Laser processing equipment

Abstract

To provide a laser processing device that can observe a workpiece accurately and reduces concerns about a processing failure caused by processed wastes.SOLUTION: A laser processing device 1 includes a holding table, a laser beam irradiation unit 20, a processed waste discharge unit 30, an oblique light lighting unit 70, and an imaging unit. The oblique light lighting unit 70 is disposed downward of a condenser 23 of the laser beam irradiation unit and is disposed while leaving a circular space 75 corresponding to an upper opening 44 of permitting a laser beam 28 to pass therethrough inside a processed waste capturing chamber 31 of the processed waste discharge unit 30 for sucking and discharging a processed waste generated from a workpiece by irradiation with a laser beam 28 and downward of an upper wall 41 of the processed waste capturing chamber 31 and includes a ring-shaped light emission surface 77. The imaging unit images a workpiece on the holding table that is irradiated by the oblique light lighting unit 70.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] In order to divide a plate-like workpiece such as a semiconductor wafer along a planned division line, a laser processing apparatus is used to form a laser processing groove by irradiating the wafer with a laser beam having a wavelength with which the wafer has absorbability (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described laser processing apparatus, stroboscopic light is irradiated in accordance with the timing of irradiating the workpiece with a laser beam, and imaging is performed by an imaging means. Since the imaging means is arranged coaxially with the laser beam for processing (processing laser), it is possible to measure in real time the positional relationship between the position of the plasma generated by the irradiation of the laser beam and the preset processing position. As a result, abnormalities in the laser processing groove can be detected quickly and quality degradation can be suppressed.

[0005] Incidentally, these laser processing devices are equipped with a separate camera for alignment, in addition to the imaging means described above. This is because, while the imaging means described above images the workpiece using only coaxial inclined illumination, normal alignment requires the use of both coaxial inclined illumination and oblique (side) illumination to observe the workpiece more accurately. However, installing a separate camera for alignment not only directly increases costs, but also presents the problem of processing debris generated by ablation adhering to the camera, potentially leading to processing defects if the adhering debris falls and adheres to the workpiece.

[0006] This invention has been made in view of the above problems, and its purpose is to provide a laser processing apparatus that allows for accurate observation of the workpiece and reduces the risk of processing defects caused by processing debris. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objective, the present invention provides a laser processing apparatus comprising: a holding table for holding a workpiece; a laser beam irradiation unit equipped with a concentrator for focusing and irradiating a laser beam onto the workpiece held on the holding table; and a processing debris discharge unit disposed below the concentrator for sucking up and discharging processing debris generated from the workpiece by the irradiation of the laser beam, wherein the processing debris discharge unit has an upper wall with an upper opening formed therein that allows the laser beam focused by the concentrator to pass through, a side wall hanging down from the upper wall, and a part formed on the side wall The chip capture chamber includes a fluid inlet, a suction port formed in a side wall facing the side wall where the fluid inlet is formed and connected to a suction source, and a lower wall facing the upper wall and having a lower opening that allows the laser beam to pass through and captures chips; and further comprises an oblique light illumination unit having a ring-shaped light emitting surface, positioned inside the chip capture chamber and below the upper wall, leaving a circular space corresponding to the upper opening that allows the laser beam to pass through, and an imaging unit that images a workpiece on a holding table illuminated by the oblique light illumination unit.

[0008] The imaging unit further comprises a laser oscillator that emits the laser beam, a light condenser, a mirror disposed between the condenser and the laser beam that transmits the laser beam and guides it to the condenser, and reflects light of wavelengths other than the wavelength of the laser beam, and a light source that illuminates the path through which the light is reflected by the mirror and guided to the condenser, and the imaging unit may image the workpiece on the holding table by receiving the light that is irradiated from the light source through the condenser onto the workpiece and reflected by the workpiece.

