Laser processing device

Abstract

The present invention provides a laser processing apparatus that can shorten the processing time when forming modified regions in an object along each of a plurality of lines. The laser processing apparatus includes a control unit. The control unit controls a spatial light modulator so that the laser beam is split into a first processing light and a second processing light, and a first convergence point of the first processing light is located on a first line, and a second convergence point of the second processing light is located on a second line, and controls a moving unit so that an irradiation region of the light for distance measurement, the first convergence point, and the second convergence point relatively move along the first line and the second line. In addition, the control unit controls a driving unit so that the first convergence point and the second convergence point are respectively located at prescribed positions with respect to the surface of the object. The distance measurement unit is configured to be able to adjust the position of the irradiation region in the Y direction by at least the amount of the interval between the first line and the second line.

Description

Technical Field

[0001] The present invention relates to a laser processing apparatus. Background Art

[0002] As a laser processing apparatus that irradiates an object with laser light to form a modified region in the object, there is known an apparatus that modulates the laser light to split the laser light into a plurality of processing light beams and converges the plurality of processing light beams to different positions (for example, refer to Japanese Patent Application Laid-Open No. 2015-223620 and Japanese Patent Application Laid-Open No. 2015-226012). Such a laser processing apparatus is very effective in shortening the processing time because it can form a plurality of rows of modified regions using a plurality of processing light beams. Summary of the Invention

[0003] For example, in an object including a substrate and a plurality of functional elements arranged in a matrix on the substrate, the refinement of the functional elements is in progress. With the development of the refinement of the functional elements, the number of lines (cutting lines) for cutting the object for each functional element increases. Therefore, how to efficiently form a modified region in the object along each of the plurality of lines is important for shortening the processing time.

[0004] An object of the present invention is to provide a laser processing apparatus capable of shortening the processing time when forming a modified region in an object along each of a plurality of lines.

[0005] One aspect of the present invention provides a laser processing apparatus that forms modified regions in an object along a first line and a second line by irradiating the object with laser light. The object has a surface that intersects 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 apparatus includes: 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 condenser portion for converging the laser light modulated by the spatial light modulator; a distance measuring portion that irradiates the surface with light for distance measurement and detects the light for distance measurement reflected by the surface; a moving portion for relatively moving the condenser portion and the distance measuring portion with respect to the support portion; a driving portion for moving the condenser portion in the Z direction; and a control portion that controls the spatial light modulator so that the laser light is split into first processing light and second processing light, and 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. The control portion controls the moving portion so that the irradiation region of the light for distance measurement, the first convergence point, and the second convergence point on the surface move relatively along the first line and the second line. The control portion controls the driving portion based on the detection result of the distance measuring portion for the light for distance measurement so that the first convergence point and the second convergence point are respectively located at predetermined positions with respect to the surface. The distance measuring portion is configured to be able to adjust the position of the irradiation region in the Y direction by at least the amount of the interval between the first line and the second line. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a perspective view of a laser processing apparatus according to an embodiment.

[0007] Figure 2 is Figure 1 a front view of a part of the laser processing apparatus shown.

[0008] Figure 3 is Figure 1 a front view of a laser processing head of the laser processing apparatus shown.

[0009] Figure 4 is Figure 3 a side view of the laser processing head shown.

[0010] Figure 5 is Figure 3 a structural diagram of an optical system of the laser processing head shown.

[0011] Figure 6 is Figure 5 a cross-sectional view of a part of the spatial light modulator shown.

[0012] Figure 7 is a top view of an object to be processed by Figure 1 the laser processing apparatus shown.

[0013] Figure 8 is Figure 7 A cross-sectional view of a part of the object shown.

[0014] Figure 9 represents Figure 1 A schematic diagram showing the state of laser processing in the laser processing apparatus shown.

[0015] Figure 10 represents Figure 1 A schematic diagram showing the state of laser processing in the laser processing apparatus shown.

[0016] Figure 11 is Figure 1 A structural diagram of the display unit of the laser processing apparatus shown.

[0017] Figure 12 is a Figure 1 Flowchart of the laser processing method implemented by the laser processing apparatus shown.

[0018] Figure 13 represents Figure 1 A schematic diagram showing the positional relationship of the reference line, the first line, and the second line in the laser processing apparatus shown.

[0019] Figure 14 represents Figure 1 A schematic diagram showing the positional relationship of the reference line, the first line, and the second line in the laser processing apparatus shown.

[0020] Figure 15 A schematic diagram showing the structure of a modified example of the laser processing apparatus.

[0021] Figure 16 represents Figure 15 A schematic diagram showing the positional relationship of the reference line, the first line, and the second line in the laser processing apparatus shown.

[0022] Figure 17 represents Figure 15 A schematic diagram showing the positional relationship of the reference line, the first line, and the second line in the laser processing apparatus shown.

[0023] Figure 18 represents Figure 1 A schematic diagram showing the positional relationship of the reference line, the first line, and the second line in the laser processing apparatus shown.

[0024] Figure 19 represents Figure 15 A schematic diagram showing the positional relationship of the reference line, the first line, and the second line in the laser processing apparatus shown.

[0025] Figure 20 is Figure 18 andFigure 19 Structural diagram of the display unit in the shown case. Detailed implementation mode

[0026] The implementation mode of the present invention will be described in detail below with reference to the accompanying drawings. The same or equivalent parts are labeled with the same reference numerals in each figure, and repeated descriptions are omitted.

[0027] [Structure of the laser processing device]

[0028] As Figure 1 shown, the laser processing device 1 includes a plurality of moving mechanisms 5, 6, a support portion 7, a pair of laser processing heads 10A, 10B, a light source unit 8, and a control portion 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 direction and the second direction will be referred to as the Y direction. In the present embodiment, the Z direction is the vertical direction, and the X direction and the Y direction are the horizontal directions.

[0029] The moving mechanism 5 has 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 can move along the Y direction. The mounting portion 55 is mounted on a track provided on the moving portion 53 and can move along the X direction.

[0030] The moving mechanism 6 has a fixed portion 61, a pair of moving portions 63, 64, and a pair of mounting portions 65, 66. The fixed portion 61 is mounted on the device frame 1a. The pair of moving portions 63, 64 are respectively mounted on tracks provided on the fixed portion 61 and can each independently move along the Y direction. The mounting portion 65 is mounted on a track provided on the moving portion 63 and can move along the Z direction. The mounting portion 66 is mounted on a track provided on the moving portion 64 and can move along the Z direction.

[0031] The support portion 7 is mounted on a rotating shaft, the rotating shaft is provided on the mounting portion 55 of the moving mechanism 5, and the support portion 7 can rotate with an axis parallel to the Z direction as the center line. The support portion 7 is used to support the object 100. The object 100 is a wafer.

[0032] As Figure 1 and Figure 2 shown, the laser processing head 10A is mounted on the mounting portion 65 of the moving mechanism 6. The laser processing head 10A is opposed to the support portion 7 in the Z direction, and in this state, irradiates the object 100 supported on the support portion 7 with the laser beam L. The laser processing head 10B is mounted on the mounting portion 66 of the moving mechanism 6. The laser processing head 10B is opposed to the support portion 7 in the Z direction, and in this state, irradiates the object 100 supported on the support portion 7 with the laser beam L.

