Processing equipment

Abstract

To provide a processing device capable of processing high-hardness workpieces with high quality. [Solution] In a plan view from a direction parallel to the first direction, three linear guides are positioned at locations corresponding to the three vertices of a triangle. A machining unit is supported by the linear guides so as to be able to move up and down in the first direction. A feed mechanism moves the machining unit up and down in the first direction. A holding mechanism holds the workpiece below the machining unit. The machining unit supports a grinding wheel so as to face the workpiece held by the holding mechanism, and includes a rotation mechanism that rotates the grinding wheel around a center of rotation parallel to the first direction. The center of gravity of the machining unit is located inside the triangle in a plan view, and when the grinding wheel is rotated around the center of rotation, the grinding wheel does not coincide with the center of gravity of the triangle and passes through a position shifted from the center of gravity of the triangle toward the point where a force in the upward direction is applied to the machining unit by the feed mechanism.

Description

Technical Field

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[0001] The present invention relates to a processing apparatus, particularly a processing apparatus using a rotating grindstone.

Background Art

[0002] A grinding machine capable of grinding a difficult-to-machine material substrate with high precision is described in Patent Document 1 below. The grinding machine described in Patent Document 1 includes three linear guides arranged in a triangular shape, a saddle slidably attached along these linear guides, a grinding wheel attached to the lower end of the saddle and rotatable around the sliding direction of the saddle, and a chuck arranged facing the grinding wheel and rotatable while holding the substrate. Grinding is performed by lowering the grinding wheel while rotating it toward the workpiece. The grinding portion where the grinding wheel grinds the substrate is arranged at a position corresponding to the centroid of the triangle formed by the linear guides.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] <​​​​​​​​ In a plan view from a direction parallel to the first direction, three linear guides are positioned at locations corresponding to the three vertices of the triangle, A processing unit supported on the linear guide so as to be able to move up and down in the first direction, A feed mechanism for raising and lowering the processing unit in the first direction, Below the processing unit is a holding mechanism for holding the workpiece. Equipped with, The processing unit includes a rotating mechanism that supports a grinding wheel so as to face the workpiece held by the holding mechanism, and rotates the grinding wheel about a rotation center parallel to the first direction. The center of gravity of the processing unit is located inside the triangle in a plan view. A processing device is provided in which, when the grinding wheel is rotated around the rotation center, the grinding wheel passes through a position that does not coincide with the centroid of the triangle, and passes through a position that is offset from the centroid of the triangle toward the point where a force in the vertical direction is applied to the processing unit by the feed mechanism. [Effects of the Invention]

[0006] When the grinding wheel rotates, it passes through a position that does not coincide with the center of gravity of the triangle formed by the three linear guides, and is also shifted from the center of gravity of the triangle toward the point where the feeding mechanism applies a vertical force to the machining unit. This suppresses the tilting and rotational movement of the machining unit, making it possible to perform high-quality machining. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic cross-sectional view of the processing apparatus according to the first embodiment. [Figure 2] Figure 2 shows the positional relationship of the components of the processing apparatus according to the first embodiment in a plan view. [Figure 3] Figure 3 is a schematic diagram showing the positional relationship in plan view of the trajectory 25A of the three linear guides 10, saddle 21, grinding wheel flange 23, and grinding wheel 25 of the processing apparatus according to the first embodiment. [Figure 4] Figure 4 is a schematic diagram showing the positional relationship in plan view of the three linear guides 10, saddle 21, grinding wheel flange 23, grinding wheel 25 trajectory 25A, and lifting force application point 26F of the processing apparatus according to a modified example of the first embodiment. [Figure 5] Figure 5 is a schematic cross-sectional view of the processing apparatus according to the second embodiment. [Modes for carrying out the invention]

[0008] The processing apparatus according to the first embodiment will be described with reference to Figures 1 to 3. Figure 1 is a schematic cross-sectional view of the processing apparatus according to the first embodiment, and Figure 2 is a diagram showing the positional relationship of the components of the processing apparatus according to the first embodiment in a plan view. The main frame 62 is fixed to the base 60 via four frame legs 61. The main frame 62 (Figure 2) has a cylindrical shape with a cross section perpendicular to the first direction D1 having a square or rectangular outer surface and an inner surface. During operation, the main frame 62 is supported in a position where the first direction D1 is parallel to the direction of gravity.

