Laser processing device and method for laser processing

Abstract

To provide a laser processing device and a method for laser processing that can efficiently perform laser processing and washing to a workpiece.SOLUTION: A laser processing device includes: a holding mechanism for holding a workpiece; an irradiation part for irradiating the workpiece held to the holding mechanism with a laser beam; a jetting part for jetting cleaning fluid to the workpiece held to the holding mechanism; a recovery part for recovering the cleaning fluid that is jetted to a surface of the workpiece held to the holding mechanism; and a movement mechanism for moving the irradiation part and the holding mechanism relative to each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for performing laser processing on a workpiece such as a semiconductor wafer. [Background technology]

[0002] A known technique involves irradiating a wafer formed of a semiconductor or the like with a pulsed laser beam having a wavelength that is absorbed by the material of the wafer, thereby cutting the wafer or forming grooves in the wafer through ablation processing.

[0003] A plurality of planned dividing lines (streets) are set in a grid pattern on the surface of the wafer, and devices are formed in each area surrounded by the streets. When cutting the wafer by ablation processing, a laser beam is irradiated along the streets. This ablation processing generates processing waste called debris.

[0004] Particles such as debris can cause defects and must be removed by cleaning. One such technique has been proposed: before ablation processing, the surface of the wafer is covered with a protective film made of a water-soluble resin, and after processing, the debris is removed by cleaning along with the protective film (see, for example, Patent Document 1). Another proposed method for cleaning after ablation processing is to use a gas-liquid mixed fluid (two-fluid) made by mixing cleaning water such as pure water with a gas such as air (see, for example, Patent Document 2).

[0005] Incidentally, when performing the above-mentioned laser beam ablation processing and subsequent cleaning, the processing and cleaning are performed in the following procedure: first, ablation processing is performed on a wafer in a laser processing chamber, and then the wafer is moved to a cleaning chamber and cleaned.

[0006] The reason for carrying out the laser processing and cleaning processes separately in this way is to prevent the mist generated during cleaning from adhering to the laser processing equipment. However, this procedure poses the problem that it takes time and effort to move the wafer between the laser processing chamber and the cleaning chamber, which reduces productivity. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-188475 [Patent Document 2] Japanese Patent Publication No. 2022-35059 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a laser processing apparatus and a laser processing method that can efficiently perform laser processing and cleaning on a workpiece. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a laser processing apparatus comprising a holding mechanism for holding a workpiece, an irradiation unit for irradiating a laser beam onto the workpiece held by the holding mechanism, an injection unit for injecting a cleaning liquid onto the workpiece held by the holding mechanism, a recovery unit for recovering the cleaning liquid sprayed onto the surface of the workpiece held by the holding mechanism, and a moving mechanism for moving the irradiation unit and the holding mechanism relative to one another.

[0010] Preferably, in the laser processing device, the injection section and the recovery section are integrally configured as an injection / recovery unit, and the injection / recovery unit comprises a cleaning nozzle having a cleaning liquid flow path, and a recovery nozzle having a suction port surrounding the injection port of the cleaning nozzle and sucking in the cleaning liquid together with gas.

[0011] Preferably, the laser processing device is configured to be able to spray a cleaning liquid from the spray unit onto the surface of the workpiece that is being irradiated with the laser beam by the irradiation unit.

[0012] Preferably, the laser processing device is configured to be able to inject a cleaning liquid from the injector onto the surface of the workpiece after the surface has been irradiated with the laser beam by the irradiation unit.

[0013] Preferably, the laser processing device includes a measuring unit capable of measuring the surface of the workpiece held by the holding mechanism.

[0014] According to another aspect of the present invention, there is provided a laser processing method including a holding step of holding a workpiece in a holding mechanism for holding the workpiece, a processing step of irradiating a laser beam onto the workpiece held by the holding mechanism, and a cleaning step of spraying a cleaning liquid onto the surface of the workpiece held by the holding mechanism, wherein the cleaning liquid sprayed onto the surface of the workpiece in the cleaning step is collected. [Effects of the Invention]

