JP2008149388A - Cutting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting apparatus which can accurately achieve various image data and detected data necessary for cutting work by preventing the dirt of a light receiving lens, etc. of a lens instrument such as an optical sensor, due to chips, and further by easily removing the chips even if the chips have stuck to the light receiving lens. <P>SOLUTION: In order to suppress the sticking of chips, a light emitting lens 64 and the light receiving lens 65 of the optical sensor 60 for setting-up, and the respective surfaces of the respective covers 76, 86 of a camera unit 70 for photographing the wear, chipping, etc. of the cutting edge 32 of a rotary blade 30, are coated with a hydrophilic coating material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cutting apparatus for cutting a workpiece such as a device substrate using a cutting tool such as a rotary blade or performing grooving, and in particular for grasping in advance the position in the feed direction of the cutting tool. The present invention relates to a cutting apparatus provided with an optical sensor used for the setup of the above and an imaging device for recognizing the wear state of the cutting tool.

  For example, many semiconductor chips having electronic circuits such as ICs and LSIs are formed in advance on a semiconductor substrate such as silicon, and the substrate is manufactured by cutting and dividing. For cutting a semiconductor wafer, a dicing apparatus is often used that cuts with a rotating blade formed by bonding diamond abrasive grains with a bonding material and forming a thin disk.

  In such a dicing apparatus, in order to determine the cutting amount of the rotating blade with respect to the wafer, the position of the cutting edge, which is the lower end of the cutting blade, is accurately grasped, and it is called a setup that enables control of the feeding amount of the rotating blade based on it. Work is usually done before cutting. In this setup, there is a method using an optical sensor for measuring the distance between the reference surface and the blade edge position, in addition to the contact method in which the blade edge is brought into contact with a reference surface unique to the apparatus (for example, the surface of the table holding the wafer) ( For example, see Patent Document 1). There is also a cutting apparatus equipped with an imaging device for observing changes in the degree of wear or chipping of the cutting blade of the rotating blade to determine the life of the rotating blade.

JP 9-47943 A

  As described above, the dicing apparatus is provided with an optical sensor for setup, an imaging device for observation of a rotating blade, or the like. Each of these accessory devices has a lens close to the rotating blade that is the object. In a dicing apparatus, cutting water is usually supplied to a processing point where a rotating blade is cut into a workpiece. Therefore, if the lens or lens is covered with a cover, the cover is in an environment where it is exposed to cutting water splashes or mist mixed with cutting debris. It is inevitable to do.

  The contamination of the lens and the like due to the attachment of cutting waste significantly impairs the imaging performance. In the case of the optical sensor, it is difficult to detect the accurate blade edge position. As a result, a defect occurs in the position recognition, and normal cutting is not performed. Accordingly, it has been considered that coating is made to make it difficult for cutting scraps to adhere to the surfaces of these lenses or the like, or to make it easier to remove them even if they adhere, but there has been no one that can provide good results.

  Therefore, according to the present invention, the lens or the like is less likely to be contaminated by cutting waste, and can be in an attachment state that is relatively easy to remove even if cutting waste adheres. As a result, accurate imaging and detection can be performed. An object of the present invention is to provide a cutting device capable of stably continuing a stable operation.

  The inventor of the present invention has made extensive studies to achieve the above-mentioned object. As a result, the coating material is made of a hydrophilic material, particularly silicon oxide, as a coating material that is difficult to attach cutting scraps and is easy to remove. I have come to know that things are extremely effective. The present invention has been made on the basis of such knowledge. A holding means for holding a workpiece, a cutting tool that is rotatably held, and the rotated cutting tool is held by the holding means. Recognizes the status of cutting tools in a cutting device equipped with a cutting means for applying a cutting action to a workpiece and a cutting fluid supply means for supplying a cutting fluid to a processed portion of the workpiece by the cutting tool. A light-receiving end portion is provided, and a recognition means for optically recognizing the situation through the light-receiving end portion is provided, and the surface of the light-receiving end portion is coated with a coating layer made of a hydrophilic material. It is characterized by being. The light receiving end of the present invention refers to a light receiving lens of the optical sensor or a lens provided in the imaging device for observing the rotating blade, and when these lenses are covered with a cover, the cover Refers to that. In any case, the light receiving end portion is placed in an environment where it is exposed to splashes or mist of cutting water mixed with cutting waste.