[0009] Within the space enclosed by the main frame 62, the saddle 21 is supported by three linear guides 10 so as to be able to move up and down in a first direction D1. The three linear guides 10 (Figure 2) are not arranged in a straight line in a plan view taken from a direction parallel to the first direction D1. That is, the three linear guides 10 are positioned at the three vertices of a triangle. A feed mechanism 26 moves (raises and lowers) the saddle 21 relative to the main frame 62 in the first direction D1. For example, a ball screw can be used as the feed mechanism 26.

[0010] A spindle unit 22 is fixed to a saddle 21. The spindle unit 22 rotates a grinding wheel flange 23 attached to its lower end around a rotation center RC parallel to the first direction D1. Multiple grinding wheels 25 are fixed to the downward-facing surface of the grinding wheel flange 23. The grinding wheel flange 23 and the grinding wheels 25 are rotatable together with the spindle unit 22 around the rotation center RC. The saddle 21, spindle unit 22, and grinding wheel flange 23 are collectively referred to as the machining unit 20.

[0011] Multiple grinding wheels 25 (Figure 2) are arranged at equal intervals in the circumferential direction along the circumference of a circle centered on the rotation center RC. When the grinding wheel flange 23 rotates, the multiple grinding wheels 25 trace an annular trajectory 25A (the gray-colored area in Figure 2).

[0012] A holding mechanism 40 holds a workpiece 50 below the processing unit 20. The workpiece 50 is, for example, a high-hardness semiconductor wafer such as SiC or GaN. The processing unit 20 supports a grinding wheel 25 opposite to the workpiece 50 held by the holding mechanism 40. The holding mechanism 40 includes a linear guide 43, a slider 42, and a rotating mechanism 41. The linear guide 43 is mounted on a base 60 and supports the slider 42 so as to be movable in a direction perpendicular to the first direction D1 (horizontal direction).

[0013] The rotating mechanism 41 is attached to the slider 42 and can hold the workpiece 50 horizontally on its upper surface, for example, by a vacuum chuck, and rotate the workpiece 50 around a rotation center parallel to the first direction D1. By moving the rotating mechanism 41 in the horizontal direction, it is possible to take either a retracted state in which the workpiece 50 does not overlap with the grinding wheel flange 23 in a plan view, or a machining state in which the workpiece 50 overlaps with the grinding wheel flange 23 at least partially.

[0014] During processing, the slider 42 is moved horizontally until it overlaps with the range through which the grinding wheel 25 passes over the object to be processed 50 (the locus 25A of the grinding wheel 25, which will be described later with reference to FIG. 3), and the processing unit 20 is lowered to the height at which the grinding wheel 25 contacts the surface of the object to be processed 50, thereby performing grinding or polishing.

[0015] Next, referring to FIG. 3, the positional relationship in a plan view of a plurality of components of the processing apparatus according to the first embodiment will be described. FIG. 3 is a schematic diagram showing the positional relationship in a plan view of the three linear guides 10, the saddle 21, the grinding wheel flange 23, and the locus 25A of the grinding wheel 25 (FIGS. 1 and 2) of the processing apparatus according to the first embodiment.

[0016] In a plan view, a triangle 30 having the three linear guides 10 as vertices is defined. The center of gravity 20G of the processing unit 20 is located inside the triangle 30 in a plan view. The location where a lifting force is applied to the processing unit 20 by the feed mechanism 26 (FIG. 1) (hereinafter referred to as the lifting force application point 26F) is located on the line segment having as its ends the geometric center of gravity 30G of the triangle 30 and the midpoint of one side of the triangle 30. The center of gravity 30G of the triangle 30 does not overlap with the locus 25A of the grinding wheel 25 and is located within the circular region surrounded by the annular locus 25A. When the grinding wheel flange 23 rotates, the grinding wheel 25 passes through a position shifted from the center of gravity 30G of the triangle 30 toward the lifting force application point 26F.

