CN114074217A

CN114074217A - Laser processing apparatus

Info

Publication number: CN114074217A
Application number: CN202110957529.2A
Authority: CN
Inventors: 荻原孝文
Original assignee: Hamamatsu Photonics KK
Current assignee: Hamamatsu Photonics KK
Priority date: 2020-08-20
Filing date: 2021-08-19
Publication date: 2022-02-22
Also published as: TW202224823A; KR20220023294A; JP7487045B2; JP2022035132A

Abstract

The invention provides a laser processing device, which can shorten processing time when a modified region is formed in an object along each of a plurality of lines. The laser processing apparatus includes a control unit. The control unit controls the spatial light modulator so that the laser beam is split into first processing light and second processing light, a first convergence point of the first processing light is located on a first line, a second convergence point of the second processing light is located on a second line, and controls the moving unit so that an irradiation area of the light for distance measurement, the first convergence point, and the second convergence point are relatively moved along the first line and the second line, and further controls the driving unit so that the first convergence point and the second convergence point are located at predetermined positions with respect to a surface of the object. The distance measuring unit is configured to be capable of adjusting the position of the irradiation region in the Y direction by at least the interval between the first line and the second line.

Description

Laser processing apparatus

Technical Field

The present disclosure relates to a laser processing apparatus.

Background

As a laser processing apparatus for irradiating a laser beam onto an object to form a modified region in the object, there is known an apparatus for modulating the laser beam to split the laser beam into a plurality of processing beams and converging the plurality of processing beams at different locations (for example, refer to japanese patent application laid-open nos. 2015-223620 and 2015-226012). Such a laser processing apparatus is very effective in shortening the processing time because it can form a plurality of modified regions in a plurality of rows by a plurality of processing beams.

Disclosure of Invention

For example, in an object including a substrate and a plurality of functional elements arranged in a matrix on the substrate, the miniaturization of the functional elements is in progress. With the progress of the refinement of the functional elements, the number of lines (cutting lines) for cutting the object for each functional element increases, and therefore, how to efficiently form the modified region in the object along each of the plurality of lines becomes important in shortening the processing time.

An object of the present disclosure is to provide a laser processing apparatus capable of shortening a processing time in a case where a modified region is formed in an object along each of a plurality of lines.

One aspect of the present disclosure provides a laser processing apparatus that forms a modified region in an object along a first line and a second line, respectively, by irradiating laser light to the object, wherein the object has a surface intersecting a Z direction, the first line and the second line extend in an X direction perpendicular to the Z direction and are adjacent in a Y direction perpendicular to both the Z direction and the X direction, the laser processing apparatus comprising: a support portion for supporting an object; a light source for emitting laser light; a spatial light modulator for modulating laser light emitted from the light source; a light-condensing unit that condenses the laser light modulated by the spatial light modulator; a distance measuring unit that irradiates light for distance measurement to a surface and detects light for distance measurement reflected by the surface; a moving part for moving the light-condensing part and the distance-measuring part relative to the support part; a drive unit for moving the light-condensing unit in the Z direction; and a control unit that controls the spatial light modulator so that the laser beam is split into first processing light and second processing light, a first convergence point of the first processing light is located on a first line, a second convergence point of the second processing light is located on a second line, and controls the moving unit so that an irradiation area of the distance measuring light on the surface, the first convergence point, and the second convergence point are relatively moved along the first line and the second line, and the driving unit is controlled based on a detection result of the distance measuring unit on the distance measuring light so that the first convergence point and the second convergence point are respectively located at predetermined positions with respect to the surface, and the distance measuring unit is configured to be capable of adjusting a position of the irradiation area in a Y direction by an amount of at least an interval between the first line and the second line.

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 structural diagram of an optical system of the laser processing head shown in fig. 3.

Fig. 6 is a cross-sectional view of a portion of the spatial light modulator shown in fig. 5.

Fig. 7 is a plan view of an object to be processed by the laser processing apparatus shown in fig. 1.

Fig. 8 is a cross-sectional view of a part of the object shown in fig. 7.

Fig. 9 is a schematic view showing a state of laser processing in the laser processing apparatus shown in fig. 1.

Fig. 10 is a schematic view showing a state of laser processing in the laser processing apparatus shown in fig. 1.

Fig. 11 is a structural diagram of a display portion of the laser processing apparatus shown in fig. 1.

Fig. 12 is a flowchart of a laser processing method performed by the laser processing apparatus shown in fig. 1.

Fig. 13 is a schematic diagram showing a positional relationship among the reference line, the first line, and the second line in the laser processing apparatus shown in fig. 1.

Fig. 14 is a schematic diagram showing a positional relationship among the reference line, the first line, and the second line in the laser processing apparatus shown in fig. 1.

Fig. 15 is a schematic diagram showing a configuration of a laser processing apparatus according to a modification.

Fig. 16 is a schematic diagram showing a positional relationship among the reference line, the first line, and the second line in the laser processing apparatus shown in fig. 15.

Fig. 17 is a schematic view showing a positional relationship among the reference line, the first line, and the second line in the laser processing apparatus shown in fig. 15.

Fig. 18 is a schematic view showing a positional relationship among the reference line, the first line, and the second line in the laser processing apparatus shown in fig. 1.

Fig. 19 is a schematic diagram showing a positional relationship among the reference line, the first line, and the second line in the laser processing apparatus shown in fig. 15.

Fig. 20 is a structural diagram of a display unit in the case shown in fig. 18 and 19.

Detailed Description

Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and redundant description thereof will be omitted.

[ Structure of laser processing apparatus ]

As shown in fig. 1, the laser processing apparatus 1 includes a plurality of

moving mechanisms

5, 6, a support 7, a pair of

laser processing heads

10A, 10B, a light source unit 8, and a control unit 9. Hereinafter, the first direction is referred to as a Z direction, the second direction perpendicular to the first direction is referred to as an X direction, and the third direction perpendicular to both the first direction and the second direction is referred to as a Y direction. In the present embodiment, the Z direction is a vertical direction, and the X direction and the Y direction are horizontal directions.

The moving mechanism 5 has a fixed portion 51, a moving portion 53, and a mounting portion 55. The fixing portion 51 is attached to the apparatus frame 1 a. The moving unit 53 is attached to a rail provided on the fixed unit 51 and is movable in the Y direction. The mounting portion 55 is mounted on a rail provided on the moving portion 53 and is movable in the X direction.

The moving mechanism 6 includes a fixed portion 61, a pair of moving

portions

63 and 64, and a pair of

mounting portions

65 and 66. The fixing portion 61 is attached to the apparatus frame 1 a. The pair of moving

portions

63 and 64 are respectively attached to rails provided on the fixed portion 61 and are independently movable in the Y direction. The mounting portion 65 is mounted on a rail provided on the moving portion 63 and is movable in the Z direction. The mounting portion 66 is mounted on a rail provided on the moving portion 64 and is movable in the Z direction.

The support portion 7 is attached to a rotary shaft provided in the attachment portion 55 of the moving mechanism 5, and the support portion 7 is rotatable about an axis parallel to the Z direction as a center line. The support portion 7 supports the object 100. The object 100 is a wafer.

As shown in fig. 1 and 2, the laser processing head 10A is attached to an attachment portion 65 of the moving mechanism 6. The laser processing head 10A faces the support 7 in the Z direction, and in this state, irradiates the object 100 supported by the support 7 with the laser light L. The laser processing head 10B is attached to the attachment 66 of the moving mechanism 6. The laser processing head 10B faces the support 7 in the Z direction, and in this state, irradiates the object 100 supported by the support 7 with the laser light L.

The light source unit 8 has a pair of

light sources

81, 82. A pair of

light sources

81, 82 is mounted on the apparatus frame 1 a. The pair of

light sources

81 and 82 emit laser light L. The laser light L emitted from the emission portion 81a of the light source 81 is guided to the laser processing head 10A by the optical fiber 2. The laser light L emitted from the emission portion 82a of the light source 82 is guided to the laser processing head 10B by the other optical fiber 2.

