JP6942437B2 - Laser oscillator and laser machining equipment - Google Patents

Description

The present invention relates to a laser oscillator and a laser processing apparatus.

In order to cut an object to be processed such as a semiconductor wafer into a plurality of chips, a laser processing apparatus is known that forms a modified region inside the object to be processed along a scheduled cutting line set in a grid pattern (a laser processing apparatus is known. For example, see Patent Document 1).

Japanese Patent No. 5456510

In the laser oscillator mounted on the laser processing apparatus as described above, it is desirable that the footprint is small, but the laser amplification unit tends to be larger than the laser light emitting unit.

An object of the present invention is to provide a laser oscillator capable of reducing the size of a laser amplification unit, and a laser processing apparatus including such a laser oscillator.

The laser oscillator of the present invention comprises a seed light emitting unit having a seed light source that emits laser light that is seed light, a first laser fiber that propagates the laser light emitted from the seed light emitting unit, and a first laser fiber. To excite the first amplifier section having the first excitation light source that emits the first excitation light for excitation, the second laser fiber that propagates the laser light amplified by the first amplifier section, and the second laser fiber. A second amplifier unit having a second excitation light source that emits the second excitation light of the above, and a laser light emitting unit having an optical component provided with an emission end that emits the laser light amplified by the second amplifier unit to the outside. A first support plate on which the first laser fiber is arranged, and a second support plate on which the second laser fiber, the first excitation light source, and the second excitation light source are arranged and a flow path for a refrigerant is provided are provided. The first support plate and the second support plate are arranged so as to face each other.

In this laser oscillator, in addition to cooling the second laser fiber, which easily generates heat, the first excitation light source and the second excitation light source, which easily generate heat, are cooled by a second support plate provided with a flow path for the refrigerant. Will be implemented. Moreover, the thickness directions of the first support plate on which the first laser fiber is arranged so as to face the second support plate (that is, the thickness directions of the first support plate and the second support plate coincide with each other and the thickness thereof). The first support plate and the second support plate are arranged so as to overlap each other when viewed from the vertical direction. As a result, the size of the first amplifier unit and the second amplifier unit, which are the laser amplification units, can be reduced.

In the laser oscillator of the present invention, the front surface and the back surface of the second support plate may be the arrangement surface of the second laser fiber, the first excitation light source, and the second excitation light source. According to this, it is possible to effectively utilize the front surface and the back surface of the second support plate and suppress the increase in size of the second support plate.

In the laser oscillator of the present invention, the side surface of the second support plate may be an arrangement surface. According to this, it is possible to effectively utilize the side surface of the second support plate and more reliably suppress the increase in size of the second support plate.

The laser oscillator of the present invention may further include a housing that houses a seed light emitting unit, a first amplifier unit, a second amplifier unit, a laser light emitting unit, a first support plate, and a second support plate. This facilitates the handling of the laser oscillator.

The laser oscillator of the present invention has a first housing that houses a seed light emitting unit, a first amplifier unit, a second amplifier unit, a first support plate, and a second support plate, and a second housing that houses a laser light emitting unit. A fiber cable that is hung between the body and the first housing and the second housing and propagates the laser light from the second amplifier portion to the laser light emitting portion may be further provided. According to this, the degree of freedom of arrangement of the laser light emitting part with respect to the 1st amplifier part and the 2nd amplifier part which is a laser amplification part is improved.

The laser oscillator of the present invention has at least a position between the seed light source and the first laser fiber, a position between the first laser fiber and the second laser fiber, and a position between the second laser fiber and the optical component. At one position, at least one light receiving element for detecting a part of the laser beam may be further provided, and the at least one light receiving element may be arranged on the second support plate. According to this, the light receiving element can be operated at an appropriate temperature.

The laser processing apparatus of the present invention is for adjusting the laser oscillator, an output adjusting unit for adjusting the output of the laser light emitted from the emission end of the laser oscillator, and an optical axis of the laser light passing through the output adjusting unit. A mirror unit having a mirror, a mounting plate to which a laser oscillator, an output adjusting unit and a mirror unit are mounted, a device frame to which the mounting plate is mounted, and a support section mounted on the device frame to support an object to be machined. It is provided with a laser condensing unit that is attached to the device frame so as to be movable with respect to the mirror unit and that condenses the laser light that has passed through the mirror unit onto the object to be processed.

Since this laser processing device includes a laser oscillator that can reduce the size of the laser amplification unit, it is possible to suppress the increase in size of the laser processing device.

According to the present invention, it is possible to provide a laser oscillator capable of downsizing the laser amplification unit and a laser processing apparatus including such a laser oscillator.

It is a schematic block diagram of the laser processing apparatus used for forming a reforming region. It is a top view of the processing object which is the object of formation of the modification region. FIG. 3 is a cross-sectional view taken along the line III-III of the object to be processed in FIG. It is a top view of the processing object after laser processing. It is sectional drawing along the VV line of the processing object of FIG. It is sectional drawing along the VI-VI line of the processing object of FIG. It is a perspective view of the laser processing apparatus of 1st Embodiment. It is a perspective view of the processing object attached to the support base of the laser processing apparatus of FIG. It is sectional drawing of the laser output part along the XY plane of FIG. It is a perspective view of a part of a laser output part and a laser condensing part in the laser processing apparatus of FIG. It is a figure which shows the optical arrangement relation of the λ / 2 wave plate unit and the polarizing plate unit in the laser output part of FIG. FIG. 9A is a diagram showing the polarization direction of the λ / 2 wave plate unit of the laser output unit of FIG. 9, and FIG. 9B is a diagram showing the polarization direction of the polarizing plate unit of the laser output unit of FIG. It is a figure which shows the whole structure of the laser oscillator of 1st Embodiment. It is a front view of the laser oscillator of 1st Embodiment. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. (A) is a diagram showing the overall configuration of the first modification of the laser oscillator of the first embodiment, and (b) is a diagram showing the overall configuration of the second modification of the laser oscillator of the first embodiment. (C) is a figure which shows the whole structure of the 3rd modification of the laser oscillator of 1st Embodiment. It is a front view of the laser oscillator of the 2nd Embodiment. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG. It is a figure which shows the internal structure of the laser oscillator of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and duplicate description will be omitted.

In the laser processing apparatus (described later) of the first embodiment, a modified region is formed on the processing target along the planned cutting line by condensing the laser light on the processing target. Therefore, first, the formation of the modified region will be described with reference to FIGS. 1 to 6.

As shown in FIG. 1, the laser processing apparatus 100 includes a laser light source 101 that pulse-oscillates a laser beam L, and a dichroic mirror 103 arranged so as to change the direction of the optical axis (optical path) of the laser beam L by 90 °. A condensing lens 105 for condensing the laser beam L is provided. Further, the laser processing apparatus 100 includes a support base 107 for supporting the processing object 1 irradiated with the laser light L focused by the light collecting lens 105, and a stage 111 for moving the support base 107. The laser light source control unit 102 that controls the laser light source 101 to adjust the output of the laser light L, the pulse width, the pulse waveform, and the like, and the stage control unit 115 that controls the movement of the stage 111 are provided.

In the laser processing apparatus 100, the direction of the optical axis of the laser light L emitted from the laser light source 101 is changed by 90 ° by the dichroic mirror 103, and the laser light L is placed inside the processing object 1 placed on the support base 107. The light is collected by the light collecting lens 105. At the same time, the stage 111 is moved, and the workpiece 1 is moved relative to the laser beam L along the planned cutting line 5. As a result, a modified region along the planned cutting line 5 is formed on the workpiece 1. Here, although the stage 111 is moved in order to relatively move the laser beam L, the condensing lens 105 may be moved, or both of them may be moved.