[0017] Next, the excellent effects of the first embodiment will be described. In the first embodiment, since the center of gravity 20G of the processing unit 20 is located inside the triangle 30, compared with the configuration where the center of gravity 20G is located outside the triangle 30, the force applied to the three linear guides 10 by the rotational moment centered on the center of gravity 20G and with the first direction D1 as the rotation center is less likely to be localized on a specific one of the linear guides 10. Therefore, the frictional resistance generated in the three linear guides 10 can be made closer to uniform. As a result, rotational motions such as rolling, pitching, and yawing of the processing unit 20 during translational movement in the direction where the traveling direction is parallel to the first direction D1 are suppressed. For example, assuming that the side of the triangle 30 closest to the lifting force application point 26F (the right side in FIG. 3) is horizontal, rolling, pitching, and yawing can be defined.

[0018] During processing, since the grindstone 25 contacts the workpiece 50 (FIG. 1), an upward reaction force is generated on a part of the region corresponding to the locus 25A of the grindstone 25 with respect to the processing unit 20. During processing, since the grindstone 25 passes through a position shifted from the center of gravity 30G of the triangle 30 toward the lifting force application point 26F, compared with the configuration where it passes through the position of the center of gravity 30G of the triangle 30, the location where the reaction force is generated approaches the lifting force application point 26F. That is, the distance between the location where the upward reaction force is applied and the lifting force application point 26F where the downward force is applied becomes shorter. Therefore, the moment for tilting the processing unit 20 becomes weaker, and the tilting of the processing unit 20 can be suppressed.

[0019] Since rotational motions such as rolling, pitching, and yawing of the processing unit 20 are suppressed and the tilting of the processing unit 20 can be suppressed, it becomes possible to perform high-quality processing (grinding, polishing, etc.).

[0020] Next, a more preferable positional relationship between the center of gravity 20G of the processing unit 20 and the center of gravity 30G of the triangle 30 will be described.

[0021] In order to enhance the effect of suppressing rotational motion such as rolling, pitching, and yawing of the processing unit 20, it is preferable to bring the center of gravity 30G of triangle 30 and the center of gravity 20G of the processing unit 20 closer together in a plan view. For example, when a small triangle 31 is defined that has its center of gravity 31G at the same position as the center of gravity 30G of triangle 30, has sides parallel to each side of triangle 30, and has an area of ​​1 / 4 of the area of ​​triangle 30, it is preferable to configure the center of gravity 20G of the processing unit 20 to be located inside the small triangle 31. In Figure 3, the small triangle 31 is hatched. Furthermore, it is even more preferable to make the center of gravity 20G of the processing unit 20 coincide with the center of gravity 30G of triangle 30.

[0022] Next, a preferred shape for triangle 30 will be described. In a plan view, it is preferable that triangle 30 be an isosceles triangle symmetric with respect to the line connecting the centroid 20G of the processing unit 20 and the centroid of triangle 30, and more preferably an equilateral triangle. With this shape for triangle 30, the rotational moment generated in the processing unit 20 can be received more uniformly by the three linear guides 10. As a result, the rotational moment is distributed and received uniformly by the three linear guides 10, making it possible to receive a larger rotational moment.

[0023] Next, a modified example of the first embodiment will be described with reference to Figure 4. Figure 4 is a schematic diagram showing the positional relationship in plan view of the three linear guides 10, saddle 21, grinding wheel flange 23, the trajectory 25A of the grinding wheel 25, and the lifting force application point 26F of the processing apparatus according to a modified example of the first embodiment. In the first embodiment (Figure 3), when the grinding wheel 25 is rotated around the rotation center RC, the grinding wheel 25 passes through a position shifted from the centroid 30G of the triangle 30 toward the lifting force application point 26F.

[0024] In the modified example shown in Figure 4, the position through which the grinding wheel 25 passes is further restricted. Specifically, the grinding wheel 25 passes through the point where the lifting force is applied 26F. In other words, the point where the lifting force is applied 26F is located within the trajectory 25A of the grinding wheel 25 in a plan view.

