Source: https://patents.google.com/patent/US8993922B2/en
Timestamp: 2020-01-28 18:11:44
Document Index: 449056862

Matched Legal Cases: ['art 4', 'art 4', 'art 4', 'art 4', 'art 45', 'art 45', 'art 45', 'art 45', 'art 45', 'art 706', 'art 45', 'art 45', 'art 706', 'art 706']

US8993922B2 - Laser processing method and device - Google Patents
US8993922B2
US8993922B2 US10/585,451 US58545104A US8993922B2 US 8993922 B2 US8993922 B2 US 8993922B2 US 58545104 A US58545104 A US 58545104A US 8993922 B2 US8993922 B2 US 8993922B2
US10/585,451
US20080037003A1 (en
2004-01-09 Priority to JPP2004-004312 priority
2004-12-13 Priority to PCT/JP2004/018591 priority patent/WO2005065880A1/en
2007-05-04 Assigned to HAMAMATSU PHOTONICS K.K. reassignment HAMAMATSU PHOTONICS K.K. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KUSUNOKI, MASAYOSHI, SUZUKI, TATSUYA, ATSUMI, KAZUHIRO, KUNO, KOJI
2008-02-14 Publication of US20080037003A1 publication Critical patent/US20080037003A1/en
2015-03-31 Publication of US8993922B2 publication Critical patent/US8993922B2/en
238000003672 processing method Methods 0 abstract claims description title 37
238000006073 displacement Methods 0 abstract description 135
It will also be preferred in the laser processing method of the present invention if the line to cut includes first and second lines to cut; the displacement acquiring step moves the lens relative to the object in a first direction extending along the first line to cut, so as to acquire the displacement of the main surface along the first line to cut, and then moves the lens relative to the object in a second direction opposite from the first direction, so as to acquire the displacement of the main surface along the second line to cut; and the processing step forms the modified region along the first line to cut in the first direction, and then forms the modified region along the second line to cut in the second direction. Since the lens acquires the displacement along the first line to cut while moving in the first direction, and acquires the displacement along the second line to cut while moving in the second direction opposite from the first direction, displacements can be acquired as the lens moves back and forth with respect to the object. Since the respective modified regions are formed along the first and second lines to cut as the lens moves back and forth with respect to the object, modified regions can be formed more efficiently.
FIG. 6 is a chart for explaining the laser processing method in accordance with the embodiment.
FIG. 7 is a flowchart for explaining the laser processing method in accordance with the embodiment.
FIG. 8 is a view for explaining the laser processing method in accordance with the embodiment.
FIG. 10 is a flowchart for explaining the laser processing method in accordance with the embodiment.
In the laser head unit 3, an adjuster 15 for adjusting the inclination of the cooling jacket 11 and the like is attached to the lower face of a bottom wall 11 b of the cooling jacket 11. The adjuster 15 is used for aligning an optical axis α of the processing laser beam L1 emitted from the laser head 13 with an axis β which is set in the optical system main part 4 and objective lens unit 5 such as to extend vertically. Namely, the laser head unit 3 is attached to the optical system main part 4 by way of the adjuster 15. When the inclination of the cooling jacket 11 or the like is adjusted by the adjuster 15 thereafter, the inclination of the laser head 13 or the like is adjusted in conformity to the movement of the cooling jacket 11. As a consequence, the processing laser beam L1 advances into the optical system main part 4 while in a state where its optical axis α coincides with the axis β. The bottom wall 11 b of the cooling jacket 11, the adjuster 15, and a housing 21 of the optical system main part 4 are formed with through holes through which the processing laser beam L1 passes.
First, the wafer-like object S used in this explanation will be explained with reference to FIG. 3. In the object S, 2n lines to cut C1 to C2n are set. The lines to cut C1 to C2n are subjected to laser processing in groups of two each. In the case of the lines to cut C1 and C2, for example, the displacement of the line to cut C1 is acquired from a point X1 to a point X2 on an extension of the line to cut C1, and then the displacement of the line to cut C2 is acquired from a point X3 to a point X4 on an extension of the line to cut C2. When displacements are acquired as such, the stage 2. (see FIG. 1) can efficiently be moved such that the processing objective lens 42 (see FIG. 1) shifts from the point X1 to the point X2 and then in reverse from the point X3 to the point X4. After the displacements concerning the lines to cut C1 and C2 are acquired, while reproducing the amount of movement of the actuator 43 according to thus acquired displacements, a modified region is formed along the line to cut C1 from the point X1 to X2 on the extension of the line to cut C1, and then a modified region is formed along the line to cut C1 from the point X3 to X4 on the extension of the line to cut C2.