As the object to be processed 1, a plate-shaped member (for example, a substrate, a wafer, etc.) including a semiconductor substrate formed of a semiconductor material, a piezoelectric substrate formed of a piezoelectric material, or the like is used. As shown in FIG. 2, a cut schedule line 5 for cutting the work target 1 is set in the work target 1. The line 5 to be cut is a virtual line extending in a straight line. When a modified region is formed inside the object to be processed 1, as shown in FIG. 3, the laser beam L is cut while the condensing point (condensing position) P is aligned with the inside of the object to be processed 1. Move relative to the scheduled line 5 (ie, in the direction of arrow A in FIG. 2). As a result, as shown in FIGS. 4, 5 and 6, the modified region 7 is formed on the workpiece 1 along the scheduled cutting line 5, and the modified region formed along the scheduled cutting line 5. 7 is the cutting starting point region 8.

The condensing point P is a point where the laser beam L condenses. The line 5 to be cut may be not limited to a straight line but may be a curved line, a three-dimensional shape in which these are combined, or a coordinate-designated line 5. The line 5 to be cut is not limited to the virtual line, but may be a line actually drawn on the surface 3 of the object 1 to be processed. The modified region 7 may be formed continuously or intermittently. The modified region 7 may be in a row or a dot shape, and in short, the modified region 7 may be formed at least inside the object to be processed 1. Further, cracks may be formed starting from the modified region 7, and the cracks and the modified region 7 may be exposed on the outer surface (front surface 3, back surface, or outer peripheral surface) of the object to be processed 1. .. The laser beam incident surface when forming the modified region 7 is not limited to the surface 3 of the object to be processed 1, and may be the back surface of the object to be processed 1.

By the way, when the modified region 7 is formed inside the object to be processed 1, the laser beam L passes through the object 1 to be processed and is near the condensing point P located inside the object 1 to be processed. Especially absorbed. As a result, the modified region 7 is formed on the object to be machined 1 (that is, internal absorption type laser machining). In this case, since the laser beam L is hardly absorbed by the surface 3 of the object to be processed 1, the surface 3 of the object to be processed 1 is not melted. On the other hand, when the modified region 7 is formed on the surface 3 of the object to be processed 1, the laser beam L is particularly absorbed in the vicinity of the condensing point P located on the surface 3, and is melted and removed from the surface 3. , Holes, grooves, etc. are removed (surface absorption type laser machining).

The modified region 7 refers to a region in which the density, refractive index, mechanical strength and other physical properties are different from those of the surroundings. The modified region 7 includes, for example, a melting treatment region (meaning at least one of a region once melted and then resolidified, a region in a molten state, and a region in a state of being resolidified from melting) and a crack region. , Dielectric breakdown region, refractive index change region, etc., and there is also a region where these are mixed. Further, the modified region 7 includes a region in which the density of the modified region 7 is changed in comparison with the density of the non-modified region in the material of the object 1 to be processed, and a region in which lattice defects are formed. When the material of the object to be processed 1 is single crystal silicon, the modified region 7 can be said to be a high dislocation density region.

The melt-treated region, the refractive index change region, the region where the density of the modified region 7 changes as compared with the density of the non-modified region, and the region where the lattice defects are formed are further inside those regions and modified. Cracks (cracks, microcracks) may be included at the interface between the region 7 and the non-modified region. The included cracks may extend over the entire surface of the modified region 7, or may be formed only in a part or in a plurality of parts. The object to be processed 1 includes a substrate made of a crystalline material having a crystal structure. For example, the object to be processed 1 includes a substrate formed of at least one of gallium nitride (GaN), silicon (Si), silicon carbide (SiC), LiTaO ₃ , and sapphire (Al ₂ O _3). In other words, the object to be processed 1 includes, for example, a gallium nitride substrate, a silicon substrate, a SiC substrate, a LiTaO ₃ substrate, or a sapphire substrate. The crystal material may be either an anisotropic crystal or an isotropic crystal. Further, the object to be processed 1 may include a substrate made of a non-crystalline material having a non-crystalline structure (amorphous structure), and may include, for example, a glass substrate.

In the embodiment, the modified region 7 can be formed by forming a plurality of modified spots (processing marks) along the planned cutting line 5. In this case, the reformed region 7 is formed by gathering a plurality of reformed spots. The reforming spot is a reforming portion formed by a one-pulse shot of pulsed laser light (that is, one-pulse laser irradiation: laser shot). Examples of the modified spot include crack spots, melting treatment spots, refractive index changing spots, and spots in which at least one of these is mixed. Regarding the modified spot, the size and the length of the crack to be generated are appropriately adjusted in consideration of the required cutting accuracy, the required flatness of the cut surface, the thickness, type, crystal orientation, etc. of the object 1 to be processed. Can be controlled. Further, in the embodiment, the reforming spot can be formed as the reforming region 7 along the planned cutting line 5.
[Laser Machining Device of the First Embodiment]

Next, the laser processing apparatus of the first embodiment will be described. In the following description, the directions orthogonal to each other in the horizontal plane are defined as the X-axis direction and the Y-axis direction, and the vertical direction is defined as the Z-axis direction.
[Overall configuration of laser processing equipment]

As shown in FIG. 7, the laser processing apparatus 200 includes an apparatus frame 210, a first moving mechanism 220, a support base (support portion) 230, and a second moving mechanism 240. Further, the laser processing apparatus 200 includes a laser output unit 300, a laser condensing unit 500, and a control unit 600.

The first moving mechanism 220 is attached to the device frame 210. The first moving mechanism 220 includes a first rail unit 221, a second rail unit 222, and a movable base 223. The first rail unit 221 is attached to the device frame 210. The first rail unit 221 is provided with a pair of rails 221a and 221b extending along the Y-axis direction. The second rail unit 222 is attached to a pair of rails 221a and 221b of the first rail unit 221 so as to be movable along the Y-axis direction. The second rail unit 222 is provided with a pair of rails 222a and 222b extending along the X-axis direction. The movable base 223 is attached to a pair of rails 222a and 222b of the second rail unit 222 so as to be movable along the X-axis direction. The movable base 223 can rotate about an axis parallel to the Z-axis direction as a center line.

The support base 230 is attached to the movable base 223. The support base 230 supports the object 1 to be processed. The object to be processed 1 has, for example, a plurality of functional elements (light receiving elements such as photodiodes, light emitting elements such as laser diodes, circuit elements formed as circuits, etc.) on the surface side of a substrate made of a semiconductor material such as silicon. It is formed in a matrix. When the object to be processed 1 is supported by the support base 230, for example, the surface 1a of the object to be processed 1 (a plurality of functional elements) is placed on the film 12 stretched on the annular frame 11 as shown in FIG. Side surface) is attached. The support base 230 supports the object 1 to be processed by holding the frame 11 by a clamp and sucking the film 12 by a vacuum chuck table. On the support base 230, a plurality of scheduled cutting lines 5a parallel to each other and a plurality of scheduled cutting lines 5b parallel to each other are set in a grid pattern on the workpiece 1 so as to pass between adjacent functional elements. NS.

As shown in FIG. 7, the support base 230 is moved along the Y-axis direction by the operation of the second rail unit 222 in the first moving mechanism 220. Further, the support base 230 is moved along the X-axis direction by the operation of the movable base 223 in the first moving mechanism 220. Further, the support base 230 is rotated about an axis parallel to the Z-axis direction as a center line by operating the movable base 223 in the first moving mechanism 220. In this way, the support base 230 is attached to the device frame 210 so as to be movable along the X-axis direction and the Y-axis direction and to be rotatable about an axis parallel to the Z-axis direction as a center line.