The control unit 9 controls each part (the plurality of

moving mechanisms

5 and 6, the pair of

laser processing heads

10A and 10B, the light source unit 8, and the like) of the laser processing apparatus 1. The control unit 9 is a computer device including a processor, a memory, a storage, a communication device, and the like. In the control section 9, software (program) read into a memory or the like is executed by a processor, and the processor controls reading and writing of data on the memory and the storage and communication of the communication device. Thereby, the control unit 9 can realize various functions.

An example of the processing performed by the laser processing apparatus 1 configured as described above will be described. One example of such processing is an example in which a modified region is formed inside the object 100 along each of a plurality of lines set in a lattice shape in order to cut the object 100, which is a wafer, into a plurality of chips.

First, the moving mechanism 5 moves the support 7 in the X direction and the Y direction, respectively, so that the support 7 supporting the object 100 faces the pair of

laser processing heads

10A and 10B in the Z direction. Next, the moving mechanism 5 rotates the support 7 about an axis parallel to the Z direction as a center line so that a plurality of lines extending in one direction on the object 100 are along the X direction.

Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction so that the converging point of the laser light L emitted from the laser processing head 10A (hereinafter referred to as "laser light L of the laser processing head 10A") is positioned on one 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 a convergence point of the laser light L emitted from the laser processing head 10B (hereinafter referred to as "laser light L of the laser processing head 10B") is positioned on another line extending in 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 L of the laser processing head 10A is positioned 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 L of the laser processing head 10B is positioned inside the object 100.

Next, the light source 81 emits the laser beam L, and the laser processing head 10A irradiates the object 100 with the laser beam L, and the light source 82 emits the laser beam L, and the laser processing head 10B irradiates the object 100 with the laser beam L. At the same time, the moving mechanism 5 moves the support 7 in the X direction so that the convergence point of the laser light L of the laser processing head 10A relatively moves along one line extending in one direction, and the convergence point of the laser light L of the laser processing head 10B relatively moves along another line extending in one direction. In this way, the laser processing apparatus 1 can form the reformed region inside the object 100 along each of a plurality of lines extending in one direction on the object 100.

Next, the moving mechanism 5 rotates the support 7 about an axis parallel to the Z direction as a center line, and causes a plurality of lines extending in the other direction orthogonal to the one direction on the object 100 to be along the X direction.

Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction so that the converging point of the laser light L of the laser processing head 10A 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 convergence point of the laser light L of the laser processing head 10B is located on another line extending in another 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 L of the laser processing head 10A is positioned 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 L of the laser processing head 10B is positioned inside the object 100.

Next, the light source 81 emits the laser beam L, and the laser processing head 10A irradiates the object 100 with the laser beam L, and the light source 82 emits the laser beam L, and the laser processing head 10B irradiates the object 100 with the laser beam L. At the same time, the moving mechanism 5 moves the support 7 in the X direction so that the convergence point of the laser light L of the laser processing head 10A relatively moves along one line extending in the other direction, and the convergence point of the laser light L of the laser processing head 10B relatively moves along the other line extending in the other direction. In this way, the laser processing apparatus 1 can form the reformed region in the object 100 along each of a plurality of lines extending in the other direction orthogonal to the one direction on the object 100.

In one example of the above processing, the pair of

light sources

81 and 82 emit the laser light L having transmissivity to the object 100 by, for example, a pulse oscillation method. When such laser light L is condensed inside the object 100, the laser light L is absorbed particularly much in a portion corresponding to the condensing point of the laser light L, and a reformed region is formed inside the object 100. The modified region is a region having a density, refractive index, mechanical strength, and other physical properties different from those of the surrounding non-modified region. Examples of the modified region include a melt-processed region, a crack region, an insulation breakdown region, and a refractive index change region.

When the object 100 is irradiated with the laser light L emitted by the pulse oscillation method and the converging point of the laser light L is relatively moved along a line set on the object 100, a plurality of modified points are formed so as to be aligned in a row along the line. A modified spot is formed by irradiation of one pulse of the laser light L. A row of modification regions is a collection of modification points arranged in a row. Depending on the relative movement speed of the converging point of the laser light L with respect to the object 100 and the pulse repetition frequency of the laser light L, adjacent modified points may be connected to each other or separated from each other.

[ Structure of laser processing head ]

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

The housing 11 includes first and

second wall portions

21 and 22, third and

fourth wall portions

23 and 24, and fifth and

sixth wall portions

25 and 26. The first wall portion 21 and the second wall portion 22 are opposed to each other in the X direction. The third wall portion 23 and the fourth wall portion 24 face each other in the Y direction. The fifth wall portion 25 and the sixth wall portion 26 are opposed to each other in the Z direction.

The distance between the third wall portion 23 and the fourth wall portion 24 is smaller than the distance between the first wall portion 21 and the second wall portion 22. The distance between the first wall portion 21 and the second wall portion 22 is smaller than the distance between the fifth wall portion 25 and the sixth wall portion 26. The distance between the first wall portion 21 and the second wall portion 22 may be equal to the distance between the fifth wall portion 25 and the sixth wall portion 26, or may be greater than the distance between the fifth wall portion 25 and the sixth wall portion 26.

In the laser processing head 10A, the first wall portion 21 is located on the opposite side of the fixed portion 61 of the movement mechanism 6, and the second wall portion 22 is located on the fixed portion 61 side. The third wall portion 23 is located on the side of the mounting portion 65 of the moving mechanism 6, and the fourth wall portion 24 is located on the side opposite to the mounting portion 65, that is, on the side of the laser processing head 10B (see fig. 2). The fifth wall portion 25 is located on the opposite side of the support portion 7, and the sixth wall portion 26 is located on the support portion 7 side.

The housing 11 is configured such that the housing 11 is attached to the attachment portion 65 of the moving mechanism 6 in a state where the third wall portion 23 is disposed on the attachment portion 65 side. The details are as follows. The mounting portion 65 includes a bottom plate 65a and a mounting plate 65 b. The bottom plate 65a is mounted on a rail provided in the moving portion 63 (see fig. 2). The mounting plate 65B is provided upright on the end portion of the base plate 65a on the laser processing head 10B side (see fig. 2). The housing 11 is mounted to the mounting portion 65 by screwing the bolt 28 to the mounting plate 65b via the base 27 in a state where the third wall portion 23 is in contact with the mounting plate 65 b. The bases 27 are provided on the first wall portion 21 and the second wall portion 22, respectively. The housing 11 is detachable from the mounting portion 65.

The incident portion 12 is disposed on the fifth wall portion 25. The incident unit 12 causes the laser beam L to enter the housing 11. The incident portion 12 is biased toward the first wall portion 21 in the X direction and biased toward the fourth wall portion 24 in the Y direction. That is, the distance between the incident portion 12 and the first wall member 21 in the X direction is smaller than the distance between the incident portion 12 and the second wall member 22 in the X direction, and the distance between the incident portion 12 and the fourth wall member 24 in the Y direction is smaller than the distance between the incident portion 12 and the third wall member 23 in the X direction.

The incident portion 12 is connected to the emission end portion 2a of the optical fiber 2. Specifically, incident portion 12 is a portion including hole 25a formed in fifth wall 25. The fifth wall portion 25 is provided with a mounting portion 25 b. The main body portion 2b of the emission end portion 2a is attached to the attachment portion 25b by a bolt or the like. In this state, the front end portion 2c of the exit end portion 2a is inserted into the hole 25 a. Thereby, the output end portion 2a of the optical fiber 2 is detachable from the incident portion 12. A cover 25c is disposed between the fifth wall portion 25 and the main body portion 2 b. The cover 25c covers a gap formed between the hole 25a and the front end portion 2 c. As an example, in the emission end portion 2a, a spacer for suppressing the return light is disposed in the main body portion 2b, and a collimator lens for collimating the laser light L is disposed in the tip end portion 2 c. The incident portion 12 may be a connector or the like to which the output end portion 2a of the optical fiber 2 can be connected.

