PROCESSING DEVICE

Abstract

A processing device includes: three linear guides disposed at three vertices of a triangle in plan view as viewed from a direction parallel to a first direction; a processing unit supported by the linear guides to lift and lower in the first direction; a feed mechanism that lifts and lowers the processing unit in the first direction; and a holding mechanism that holds a processing object below the processing unit, in which the processing unit supports a grindstone to face the processing object and includes a spindle unit that rotates the grindstone around a rotation center, a centroid of the processing unit is located inside the triangle, and when the grindstone is rotated, the grindstone passes through a position not overlapping a centroid of the triangle and passes through a position deviated from the centroid of the triangle toward a location where a force is applied to the processing unit.

Claims

1. A processing device comprising: three linear guides disposed at positions corresponding to three vertices of a triangle in plan view as viewed from a direction parallel to a first direction; a processing unit supported by the linear guides to lift and lower in the first direction; a feed mechanism that lifts and lowers the processing unit in the first direction; and a holding mechanism that holds a processing object below the processing unit, wherein the processing unit supports a grindstone such that the grindstone faces the processing object held by the holding mechanism and includes a spindle unit that rotates the grindstone around a rotation center parallel to the first direction, a centroid of the processing unit is located inside the triangle in plan view, and when the grindstone is rotated around the rotation center, the grindstone passes through a position not overlapping a centroid of the triangle and passes through a position deviated from the centroid of the triangle toward a location where a force in a lifting and lowering direction is applied to the processing unit by the feed mechanism.

2. The processing device according to claim 1, wherein the processing unit supports the grindstone and one or more additional grindstones disposed at equal intervals in a circumferential direction along a circumference around the rotation center.

3. The processing device according to claim 2, wherein when the grindstone is rotated around the rotation center, the grindstone passes through the location where the force in the lifting and lowering direction is applied to the processing unit by the feed mechanism in plan view.

4. The processing device according to claim 1, wherein the processing unit includes a slider, and the linear guide supports the slider to be movable in a direction perpendicular to the first direction.

5. The processing device according to claim 4, wherein during processing of the processing object, the slider is moved in the direction perpendicular to the first direction until the processing object overlaps a range through which the grindstone passes, and the processing unit is lowered to a height at which the grindstone comes into contact with a surface of the processing object, so that processing of grinding or polishing is performed.

6. The processing device according to claim 1, wherein the centroid of the processing unit is located inside a small triangle that shares a centroid with the triangle in plan view, has each side parallel to each side of the triangle, and has an area that is 1/4 of the triangle.

7. The processing device according to claim 1, further comprising: a gravity compensation mechanism that applies a force to the processing unit in a direction parallel to the first direction, the force being opposite to gravity and passing through the centroid of the processing unit.

8. The processing device according to claim 7, wherein the gravity compensation mechanism includes a connecting part attached to the processing unit, and a force generating unit that applies a force in a direction opposite to gravity to the processing unit via the connecting part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a schematic cross-sectional view of a processing device according to a first example.

[0006] FIG. 2 is a diagram illustrating a positional relationship between components of the processing device according to the first example in plan view.

[0007] FIG. 3 is a schematic diagram illustrating a positional relationship of three linear guides, a saddle, a grindstone flange, and a trajectory of a grindstone of the processing device according to the first example in plan view.

[0008] FIG. 4 is a schematic diagram illustrating a positional relationship of three linear guides, a saddle, a grindstone flange, a trajectory of a grindstone, and a lifting and lowering force application location of a processing device according to a modification example of the first example in plan view.

[0009] FIG. 5 is a schematic cross-sectional view of a processing device according to a second example.

DETAILED DESCRIPTION

[0010] In a grinding machine in the related art, when a processing reaction force increases during the processing of a processing object with high hardness, there is a case where the processing quality deteriorates. This is considered to be caused by the fact that when the saddle holding a rotary grindstone is lowered, a rotating motion such as rolling, pitching, and yawing occurs in a processing unit such as the saddle and the grinding wheel. It is desirable to provide a processing device capable of processing a processing object with high hardness with a high quality.

[0011] When the grindstone is rotated, the grindstone passes through a position not overlapping the centroid of the triangle having three linear guides as vertices, and passes through the position deviated from the centroid of the triangle toward the location where the force in the lifting and lowering direction is applied to the processing unit by the feed mechanism. Therefore, the inclination or the rotating motion of the processing unit is suppressed. Therefore, it is possible to perform processing with a high quality.

[0012] A processing device according to a first example will be described with reference to FIGS. 1 to 3.

[0013] FIG. 1 is a schematic cross-sectional view of the processing device according to the first example, and FIG. 2 is a diagram illustrating a positional relationship of components of the processing device according to the first example in plan view. A main frame 62 is fixed to a base 60 via four frame legs 61. The main frame 62 (FIG. 2) has a cylindrical shape with an outer peripheral surface and an inner peripheral surface each having a square or rectangular cross-section perpendicular to the first direction D1. During the operation, the main frame 62 is supported in a posture in which the first direction D1 is parallel to a direction of gravity.