[0015] According to the laser processing apparatus and laser processing method of one aspect of the present invention, laser processing and subsequent cleaning can be performed in the same space, eliminating the time and effort required to move the workpiece for cleaning after laser processing. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view schematically showing an example of a configuration of a laser processing device. [Figure 2] FIG. 2 is a front view schematically showing the configuration of the working unit in the first embodiment of the laser processing device. [Figure 3] 3 is a front cross-sectional view of the injection / recovery unit in the working unit of FIG. 2. FIG. [Figure 4] FIG. 4 is a front cross-sectional view showing a modification of the injection and recovery unit of FIG. [Figure 5]FIG. 5 is a flowchart showing an example of the procedure of a laser processing method using the laser processing device. [Figure 6] FIG. 6 is a flowchart showing an example of a conventional procedure for a laser processing method. [Figure 7] FIG. 7 is a front view schematically showing the configuration of a working unit in a second embodiment of the laser processing device. [Figure 8] FIG. 8 is a front cross-sectional view of the irradiation / recovery unit in the working unit of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view showing an example of the configuration of a laser processing device 2 according to this embodiment. The laser processing device 2 is configured to include a housing 4 that defines a space where laser processing and cleaning are performed, a support base 6 as a holding mechanism provided inside the housing 4, and a working unit 32.

[0018] The support table 6 is a table that supports a workpiece 8 such as a wafer, which is an object to be processed by the laser processing device 2. The support table 6 includes a table base 10 that is supported so as to be movable back and forth and left and right by a movement mechanism 14, and a chuck table 12 attached to the table base 10, and constitutes a holding mechanism that holds the workpiece 8.

[0019] The chuck table 12 is mounted on the table base 10 so as to be rotatable about a vertical axis. The upper surface of the chuck table 12 functions as a holding surface 12a that holds the workpiece 8 by negative pressure transmitted from a suction source (not shown) such as an ejector.

[0020] The support table 6 is provided near the bottom of the housing 4, which forms a rectangular parallelepiped space, and can be freely moved horizontally within the space inside the housing 4 by a movement mechanism 14. The movement mechanism 14 is a mechanism that moves the workpiece 8 relative to the irradiation section 34, spray section 36, recovery section 38, and measurement section 40 that make up the working unit 32. In the laser processing apparatus 2 of this embodiment, the movement mechanism 14 moves the support table 6 relative to the working unit 32, which is supported at a specific position inside the housing 4, thereby causing relative movement between the workpiece 8 and the working unit 32.

[0021] The movement mechanism 14 has, for example, the following configuration, and supports the support base 6 so that it can move back and forth and left and right along the horizontal direction.

[0022] A pair of Y-axis guide rails 16 extending parallel to each other are fixed to the bottom surface of the housing 4. A Y-axis moving table 18 is attached on the Y-axis guide rails 16 so as to be slidable along the longitudinal direction of the Y-axis guide rails 16.

[0023] A Y-axis ball screw 20 is provided between the pair of Y-axis guide rails 16 and along the longitudinal direction of the Y-axis guide rails 16. A nut portion (not shown) is provided on the back surface (lower surface) of the Y-axis moving table 18, and the Y-axis ball screw 20 passes through the nut portion and meshes with the Y-axis ball screw 20. A Y-axis pulse motor 22 is connected to one end of the Y-axis ball screw 20.

[0024] When the Y-axis pulse motor 22 is operated, the Y-axis ball screw 20 rotates about its axis, and the Y-axis moving table 18 moves on the Y-axis guide rail 16 in the direction in which the Y-axis guide rail 16 extends.

[0025] A pair of X-axis guide rails 24 are fixed to the surface (upper surface) of the Y-axis moving table 18, and are oriented substantially perpendicular to the Y-axis guide rails 16 in a plan view. An X-axis moving table 26 is attached to the X-axis guide rails 24 so as to be slidable along the longitudinal direction of the X-axis guide rails 24.

[0026] An X-axis ball screw 28 is provided between the pair of X-axis guide rails 24 and along the longitudinal direction of the X-axis guide rails 24. A nut portion (not shown) is provided on the back surface (lower surface) of the X-axis moving table 26, and the X-axis ball screw 28 passes through the nut portion and meshes with the X-axis ball screw 28. An X-axis pulse motor 30 is connected to one end of the X-axis ball screw 28.

[0027] When the X-axis pulse motor 30 is operated, the X-axis ball screw 28 rotates about its axis, and the X-axis moving table 26 moves on the X-axis guide rail 24 in the direction in which the X-axis guide rail 24 extends.

[0028] A table base 10 is fixed to the surface (top surface) of the X-axis moving table 26, and a chuck table 12 that holds the workpiece 8 is attached to the table base 10. The chuck table 12 moves vertically and horizontally within the housing 4 along the horizontal direction by the operation of a Y-axis pulse motor 22 and an X-axis pulse motor 30 provided in the moving mechanism 14.