[0033] The light source unit 8 has a pair of light sources 81 and 82. The pair of light sources 81 and 82 are mounted on the apparatus frame 1a. The pair of light sources 81 and 82 each emit a laser beam L. The laser beam L emitted from the emission portion 81a of the light source 81 is guided by the optical fiber 2 to the laser processing head 10A. The laser beam L emitted from the emission portion 82a of the light source 82 is guided by another optical fiber 2 to the laser processing head 10B.

[0034] The control unit 9 controls each part of the laser processing apparatus 1 (a plurality of moving mechanisms 5 and 6, a pair of laser processing heads 10A and 10B, the light source unit 8, etc.). The control unit 9 is configured as a computer device including a processor, a memory, a storage, a communication device, etc. In the control unit 9, software (program) read into the memory etc. is executed by the processor, and the processor controls the reading and writing of data on the memory and the storage and the communication of the communication device. Thereby, the control unit 9 can realize various functions.

[0035] An example of the processing performed on the laser processing apparatus 1 configured as described above will be described. An example of this processing is an example in which, in order to cut a wafer, i.e., an object 100, into a plurality of chips, a modified region is formed inside the object 100 along each of a plurality of lines set in a grid pattern.

[0036] First, the moving mechanism 5 moves the support portion 7 in the X direction and the Y direction respectively so that the support portion 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 portion 7 about an axis parallel to the Z direction so that a plurality of lines extending in one direction on the object 100 are along the X direction.

[0037] Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction so that the convergence point of the laser beam L emitted from the laser processing head 10A (hereinafter referred to as "the laser beam L of the laser processing head 10A") is located on one of the lines extending in one direction. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Y direction so that the convergence point of the laser beam L emitted from the laser processing head 10B (hereinafter referred to as "the laser beam L of the laser processing head 10B") is located on another one of the lines extending in one direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction so that the convergence point of the laser beam L of the laser processing head 10A is located inside the object 100. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Z direction so that the convergence point of the laser beam L of the laser processing head 10B is located inside the object 100.

[0038] Next, the light source 81 emits the laser beam L, and the laser beam L is irradiated onto the object 100 by the laser processing head 10A. Also, the light source 82 emits the laser beam L, and the laser beam L is irradiated onto the object 100 by the laser processing head 10B. At the same time, the moving mechanism 5 moves the support portion 7 in the X direction so that the convergence point of the laser beam L of the laser processing head 10A moves relatively along a line extending in one direction, and the convergence point of the laser beam L of the laser processing head 10B moves relatively along another line extending in one direction. In this way, the laser processing apparatus 1 can form a modified region inside the object 100 along each of a plurality of lines extending in one direction on the object 100.

[0039] Next, the moving mechanism 5 rotates the support portion 7 about an axis parallel to the Z direction so that a plurality of lines extending in another direction orthogonal to one direction on the object 100 are along the X direction.

[0040] Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction so that the convergence point of the laser beam L of the laser processing head 10A is located on a line extending in another 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 beam 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 convergence point of the laser beam L of the laser processing head 10A is located inside the object 100. On the other hand, the moving mechanism 6 moves the laser processing head 10B in the Z direction so that the convergence point of the laser beam L of the laser processing head 10B is located inside the object 100.

[0041] Next, the light source 81 emits the laser beam L, and the laser beam L is irradiated onto the object 100 by the laser processing head 10A. Also, the light source 82 emits the laser beam L, and the laser beam L is irradiated onto the object 100 by the laser processing head 10B. At the same time, the moving mechanism 5 moves the support portion 7 in the X direction so that the convergence point of the laser beam L of the laser processing head 10A moves relatively along a line extending in another direction, and the convergence point of the laser beam L of the laser processing head 10B moves relatively along another line extending in another direction. In this way, the laser processing apparatus 1 can form a modified region inside the object 100 along each of a plurality of lines extending in another direction orthogonal to one direction on the object 100.

[0042] In one example of the above processing, a pair of light sources 81 and 82 respectively emit transmissive laser light L toward the object 100 by, for example, pulse oscillation. When such laser light L converges inside the object 100, at the portion corresponding to the convergence point of the laser light L, the laser light L is particularly absorbed more, and a modified region is formed inside the object 100. The modified region is a region where the density, refractive index, mechanical strength, and other physical properties are different from those of the surrounding unmodified region. As the modified region, for example, there are a melting treatment region, a crack region, an insulation breakdown region, a refractive index change region, and the like.

[0043] When the laser light L emitted by pulse oscillation irradiates the object 100 and the convergence point of the laser light L relatively moves along a line set on the object 100, a plurality of modified points are formed in a row along the line. One modified point is formed by the irradiation of one pulse of the laser light L. A row of modified regions is a set of a plurality of modified points arranged in a row. Depending on the relative movement speed of the convergence 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 are sometimes connected to each other and sometimes separated from each other.

[0044] [Structure of the laser processing head]

[0045] As Figure 3 and Figure 4 shown, the laser processing head 10A includes a housing 11, an incident portion 12, a laser adjustment portion 13, and a condensing portion 14.

[0046] The housing 11 includes a first wall portion 21 and a second wall portion 22, a third wall portion 23 and a fourth wall portion 24, and a fifth wall portion 25 and a sixth wall portion 26. The first wall portion 21 and the second wall portion 22 face 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 face each other in the Z direction.

[0047] 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. In addition, 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 also be greater than the distance between the fifth wall portion 25 and the sixth wall portion 26.

[0048] In the laser processing head 10A, the first wall portion 21 is located on the side opposite to the fixed portion 61 of the moving mechanism 6, and the second wall portion 22 is located on the side of the fixed portion 61. 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 (refer to Figure 2The fifth wall portion 25 is located on the side opposite to the support portion 7 , and the sixth wall portion 26 is located on the side of the support portion 7 .

[0049] The housing 11 is configured so that the housing 11 is mounted on the mounting portion 65 in a state where the third wall portion 23 is disposed on one side of the mounting portion 65 of the moving mechanism 6. Specifically, the mounting portion 65 includes a bottom plate 65a and a mounting plate 65b. The bottom plate 65a is mounted on a rail provided on the moving portion 63 (see FIG. Figure 2 The mounting plate 65b is erected on the end portion of the bottom plate 65a on the side of the laser processing head 10B (see Figure 2 With the third wall 23 in contact with the mounting plate 65b, bolts 28 are screwed onto the mounting plate 65b via the base 27, thereby mounting the housing 11 to the mounting portion 65. The base 27 is provided on the first wall 21 and the second wall 22, respectively. The housing 11 is attachable to and detachable from the mounting portion 65.

[0050] 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.

