JP2012245534A - Laser beam machining apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus having a dust treatment function to prevent a fire caused by dusts made by application of a laser beam.SOLUTION: The apparatus includes: a chuck table for holding a workpiece; a laser beam irradiation means provided with a condenser that applies a laser beam to the workpiece held on the chuck table; and a cleaning means for cleaning the workpiece. Further, the laser beam machining apparatus has a dust exhausting means including: a dust suction member opened to an application unit of the laser beam applied from the condenser of the means for laser beam irradiation; a first duct one end of which is connected to the dust suction member, and the other end of which is connected to the means for cleaning; a second duct one end of which is connected to the means for cleaning; and an air exhausting means which is connected to the other end of the second duct.

Description

  The present invention relates to a laser processing apparatus having a dust processing function for processing dust generated during laser processing.

  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 semiconductor substrate having a substantially disk shape, and devices such as ICs, LSIs, etc. are partitioned in these 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 devices. 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. The method of breaking is practically used. However, when laser light is irradiated along the street of the wafer, thermal energy concentrates on the irradiated area and debris is generated. This debris adheres to the bonding pads connected to the circuit and degrades the quality of the chip. New problems arise. In order to solve such a problem, a laser processing method has been proposed in which a processed film of a wafer is coated with a protective film such as polyvinyl alcohol, and the wafer is irradiated with a laser beam through the protective film. (For example, refer to Patent Document 1.)

JP 2004-188475 A

  As described above, when a wafer, which is a workpiece, is irradiated with a laser beam, debris is generated, and dust containing the debris is scattered. Therefore, the laser processing apparatus includes dust discharging means for sucking and discharging the scattered dust. ing. However, if dust accumulates in the suction duct of the dust discharge means and high-temperature debris scattered on the accumulated dust adheres, there is a problem that a fire occurs due to ignition. In particular, when a laser processing method in which a wafer is processed with a protective coating such as polyvinyl alcohol and the wafer is irradiated with a laser beam through the protective coating, the accumulated dust is ignited and a fire occurs. The rate of occurrence is high.

  The present invention has been made in view of the above facts, and its main technical problem is to provide a laser processing apparatus having a dust processing function capable of preventing a fire due to dust generated by irradiating a laser beam. That is.

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 including a condenser for irradiating the workpiece held on the chuck table with a laser beam; In a laser processing apparatus having a cleaning means for cleaning a workpiece,
A dust suction member that opens toward a laser beam irradiating unit irradiated from a condenser of the laser beam irradiation means; a first duct having one end connected to the dust suction member and the other end connected to the cleaning means; A dust discharge means comprising a second duct having one end connected to the cleaning means, and an exhaust means connected to the other end of the second duct.
A laser processing apparatus is provided.

  A laser processing apparatus according to the present invention includes a dust suction member that opens toward a laser beam irradiation unit irradiated from a condenser of a laser beam irradiation unit, one end connected to the dust suction member, and the other end connected to a cleaning unit. A dust discharge means comprising a first duct, a second duct having one end connected to the cleaning means, and an exhaust means connected to the other end of the second duct. The dust such as debris generated by the irradiation is sucked from the dust suction member through the first duct and introduced into the cleaning means because the dust discharge means operates and the vicinity of the opening of the dust suction member becomes negative pressure. Is done. Dust such as debris introduced into the cleaning means is sucked into the exhaust means through the second duct in a state where mist floating in the cleaning means is attached. In this way, dust such as debris generated by the laser beam irradiation is sucked from the dust suction member through the first duct, introduced into the cleaning means, and attached with mist to the dust through the second duct. Since the air is sucked into the exhaust means, sparks scattered by the laser beam irradiation, high-temperature debris, etc. ignite the dust accumulated in the duct and no fire is generated. In the present invention, since the mist is attached to the dust such as debris generated by the irradiation of the laser beam using the cleaning means equipped in the laser processing apparatus, an apparatus for attaching the mist to the dust is provided. Since it is not necessary to provide it, it is possible to suppress an increase in the size and cost of the entire laser processing apparatus.

