CN121467902A - Laser processing head and laser processing device - Google Patents

Abstract

The present invention relates to a laser processing head and a laser processing apparatus. The laser processing head includes a housing, a first mirror that reflects laser light, a plate-shaped second mirror that reflects a part of the laser light reflected by the first mirror and transmits another part of the laser light reflected by the first mirror, a light condensing unit that condenses a part of the laser light on an object, a light detecting unit that detects another part of the laser light, and a measuring unit that outputs measuring light, and the measuring light reflected by the object is detected via the light condensing unit. The second mirror transmits the measurement light traveling from the measurement unit to the light condensing unit and the measurement light traveling from the light condensing unit to the measurement unit.

Description

Laser processing head and laser processing device

Technical Field

The present disclosure relates to a laser processing head and a laser processing apparatus.

Background

As a laser processing head applied to a laser processing apparatus, a laser processing head is known which includes a housing, an adjusting portion disposed in the housing for adjusting a laser beam for processing, and a light converging portion mounted to the housing for converging the laser beam adjusted by the adjusting portion on an object, and a measuring portion disposed in the housing for outputting measuring light, and detecting the measuring light reflected by the object via the light converging portion (for example, refer to japanese patent application laid-open No. 2021-171802). In such a laser processing head, the light collecting portion may be mounted on the housing via a driving portion, and the driving portion may move the light collecting portion in a direction parallel to an optical axis of the light collecting portion based on a signal output from the measuring portion.

Disclosure of Invention

In the laser processing head described above, for example, when forming a modified region at a predetermined depth inside an object, it is important to detect measurement light in a measuring unit with high accuracy. In addition, for example, when forming a modified region in a desired state in the interior of an object, it is important to accurately detect a part of laser light irradiated to the object.

The purpose of the present disclosure is to provide a laser processing head capable of detecting a part of laser light and measuring light with high accuracy, and a laser processing device provided with such a laser processing head.

The laser processing head according to one aspect of the present disclosure is [1] "a laser processing head including a housing, a first mirror disposed in the housing to reflect laser light for processing, a plate-shaped second mirror disposed in the housing to reflect a part of the laser light reflected by the first mirror and transmit another part of the laser light reflected by the first mirror, a light converging portion mounted to the housing to converge the part of the laser light reflected by the second mirror on an object, a light detecting portion disposed in the housing to detect the part of the laser light transmitted through the second mirror, and a measuring portion disposed in the housing to output measuring light, the measuring light reflected by the object being detected via the light converging portion, the second mirror causing the measuring light traveling from the measuring portion to the light converging portion and the measuring light traveling from the light converging portion to the measuring portion to travel through the measuring portion.

In the laser processing head, a part of the laser light reflected by the first mirror is incident on the light detection section through the second mirror. Thus, for example, ghost reflection (reflection by a surface other than a mirror surface) that may occur in the second mirror when a part of the laser light is reflected by the second mirror and enters the light detection unit can be avoided, and therefore, a part of the laser light can be detected with high accuracy in the light detection unit. The measurement light passing through the light collecting section from the object side is incident on the measurement section through the second mirror. In this way, for example, ghost reflection that may occur in the second mirror when the measurement light is reflected by the second mirror and enters the measurement unit can be avoided, and therefore the measurement light can be detected in the measurement unit with high accuracy. Thus, according to the laser processing head, a part of the laser light and the measuring light can be detected with high accuracy.

The laser processing head according to one aspect of the present disclosure may be the laser processing head according to [2] "the above [1], further comprising an observation unit disposed in the housing and outputting observation light, wherein the observation light reflected by the object is detected via the light collecting unit, wherein the first mirror transmits the observation light traveling from the observation unit to the light collecting unit and the observation light traveling from the light collecting unit to the observation unit, and wherein the second mirror reflects the observation light traveling from the first mirror to the light collecting unit and the observation light traveling from the light collecting unit to the first mirror. According to this laser processing head, the observation light passing through the light converging portion from the object side is transmitted through the first mirror and is incident on the observation portion. Thus, for example, ghost reflection that may occur in the first mirror when the observation light is reflected by the first mirror and enters the observation portion can be avoided.

The laser processing head according to one aspect of the present disclosure may be the laser processing head according to [3] "the laser processing head according to [2] above, further comprising a third mirror disposed in the housing and reflecting the observation light traveling from the observation portion to the first mirror, and a fourth mirror disposed in the housing and reflecting the observation light traveling from the first mirror to the observation portion. According to this laser processing head, the optical path length of the observation light can be prolonged while suppressing an increase in the size of the housing. Extending the optical path length of the observation light is advantageous for improving the observation magnification of the observation portion and performing high-precision observation. When the focal length of the observation light is determined by the focal length of the light collecting unit and the observation magnification of the observation unit, the observation magnification of the observation unit can be increased by lengthening the focal length of the observation light in a case where it is difficult to change the focal length of the light collecting unit in order to obtain a desired light collecting state for the laser beam for processing.

The laser processing head according to one aspect of the present disclosure may be the laser processing head according to [4] "the above [2] or [3], wherein the observation portion detects a part of the measurement light reflected by the object and passing through the light collecting portion, which is reflected by the second mirror and passes through the first mirror, and a part of the laser light reflected by the object and passing through the light collecting portion, which is reflected by the second mirror and passes through the first mirror. According to this laser processing head, the state of the measuring light and the state of the laser light (for example, the spot positions of the measuring light and the laser light for processing on the surface of the object) can be monitored.

The laser processing head according to one aspect of the present disclosure may be the laser processing head according to any one of [5] "1 to [4] above, wherein an optical axis of the measurement light traveling from the measurement portion to the light collection portion is offset from an optical axis of the light collection portion to one side in the light collection portion, and an optical axis of the measurement light traveling from the light collection portion to the measurement portion is offset from the optical axis of the light collection portion to the other side in the light collection portion. According to this laser processing head, the height information of the predetermined surface of the object can be obtained by using the eccentric triangulation method.