The laser adjustment unit 13 is disposed in the housing 11. The laser light adjustment unit 13 adjusts the laser light L incident from the incident unit 12. The laser light adjustment unit 13 is disposed on the fourth wall portion 24 side with respect to the partition wall portion 29 in the housing 11. The laser adjustment unit 13 is mounted on the partition wall 29. The partition wall 29 is provided in the housing 11, and partitions an area in the housing 11 into an area on the third wall 23 side and an area on the fourth wall 24 side. The partition wall 29 is a part of the housing 11. The respective components of the laser adjustment unit 13 are attached to the partition wall 29 on the fourth wall 24 side. The partition wall 29 functions as an optical base for supporting the respective structures of the laser light adjuster 13.

The light-condensing portion 14 is disposed on the sixth wall portion 26. Specifically, the light converging portion 14 is disposed on the sixth wall 26 in a state of being inserted into a hole 26a (see fig. 5) formed in the sixth wall 26. The light condensing unit 14 condenses the laser light L adjusted by the laser light adjusting unit 13 and emits the condensed laser light L to the outside of the housing 11. The light-condensing portion 14 is biased toward the second wall portion 22 in the X direction and biased toward the fourth wall portion 24 in the Y direction. That is, the distance between the light-condensing portion 14 and the second wall portion 22 in the X direction is smaller than the distance between the light-condensing portion 14 and the first wall portion 21 in the X direction, and the distance between the light-condensing portion 14 and the fourth wall portion 24 in the Y direction is smaller than the distance between the light-condensing portion 14 and the third wall portion 23 in the X direction.

As shown in fig. 5, the laser light adjustment section 13 includes a reflection section 31, an attenuator 32, and a reflection section 33. The reflection unit 31, the attenuator 32, and the reflection unit 33 are arranged on a first straight line a1 extending in the X direction. The reflection portion 31 faces the incident portion 12 in the Z direction. That is, the reflection portion 31 faces the emission end portion 2a of the optical fiber 2 in the Z direction. The reflection unit 31 reflects the laser light L incident from the incident unit 12 toward the second wall 22. The attenuator 32 adjusts the output of the laser light L reflected by the reflection unit 31. The reflection unit 33 reflects the laser light L whose output is adjusted by the attenuator 32 toward the sixth wall 26. Each of the

reflection portions

31 and 33 is, for example, a mirror or a prism.

The laser light adjustment section 13 further includes a beam expander 34 and a reflection section 35. The reflection unit 33, the beam expander 34, and the reflection unit 35 are arranged on a second straight line a2 extending in the Z direction. The beam expander 34 expands the diameter of the laser light L reflected by the reflecting member 33. The reflection portion 35 reflects the laser light L whose diameter is expanded by the beam expander 34 to the first wall portion 21 side and the fifth wall portion 25 side. The reflection unit 35 is, for example, a mirror or a prism.

The laser light adjustment section 13 further includes a spatial light modulator 36 and an imaging optical system 37. The spatial light modulator 36, the imaging optical system 37, and the light condensing portion 14 are arranged on a third straight line a3 extending along the Z direction. The spatial light modulator 36 modulates the laser light L reflected by the reflection unit 35 and reflects the modulated laser light L to the sixth wall 26 side. The Spatial Light Modulator 36 is a reflective Spatial Light Modulator (SLM). The imaging optical system 37 is configured as a double-sided telecentric optical system in which the reflection surface 36a of the spatial light modulator 36 and the entrance pupil surface 14a of the light condensing portion 14 are in an imaging relationship. The imaging optical system 37 is composed of three or more lenses. In this way, the spatial light modulator 36 modulates the laser light L emitted from the light source 81 (see fig. 1), and the condensing unit 14 condenses the laser light L modulated by the spatial light modulator 36.

The first straight line a1, the second straight line a2, and the third straight line A3 are located on a plane perpendicular to the Y direction. The second straight line a2 is located on the second wall portion 22 side with respect to the third straight line A3. In the laser processing head 10A, the laser light L incident into the housing 11 from the incident portion 12 along the Z direction is reflected by the reflection portion 31 so as to travel on the first straight line a 1. The laser light L traveling on the first straight line a1 is reflected by the reflecting member 33 to travel on the second straight line a 2. The laser light L traveling on the second straight line a2 travels on the third straight line A3 by being reflected in sequence by the reflection unit 35 and the spatial light modulator 36. The laser light L traveling on the third straight line a3 exits from the light-condensing portion 14 to the outside of the housing 11 along the Z direction.

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

The dichroic mirror 15 is disposed between the imaging optical system 37 and the light collecting unit 14 on the third straight line a 3. That is, the dichroic mirror 15 is disposed between the laser light adjusting section 13 and the light collecting section 14 in the housing 11. The dichroic mirror 15 is mounted on the partition wall portion 29 on the fourth wall portion 24 side. The dichroic mirror 15 transmits the laser light L. From the viewpoint of suppressing astigmatism, for example, the dichroic mirror 15 is preferably of a cubic type or a type configured by two sheets of plates arranged in a twisted relationship, for example.

The distance measuring unit 16 is disposed on the first wall portion 21 side with respect to the first straight line a3 in the housing 11. That is, the distance measuring unit 16 is disposed on the first wall 21 side with respect to the light converging unit 14 in the X direction. The distance measuring section 16 is attached to the partition wall 29 on the fourth wall 24 side. The distance measuring unit 16 irradiates the surface of the object 100 with distance measuring light L10 (for example, distance measuring laser light) for measuring the distance between the surface of the object 100 (for example, the surface on the side on which the laser light L is incident) and the light condensing unit 14, and detects light L10 reflected on the surface of the object 100.

In the present embodiment, the distance measuring unit 16 is configured to pass light L10 to be irradiated onto the surface of the object 100 and light L10 reflected from the surface of the object 100 through the light condensing unit 14. That is, the light L10 emitted from the distance measuring unit 16 is irradiated to the surface of the object 100 by the light converging unit 14, and the light L10 reflected by the surface of the object 100 is incident on the distance measuring unit 16 by the light converging unit 14. The distance measuring unit 16 is an astigmatic sensor including a 4-quadrant photodiode as a light receiving sensor.

More specifically, the distance measuring unit 16 includes a main body 161 and an adjusting unit 162. The body 161 irradiates light L10 on the surface of the object 100 and detects light L10 reflected by the surface of the object 100. The adjusting unit 162 is a unit for adjusting the optical axis of the light L10 emitted to the surface of the object 100. The adjusting part 162 includes a first steering mirror 162a and a second steering mirror 162 b. The first steering mirror 162a and the second steering mirror 162b are mounted on the partition wall 29 on the fourth wall 24 side so that the angles of the mirror surfaces thereof are adjustable.

The light L10 emitted from the main body 161 is reflected in this order by the first steering mirror 162a, the second steering mirror 162b, the beam splitter 20, and the dichroic mirror 15, is emitted outside the housing 11 through the light collection unit 14, and is irradiated onto the surface of the object 100. The light L10 reflected by the surface of the object 100 is incident into the housing 11 through the light collecting unit 14, is sequentially reflected by the dichroic mirror 15, the beam splitter 20, the second steering mirror 162b, and the first steering mirror 162a, and is incident on the main body 161. The beam splitter 20 is attached to the partition wall 29 on the fourth wall 24 side.

The observation portion 17 is disposed on the first wall portion 21 side with respect to the third straight line a3 in the housing 11. That is, the observation unit 17 is disposed on the first wall 21 side with respect to the light converging unit 14 in the X direction. The observation portion 17 is attached to the partition wall portion 29 on the fourth wall portion 24 side. The observation unit 17 irradiates light L20 (for example, visible light) for observation to observe the surface of the object 100 (for example, the surface on the side on which the laser light L is incident) onto the surface of the object 100, and detects light L20 reflected by the surface of the object 100.

