100G and the inner peripheral portion 100F on the inner peripheral side thereof. Then, the number of processing lines set, that is, the number of processing lines is changed for the cracks on the index direction rear side (outer peripheral portion 100G side) of the inner peripheral portion 100F, the cracks on the index direction front side of the inner peripheral portion 100F, and the cracks on the index direction front side of the outer peripheral portion 100G.

In the figure, the horizontal direction is the scanning direction (the extending direction of the processing line), and the vertical direction is the index direction. The 1 st laser L1 had a branching number of 4, a branching pitch BPy of 20 μm, a branching pitch BPx of 30 μm, a pulse energy of 16.73. Mu.J, a processing speed of 800mm/s, a pulse pitch of 10 μm, and a pulse width of 700ns. The object 100 is a silicon wafer having a (100) plane as a main surface. The object 100 has a thickness of 775. Mu.m.

As shown in fig. 22 and 23, the crack extension amount greatly fluctuates on the front side in the index direction, and does not depend on the number of processing lines. At the rear side in the index direction, the crack extension amount increases as the number of processing lines increases. The cracks were found to extend in a direction opposite to the index direction (the rear side in the index direction). The amount of crack extension of the crack was determined by the number of processing lines. That is, it was found that when the modified region 4 is formed along the virtual plane M1, the direction of extension of the crack extending from the modified region 4 along the virtual plane M1 greatly contributes to the migration direction (index direction) of the region of the object 100 in which the modified region 4 is formed. Specifically, it was found that cracks were easily and stably spread in a direction opposite to the migration direction.

The wafer having the bevel portion BB is subjected to laser processing so that the processing state becomes a dicing complete cut state, using the processing condition I. The experimental results are shown below. The width of the modified region is the width in the index direction. "X" represents poor (No Good), "delta" represents Good (Good), and "O" represents Good (Very Good).

< processing conditions I >

Branch number 4, branch pitch BPy20 μm, branch pitch BPx30 μm, processing speed 800mm, frequency 80kHz

< experimental results >

The width of the modified region was 10mm (500 lines) and the crack reached BBX in the inclined surface portion

The width of the modified region was 20mm (the number of the processing lines was 1000), and the crack reached the inclined surface BBX

The width of the modified region was 25mm (the number of processing lines was 1252), and the crack reached the inclined surface BBX

The width of the modified region was 30mm (the number of the processing lines was 1500), and the crack reached the inclined surface BB

The width of the modified region was 35mm (the number of processing lines was 1752), and the crack reached the inclined surface BB (warpage 0.3 mm)

The wafer having the bevel portion BB is subjected to laser processing using the processing condition II so that the processing state is a cut-half state. The experimental results are shown below. The width of the modified region is the width in the index direction thereof. "X" represents poor (No Good), "delta" represents Good (Good), and "O" represents Good (Very Good).

< processing Condition II >

Branch number 4, branch pitch BPy30 μm, branch pitch BPx30 μm, processing speed 800mm, frequency 80kHz

< experimental results >

The width of the modified region was 10mm (333 lines), and the crack reached BBX in the inclined surface portion

The width of the modified region was 20mm (666 lines) and the crack reached BBX in the inclined surface portion

The width of the modified region was 25mm (number of lines 833), and the crack reached the inclined surface BBX

The width of the modified region was 30mm (the number of the processing lines was 1000), and the crack reached the inclined surface BBX

The width of the modified region was 100mm (3333 lines) and the crack reached BBX in the inclined surface portion

From these experimental results, it is found that when the modified region is in a completely cut state, the crack can reach the inclined surface portion BB. When the modified region is in a cut-and-half state, the crack hardly reaches the inclined surface portion BB. That is, in order to extend the crack in the inclined surface portion BB, at least the modified region is required to be in a cut-and-fully-cut state in the processing state.

As described above, in the laser processing apparatus 101 and the laser processing method, the region forming the modified region 4 in the inclined surface peripheral portion 100X is shifted in the 1 st direction E1 from the peripheral edge toward the inside. That is, the index direction of the 1 st laser light L1 is set to the 1 st direction E1. In this way, the crack is stably spread in the direction opposite to the 1 st direction E1, that is, in the direction from the inner side toward the peripheral edge. The crack is stably spread in the direction opposite to the 1 st direction E1 of the modified region 4, that is, in the direction from the inner side toward the peripheral edge. As a result, the crack can be formed even in the slope portion BB where processing is difficult, and the object 100 can be peeled off reliably. Further, laser processing is performed on the inner peripheral portion 100Y on the inner side of the inclined surface peripheral portion 100X, in which the desired processing condition is set to the 2 nd processing condition, and laser processing can be performed in accordance with various demands such as reduction in the tact time.

In the 1 st processing step of the laser processing apparatus 101 and the 1 st processing step of the laser processing method, the modified regions 4 are formed from the peripheral edge toward the inside along the line M11 extending spirally from the peripheral edge toward the inside in the object 100, or the modified regions 4 are formed sequentially from the peripheral edge toward the inside along a plurality of straight parallel lines arranged in the direction from the peripheral edge toward the inside in the object 100. This can be achieved in particular: in the inclined surface peripheral portion 100X including the inclined surface portion BB, the region in which the modified region 4 is formed is shifted along the 1 st direction E1 from the peripheral edge toward the inside.

In the case where the laser processing apparatus 101 and the laser processing method are used under the 1 st processing condition and the 2 nd processing condition, and the modified region is formed by irradiating laser light along one processing line, the processing state is set to the cut-and-half state. According to such processing conditions, the object 100 can be reliably peeled off.

In the 1 st processing condition and the 2 nd processing condition of the laser processing apparatus 101 and the laser processing method, when the 1 st laser beam L1 is irradiated along the processing line (the spiral line M11 and the plurality of straight lines) having the plurality of parallel lines to form the modified region 4, the processing state is set to the cut-off state. According to such processing conditions, the object 100 can be reliably peeled off.

The 1 st processing condition of the laser processing apparatus 101 and the laser processing method is a condition for setting the processing state after the laser processing of the 1 st predetermined amount to the cutting complete cutting state. The 2 nd processing condition is a condition for setting the processing state after the laser processing of the 2 nd predetermined amount more than the 1 st predetermined amount to the cutting complete cutting state. In this case, according to the 2 nd processing condition, the plurality of modified spots SA included in the formed modified region 4 are coarsened as compared with the 1 st processing condition, and laser processing can be efficiently performed. Thus, laser processing with a reduced production interval time can be realized.

In the laser processing apparatus 101 and the laser processing method, before the peeling process (peeling process), a trimming process (trimming process) is performed in which the modified region 43 is formed in the object 100 at a portion on the surface 100a side of the virtual plane M1 along the line M3 extending annularly inside the peripheral edge of the object 100. In this way, the trimming process of removing the peripheral portion of the line M3 can be performed. Since the trimming process can be performed before the object 100 is peeled off, it is possible to avoid the irradiation of the 1 st laser beam L1 to form a crack generated by peeling, as compared with the case where the trimming process is performed after the peeling off. The removed portion removed from the object 100 by the trimming process and the peeling process is reusable.

In the 2 nd processing step of the laser processing apparatus 101 and the 2 nd processing step of the laser processing method, the region of the object 100 where the modified region 4 is formed is shifted along the 1 st direction E1. That is, the index direction of the 1 st laser light L1 in the 2 nd processing or 2 nd processing step is set to be the 1 st direction E1. Thus, the object 100 can be reliably peeled off.

As described above, it has been found that it is difficult to peel the object 100 if the processing state in which the modified region 4 is formed along the processing line having a plurality of parallel lines is not a completely cut state. Then, in the laser processing apparatus 101 and the laser processing method, it is monitored whether the processing state in the case of forming the modified region 4 along the line M11 is the cut-through state. Based on the monitoring result, it is possible to easily grasp whether or not the object 100 can be peeled off.

In the laser processing apparatus 101 and the laser processing method, in the 1 st processing (1 st processing step), it is monitored whether or not the processing state after the 1 st predetermined amount of laser processing is the cut-off state. In the 2 nd processing (2 nd processing step), it is monitored whether or not the processing state after the 2 nd predetermined amount of laser processing is the cut-complete-cut state. In this way, it is possible to easily grasp whether or not the object 100 can be peeled off by the 1 st processing (1 st processing step). It is possible to easily grasp whether or not the object 100 can be peeled off by the 2 nd processing (2 nd processing step).

In the laser processing apparatus 101, the control unit 9 determines from the monitoring result of the imaging unit IR that: whether the processing state after the laser processing of the 1 st prescribed amount of the 1 st processing treatment is the cut-through state or not, and whether the processing state after the laser processing of the 2 nd prescribed amount of the 2 nd processing treatment is the cut-through state or not. In this case, the control unit 9 can automatically determine whether the machining state is the complete cutting state based on the monitoring result.