The laser processing head according to one aspect of the present disclosure may be the laser processing head according to any one of [6] "1 to [5] above, wherein the mirror unit including the first mirror and the second mirror, the light detection unit including the light detection portion, and the measurement unit including the measurement portion are detachable from the housing, respectively. According to this laser processing head, maintenance of the first mirror and the second mirror, maintenance of the light detection unit, and maintenance of the measurement unit can be easily performed. That is, the target unit can be independently attached and detached without affecting other units when the target unit is maintained.

The laser processing head according to one aspect of the present disclosure may be the laser processing head according to any one of [7] "1 to [6], further comprising a driving unit attached to the housing so that the light converging unit moves in a direction parallel to an optical axis of the light converging unit, and a circuit unit disposed in the housing and configured to control the driving unit based on a signal output from the measuring unit. According to this laser processing head, the light-condensing spot of the laser light can be positioned at a predetermined position inside the object with reference to the predetermined surface of the object.

The laser processing head according to one aspect of the present disclosure may be the laser processing head according to any one of [1] to [7], further comprising a spatial light modulator disposed in the housing, modulating and reflecting the laser light traveling toward the first mirror, and an imaging optical system disposed in the housing, transmitting the laser light traveling from the spatial light modulator to the first mirror, wherein the imaging optical system constitutes a two-sided telecentric optical system in which a reflection surface of the spatial light modulator is in an imaging relationship with an entrance pupil surface of the light converging portion and the reflection surface of the spatial light modulator is in an imaging relationship with a light receiving surface of the light detecting portion. According to this laser processing head, the modulated image of the laser light on the reflection surface of the spatial light modulator is transferred to the entrance pupil surface of the light converging portion, and therefore the object can be processed with high accuracy by the modulated laser light. Further, since the modulated image of the laser light on the reflection surface of the spatial light modulator is transferred to the light receiving surface of the light detection unit, the modulated state of the laser light can be monitored.

The laser processing head according to one aspect of the present disclosure may be the laser processing head according to [9] "the laser processing head according to [8], further comprising an attenuator disposed in the housing and adjusting an output of the laser light traveling to the spatial light modulator, and a beam expander disposed in the housing and expanding a beam diameter of the laser light traveling to the spatial light modulator. According to this laser processing head, the laser beam can be modulated with the output adjusted and the beam diameter enlarged.

The laser processing apparatus according to one aspect of the present disclosure is a laser processing apparatus according to [10] "including the laser processing head according to any one of [1] to [9], the housing to which the laser processing head is attached, a light source that outputs the laser light incident on the laser processing head, and a support portion that supports the object.

According to the laser processing apparatus, since the laser processing head can accurately detect a part of the laser beam and the measuring light, the object can be processed with high accuracy.

Drawings

Fig. 1 is a perspective view of a laser processing apparatus as an example.

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

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

Fig. 4 is a side view of the laser processing head shown in fig. 1.

Fig. 5 is a structural view of the laser processing head shown in fig. 4.

Fig. 6 is a configuration diagram of a part of the measuring unit shown in fig. 5.

Fig. 7 is a block diagram of a portion of the laser processing head shown in fig. 5.

Detailed Description

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

[ Structure of laser processing apparatus ]

As shown in fig. 1, the laser processing apparatus 1 includes a plurality of moving mechanisms 5 and 6, a support 7, a pair of laser processing heads 10A and 10B, a light source unit 8, and a control unit 9. Hereinafter, three directions perpendicular to each other are referred to as an X direction, a Y direction, and a Z direction. In the laser processing apparatus 1, the Z direction is the vertical direction, and the X direction and the Y direction are the horizontal directions.

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

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 fixing portion 61 is attached to the apparatus frame 1a. The pair of moving portions 63 and 64 are each mounted on a rail provided in the fixed portion 61 and can move independently in the Y direction. The mounting portion 65 is mounted on a rail provided in the moving portion 63 and is movable in the Z direction. The mounting portion 66 is mounted on a rail provided in the moving portion 64 and is movable in the Z direction.

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

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

As shown in fig. 1, the light source unit 8 has a pair of light sources 81, 82. A pair of light sources 81, 82 are mounted to the device frame 1a. The pair of light sources 81, 82 outputs laser light L, respectively. The laser beam L emitted from the emission portion 81a of the light source 81 is guided to the laser processing head 10A by the optical fiber 2. The laser beam L emitted from the emission portion 82a of the light source 82 is guided to the laser processing head 10B by the other optical fiber 2.

The control unit 9 controls the respective units (the plurality of moving mechanisms 5, 6, the pair of laser processing heads 10A, 10B, the light source unit 8, and the like) of the laser processing apparatus 1. The control unit 9 is configured as a computer device including a processor, a memory, a storage, a communication device, and the like. In the control unit 9, software (program) read into a memory or the like is executed by a processor, and reading and writing of data in the memory and communication by a communication device are controlled by the processor. Thereby, the control unit 9 realizes various functions. The control unit 9 has a display 91. The display 91 displays various information. The display 91 may be configured as a touch panel that receives an instruction from an operator.

The laser processing apparatus 1 configured as described above can be used for various applications such as dicing for dividing a wafer, dicing for thinning a wafer, and trimming for removing an outer peripheral portion from a wafer. An example of processing by the laser processing apparatus 1 will be described. An example of this processing is an example in which modified regions are formed in the object W along a plurality of lines set in a lattice shape in order to cut the object W as a wafer into a plurality of chips (i.e., an example of the first half of the dicing processing).

First, in a state where the support 7 supports the object W, the moving mechanism 5 moves the support 7 in the X direction and the Y direction, respectively, so that the laser processing head 10A faces the support 7, and the moving mechanism 6 moves the laser processing head 10A in the Y direction. Next, the moving mechanism 5 rotates the support 7 about an axis parallel to the Z direction so that a plurality of lines extending in one direction in the object W extend along the X direction.

Next, the moving mechanism 6 moves the support 7 in the Y direction so that the light spot of the laser beam L emitted from the laser processing head 10A (hereinafter, referred to as "laser beam L of the laser processing head 10A") is located on a line extending in one direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction so that the light spot of the laser light L of the laser processing head 10A is positioned inside the object W.