[0051] The incident portion 12 is connected to the output end 2a of the optical fiber 2. Specifically, the incident portion 12 is a portion including 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 2b of the output end 2a is mounted to the mounting portion 25b using bolts or the like. In this state, the front end 2c of the output end 2a is inserted into the hole 25a. This allows the output end 2a of the optical fiber 2 to be removable relative to the incident portion 12. A cover 25c is disposed between the fifth wall portion 25 and the main body 2b. The cover 25c covers the gap formed between the hole 25a and the front end 2c. As an example, in the output end 2a, an isolator for suppressing return light is disposed within the main body 2b, and a collimating lens for collimating the laser light L is disposed within the front end 2c. Alternatively, the incident portion 12 may be a connector, etc., configured to connect the output end 2a of the optical fiber 2.

[0052] The laser adjustment unit 13 is disposed within the housing 11. The laser adjustment unit 13 adjusts the laser beam L incident from the incident unit 12. The laser adjustment unit 13 is disposed on the side of the fourth wall portion 24 with respect to the partition wall portion 29 within the housing 11. The laser adjustment unit 13 is mounted on the partition wall portion 29. The partition wall portion 29 is provided within the housing 11 and divides the region within the housing 11 into a region on the side of the third wall portion 23 and a region on the side of the fourth wall portion 24. The partition wall portion 29 is configured as a part of the housing 11. Each structure of the laser adjustment unit 13 is mounted on the partition wall portion 29 on the side of the fourth wall portion 24. The partition wall portion 29 functions as an optical base for supporting each structure of the laser adjustment unit 13.

[0053] The condensing unit 14 is disposed on the sixth wall portion 26. Specifically, the condensing unit 14 is disposed on the sixth wall portion 26 in a state of being inserted into the hole 26a formed in the sixth wall portion 26 (see Figure 5 ). The condensing unit 14 condenses the laser beam L adjusted by the laser adjustment unit 13 and emits it outside the housing 11. The condensing unit 14 is deflected toward the second wall portion 22 in the X direction and toward the fourth wall portion 24 in the Y direction. That is, the distance between the condensing unit 14 and the second wall portion 22 in the X direction is smaller than the distance between the condensing unit 14 and the first wall portion 21 in the X direction, and the distance between the condensing unit 14 and the fourth wall portion 24 in the Y direction is smaller than the distance between the condensing unit 14 and the third wall portion 23 in the X direction.

[0054] As Figure 5 shown, the laser adjustment unit 13 includes a reflecting portion 31, an attenuator 32, and a reflecting portion 33. The reflecting portion 31, the attenuator 32, and the reflecting portion 33 are arranged on a first straight line A1 extending along the X direction. The reflecting portion 31 faces the incident unit 12 in the Z direction. That is, the reflecting portion 31 faces the emission end portion 2a of the optical fiber 2 in the Z direction. The reflecting portion 31 reflects the laser beam L incident from the incident unit 12 toward the second wall portion 22 side. The attenuator 32 adjusts the output of the laser beam L reflected by the reflecting portion 31. The reflecting portion 33 reflects the laser beam L whose output has been adjusted by the attenuator 32 toward the sixth wall portion 26 side. Each of the reflecting portions 31, 33 is, for example, a mirror or a prism.

[0055] The laser adjustment unit 13 further includes a beam expander 34 and a reflecting portion 35. The reflecting portion 33, the beam expander 34, and the reflecting portion 35 are arranged on a second straight line A2 extending along the Z direction. The beam expander 34 expands the diameter of the laser beam L reflected by the reflecting member 33. The reflecting portion 35 reflects the laser beam L whose diameter has been expanded by the beam expander 34 toward the first wall portion 21 side and also toward the fifth wall portion 25 side. The reflecting portion 35 is, for example, a mirror or a prism.

[0056] The laser adjustment unit 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 condensing unit 14 are arranged on a third straight line A3 extending in the Z direction. The spatial light modulator 36 modulates the laser beam L reflected by the reflecting unit 35 and reflects it toward the sixth wall portion 26 side at the same time. The spatial light modulator 36 is a reflective spatial light modulator (SLM: Spatial Light Modulator). 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 and the entrance pupil surface 14a of the condensing unit 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 beam L emitted from the light source 81 (refer to Figure 1 ), and the condensing unit 14 converges the laser beam L modulated by the spatial light modulator 36.

[0057] The first straight line A1, the second straight line A2, and the third straight line A3 are located in 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 beam L incident into the housing 11 from the incident unit 12 in the Z direction is reflected by the reflecting unit 31 and travels on the first straight line A1. The laser beam L traveling on the first straight line A1 is reflected by the reflecting member 33 and travels on the second straight line A2. The laser beam L traveling on the second straight line A2 is sequentially reflected by the reflecting unit 35 and the spatial light modulator 36 and travels on the third straight line A3. The laser beam L traveling on the third straight line A3 exits the housing 11 from the condensing unit 14 in the Z direction.

[0058] The laser processing head 10A further includes a dichroic mirror 15, a distance measuring unit 16, an observation unit 17, a driving unit 18, and a circuit unit 19.

[0059] The dichroic mirror 15 is arranged between the imaging optical system 37 and the condensing unit 14 on the third straight line A3. That is, the dichroic mirror 15 is arranged between the laser adjustment unit 13 and the condensing unit 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 beam L. From the viewpoint of suppressing astigmatism, for example, the dichroic mirror 15 is preferably of a cubic type or a type composed of two plates arranged in a twisted relationship.

[0060] The distance measuring unit 16 is disposed on the first wall portion 21 side with respect to the first straight line A3 within the housing 11. That is, the distance measuring unit 16 is disposed on the first wall portion 21 side with respect to the condensing unit 14 in the X direction. The distance measuring unit 16 is mounted on the partition wall portion 29 on the fourth wall portion 24 side. The distance measuring unit 16 irradiates the surface of the object 100 with light L10 for distance measurement (e.g., laser for distance measurement) for measuring the distance between the surface of the object 100 (e.g., the surface on the side where the laser L is incident) and the condensing unit 14, and detects the light L10 reflected from the surface of the object 100.

[0061] In the present embodiment, the distance measuring unit 16 is configured such that the light L10 to be irradiated to the surface of the object 100 and the light L10 reflected from the surface of the object 100 pass through the condensing unit 14. That is, the light L10 emitted from the distance measuring unit 16 passes through the condensing unit 14 and irradiates the surface of the object 100, and the light L10 reflected from the surface of the object 100 passes through the condensing unit 14 and is incident on the distance measuring unit 16. The distance measuring unit 16 is an astigmatic sensor including a quadrant photodiode as a light receiving sensor.

[0062] More specifically, the distance measuring unit 16 includes a main body portion 161 and an adjustment portion 162. The main body portion 161 irradiates the surface of the object 100 with light L10 and detects the light L10 reflected from the surface of the object 100. The adjustment portion 162 is a portion for adjusting the optical axis of the light L10 irradiated to the surface of the object 100. The adjustment portion 162 includes a first turning mirror 162a and a second turning mirror 162b. The first turning mirror 162a and the second turning mirror 162b are mounted on the partition wall portion 29 on the fourth wall portion 24 side in such a manner that the angles of their respective mirror surfaces are adjustable.