In the laser processing apparatus 101 and the laser processing method, it is further monitored whether the processing state after the processing is completed is a cut-off state. In this way, it can be grasped that the object 100 can be peeled off after the completion of the processing. After completion of the machining, it is also possible to omit the above-described step S8 of determining whether the machining state is the cut-through state and the respective processes related thereto.

Incidentally, in the present embodiment, the image pickup unit IR may also monitor: whether or not the processing state in the case of forming the modified region 4 along one processing line is a cut-and-half state. For example, when the processing line includes a plurality of lines, the processing state in the case of forming the modified region 4 along any one of the lines may be monitored. For example, in the case where the processing line is a spiral line M11, the processing state in the case where the modified region 4 is formed along the line of the peripheral portion thereof can be monitored.

In this case, the control unit 9 may determine whether or not the processing state in the case of forming the modified region 4 along one processing line is a cut-and-half state, based on the monitoring result of the imaging unit IR. In this way, whether the machining state is the cut half-cut state can be automatically determined based on the monitoring result. When the machining state in the case of forming the modified region 4 along one machining line is not a half-cut state (but a hidden state), it is determined that an error has occurred in the machining state, for example, the error in the machining state is notified via the GUI111, and the machining conditions are reset.

In the present embodiment, the 1 st processing (1 st processing method) is performed on the inclined surface peripheral portion 100X and the 2 nd processing (2 nd processing) is performed on the inner peripheral portion 100Y, but the 1 st processing (1 st processing) may be performed on the entire region of the object 100 instead of the 2 nd processing (2 nd processing).

In the 2 nd processing (2 nd processing step) of the present embodiment, as shown in fig. 24 (a) and 24 (b), the region in which the modified region 4 is formed may be shifted in the 2 nd direction E2. Specifically, the modified region 4 is formed along the line M11 from the outer edge of the spiral shape toward the inner periphery of the inclined surface peripheral portion 100X by performing laser processing on the inclined surface peripheral portion 100X with the index direction set to the 1 st direction E1. Then, the index direction is set to the 2 nd direction E2, and laser processing is performed on the inner peripheral portion 100Y, so that the modified region 4 is formed along the line M11 from the inner periphery of the spiral shape toward the outer periphery of the spiral shape in the inner peripheral portion 100Y.

As described above, even when the index direction of the 1 st laser beam L1 in the 2 nd processing (2 nd processing step) is set to the 2 nd direction E2, the object 100 can be peeled off reliably. In this case, the distance of the inclined surface peripheral portion 100X in the index direction may be equal to or less than a predetermined distance set in advance. The predetermined distance is, for example, 35mm or less, specifically 20mm or less. In this way, the object 100 can be peeled off without causing cracks.

In the present embodiment, the 1 st processing (1 st processing step) and the 2 nd processing (2 nd processing step) may be sequentially exchanged, and the 1 st processing may be performed after the 2 nd processing. In this case, although cracks are likely to occur during processing of the bevel peripheral portion 100X, at least the bevel peripheral portion 100X is peelable. In the present embodiment, as long as the index direction of the 1 st processing is the 1 st direction E1, other processing conditions (the order of the 1 st and 2 nd processing, the processing state of the 1 st and 2 nd processing, and the like) are not particularly limited, and the object 100 can be reliably peeled off under the processing conditions described above.

In the laser processing apparatus 101 and the laser processing method, the input from the user may be received by the GUI111, and the control unit 9 may set at least one of the 1 st processing condition and the 2 nd processing condition based on the input from the GUI 111. The 1 st processing condition and the 2 nd processing condition may be desirably set. The setting screen displayed on the GUI111 is exemplified below.

Fig. 25 shows an example of a setting screen of the GUI 111. The setting screen shown in fig. 25 is used for mass production or when a user determines processing conditions. The setting screen shown in fig. 25 includes: a machining method selection button 201 for selecting which one of the plurality of machining methods is selected, an input field 202 for setting the size of the inclined surface peripheral portion 100X, an input field 203 for setting the size of the inner peripheral portion 100Y, and a detailed button 204 for shifting to detailed setting. The plurality of processing methods are different in the index direction of the 1 st processing, the index direction of the 2 nd processing, and the presence or absence of the 2 nd processing. The input field 202a in the case where no processing is performed in the 2 nd processing (i.e., in the case where processing is performed in the 1 st processing) includes a full-face option.

Fig. 26 shows another example of the setting screen of the GUI 111. The setting screen shown in fig. 26 is, for example, a screen for detailed setting when the user touches the detailed button 204 (see fig. 25). The setting screen shown in fig. 26 includes: a machining condition selection button 211 for selecting a machining condition, a branch number field 212 for inputting or selecting the number of branches of the 1 st laser beam L1, an index field 213 for inputting an index (index) which is a moving distance from the laser machining along the 1 st machining line to the next machining line, a schematic diagram 214 for inputting or displaying the branch number and the index, a machining Z height field 215 for inputting the position of the modified point SA in the Z direction, a machining speed field 216 for inputting a machining speed, and a condition switching method button 217 for selecting a switching method of the machining condition.

In the machining condition selection button 211, which of the 1 st machining condition and the 2 nd machining condition is set is selectable. According to the index field 213, when the number of branches is 1, the laser processing head 10A is automatically moved in the index direction by an amount corresponding to the input value. When the number of branches is larger than 1, the laser processing head 10A is automatically moved in the index direction according to the index of the following calculation formula.

Index= (number of branches) ×index input value

Schematic 214 includes: a display unit 214a for displaying the index input value, and a power input field 214b for inputting the power of each modified dot SA. The processing speed column 216 may be a rotational speed because the stage 107 is actually rotated. The machining speed column 216 may be automatically changed from the inputted machining speed to the rotational speed. The conditional switch method button 217 is selected: the processing 1 is automatically continued when the processing 1 is completed, or the processing 1 is continued after the device is stopped once and the state is monitored when the processing 1 is completed.

Fig. 27 shows an example of the manager mode of the setting screen of the GUI 111. The setting screen shown in fig. 27 includes: a branch direction selection button 221 for selecting the branch direction of the 1 st laser L1, a branch number field 222 for inputting or selecting the number of branches of the 1 st laser L1, a branch pitch input field 223 for inputting the branch pitch BPx, a branch pitch column number input field 224 for inputting the column number of the branch pitch BPx, a branch pitch input field 225 for inputting the branch pitch BPy, an index field 226 for inputting an index, an optical axis diagram 227 for selecting the scanning direction of the 1 st laser L1 as one direction (going-out) or the other direction (return) according to the number of branches, a balance adjustment start button 229 for automatically adjusting the balance of various values.

When the number of branches and the branching pitches BPx, BPy are inputted, the distance of the optical axis is automatically calculated, and when the calculated value becomes the wrong distance based on the relation of the imaging optical system 35 (see fig. 5), the GUI111 is caused to display the result. To perform this calculation, information about the imaging optical system 35 may be input. In the branching direction selection button 221, when the branching direction is selected to be vertical, the plurality of branching pitches 227a may be set not to be displayed in the optical axis diagram 227. The square of the branching pitches 227a,227b of the optical axis diagram 227 may be increased or decreased depending on the number of branches. In the optical axis diagram 227, the input values of the branch pitch column number input field 224 and the branch pitch input field 225 are used, and if the selection is performed in each selection field CK, the distances between the branch pitches 227a,227b corresponding to the selected selection field CK can be changed.

Fig. 28 shows an investigation example of the optimum pulse energy for the peeling process. Fig. 28 shows a processing state in the case of performing laser processing along one processing line, and the possibility of delamination after performing laser processing along a plurality of processing lines (parallel lines). The 1 st laser L1 had a branching number of 4, branching pitches BPx, BPy of 30 μm, a processing speed of 800mm/s, a pulse pitch of 10 μm, and a pulse width of 700ns. The "SST" in the figure indicates the cut hidden state. In the figure, "SHC" represents a half cut state. As shown in fig. 28, the optimum pulse energy for generating the half cut state was in the range of 9.08 to 56 μj. In addition, it was found that peeling was possible without any problem, particularly in the pulse energy range of 12.97 to 25. Mu.J. In addition, in the case where the pulse pitch is larger than 10 μm, the optimum pulse energy tends to become higher than the experimental result in the figure. In the case where the pulse pitch is smaller than 10 μm, the optimum pulse energy tends to become smaller than the experimental result in the figure.

In the present embodiment, the processing state is automatically determined by the control unit 9, but the processing state may be determined by the user based on the monitoring result of the imaging unit IR. The determination that the machining state is in the cut-complete-cut state corresponds to the determination that the machining state is not the cut-half-cut state or the cut-hidden state.

