TWI894327B - Laser processing equipment - Google Patents

Abstract

The present invention provides a laser processing device capable of shortening processing time when forming a modified area in an object along each of a plurality of lines. The laser processing device includes a control unit. The control unit controls a spatial light modulator so that the laser light is split into a first processing light and a second processing light, with the first focal point of the first processing light being located on the first line and the second focal point of the second processing light being located on the second line. The control unit also controls a moving unit so that the irradiation area of the distance-measuring light, the first focal point, and the second focal point move relative to each other along the first line and the second line. The driving unit also controls a driving unit so that the first focal point and the second focal point are located at predetermined positions relative to the surface of the object. The distance-measuring unit is configured to adjust the position of the irradiation area in the Y direction by at least the amount of the interval between the first line and the second line.

Description

Laser processing equipment

This invention relates to a laser processing device.

Laser processing devices that irradiate an object with laser light to form modified areas within the object are known. These devices modulate the laser light to split it into multiple beams of processing light and focus the multiple beams of processing light onto different locations (see, for example, Japanese Patent Application Publication Nos. 2015-223620 and 2015-226012). Because these laser processing devices can form multiple rows of modified areas using multiple beams of processing light, they are very effective in reducing processing time.

For example, in objects comprising a substrate and multiple functional elements arranged in a matrix on the substrate, the functional elements are becoming increasingly refined. As the functional elements become increasingly refined, the number of lines (cutting lines) used to cut the object into individual functional elements increases. Therefore, efficiently forming a modified region in the object along each of these multiple lines becomes crucial for reducing processing time.

An object of the present invention is to provide a laser processing device that can shorten processing time while forming a modified region in an object along each of a plurality of lines.

The laser processing device of the present invention forms a modified area in the object along a first line and a second line respectively by irradiating the object with laser light, wherein the object has a surface intersecting the Z direction, the first line and the second line extend in the X direction perpendicular to the Z direction and are adjacent to each other in the Y direction perpendicular to both the Z direction and the X direction. The laser processing device comprises: a support portion for supporting the object; a light source for emitting laser light; a spatial light modulator for modulating the laser light emitted from the light source; a focusing portion for focusing the laser light modulated by the spatial light modulator; a distance measuring portion for irradiating the surface with light for distance measuring and detecting the light for distance measuring reflected from the surface; and a method for aligning the focusing portion and the distance measuring portion relative to the support portion. A moving unit for moving; a driving unit for moving the focusing unit in the Z direction; and a control unit that controls the spatial light modulator to split the laser light into a first processing light and a second processing light, with the first focusing point of the first processing light being located on the first line and the second focusing point of the second processing light being located on the second line. Furthermore, the moving unit is controlled to move the irradiation area, the first focusing point, and the second focusing point on the surface of the distance-measuring light relative to each other along the first line and the second line. Furthermore, the driving unit is controlled based on the detection result of the distance-measuring light by the distance-measuring unit to position the first focusing point and the second focusing point at predetermined positions relative to the surface. The distance-measuring unit is configured to adjust the position of the irradiation area in the Y direction by at least the distance between the first line and the second line.

1: Laser processing equipment

1a: Device frame

2: Fiber optics

2a: Injection end

4: Input receiving unit

4a: Display unit

5,6: Moving mechanism

7: Supporting part

8: Light source unit

9: Control Department

10A, 10B: Laser processing head

11: Frame

12: Injection

13: Laser light adjustment unit

14: Spotlight Department

14a: Entrance pupil plane

15: Color separation mirror

16: Distance measurement unit

17: Observation Department

18: Drive Department

19: Circuit Department

20: Diverger

21: Wall 1

22: Second wall

23: Third Wall

24: 4th wall

25: 5th Wall

26: Wall 6

26a: Hole

27: Base

28: Bolts

29: The adjacent area

31: Reflector

32: Attenuator

33: Reflector

34: Expander

35: Reflector

36: Spatial Light Modulator

37: Imaging Optical System

41: Semiconductor substrate

42: Driver circuit layer

43: Pixel electrode layer

43a: Pixel electrode

44: Reflective film

45: Oriented Film

46:Liquid crystal layer

47: Oriented Film

48:Transparent conductive film

49:Transparent substrate

51: Fixed part

53:Mobile Department

55: Installation Department

61: Fixed part

63,64:Mobile Department

65,66: Installation Department

65a, 66a: Bottom plate

65b, 66b: Mounting plate

81,82: Light Source

81a, 82a: Injection section

91: Line 1

92: Line 2

93:baseline

100: Object

101a: Surface

101b: Back

103: Trail Area

161: Main body

162: Adjustment Department

163: Main Department

164: Adjustment Department

A1: Line 1

A2: Second straight line

A3: The third straight line

C1: First focal point

C2: Second focal point

L1: 1st processing light

L2: Second processing light

L10: Light (for distance measurement)

L20: Light (for observation)

M: modified area

R: Irradiation area

[Figure 1] is a perspective view of a laser processing device according to one embodiment.

[Figure 2] is a front view of a portion of the laser processing device shown in Figure 1.

[Figure 3] is a front view of the laser processing head of the laser processing device shown in Figure 1.

[Figure 4] is a side view of the laser processing head shown in Figure 3.

[Figure 5] is a structural diagram of the optical system of the laser processing head shown in Figure 3.

[Figure 6] is a cross-sectional view of a portion of the spatial light modulator shown in Figure 5.

[Figure 7] is a top view of the object to be processed by the laser processing device shown in Figure 1.

[Figure 8] is a cross-sectional view of a portion of the object shown in Figure 7.

[Figure 9] is a schematic diagram showing the laser processing state in the laser processing device shown in Figure 1.

Figure 10 is a schematic diagram showing the laser processing state in the laser processing device shown in Figure 1.

[Figure 11] is a structural diagram of the display unit of the laser processing device shown in Figure 1.

[Figure 12] is a flow chart of the laser processing method implemented by the laser processing apparatus shown in Figure 1.

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

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

[Figure 15] is a schematic diagram showing the structure of a laser processing device according to a modified example.

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

Figure 17 is a schematic diagram showing the positional relationship between the reference line, the first line, and the second line in the laser processing apparatus shown in Figure 15.

Figure 18 is a schematic diagram showing the positional relationship between the reference line, the first line, and the second line in the laser processing apparatus shown in Figure 1.

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

[Figure 20] is a structural diagram of the display unit in the case shown in Figures 18 and 19.

The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. Identical or corresponding parts are denoted by the same reference numerals in the various drawings, and repeated descriptions are omitted.

[Structure of laser processing equipment]

As shown in Figure 1, the laser processing device 1 includes a plurality of moving mechanisms 5 and 6, a support unit 7, a pair of laser processing heads 10A and 10B, a light source unit 8, and a control unit 9. Hereinafter, the first direction will be referred to as the Z direction, the second direction perpendicular to the first direction will be referred to as the X direction, and the third direction perpendicular to both the first and second directions will be referred to as the Y direction. In this embodiment, the Z direction is the vertical direction, and the X and Y directions are horizontal directions.

The moving mechanism 5 comprises a fixed portion 51, a moving portion 53, and a mounting portion 55. The fixed portion 51 is mounted on the device frame 1a. The moving portion 53 is mounted on a track provided on the fixed portion 51 and is movable in the Y direction. The mounting portion 55 is mounted on the track provided on the moving portion 53 and is movable in the X direction.