In the present embodiment, the light L20 emitted from the observation unit 17 is transmitted through the beam splitter 20, reflected by the dichroic mirror 15, emitted to the outside of the housing 11 through the light condensing unit 14, and irradiated onto the surface of the object 100. The light L20 reflected by the surface of the object 100 is incident into the housing 11 through the light collecting unit 14, reflected by the dichroic mirror 15, transmitted through the beam splitter 20, and incident on the observation unit 17. The laser light L, the light L10, and the light L20 have respective wavelengths different from each other (at least respective center wavelengths are shifted from each other).

The driving portion 18 is attached to the partition wall portion 29 on the fourth wall portion 24 side. The driving unit 18 moves the condensing unit 14 disposed on the sixth wall 26 in the Z direction by the driving force of the piezoelectric element, for example.

Circuit portion 19 is disposed on the third wall portion 23 side with respect to partition wall portion 29 in case 11. That is, the circuit unit 19 is disposed on the third wall 23 side with respect to the laser adjustment unit 13, the distance measurement unit 16, and the observation unit 17 in the housing 11. The circuit portion 19 is spaced apart from the partition wall portion 29. The circuit section 19 is, for example, a plurality of circuit boards. The circuit unit 19 processes the signal output from the distance measuring unit 16 and the signal to be input to the spatial light modulator 36. The circuit unit 19 controls the driving unit 18 based on the signal output from the distance measuring unit 16. For example, the circuit unit 19 controls the driving unit 18 based on the signal output from the distance measuring unit 16 so that the distance between the surface of the object 100 and the light condensing unit 14 is kept constant (that is, the distance between the surface of the object 100 and the condensing point of the laser light L is kept constant).

Further, the partition wall portion 29 is formed with a slit, a hole, or the like (not shown) through which wiring for electrically connecting the distance measuring unit 16, the observation unit 17, the drive unit 18, and the spatial light modulator 36 to the circuit portion 19, respectively, passes. The housing 11 is provided with a connector (not shown) to which wiring or the like for electrically connecting the circuit section 19 and the control section 9 (see fig. 1) is connected.

The laser processing head 10B includes a housing 11, an incident portion 12, a laser light adjusting portion 13, a light condensing portion 14, a dichroic mirror 15, a distance measuring portion 16, an observation portion 17, a driving portion 18, and a circuit portion 19, similarly to the laser processing head 10A. However, as shown in fig. 2, the respective structures of the laser processing head 10B are arranged in a plane-symmetric relationship with the respective structures of the laser processing head 10A with respect to a virtual plane passing through a midpoint between the pair of mounting

portions

65, 66 and perpendicular to the Y direction.

For example, the housing 11 of the laser processing head 10A is attached to the attachment portion 65 such that the fourth wall portion 24 is located on the laser processing head 10B side with respect to the third wall portion 23 and the sixth wall portion 26 is located on the support portion 7 side with respect to the fifth wall portion 25. On the other hand, the housing 11 of the laser processing head 10B is attached to the attachment 66 such that the fourth wall portion 24 is positioned on the laser processing head 10A side with respect to the third wall portion 23 and the sixth wall portion 26 is positioned on the support portion 7 side with respect to the fifth wall portion 25.

The housing 11 of the laser processing head 10B is configured such that the housing 11 is attached to the attachment 66 in a state where the third wall portion 23 is disposed on the attachment 66 side. The details are as follows. The mounting portion 66 includes a base plate 66a and a mounting plate 66 b. The bottom plate 66a is mounted on a rail provided on the moving portion 63. The attachment plate 66b is provided upright on the end portion of the base 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 third 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.

[ Structure of spatial light Modulator ]

As shown in fig. 6, the spatial light modulator 36 is configured by sequentially laminating a driver circuit layer 42, a pixel electrode layer 43, a reflective film 44, an alignment film 45, a liquid crystal layer 46, an alignment film 47, a transparent conductive film 48, and a transparent substrate 49 on a semiconductor substrate 41. The spatial light modulator 36 is a reflective Liquid Crystal On Silicon (LCOS) spatial light modulator.

The semiconductor substrate 41 is, for example, a silicon substrate. The drive circuit layer 42 constitutes an active matrix circuit on the semiconductor substrate 41. The pixel electrode layer 43 includes a plurality of pixel electrodes 43a arranged in a matrix along the surface of the semiconductor substrate 41. Each pixel electrode 43a is formed of a metal material such as aluminum. A voltage is applied to each pixel electrode 43a through the driving circuit layer 42.

The reflective film 44 is, for example, a dielectric multilayer film. The alignment film 45 is provided on the surface of the liquid crystal layer 46 on the side of the reflective film 44, and the alignment film 47 is provided on the surface of the liquid crystal layer 46 on the side opposite to the reflective film 44. Each of the

alignment films

45 and 47 is formed of a polymer material such as polyimide, for example, and a rubbing treatment is performed on the surface of each of the

alignment films

45 and 47 that is in contact with the liquid crystal layer 46, for example. The

alignment films

45 and 47 align liquid crystal molecules 46a included in the liquid crystal layer 46 in a predetermined direction.

The transparent conductive film 48 is provided on the surface of the transparent substrate 49 on the alignment film 47 side, and faces the pixel electrode layer 43 with the liquid crystal layer 46 and the like interposed therebetween. The transparent substrate 49 is, for example, a glass substrate. The transparent conductive film 48 is formed of a light-transmitting conductive material such as ITO. The transparent substrate 49 and the transparent conductive film 48 transmit the laser light L.

In the spatial light modulator 36 configured as described above, when a signal indicating a modulation pattern is input from the control unit 10 to the drive circuit layer 42, a voltage corresponding to the signal is applied to each pixel electrode 43a, and an electric field is formed between each pixel electrode 43a and the transparent conductive film 48. When the electric field is generated, in the liquid crystal layer 46, the arrangement direction of the liquid crystal molecules 216a changes for each region corresponding to each pixel electrode 43a, and the refractive index changes for each region corresponding to each pixel electrode 43 a. This state is a state in which a modulation pattern is displayed on the liquid crystal layer 46.

In a state where a modulation pattern is displayed on the liquid crystal layer 46, when laser light L enters the liquid crystal layer 46 from the outside through the transparent substrate 49 and the transparent conductive film 48, is reflected by the reflective film 44, and is emitted from the liquid crystal layer 46 to the outside through the transparent conductive film 48 and the transparent substrate 49, the laser light L is modulated in accordance with the modulation pattern displayed on the liquid crystal layer 46. In this way, with the spatial light modulator 36, modulation of the laser light L (for example, modulation of the intensity, amplitude, phase, polarization, and the like of the laser light L) can be performed by appropriately setting the modulation pattern displayed on the liquid crystal layer 46.

[ Structure of object ]

As shown in fig. 7 and 8, the object 100 includes a substrate 101 and a plurality of functional elements 102. The plurality of functional elements 102 are arranged in a matrix on the substrate 101.

The substrate 101 has a front side 101a and a back side 101 b. The substrate 101 is a semiconductor substrate such as a silicon substrate. A notch 101c indicating a crystal direction is provided in the substrate 101. In addition, an orientation flat (alignment flat) may be provided on the substrate 101 instead of the groove 101 c.

A plurality of functional elements 102 are disposed on the front side 101a of the substrate 101. Each of the functional elements 102 is, 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, or the like. Each functional element 102 may have a three-dimensional structure formed by stacking a plurality of layers.

The object 100 is to be cut along each of the plurality of lines 90 by the functional element 102. The plurality of lines 90 extend in a grid pattern so as to pass between the plurality of functional elements 102 when viewed from the thickness direction of the object 100 (the direction intersecting the front surface 101a and the back surface 101 b). In the object 100, a street (street) area 103 extends in a lattice shape so as to pass through the plurality of functional elements 102, and each line 90 passes through the center of the street area 103. The plurality of lines 90 are virtual lines set on the object 100 by the laser processing apparatus 1. The plurality of lines 90 may be actually drawn on the object 100.

