JP2018094682A - Cutting process and cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting method and a cutting device that are able to allow easy check of the flatness of an annular end face and are able to cut a work piece without unstably moving a cutting blade.SOLUTION: A mount flange 32 comprises: a flange part 36 fixed to the leading end of a spindle 26 and defining an annular recess 58 on the inner periphery of an annular end face 36a and from a boss part 34; and a suction passage 64 one end of which opens in the annular recess 58 and the other end of which communicates with a suction source 72. A cutting process comprises: a leak detection step in which, after a cutting blade 28 is attached to the spindle 26, air is sucked by the suction source 72 and the presence or absence of leak of air from the annular recess 36a is detected; a spindle rotation step in which, in a case where a leak of air is not detected in the leak detection step, the spindle 26 is rotated; and a cutting step in which, after the spindle rotation step, a work piece is cut by the cutting blade 28.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a cutting method and a cutting apparatus for cutting a workpiece with a cutting blade.

  2. Description of the Related Art A cutting apparatus using a cutting blade that rotates at high speed is often used to divide a semiconductor wafer, a resin package substrate, a plate-like object such as ceramics or glass into a plurality of chips. The cutting unit of the cutting apparatus includes a spindle that is rotationally driven by a motor, a mounting flange that is attached to the tip of the spindle, a cutting blade that has a thin cutting blade attached to the mounting flange, and the cutting blade that is mounted on the mounting flange. Includes a fixing nut to fix.

  Since the cutting blade is fixed in a state where it is pressed against the annular end surface (support surface) of the flange portion of the mount flange by a fixing nut, if the annular end surface is not a flat surface, the cutting blade is fixed obliquely or rattling. Therefore, normal cutting cannot be performed.

  Moreover, since the circular base is pressed against the annular end surface of the flange portion by tightening the fixing nut, the metal powder of the circular base adheres to the annular end surface of the flange portion and the flange portion of the mounting flange of the circular base is fixed. Adhesion to the surface deteriorates over time.

  It is well known that cutting blades include a hub blade in which a cutting blade is fixed to the outer periphery of a base having a circular hub and a washer-shaped washer blade in which the entire blade is a cutting blade (grinding stone).

  In the hub blade, the base is made of an aluminum alloy, and when the workpiece is continuously cut by the hub blade, foreign matter including aluminum may adhere to the annular end surface of the mount flange.

  If the annular end face is not flat due to the adhesion of foreign matter, there is a problem that the cutting blade flutters when the spindle rotates and precise processing cannot be performed. Therefore, conventionally, the end face of the mount flange is appropriately corrected. The flatness of the annular end face was confirmed by bringing a dial gauge into contact with the annular end face of the mount flange.

JP 2009-297855 A

  However, there is a problem that it takes time and effort to set the contact needle of the dial gauge so as to contact the annular end surface of the mount flange and measure the flatness of the annular end surface.

  The present invention has been made in view of the above points, and an object of the present invention is to make it possible to more easily check the flatness of the annular end face and to cut the workpiece without flapping the cutting blade. It is to provide a method and a cutting device.

  According to the first aspect of the present invention, there is provided a cutting method in which a workpiece is cut with a cutting blade that is mounted on the tip of a spindle via a mount flange, has a fitting hole at the center, and has a cutting blade at least on the outer periphery. The mounting flange is fixed to the front end of the spindle, and is formed with a boss part into which the fitting hole of the cutting blade is fitted, and a boss part protruding in the radial direction from the rear end of the boss part. A flange portion defining an annular recess between the inner end of the annular end surface and the boss portion, and a suction path having one end opened in the annular recess and the other end communicating with a suction source The cutting hole is fitted in the boss portion of the mount flange fixed to the tip of the spindle, and the cutting blade is brought into contact with the annular end surface. Blade on the spindle A cutting blade mounting step to be worn, a suction step for sucking air by connecting the annular recess to a suction source after performing the cutting blade mounting step, and air from the annular recess during the suction step. A leak detection step for detecting the presence or absence of a leak, a spindle rotation step for rotating the spindle when no air leak is detected in the leak detection step, and a workpiece after the spindle rotation step is performed. And a cutting step for cutting with a blade.