The moving mechanism 6 comprises a fixed portion 61, a pair of moving portions 63 and 64, and a pair of mounting portions 65 and 66. The fixed portion 61 is mounted on the device frame 1a. The pair of moving portions 63 and 64 are each mounted on a track provided on the fixed portion 61 and are independently movable in the Y direction. The mounting portion 65 is mounted on the track provided on the moving portion 63 and is movable in the Z direction. The mounting portion 66 is mounted on the track provided on the moving portion 64 and is movable in the Z direction.

The support portion 7 is mounted on a rotation axis provided on the mounting portion 55 of the moving mechanism 5. The support portion 7 is capable of rotating about an axis parallel to the Z direction. The support portion 7 is used to support the object 100. The object 100 is a wafer.

As shown in Figures 1 and 2 , the laser machining head 10A is mounted on the mounting portion 65 of the moving mechanism 6 . The laser machining head 10A faces the support portion 7 in the Z direction and, in this position, irradiates the object 100 supported on the support portion 7 with laser light L. The laser machining head 10B is mounted on the mounting portion 66 of the moving mechanism 6 . The laser machining head 10B faces the support portion 7 in the Z direction and, in this position, irradiates the object 100 supported on the support portion 7 with laser light L.

The light source unit 8 includes a pair of light sources 81 and 82. These light sources 81 and 82 are mounted on the device frame 1a. Each light source 81 and 82 emits laser light L. Laser light L emitted from the emission portion 81a of light source 81 is guided by an optical fiber 2 to the laser processing head 10A. Laser light L emitted from the emission portion 82a of light source 82 is guided by another optical fiber 2 to the laser processing head 10B.

The control unit 9 controls various components of the laser processing device 1 (e.g., the plurality of moving mechanisms 5 and 6, the pair of laser processing heads 10A and 10B, and the light source unit 8). The control unit 9 is configured as a computer device equipped with a processor, memory, storage, and communication devices. Within the control unit 9, the processor executes software (programs) stored in the memory and controls the reading and writing of data to and from the memory, as well as communications with the communication devices. This enables the control unit 9 to implement various functions.

An example of processing performed by the laser processing apparatus 1 configured as described above will be described. This example of processing is an example of forming a modified region within the object 100 along each of a plurality of lines arranged in a grid pattern in order to cut the wafer (object 100) into a plurality of chips.

First, the moving mechanism 5 moves the support 7 in the X and Y directions, 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, so that multiple lines extending in one direction on the object 100 are aligned along the X direction.

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

Next, light source 81 emits laser light L, and laser processing head 10A irradiates object 100 with laser light L. Meanwhile, light source 82 emits laser light L, and laser processing head 10B irradiates object 100 with laser light L. Simultaneously, movement mechanism 5 moves support portion 7 in the X direction, causing the focal point of laser light L from laser processing head 10A to move relative to one another along a line extending in one direction, and the focal point of laser light L from laser processing head 10B to move relative to one another along another line extending in one direction. In this way, laser processing apparatus 1 can form a modified region within object 100 along each of a plurality of lines extending in one direction on object 100.

Next, the moving mechanism 5 rotates the support portion 7 about an axis parallel to the Z direction, so that the multiple lines on the object 100 extending in a direction perpendicular to the one direction are aligned along the X direction.

Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction so that the focal point of the laser beam L from the laser processing head 10A is located on a line extending in the other direction. Meanwhile, the moving mechanism 6 moves the laser processing head 10B in the Y direction so that the focal point of the laser beam L from the laser processing head 10B is located on another line extending in the other direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction so that the focal point of the laser beam L from the laser processing head 10A is located inside the object 100. Meanwhile, the moving mechanism 6 moves the laser processing head 10B in the Z direction so that the focal point of the laser beam L from the laser processing head 10B is located inside the object 100.

Next, light source 81 emits laser light L, and laser processing head 10A irradiates object 100 with laser light L. Light source 82 emits laser light L, and laser processing head 10B irradiates object 100 with laser light L. Simultaneously, movement mechanism 5 moves support portion 7 in the X direction, causing the focal point of laser light L from laser processing head 10A to move relative to one another along a line extending in another direction, and the focal point of laser light L from laser processing head 10B to move relative to one another along another line extending in another direction. In this way, laser processing apparatus 1 can form a modified region within object 100 along each of a plurality of lines extending in a direction perpendicular to the one direction on object 100.

Furthermore, in the aforementioned processing example, a pair of light sources 81 and 82 each emits transmissive laser light L toward an object 100 using, for example, a pulsed oscillation method. When this laser light L is focused within the object 100, it is particularly absorbed in the area corresponding to the focal point of the laser light L, forming a modified region within the object 100. A modified region is a region whose density, refractive index, mechanical strength, and other physical properties differ from those of the surrounding unmodified region. Examples of modified regions include melt-processed regions, cracked regions, insulation breakdown regions, and regions with altered refractive index.

When pulsed laser light L is emitted and irradiated onto an object 100, and the focal point of the laser light L moves relative to a line set on the object 100, multiple modified spots are formed in a row along the line. Each modified spot is formed by irradiation with a single pulse of laser light L. A row of modified areas is a collection of these multiple modified spots arranged in a row. Depending on the relative movement speed of the focal point of the laser light L relative to the object 100 and the pulse repetition frequency of the laser light L, adjacent modified spots may be connected or separated.

[Structure of the laser processing head]

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

The frame 11 includes a first wall 21, a second wall 22, a third wall 23, a fourth wall 24, and a fifth wall 25 and a sixth wall 26. The first wall 21 and the second wall 22 face each other in the X direction. The third wall 23 and the fourth wall 24 face each other in the Y direction. The fifth wall 25 and the sixth wall 26 face 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. Furthermore, the distance between the first wall portion 21 and the second wall portion 22 may be equal to or greater than the distance between the fifth wall portion 25 and the sixth wall portion 26.

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

The frame 11 is configured so that, with the third wall 23 positioned on the mounting portion 65 side of the moving mechanism 6, the frame 11 is mounted on the mounting portion 65. Specifically, the mounting portion 65 includes a base plate 65a and a mounting plate 65b. The base plate 65a is mounted on a rail provided on the moving portion 63 (see Figure 2). The mounting plate 65b is erected on the end of the base plate 65a on the laser processing head 10B side (see Figure 2). With the third wall 23 in contact with the mounting plate 65b, bolts 28 are threadedly connected to the mounting plate 65b via the base 27, thereby securing the frame 11 to the mounting portion 65. The base 27 is provided on the first wall 21 and the second wall 22, respectively. The frame 11 is attachable to and detachable from the mounting portion 65.

The incident portion 12 is disposed on the fifth wall portion 25. The incident portion 12 allows the laser light L to enter the housing 11. The incident portion 12 is offset toward the first wall portion 21 in the X direction and toward the fourth wall portion 24 in the Y direction. Specifically, the distance between the incident portion 12 and the first wall portion 21 in the X direction is smaller than the distance between the incident portion 12 and the second wall portion 22 in the X direction, and the distance between the incident portion 12 and the fourth wall portion 24 in the Y direction is smaller than the distance between the incident portion 12 and the third wall portion 23 in the X direction.

The incident portion 12 is connected to the emitting end portion 2a of the optical fiber 2. Specifically, the incident portion 12 is a portion having a hole 25a formed in the fifth wall portion 25. The fifth wall portion 25 is provided with a mounting portion 25b. The main body portion 2b of the emitting end portion 2a is mounted to the mounting portion 25b using bolts or the like. In this state, the front end portion 2c of the emitting end portion 2a is inserted into the hole 25a. This allows the emitting end portion 2a of the optical fiber 2 to be attached and detached relative to the incident portion 12. A cover 25c is arranged between the fifth wall portion 25 and the main body portion 2b. The cover 25c covers the gap formed between the hole 25a and the front end portion 2c. For example, at the emitting end 2a, an isolator for suppressing return light is disposed within the body portion 2b, and a collimating lens for collimating the laser light L is disposed within the tip portion 2c. Alternatively, the incident portion 12 may be a connector or the like, to which the emitting end 2a of the optical fiber 2 can be connected.