[0009] The processing chip capture chamber may further include an oblique light illumination reflector, which is positioned inside the chamber and on the lower wall side of the oblique light illumination unit, and is formed in the shape of an inverted frustocone to reflect light emitted from the oblique light illumination unit and change the direction of the light's propagation. [Effects of the Invention]

[0010] This invention incorporates an oblique light illumination unit having a ring-shaped light-emitting surface inside the chip capture chamber of a chip discharge unit. This allows the chip discharge unit to capture, suck up, and discharge chips generated from the workpiece by laser beam irradiation, while the oblique light illumination unit illuminates the workpiece by irradiating it with light from an oblique angle. As a result, it is possible to accurately observe the workpiece and reduce the risk of processing defects caused by chips. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a perspective view showing an example of the configuration of a laser processing apparatus according to an embodiment. [Figure 2] Figure 2 is a schematic diagram showing an example of the configuration of the laser beam irradiation unit and the surrounding area of ​​the laser processing apparatus shown in Figure 1. [Figure 3] Figure 3 is a perspective view showing an example of the configuration of the processing waste discharge unit and the surrounding area of ​​the laser processing apparatus according to the embodiment. [Figure 4] Figure 4 is a cross-sectional view showing the main parts surrounding the processing waste discharge unit shown in Figure 3. [Modes for carrying out the invention]

[0012] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. In addition, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.

[0013] [Embodiment] A laser processing apparatus 1 according to an embodiment of the present invention will be described based on the drawings. Figure 1 is a perspective view showing an example of the configuration of the laser processing apparatus 1 according to the embodiment. Figure 2 is a schematic configuration diagram showing an example of the configuration of the laser beam irradiation unit 20 and the surrounding area of ​​the laser beam irradiation unit 20 of the laser processing apparatus 1 of Figure 1. Figure 3 is a perspective view showing an example of the configuration of the processing waste discharge unit 30 and the surrounding area of ​​the processing waste discharge unit 30 of the laser processing apparatus 1 according to the embodiment. Figure 4 is a cross-sectional view showing the main parts around the processing waste discharge unit 30 of Figure 3. Note that the processing waste discharge unit 30 is omitted in Figures 1 and 2. As shown in Figures 1, 2 and 3, the laser processing apparatus 1 according to the embodiment includes a holding table 10, a laser beam irradiation unit 20, a processing waste discharge unit 30, an X-axis direction movement unit 51, a Y-axis direction movement unit 52, a Z-axis direction movement unit 53, a display unit 60, an oblique light illumination unit 70, an oblique light illumination reflector 78, an imaging unit 80, a mirror 81, a light source 82, and a control unit 90.

[0014] In this embodiment, the workpiece 100 processed by the laser processing apparatus 1 is, for example, a disc-shaped semiconductor wafer or optical device wafer made of silicon, sapphire, silicon carbide (SiC), gallium arsenide, glass, etc. As shown in Figure 1, the workpiece 100 has chip-sized devices 103 formed in areas demarcated by a plurality of division lines 102 formed in a grid pattern on a flat surface 101. In this embodiment, an adhesive tape 105 is attached to the back surface 104 of the back side of the surface 101 of the workpiece 100, and an annular frame 106 is attached to the outer edge of the adhesive tape 105, but the present invention is not limited to this. In addition, the workpiece 100 in the present invention may be a rectangular package substrate having a plurality of devices sealed with resin, a ceramic plate, or a glass plate, etc.

[0015] As shown in Figures 1 and 2, the holding table 10 holds the workpiece 100. The holding table 10 comprises a disc-shaped frame with a recess formed therein, and a disc-shaped suction part fitted into the recess. The suction part of the holding table 10 is made of porous ceramic or the like, which has a large number of porous holes, and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). As shown in Figure 1, the upper surface of the suction part of the holding table 10 is a holding surface 11 on which the workpiece 100 is placed and which holds the placed workpiece 100 by suction. In this embodiment, the workpiece 100 is placed with its surface 101 facing upward, and the placed workpiece 100 is held by suction from the back surface 104 side via adhesive tape 105. Note that in Figure 2, the adhesive tape 105 and frame 106 are not shown. The holding surface 11 and the upper surface of the frame of the holding table 10 are located on the same plane and are formed parallel to the horizontal XY plane.