In a general peeling process, the pitch of the plurality of modified spots SA included in the modified region 4 to be formed is narrowed, and the object 100 may be peeled by filling the modified spots SA on the virtual plane M1 that is a planned peeling surface. In this case, as the processing conditions, conditions are selected under which cracks are less likely to spread from the modified spots SA (for example, the wavelength of the laser is a short wavelength (1028 nm), the pulse width is 50nsec, and the pulse pitch is 1 to 10 μm (particularly 1.5 to 3.5 μm)). In contrast, in the present embodiment, as the processing conditions, conditions for extending the crack along the virtual plane M1 are selected. For example, the processing conditions for the 1 st laser light L1 for forming the modified region 4 along the virtual plane M1 are selected as follows: the 1 st laser light L1 has a long wavelength (e.g., 1099 nm) and a pulse width of 700nsec. As a result, a new processing state (a half cut state, a full cut state, etc.) was found.

In the present embodiment, the control unit 9 may perform the 3 rd processing on the way of the 1 st processing, and the 3 rd processing irradiates the 1 st laser beam L1 on the inclined surface peripheral portion 100X under a processing condition different from the 1 st processing condition. In other words, the 3 rd processing step may be performed in the middle of the 1 st processing step, and the 3 rd processing step is to irradiate the 1 st laser beam L1 to the inclined surface peripheral portion 100X under a different processing condition from the 1 st processing condition. The other processing conditions are not particularly limited, and may be various conditions. The other processing conditions are, for example, processing conditions when the processing state of the inside of the object 100 is set to a cut hidden state, a cut half-cut state, or a cut full-cut state. In this case, the object 100 can be peeled off surely. The interval in the index direction of the processing line in the 3 rd processing (3 rd processing step) may be wider than the interval in the index direction of the processing line in the 1 st processing (1 st processing step).

In the present embodiment, when the 1 st processing (1 st processing step) and the 2 nd processing (2 nd processing step) are switched, the processing may be stopped once and then switched, or the processing may be switched without stopping. In the present embodiment, when the 1 st processing (1 st processing step) and the 3 rd processing (3 rd processing step) are switched, the processing may be stopped once and then switched, or the processing may be switched without stopping. When the processing (processing step) is switched without stopping the processing, the processing conditions can be smoothly switched. For example, when the difference between the 1 st processing condition and the 2 nd processing condition is only the branch pitch BPy, the branch pitch BPy may be changed gradually (in the order of 20 μm, 21 μm, 22 μm, 23 μm … μm) without stopping the rotation of the stage 107, instead of switching after the processing is stopped when the branch pitch BPy is changed from 20 μm to 30 μm.

[ embodiment 2 ]

Embodiment 2 will be described next. In the description of embodiment 2, differences from embodiment 1 are described, and the description repeated with embodiment 1 will be omitted.

In embodiment 1, the peeling process is performed by the 1 st and 2 nd processes, whereas in this embodiment, the peeling process is performed by 1 st process. That is, as shown in fig. 29 (a) and 29 (b), this embodiment is different from embodiment 1 in that: the entire region of the object 100 including the inclined surface peripheral portion 100X and the inner peripheral portion 100Y was laser-machined under 1 machining condition.

The control unit 9 performs a processing process of irradiating the entire region of the object 100 with the 1 st laser beam L1 under the 2 nd processing condition. Specifically, the 1 st laser beam L1 is irradiated to the object 100 under the 2 nd processing condition, and the position of the 1 st focal point P1 is moved along the spiral line M11 from the peripheral edge toward the inner side with respect to the object 100, whereby the modified region 4 is formed along the line M11. That is, the region of the object 100 in which the modified region 4 is formed is shifted in the 1 st direction E1 from the peripheral edge toward the inside.

The control unit 9 operates the suction tool for sucking the object 100 after laser processing to twist around the Z direction. In this way, external stress can be applied to the object 100 so as to peel it off.

Next, the peeling process according to the present embodiment will be described in detail with reference to the flowchart of fig. 30.

The peeling process according to the present embodiment controls each unit of the laser processing apparatus 101 by the control unit 9, and performs the following processes. That is, the rotation of the stage 107 is started. While the 1 st laser beam L1 is irradiated to the object 100 under the 2 nd processing condition, the 1 st converging point P1 is moved along the Y-axis rail 108 so as to move toward the inner peripheral side along the Y-direction (step S11, processing step).

In step S11, laser processing is performed with the index direction set to the 1 st direction E1. In step S11, the 1 st focal point P1 is moved along the spiral line M11 from the peripheral edge to the inner side to form the modified region 4. In step S11, the irradiation of the 1 st laser beam L1 may be started when the optical axis of the 1 st laser beam L1 is still located outside the object 100 or when it is located at the inclined surface peripheral portion 100X.

After the processing in the processing step of the 2 nd predetermined amount, the rotation of the stage 107, the irradiation of the 1 st laser beam L1, and the like are stopped, and the processing step is stopped. Based on the imaging result of the imaging unit IR, it is determined whether or not the processing state after the 2 nd predetermined amount of processing is the cut-through state (i.e., whether or not it is the 2 nd cut-through state) (step S12). When the result of step S12 is Yes, the rotation of the stage 107, the irradiation of the 1 st laser beam L1, and the like are restarted, and the processing step is restarted (step S13). In this way, the object 100 is formed with the modified region 4 along the spiral line M11, and the processing state is set to the cut-complete state (see fig. 29 b). Through the above operation, the modified region 4 is formed along the line M11 over the entire virtual plane M1, and the processing is completed (step S14).

Based on the imaging result of the imaging unit IR, it is determined whether the processing state after the completion of the processing is a cut-through state over the entire area of the virtual plane M1 (step S15). If yes in step S15, stress is applied to peel off a part of the object 100 (step S16). In step S16, for example, an adsorbing tool for adsorbing the object 100 is twisted around the Z direction, thereby applying an external stress to the object 100. Then, when the peeling process has been completed normally, the process is ended normally. On the other hand, if the step S12 is No (No) or the step S15 is No, it is determined that an error has occurred in the machining state, and for example, the error in the machining state is notified via the GUI111 (step S17). For example, after the step S17, the 2 nd processing condition is reset by another process (for example, the process of embodiment 4 described later).

As described above, the laser processing apparatus 101 and the laser processing method according to the present embodiment can also exhibit the same effects as those of embodiment 1. The laser processing apparatus 101 and the laser processing method according to the present embodiment can peel the object 100 by applying stress only by changing the processing state to the cut-to-full state by laser processing.

In the present embodiment, the machining conditions may be set to conditions for bringing the machining state into the half-cut state. Further, the condition for setting the machining state to the 1 st cut complete-cutting state may be set as the machining condition. In the machining condition for setting the machining state to the 1 st cut-through state, the step S16 of applying stress may be omitted.

In the present embodiment, the method of applying stress and the structure are not particularly limited. For example, the crack may be stretched and peeled by physical application of stress (adsorption, pressurization, water pressure, or the like). For example, the crack may be stretched by applying stress by laser preheating, ultrasonic wave, or the like, and the peeling may be performed.

Fig. 31 is a flowchart showing a peeling process according to a modification of embodiment 2. In the modification, the laser processing and the stress application are performed to change the processing state to the cut-and-fully-cut state, and the peeling is performed. In the modification, the following processes shown in fig. 31 are performed instead of the process shown in fig. 30. That is, the rotation of the stage 107 is started, and the 1 st laser beam L1 is irradiated to the object 100 under the 3 rd processing condition, and the laser processing head 10A is moved along the Y-axis rail 108 so that the 1 st focal point P1 moves toward the inner peripheral side in the Y-direction (step S21). The 3 rd processing condition is a condition for forming the modified region 4 by irradiating the 1 st laser light L1 along one processing line, in which the processing state is set to the half-cut state, and a condition for forming the modified region 4 by irradiating the 1 st laser light L1 along a processing line having a plurality of parallel lines arranged side by side, in which the processing state is not set to the full-cut state. The 3 rd machining condition is configured by appropriately setting various parameters according to known techniques so that the machining state is a half-cut state and is not a full-cut state. In this way, the modified region 4 is formed along the line M11 over the entire virtual plane M1, and the processing is completed (step S22). The object 100 is stressed so that the machining state is brought into a complete cutting state (step S23).

Based on the imaging result of the imaging unit IR, it is determined whether the processing state after the completion of the processing is a cut-through state over the entire area of the virtual plane M1 (step S24). In the case where yes in the above-described step S24, when the peeling process has been completed normally, the process is ended normally. On the other hand, if no in step S24, it is determined that an error has occurred in the machining state, for example, the error in the machining state is notified via the GUI111 (step S25). The laser processing apparatus and the laser processing method according to the modification can also exhibit the same effects as described above.