[ function of control section ]

As a premise, as shown in fig. 9 and 10, the laser processing apparatus 1 irradiates the object 100 having a surface (in this embodiment, the front surface 101a or the back surface 101b of the substrate 101) intersecting with the Z direction with the laser light L to form the modified regions M on the object 100 along the first line 91 and the second line 92, respectively. The first line 91 and the second line 92 are any pair of lines 90 extending in the X direction and adjacent in the Y direction among the plurality of lines 90.

In each of the laser processing heads 10A and 10B, the distance measuring unit 16 (see fig. 5) is configured to be able to adjust the position of the irradiation region R of the distance measuring light L10 by at least the distance between the first line 91 and the second line 92 in the Y direction. The irradiation region R of the light L10 is an irradiation region of the light L10 at the front surface (front surface 101a or back surface 101b of the substrate 101 in the present embodiment) of the object 100. In the present embodiment, the optical axis of the light L10 (see fig. 5) irradiated to the front surface 101a or the back surface 101b of the substrate sheet 101 is adjusted by the adjusting unit 162, and the position of the irradiation region R of the light L10 can be adjusted in the Y direction by at least the distance between the first line 91 and the second line 92.

Under the above-described premise, the function of the control unit 9 will be described below with attention paid to the first wire 91 and the second wire 92 extending in the X direction and adjacent to each other in the Y direction. In the following description, it is not explicitly described which of the pair of laser processing heads 10A and 10B is the subject to irradiate the object 100 with the laser light L, but the subject may be either one of the pair of laser processing heads 10A and 10B or both of the pair of laser processing heads 10A and 10B. In addition, the following description can be applied to all the lines 90 with the first line 91 and the second line 92 extending in the X direction and adjacent in the Y direction as a minimum unit.

As shown in fig. 9, the control unit 9 functions as follows when the object 100 is supported by the support unit 7 so that the laser light L is incident on the substrate 101 from the side of the plurality of functional elements 102 (that is, the laser light L is incident on the substrate 101 from the region corresponding to the track region 103 in the front surface 101a of the substrate 101) (hereinafter, referred to as "front surface incidence case"). The controller 9 controls the spatial light modulator 36 so that the laser light L is split into the first processing light L1 and the second processing light L2, and the first convergence point C1 of the first processing light L1 is located on the first line 91 and the second convergence point C2 of the second processing light L2 is located on the second line 92. The controller 9 controls the moving mechanism 5 (see fig. 1) so that the irradiation region R of the distance measuring light L10 on the front surface 101a and the first and second convergence points C1 and C2 move relative to each other along the first and

second lines

91 and 92. Further, the controller 9 controls the driving unit 18 (see fig. 5) based on the detection result of the light L10 by the distance measuring unit 16 such that the first convergence point C1 and the second convergence point C2 are located at predetermined positions with respect to the front surface 101a (e.g., such that the distances between the front surface 101a and the first convergence point C1 and the second convergence point C2 are maintained constant).

When the light enters from the front, the optical axis of the light L10 (see fig. 5) irradiated to the front 101a is adjusted by the adjusting unit 162, so that the irradiation region R is positioned on the first line 91 or the second line 92. The adjustment of the adjustment unit 162 may be performed manually by an operator or automatically by the control unit 9.

As shown in fig. 10, the control unit 9 functions as follows when the object 100 is supported by the support unit 7 so that the laser beam L enters the substrate 101 from the side opposite to the plurality of functional devices 102 (that is, the laser beam L enters the substrate 101 from the back surface 101b of the substrate 101) (hereinafter, referred to as "back surface incidence case"). The controller 9 controls the spatial light modulator 36 so that the laser light L is split into the first processing light L1 and the second processing light L2, and the first convergence point C1 of the first processing light L1 is located on the first line 91 and the second convergence point C2 of the second processing light L2 is located on the second line 92. The controller 9 controls the moving mechanism 5 (see fig. 1) so that the irradiation region R of the distance measuring light L10 on the back surface 101b and the first and second convergence points C1 and C2 move relative to each other along the first and

second lines

91 and 92. Further, the controller 9 controls the driving unit 18 (see fig. 5) based on the detection result of the light L10 by the distance measuring unit 16 such that the first convergence point C1 and the second convergence point C2 are located at predetermined positions with respect to the rear surface 101b (for example, the distances between the rear surface 101b and the first convergence point C1 and the second convergence point C2 are maintained constant).

When light enters the rear surface, the optical axis of the light L10 (see fig. 5) irradiated to the rear surface 101b is adjusted by the adjusting unit 162, so that the irradiation region R is positioned on the center line between the first line 91 and the second line 92 (i.e., a line equidistant from the first line 91 and the second line 92). The adjustment of the adjustment unit 162 may be performed manually by an operator or automatically by the control unit 9.

The first convergence point C1, the second convergence point C2, or the irradiation region R being located at a predetermined position (the first line 91, the second line 92, a center line between the first line 91 and the second line 92, a space between the first line 91 and the second line 92, or the like) means that the first convergence point C1, the second convergence point C2, or the irradiation region R is located at the predetermined position when viewed from the Z direction. In the above description, the moving mechanism 5 functions as a moving unit that moves the light converging unit 14 and the distance measuring unit 16 relative to the support unit 7, but the moving mechanism 6 may function as the moving unit, or a plurality of moving

mechanisms

5 and 6 may function as the moving unit (see fig. 1). The circuit section 19 (see fig. 5) provided in each of the laser processing heads 10A and 10B may function as at least a part of the control section 9.

[ operation of laser processing apparatus ]

As a premise, as shown in fig. 2, the laser processing apparatus 1 includes an imaging unit 3. The imaging unit 3 acquires an image of the object 100. The imaging unit 3 is composed of, for example, an InGaAs camera, and acquires an image of the object 100 by near infrared rays. The imaging unit 3 is attached to an attachment unit 65 of the moving mechanism 6, for example. For example, when the substrate 101 of the object 100 is a silicon substrate and the imaging unit 3 acquires an image of the object 100 based on near infrared rays, the imaging unit 3 can acquire not only images of the plurality of functional elements 102 and the trace region 103 (see fig. 7) from the side of the plurality of functional elements 102 but also an image from the side of the back surface 101b of the substrate 101.

As shown in fig. 11, the laser processing apparatus 1 includes an input receiving unit 4 including a display unit 4 a. The display unit 4a displays the image of the object 100 acquired by the imaging unit 3 as a graphic (graphic) of the object 100. The display unit 4a constitutes a gui (graphical User interface). The input receiving unit 4 also includes an input device (not shown) such as a mouse and a keyboard.

Under the above-described premise, the operation of the laser processing apparatus 1 will be described below with attention paid to the first wire 91 and the second wire 92 extending in the X direction and adjacent to each other in the Y direction. In the following description, it is not explicitly described which of the pair of laser processing heads 10A and 10B is the subject to irradiate the object 100 with the laser light L, but the subject may be either one of the pair of laser processing heads 10A and 10B or both of the pair of laser processing heads 10A and 10B. In addition, the following description can be applied to all the lines 90 with the first line 91 and the second line 92 extending in the X direction and adjacent in the Y direction as a minimum unit.

First, the object 100 is placed on the support 7. Next, as shown in fig. 11, when the operator operates the input receiving unit 4 and selects "double-split machining" on the display unit 4a, the display unit 4a displays the respective graphics of the object 100, the first line 91, the second line 92, and the reference line 93. The figure of the object 100 is an image of the object 100 acquired by the imaging unit 3. The reference line 93 is a line corresponding to a trajectory along which the optical axis of the condensing unit 14 moves relative to the object 100.

