Grinding Equipment

Abstract

To provide a grinding device for accurately measuring a dress amount of a grinding wheel.SOLUTION: A grinding device 1 includes: a grinding wheel spindle 22 which is provided with a grinding wheel 21 and is rotated together with the grinding wheel 21; regulation means 5 which has a notch 53a provided on the grinding wheel spindle 22 and a pin 53b that can be engaged with the notch 53a, and regulates rotation of the grinding wheel spindle 22 so that the grinding wheel spindle 22 is stopped at the same stop position; and a first sensor 25 which measures the thickness of the grinding wheel 21 at a measurement position corresponding to the stop position before and after dress execution by a dress board 31, and measures the dress amount of the grinding wheel 21.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a grinding device. [Background technology]

[0002] 2. Description of the Related Art In the field of semiconductor manufacturing, grinding devices are known that grind semiconductor wafers such as silicon wafers (hereinafter referred to as "wafers") to make them thin and flat.

[0003] The grinding device 4 described in Patent Document 1 dresses the grinding surface 310a by bringing a dressing board 8 into contact with a grinding wheel 310 before or after grinding the upper surface W1 of the workpiece W. Note that the reference symbols are the same as those in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-189456 A Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the dressing amount of a grinding wheel dressed with a dressing board is calculated from the difference in thickness of the grinding wheel before and after dressing. However, since the grinding wheel has a thickness variation of about 5 to 10 μm depending on the measurement position, it is difficult to accurately measure the dressing amount of the grinding wheel, and there is a problem that it is possible to not know whether the grinding wheel is properly dressed or not.

[0006] Therefore, a technical problem arises that must be solved in order to accurately measure the dressing amount of a grinding wheel, and an object of the present invention is to solve this problem. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the grinding apparatus of the present invention is a grinding apparatus equipped with a dressing board for dressing a grinding wheel, and is equipped with a grinding wheel spindle on which the grinding wheel is mounted and which rotates together with the grinding wheel, a regulating means for regulating the rotation of the grinding wheel spindle so that the grinding wheel spindle stops at the same stopping position, and a dressing amount measuring means for measuring the thickness of the grinding wheel at a measurement position corresponding to the stopping position before and after dressing by the dressing board, thereby measuring the amount of dressing of the grinding wheel.

[0008] According to this configuration, the regulating means regulates the rotation of the grinding wheel spindle so that it stops at a predetermined stopping position, so that the dressing amount measuring means measures the thickness of the grinding wheel at the same measurement position each time a thickness measurement is performed, thereby making it possible to accurately grasp the dressing amount of the grinding wheel.

[0009] In addition, it is preferable that the grinding apparatus according to the present invention further comprises a dress spindle that supports and rotates the dress board, and a remaining amount measuring means that measures the remaining amount of the dress board at a predetermined measurement position within the dress board.

[0010] According to this configuration, the servo motor can stop the dress spindle at a predetermined stopping position, so that each time the remaining amount is measured, the remaining amount measuring means measures the thickness of the dress board at the same measurement position, thereby making it possible to accurately grasp the remaining amount of the dress board. Effect of the Invention

[0011] In the present invention, the regulating means regulates the grinding wheel spindle at a predetermined stopping position, and the dressing amount measuring means measures the thickness of the grinding wheel at the same measurement position, so that the dressing amount of the grinding wheel can be accurately grasped. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a front view showing a grinding device according to an embodiment of the present invention. [Diagram 2]FIG. 2 is a front view showing how a grinding wheel is dressed with a dressing board. [Diagram 3] Schematic diagram showing a procedure for stopping the spindle at a predetermined position. [Figure 4] 5A to 5C are schematic diagrams showing a procedure for stopping a spindle at a predetermined position in the grinding device according to the first modified example. [Diagram 5] 13A and 13B are schematic diagrams showing a procedure for stopping the spindle at a predetermined position in the grinding device according to the second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present invention will be described with reference to the drawings. In the following, when the number, numerical value, amount, range, etc. of components are mentioned, the number is not limited to the specific number, and may be more or less than the specific number, unless otherwise specified or when it is clearly limited to a specific number in principle.