The explanation will be made with reference to FIGS. 4(A) to 4(C). FIGS. 4(A) to 4(C) are views showing the cross section II-II of FIG. 3. For easier understanding, the hatching indicating the cross section is omitted in FIGS. 4(A) to 4(C). As shown in FIG. 4(A), the object S is attracted and secured to the stage 2 by way of a dicing film 2 a. The dicing film 2 a is secured with a dicing ring (not depicted).
As shown in FIG. 4(A), the stage 2 moves such that the processing objective lens 42 is placed at a position corresponding to a point Q1 on the line to cut C1 in the object S. The actuator 43 holding the processing objective lens 42 is in a state expanded by 25 μm from the most contracted state. This amount of expansion, i.e., 25 μm, is set as one half of the maximum amount of expansion of the actuator 43, i.e., 50 μm. In this state, the stage 2 is moved up/down so that a reflected light beam of the observation visible ray is in focus. In this in-focus state, the rangefinding laser beam L2 is emitted, an astigmatism signal is obtained according to a reflected light beam of the rangefinding laser beam L2, and the value of the astigmatism signal is taken as a reference value.
The rangefinding laser beam L2 is reflected less by the dicing film 2 a so that the total quantity of light reflected thereby is smaller, whereas the total quantity of reflected light increases in the object S. Namely, the total quantity of reflected light beam of the rangefinding laser beam L2 detected by the four-divided position detecting device in the light-receiving part 45 (see FIG. 1) increases, whereby it can be determined that the processing objective lens 42 is located at a position intersecting the line to cut C1 in the object S when the total quantity of reflected light beam exceeds a predetermined threshold. Therefore, when the total light quantity detected by the four-divided position detecting device in the light-receiving part 45 (see FIG. 1) is greater than the predetermined threshold, the processing objective lens 42 is assumed to be located at one end of the line to cut C1, and expansion amount control of the actuator 43 is started so as to release the expansion amount of the actuator 43 from being held at this time, such that the astigmatism signal becomes the reference value (first measurement step).
Hence, when the processing objective lens 42 moves in the direction of arrow F in FIG. 4(B), the state shown in FIG. 4(C) is attained. As shown in FIG. 4(C), area G1 (one end part) becomes a transition area in which the processing objective lens 42 shifts from the held state to a state capable of following the displacement of the surface S1 of the object S, whereby the amount of movement of the actuator 43 does not correspond to the displacement of the surface S1 in this area. In the next area G2 in which the amount of expansion of the actuator 43 is released from being held and the expansion amount control for the actuator 43 is carried out such that the astigmatism signal becomes the reference value, the amount of movement of the actuator 43 corresponds to the displacement of the surface S1. Therefore, the track G of the change in expansion amount of the actuator 43 corresponds to the displacement of the surface S1. Thereafter, when the processing objective lens 42 is located at the other end of the line to cut C1 as shown in FIG. 4(C), the total light quantity detected by the four-divided position detecting device in the light-receiving part 45 (see FIG. 1) decreases. Hence, when the total light quantity detected by the four-divided position detecting device in the light-receiving part 45 (see FIG. 1) becomes smaller than a predetermined threshold, the processing objective lens 42 is assumed to be located at a position corresponding to one end of the line to cut C1, the amount of expansion of the actuator at this time is held, and the recording of the track G is terminated. Information of the track G is stored into the displacement storage 707 (second measurement step).
Operations of the laser processing apparatus 1 in the displacement acquiring step will be explained with reference to the flowchart shown in FIG. 7. The stage controller 702 of the control unit 7 outputs a control signal to the stage 2 so as to move the processing objective lens 42 to a point Q1 on the C1 (step S01). In response to the output of this control signal, the stage 2 moves. The actuator controller 703 of the control unit 7 outputs a control signal to the actuator 43 so as to make the latter expand by 20 μm. In response to the output of this control signal, the actuator 43 expands by 20 μm. In this state, the stage 2 is moved up/down so that the observation visible ray is in focus therewith, and a focal position of the observation visible ray is set (step S02).