[0029] An operating unit 32 is provided at the top of the housing 4. The operating unit 32 includes an irradiation unit 34, a spray unit 36, a collection unit 38, and a measurement unit 40. The irradiation unit 34, the spray unit 36, the collection unit 38, and the measurement unit 40 are attached to the tip of an arm-shaped support unit 42, which is supported above the chuck table 12.

[0030] The irradiation unit 34 is an irradiation device that irradiates a laser beam from above onto the workpiece 8 supported on the holding surface 12a of the chuck table 12. The spray unit 36 ​​is a cleaning nozzle that sprays a cleaning liquid onto the workpiece 8. The recovery unit 38 is a suction nozzle that recovers the cleaning liquid sprayed onto the workpiece 8.

[0031] In the embodiment described below, the recovery unit 38 is assumed to be a suction nozzle that recovers the cleaning liquid together with the surrounding gas (air), but the recovery unit may be any unit that can recover the cleaning liquid in an appropriate manner. For example, the recovery unit may be a mechanism that includes a fibrous or sponge-like material that absorbs the liquid and wipes the liquid off the surface of the workpiece.

[0032] In the laser processing device 2 of this embodiment, the irradiation unit 34, the spray unit 36, and the recovery unit 38 are arranged at the tip of the same support unit 42, and processing by laser irradiation, spraying of cleaning liquid, and recovery thereof can be performed simultaneously or in parallel in the same space. The specific configurations of the irradiation unit 34, the spray unit 36, and the recovery unit 38, as well as the processing and cleaning procedures, will be described in detail later.

[0033] The measurement unit 40 is configured with a laser microscope, a white light interference microscope, etc., and is capable of optically measuring the surface of the workpiece 8 after ablation processing by the irradiation unit 34 and the surface of the workpiece 8 after cleaning by the injection unit 36.

[0034] The support part 42 is an arm-shaped member that extends from one point on the side of the housing 4 to the center of the space within the housing 4, with its base end fixed to the side wall of the housing 4 and its tip attached to the working unit 32, so that the working unit 32 is supported above the chuck table 12 in a cantilever structure.

[0035] 2 shows a front view of the first embodiment of the working unit 32. The working unit 32 in the first embodiment is configured with an injection / recovery unit 44, which is located next to the irradiation unit 34 and integrally comprises a structure as the injection unit 36 ​​and a structure as the recovery unit 38.

[0036] The structure of the jetting and recovery unit 44 is as shown in Fig. 3, for example. Fig. 3 is a front cross-sectional view showing the internal structure of the jetting and recovery unit 44 in the first embodiment. The jetting and recovery unit 44 is a structure formed by combining a cleaning nozzle 46 as the jetting unit 36 ​​that jets the cleaning liquid and a suction nozzle 48 as the recovery unit 38 that sucks the gas and liquid.

[0037] The jetting and collecting unit 44 has a cylindrical shape extending in the vertical direction as a whole, and is provided with a cleaning liquid flow path 50, which is a flow path through which the cleaning liquid flows, along its central axis. The part of the jetting and collecting unit 44 that forms the cleaning liquid flow path 50 corresponds to the cleaning nozzle 46 serving as the jetting section 36. The cleaning nozzle 46 extends to the tip (lower end) of the jetting and collecting unit 44, and is formed to be particularly thin near the tip (for convenience, this part will be referred to as the "nozzle tip portion 46a").

[0038] A main body 52, which is a nozzle tip used for high-pressure water jets, is housed inside the cleaning nozzle 46. A cylindrical space is formed inside the main body 52 along the central axis, and this space forms part of a cleaning liquid flow path 50 inside the cleaning nozzle 46. A conical reduced diameter section 50a, whose flow path diameter decreases toward the tip (downward), is provided near the tip of the cleaning liquid flow path 50 provided inside the main body 52.

[0039] The fluid flowing through the cleaning liquid flow path 50 is narrowed to about 100 μm in the reduced diameter section 50 a before being released. The part of the main body 52 that forms the reduced diameter section 50 a is made of a hard material such as artificial diamond or artificial corundum to reduce wear caused by the high-pressure fluid.

[0040] An outer wall 54 is provided at the tip of the injection / recovery unit 44 so as to surround the nozzle tip 46a of the thin cleaning nozzle 46. This outer wall 54 has an internal space for accommodating the nozzle tip 46a, and is open at the bottom so as to function as a suction nozzle 48.