[0063] The light L10 emitted from the main body portion 161 is sequentially reflected by the first turning mirror 162a, the second turning mirror 162b, the beam splitter 20, and the dichroic mirror 15, passes through the condensing unit 14, exits the housing 11, and irradiates the surface of the object 100. The light L10 reflected from the surface of the object 100 enters the housing 11 through the condensing unit 14, is sequentially reflected by the dichroic mirror 15, the beam splitter 20, the second turning mirror 162b, and the first turning mirror 162a, and is incident on the main body portion 161. In addition, the beam splitter 20 is mounted on the partition wall portion 29 on the fourth wall portion 24 side.

[0064] The observation unit 17 is disposed on the first wall portion 21 side within the housing 11 with respect to the third straight line A3. That is, the observation unit 17 is disposed on the first wall portion 21 side with respect to the condenser unit 14 in the X direction. The observation unit 17 is mounted on the partition wall portion 29 on the fourth wall portion 24 side. The observation unit 17 irradiates the surface of the object 100 with the 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 L is incident), and detects the light L20 reflected from the surface of the object 100.

[0065] In the present embodiment, the light L20 emitted from the observation unit 17 passes through the beam splitter 20 and is reflected by the dichroic mirror 15, exits the housing 11 through the condenser unit 14, and irradiates the surface of the object 100. The light L20 reflected from the surface of the object 100 enters the housing 11 through the condenser unit 14, is reflected by the dichroic mirror 15, and passes through the beam splitter 20 and enters the observation unit 17. In addition, the wavelengths of the laser L, the light L10, and the light L20 are different from each other (at least their central wavelengths are offset from each other).

[0066] The drive unit 18 is mounted on the partition wall portion 29 on the fourth wall portion 24 side. The drive unit 18 moves the condenser unit 14 disposed on the sixth wall portion 26 in the Z direction, for example, by the driving force of a piezoelectric element.

[0067] The circuit unit 19 is disposed on the third wall portion 23 side within the housing 11 with respect to the partition wall portion 29. That is, the circuit unit 19 is disposed on the third wall portion 23 side within the housing 11 with respect to the laser adjustment unit 13, the distance measurement unit 16, and the observation unit 17. The circuit unit 19 is spaced apart from the partition wall portion 29. The circuit unit 19 is, for example, a plurality of circuit boards. The circuit unit 19 processes the signal output from the distance measurement unit 16 and the signal to be input to the spatial light modulator 36. The circuit unit 19 controls the drive unit 18 based on the signal output from the distance measurement unit 16. As an example, the circuit unit 19 controls the drive unit 18 based on the signal output from the distance measurement unit 16 so as to maintain the distance between the surface of the object 100 and the condenser unit 14 constant (i.e., maintain the distance between the surface of the object 100 and the convergence point of the laser L constant).

[0068] In addition, cuts, holes, etc. (not shown) are formed in the partition wall portion 29 through which the wirings for electrically connecting the distance measurement unit 16, the observation unit 17, the drive unit 18, and the spatial light modulator 36 to the circuit unit 19 pass. Further, a connector (not shown) is provided on the housing 11 to which the wiring for electrically connecting the circuit unit 19 and the control unit 9 (refer to Figure 1 ) is connected.

[0069] The laser processing head 10B, like the laser processing head 10A, includes a housing 11, an incident section 12, a laser adjustment section 13, a condenser section 14, a dichroic mirror 15, a distance measurement section 16, an observation section 17, a drive section 18, and a circuit section 19. However, as Figure 2 shown, the structures of the laser processing head 10B are configured to have a facing symmetry relationship with the structures of the laser processing head 10A with respect to a virtual plane that passes through the midpoint between the pair of mounting portions 65 and 66 and is perpendicular to the Y direction.

[0070] For example, the housing 11 of the laser processing head 10A is mounted on the mounting portion 65 such that the fourth wall portion 24 is located on the side of the laser processing head 10B with respect to the third wall portion 23, and the sixth wall portion 26 is located on the side of the support portion 7 with respect to the fifth wall portion 25. In contrast, the housing 11 of the laser processing head 10B is mounted on the mounting portion 66 such that the fourth wall portion 24 is located on the side of the laser processing head 10A with respect to the third wall portion 23, and the sixth wall portion 26 is located on the side of the support portion 7 with respect to the fifth wall portion 25.

[0071] The housing 11 of the laser processing head 10B is configured to mount the housing 11 on the mounting portion 66 in a state where the third wall portion 23 is disposed on the side of the mounting portion 66. Specifically as follows. The mounting portion 66 includes a bottom plate 66a and a mounting plate 66b. The bottom plate 66a is mounted on a track provided on the moving portion 63. The mounting plate 66b is erected at an end portion on the side of the laser processing head 10A on the bottom plate 66a. The housing 11 of the laser processing head 10B is mounted on the mounting portion 66 in a state where the third wall portion 23 is in contact with the mounting plate 66b. The housing 11 of the laser processing head 10B is detachable from the mounting portion 66.

[0072] [Structure of the spatial light modulator]

[0073] As Figure 6 shown, the spatial light modulator 36 is formed by sequentially laminating a drive 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 (LCOS: Liquid Crystal on Silicon) spatial light modulator.

[0074] The semiconductor substrate 41 is, for example, a silicon substrate. The drive 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, for example. A voltage is applied to each pixel electrode 43a through the drive circuit layer 42.

[0075] 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, and, for example, a rubbing process is performed on the surface of each of the alignment films 45 and 47 that contacts the liquid crystal layer 46. The alignment films 45 and 47 align the liquid crystal molecules 46a contained in the liquid crystal layer 46 in a certain direction.

[0076] The transparent conductive film 48 is provided on the surface of the alignment film 47 on the side of the transparent substrate 49, and faces the pixel electrode layer 43 across the liquid crystal layer 46 and the like. The transparent substrate 49 is, for example, a glass substrate. The transparent conductive film 48 is formed of a light-transmissive conductive material such as ITO. The transparent substrate 49 and the transparent conductive film 48 transmit the laser L.

[0077] In the spatial light modulator 36 configured as described above, when a signal representing a modulation pattern is input from the control unit 10 to the drive circuit layer 42, each pixel electrode 43a is applied with a voltage corresponding to the signal, and an electric field is formed between each pixel electrode 43a and the transparent conductive film 48. When this electric field is formed, in the liquid crystal layer 46, the alignment 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 43a. This state is the state in which the modulation pattern is displayed on the liquid crystal layer 46.

[0078] In the state where the modulation pattern is displayed on the liquid crystal layer 46, when the laser L is incident on the liquid crystal layer 46 from the outside via the transparent substrate 49 and the transparent conductive film 48, is reflected by the reflective film 44, and then exits from the liquid crystal layer 46 to the outside via the transparent conductive film 48 and the transparent substrate 49, the laser L is modulated in accordance with the modulation pattern displayed on the liquid crystal layer 46. Thus, with the spatial light modulator 36, the laser L can be modulated (for example, modulation of the intensity, amplitude, phase, polarization, etc. of the laser L) by appropriately setting the modulation pattern displayed on the liquid crystal layer 46.