The laser output unit 300 is attached to the device frame 210. The laser condensing unit 500 is attached to the device frame 210 via the second moving mechanism 240. The laser condensing unit 500 is moved along the Z-axis direction by operating the second moving mechanism 240. In this way, the laser condensing unit 500 is attached to the device frame 210 so as to be movable along the Z-axis direction with respect to the laser output unit 300.

The control unit 600 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The control unit 600 controls the operation of each unit of the laser processing apparatus 200.

As an example, in the laser machining apparatus 200, a modified region is formed inside the machining object 1 along the scheduled cutting lines 5a and 5b (see FIG. 8) as follows.

First, the machining object 1 is supported by the support base 230 so that the back surface 1b (see FIG. 8) of the machining object 1 becomes the laser beam incident surface, and each scheduled cutting line 5a of the machining object 1 is in the X-axis direction. Aligned in a direction parallel to. Subsequently, the laser condensing unit is determined by the second moving mechanism 240 so that the condensing point of the laser light L is located at a position separated from the laser beam incident surface of the processing object 1 by a predetermined distance inside the processing object 1. 500 is moved. Subsequently, the focusing point of the laser light L moves relatively along each scheduled cutting line 5a while the distance between the incident surface of the laser light of the object 1 to be processed and the focusing point of the laser light L is kept constant. Be made to. As a result, a modified region is formed inside the workpiece 1 along each scheduled cutting line 5a.

When the formation of the modified region along each scheduled cutting line 5a is completed, the support base 230 is rotated by the first moving mechanism 220, and each scheduled cutting line 5b of the workpiece 1 is in a direction parallel to the X-axis direction. Is matched to. Subsequently, the laser condensing unit is determined by the second moving mechanism 240 so that the condensing point of the laser light L is located at a position separated from the laser beam incident surface of the processing object 1 by a predetermined distance inside the processing object 1. 500 is moved. Subsequently, the focusing point of the laser light L moves relatively along each scheduled cutting line 5b while the distance between the incident surface of the laser light of the object 1 to be processed and the focusing point of the laser light L is kept constant. Be made to. As a result, a modified region is formed inside the workpiece 1 along each scheduled cutting line 5b.

As described above, in the laser processing apparatus 200, the direction parallel to the X-axis direction is the processing direction (scanning direction of the laser beam L). The relative movement of the focusing point of the laser beam L along each scheduled cutting line 5a and the relative movement of the focusing point of the laser beam L along each scheduled cutting line 5b are the first moving mechanisms. This is carried out by moving the support 230 along the X-axis direction by the 220. Further, the relative movement of the focusing point of the laser beam L between the scheduled cutting lines 5a and the relative movement of the focusing point of the laser beam L between the scheduled cutting lines 5b are performed by the first moving mechanism 220. This is carried out by moving the support base 230 along the Y-axis direction.

As shown in FIG. 9, the laser output unit 300 includes a mounting plate 301, a cover 302, and a plurality of mirrors 303 and 304. Further, the laser output unit 300 includes a laser oscillator 400, a shutter 320, a λ / 2 wave plate unit (output adjustment unit, polarization direction adjustment unit) 330, and a polarizing plate unit (output adjustment unit, polarization direction adjustment unit) 340. It also has a beam expander (laser light parallelizing unit) 350 and a mirror unit 360.

The mounting plate 301 supports a plurality of mirrors 303, 304, a laser oscillator 400, a shutter 320, a λ / 2 wave plate unit 330, a polarizing plate unit 340, a beam expander 350, and a mirror unit 360. The plurality of mirrors 303, 304, the laser oscillator 400, the shutter 320, the λ / 2 wave plate unit 330, the polarizing plate unit 340, the beam expander 350, and the mirror unit 360 are mounted on the main surface 301a of the mounting plate 301. The mounting plate 301 is a plate-shaped member and is removable from the device frame 210 (see FIG. 7). The laser output unit 300 is attached to the device frame 210 via the attachment plate 301. That is, the laser output unit 300 is removable from the device frame 210.

The cover 302 has a plurality of mirrors 303, 304, a laser oscillator 400, a shutter 320, a λ / 2 wave plate unit 330, a polarizing plate unit 340, a beam expander 350, and a mirror unit 360 on the main surface 301a of the mounting plate 301. Covering. The cover 302 is removable from the mounting plate 301.

The laser oscillator 400 pulse-oscillates a linearly polarized laser beam L along the X-axis direction. As will be described later, the laser oscillator 400 is configured as a MOPA (Master Oscillator Power Amplifier) type fiber laser. Therefore, in the laser oscillator 400, the output of the laser beam L can be switched on / off at high speed by switching the output of the seed light LD (Laser Diode / semiconductor laser) and the excitation LD ON / OFF. The wavelength of the laser beam L emitted from the laser oscillator 400 is included in, for example, any wavelength band of 500 to 550 nm, 1000 to 1150 nm, or 1300 to 1400 nm. The laser beam L in the wavelength band of 500 to 550 nm is suitable for internal absorption type laser machining on a substrate made of sapphire, for example. The laser beam L in each wavelength band of 1000 to 1150 nm and 1300 to 1400 nm is suitable for internal absorption type laser machining on a substrate made of silicon, for example. The polarization direction of the laser beam L emitted from the laser oscillator 400 is, for example, a direction parallel to the Y-axis direction. The laser beam L emitted from the laser oscillator 400 is reflected by the mirror 303 and is incident on the shutter 320 along the Y-axis direction.

The shutter 320 opens and closes the optical path of the laser beam L by a mechanical mechanism. As described above, the switching of ON / OFF of the output of the laser beam L from the laser output unit 300 is performed by switching ON / OFF of the output of the laser beam L in the laser oscillator 400, but the shutter 320 is provided. This prevents the laser beam L from being unexpectedly emitted from, for example, the laser output unit 300. The laser beam L that has passed through the shutter 320 is reflected by the mirror 304 and sequentially enters the λ / 2 wave plate unit 330 and the polarizing plate unit 340 along the X-axis direction.

The λ / 2 wave plate unit 330 and the polarizing plate unit 340 function as output adjusting units for adjusting the output (light intensity) of the laser beam L. Further, the λ / 2 wave plate unit 330 and the polarizing plate unit 340 function as polarization direction adjusting units for adjusting the polarization direction of the laser beam L. Details of these will be described later. The laser beam L that has sequentially passed through the λ / 2 wave plate unit 330 and the polarizing plate unit 340 is incident on the beam expander 350 along the X-axis direction.

The beam expander 350 parallelizes the laser beam L while adjusting the diameter of the laser beam L. The laser beam L that has passed through the beam expander 350 is incident on the mirror unit 360 along the X-axis direction.

The mirror unit 360 has a support base 361 and a plurality of mirrors 362 and 363. The support base 361 supports a plurality of mirrors 362 and 363. The support base 361 is attached to the mounting plate 301 so that its position can be adjusted along the X-axis direction and the Y-axis direction. The mirror 362 reflects the laser beam L that has passed through the beam expander 350 in the Y-axis direction. The mirror 362 is attached to the support base 361 so that its reflective surface can be angle-adjusted, for example, around an axis parallel to the Z axis. The mirror 363 reflects the laser beam L reflected by the mirror 362 in the Z-axis direction. The mirror 363 is attached to the support base 361 so that the reflecting surface thereof can be adjusted in angle around an axis parallel to the X-axis and can be adjusted in position along the Y-axis direction, for example. The laser beam L reflected by the mirror 363 passes through the opening 361a formed in the support base 361 and is incident on the laser condensing unit 500 (see FIG. 7) along the Z-axis direction. That is, the emission direction of the laser beam L by the laser output unit 300 coincides with the moving direction of the laser condensing unit 500.