The perspective view of the laser processing apparatus comprised according to this invention. The perspective view of the semiconductor wafer as a wafer which is a workpiece. The perspective view which fractures | ruptures and shows a part of protective film coating and washing | cleaning means with which the laser processing apparatus shown in FIG. 1 is equipped. Explanatory drawing which shows the state which positioned the spinner table of the protective film coating and washing | cleaning means shown in FIG. 3 in the workpiece carrying in / out position. Explanatory drawing which shows the state which located the spinner table of the protective film coating and washing | cleaning means shown in FIG. 3 in the working position. The front view which fractures | ruptures and shows a part of dust discharge means with which the laser processing apparatus shown in FIG. 1 is equipped. Explanatory drawing of the protective film coating process implemented by the protective film coating and washing | cleaning means shown in FIG. Explanatory drawing which shows the laser processing groove | channel formation process implemented using the laser processing apparatus shown in FIG. The principal part expanded sectional view of the semiconductor wafer by which the laser processing groove | channel was formed by the laser processing groove | channel formation process shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a laser processing apparatus configured according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a laser processing apparatus 1 configured according to the present invention.
A laser processing apparatus 1 shown in FIG. 1 includes an apparatus housing 2 having a substantially rectangular parallelepiped shape. A chuck table 3 for holding a wafer as a workpiece is disposed in the apparatus housing 2 so as to be movable in a machining feed direction indicated by an arrow X and an index feed direction Y orthogonal to the machining feed direction X. . The chuck table 3 includes a suction chuck support 31 and a suction chuck 32 mounted on the suction chuck support 31, and is a workpiece on a mounting surface that is a surface of the suction chuck 32. The wafer is held by suction means (not shown). The chuck table 3 is configured to be rotatable by a rotation mechanism (not shown). The suction chuck support 31 of the chuck table 3 configured as described above is provided with a clamp 34 for fixing an annular frame described later. The laser machining apparatus 1 includes a machining feed means (not shown) for feeding the chuck table 3 in the machining feed direction X and an index feed means (not shown) for indexing and feeding in the index feed direction Y.

  The illustrated laser processing apparatus 1 includes laser beam irradiation means 4 that performs laser processing on a wafer as a workpiece held on the chuck table 3. The laser beam irradiation unit 4 includes a laser beam oscillation unit 41 and a condenser 42 that condenses the laser beam oscillated by the laser beam oscillation unit 41. The laser beam machining apparatus 1 moves the laser beam oscillation unit 41 in a focusing point position adjusting unit (not shown) that moves in a focusing point position adjusting direction indicated by an arrow Z that is perpendicular to the mounting surface that is the upper surface of the chuck table 3. It has.

  The illustrated laser processing apparatus 1 captures an image of the surface of the workpiece held on the suction chuck 32 of the chuck table 3 and is to be processed by a laser beam irradiated from the condenser 42 of the laser beam irradiation means 4. The imaging means 5 which detects this is provided. The imaging unit 5 includes an infrared illumination unit that irradiates a workpiece with infrared rays, an optical system that captures infrared rays emitted by the infrared illumination unit, in addition to a normal imaging device (CCD) that captures visible light. An image sensor (infrared CCD) that outputs an electrical signal corresponding to the infrared rays captured by the optical system is used, and the captured image signal is sent to a control means to be described later. The illustrated laser processing apparatus 1 includes a display unit 6 that displays an image captured by the imaging unit 5.

  The illustrated laser processing apparatus 1 includes a cassette mounting portion 11a on which a cassette that houses a semiconductor wafer 10 as a wafer to be processed is mounted. A cassette table 111 is disposed on the cassette mounting portion 11 a so as to be movable up and down by lifting means (not shown). The cassette 11 is mounted on the cassette table 111. The semiconductor wafer 10 is attached to the surface of the protective tape T attached to the annular frame F, and is accommodated in the cassette 11 while being supported by the annular frame F via the protective tape T. The semiconductor wafer 10 is made of a silicon wafer, and a plurality of regions are partitioned by a plurality of division lines 101 arranged in a lattice pattern on the surface 10a as shown in FIG. 2, and ICs, LSIs, etc. are partitioned in these partitioned regions. Device 102 is formed. As shown in FIG. 1, the semiconductor wafer 10 configured in this manner is attached to the protective tape T mounted on the annular frame F with the front surface 10a, that is, the surface on which the street 101 and the device 102 are formed facing upward. Worn.