[0079] [Structure of the object]

[0080] As Figure 7 and Figure 8 shown, the object 100 includes a substrate 101 and a plurality of functional elements 102. The plurality of functional elements 102 are arranged on the substrate 101 in a matrix.

[0081] The substrate 101 has a front surface 101a and a back surface 101b. The substrate 101 is a semiconductor substrate such as a silicon substrate, for example. A notch 101c indicating the crystal orientation is provided on the substrate 101. Alternatively, an orientation flat may be provided on the substrate 101 instead of the notch 101c.

[0082] A plurality of functional elements 102 are provided on the front surface 101a of the substrate 101. Each functional element 102 is, 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 obtained by stacking multiple layers.

[0083] The object 100 is to be cut along each of a plurality of lines 90 according to the functional elements 102. The plurality of lines 90 extend in a grid pattern in such a manner that they 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 101b). In the object 100, a street region 103 extends in a grid pattern in such a manner that it passes between the plurality of functional elements 102, and each line 90 passes through the center of the street region 103. The plurality of lines 90 are virtual lines set on the object 100 by the laser processing apparatus 1. Alternatively, the plurality of lines 90 may be lines actually drawn on the object 100.

[0084] [Functions of the control unit]

[0085] As a premise, as Figure 9 and Figure 10 shown, the laser processing apparatus 1 irradiates the object 100 having a surface intersecting the Z direction (the front surface 101a or the back surface 101b of the substrate 101 in this embodiment) with the laser L to form 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 among the plurality of lines 90 that extend in the X direction and are adjacent in the Y direction.

[0086] In addition, in each of the laser processing heads 10A and 10B, the distance measuring unit 16 (refer to Figure 5 ) is configured to be able to adjust the position of the irradiation region 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. The irradiation region R of the light L10 is the irradiation region of the light L10 on the surface of the object 100 (the front surface 101a or the back surface 101b of the substrate 101 in this embodiment). In this embodiment, the optical axis of the light L10 irradiated onto the front surface 101a or the back surface 101b of the substrate 101 is adjusted by the adjustment unit 162 (refer to Figure 5) is capable of adjusting the position of the irradiation region R of the light L10 in the Y direction by at least the amount of the interval between the first line 91 and the second line 92.

[0087] On the above premise, the function of the control unit 9 will be described below by focusing on the first line 91 and the second line 92 that extend in the X direction and are adjacent in the Y direction. In the following description, it is not clearly stated which one of the pair of laser processing heads 10A and 10B is the main body that irradiates the object 100 with the laser L, but this main body can be any 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 takes the first line 91 and the second line 92 that extend in the X direction and are adjacent in the Y direction as the minimum unit, and can be applied to all the lines 90.

[0088] As shown in Figure 9 , when the object 100 is supported by the support portion 7 in such a manner that the laser L enters the substrate 101 from the side of the plurality of functional elements 102 (that is, the laser L enters the substrate 101 from the region corresponding to the track region 103 on the front surface 101a of the substrate 101) (hereinafter referred to as "the case of front incidence"), the control unit 9 functions as follows. The control unit 9 controls the spatial light modulator 36 so that the laser 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. And, the control unit 9 controls the moving mechanism 5 (refer to Figure 1 ) so that the irradiation region R of the distance measurement light L10 on the front surface 101a and the first convergence point C1 and the second convergence point C2 move relative to each other along the first line 91 and the second line 92. Further, the control unit 9 controls the drive unit 18 (refer to Figure 5 ) based on the detection result of the light L10 by the distance measurement unit 16 so that the first convergence point C1 and the second convergence point C2 are respectively located at prescribed positions with respect to the front surface 101a (for example, maintaining the distances between the front surface 101a and the first convergence point C1 and the second convergence point C2 constant).

[0089] In the case of front incidence, by adjusting the optical axis of the light L10 irradiated onto the front surface 101a using the adjustment unit 162 (refer to Figure 5 ), the irradiation region R is located on the first line 91 or the second line 92. The adjustment of the adjustment unit 162 can be manually performed by the operator or automatically performed by the control unit 9.

[0090] As shown in Figure 10As shown, in the case where the object 100 is supported by the support portion 7 in such a manner that the laser L is incident on the substrate 101 from the side opposite to the plurality of functional elements 102 (i.e., the laser L is incident on the substrate 101 from the back surface 101b of the substrate 101) (hereinafter referred to as "the case of back surface incidence"), the control unit 9 functions as follows. The control unit 9 controls the spatial light modulator 36 so that the laser L is split into a first processing light L1 and a 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. Further, the control unit 9 controls the moving mechanism 5 (see Figure 1 ) so that the irradiation region R of the distance measuring light L10 on the back surface 101b and the first convergence point C1 and the second convergence point C2 relatively move along the first line 91 and the second line 92. Furthermore, the control unit 9 controls the driving unit 18 (see Figure 5 ) based on the detection result of the light L10 by the distance measuring unit 16 so that the first convergence point C1 and the second convergence point C2 are respectively located at predetermined positions with respect to the back surface 101b (for example, maintaining the distances between the back surface 101b and the first convergence point C1 and the second convergence point C2 constant).

[0091] In the case of back surface incidence, by adjusting the optical axis of the light L10 irradiated on the back surface 101b using the adjustment unit 162 (see Figure 5 ), the irradiation region R is located on the center line between the first line 91 and the second line 92 (i.e., the line equidistant from the first line 91 and the second line 92). The adjustment of the adjustment unit 162 can be manually performed by the operator or automatically performed by the control unit 9.

[0092] Herein, the first convergence point C1, the second convergence point C2, or the irradiation region R being located at a predetermined portion (such as the first line 91, the second line 92, the center line between the first line 91 and the second line 92, between the first line 91 and the second line 92, etc.) means that, when viewed from the Z direction, the first convergence point C1, the second convergence point C2, or the irradiation region R is located at the predetermined portion. In addition, in the above description, the moving mechanism 5 functions as a moving unit that relatively moves the condensing unit 14 and the distance measuring unit 16 with respect to the support portion 7, but it may also be the moving mechanism 6 that functions as the moving unit, or multiple moving mechanisms 5, 6 may function as the moving unit (see Figure 1 ). In addition, the circuit unit 19 (see Figure 5 ) provided in each laser processing head 10A, 10B may also function as at least a part of the control unit 9.

[0093] [Operation of Laser Processing Device]

[0094] As a prerequisite, as Figure 2As shown, 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 constituted by, for example, an InGaAs camera, and acquires an image of the object 100 based on near-infrared rays. The imaging unit 3 is mounted on, for example, the mounting portion 65 of the moving mechanism 6. As an 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 images of the plurality of functional elements 102 and the trace region 103 (see Figure 7 ) not only from the side of the plurality of functional elements 102, but also from the side of the back surface 101b of the substrate 101.