Next, when the operator operates the input receiving unit 4 and inputs a numerical value to the column of "split interval" on the display unit 4a, the display unit 4a moves the first line 91 and the second line 92 in the Y direction with the reference line 93 as the center line in the figure so that the distance between the first line 91 and the second line 92 in the figure becomes the numerical value. When the operator operates the input receiving unit 4 to move the first line 91 and the second line 92 in the Y direction about the reference line 93 as the center line in the figure, the display unit 4a displays the distance between the first line 91 and the second line 92 in the figure in the column "split interval". The numerical value of the beam splitting interval is a distance (distance in the Y direction) between the first convergence point C1 of the first processing light L1 and the second convergence point C2 of the second processing light L2. In this way, the input receiving section 4 can receive an input of "information on the positions of the first convergence point C1 and the second convergence point C2 in the Y direction, respectively" (first information). Further, in order to change the first line 91 and the second line 92 to be laser-processed, the control unit 9 controls the moving mechanism 5 based on the input numerical value of the beam splitting interval so that the light condensing unit 14 and the distance measuring unit 16 move in the Y direction by a distance 2 times the numerical value of the beam splitting interval.

Further, the operator operates the input receiving unit 4 to select "reference line", "adjust to the first line side", and "adjust to the second line side" as "distance measuring position" on the display unit 4 a. The distance measurement position is the position (position in the Y direction) of the irradiation region R of the distance measurement light L10. As in the case of front incidence shown in fig. 9, when the irradiation region R should be positioned on the first line 91 or the second line 92, the operator may simply select "adjust to the first line side" or "adjust to the second line side". As in the case of back-surface incidence shown in fig. 10, when the irradiation region R should be located on the center line between the first line 91 and the second line 92, the operator may simply select the "reference line". In this way, the input receiving section 4 can receive the input of "information on the position of the irradiation region R in the Y direction" (second information).

Next, as shown in fig. 12, the control unit 9 sequentially performs these processes: a process of determining a modulation pattern to be input to the spatial light modulator 36 based on the irradiation condition of the laser light L including the numerical value input to the column of "beam splitting interval" (step S01); a process of adjusting the position of the irradiation region R based on any one of the "reference line", "adjusted to the first line side", and "adjusted to the second line side" selected as the "distance measurement position" (step S02); and performing laser processing (step S03). In this way, the control section 9 controls the spatial light modulator 36 based on "information on the positions of the first convergence point C1 and the second convergence point C2 in the Y direction, respectively" such that the first convergence point C1 is located on the first line 91 and the second convergence point C2 is located on the second line 92. Further, the control section 9 controls the distance measuring section 16 based on the "information on the position of the irradiation region R in the Y direction" so that the irradiation region R is located on the first line 91 or the second line 92, or on the center line between the first line 91 and the second line 92.

Fig. 13 is a schematic view showing a positional relationship among the reference line 93, the first line 91, and the second line 92 when laser processing is performed by the laser processing apparatus 1 shown in fig. 1 by front incidence (see fig. 9). As shown in (a) and (b) of fig. 13, the first line 91 and the second line 92 are located on both sides of the reference line 93 in the Y direction with the reference line 93 as a center line. As shown in fig. 13 (a), the light condensing portion 14 is located on the reference line 93. As shown in fig. 13 (b), the first convergence point C1 and the irradiation region R are located on the first line 91, and the second convergence point C2 is located on the second line 92.

Fig. 14 is a schematic view showing a positional relationship among the reference line 93, the first line 91, and the second line 92 when laser processing is performed by the laser processing apparatus 1 shown in fig. 1 by back surface incidence (see fig. 10). As shown in (a) and (b) of fig. 14, the first line 91 and the second line 92 are located on both sides of the reference line 93 in the Y direction with the reference line 93 as a center line. As shown in fig. 14 (a), the light condensing portion 14 is located on the reference line 93. As shown in fig. 14 (b), the first convergence point C1 is located on the first line 91, the second convergence point C2 is located on the second line 92, and the irradiation region R is located on the reference line 93 (the center line between the first line 91 and the second line 92).

The input receiving unit 4 may receive input of "information on the incident side of the laser light L to the object 100" (third information). Also, in the case of front-side incidence as shown in fig. 9, the control section 9 controls the distance measuring section 16 based on "information on the position of the irradiation region R in the Y direction" so that the irradiation region R is positioned on the first line 91 or the second line 92. On the other hand, in the case of back-surface incidence shown in fig. 10, the control section 9 controls the distance measuring section 16 based on "information on the position of the irradiation region R in the Y direction" so that the irradiation region R is located on the center line between the first line 91 and the second line 92.

The operator may manually adjust the adjustment unit 162 so that the irradiation region R is positioned on the first line 91, the second line 92, or a center line between the first line 91 and the second line 92. In this case, the process of adjusting the position of the irradiation region R by the control unit 9 is omitted (step S02).

[ action and Effect ]

In the laser processing apparatus 1, the controller 9 controls the spatial light modulator 36 so that the laser light L is split into the first processing light L1 and the second processing light L2, the first convergence point C1 of the first processing light L1 is located on the first line 91, the second convergence point C2 of the second processing light L2 is located on the second line 92, and the controller 9 controls the moving mechanism 5 so that the irradiation region R of the distance measuring light L10, the first convergence point C1, and the second convergence point C2 are relatively moved along the first line 91 and the second line 92. At this time, the controller 9 controls the driving unit 18 based on the detection result of the distance measuring light L10 by the distance measuring unit 16 so that the first convergence point C1 and the second convergence point C2 are located at predetermined positions with respect to the front surface 101a or the back surface 101b of the object 100, respectively. Thus, the modified region M can be formed in the object 100 along the first line 91 and the second line 92 in a state where the modified region M is located at a predetermined position with respect to the front surface 101a or the rear surface 101b of the object 100. Here, in the laser processing apparatus 1, the distance measuring unit 16 is configured to be able to adjust the position of the irradiation region R of the distance measuring light L10 by at least the interval between the first line 91 and the second line 92 in the Y direction. Therefore, the position of the irradiation region R of the distance measuring light L10 can be adjusted in the Y direction according to the irradiation conditions of the laser light L, and the modified region M can be formed at a predetermined position with respect to the front surface 101a or the rear surface 101b of the object 100 with high accuracy. Therefore, with the laser processing apparatus 1, in the case where the modified region M is formed in the object 100 along each of the plurality of lines, the processing time can be shortened.

In the laser processing apparatus 1, the input receiving section 4 receives an input of "information on the positions of the first convergence point C1 and the second convergence point C2 in the Y direction", and the control section 9 controls the spatial light modulator 36 based on the information so that the first convergence point C1 is located on the first line 91 and the second convergence point C2 is located on the second line 92. Thereby, the modified regions M can be formed along the first and

second lines

91 and 92, respectively, easily and with high accuracy.

In the laser processing apparatus 1, the input receiving section 4 receives an input of "information on the position of the irradiation region R in the Y direction", and the control section 9 controls the distance measuring section 16 based on the information so that the irradiation region R is positioned on the first line 91 or the second line 92, or on the center line between the first line 91 and the second line 92. This makes it possible to easily and accurately form the modified region M at a predetermined position with respect to the front surface 101a or the rear surface 101b of the object 100.

In the laser processing apparatus 1, the input receiving unit 4 receives an input of "information on the incident side of the laser light L to the object 100", and the control unit 9 controls the distance measuring unit 16 based on the information so that the irradiation region R is positioned on the first line 91 or the second line 92 when the laser light L is incident on the front side as shown in fig. 9, and controls the distance measuring unit 16 based on the information so that the irradiation region R is positioned on the center line between the first line 91 and the second line 92 when the laser light L is incident on the back side as shown in fig. 10. Accordingly, when the light L10 for distance measurement is incident on the front surface, the modified region M can be formed at a predetermined position with respect to the front surface 101a or the rear surface 101b of the object 100 while preventing the light L10 from being affected by the functional element 102. Also, in the case of back surface incidence, the modified regions M can be formed uniformly along the first and

second lines

91 and 92, respectively.

