JP2011218477A - Machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining device that levels a tilted holding surface.SOLUTION: The machining device includes: a chuck table mechanism including a chuck table having a holding surface for holding a workpiece and a chuck table base having a rotary shaft perpendicular to the holding surface and mounting the chuck table; a machining device for machining the workpiece held by the chuck table; a machining feed device for relatively moving the chuck table mechanism and the machining device in a machining feed direction; and an indexing device for relatively displacing the chuck table mechanism and the machining device in an indexing direction that is perpendicular to the machining feed direction. The chuck table base includes a tilt adjustment device disposed on a supporting surface for supporting the chuck table to adjust the tilt of the holding surface of the chuck table.

Description

  The present invention relates to a processing apparatus including a chuck table having a holding surface for holding a workpiece, and processing means for processing the workpiece held by the chuck table in two directions perpendicular to each other.

  For example, in the manufacturing process of a semiconductor device or an optical device, a device is formed in each region partitioned by scheduled dividing lines (streets) formed in a lattice pattern on a wafer surface such as sapphire or silicon.

  A semiconductor device or an optical device is manufactured by dividing a workpiece such as a semiconductor wafer or an optical device wafer along the planned dividing line into individual devices. The manufactured semiconductor devices and optical devices are widely used in various electric devices such as mobile phones and personal computers.

  In order to divide such a workpiece into pieces, it is disclosed in, for example, a cutting device as disclosed in JP-A-10-62596, JP-A 2009-262219, or JP-A-2009-269074. Such a laser processing apparatus is used.

  These processing apparatuses include a chuck table that rotatably holds a workpiece, a processing unit that includes a cutting blade and a laser processing head for processing the workpiece held on the chuck table, a chuck table, and a processing unit. Moving means for relatively moving the two.

  When processing along the planned division lines formed in a lattice shape, after processing along the planned division lines formed in the first direction of the workpiece held by the chuck table, the chuck table is Processing is performed along the planned dividing line formed in the second direction orthogonal to the first direction by rotating 90 degrees.

Japanese Patent Laid-Open No. 10-62596 JP 2009-262219 A JP 2009-269074 A

  However, it is very difficult to make the rotation axis of the chuck table and the holding surface strictly orthogonal when assembling the processing apparatus, and the holding surface is slightly inclined. Furthermore, the assembling accuracy of the chuck table may be deteriorated due to a change with time, unexpected contact during work or adjustment, and the holding surface may be inclined.

  When the workpiece is held by the chuck table with the holding surface tilted, for example, the cutting blade cuts into the chuck table, or the altered layer formed by the laser beam has a desired depth of the workpiece. A defect such as a defective work piece occurs without being formed at the position.

  The present invention has been made in view of these points, and an object of the present invention is to provide a machining apparatus capable of correcting a tilted holding surface horizontally.

  According to the present invention, a chuck table mechanism including a chuck table having a holding surface for holding a workpiece, a chuck table base having a rotating shaft orthogonal to the holding surface and on which the chuck table is mounted, and the chuck A processing means for processing a workpiece held by a table, a processing feed means for moving the chuck table mechanism and the processing means in a processing feed direction, and the chuck table mechanism and the processing means. An indexing and feeding means for relatively moving in an indexing and feeding direction orthogonal to the feeding direction, wherein the chuck table base is disposed on a support surface that supports the chuck table and the chuck table There is provided a processing apparatus comprising an inclination adjusting means for adjusting the inclination of the holding surface.

  Preferably, the tilt adjusting means is composed of one fixed support portion and two movable support portions.

  Preferably, the processing apparatus is configured such that the holding surface of the chuck table is tilted in a state where the chuck table is positioned so that a first direction in which the workpiece is processed by the processing means coincides with the processing feed direction. And a first storage means for storing the first operation information of the movable support portion for adjusting the holding surface horizontally, and a second orthogonal to the first direction for processing the workpiece by the processing means. The second operation of the movable support unit that detects the inclination of the holding surface of the chuck table and adjusts the holding surface horizontally in a state where the chuck table is positioned so that the direction of the machining and the processing feed direction coincide with each other A second storage means for storing information, and the movable support of the inclination adjusting means based on the first operation information stored in the first storage means when the workpiece is processed in the first direction. Actuate the part to the workpiece To when performing processing and a control means for actuating the movable support portion of the tilt adjusting means based on the second operation information stored in the second storage means.