[0095] In addition, as Figure 11 shown, the laser processing apparatus 1 has an input receiving unit 4 including a display unit 4a. The display unit 4a displays the image of the object 100 acquired by the imaging unit 3 as a graphic of the object 100. The display unit 4a constitutes a GUI (Graphical User Interface). In addition, the input receiving unit 4 further includes input devices (not shown) such as a mouse and a keyboard.

[0096] On the above premise, the operation of the laser processing apparatus 1 will be described below focusing on the first line 91 and the second line 92 that extend in the X direction and are adjacent in the Y direction. In the following description, it is not clearly stated which one of the pair of laser processing heads 10A and 10B is the main body that irradiates the laser L to the object 100, but the main body can 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 takes the first line 91 and the second line 92 that extend in the X direction and are adjacent in the Y direction as the minimum unit, and can be applied to all the lines 90.

[0097] First, the object 100 is placed on the support portion 7. Then, as Figure 11 shown, when the operator operates the input receiving unit 4 and selects "double-line split 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 acquired by the imaging unit 3. The reference line 93 is a line corresponding to the trajectory of the optical axis of the condensing unit 14 relative to the object 100 moving.

[0098] Next, when the operator operates the input receiving unit 4 and enters a value in the "beam splitting interval" column 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 graph so that the distance between the first line 91 and the second line 92 in the graph becomes the above value. Further, when the operator operates the input receiving unit 4 and 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 graph, the display unit 4a displays the distance between the first line 91 and the second line 92 in the graph in the "beam splitting interval" column. The value of the beam splitting interval is the 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 unit 4 can receive the input of "information on the positions of the first convergence point C1 and the second convergence point C2 in the Y direction" (first information). In addition, in order to change the first line 91 and the second line 92 that are the objects of laser processing, the control unit 9 controls the moving mechanism 5 based on the input value of the beam splitting interval so that the condensing unit 14 and the distance measuring unit 16 move a distance twice the value of the beam splitting interval in the Y direction.

[0099] Furthermore, 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" on the display unit 4a as the "distance measuring position". The distance measuring position is the position (position in the Y direction) of the irradiation area R of the distance measuring light L10. As Figure 9 in the case of front incidence shown, when the irradiation area R should be located on the first line 91 or the second line 92, the operator only needs to select "adjust to the first line side" or "adjust to the second line side". As Figure 10 in the case of back incidence shown, when the irradiation area R should be located on the center line between the first line 91 and the second line 92, the operator only needs to select "reference line". In this way, the input receiving unit 4 can receive the input of "information on the position of the irradiation area R in the Y direction" (second information).

[0100] Next, as Figure 12As shown, the control unit 9 sequentially performs the following processes: a process of determining the modulation pattern to be input to the spatial light modulator 36 based on the irradiation conditions of the laser L including the value input to the "beam splitting interval" column (step S01); a process of adjusting the position of the irradiation region R according to any one of the "reference line", "adjusted to one side of the first line", and "adjusted to one side of the second line" selected as the "distance measurement position" (step S02); and a process of performing laser processing (step S03). In this way, the control unit 9 controls the spatial light modulator 36 based on the "information about the positions of the first focal point C1 and the second focal point 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. Further, the control unit 9 controls the distance measurement unit 16 based on the "information about 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.

[0101] Figure 13 is a schematic diagram showing the positional relationship among the reference line 93, the first line 91, and the second line 92 when the laser processing apparatus 1 shown in Figure 1 performs laser processing by front incidence (refer to Figure 9 ). As shown in Figure 13 (a) and (b) therein, 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 the center line. As shown in Figure 13 (a) therein, the condensing unit 14 is located on the reference line 93. As shown in Figure 13 (b) therein, the first focal point C1 and the irradiation region R are located on the first line 91, and the second focal point C2 is located on the second line 92.

[0102] Figure 14 is a schematic diagram showing the positional relationship among the reference line 93, the first line 91, and the second line 92 when the laser processing apparatus 1 shown in Figure 1 performs laser processing by back incidence (refer to Figure 10 ). As shown in Figure 14 (a) and (b) therein, 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 the center line. As shown in Figure 14 (a) therein, the condensing unit 14 is located on the reference line 93. As shown in Figure 14 (b) therein, 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 region R is located on the reference line 93 (the center line between the first line 91 and the second line 92).

[0103] In addition, the input receiving unit 4 may also receive the input of the "information about the incident side of the laser L incident on the object 100" (third information). AndFigure 9 In the case of front incidence as shown, the control unit 9 controls the distance measuring unit 16 based on "information about 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. On the other hand, in Figure 10 In the case of back incidence as shown, the control unit 9 controls the distance measuring unit 16 based on "information about 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.

[0104] The adjustment of the adjustment unit 162 can also be manually performed by the operator 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. In this case, the process of adjusting the position of the irradiation region R by the control unit 9 (step S02) is omitted.

[0105] [Function and Effect]

[0106] In the laser processing apparatus 1, the control unit 9 controls the spatial light modulator 36 so that the laser beam L is split into a first processing light beam L1 and a second processing light beam L2, and the first convergence point C1 of the first processing light beam L1 is located on the first line 91, and the second convergence point C2 of the second processing light beam L2 is located on the second line 92. Further, the control unit 9 controls the moving mechanism 5 so that the irradiation region R of the distance measuring light beam L10 and the first convergence point C1 and the second convergence point C2 move relatively along the first line 91 and the second line 92. At this time, the control unit 9 controls the drive unit 18 based on the detection result of the distance measuring unit 16 for the distance measuring light beam L10 so that the first convergence point C1 and the second convergence point C2 are respectively located at prescribed positions with respect to the front surface 101a or the back surface 101b of the object 100. Thereby, the modified region M can be formed in the object 100 along the first line 91 and the second line 92 respectively in a state where the modified region M is located at a prescribed position with respect to the front surface 101a or the back 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 beam L10 in the Y direction by at least the amount of the interval between the first line 91 and the second line 92. Therefore, the position of the irradiation region R of the distance measuring light beam L10 can be adjusted in the Y direction according to the irradiation conditions of the laser beam L or the like, and the modified region M can be formed at a prescribed position with high precision with respect to the front surface 101a or the back surface 101b of the object 100. Therefore, when using the laser processing apparatus 1 to form the modified region M in the object 100 along each of a plurality of lines, the processing time can be shortened.

[0107] In the laser processing apparatus 1, the input receiving unit 4 receives the input of "information on the positions of the first converging point C1 and the second converging point C2 in the Y direction", and the control unit 9 controls the spatial light modulator 36 based on this information so that the first converging point C1 is located on the first line 91 and the second converging point C2 is located on the second line 92. Thereby, it is possible to easily and highly accurately form the modified regions M along the first line 91 and the second line 92, respectively.

[0108] In the laser processing apparatus 1, the input receiving unit 4 receives the input of "information on the position of the irradiation region R in the Y direction", and the control unit 9 controls the distance measuring unit 16 based on this information 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. Thereby, it is possible to easily and highly accurately form the modified region M at a specified position with respect to the front surface 101a or the back surface 101b of the object 100.