As described above, each of the mirrors 362 and 363 has a mechanism for adjusting the angle of the reflecting surface. In the mirror unit 360, the position of the support base 361 with respect to the mounting plate 301 is adjusted, the position of the mirror 363 with respect to the support base 361 is adjusted, and the angle of the reflecting surface of each of the mirrors 362 and 363 is adjusted. The position and angle of the optical axis of the emitted laser light L are adjusted with respect to the laser condensing unit 500. That is, the plurality of mirrors 362 and 363 are configured to adjust the optical axis of the laser beam L emitted from the laser output unit 300.

The laser condensing unit 500 condenses the laser beam L that has passed through the mirror unit 360 onto the object 1 to be processed. As shown in FIG. 10, the laser condensing unit 500 has a housing 501. A second moving mechanism 240 is attached to the side surface of the housing 501. The housing 501 is provided with a cylindrical light incident portion 501a so as to face the opening 361a of the mirror unit 360 in the Z-axis direction. The light incident unit 501a causes the laser light L emitted from the laser output unit 300 to enter the housing 501. When the laser condensing unit 500 is moved along the Z-axis direction by the second moving mechanism 240 (that is, the laser condensing unit 500 is moved with respect to the mirror unit 360). They are separated from each other by a distance that they do not touch each other (when moved).

Although not shown, a mirror, a reflective spatial light modulator, and a 4f lens unit are arranged in the housing 501. Further, a condenser lens unit (condensing optical system), a drive mechanism, and a pair of ranging sensors are attached to the housing 501.

The laser beam L traveling in the housing 501 along the Z-axis direction is reflected by the mirror in a direction parallel to the XY plane and incident on the reflective spatial light modulator. The reflective spatial light modulator reflects the laser light L along the XY plane while modulating the laser light L reflected by the mirror. The reflective spatial light modulator is, for example, a spatial light modulator (SLM) of a liquid crystal on silicon (LCOS).

Here, in a plane parallel to the XY plane, the optical axis of the laser light L incident on the reflective spatial light modulator and the optical axis of the laser light L emitted from the reflective spatial light modulator are sharp angles. Make a certain angle α. This is because the incident angle and the reflection angle of the laser beam L are suppressed to suppress the decrease in the diffraction efficiency, and the performance of the reflection type spatial light modulator is fully exhibited. Further, in the reflective spatial light modulator, the laser beam L is reflected as P-polarized light. This is done in a plane parallel to the plane including the optical axis of the laser beam L entering and exiting the reflective spatial light modulator when a liquid crystal is used for the optical modulation layer of the reflective spatial light modulator. This is because when the liquid crystal is oriented so that the liquid crystal molecules are tilted, the laser beam L is phase-modulated while the rotation of the plane of polarization is suppressed (see, for example, Japanese Patent Application Laid-Open No. 387875). ..

The 4f lens unit constitutes a bilateral telecentric optical system in which the reflective surface of the reflective spatial light modulator and the entrance pupil surface of the condenser lens unit are in an imaging relationship. As a result, the image of the laser beam L on the reflective surface of the reflective spatial light modulator (the image of the laser beam L modulated in the reflective spatial light modulator) is transferred to the incident pupil surface of the condenser lens unit ( Image).

The condenser lens unit is attached to the housing 501 via a drive mechanism. The condensing lens unit condenses the laser beam L on the processing object 1 (see FIG. 7) supported by the support base 230. The drive mechanism moves the condenser lens unit along the Z-axis direction by the drive force of the piezoelectric element.

The pair of ranging sensors are attached to the housing 501 so as to be located on both sides of the condenser lens unit in the X-axis direction. Each distance measuring sensor emits light for distance measurement (for example, laser light) to the laser light incident surface of the workpiece 1 (see FIG. 7) supported by the support base 230, and the laser light incident surface. By detecting the distance-finding light reflected by the object 1, the displacement data of the incident surface of the laser beam of the object 1 to be processed is acquired.

In the laser processing apparatus 200, as described above, the direction parallel to the X-axis direction is the processing direction (scanning direction of the laser beam L). Therefore, when the focusing point of the laser beam L is relatively moved along the lines 5a and 5b to be cut, the distance measuring sensor that precedes the focusing lens unit of the pair of distance measuring sensors is relatively advanced. The sensor acquires displacement data of the laser beam incident surface of the workpiece 1 along the lines 5a and 5b to be cut. Then, the drive mechanism is based on the displacement data acquired by the ranging sensor so that the distance between the laser beam incident surface of the object 1 to be processed and the focusing point of the laser beam L is kept constant. Move the unit along the Z-axis direction.
[Λ / 2 wave plate unit and polarizing plate unit]

As described above, in the laser condensing unit 500, the optical axis of the laser light L incident on the reflective spatial light modulator and the laser light emitted from the reflective spatial light modulator in a plane parallel to the XY plane. The optical axis of L forms an angle α which is a sharp angle. On the other hand, as shown in FIG. 9, in the laser output unit 300, the optical path of the laser beam L is set to be along the X-axis direction or the Y-axis direction. Therefore, in the laser output unit 300, the λ / 2 wave plate unit 330 and the polarizing plate unit 340 are not only used as an output adjusting unit for adjusting the output of the laser light L, but also in the polarization direction for adjusting the polarization direction of the laser light L. It is necessary to make it function as an adjustment unit.

As shown in FIG. 11, the λ / 2 wave plate unit 330 has a holder 331 and a λ / 2 wave plate 332. The holder 331 holds the λ / 2 wave plate 332 so that the λ / 2 wave plate 332 can rotate around the axis (first axis) XL parallel to the X-axis direction as the center line. The λ / 2 wave plate 332 rotates the polarization direction by an angle of 2θ with the axis XL as the center line when the laser beam L is incident with the polarization direction tilted by an angle θ with respect to the optical axis (for example, the fast axis). The laser beam L is emitted (see (a) in FIG. 12).

The polarizing plate unit 340 includes a holder 341, a polarizing plate (polarizing member) 342, and an optical path correction plate (optical path correction member) 343. The holder 341 holds the polarizing plate 342 and the optical path correction plate 343 so that the polarizing plate 342 and the optical path correction plate 343 can rotate integrally with the axis (second axis) XL as the center line. The light incident surface and the light emitting surface of the polarizing plate 342 are tilted by a predetermined angle (for example, the Brewster angle). When the laser beam L is incident, the polarizing plate 342 transmits the P polarization component of the laser light L corresponding to the polarization axis of the polarizing plate 342, and reflects or absorbs the S polarization component of the laser light L (FIG. 12). See (b)). The light incident surface and the light emitting surface of the optical path correction plate 343 are inclined to the opposite sides of the light incident surface and the light emitting surface of the polarizing plate 342. The optical path correction plate 343 returns the optical axis of the laser beam L deviated from the axis XL by passing through the polarizing plate 342 to the axis XL.

In the polarizing plate unit 340, the polarizing plate 342 and the optical path correction plate 343 are integrally rotated with the axis XL as the center line, and as shown in FIG. 12B, polarized light is applied in a direction parallel to the Y-axis direction. The polarization axis of the plate 342 is tilted by an angle α. As a result, the polarization direction of the laser beam L emitted from the polarizing plate unit 340 is tilted by an angle α with respect to the direction parallel to the Y-axis direction. As a result, the laser beam L is reflected as P-polarized light in the reflective spatial light modulator of the laser condensing unit 500.

Further, as shown in FIG. 12B, the polarization direction of the laser beam L incident on the polarizing plate unit 340 is adjusted, and the light intensity of the laser beam L emitted from the polarizing plate unit 340 is adjusted. To adjust the polarization direction of the laser beam L incident on the polarizing plate unit 340, the λ / 2 wave plate 332 is rotated about the axis XL as the center line in the λ / 2 wavelength plate unit 330, and is shown in FIG. 12 (a). By adjusting the angle of the optical axis of the λ / 2 wave plate 332 with respect to the polarization direction (for example, the direction parallel to the Y-axis direction) of the laser beam L incident on the λ / 2 wave plate 332. Will be done.