Subsequently, the light source 81 emits the laser beam L, and the laser processing head 10A irradiates the object W with the laser beam L. At the same time, the moving mechanism 5 moves the support 7 in the X direction so that the light converging point of the laser beam L of the laser processing head 10A moves relatively along a line extending in one direction. In this way, the laser processing apparatus 1 forms a modified region inside the object W along a plurality of lines extending in one direction in the object W.

Next, the moving mechanism 5 rotates the support 7 about an axis parallel to the Z direction so that a plurality of lines extending in the other direction orthogonal to the one direction in the object W extend along the X direction.

Next, the moving mechanism 6 moves the support 7 in the Y direction so that the light spot of the laser beam L of the laser processing head 10A is positioned on a line extending in the other direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction so that the light spot of the laser light L of the laser processing head 10A is positioned inside the object W.

Subsequently, the light source 81 emits the laser beam L, and the laser processing head 10A irradiates the object W with the laser beam L. At the same time, the moving mechanism 5 moves the laser processing head 10A in the X direction so that the light converging point of the laser light L of the laser processing head 10A relatively moves along a line extending in the other direction. In this way, the laser processing apparatus 1 forms modified regions inside the object W along a plurality of lines extending in one direction in the other direction orthogonal to the one direction, respectively.

In one example of the processing, the light source 81 emits the laser light L having permeability to the object W, for example, by a pulse oscillation method. When such laser light L is condensed in the object W, the laser light L is particularly absorbed in a portion corresponding to the condensed light spot of the laser light L, and a modified region is formed in the object W. The modified region is a region having a density, refractive index, mechanical strength, and other physical properties different from those of the surrounding non-modified region. Examples of the modified region include a melt-processed region, a crack region, an insulation-damaged region, and a refractive index change region.

When the laser beam L emitted by the pulse oscillation system is irradiated to the object W, the condensed light spots of the laser beam L are relatively moved along a line set in the object W, and a plurality of modified light spots are formed in a line along the line. One modified spot is formed by irradiation of 1 pulse of laser light L. A row of modified regions is a collection of a plurality of modified light spots arranged in a row. The adjacent modified spots may be connected to each other or separated from each other depending on the relative movement speed of the condensed spot of the laser light L with respect to the object W and the repetition frequency of the laser light L.

In addition, although the laser processing head 10A is used for forming the modified region in the above example of processing, the laser processing head 10B may be used for forming the modified region. Even when the laser processing head 10B is used, a modified region can be formed in the object W by the same operation as in the case of using the laser processing head 10A. In the laser processing apparatus 1, since the laser processing head 10A and the laser processing head 10B are aligned in the Y direction, the formation of the modified regions along each of the plurality of lines extending in the X direction can be performed by one relative movement of the laser processing head 10A and the laser processing head 10B along the X direction.

[ Structure of laser processing head ]

As shown in fig. 2, 3, and 4, the laser processing head 10A includes a housing 11, an incident portion 12, an optical element portion 13, and a light condensing portion 14.

The housing 11 has first and second wall portions 21 and 22, third and fourth wall portions 23 and 24, and fifth and sixth wall portions 25 and 26. The first wall portion 21 and the second wall portion 22 are opposite to each other in the X direction. The third wall portion 23 and the fourth wall portion 24 are opposed to each other in the Y direction. The fifth wall portion 25 and the sixth wall portion 26 are opposite to each other in the Z direction.

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

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

The housing 11 is configured such that the housing 11 is attached to the attachment portion 65 in a state where the third wall portion 23 is disposed on the attachment portion 65 side of the moving mechanism 6. The mounting portion 65 has a base plate 65a and a mounting plate 65b. The substrate 65a is mounted on a rail provided in the moving section 63. The mounting plate 65B stands on the end of the base plate 65a on the laser processing head 10B side. The housing 11 is mounted on the mounting portion 65 by screwing with the mounting plate 65b via the bolts 28 of the mount 27 in a state where the third wall portion 23 is in contact with the mounting plate 65b. The pedestal 27 is provided in the first wall portion 21 and the second wall portion 22, respectively. The housing 11 is detachable from the mounting portion 65.

The incident portion 12 is disposed on the fifth wall portion 25. The incidence unit 12 causes the laser light L to be incident into 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. That is, 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 Y direction.

An emission end 2a of the optical fiber 2 is connected to the incident portion 12. 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 portion 2b of the injection end portion 2a is attached to the attachment portion 25b by bolts or the like. In this state, the tip end portion 2c of the emission end portion 2a passes through the hole 25a. Thereby, the emission end 2a of the optical fiber 2 can be attached to and detached from the incident portion 12. A cover 25c is disposed between the fifth wall portion 25 and the main body portion 2b. The cover 25c covers a gap formed between the hole 25a and the front end portion 2 c. As an example, at the emission end portion 2a, an isolator that suppresses return light is disposed in the main body portion 2b, and a collimator lens that collimates the laser light L is disposed in the front end portion 2 c. The incident portion 12 may be a connector or the like configured to be able to connect the emitting end portion 2a of the optical fiber 2.

The optical element portion 13 is disposed in the housing 11. The optical element portion 13 adjusts, for example, the laser light L incident from the incident portion 12. The optical element portion 13 is disposed on the fourth wall portion 24 side with respect to the partition wall portion 29 in the case 11. Each structure of the optical element portion 13 is attached to the partition wall portion 29 on the fourth wall portion 24 side. The partition wall 29 is provided in the housing 11, and divides the region in the housing 11 into a region on the third wall 23 side and a region on the fourth wall 24 side. The partition wall 29 is formed as a part of the housing 11. The partition wall 29 functions as an optical base for supporting each structure of the optical element 13.

The light condensing portion 14 is disposed on the sixth wall portion 26. The light condensing portion 14 is disposed on the sixth wall portion 26 in a state of passing through a hole 26a (see fig. 5) formed in the sixth wall portion 26. The condensing unit 14 condenses the laser light L adjusted by the optical element unit 13 and emits the condensed laser light L to the outside of the housing 11. The light collecting portion 14 is offset 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 light condensing portion 14 and the second wall portion 22 in the X direction is smaller than the distance between the light condensing portion 14 and the first wall portion 21 in the X direction, and the distance between the light condensing portion 14 and the fourth wall portion 24 in the Y direction is smaller than the distance between the light condensing portion 14 and the third wall portion 23 in the Y direction.