[0016] The holding table 10 is provided to move freely in the X-axis direction parallel to the horizontal direction by an X-axis movement unit 51, and is provided to move freely in the Y-axis direction parallel to the horizontal direction and perpendicular to the X-axis direction by a Y-axis movement unit 52. Furthermore, by moving the holding table 10 along the X-axis direction and the Y-axis direction by the X-axis movement unit 51 and the Y-axis movement unit 52, respectively, the focal point 29 of the laser beam 28 is moved relative to the workpiece 100 held on the holding table 10 in the X-axis direction and the Y-axis direction (both in the opposite direction to the movement direction of the holding table 10). The holding table 10 is provided to move freely around the Z-axis parallel to the vertical direction and perpendicular to the XY plane by a rotation drive source (not shown).

[0017] As shown in Figure 2, the laser beam irradiation unit 20 focuses and irradiates a laser beam 28 with a wavelength that is absorbed by the workpiece 100, which is held on the holding table 10, toward the surface 101 side of the workpiece 100, performing a so-called ablation process in which the workpiece 100 is ablated (sublimated or evaporated) by the laser beam 28 from the surface 101 side, thereby forming, for example, laser-processed grooves, laser-divided grooves, laser-processed holes, etc. As shown in Figure 2, the laser beam irradiation unit 20 comprises a laser oscillator 21, a mirror member 22, and a light concentrator 23.

[0018] The laser oscillator 21 emits a laser beam 28 with a wavelength that is absorbed by the workpiece 100. The output of the laser beam 28 emitted by the laser oscillator 21 is adjusted by an output adjustment unit (not shown) provided between the laser oscillator 21 and the mirror member 22, but the present invention is not limited to this. The mirror member 22 changes the optical axis direction of the laser beam 28 emitted by the laser oscillator 21 to a direction parallel to the Z axis, directing the laser beam 28 toward the focuser 23. The focuser 23 focuses the laser beam 28 emitted by the laser oscillator 21 to form a focal point 29, and irradiates the workpiece 100 held on the holding table 10 with the laser beam 28 that has formed the focal point 29.

[0019] The light-gathering unit 20's light-gathering unit 20 is provided to be movable in the Z-axis direction by a Z-axis direction movement unit 53. Furthermore, by moving along the Z-axis direction by the Z-axis direction movement unit 53, the light-gathering point 29 of the laser beam 28 is moved in the Z-axis direction (the same direction as the movement of the light-gathering unit 23) relative to the workpiece 100 held on the holding table 10. Note that the light-gathering unit 20's light-gathering unit 20 does not move along the X-axis direction or the Y-axis direction, but the present invention is not limited to this, and may be provided to be movable in the X-axis direction or the Y-axis direction by a separate X-axis direction movement unit or Y-axis direction movement unit (not shown) that is not connected to the holding table 10.

[0020] As shown in FIGS. 3 and 4, the machining debris discharge unit 30 includes a machining debris capture chamber 31 and a suction source 33. As shown in FIG. 4, the machining debris capture chamber 31 is disposed below the condenser 23 and captures the machining debris generated from the workpiece 100 by the irradiation of the laser beam 28. Here, the machining debris is generated by the ablation machining of the workpiece 100 and is fine dust also called debris. The machining debris discharge unit 30 sucks and discharges the machining debris captured by the machining debris capture chamber 31 by the suction source 33.