[0014] A saddle 21 is supported by three linear guides 10 to be capable of lifting and lowering in the first direction D1 in a space surrounded by the main frame 62. In plan view as viewed from a direction parallel to the first direction D1, the three linear guides 10 (FIG. 2) are not disposed on a straight line. That is, the three linear guides 10 are disposed at positions corresponding to three vertices of a triangle. The feed mechanism 26 moves (lifts and lowers) the saddle 21 in the first direction D1 with respect to the main frame 62. For example, a ball screw can be used as the feed mechanism 26.

[0015] A spindle unit 22 is fixed to the saddle 21. The spindle unit 22 rotates a grindstone flange 23 attached to a lower end thereof around a rotation center RC parallel to the first direction D1. A plurality of grindstones 25 are fixed to a surface of the grindstone flange 23 facing downward. The grindstone flange 23 and the grindstone 25 are rotatable around the rotation center RC together with the spindle unit 22. The saddle 21, the spindle unit 22, and the grindstone flange 23 are collectively referred to as a processing unit 20.

[0016] The plurality of grindstones 25 (FIG. 2) are disposed at equal intervals in a circumferential direction along a circumference around the rotation center RC. When the grindstone flange 23 rotates, the plurality of grindstones 25 draw an annular trajectory 25A (a region colored in gray in FIG. 2).

[0017] The holding mechanism 40 holds a processing object 50 below the processing unit 20. The processing object 50 is, for example, a semiconductor wafer with high hardness such as SiC and GaN. The processing unit 20 supports the grindstone 25 to face the processing object 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 attached to the base 60, and supports the slider 42 to be movable in a direction (horizontal direction) perpendicular to the first direction D1.

[0018] The rotating mechanism 41 is attached to the slider 42, and can horizontally hold the processing object 50 on an upper surface thereof, for example, with a vacuum chuck or the like, and rotate the processing object 50 around the rotation center parallel to the first direction D1. By moving the rotating mechanism 41 in the horizontal direction, the processing object 50 can take any one of a retreat state in which the processing object 50 does not overlap the grindstone flange 23 in plan view and a processing state in which the processing object 50 at least partially overlaps the grindstone flange 23.

[0019] During the processing, the slider 42 is moved in the horizontal direction until the processing object 50 overlaps a range through which the grindstone 25 passes (a trajectory 25A of the grindstone 25 to be described later with reference to FIG. 3), and the processing unit 20 is lowered to a height at which the grindstone 25 comes into contact with the surface of the processing object 50, so that processing of grinding or polishing is performed.

[0020] Next, a positional relationship between a plurality of components of the processing device according to the first example in plan view will be described with reference to FIG. 3. FIG. 3 is a schematic diagram illustrating a positional relationship of the three linear guides 10, the saddle 21, the grindstone flange 23, and the trajectory 25A of the grindstone 25 (FIGS. 1 and 2) of the processing device according to the first example in plan view.

[0021] In plan view, a triangle 30 having three linear guides 10 as vertices is defined. A centroid 20G of the processing unit 20 is located inside the triangle 30 in plan view. A location where a force in the lifting and lowering direction is applied to the processing unit 20 by the feed mechanism 26 (FIG. 1) (hereinafter, referred to as a lifting and lowering force application location 26F) is located on a line segment having a geometric centroid 30G of the triangle 30 and a midpoint of one side of the triangle 30 as both ends. The centroid 30G of the triangle 30 does not overlap the trajectory 25A of the grindstone 25, and is located in a circular region surrounded by the annular trajectory 25A. When the grindstone flange 23 rotates, the grindstone 25 passes through a position deviated from the centroid 30G of the triangle 30 toward the lifting and lowering force application location 26F.

[0022] Next, an excellent effect of the first example will be described.

[0023] In the first example, since a centroid 20G of the processing unit 20 is located inside the triangle 30, the force applied to the three linear guides 10 by a rotation moment about the centroid 20G and with the first direction D1 as the rotation center is unlikely to be localized in a specific one linear guide 10, compared to the configuration in which the centroid 20G is located outside the triangle 30. Therefore, the frictional resistance generated in the three linear guides 10 can be made close to uniform. As a result, the rotating motion of the processing unit 20 such as rolling, pitching, and yawing during the translational movement in which a traveling direction is a direction parallel to the first direction D1 is suppressed. For example, the rolling, the pitching, and the yawing can be defined by assuming the side of the triangle 30 closest to the lifting and lowering force application location 26F (right side in FIG. 3) to be the horizontal direction.