  According to the inventors of the present invention, a coating layer made of a hydrophilic material is coated on the light receiving end, and in this state, the cutting operation is performed as usual. The amount of cutting dust attached is less than when coating various anti-reflection coating materials, water-repellent coating materials, or anti-static coating materials, and it can be easily removed by wiping with a cloth. It was confirmed that the cleanliness can be maintained for a relatively long time. As described above, the reason why the hydrophilic coating material is effective for the attachment of the cutting waste is that water adhering to the surface of the hydrophilic coating layer spreads uniformly on the surface and tends to be in a fluid state. It is expected that the cutting waste flows with such water (actually cutting water) and easily drains from the lens surface, that is, the surface of the coating layer.

  Examples of the recognition means of the present invention include a device that recognizes the position of the cutting tool, which is information for performing the setup, or a device that recognizes the degree of wear of the cutting tool. In this case, the light receiving end is disposed in the vicinity of the outer peripheral edge of the cutting tool.

  According to the present invention, the light-receiving end that optically recognizes the state of the cutting tool is less likely to be contaminated by the cutting waste, and can be in an attachment state that is relatively easy to remove even if the cutting waste adheres. Accurate image capturing and detection are possible, and there is an effect that normal operation can be continued stably.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.
[1] Basic Configuration and Operation of Cutting Device FIG. 1 shows an appearance of a cutting device 1 according to an embodiment. The cutting apparatus 1 includes a vertically long casing 2 that is generally a rectangular parallelepiped, and a cutting process such as cutting or grooving is performed on the workpiece inside the casing 2. The casing 2 is provided with a hatch 3 for taking a workpiece into and out of the apparatus 1, and an operation panel 4 for operating the cutting apparatus 1 is provided above the hatch 3. It has been. In addition, an indicator lamp 5 that displays a working state or issues a warning is attached to the upper portion of the housing 2.

  A machining chamber is provided inside the machining apparatus 1, and a machining section 6 shown in FIG. 2 is provided in the machining chamber. A reference numeral 10 in FIG. 2 denotes a water case 10 formed of a rectangular thin box, and a rectangular table base 20 is disposed at the bottom of the water case 10 so as to be capable of reciprocating in the X direction. The table base 20 is reciprocated in the X direction along a guide rail (both not shown) laid on the bottom of the water case 10 by a drive mechanism. A vacuum chuck disk-shaped chuck table (holding means) 21 is supported on the table base 20 so as to be rotatable about the Z direction (vertical direction). The chuck table 21 is rotated in one or both directions by a rotation drive mechanism (not shown) incorporated in the table base 20.

  Between the both ends of the movement direction of the table base 20 and the inner surface of the water case 10, the guide rail of the table base 20 is covered to prevent the cutting waste from adhering to the guide rail, thereby preventing the movement. The bellows-like cover 22 for doing so is attached. These covers 22 expand and contract in the X direction as the table base 20 moves.

  The upper surface 21a of the chuck table 21 is set to be horizontal, and the workpiece 9 is sucked and held on the upper surface 21a. The workpiece 9 is a disk-shaped substrate such as a semiconductor wafer, and the substrate 9 is cut by a rotating blade (cutting tool) 30 disposed above the chuck table 21 such as cutting and grooving. Processing is applied. The rotary blade 30 is coaxially fixed to the tip of a spindle shaft 36 incorporated in the axial center of a cylindrical spindle (cutting means) 35. The spindle 35 and the spindle shaft 36 are parallel to the upper surface 21a of the chuck table 21 and extend in the Y direction. The rotating blade 30 is rotated at a high speed via a spindle shaft 36 by a motor built in the spindle 35.

  As shown in FIG. 3, the rotating blade 30 is formed by forming a thin cutting edge 32 in which an outer peripheral portion of one side of a hub blade 31 is bonded with, for example, diamond abrasive grains with a bonding material such as metal in an annular shape. The blade 31 is detachably fixed to the spindle shaft 36 using a hub mount 33 and a fixing nut 34.

  A blade cover 37 that covers the top of the rotary blade 30 is attached to the tip of the spindle 35, and the blade cover 37 is a cutting that supplies cutting water to a processing point that is a cut portion of the rotary blade 30 into the substrate 9. Water nozzles (cutting fluid supply means) 38 and 39 are attached. The cutting water discharged from the cutting water nozzles 38 and 39 is wound up by the rotating blade 30 and becomes splashed, but the splash is suppressed by the blade cover 37. Further, the cutting water flowing on the substrate 9 is received by the water case 10 through the chuck table 21 and the table base 20, and drained from the drain port (not shown) to the outside of the apparatus.