[0021] The machining debris capture chamber 31 includes an upper wall 41, a lower wall 42, and side walls 43. The upper wall 41 is formed in a flat plate shape and is provided immediately below the condenser 23, and an upper opening 44 is formed to allow the laser beam 28 condensed by the condenser 23 to pass through. The lower wall 42 is formed in a flat plate shape and is provided below the upper wall 41 so as to face the upper wall 41 along the Z-axis direction. The lower wall 42 allows the laser beam 28 that has passed through the upper opening 44 formed in the upper wall 41 to pass through, and a lower opening 45 is formed to capture the machining debris generated from the workpiece 100 by the irradiation of the laser beam 28.

[0022] The side walls 43 are formed in a plate shape, are provided so as to hang down from the upper wall 41, and stand upright from the lower wall 42. In this embodiment, four side walls 43 are provided so as to form a quadrilateral in plan view, but the present invention is not limited to this, and one or more side walls may be provided so as to form other shapes such as a substantially circular shape in plan view.

[0023] A fluid inlet 46 is formed in the side wall 43. The fluid inlet 46 is open to the outside of the chip capture chamber 31. Fluid from outside the chip capture chamber 31 flows into the internal space of the chip capture chamber 31 through the fluid inlet 46. Here, the internal space of the chip capture chamber 31 is the internal space formed by the upper wall 41, the lower wall 42, and the side wall 43. In this embodiment, the fluid from outside the chip capture chamber 31 is, for example, air. Note that in this invention, the chip capture chamber 31 is not limited to a configuration in which the fluid inlet 46 is open to the outside of the chip capture chamber 31. The fluid inlet 46 may be connected to a fluid supply source (not shown), and fluid supplied from the fluid supply source may flow into the internal space of the chip capture chamber 31 through the fluid inlet 46. In this case, the fluid supplied by the fluid supply source may be, for example, compressed air or a gas such as nitrogen or oxygen.

[0024] Furthermore, a suction port 47 is formed in the side wall 43 in the region facing the region where the fluid inlet 46 is formed. In other words, in this embodiment, a suction port 47 is formed in the side wall 43 facing the side wall 43 where the fluid inlet 46 is formed. The processing debris capture chamber 31 has a suction source 33 connected to the suction port 47 via a suction duct 34, and the suction source 33 sucks air, fluid, and processing debris from the space inside the chamber of the processing debris capture chamber 31 through the suction port 47 via the suction duct 34.

[0025] When the laser beam irradiation unit 20 irradiates the processing debris capture chamber 31 with a laser beam 28, the lower wall 42 is positioned close to the holding surface 11 of the holding table 10. Specifically, the lower wall 42 of the processing debris capture chamber 31 is positioned approximately 5 mm above the holding surface 11 of the holding table 10.

[0026] The X-axis movement unit 51, the Y-axis movement unit 52, and the Z-axis movement unit 53 move the holding table 10 and the light concentrator 23 of the laser beam irradiation unit 20 relative to each other in the X-axis, Y-axis, and Z-axis directions, respectively. In this embodiment, the X-axis movement unit 51 and the Y-axis movement unit 52 move the holding table 10 relative to the light concentrator 23 of the laser beam irradiation unit 20 along the X-axis and Y-axis directions, respectively. In this embodiment, the Z-axis movement unit 53 moves the light concentrator 23 of the laser beam irradiation unit 20 relative to the holding table 10 along the Z-axis direction.

[0027] The X-axis movement unit 51, the Y-axis movement unit 52, and the Z-axis movement unit 53 are all known ball screw mechanisms having a motor, a ball screw, and a guide. The X-axis movement unit 51 and the Y-axis movement unit 52 are each configured to have a ball screw rotatably mounted around the axes of the X and Y axes, a motor that rotates the ball screw around the axis, and a guide that supports the holding table 10 so as to be movable in the X and Y axes. The Z-axis movement unit 53 is configured to have a ball screw rotatably mounted around the axis of the Z axis, a motor that rotates the ball screw around the axis, and a guide that supports the light concentrator 23 of the laser beam irradiation unit 20 so as to be movable in the Z-axis direction.