  According to the second aspect of the present invention, the chuck table for holding the workpiece, the spindle, the mount flange fixed to the tip of the spindle, and mounted on the tip of the spindle via the mount flange, A cutting means having a cutting hole having a cutting edge formed at least on the outer peripheral portion with a fitting hole, and a cutting means for cutting a workpiece held on the chuck table; and the chuck table and the cutting means A cutting device comprising: a moving means for moving; and a control means for controlling at least the spindle and the moving means, wherein the mount flange is fixed to the tip of the spindle and the fitting of the cutting blade A boss part that fits into the hole, a boss part that projects radially from the rear end of the boss part, and has an annular end face on the front surface; And a suction passage having one end opened to the annular recess and the other end communicating with a suction source, and the cutting means includes the annular end surface and the cutting blade. Leak detection means for detecting the presence or absence of air leak, and the control means includes a spindle operation control unit that operates the spindle only when no air leak is detected by the leak detection means, and There is provided a cutting device including a spindle stop portion that stops the operation of the spindle when a leak is detected.

  In the present invention, the mount flange has an annular recess, and if there is an air leak in the annular recess, that is, if the annular end face is not flat, the spindle is not rotated, and if there is no air leak, that is, the annular end face. The workpiece is cut by rotating the spindle only when is flat.

  Therefore, since it is not necessary to set a dial gauge to confirm the flatness of the annular end face, the flatness of the annular end face can be confirmed more easily. Only when the annular end surface of the mount flange is flat, the workpiece is cut by rotating the spindle, so that the workpiece can be cut without flapping the cutting blade.

It is an external appearance perspective view of a cutting device. It is a disassembled perspective view which shows a hub blade mounting structure. It is a disassembled perspective view which shows a washer blade mounting structure. It is sectional drawing of the state which mounted | wore the hub blade via the mount flange at the front-end | tip of a spindle. It is a perspective view which shows a cutting step.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, there is shown a perspective view of a cutting apparatus provided with a leak detection means of the present invention. On the front side of the cutting apparatus 2, an operation panel 4 is provided for an operator to input instructions to the apparatus such as machining conditions. In the upper part of the apparatus, a display monitor 6 such as a CRT on which a guide screen for an operator and an image captured by an imaging unit described later are displayed is provided.

  As shown in FIG. 5, a semiconductor wafer 11 (which may be simply referred to as a wafer hereinafter) 11, which is a kind of workpiece, has a plurality of division lines 13 formed in a lattice shape on the surface. A device 15 such as an IC or an LSI is formed in each region partitioned by the predetermined division line 13.

  A plurality of wafers 11 are accommodated in a wafer cassette 8 in the form of a wafer unit 17, with the back surface of the wafer 11 attached to a dicing tape T whose outer peripheral portion is mounted on an annular frame F. The wafer cassette 8 is placed on a cassette elevator 9 that can move up and down.

  Behind the wafer cassette 8 placed on the cassette elevator 9 is a loading / unloading unit 10 for unloading the wafer unit 17 before cutting from the wafer cassette 8 and loading the wafer unit 17 after cutting into the wafer cassette 8. It is arranged.

  Between the wafer cassette 8 and the carry-in / out unit 10, a temporary placement region 12, which is a region on which the wafer unit 17 to be carried in / out, is temporarily placed, is provided. An alignment mechanism 14 comprising a pair of centering bars for aligning the center of the cassette 17 is provided.

  In the vicinity of the temporary placement region 12, a transfer unit 16 having a swivel arm that sucks and transfers the wafer unit 17 is disposed, and the wafer unit 17 that is disposed and aligned in the temporary placement region 12 includes: It is sucked by the transport unit 16 and transported onto the chuck table 18 and sucked and held on the chuck table 18.

  The chuck table 18 is configured to be rotatable and reciprocally movable in the X-axis direction by a machining feed mechanism (not shown). A region to be cut of the wafer 11 is located above the movement path of the chuck table 18 in the X-axis direction. An alignment unit 20 for detection is provided.