  The spindle 35 is held by a holder 40, and the holder 40 is fixed to a slider 41. The slider 41 is mounted on a column 43 made of an L-shaped plate material via a pair of guide rails 42 so as to be movable up and down in the Z direction. The slider 41 is provided by a Z-direction feed mechanism 46 including a screw rod 44 disposed between the guide rails 42 and screwed into the slider 41, and a motor 45 installed on the upper end surface of the column 43 and rotating the screw rod 44. It moves up and down along the guide rail 42. The column 43 is mounted on the base 48 so as to be movable in the Y direction via a pair of guide rails (only one is visible in FIG. 2) 47, and is moved in the Y direction by a Y direction feed motor 49. It is supposed to be.

  The rotary blade 30 moves up and down in the Z direction together with the slider 41 by the Z direction feeding mechanism 46, and moves away from or approaches the chuck table 21. Further, the rotary blade 30 moves in the Y direction within a range that crosses the table base 20 as the column 43 moves in the Y direction. In the cutting process by the rotary blade 30, the cutting amount into the workpiece is determined by the feeding operation in the Z direction by the Z direction feeding mechanism 46, and cutting or grooving is performed by the movement of the table base 20 in the X direction. The machining site is determined by the combination of the rotation of the chuck table 21 and the movement of the column 43 in the Y direction.

  The determination of the processing site by the rotary blade 30 uses the microscope 50 that constitutes the alignment means. As shown in FIG. 1, one end of an L-shaped arm 51 in plan view is fixed to the surface of the holder 40 opposite to the surface fixed to the slider 41, and the optical axis is attached to the tip of the arm 51. Is fixed vertically, and a microscope 50 is fixed so that an objective lens (not shown) faces a workpiece to be held on the chuck table 21. The microscope 50 moves integrally with the spindle 35 via the holder 40, but may be configured to be driven independently.

  The surface of the workpiece is imaged by the microscope 50, and the cutting position of the cutting blade 32 is controlled based on the position information of the cutting line of the workpiece included in the captured image information. The position in the Z direction of the microscope 50 is slightly higher than the cutting edge that is the lower end of the cutting blade 32 of the rotary blade 30, and the position in the Y direction is arranged at the same position as the cutting blade 32. Imaging of the surface of the workpiece by the microscope 50 is appropriately performed by moving the table base 20 in the X direction and moving the column 43 in the Y direction after being focused by the Z direction feeding mechanism 46.

According to the cutting apparatus 1, the substrate 9 is cut as follows.
First, the surface of the substrate 9 held on the chuck table 21 is imaged by the microscope 50, the cutting line set on the substrate 9 is aligned, and the cutting position of the cutting blade 32 by the rotary blade 30 is recognized.

  Next, the table base 20 is moved in the X direction, and the rotary blade 30 is positioned on the side of the substrate 9 sucked and held on the chuck table 21 in the X direction. Further, the Z-direction feed mechanism 46 adjusts the position of the rotary blade 30 in the Z direction, and sets the cutting amount of the cutting blade 32 from the surface of the substrate 9 to a value corresponding to the cutting process. When the cutting process is grooving, the depth of cut depends on the depth of the groove or the remaining thickness after the groove is formed. The depth penetrates the pasted substrate 9 and does not reach the chuck table 21.

  On the other hand, the chuck table 21 is rotated to adjust the cutting line parallel to the X direction, and the rotary blade 30 is further moved in the Y direction so that the position of the cutting blade 32 in the Y direction matches the cutting line. The rotating blade 30 is rotated from this state, and the table base 20 is moved in the X direction approaching the rotating blade 30. As a result, the cutting blade 32 of the rotary blade 30 cuts the cutting line of the substrate 9 in the X direction from the side by a set cutting amount, and the cutting line is cut. Such a cutting operation is repeated according to the cutting line, and the cutting blade 32 of the rotary blade 30 is cut into all the cutting lines to complete the cutting process on the substrate 9.

[2] Configuration of Various Lens Devices The above is the basic configuration and operation of the cutting apparatus 1 of the present embodiment. The apparatus 1 includes an optical sensor 60 for non-contact setup of the rotary blade 30, and A lens device (recognition means) including a lens such as a blade imaging camera unit 70 for observing the state of the cutting blade 32 of the rotating blade 30 (damage such as wear or chipping) is provided. Hereinafter, these lens devices will be described.

(I) Optical Sensor An optical sensor 60 is installed at an arbitrary position on the upper surface 20a of the table base 20 (in FIG. 2, near the corner on the column 43 side and the microscope 50 side). As shown in FIG. 3, the optical sensor 60 has a pair of wall portions 62 and 63 that are arranged in the Y direction with the slit 61 interposed therebetween and that face each other. A light emitting lens 64 that emits sensor light horizontally in the direction of the other wall 63 is attached to one wall 62, and a light receiving lens that receives the sensor light emitted from the light emitting lens 64 is attached to the other wall 63. A (light receiving end) 65 is attached. The tip portions of the lenses 64 and 65 are exposed from the wall portions 62 and 63, respectively.

  According to this optical sensor 60, the rotary blade 30 is lowered and the cutting blade 32 enters the slit 61, and is in a light-shielded state, that is, the cutting edge of the cutting blade 32 blocks the sensor light, and the light receiving lens 65 receives the sensor light. The reference height position of the cutting edge of the cutting blade 32 is obtained from the height position at the time when the cutting edge has not been reached and the fixed data (for example, the height position of the upper surface 21a of the chuck table 21) that has been measured and grasped in advance. It is done. Based on this data, the position of the rotary blade 30 in the Z direction is adjusted, and the amount of cut into the substrate 9 is set.

  The optical sensor 60 is one means for obtaining the height position of the cutting edge of the rotating blade 30. Conventionally, the cutting edge is brought into contact with the metal frame of the chuck table 21 and is electrically connected to the position of the rotating blade 30. There was a contact type with the reference height position. However, since there is a possibility that an adverse effect such as damage to the blade edge due to contact with the blade edge may occur, the non-contact type as in this embodiment is considered to be more effective. In the case of the contact type, the cutting blade 32 of the rotary blade 30 was required to be made of a metal abrasive bond in order to connect with the metal part of the chuck table 21, but in the case of the non-contact type, The bond material need not be made of metal.

(II) Blade Imaging Camera Unit As shown in FIG. 2, a blade imaging camera unit 70 that images the state of the cutting blade 32 of the rotary blade 30 is attached to the blade cover 37. As shown in FIG. 4, the blade imaging camera unit 70 includes a light emitting unit 71 and a light receiving unit 81 disposed to face the light emitting unit 71.

  The light emitting unit 71 is configured to transmit the illumination light emitted from the light source 72 through the light emitting side lens 73, reflect the illumination light on the light emitting side mirror 74, and emit light toward the light receiving unit 81. The light source 72, the lens 73 and the mirror 74 are accommodated in a casing 75, and the illumination light is emitted through a transparent cover 76 attached to the casing 75.

  On the other hand, the light receiving unit 81 is configured to reflect the illumination light emitted from the light emitting unit 71 by the light receiving side mirror 84 and form an image on the camera 82 through the lens 83. Illumination light emitted from the light emitting unit 71 illuminates a side surface (side surface on the light emitting unit side) near the upper end of the cutting blade 32 of the rotary blade 30, whereby the back side of the illumination part of the camera 82 is on the cutting blade 32. Imaged as a silhouette. In the light receiving unit 81, the lens 83 and the mirror 84 are accommodated in the casing 85, and the illumination light is received through a transparent cover (light receiving end) 86 attached to the casing 85.

  Imaging by the camera 82, that is, the cutting blade 32 is enlarged and displayed on the monitor 92 through the image processing unit 91. Although the camera 82 images a part of the cutting edge portion of the cutting blade 32, the rotating blade 30 rotates, so that the entire cutting edge is imaged. For example, the entire periphery of the cutting edge 32 of the cutting blade 32 can be imaged by synchronizing the illumination and the camera 82 to take a strobe image. Then, the state of damage such as a worn state or chipping of the cutting blade 32 is confirmed by the monitor 92, and the replacement time is determined visually. Alternatively, based on the imaging data processed by the image processing unit 91, when the wear determination unit 93 determines the wear state, or the chip determination unit 94 determines the chip state, and exceeds a predetermined threshold of image data In addition, it may be configured to notify by an alarm that the rotating blade 30 is in a state of replacement.

  Now, each of the above-mentioned various lens devices includes a lens or the like that is close to the object, and these lenses and the like are in an environment where they are exposed to cutting water splashes and mist mixed with cutting waste. Specifically, the optical sensor 60 includes a light emitting lens 64 and a light receiving lens 65, and the blade imaging camera unit 70 includes a light emitting side cover 76 and a light receiving side cover 86. It is inevitable that cutting water adheres.

  In the present embodiment, a coating layer is formed on the surfaces of the light emitting lens 64 and the light receiving lens 65 of the optical sensor 60 and the covers 76 and 86 of the blade imaging camera unit 70 by coating with a coating material made of a hydrophilic material. Has been. As the hydrophilic material, a material using silicon oxide is preferable. For example, “AZ Electronic Materials: Aquamica” is suitable. A coating layer can be formed by applying such a material to each surface to form a thin film.

  Each surface on which a hydrophilic coating layer is formed is less likely to be contaminated with cutting waste or contaminated cutting water, and can be easily removed by wiping with a cloth to compare the original cleanliness. Can be maintained for a long time. This is because the cutting water adhering to the surface of the hydrophilic coating layer spreads uniformly on the surface and tends to flow, and the cutting waste flows along with such cutting water and easily drains from the surface of the coating layer. It is thought that it is from. Therefore, each surface is not easily polluted, and the pollution can be easily removed.

  As a result, in the optical sensor 60, the cutting edge position of the cutting blade 32 of the rotary blade 30 is accurately detected, and a highly accurate setup is possible. Further, in the blade imaging camera unit 70, the cutting blade 32 of the rotary blade 30 is always clearly imaged, and changes such as wear or chipping of the cutting blade 32 can be accurately determined.

  In addition, even if it is a hydrophilic coating layer, there is a limit to the pollution control effect, and depending on the operating conditions, when the actual operation time is 24 hours per day, the contamination starts to adhere in about 14 days. This has an effect on the imaging (when using the above aquamica). In other words, this period is the duration, and after this number of days, the contamination is removed and a coating material is applied again.

  When the water-repellent coating material and the antistatic coating material were used as comparative examples under the same operating conditions, it was found that the duration was 2 days for the former and 3 days for the latter. Here, the coating liquid X described in JP 2000-033338 A is used as a water-repellent coating material, and the coating material of Example 1 described in JP 2002-265860 A is used as an antistatic coating material. did. By the way, even when the coating layer was not formed, the contamination began to adhere in about 14 days, and the influence on the imaging occurred. However, the contamination was not easily removed, and some coating layer was considered necessary.

It is a perspective view showing the appearance of the cutting device concerning one embodiment of the present invention. It is a perspective view of the cutting part which a cutting device comprises. It is a figure which shows the state which detects the position of a rotary blade with the optical sensor for setup. It is a figure which shows the structure which recognizes the state of a rotary blade by a blade imaging camera unit.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cutting device, 9 ... Substrate (workpiece), 21 ... Chuck table (holding means), 30 ... Rotating blade (cutting tool), 35 ... Spindle (cutting means), 38, 39 ... Cutting water nozzle ( Cutting fluid supply means), 60 ... optical sensor (recognition means), 64 ... light emitting lens, 65 ... light receiving lens (light receiving end), 70 ... blade imaging camera unit (recognition means), 76 ... cover, 86 ... cover ( Receiving end).

Claims (3)

Holding means for holding the workpiece;
A cutting means for holding the cutting tool rotatably, and cutting the rotating cutting tool by acting on the workpiece held by the holding means;
In a cutting apparatus provided with a cutting fluid supply means for supplying a cutting fluid to a processing portion to the workpiece by the cutting tool,
A light receiving end for recognizing the state of the cutting tool is provided, a recognition means for optically recognizing the state through the light receiving end is provided, and a hydrophilic material is provided on the surface of the light receiving end. A cutting apparatus characterized in that a coating layer comprising:   The said recognition means recognizes the position of the said cutting tool, or a wear level, The said light-receiving end part is arrange | positioned in the vicinity of the outer-periphery edge part of this cutting tool. The cutting apparatus described.   The cutting apparatus according to claim 1, wherein the coating layer is made of a silicon oxide thin film.

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