Grinding device

Abstract

To provide a grinding device in which a grindstone unit can be replaced easily and at a low cost.SOLUTION: A placement member 7, on which a grindstone unit 5 is placed, is provided on a top face of an index table 3 for moving a chuck table 2. The chuck table 2 is rotated, the placement member 7 is moved to below a spindle 4, the spindle 4 is lowered, a magnetic state of a retainer 6, to which the grindstone unit 5 is magnetically attached, is changed to a demagnetization condition, and thus, the grindstone unit 5 is placed on the placement member 7 and can be recovered. On the other hand, when a new grindstone unit 5 is attached, the grind stone 5 is attached to a pin 72 provided on the placement member 7, the index table 3 is rotated, and in the state that a rotation axis of the spindle 4 and a rotation axis of the grindstone unit are positionally aligned, the spindle 4 is lowered, and the grindstone unit 5 is magnetically attached.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a grinding apparatus for grinding the surface of a wafer, and more particularly to a grinding apparatus in which a grindstone unit for grinding a wafer can be easily replaced. [Background technology]

[0002] Conventionally, semiconductor wafers that have been cut into thin slices using a wire saw are further ground to a thinner shape using a grinding machine. Such a grinding machine is shown in Figure 6.

[0003] 6 is a top view of the grinding device, in which reference numeral 91 denotes a chuck table that holds and rotates a wafer 90 cut by a wire saw, and reference numeral 92 denotes an index table that revolves the chuck table 91. Reference numeral 93 denotes a grindstone unit equipped with a grindstone that grinds the wafer 90 held by the chuck table 91, and is attached to a spindle 94 that moves up and down toward the surface of the wafer 90. In this configuration, the rotation axis of the chuck table 91 in the Z-axis direction and the rotation axis of the spindle 94 that holds the grindstone unit 93 in the Z-axis direction are shifted laterally, and the chuck table 91 and the grindstone unit 93 are rotated, respectively, so that the surface of the wafer 90 is roughly ground by the grindstone unit 93, and then the index table 92 is rotated to perform finish grinding below the adjacent spindle 94.

[0004] After being used for a certain period of time, such a grinding wheel unit is replaced with a new one.

[0005] In relation to a method for replacing such an old grinding wheel unit with a new grinding wheel unit, a method such as that shown in Patent Document 1 below has been proposed.

[0006] In this patent document 1 (see paragraph 62), an electromagnet is provided under the spindle, and a grinding pad with a grinding wheel flange that is magnetically attached to the electromagnet is provided, so that the grinding pad can be replaced with a new one by switching the electromagnet between a magnetized state and a demagnetized state. In this way, it is no longer necessary to insert a tool from below to remove the screws during replacement, as was the case in the past, and replacement can be easily performed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2001-148361 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, even when replacing the grindstone unit using such a configuration, the following problems arise.

[0009] That is, in general, when replacing a grinding wheel unit, the spindle is moved to an upper position, a large space is formed below it, and then the grinding wheel unit is removed and replaced, but at this time, the relatively heavy grinding wheel unit must be supported with both hands, making it difficult to work alone. On the other hand, as shown in Patent Document 1, it is possible to automatically replace the grinding wheel unit using a device such as an arm, but in this case, there are problems such as the device becoming complicated and the cost becoming high.

[0010] SUMMARY OF THE PRESENT DISCLOSURE OF THE PRESENT DISCLOSURE The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a grinding device that enables the grinding wheel unit to be replaced easily and at low cost. [Means for solving the problem]

[0011] In other words, in order to solve the above-mentioned problems, the present invention provides a grinding apparatus comprising a chuck table that rotates while holding a workpiece, an index table that moves the chuck table, a grinding wheel unit that contacts the surface of the workpiece held on the chuck table to grind the workpiece, a spindle that raises and lowers the grinding wheel unit and rotates the grinding wheel unit, a holding device that detachably holds the grinding wheel unit on the spindle, and a switching unit that switches between an attached state and a detached state of the grinding wheel unit in the holding device, the grinding apparatus further comprising a mounting member that is provided on the index table for placing the grinding wheel unit, and a control unit that switches the switching unit to a detached state with the spindle lowered, and places the grinding wheel unit on the mounting member on the index table.

[0012] With this configuration, the grinding wheel unit can be replaced using the index table, eliminating the need to support the grinding wheel unit with both hands. Also, since there is no need to provide a new arm or the like, the structure can be simplified and the product can be manufactured at low cost.

[0013] In addition, in the invention, when the holding device is provided, the grindstone unit is magnetically attached by a magnet.

[0014] With this configuration, it becomes possible to attach and detach the grindstone unit with a simple configuration without using a complicated mechanism, etc. Also, when the spindle is lowered, the grindstone unit can be magnetically attached to the spindle via the holding device simply by bringing it close to the grindstone unit to a certain extent, so there is no need to fine-tune the lowered position of the spindle.

[0015] Furthermore, a positioning member is provided on the mounting member for aligning the rotation axis of the spindle with the rotation axis of the grinding wheel unit when the grinding wheel unit placed on the mounting member is moved below the spindle.

[0016] With this configuration, the rotation axis of the spindle and the rotation axis of the grinding wheel unit can be aligned simply by placing the grinding wheel unit on the positioning member and moving the index table below the spindle, and in this state, the grinding wheel unit can be attached simply by lowering the spindle.

[0017] Furthermore, in the case where the index table is provided with a plurality of openings for accommodating the chuck tables, the placement member is provided between adjacent openings.

[0018] With this configuration, even when the chuck table is attached to the index table, the grinding wheel unit can be placed on the index table via the placement member. Effect of the Invention

[0019] According to the present invention, the grinding wheel unit can be replaced by using the index table, eliminating the need to support the grinding wheel unit with both hands. In addition, since there is no need to provide a new arm or the like, the structure can be simplified and the product can be finished at low cost. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic plan view of a grinding device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional perspective view of the grinding wheel unit and the holding device in the embodiment; [Diagram 3] FIG. 13 shows an index table and a mounting member in the same embodiment. [Figure 4] FIG. 13 is a diagram showing a state in which the grindstone unit is replaced in the same embodiment. [Diagram 5] FIG. 13 is a diagram showing a state in which the grindstone unit is replaced in the same embodiment. [Figure 6] FIG. 1 is a schematic plan view of a conventional grinding device; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] As shown in Fig. 1, the grinding device 1 in this embodiment includes a chuck table 2 that rotates while holding a wafer 10, an index table 3 that moves the chuck table 2 between a rough grinding position A1 and a finish grinding position A2, etc., a grindstone unit 5 that grinds the wafer 10 held on the chuck table 2, a spindle 4 that raises and lowers the grindstone unit 5 and rotates the grindstone unit 5, a holding device 6 that detachably holds the grindstone unit 5 on the spindle 4, and a switching unit 60 that switches between an attached state and a detached state of the grindstone unit 5 in the holding device 6, as shown in Fig. 2. Characteristically, as shown in Fig. 3, a mounting member 7 on which the grindstone unit 5 is placed is provided on the index table 3, and when the spindle 4 is lowered (Fig. 4(b)), the old grindstone unit 5 is placed on the mounting member 7 (Fig. 5(c)), and the index table 3 is rotated to collect the grindstone unit 5 at the grindstone replacement position A3. Conversely, when a new grinding wheel unit 5 is to be attached, the new grinding wheel unit 5 is placed on the mounting member 7 at the grinding wheel replacement position A3, the index table 3 is rotated to move the grinding wheel unit 5 to below the spindle 4, and then the spindle 4 is lowered, and the new grinding wheel unit 5 is attached to the spindle 4. This embodiment will be described in detail below.

[0023] 1, the chuck table 2 of the grinding device 1 is configured to have a diameter slightly larger than the wafer 10, and is configured to hold the wafer 10 on its upper surface by an air suction mechanism (not shown). With the wafer 10 held by air, it is rotated by a motor (not shown) provided below.

[0024] 3, the index table 3 has a plurality of openings 31 for accommodating the chuck table 2, and is configured so that the chuck table 2 accommodated in the openings 31 can be rotated by a motor (not shown) to move the chuck table 2 between a rough grinding position A1 (see FIG. 1), a finish grinding position A2, etc. Between the openings 31 of the index table 3, an intermediate section 32 having an upper surface portion at a position higher than the position of the openings 31 is provided, and a mounting member 7, which will be described later, is attached to an elongated hole 33 provided in the upper surface portion of the intermediate section 32.

[0025] Meanwhile, a spindle 4 is provided near the index table 3 (see FIG. 1). As shown in FIGS. 4 and 5, this spindle 4 uses a cylinder to raise and lower a grindstone unit 5 along the normal direction (Z-axis direction) of the wafer 10, and rotates the grindstone unit 5 by pressing it against the surface of the wafer 10. On one side of the spindle 4, a grindstone unit 5 for rough grinding is attached, and on the other side, a grindstone unit 5 for finish grinding is attached.

[0026] 2, the grindstone unit 5 attached to the spindle 4 has a plurality of grindstones 53 arranged in the circumferential direction on the underside of a magnetically attachable metallic grindstone flange 51, and is attached in alignment with the rotation axis of the spindle 4. The rotation axis of the grindstone unit 5 and the rotation axis of the chuck table 2 below it are shifted in parallel to each other in the horizontal direction, and the grindstone unit 5 and the chuck table 2 are rotated, respectively, to grind the entire wafer 10. Note that, although the grindstone flange 51 is constituted by a disk-shaped member here, a handle (not shown) may be provided on the outer periphery thereof so that the grindstone unit 5 can be carried by using the handle.

[0027] The holding device 6 provided below the spindle 4 is adapted to automatically attach and detach the grindstone unit 5 from the spindle 4, and is adapted to switch between an attached state and a detached state by a switching unit 60 as shown in FIG. 2. Various structures can be used for the holding device 6, but here, a structure that allows the grindstone unit 5 to be attached and detached by a magnet is used. Specifically, the holding device 6 has a permanent magnet inside, and is adapted to switch between a magnetized state and a demagnetized state by the permanent magnet by inserting a pin 62 of the switching unit 60 into a switching hole 61 provided on the side of the holding device 6 and rotating it 180 degrees. The pin 62 for this switching is provided so as to slide from the side when the spindle 4 is lowered, and the pin 62 is advanced by a cylinder 63 to insert it into the switching hole 61, and in that state, the pin 62 is rotated 180 degrees by a motor 64 to switch between a magnetized state (attached state) and a demagnetized state (detached state). In this way, the grindstone unit 5 can be removed only when the grindstone unit 5 is lowered, thereby preventing the grindstone unit 5 from being dropped accidentally from a high place. If the grindstone unit 5 is merely magnetically attached to the underside of the spindle 4, the grindstone unit 5 may slide against the underside of the spindle 4 due to frictional force during rotation. Therefore, a columnar member hanging down from the spindle 4 is provided as a friction regulation part 41 for regulating the friction, and the lower end part of this columnar member is fitted into a hole 54 in the upper surface of the grindstone flange to prevent sliding.

[0028] With such a configuration, in this embodiment, a mounting member 7 for mounting the grindstone unit 5 on the index table 3 is provided.

[0029] The mounting member 7 mounts and fixes the grindstone unit 5, and in this embodiment, the thickness of the mounting member 7 is set so that the grindstone 53 does not come into contact with the index table 3 or the chuck table 2 when the grindstone unit 5 is mounted, and the size of the mounting member 7 is set so that the grindstone flange 51 does not interfere with the chuck table 2. The mounting member 7 has a plurality of standing pins 72 (see FIG. 3) on the upper surface thereof, and is fixed by fitting the pins 72 into holes 52 (see FIG. 2) provided in the grindstone flange 51. Meanwhile, the mounting member 7 is slidably attached to the elongated hole 33 along the radial direction of the index table 3, and is fixed at a predetermined position by the screw 71. When the mounting member 7 is attached to the index table 3, the rotation axis of the grindstone flange 51 fixed to the pin 72 is adjusted within the range of the elongated hole 33 so as to coincide with the rotation axis of the spindle 4 when the index table 3 is rotated, and is fixed by the screw 71.

[0030] The control unit 8 (FIG. 2) controls the cylinder 63, the motor 64, etc., so as to perform a series of these operations, and controls the mounting member 7 to move to a position below the spindle 4 by operating a switch, and controls the grindstone unit 5 to be placed on the mounting member 7 by driving the switching unit 60 in a state where the grindstone unit 5 is lowered to the vicinity of the mounting member 7. When a new grindstone unit 5 is to be attached, the new grindstone unit 5 is placed on the mounting member 7 at the grindstone replacement position A3, and in a state where the grindstone unit 5 is moved to a position below the spindle 4, the spindle 4 is lowered, and the switching unit 60 is driven to magnetize the grindstone unit 5. When the grindstone unit 5 placed on the mounting member 7 is stopped at a position below the rotation axis of the spindle 4, a method can be used in which a mark or the like is attached to the index table 3 or the mounting member 7, and the mark is read by an optical sensor to control the stop position so that the respective rotation axes are aligned.

[0031] Next, a method for replacing the grinding wheel unit 5 in the grinding device 1 configured as above will be described. In the explanation, it is assumed that the old grinding wheel unit 5 is attached to the holding device 6 of the spindle 4 in advance, and the explanation will be given of a case where the old grinding wheel unit 5 is removed and replaced with a new grinding wheel unit 5.

[0032] First, when removing the old grinding wheel unit 5, the switch is set to "removal mode 81" (Fig. 2), and the mounting member 7 on the index table 3 is rotated to directly below the rotation axis of the spindle 4 (the state shown in Fig. 4(a)).

[0033] In this state, the spindle 4 is lowered and the grindstone unit 5 is stopped in the vicinity of the mounting member 7 (for example, at a position several millimeters away) (the state of FIG. 4(b)).

[0034] Next, the switching hole 61 of the holding device 6 provided on the spindle 4 is oriented in the sliding direction of the pin 62, and in this state, the pin 62 is advanced via the cylinder 63. Then, the pin 62 is inserted into the switching hole 61, and rotated 180 degrees.

[0035] Then, the holding device 6 switches from a magnetized state to a demagnetized state, and the grindstone unit 5 falls onto the mounting member 7 (the state shown in FIG. 5(c)). When the grindstone flange 51 falls in this manner, the hole 52 of the grindstone flange 51 fits into the pin 72 of the mounting member 7, and the grindstone flange 51 is fixed in place.

[0036] In this state, the spindle 4 is raised (state of FIG. 5(d)), and the index table 3 is rotated to move the grindstone unit 5 to the grindstone replacement position A3. Then, the old grindstone unit 5 is collected by holding it with both hands.

[0037] Next, when attaching a new grindstone unit 5, the reverse operation is performed. That is, the new grindstone unit 5 is carried to the grindstone replacement position A3 and placed on the mounting member 7. At that time, the pin 72 of the mounting member 7 is fitted into the hole portion 52 of the grindstone unit 5.

[0038] Then, the switch is changed to “attachment mode 82 ”, the index table 3 is rotated, and the grindstone unit 5 placed on the placement member 7 is moved to directly below the rotation axis of the spindle 4 .

[0039] Then, the spindle 4 is lowered, and at that position, the pin 62 of the switching portion 60 is advanced and inserted into the switching hole 61 of the holding device 6, and then rotated 180 degrees in the opposite direction.

[0040] Then, the grindstone unit 5 is magnetically attached to the holding device 6 of the spindle 4, and is lifted from the mounting member 7. At this time, a columnar member (slide restriction portion 41) hanging down from the spindle 4 is fitted into a hole portion 54 provided on the upper surface of the grindstone flange, and the grindstone unit 5 is fixed so as not to be able to slide along the rotation direction.

[0041] Then, the pin 62 of the switching portion 60 is retracted and the spindle 4 is raised, after which the wafer 10 can be ground using this new grindstone unit 5.

[0042] According to the above embodiment, the grinding apparatus 1 includes the chuck table 2 that rotates while holding the wafer 10, the index table 3 that revolves the chuck table 2, the grinding stone unit 5 that comes into contact with the surface of the wafer 10 held by the chuck table 2 to grind the wafer 10, the spindle 4 that raises and lowers the grinding stone unit 5 and rotates the grinding stone unit 5, a holding device 6 that detachably holds the grinding stone unit 5 on the spindle 4, and a switching unit 60 that switches between a magnetized state and a demagnetized state of the grinding stone unit 5 in the holding device 6. The grinding apparatus 1 further includes a mounting member 7 that is provided on the index table 3 and on which the grinding stone unit 5 is mounted, and a control unit 8 that switches the switching unit 60 to a removal mode 81 with the spindle 4 lowered, and mounts the grinding stone unit 5 on the mounting member 7 on the index table 3. This makes it possible to replace the grinding stone unit 5 by utilizing the index table 3, eliminating the need to support the grinding stone unit 5 with both hands when replacing it. Furthermore, since there is no need to provide a new arm or the like, the structure can be simplified and the product can be manufactured at low cost.

[0043] The present invention is not limited to the above-described embodiment, but can be embodied in various forms.

[0044] For example, in the above embodiment, as shown in Fig. 3, the index table 3 is provided with three openings 31 to attach the chuck table 2, but the number of openings 31 is not limited to this. Also, the index table 3 is rotated and moved to below the spindle 4, but the index table 3 may be moved in a linear direction.

[0045] In the above embodiment, the mounting member 7 is provided on the index table 3 in a substantially elliptical shape, but the shape is not limited to this and various shapes can be used. In the above embodiment, the mounting member 7 is provided separately from the index table 3, but the upper surface of the index table 3 may be configured as the mounting member 7.

[0046] Furthermore, in the above embodiment, the switching unit 60 is provided near the lowered position of the spindle 4 so that the magnetized state and the demagnetized state can be switched depending on the lowered position of the spindle 4, but if the holding device 6 is configured with an electromagnet, the electromagnet may be switched on and off only when the grinding wheel unit 5 is in the lowered state. Also, if the grinding wheel unit 5 is attached and detached to and from the spindle 4 by providing a physical claw instead of using such a permanent magnet or electromagnet, the grinding wheel unit 5 may be removed by advancing and retracting the claw when the grinding wheel unit 5 is in the lowered state.

[0047] In addition, in the above embodiment, the index table 3 is rotated by a motor to rotate the grinding wheel unit 5 between below the spindle 4 and the grinding wheel replacement position A3, but the index table 3 may also be rotated by hand.

[0048] In the above embodiment, the sliding control portion 41 is configured as a columnar member hanging down from the spindle 4 which fits into the hole 54. Alternatively, a convex portion and a concave portion may be provided on the joint surface between the holding device 6 and the grinding wheel unit 5 and these may be fitted together to control sliding in the rotational direction, or a radial wavy portion may be provided on the joint surface between the spindle 4 and the holding device 6 and these wavy portions may be joined to control sliding in the rotational direction.

[0049] In the above embodiment, the index table 3 is rotated after the grindstone unit 5 is placed on the mounting member 7, but in this case, the index table 3 may be rotated after detecting that the grindstone unit 5 is placed on the mounting member 7. In this case, a method for detecting that the grindstone unit 5 is placed on the mounting member 7 may be to provide a detection means such as a load sensor, optical sensor, or magnetic sensor on the mounting member 7, and use this detection means to detect that the grindstone unit 5 is placed on the mounting member 7.

[0050] In the above embodiment, the pin 72 is protruded from the mounting member 7 to position the grinding wheel unit 5 and place it thereon. However, in addition to the pin 72, a recess and a protrusion may be formed on the joint surfaces of the mounting member 7 and the grinding wheel unit 5, and these may be fitted together.

[0051] In addition, in the above embodiment, the grinding wheel unit 5 is held by the spindle 4. In this case, in order to align the rotational centers of the spindle 4 and the grinding wheel unit 5, a pointed portion protruding from the tip end and a fitting portion that fits into the pointed portion may be provided at the center of the spindle 4 and the center of the grinding wheel unit 5, and the respective rotational centers may be aligned by using the pointed portion.

[0052] In addition, when the grinding wheel unit 5 is held on the spindle 4 in this manner, in order to detect whether the grinding wheel unit 5 is magnetized, a magnetization detection means such as a load sensor, an optical sensor, or a magnetic sensor may be provided to detect the magnetized state of the grinding wheel unit 5. [Explanation of symbols]

[0053] 1. Grinding device 2. Chuck table 3. Index table 4. Spindle 5. Grinding wheel unit 6...Holding device 60...Switching section 61...Switching hole 62···pin 7. Placing member 72 Pin (positioning member) 8. Control section

Claims

1. A chuck table that rotates while holding the workpiece; an index table that moves the chuck table; a grindstone unit that comes into contact with a surface of the workpiece held on the chuck table to grind the workpiece; a spindle for raising and lowering the grindstone unit and rotating the grindstone unit; a holding device for detachably holding the grindstone unit on the spindle; a switching unit that switches between an attached state and a detached state of the grindstone unit in the holding device; In a grinding apparatus comprising: a mounting member provided on the index table for mounting the grindstone unit; a control unit that switches the switching unit to a detached state with the spindle lowered and places the grindstone unit on a placement member on the index table; A grinding apparatus comprising:

2. 2. The grinding device according to claim 1, wherein the holding device is configured to magnetically attract the grindstone unit by a magnet.

3. 2. The grinding device according to claim 1, wherein the mounting member is provided with a positioning member for aligning the rotation axis of the spindle with the rotation axis of the grinding wheel unit when the grinding wheel unit mounted on the mounting member is moved below the spindle.

4. the index table has a plurality of openings for receiving the chuck table; 2. The grinding device according to claim 1, wherein the placement member is provided between adjacent openings of the index table.

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