The laser light adjustment unit 13 is disposed within the housing 11. It adjusts the laser light L incident from the incident portion 12. The laser light adjustment unit 13 is disposed within the housing 11 on the side of the fourth wall 24 relative to the partition wall 29. The laser light adjustment unit 13 is mounted on the partition wall 29. The partition wall 29 is provided within the housing 11 and divides the interior of the housing 11 into an area on the side of the third wall 23 and an area on the side of the fourth wall 24. The partition wall 29 constitutes a portion of the housing 11. The various components of the laser light adjustment unit 13 are mounted on the partition wall 29 on the side of the fourth wall 24. The partition wall 29 functions as an optical base, supporting the various components of the laser light adjustment unit 13.

The focusing unit 14 is disposed on the sixth wall 26. Specifically, the focusing unit 14 is disposed on the sixth wall 26 while being inserted into a hole 26a formed in the sixth wall 26 (see Figure 5). The focusing unit 14 focuses the laser light L adjusted by the laser light adjustment unit 13 and simultaneously emits the laser light L out of the housing 11. The focusing unit 14 is offset toward the second wall 22 in the X direction and toward the fourth wall 24 in the Y direction. Specifically, the distance between the focusing unit 14 and the second wall 22 in the X direction is smaller than the distance between the focusing unit 14 and the first wall 21 in the X direction, and the distance between the focusing unit 14 and the fourth wall 24 in the Y direction is smaller than the distance between the focusing unit 14 and the third wall 23 in the X direction.

As shown in Figure 5, the laser light adjustment unit 13 includes a reflector 31, an attenuator 32, and a reflector 33. The reflector 31, attenuator 32, and reflector 33 are arranged on a first straight line A1 extending in the X direction. The reflector 31 faces the incident portion 12 in the Z direction. Specifically, the reflector 31 faces the emitting end 2a of the optical fiber 2 in the Z direction. The reflector 31 reflects the laser light L incident from the incident portion 12 toward the second wall 22. The attenuator 32 adjusts the output of the laser light L reflected by the reflector 31. The reflector 33 reflects the laser light L, whose output has been adjusted by the attenuator 32, toward the sixth wall 26. Each reflector 31 and 33 is, for example, a mirror or a prism.

The laser light adjustment unit 13 further includes a beam expander 34 and a reflector 35. The reflector 33, the beam expander 34, and the reflector 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 reflector 33. The reflector 35 reflects the laser light L, whose diameter has been expanded by the beam expander 34, toward the first wall 21 and the fifth wall 25. The reflector 35 is, for example, a mirror or a prism.

The laser light adjustment section 13 also includes a spatial light modulator 36 and an imaging optical system 37. The spatial light modulator 36, the imaging optical system 37, and the focusing section 14 are arranged on the third straight line A3 extending along the Z direction. The spatial light modulator 36 modulates the laser light L reflected by the reflecting section 35 and reflects it to the side of the sixth wall 26. The spatial light modulator 36 is a reflective spatial light modulator (SLM). The imaging optical system 37 is configured as a bilateral telecentric optical system, in which the reflecting surface 36a of the spatial light modulator 36 is in an imaging relationship with the entrance pupil surface 14a of the focusing section 14. 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 Figure 1), and the focusing unit 14 focuses 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 lie on a plane perpendicular to the Y direction. The second straight line A2 is located on the second wall portion 22 side relative to the third straight line A3. In the laser machining head 10A, laser light L incident from the incident portion 12 into the housing 11 in the Z direction is reflected by the reflecting portion 31 and travels along the first straight line A1. The laser light L traveling along the first straight line A1 is reflected by the reflecting member 33 and travels along the second straight line A2. The laser light L traveling along the second straight line A2 is sequentially reflected by the reflecting portion 35 and the spatial light modulator 36 and travels along the third straight line A3. The laser light L traveling along the third straight line A3 is emitted from the focusing portion 14 in the Z direction to the outside of the housing 11.

The laser processing head 10A also 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 positioned between the imaging optical system 37 and the focusing section 14 on the third straight line A3. Specifically, the dichroic mirror 15 is positioned within the housing 11 between the laser light adjustment section 13 and the focusing section 14. The dichroic mirror 15 is attached to the partition wall 29 on the side of the fourth wall 24. The dichroic mirror 15 transmits the laser light L. To minimize astigmatism, the dichroic mirror 15 is preferably a cubic shape or a type composed of two plates arranged in a twisted relationship.

The distance measuring unit 16 is located on the first wall 21 side relative to the third straight line A3 within the housing 11. Specifically, the distance measuring unit 16 is located on the first wall 21 side relative to the light focusing unit 14 in the X direction. The distance measuring unit 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 (e.g., distance measuring laser light) for measuring the distance between the surface of the object 100 (e.g., the surface on the side where the laser light L is incident) and the light focusing unit 14, and detects the light L10 reflected from the surface of the object 100.

In this embodiment, the distance measuring unit 16 is configured to allow light L10 intended for illumination of the surface of the object 100 and light L10 reflected from the surface of the object 100 to pass through the focusing unit 14. Specifically, the light L10 emitted from the distance measuring unit 16 passes through the focusing unit 14 and is incident on the surface of the object 100, while the light L10 reflected from the surface of the object 100 passes through the focusing unit 14 and enters the distance measuring unit 16. The distance measuring unit 16 is an astigmatic sensor equipped with a four-quadrant photodiode as a light-receiving sensor.

More specifically, the distance measuring unit 16 includes a main body 161 and an adjustment unit 162. The main body 161 irradiates light L10 onto the surface of the object 100 and detects the light L10 reflected from the surface of the object 100. The adjustment unit 162 is used to adjust the optical axis of the light L10 irradiated onto the surface of the object 100. The adjustment unit 162 includes a first turning mirror 162a and a second turning mirror 162b. The first and second turning mirrors 162a, 162b are attached to the partition wall 29 on the fourth wall 24 side so that the angles of their respective mirror surfaces can be adjusted.

Light L10 emitted from the main body 161 is sequentially reflected by the first turning mirror 162a, the second turning mirror 162b, the splitter 20, and the dichroic mirror 15. It is then emitted from the housing 11 by the focusing unit 14 and illuminates the surface of the object 100. Light L10 reflected from the surface of the object 100 enters the housing 11 through the focusing unit 14, is sequentially reflected by the dichroic mirror 15, the splitter 20, the second turning mirror 162b, and the first turning mirror 162a, and then enters the main body 161. Furthermore, the splitter 20 is attached to the partition wall 29 on the side of the fourth wall 24.

The observation unit 17 is positioned within the housing 11 on the side of the first wall 21 relative to the third straight line A3. Specifically, the observation unit 17 is positioned on the side of the first wall 21 relative to the focusing unit 14 in the X direction. The observation unit 17 is attached to the partition wall 29 on the side of the fourth wall 24. The observation unit 17 irradiates the surface of the object 100 with observation light L20 (e.g., visible light) for observing the surface of the object 100 (e.g., the surface on the side where the laser light L is incident) and detects the light L20 reflected from the surface of the object 100.