[0041] That is, outer wall 54 surrounds the radial outside of nozzle tip 46a, and the space between the inner circumferential surface of outer wall 54 and nozzle tip 46a forms suction flow path 54a, which is a flow path through which gas and liquid flow when the gas and liquid are sucked. During suction, the opening provided at the lower end of outer wall 54 functions as suction port 54b, which is an inlet for the gas and liquid.

[0042] In the ejection / recovery unit 44, the portion that constitutes the suction flow path 54a corresponds to the suction nozzle 48 as the recovery section .

[0043] When the injection / recovery unit 44 is viewed from the tip side (the lower side in FIG. 3), the central portion of the outer wall portion 54 is opened in a circular shape, with the nozzle tip portion 46a located in the central portion and the outlet (referred to as "injection port 50b") of the cleaning liquid flow path 50 opening in the center of the nozzle tip portion 46a. That is, with respect to the injection port 50b that injects the cleaning liquid, the suction port 54b that sucks and collects the injected cleaning liquid is located concentrically around the injection port 50b so as to surround the injection port 50b.

[0044] An outer wall portion 54 surrounding the nozzle tip 46a has a suction outlet 54c, which is a hole that radially penetrates the outer wall portion 54, provided at a position on the base end side. An unillustrated suction mechanism is connected to the suction outlet 54c, and during suction, negative pressure is applied to the suction flow path 54a from the suction mechanism through the suction outlet 54c.

[0045] The tip of the outer wall portion 54 is tapered so that its diameter decreases toward the suction port 54b. In accordance with this, the nozzle tip portion 46a located inside the outer wall portion 54 is also tapered so that its diameter decreases toward the injection port 50b.

[0046] The dimensions of each part of the jetting / recovery unit 44, which is composed of the cleaning nozzle 46 (jetting part 36) and the suction nozzle 48 (recovery part 38), will be described.

[0047] The width of the suction flow channel 54a is defined as the distance between the outer peripheral surface of the nozzle tip 46a and the inner peripheral surface of the outer wall 54. This width is preferably, for example, between 1 mm and 3 mm. If the width of the suction flow channel 54a is too narrow, there is a risk that the suction flow channel 54a will become clogged when the cleaning liquid is collected through the suction port 54b. On the other hand, if the width of the suction flow channel 54a is too wide, there is a risk that droplets of the cleaning liquid sucked into the suction flow channel 54a will drip down to the suction port 54b and will not be collected properly through the suction port 54c.

[0048] The diameter of the suction port 54b of the suction flow path 54a is preferably, for example, between 1 mm and 10 mm. If the suction port 54b is too narrow, the area in which the cleaning liquid can be sucked in, i.e., the area in which the suction port 54b can exert a negative pressure sufficient to suck in the scattered cleaning liquid, becomes narrow, making it difficult to efficiently collect the cleaning liquid. On the other hand, if the suction port 54b is too wide, there is a risk that sufficient suction force will not be obtained.

[0049] The diameter of the injection port 50b is preferably, for example, about 0.5 mm to 2 mm. If the diameter of the injection port 50b is too large, air sucked in through the suction port 54b of the suction flow path 54a may flow from the injection port 50b into the cleaning liquid flow path 50, hindering the injection of the cleaning liquid. Therefore, the diameter of the injection port 50b should be narrowed to a certain extent. On the other hand, if the diameter of the cleaning liquid flow path 50 is too narrow, the pressure required to inject the cleaning liquid becomes excessive.

[0050] It is preferable that the positions of the injection port 50b and the suction port 54b coincide with each other in the axial direction (vertical direction) of the injection / recovery unit 44, or that the injection port 50b be located slightly further back (towards the base end, above) than the suction port 54b. Specifically, it is preferable that the difference in position between the injection port 50b and the suction port 54b in the axial direction be approximately 0 mm or more and 5 mm or less.

[0051] Fig. 3 shows a configuration in which the injection port 50b and the suction port 54b are located at the same position in the axial direction. Fig. 4 shows a modified configuration in which the injection port 50b is located slightly recessed from the suction port 54b in the axial direction.

[0052] If the ejection port 50b is located far back from the suction port 54b, the airflow generated by suction through the suction port 54b may flow from the ejection port 50b into the cleaning liquid flow path 50, possibly interfering with the ejection of the cleaning liquid.

[0053] On the other hand, if the injection port 50b protrudes further toward the tip than the suction port 54b, the greater the amount of protrusion, the greater the distance between the area where the cleaning liquid is injected and the suction port 54b, making it more difficult to efficiently suck in and recover the scattered cleaning liquid.