[0014] In addition, when referring to the shape or positional relationship of components, etc., this includes things that are substantially similar or approximate to those shapes, etc., unless otherwise specified or considered to be clearly different in principle.

[0015] In addition, the drawings may exaggerate characteristic parts to make the features easier to understand, and the dimensional ratios of the components may not be the same as the actual ones. In addition, in cross-sectional views, hatching of some components may be omitted to make the cross-sectional structure of the components easier to understand.

[0016] 1 is a front view showing the basic configuration of a grinding apparatus 1. The grinding apparatus 1 performs grinding processing on a wafer. The grinding apparatus 1 includes a grinding means 2 and a dressing means 3.

[0017] The grinding means 2 includes a grinding wheel 21, a grinding wheel spindle 22, and a spindle feed mechanism .

[0018] The grinding wheel 21 is, for example, a cup-shaped grinding wheel, and is attached to the lower end of a grinding wheel spindle 22 .

[0019] The grindstone spindle 22 is configured to be driven to rotate around the rotation axis 2a. Since a load acts on the grinding wheel 21 during grinding, an induction motor is used to drive the rotation of the grindstone spindle 22. At the upper end of the grindstone spindle 22, a small diameter rotation axis 22a and a large diameter rotation axis 22b, which will be described later, are provided in this order from the top.

[0020] The spindle feed mechanism 23 raises and lowers the grindstone spindle 22 in the vertical direction. The spindle feed mechanism 23 has a known configuration and is composed of, for example, a plurality of linear guides that guide the movement direction of the grindstone spindle 22, and a ball screw slider mechanism that raises and lowers the grindstone spindle 22. The spindle feed mechanism 23 is interposed between the grindstone spindle 22 and a column 24.

[0021] The grinding means 2 also includes a first sensor 25 for measuring the thickness of the grinding wheel 21 (height of the grinding surface 21a). The first sensor 25 is, for example, a contact-type thickness sensor that can be used in a wet environment. The first sensor 25 is supported by an arm 26 that can move back and forth in the horizontal direction. The first sensor 25 sends the measurement value to a control device 6, which will be described later.

[0022] The dressing means 3 includes a dressing board 31 and a dressing spindle 32. The dressing board 31 dresses the grinding surface 21a of the grinding wheel 21. The dressing spindle 32 is configured to be rotated around a rotation axis 3a by a servo motor (not shown). The dressing spindle 32 is also configured to be movable up and down.

[0023] The dressing means 3 also includes a second sensor 33 for measuring the height of the dressing board 31. The second sensor 33 is, for example, a contact-type thickness sensor that can be used in a wet environment. The second sensor 33 is supported by an arm 34 that can move back and forth in the horizontal direction. The second sensor 33 sends the measurement value to the control device 6, which will be described later.

[0024] The chuck 4 has an adsorbent (not shown) made of a porous material such as alumina embedded in its upper surface. The chuck 4 has a conduit (not shown) that runs through the inside and reaches the surface. The conduit is connected to a vacuum source, a compressed air source, or a water supply source via a rotary joint (not shown). When the vacuum source is activated, the workpiece placed on the chuck 4 is adsorbed and held by the chuck 4. When the compressed air source or water supply source is activated, the adsorption between the workpiece and the chuck 4 is released.

[0025] The chuck 4 includes a chuck spindle 41. The chuck spindle 41 is configured to be rotatably driven around a rotation axis 4a.

[0026] The grinding device 1 is provided with a regulating means 5 that regulates the stop position of the grindstone spindle 22. A specific configuration of the regulating means 5 will be described later.

[0027] The operation of the grinding apparatus 1 is controlled by a control device 6. The control device 6 controls each of the components constituting the grinding apparatus 1. The control device 6 is composed of, for example, a CPU, a memory, and the like. The functions of the control device 6 may be realized by control using software, or may be realized by operation using hardware.

[0028] As shown in FIG. 2, the grinding device 1 presses a dressing board 31 against the grinding wheel 21 to dress the grinding surface 21a.

[0029] Specifically, the upper surface of the dress board 31 is positioned higher than the upper surface of the chuck 4. Then, while rotating the grinding wheel spindle 22 and the dress spindle 32, the grinding wheel 21 is pressed against the dress board 31, thereby dressing the grinding surface 21a.