In this embodiment, light L20 emitted from the observation section 17 passes through the splitter 20, is reflected by the dichroic mirror 15, and is emitted from the housing 11 by the focusing section 14, irradiating the surface of the object 100. Light L20 reflected from the surface of the object 100 enters the housing 11 by the focusing section 14, is reflected by the dichroic mirror 15, and passes through the splitter 20 to enter the observation section 17. Furthermore, the wavelengths of the laser light L, light L10, and light L20 differ from each other (at least their center wavelengths are offset from each other).

The driver 18 is attached to the partition wall 29 on the side of the fourth wall 24. The driver 18 moves the light focusing unit 14 disposed on the sixth wall 26 in the Z direction using the driving force of a piezoelectric element, for example.

The circuit unit 19 is located within the housing 11 on the side of the third wall 23 relative to the partition wall 29. Specifically, the circuit unit 19 is located within the housing 11 on the side of the third wall 23 relative to the laser light adjustment unit 13, the distance measuring unit 16, and the observation unit 17. The circuit unit 19 is spaced apart from the partition wall 29. The circuit unit 19 may be, 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 driver 18 based on the signal output from the distance measuring unit 16. For example, the circuit unit 19 controls the driver unit 18 based on the signal output from the distance measuring unit 16 to maintain a constant distance between the surface of the object 100 and the focusing unit 14 (i.e., to maintain a constant distance between the surface of the object 100 and the focal point of the laser light L).

Furthermore, the partition wall 29 has cutouts and holes (not shown) formed therein for passage of wiring that electrically connects the distance measuring unit 16, the observation unit 17, the driver unit 18, and the spatial light modulator 36 to the circuit unit 19. Furthermore, the housing 11 is provided with a connector (not shown) to which wiring, etc., that electrically connects the circuit unit 19 to the control unit 9 (see Figure 1) are connected.

Similar to the laser machining head 10A, the laser machining head 10B includes a housing 11, an incident portion 12, a laser beam adjustment unit 13, a focusing unit 14, a dichroic mirror 15, a distance measuring unit 16, an observation unit 17, a drive unit 18, and a circuit unit 19. However, as shown in Figure 2, the various components of the laser machining head 10B are arranged so as to be plane-symmetrical with those of the laser machining head 10A about a virtual plane perpendicular to the Y direction and passing through the midpoint between the pair of mounting portions 65 and 66.

For example, the frame 11 of the laser machining head 10A is mounted on the mounting portion 65 such that the fourth wall portion 24 is located on the laser machining head 10B side relative to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25. Conversely, the frame 11 of the laser machining head 10B is mounted on the mounting portion 66 such that the fourth wall portion 24 is located on the laser machining head 10A side relative to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25.

The frame 11 of the laser machining head 10B is mounted on the mounting portion 66 with the third wall 23 positioned on the mounting portion 66 side. Specifically, the mounting portion 66 includes a base plate 66a and a mounting plate 66b. The base plate 66a is mounted on a rail provided on the moving portion 63. The mounting plate 66b is erected on the end of the base plate 66a on the laser machining head 10A side. The frame 11 of the laser machining head 10B is mounted on the mounting portion 66 with the third wall 23 in contact with the mounting plate 66b. The frame 11 of the laser machining head 10B is removable from the mounting portion 66.

[Structure of spatial light modulator]

As shown in Figure 6, the spatial light modulator 36 is constructed by sequentially stacking 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 driver circuit layer 42 forms 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 via the driver circuit layer 42.

The reflective film 44 is, for example, a dielectric multilayer film. An alignment film 45 is provided on the surface of the liquid crystal layer 46 on the side facing the reflective film 44, while an alignment film 47 is provided on the surface of the liquid crystal layer 46 on the side opposite the reflective film 44. Each alignment film 45, 47 is formed from a polymer material such as polyimide, and the surface of each alignment film 45, 47 that contacts the liquid crystal layer 46 is subjected to a rubbing treatment, for example. The alignment films 45, 47 align the liquid crystal molecules 46a contained in the liquid crystal layer 46 in a specific direction.

A transparent conductive film 48 is provided on the surface of a transparent substrate 49 on the alignment film 47 side, facing the pixel electrode layer 43 via the liquid crystal layer 46 and other components. Transparent substrate 49 is, for example, a glass substrate. Transparent conductive film 48 is formed from a light-transmitting conductive material such as ITO. Transparent substrate 49 and transparent conductive film 48 transmit 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 9 to the drive circuit layer 42, a voltage corresponding to the signal is applied to each pixel electrode 43a, forming an electric field between each pixel electrode 43a and the transparent conductive film 48. When this electric field is formed, the alignment direction of the liquid crystal molecules 216a in the liquid crystal layer 46 changes for each region corresponding to each pixel electrode 43a, and the refractive index changes for each region corresponding to each pixel electrode 43a. This state indicates that the modulation pattern is displayed on the liquid crystal layer 46.

With the modulation pattern displayed on the liquid crystal layer 46, laser light L is incident on the liquid crystal layer 46 from the outside via the transparent substrate 49 and the transparent conductive film 48. It is reflected by the reflective film 44 and then emitted from the liquid crystal layer 46 to the outside via the transparent conductive film 48 and the transparent substrate 49. In this way, the spatial light modulator 36 can modulate the laser light L (for example, the intensity, amplitude, phase, polarization, etc. of the laser light L) by appropriately setting the modulation pattern displayed on the liquid crystal layer 46.

[Structure of the object]

As shown in Figures 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.

Substrate 101 has a surface 101a and a back surface 101b. Substrate 101 is a semiconductor substrate such as a silicon substrate. Substrate 101 has a notch 101c that indicates the crystal orientation. Alternatively, substrate 101 may have an orientation flat instead of notch 101c.

A plurality of functional elements 102 are disposed on the surface 101a of the substrate 101. Each functional element 102 may be, for example, a light-receiving element such as a photodiode, a light-emitting element such as a laser diode, or a circuit element such as a memory. Each functional element 102 may sometimes be a three-dimensional structure formed by stacking multiple layers.

The object 100 is cut into functional elements 102 along each of a plurality of lines 90. The lines 90 extend in a grid pattern, passing through the plurality of functional elements 102 when viewed in the thickness direction of the object 100 (a direction intersecting the front surface 101a and the back surface 101b). In the object 100, a street region 103 extends in a grid pattern, passing through the plurality of functional elements 102, with each line 90 passing through the center of the street region 103. The lines 90 are virtual lines set on the object 100 using the laser processing apparatus 1. Alternatively, the lines 90 may be lines actually drawn on the object 100.

[Functions of the Control Unit]

As a prerequisite, as shown in Figures 9 and 10 , a laser processing device 1 irradiates laser light L onto an object 100 having a surface intersecting the Z direction (in this embodiment, the front surface 101a or the back surface 101b of the substrate 101). This forms a modified region M on the object 100 along a first line 91 and a 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 to each other in the Y direction, among a plurality of lines 90.

Furthermore, in each laser machining head 10A or 10B, the distance measuring unit 16 (see FIG. 5 ) is configured to adjust the position of the irradiation area R of the distance measuring light L10 in the Y direction by at least the distance between the first line 91 and the second line 92. The irradiation area R of the light L10 is the area of the light L10 irradiated on the surface of the object 100 (in this embodiment, the surface 101a or the back surface 101b of the substrate 101). In this embodiment, the adjustment unit 162 adjusts the optical axis of the light L10 irradiated onto the surface 101a or the back surface 101b of the substrate 101 (see FIG. 5 ), enabling the position of the irradiation area R of the light L10 in the Y direction to be adjusted by at least the distance between the first line 91 and the second line 92.