  The illustrated laser processing apparatus 1 carries out the unprocessed semiconductor wafer 10 housed in the cassette 11 to the alignment means 12 disposed in the temporary placement portion 12 a and also loads the processed semiconductor wafer 10 into the cassette 11. The wafer unloading / loading means 13 and the unprocessed semiconductor wafer 10 unloaded to the alignment means 12 are transported to a protective film coating / cleaning means 7 to be described later, and a protective film is coated on the surface by the protective film coating / cleaning means 7. A first wafer transport means 14 for transporting the coated semiconductor wafer 10 onto the chuck table 3 and a second wafer for transporting the semiconductor wafer 10 processed on the chuck table 3 to the protective film coating / cleaning means 7. Conveying means 15 is provided. The second wafer transport means 15 includes a lid 151 that covers the upper surface of a cleaning water receiving container of a protective film coating / cleaning means described later.

Next, a protective film is applied to the surface (processed surface) of the semiconductor wafer 10 that is a workpiece before processing, and the protective film coated on the surface of the semiconductor wafer 10 after processing is removed. The cleaning means 7 will be described with reference to FIGS.
The protective film coating / cleaning means 7 in the illustrated embodiment includes a spinner table mechanism 71 and a water receiving means 72 disposed so as to surround the spinner table mechanism 71. The spinner table mechanism 71 includes a spinner table 711, an electric motor 712 as a rotational drive unit that rotationally drives the spinner table 711, and a support unit 713 that supports the electric motor 712 so as to be movable in the vertical direction. . The spinner table 711 includes a suction chuck 711a formed of a porous material, and the suction chuck 711a communicates with suction means (not shown). Accordingly, the spinner table 711 holds the wafer on the suction chuck 711 by placing a wafer as a workpiece on the suction chuck 711a and applying a negative pressure by suction means (not shown). The electric motor 712 connects the spinner table 711 to the upper end of the drive shaft 712a. The support means 713 includes a plurality of (three in the illustrated embodiment) support legs 713a and a plurality of (three in the illustrated embodiment) attached to the electric motor 712 by connecting the support legs 713a. ) Air cylinder 713b. The support means 713 configured as described above operates the air cylinder 713b to move the electric motor 712 and the spinner table 711 to the workpiece loading / unloading position, which is the upper position shown in FIG. 4, and the lower position shown in FIG. Position to the working position that is the position.

  The water receiving means 72 includes a cleaning water receiving container 721, three supporting legs 722 (two are shown in FIG. 3) that support the cleaning water receiving container 721, and driving of the electric motor 712. And a cover member 723 attached to the shaft 712a. As shown in FIGS. 4 and 5, the washing water receiving container 721 is composed of a cylindrical outer wall 721a, a bottom wall 721b, and an inner wall 721c. A hole 721d through which the drive shaft 712a of the electric motor 712 is inserted is provided at the center of the bottom wall 721b, and an inner wall 721c protruding upward from the periphery of the hole 721d is formed. Further, as shown in FIG. 3, the bottom wall 721b is provided with a drain port 721e, and a drain hose 724 is connected to the drain port 721e. The cover member 723 is formed in a disc shape, and includes a cover portion 723a that protrudes downward from the outer peripheral edge thereof. When the electric motor 712 and the spinner table 711 are positioned at the work position shown in FIG. 5, the cover member 723 configured as described above has a gap between the cover portion 723a and the inner wall 721c constituting the cleaning water receiving container 721. Is positioned to polymerize.