[0024] During the processing, since the grindstone 25 comes into contact with the processing object 50 (FIG. 1), an upward reaction force is generated in a part of the region corresponding to the trajectory 25A of the grindstone 25 with respect to the processing unit 20. During the processing, the grindstone 25 passes through a position deviated from the centroid 30G of the triangle 30 toward the lifting and lowering force application location 26F. Therefore, a location where a reaction force is generated is closer to the lifting and lowering force application location 26F as compared to a configuration in which the grindstone 25 passes through the position of the centroid 30G of the triangle 30. That is, a distance between the location where the upward reaction force is applied and the lifting and lowering force application location 26F where the downward force is applied is shortened. Therefore, the moment for inclining the processing unit 20 is weakened, and the inclination of the processing unit 20 can be suppressed.

[0025] The rotating motion of the processing unit 20 such as rolling, pitching, and yawing is suppressed, and the inclination of the processing unit 20 can be suppressed. Therefore, it is possible to perform high-quality processing (grinding, polishing, and the like).

[0026] Next, a more preferable positional relationship between the centroid 20G of the processing unit 20 and the centroid 30G of the triangle 30 will be described.

[0027] In order to enhance the effect of suppressing the rotating motion of the processing unit 20 such as rolling, pitching, and yawing, it is preferable to bring the centroid 30G of the triangle 30 and the centroid 20G of the processing unit 20 close to each other in plan view. For example, when a small triangle 31 is defined that has a centroid 31G at the same position as the centroid 30G of the triangle 30, has sides parallel to each side of the triangle 30, and has an area that is 1/4 of the area of the triangle 30, it is preferable that the centroid 20G of the processing unit 20 is located inside the small triangle 31. In FIG. 3, the small triangle 31 is hatched. Furthermore, it is more preferable that the centroid 20G of the processing unit 20 coincides with the centroid 30G of the triangle 30.

[0028] Next, a preferable shape of the triangle 30 will be described. In plan view, it is preferable that the triangle 30 is an isosceles triangle that is line-symmetric with respect to a straight line connecting the centroid 20G of the processing unit 20 and the centroid of the triangle 30, and is more preferable that the triangle 30 is an equilateral triangle. When the triangle 30 has such a shape, the three linear guides 10 can more uniformly receive the rotation moment generated in the processing unit 20. As a result, the rotation moment is uniformly distributed to and received by the three linear guides 10, and thus it is possible to receive a larger rotation moment.

[0029] Next, a modification example of the first example will be described with reference to FIG. 4. FIG. 4 is a schematic diagram illustrating a positional relationship of three linear guides 10, a saddle 21, a grindstone flange 23, a trajectory 25A of a grindstone 25, and a lifting and lowering force application location 26F of a processing device according to a modification example of the first example in plan view. In the first example (FIG. 3), when the grindstone 25 is rotated around the rotation center RC, the grindstone 25 passes through a position deviated from the centroid 30G of the triangle 30 toward the lifting and lowering force application location 26F.

[0030] In the modification example illustrated in FIG. 4, the position through which the grindstone 25 passes is further limited. Specifically, the grindstone 25 passes through the lifting and lowering force application location 26F. In other words, the lifting and lowering force application location 26F is located inside the trajectory 25A of the grindstone 25 in plan view.

[0031] In the present modification example, the location where the upward reaction force is applied to the processing unit 20 during processing and the lifting and lowering force application location 26F to which the downward lifting and lowering force is applied substantially coincide with each other. Therefore, there is an excellent effect that the inclination of the processing unit 20 during processing is unlikely to occur.

[0032] Next, a processing device according to a second example will be described with reference to FIG. 5. Hereinafter, a description of a configuration common to the processing device according to the first example and the modification example thereof described with reference to FIGS. 1 to 4 will be omitted.

[0033] FIG. 5 is a schematic cross-sectional view of the processing device according to the second example. The processing device according to the second example includes a gravity compensation mechanism 70 in addition to the configuration of the processing device according to the first example. The gravity compensation mechanism 70 includes a connecting part 71 attached to the processing unit 20 and a force generating unit 72 that applies a force in a direction opposite to gravity to the processing unit 20 via the connecting part 71. The force generating unit 72 is fixed to the main frame 62 via a subframe 66. The composite force applied to the processing unit 20 by the gravity compensation mechanism 70 passes through the centroid of the processing unit 20 and cancels the gravity applied to the processing unit 20. Here, the case of "canceling" includes not only a case where the gravity is completely canceled but also a case where a part of the gravity is canceled.

[0034] Next, an excellent effect of the second example will be described. In the second example, since at least a part of the gravity applied to the processing unit 20 is canceled, the force applied to the linear guide 10 due to the gravity is reduced.

[0035] It goes without saying that each of the examples described above is exemplary and the configurations illustrated in different examples can be partially replaced or combined. The same operation and effects due to the same configuration of a plurality of examples are not described sequentially for each example. Furthermore, the present invention is not limited to the examples described above. For example, it will be obvious to those skilled in the art that various changes, improvements, combinations, or the like can be made.

[0036] It should be understood that the invention is not limited to the above-described embodiment, but may be modified into various forms on the basis of the spirit of the invention. Additionally, the modifications are included in the scope of the invention.