[0028] The X-axis movement unit 51, the Y-axis movement unit 52, and the Z-axis movement unit 53 each include an encoder for reading the rotational position of a motor. Based on the rotational position of the motor read by the encoder, they detect the relative positions of the holding table 10 and the light concentrator 23 of the laser beam irradiation unit 20 in the X-axis, Y-axis, and Z-axis directions, and output the detected relative positions to the control unit 90. Note that the X-axis movement unit 51, the Y-axis movement unit 52, and the Z-axis movement unit 53 are not limited to a configuration in which the relative positions of the holding table 10 and the light concentrator 23 of the laser beam irradiation unit 20 are detected by an encoder. They may also be configured with linear scales parallel to the X-axis, Y-axis, and Z-axis directions, and reading heads that are movable in the X-axis, Y-axis, and Z-axis directions by the X-axis movement unit 51, the Y-axis movement unit 52, and the Z-axis movement unit 53, respectively, and read the scales of the linear scales.

[0029] The display unit 60 is mounted on a cover (not shown) of the laser processing apparatus 1, with the display surface facing outwards. The display unit 60 displays to the operator in a visible manner various conditions related to various processes of the laser processing apparatus 1, such as irradiation of the laser beam 28 by the laser beam irradiation unit 20 and imaging by the imaging unit 80, as well as acquired images and data, inspection judgment results, etc. The display unit 60 is composed of a liquid crystal display or the like. The display unit 60 is equipped with an input unit 61 used by the operator to input information related to the various conditions of the laser processing apparatus 1 as described above, information related to the display of images, etc. The input unit 61 provided on the display unit 60 is composed of at least one of a touch panel provided on the display unit 60 and a keyboard or the like. Note that the display unit 60 is not fixed to the laser processing apparatus 1, but may be provided on any communication device, and any communication device may be connected to the laser processing apparatus 1 wirelessly or by wire.

[0030] As shown in Figures 3 and 4, the oblique light illumination unit 70 is positioned inside the processing debris capture chamber 31 and below the upper wall 41, for example, directly below the upper wall 41 in this embodiment, leaving a circular space 75 corresponding to the upper opening 44 that allows the laser beam 28 to pass through, and has a ring-shaped light emitting surface 77. In this embodiment, the oblique light illumination unit 70 is positioned below the upper wall 41 without any structures in between, but the present invention is not limited to this, and any structure that does not hinder the function of the present invention may be positioned below the upper wall 41. As shown in Figures 3 and 4, the oblique light illumination unit 70 comprises a ring-shaped illumination 71, an illumination housing case 72, a light guide wire 73, and a light source 74. The ring-shaped illumination 71 is a light guide material arranged in a ring shape, housed and positioned within the illumination housing case 72, and connected to the light source 74 via the light guide wire 73. The ring-shaped light fixture 71 illuminates the outside by directing light supplied from the light source 74 via the light guide line 73 toward the outside of the ring-shaped light fixture 71.

[0031] The lighting housing case 72 is formed in a cylindrical shape and is located inside the processing debris capture chamber 31 and below the upper wall 41, for example, directly below the upper wall 41 in this embodiment. In this embodiment, the lighting housing case 72 is located below the upper wall 41 without any structures in between, but the present invention is not limited to this, and any structure that does not hinder the function of the present invention may be located below the upper wall 41. The lighting housing case 72 is made of a material that blocks the light emitted by the ring-shaped lighting 71, i.e., a light-shielding material. The lighting housing case 72 corresponds to the upper opening 44 that allows the laser beam 28 to pass through, and a circular space 75 (a circular space in plan view, i.e., a cylindrical space) that allows the laser beam 28 to pass through is formed therein. The lighting housing case 72 houses the ring-shaped lighting 71 in the space formed inside. The lighting housing case 72 has a ring-shaped open area 76 formed below the ring-shaped light fixture 71, for example, directly below it in this embodiment, and in a region facing the lower wall 42. In this embodiment, the ring-shaped open area 76 is positioned below the ring-shaped light fixture 71 without any structures in between, but the present invention is not limited to this, and any structure that does not hinder the function of the present invention may be positioned below the ring-shaped light fixture 71. The oblique light lighting unit 70 houses the ring-shaped light fixture 71 in the lighting housing case 72 with this configuration, and emits light downwards with the surface of the region of the ring-shaped light fixture 71 facing the open area 76 as a ring-shaped light emitting surface 77. The oblique light lighting unit 70 emits light at an inclination of about 20 degrees in the inward direction with respect to the vertical direction.