[ embodiment 3 ]

Embodiment 3 will be described next. In the description of embodiment 3, differences from embodiment 1 are described, and the description repeated with embodiment 1 will be omitted.

In the peeling process of the present embodiment, the distance measuring sensor 36 (see fig. 9) of the laser processing head 10A detects the height (displacement) of the inclined surface portion BB, thereby monitoring the warpage of the inclined surface portion BB. In the peeling process of the present embodiment, the control unit 9 controls each unit of the laser processing apparatus 101, and the following processes shown in fig. 32 are performed.

Rotation of the stage 107 is started. While the 1 st laser beam L1 is being irradiated to the inclined surface peripheral portion 100X under the 1 st processing condition, the 1 st converging point P1 is moved to the inner peripheral side in the Y direction, and the laser processing head 10A is moved along the Y-axis rail 108 (step S31). While the 1 st laser beam L1 is being irradiated to the inner peripheral portion 100Y under the 1 st processing condition or the 2 nd processing condition, the laser processing head 10A is moved along the Y-axis rail 108 so that the 1 st converging point P1 moves toward the inner peripheral side along the Y-direction (step S32). In the steps S31 and S32, the 1 st focal point P1 is moved along the spiral line M11 from the peripheral edge to the inner side to form the modified region 4.

Rotation of the stage 107, irradiation of the 1 st laser beam L1, and the like are stopped, and laser processing on the inner peripheral portion 100Y is stopped. Based on the detection result of the distance measuring sensor 36, it is determined whether or not warpage has occurred in the inclined surface portion BB (step S33). In step S33, when the height of the slope BB detected by the distance measuring sensor 36 is equal to or greater than a predetermined height set in advance, it is determined that warpage is generated in the slope BB.

If yes in step S33, the rotation of the stage 107, the irradiation of the 1 st laser beam L1, and the like are restarted, and the laser processing of the inner peripheral portion 100Y is restarted (step S34). Then, the modified region 4 is formed along the line M11 over the entire virtual plane M1, and the processing is completed (step S35). On the other hand, if no in step S33, it is determined that an error has occurred in the machining state, for example, the error in the machining state is notified via the GUI111 (step S36). For example, after the step S36, the 1 st processing condition and the 2 nd processing condition are reset by another process (for example, the process of embodiment 4 described later).

As described above, the laser processing apparatus and the laser processing method according to the present embodiment can also exhibit the same effects as those of embodiment 1. It was found that if the crack extends along the virtual plane M1 and reaches the inside of the inclined surface portion BB, warpage occurs in the inclined surface portion BB. In this way, the laser processing apparatus 101 and the laser processing method according to the present embodiment can grasp that the crack reaches the slope portion BB by monitoring (appearance monitoring) the warpage of the slope portion BB.

In addition, if the warpage of the inclined surface portion BB becomes remarkable, the laser processing apparatus 1 may come into contact with the inclined surface portion BB. Therefore, in the present embodiment, if yes in step S33, the magnitude of the warp of the inclined surface portion BB is calculated based on the detection result of the distance measuring sensor 36, and if the magnitude of the warp of the inclined surface portion BB is equal to or greater than a predetermined value set in advance, the process proceeds to step S36 in which an error is notified.

However, in a portion of the object 100 located at a position at a predetermined distance (for example, 35 mm) or more from the peripheral edge, if laser processing is performed so that the processing state is the 1 st cut-and-complete cutting state, the inclined surface portion BB tends to warp. After the laser processing, if the laser processing is further performed with the 2 nd direction E2 from the inner periphery of the object 100 toward the peripheral edge as the index direction, the stress of the object 100 due to the warpage may be split. In this case, it is possible to prevent the object 100 from cracking in advance by monitoring that no warpage occurs before the laser processing is performed with the 2 nd direction E2 as the index direction.

In the present embodiment, the distance measuring sensor 36 is used as the peripheral edge monitoring unit for monitoring the warpage of the inclined surface portion BB, but the present invention is not limited thereto. As long as the appearance of the inclined surface portion BB can be monitored, various devices such as an observation camera and a noncontact sensor can be employed as the peripheral edge monitoring portion. When the warpage of the inclined surface portion BB is monitored using a non-contact sensor, the presence or absence of warpage and the amount of warpage of the inclined surface portion BB can be monitored in real time (real time) without stopping the laser processing. In the present embodiment, the control unit 9 determines the warpage of the inclined surface portion BB, but the user may determine the warpage of the inclined surface portion BB based on the detection result of the distance measuring sensor 36. This embodiment is applicable not only to embodiment 1 but also to embodiment 2.

[ embodiment 4 ]

Embodiment 4 will be described next. In the description of embodiment 4, differences from embodiment 1 are described, and the description repeated with embodiment 1 will be omitted.

In the present embodiment, the processing conditions for the case where the internal processing state of the object 100 is set to the cut half-cut state, that is, the half-cut processing conditions, are determined (clarified) in advance of the actual laser processing of the object 100.

That is, the control unit 9 performs 1-line processing (2 nd pretreatment) in which the 1 st laser beam L1 is irradiated to the object 100 along one processing line under half-cut processing conditions, thereby forming the modified region 4 in the object 100. The imaging unit IR acquires a 1-line image (2 nd image), which is a processing state in which the modified region 4 is formed along one processing line by 1-line processing. The control unit 9 determines the processing state represented by the 1-line image, and changes the half-cut processing condition according to the determination result. Specifically, the control unit 9 determines whether or not the processing state shown in the 1-line image is a cut half-cut state, and changes the half-cut processing condition when the processing state is not the cut half-cut state. The half-cut processing conditions are conditions which are the preconditions for the processing conditions 1 and 2. The control unit 9 sets the half-cut processing conditions (the processing conditions of the 2 nd pretreatment) based on the input of the GUI 111.

Fig. 33 is a flowchart showing an example of processing for determining the half-cut processing conditions. When the half-cut processing conditions are determined, the control unit 9 controls the respective units of the laser processing apparatus 101, and the following processes illustrated in fig. 33 are performed.

First, the 1 st laser beam L1 is irradiated to the object 100 along one processing line under the set half-cut processing conditions, whereby the modified region 4 is formed in the object 100 (step S41, 1-line processing). The 1-line image showing the processing state when the modified region 4 is formed in step S41 is acquired by the imaging unit IR (step S42). From the 1-line image, it is determined whether the machining state is a cut-and-half state (step S43).

If yes in step S43, it is determined that the half-cut machining condition set at present is the final machining condition (step S44). If no in step S43, the half-cut processing conditions are adjusted (step S45). In step S45, for example, the pulse energy of the 1 st laser light L1 is optimized (see fig. 28) and/or the branching pitch BPy, BPx or pulse pitch is narrowed. After the step S45, the process returns to the step S41. The initial value of the half-cut processing condition in step S41 can be set by the user via the GUI 111.

In the present embodiment, the processing condition for the case where the processing state of the interior of the object 100 is set to the 1 st cut-through state, that is, the 1 st processing condition, is determined (recognized) in advance of the actual laser processing of the object 100.

That is, the control unit 9 performs multi-line processing (1 st pretreatment) of irradiating the object 100 with the 1 st laser beam L1 under the 1 st processing condition along a processing line having a plurality of lines (parallel lines) arranged side by side, thereby forming the modified region 4 in the object 100. The imaging unit IR acquires a multi-line image (1 st image) which is a processed state in which the modified region 4 is formed by multi-line processing. The control unit 9 determines the processing state represented by the multi-line image, and changes the 1 st processing condition according to the determination result. The control unit 9 sets the 1 st machining condition based on the input of the GUI 111.

The imaging unit IR acquires, as a multi-line image, a 1 st multi-line image showing a processing state after the laser processing of the 1 st predetermined amount. The control unit 9 determines whether or not the processing state after the laser processing of the 1 st predetermined amount is the cut-through state (that is, whether or not the processing state is the 1 st cut-through state) based on the 1 st multi-line image. The control unit 9 changes the 1 st machining condition when the machining state is not the 1 st cutting complete cutting state.

Fig. 34 is a flowchart showing an example of processing for determining the 1 st processing condition. When the 1 st processing condition is determined, the control unit 9 controls each unit of the laser processing apparatus 101 to execute the following processing illustrated in fig. 34.

