JP5587595B2 - Laser processing equipment - Google Patents

Description

  The present invention relates to a laser processing apparatus that performs laser processing on a workpiece such as a semiconductor wafer.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a lattice pattern on the surface of a substantially wafer-shaped semiconductor wafer, and devices such as ICs, LSIs, etc. are partitioned in the partitioned regions. Form. Then, the semiconductor wafer is cut along the streets to divide the region in which the device is formed to manufacture individual semiconductor chips. In addition, optical device wafers in which light-receiving elements such as photodiodes and light-emitting elements such as laser diodes are stacked on the surface of the sapphire substrate are also divided into optical devices such as individual photodiodes and laser diodes by cutting along the streets. And widely used in electrical equipment.

  As a method of dividing the wafer such as the semiconductor wafer or the optical device wafer described above along the street, a laser processing groove is formed by irradiating a pulse laser beam along the street formed on the wafer, and along the laser processing groove. A method of breaking is proposed. (For example, refer to Patent Document 1.)

  However, when a laser beam is irradiated along a wafer street such as silicon or sapphire, which is the workpiece, the silicon or sapphire is melted, and molten debris (debris) is scattered to form a rectangular area of the wafer. There is a problem that it adheres to the surface of the device and degrades the quality of the device. In addition, as described above, there is a problem that dust such as debris scattered adheres to a condensing lens incorporated in a condenser that irradiates a laser beam and prevents irradiation of the laser beam.

  In order to solve the above problem, there is provided a laser processing apparatus including a dust discharging unit that collects and discharges dust such as debris generated by irradiating a workpiece with a laser beam from a condenser of the laser beam irradiation unit. Proposed. (For example, refer to Patent Document 2.) The dust discharging means includes a first cover member attached to a lower end portion of the condenser and a second cover disposed so as to surround the first cover member. And a dust collecting chamber formed by the first cover member and the second cover member, wherein the air introduction chamber formed by the condenser and the first cover member is connected to the air supply means. Is connected to the exhaust means, and dust such as debris generated by laser processing is sucked from the dust collection chamber to the exhaust means.

JP 2004-9139 A JP 2007-69249 A

  Thus, even in the laser processing apparatus provided with the dust discharging means described in Patent Document 2, dust such as debris generated by laser processing does not smoothly flow into the dust collecting chamber and is incorporated in the condenser. The problem of sticking to the condensing lens cannot be solved.

  The present invention has been made in view of the above facts, and its main technical problem is to efficiently collect and discharge dust such as debris produced by irradiating a workpiece with a laser beam from a condenser. It is providing the laser processing apparatus which can do.

In order to solve the main technical problem, according to the present invention, a chuck table for holding a workpiece, and a laser beam irradiation means for irradiating a workpiece held on the chuck table with a laser beam, A laser beam oscillator for oscillating the laser beam by the laser beam irradiation means; a condenser having a condenser lens for collecting the laser beam oscillated from the laser beam oscillator; and an end of the condenser on the downstream side in the laser beam irradiation direction. In the laser processing apparatus comprising the arranged dust discharge means,
The dust discharge means allows passage of the laser beam irradiated from the condenser and allows passage of the laser beam irradiated through the first opening and an upstream side wall having a first opening for taking in air. And a downstream side wall having a second opening for sucking dust, and an outer wall having an exhaust port connecting the upstream side wall and the downstream side wall to form a dust collection chamber and communicating the dust collection chamber to a suction source A dust collector consisting of
Between the dust collector and the collector, an outside air intake passage that communicates the first opening with outside air is provided ,
The upstream side wall of the dust collector is provided with a rectifying nozzle that gradually reduces the diameter from the periphery of the first opening toward the dust collection chamber,
The concentrator is provided with a cover glass for protecting the condensing lens on the downstream side in the laser beam irradiation direction of the condensing lens, and along the surface of the cover glass on the downstream side in the laser beam irradiation direction. An air passage formed and communicated with the air supply means, and an air circulation opening communicating with the air passage and facing the first opening are provided.
A laser processing apparatus is provided.