As shown in fig. 5, the optical element section 13 has a mirror 31, an attenuator 32, a beam expander 33, and a mirror 34. The mirror 31, the attenuator 32, the beam expander 33, and the mirror 34 are arranged on a straight line parallel to the X direction. The mirror 31 is opposed to the incident portion 12 in the Z direction. The mirror 31 reflects the laser light L (shown by a solid line in fig. 5) incident from the incident portion 12 toward the second wall portion 22 side. The attenuator 32 adjusts the output of the laser light L reflected by the mirror 31. The beam expander 33 expands the diameter of the laser light L that is output adjusted by the attenuator 32. The mirror 34 reflects the laser light L having the diameter enlarged by the beam expander 33 toward the sixth wall portion 26. The mirror 31 and the mirror 34 are, for example, plate-type mirrors or prism-type mirrors, respectively.

The optical element portion 13 further has an optical axis adjusting portion 35 and a mirror 36. The optical axis adjusting unit 35 is a mechanism for adjusting the optical axis of the laser beam L. The optical axis adjusting section 35 includes a first turning mirror 351 and a second turning mirror 352. The mirror 36 reflects the laser light L reflected by the first turning mirror 351 and the second turning mirror 352 in this order toward the first wall portion 21 side and toward the fifth wall portion 25 side. The mirror 36 is, for example, a plate-type mirror or a prism-type mirror.

The first turning mirror 351 includes a mirror 351a and a holder 351b. The mirror 351a is mounted to the holder 351b. The holder 351b is attached to the partition wall portion 29. The holder 351b holds the mirror 351a so that the orientation of the mirror 351a can be adjusted. The first turning mirror 351 reflects the laser light L reflected by the mirror 34 toward the first wall portion 21 side and toward the fifth wall portion 25 side.

The second turning mirror 352 includes a mirror 352a and a holder 352b. The mirror 352a is mounted to the holder 352b. The holder 352b is attached to the partition wall portion 29. The holder 352b holds the mirror 352a in such a manner that the orientation of the mirror 352a can be adjusted. The second turning mirror 352 reflects the laser light L reflected by the first turning mirror 351 toward the first wall portion 21 side and toward the sixth wall portion 26 side.

As an example, the holders 351b and 352b can be accessed by a tool through a capped opening (not shown) formed in the housing 11. Thus, by observing an image or the like obtained by the observation unit 45 described below and operating a tool, the orientation of each mirror 351a, 352a can be adjusted so that the optical axis of the laser light L incident on the light collecting unit 14 coincides with the optical axis of the light collecting unit 14.

The optical element section 13 also has a spatial light modulator 37 and an imaging optical system 38. The spatial light modulator 37 and the imaging optical system 38 are arranged on a straight line parallel to the Z direction. The spatial light modulator 37 modulates the laser light L reflected by the mirror 36 and reflects the laser light L toward the sixth wall portion 26. The spatial light modulator 37 is a reflective spatial light modulator. The spatial light Modulator 37 is, for example, LCOS (Liquid Crystal on Silicon) -SLM (SPATIAL LIGHT Modulator). The imaging optical system 38 constitutes a two-sided telecentric optical system in which the reflection surface 37a of the spatial light modulator 37 is in imaging relation with the entrance pupil plane 14a of the condenser section 14. The imaging optical system 38 is constituted by a plurality of lenses.

The optical element portion 13 further has a first mirror 41 and a second mirror 42. The first mirror 41 and the second mirror 42 are arranged on a straight line parallel to the X direction. The first mirror 41 is opposite to the imaging optical system 38 in the Z direction. The first mirror 41 reflects the laser light L having passed through the imaging optical system 38 toward the second wall portion 22. The second mirror 42 is opposed to the light condensing portion 14 in the Z direction. The second mirror 42 reflects a part La of the laser light L reflected by the first mirror 41 toward the sixth wall portion 26, and transmits the other part Lb of the laser light L reflected by the first mirror 41 toward the second wall portion 22. The condensing unit 14 condenses a part La of the laser light L reflected by the second mirror 42 with respect to the object W.

The optical element portion 13 further has a light detection portion 43. The light detection section 43 is opposed to the second mirror 42 in the X direction. The light detection unit 43 detects a part Lb of the laser light L transmitted through the second mirror 42. The light detection unit 43 is constituted by a two-dimensional sensor such as a CMOS (Complementary Metal Oxide Semiconductor (complementary metal oxide semiconductor)) image sensor, for example. In the two-sided telecentric optical system of the imaging optical system 38, the reflection surface 37a of the spatial light modulator 37 is in imaging relation with the light receiving surface 43a of the light detecting section 43. That is, the imaging optical system 38 constitutes a two-sided telecentric optical system in which the reflection surface 37a of the spatial light modulator 37 is in imaging relation with the entrance pupil surface 14a of the condenser section 14 and the reflection surface 37a of the spatial light modulator 37 is in imaging relation with the light receiving surface 43a of the light detecting section 43.

The optical element section 13 further includes a measurement section 44. The measuring unit 44 is disposed on the opposite side of the light condensing unit 14 from the second mirror 42. The measurement unit 44 outputs measurement light L10 (indicated by a single-dot chain line in fig. 5), and detects the measurement light L10 reflected by the object W via the light collecting unit 14. At this time, the second mirror 42 transmits the measurement light L10 traveling from the measurement unit 44 to the light condensing unit 14 and the measurement light L10 traveling from the light condensing unit 14 to the measurement unit 44. As an example, the measurement light L10 is laser light for measuring the height of the surface (for example, the surface on the side on which the laser light L is incident) of the object W (in other words, the distance between the surface and the light collecting section 14). In this case, the measurement light L10 output from the measurement unit 44 is irradiated onto the surface of the object W via the second mirror 42 and the light collecting unit 14, and the measurement light L10 reflected by the surface of the object W is detected in the measurement unit 44 via the light collecting unit 14 and the second mirror 42.