First, the 1 st laser beam L1 is irradiated to the object 100 along a plurality of parallel lines arranged side by side under the 1 st processing condition set, whereby the modified region 4 is formed in the object 100 (step S51, multi-line processing). The 1 st multi-line image is acquired by the imaging means IR, and the 1 st multi-line image is displayed in the processing state when the modified region 4 is formed in the step S51, that is, in the processing state after the 1 st predetermined amount of laser processing (step S52). From the 1 st multi-line image, it is determined whether or not the processing state after the 1 st predetermined amount of laser processing is the cut-through state (1 st cut-through state) (step S53).

If yes in step S53, it is determined that the 1 st machining condition set at present is the final machining condition (step S54). If no in step S52, the 1 st processing condition is adjusted (step S55). In step S55, for example, the pulse energy of the 1 st laser light L1 is optimized (see fig. 28) and/or the branching pitch BPy, BPx or pulse pitch is narrowed. After the step S55, the process returns to the step S51. The initial value of the 1 st processing condition in step S51 can be set by the user via the GUI 111.

In the present embodiment, the processing condition for the case where the processing state of the interior of the object 100 is set to the 2 nd cut-through state, that is, the 2 nd processing condition, is determined (recognized) in advance of the actual laser processing of the object 100.

That is, the control unit 9 performs multi-line processing (1 st pretreatment) of irradiating the object 100 with the 1 st laser light L1 under the 2 nd processing conditions along a processing line having a plurality of lines (parallel lines) arranged side by side, thereby forming the modified region 4 in the object 100. The imaging unit IR acquires a multi-line image (1 st image) which is a processed state in which the modified region 4 is formed by multi-line processing. The control unit 9 determines the processing state represented by the multi-line image, and changes the 2 nd processing condition according to the determination result. The control unit 9 sets the 2 nd processing condition based on the input of the GUI 111.

The imaging unit IR acquires, as a multi-line image, a 2 nd multi-line image showing a processing state after the laser processing of the 2 nd predetermined amount and after the stress application. The stress is applied, for example, in the same manner as the stress applied in the step S16 (see fig. 30). The control unit 9 determines whether or not the processing state after the laser processing of the 2 nd predetermined amount is the cut-through state (that is, whether or not the processing state is the 2 nd cut-through state) based on the 2 nd multi-line image. The control unit 9 changes the processing condition 2 when the processing state is not the 2 nd complete cutting state.

Alternatively, the imaging unit IR acquires, as the multi-line image, a 1 st multi-line image showing a processing state after the laser processing of the 1 st predetermined amount. The control unit 9 determines whether the machining state is the 1 st full cut state based on the 1 st multi-line image. When the machining state is the 1 st cut complete-off state, the control unit 9 changes the 2 nd machining condition. When the machining state is not the 1 st cut-off state, the imaging unit IR acquires a 2 nd multi-line image showing the machining state after the 2 nd predetermined amount of laser machining as the multi-line image. The control unit 9 determines whether the machining state is the 2 nd full cut state based on the 2 nd multi-line image. The control unit 9 changes the processing condition 2 when the processing state is not the 2 nd complete cutting state.

Fig. 35 is a flowchart showing an example of processing for determining the 2 nd processing condition. In determining the 2 nd processing condition, the control unit 9 controls each unit of the laser processing apparatus 101 to execute the following processing illustrated in fig. 35.

First, the 1 st laser beam L1 is irradiated to the object 100 along a plurality of parallel lines arranged side by side under the set 2 nd processing condition, whereby the modified region 4 is formed in the object 100 (step S61, multi-line processing). The 1 st multi-line image showing the processing state after the laser processing of the 1 st predetermined amount is acquired by the imaging unit IR (step S62). From the 1 st multi-line image, it is determined whether or not the processing state after the laser processing of the 1 st predetermined amount is the cut-through state (1 st cut-through state) (step S63).

If no in step S63, that is, if the machining state is a cut hidden state or a cut half-cut state, the multi-line machining is continued (step S64). The 2 nd multi-line image showing the processing state after the laser processing of the 2 nd predetermined amount is acquired by the imaging unit IR (step S65). From the 2 nd multi-line image, it is determined whether or not the processing state after the laser processing of the 2 nd predetermined amount is the cut-through state (2 nd cut-through state) (step S66).

If yes in step S66, it is determined that the 2 nd processing condition set now is the final processing condition (step S67). If yes in step S63, the 2 nd processing condition is adjusted (step S68). In step S68, for example, the branch pitch BPy, BPx or pulse pitch is enlarged.

If no in step S66, the 2 nd processing condition is adjusted (step S69). In step S69, for example, the pulse energy of the 1 st laser light L1 is optimized (see fig. 28) and/or the branching pitch BPy, BPx or pulse pitch is narrowed. After the step S68 or the step S69, the process returns to the step S61. The initial value of the processing condition 2 in step S61 can be set by the user via the GUI 111.

As described above, the laser processing apparatus 101 and the laser processing method according to the present embodiment can also exhibit the same effects as those of embodiment 1. It was found that there is a correlation between the peeling of the object 100 and the processing state in the case of forming the modified region 4 along the processing line having a plurality of parallel lines. Then, the laser processing apparatus 101 and the laser processing method according to the present embodiment acquire a multi-line image showing a processing state in which the modified region 4 is formed along a processing line having a plurality of parallel lines. From the multi-line image, the processing conditions can be determined so that the object 100 can be peeled off. Therefore, the object 100 can be reliably peeled off.

Found that: there is a correlation between the peeling of the object 100 and the processing state in the case of forming the modified region 4 along one processing line. Then, the laser processing apparatus 101 and the laser processing method according to the present embodiment acquire a 1-line image showing a processing state in which the modified region 4 is formed along one processing line. From the 1-line image, the processing conditions can be determined so that the object 100 can be peeled off. Therefore, the object 100 can be peeled off reliably.

The laser processing apparatus 101 and the laser processing method according to the present embodiment determine the processing state represented by the 1-line image. The half-cut processing conditions are changed according to the determination result. In this case, the half-cut processing conditions can be automatically changed according to the 1-line image.

Found that: if the processing state in the case of forming the modified region 4 along one processing line is not a cut-and-half state, the object 100 is difficult to peel off. Then, in the laser processing apparatus 101 and the laser processing method according to the present embodiment, when the processing state shown in the 1-line image is not the cut half-cut state, the half-cut processing condition is changed. In this way, the half-cut processing conditions can be determined so that the object 100 can be peeled off.

The laser processing apparatus 101 and the laser processing method according to the present embodiment determine a processing state represented by a multi-line image. According to the determination result, the 1 st and 2 nd processing conditions are changed. In this case, the 1 st and 2 nd processing conditions can be automatically changed according to the 1 st image.

Found that: when forming the modified region 4 along the processing line having a plurality of parallel lines, the object 100 can be peeled off reliably by performing the laser processing so that the processing state after the laser processing of the first predetermined amount becomes the cut-and-fully-cut state. Then, in the laser processing apparatus and the laser processing method according to the present embodiment, whether the processing state after the laser processing of the 1 st predetermined amount is the cut-through state is determined based on the 1 st multi-line image, and when the processing state is not the cut-through state, the 1 st processing condition is changed. In this way, the 1 st processing condition under which the object 100 can be reliably peeled can be determined.

Found that: when the modified region 4 is formed along the processing line having a plurality of parallel lines, the object 100 can be peeled while suppressing an increase in the tact time by performing the processing state after the laser processing of the 2 nd predetermined amount to be the cut-through state. Then, in the laser processing apparatus 101 and the laser processing method according to the present embodiment, whether the processing state after the laser processing of the 2 nd predetermined amount is the cut-through state is determined based on the 2 nd multi-line image, and when the processing state is not the cut-through state, the 2 nd processing condition is changed. In this way, the 2 nd processing condition that can peel the object 100 while suppressing an increase in the tact time can be determined.

In the present embodiment, the half-cut machining condition, the 1 st machining condition, and the 2 nd machining condition are determined, but at least one of them may be determined. For example, when the half cut state cannot be confirmed by the imaging unit IR, at least one of the 1 st processing condition and the 2 nd processing condition may be determined. In the present embodiment, the processing state is automatically determined by the control unit 9, but the processing state may be determined by the user based on the imaging result of the imaging unit IR. The steps S51 and S61 constitute the 1 st pre-process, and the steps S52 and S62 constitute the 1 st image capturing process. This embodiment is applicable not only to embodiment 1 but also to embodiment 2 or 3.

Examples of the object 100 used in determining the processing conditions in the present embodiment include: for example, the wafer (wafer for condition determination) is not a wafer for operation (practie) of a semiconductor device (product) which is finally formed by a peeling process or the like, and the wafer (wafer for semiconductor device) is finally formed by a peeling process or the like for production (production) of a semiconductor device. In the former case, the processing line may be set at any one of the entire regions of the wafer, and the processing conditions may be determined. In the latter case, the processing line may be set in an outer edge region of the wafer where the influence on the peeling quality is small to determine the processing conditions, and the peeling processing may be continuously performed under the determined processing conditions. The latter may be employed, for example, in the case where the processing conditions must be adjusted for every 1 sheet because of uneven back surface film of the wafer, or the like.