  The alignment unit 20 includes an imaging unit 22 including a microscope and a camera that images the surface of the wafer 11, and can detect a region to be cut by image processing such as pattern matching based on an image acquired by imaging. . The image acquired by the imaging unit 22 is displayed on the display monitor 6.

  On the left side of the alignment unit 20, a cutting unit 24 for cutting the wafer held on the chuck table 18 is disposed. The cutting unit 24 is configured integrally with the alignment unit 20, and both move together in the Y-axis direction and the Z-axis direction.

  The cutting unit 24 is configured by mounting a cutting blade 28 having a cutting edge on the outer periphery at the tip of a rotatable spindle 26 and is movable in the Y-axis direction and the Z-axis direction. The cutting blade 28 is located on the extended line of the imaging unit 22 in the X-axis direction. The movement of the cutting unit 24 in the Y-axis direction is achieved by an index feed mechanism (not shown).

  Reference numeral 27 denotes a spinner cleaning unit that cleans the wafer 11 that has been subjected to the cutting process. The wafer unit 17 that has been subjected to the cutting process is transported to the spinner cleaning unit 27 by the transport unit 25, and is subjected to spin cleaning and spin drying by the spinner cleaning unit 27. The

  Referring to FIG. 2, an exploded perspective view of a mounting structure for mounting the hub blade 28 to the tip of the spindle 26 is shown. A spindle 26 that is rotationally driven by a servo motor (not shown) is rotatably accommodated in the spindle housing 30 of the cutting unit 24. As shown in FIG. 5, the spindle 26 has a tapered portion 26a and a tip small diameter portion 26b, and a male screw is formed on the tip small diameter portion 26b.

  A mount flange 32 is attached to the tapered portion 26 a of the spindle 26. The mount flange 32 includes a boss portion 34 that fits into a fitting hole of the cutting blade 28, and a flange portion 36 that is formed to project radially from the rear end of the boss portion 34 and has an annular end surface 36 a on the front surface. Is done.

  A male screw 38 is formed on the boss portion 34. The mount flange 32 is fixed to the tapered portion 26a of the spindle 26 by fitting the nut 40 to the male screw of the small diameter end portion 26b and then tightening the nut 40 after being fitted to the tapered portion 26a of the spindle 26.

  The cutting blade 28 is called a hub blade, and is configured by electrodepositing a cutting blade 46 in which diamond abrasive grains are dispersed in a nickel base material on the outer periphery of a circular base 42 having a circular hub 44. The circular base 42 is made of an aluminum alloy.

  By inserting the fitting hole 48 of the cutting blade 28 into the boss portion 34 of the mount flange 32 and screwing and fastening the fixing nut 50 to the male screw 38 of the boss portion 34, the circular base 42 of the cutting blade 28 is mounted on the mount flange. The cutting blade 28 is mounted on the spindle 26 in pressure contact with the annular end surface 36 a of the 32 boss portions 36.

  FIG. 4 shows a cross-sectional view of the cutting blade 28 attached to the tapered portion 26a of the spindle 26. As shown in FIG. When the mount flange 32 is fixed to the tapered portion 26 a of the spindle 26, an annular recess 58 is defined between the inner periphery of the annular end surface 36 a and the boss portion 34, and the annular recess 58 is formed in the mount flange 32. The suction passage 64 is formed in the spindle 26 through the communication passage 62 and the annular communication passage 62.

  The front end (one end) of the suction path 64 is closed by a plug 66 inserted into a plug hole formed in the tip small diameter portion 26 b of the spindle 26, and the other end of the suction path 64 is a flow meter 68 and an electromagnetic switching valve 70. Is selectively connected to the suction source 72.

  Referring to FIG. 3, an exploded perspective view of a mounting structure for mounting a washer blade 52, which is a kind of cutting blade, to the spindle 26 is shown. The mounting structure of the mount flange 32 is the same as the mounting structure of the hub blade 28 shown in FIG.

  After the washer blade 52 is mounted on the boss portion 34 of the mount flange 32, the front flange (detachable flange) 54 is inserted into the boss portion, and the fixing nut 50 is screwed onto the male screw 34 of the boss portion 34 and tightened. The washer blade 52 is sandwiched between the flange portion 36 of the mount flange 32 and the front flange 54 and attached to the spindle 26.