According to the signal outputted from the light-receiving part 45, the end part determiner 705 determines whether the processing objective lens 42 is located at the other end part of the object S or not (step S09). When it is determined that the processing objective lens 42 is located at an end part of the object S, the end part determiner 705 outputs an instruction signal to the actuator controller 703 so as to make the latter stop the expansion/contraction of the actuator 43. In response to the output of this instruction signal, the actuator controller 703 outputs a control signal to the actuator 43 so as to make the latter stop expanding/contracting and attain a held state (step S10). In response to the output of this control signal, the actuator 43 stops expanding/contracting. In response to the output of the control signal from the actuator controller 703 to the actuator 43, the displacement acquiring/reproducing part 706 terminates the recording of the amount of expansion/contraction of the actuator 43 (step S11). When the processing objective lens 42 is located at the point X2 on an extension of the line to cut C1, the stage movement controller 702 outputs a control signal to the stage 2 so as to make the latter stop moving (step S12). Thereafter, an average value of the amounts of expansion/contraction of the actuator 43 stored as those recorded before a predetermined time from when the recording is terminated among the amounts of expansion/contraction of the actuator 43 stored in the displacement storage 707 is calculated, and the amount of expansion/contraction of the actuator 43 is fixed so as to become this average value (step S13).
The explanation will be set forth with reference to FIGS. 8(A) to 8(C) showing the cross section II-II of FIG. 3 as with FIGS. 4(A) to 4(C). For easier understanding, the hatching indicating the cross section is omitted in FIGS. 8(A) to 8(C). FIG. 8(A) shows a state where the processing objective lens 42 has started forming a modified region on the line to cut C1. Before attaining the state of FIG. 8(A), the stage 2 is further raised by a predetermined distance (hereinafter referred to as processing height), such that the distance between the surface S1 of the object S and the processing objective lens 42 is set shorter by the processing height. Here, assuming that the focal point of the visible range and the converging point of the laser beam coincide with each other, the processing laser beam L1 is converged at a position corresponding to the value of product of the processing height from the surface S1 and the refractive index of the object S at the laser wavelength within the object S. When the object S is a silicon wafer having a refractive index of 3.6 (at a wavelength of 1.06 μm) and a processing height of 10 μm, for example, the processing laser beam L1 is converged at a position of 3.6×10=36 μm.
The rangefinding laser beam L2 is reflected less by the dicing film 2 a so that the total quantity of light reflected thereby is smaller, whereas the total quantity of reflected light increases in the object S. Namely, the total quantity of reflected light beam of the rangefinding laser beam L2 detected by the four-divided position detecting device in the light-receiving part 45 (see FIG. 1) increases, whereby it can be determined that the processing objective lens 42 is located at a position intersecting the line to cut C1 in the object S when the total quantity of reflected light beam exceeds a predetermined threshold. Therefore, when the total light quantity detected by the four-divided position detecting device in the light-receiving part 45 (see FIG. 1) is greater than the predetermined threshold, the processing objective lens 42 is assumed to be located at one end of the line to cut C1, and expansion amount control of the actuator 43 is started so as to release the expansion amount of the actuator 43 from being held at this time. The amount of expansion is controlled according to the track G of the expansion amount of the actuator 43 acquired as explained with reference to FIGS. 4(A) to 4(C). More specifically, the displacement acquiring/reproducing part 706 generates reproducing information according to the information of track G stored in the displacement storage 707, and the actuator controller 703 outputs a control signal to the actuator 43 according to the reproducing information outputted from the displacement acquiring/reproducing part 706 to the actuator controller 703. Therefore, when the processing objective lens 42 moves in the direction of arrow H in FIG. 6(A), the state shown in FIG. 8(B) is attained. As shown in FIG. 8(B), the modified region R is formed by a fixed processing height in area J (one end part). After the modified region R is formed by the fixed processing height in this area J, the processing objective lens 42 moves along the line to cut C1, thereby forming the modified region R with the processing laser beam L1 (first processing step).
1. A laser processing method for irradiating an object to be processed with a first laser beam while converging the first laser beam with a lens such that a converging point is positioned within the object, and forming a modified region within the object along a cutting line, the method comprising:
a height acquiring step of irradiating the object with a second laser beam for measuring height of a main surface of the object in an optical axis direction of the lens while converging the second laser beam with the lens, and acquiring the height of the main surface along the cutting line by detecting reflected light reflected by the main surface in response to the irradiation of the object with the second laser beam; and
a processing step of emitting the first laser beam and moving the lens and the object relative to each other in a perpendicular direction to the optical axis direction of the lens while adjusting a distance between the lens and the main surface according to the acquired height, so as to form the modified region along the cutting line in a predetermined depth relative to the main surface of the object;
wherein the height acquiring step is performed at a first time interval while moving the lens and the object relative to each other at a first speed in the perpendicular direction to the optical axis direction of the lens; and
wherein the processing step is performed at a second time interval shorter than the first time interval while moving the lens and the object relative to each other at a second speed faster than the first speed in the perpendicular direction to the optical axis direction of the lens.