Modification example

The above is an embodiment of the present invention, and is not limited to the above embodiment.

In the above embodiment, the trimming process for forming the modified region 43 is performed before the object 100 is peeled by the peeling process, but as shown in fig. 36 (a) and 36 (b), the removal region E may be removed by the trimming process after the object 100 is peeled by the peeling process. In this case, too, the removed portion removed from the object 100 by the peeling process is reusable.

As shown in fig. 37 (a) and 37 (b), after the modified region 4 is formed along the virtual plane M1 in the effective region R of the object 100 by the peeling process, the removed region E may be removed by the trimming process. As shown in fig. 38 (a) and 38 (b), after the removal region E is removed by the trimming process, the object 100 may be peeled off by the peeling process.

In the above embodiment, the processing line is not limited to the spiral line M11, and various shapes of processing lines may be set to the object 100. For example, as shown in fig. 39, a plurality of linear lines (parallel lines) M12 may be set to the object 100 so as to be aligned in a predetermined direction. These plural lines M12 are included in a line (processing line) M20. The line M12 is a virtual line, but may be an actually drawn line. Line M12 may also be assigned coordinates. The plurality of lines M12 arranged side by side may be partially or entirely connected or disconnected.

The above embodiment may include a plurality of laser processing heads as the irradiation sections. In the case of providing a plurality of laser processing heads as the irradiation section, laser processing may be performed using the plurality of laser processing heads in each of the above-described 1 st processing (1 st processing step), 2 nd processing (2 nd processing step), 1 st pretreatment (1 st pretreatment) and 2 nd pretreatment (2 nd pretreatment).

In the above embodiment, the reflective spatial light modulator 34 is used, but the spatial light modulator is not limited to the reflective one, and a transmissive spatial light modulator may be used. In the above embodiment, the type of the object 100, the shape of the object 100, the size of the object 100, the number and direction of crystal orientations of the object 100, and the plane orientation of the main surface of the object 100 are not particularly limited.

In the above embodiment, the rear surface 100b of the object 100 is set as the laser light incident surface, but the front surface 100a of the object 100 may be set as the laser light incident surface. In the above embodiment, the modified region may be, for example, a crystal region, a recrystallized region, or a gettering (gettering) region formed inside the object 100. The crystal region is a region in which the structure of the object 100 before processing is maintained. The recrystallization region is a region which is once evaporated, plasmatized or melted, and then becomes single crystal or polycrystalline and solidifies upon resolidification. The gettering region is a region in which impurities such as heavy metals are collected and trapped to exert a gettering effect, and may be formed continuously or intermittently. The above embodiment can also be applied to machining such as ablation (ablation).

In the laser processing according to the above embodiment, in the processing 2, if the limit of the apparatus is reached (the rotational speed of the stage 107 is the maximum rotational speed), the pitch of the modified spots SA included in the modified region 4 may be narrowed. In this case, other processing conditions can be changed so that the pitch becomes a constant interval.

Further modifications will be described below.

As shown in fig. 40, the main points of difference between the laser processing apparatus 1A and the laser processing apparatus 1 described above are: an alignment camera AC and an imaging unit IR are provided, and a laser processing head (1 st irradiation section) 10B is attached to an attachment section 66 via a swivel mechanism 67. In the present embodiment, the laser processing apparatus 1A performs trimming and peeling processing on an object 100 having a surface 100a (hereinafter also referred to as "the 1 st main surface 100 a") and a surface 100b (hereinafter also referred to as "the 2 nd main surface 100 b"), thereby obtaining (manufacturing) a semiconductor device. The trimming process is a process for removing unnecessary portions of the object 100. The peeling process is a process for peeling a part of the object 100. First, the structure of the laser processing apparatus 1A will be described centering on the difference from the laser processing apparatus 1. In fig. 40, the device frame 1a, the light source unit 8, and the like are omitted.

As shown in fig. 40, the alignment camera AC and the imaging unit IR are mounted on the mounting portion 65 together with the laser processing head (the 2 nd irradiation portion) 10A. The alignment camera AC uses, for example, a light-capturing device pattern or the like penetrating the object 100. Alignment of the irradiation position of the laser light L1 to the object 100 and the like are performed based on the image obtained by the alignment camera AC. The imaging unit IR photographs the object 100 by light transmitted through the object 100. For example, when the object 100 is a wafer containing silicon, light in the near infrared region is used in the imaging unit IR. Based on the image obtained by the imaging unit IR, the state of the modified region formed in the object 100 and the crack extending from the modified region is checked.

The laser processing head 10B is attached to the attachment portion 66 via a swivel mechanism 67. The swivel mechanism 67 is rotatably mounted on the mounting portion 66 with an axis parallel to the X direction as a center line. In this way, the moving mechanism 6 can change the direction in which the laser processing head 10B is directed, and can bring the optical axis of the light collecting portion (1 st light collecting portion) 14 of the laser processing head 10B into a state along the Y direction (1 st direction intersecting with the direction perpendicular to the surface of the object) parallel to the 2 nd main surface 100B of the object 100, or bring the optical axis of the light collecting portion 14 of the laser processing head 10B into a state along the Z direction (2 nd direction) perpendicular to the 2 nd main surface 100B. In the laser processing apparatus 1A, the state in which the optical axis of the light converging portion 14 is along the 1 st direction means a state in which the optical axis forms an angle of 10 ° or less with respect to the 1 st direction; the state in which the optical axis of the light collecting portion 14 is along the 2 nd direction means a state in which the optical axis forms an angle of 10 ° or less with respect to the 2 nd direction.

Next, an object 100 to be processed by the laser processing apparatus 1A will be described. The object 100 includes, for example, a semiconductor wafer formed in a disk shape. The object 100 may be formed of various materials and may have various shapes. A functional element (not shown) is formed on the 1 st main surface 100a of the object 100. Examples of the functional element include a light receiving element such as a photodiode, a light emitting element such as a laser diode, and a circuit element such as a memory.

As shown in fig. 41 (a) and (b), the effective portion RR and the peripheral portion EE are set in the object 100. The effective portion RR corresponds to the semiconductor device to be obtained. The effective portion RR is, for example, a disk-shaped portion including a central portion when the object 100 is viewed in the thickness direction. The peripheral edge portion EE is an area outside the effective portion RR in the object 100. The peripheral edge portion EE is an outer edge portion other than the effective portion RR in the object 100. The peripheral edge portion EE is, for example, a ring-shaped slope portion (slope portion) surrounding the effective portion RR.

A virtual plane M1, which is a predetermined surface to be peeled, is set in the object 100. The virtual plane M1 is a plane on which the modified region is to be formed. The virtual plane M1 is a plane facing the object 100 on which the laser light enters, that is, the 2 nd main surface 100b (that is, a plane facing the 2 nd main surface 100 b). The virtual plane M1 includes a 1 st region M1a and a 2 nd region M1b. The 1 st region M1a is a region located in the effective portion RR among the virtual plane M1. The 2 nd region M1b is a region located at the peripheral edge portion EE among the virtual plane M1. The virtual plane M1 is a plane parallel to the 2 nd main surface 100b, and is, for example, circular. The virtual plane M1 is a virtual area, is not limited to a plane, and may be a curved surface or a 3-dimensional surface. The effective portion RR, the peripheral edge portion EE, and the virtual plane M1 can be set by the control unit 9. The effective portion RR, the peripheral portion EE, and the virtual plane M1 may also be assigned coordinates.

A line M3 as a trimming target line is set in the object 100. The line M3 is a line predetermined to form the modified region. Line M3 extends annularly inside the outer edge of object 100. The line M3 extends, for example, in a circular shape. The line M3 is a portion on the opposite side of the laser light incident surface from the virtual plane M1 in the object 100, and is set at the boundary between the effective portion RR and the peripheral edge portion EE. The setting of the line M3 can be performed by the control unit 9. Line M3 may also be assigned coordinates.

Next, an example of a method of manufacturing (obtaining) a semiconductor device by performing trimming processing and peeling processing on the object 100 using the laser processing apparatus 1A will be described. The manufacturing method described below is reusable with respect to a removed portion (a portion of the object 100 that is not used as a semiconductor device) removed from the object 100 by the trimming process and the peeling process.

First, as shown in fig. 40, the object 100 is supported by the support portion 7 with the 2 nd main surface 100b being on the laser light incident surface side. On the 1 st principal surface 100a side of the object 100 where the functional element is formed, a substrate such as a supporting substrate is bonded, or an adhesive tape is attached.