As described above, in the laser output unit 300, the λ / 2 wave plate unit 330 and the polarizing plate unit 340 are not only used as an output adjusting unit (output attenuation unit in the above example) for adjusting the output of the laser beam L. It also functions as a polarization direction adjusting unit for adjusting the polarization direction of the laser beam L.
[Laser Oscillator of First Embodiment]

As shown in FIG. 13, the laser oscillator 400 includes a seed light emitting unit 410, a preamplifier unit (first amplifier unit) 420, a power amplifier unit (second amplifier unit) 430, and a laser light emitting unit 440. It has. The laser oscillator 400 is configured as a MOPA type fiber laser.

The seed light emitting unit 410 has a seed light LD (seed light source) 411. The seed light LD411 is driven by a pulse generator and pulse-oscillates the laser light L, which is the seed light. The laser beam L emitted from the seed light LD411 is propagated to the preamplifier section 420 by the fiber F1 and the fiber cable FC1. The laser beam L has a predetermined wavelength (for example, 1098 nm).

The preamplifier unit 420 includes an isolator 421, a clad mode stripper 422, a first laser fiber 423, for example, one first excited LD (first excited light source) 424, and a combiner 425. In the preamplifier section 420, the laser beam L is propagated to the first laser fiber 423 by the fibers F3, F4, F5, amplified by the first laser fiber 423, and then propagated to the power amplifier section 430 by the fibers F6, F7. Be done.

The first excitation LD424 emits the first excitation light PL1 having a predetermined wavelength (for example, 915 nm) for exciting the first laser fiber 423. The first excitation light PL1 emitted from the first excitation LD424 is propagated to the combiner 425 by the fiber F21. The combiner 425 couples the first excitation light PL1 to the fiber F6 between the fiber F6 and the fiber F7. The first excitation light PL1 coupled to the fiber F6 is incident on the first laser fiber 423 and travels in the first laser fiber 423 in the direction opposite to the traveling direction of the laser light L. As described above, the preamplifier unit 420 adopts a rear-excitation configuration.

The first laser fiber 423 amplifies the laser light L by propagating the laser light L emitted from the seed light emitting unit 410 in a state of being excited by the first excitation light PL1. The isolator 421 blocks the return light (light traveling toward the seed light emitting unit 410 side) between the fiber F3 and the fiber F4. The clad mode stripper 422 removes the first excitation light PL1 that was not absorbed by the first laser fiber 423 between the fiber F5 and the first laser fiber 423.

The power amplifier unit 430 includes an isolator 431, a bandpass filter 432, a clad mode stripper 433, a second laser fiber 434, and, for example, a plurality of (six in this case) second excited LDs (second excited light sources) 435. , Combiner 436, and. In the power amplifier unit 430, the laser light L is propagated to the second laser fiber 434 by the fibers F8, F9, F10, amplified by the second laser fiber 434, and then the laser light emitting unit by the fibers F11, F12, F13. It is propagated to 440.

Each second excitation LD435 emits a second excitation light PL2 having a predetermined wavelength (for example, 915 nm) for exciting the second laser fiber 434. The second excitation light PL2 emitted from each second excitation LD435 is propagated to the combiner 436 by the fiber F22. The combiner 436 couples the second excitation light PL2 to the fiber F11 between the fiber F11 and the fiber F12. The second excitation light PL2 coupled to the fiber F11 is incident on the second laser fiber 434 and travels in the second laser fiber 434 in the direction opposite to the traveling direction of the laser light L. As described above, the power amplifier unit 430 adopts a rear excitation configuration.

The second laser fiber 434 amplifies the laser light L by propagating the laser light L amplified by the preamplifier unit 420 in a state of being excited by the second excitation light PL2. The isolator 431 blocks the return light (light traveling toward the preamplifier unit 420 side) between the fiber F7 and the fiber F8. The bandpass filter 432 removes ASE (Amplified Spontaneous Emission) light generated in the preamplifier unit 420. The clad mode stripper 433 removes the second excitation light PL2 that was not absorbed by the second laser fiber 434 between the fiber F10 and the second laser fiber 434.

The laser beam emitting unit 440 includes a collimator 441 and an isolator (optical component) 442. The collimator 441 parallelizes the laser beam L emitted from the exit end of the fiber F13. The isolator 442 blocks the return light (light traveling in the laser oscillator 400). The emission end of the isolator 442 constitutes an emission end 443 that emits the laser beam L amplified by the power amplifier unit 430 to the outside.

In the laser oscillator 400, the output of the laser light L emitted from the seed light emitting unit 410, the output of the laser light L amplified by the preamplifier unit 420, the output of the laser light L amplified by the power amplifier unit 430, and the power amplifier The output of the return light in unit 430 is monitored. Further, the output of the first excitation light PL1 emitted from the first excitation LD424 and the output of the second excitation light PL2 emitted from the plurality of second excitation LD435s are monitored.

A part of the laser beam L emitted from the seed light emitting unit 410 is incident on the fiber F31 via the coupler 451 provided between the fiber F4 and the fiber F5, and is incident on the PD (light receiving element) 452 by the fiber F31. It is propagated and detected by PD452. The output of the laser beam L emitted from the seed light emitting unit 410 is monitored based on the signal output from the PD 452.

A part of the laser beam L amplified by the preamplifier unit 420 enters the fiber F32 via the coupler 454 provided between the fiber F9 and the fiber F10, and propagates to the PD (light receiving element) 455 by the fiber F32. It is detected by PD455. The output of the laser beam L amplified by the preamplifier unit 420 is monitored based on the signal output from the PD455.

A part of the laser beam L amplified by the power amplifier unit 430 enters the fiber F34 via the coupler 458 provided between the fiber F12 and the fiber F13, and propagates to the PD (light receiving element) 459 by the fiber F34. It is made to be detected by PD459. The output of the laser beam L amplified by the power amplifier unit 430 is monitored based on the signal output from the PD459.

When return light (light traveling toward the bandpass filter 432 side) is generated in the second laser fiber 434 of the power amplifier unit 430, a part of the return light is incident on the fiber F33 via the coupler 454 and enters the fiber F33. It is propagated to PD456 by PD456 and detected by PD456. The output of the return light in the power amplifier unit 430 is monitored based on the signal output from the PD456.

A part of the first excitation light PL1 emitted from the first excitation LD424 enters the PD453 arranged at the junction between the fiber F6 and the first laser fiber 423 and is detected by the PD453. The output of the first excitation light PL1 emitted from the first excitation LD424 is monitored based on the signal output from the PD453.

A part of the second excitation light PL2 emitted from the plurality of second excitation LD435s is incident on the PD457 arranged at the junction between the fiber F11 and the second laser fiber 434 and detected by the PD457. The output of the second excitation light PL2 emitted from the plurality of second excitation LD435s is monitored based on the signal output from the PD457.

As shown in FIG. 14, the laser oscillator 400 includes a first support plate 461, a second support plate 462, and a housing 470. The housing 470 is provided with a mounting base 471. The housing 470 has a first portion 470a and a second portion 470b. The second portion 470b is removable from the first portion 470a. As an example, the first portion 470a has a rectangular parallelepiped shape, and the mounting base 471 is composed of a lower wall of the first portion 470a. The second portion 470b has a rectangular parallelepiped shape and is attached to the upper surface of the first portion 470a.