  The protective film coating and cleaning means 7 in the illustrated embodiment is a resin liquid supply mechanism that supplies a liquid resin to the surface (surface to be processed) of the semiconductor wafer 10 that is an object to be processed that is held by the spinner table 711. 74. The resin liquid supply mechanism 74 swings the resin supply nozzle 741 that supplies a liquid resin toward the surface (surface to be processed) of the unprocessed semiconductor wafer 10 held by the spinner table 711, and the resin supply nozzle 741. An electric motor 742 capable of normal rotation and reverse rotation is provided, and a resin supply nozzle 741 is connected to a resin liquid supply means (not shown). The resin supply nozzle 741 includes a nozzle portion 741a extending horizontally and a support portion 741b extending downward from the nozzle portion 741a, and the support portion 741b is provided on the bottom wall 721b constituting the washing water receiving container 721. It is disposed through an insertion hole (not shown). A seal member (not shown) that seals between the support portion 741b is attached to the periphery of an insertion hole (not shown) through which the support portion 741b of the resin supply nozzle 741 is inserted.

  The protective film coating / cleaning means 7 in the illustrated embodiment includes a cleaning water supply mechanism 75 for supplying cleaning water to the semiconductor wafer 10 which is a processed object held by the spinner table 711. Yes. The cleaning water supply mechanism 75 includes a cleaning water injection nozzle 751 that supplies cleaning water toward the wafer held by the spinner table 711, and an electric motor 752 that can rotate forward and reverse to swing the cleaning water injection nozzle 751. I have. The washing water injection nozzle 751 is composed of a nozzle portion 751a that extends horizontally and has a tip bent downward, and a support portion 751b that extends downward from the base end of the nozzle portion 751a. It is disposed through an insertion hole (not shown) provided in the bottom wall 721 b constituting the 721. The nozzle portion 751a of the cleaning water jet nozzle 751 includes a cleaning water passage and an air passage, the cleaning water passage is connected to the cleaning water supply means, and the air passage is connected to the air supply means. A sealing member (not shown) that seals between the support portion 751b and the support portion 751b is attached to the periphery of the insertion hole (not shown) through which the support portion 751b of the cleaning water jet nozzle 751 configured as described above is inserted.

  Further, the protective film coating / cleaning means 7 in the illustrated embodiment includes an air supply mechanism 76 for supplying air to the semiconductor wafer 10 which is a processed object held by the spinner table 711. Yes. The air supply mechanism 76 includes an air nozzle 761 that blows air toward the cleaned wafer held by the spinner table 711, and an electric motor 762 that can rotate forward and reverse to swing the air nozzle 761. The air nozzle 761 is connected to air supply means (not shown). The air nozzle 761 includes a nozzle portion 761a that extends horizontally and has a distal end bent downward, and a support portion 761b that extends downward from the base end of the nozzle portion 761a. The support portion 761b is the cleaning water receiving container. It is disposed through an insertion hole (not shown) provided in the bottom wall 721 b constituting the 721. A seal member (not shown) that seals between the support portion 761b is attached to the periphery of an insertion hole (not shown) through which the support portion 761b of the air nozzle 761 is inserted.

  As shown in FIG. 6, the laser processing apparatus 1 in the illustrated embodiment includes dust discharge means 8 that discharges dust generated by irradiating a workpiece with a laser beam from a condenser 42 of the laser beam irradiation means 4. Yes. The dust discharging means 8 includes a dust suction member 81 mounted on the case 421 of the condenser 42, and one end connected to the dust suction member 81, and the other end is a cleaning water receiving container 721 of the protective film coating / cleaning means 7. The first duct 82 is connected to the cleaning water receiving container 721, the second duct 83 is connected to one end of the cleaning water receiving container 721, and the exhaust means 84 is connected to the other end of the second duct 83. . The dust suction member 81 includes an annular bottom portion 811 having a fitting hole 811a for fitting with the case 421 of the condenser 42, a cylindrical mounting portion 812 standing from the inner periphery of the annular bottom portion 811, It is formed of a suction part 813 formed by hanging from the outer peripheral edge of the annular bottom part 811 and having an opening 813a at the lower end. The opening 813a is opened toward the irradiation part of the laser beam emitted from the condenser 42. . One end of the first duct 82 is connected to a hole 811b provided in the bottom 811 of the dust suction member 81, and the other end is an outer wall 721a constituting the cleaning water receiving container 721 of the protective film covering / cleaning means 7. Is connected to a hole 721f. One end of the second duct 83 is connected to a hole 721g provided on the opposite side of the hole 721f on the lower side of the outer wall 721a constituting the washing water receiving container 721 approximately 180 degrees. The exhaust means 84 includes a first filter 841 and a second filter 842 that are arranged at intervals, and a blower 843 that is arranged between the first filter 841 and the second filter 842. The first filter 841 is connected to the other end of the second duct 83.