[0032] The light guide wire 73 connects the ring-shaped illumination 71 and the light source 74, guiding the light supplied from the light source 74 to the ring-shaped illumination 71. The light guide wire 73 is formed by having, for example, a light guiding material such as an optical fiber, and a light shielding material that covers the outer circumference of the light guiding material and prevents light leakage from the outer circumference of the light guiding material.

[0033] As shown in Figures 3 and 4, the oblique light reflective member 78 is located inside the processing debris capture chamber 31 and on the lower wall 42 side of the oblique light illuminating unit 70. That is, the oblique light reflective member 78 is installed below the ring-shaped light 71 and the light housing case 72 of the oblique light illuminating unit 70, for example, directly below them, and above the lower wall 42. In this embodiment, the oblique light reflective member 78 is positioned below the ring-shaped light 71 and the light housing case 72 of the oblique light illuminating unit 70 without any structures in between, but the present invention is not limited to this, and any structure that does not hinder the function of the present invention may be positioned below the ring-shaped light 71 and the light housing case 72 of the oblique light illuminating unit 70. The oblique light reflective member 78 is made of a material that reflects the light emitted by the ring-shaped light 71, for example, stainless steel. As shown in Figure 4, the oblique light illumination reflector 78 has an upper opening 44 that allows the laser beam 28 to pass through, and an opening 79 corresponding to the circular space 75. The oblique light illumination reflector 78 is formed in the shape of an inverted frustocone, where the inner surface of the opening 79 is inclined to protrude inwards as it goes downwards. The oblique light illumination reflector 78 is formed so that the inner surface of the inverted frustocone-shaped opening 79 faces the ring-shaped light emission surface 77 in the vertical direction around its entire circumference. In the example of this embodiment shown in Figure 4, the angle of inclination of the inner surface of the inverted frustocone-shaped opening 79 with respect to the vertical direction is set to an angle that reflects the light emitted from the ring-shaped illumination 71 and focuses it at the focal point 29 of the laser beam 28. The angle of inclination of the inner surface of the opening 79 with respect to the vertical direction can be appropriately changed according to the focal length of the oblique light illumination unit 70 and the light concentrator 23.

[0034] Since the oblique light illumination reflector 78 has an inner circumferential surface formed on such an opening 79, it reflects the light emitted from the oblique light illumination unit 70, changing the direction of light propagation toward the radially inward side of the opening 79, and shortening the focal length of the light compared to when it is emitted from the oblique light illumination unit 70. In other words, the oblique light illumination reflector 78 reflects the light emitted from the oblique light illumination unit 70 with its inner circumferential surface on such an opening 79, illuminating the workpiece 100 with a focal length shorter than the focal length of the light emitted from the oblique light illumination unit 70.

[0035] The imaging unit 80 includes an image sensor that images the workpiece 100 on the holding table 10, which is illuminated by the oblique light illumination unit 70. The image sensor is, for example, a CCD (Charge-Coupled Device) image sensor or a CMOS (Complementary MOS) image sensor.