The first portion 470a houses the preamplifier unit 420, the power amplifier unit 430, and the laser light emitting unit 440. The second portion 470b accommodates the seed light emitting unit 410. The fiber cable FC1 that propagates the laser beam L from the seed light emitting unit 410 to the preamplifier unit 420 is laid between the first portion 470a and the second portion 470b (see FIG. 9).

The first support plate 461 and the second support plate 462 are housed in the first portion 470a so that they face each other (that is, the thickness directions of the first support plate 461 and the second support plate 462 are relative to each other. The first support plate 461 and the second support plate 462 are arranged so as to coincide with each other and to overlap each other when viewed from the thickness direction. The second support plate 462 is arranged above the mounting base 471. The first support plate 461 is arranged above the second support plate 462. More specifically, the front surface 471a of the mounting base 471 and the back surface 462b of the second support plate 462 face each other with a space, and the front surface 462a of the second support plate 462 and the back surface 461b of the first support plate 461 b. Are facing each other through space. The first support plate 461 and the second support plate 462 are supported by columns (not shown) or the like, respectively.

In the laser oscillator 400, the back surface 471b of the mounting base 471 is in contact with the main surface 301a of the mounting plate 301, and the emission end 443 of the laser beam emitting portion 440 is facing the mirror 303, and the laser oscillator 400 is connected to the mounting plate 301 via the mounting base 471. It is attached to (see FIG. 9). That is, the laser oscillator 400 is removable from the mounting plate 301 (and thus the device frame 210).

As shown in FIG. 15 (see FIG. 13), the surface 461a of the first support plate 461 has a fiber connector 401, an isolator 421, a coupler 451 and a clad mode stripper 422, a first laser fiber 423, a PD453, and a combiner 425. An isolator 431, a bandpass filter 432 and a coupler 454 are attached. The fiber connector 401 connects the fiber cable FC1 and the fiber F3 to each other. The first laser fiber 423 is held by a fiber reel (not shown). The fiber F10 that propagates the laser beam L to the second laser fiber 434 passes from the surface 461a of the first support plate 461 to the surface 462a of the second support plate 462 via the notch 461c formed in the first support plate 461. It is postponed.

As shown in FIGS. 16 and 17, the front surface 462a, the back surface 462b, and the side surface 462c of the second support plate 462 are the second laser fiber 434 of the power amplifier unit 430, the plurality of second excitation LD435s, and the preamplifier unit 420. It is an arrangement surface of the 1st excitation LD424 and the like. It should be noted that FIG. 17 is a view of the configuration of the back surface 462b side of the second support plate 462 as viewed from the surface 462a side of the second support plate 462, and in FIG. 17, the configuration of the surface 462a side of the second support plate 462 is It has been omitted.

As shown in FIG. 16 (see FIG. 13), a clad mode stripper 433, a second laser fiber 434, PD457, a combiner 436, a coupler 458 and a PD459 are attached to the surface 462a of the second support plate 462. The second laser fiber 434 is held by a fiber reel (not shown). The fiber F13 that propagates the laser beam L to the laser beam emitting portion 440 extends from the surface 462a of the second support plate 462 to the surface 471a of the mounting base 471 via the notch 462e formed in the second support plate 462. doing.

PD452,455,456 and the first excited LD424 are attached to the side surface 462c of the second support plate 462. The fiber F31 that propagates a part of the laser beam L to the PD452, the fiber F32 that propagates a part of the laser beam L to the PD455, and the fiber F33 that propagates the return light to the PD456 are the first support plate 461 and the housing 470. It extends from the surface 461a of the first support plate 461 to the side surface 462c of the second support plate 462 through a gap formed between the inner surface and the inner surface of the first portion 470a. The fiber F21 that propagates the first excitation light PL1 to the combiner 425 passes through a gap formed between the first support plate 461 and the inner surface of the first portion 470a of the housing 470, and the side surface 462c of the second support plate 462. Extends from to the surface 461a of the first support plate 461.

As shown in FIG. 17, a plurality of second excited LD435s are attached to the back surface 462b of the second support plate 462. The fiber F22 that propagates the second excitation light PL2 to the combiner 436 extends from the back surface 462b of the second support plate 462 to the surface 462a of the second support plate 462 via the notch 462d formed in the second support plate 462. Exists.

As shown in FIGS. 16 and 17, a pipe 462f is embedded in the second support plate 462. Cooling water (refrigerant) W is circulated and supplied to the pipe 462f. As a result, the second support plate 462 functions as a cooling plate provided with a flow path for the cooling water W. In the laser oscillator 400, the first laser fiber 423 of the preamplifier unit 420 is arranged on the first support plate 461, while the second laser fiber 434 of the power amplifier unit 430, the plurality of second excited LD435s, and the preamplifier unit The first excited LD424 of 420 is arranged on the second support plate 462. As a result, the second laser fiber 434 of the power amplifier unit 430, the plurality of second excited LD435s, and the first excited LD424 of the preamplifier unit 420 are cooled.

As shown in FIG. 18, a support member 402, a collimator 441, and an isolator 442 are attached to the surface 471a of the attachment base 471. That is, the laser light emitting unit 440 is arranged on the mounting base 471. As shown in FIG. 19, a recess 471c is formed on the back surface 471b of the mounting base 471. On the inner surface of the recess 471c, processing boards 403 and 404 for signals output from PD452,455,456,457,459 and a memory board 405 are attached. Note that FIG. 19 is a view of the configuration on the back surface 471b side of the mounting base 471 as viewed from the front surface 471a side of the mounting base 471, and in FIG. 19, the configuration on the front surface 471a side of the mounting base 471 is omitted.

As shown in FIG. 20, the support member 402 has a support surface 402a. On the support surface 402a, a fiber F13 that propagates the laser light L from the power amplifier unit 430 to the laser light emitting unit 440 is arranged. More specifically, the support surface 402a extends from directly below the notch 462e formed in the second support plate 462 (see FIGS. 16 and 18) toward the incident end of the collimator 441, and the collimator 441 extends. It is inclined so that it is located on the lower side as it gets closer to.
[Action and effect of the first embodiment]

The laser oscillator 400 includes a seed light emitting unit 410 having a seed light LD411 that emits a laser light L that is a seed light, a first laser fiber 423 that propagates the laser light L emitted from the seed light emitting unit 410, and a first laser oscillator 400. A preamplifier section 420 having a first excitation LD424 that emits a first excitation light PL1 for exciting one laser fiber 423, a second laser fiber 434 that propagates the laser beam L amplified by the preamplifier section 420, and a second A power amplifier unit 430 having a second excitation LD435 that emits a second excitation light PL2 for exciting the laser fiber 434 and an emission end 443 that emits the laser light L amplified by the power amplifier unit 430 to the outside are provided. A laser light emitting unit 440 having an isolator 442, a first support plate 461 on which the first laser fiber 423 is arranged, a second laser fiber 434, a first excited LD424 and a second excited LD435 are arranged, and cooling water W A second support plate 462 provided with a flow path of the above is provided. The first support plate 461 and the second support plate 462 face each other (that is, the thickness directions of the first support plate 461 and the second support plate 462 coincide with each other and are viewed from the thickness direction. In some cases, the first support plate 461 and the second support plate 462 are arranged so as to overlap each other).

In the laser oscillator 400, in addition to cooling the second laser fiber 434, which easily generates heat, cooling of the first excited LD424 and the second excited LD435, which easily generate heat, is provided with a second flow path for the cooling water W. It is carried out by a support plate 462. Moreover, the first support plate 461 on which the first laser fiber 423 is arranged is arranged so as to face the second support plate 462. As a result, the size of the preamplifier unit 420 and the power amplifier unit 430, which are the laser amplification units, can be reduced.