In the laser processing apparatus according to the present invention, since the dust discharging means is configured as described above, the dust generated by irradiating the laser beam has the second opening in the dust collection chamber where the suction source is sucked. Is sucked together with outside air. On the other hand, when the suction source is activated, the outside air is sucked into the dust collecting chamber from the outside air intake passage through the first opening, and is discharged from the exhaust port together with the dust sucked from the second opening. Thus, since the outside air sucked into the dust collecting chamber from the outside air intake passage through the first opening by the operation of the suction source is rectified and discharged from the exhaust port, it is sucked into the dust collecting chamber. Dust can be effectively led to the exhaust port. Therefore, it is possible to suppress the dust sucked into the dust collection chamber from adhering to the condenser lens through the first opening.
Further, the dust discharging means constituting the laser processing apparatus according to the present invention is provided with a rectifying nozzle that gradually reduces the diameter from the periphery of the first opening toward the dust collecting chamber on the upstream side wall in which the first opening is formed. Therefore, the outside air sucked into the dust collection chamber is more rectified. Therefore, the dust sucked into the dust collection chamber can be prevented from adhering to the cover glass or the condenser lens through the first opening.
Furthermore, the dust discharging means constituting the laser processing apparatus according to the present invention is supplied with air along the lower surface of the cover glass for protecting the condenser lens from the air supply means, that is, the surface on the downstream side in the laser beam irradiation direction. It is possible to prevent dust from adhering to the cover glass.

The perspective view of the laser processing apparatus comprised according to this invention. The block diagram which shows simply the structure of the laser beam irradiation means with which the laser processing apparatus shown in FIG. 1 is equipped. The perspective view of the collector with which the laser processing apparatus shown in FIG. 1 is equipped, and a dust discharge means. The disassembled perspective view of the collector shown in FIG. 3 and a dust discharge means. Sectional drawing of the collector shown in FIG. 3 and a dust discharge means. Explanatory drawing of the laser processing groove | channel formation process implemented with the laser processing apparatus shown in FIG. Sectional drawing of the dust discharge | emission means in the state which is implementing the laser processing groove | channel formation process shown in FIG.

  Preferred embodiments of a laser processing apparatus configured according to the present invention will be described below in more detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view of a laser processing apparatus constructed according to the present invention. A laser processing apparatus shown in FIG. 1 includes a stationary base 2, a chuck table mechanism 3 that is disposed on the stationary base 2 so as to be movable in a machining feed direction indicated by an arrow X, and holds a workpiece. The laser beam irradiation unit support mechanism 4 is movably disposed in an index feed direction indicated by an arrow Y perpendicular to the direction indicated by the arrow X in FIG. 2, and the laser beam unit support mechanism 4 is movable in a direction indicated by an arrow Z. And an arranged laser beam irradiation unit 5.

  The chuck table mechanism 3 includes a pair of guide rails 31, 31 arranged in parallel along the machining feed direction indicated by the arrow X on the stationary base 2, and the arrow X on the guide rails 31, 31. A first slide block 32 movably disposed in the processing feed direction; a second slide block 33 disposed on the first slide block 32 movably in the index feed direction indicated by an arrow Y; A support table 35 supported by a cylindrical member 34 on the second sliding block 33 and a chuck table 36 as a workpiece holding means are provided. The chuck table 36 includes a suction chuck 361 formed of a porous material, and holds, for example, a disk-shaped semiconductor wafer, which is a workpiece, on the suction chuck 361 by suction means (not shown). . The chuck table 36 configured as described above is rotated by a pulse motor (not shown) disposed in the cylindrical member 34.

  The first sliding block 32 is provided with a pair of guided grooves 321 and 321 fitted to the pair of guide rails 31 and 31 on the lower surface thereof, and in the index feed direction indicated by an arrow Y on the upper surface thereof. A pair of guide rails 322 and 322 formed in parallel with each other are provided. The first sliding block 32 configured in this way is processed by the arrow X along the pair of guide rails 31, 31 when the guided grooves 321, 321 are fitted into the pair of guide rails 31, 31. It is configured to be movable in the feed direction. The chuck table mechanism 3 in the illustrated embodiment includes a machining feed means 37 for moving the first sliding block 32 along the pair of guide rails 31 and 31 in the machining feed direction indicated by the arrow X. The processing feed means 37 includes a male screw rod 371 disposed in parallel between the pair of guide rails 31 and 31, and a drive source such as a pulse motor 372 for rotationally driving the male screw rod 371. One end of the male screw rod 371 is rotatably supported by a bearing block 373 fixed to the stationary base 2, and the other end is connected to the output shaft of the pulse motor 372 by transmission. The male screw rod 371 is screwed into a penetrating female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the first sliding block 32. Accordingly, when the male screw rod 371 is driven to rotate forward and backward by the pulse motor 372, the first sliding block 32 is moved along the guide rails 31 and 31 in the machining feed direction indicated by the arrow X.