The laser processing apparatus 1 equipped with the protective film coating / cleaning means 7 and the dust discharge means 8 described above is configured as described above, and the operation thereof will be described below.
As shown in FIG. 1, an unprocessed semiconductor wafer 10 (hereinafter simply referred to as “semiconductor wafer 10”) supported on an annular frame F via a protective tape T is a cassette 11 with a surface 10a as a processing surface facing upward. In a predetermined position. The unprocessed semiconductor wafer 10 accommodated in a predetermined position of the cassette 11 is positioned at the unloading position by the cassette table 111 moving up and down by an elevating means (not shown). Next, the workpiece carry-out / carry-in means 13 is advanced and retracted, and the semiconductor wafer 10 positioned at the carry-out position is carried out to the alignment means 12 disposed in the temporary placement portion 12a. The semiconductor wafer 10 carried out to the alignment means 12 is aligned at a predetermined position by the alignment means 12. Next, the unprocessed semiconductor wafer 10 aligned by the alignment means 12 is placed on the suction chuck 711a of the spinner table 711 constituting the protective film coating / cleaning means 7 by the turning operation of the first wafer transport means 14. It is conveyed and sucked and held by the suction chuck 711a (wafer holding step). At this time, the spinner table 711 is positioned at the wafer loading / unloading position shown in FIG. 4, and the resin supply nozzle 741, the washing water injection nozzle 751 and the air nozzle 761 are arranged on the spinner table 711 as shown in FIGS. It is positioned at a standby position separated from above.

  If the wafer holding process in which the unprocessed semiconductor wafer 10 is held on the spinner table 711 of the protective film coating / cleaning means 7 is performed, the second wafer transport means 15 is operated to remove the lid 151 from the cleaning water receiving container 721. Then, a protective film coating step of coating the protective film on the surface 10a that is the processing surface of the semiconductor wafer 10 is performed. That is, by operating the electric motor 742 of the resin liquid supply mechanism 74, the nozzle portion 741a of the resin supply nozzle 741 is a surface to be processed of the semiconductor wafer 10 held on the spinner table 711 as shown in FIG. It is positioned above the center of the surface 10a. Then, a predetermined amount of the liquid resin 110 is dropped onto the central portion of the surface 10a, which is the processing surface of the semiconductor wafer 10 held by the spinner table 711, by operating a resin liquid supply means (not shown) (liquid resin dropping step). The amount of the liquid resin 110 to be dropped in this liquid resin dropping step may be 2 milliliters when the diameter of the semiconductor wafer 10 that is a workpiece is 200 mm. The liquid resin 110 dropped in the liquid resin dropping step is preferably a water-soluble resist such as PVA (Poly Vinyl Alcohol), PEG (Poly Ethylene Glycol), or PEO (Poly Ethylene Oxide).

  When the above-described liquid resin dropping step is performed, the electric motor 712 of the spinner table mechanism 71 is operated as shown in FIG. 7B to move the spinner table 711 to 15 in the direction indicated by the arrow A at a rotation speed of 500 rpm. Rotate for seconds. As a result, the liquid resin 110 dropped by the centrifugal force accompanying the rotation of the semiconductor wafer 10 is caused to flow toward the outer periphery, whereby the surface 10a, which is the work surface of the semiconductor wafer 10, has a thickness of 0.2 to 1.0 μm. A protective film 120 is formed (protective film coating step).