[0054] Furthermore, in order to ensure sufficient suction force and quickly collect the sprayed cleaning liquid, it is desirable to make the distance between the suction port 54b and the workpiece 8 as small as possible (for example, about 1 mm or less). If the spray port 50b protrudes from the suction port 54b, it becomes more difficult to bring the suction port 54b and the workpiece 8 close to each other.

[0055] During use, approximately 50 ml of cleaning liquid is sprayed per minute through the cleaning liquid flow path 50 at a pressure of, for example, 0.5 MPa or more and 3 MPa or less, thereby cleaning the workpiece 8. The cleaning liquid is, for example, pure water, but other liquids can also be used. For example, a substance such as a surfactant may be mixed with water. Also, a gas such as air may be mixed with the cleaning liquid to perform two-fluid cleaning.

[0056] At the same time, a negative pressure is applied to the suction flow path 54a from a suction mechanism (not shown) connected to the suction port 54c, and the cleaning liquid sprayed onto the workpiece 8 is sucked in from the suction port 54b together with the surrounding gas. Suction is performed, for example, at a flow rate of about 120 L per minute and a negative pressure of about 3.3 kPa. The cleaning liquid sprayed onto the workpiece 8 is collected from the suction port 54b in a state in which the components of the water-soluble protective film applied to the surface of the workpiece 8 have dissolved and which also contains debris generated by the ablation process.

[0057] The flow rate of the suction from the suction outlet 54c should be set taking into consideration the choking (blockage) phenomenon. In a mechanism in which gas flows through a nozzle, if the back pressure on the outlet side is lowered below a certain threshold, the flow rate will be the same as if the back pressure was set at that threshold. This is the choking phenomenon. In other words, it is meaningless to lower the negative pressure applied to the suction flow path 54a from a suction mechanism (not shown) connected to the suction outlet 54c below a certain threshold.

[0058] If the negative pressure applied to the suction flow path 54a is set to a level that realizes the maximum flow rate calculated based on the choking phenomenon, suction can be performed highly efficiently without wasting energy required to generate the negative pressure. The value of 120 L per minute mentioned above is an example of a flow rate calculated based on the choking phenomenon for the injection / recovery unit 44 having the dimensions described above.

[0059] A procedure for performing laser processing on the workpiece 8 using the laser processing device 2 having the above configuration will be described below. Fig. 5 is a flowchart showing an example of the procedure for processing the workpiece 8 using the laser processing device 2.

[0060] First, the workpiece 8 is held on the holding surface 12a of the chuck table 12 (holding step; step S10). Next, laser processing is performed on the workpiece 8 on the chuck table 12 (processing step; step S20). A laser beam is irradiated from the irradiation unit 34 of the working unit 32, and at the same time, the chuck table 12, located below the working unit 32, is moved horizontally by the movement mechanism 14. In this way, processing such as cutting and groove formation is performed on the workpiece 8 held on the chuck table 12. Processing waste is generated around the workpiece 8 during processing.

[0061] In parallel with the machining process (step S20), the workpiece 8 is cleaned by the jetting and collecting unit 44 (cleaning process; step S30). Cleaning liquid is sprayed from the jetting nozzle 50b onto the surface of the workpiece 8 held on the chuck table 12, machining debris generated during the machining process mixes with the cleaning liquid, and components of the protective film covering the surface of the workpiece 8 dissolve in the cleaning liquid.

[0062] In parallel with the cleaning process (step S30), cleaning liquid is sucked through suction port 54b, which is provided so as to surround injection port 50b, via suction flow path 54a, and collected together with the processing debris and components of the protective film. During collection, an air current is generated in the vicinity as the gas and liquid are sucked through suction port 54b, and this air current evaporates the components of the cleaning liquid scattered on the surface of workpiece 8, drying the surface of workpiece 8 while workpiece 8 is held on chuck table 12.

[0063] The spraying and recovery unit 44 is attached to the tip of the support part 42 together with the irradiation part 34, and constitutes part of the working unit 32. When the spraying and recovery unit 44 sprays and recovers the cleaning liquid, the relative positional relationship between the irradiation part 34 and the spraying and recovery unit 44, and the relative movement direction between the working unit 32 and the workpiece 8 are set in advance, for example, so that the spraying and recovery unit 44 is located downstream in the direction of processing by the irradiation part 34 on the workpiece 8.