  Next, with reference mainly to FIG. 4, the cutting method of this embodiment is demonstrated. Before starting the cutting of the workpiece, the electromagnetic switching valve 70 is switched to the communication position shown in FIG. 4 while the rotation of the spindle 26 is stopped, and the suction source 72 sucks air. Since the tip of the suction path 64 is closed by a plug 66 and the mount flange 32 is fitted to the tapered portion 26a of the spindle 26, there is no air leakage from these places.

  When the annular end surface 36a of the flange portion 36 of the mount flange 32 has sufficient flatness, the circular base 42 of the cutting blade 28 presses against the annular end surface 36a, so that the annular recess 58 has sufficient airtightness. Is kept. Therefore, since air flowing through the flow meter 68 as the leak detection means is not generated, the reading of the flow meter 68 becomes 0 (leak detection step).

  Therefore, if no leak is confirmed in the leak detection step, the spindle 26 is rotated (spindle rotation step), the spindle rotation step is performed, and then the wafer 11 is cut with the cutting blade 28 (cutting step).

  On the other hand, when the air flow exceeding the allowable value is detected by the flow meter 68, it is detected that there is an air leak from the annular recess 58 of the mount flange 32. When it is detected that there is an air leak from the annular recess 58, it is determined that the foreign matter is fixed to the annular end surface 36a and the flatness of the annular end surface 36a is not sufficiently obtained.

  In this case, the conventionally known end face correction for removing the cutting blade 28 and the mount flange 32 from the taper part 26a of the spindle 26 to obtain the flatness of the annular end face 36a of the flange part 36 of the mount flange 32 is appropriately performed.

  Although not particularly shown in FIG. 1, the cutting apparatus 2 includes a controller (cutting means) that controls each mechanism of the apparatus, and the cutting means is an air leak by a leak detection means (flow meter) 68. A spindle operation control unit that operates the spindle 26 only when no leakage is detected, and a spindle stop unit that stops the operation of the spindle 26 when an air leak is detected by the leak detection means.

  Next, with reference to FIG. 5, a cutting step of cutting the wafer 11 with the cutting blade 28 after rotating the spindle 26 when the leak detection unit does not detect air leak will be described briefly.

  Before performing the cutting step, the wafer unit 17 is sucked and held by the chuck table 18, and then the surface of the wafer 11 is imaged by the imaging unit 22 of the alignment unit 20, and the wafer 11 is divided in the first direction by image processing. Alignment is performed in which the planned line 13 and the cutting blade 28 are aligned in the processing feed direction indicated by the arrow X1. Similar alignment is performed for the planned division line 13 extending in the second direction orthogonal to the planned division line 13 extending in the first direction.

  After alignment, the cutting blade 28 that rotates at a high speed in the direction of the arrow A is cut into the predetermined dividing line 13 extending in the first direction up to the dicing tape T, and the chuck table 18 is processed and fed in the direction of the arrow X1. Then, the division grooves 21 for completely cutting the wafer 11 are formed.

  The same cutting groove along all the division lines 13 extending in the first direction while indexing and feeding the cutting unit 24 by the pitch of the division lines 13 in the Y-axis direction orthogonal to the X-axis direction shown in FIG. 21 is formed.

  Next, after the chuck table 18 is rotated by 90 °, similar cutting grooves 21 are formed along all the division lines 13 extending in the second direction orthogonal to the first direction, and the wafers 11 are individually separated. Divide into device chips.

  In the embodiment described above, the annular recess 58 formed in the mount flange 32 is communicated with the suction path 64 formed in the spindle 26. Further, the rear end of the suction path 64 is selectively connected to a suction source 72 via a flow meter 68 and an electromagnetic switching valve 70.

  In the leak detection step, when air leak is detected by the flow meter 68, the air leak is not sufficiently flat on the annular end surface 36a of the mount flange 32, and air leaks at the contact point between the annular end surface 36a and the cutting blade 28. Judge that you are doing.