  As described above, when the protective film coating process for coating the protective film 120 on the surface 10a that is the processed surface of the semiconductor wafer 10 is performed, the spinner table 711 is positioned at the workpiece loading / unloading position shown in FIG. Then, the suction holding of the semiconductor wafer 10 held on the spinner table 711 is released. The semiconductor wafer 10 on the spinner table 711 is transported onto the suction chuck 32 of the chuck table 3 by the second wafer transport means 15 and sucked and held by the suction chuck 32. The chuck table 3 that sucks and holds the semiconductor wafer 10 in this way is positioned immediately below the image pickup means 5 disposed in the laser beam irradiation means 4 by a processing feed means (not shown).

  When the chuck table 3 is positioned immediately below the image pickup means 5, a street 101 formed in a predetermined direction on the semiconductor wafer 10 by the image pickup means 5 and a control means (not shown), and a laser beam irradiation means for irradiating the laser beam along the street 101 Image processing such as pattern matching for performing alignment with the four condensers 42 is performed, and alignment of the laser beam irradiation position is performed. Similarly, alignment of the laser beam irradiation position is performed on the street 101 formed in the semiconductor wafer 10 and extending in a direction perpendicular to the predetermined direction. At this time, the protective film 120 is formed on the surface 10a where the street 101 of the semiconductor wafer 10 is formed. However, if the protective film 120 is not transparent, it can be imaged with infrared rays and aligned from the surface.

  If the street 101 formed on the semiconductor wafer 10 held on the chuck table 3 is detected as described above and the laser beam irradiation position is aligned, as shown in FIG. The chuck table 3 is moved to a laser beam irradiation region where the condenser 42 of the laser beam application means 4 for irradiating the laser beam is located, and a predetermined street 101 is positioned immediately below the condenser 42. At this time, as shown in FIG. 8A, the semiconductor wafer 10 is positioned so that one end of the street 101 (the left end in FIG. 8A) is located directly below the condenser 42.

  On the other hand, as shown in FIG. 6, the second wafer transfer means 15 is operated to cover the cover 151 at the upper end of the cleaning water receiving container 721 of the protective film covering and cleaning means 7. Then, the electric motor 752 of the cleaning water supply mechanism 75 is operated to position the nozzle portion 751a of the cleaning water injection nozzle 751 above the rotation center of the spinner table 711 as shown in FIG. 6 (injection nozzle positioning step). Next, the electric motor 712 is operated to rotate the spinner table 711 in the direction indicated by the arrow B at a rotational speed of 700 rpm, for example, and a cleaning water supply means (not shown) is operated to inject cleaning water of 0.2 Mpa, for example. Air supplied to the nozzle 751 and an air supply means (not shown) are operated to supply, for example, 0.3 Mpa of air to the cleaning water jet nozzle 751. As a result, the cleaning water is ejected from the nozzle portion 751a of the cleaning water injection nozzle 751 by the pressure of the air, sprayed onto the upper surface of the rotating spinner table 711, and becomes a mist and floats in the cleaning water receiving container 721. Further, the blower 843 constituting the exhaust means 84 of the dust discharge means 8 is operated. As a result, the air in the vicinity of the opening 813a of the dust suction member 81 constituting the dust discharge means 8 is sucked through the first duct 82, the washing water receiving container 721, the second duct 83, and the first filter 841. Since the liquid is discharged through the second filter 842, the vicinity of the opening 813a is negative pressure.

  In this manner, while the cleaning water is ejected from the cleaning water jet nozzle 751 and the blower 843 of the dust discharging means 8 is in operation, the chuck table 3 is irradiated with the pulse laser beam from the condenser 42 of the laser beam irradiation means 4. Is moved at a predetermined machining feed rate in the direction indicated by the arrow X1 in FIG. Then, as shown in FIG. 8B, when the other end of the street 101 (the right end in FIG. 8B) reaches a position immediately below the condenser 42, the irradiation of the pulse laser beam is stopped and the chuck table 3 is stopped. That is, the movement of the semiconductor wafer 10 is stopped. In this laser processing groove forming step, the condensing point P of the pulse laser beam is matched with the vicinity of the surface of the street 101.