  The second sliding block 33 is provided with a pair of guided grooves 331 and 331 which are fitted to a pair of guide rails 322 and 322 provided on the upper surface of the first sliding block 32 on the lower surface thereof. By fitting the guided grooves 331 and 331 to the pair of guide rails 322 and 322, the guided grooves 331 and 331 are configured to be movable in the indexing and feeding direction indicated by the arrow Y. The chuck table mechanism 3 in the illustrated embodiment is for moving the second slide block 33 along the pair of guide rails 322 and 322 provided in the first slide block 32 in the index feed direction indicated by the arrow Y. First index feeding means 38 is provided. The first index feed means 38 includes a male screw rod 381 disposed in parallel between the pair of guide rails 322 and 322, and a drive source such as a pulse motor 382 for rotationally driving the male screw rod 381. It is out. One end of the male screw rod 381 is rotatably supported by a bearing block 383 fixed to the upper surface of the first sliding block 32, and the other end is connected to the output shaft of the pulse motor 382. The male screw rod 381 is screwed into a penetrating female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the second sliding block 33. Therefore, when the male screw rod 381 is driven to rotate forward and reversely by the pulse motor 382, the second slide block 33 is moved along the guide rails 322 and 322 in the index feed direction indicated by the arrow Y.

  The laser beam irradiation unit support mechanism 4 includes a pair of guide rails 41, 41 arranged in parallel along the indexing feed direction indicated by the arrow Y on the stationary base 2, and the arrow Y on the guide rails 41, 41. The movable support base 42 is provided so as to be movable in the direction indicated by. The movable support base 42 includes a movement support portion 421 that is movably disposed on the guide rails 41, 41, and a mounting portion 422 that is attached to the movement support portion 421. The mounting portion 422 is provided with a pair of guide rails 423 and 423 extending in the direction indicated by the arrow Z on one side surface in parallel. The laser beam irradiation unit support mechanism 4 in the illustrated embodiment includes a second index feed means 43 for moving the movable support base 42 along the pair of guide rails 41, 41 in the index feed direction indicated by the arrow Y. doing. The second index feed means 43 includes a male screw rod 431 disposed in parallel between the pair of guide rails 41, 41, and a drive source such as a pulse motor 432 for rotationally driving the male screw rod 431. It is out. One end of the male screw rod 431 is rotatably supported by a bearing block (not shown) fixed to the stationary base 2, and the other end is connected to the output shaft of the pulse motor 432. The male screw rod 431 is screwed into a female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the moving support portion 421 constituting the movable support base 42. For this reason, when the male screw rod 431 is driven to rotate forward and backward by the pulse motor 432, the movable support base 42 is moved along the guide rails 41, 41 in the index feed direction indicated by the arrow Y.

  The laser beam irradiation unit 5 in the illustrated embodiment includes a unit holder 51 and laser beam irradiation means 52 attached to the unit holder 51. The unit holder 51 is provided with a pair of guided grooves 511 and 511 that are slidably fitted to a pair of guide rails 423 and 423 provided in the mounting portion 422. By being fitted to the guide rails 423 and 423, the guide rails 423 and 423 are supported so as to be movable in the condensing point position adjustment direction indicated by the arrow Z.

  The illustrated laser beam irradiation means 52 includes a cylindrical casing 521 that is fixed to the unit holder 51 and extends substantially horizontally. The laser beam irradiation means 52 adjusts the output of the pulse laser beam oscillated by the pulse laser beam oscillation means 522 and the pulse laser beam oscillation means 522 disposed in the casing 521 as shown in FIG. An output adjusting means 523 and a condenser 53 for irradiating a workpiece held on the chuck table 36 with a pulse laser beam provided at the tip of the casing 521 and oscillated by the pulse laser beam oscillation means 522 are provided. The pulse laser beam oscillation means 522 is composed of a pulse laser beam oscillator 522a composed of a YAG laser oscillator or a YVO4 laser oscillator, and a repetition frequency setting means 522b attached thereto. The condenser 53 is attached to the tip of the casing 521 as shown in FIG.