  Therefore, when air leak is detected by reading the flow meter 68, it is determined that the annular end surface 36a is not sufficiently flat, the spindle 26 is not rotated, the mount flange 32 is removed from the spindle 26, and the annular end surface 36a is removed. Correct the end face.

  When the reading of the flow meter 68 is substantially zero and no air leak is detected, it is determined that the annular end surface 36a is sufficiently flat and sufficiently in pressure contact with the cutting blade 28, and the spindle 26 is rotated to remove the wafer 11 To cut.

  In the cutting method and the cutting apparatus according to the above-described embodiment, the example in which the hub blade 28 is attached to the mount flange 32 has been described. However, a washer blade that is entirely composed of a cutting blade (grinding stone) is used as the mount flange 32 instead of the hub blade 28. You may make it wear.

  In this case, the washer blade is clamped between the mount flange 32 and the detachable flange by holding the front side of the washer blade with the detachable flange and screwing the fixing nut 50 into the male screw 38 of the boss portion 34 of the mount flange 32. To be fixed.

2 Cutting device 18 Chuck table 24 Cutting unit 26 Spindle 28 Cutting blade 32 Mount flange 34 Boss part 36 Flange part 36a Annular end face 42 Circular base 46 Cutting blade 52 Washer blade 58 Annular recess 60 Communication path 62 Annular communication path 64 Suction path 68 Flow meter 72 Suction source

Claims (4)

A cutting method in which a workpiece is cut with a cutting blade that is mounted on the tip of a spindle via a mount flange, a fitting hole is formed in the center, and at least an outer peripheral portion has a cutting blade,
The mounting flange is fixed to the tip of the spindle, and is formed with a boss portion into which the fitting hole of the cutting blade fits, and a radial end surface protruding from the rear end of the boss portion, and an annular end surface on the front surface. A flange portion defining an annular recess between the inner end of the annular end surface and the boss portion, and a suction path having one end opened in the annular recess and the other end communicating with a suction source. ,
The cutting blade is fitted to the spindle in a state where the fitting hole of the cutting blade is fitted to the boss portion of the mount flange fixed to the tip of the spindle and the cutting blade is brought into contact with the annular end surface. A cutting blade mounting step to be mounted;
A suction step for sucking air by connecting the annular recess to a suction source after performing the cutting blade mounting step;
A leak detecting step for detecting the presence or absence of air leak from the annular recess during the suction step;
A spindle rotation step for rotating the spindle when no air leak is detected in the leak detection step;
A cutting step of cutting the workpiece with the cutting blade after performing the spindle rotation step;
A cutting method comprising: A chuck table for holding a workpiece, a spindle, a mount flange fixed to the tip of the spindle, and mounted on the tip of the spindle through the mount flange, and a fitting hole is formed at the center and at least A cutting blade having a cutting blade on the outer periphery, cutting means for cutting a workpiece held on the chuck table, moving means for moving the chuck table and the cutting means relative to each other, and at least the spindle And a control means for controlling the moving means,
The mount flange is fixed to the tip of the spindle, is formed with a boss part that fits into the fitting hole of the cutting blade, and projects radially from the rear end of the boss part, and has an annular end face on the front surface. A flange portion defining an annular recess between the inner periphery of the annular end surface and the boss portion, and a suction path having one end opened in the annular recess and the other end communicating with a suction source,
The cutting means includes a leak detection means for detecting the presence or absence of air leakage from the annular end face and the cutting blade,
The control means includes a spindle operation control unit that operates the spindle only when no air leak is detected by the leak detection means;
A cutting device comprising: a spindle stop portion that stops the operation of the spindle when air leak is detected by the leak detection means. The cutting blade has a base and a cutting blade disposed on the outer periphery of the base,
The cutting apparatus according to claim 2, wherein the cutting means further includes a fixing nut that holds the cutting blade together with the mount flange. The cutting blade is composed of a cutting blade having a fitting hole formed in the center,
The cutting apparatus according to claim 2, wherein the cutting means further includes a front flange that holds the cutting blade together with the mount flange, and a fixing nut that fixes the front flange.