As shown in fig. 6, the optical axis A1 of the measurement light L10 traveling from the light source 441 of the measurement unit 44 to the light-collecting unit 14 is offset to one side from the optical axis a of the light-collecting unit 14 in the light-collecting unit 14. The optical axis A2 of the measurement light L10 reflected by the surface Wa of the object W and traveling from the light collecting unit 14 to the light detecting unit 442 of the measuring unit 44 is shifted from the optical axis a of the light collecting unit 14 to the other side (the side opposite to the one side) in the light collecting unit 14. The optical axis A1 of the measurement light L10 incident on the light condensing unit 14 from the light source 441 of the measurement unit 44 is parallel to the optical axis a of the light condensing unit 14, and the optical axis A1 of the measurement light L10 emitted from the light condensing unit 14 is inclined so that the light condensing spot C of the measurement light L10 condensed by the light condensing unit 14 is positioned on the optical axis a of the light condensing unit 14. As a result, the optical path of the measurement light L10 reflected by the surface Wa and transmitted through the light collecting unit 14 changes according to the height of the surface Wa of the object W, and as a result, the incident position of the measurement light L10 changes on the light receiving surface of the light detecting unit 442 of the measuring unit 44 according to the height of the surface Wa of the object W. Therefore, the height of the surface Wa of the object W can be measured based on the incidence position of the measurement light L10 on the light receiving surface of the light detection unit 442.

As shown in fig. 5, the optical element section 13 further has an observation section 45, a third mirror 46, and a fourth mirror 47. The observation portion 45 includes a light source 451 and a camera 452. The third mirror 46 is disposed on the opposite side of the second mirror 42 from the first mirror 41. The fourth mirror 47 is disposed opposite to the first mirror 41 with respect to the third mirror 46. The light source 451 is disposed on the fifth wall portion 25 side with respect to the third mirror 46. The camera 452 is disposed on the fifth wall portion 25 side with respect to the fourth mirror 47. The camera 452 is constituted by a two-dimensional sensor such as a CMOS image sensor, for example.

The observation unit 45 outputs observation light L20 (indicated by a broken line in fig. 5), and detects the observation light L20 reflected by the object W via the light collecting unit 14. In the observation unit 45, observation light L20 is output from the light source 451, and the observation light L20 is detected by the camera 452. At this time, the third mirror 46 reflects the observation light L20 traveling from the light source 451 toward the first mirror 41, and transmits the observation light L20 traveling from the first mirror 41 toward the fourth mirror 47. The fourth mirror 47 reflects the observation light L20 traveling from the first mirror 41 to the camera 452 via the third mirror 46. The first mirror 41 transmits the observation light L20 traveling from the light source 451 to the light condensing unit 14 and the observation light L20 traveling from the light condensing unit 14 to the camera 452. The second mirror 42 reflects the observation light L20 traveling from the first mirror 41 toward the light condensing portion 14 and the observation light L20 traveling from the light condensing portion 14 toward the first mirror 41. As an example, the observation light L20 is visible light for observing the surface of the object W (for example, the surface on the side on which the laser light L is incident). In this case, the observation light L20 output from the light source 451 is irradiated onto the surface of the object W via the third mirror 46, the first mirror 41, the second mirror 42, and the light-collecting unit 14, and the observation light L20 reflected by the surface of the object W is detected by the camera 452 via the light-collecting unit 14, the second mirror 42, the first mirror 41, the third mirror 46, and the fourth mirror 47. The wavelengths of the laser light L, the measuring light L10, and the observation light L20 are different from each other (at least the center wavelengths are shifted from each other).

As described above, in the optical element section 13, the attenuator 32 adjusts the output of the laser light L traveling to the spatial light modulator 37. The beam expander 33 expands the beam diameter of the laser light L traveling from the attenuator 32 to the spatial light modulator 37. The spatial light modulator 37 modulates and reflects the laser light L traveling toward the first mirror 41. The imaging optical system 38 transmits the laser light L traveling from the spatial light modulator 37 to the first mirror 41. The optical element section 13 includes "an optical unit 300 including the spatial light modulator 37 and the imaging optical system 38", "a mirror unit 400 including the first mirror 41, the second mirror 42, the third mirror 46, and the fourth mirror 47", "a light detection unit 430 including the light detection section 43", "a measurement unit 440 including the measurement section 44", and "an observation unit 450 including the observation section 45". The optical unit 300, the mirror unit 400, the light detection unit 430, the measurement unit 440, and the observation unit 450 are detachable from the partition wall 29. That is, each unit 300, 400, 430, 440, 450 is detachable from the housing 11. As an example, the units 300, 400, 430, 440, and 450 can be accessed through a capped opening (not shown) formed in the case 11. Thereby, maintenance can be performed for each unit.

As shown in fig. 3 and 5, the laser processing head 10A further includes a driving section 18 and a circuit section 19. In the laser processing apparatus 1, the circuit portion 19 is electrically connected to the control portion 9, and thus the circuit portion 19 functions as a part of the control portion 9. That is, in the laser processing apparatus 1, the circuit section 19 constitutes a part of the control section 9.

The driving portion 18 is attached to the partition wall portion 29 on the fourth wall portion 24 side. The light condensing unit 14 is attached to the partition wall 29 via the driving unit 18. That is, the driving unit 18 is attached to the housing 11, and the light condensing unit 14 is attached to the housing 11 via the driving unit 18. The driving unit 18 moves the light condensing unit 14 in a direction parallel to the optical axis a of the light condensing unit 14 by, for example, driving force of a piezoelectric element.

The circuit portion 19 is disposed on the third wall portion 23 side with respect to the partition wall portion 29 in the case 11. That is, the circuit portion 19 is disposed on the third wall portion 23 side with respect to the optical element portion 13 in the case 11. The circuit portion 19 is separated from the partition wall portion 29. The circuit portion 19 is constituted by a plurality of circuit boards, for example. The circuit unit 19 processes the signal output from the measurement unit 44 and the signal input to the spatial light modulator 37. The circuit unit 19 controls the driving unit 18 based on the signal output from the measuring unit 44. As an example, the circuit unit 19 controls the driving unit 18 so as to maintain the distance between the surface of the object W and the light converging unit 14 (i.e., to maintain the distance between the surface of the object W and the light converging spot C of the laser beam L constant) based on the signal output from the measuring unit 44.