In the laser oscillator 400, the front surface 462a, the back surface 462b, and the side surface 462c of the second support plate 462 serve as arrangement surfaces for the second laser fiber 434, the first excitation LD424, the second excitation LD435, and the like. As a result, the front surface 462a, the back surface 462b, and the side surface 462c of the second support plate 462 that function as the cooling plate can be effectively utilized, and the increase in size of the second support plate 462 can be reliably suppressed.

In the laser oscillator 400, the seed light emitting unit 410, the preamplifier unit 420, the power amplifier unit 430, the laser light emitting unit 440, the first support plate 461 and the second support plate 462 are housed in the housing 470. This facilitates the handling of the laser oscillator 400.

In the laser oscillator 400, each PD 452,455,459 that detects a part of the laser beam L is arranged on a second support plate 462 that functions as a cooling plate. As a result, each PD 452, 455, 459 can be operated at an appropriate temperature. In particular, when a Si (silicon) photodiode is used for each PD452,455,459 and the wavelength of the laser beam L to be detected is 1098 nm, each PD452,455,459 is arranged on the second support plate 462. It is important to maintain stable sensitivity to the wavelength of 1098 nm. When a Si photodiode is used for the PD453 and the wavelength of the first excitation light PL1 to be detected is 915 nm, even if the temperature of the PD453 rises slightly, the sensitivity is stable with respect to the wavelength of 915 nm. The need to place the PD453 on the second support plate 462 is low because it is maintained.

The laser processing apparatus 200 includes a laser oscillator 400 that can reduce the size of the laser amplification unit. As a result, it is possible to suppress the increase in size of the laser processing apparatus 200.

Further, the laser oscillator 400 includes a seed light emitting unit 410 having a seed light LD411 that emits a laser light L that is a seed light, and a first laser fiber 423 that propagates the laser light L emitted from the seed light emitting unit 410. And the preamp section 420 having the first excitation LD424 that emits the first excitation light PL1 for exciting the first laser fiber 423, the second laser fiber 434 that propagates the laser beam L amplified by the preamp section 420, and The power amplifier unit 430 having the second excitation LD435 that emits the second excitation light PL2 for exciting the second laser fiber 434 and the emission end 443 that emits the laser light L amplified by the power amplifier unit 430 to the outside A laser light emitting unit 440 having an isolator 442 provided, and a housing 470 having a mounting base 471 and accommodating a seed light emitting unit 410, a preamplifier unit 420, a power amplifier unit 430, and a laser light emitting unit 440. Be prepared. The isolator 442 provided with the exit end 443 is arranged on the mounting base 471.

In the laser oscillator 400, the seed light emitting unit 410, the preamplifier unit 420, the power amplifier unit 430, and the laser light emitting unit 440 are housed in the housing 470. Therefore, the laser oscillator 400 is easy to handle. Further, an isolator 442 provided with an emission end 443 is arranged on a mounting base 471 of the housing 470. As a result, for example, when the laser oscillator 400 is mounted on the laser processing apparatus 200 via the mounting base 471, vibration is generated in the laser processing apparatus 200, or a change in the operating environment temperature of the laser processing apparatus 200 is caused. Even if the housing 470 or the like is deformed, the position and angle of the emission end 443 are unlikely to shift. Therefore, the position and angle of the optical axis of the laser beam L emitted from the laser oscillator 400 to the outside are stable. In particular, when a modified region is formed inside the object 1 to be processed, more severe laser light L irradiation conditions are required as compared with the case where ablation processing, welding processing, etc. are performed. It is desirable that the position and angle of the optical axis of the laser beam L emitted from the oscillator 400 to the outside are stable.

In the laser oscillator 400, at least the first laser fiber 423 is arranged on the first support plate 461 housed in the housing 470, and at least the second laser fiber is placed on the second support plate 462 housed in the housing 470. 434 is arranged. Thereby, the first laser fiber 423 and the second laser fiber 434 can be appropriately supported in the housing 470.

In the laser oscillator 400, the second support plate 462 is provided with a flow path for the cooling water W, and the first excitation LD424 and the second excitation LD435 are arranged on the second support plate 462. As a result, in addition to the second laser fiber 434 that easily generates heat, the first excited LD424 and the second excited LD435 that easily generate heat can be efficiently cooled in a small space.

In the laser oscillator 400, the second support plate 462 is arranged above the mounting base 471, and the first support plate 461 is arranged above the second support plate 462. As a result, the footprint of the laser oscillator 400 can be reduced while simplifying the arrangement of the optical path of the laser beam L from the preamplifier unit 420 to the laser light emitting unit 440 via the power amplifier unit 430.

In the laser oscillator 400, the housing 470 is detachable from the first portion 470a accommodating the preamplifier unit 420, the power amplifier unit 430, and the laser light emitting unit 440 and the first portion 470a, and the seed light emitting unit 410. It has a second portion 470b and a second portion for accommodating the 470b. As a result, the seed light emitting unit 410 can be easily maintained by attaching / detaching the second portion 470b to / from the first portion 470a.

In the laser oscillator 400, the fiber F13 that propagates the laser light L from the power amplifier unit 430 to the laser light emitting unit 440 is arranged on the support surface 402a of the support member 402 provided on the mounting base 471. As a result, the fiber F13 that propagates the amplified laser light L can be appropriately supported (while maintaining the required bending diameter), so that a situation in which the laser light L leaks from the fiber F13 can be prevented. can.

In the laser processing apparatus 200, since the laser condensing unit 500 is attached to the apparatus frame 210 so as to be movable, it is not necessary to move the laser oscillator 400. Therefore, the stability of the position and angle of the optical axis of the laser beam L emitted from the laser oscillator 400 to the outside can be more reliably maintained, and the laser beam L is irradiated to the workpiece 1 under severe irradiation conditions. be able to.

Further, in the laser output unit 300, the laser oscillator 400, the λ / 2 wave plate unit 330, the polarizing plate unit 340, and the mirror unit 360 are arranged on the main surface 301a of the mounting plate 301. As a result, the laser output unit 300 can be easily attached to and detached from the laser processing apparatus 200 by attaching and detaching the mounting plate 301 to and from the apparatus frame 210 of the laser processing apparatus 200. Further, the optical path of the laser beam L from the laser oscillator 400 to the mirror unit 360 via the λ / 2 wave plate unit 330 and the polarizing plate unit 340 is set along a plane parallel to the main surface 301a of the mounting plate 301. The mirror unit 360 emits the laser beam L to the outside along the direction intersecting the plane. As a result, for example, when the emission direction of the laser beam L is along the vertical direction, the height of the laser output unit 300 is lowered, so that the laser output unit 300 can be easily attached to and detached from the laser processing apparatus 200. .. Further, the mirror unit 360 has mirrors 362 and 363 for adjusting the optical axis of the laser beam L. Thereby, when the laser output unit 300 is attached to the device frame 210 of the laser processing device 200, the position and angle of the optical axis of the laser light L incident on the laser condensing unit 500 can be adjusted. As described above, the laser output unit 300 can be easily attached to and detached from the laser processing apparatus 200.