[0064] In this way, the irradiation of laser light from the irradiation unit 34, the spraying of cleaning liquid from the spray port 50b of the spray / recovery unit 44, and the suction of gas and liquid from the suction port 54b are carried out simultaneously, while the chuck table 12 moves together with the workpiece 8 relative to the working unit 32. As a result, the laser processing of the workpiece 8 by the irradiation unit 34 (processing step; step S20), cleaning of the processed portion, and collection by suction of the cleaning liquid (cleaning step; step S30) are carried out in parallel.

[0065] Although step S30 is shown after step S20 in FIG. 5, in the procedure described above, step S20 and step S30 can actually be executed simultaneously or in parallel as described above.

[0066] 2, if the position on the surface of the workpiece 8 that is processed by the irradiation unit 34 is misaligned with the position that is cleaned by the injection / recovery unit 44, the laser beam is irradiated by the irradiation unit 34, and the surface of the workpiece 8 that has been subjected to laser processing is cleaned and the cleaning liquid is recovered. In this case, the cleaning process starts slightly later than the start of the processing process, but after the cleaning process starts, the two processes proceed almost simultaneously in parallel.

[0067] Furthermore, for example, by adjusting the position of the spraying unit 36 ​​relative to the irradiation unit 34, it is possible to spray the cleaning liquid accurately onto the area where a groove has been formed by laser processing, as shown in Figure 2. During processing, processing debris is naturally generated in the area where laser processing has been performed. Therefore, by spraying the cleaning liquid accurately onto that area, effective cleaning can be performed with the minimum amount of cleaning required, resulting in effects such as saving on cleaning liquid and improving productivity.

[0068] Although not shown here, the jetting and collecting unit 44 may be tilted so that the ray of the cleaning liquid intersects with the ray of the laser beam irradiated from the irradiating unit 34, and the laser irradiation and the jetting of the cleaning liquid may be performed simultaneously on the same area on the surface of the workpiece 8. In this case, the jetting unit jets the cleaning liquid onto the surface of the workpiece irradiated with the laser beam from the irradiating unit, and the cleaning liquid is then collected.

[0069] The surface of the workpiece 8 after the processing, cleaning, and recovery processes is observed by a measuring unit 40 provided in the working unit 32, and the processing accuracy, etc. is evaluated (evaluation process; step S40). In this evaluation process, the surface of the workpiece 8 that has been cleaned in the previous cleaning process and from which the cleaning liquid has been removed is optically observed and measured, so that the surface of the workpiece 8 in a state where no processing debris or droplets remain can be observed, enabling highly accurate evaluation.

[0070] 6 is a flowchart showing, as a reference example, an example of a procedure for conventional laser processing. In conventional laser processing devices, a series of steps are performed in a processing chamber equipped with a laser irradiation device, where the workpiece is first subjected to laser processing (steps S10 to S20), after which the workpiece is transferred to a cleaning chamber (transport step; step S50), where it is washed with a cleaning liquid in the cleaning chamber (step S30), and after the cleaning liquid is removed and the workpiece is dried, it is transferred to the next step.

[0071] In this conventional procedure, after one workpiece has been subjected to laser processing, the workpiece is moved to another room and cleaned. In other words, the processing step (step S20) and the cleaning step (step S30) cannot be performed in parallel, and the workpiece needs to be moved between the processing step and the cleaning step (step S50), which limits the improvement of production efficiency in processing the workpiece.

[0072] In contrast, in the laser processing apparatus 2 of the first embodiment, the irradiation section 34, the injection section 36, and the recovery section 38 (injection / recovery unit 44) are attached to the same support section 42 to form the working unit 32, so that laser processing and subsequent cleaning are performed in the same space.

[0073] In conventional laser processing equipment, the space where processing is performed and the space where cleaning are performed are separated in order to prevent deterioration of laser quality due to cleaning fluid or the like adhering to the mechanism for laser irradiation. Since mist is generated when cleaning fluid is sprayed at high pressure onto the surface of the workpiece, it was avoided to install the laser equipment in a space filled with this mist.

[0074] In contrast to this, in the laser processing apparatus 2 of the first embodiment, the cleaning nozzle 46 as the injection section 36 that injects the cleaning liquid and the suction nozzle 48 as the recovery section 38 that recovers the cleaning liquid are integrally configured in the form of an injection / recovery unit 44, and a suction port 54b that sucks in gas and liquid is provided in a position immediately adjacent to the injection port 50b that injects the cleaning liquid, so that after the cleaning liquid is injected onto the workpiece 8 to clean it, the cleaning liquid is quickly recovered and dried.