Further, a slit, a hole, or the like (not shown) through which wiring for electrically connecting each structure of the optical element portion 13 and the circuit portion 19 passes is formed in the partition wall portion 29. The housing 11 is provided with a connector (not shown) connected to a wiring or the like for electrically connecting the circuit unit 19 and the control unit 9.

The laser processing head 10B includes a housing 11, an incident portion 12, an optical element portion 13, a light condensing portion 14, a driving portion 18, and a circuit portion 19, similarly to the laser processing head 10A. However, as shown in fig. 2, the respective structures of the laser processing head 10B are arranged so as to have a plane-symmetrical relationship with the respective structures of the laser processing head 10A with respect to a virtual plane passing through the midpoint between the pair of mounting portions 65, 66 and perpendicular to the Y direction.

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

The housing 11 of the laser processing head 10B is configured such that the housing 11 is attached to the attachment portion 66 in a state where the third wall portion 23 is disposed on the attachment portion 66 side. The mounting portion 66 has a base plate 66a and a mounting plate 66b. The substrate 66a is mounted on a rail provided in the moving portion 63. The mounting plate 66b stands on the end of the base plate 66a on the laser processing head 10A side. The housing 11 of the laser processing head 10B is attached to the attachment portion 66 in a state where the third wall portion 23 is in contact with the attachment plate 66B. The housing 11 of the laser processing head 10B is detachable from the mounting portion 66.

[ Structure of each mirror contained in mirror Unit ]

The respective mirrors 41, 42, 46, 47 included in the mirror unit 400 will be described with reference to fig. 7. In fig. 7, as in fig. 5, the laser light L is indicated by a solid line, the measurement light L10 is indicated by a one-dot chain line, and the observation light L20 is indicated by a broken line.

As shown in fig. 7, the first mirror 41 is a plate-type mirror having a pair of main surfaces 41a and 41 b. As an example, the first mirror 41 is a plate-type dichroic mirror formed by forming a dielectric multilayer film on the surface of a light-transmitting substrate. In the first mirror 41, the main surface 41a is a main surface on the side of the dielectric multilayer film on which the light transmitting substrate is located. The main surface 41a is inclined parallel to the Y direction at an angle of 45 ° with respect to the X direction and the Z direction in a state of facing the second wall portion 22 side and the fifth wall portion 25 side (see fig. 5).

The second mirror 42 is a plate-type mirror having a pair of main surfaces 42a and 42 b. As an example, the second mirror 42 is a plate-type dichroic mirror formed by forming a dielectric multilayer film on the surface of a light-transmitting substrate. In the second mirror 42, the main surface 42a is a main surface on the side of the dielectric multilayer film on which the light transmitting substrate is located. The main surface 42a is inclined parallel to the Y direction and at an angle of 45 ° with respect to the X direction and the Z direction in a state of facing the first wall portion 21 side and the sixth wall portion 26 side (see fig. 5).

The third mirror 46 is a plate-type mirror having a pair of main surfaces 46a and 46 b. As an example, the third mirror 46 is a plate-type dichroic mirror formed by forming a dielectric multilayer film on the surface of a light-transmitting substrate. In the third mirror 46, the main surface 46a is a main surface on the side of the dielectric multilayer film on which the light transmitting substrate is located. The main surface 46a is inclined parallel to the Y direction at an angle of 45 ° with respect to the X direction and the Z direction in a state of facing the second wall portion 22 side and the fifth wall portion 25 side (see fig. 5).

The fourth mirror 47 is a plate-type mirror having a pair of main surfaces 47a and 47 b. As an example, the fourth mirror 47 is a plate type total reflection formed by forming a metal film on the surface of the substrate. In the fourth mirror 47, the main surface 47a is a main surface on the side where the metal film is located with respect to the substrate. The main surface 47a is inclined parallel to the Y direction at an angle of 45 ° with respect to the X direction and the Z direction in a state of facing the second wall portion 22 side and the fifth wall portion 25 side (see fig. 5). The fourth mirror 47 may be a prism-type mirror.

Here, an example of the reflectance of each of the mirrors 41, 42, 46, and 47 with respect to the laser light L having a center wavelength of 1099nm, the measurement light L10 having a center wavelength of 850nm, and the observation light L20 having a center wavelength of 630nm will be described. The reflectance of the first mirror 41 with respect to the laser light L is 95% or more, the reflectance of the first mirror 41 with respect to the measurement light L10 is 5% or less, and the reflectance of the first mirror 41 with respect to the observation light L20 is 5% or less. The reflectance of the second mirror 42 with respect to the laser light L is 95% or more, the reflectance of the second mirror 42 with respect to the measurement light L10 is less than 50%, and the reflectance of the second mirror 42 with respect to the observation light L20 is 50% or more.

The reflectance of the third mirror 46 with respect to the laser light L is 95% or more, the reflectance of the third mirror 46 with respect to the measurement light L10 is less than 50%, and the reflectance of the third mirror 46 with respect to the observation light L20 is 50% or more. In the second mirror 42 and the third mirror 46, the dielectric multilayer film is coated with a coating layer having a reflectance for the measurement light L10 larger than a reflectance for the observation light L20, thereby realizing sharing of the components. The reflectance of the fourth mirror 47 with respect to the laser light L is 99% or more, the reflectance of the fourth mirror 47 with respect to the measurement light L10 is 99% or more, and the reflectance of the fourth mirror 47 with respect to the observation light L20 is 99% or more.

As described above, "part Lb of the laser light L transmitted through the second mirror 42 among the laser light L reflected by the first mirror 41 through the imaging optical system 38", "part L10 of the measurement light L10 reflected by the second mirror 42 among the measurement light L10 output from the measurement unit 44", and "part L20 of the observation light L20 transmitted through the first mirror 41 and the second mirror 42 by being reflected by the third mirror 46 among the observation light L20 output from the light source 451 of the observation unit 45" are incident on the light detection unit 43. That is, the light detection unit 43 can detect not only a part Lb of the laser light L but also a part of the measurement light L10 and a part of the observation light L20. This allows the contours of the laser light L, the measuring light L10, and the observation light L20 to be observed.