2. A laser processing method for irradiating an object to be processed with a first laser beam while converging the first laser beam with a lens such that a converging point is positioned within the object, and forming a modified region within the object along a cutting line, the method comprising:
a processing step of emitting the first laser beam and moving the lens and the object relative to each other in a perpendicular direction to the optical axis direction of the lens while adjusting a distance between the lens and the main surface in the optical axis direction of the lens according to the acquired height, so as to form the modified region along the cutting line in a predetermined depth relative to the main surface of the object;
wherein the height acquiring step comprises:
a step of starting emitting of the second laser beam while holding the lens at the measurement initial position, moving the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens by releasing the lens from the measurement initial position in response to reflected light of the second laser beam reflected by the main surface; and
a step of adjusting the distance between the lens and the main surface after said releasing by detecting the reflected light of the second laser beam reflected by the main surface, so as to acquire the height of the main surface along the cutting line.
3. A laser processing method for irradiating an object to be processed with a first laser beam while converging the first laser beam with a lens such that a converging point is positioned within the object, and forming a modified region within the object along a cutting line, the method comprising:
a height acquiring step of irradiating the object with a second laser beam for measuring height of a main surface of the object in an optical axis direction of the lens while converging the second laser beam with the lens, and acquiring the height of the main surface along the cutting line by detecting reflected light reflected by the main surface in response to the irradiation of the object by the second laser beam; and
a processing preparatory step of setting a processing initial position for holding the lens with respect to the main surface according to the height of the main surface along the cutting line acquired by the height acquiring step so that the converging point is positioned at the predetermined depth under the main surface;
a first processing step of starting emitting the first laser beam while holding the lens at the processing initial position, and moving the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens so as to form the modified region in one end part of the cutting line in the predetermined depth relative to the main surface of the object; and
a second processing step of releasing the lens from the processing initial position after forming the modified region in the one end part of the cutting line, and moving the lens and the object relative to each other after said releasing while adjusting the distance between the lens and the main surface according to the height of the main surface along the cutting line acquired in the height acquiring step, so as to form the modified region.
4. A laser processing method according to any one of claims 1 to 3, wherein, in the height acquiring step, the first laser beam is emitted when acquiring the height of the main surface along the cutting line, so as to form the modified region along the cutting line.
5. A laser processing method according to claim 4, wherein the modified region formed in the height acquiring step is formed between the modified region formed in the processing step and the main surface.
6. A laser processing method according to any one of claims 1 to 3, wherein cutting the line includes first and second cutting lines;
wherein the height acquiring step moves the lens relative to the object in a first direction extending along the first cutting line, so as to acquire the height of the main surface along the first cutting line, and then moves the lens relative to the object in a second direction opposite from the first direction, so as to acquire the height of the main surface along the second cutting line; and
wherein the processing step forms the modified region along the first cutting line in the first direction, and then forms the modified region along the second cutting line in the second direction.
7. A laser processing apparatus for irradiating an object to be processed with a first laser beam while converging the first laser beam with a lens such that a converging point is positioned within the object, and forming a modified region within the object along a cutting line, the apparatus comprising:
a lens for converging the first laser beam and a second laser beam toward the object for measuring height of a main surface of the object in an optical axis direction of the lens;
an optical measurement device for acquiring the height of the main surface of the object by detecting reflected light reflected by the main surface in response to irradiation of the object with the second laser beam;
a stage for moving the object and the lens relative to each other in a perpendicular direction to the optical axis direction of the lens;
an actuator for holding the lens such that the lens freely advances and retracts with respect to the main surface in the optical axis direction of the lens; and
a control device for controlling respective behaviors of the stage and the actuator;
wherein, while the second laser beam is being emitted, the control device controls the stage so as to move the object and the lens relative to each other in the perpendicular direction to the optical axis direction of the lens, the optical measurement device acquiring the height of the main surface along the cutting line; and
wherein, while the first laser beam is being emitted, the control device controls the actuator so as to hold the lens while adjusting a distance between the lens and the main surface in the optical axis direction of the lens according to the height acquired by the optical measurement device, and controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens, so that the modified region is formed in a predetermined depth relative to the main surface of the object;
wherein, while the second laser beam is being emitted, the control device controls the stage so as to move the object and the lens relative to each other in the perpendicular direction to the optical axis direction of the lens at a first speed; and
wherein, while the first laser beam is being emitted, the control device controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens at a second speed faster than the first speed.