In the laser processing apparatus 1, the input receiving unit 4 includes a display unit 4a for displaying the graphics of the object 100, the first line 91, and the second line 92. This makes it possible to visually grasp the machining scheduled state.

In the laser processing apparatus 1, the display unit 4a displays a reference line 93 corresponding to a trajectory along which the optical axis of the condensing unit 14 moves relative to the object 100. This makes it possible to visually recognize the machining scheduled state with respect to the optical axis of the condensing unit 14.

In the laser processing apparatus 1, the image pickup unit 3 acquires an image of the object 100, and the display unit 4a displays the image of the object 100 as a figure of the object 100. This makes it possible to easily acquire the figure of the object 100.

In the laser processing apparatus 1, the distance measuring unit 16 is configured such that the distance measuring light L10 passes through the light converging unit 14, wherein the main body 161 irradiates the front surface 101a or the rear surface 101b with the light L10 and detects the light L10 reflected by the front surface 101a or the rear surface 101b, and the adjusting unit 162 adjusts the optical axis of the light L10 irradiated to the front surface 101a or the rear surface 101 b. This structure is effective in the case where the irradiation area R of the light L10 for ranging should be reduced (for example, when the width of the track area 103 is narrow in the case of front incidence).

[ modified examples ]

The present disclosure is not limited to the above-described embodiments. For example, the distance measuring unit 16 may be configured so that the distance measuring light L10 does not pass through the light collecting unit 14. Specifically, as shown in fig. 15, the distance measuring unit 16 may be attached to the apparatus frame 1a so as to be not coaxial with the light condensing unit 14. In this case, the ranging section 16 may include a body section 163 and an adjusting section 164. The main body 163 irradiates the light L10 to the front surface 101a or the rear surface 101b and detects the light L10 reflected by the front surface 101a or the rear surface 101 b. The adjusting unit 164 is a unit for adjusting the position of the body 163 in the Y direction. The adjusting unit 164 moves the body 163 in the Y direction so as to adjust the position of the irradiation region R of the distance measuring light L10 in the Y direction by at least the interval between the first line 91 and the second line 92. This structure is effective when the light L10 for distance measurement is irradiated onto the surface of the object 100 through a member such as a tape (tape). The distance measuring unit 16 shown in fig. 15 may use a sensor of a triangulation method, a laser confocal method, a white light confocal method, a spectral interference method, an astigmatism method, or the like.

Fig. 16 is a schematic diagram showing a positional relationship among the reference line 93, the first line 91, and the second line 92 when laser processing is performed by the laser processing apparatus 1 shown in fig. 15 using front incidence (see fig. 9). As shown in (a) and (b) of fig. 16, the first line 91 and the second line 92 are located on both sides of the reference line 93 in the Y direction with the reference line 93 as a center line. As shown in fig. 16 (a), the light condensing unit 14 is located on the reference line 93, and the body 163 is located on the first line 91. As shown in (b) of fig. 16, the first convergence point C1 and the irradiation region R are located on the first line 91, and the second convergence point C2 is located on the second line 92.

Fig. 17 is a schematic view showing a positional relationship among the reference line 93, the first line 91, and the second line 92 when laser processing is performed by the laser processing apparatus 1 shown in fig. 15 using back surface incidence (see fig. 10). As shown in (a) and (b) of fig. 17, the first line 91 and the second line 92 are located on both sides of the reference line 93 in the Y direction with the reference line 93 as a center line. As shown in fig. 17 (a), the condensing unit 14 and the body 163 are positioned on the reference line 93. As shown in fig. 17 (b), the first convergence point C1 is located on the first line 91, the second convergence point C2 is located on the second line 92, and the irradiation region R is located on the reference line 93 (the center line between the first line 91 and the second line 92).

In either of the laser processing apparatus 1 shown in fig. 1 and the laser processing apparatus shown in fig. 15, the first wire 91 may be located on the reference wire 93.

Fig. 18 is a schematic diagram showing a positional relationship among the reference line 93, the first line 91, and the second line 92 when the laser processing is performed by the laser processing apparatus 1 shown in fig. 1 by front incidence (see fig. 9) or back incidence (see fig. 10). As shown in (a) and (b) of fig. 18, the first line 91 is located on the reference line 93, and the second line 92 is located on one side of the reference line 93 in the Y direction. As shown in fig. 18 (a), the light condensing portion 14 is located on the reference line 93. As shown in fig. 18 (b), the first convergence point C1 and the irradiation region R are located on the reference line 93 (located on the first line 91), and the second convergence point C2 is located on the second line 92.

Fig. 19 is a schematic diagram showing a positional relationship among the reference line 93, the first line 91, and the second line 92 when the laser processing is performed by the laser processing apparatus 1 shown in fig. 15 by front incidence (see fig. 9) or back incidence (see fig. 10). As shown in (a) and (b) of fig. 19, the first line 91 is located on the reference line 93, and the second line 92 is located on one side of the reference line 93 in the Y direction. As shown in fig. 19 (a), the condensing unit 14 and the body 163 are located on the reference line 93. As shown in fig. 19 (b), the first convergence point C1 and the irradiation region R are located on the reference line 93 (on the first line 91), and the second convergence point C2 is located on the second line 92.

Fig. 20 is a structural diagram of the display unit 4a in the case shown in fig. 18 and 19. In the case shown in fig. 18 and 19, the irradiation region R is always located on the reference line 93 (on the first line 91). Therefore, the display unit 4a shown in fig. 20 is not provided with a column for selecting the "distance measuring position" as in the display unit 4a shown in fig. 11.

In the laser processing apparatus 1 shown in fig. 1, the main body 161 may be configured such that the position and angle of a light receiving sensor (a light receiving sensor that detects the light L10 reflected by the front surface 101a or the rear surface 101b) is adjustable. This is to enable the light receiving sensor to reliably detect the light L10 reflected by the front surface 101a or the rear surface 101b when the optical axis of the light L10 is adjusted by the adjustment unit 162.

In the laser processing apparatus 1 shown in fig. 15, a pair of distance measuring units 16 may be provided on both sides of the light converging unit 14 in the X direction. When the first convergence point C1 and the second convergence point C2 are relatively moved along the first line 91 and the second line 92 on one side in the X direction, one distance measuring section 16 may be used, and when the first convergence point C1 and the second convergence point C2 are relatively moved along the first line 91 and the second line 92 on the other side in the X direction, the other distance measuring section 16 may be used.

The distance measuring unit 16 may irradiate light L10 on the surface of the object 100 other than the front surface 101a and the back surface 101b and detect light L10 reflected by the surface, as long as the surface intersects the Z direction.

In the case where laser processing is performed by the laser processing apparatuses 1 shown in fig. 1 and 15 using front incidence (see fig. 9), the irradiation region R may be slightly shifted from the first line 91 or the second line 92 as long as it is located within the track region 103, for example, when viewed from the Z direction.

When laser processing is performed by the laser processing apparatuses 1 shown in fig. 1 and 15 using back-surface incidence (see fig. 10), the irradiation region R may be located on the first line 91, on the second line 92, or between the first line 91 and the second line 92.

The input receiving unit 4 may receive input of information on the object 100 (the size of each functional element 102, the width of the track area 103, and the like), the control unit 9 may generate a graphic of the object 100 based on the information, and the graphic may be displayed on the display unit 4 a.