[0109] In the laser processing apparatus 1, the input receiving unit 4 receives the input of "information on the incident side where the laser L enters the object 100", and the control unit 9 Figure 9 in the case of the front surface incidence shown, controls the distance measuring unit 16 based on this information so that the irradiation region R is located on the first line 91 or the second line 92, and Figure 10 in the case of the back surface incidence shown, controls the distance measuring unit 16 based on this information so that the irradiation region R is located on the center line between the first line 91 and the second line 92. Thereby, in the case of front surface incidence, it is possible to prevent the light L10 for distance measurement from being affected by the functional element 102, and it is possible to form the modified region M at a specified position with respect to the front surface 101a or the back surface 101b of the object 100. Also, in the case of back surface incidence, it is possible to form the modified regions M along the first line 91 and the second line 92 evenly.

[0110] 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, respectively. Thereby, it is possible to visually grasp the machining preparation state.

[0111] In the laser processing apparatus 1, the display unit 4a displays a reference line 93 corresponding to the locus of the relative movement of the optical axis of the condensing unit 14 with respect to the object 100. Thereby, it is possible to visually grasp the machining preparation state based on the optical axis of the condensing unit 14.

[0112] In the laser processing apparatus 1, the imaging unit 3 acquires an image of the object 100, and the display unit 4a displays the image of the object 100 as the graphic of the object 100. Thereby, it is possible to easily acquire the graphic of the object 100.

[0113] 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 front incidence).

[0114] [Modification]

[0115] The present invention is not limited to the above-mentioned embodiment. For example, the distance measuring unit 16 may be configured so that the light L10 for distance measurement does not pass through the focusing unit 14. Specifically, Figure 15 As shown, the distance measuring unit 16 is installed on the device frame 1a in a manner that is not coaxial 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 light L10 to the front side 101a or the back side 101b, and at the same time detects the light L10 reflected from the front side 101a or the back side 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 along the Y direction so as to be able 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 the distance measuring light L10 is irradiated to the surface of the object 100 through a component such as a tape. In addition, Figure 15 The distance measuring unit 16 shown can use a sensor of a triangulation distance measuring method, a laser confocal method, a white light confocal method, a spectral interferometry method, an astigmatism method, or the like.

[0116] Figure 16 It means by Figure 15 The laser processing device 1 shown adopts front incidence (refer to Figure 9 ) 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. Figure 16 As shown in (a) and (b), 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 the center line. Figure 16 As shown in (a), the focusing portion 14 is located on the reference line 93, and the main body 163 is located on the first line 91. Figure 16 As shown in (b), the first convergence point C1 and the irradiation area R are located on the first line 91, and the second convergence point C2 is located on the second line 92.

[0117] Figure 17 It means by Figure 15The laser processing device 1 shown adopts back-incident (refer to Figure 10 ) 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. Figure 17 As shown in (a) and (b), 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 the center line. Figure 17 As shown in (a), the focusing portion 14 and the main body 163 are located on the reference line 93. Figure 17 As shown in (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 area R is located on the reference line 93 (the center line between the first line 91 and the second line 92).

[0118] exist Figure 1 The laser processing device 1 shown and Figure 15 In any of the laser processing devices shown, the first line 91 can be located on the reference line 93 .

[0119] Figure 18 It means by Figure 1 The laser processing device 1 shown adopts front incidence (refer to Figure 9 ) or back-incident (refer to Figure 10 ) 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. Figure 18 As shown in (a) and (b), 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. Figure 18 As shown in (a), the focusing portion 14 is located on the reference line 93. Figure 18 As shown in (b), the first convergence point C1 and the irradiation area 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.

[0120] Figure 19 It means by Figure 15 The laser processing device 1 shown adopts front incidence (refer to Figure 9 ) or back-incident (refer to Figure 10 ) 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. Figure 19 As shown in (a) and (b), 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. Figure 19 As shown in (a), the focusing portion 14 and the main body 163 are located on the reference line 93. Figure 19 As shown in (b), the first convergence point C1 and the irradiation area 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 .

[0121] Figure 20 is Figure 18 and Figure 19 The structural diagram of the display unit 4a in the case shown. In Figure 18 and Figure 19 the case shown, the irradiation area R is always located on the reference line 93 (on the first line 91). Therefore, in Figure 20 the display unit 4a shown, there is no column for selecting the "ranging position" set as in Figure 11 the display unit 4a shown.

[0122] In Figure 1 the laser processing apparatus 1 shown, the position and angle of the light receiving sensor (the light receiving sensor that detects the light L10 reflected by the front surface 101a or the back surface 101b) can also be adjusted in the main body portion 161. This is to enable the light receiving sensor to reliably detect the light L10 reflected by the front surface 101a or the back surface 101b when the optical axis of the light L10 is adjusted by the adjusting portion 162.

[0123] In Figure 15 the laser processing apparatus 1 shown, a pair of ranging portions 16 can also be provided on both sides in the X direction of the condensing portion 14. 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 of the ranging portions 16 can 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 ranging portion 16 can be used.

[0124] The ranging portion 16 can also irradiate the light L10 to a surface other than the front surface 101a and the back surface 101b of the object 100 and detect the light L10 reflected by the surface, as long as the surface intersects with the Z direction.

[0125] In the case where each laser processing apparatus 1 shown by Figure 1 and Figure 15 performs laser processing by front incidence (refer to Figure 9 ), the irradiation area R only needs to be located within the track area 103 when viewed from the Z direction, for example, and can deviate slightly from the first line 91 or the second line 92.

[0126] In the case where each laser processing apparatus 1 shown by Figure 1 and Figure 15 performs laser processing by back incidence (refer to Figure 10 ), the irradiation area R can also be located on the first line 91 or the second line 92, or between the first line 91 and the second line 92.

[0127] Alternatively, the input receiving unit 4 receives an input of information about the object 100 (such as the dimensions of each functional element 102, the width of the track region 103, etc.), the control unit 9 generates a graphic of the object 100 based on this information, and the graphic is displayed by the display unit 4a.

[0128] One aspect of the present invention provides a laser processing apparatus that forms modified regions in an object along a first line and a second line by irradiating the object with laser light. 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 in the Y direction perpendicular to both the Z direction and the X direction. The laser processing apparatus includes: a support unit 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 condenser unit for converging the laser light modulated by the spatial light modulator; a distance measuring unit that irradiates the surface with light for distance measurement and detects the light for distance measurement reflected by the surface; a moving unit for relatively moving the condenser unit and the distance measuring unit with respect to the support unit; a driving unit for moving the condenser unit in the Z direction; and a control unit that controls the spatial light modulator so that the laser light is split into first processing light and second processing light, the first convergence point of the first processing light is located on the first line, the second convergence point of the second processing light is located on the second line, and controls the moving unit so that the irradiation region of the light for distance measurement, the first convergence point, and the second convergence point on the surface relatively move along the first line and the second line, and controls the driving unit based on the detection result of the distance measuring unit for the light for distance measurement so that the first convergence point and the second convergence point are respectively located at prescribed positions with respect to the surface. The distance measuring unit is configured to be able to adjust the position of the irradiation region in the Y direction by at least the amount of the interval between the first line and the second line.