[0025] In this modified example, the point where an upward reaction force is applied to the processing unit 20 during processing and the point where a downward lifting force is applied (26F) almost coincide. This provides the excellent effect of further reducing the likelihood of the processing unit 20 tilting during processing.

[0026] Next, the processing apparatus according to the second embodiment will be described with reference to Figure 5. The following description will omit the explanation of components common to the processing apparatus according to the first embodiment and its modified examples, which were described with reference to Figures 1 to 4.

[0027] Figure 5 is a schematic cross-sectional view of a processing apparatus according to the second embodiment. The processing apparatus according to the second embodiment includes a gravity compensation mechanism 70 in addition to the configuration of the processing apparatus according to the first embodiment. The gravity compensation mechanism 70 includes a connecting part 71 attached to the processing unit 20, and a force generating part 72 that applies a force opposite to gravity to the processing unit 20 via the connecting part 71. The force generating part 72 is fixed to the main frame 62 via a subframe 66. The combined force applied to the processing unit 20 by the gravity compensation mechanism 70 passes through the center of gravity of the processing unit 20 and cancels out the gravity acting on the processing unit 20. Here, "cancellation" includes not only cases where gravity is completely canceled out, but also cases where only a portion of gravity is canceled out.

[0028] Next, the superior effects of the second embodiment will be described. In the second embodiment, at least a portion of the gravitational force acting on the processing unit 20 is canceled, thereby reducing the force acting on the linear guide 10 due to gravity.

[0029] The embodiments described above are illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. Similar effects and benefits from similar configurations in multiple embodiments will not be mentioned sequentially for each embodiment. Furthermore, the present invention is not limited to the embodiments described above. For example, it will be obvious to those skilled in the art that various modifications, improvements, and combinations are possible. [Explanation of Symbols]

[0030] 10 Linear Guides 20 processing units Center of gravity of the 20G processing unit 21 Saddle 22 Spindle Units 23 Grinding wheel flange 25 whetstones 25A The trajectory of the grinding wheel 26 Feed mechanism 26F Lifting force application point 30 triangles 30G Centroid of a triangle 31 small triangle 31G Centroid of a small triangle 40 Retention mechanism 41 Rotation mechanism 42 Slider 43 Linear Guide 50. Object to be processed 60 base 61 Frame legs 62 Mainframes 66 Subframes 70 Gravity compensation mechanism 71 Connection part 72 Force generating section RC rotation center

Claims

1. In a plan view from a direction parallel to the first direction, three linear guides are positioned at locations corresponding to the three vertices of the triangle, A processing unit supported on the linear guide so as to be able to move up and down in the first direction, A feed mechanism for raising and lowering the processing unit in the first direction, Below the processing unit is a holding mechanism for holding the workpiece. Equipped with, The processing unit includes a rotating mechanism that supports a grinding wheel so as to face the workpiece held by the holding mechanism, and rotates the grinding wheel around a rotation center parallel to the first direction. The center of gravity of the processing unit is located inside the triangle in a plan view. A machining apparatus in which, when the grinding wheel is rotated around the center of rotation, the grinding wheel passes through a position that does not coincide with the centroid of the triangle, and passes through a position that is offset from the centroid of the triangle toward the point where a force in the upward or downward direction is applied to the machining unit by the feed mechanism.

2. The machining apparatus according to claim 1, wherein when the grinding wheel is rotated around the rotation center, the grinding wheel passes through a point in a plan view where a force in the upward or downward direction is applied to the machining unit by the feed mechanism.

3. The processing apparatus according to claim 1 or 2, wherein the center of gravity of the processing unit shares the center of gravity with the triangle in a plan view, and is located inside a small triangle whose sides are parallel to the sides of the triangle and whose area is 1 / 4 of the triangle.

4. Furthermore, the processing apparatus according to claim 1 or 2, further comprising a gravity compensation mechanism that applies a force to the processing unit parallel to the first direction, in the opposite direction to gravity, and passing through the center of gravity of the processing unit.

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