Based on the above premise, the functions of the control unit 9 will be explained below, focusing on the first line 91 and the second line 92 extending in the X-direction and adjacent to each other in the Y-direction. The following description does not specify which of the pair of laser processing heads 10A and 10B is the entity irradiating the object 100 with laser light L. However, this entity may be either or both of the pair of laser processing heads 10A and 10B. Furthermore, the following description uses the first line 91 and the second line 92 extending in the X-direction and adjacent to each other in the Y-direction as the minimum unit, but is applicable to all lines 90.

As shown in FIG9 , when the object 100 is supported by the support unit 7 (hereinafter referred to as "surface incidence") such that laser light L is incident on the substrate 101 from the side of the plurality of functional elements 102 (i.e., laser light L is incident on the substrate 101 from the area corresponding to the track area 103 on the surface 101a of the substrate 101), the control unit 9 functions as follows. The control unit 9 controls the spatial light modulator 36 so that the laser light L is split into first processing light L1 and second processing light L2, with the first focal point C1 of the first processing light L1 being located on the first line 91 and the second focal point C2 of the second processing light L2 being located on the second line 92. Furthermore, the control unit 9 controls the moving mechanism 5 (see Figure 1) to move the illumination area R of the distance-measuring light L10 on the surface 101a and the first and second light-converging points C1 and C2 relative to each other along the first and second lines 91 and 92. Furthermore, based on the detection results of the light L10 by the distance-measuring unit 16, the control unit 9 controls the driving unit 18 (see Figure 5) to position the first and second light-converging points C1 and C2 at predetermined positions relative to the surface 101a (for example, to maintain the distances between the surface 101a and the first and second light-converging points C1 and C2 constant).

In the case of surface incidence, the optical axis of the light L10 irradiating the surface 101a is adjusted by the adjustment unit 162 (see FIG5 ) so that the irradiation area R is located on the first line 91 or the second line 92. Adjustment by the adjustment unit 162 can be performed manually by an operator or automatically by the control unit 9.

As shown in FIG10 , when the object 100 is supported by the support unit 7 so that the laser light L enters the substrate 101 from the side opposite to the plurality of functional elements 102 (i.e., the laser light L enters the substrate 101 from the back surface 101b of the substrate 101) (hereinafter referred to as the back surface incidence case), the control unit 9 functions as follows. The control unit 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, with the first focal point C1 of the first processing light L1 being located on the first line 91 and the second focal point C2 of the second processing light L2 being located on the second line 92. Furthermore, the control unit 9 controls the movement mechanism 5 (see FIG1 ) to move the illumination area R of the distance-measuring light L10 on the back surface 101b and the first and second light-converging points C1 and C2 relative to each other along the first and second lines 91 and 92 . Furthermore, based on the detection results of the light L10 by the distance-measuring unit 16 , the control unit 9 controls the drive unit 18 (see FIG5 ) to position the first and second light-converging points C1 and C2 at predetermined positions relative to the back surface 101b (e.g., to maintain the respective distances between the back surface 101b and the first and second light-converging points C1 and C2 at a constant level).

In the case of back-side incidence, the optical axis of light L10 directed toward back surface 101b is adjusted using adjustment unit 162 (see Figure 5 ) so that irradiation area R is located on the center line between first line 91 and second line 92 (i.e., a line equidistant from first line 91 and second line 92, respectively). Adjustment by adjustment unit 162 can be performed manually by an operator or automatically by control unit 9.

Furthermore, the phrase "the first light-converging point C1, the second light-converging point C2, or the irradiation area R is located at a predetermined location (the first line 91, the second line 92, the center line between the first and second lines 91, 92, the area between the first and second lines 91, 92, etc.) means that the first light-converging point C1, the second light-converging point C2, or the irradiation area R is located at the predetermined location when viewed from the Z direction. In the above description, the moving mechanism 5 functions as the moving portion that moves the light-converging portion 14 and the distance-measuring portion 16 relative to the support portion 7. However, the moving mechanism 6 may function as the moving portion, or a plurality of moving mechanisms 5 and 6 may function as the moving portion (see FIG. 1 ). Furthermore, the circuit unit 19 (see FIG. 5 ) included in each of the laser processing heads 10A and 10B can also function as at least a portion of the control unit 9.

[Laser processing device operation]

As a prerequisite, as shown in Figure 2 , the laser processing apparatus 1 includes an imaging unit 3. The imaging unit 3 captures an image of the object 100. The imaging unit 3 is comprised of, for example, an InGaAs camera and captures an image of the object 100 using near-infrared light. The imaging unit 3 is mounted, for example, on the mounting portion 65 of the moving mechanism 6 . For example, if the substrate 101 of the object 100 is a silicon substrate and the imaging unit 3 captures an image of the object 100 using near-infrared light, the imaging unit 3 can capture images of the functional elements 102 and the track region 103 (see Figure 7 ) not only from the functional elements 102 side, but also from the back surface 101b of the substrate 101.

As shown in FIG11 , the laser processing apparatus 1 includes an input receiving unit 4 including a display unit 4a. The display unit 4a displays the image of the object 100 captured by the imaging unit 3 as a 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 keyboard.

Based on the above premise, the following description of the operation of the laser processing device 1 focuses on a first line 91 and a second line 92 extending in the X-direction and adjacent to each other in the Y-direction. While the following description does not specify which of the pair of laser processing heads 10A and 10B is the entity irradiating the object 100 with laser light L, the entity may be either or both of the pair of laser processing heads 10A and 10B. Furthermore, the following description uses the first line 91 and the second line 92 extending in the X-direction and adjacent to each other in the Y-direction as the minimum unit and is applicable to all lines 90.

First, the object 100 is placed on the support 7. Next, as shown in Figure 11, when the operator operates the input receiving unit 4 and selects "Dual Line Divergence Processing" on the display unit 4a, the display unit 4a displays the graphics of the object 100, the first line 91, the second line 92, and the reference line 93. The graphic of the object 100 is the image of the object 100 captured by the imaging unit 3. The reference line 93 corresponds to the trajectory of the optical axis of the focusing unit 14 as it moves relative to the object 100.

Next, when the operator operates the input receiving unit 4 and inputs a numerical value into the "Branch Gap" field on the display unit 4a, the display unit 4a shifts the first line 91 and the second line 92 in the Y direction about the reference line 93 in the graph so that the distance between the first line 91 and the second line 92 in the graph becomes the numerical value. Furthermore, when the operator operates the input receiving unit 4 and shifts the first line 91 and the second line 92 in the Y direction about the reference line 93 in the graph, the display unit 4a displays the distance between the first line 91 and the second line 92 in the graph in the "Branch Gap" field. The numerical value of the divergence gap is the distance (in the Y direction) between the first focal point C1 of the first processing light beam L1 and the second focal point C2 of the second processing light beam L2. In this way, the input receiving unit 4 can receive information (first information) regarding the positions of the first and second focal points C1, C2 in the Y direction. Furthermore, to change the first and second lines 91, 92, which are the laser processing targets, the control unit 9 controls the moving mechanism 5 based on the input divergence interval value, causing the focusing unit 14 and distance measuring unit 16 to move in the Y direction by a distance twice the divergence interval value.

The operator then operates the input receiving unit 4 to select [Baseline], [Adjust to Line 1], or [Adjust to Line 2] as the [Distance Measurement Position] on the display unit 4a. The distance measurement position is the position (in the Y direction) of the irradiation area R of the distance measurement light L10. In the case of surface incidence, as shown in FIG9 , if the irradiation area R is to be positioned on the first line 91 or on the second line 92, the operator simply selects [Adjust to Line 1] or [Adjust to Line 2]. In the case of backside incidence, as shown in FIG10 , if the irradiation area R is to be positioned on the center line between the first line 91 and the second line 92, the operator simply selects the Baseline. In this way, the input receiving unit 4 can receive input of [information regarding the position of the irradiation area R in the Y direction (second information)].