[0075] Even if mist is generated by the spraying of the cleaning liquid, it is quickly sucked up to prevent droplets from adhering to the irradiation section 34, making it possible to carry out the processing process and the cleaning process in the same space.

[0076] As a result, in the processing method using the laser processing device 2 of the first embodiment, the time and effort required to transport the workpiece 8 to the cleaning chamber after laser processing is eliminated (step S50). Furthermore, rather than performing the cleaning step (step S30) after the processing step (step S20), the processing step and cleaning step can be performed in parallel, further reducing the time required from processing to cleaning.

[0077] In addition, the mechanism for laser processing (irradiation unit 34) and the mechanism for cleaning (spray / recovery unit 44) are held close to each other on the same support part 42, and the surface of the workpiece 8 that has been laser processed by the irradiation unit 34 can be cleaned with pinpoint accuracy at the same time as the laser processing or immediately after the laser processing, allowing for rapid cleaning with high cleaning power.

[0078] Although the above describes a case where the processing step and the cleaning step are performed in parallel, it is also possible to perform the cleaning step (step S30) after the processing step (step S20) has been completed for one workpiece 8. Even in this case, compared to the conventional procedure shown in Fig. 6, labor and time can be saved by not needing the transport step (step S50).

[0079] FIG. 7 shows the configuration of a working unit in a second embodiment of the laser processing device, and FIG. 8 shows a front cross section of an irradiation / recovery unit in the working unit of FIG.

[0080] In the first embodiment of FIG. 2, of the irradiation section 34, the injection section 36, and the recovery section 38, the injection section 36 and the recovery section 38 are integrated to form an injection / recovery unit 44, but in the second embodiment of FIG. 7, the irradiation section 34 and the recovery section 38 are integrated to form an irradiation / recovery unit 56, and the injection section 36 is provided separately from the irradiation / recovery unit 56.

[0081] The configuration of the irradiation and recovery unit 56 in the second embodiment is as shown in Fig. 8. The irradiation and recovery unit 56 has an overall cylindrical shape and includes an optical path 58 through which laser light passes along the central axis. The members forming the optical path 58 and the part that surrounds and supports the members correspond to the irradiation section 34.

[0082] The portion of the irradiation unit 34 near the irradiation port 58a at the tip is formed to have a narrow diameter, and an outer wall 60 is provided to surround this portion. The outer wall 60 has an internal space that accommodates the narrow tip of the irradiation unit 34, and the lower end is open so that it functions as a suction nozzle.

[0083] The shape and function of the outer wall 60 as a suction nozzle are generally similar to those of the first embodiment (see FIGS. 2 to 4). The outer wall 60 surrounds the radially outer side of the tip of the irradiation unit 34, and the space between the inner circumferential surface of the outer wall 60 and the tip of the irradiation unit 34 forms a suction flow path 60a, which is a flow path through which gas and liquid flow when the gas and liquid are suctioned. During suction, the opening provided at the lower end of the outer wall 64 functions as a suction port 60b, which is an inlet for the gas and liquid.

[0084] When the irradiation / recovery unit 56 is viewed from the tip side (the bottom side in FIG. 8), the central portion of the outer wall portion 60 is opened in a circular shape, with the tip portion of the irradiation section 34 located in the central portion and the irradiation port 58a located in the center. That is, the suction port 60b is located concentrically around the irradiation port 58a.

[0085] A suction outlet 60c, which is a hole that radially penetrates the outer wall 60, is provided at a position on the base end side of the surrounding outer wall 60. A suction mechanism (not shown) is connected to the suction outlet 60c, and during suction, negative pressure is applied to the suction flow path 60a from the suction mechanism through the suction outlet 60c.

[0086] The tip of the outer wall portion 60 is tapered so that the diameter decreases toward the suction port 60b.

[0087] The spraying unit 36, which is provided separately from the irradiation / recovery unit 56, is a nozzle that sprays cleaning liquid, and is arranged in the working unit 32 so that the cleaning liquid is sprayed in a direction that intersects with the axis of the irradiation / recovery unit 56, as shown in Figure 7.

[0088] When processing the workpiece 8, a laser beam is irradiated onto the surface of the workpiece 8 from the irradiation port 58a of the irradiation / recovery unit 56, and a cleaning liquid is sprayed onto the area irradiated with the laser beam from the spray unit 36. At the same time, a negative pressure is applied to the suction flow path 60a from a suction mechanism (not shown) connected to the suction port 60c of the irradiation / recovery unit 56, and the cleaning liquid is sucked together with air from the suction port 60b and recovered.