8. A laser processing apparatus for irradiating an object to be processed with a first laser beam while converging the first laser beam with a lens such that a converging point is positioned within the object, and forming a modified region within the object along a cutting line, the apparatus comprising:
an optical measurement device for acquiring height of the main surface of the object by detecting reflected light reflected by the main surface in response to irradiation of the object with the second laser beam;
wherein the control device controls the actuator so as to hold the lens at a measurement initial position set such that a converging point of the second laser beam is located at a predetermined position with respect to the object;
wherein, while starting the emission of the second laser beam with the lens being held at the measurement initial position, the control device controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens, and controls the actuator so as to release the lens from being held at the measurement initial position in response to the reflected light of the second laser beam reflected by the main surface; and
wherein, after the release, the control device controls the actuator so as to adjust the distance between the lens and the main surface while detecting the reflected light of the second laser beam reflected by the main surface, the height acquiring optical measurement device acquiring the height of the main surface along the cutting line.
9. A laser processing apparatus for irradiating an object to be processed with a first laser beam while converging the first laser beam with a lens such that a converging point is positioned within the object, and forming a modified region within the object along a cutting line, the apparatus comprising:
wherein, while the first laser beam is being emitted, the control device controls the actuator so as to hold the lens while adjusting a distance between the lens and the main surface in the optical axis direction of the lens according to the height acquired by the optical measurement device, and controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens so that the modified region is formed in a predetermined depth relative to the main surface of the object;
wherein the control device controls the actuator so as to set a processing initial position for holding the lens with respect to the main surface according to the height of the main surface along the cutting line acquired by the optical measurement device so that the converging point is positioned at the predetermined depth under the main surface;
wherein, while starting the emission of the first laser beam with the lens being held at the processing initial position, the control device controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens so as to form the modified region in one end part of the cutting line in the predetermined depth relative to the main surface of the object; and
wherein, after forming the modified region in the one end part, the control device controls the actuator so as to release the lens from the processing initial position and to adjust the distance between the lens and the object according to the height of the main surface acquired by the optical measurement device, and controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens, thereby forming the modified region.
10. A laser processing apparatus according to any one of claims 7 to 9, wherein the optical measurement device emits the first laser beam when acquiring the height of the main surface, so as to form the modified region along the cutting line.
11. A laser processing apparatus according to claim 10, wherein the stage is adapted to move the object toward the lens; and
wherein the control device controls the stage such that the modified region formed along the cutting line when the optical measurement device acquires the height is formed between the modified region formed later along the cutting line and the main surface.
12. A laser processing apparatus according to any one of claims 7 to 9, wherein the cutting line includes first and second cutting lines;
wherein the control device controls the stage so as to move the lens relative to the object in a first direction along the first cutting line, while the optical measurement device acquires the height of the main surface along the first cutting line, and then the control device controls the stage such that the lens moves relative to the object in a second direction opposite from the first direction, while the optical measurement device acquires the height of the main surface along the second cutting line; and
wherein, after forming the modified region along the first cutting line in the first direction, the control device controls the stage so as to form the modified region along the second cutting line in the second direction.
13. A laser processing method according to claim 2, wherein the lens is held at the measurement initial position between a position corresponding to one end of the cutting line and a position corresponding to a position on the outside of the one end on an extension of the cutting line, and between a position corresponding to the other end of the cutting line and a position corresponding to a position on the outside of the other end on the extension of the cutting line.
14. A laser processing method according to claim 2, wherein the processing step comprises:
a processing preparatory step of setting a processing initial position for holding the lens with respect to the main surface according to the height of the main surface along the cutting line acquired by the height acquiring step, and holding the lens at thus set processing initial position;
a first processing step of starting emitting of the first laser beam while holding the lens at the processing initial position, and moving the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens so as to form the modified region in the one end part of the cutting line; and
a second processing step of releasing the lens from the processing initial position after forming the modified region in the one end part of the cutting line, and moving the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens after the release while adjusting the distance between the lens and the main surface according to the height of the main surface along the cutting line acquired in the height acquiring step, so as to form the modified region in the predetermined depth relative to the main surface of the object.