Next, as shown in Figure 12, the control unit 9 sequentially performs the following processes: Based on the irradiation conditions of laser light L, including the value input to the "Bifurcation Interval" field, it determines the modulation pattern to be input to the spatial light modulator 36 (step S01); adjusts the position of the irradiation area R in accordance with the "Baseline," "Adjust to First Line Side," or "Adjust to Second Line Side" selected as the "Range Measurement Position" (step S02); and performs laser processing (step S03). In this way, the control unit 9 controls the spatial light modulator 36 based on the information regarding the positions of the first and second focal points C1, C2 in the Y direction, so that the first focal point C1 is located on the first line 91 and the second focal point C2 is located on the second line 92. Furthermore, the control unit 9 controls the distance measuring unit 16 based on the information regarding the position of the irradiation area R in the Y direction, so that the irradiation area R is located on the first line 91, the second line 92, or the center line between the first and second lines 91, 92.

Figure 13 is a schematic diagram illustrating the positional relationship between a reference line 93, a first line 91, and a second line 92 when laser processing is performed using surface incidence (see Figure 9) by the laser processing apparatus 1 shown in Figure 1. As shown in Figures 13(a) and 13(b), the first line 91 and the second line 92 are located on either side of the reference line 93 in the Y direction, with the reference line 93 as the center line. As shown in Figure 13(a), the focusing unit 14 is located on the reference line 93. As shown in Figure 13(b), the first focal point C1 and the irradiation area R are located on the first line 91, and the second focal point C2 is located on the second line 92.

Figure 14 is a schematic diagram showing the positional relationship between a reference line 93, a first line 91, and a second line 92 when laser processing is performed using back-injection (see Figure 10) by the laser processing apparatus 1 shown in Figure 1. As shown in Figures 14(a) and 14(b), the first line 91 and the second line 92 are located on either side of the reference line 93 in the Y direction, with the reference line 93 as the center line. As shown in Figure 14(a), the focusing unit 14 is located on the reference line 93. As shown in Figure 14(b), the first focal point C1 is located on the first line 91, the second focal point C2 is located on the second line 92, and the irradiation area R is located on the reference line 93 (the center line between the first and second lines 91, 92).

Furthermore, the input receiving unit 4 may also receive input of information regarding the incident side of the laser light L on the object 100 (third information). Furthermore, in the case of surface incidence as shown in FIG9 , the control unit 9 controls the distance measuring unit 16 based on the information regarding the position of the irradiation area R in the Y direction so that the irradiation area R is located on the first line 91 or the second line 92 . On the other hand, in the case of backside incidence as shown in FIG10 , the control unit 9 controls the distance measuring unit 16 based on the information regarding the position of the irradiation area R in the Y direction so that the irradiation area R is located on the center line between the first line 91 and the second line 92 .

Alternatively, the operator can manually adjust the adjustment unit 162 so that the irradiation area 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. In this case, the control unit 9 can omit the process of adjusting the position of the irradiation area R (step S02).

[Functions and Effects]

In the laser processing apparatus 1, the control unit 9 controls the spatial light modulator 36 to split the laser light L into the first processing light L1 and the second processing light L2. The first focal point C1 of the first processing light L1 is located on the first line 91, and the second focal point C2 of the second processing light L2 is located on the second line 92. Furthermore, the control unit 9 controls the moving mechanism 5 to move the irradiation area R of the distance-measuring light L10 and the first and second focal points C1 and C2 relative to each other along the first and second lines 91 and 92. At this time, the control unit 9 controls the driver 18 based on the detection results of the distance-measuring light L10 by the distance-measuring unit 16, so that the first and second focal points C1 and C2 are located at predetermined positions relative to the front surface 101a and back surface 101b of the object 100, respectively. In this manner, the modified region M can be formed in the object 100 along the first line 91 and the second line 92, respectively, with the modified region M located at a predetermined position relative to the surface 101a or the back surface 101b of the object 100. In the laser processing apparatus 1, the distance measuring unit 16 is configured to adjust the position of the irradiation region R of the distance measuring light L10 in the Y direction by at least the distance between the first line 91 and the second line 92. Therefore, the position of the irradiation region R of the distance measuring light L10 can be adjusted in the Y direction based on the irradiation conditions of the laser light L, and the modified region M can be formed with high precision at a predetermined position relative to the surface 101a or the back surface 101b of the object 100. Therefore, using the laser processing apparatus 1, when forming the modified region M in the object 100 along each of a plurality of lines, the processing time can be shortened.

In the laser processing apparatus 1, the input receiving unit 4 receives information regarding the Y-direction positions of the first and second focal points C1, C2. Based on this information, the control unit 9 controls the spatial light modulator 36 so that the first focal point C1 is located on the first line 91 and the second focal point C2 is located on the second line 92. This allows the modified region M to be easily and accurately formed along the first and second lines 91, 92, respectively.

In the laser processing apparatus 1, the input receiving unit 4 receives information regarding the position of the irradiation area R in the Y direction. Based on this information, the control unit 9 controls the distance measuring unit 16 so that the irradiation area R is located on the first line 91, the second line 92, or the center line between the first and second lines 91, 92. This allows the modified area M to be easily and accurately formed at a predetermined position on the front surface 101a or back surface 101b of the object 100.

In the laser processing apparatus 1, the input receiving unit 4 receives information regarding the incident side of the laser light L on the object 100. In the case of surface incidence as shown in FIG9 , the control unit 9 controls the distance measuring unit 16 based on this information so that the irradiation area R is located on the first line 91 or the second line 92. In the case of rear-side incidence as shown in FIG10 , the control unit 9 controls the distance measuring unit 16 based on this information so that the irradiation area R is located on the center line between the first line 91 and the second line 92. In this way, in the case of surface incidence, the distance measuring light L10 can be prevented from being affected by the functional element 102, and the modified area M can be formed at a predetermined position relative to the front surface 101a or rear surface 101b of the object 100. Furthermore, in the case of back-side illumination, the modified region M can be formed uniformly along the first line 91 and the second line 92.

In the laser processing device 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 allows the user to visually grasp the status of the processing.

In the laser processing device 1, the display unit 4a displays a reference line 93 corresponding to the trajectory of the optical axis of the focusing unit 14 relative to the object 100. This allows the user to visually grasp the planned processing status based on the optical axis of the focusing unit 14.

In the laser processing device 1, the imaging unit 3 captures an image of the object 100, and the display unit 4a displays the image of the object 100 as a graphic of the object 100. This makes it possible to easily capture a graphic 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 focusing unit 14. The main body 161 irradiates the light L10 toward the front surface 101a or the back surface 101b while detecting the light L10 reflected from the front surface 101a or the back surface 101b. The adjustment unit 162 adjusts the optical axis of the light L10 irradiated toward the front surface 101a or the back surface 101b. This configuration is effective when the irradiation area R of the distance measuring light L10 needs to be reduced (for example, when the width of the track area 103 is narrow in the case of surface incidence).