In addition, "a part of the observation light L20 reflected by the surface of the object W and passing through the light converging portion 14 and reflected by the second mirror 42 and transmitted through the first mirror 41 and the third mirror 46 and reflected by the fourth mirror 47", "a part of the laser light L reflected by the surface of the object W and passing through the light converging portion 14 and reflected by the second mirror 42 and transmitted through the first mirror 41 and the third mirror 46 and reflected by the fourth mirror 47" and "a part of the measurement light L10 reflected by the surface of the object W and passing through the light converging portion 14 and reflected by the second mirror 42 and transmitted through the first mirror 41 and the third mirror 46 and reflected by the fourth mirror 47" are incident on the camera 452 of the observation portion 45. That is, the observation unit 45 can detect not only a part of the observation light L20 but also a part of the laser light L and a part of the measurement light L10. By detecting the observation light L20 by the observation unit 45, it is possible to observe the object W, observe the reticle, and acquire relative positional information of the laser processing head 10A with respect to the object W. By detecting the laser beam L by the observation unit 45, the position information of the laser beam L can be acquired. By detecting the measuring light L10 by the observation unit 45, positional information of the measuring light L10 can be obtained.

[ Action and Effect ]

In the laser processing head 10A, a part Lb of the laser light L reflected by the first mirror 41 passes through the second mirror 42 and enters the light detection unit 43. Thus, for example, ghost reflection (reflection by a surface other than a mirror surface) that may occur in the second mirror 42 when a part of the laser light L is reflected by the second mirror 42 and enters the light detection unit 43 can be avoided, and therefore a part of the laser light L can be detected with high accuracy in the light detection unit 43. The measurement light L10 having passed through the light collecting unit 14 from the object W side passes through the second mirror 42 and enters the measurement unit 44. Thus, for example, ghost reflection that may occur in the second mirror 42 when the measurement light L10 is reflected by the second mirror 42 and enters the measurement unit 44 can be avoided, and thus the measurement light L10 can be detected at the measurement unit 44 with high accuracy. Therefore, according to the laser processing head 10A, a part of the laser light L and the measuring light L10 can be detected with high accuracy. It is extremely useful to be able to use the plate-type second mirror 42 without using an expensive cube-type beam splitter to avoid ghost reflections in the second mirror 42.

In the laser processing head 10A, the first mirror 41 transmits the observation light L20 traveling from the observation portion 45 to the light-collecting portion 14 and the observation light L20 traveling from the light-collecting portion 14 to the observation portion 45, and the second mirror 42 reflects the observation light L20 traveling from the first mirror 41 to the light-collecting portion 14 and the observation light L20 traveling from the light-collecting portion 14 to the first mirror 41. Thereby, the observation light L20 having passed through the light condensing unit 14 from the object W side passes through the first mirror 41 and enters the observation unit 45. Thus, for example, ghost reflection that may occur in the first mirror 41 when the observation light L20 is reflected by the first mirror 41 and enters the observation portion 45 can be avoided.

In the laser processing head 10A, the observation light L20 traveling from the observation portion 45 to the first mirror 41 is reflected by the third mirror 46, and the observation light L20 traveling from the first mirror 41 to the observation portion 45 is reflected by the fourth mirror 47. This can suppress an increase in size of the housing 11 and can lengthen the optical path length of the observation light L20. Extending the optical path length of the observation light L20 is advantageous in improving the observation magnification of the observation portion 45 and performing high-precision observation. When the optical path length of the observation light L20 is determined by the focal length of the light collecting unit 14 and the observation magnification of the observation unit 45, the observation magnification of the observation unit 45 can be increased by lengthening the optical path length of the observation light L20 in a case where it is difficult to change the focal length of the light collecting unit 14 in order to obtain a desired light collecting state for the processing laser light L.

In the laser processing head 10A, the observation unit 45 detects "a part of the measurement light L10 reflected by the object W and passing through the light converging unit 14 and reflected by the second mirror 42 and passing through the first mirror 41" and "a part of the laser light L reflected by the object W and passing through the light converging unit 14 and reflected by the second mirror 42 and passing through the first mirror 41" among the measurement light L10 reflected by the object W and passing through the light converging unit 14. This allows monitoring of the state of the measuring light L10 and the state of the laser light L (for example, the spot positions of the measuring light L10 and the laser light L on the surface of the object W).

In the laser processing head 10A, an optical axis A1 of the measurement light L10 traveling from the measurement unit 44 to the light collection unit 14 is offset from the optical axis a of the light collection unit 14 to one side in the light collection unit 14, and an optical axis A2 of the measurement light L10 traveling from the light collection unit 14 to the measurement unit 44 is offset from the optical axis a of the light collection unit 14 to the other side in the light collection unit 14. This makes it possible to obtain the height information of the predetermined surface of the object W by using the eccentric triangulation method.

In the laser processing head 10A, the units 300, 400, 430, 440, 450 are detachable from the housing 11. This makes it possible to easily perform maintenance of the spatial light modulator 37 and the imaging optical system 38, maintenance of the mirrors 41, 42, 46, and 47, maintenance of the light detection unit 43, maintenance of the measurement unit 44, and maintenance of the observation unit 45. That is, the target unit can be independently attached and detached without affecting other units when the target unit is maintained.

In the laser processing head 10A, the driving unit 18 that moves the light collecting unit 14 in a direction parallel to the optical axis a of the light collecting unit 14 is controlled based on the signal output from the measuring unit 44. This makes it possible to position the light spot C of the laser light L at a predetermined position inside the object W with respect to the predetermined surface of the object W.

In the laser processing head 10A, the imaging optical system 38 constitutes a two-sided telecentric optical system in which the reflection surface 37a of the spatial light modulator 37 is in imaging relation with the entrance pupil surface 14a of the condenser section 14 and the reflection surface 37a of the spatial light modulator 37 is in imaging relation with the light receiving surface 43a of the light detecting section 43. Thus, the modulated image of the laser light L on the reflection surface 37a of the spatial light modulator 37 is transferred to the entrance pupil surface 14a of the condenser 14, and thus the object W can be processed with high precision by the modulated laser light L. Further, since the modulated image of the laser light L on the reflection surface 37a of the spatial light modulator 37 is transferred to the light receiving surface 43a of the light detection unit 43, the modulated state of the laser light L can be monitored.