  According to the present invention, since the support surface of the chuck table base supporting the chuck table is provided with a plurality of movable support portions, the movable support portion is based on the first or second operation information for correcting the measured inclination of the holding surface. By actuating, the inclination of the holding surface can be eliminated and the holding surface can be corrected horizontally.

It is a perspective view of a cutting device. It is a perspective view of the semiconductor wafer supported by the annular frame via the dicing tape. It is a disassembled perspective view of a chuck table mechanism. It is a perspective view of a chuck table mechanism. It is a side view which shows 1st Embodiment of the inclination detection method of a holding surface. FIG. 6A is a plan view for explaining the horizontal adjustment of the chuck table by measuring the height of three points on the holding surface, and FIG. 6B shows the height of the three points after the chuck table is rotated 90 degrees. It is a top view which measures and demonstrates the horizontal adjustment of a chuck table. It is a side view which shows the inclination detection method of 2nd Embodiment. 8A is a plan view showing a state where three chopper cut marks are formed on a silicon wafer having good flatness by the tilt detection method of the second embodiment, and FIG. 8B is a diagram in which the chuck table is rotated 90 degrees. It is a top view in the state where three chopper cut marks were formed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an appearance of a cutting apparatus 2 that can divide a semiconductor wafer suitable for mounting a chuck table (chuck table) according to an embodiment of the present invention and divide the wafer into individual chips (devices).

  On the front side of the cutting device 2, there is provided operating means 4 for an operator to input instructions to the device such as machining conditions. In the upper part of the apparatus, there is provided a display means 6 such as a CRT for displaying a guidance screen for an operator and an image taken by an imaging means described later.

  As shown in FIG. 2, on the surface of the wafer W to be diced, the first street S1 and the second street S2 are formed orthogonally, and the first street S1 and the second street S2 A plurality of devices D are partitioned and formed on the wafer W.

  The wafer W is attached to a dicing tape T that is an adhesive tape, and the outer peripheral edge of the dicing tape T is attached to an annular frame F. As a result, the wafer W is supported by the frame F via the dicing tape T, and a plurality of wafers (for example, 25 sheets) are accommodated in the wafer cassette 8 shown in FIG. The wafer cassette 8 is placed on a cassette elevator 9 that can move up and down.

  Behind the wafer cassette 8, a loading / unloading means 10 for unloading the wafer W before cutting from the wafer cassette 8 and loading the wafer after cutting into the wafer cassette 8 is disposed. Between the wafer cassette 8 and the loading / unloading means 10, a temporary placement area 12, which is an area on which a wafer to be carried in / out, is temporarily placed, is provided. Positioning means 14 for positioning at a certain position is provided.

  In the vicinity of the temporary placement area 12, transport means 16 having a turning arm that sucks and transports the frame F integrated with the wafer W is disposed, and the wafer W carried to the temporary placement area 12 is It is sucked by the transport means 16 and transported onto the chuck table 18 and is sucked by the chuck table 18 and is held on the chuck table 18 by fixing the frame F by a plurality of clamps 46.

  The chuck table 18 is configured to be rotatable and reciprocally movable in the X-axis direction. Above the movement path of the chuck table 18 in the X-axis direction, an alignment unit 20 that detects a street to be cut of the wafer W is provided. It is arranged.

  The alignment unit 20 includes an imaging unit 22 that images the surface of the wafer W, and can detect a street to be cut by a process such as pattern matching based on an image acquired by imaging. The image acquired by the imaging unit 22 is displayed on the display unit 6.

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

  The cutting means 24 is configured by mounting a cutting blade (hub blade) 28 on 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 means 22 in the X-axis direction.

  Referring to FIG. 3, an exploded perspective view of the chuck table mechanism according to the embodiment of the present invention is shown. FIG. 4 is a perspective view of the chuck table mechanism. The chuck table base (support base) 32 of the chuck table mechanism 30 has an annular support surface 34 on its upper surface.

  A central suction groove 36 and an annular suction groove 38 are formed inside the annular support surface 34, and the central suction groove 36 is connected to a negative pressure suction source via a suction hole 36a. The annular suction groove 38 is a suction hole. It is connected to a negative pressure suction source via 38a.

  The annular support surface 34 is provided with one fixed support portion 40 and two movable support portions 42, and the movable support portion 42 can be moved in the vertical direction by a driving means. The fixed support portion 40 and the two movable support portions 42 are arranged 120 degrees apart from each other in the circumferential direction. The fixed support part 40 and the movable support part 42 constitute an inclination adjusting means 44. In addition, you may comprise so that the fixed support part 40 may be moved.