  Continuing the description with reference to FIG. 1, an image pickup means 6 for picking up an image of a processing region to be laser processed by the laser beam irradiation means 52 is disposed at the front end portion of the casing 521 constituting the laser beam irradiation means 52. . The image pickup means 6 is composed of an image pickup device (CCD) or the like, and sends a picked up image signal to a control means (not shown). In addition, the dust discharge means 7 which collects and discharge | emits the dust produced | generated when a workpiece | work is irradiated with a laser beam from the collector 53 is arrange | positioned at the lower end part of the collector 53. FIG. The dust discharging means 7 will be described in detail later.

  The laser beam irradiation unit 5 in the illustrated embodiment includes a moving means 54 for moving the unit holder 51 along the pair of guide rails 423 and 423 in the direction indicated by the arrow Z. The moving means 54 includes a male screw rod (not shown) disposed between the pair of guide rails 423 and 423, and a driving source such as a pulse motor 542 for rotationally driving the male screw rod. By driving the male screw rod (not shown) by the motor 542 in the normal and reverse directions, the unit holder 51 and the laser beam irradiation means 52 are moved along the guide rails 423 and 423 in the direction indicated by the arrow Z. In the illustrated embodiment, the laser beam irradiation means 52 is moved upward by driving the pulse motor 542 forward, and the laser beam irradiation means 52 is moved downward by driving the pulse motor 542 in reverse. It has become.

Next, the condenser 53 and the dust discharge means 7 will be described with reference to FIGS.
The concentrator 53 in the illustrated embodiment includes a cylindrical concentrator housing 531 whose upper end is closed, and the casing 521 is disposed above the concentrator housing 531 as shown in FIG. An opening 531a into which the distal end portion is inserted is provided. In the condenser housing 531, a direction changing mirror 532 that changes the direction of the pulse laser beam oscillated from the pulse laser beam oscillating means 522 downward, and a pulse whose direction is changed downward by the direction changing mirror 532. A condensing lens 533 for condensing the laser beam and irradiating the workpiece W held on the chuck table 36 is provided. The condenser housing 531 is provided with a cover glass 534 for protecting the condenser lens 533 below the condenser lens 533, that is, downstream in the laser beam irradiation direction. Further, a rectangular mounting portion 535 for mounting the dust discharging means 7 is provided at the lower end portion of the condenser housing 531. As shown in FIG. 4, a pair of engaging portions 535c and 535c having a pair of engaging grooves 535b and 535b extending in parallel on both sides of the lower surface are provided on the bottom wall 535a of the mounting portion 535. As shown in FIG. 5, the mounting portion 535 is provided with an air passage 535d formed along the lower surface of the condenser lens 533, that is, the downstream surface in the laser beam irradiation direction. The air passage 535d is connected to the communication passage 535e. The air supply means 71 communicates with the air supply means 71. Further, the mounting portion 535 communicates with the air passage 535d and allows the passage of the laser beam irradiated through the condenser lens 533, and also allows the air to flow out toward the dust discharging means 7 downstream in the laser beam irradiation direction. 535f is provided.