[Variations]

The present invention is not limited to the above-described embodiment. For example, the distance measuring unit 16 may be configured so that the distance measuring light L10 does not pass through the focusing unit 14. Specifically, as shown in FIG15 , the distance measuring unit 16 may be mounted on the device frame 1a in a non-coaxial manner with the focusing unit 14. In this case, the distance measuring unit 16 may include a main body 163 and an adjustment unit 164. The main body 163 irradiates the surface 101a or the back surface 101b with light L10, and simultaneously detects the light L10 reflected from the surface 101a or the back surface 101b. The adjustment unit 164 is a portion for adjusting the position of the main body 163 in the Y direction. The adjustment unit 164 moves the main body 163 in the Y direction so as to adjust the position of the irradiation area R of the distance measuring light L10 in the Y direction by at least the amount of the interval between the first line 91 and the second line 92. This structure is effective when irradiating the surface of object 100 with distance-measuring light L10 through a member such as tape. Furthermore, the distance-measuring unit 16 shown in FIG15 can use sensors using triangulation, laser confocal, white light confocal, spectral interferometry, or astigmatism.

Figure 16 is a schematic diagram illustrating the positional relationship between a reference line 93, a first line 91, and a second line 92 when laser processing is performed using surface incidence (see Figure 9) by the laser processing apparatus 1 shown in Figure 15. As shown in Figures 16(a) and 16(b), the first line 91 and the second line 92 are located on either side of the reference line 93 in the Y direction, with the reference line 93 as the center line. As shown in Figure 16(a), the focusing unit 14 is located on the reference line 93, and the main body 163 is located on the first line 91. As shown in Figure 16(b), the first focal point C1 and the irradiation area R are located on the first line 91, while the second focal point C2 is located on the second line 92.

Figure 17 is a schematic diagram showing the positional relationship between the reference line 93, the first line 91, and the second line 92 when laser processing is performed using back-injection (see Figure 10) by the laser processing apparatus 1 shown in Figure 15. As shown in Figures 17(a) and 17(b), the first line 91 and the second line 92 are located on either side of the reference line 93 in the Y direction, with the reference line 93 as the center line. As shown in Figure 17(a), the focusing unit 14 and the main body 163 are located on the reference line 93. As shown in Figure 17(b), the first focal point C1 is located on the first line 91, the second focal point C2 is located on the second line 92, and the irradiation area R is located on the reference line 93 (the center line between the first line 91 and the second line 92).

In either the laser processing apparatus 1 shown in FIG. 1 or the laser processing apparatus shown in FIG. 15 , the first line 91 can be located on the reference line 93.

Figure 18 is a schematic diagram showing the positional relationship between a reference line 93, a first line 91, and a second line 92 when laser processing is performed by the laser processing apparatus 1 shown in Figure 1 using either surface incidence (see Figure 9) or back incidence (see Figure 10). As shown in Figures 18(a) and 18(b), the first line 91 is located on the reference line 93, and the second line 92 is located to one side of the reference line 93 in the Y direction. As shown in Figure 18(a), the focusing unit 14 is located on the reference line 93. As shown in Figure 18(b), the first focal point C1 and the irradiation area R are located on the reference line 93 (on the first line 91), and the second focal point C2 is located on the second line 92.

Figure 19 is a schematic diagram illustrating the positional relationship between a reference line 93, a first line 91, and a second line 92 when laser processing is performed using the laser processing apparatus 1 shown in Figure 15 using either surface incidence (see Figure 9) or back incidence (see Figure 10). As shown in Figures 19(a) and 19(b), the first line 91 is located on the reference line 93, and the second line 92 is located to one side of the reference line 93 in the Y direction. As shown in Figure 19(a), the focusing unit 14 and the main body 163 are located on the reference line 93. As shown in Figure 19(b), the first focal point C1 and the irradiation area R are located on the reference line 93 (on the first line 91), and the second focal point C2 is located on the second line 92.

Figure 20 shows the structure of the display unit 4a in the case shown in Figures 18 and 19. In the case shown in Figures 18 and 19, the irradiation area R is always located on the reference line 93 (on the first line 91). Therefore, the display unit 4a shown in Figure 20 does not have a column for selecting the distance measurement position, as in the display unit 4a shown in Figure 11.

In the laser processing device 1 shown in Figure 1 , the position and angle of the photodetector (which detects light L10 reflected from the front surface 101a or back surface 101b) can also be adjusted in the main body 161. This allows the photodetector to reliably detect light L10 reflected from the front surface 101a or back surface 101b when the optical axis of light L10 is adjusted by the adjustment unit 162.

In the laser processing apparatus 1 shown in FIG15 , a pair of distance measuring units 16 may be provided on both sides of the light focusing unit 14 in the X direction. When the first and second light focusing points C1, C2 are moved relative to each other along the first and second lines 91, 92 in one direction in the X direction, one distance measuring unit 16 may be used. When the first and second light focusing points C1, C2 are moved relative to each other along the first and second lines 91, 92 in the other direction in the X direction, the other distance measuring unit 16 may be used.

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

When laser processing is performed using surface injection (see FIG9 ) by the laser processing apparatuses 1 shown in FIG1 and FIG15 , the irradiation region R only needs to be within the track region 103 when viewed from the Z direction, and may be slightly offset from the first line 91 or the second line 92.

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

Alternatively, the input receiving unit 4 receives information about the object 100 (such as the size of each functional element 102 and the width of the track area 103), and the control unit 9 generates a graphic of the object 100 based on the information, which is then displayed on the display unit 4a.

One aspect of the present invention provides a laser processing apparatus for forming a modified region in an object along a first line and a second line, respectively, by irradiating an object with laser light. The object has a surface intersecting a Z direction, and the first line and the second line extend in an X direction perpendicular to the Z direction and are adjacent to each other in a Y direction perpendicular to both the Z and X directions. The laser processing apparatus comprises: a support portion for supporting the object; a light source for emitting laser light; a spatial light modulator for modulating the laser light emitted from the light source; a focusing portion for focusing the laser light modulated by the spatial light modulator; a distance measuring portion for irradiating the surface with distance measuring light and detecting the distance measuring light reflected from the surface; and a positioning mechanism for positioning the focusing portion and the distance measuring portion relative to the support portion. A moving portion that moves relative to the support portion; a driving portion that moves the focusing portion in the Z direction; and a control portion that controls the spatial light modulator to split the laser light into a first processing light and a second processing light, with the first focusing point of the first processing light positioned on the first line and the second focusing point of the second processing light positioned on the second line. Furthermore, the moving portion is controlled to move the irradiation area, the first focusing point, and the second focusing point on the surface of the distance-measuring light relative to each other along the first line and the second line. Furthermore, the driving portion is controlled based on the detection result of the distance-measuring light by the distance-measuring portion to position the first focusing point and the second focusing point at predetermined positions relative to the surface. The distance-measuring portion is configured to adjust the position of the irradiation area in the Y direction by at least the distance between the first line and the second line.

In the above-described laser processing device, a control unit controls the spatial light modulator to split the laser light into a first processing light and a second processing light, with the first focal point of the first processing light positioned on a first line and the second focal point of the second processing light positioned on a second line. Furthermore, the control unit controls the moving unit to move the illumination area of the distance-measuring light on the surface of the object, the first focal point, and the second focal point relative to each other along the first and second lines. At this time, the control unit controls the driving unit based on the detection results of the distance-measuring light by the distance-measuring unit to position the first and second focal points at predetermined positions relative to the surface of the object. In this manner, a modified region can be formed in the object along the first and second lines, respectively, while the modified region is positioned at the predetermined position relative to the surface of the object. In the laser processing apparatus described above, the distance measuring unit is configured to adjust the position of the area irradiated by the distance measuring light in the Y direction by at least the distance between the first and second lines. Therefore, the position of the area irradiated by the distance measuring light can be adjusted in the Y direction based on, for example, the laser light irradiation conditions, enabling the formation of a modified area at a predetermined position on the surface of the object with high precision. Consequently, the laser processing apparatus can shorten processing time when forming a modified area in an object along each of a plurality of lines.