  Two clamps 46 are attached to the chuck table base 32 at a distance of 180 degrees in the circumferential direction. Each clamp 46 includes a pair of parallel guide rails 48 fixed at one end to the chuck table base 32, a pair of slide members 50 movably attached along the guide rails 48, and a slide member A receiving member 52 fixed to 50, an air actuator 54 fixed to the receiving member 52, a rotating shaft (not shown) rotated 90 degrees by the air actuator 54, and an L-shaped clamp claw 56 fixed to the rotating shaft. Contains.

  By adjusting the mounting position of the slide member 50 along the guide rail 48, it is possible to cope with different sizes of the annular frame F holding the wafer. By rotating the rotating shaft by the air actuator 54, the clamp pawl 56 is rotated between the illustrated clamp position and a release position rotated 90 degrees from the clamp position.

  The chuck table 18 includes a holding portion 60 formed from porous ceramics and the like, and an annular frame body 58 formed from a metal surrounding the holding portion 60. The holding surface 60 a of the holding part 60 and the upper surface of the frame body 58 are formed flush with each other.

  When the chuck table 18 is mounted on the chuck table base 32, the chuck table 18 is supported by the fixed support portion 40 and the pair of movable support portions 42. FIG. 4 shows a perspective view of the state where the chuck table 18 is mounted on the chuck table base 32.

  Next, an inclination detection method according to the first embodiment of the present invention will be described with reference to FIGS. In the tilt detection method of the present embodiment, the contact-type height detector 62 is lowered in the Z direction so as to come into contact with the holding surface 60a, and the height of the holding surface 60a is measured at a plurality of locations to tilt the chuck table 18. Adjust.

  The height measurement position of the holding surface 60a by the contact-type height detector 62 corresponds to, for example, a fixed support portion 40 and a pair of movable support portions 42 that constitute the inclination adjusting means 44, as shown in FIG. The three points P1, P2, and P3 to be used are as follows. For example, P1 corresponds to the fixed support portion 40, and P2 and P3 correspond to the movable support portion 42.

  The contact-type height detector 62 measures the height of the holding surface 60a of the chuck table 18 at three points P1, P2, and P3, and the inclination of the holding surface 60a is calculated by the CPU of the controller from the measured values. The first operation information for driving the movable support portion 42 to adjust to be horizontal, that is, the first operation information of the movable support portion 42 for adjusting the holding surface 60a horizontally is stored in the memory of the controller.

  FIG. 6A shows a chuck table in which the first street S1 is parallel to the X-axis direction (machining feed direction) so that the cutting blade 28 performs cutting along the first street S1 of the wafer W. 18 is positioned.

  Next, as shown in FIG. 6B, after the chuck table 18 is rotated 90 degrees, the heights of the three points P1, P2, and P3 are measured again by the contact-type height detector 62. In the state shown in FIG. 6B, the second street S2 is parallel to the X-axis direction (machining feed direction) so that the cutting blade 28 performs cutting along the second street S2. The chuck table 18 is positioned.

  To input the measured height positions of the three points P1, P2, and P3 to the controller, calculate the inclination of the holding surface 60a by the CPU of the controller, and drive the movable holding unit 42 so that the holding surface 60a is horizontal. The second operation information, that is, the second operation information of the movable support portion 42 that adjusts the holding surface 60a horizontally is stored in the memory of the controller.

  When the controller of the cutting device 2 performs the cutting process along the first street S <b> 1 of the wafer W, it drives the movable support unit 42 based on the first operation information stored in the memory, and the chuck table 18. The holding surface 60a is adjusted to be horizontal.

  When cutting along the second street S2 of the wafer W, the movable support portion 42 is driven based on the second operation information stored in the memory so that the holding surface 60a of the chuck table 18 is horizontal. Adjust so that

  Instead of detecting the height of the holding surface 60a by the contact type height detector 62, the height of the holding surface 60a is set at a plurality of positions by a non-contact type height detector such as a back pressure sensor or a level. You may make it measure.

  For example, a pulse motor, a piezo element, an air cylinder, or the like can be used as a driving unit for the movable support portion 42. The operation information of the movable support section 42 is the number of pulses when the driving means is a pulse motor, the applied voltage when the driving means is a piezo element, and the supply air amount when the driving means is an air cylinder.

  Next, an inclination detection method according to the second embodiment of the present invention will be described with reference to FIGS. In this embodiment, as shown in FIG. 7, the silicon wafer SW with very good flatness is sucked and held by the chuck table 18, the cutting blade 28 is lowered in the Z direction, and the chopper cutting is performed on the silicon wafer SW by the cutting blade 28. Apply.