  The dust discharge means 7 in the illustrated embodiment includes a dust collector 72 mounted on the lower surface of the mounting portion 535 of the condenser 53. As shown in FIG. 4, the dust collector 72 includes a rectangular upstream side wall 721, a rectangular downstream side wall 722, and an outer side wall 723 that connects the upstream side wall 721 and the downstream side wall 722. As shown in FIG. 5, a dust collection chamber 720 is formed by each wall. On the upper surface of the upstream side wall 721, as shown in FIG. 4, a pair of engagements that engage with a pair of engagement grooves 535b and 535b provided on the lower surface of the bottom wall 535a constituting the mounting portion 535 of the condenser 53. Stop protrusions 721a and 721a are formed in parallel. By engaging the pair of locking protrusions 721 a and 721 a with a pair of engaging grooves 535 b and 535 b provided on the lower surface of the bottom wall 535 a constituting the mounting portion 535 of the condenser 53, the dust collector 72. Is mounted on the lower surface of the mounting portion 535 of the condenser 53. Thus, in a state where the dust collector 72 is mounted on the lower surface of the mounting portion 535 of the condenser 53, as shown in FIG. 3 and FIG. An outside air intake passage 721b communicating with the outside air is provided between the lower surface and the lower surface. Further, as shown in FIGS. 4 and 5, the upstream side wall 721 is formed so as to face the air circulation opening 535 f provided in the bottom wall 535 a constituting the mounting portion 535 of the collector 53. A first opening 721c that allows passage of the laser beam irradiated from the outside and takes in outside air is provided. Accordingly, the first opening 721c communicates with the air circulation opening 535d and also communicates with the air intake passage 721b. Further, the upstream side wall 721 is provided with a rectifying nozzle 721d that gradually decreases in diameter from the periphery of the first opening 721c toward the dust collection chamber 720. In the downstream side wall 722, a second opening 722a that allows passage of a laser beam irradiated through the first opening 721c provided in the upstream side wall 721 and sucks dust generated by laser processing as will be described later. Is provided. The outer wall 723 constituting the dust collector 72 is provided with an exhaust port 723 a that opens to the dust collecting chamber 720. The exhaust port 723 a communicates with the suction source 73.

  The dust discharge means 7 in the illustrated embodiment is configured as described above. For example, 10 liters of air per minute is supplied from the air supply means 71 and 100 liters of air is sucked by the suction source 73. The The air supplied from the air supply means 71 includes a communication passage 535e, an air passage 535d, an air circulation opening 535f provided in the mounting portion 535 of the dust collector 72, and a first side wall 721 provided in the upstream side wall 721 of the dust collector 72. Flows into the dust collection chamber 720 through the opening 721c. Further, when the suction source 73 is activated, 100 liters of air per minute is sucked from the dust collection chamber 720. As a result, as will be described later, dust generated by laser processing is sucked into the dust collection chamber 720 together with the outside air from the second opening 722a, and the outside air is collected through the first opening 721c from the outside air intake passage 721b. The air is sucked into the chamber 720 and discharged through the exhaust port 723a.

The laser processing apparatus in the illustrated embodiment is configured as described above, and the operation thereof will be described below.
A semiconductor wafer 10 as a workpiece is placed on the chuck table 36 of the laser processing apparatus shown in FIG. 1, and the semiconductor wafer 10 is sucked and held on the chuck table 36 by operating a suction means (not shown). The semiconductor wafer 10 has lattice streets formed on the surface, and devices such as ICs and LSIs are formed in a plurality of regions partitioned by the lattice streets. The chuck table 36 that sucks and holds the semiconductor wafer 10 is positioned immediately below the processing area detection unit 6 by the processing feeding unit 37. When the chuck table 36 is positioned immediately below the image pickup means 6, an alignment operation for detecting a processing region to be laser processed of the semiconductor wafer 10 is executed by the image pickup means 6 and a control means (not shown). That is, the imaging means 6 and the control means (not shown) perform pattern matching for alignment with the condenser 53 of the laser beam irradiation means 52 that irradiates a laser beam along a street formed in a predetermined direction of the semiconductor wafer 10. The image processing such as the above is executed to align the laser beam irradiation position. Similarly, the alignment of the laser beam irradiation position is performed on the street formed in the direction orthogonal to the predetermined direction formed in the semiconductor wafer 10.

  When the streets formed on the semiconductor wafer 10 held on the chuck table 36 are detected as described above and alignment of the laser beam irradiation position is performed, the chuck table as shown in FIG. 36 is moved to the laser beam irradiation area where the condenser 53 of the laser beam irradiation means 52 is located, and one end of the predetermined street (the left end in FIG. 6A) is positioned directly below the collector 53. Then, the condensing point P of the pulse laser beam irradiated from the condenser 53 is matched with the vicinity of the surface (upper surface) of the semiconductor wafer 10. Next, the chuck table 36, that is, the semiconductor wafer 10 is directed in the direction indicated by arrow X 1 in FIG. At a predetermined machining feed rate. When the other end of the street (the right end in FIG. 6B) reaches a position directly below the condenser 53, the irradiation of the pulse laser beam is stopped and the movement of the chuck table 36 is stopped. As a result, as shown in FIG. 6B, the laser processed groove 101 is formed along the street in the semiconductor wafer 10 (laser processed groove forming step).