Next, as shown in fig. 42 and 43 (a), the object 100 is subjected to finishing processing. Specifically, the support 7 is moved by the movement mechanism 5 and the laser processing head 10A is moved by the movement mechanism 6 so that the light converging portion (2 nd light converging portion) 14 of the laser processing head 10A is positioned above the line M3 and the 1 st light converging point P1 (hereinafter also simply referred to as "light converging point P1") of the laser light L1 is positioned on the line M3. The moving mechanism 5 rotates the support 7 at a constant rotational speed about a rotational axis C (hereinafter also referred to as "axis C") and emits the laser beam L1 from the laser processing head 10A while locating the converging point P1 of the laser beam L1 at a position on the line M3. The irradiation of the laser beam L1 as described above is repeated while changing the position of the converging point P1 in the Z direction. As a result, as shown in fig. 43 b, before the peeling process, the modified region 43 is formed along the line M3 (see fig. 41) at a portion of the object 100 on the opposite side of the laser light incident surface from the virtual plane M1 (see fig. 41). In the trimming of the object 100, the optical axis of the light converging portion 14 of the laser processing head 10A is along the Z direction, and the 2 nd main surface 100b of the object 100 is the plane on which the laser light L1 is incident.

Next, as shown in fig. 42 and 44 (a), the effective portion RR of the object 100 is subjected to peeling processing. Specifically, the laser processing head 10A is moved by the moving mechanism 6 so that the converging point P1 moves in the Y direction from the outside to the inside in the 1 st region M1a (see fig. 41) of the virtual plane M1 while the support 7 is rotated at a constant rotation speed about the axis C by the moving mechanism 5 and the laser light L1 is emitted from the laser processing head 10A. As shown in fig. 44 b and c, the modified region 4 extending in a spiral shape (involute shape) is formed along the 1 st region M1a (see fig. 41) in the object 100. In the peeling process of the effective portion RR of the object 100, the optical axis of the light-collecting portion 14 of the laser processing head 10A is along the Z direction, and the 2 nd main surface 100b of the object 100 is the plane on which the laser light L1 is incident. As described above, in the peeling process of the effective portion RR of the object 100, the support portion 7, the laser processing head 10A, and the plurality of moving mechanisms 5,6 are controlled by the control portion 9 so that the modified region 4 is formed along the 1 st region M1a inside the effective portion RR in a state where the optical axis of the light converging portion 14 of the laser processing head 10A is along the Z direction.

Next, as shown in fig. 45 and 46, peeling processing is performed on the peripheral edge portion EE of the object 100. Specifically, the direction in which the laser processing head 10B is directed is changed by the moving mechanism 6 so that the optical axis of the light converging portion 14 of the laser processing head 10B is in a state along the Y direction, and as shown in fig. 41 and 47, the support portion 7 is moved by the moving mechanism 5 and the laser processing head 10B is moved by the moving mechanism 6 so that the light converging point P2 of the laser beam L2 is located at the position on the 2 nd region M1B of the virtual plane M1. The laser beam L2 is emitted from the laser processing head 10B in a state where the converging point P2 of the laser beam L2 is located at the 2 nd region M1B while the support 7 is rotated at a constant rotation speed by the moving mechanism 5 about the axis C as the center line. In this way, the modified region 4a is formed along the 2 nd region M1b inside the peripheral edge portion EE. From the modified region 4a, the crack 4b is extended inward (i.e., along the modified region 4 side of the 1 st region M1 a) and outward (i.e., along the side surface EE1 side of the object 100).

In the peeling process of the peripheral edge portion EE of the object 100, the optical axis of the light collecting portion 14 of the laser processing head 10B is along the Y direction, and the side face EE1 of the object 100 is the plane on which the laser light L2 is incident. As shown in fig. 46 and 47, the side surface EE1 is a surface perpendicular to the 1 st main surface 100a and the 2 nd main surface 100b (a perpendicular surface when viewed from a direction parallel to the 1 st main surface 100a and the 2 nd main surface 100 b) among the side surfaces intersecting the 1 st main surface 100a and the 2 nd main surface 100 b. The side face EE2 is a chamfer formed between the 1 st main face 100a and the side face EE1 and between the 2 nd main face 100b and the side face EE1, for example, a circular arc shape protruding outward, among the side faces intersecting the 1 st main face 100a and the 2 nd main face 100 b. Side EE1 and side EE2 are included in the peripheral portion EE. In the present embodiment, the side surfaces EE1, EE2 constitute inclined surface portions.

As described above, in the peeling process of the peripheral edge portion EE of the object 100, the support portion 7, the laser processing head 10B, and the plurality of moving mechanisms 5,6 are controlled by the control portion 9 so that the modified region 4a is formed in the peripheral edge portion EE in a state where the optical axis of the light converging portion 14 of the laser processing head 10B is along the Y direction. The movement mechanism 5 is controlled by the control unit 9 so that the support unit 7 is rotated about an axis C perpendicular to the 2 nd main surface 100B of the object 100 with the optical axis of the light converging unit 14 of the laser processing head 10B along the Y direction. In a state where the optical axis of the light collecting portion 14 of the laser processing head 10B is along the Y direction, the polarization direction of the laser beam L2 emitted from the light collecting portion 14 of the laser processing head 10B is a direction along which the light collecting point P2 of the laser beam L2 moves relative to the object 100.

Next, as shown in fig. 48 a, a part of the object 100 is peeled off with the modified region extending over the virtual plane M1 (see fig. 41) and the crack extending from the modified region as boundaries. At the same time, the peripheral edge portion EE is removed with the modified region along the line M3 (see fig. 41) and the crack extending from the modified region as boundaries. The peeling of a part of the object 100 and the removal of the peripheral edge portion EE can be performed using, for example, an adsorbent. The peeling of a part of the object 100 may be performed on the support 7 or may be performed by moving the support to a peeling dedicated area. The peeling of a part of the object 100 may be performed by air blowing (air blow) or an adhesive tape. When the object 100 cannot be peeled off by the external stress alone, the modified regions 4 and 43 can be selectively etched by an etching solution (KOH, TMAH, or the like) that reacts with the object 100. Thus, the object 100 can be easily peeled off. The support portion 7 is rotated at a constant rotation speed, but the rotation speed may be changed. For example, the rotational speed of the support portion 7 may be changed so that the pitch of the modified spots included in the modified regions 4 becomes constant.

Next, as shown in fig. 48 (b), the peeled surface 100h of the object 100 is ground by finish machining or by polishing with a polishing material such as a grindstone. When the object 100 is peeled off by etching, the polishing can be simplified. As a result of the above, the semiconductor device 100k is obtained.

In the general peeling process, the pitch of the plurality of modified spots SA included in the modified region 4 to be formed is narrowed, and the object 100 may be peeled by filling the modified spots SA on the virtual plane M1, which is a predetermined surface to be peeled. In this case, as the processing conditions, conditions are selected under which cracks are less likely to spread from the modified spots SA (for example, the wavelength of the laser is a short wavelength (1028 nm), the pulse width is 50nsec, and the pulse pitch is 1 to 10 μm (particularly 1.5 to 3.5 μm)). In contrast, in the present embodiment, as the processing conditions, conditions for extending the crack along the virtual plane M1 are selected. For example, the processing conditions for the 1 st laser light L1 for forming the modified region 4 along the 1 st region M1a of the virtual plane M1 are selected as follows: the 1 st laser light L1 has a long wavelength (e.g., 1099 nm) and a pulse width of 700nsec.

[ action and Effect ]

In the laser processing apparatus 1A, the modified region 4a is formed in the peripheral edge portion EE of the object 100 by emitting the laser light L2 from the light-collecting portion 14 of the laser processing head 10B while collecting the laser light L2 in a state in which the optical axis of the light-collecting portion 14 of the laser processing head 10B is along the Y direction intersecting the direction perpendicular to the 2 nd main surface 100B of the object 100. As described above, even when the side surfaces EE1, EE2 of the object 100 include chamfered surfaces for improving strength, the laser light L2 can be appropriately condensed in the peripheral edge portion EE including the side surfaces EE1, EE2 in the object 100. As described above, according to the laser processing apparatus 1A, the modified region 4a can be formed with high accuracy in the peripheral edge portion EE of the object 100.