  As shown in FIG. 8A, the chopper cut by the cutting blade 28 is chucked so that the first direction in which the silicon wafer SW is cut by the cutting blade 28 coincides with the X-axis direction (machining feed direction). With the table 18 positioned, the silicon wafer SW is chopper-cut at three points 64A, 64B, and 64C.

  Preferably, the silicon wafer SW is chopper-cut so that the chopper cut traces of 64A correspond to the fixed support portion 40 and the chopper cut traces of 64B and 64C correspond to the movable support portion.

  Then, the outer diameter size of the cutting blade 28, the set cutting depth, and the lengths of the chopper cut marks 64A, 64B, 64C are input to the controller of the cutting apparatus 2, and the CPU of the controller 3 points 64A, 64B, 64C height positions are calculated, the inclination of the holding surface 60a is detected from these height positions, and the first operation information of the movable support 42 that adjusts the holding surface 60a to be horizontal is stored in the memory of the controller. To remember.

  Next, in a state where the chuck table 18 is rotated 90 degrees as shown in FIG. 8B so that the second direction orthogonal to the first direction is parallel to the X axis (machining feed direction), three points 64D, Chopper cut at 64E and 64F.

  The outer diameter size of the cutting blade 28, the set cutting depth and the length of the chopper cut marks 64D, 64E, 64F are input to the controller of the cutting device 2, and the height of the three points 64D, 64E, 64F is calculated by the controller CPU. Then, the inclination of the holding surface 60a is detected from these heights, and the second operation information of the movable support portion 42 for adjusting the holding surface 60a to be horizontal is stored in the memory of the controller.

  When cutting along the first street S1 of the wafer W, the wafer W is sucked and held by the chuck table 18 so that the first street S1 of the wafer W coincides with the first direction.

  And after moving the movable support part 42 based on the 1st operation | movement information memorize | stored in memory and adjusting the holding surface 60a horizontally, it cuts along the 1st street S1 with the cutting blade 28. FIG.

  When cutting along the second street S2, the chuck table 18 is rotated 90 degrees to position the second street S2 parallel to the X-axis direction (machining feed direction). Based on this, the movable support portion 42 is moved to adjust the holding surface 60a horizontally, and then cutting along the second street S2 is performed.

  In the embodiment described above, an example in which the tilt adjusting means of the present invention is applied to a cutting apparatus has been described. However, the present invention is not limited to this, and the present invention is also applicable to other processing apparatuses such as a laser processing apparatus. The tilt adjusting means can be similarly applied.

18 Chuck table 28 Cutting blade 30 Chuck table mechanism 32 Chuck table base 34 Support surface 40 Fixed support portion 42 Movable support portion 44 Tilt adjusting means 46 Clamp 60a Holding surface 62 Contact type height detectors 64A to 64F Chopper cut marks

Claims (3)

A chuck table mechanism including a chuck table having a holding surface for holding a workpiece and a chuck table base having a rotation axis orthogonal to the holding surface and on which the chuck table is mounted; and held by the chuck table Processing means for processing a workpiece, processing feed means for relatively moving the chuck table mechanism and the processing means in the processing feed direction, and the chuck table mechanism and the processing means orthogonal to the processing feed direction An indexing and feeding means for relatively moving in the indexing and feeding direction;
The processing apparatus according to claim 1, wherein the chuck table base is provided with a tilt adjusting unit that is disposed on a support surface that supports the chuck table and adjusts a tilt of the holding surface of the chuck table.   The processing apparatus according to claim 1, wherein the inclination adjusting means includes one fixed support portion and two movable support portions. The holding surface is detected by detecting the inclination of the holding surface of the chuck table in a state where the chuck table is positioned so that the first direction in which the workpiece is processed by the processing means coincides with the processing feed direction. First storage means for storing first operation information of the movable support portion for horizontally adjusting
Inclination of the holding surface of the chuck table in a state where the chuck table is positioned so that the second direction perpendicular to the first direction in which the workpiece is processed by the processing means coincides with the processing feed direction. And second storage means for storing second operation information of the movable support part for detecting the position and adjusting the holding surface horizontally,
When processing the workpiece in the first direction, the movable support portion of the tilt adjusting means is operated based on the first operation information stored in the first storage means, and the workpiece is applied to the workpiece. Control means for operating the movable support portion of the inclination adjusting means based on the second operation information stored in the second storage means when processing in the second direction;
The processing apparatus according to claim 2, comprising:

Images