JP2016203290A - Machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining device capable of achieving efficient machining.SOLUTION: A machining device (2) includes: a chuck table (12); machining means (24, 26, 28, 50); and machining feeding means (14) for feeding the machining means for machining. Each of the machining means includes: a spindle housing (30) for supporting a spindle (34) to which a machining tool (42) is attached; a holder (24) to which the spindle housing is attached; inclination control means (26) for controlling inclination of the spindle housing between the holder and the spindle housing; and control means (50) for controlling each component. The inclination control means includes load detection means (44a) and inclination adjustment means (44b) constituted of a piezoelectric element. When a workpiece (11) is machined, the control means elongates and contracts the inclination adjustment means by applying voltage corresponding to the load detected by the load detection means to the piezoelectric element of the inclination adjustment means so as to control the inclination of the spindle housing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a processing apparatus for grinding or polishing a plate-shaped workpiece.

  In recent years, in order to manufacture a small and light semiconductor chip, it is required to thinly process a wafer made of a material such as silicon. For example, the wafer can be thinned by grinding or polishing the wafer by rotating a grinding wheel including a grinding wheel or a polishing pad made of a nonwoven fabric and pressing the grinding pad.

  By the way, when grinding or polishing a plate-like workpiece such as a wafer, a machining tool such as a grinding wheel or a polishing pad is usually slightly inclined with respect to a chuck table that holds the workpiece. (For example, refer to Patent Document 1). By adjusting this inclination, the load applied to the workpiece from the machining tool can be controlled.

JP 2013-4726 A

  The inclination of the processing tool with respect to the chuck table described above is adjusted based on the thickness of the workpiece after processing. For example, in a region where a load is easily applied during machining, the workpiece is relatively thin. Therefore, if you want to make the load uniform over the entire workpiece surface, the machining tool will work in the relatively thin region. Adjust the tilt away from the

  However, in this adjustment, since it is necessary to actually process the workpiece and measure the thickness, it is not always possible to realize efficient machining. The present invention has been made in view of such problems, and an object of the present invention is to provide a machining apparatus capable of realizing efficient machining.

  According to the present invention, a chuck table for holding a workpiece, a processing means on which a processing tool for grinding or polishing the workpiece held on the chuck table is rotatably mounted, and the processing means as a chuck table. A machining feed means for machining and feeding in a direction perpendicular to the holding surface, the machining means comprising: a spindle housing that rotatably supports a spindle on which the machining tool is mounted; A tilt control unit including a holder to which the spindle housing is mounted, an inclination control unit that is interposed between the holder and the spindle housing, and controls the tilt of the spindle housing; and a control unit that controls each component. The means includes a load detecting means and an inclination adjusting means comprising a piezoelectric element, and supports the spindle housing at three or more locations, and the control means When processing the workpiece by processing the processing means, a voltage corresponding to the load detected by the load detecting means is applied to the piezoelectric element of the tilt adjusting means to expand and contract the tilt adjusting means. Thus, there is provided a machining apparatus that controls the inclination of the spindle housing to adjust the load applied from the machining tool to the workpiece surface of the workpiece.

  In the present invention, the processing tool is preferably a grinding wheel or a polishing pad.

  In the present invention, it is preferable that the load detecting means of the inclination control means is constituted by a piezoelectric element.

  The processing apparatus according to the present invention includes an inclination control means including an inclination adjustment means and a load detection means made of a piezoelectric element between the holder and the spindle housing, and therefore according to the load detected by the load detection means. By applying the applied voltage to the piezoelectric element of the tilt adjusting means to expand and contract the tilt adjusting means, it is possible to control the tilt of the spindle housing and adjust the load applied from the processing tool to the work surface of the work piece.

  That is, in the processing apparatus according to the present invention, the load can be detected and adjusted during processing of the workpiece, so that it is not necessary to actually process the workpiece and measure the thickness as in the conventional case. Therefore, the processing of the workpiece is made efficient. Thus, according to this invention, the processing apparatus which can implement | achieve an efficient process can be provided.