  By performing the laser processing groove forming step described above, the laser processing groove 140 is formed on the street 101 of the semiconductor wafer 10 as shown in FIG. At this time, even if the debris 150 is generated by the irradiation of the laser beam as shown in FIG. 9, the debris 150 is blocked by the protective film 120 and does not adhere to the device 102 and the bonding pad. Then, the above-described laser processing groove forming process is performed on all the streets 101 of the semiconductor wafer 10. In addition, when the above-mentioned laser processing groove forming process is performed, dust such as debris is generated by the irradiation of the laser beam. Since the dust such as debris generated in this way has a negative pressure near the opening 813a portion of the dust suction member 81 constituting the dust discharge means 8 by operating the dust discharge means 8 as described above. The dust is sucked from the dust suction member 81 through the first duct 82 and introduced into the cleaning water receiving container 721. The dust such as debris introduced into the cleaning water receiving container 721 is sucked into the exhaust means 84 through the second duct 83 in a state where the mist floating in the cleaning water receiving container 721 is attached as described above. In this manner, dust such as debris to which the mist sucked by the exhaust means 84 is attached is captured by the first filter 841 and the second filter 842. As described above, dust such as debris generated by the laser beam irradiation is sucked from the dust suction member 81 through the first duct 82, introduced into the cleaning water receiving container 721, and attached with mist. Therefore, sparks scattered by the irradiation of the laser beam, high-temperature debris, etc. ignite the dust accumulated in the duct and no fire is generated. In the illustrated embodiment, since the mist is attached to dust such as debris generated by the irradiation of the laser beam using the cleaning means equipped in the laser processing apparatus, an apparatus for attaching the mist to the dust is provided. Since it is not necessary to provide it, it is possible to suppress an increase in the size and cost of the entire laser processing apparatus.

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
Output: 4W
Condensing spot diameter: 9.2 μm
Processing feed rate: 200 mm / sec

  If the above-described laser processing groove forming process is performed along all the streets 101 of the semiconductor wafer 10, the chuck table 3 holding the semiconductor wafer 10 is returned to the position where the semiconductor wafer 10 is first sucked and held. Here, the suction holding of the semiconductor wafer 10 is released. Then, the semiconductor wafer 10 is transported onto the suction chuck 711a of the spinner table 711 constituting the protective film coating / cleaning means 7 by the second wafer transport means 15, and sucked and held by the suction chuck 711a. At this time, the resin supply nozzle 741, the washing water injection nozzle 751 and the air nozzle 761 are positioned at a standby position separated from the upper side of the spinner table 711 as shown in FIGS.

  If the processed semiconductor wafer 10 is held on the spinner table 711 of the protective film coating and cleaning means 7, a cleaning process is executed. That is, as shown in FIG. 5, the spinner table 711 is positioned at the working position, and the electric motor 752 of the cleaning water supply mechanism 75 is operated to hold the nozzle portion 751a of the cleaning water injection nozzle 751 on the spinner table 711. Positioning above the rotation center of the wafer 10 (injection nozzle positioning step). The cleaning water supply means (not shown) is operated while rotating the spinner table 711 in the direction indicated by the arrow B at a rotation speed of 700 rpm, for example, to supply 0.2 Mpa of cleaning water to the cleaning water jet nozzle 751 and not shown. For example, 0.3 Mpa of air is supplied to the cleaning water jet nozzle 751 by operating the air supply means. As a result, the cleaning water is ejected from the nozzle portion 751a of the cleaning water injection nozzle 751 by the air pressure. Note that the amount of cleaning water sprayed from the nozzle portion 751a of the cleaning water spray nozzle 751 is set to 2 liters / minute in the illustrated embodiment. At this time, the nozzle portion 751 a of the cleaning water spray nozzle 751 is stopped at a position above the rotation center of the semiconductor wafer 10 for 1 to 3 seconds, and the cleaning water is sprayed to the rotation center of the semiconductor wafer 10. If the cleaning water is sprayed to the rotation center of the semiconductor wafer 10 for 1 to 3 seconds in this way, the cleaning water injection nozzle 751 is swung by operating the electric motor 752 of the cleaning water supply mechanism 75, and the nozzle portion 751a is moved to the semiconductor. The wafer 10 is moved from the center of rotation toward the outer periphery (cleaning step). In this way, in the cleaning process, the cleaning water sprayed from the nozzle portion 751a of the cleaning water spray nozzle 751 moves from the rotation center of the semiconductor wafer 10 toward the outer periphery, so the cleaning spray sprayed to the rotation center of the semiconductor wafer 10 is performed. The water moves from the rotation center of the semiconductor wafer 10 toward the outer periphery due to the centrifugal force of the rotating semiconductor wafer 10 and scatters while dissolving the protective film 120 coated on the surface 10 a of the semiconductor wafer 10. The protective film 120 can be efficiently washed away by one movement of the nozzle portion 751a of the washing water jet nozzle 751 without causing stagnation in the center, and the debris 150 generated during laser processing can also be removed.