[0129] In the above laser processing apparatus, the control unit controls the spatial light modulator so that the laser beam is split into a first processing light beam and a second processing light beam, and the first convergence point of the first processing light beam is located on a first line, and the second convergence point of the second processing light beam is located on a second line. Further, the control unit controls the moving unit so that the irradiation region of the light for distance measurement, the first convergence point, and the second convergence point on the surface of the object move relative to each other along the first line and the second line. At this time, the control unit controls the driving unit based on the detection result of the light for distance measurement by the distance measurement unit so that the first convergence point and the second convergence point are respectively located at prescribed positions with respect to the surface of the object. Thereby, it is possible to form modified regions in the object along the first line and the second line in a state where the modified regions are located at prescribed positions with respect to the surface of the object. Here, in the above laser processing apparatus, the distance measurement unit is configured to be able to adjust the position of the irradiation region of the light for distance measurement in the Y direction by at least the amount of the interval between the first line and the second line. Therefore, it is possible to adjust the position of the irradiation region of the light for distance measurement in the Y direction according to the irradiation conditions of the laser beam or the like, and it is possible to form modified regions at prescribed positions with high precision with respect to the surface of the object. Accordingly, by using the above laser processing apparatus, it is possible to shorten the processing time when forming modified regions in the object along each of a plurality of lines.

[0130] The laser processing apparatus according to an aspect of the present invention may also include an input receiving unit that receives an input of first information regarding the positions of the first convergence point and the second convergence point in the Y direction, and the control unit 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. Thereby, it is possible to easily and highly accurately form modified regions along the first line and the second line, respectively.

[0131] The laser processing apparatus according to an aspect of the present invention may also be such that the input receiving unit further receives an input of second information regarding the position of the irradiation region in the Y direction, and the control unit controls the distance measurement 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. Thereby, it is possible to easily and highly accurately form modified regions at prescribed positions with respect to the surface of the object.

[0132] 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 input of third information regarding the incident side of the laser light on the object. The control unit controls the distance measuring unit based on the third information so that when the laser light is incident on 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 control unit controls the distance measuring unit based on the third information so that when the laser light is incident on 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. Thus, when the laser light is incident on the substrate from the side of the plurality of functional elements, the distance measuring light is prevented from being affected by the functional elements, and a modified area can be formed at a predetermined position relative to the surface of the object. Furthermore, when the laser light is incident on the substrate from the side opposite to the plurality of functional elements, the modified area can be formed uniformly along both the first line and the second line.

[0133] In the laser processing apparatus according to one aspect of the present invention, the input receiving unit may include a display unit for displaying graphics of the object, the first line, and the second line, thereby enabling visual understanding of the planned processing status.

[0134] In one aspect of the laser processing apparatus of the present invention, the display unit may further display a reference line corresponding to a trajectory of relative movement of the optical axis of the focusing unit with respect to the object, thereby enabling visual understanding of the planned processing state based on the optical axis of the focusing unit.

[0135] The laser processing apparatus according to one aspect of the present invention may further include an imaging unit for capturing an image of the object, and the display unit may display the image of the object as a graphic of the object.

[0136] In one aspect of the present invention, a laser processing apparatus may include a distance measuring unit configured such that distance measuring light irradiated onto a surface and distance measuring light reflected from the surface pass through a light-collecting 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.

[0137] In one aspect of the present invention, a laser processing apparatus may include a distance measuring unit 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 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 position of the main unit 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.

[0138] By using the present invention, a laser processing apparatus can be provided, which can shorten the processing time when forming a modified region in an object along each of a plurality of lines.

Claims

1. A laser processing apparatus that forms modified regions in the object along a first line and a second line by irradiating the object with laser light, wherein, The object has a surface intersecting the Z direction, and the first line and the second line extend in the X direction perpendicular to the Z direction and are adjacent in the Y direction perpendicular to both the Z direction and the X direction. The laser processing apparatus is characterized by comprising: a supporting portion for supporting the object; a light source for emitting the laser; a spatial light modulator for modulating the laser emitted from the light source; a condensing portion for condensing the laser modulated by the spatial light modulator; a distance measuring portion that irradiates the surface with light for distance measurement and detects the light for distance measurement reflected by the surface; a moving portion that relatively moves the condensing portion and the distance measuring portion with respect to the supporting portion; a driving portion that moves the condensing portion in the Z direction; and a control portion that controls the spatial light modulator so that the laser 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, and controls the moving portion so that an irradiation region of the light for distance measurement, the first convergence point, and the second convergence point on the surface relatively move along the first line and the second line, and controls the driving portion based on a detection result of the distance measuring portion for the light for distance measurement so that the first convergence point and the second convergence point are respectively located at prescribed positions with respect to the surface. The distance measuring portion is configured to be able to adjust the position of the irradiation region in the Y direction by at least an amount equal to the interval between the first line and the second line.

2. The laser processing apparatus according to claim 1, wherein: it further includes an input receiving portion that receives an input of first information regarding positions of the first convergence point and the second convergence point in the Y direction respectively. The control portion 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 portion further receives an input of second information regarding a position of the irradiation region in the Y direction. The control portion controls the distance measuring portion 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 portion further receives an input of third information regarding an incident side where the laser is incident on the object. The control portion, based on the third information, controls the distance measuring portion such that when the laser is incident on the substrate from the side of the plurality of functional elements, the irradiation region is located on the first line or the second line, and Controlling the ranging unit based on the third information such that when the laser is incident on the substrate from the side opposite to the plurality of functional elements, the irradiation area is located on the center line between the first line and the second line.

5. The laser processing apparatus according to any one of claims 2 to 4, characterized in that: The input receiving unit includes a display unit for displaying the graphics of the object, the first line, and the second line respectively.

6. The laser processing apparatus according to claim 5, characterized in that: The display unit further displays a reference line corresponding to the trajectory of the optical axis of the condensing unit relative to the object moving relatively.

7. The laser processing apparatus according to claim 5 or 6, characterized in that: It further includes an imaging unit for acquiring an image of the object, The display unit displays the image of the object as the graphic of the object.

8. The laser processing apparatus according to any one of claims 1 to 7, characterized in that: The ranging unit is configured such that the ranging light irradiated on the surface and the ranging light reflected from the surface pass through the condensing unit, The ranging unit includes: A main body that irradiates the surface with the ranging light and detects the ranging light reflected from the surface; and An adjustment unit for adjusting the optical axis of the ranging light irradiated on the surface.

9. The laser processing apparatus according to any one of claims 1 to 7, characterized in that: The ranging unit is configured such that the ranging light irradiated on the surface and the ranging light reflected from the surface do not pass through the condensing unit, The ranging unit includes: A main body that irradiates the surface with the ranging light and detects the ranging light reflected from the surface; and An adjustment unit for adjusting the position of the main body in the Y direction.

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