In addition, the said laser processing groove | channel formation process is performed on the following processing conditions, for example.
Laser light source: YVO4 laser or YAG laser Wavelength: 355 nm
Repetition frequency: 50 kHz
Average output: 4W
Condensing spot diameter: φ20μm
Processing feed rate: 150 mm / sec

  In the above-described laser processing groove forming step, the semiconductor wafer is melted and dust such as debris is generated by irradiating the surface of the semiconductor wafer 10 with a pulse laser beam from the condenser 53. However, since the dust discharging means 7 described above is provided in the illustrated embodiment, the dust 110 generated by irradiating the semiconductor wafer 10 with a pulsed laser beam as shown in FIG. Is sucked together with outside air into the dust collection chamber 720 sucked by the operation of the second opening 722a. On the other hand, as described above, when the suction source 73 is activated, outside air is sucked into the dust collecting chamber 720 from the outside air intake passage 721b through the first opening 721c, and exhausted together with the dust 110 sucked from the second opening 722a. It is discharged from the mouth 723a. As described above, when the suction source 73 is operated, the outside air sucked into the dust collecting chamber 720 from the outside air intake passage 721b through the first opening 721c is rectified and discharged from the exhaust port 723a. Therefore, the dust 110 sucked into the dust collection chamber 720 can be effectively guided to the exhaust port 723a. At this time, in the illustrated embodiment, the upstream side wall 721 in which the first opening 721c is formed is provided with a rectifying nozzle 721d that gradually decreases in diameter from the periphery of the first opening 721c toward the dust collection chamber 720. Therefore, the outside air sucked into the dust collection chamber 720 becomes more rectified. Therefore, the dust 110 sucked into the dust collecting chamber 720 can be prevented from adhering to the cover glass 534 or the condenser lens 533 through the first opening 721c. In the dust discharge means 7 in the illustrated embodiment, air is supplied from the air supply means 71 along the lower surface of the cover glass 534 for protecting the condenser lens 533, that is, the downstream surface in the laser beam irradiation direction. The dust can be prevented from adhering to the cover glass 534.

2: stationary base 3: chuck table mechanism 31: guide rail 36: chuck table 37: processing feed means 38: first index feed means 4: laser beam irradiation unit support mechanism 41: guide rail 42: movable support base 43: 2nd index sending means 5: Laser beam irradiation unit 51: Unit holder 52: Laser beam processing means 53: Condenser 531: Condenser housing 532: Direction change mirror 533: Condensing lens 534: Cover glass 535: Mounting part 6 : Imaging means 7: Dust discharging means 71: Air supply means 72: Dust collector 721: Upstream side wall 722: Downstream side wall 723: Outer wall 73: Suction source 10: Semiconductor wafer

Claims (1)

A chuck table for holding a workpiece, and a laser beam irradiating means for irradiating the workpiece held on the chuck table with a laser beam, wherein the laser beam irradiating means oscillates a laser beam, and the laser beam Laser processing comprising a condenser having a condenser lens for condensing a laser beam oscillated from an oscillator, and a dust discharging means disposed at the downstream end of the condenser in the laser beam irradiation direction In the device
The dust discharge means allows passage of the laser beam irradiated from the condenser and allows passage of the laser beam irradiated through the first opening and an upstream side wall having a first opening for taking in air. And a downstream side wall having a second opening for sucking dust, and an outer wall having an exhaust port connecting the upstream side wall and the downstream side wall to form a dust collection chamber and communicating the dust collection chamber to a suction source A dust collector consisting of
Between the dust collector and the collector, an outside air intake passage that communicates the first opening with outside air is provided ,
The upstream side wall of the dust collector is provided with a rectifying nozzle that gradually reduces the diameter from the periphery of the first opening toward the dust collection chamber,
The concentrator is provided with a cover glass for protecting the condensing lens on the downstream side in the laser beam irradiation direction of the condensing lens, and along the surface of the cover glass on the downstream side in the laser beam irradiation direction. An air passage formed and communicated with the air supply means, and an air circulation opening communicating with the air passage and facing the first opening are provided.
Laser processing equipment characterized by that.

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