Fig. 49 (a) is a sectional view showing a peripheral portion of the object, and fig. 49 (b) is a sectional view showing an enlarged portion of fig. 49 (a). In the example shown in fig. 49 (a) and (b), the object is a silicon wafer, and the peripheral edge portion is a bevel portion. The width of the inclined surface portion in the horizontal direction (direction parallel to the main surface of the silicon wafer) is about 200 to 300 μm, and the width of the inclined surface portion in the vertical direction (direction perpendicular to the main surface of the silicon wafer) of the side surfaces constituting the inclined surface portion is about 100 μm. In the example shown in fig. 49 (a) and (b), a plane perpendicular to the main surface of the silicon wafer among the side surfaces constituting the inclined surface portion is a laser light incident plane, and laser light is condensed in the horizontal direction from the outside of the inclined surface portion toward the inside of the inclined surface portion. As a result, a modified region and cracks extending in the horizontal direction from the modified region inward and outward are formed in the peripheral portion. The crack extension was about 120. Mu.m.

In the laser processing apparatus 1A, the laser light L1 is emitted from the light collecting portion 14 of the laser processing head 10A while being collected in a state in which the optical axis of the light collecting portion 14 of the laser processing head 10A is along the Z direction perpendicular to the 2 nd main surface 100b of the object 100, whereby the modified region 4 is formed along the virtual plane M1 inside the effective portion RR of the object 100. In this way, the modified region 4 can be formed precisely along the virtual plane M1 in the effective portion RR of the object 100.

In the laser processing apparatus 1A, the support 7 is rotated about the axis C perpendicular to the 2 nd main surface 100B with the optical axis of the light converging portion 14 of the laser processing head 10B along the Y direction, so that the modified region 4a is formed in the peripheral edge portion EE of the object 100. In this way, the modified region 4a can be efficiently formed inside the peripheral edge portion EE of the object 100.

In the laser processing apparatus 1A, the polarization direction of the laser beam L2 emitted from the light collecting section 14 of the laser processing head 10B is a direction along which the light collecting point P2 of the laser beam L2 moves relative to the object 100 in a state in which the optical axis of the light collecting section 14 of the laser processing head 10B is along the Y direction. In this way, the extension amount of the crack 4b extending from the modified region 4a toward the direction parallel to the 2 nd main surface 100b of the object 100 can be increased in the peripheral edge portion EE of the object 100.

In the modification described above, for example, the moving mechanisms 5,6 may be configured to move at least 1 of the support portion 7 and the laser processing head 10A. Similarly, the moving mechanisms 5,6 may be configured to move at least 1 of the support portion 7 and the laser processing head 10B.

The support 7, the laser processing head 10B, and the movement mechanisms 5,6 may be controlled by the control unit 9 so that the modified region 4 is formed along the virtual plane M1 inside the effective portion RR of the object 100 in a state where the optical axis of the light converging portion 14 of the laser processing head 10B is along the Z direction. As described above, the modified region 4 can be formed with high accuracy along the virtual plane M1 in the interior of the effective portion RR of the object 100 together with or instead of the laser processing head 10A.

The laser processing head 10B may be configured such that the laser processing device 1A does not include the laser processing head 10A when the object 100 is formed with the optical axis of the light converging portion 14 along the Z direction and the optical axis of the light converging portion 14 along the Y direction.

Furthermore, the laser processing head 10B may also be dedicated to implementation: the modified region 4a is formed in the peripheral edge portion EE of the object 100 with the optical axis of the light converging portion 14 extending in the Y direction. In this case, when the laser processing apparatus 1A is dedicated to forming the modified region 4a at the peripheral edge portion EE of the object 100, the laser processing apparatus 1A may not be provided with the laser processing head 10A.

In the laser processing apparatus 1A, as shown in fig. 50, the laser light L2 may be emitted from the light collecting portion 14 of the laser processing head 10B while being collected while the light axis of the light collecting portion 14 of the laser processing head 10B is directed in a direction other than the Y direction, which is a direction intersecting the direction perpendicular to the 2 nd main surface 100B of the object 100 (i.e., the Z direction), so that the modified region 4a is formed in the peripheral edge portion EE of the object 100. In this way, the optical axis angle of the light converging portion 14 of the laser processing head 10B can be adjusted so that the laser light L2 is properly converged inside the peripheral edge portion EE in accordance with the shape of the side surfaces EE1, EE2 constituting the peripheral edge portion EE, or the like. The optical axis of the light converging portion 14 of the laser processing head 10B intersects the direction perpendicular to the 2 nd main surface 100B of the object 100 (the 1 st direction intersecting the direction perpendicular to the surface of the object), for example, a direction forming an angle of 10 to 90 ° with respect to the direction perpendicular to the 2 nd main surface 100B of the object 100 or a direction forming an angle of 30 to 90 ° with respect to the direction perpendicular to the 2 nd main surface 100B of the object 100.

In the above embodiment, the peeling process is performed on the peripheral edge portion EE of the object 100 after the peeling process is performed on the effective portion RR of the object 100, but the peeling process may be performed on the effective portion RR of the object 100 after the peeling process is performed on the peripheral edge portion EE of the object 100. In the above embodiment, the 2 nd main surface 100b of the object 100 is the laser light incident surface, but the 1 st main surface 100a of the object 100 may be the laser light incident surface. The laser processing device 1A can also be applied to processing such as ablation.

The type of the object 100, the shape of the object 100, the size of the object 100, the number and direction of crystal orientations of the object 100, and the plane orientation of the main surface of the object 100 are not particularly limited. The modified region may be a crystal region, a recrystallized region, a gettering region, or the like formed in the object 100. The crystal region is a region in which the structure of the object 100 before processing is maintained. The recrystallization region is a region which becomes single crystal or polycrystalline and solidifies upon resolidification after evaporation, plasma or melting. The gettering region is a region in which impurities such as heavy metals are collected and trapped to exert a gettering effect.

The respective configurations in the above embodiments and modifications are not limited to the above materials and shapes, and various materials and shapes can be used. The above-described embodiments and modifications can be applied to any other embodiments and modifications.

[ description of the symbols ]

1,101 laser processing apparatus

4,43 modified region

6,300 moving mechanism

9 control part

10A,10B laser processing head (irradiation portion)

Distance measuring sensor (circumference monitor)

100 object(s)

100a surface

100b back side (laser incident side)

100X inclined surface peripheral portion (part 1)

100Y inner peripheral portion (part 2)

107 carrier (support)

111 GUI (input part)

BB inclined plane part (peripheral edge part)

E1:1st direction

E2:2 nd direction

IR imaging unit (imaging section, processing state monitoring section)

L1:1st laser (laser)

L2:2nd laser (laser)

M1 imaginary plane

M11:line (processing line)

M11a parallel line

M12 line (parallel line, processing line)

M20:line (processing line)

P1:1st focal point (focal point)

SA, modified dot.

Claims

1. A laser processing apparatus, wherein,

a laser processing apparatus for forming a modified region along a virtual plane in an object by irradiating a laser beam on the object, wherein the object includes a peripheral portion having a side surface intersecting a laser beam incident surface,

The laser processing device is provided with:

a support section for supporting the object;

an irradiation unit that irradiates the object supported by the support unit with the laser beam;

a moving mechanism that moves at least one of the support portion and the irradiation portion so as to move a position of a converging point of the laser light along the virtual plane; and

a control unit for controlling the support unit, the irradiation unit, and the movement mechanism,

the control part is provided with a control part,

along a processing line extending spirally inward from the peripheral edge portion of the object, irradiating the object with the laser beam under a condition that the processing state is a completely cut-off state, forming the modified region extending spirally inward from the peripheral edge portion of the object,

the cut-and-fully-cut state is a state in which cracks extending from a plurality of modified spots included in the modified region are stretched and connected in a direction along and intersecting the processing line.

2. The laser processing apparatus according to claim 1, wherein,

the control section is adapted to perform,

a 1 st processing step of irradiating the 1 st portion including the peripheral portion with the laser light under 1 st processing conditions;

A 2 nd processing step of irradiating a 2 nd portion of the object, which is located further inward than the 1 st portion, with the laser light under a 2 nd processing condition after the 1 st processing step,

the 1 st processing condition is a condition that a processing state after the 1 st prescribed amount of laser processing becomes the cutting complete cutting state,

the 2 nd processing condition is a condition that a processing state after the laser processing of the 2 nd predetermined amount more than the 1 st predetermined amount becomes the cut-complete-cutting state.

3. A laser processing method, wherein,

a laser processing method for forming a modified region along a virtual plane in an object by irradiating a laser beam on the object, wherein the object includes a peripheral portion having a side surface intersecting a laser beam incident surface,

the laser processing method includes:

a step of irradiating the object with the laser beam along a processing line extending spirally inward from the peripheral edge portion of the object under a condition that the processing state is a completely cut state, thereby forming the modified region extending spirally inward from the peripheral edge portion of the object,

4. The laser processing method according to claim 3, wherein,

the step of forming the modified region extending in a spiral shape includes: