Processing method of workpiece

Abstract

To provide a method for machining a workpiece with which it is possible to appropriately polish an end surface of the workpiece having a columnar shape.SOLUTION: A method for machining a workpiece is intended to machine an end surface of the workpiece having a columnar shape. The method includes: a workpiece unit formation step of forming a workpiece unit including a workpiece and a pair of support members interposing the workpiece therebetween; a cutting step of forming a cut surface including an end surface of the workpiece and end surfaces of the support members in the workpiece unit by causing a cutting blade to cut along a lateral surface of the workpiece unit so as to cut out an end part of the workpiece and end parts of the support members; and a polishing step of polishing the cut surface of the workpiece unit.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for machining a workpiece for machining an end face of a columnar workpiece.

Background Art

[0002] Device chips including devices are manufactured by dividing a semiconductor wafer on which a plurality of devices are formed into individual pieces. Further, a plurality of device chips are mounted on a predetermined substrate, and the mounted device chips are covered with a sealing material (mold resin) made of resin, thereby obtaining a package substrate. By dividing this package substrate into individual pieces, a packaged device including a plurality of packaged device chips is manufactured. Device chips and packaged devices are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] For dividing workpieces such as semiconductor wafers and package substrates, a cutting device is used. The cutting device includes a chuck table for holding the workpiece and a cutting unit for performing cutting on the workpiece. The cutting unit incorporates a spindle, and an annular cutting blade is attached to the tip of the spindle. The workpiece is cut and divided by holding the workpiece with the chuck table and cutting into the workpiece while rotating the cutting blade.

[0004] [[ID=二十]]Note that the cutting device has high versatility and can be used for cutting workpieces made of various materials, shapes, and structures other than semiconductor wafers and package substrates. For example, Patent Document 1 discloses a cutting device that cuts a pipe-shaped or columnar member made of a metal such as a Ni-Ti alloy with a cutting blade.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] As described above, cutting equipment can also be used to cut columnar (rod-shaped) workpieces. For example, by cutting columnar members made of glass, ceramics, resin, etc. with a cutting blade, columnar mechanical parts or optical parts of a desired length can be manufactured. Furthermore, if the resulting parts are to be used as optical parts or other parts that require a good surface finish, the end faces (cut surfaces) of the parts are polished. This removes any remaining fine irregularities on the cut surface, resulting in a mirror-like finish.

[0007] When polishing the cut surface of a columnar workpiece (part), a polishing device is used. The polishing device consists of a chuck table that holds the workpiece and a polishing unit that performs the polishing process on the workpiece. The polishing unit has a built-in spindle, and a disc-shaped polishing pad is attached to the tip of the spindle. The workpiece is held in place by the chuck table, and the workpiece is polished by rotating the polishing pad and pressing it against the workpiece.

[0008] Furthermore, it is difficult to hold a columnar workpiece by itself using a chuck table. Therefore, a method is sometimes used in which the columnar workpiece is sandwiched between a pair of support members to form a block-shaped workpiece unit in which the workpiece and support members are integrated. On the sides of the workpiece unit, the end faces of the columnar workpiece and the support members are exposed. Then, by holding the workpiece unit with a chuck table and pressing a polishing pad against the side of the workpiece unit, the end faces of the columnar workpiece are polished together with the end faces of the support members.

[0009] However, when clamping a columnar workpiece between a pair of support members, it is difficult to precisely align the end face of the columnar workpiece with the end face of the support member. As a result, the side surface of the workpiece unit cannot be made perfectly flush, and a slight step is formed between the end face of the columnar workpiece and the end face of the support member. If the side surface of the workpiece unit is polished in this state, the polishing pad will not make uniform contact with the side surface of the workpiece unit, resulting in improper polishing of the end face of the columnar workpiece and potentially causing machining defects. Consequently, the machining quality deteriorates, and the yield of parts decreases.

[0010] This invention has been made in view of the above problems, and aims to provide a method for processing a workpiece that can appropriately polish the end face of a columnar workpiece. [Means for solving the problem]

[0011] According to one aspect of the present invention, a method for processing the end face of a columnar workpiece comprises: a workpiece unit forming step of forming a workpiece unit including the workpiece and a pair of support members that sandwich the workpiece; a cutting step of forming a cut surface on the workpiece unit including the end face of the workpiece and the end face of the support members by cutting the end of the workpiece and the end of the support members by cutting along the side surface of the workpiece unit with a cutting blade; and a polishing step of polishing the cut surface of the workpiece unit. The cutting step includes: a first cutting step of cutting the end of the workpiece and the end of one of the support members by inserting the cutting blade into the workpiece unit from one of the support members with a cutting depth less than the thickness of the workpiece unit; and a second cutting step of cutting the end of the other support member by inserting the cutting blade into the workpiece unit from the other support member with a cutting depth less than the thickness of the workpiece unit. A method for processing a workpiece is provided.

[0013] Preferably, the depth of cut of the cutting blade into the workpiece unit in the second cutting step is greater than the depth of cut of the cutting blade into the workpiece unit in the first cutting step.

[0014] Preferably, in the workpiece unit formation step, the workpiece and the support member are joined via an adhesive, and in the cutting step, the workpiece unit is held in the chuck table via tape. [Effects of the Invention]

[0015] In a workpiece processing method according to one aspect of the present invention, a flat cut surface including the end face of the workpiece is formed by cutting the side of a workpiece unit, which is formed by sandwiching the workpiece between a pair of support members, with a cutting blade. This makes it possible to uniformly polish the cut surface of the workpiece unit, and the end face of the workpiece is processed appropriately. [Brief explanation of the drawing]

[0016] [Figure 1] This is a perspective view showing a cutting machine. [Figure 2] This is an exploded perspective view showing the cutting unit. [Figure 3] This is a flowchart showing the processing method for a workpiece. [Figure 4] Figure 4(A) is a perspective view showing the workpiece during the workpiece unit formation step, and Figure 4(B) is a perspective view showing the workpiece unit. [Figure 5] This is a perspective view showing a workpiece unit supported by an annular frame via tape. [Figure 6] Figure 6(A) is a partial cross-sectional side view showing the workpiece unit held by the chuck table in the first cutting step, and Figure 6(B) is a partial cross-sectional front view showing the workpiece unit being cut by the cutting blade in the first cutting step. [Figure 7] Figure 7(A) is a partial cross-sectional side view showing the workpiece unit held by the chuck table in the second cutting step, and Figure 7(B) is a partial cross-sectional front view showing the workpiece unit being cut by the cutting blade in the second cutting step. [Figure 8] This is a front view showing the workpiece unit after the cutting step. [Figure 9] This is a front view showing the workpiece unit during the polishing step. [Modes for carrying out the invention]

[0017] Hereinafter, an embodiment according to an aspect of the present invention will be described with reference to the accompanying drawings. First, a configuration example of a cutting device that can be used to implement a method for processing a workpiece according to this embodiment will be described. FIG. 1 is a perspective view showing a cutting device 2. In FIG. 1, the X-axis direction (machining feed direction, first horizontal direction, front-rear direction), the Y-axis direction (indexing feed direction, second horizontal direction, left-right direction), and the Z-axis direction (vertical direction, height direction, up-down direction) are perpendicular to each other.

[0018] The cutting device 2 includes a base 4 that supports or houses each component constituting the cutting device 2. A rectangular opening 4a is provided at the front corner of the base 4. Inside the opening 4a, a cassette support base (cassette elevator) 6 is provided. An elevating mechanism (not shown) for raising and lowering the cassette support base 6 along the Z-axis direction is connected to the cassette support base 6.

[0019] A cassette 8 is installed on the cassette support base 6. The cassette 8 is a box-shaped container capable of accommodating a plurality of workpieces 11 that are objects to be processed by the cutting device 2. In FIG. 1, only the outline of the cassette 8 is shown by a two-dot chain line.

[0020] The workpiece 11 is a columnar (bar-shaped) member used in the manufacture of components such as mechanical parts and optical parts. For example, the workpiece 11 is made of glass (such as soda glass, quartz glass, borosilicate glass, etc.), ceramics (such as alumina ceramics, etc.), semiconductors (such as single crystal silicon, etc.), resin, metal, etc., and is formed in a cylindrical shape with a predetermined diameter.

[0021] By cutting the workpiece 11 with the cutting device 2, a columnar part having a predetermined length is manufactured. For example, by cutting a cylindrical workpiece 11 made of glass or ceramics that is transparent to visible light, an optical part that can be used as an optical waveguide or the like can be obtained. However, there are no restrictions on the material, shape, and dimensions of the workpiece 11. For example, the workpiece 11 may be polygonal columnar or hollow columnar.

[0022] A rectangular opening 4b is provided to the side of the opening 4a, with its longitudinal direction aligned with the X-axis. Inside the opening 4b, a chuck table (holding table) 10 for holding the workpiece 11 is provided.

[0023] The upper surface of the chuck table 10 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes a holding surface 10a for holding the workpiece 11. For example, the holding surface 10a includes a suction surface made of a porous material such as porous ceramics. The holding surface 10a is connected to a suction source (not shown), such as an ejector, via a suction passage (not shown), a valve (not shown), etc., formed inside the chuck table 10.

[0024] A moving unit 12 is connected to the chuck table 10. For example, the moving unit 12 is a ball screw type moving mechanism and includes an X-axis ball screw (not shown) arranged along the X-axis direction and an X-axis pulse motor (not shown) that rotates the X-axis ball screw. The moving unit 12 also has a table cover 14 that surrounds the chuck table 10, and a bellows-shaped dustproof and waterproof cover 16 that can be extended and retracted along the X-axis direction is provided at the front and rear of the table cover 14. The components of the moving unit 12 (X-axis ball screw, X-axis pulse motor, etc.) are covered by the table cover 14 and the dustproof and waterproof cover 16.

[0025] The moving unit 12 moves the chuck table 10 along the X-axis direction together with the table cover 14. The chuck table 10 is also connected to a rotational drive source (not shown), such as a motor, which rotates the chuck table 10 around a rotation axis that is roughly parallel to the Z-axis direction. Furthermore, multiple clamps 18 are provided around the chuck table 10 to grip and fix the frame 19 (see Figure 5), which will be described later.

[0026] A support structure 20 is provided in the area adjacent to the opening 4b of the base 4. The upper part of the support structure 20 is positioned along the Y-axis so as to overlap with the opening 4b. A movable unit 22 is also provided on the front side of the upper part of the support structure 20. For example, the movable unit 22 is a ball screw type movable mechanism.

[0027] Specifically, the mobile unit 22 includes a pair of Y-axis guide rails 24 fixed to the front side of the support structure 20. The pair of Y-axis guide rails 24 are arranged approximately parallel to each other along the Y-axis direction. A flat Y-axis mobile plate 26 is slidably mounted on the pair of Y-axis guide rails 24.

[0028] A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 26. A Y-axis ball screw 28, which is positioned along the Y-axis direction between a pair of Y-axis guide rails 24, is screwed into this nut portion. A Y-axis pulse motor (not shown) that rotates the Y-axis ball screw 28 is connected to the end of the Y-axis ball screw 28. When the Y-axis ball screw 28 is rotated by the Y-axis pulse motor, the Y-axis moving plate 26 moves along the Y-axis guide rails 24 in the Y-axis direction.

[0029] On the front surface (front side) of the Y-axis moving plate 26, a pair of Z-axis guide rails 30 are arranged approximately parallel to each other along the Z-axis direction. A flat Z-axis moving plate 32 is slidably mounted on the pair of Z-axis guide rails 30.

[0030] A nut portion (not shown) is provided on the back side (rear side) of the Z-axis moving plate 32. A Z-axis ball screw 34, which is positioned along the Z-axis direction between a pair of Z-axis guide rails 30, is screwed into this nut portion. A Z-axis pulse motor 36, which rotates the Z-axis ball screw 34, is connected to the end of the Z-axis ball screw 34. When the Z-axis pulse motor 36 rotates the Z-axis ball screw 34, the Z-axis moving plate 32 moves along the Z-axis guide rails 30 in the Z-axis direction.

[0031] A cutting unit 38 is fixed to the lower part of the Z-axis moving plate 32 to perform cutting on the workpiece 11. The cutting unit 38 is fitted with an annular cutting blade 40. The cutting unit 38 cuts the workpiece 11 by rotating the cutting blade 40 and cutting into the workpiece 11 held by the chuck table 10.

[0032] Figure 2 is an exploded perspective view showing the cutting unit 38. The cutting blade 40 is a washer-type cutting blade (washer blade) and consists only of an annular cutting edge containing abrasive grains and a binder that fixes the abrasive grains. For example, diamond is used as the abrasive grain and resin bond is used as the binder. However, the binder may be a metal bond, vitrified bond, etc. In addition, a circular through hole 40a is provided in the center of the cutting blade 40, penetrating the cutting blade 40 in the thickness direction.

[0033] The cutting unit 38 includes a columnar housing 42. The housing 42 houses a cylindrical spindle 76 arranged along the Y-axis. The tip (one end) of the spindle 76 is exposed to the outside of the housing 42. A rotational drive source (not shown), such as a motor, is connected to the base (other end) of the spindle 76 to rotate it.

[0034] A blade mount 46 is fixed to the tip of the spindle 76. The blade mount 46 is made of a metal such as an aluminum alloy and comprises a disc-shaped flange portion 48 and a cylindrical boss portion (support shaft) 50 that protrudes from the center of the surface 48a of the flange portion 48.

[0035] An annular projection 48b is provided on the outer surface 48a side of the flange portion 48, protruding from the surface 48a. The tip surface of the projection 48b is a flat surface that is generally parallel to the surface 48a and constitutes a support surface 48c that supports the cutting blade 40. In addition, a screw groove (male thread portion) 50a is provided on the outer surface of the boss portion 50, to which the fixing nut 54 described later is fixed.

[0036] An annular retaining flange 52 is attached to the blade mount 46 to hold the cutting blade 40 in place. The retaining flange 52 is made of a metal such as an aluminum alloy, and a circular through hole 52a is provided in the center of the retaining flange 52, penetrating the flange 52 in the thickness direction.

[0037] Furthermore, an annular fixing nut 54 is fastened to the blade mount 46. A circular through hole 54a is provided in the center of the fixing nut 54, penetrating the fixing nut 54 in the thickness direction. The through hole 54a is formed to be approximately the same diameter as the boss portion 50. In addition, a screw groove (female screw portion) corresponding to the screw groove 50a of the boss portion 50 is provided on the inner circumferential surface of the fixing nut 54 that is exposed inside the through hole 54a.

[0038] When the boss portion 50 of the blade mount 46 is inserted sequentially into the through hole 40a of the cutting blade 40 and the through hole 52a of the retaining flange 52, the cutting blade 40 and the retaining flange 52 are supported by the blade mount 46. In this state, when the fixing nut 54 is screwed into the threaded groove 50a of the boss portion 50 and tightened, the cutting blade 40 and the retaining flange 52 are fixed to the blade mount 46. As a result, the cutting blade 40 is held between the flange portion 48 and the retaining flange 52 and mounted on the tip of the spindle 76 (blade mount 46).

[0039] The cutting unit 38 may also be equipped with a hub-type cutting blade (hub blade). The hub blade comprises an annular hub base made of metal or the like, and an annular cutting edge formed along the outer edge of the hub base. The cutting edge of the hub blade is made of an electroformed grinding wheel containing abrasive grains made of diamond or the like, and a binder such as a nickel plating layer that fixes the abrasive grains.

[0040] As shown in Figure 1, an imaging unit 56 is provided adjacent to the cutting unit 38 to image the workpiece 11 held by the chuck table 10. The imaging unit 56 comprises an optical microscope and an image sensor such as a CCD (Charged-Coupled Devices) sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. For example, a visible light camera or an infrared camera can be used as the imaging unit 56.

[0041] The workpiece 11 held by the chuck table 10 is imaged by the imaging unit 56, thereby acquiring an image of the workpiece 11. For example, the image is used to align the workpiece 11 and the cutting blade 40 when the cutting blade 40 is used to cut into the workpiece 11.

[0042] On the side of opening 4b opposite to opening 4a, there is an opening 4c that defines a cylindrical cleaning space (cleaning chamber). Inside opening 4c, there is a cleaning unit 58 for cleaning the workpiece 11. For example, the cleaning unit 58 includes a spinner table for holding the workpiece 11 and a nozzle for supplying cleaning fluid to the workpiece 11. The workpiece 11 is cleaned by holding it with the spinner table and supplying cleaning fluid to the workpiece 11 from the nozzle while rotating the spinner table. The cleaning fluid used can be a liquid such as pure water, or a mixed fluid which is a mixture of liquid (such as pure water) and gas (such as air).

[0043] Furthermore, the cutting device 2 includes a control unit (control unit, control device) 60 that controls the cutting device 2. The control unit 60 is connected to each component that makes up the cutting device 2 (cassette support base 6, chuck table 10, moving unit 12, clamp 18, moving unit 22, cutting unit 38, imaging unit 56, cleaning unit 58, etc.). The control unit 60 operates the cutting device 2 by generating and outputting control signals that control the operation of the components of the cutting device 2.

[0044] For example, the control unit 60 is comprised of a computer. Specifically, the control unit 60 includes a calculation unit that performs various calculations necessary for the operation of the cutting device 2, and a storage unit that stores various information (data, programs, etc.) used for the operation of the cutting device 2. The calculation unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0045] Next, a specific example of a method for processing a columnar workpiece 11 will be described. In this embodiment, the end of the columnar workpiece 11 is cut with a cutting device 2 to form a cut surface, and then the cut surface of the workpiece 11 is polished. Figure 3 is a flowchart of the processing method for the workpiece 11.

[0046] When processing a columnar workpiece 11 with a cutting device 2, first, a workpiece unit is formed including the workpiece 11 and a pair of support members that sandwich the workpiece 11 (workpiece unit formation step S1). Figure 4(A) is a perspective view showing the workpiece 11 in the workpiece unit formation step S1.

[0047] In the workpiece unit formation step S1, a columnar workpiece 11 and a pair of support members 13 and 15 are first prepared. The support members 13 and 15 are formed to be approximately the same shape and dimensions, and support one or more workpieces 11 by sandwiching them between them. Below, as an example, a case in which multiple workpieces 11 are sandwiched between the support members 13 and 15 will be described.

[0048] The support member 13 is formed in a rectangular parallelepiped shape and includes a first surface 13a and a second surface 13b that are generally parallel to each other, and a side surface 13c connected to the first surface 13a and the second surface 13b. Similarly, the support member 15 is formed in a rectangular parallelepiped shape and includes a first surface 15a and a second surface 15b that are generally parallel to each other, and a side surface 15c connected to the first surface 15a and the second surface 15b.

[0049] For example, high-rigidity substrates made of glass (soda-lime glass, quartz glass, borosilicate glass, etc.), ceramics (alumina ceramics, etc.), semiconductors (single-crystal silicon, etc.), resins, metals, etc. can be used as support members 13 and 15. However, there are no restrictions on the material and shape of the support members 13 and 15, as long as the workpiece 11 can be supported by the support members 13 and 15 and the support members 13 and 15 can be cut by the cutting blade 40 (see Figure 2).

[0050] In the workpiece unit formation step S1, multiple workpieces 11 are arranged roughly parallel to each other along the same direction and are held between support members 13 and 15. Specifically, first, support members 13 and 15 are arranged so that the first surface 13a of support member 13 and the first surface 15a of support member 15 face each other. Multiple workpieces 11 are then placed between support members 13 and 15.

[0051] The workpiece 11 is arranged such that its length aligns with the width (short side) of the first surface 13a and the first surface 15a, and its radial direction aligns with the length (long side) of the first surface 13a and the first surface 15a. In addition, multiple workpieces 11 are arranged along the length of the first surface 13a and the first surface 15a, each in contact with other adjacent workpieces 11.

[0052] Next, the multiple workpieces 11 are held between the support members 13 and 15. For example, with an adhesive such as epoxy resin applied to the first surface 13a of the support member 13 and the first surface 15a of the support member 15, the multiple workpieces 11 are held between the support members 13 and 15. This joins the workpieces 11 to the support members 13 and 15 via the adhesive. The adhesive may also be applied to the sides of the multiple workpieces 11. Furthermore, adjacent workpieces 11 may be joined and fixed to each other by the adhesive.

[0053] Figure 4(B) is a perspective view showing the workpiece unit 17. When multiple workpieces 11 are sandwiched between the support members 13 and 15, a block-shaped workpiece unit 17 comprising multiple workpieces 11 and support members 13 and 15 is formed.

[0054] The workpiece unit 17 has a first surface 17a and a second surface 17b that are generally parallel to each other. The first surface 17a corresponds to the second surface 13b of the support member 13, and the second surface 17b corresponds to the second surface 15b of the support member 15. Furthermore, the side surface of the workpiece unit 17 is formed by the end faces of the multiple workpieces 11, the side surface 13c of the support member 13, and the side surface 15c of the support member 15. That is, the end faces of the workpieces 11 are exposed on the side surface of the workpiece unit 17. Also, the sum of the diameter of the workpieces 11, the thickness of the support member 13, and the thickness of the support member 15 corresponds to the thickness of the workpiece unit 17.

[0055] The widths of the support members 13 and 15 are set to be approximately the same as the length of the workpiece 11. The support members 13 and 15 then sandwich multiple workpieces 11 so that the end faces of the workpieces 11 and the sides 13c of the support member 13 and the sides 15c of the support member 15 are positioned on approximately the same plane.

[0056] However, due to dimensional errors in the workpiece 11 and support members 13 and 15, or errors in the bonding position, the position of the end face of the workpiece 11 and the side surface 13c of the support member 13 and the side surface 15c of the support member 15 may be slightly misaligned. In this case, a slight step will be formed at the boundary between the side surface 13c of the support member 13 and the end face of the workpiece 11, and at the boundary between the side surface 15c of the support member 15 and the end face of the workpiece 11.

[0057] Next, the cutting blade 40 is used to cut along the side surface of the workpiece unit 17, thereby cutting the end of the workpiece 11 and the end of the support members 13 and 15, forming a cut surface on the workpiece unit 17 that includes the end face of the workpiece 11 and the end faces of the support members 13 and 15 (cutting step S2). In cutting step S2, the workpiece unit 17 is cut by the cutting device 2 (see Figure 1).

[0058] Figure 5 is a perspective view showing a workpiece unit 17 supported by an annular frame 19 via a tape 21. When the workpiece unit 17 is processed by the cutting device 2, the workpiece unit 17 is supported by an annular frame 19 via a tape 21 for convenience in handling (transporting, holding, etc.) the workpiece unit 17.

[0059] The frame 19 is an annular member made of a metal such as SUS (stainless steel), and a circular opening 19a is provided in the center of the frame 19, penetrating the frame 19 in the thickness direction. The diameter of the opening 19a is larger than the length and width of the workpiece unit 17 (the length and width of the support members 13 and 15).

[0060] Tape 21 is applied to the workpiece 11 and the frame 19. The tape 21 includes a circularly formed film-like base material and an adhesive layer (glue layer) provided on the base material. The base material is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate. The adhesive layer is made of an epoxy, acrylic, or rubber-based adhesive. The adhesive layer may also be made of an ultraviolet-curable resin.

[0061] For example, the workpiece unit 17 is positioned inside the opening 19a of the frame 19 such that its first surface 17a faces upward and its second surface 17b faces downward. In this state, the central part of the tape 21 is attached to the second surface 17b side of the workpiece unit 17, and the outer periphery of the tape 21 is attached to the frame 19. As a result, the workpiece unit 17 is supported by the frame 19 via the tape 21.

[0062] However, the workpiece unit 17 may be positioned so that its second surface 17b faces upward and its first surface 17a faces downward. In this case, the tape 21 is attached to the first surface 17a side of the workpiece unit 17. The workpiece unit 17 is then housed in the cassette 8 (see Figure 1) while being supported by the frame 19.

[0063] When processing the workpiece unit 17 with the cutting device 2, first, a cassette 8 containing multiple workpiece units 17 is set on the cassette support base 6. Then, the workpiece units 17 contained in the cassette 8 are transported to the chuck table 10 (see Figure 1) by a transport mechanism (not shown) and held by the chuck table 10. After that, the cutting blade 40 is rotated to cut into the workpiece units 17 held by the chuck table 10, thereby cutting the workpiece units 17.

[0064] In cutting step S2, the end face of the workpiece 11 and the end faces of the support members 13 and 15 are aligned by cutting the end of the workpiece 11 and the end of the support members 13 and 15 with the cutting blade 40. In this embodiment, the case in which cutting step S2 includes a first cutting step S21 and a second cutting step S22 will be described.

[0065] Figure 6(A) is a partial cross-sectional side view showing the workpiece unit 17 held by the chuck table 10 in the first cutting step S21. In the first cutting step S21, the workpiece unit 17 is first placed on the chuck table 10 with its first surface 17a facing upwards and its second surface 17b (tape 21 side) facing the holding surface 10a. The frame 19 (see Figure 5) is also fixed by a plurality of clamps 18 (see Figure 1). In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 10a, the workpiece unit 17 is held by the chuck table 10 via the tape 21.

[0066] Figure 6(B) is a partial cross-sectional front view showing the workpiece unit 17 being cut by the cutting blade 40 in the first cutting step S21. In the first cutting step S21, the cutting blade 40 is made to cut into the first surface 17a side (support member 13 side) of the workpiece unit 17 held by the chuck table 10, thereby cutting the end of the workpiece 11 and the end of the support member 13.

[0067] Specifically, first, the chuck table 10 is rotated to align the length direction of the workpiece unit 17 (the radial direction of the workpiece 11 and the length direction of the support members 13 and 15) with the X-axis direction. This positions the sides of the workpiece unit 17 (the end face of the workpiece 11, the side 13c of the support member 13, and the side 15c of the support member 15) approximately parallel to the X-axis direction.

[0068] Furthermore, the height (position in the Z-axis direction) of the cutting unit 38 is adjusted so that the lower end of the cutting blade 40 is positioned below the first surface 17a and above the second surface 17b. Specifically, the lower end of the cutting blade 40 is positioned below the first surface 15a of the support member 15. The difference in height between the first surface 17a of the workpiece unit 17 and the lower end of the cutting blade 40 at this time corresponds to the depth of cut by the cutting blade 40 into the workpiece unit 17 in the first cutting step S21.

[0069] Furthermore, the position of the cutting unit 38 in the Y-axis direction is adjusted so that the cutting blade 40 overlaps with the side of the workpiece unit 17 when viewed from the front. At this time, the distance in the Y-axis direction between the side of the workpiece unit 17 (end face of the workpiece 11, side 13c of the support member 13, side 15c of the support member 15) and the side of the cutting blade 40 on the workpiece unit 17 side corresponds to the cutting width W1 of the cutting blade 40 into the workpiece unit 17 in the first cutting step S21.

[0070] Then, while rotating the cutting blade 40, the chuck table 10 is moved along the X-axis. This causes the chuck table 10 and the cutting blade 40 to move relative to each other along the X-axis. As a result, the cutting blade 40 cuts along the side of the workpiece unit 17 with a cutting depth less than the thickness of the workpiece unit 17, and the side of the workpiece unit 17 is cut.

[0071] As described above, in the first cutting step S21, the cutting blade 40 is made to cut from the first surface 17a side (support member 13 side) of the workpiece unit 17 to the support member 15. As a result, the end of the workpiece 11 and the end of the support member 13 are cut, and a first cut surface 17c is formed on the workpiece unit 17.

[0072] The first cutting surface 17c includes the end face (cut surface) 11a of the workpiece 11 and the end face (cut surface) 13d of the support member 13, both formed by the cutting blade 40. The first cutting surface 17c is formed flush with the surface, and the end face 11a of the workpiece 11 and the end face 13d of the support member 13 are formed on approximately the same plane. In this way, by cutting the workpiece 11 and the support member 13 simultaneously, the positions of the end face 11a of the workpiece 11 and the end face 13d of the support member 13 are aligned.

[0073] The workpiece unit 17, cut by the cutting blade 40, is transported to a cleaning unit 58 (see Figure 1) by a transport mechanism (not shown) and cleaned by the cleaning unit 58. After that, the workpiece 11 is transported to a cassette 8 (see Figure 1) by a transport mechanism (not shown) and placed back into the cassette 8.

[0074] Next, the workpiece unit 17 is inverted. Specifically, after peeling the workpiece unit 17 from the tape 21, the tape 21 is attached to the first surface 17a side of the workpiece unit 17. As a result, the workpiece unit 17 is supported by the frame 19 (see Figure 5) via the tape 21, with the first surface 17a side fixed to the tape 21 and the second surface 17b side exposed upwards. After that, the second cutting step S22 is performed in the same procedure as the first cutting step S21.

[0075] Figure 7(A) is a partial cross-sectional side view showing the workpiece unit 17 held by the chuck table 10 in the second cutting step S22. In the second cutting step S22, the workpiece unit 17 is first placed on the chuck table 10 with the second surface 17b facing upwards and the first surface 17a (tape 21 side) facing the holding surface 10a. The frame 19 (see Figure 5) is also fixed by a plurality of clamps 18 (see Figure 1). In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 10a, the workpiece unit 17 is held by the chuck table 10 via the tape 21.

[0076] Figure 7(B) is a partial cross-sectional front view showing the workpiece unit 17 being cut by the cutting blade 40 in the second cutting step S22. In the second cutting step S22, the cutting blade 40 is made to cut into the second surface 17b side (support member 15 side) of the workpiece unit 17 held by the chuck table 10, thereby cutting the end of the support member 15 that was not cut in the first cutting step S21.

[0077] Specifically, first, the chuck table 10 is rotated to align the length direction of the workpiece unit 17 (the radial direction of the workpiece 11 and the length direction of the support members 13 and 15) with the X-axis direction. This positions the sides of the workpiece unit 17 (the first cutting surface 17c and the side 15c of the support member 15) approximately parallel to the X-axis direction.

[0078] Furthermore, the height (position in the Z-axis direction) of the cutting unit 38 is adjusted so that the lower end of the cutting blade 40 is positioned below the second surface 17b and above the first surface 17a. Specifically, the lower end of the cutting blade 40 is positioned below the area of ​​the workpiece unit 17 that was not cut in the first cutting step S21 (remaining area).

[0079] More specifically, a portion (protrusion) remains on the side of the support member 15, extending from the first cut surface 17c. The lower end of the cutting blade 40 is positioned below the lower end of the protrusion. The height difference between the second surface 17b of the workpiece unit 17 and the lower end of the cutting blade 40 at this time corresponds to the depth of cut by the cutting blade 40 into the workpiece unit 17 in the second cutting step S22.

[0080] Furthermore, the position of the cutting unit 38 in the Y-axis direction is adjusted so that the cutting blade 40 overlaps with the side of the workpiece unit 17 when viewed from the front. At this time, the distance in the Y-axis direction between the side of the workpiece unit 17 (side 15c of the support member 15) and the side of the cutting blade 40 on the workpiece unit 17 side corresponds to the cutting width W2 of the cutting blade 40 into the workpiece unit 17 in the second cutting step S22.

[0081] Furthermore, it is preferable that the cutting width W2 of the cutting blade 40 into the workpiece unit 17 in the second cutting step S22 is greater than the cutting width W1 of the cutting blade 40 into the workpiece unit 17 in the first cutting step S21 (see Figure 6(B)). In this case, in the second cutting step S22, the cutting blade 40 is positioned further inside the workpiece unit 17 than in the first cutting step S21.

[0082] Then, while rotating the cutting blade 40, the chuck table 10 is moved along the X-axis. This causes the chuck table 10 and the cutting blade 40 to move relative to each other along the X-axis. As a result, the cutting blade 40 cuts along the side of the workpiece unit 17 with a cutting depth less than the thickness of the workpiece unit 17, and the side of the workpiece unit 17 is cut.

[0083] As described above, in the second cutting step S22, the cutting blade 40 is made to cut into the workpiece unit 17 from the second surface 17b side (support member 15 side). As a result, the end of the support member 15 that remained uncut in the first cutting step S21 is cut and removed. As a result, a second cut surface 17d is formed on the workpiece unit 17. The second cut surface 17d corresponds to the end surface (cut surface) 15d of the support member 15 formed by the cutting blade 40.

[0084] The workpiece unit 17, cut by the cutting blade 40, is transported to a cleaning unit 58 (see Figure 1) by a transport mechanism (not shown) and cleaned by the cleaning unit 58. After that, the workpiece 11 is transported to a cassette 8 (see Figure 1) by a transport mechanism (not shown) and placed back into the cassette 8.

[0085] The machining conditions in the first cutting step S21 and the second cutting step S22 are set appropriately according to the material, dimensions, etc., of the workpiece unit 17. For example, a cylindrical member made of alumina ceramics (2.3 mm in diameter, 40 mm in length) is used as the workpiece 11, and rectangular parallelepiped substrates made of soda glass (40 mm in length, 12.4 mm in width, 13.8 mm in thickness) are used as the support members 13 and 15. In this case, the rotational speed of the cutting blade 40 (rotational speed of the spindle 44) can be set to 6000 rpm, and the machining feed rate can be set to 0.5 mm / s.

[0086] Figure 8 is a front view showing the workpiece unit 17 after the cutting step S2. When the cutting step S2 is performed, a first cutting surface 17c and a second cutting surface 17d are formed on the side of the workpiece unit 17. The first cutting surface 17c and the second cutting surface 17d are formed flush with each other, and the second cutting surface 17d is formed further inside the workpiece unit 17 (on the right side in Figure 8) than the first cutting surface 17c.

[0087] Although the above description explains the case where the workpiece unit 17 is held by the chuck table 10 via the tape 21, there are no restrictions on the method of holding the workpiece unit 17. For example, the workpiece unit 17 may be fixed to a predetermined support substrate with wax, and the workpiece unit 17 may be held by the chuck table 10 via the support substrate. In this case, after the cutting of the workpiece unit 17 is completed, the wax is melted by heat treatment, and the workpiece unit 17 is separated from the support substrate.

[0088] However, if the workpiece 11 and the support members 13 and 15 are joined via an adhesive, applying heat treatment to the wax may simultaneously heat and liquefy the adhesive, causing the workpiece 11 and the support members 13 and 15 to separate. For this reason, it is preferable to use tape 21 to hold the workpiece unit 17.

[0089] Here, when the workpiece unit 17 is held by the chuck table 10 via the tape 21, when the cutting blade 40 cuts into the workpiece unit 17, the flexible adhesive layer contained in the tape 21 deforms due to the machining load applied to the workpiece unit 17, and the position of the workpiece unit 17 may change. In particular, when the cutting blade 40 cuts with a depth exceeding the thickness of the workpiece unit 17, the contact area between the cutting blade 40 and the workpiece unit 17 increases, and the machining load applied to the workpiece unit 17 increases. As a result, the position of the workpiece unit 17 changes significantly during cutting, making it difficult to form a flat cut surface of the workpiece unit 17.

[0090] On the other hand, if the cutting step S2 is divided into a first cutting step S21 and a second cutting step S22 as described above, the cutting depth of the cutting blade 40 can be set to less than the thickness of the workpiece unit 17 (see Figures 6(B) and 7(B)). As a result, the contact area between the cutting blade 40 and the workpiece unit 17 is kept small, and the machining load applied to the workpiece unit 17 is reduced. Consequently, the position of the workpiece unit 17 is less likely to fluctuate, and flat first and second cutting surfaces 17c and 17d are formed.

[0091] Furthermore, after using the cutting blade 40 for a certain period of time, the tip of the cutting blade 40 may wear down and become rounded (R-shaped), and this R-shape of the cutting blade 40 may be reflected in the workpiece unit 17. Therefore, when cutting with the cutting blade 40 to a depth exceeding the thickness of the workpiece unit 17, it is necessary to cut deeply into the tape 21 with the cutting blade 40 so that the tip of the cutting blade 40 does not come into contact with the workpiece unit 17.

[0092] In order to increase the cutting depth of the cutting blade 40 into the tape 21, it is necessary to form a thicker adhesive layer on the tape 21. However, when the adhesive layer of the tape 21 is thicker, the adhesive layer easily deforms during cutting, and the position of the workpiece unit 17 tends to fluctuate. As a result, it becomes difficult to make the cut surface of the workpiece unit 17 flat.

[0093] On the other hand, if the cutting step S2 is divided into a first cutting step S21 and a second cutting step S22, it is not necessary to cut into the tape 21 with the cutting blade 40. Furthermore, even if the R shape of the cutting blade 40 is reflected at the lower end of the first cut surface 17c in the first cutting step S21, the area of ​​the first cut surface 17c in which the R shape is reflected can be removed in the subsequent second cutting step S22. This prevents the adhesive layer of the tape 21 from becoming thicker and suppresses fluctuations in the position of the workpiece unit 17.

[0094] Furthermore, if the cutting width W2 (see Figure 7(B)) of the cutting blade 40 into the workpiece unit 17 in the second cutting step S22 is made larger than the cutting width W1 (see Figure 6(B)) of the cutting blade 40 into the workpiece unit 17 in the first cutting step S21, even if the position of the workpiece unit 17 fluctuates to some extent in the second cutting step S22, it is possible to avoid the second cutting surface 17d protruding outside the workpiece unit 17 beyond the first cutting surface 17c. This prevents the polishing of the end face 11a of the workpiece 11 from being hindered by the second cutting surface 17d in the polishing step S3 described later. However, if the workpiece unit 17 is cut under processing conditions in which fluctuations in the position of the workpiece unit 17 are unlikely to occur, the cutting widths W1 and W2 may be set to the same value.

[0095] Next, the cutting surface of the workpiece unit 17 is polished (polishing step S3). Figure 9 is a front view showing the workpiece unit 17 in polishing step S3.

[0096] For example, in polishing step S3, the workpiece unit 17 is polished using a polishing device 70. The polishing device 70 includes a chuck table (holding table) 72 for holding the workpiece unit 17 and a polishing unit 74 for polishing the workpiece unit 17.

[0097] The upper surface of the chuck table 72 is a flat surface that is generally parallel to the horizontal plane and constitutes a holding surface 72a for holding the workpiece unit 17. For example, the holding surface 72a includes a suction surface made of a porous material such as porous ceramics. The holding surface 72a is connected to a suction source (not shown), such as an ejector, via a suction passage (not shown), a valve (not shown), etc., formed inside the chuck table 72.

[0098] The chuck table 72 is connected to a moving mechanism (not shown) that moves the chuck table 72 along the horizontal direction. The moving mechanism could be a ball screw type mechanism or a turntable that supports and rotates the chuck table 72. Furthermore, the chuck table 72 is connected to a rotational drive source (not shown), such as a motor, that rotates the chuck table 72 around a rotation axis approximately parallel to the vertical direction.

[0099] A polishing unit 74 is provided above the chuck table 72. The polishing unit 74 includes a cylindrical spindle 76 arranged along the Z-axis. A disc-shaped mount 78 made of metal or the like is fixed to the tip (lower end) of the spindle 76. A rotational drive source (not shown), such as a motor, is connected to the base (upper end) of the spindle 76.

[0100] A polishing pad 80 for polishing the workpiece unit 17 is mounted on the lower side of the mount 78. For example, the polishing pad 80 is fixed to the mount 78 by fasteners such as bolts. The polishing pad 80 rotates around a rotation axis that is roughly parallel to the vertical direction by power transmitted from the rotation drive source via the spindle 76 and the mount 78.

[0101] The polishing pad 80 comprises a disc-shaped base 82 made of a metal such as stainless steel or aluminum, and a disc-shaped polishing layer 84 fixed to the lower surface of the base 82. The polishing layer 84 is formed to be approximately the same diameter as the base 82 and is fixed to the lower surface of the base 82 by adhesive or the like. The lower surface of the polishing layer 84 forms a flat polishing surface that contacts the workpiece unit 17 and polishes the workpiece unit 17.

[0102] The abrasive layer 84 is formed by incorporating abrasive grains made of silicon oxide (SiO2), green carborundum (GC), white alundum (WA), etc., into a base material made of nonwoven fabric, foamed urethane, etc. For example, abrasive grains with an average particle size of 0.1 μm or more and 10 μm or less are used. However, the material of the abrasive layer 84, the material of the abrasive grains, the particle size of the abrasive grains, etc., can be appropriately selected according to the material of the object to be polished, etc.

[0103] In polishing step S3, the workpiece unit 17 is first peeled off the tape 21 (see Figure 5, etc.) and fixed to the support substrate 23. For example, a disc-shaped, high-rigidity substrate is prepared as the support substrate 23, and the side of the workpiece unit 17 opposite to the first cut surface 17c and the second cut surface 17d (the bottom surface in Figure 9) is fixed to the support substrate 23 via adhesive or the like. The material of the support substrate 23 is the same as that of the support members 13 and 15. However, there are no restrictions on the shape and material of the support substrate 23 as long as it can support the workpiece unit 17.

[0104] Next, the workpiece unit 17 is held by the chuck table 72. Specifically, the workpiece unit 17 is positioned on the chuck table 72 such that the first cutting surface 17c and the second cutting surface 17d are exposed upwards, and the lower surface of the support substrate 23 faces the holding surface 72a. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 72a, the workpiece unit 17 is held by the chuck table 72 via the support substrate 23.

[0105] Next, the chuck table 72 is positioned below the polishing unit 74. At this time, the positional relationship between the chuck table 72 and the polishing pad 80 is adjusted so that the polishing layer 84 overlaps with the entire first cut surface 17c. Then, while rotating the chuck table 72 and the polishing pad 80, the polishing pad 80 is lowered and the polishing layer 84 is pressed against the first cut surface 17c of the workpiece unit 17. As a result, the end face 11a of the workpiece 11 is polished together with the end face 15d of the support member 15. As a result, any remaining fine irregularities on the end face 11a of the workpiece 11 are removed, and the end face 11a is made mirror-like.

[0106] During polishing of the workpiece unit 17, a polishing solution that does not contain abrasive particles is supplied to the workpiece unit 17 and the polishing pad 80. As the polishing solution, for example, an acidic polishing solution, an alkaline polishing solution, or pure water can be used. As an acidic polishing solution, an acidic solution containing permanganate or the like can be used, and as an alkaline polishing solution, an alkaline solution containing sodium hydroxide or potassium hydroxide can be used.

[0107] If the polishing layer 84 does not contain abrasive grains, a slurry containing abrasive grains may be supplied to the workpiece unit 17 and the polishing pad. For example, the slurry may contain free abrasive grains made of silicon oxide (SiO2), alumina (Al2O3), etc.

[0108] Furthermore, the workpiece unit 17 may be processed by dry polishing. In this case, no liquid (polishing solution) such as slurry or pure water is supplied to the workpiece unit 17 or the polishing pad 80 during polishing.

[0109] In this way, the end face 11a of the workpiece 11 is polished and made flat. Note that in the aforementioned cutting step S2, the workpiece 11 and the support member 13 are cut simultaneously by the cutting blade 40 (see Figure 6(A)), so the end face 11a of the workpiece 11 and the end face 13d of the support member 13 are located on the same plane. Also, the second cutting surface 17d is positioned inside (below in Figure 9) the first cutting surface 17c. Therefore, in the polishing step S3, the polishing pad 80 makes uniform contact with the entire first cutting surface 17c, but does not come into contact with the second cutting surface 17d. As a result, the end face 11a of the workpiece 11 is polished uniformly without excess or deficiency, improving the processing quality.

[0110] As described above, in the workpiece processing method according to this embodiment, a flat first cut surface 17c including the end face 11a of the workpiece 11 is formed by cutting the side of the workpiece unit 17, which is formed by sandwiching the workpiece 11 between a pair of support members 13 and 15, with a cutting blade 40. This makes it possible to uniformly polish the first cut surface 17c of the workpiece unit 17, and the end face 11a of the workpiece 11 is processed appropriately.

[0111] In this embodiment, a configuration in which the workpiece unit 17 is cut in two stages in cutting step S2 has been described (see Figures 6(B) and 7(B)). However, if there is no impact on the machining quality, multiple workpieces 11 and support members 13, 15 may be cut all at once in cutting step S2.

[0112] For example, if the workpiece 11 and support members 13 and 15 are made of easily machinable material, and cutting the workpiece unit 17 with the cutting blade 40 does not place a large machining load on the workpiece unit 17, the cutting blade 40 may be made to cut into the workpiece unit 17 with a cutting depth exceeding the thickness of the workpiece unit 17. In this case, a cut surface is formed that includes the end face 11a of the workpiece 11, the end face 13d of the support member 13, and the end face 15d of the support member 15 on the same plane.

[0113] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of symbols]

[0114] 11 Workpiece 11a End surface (cut surface) 13 Support Member 13a 1st page 13b Side 2 13c side 13d End surface (cut surface) 15 Support member 15a 1st page 15b Side 2 15c side 15d End surface (cut surface) 17 Workpiece Unit 17a 1st page 17b Side 2 17c 1st cutting plane 17d 2nd cutting plane 19 frames 19a aperture 21 Tapes 23 Support substrate 2 Cutting equipment 4 bases 4a,4b,4c opening 6. Cassette support stand (cassette elevator) 8 cassettes 10. Chuck table (holding table) 10a Holding surface 12 Mobile Units 14 Table Covers 16 Dustproof and splashproof cover 18 clamps 20 Support structure 22 Mobile Units 24 Y-axis guide rails 26 Y-axis moving plate 28 Y-axis ball screw 30 Z-axis guide rail 32 Z-axis moving plate 34 Z-axis ball screw 36 Z-axis pulse motor 38 Cutting Units 40 cutting blades 40a through hole 42 Housing 44 spindles 46 Blade Mount 48 Flange section 48a surface 48b Convex part 48c support surface 50 Boss section (support shaft) 50a Screw groove (male thread portion) 52 Retaining flange 52a through hole 54 Fixing nut 54a through hole 56 Imaging Unit 58 Washing Unit 60 Control Unit (Control Unit, Control Device) 70 Polishing equipment 72 Chuck Table (Holding Table) 72a Holding surface 74 Polishing Units 76 spindles 78 mount 80 polishing pads 82 base 84 Polishing layer

Claims

1. A method for processing the end face of a columnar workpiece, A workpiece unit forming step, which includes the workpiece and a pair of support members that sandwich the workpiece, A cutting step in which a cutting blade is made to cut along the side surface of the workpiece unit to cut the end of the workpiece and the end of the support member, thereby forming a cut surface on the workpiece unit that includes the end face of the workpiece and the end face of the support member, The polishing step includes polishing the cut surface of the workpiece unit, The cutting step is, A first cutting step involves cutting the end of the workpiece and the end of one of the support members by inserting the cutting blade into the workpiece unit from one of the support members with a cutting depth less than the thickness of the workpiece unit, A method for processing a workpiece, comprising: a second cutting step of cutting the end of the other support member by inserting the cutting blade into the workpiece unit from the other support member side with a cutting depth less than the thickness of the workpiece unit.

2. The method for machining a workpiece according to claim 1, characterized in that the cutting width of the cutting blade into the workpiece unit in the second cutting step is greater than the cutting width of the cutting blade into the workpiece unit in the first cutting step.

3. In the workpiece unit formation step, the workpiece and the support member are joined together via an adhesive. The method for machining a workpiece according to claim 1 or 2, characterized in that the workpiece unit is held in a chuck table via tape during the cutting step.

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