[0089] That is, when laser processing of the workpiece 8 is performed using the laser processing device 2 equipped with the working unit 32 of this second embodiment, cleaning liquid is sprayed from the spraying section 36 onto the surface of the workpiece 8 that is being irradiated with a laser beam by the irradiation section 34.

[0090] According to the second embodiment, similarly to the first embodiment, laser processing and cleaning of the workpiece 8 can be carried out in the same space and in parallel. The procedure is the same as that shown in the flowchart of FIG.

[0091] The structures, methods, etc. according to the above-described embodiments are not limited to the above-described embodiments. For example, the first embodiment describes an example in which the irradiation unit, injection unit, and recovery unit are integrated into one unit, and the second embodiment describes an example in which the irradiation unit and recovery unit are integrated into one unit. However, the present invention is not limited to these configurations. For example, the irradiation unit, injection unit, and recovery unit may be configured as separate devices and attached to the tip of the same support unit. Laser processing and cleaning can also be performed in the same manner as in the flowchart of FIG. 5.

[0092] However, as in the first and second embodiments, if at least some of the irradiation section, ejection section, and recovery section share the functions of each other, the working unit can be made more compact.

[0093] Furthermore, for example, when moving the operational unit and the workpiece relative to each other, instead of moving the workpiece relative to the operational unit, it is also possible to consider an apparatus in which the operational unit is moved relative to the workpiece. Alternatively, a mechanism may be adopted in which the workpiece is moved in the X-axis direction and the operational unit is moved in the Y-axis direction. In this way, the laser processing apparatus is not limited to the above embodiment, and various configurations of apparatuses are possible.

[0094] In addition, the above embodiment can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0095] 2: Laser processing device, 4: Housing, 6: Support table (holding mechanism), 8: Workpiece 10: Table base (holding mechanism), 12: Chuck table (holding mechanism) 12a: holding surface, 14: moving mechanism, 16: Y-axis guide rail, 18: Y-axis moving table 20: Y-axis ball screw, 22: Y-axis pulse motor, 24: X-axis guide rail 26: X-axis moving table, 28: X-axis ball screw, 30: X-axis pulse motor 32: working unit, 34: irradiation section, 36: ejection section, 38: recovery section, 40: measurement section 42: Support part, 44: Injection and recovery unit, 46: Cleaning nozzle, 46a: Nozzle tip 48: suction nozzle, 50: cleaning liquid flow path, 50a: reduced diameter portion, 50b: injection port, 52: main body portion 54: Outer wall, 54a: Suction channel, 54b: Suction port, 54c: Suction 56: irradiation and recovery unit, 58: optical path, 58a: irradiation port, 60: outer wall 60a: Suction channel, 60b: Suction port, 60c: Suction port

Claims

1. a holding mechanism for holding the workpiece; an irradiation unit that irradiates a laser beam onto the workpiece held by the holding mechanism; an ejection unit that ejects a cleaning liquid onto the workpiece held by the holding mechanism; a recovery unit that recovers the cleaning liquid sprayed onto the surface of the workpiece held by the holding mechanism; a moving mechanism that moves the irradiation unit and the holding mechanism relatively; A laser processing device equipped with:

2. the injection section and the recovery section are integrally configured as an injection / recovery unit, The injection and recovery unit comprises: a cleaning nozzle having a cleaning liquid flow path; a recovery nozzle having a suction port surrounding the injection port of the cleaning nozzle and configured to suck in the cleaning liquid together with the gas; The laser processing device according to claim 1 ,

3. 2. The laser processing apparatus according to claim 1, wherein the spray unit is configured to spray a cleaning liquid onto the surface of the workpiece irradiated with the laser beam by the irradiation unit.

4. 2. The laser processing apparatus according to claim 1, wherein the spray unit is configured to spray a cleaning liquid onto the surface of the workpiece after the surface has been irradiated with the laser beam by the irradiation unit.

5. 2. The laser processing device according to claim 1, further comprising a measuring unit capable of measuring the surface of the workpiece held by the holding mechanism.

6. a holding step of holding the workpiece in a holding mechanism that holds the workpiece; a processing step of irradiating a laser beam onto the workpiece held by the holding mechanism; a cleaning step of spraying a cleaning liquid onto the surface of the workpiece held by the holding mechanism, In the cleaning step, the cleaning liquid sprayed onto the surface of the workpiece is collected. Laser processing method.

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