  When the above-described cleaning process is completed, a drying process is performed. That is, the cleaning water jet nozzle 751 is positioned at the standby position, and the spinner table 711 is rotated at a rotational speed of, for example, 3000 rpm for about 15 seconds. At this time, the electric motor 762 of the air supply mechanism 76 is operated so that the nozzle portion 761a of the air nozzle 761 is positioned above the center portion of the surface 10a that is the surface to be processed of the semiconductor wafer 10 held by the spinner table 711, and air supply is performed. The means 760 is operated to supply 200 milliliters / second of air from the nozzle portion 761a of the air nozzle 761 to the surface 10a, which is the work surface of the semiconductor wafer 10, and the nozzle portion 761a of the air nozzle 761 is swung within a required angle range. It is desirable that

  As described above, after cleaning and drying of the processed semiconductor wafer 10, the rotation of the spinner table 711 is stopped and the air nozzle 761 of the air supply means 76 is positioned at the standby position. Then, the spinner table 711 is positioned at the workpiece loading / unloading position shown in FIG. 4 and the suction holding of the semiconductor wafer 10 held on the spinner table 711 is released. Next, the processed semiconductor wafer 10 on the spinner table 711 is carried out by the first wafer transfer means 14 to the alignment means 12 disposed in the temporary placement portion 12a. The processed semiconductor wafer 10 unloaded to the alignment means 12 is stored in a predetermined position of the cassette 11 by the wafer unloading means 13.

DESCRIPTION OF SYMBOLS 1: Laser processing apparatus 2: Apparatus housing 3: Chuck table 4: Laser beam irradiation means 41: Laser beam oscillation means 42: Condenser 5: Imaging means 6: Display means 7: Protection film coating and washing means 71: Spinner table mechanism 711 : Spinner table 712: Electric motor 72: Water receiving means 74: Resin liquid supply mechanism 741: Resin supply nozzle 75: Wash water supply mechanism 751: Wash water injection nozzle 76: Air supply mechanism 760: Air supply means 761: Air nozzle 8 : Dust discharging means 81: dust suction member 82: first duct 83: second duct 84: exhaust means 841: first filter 842: second filter 843: blower 10: semiconductor wafer 11: cassette 12: position Matching means 13: Wafer unloading / loading means 14: First Eha conveying means 15: second wafer transporting means
F: Ring frame
T: Protective tape

Claims (1)

Laser processing apparatus comprising: a chuck table for holding a workpiece; a laser beam irradiation means including a condenser for irradiating a workpiece with a laser beam to the workpiece held on the chuck table; and a cleaning means for cleaning the workpiece. In
A dust suction member that opens toward a laser beam irradiating unit irradiated from a condenser of the laser beam irradiation means; a first duct having one end connected to the dust suction member and the other end connected to the cleaning means; A dust discharge means comprising a second duct having one end connected to the cleaning means, and an exhaust means connected to the other end of the second duct.
Laser processing equipment characterized by that.

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