[0036] As shown in Figure 2, the mirror 81 is positioned between the laser oscillator 21, which emits the laser beam 28, and the light concentrator 23. The mirror 81 transmits the laser beam 28 and guides it to the light concentrator 23, while also reflecting light of wavelengths other than the wavelength of the laser beam 28. As shown in Figure 2, the light source 82 illuminates the path through which the light is reflected by the mirror member 84 and the mirror 81 and guided to the light concentrator 23 with illumination light 88. For example, the light source 82 illuminates the workpiece 100 with strobe light in sync with the timing when the laser beam 28 is irradiated, or illuminates the workpiece 100 with strobe light in sync with the shutter of the imaging unit 80 during alignment to align the workpiece 100 with the focal point 29 of the laser beam 28.

[0037] As shown in Figure 2, the imaging unit 80 receives light from the light source 82 onto the workpiece 100 via the mirror member 84, mirror 81, and light concentrator 23. The light 89 reflected from the workpiece 100 is then received by the light concentrator 23 and mirror 81, passing through the mirror member 84 and reflected by the mirror member 83, thereby imaging the workpiece 100 on the holding table 10. The imaging unit 80 outputs the captured image to the control unit 90. Since the imaging unit 80 is positioned coaxially with the processing laser beam 28 relative to the workpiece 100, it can measure the positional relationship between the position of the plasma generated by the irradiation of the laser beam 28 and the preset processing position (the set position of the focusing point 29 of the laser beam 28) in real time, thereby enabling early detection of abnormalities in the laser processing groove.

[0038] In this embodiment, it is also preferable to further provide an optical system 85 between the mirror 81 and the mirror member 84, as shown in Figure 2, and the optical system 85 can eliminate chromatic aberration that may be caused by the light condenser 23.

[0039] Furthermore, the imaging unit 80 uses coaxial inclined illumination from the light source 82 and oblique illumination from the oblique illumination unit 70 to image the workpiece 100 on the holding table 10, thereby obtaining an image that allows for alignment of the workpiece 100 with the focal point 29 of the laser beam 28.

[0040] The control unit 90 controls the operation of each component of the laser processing apparatus 1 to cause the laser processing apparatus 1 to perform laser irradiation processing (ablation processing) on ​​the workpiece 100. In this embodiment, the control unit 90 includes a computer system. The computer system included in the control unit 90 has an arithmetic processing unit having a microprocessor such as a CPU (Central Processing Unit), a storage device having memory such as ROM (Read Only Memory) or RAM (Random Access Memory), and an input / output interface device. The arithmetic processing unit of the control unit 90 performs arithmetic processing according to a computer program stored in the storage device of the control unit 90 and outputs control signals for controlling the laser processing apparatus 1 to each component of the laser processing apparatus 1 via the input / output interface device of the control unit 90.

[0041] In the laser processing apparatus 1 according to the embodiment described above, by incorporating an oblique light illumination unit 70 having a ring-shaped light emitting surface 77 inside the processing debris capture chamber 31 of the processing debris discharge unit 30, the processing debris discharge unit 30 can capture, suck up, and discharge processing debris generated from the workpiece 100 by irradiation with the laser beam 28, and the oblique light illumination unit 70 can illuminate the workpiece 100 by irradiating it with light from an oblique angle. Therefore, the laser processing apparatus 1 according to the embodiment has the effect of being able to accurately observe the workpiece 100 with a single imaging unit 80 arranged coaxially with the laser beam 28 and obtain an image that enables alignment. Furthermore, in the laser processing apparatus 1 according to the embodiment, since the imaging unit 80 is coaxial with the laser beam 28 and there is no need to provide a separate camera for alignment, the risk of processing debris generated by ablation adhering to the workpiece is reduced, thereby reducing the risk of processing defects caused by processing debris. Furthermore, the laser processing apparatus 1 according to this embodiment has the effect of reducing the cost of providing an alignment camera.