[0030] 1, the first sensor 25 measures the thickness of the grinding wheel 21 before and after dressing, and calculates the dressing amount of the grinding wheel 21 from the difference between the measured thicknesses. When the thickness of the grinding wheel 21 is measured, the grinding wheel 21 is stopped.

[0031] Since the grinding wheel spindle 22 is rotated by an induction motor, the stopping direction of the grinding wheel spindle 22 is not constant. Furthermore, the grinding surface 21a has a circumferential variation of about 5 to 10 μm. Therefore, the regulating means 5 regulates the stopping position of the grinding wheel spindle 22 as described below so that the measurement position where the first sensor 25 contacts the grinding surface 21a is consistent every time measurement is performed, thereby making it possible to accurately grasp the dressing amount of the grinding wheel 21.

[0032] The second sensor 33 measures the thickness of the dress board 31 after dressing, and calculates the remaining amount of the dress board 31. The second sensor 33 also measures the thickness of the dress board 31 before and after dressing, and calculates the amount of wear of the dress board 31 from the difference between the thicknesses.

[0033] Since the dress spindle 32 is rotated by a servo motor, the direction in which the dress spindle 32 stops can be set arbitrarily. That is, by controlling the stop position of the dress spindle 32 so that the measurement position where the second sensor 33 contacts the dress board 31 is always the same, the wear amount and remaining amount of the dress board 31 can be accurately grasped.

[0034] Next, the configuration of the restricting means 5 will be described with reference to FIG.

[0035] The regulating means 5 includes a wheel 51 , a rotational speed sensor 52 , and a positioning mechanism 53 .

[0036] The wheel 51 is provided around the outer surface of the small diameter rotating shaft 22a connected to the induction motor, and is formed with projections and recesses along the circumferential direction.

[0037] The rotation speed sensor 52 is provided to face the wheel 51. The rotation speed sensor 52 detects unevenness of the wheel 51 and detects the rotation speed of the grindstone spindle 22.

[0038] The positioning mechanism 53 includes a notch 53a recessed in the outer surface of the large diameter rotating shaft 22b connected to the induction motor, and a pin 53b that can fit into the notch 53a. The pin 53b is attached to the tip of an air cylinder 53c and can move back and forth in the horizontal direction.

[0039] Next, the operation of the regulating means 5 will be described with reference to Fig. 3. First, the rotation speed sensor 52 detects the rotation speed of the grindstone spindle 22, as shown in Fig. 3(a).

[0040] Next, when the rotation speed sensor 52 detects that the rotation speed of the grindstone spindle 22 has decelerated to a predetermined speed or lower, as shown in Fig. 3(b), the air cylinder 53c presses the pin 53b against the grindstone spindle 22. In this way, by pressing the pin 53b against the grindstone spindle 22 after the grindstone spindle 22 has shifted to a low-speed rotation range, it is possible to prevent the pin 53b from colliding with the grindstone spindle 22 rotating at high speed and causing damage.

[0041] Then, when the notch 53a reaches the pin 53b, the pin 53b fits into the notch 53a, as shown in Fig. 3(c), thereby positioning the grinding wheel spindle 22 at a predetermined stop position. This ensures that the measurement position where the first sensor 25 contacts the grinding surface 21a is always the same, and the dressing amount of the grinding wheel 21 can be accurately grasped.

[0042] Next, a grinding device 1 according to a first modified example of the above-mentioned embodiment will be described with reference to Fig. 4. This modified example has the same configuration as the above-mentioned embodiment except for the configuration described below.

[0043] The wheel 51 is formed in a substantially circular ring shape, and has one protrusion 51a formed on the outer periphery.

[0044] The positioning mechanism 53 is a so-called electromagnetic braking mechanism, and includes a rotating magnet 53d embedded in the outer circumferential surface of the large-diameter rotating shaft 22b, and a fixed magnet 53e attached to the tip of an air cylinder 53c and movable back and forth in the horizontal direction. The rotating magnet 53d and the fixed magnet 53e have magnetic poles set so that they attract each other. The rotating magnet 53d and the fixed magnet 53e may be either permanent magnets or electromagnets.