If the optical component provided with the emission end 443 in the laser beam emitting unit 440 is arranged on the mounting base 471, for example, when the laser oscillator 400 is mounted on the laser processing apparatus 200 via the mounting base 471, Even if vibration is generated in the laser processing device 200 or the housing 470 or the like is deformed due to a change in the operating environment temperature of the laser processing device 200 or the like, the position and angle of the emission end 443 are unlikely to shift. Therefore, if the optical component provided with the emission end 443 in the laser light emitting unit 440 is arranged on the mounting base 471, the position and angle of the optical axis of the laser light L emitted to the outside from the laser oscillator 400 are stable. .. As an example, as shown in FIG. 21 (a), the pre-amp unit 420 and the power amplifier unit 430 may be arranged side by side in the horizontal direction on the laser light emitting unit 440, or as shown in FIG. 21 (b). ) And (c), even if the laser light emitting unit 440, the preamplifier unit 420, and the power amplifier unit 430 are arranged side by side in the horizontal direction, the laser light emitting unit 440 is provided with the emission end 443. If the optical component is arranged on the mounting base 471, the position and angle of the optical axis of the laser beam L emitted to the outside from the laser oscillator 400 are stable.
[Laser Oscillator of the Second Embodiment]

The laser oscillator 400 of the second embodiment is mainly different from the laser oscillator 400 of the first embodiment described above in that it includes a first housing 470, a second housing 480, and a fiber cable FC2. There is. As shown in FIG. 22, the first housing 470 accommodates a seed light emitting unit 410, a preamplifier unit 420, a power amplifier unit 430, a first support plate 461, and a second support plate 462. The second housing 480 accommodates the laser light emitting unit 440. The fiber cable FC2 is laid between the first housing 470 and the second housing 480, and propagates the laser light L from the power amplifier unit 430 to the laser light emitting unit 440.

As shown in FIG. 23, the signal processing boards 403 and 404 and the memory board 405 output from PD452,455,456,457,459 are attached to the back surface 461b of the first support plate 461. The configuration of the first support plate 461 on the surface 461a side is the same as that of the laser oscillator 400 of the first embodiment described above. Note that FIG. 23 is a view of the configuration of the back surface 461b side of the first support plate 461 as viewed from the surface 461a side of the first support plate 461, and in FIG. 23, the configuration of the surface 461a side of the first support plate 461 is It has been omitted.

As shown in FIG. 24, the fiber F13 that propagates the laser light L from the power amplifier unit 430 to the laser light emitting unit 440 is connected to the fiber cable FC2. The configuration of the second support plate 462 on the front surface 462a side and the configuration on the back surface 462b side are the same as those of the laser oscillator 400 of the first embodiment described above.

As shown in FIG. 25, a collimator 441 and an isolator 442 are attached to the surface 481a of the attachment base 481 included in the second housing 480. The laser beam L propagated by the fiber cable FC2 is propagated to the collimator 441 by the fiber F14.

According to the laser oscillator 400 configured as described above, the degree of freedom in arranging the laser light emitting unit 440 with respect to the preamplifier unit 420 and the power amplifier unit 430, which are the laser amplification units, is improved.
[Modification example]

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, in the above embodiment, the preamplifier unit 420 employs a rear excitation configuration, but in the first laser fiber 423, the first excitation light PL1 travels in the same direction as the traveling direction of the laser light L. The configuration may be adopted. Similarly, in the above embodiment, the rear excitation configuration is adopted for the power amplifier unit 430, but in the second laser fiber 434, the second excitation light PL2 travels in the same direction as the traveling direction of the laser light L. Excitation configurations may be adopted.

Further, the laser oscillator of the present invention is not limited to the laser processing apparatus 200 that forms a modified region inside the object 1 to be processed, and is mounted on a laser processing apparatus that performs other laser processing such as ablation processing and welding processing. It is also possible to do.

Further, in the laser processing apparatus 200, the polarizing plate unit 340 may be provided with a polarizing member other than the polarizing plate 342. As an example, a cube-shaped polarizing member may be used instead of the polarizing plate 342 and the optical path correction plate 343. The cube-shaped polarizing member is a member having a rectangular parallelepiped shape, and the side surfaces of the member facing each other are a light incident surface and a light emitting surface, and a layer having a function of a polarizing plate is provided between them. It is a member.

Further, in the laser processing apparatus 200, the axis on which the λ / 2 wave plate 332 rotates and the axis on which the polarizing plate 342 rotates do not have to coincide with each other.

Further, in the laser processing apparatus 200, the laser output unit 300 has mirrors 362 and 363 for adjusting the optical axis of the laser light L emitted from the laser output unit 300, but the laser output unit 300 emits light. It suffices to have at least one mirror for adjusting the optical axis of the laser beam L to be produced.

1 ... Machining object, 200 ... Laser processing device, 210 ... Device frame, 230 ... Support base (support part), 301 ... Mounting plate, 330 ... λ / 2 wavelength plate unit (output adjustment part), 340 ... Plate plate unit (Output adjustment unit) 360 ... Mirror unit, 362, 363 ... Mirror, 400 ... Laser oscillator, 410 ... Seed light emitting part, 411 ... Seed light LD (seed light source), 420 ... Preamp part (first amplifier part), 423 ... 1st laser fiber, 424 ... 1st excitation LD (1st excitation light source), 430 ... Power amplifier section (2nd amplifier section), 434 ... 2nd laser fiber, 435 ... 2nd excitation LD (2nd excitation light source) ), 440 ... Laser light emitting part, 442 ... Isolator (optical component), 443 ... Emitting end, 452,455,459 ... PD (light receiving element), 461 ... First support plate, 462 ... Second support plate, 462a ... Front surface, 462b ... Back surface, 462c ... Side surface, 470 ... Housing, first housing, 480 ... Second housing, 500 ... Laser condensing unit, FC2 ... Fiber cable, L ... Laser light, PL1 ... First excitation light , PL2 ... Second excitation light, W ... Cooling water (refrigerator).

Claims (5)

A seed light emitting unit having a seed light source that emits a laser beam that is a seed light,
A first laser fiber that propagates the laser light emitted from the seed light emitting unit, a first amplifier unit that has a first excitation light source that emits a first excitation light for exciting the first laser fiber, and a first amplifier unit.
A second amplifier unit having a second laser fiber that propagates the laser light amplified by the first amplifier unit and a second excitation light source that emits a second excitation light for exciting the second laser fiber, and a second amplifier unit.
A laser beam emitting unit having an optical component provided with an emitting end for emitting the laser light amplified by the second amplifier unit to the outside, and a laser beam emitting unit.
The first support plate on which the first laser fiber is arranged and
A second support plate in which the second laser fiber, the first excitation light source, and the second excitation light source are arranged and a flow path for a refrigerant is provided.
A first housing for accommodating the seed light emitting unit, the first amplifier unit, the second amplifier unit, the first support plate, and the second support plate.
A second housing for accommodating the laser beam emitting portion and
A fiber cable that is hung between the first housing and the second housing and propagates the laser light from the second amplifier portion to the laser light emitting portion is provided.
A laser oscillator in which the first support plate and the second support plate are arranged so as to face each other. The laser oscillator according to claim 1, wherein the front surface and the back surface of the second support plate are arrangement surfaces of the second laser fiber, the first excitation light source, and the second excitation light source. The laser oscillator according to claim 2, wherein the side surface of the second support plate is the arrangement surface. At least one of the positions between the seed light source and the first laser fiber, the position between the first laser fiber and the second laser fiber, and the position between the second laser fiber and the optical component. Further, at one position, at least one light receiving element for detecting a part of the laser beam is provided.
The laser oscillator according to any one of claims 1 to 3, wherein the at least one light receiving element is arranged on the second support plate. The laser oscillator according to any one of claims 1 to 4 and
An output adjusting unit that adjusts the output of the laser beam emitted from the emitting end of the laser oscillator, and an output adjusting unit.
A mirror unit having a mirror for adjusting the optical axis of the laser beam that has passed through the output adjusting unit, and
A mounting plate to which the laser oscillator, the output adjusting unit, and the mirror unit are mounted,
The device frame to which the mounting plate is mounted and
A support portion that is attached to the device frame and supports the object to be machined,
A laser processing apparatus including a laser condensing unit that is attached to the apparatus frame so as to be movable with respect to the mirror unit and that condenses the laser light that has passed through the mirror unit onto the object to be processed.

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