It is a figure which shows a grinding device typically. It is a disassembled perspective view which shows a holder, an inclination control unit, and a processing unit typically. 3A is a perspective view schematically showing a workpiece, and FIG. 3B is a perspective view schematically showing a state in which a protective member is attached to the workpiece. (C) is sectional drawing which shows a mode that a protection member is affixed on a to-be-processed object typically. It is a figure which shows typically a mode that a to-be-processed object is ground. It is a figure which shows typically the structural example of a grinding | polishing apparatus.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing the structure of a grinding apparatus (processing apparatus) according to this embodiment. As shown in FIG. 1, the grinding device (processing device) 2 includes a rectangular parallelepiped base 4 on which each structure is mounted. A wall-like support structure 6 extending upward is provided at the rear end of the base 4.

  A rectangular opening 4 a that is long in the X-axis direction (front-rear direction) is formed on the upper surface of the base 4. In this opening 4a, there are provided an X-axis moving table 8, an X-axis moving mechanism (not shown) for moving the X-axis moving table 8 in the X-axis direction, and a dustproof and drip-proof cover 10 that covers the X-axis moving mechanism. Yes.

  The X-axis movement mechanism includes a pair of X-axis guide rails (not shown) parallel to the X-axis direction, and an X-axis movement table 8 is slidably attached to the X-axis guide rails. A nut portion (not shown) is provided on the lower surface side of the X-axis moving table 8, and an X-axis ball screw (not shown) parallel to the X-axis guide rail is screwed to the nut portion.

  An X-axis pulse motor (not shown) is connected to one end of the X-axis ball screw. By rotating the X-axis ball screw with the X-axis pulse motor, the X-axis moving table 8 moves in the X-axis direction along the X-axis guide rail.

  On the X-axis moving table 8, there is provided a chuck table 12 that sucks and holds the workpiece 11 (see FIGS. 3 and 4). The chuck table 12 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis that is substantially parallel to the Z-axis direction (vertical direction). Further, the chuck table 12 moves in the X-axis direction together with the X-axis moving table 8 by the above-described X-axis moving mechanism.

  The upper surface of the chuck table 12 is a holding surface 12 a that sucks and holds the workpiece 11. The holding surface 12a is connected to a suction source (not shown) through a flow path (not shown) formed inside the chuck table 12. The workpiece 11 is sucked and held on the chuck table 12 by the negative pressure of the suction source acting on the holding surface 12a.

  On the front surface of the support structure 6, a Z-axis moving mechanism (processing feed means) 14 is provided. The Z-axis movement mechanism 14 includes a pair of Z-axis guide rails 16 parallel to the Z-axis direction, and a Z-axis movement plate 18 is slidably attached to the Z-axis guide rails 16.

  A nut portion (not shown) is provided on the rear surface side (back surface side) of the Z-axis moving plate 18, and a Z-axis ball screw 20 parallel to the Z-axis guide rail 16 is screwed into the nut portion. Yes. A Z-axis pulse motor 22 is connected to one end of the Z-axis ball screw 20. By rotating the Z-axis ball screw 20 by the Z-axis pulse motor 22, the Z-axis moving plate 18 moves in the Z-axis direction along the Z-axis guide rail 16.

  A holder (processing means) 24 that protrudes forward is provided on the front surface (front surface) of the Z-axis moving plate 18. A processing unit (processing means) 28 is mounted on the holder 24 via an inclination control unit (tilt control means, processing means) 26.

  FIG. 2 is an exploded perspective view schematically showing the holder 24, the tilt control unit 26, and the processing unit 28. As shown in FIG. 2, a circular through hole 24 a that vertically penetrates the holder 24 is provided at the center of the holder 24. A cylindrical spindle housing 30 constituting the processing unit 28 is inserted into the through hole 24a from above.

  An annular flange 32 is provided on the side surface 30 a of the spindle housing 30. The outer diameter of the flange 32 is larger than the diameter of the through hole 24a. In addition, the flange portion 32 is provided with a plurality of (four in this embodiment) through holes 32a penetrating the flange portion 32 in the vertical direction at substantially equal angular intervals.

  Inside the spindle housing 30, a spindle 34 that constitutes a rotation shaft is accommodated. A lower end portion of the spindle 34 is exposed to the outside of the spindle housing 30. A disc-shaped mount 36 is fixed to the lower end portion of the spindle 34. A grinding wheel 38 having substantially the same diameter as the mount 36 is mounted on the lower surface of the mount 36.

  The grinding wheel 38 includes a wheel base 40 formed of a metal material such as aluminum or stainless steel. A plurality of grinding wheels (processing tools) 42 are arranged in an annular shape on the lower surface of the wheel base 40. A rotation drive source (not shown) such as a motor is connected to the upper end side of the spindle 34. The grinding wheel 38 is rotated by the rotational force transmitted from the rotational drive source.

  In a state where the spindle housing 30 is inserted into the through hole 24a, an inclination control unit 26 is disposed between the holder 24 and the flange portion 32. The tilt control unit 26 includes a plurality of (four in this embodiment) actuators 44 with load sensors formed in a cylindrical shape. The actuator 44 with a load sensor includes, for example, a load sensor unit (load detection unit) 44a and an actuator unit (tilt adjustment unit) 44b.

The load sensor unit 44a and the actuator unit 44b are configured by, for example, piezoelectric elements. The piezoelectric element is made of a material such as barium titanate (BaTiO ₃ ), lead zirconate titanate (Pb (Zi, Ti) O ₃ ), lithium niobate (LiNbO ₃ ), or lithium tantalate (LiTaO ₃ ). And convert mechanical force and voltage to each other.

  Each actuator 44 with a load sensor is provided with an insertion hole 44c through which a cylindrical guide rod 46 passes. Further, a guide hole 24b (see FIG. 4) through which the guide rod 46 passes is provided at a position corresponding to the through hole 32a of the holder 24.

  The guide rod 46 is inserted into the through hole 32a, the insertion hole 44c, and the guide hole 24b with the nut 48 fixed to the upper end portion. As a result, the flange portion 32 of the spindle housing 30 is supported by the load sensor-equipped actuator 44 of the tilt control unit 26 at a plurality of locations (four locations in the present embodiment).

  The tilt control unit 26 is connected to a control device (control means, processing means) 50 as shown in FIG. The control device 50 detects a load applied to the load sensor unit 44a based on a voltage transmitted from the piezoelectric element of the load sensor unit 44a, and applies a voltage corresponding to the detected load to the piezoelectric element of the actuator unit 44b. To do.

  The load applied to the load sensor portion 44a corresponds to the load applied to the workpiece 11 from the grinding wheel 42. Therefore, the inclination control of the spindle housing 30 according to the load applied to the workpiece 11 is performed by applying a voltage according to the load applied to the load sensor unit 44a to the piezoelectric element of the actuator unit 44b and expanding and contracting the actuator unit 44b. Is possible.

  The control device 50 is also connected to the operation panel 52 installed in front of the opening 4a, the X-axis movement mechanism, the chuck table 12, the Z-axis movement mechanism 14, the processing unit 28, and the like. The operation of each part is controlled on the basis of the processing conditions set through.

  Next, how the workpiece 11 is ground by the grinding apparatus 2 according to this embodiment will be described. FIG. 3A is a perspective view schematically showing the workpiece 11 according to the present embodiment, and FIG. 3B is a perspective view schematically showing a state in which the protective member is attached to the workpiece 11. FIG. 3C is a cross-sectional view schematically showing how the protective member is attached to the workpiece 11.

  As shown in FIG. 3A, the workpiece 11 is a circular wafer made of a material such as silicon or sapphire, for example, and the surface 11a has a central device region 13 and an excess of the outer periphery surrounding the device region 13. The area 15 is divided. The device region 13 is further divided into a plurality of regions by division lines (streets) 17 arranged in a lattice pattern, and devices 19 such as ICs and LEDs are formed in each region.

  When grinding the back surface (work surface) 11b side of the workpiece 11, the protective member 21 is placed on the surface 11a side of the workpiece 11 as shown in FIGS. 3 (B) and 3 (C). The first surface 21a side is pasted. The protection member 21 is, for example, a pressure-sensitive adhesive tape, a resin substrate, a wafer of the same or different type as the workpiece 11, and the like, which are substantially the same shape as the workpiece 11. In this way, by attaching the protective member 21 to the surface 11a side of the workpiece 11, damage to the device 19 due to a load applied during grinding can be prevented.

  FIG. 4 is a diagram schematically illustrating how the workpiece 11 is ground. When the workpiece 11 is ground by the grinding device 2, first, the second surface 21 b of the protection member 21 attached to the workpiece 11 is brought into contact with the holding surface 12 a of the chuck table 12, and the suction source 21 Apply negative pressure. Thereby, the workpiece 11 is sucked and held by the chuck table 12 with the back surface 11b side exposed upward.

  Next, the chuck table 12 is moved below the grinding wheel 38, and the machining unit 28 (grinding wheel 42) is lowered (machining feed) while rotating the chuck table 12 and the grinding wheel 38, respectively. The lowering speed (lowering amount) of the processing unit 28 is set such that the lower surface of the grinding wheel 42 is pressed against the back surface 11 b side of the workpiece 11. Thereby, the back surface 11b side of the workpiece 11 can be ground.

  In the present embodiment, a load is detected by the load sensor unit 44a during grinding of the workpiece 11, and a voltage corresponding to the load is applied to the piezoelectric element of the actuator unit 44b. As described above, the load applied to the load sensor unit 44a corresponds to the load applied to the back surface 11b of the workpiece 11 from the grinding wheel 42.

  Therefore, by applying a voltage according to the load detected by the load sensor unit 44a to the piezoelectric element of the actuator unit 44b to expand and contract the actuator unit 44b, the inclination of the spindle housing 30 is controlled and the grinding wheel 42 is applied. The load applied to the back surface 11b of the workpiece 11 can be adjusted. The adjustment of the load may be repeated continuously during the grinding process, or may be performed intermittently at an arbitrary interval.

  Further, the inclination of the spindle housing 30 may be controlled so that the load is made uniform over the entire back surface 11b, or may be controlled so that the load can be biased within the back surface 11b. For example, when it is desired to make the load uniform over the entire back surface 11b, control may be performed to extend the actuator unit 44b corresponding to the load sensor unit 44a in which a relatively large load is detected.

  As described above, the grinding device (processing device) 2 according to the present embodiment has the load sensor portion (load detection means) 44a and the actuator portion (tilt adjustment) composed of a piezoelectric element between the holder 24 and the spindle housing 30. And a tilt control unit (tilt control means) 26 including a means 44b, so that a voltage corresponding to the load detected by the load sensor portion 44a is applied to the piezoelectric element of the actuator portion 44b to expand and contract the actuator portion 44b. Thus, the load applied to the back surface (work surface) 11b of the workpiece 11 from the grinding wheel (work tool) 42 can be adjusted by controlling the inclination of the spindle housing 30.

  That is, in the processing apparatus 2 according to the present embodiment, since the load can be detected and adjusted during the processing of the workpiece 11, it is necessary to measure the thickness after actually processing the workpiece 11 as in the past. Absent. Therefore, the processing of the workpiece 11 is made efficient.

  In addition, this invention is not limited to description of the said embodiment, A various change can be implemented. For example, in the above-described embodiment, the grinding device 2 that grinds the workpiece 11 is described. However, the processing device according to the present invention may be a polishing device that polishes the workpiece 11. FIG. 5 is a diagram schematically illustrating a configuration example of the polishing apparatus.

  As shown in FIG. 5, the basic configuration of the polishing apparatus (processing apparatus) 62 is the same as that of the grinding apparatus 2. Therefore, the same components as those of the grinding apparatus 2 are denoted by the same reference numerals, and detailed description thereof is omitted. The polishing device 62 is provided with a polishing pad (processing tool) 64 made of a nonwoven fabric or the like instead of the grinding wheel 38. The polishing apparatus 62 can be applied to both wet polishing such as CMP using a polishing liquid and dry polishing (dry polishing) without using a polishing liquid.

  The polishing apparatus 62 also includes an inclination control unit (inclination control) including a load sensor portion (load detection means) 44a and an actuator portion (inclination adjustment means) 44b made of a piezoelectric element between the holder 24 and the spindle housing 30. Means) 26, so that a voltage corresponding to the load detected by the load sensor 44a is applied to the piezoelectric element of the actuator 44b to expand and contract the actuator 44b, thereby controlling the inclination of the spindle housing 30 and polishing. The load applied from the pad 64 to the back surface (processed surface) 11b of the workpiece 11 can be adjusted.

  In the above-described embodiment and the modification, the load sensor actuator (load detection means) 44a and the actuator section (tilt adjustment means) 44b that are integrally formed of piezoelectric elements are used. These load sensors (load detection means) and arbitrary actuators (tilt adjustment means) can also be used in combination. For example, instead of a load sensor (load detection means) constituted by a piezoelectric element, a load cell (load detection means) constituted by a strain generating body that is distorted by stress and a strain gauge whose electric resistance changes according to the strain. It may be used.

  In the embodiment and the modification described above, the spindle housing 30 is supported by the tilt control unit (tilt control means) 26 at four locations, but the spindle housing 30 is supported by the tilt control unit 26 at at least three locations. It only has to be done. Moreover, there is no restriction | limiting in the workpiece 11, For example, the arbitrary substrates which consist of materials, such as a semiconductor, a ceramic, resin, a metal, can be used as the workpiece 11. FIG.

  In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented without departing from the scope of the object of the present invention.

2 Grinding equipment (processing equipment)
4 Base 4a Opening 6 Support structure 8 X-axis moving table 10 Dust-proof and drip-proof cover 12 Chuck table 12a Holding surface 14 Z-axis moving mechanism (processing feed means)
16 Z-axis guide rail 18 Z-axis moving plate 20 Z-axis ball screw 22 Z-axis pulse motor 24 Holder (machining means)
24a Through hole 24b Guide hole 26 Tilt control unit (tilt control means, processing means)
28 Processing unit (processing means)
30 spindle housing 30a side surface 32 flange 32a through hole 34 spindle 36 mount 38 grinding wheel 40 wheel base 42 grinding wheel (processing tool)
44 Actuator with load sensor 44a Load sensor (load detection means)
44b Actuator section (tilt adjustment means)
44c Insertion hole 46 Guide rod 48 Nut 50 Control device (control means, processing means)
52 Operation panel 11 Work piece 11a Front surface 11b Back surface (work surface)
13 Device area 15 Peripheral surplus area 17 Scheduled line (street)
19 Device 21 Protection member 21a First surface 21b Second surface

Claims (3)

A chuck table for holding a workpiece, a processing means rotatably mounted with a processing tool for grinding or polishing the workpiece held on the chuck table, and the processing means perpendicular to the holding surface of the chuck table A processing device comprising a processing feed means for processing and feeding in a specific direction,
The processing means includes a spindle housing that rotatably supports a spindle to which the processing tool is mounted, a holder to which the spindle housing is mounted, and an inclination of the spindle housing that is interposed between the holder and the spindle housing. Inclination control means for controlling the control unit, and control means for controlling each component,
The inclination control means includes a load detection means and an inclination adjustment means including a piezoelectric element, and supports the spindle housing at three or more locations.
The control means applies a voltage corresponding to the load detected by the load detecting means to the piezoelectric element of the inclination adjusting means when the workpiece is processed by feeding the processing means. A machining apparatus characterized by adjusting the load applied to the work surface of the work piece from the work tool by controlling the inclination of the spindle housing by expanding and contracting the adjusting means.   The processing apparatus according to claim 1, wherein the processing tool is a grinding wheel or a polishing pad.   3. The processing apparatus according to claim 1, wherein the load detection means of the inclination control means is constituted by a piezoelectric element.

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