[0045] Next, the operation of the regulating means 5 applied to this modified example will be described with reference to Fig. 4. First, as shown in Fig. 4(a), the rotation speed sensor 52 detects the convex portion 51a of the wheel 51 and detects the rotation speed of the grindstone spindle 22.

[0046] Next, when the rotation speed sensor 52 detects that the rotation speed of the grindstone spindle 22 has decelerated to a predetermined speed or lower, as shown in Fig. 4(b), the air cylinder 53c brings the fixed-side magnet 53e closer to the grindstone spindle 22. Every time the rotation-side magnet 53d passes near the fixed-side magnet 53e, an attractive force acts between the rotation-side magnet 53d and the fixed-side magnet 53e, and the grindstone spindle 22 is further decelerated.

[0047] 4(c), the rotating magnet 53d and the fixed magnet 53e attract each other at the opposing positions, so that the grinding wheel spindle 22 is positioned at a predetermined stop position. This ensures that the measurement position where the first sensor 25 contacts the grinding surface 21a is always the same, and the dressing amount of the grinding wheel 21 can be accurately grasped.

[0048] Next, a grinding device 1 according to a second modified example of the above-mentioned embodiment will be described with reference to Fig. 5. This modified example has the same configuration as the above-mentioned embodiment except for the configuration described below.

[0049] The wheel 51 is formed in a substantially circular ring shape, and has one protrusion 51a formed on the outer periphery.

[0050] The positioning mechanism 53 is a so-called friction braking mechanism, and includes a brake pad 53f that is pressed against the outer periphery of the large diameter rotating shaft 22b. The brake pad 53f is configured to be movable back and forth in the horizontal direction by an air cylinder (not shown).

[0051] Next, the operation of the regulating means 5 applied to this modified example will be described with reference to Fig. 5. First, the rotation speed sensor 52 detects the convex portion 51a of the wheel 51, and detects the rotation speed of the grindstone spindle 22.

[0052] Next, when the rotation speed sensor 52 detects that the rotation speed of the grindstone spindle 22 has decelerated to a predetermined speed or lower, the air cylinder presses the brake pad 53f against the large diameter rotating shaft 22b, and the grindstone spindle 22 is braked.

[0053] The brake pad 53f stops the grindstone spindle 22 so that the rotation speed sensor 52 faces the protrusion 51a of the wheel 51, and the grindstone spindle 22 is positioned at a predetermined stop position. This ensures that the measurement position where the first sensor 25 contacts the grinding surface 21a is always the same, and the dressing amount of the grinding wheel 21 can be accurately grasped.

[0054] Furthermore, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention, and the present invention naturally includes such modified versions. Furthermore, the above-described embodiments and modifications may be combined with each other. [Explanation of symbols]

[0055] 1. Grinding device 2. Grinding means 21 Grinding wheel 21a: Grinding surface 22 Grinding wheel spindle 22a Small diameter rotating shaft 22b Large diameter rotating shaft 23 Spindle feed mechanism 24 Column 25 First sensor (dress amount measuring means) 26 Arm 3. Dressing means 31 ···Dress Board 32 ···Dressing spindle 33 Second sensor (remaining amount measuring means) 34 Arm 4. Chuck 41 Chuck spindle 5. Regulatory measures 51 ···Wheels 51a...Convex part 52 Rotational speed sensor 53 Positioning mechanism 53a...Notch 53b···Pin 53c Air cylinder 53d Rotating magnet 53e Fixed side magnet 53f Brake pads 6. Control device

Claims

1. A grinding device equipped with a dressing board for dressing a grinding wheel, a grinding wheel spindle on which the grinding wheel is mounted and which rotates together with the grinding wheel; a restricting means for restricting the rotation of the grindstone spindle so that the grindstone spindle stops at the same stop position; a dressing amount measuring means for measuring a thickness of the grinding wheel at the same measuring position corresponding to the stop position before and after dressing by the dressing board, thereby measuring a dressing amount of the grinding wheel; A grinding device comprising:

2. a dressing spindle for supporting and rotating the dressing board; a remaining amount measuring means for measuring a remaining amount of the dress board at a predetermined measuring position within the dress board; 2. The grinding apparatus of claim 1, further comprising:

Images