15. A laser processing method according to claim 14, wherein the cutting line includes first and second cutting lines;
16. A laser processing method according to claim 2 or 3, wherein the cutting line includes first and second cutting lines;
17. A laser processing apparatus according to claim 8, wherein the lens is held at the measurement initial position between a position corresponding to one end of the cutting line and a position corresponding to a position on the outside of the one end on an extension of the cutting line, and between a position corresponding to the other end of the cutting line and a position corresponding to a position on the outside of the other end on the extension of the cutting line.
18. A laser processing apparatus according to claim 8, wherein the control device controls the actuator so as to set a processing initial position for holding the lens with respect to the main surface according to the height of the main surface along the cutting line acquired by the optical measurement device, and hold the lens at thus set processing initial position;
wherein, while starting the emission on the first laser beam with the lens being held at the processing initial position, the control device controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens, thereby forming the modified region in one end part of the cutting line; and
wherein, after forming the modified region in the one end part, the control device controls the actuator so as to release the lens from the processing initial position and adjust the distance between the lens and the main surface of the object according to the height of the main surface acquired by the optical measurement device, and controls the stage so as to move the lens and object relative to each other in the perpendicular direction to the optical axis direction of the lens, thereby forming the modified region.
19. A laser processing apparatus according to claim 18, wherein the cutting line includes first and second cutting lines;
20. A laser processing apparatus according to claim 8 or 9, wherein the cutting line includes first and second cutting lines;
wherein the control device controls the stage so as to move the lens relative to the object in a first direction along the first cutting line, while the optical measurement device acquires the height of the main surface along the first cutting line, and then control device controls the stage such that the lens moves relative to the object in a second direction opposite from the first direction, while the optical measurement device acquires the height of the main surface along the second cutting line; and
21. A laser processing method according to claim 1, wherein the height acquiring step comprises:
a first measurement step of starting emitting the second laser beam while holding the lens at the measurement initial position, moving the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens, and releasing the lens from the measurement initial position in response to reflected light of the second laser beam reflected by the main surface; and
a second measurement step of adjusting the distance between the lens and the main surface after the release while detecting the reflected light of the second laser beam reflected by the main surface, so as to acquire the height of the main surface along the cutting line.
22. A laser processing method according to claim 21, wherein the processing step comprises:
a first processing step of starting emitting the first laser beam while holding the lens at the processing initial position, and moving the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens so as to form the modified region in one end part of the cutting line; and
a second processing step of releasing the lens from the processing initial position after forming the modified region in the one end part of the cutting line, and moving the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens after the release while adjusting the distance between the lens and the main surface according to the height of the main surface along the cutting line acquired in the height acquiring step, so as to form the modified region.
23. A laser processing apparatus according to claim 7, wherein the control device controls the actuator so as to hold the lens at a measurement initial position set such that a converging point of the second laser beam is located at a predetermined position with respect to the object;
wherein, while starting the emission of the second laser beam with the lens being held at the measurement initial position, the control device controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens, and controls the actuator so as to release the lens from the measurement initial position in response to the reflected light of the second laser beam reflected by the main surface; and
wherein, after the release, the control device controls the actuator so as to adjust the distance between the lens and the main surface while detecting the reflected light of the second laser beam reflected by the main surface, the optical measurement device acquiring the height of the main surface along the cutting line.
24. A laser processing apparatus according to claim 23, wherein the control device controls the actuator so as to set a processing initial position for holding the lens with respect to the main surface according to the height of the main surface along the cutting line acquired by the optical measurement device, and hold the lens at thus set processing initial position;
wherein, while starting the emission of the first laser beam with the lens being held at the processing initial position, the control device controls the stage so as to move the lens and the object relative to each other in the perpendicular direction to the optical axis direction of the lens, thereby forming the modified region in one end part of the cutting line; and
wherein, after forming the modified region in the one end part, the control device controls the actuator so as to release the lens from the processing initial position and adjust the distance between the lens and the object according to the height of the main surface acquired by the optical measurement device, and controls the stage so as to move the lens and the object relative to each other, thereby forming the modified region.
US10/585,451 2004-01-09 2004-12-13 Laser processing method and device Active 2028-03-09 US8993922B2 (en)
JPP2004-004312 2004-01-09
US20080037003A1 US20080037003A1 (en) 2008-02-14
US8993922B2 true US8993922B2 (en) 2015-03-31
US10/585,451 Active 2028-03-09 US8993922B2 (en) 2004-01-09 2004-12-13 Laser processing method and device
EP (4) EP2390043B1 (en)
CN (4) CN102019507B (en)
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