[0042] Furthermore, the laser processing apparatus 1 according to this embodiment includes, in addition to the oblique light illumination unit 70, a mirror 81 disposed between the laser oscillator 21 that emits the laser beam 28 and the light concentrator 23, which transmits the laser beam 28 and guides it to the light concentrator 23, and reflects light of wavelengths other than the wavelength of the laser beam 28, and a light source 82 that irradiates illumination light 88 into the path that is reflected by the mirror 81 and guided to the light concentrator 23, and an imaging unit 80 images the workpiece 100 on the holding table 10 by receiving the light 89 that is irradiated onto the workpiece 100 from the light source 82 via the light concentrator 23 and reflected by the workpiece 100.Therefore, the laser processing apparatus 1 according to this embodiment can suitably realize both functions: real-time measurement of the positional relationship between the position of the plasma generated by the irradiation of the laser beam 28 and a preset processing position, and accurate observation of the workpiece 100 at a level that enables alignment.

[0043] Furthermore, the laser processing apparatus 1 according to this embodiment further includes an oblique light illumination reflector 78 located inside the processing debris capture chamber 31 and on the lower wall 42 side of the oblique light illumination unit 70, which is formed in the shape of an inverted frustocone and reflects the light emitted from the oblique light illumination unit 70 to change the direction of light propagation, thereby illuminating the workpiece 100 with a focal length shorter than the focal length of the oblique light illumination unit 70. For this reason, the laser processing apparatus 1 according to this embodiment can suitably use an inexpensive oblique light illumination unit 70 with a long focal length, and the cost of irradiating the workpiece 100 with a short focal length can be reduced.

[0044] It should be noted that the present invention is not limited to the embodiments described above. That is, it can be implemented with various modifications without departing from the core principles of the present invention. [Explanation of Symbols]

[0045] 1. Laser processing device 10 Retention Table 20 Laser beam irradiation unit 21. Laser Oscillator 23. Light concentrator 28 Laser beams 30. Processing waste discharge unit 31. Processing waste capture chamber 33 Suction source 41 Upper wall 42 Lower wall 43 Side wall 44 Upper opening 45 Lower opening 46 Fluid inlet 47 Suction port 70 Oblique Lighting Unit 75 Circular Space 77 Light exit surface 78 Oblique light illumination reflector 80 imaging units 81 Mirror 82 Light source 88 Illumination Light 89 light 100 Workpiece

Claims

1. A laser processing device, A holding table for holding the workpiece, A laser beam irradiation unit equipped with a light concentrator that focuses and irradiates a workpiece held on the holding table, The system includes a chip removal unit positioned below the light concentrator, which sucks up and discharges processing chips generated from the workpiece by the irradiation of the laser beam, The processing waste discharge unit is, An upper wall having an upper opening that allows the laser beam focused by the light condenser to pass through, The side wall hanging down from the upper wall, A fluid inlet formed in the side wall, A suction port is formed in the side wall facing the side wall in which the fluid inlet is formed and is connected to a suction source, A lower wall facing the upper wall, having a lower opening that allows the laser beam to pass through and captures processing debris, It has a processing debris capture chamber that includes, An oblique light illumination unit having a ring-shaped light-emitting surface is positioned inside the processing debris capture chamber and below the upper wall, leaving a circular space corresponding to the upper opening that allows the laser beam to pass through. An imaging unit for imaging a workpiece on a holding table illuminated by the oblique light illumination unit, A laser processing apparatus characterized by further comprising the following features.

2. A mirror is disposed between a laser oscillator that emits the laser beam and a light concentrator, and which transmits the laser beam to guide it to the light concentrator and reflects light of wavelengths other than the wavelength of the laser beam. A light source that illuminates the path through which the light is reflected by the mirror and guided to the light concentrator, Furthermore, The laser processing apparatus according to claim 1, characterized in that the imaging unit images the workpiece on the holding table by receiving light that is irradiated onto the workpiece from the light source via the light concentrator and reflected by the workpiece.

3. The laser processing apparatus according to claim 1 or 2, further comprising an oblique light illumination reflecting member located inside the processing debris capture chamber and positioned on the lower wall side of the oblique light illumination unit, which is formed in the shape of an inverted frustocone and reflects light emitted from the oblique light illumination unit to change the direction of the light's propagation.

Images