In the laser processing apparatus, the control unit controls the spatial light modulator so that the laser beam is split into the first processing light and the second processing light, a first convergence point of the first processing light is located on the first line, and a second convergence point of the second processing light is located on the second line, and controls the moving unit so that an irradiation area of the distance measuring light on the surface of the object, the first convergence point, and the second convergence point are relatively moved along the first line and the second line. In this case, the control unit controls the drive unit so that the first convergence point and the second convergence point are located at predetermined positions with respect to the surface of the object, respectively, based on the detection result of the distance measuring light by the distance measuring unit. Thus, the modified region can be formed in the object along the first line and the second line, respectively, in a state where the modified region is located at a predetermined position with respect to the surface of the object. In the laser processing apparatus, the distance measuring unit may be configured to adjust a position of an irradiation region of the distance measuring light by an amount of at least an interval between the first line and the second line in the Y direction. Therefore, the position of the irradiation region of the distance measuring light can be adjusted in the Y direction according to the irradiation conditions of the laser light, and the modified region can be formed at a predetermined position with high accuracy with respect to the surface of the object. Therefore, with the laser processing apparatus described above, when the modified region is formed in the object along each of the plurality of lines, the processing time can be shortened.

The laser processing apparatus according to one aspect of the present disclosure may further include an input receiving unit that receives input of first information regarding positions of the first convergence point and the second convergence point in the Y direction, respectively, and the control unit may control the spatial light modulator based on the first information so that the first convergence point is located on the first line and the second convergence point is located on the second line. Thus, the modified regions can be formed along the first line and the second line, respectively, easily and with high accuracy.

In the laser processing apparatus according to one aspect of the present disclosure, the input receiving unit may further receive input of second information on a position of the irradiation region in the Y direction, and the control unit may control the distance measuring unit based on the second information so that the irradiation region is located on the first line or the second line, or between the first line and the second line. Thus, the reformed region can be easily and accurately formed at a predetermined position with respect to the surface of the object.

In the laser processing apparatus according to one aspect of the present disclosure, the object may include a substrate and a plurality of functional elements arranged in a matrix on the substrate, the input receiving unit may further receive input of third information on an incident side of the laser light to the object, and the control unit may control the distance measuring unit based on the third information such that the irradiation region is positioned on the first line or the second line when the laser light is incident on the substrate from a side of the plurality of functional elements, and control the distance measuring unit based on the third information such that the irradiation region is positioned on a center line between the first line and the second line when the laser light is incident on the substrate from a side opposite to the plurality of functional elements. Thus, when laser light is incident on the substrate from the side of the plurality of functional elements, the light for distance measurement can be prevented from being affected by the functional elements, and the reformed region can be formed at a predetermined position with respect to the surface of the object. Further, in the case where laser light is incident on the substrate from the side opposite to the plurality of functional elements, the modified regions can be formed uniformly along the first line and the second line, respectively.

In the laser processing apparatus according to one aspect of the present disclosure, the input receiving unit may include a display unit for displaying the object, and the respective graphics of the first line and the second line. This makes it possible to visually grasp the machining scheduled state.

In the laser processing apparatus according to the aspect of the present disclosure, the display unit may further display a reference line corresponding to a trajectory along which the optical axis of the light condensing unit moves relative to the object. This makes it possible to visually recognize the state of the machining schedule with respect to the optical axis of the light converging unit.

The laser processing apparatus according to one aspect of the present disclosure may further include an imaging unit for acquiring an image of the object, and the display unit may display the image of the object as a graph of the object. This makes it possible to easily acquire the figure of the object.

In the laser processing apparatus according to one aspect of the present disclosure, the distance measuring unit may be configured such that light for distance measurement irradiated to the surface and light for distance measurement reflected by the surface pass through the light condensing unit, and the distance measuring unit includes: a main body that irradiates light for distance measurement to a surface and detects light for distance measurement reflected by the surface; and an adjusting unit for adjusting the optical axis of the distance measuring light irradiated to the surface. This structure is effective in the case where the irradiation area of light for ranging should be reduced.

In the laser processing apparatus according to one aspect of the present disclosure, the distance measuring unit may be configured such that the light for distance measurement irradiated to the surface and the light for distance measurement reflected by the surface do not pass through the light collecting unit, and the distance measuring unit includes: a main body that irradiates light for distance measurement to a surface and detects light for distance measurement reflected by the surface; and an adjusting section for adjusting the position of the main body section in the Y direction. This structure is effective when light for distance measurement is irradiated onto the surface of an object through a member such as a tape (tape).

With the present disclosure, it is possible to provide a laser processing apparatus capable of shortening a processing time in a case where a modified region is formed in an object along each of a plurality of lines.

Claims

1. A laser processing apparatus for forming a modified region in an object along a first line and a second line, respectively, by irradiating the object with laser light, wherein the object has a surface intersecting a Z direction, the first line and the second line extend in an X direction perpendicular to the Z direction and are adjacent in a Y direction perpendicular to both the Z direction and the X direction,

the laser processing apparatus is characterized by comprising:

a support portion for supporting the object;

a light source for emitting the laser light;

a spatial light modulator for modulating the laser light emitted from the light source;

a light-condensing unit that condenses the laser light modulated by the spatial light modulator;

a distance measuring unit that irradiates light for distance measurement to the surface and detects the light for distance measurement reflected by the surface;

a moving unit that moves the light collecting unit and the distance measuring unit relative to the support unit;

a drive unit that moves the light condensing unit in the Z direction; and

a control unit that controls the spatial light modulator so that the laser beam is split into first processing light and second processing light, a first convergence point of the first processing light is located on the first line, a second convergence point of the second processing light is located on the second line, the moving unit is controlled so that an irradiation region of the light for distance measurement on the surface, the first convergence point, and the second convergence point are relatively moved along the first line and the second line, and the driving unit is controlled based on a detection result of the light for distance measurement by the distance measuring unit so that the first convergence point and the second convergence point are located at predetermined positions with respect to the surface, respectively,

the distance measuring unit is configured to be capable of adjusting a position of the irradiation region in the Y direction by an amount corresponding to at least an interval between the first line and the second line.

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

further comprising an input receiving section that receives an input of first information on positions of the first convergence point and the second convergence point in the Y direction, respectively,

the control section controls the spatial light modulator based on the first information so that the first convergence point is located on the first line and the second convergence point is located on the second line.

3. The laser processing apparatus according to claim 2, wherein:

the input receiving section further receives an input of second information on a position of the irradiation region in the Y direction,

the control unit controls the distance measuring unit based on the second information so that the irradiation region is located on the first line or the second line, or between the first line and the second line.

4. The laser processing apparatus according to claim 2, wherein:

the object includes a substrate and a plurality of functional elements arranged in a matrix on the substrate,

the input receiving unit further receives an input of third information on an incident side on which the laser light is incident to the object,

the control part is used for controlling the operation of the motor,

controlling the distance measuring section based on the third information so that the irradiation region is located on the first line or the second line in a case where the laser light is incident on the substrate from the plurality of functional elements side, and,

controlling the distance measuring portion based on the third information so that the irradiation region is located on a center line between the first line and the second line in a case where the laser light is incident on the substrate from a side opposite to the plurality of functional elements.

5. A laser processing apparatus according to any one of claims 2 to 4, wherein:

the input receiving unit includes a display unit for displaying the respective graphics of the object, the first line, and the second line.

6. The laser processing apparatus according to claim 5, wherein:

the display unit further displays a reference line corresponding to a trajectory along which the optical axis of the light condensing unit moves relative to the object.

7. The laser processing apparatus according to claim 5 or 6, wherein:

further comprises an image pickup unit for acquiring an image of the object,

the display unit displays an image of the object as the graphic of the object.

8. The laser processing apparatus according to any one of claims 1 to 7, wherein:

the distance measuring unit is configured such that the light for distance measurement irradiated to the surface and the light for distance measurement reflected by the surface pass through the light condensing unit,

the distance measuring unit includes:

a main body that irradiates the distance measuring light to the surface and detects the distance measuring light reflected by the surface; and

and an adjusting unit for adjusting an optical axis of the distance measuring light irradiated to the surface.

9. The laser processing apparatus according to any one of claims 1 to 7, wherein:

the distance measuring unit is configured such that the light for distance measurement irradiated to the surface and the light for distance measurement reflected by the surface do not pass through the light collecting unit,

the distance measuring unit includes:

and an adjusting unit for adjusting the position of the main body unit in the Y direction.