One aspect of the present invention may further include an input receiving unit that receives first information regarding the positions of the first and second focal points in the Y direction. The control unit controls the spatial light modulator based on the first information so that the first focal point is located on the first line and the second focal point is located on the second line. This allows for easy and highly accurate formation of modified regions along the first and second lines.

In one aspect of the laser processing apparatus of the present invention, the input receiving unit may further receive second information regarding the position of the irradiation area in the Y direction, and the control unit may control the distance measuring unit based on the second information so that the irradiation area is located on the first line, on the second line, or between the first and second lines. This allows for easy and highly accurate formation of a modified area at a predetermined position on the surface of an object.

In one aspect of the present invention, a laser processing apparatus may include an object including a substrate and a plurality of functional elements arranged in a matrix on the substrate. The input receiving unit further receives third information regarding the incident side of the laser light entering the object. The control unit controls the distance measuring unit based on the third information so that an irradiation area is located on a first line or a second line when the laser light enters the substrate from the side facing the plurality of functional elements. Furthermore, the control unit controls the distance measuring unit based on the third information so that an irradiation area is located on a center line between the first line and the second line when the laser light enters the substrate from a side opposite to the plurality of functional elements. This allows laser light to enter the substrate from the side facing multiple functional elements, preventing the functional elements from affecting the distance-measuring light and forming a modified region at a predetermined position relative to the object's surface. Furthermore, when laser light enters the substrate from the side opposite the functional elements, the modified region can be uniformly formed along both the first and second lines.

In one aspect of the laser processing apparatus of the present invention, the input receiving unit may include a display unit for displaying the graphics of the object, the first line, and the second line. This allows the user to visually grasp the status of the processing.

In one embodiment of the laser processing device of the present invention, the display unit may further display a reference line corresponding to the trajectory of the optical axis of the focusing unit moving relative to the object. This allows for visual understanding of the planned processing status relative to the optical axis of the focusing unit.

One aspect of the present invention may further include a camera unit for capturing an image of an object, and a display unit for displaying the image of the object as a pattern of the object. This facilitates capturing a pattern of the object.

In one aspect of the laser processing device of the present invention, the distance measuring unit may be configured such that distance measuring light irradiated onto a surface and distance measuring light reflected from the surface pass through a focusing unit. The distance measuring unit includes: a main unit for irradiating the distance measuring light onto the surface and detecting the distance measuring light reflected from the surface; and an adjustment unit for adjusting the optical axis of the distance measuring light irradiated onto the surface. This configuration is effective when the irradiation area of the distance measuring light needs to be reduced.

In one aspect of the laser processing device of the present invention, the distance measuring unit may be configured so that distance measuring light irradiated onto a surface and distance measuring light reflected from the surface do not pass through a focusing unit. The distance measuring unit includes a main body for irradiating the distance measuring light onto the surface and detecting the distance measuring light reflected from the surface; and an adjustment unit for adjusting the position of the main body in the Y direction. This configuration is effective when irradiating the distance measuring light onto the surface of an object through a member such as tape.

According to the present invention, a laser processing device can be provided that can shorten processing time while forming a modified region in an object along each of a plurality of lines.

7: Supporting part

14: Spotlight Department

90: Line

91: Line 1

92: Line 2

101:Substrate

101a: Surface

101b: Back

102: Functional Components

103: Trail Area

C1: First focal point

C2: Second focal point

L: Laser light

L1: 1st processing light

L2: Second processing light

L10: Light (for distance measurement)

M: modified area

R: Irradiation area

Claims (10)

A laser processing device is provided for forming a modified region in an object along a first line and a second line respectively by irradiating a laser beam onto the object, wherein the object has a surface intersecting the Z direction, the first line and the second line extend in the X direction perpendicular to the Z direction and are adjacent to each other in the Y direction perpendicular to both the Z direction and the X direction, and the device is characterized by comprising: a support portion for supporting the object; a support portion for emitting the laser beam; a light source for laser light; a spatial light modulator for modulating the laser light emitted from the light source; a light-collecting unit for collecting the laser light modulated by the spatial light modulator; a distance-finding unit for irradiating the distance-finding light onto the surface and detecting the distance-finding light reflected from the surface; a moving unit for moving the light-collecting unit and the distance-finding unit relative to the supporting unit; a driving unit for moving the light-collecting unit in the Z direction; and a control unit for controlling the light-collecting unit. The spatial light modulator is controlled so that the laser light is split into a first processing light and a second processing light, and the first focal point of the first processing light is located on the first line and the second focal point of the second processing light is located on the second line. The moving unit is controlled so that the irradiation area of the distance measurement light on the surface, the first focal point, and the second focal point move relative to each other along the first line and the second line. The distance measuring unit controls the driving unit based on the detection result of the distance measuring light so that the first and second light focusing points are respectively located at predetermined positions relative to the surface. The distance measuring unit is configured to adjust the position of the irradiated area in the Y direction by at least the distance between the first and second lines. The first and second lines are respectively lines for segmenting the object, and the modified area is a modified area for severing the object. The laser processing apparatus of claim 1 further comprises an input receiving unit that receives first information regarding the positions of the first and second focal points in the Y direction, wherein the control unit controls the spatial light modulator based on the first information so that the first focal point is located on the first line and the second focal point is located on the second line. In the laser processing apparatus of claim 2, the input receiving unit further receives second information regarding the position of the irradiation area in the Y direction, and the control unit controls the distance measuring unit based on the second information so that the irradiation area is located on the first line or the second line, or between the first line and the second line. The laser processing apparatus of claim 2, wherein the object comprises a substrate and a plurality of functional elements arranged in a matrix on the substrate; the input receiving unit further receives third information regarding the incident side of the laser light on the object; and the control unit controls the distance measuring unit based on the third information so that when the laser light enters the substrate from the side of the plurality of functional elements, the irradiation area is located on the first line or the second line. Furthermore, the distance measuring unit controls the distance measuring unit based on the third information so that when the laser light enters the substrate from the side opposite to the plurality of functional elements, the irradiation area is located on a center line between the first line and the second line. The laser processing device according to any one of claims 2 to 4, wherein the input receiving unit includes a display unit for displaying the respective patterns of the object, the first line, and the second line. The laser processing device of claim 5, wherein the display unit further displays a reference line, the reference line corresponding to a trajectory of the optical axis of the focusing unit moving relative to the object. The laser processing apparatus of claim 5 further comprises an imaging unit for acquiring an image of the object, wherein the display unit displays the image of the object as the graphic of the object. The laser processing apparatus of claim 6 further comprises an imaging unit for acquiring an image of the object, wherein the display unit displays the image of the object as the graphic of the object. The laser processing apparatus according to any one of claims 1 to 4, wherein the distance measuring unit is configured such that the distance measuring light irradiated onto the surface and the distance measuring light reflected from the surface pass through the light focusing unit, and the distance measuring unit includes: a main body for irradiating the distance measuring light onto the surface and detecting the distance measuring light reflected from the surface; and an adjustment unit for adjusting the optical axis of the distance measuring light irradiated onto the surface. The laser processing apparatus according to any one of claims 1 to 4, wherein the distance measuring unit is configured so that the distance measuring light irradiated onto the surface and the distance measuring light reflected from the surface do not pass through the light focusing unit, and the distance measuring unit includes: a main body for irradiating the distance measuring light onto the surface and detecting the distance measuring light reflected from the surface; and an adjustment unit for adjusting the position of the main body in the Y direction.