In the laser processing head 10A, the output of the laser beam L traveling to the spatial light modulator 37 is adjusted by the attenuator 32, and the beam diameter of the laser beam L traveling to the spatial light modulator 37 is enlarged by the beam expander 33. This makes it possible to modulate the laser beam L in a state where the output is adjusted and the beam diameter is enlarged.

The above operation and effects are similarly achieved by the laser processing head 10B.

According to the laser processing apparatus 1, the laser processing heads 10A and 10B can accurately detect a part of the laser light L and the measuring light L10, and thus can accurately process the object W.

Modification example

The present disclosure is not limited to the above-described one example. For example, the attenuator 32 may be disposed on the optical path of the laser beam L between the beam expander 33 and the spatial light modulator 37. In the case where the measurement unit 44 obtains the height information of the predetermined surface of the object W by the eccentric triangulation method, the direction in which the optical axis A1 and the optical axis A2 of the measurement light L10 are offset is not limited to the X direction, but may be, for example, the Y direction. In this case, the position of the spot of the measuring light L10 can be monitored by the observation unit 45 so that the spot of the measuring light L10 on the predetermined surface of the object W is positioned in the street to be cut. The measurement unit 44 may acquire the height information of the predetermined surface of the object W by a method other than the eccentric triangulation method (for example, a laser confocal method, a white confocal method, a spectroscopic interference method, an astigmatic method, or the like). The third mirror 46 and the fourth mirror 47 may not be disposed on the optical path of the observation light L20 between the first mirror 41 and the observation unit 45.

The housing 11 may be configured such that the housing 11 is attached to the attachment portion 65 (or the attachment portion 66) in a state where at least one of the first wall portion 21, the second wall portion 22, the third wall portion 23, and the fifth wall portion 25 is disposed on the attachment portion 65 (or the attachment portion 66) side of the laser processing apparatus 1.

The light source unit 8 may also have one light source. In this case, the light source unit 8 may be configured to emit a part of the laser light output from one light source from the emission portion 81a and to emit the other part of the laser light from the emission portion 82 a.

The laser processing apparatus 1 may include one laser processing head or three or more laser processing heads. The laser processing apparatus 1 is not limited to the use for forming the modified region in the object W, and may be used for performing other laser processing.

According to the present disclosure, a laser processing head capable of detecting a part of laser light and measuring light with high accuracy, and a laser processing apparatus including such a laser processing head can be provided.

Claims (10)

1. A laser processing head, wherein,

The device is provided with:

a housing;

a first mirror disposed in the housing and reflecting laser light for processing;

A second mirror of a plate type disposed in the housing, reflecting a part of the laser light reflected by the first mirror, and transmitting another part of the laser light reflected by the first mirror;

A light condensing unit attached to the housing and configured to condense the part of the laser light reflected by the second mirror with respect to an object;

a light detection unit disposed in the housing and detecting the part of the laser light transmitted through the second mirror, and

A measuring unit disposed in the housing and configured to output measuring light, the measuring light being reflected by the object via the light collecting unit,

The second mirror transmits the measurement light traveling from the measurement unit to the light collection unit and the measurement light traveling from the light collection unit to the measurement unit.

2. The laser processing head of claim 1, wherein,

The device further comprises an observation unit disposed in the housing and outputting observation light, wherein the observation light reflected by the object is detected by the light collecting unit,

The first mirror transmits the observation light traveling from the observation portion to the light condensing portion and the observation light traveling from the light condensing portion to the observation portion,

The second mirror reflects the observation light traveling from the first mirror toward the light condensing portion and the observation light traveling from the light condensing portion toward the first mirror.

3. The laser processing head of claim 2, wherein,

The device further comprises:

a third mirror disposed in the housing and reflecting the observation light traveling from the observation portion to the first mirror, and

And a fourth mirror disposed in the housing and reflecting the observation light traveling from the first mirror to the observation portion.

4. A laser processing head according to claim 2 or 3, wherein,

The observation unit detects a part of the measurement light reflected by the object and passing through the light converging unit and reflected by the second mirror and passing through the first mirror, and a part of the laser light reflected by the object and passing through the light converging unit and reflected by the second mirror and passing through the first mirror.

5. The laser processing head according to any one of claims 1 to 4, wherein,

The optical axis of the measurement light traveling from the measurement section to the light collection section is offset to one side from the optical axis of the light collection section in the light collection section,

An optical axis of the measurement light traveling from the light condensing unit to the measurement unit is offset from the optical axis of the light condensing unit to the other side in the light condensing unit.

6. The laser processing head according to any one of claims 1 to 5, wherein,

The mirror unit including the first mirror and the second mirror, the light detection unit including the light detection section, and the measurement unit including the measurement section are detachable from the housing, respectively.

7. The laser processing head according to any one of claims 1 to 6, wherein,

The device further comprises:

A driving part mounted on the housing for moving the light condensing part in a direction parallel to an optical axis of the light condensing part, and

And a circuit unit disposed in the housing and configured to control the driving unit based on a signal output from the measuring unit.

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

The device further comprises:

A spatial light modulator disposed in the housing, for modulating and reflecting the laser light traveling toward the first mirror, and

An imaging optical system disposed in the housing and transmitting the laser light traveling from the spatial light modulator to the first mirror,

The imaging optical system forms a two-side telecentric optical system in which a reflecting surface of the spatial light modulator is in imaging relation with an incident pupil surface of the light condensing part and the reflecting surface of the spatial light modulator is in imaging relation with a light receiving surface of the light detecting part.

9. The laser processing head of claim 8, wherein,

The device further comprises:

An attenuator disposed in the housing and adjusting an output of the laser light traveling toward the spatial light modulator, and

And a beam expander disposed in the housing to expand a beam diameter of the laser beam traveling toward the spatial light modulator.

10. A laser processing apparatus, wherein,

The device is provided with:

the laser processing head of any one of claims 1 to 9;

a mounting portion to which the housing of the laser processing head is mounted;

A light source outputting the laser light incident on the laser processing head, and

And a support unit that supports the object.