A device and method for dressing a grinding wheel

Abstract

An embodiment of the present invention discloses a device for dressing a grinding wheel, the device comprising: a columnar dressing portion, the dressing portion being configured to rotate around its own central axis so as to dress the grinding teeth of the grinding wheel through the circumferential surface of the dressing portion; a distance sensor, the distance sensor being used to sense the feed distance of the grinding wheel relative to the circumferential surface of the dressing portion; wherein, when the distance sensor senses that the feed distance of the grinding wheel relative to the circumferential surface of the dressing portion reaches a first predetermined distance, the dressing operation ends.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a device and method for dressing a grinding wheel. Background Art

[0002] The production process of semiconductor silicon wafers usually includes processes such as crystal pulling, wire cutting, grinding, and polishing. Double-sided grinding is a grinding process used to grind the two main surfaces of the silicon wafer at the same time so that the silicon wafer has a highly flat surface. During the double-sided grinding process, a special device is required to hold the silicon wafer so that the grinding wheel can grind the two main surfaces of the silicon wafer at the same time. Usually, this holding device includes a pair of fluid static pressure plates arranged opposite to each other, and the silicon wafer is arranged between the two fluid static pressure plates in the vertical direction. The fluid static pressure plate can form a fluid barrier between itself and the main surface of the silicon wafer so that the silicon wafer can be kept upright without contacting the two fluid static pressure plates. At the same time, the two main surfaces of the silicon wafer can be ground using the opposing grinding wheels. Compared with physical clamping, the fluid clamping method of the fluid static pressure plate reduces damage to the silicon wafer and allows the silicon wafer to move (rotate) in the tangential direction relative to the surface of the fluid static pressure plate with less friction.

[0003] During the above-mentioned grinding process, the quality of the grinding wheel is crucial to the grinding quality. As the equipment continues to process, the grinding wheels on the left and right sides, especially the grinding teeth, will continue to be worn out. The worn grinding teeth may no longer be flat as a whole, and the roughness of the grinding teeth themselves may not meet the process requirements. These factors ultimately lead to the deterioration of the precision of processed silicon wafers. Therefore, regular dressing of the grinding wheel has a significant impact on the grinding process and the quality of silicon wafers. The grinding wheel needs to be dressed regularly. The current method is to align the circumferential edge of the disc-shaped dresser with the grinding surface of the grinding teeth. When the dresser and the grinding wheel rotate at the same time, the operator manually feeds the grinding wheel toward the dresser so that the dresser can dress the grinding surface of the grinding wheel.

[0004] However, how to accurately control the dressing amount of the grinding wheel by the dresser so that the dressed grinding wheel meets the predetermined requirements and multiple dressed grinding wheels have good consistency is a problem that needs to be solved urgently in the art. Summary of the invention

[0005] In view of this, an embodiment of the present invention hopes to provide a device and method for dressing grinding wheels, so as to control the progress of the dressing operation according to the feed amount of the grinding wheel relative to the dressing device, thereby accurately controlling the dressing amount of the grinding wheel, so that the dressed grinding wheel can meet the predetermined requirements and multiple dressed grinding wheels can have better consistency.

[0006] The technical solution of the present invention is achieved in this way:

[0007] In a first aspect, an embodiment of the present invention provides a device for dressing a grinding wheel, the device comprising:

[0008] A cylindrical dressing portion, the dressing portion being arranged to be rotatable about its own central axis so as to dress the grinding teeth of the grinding wheel through the circumferential surface of the dressing portion;

[0009] a distance sensor for sensing a feed distance of the grinding wheel relative to the circumferential surface of the dressing portion;

[0010] When the distance sensor senses that the feeding distance of the grinding wheel relative to the circumferential surface of the dressing portion reaches a first predetermined distance, the dressing operation ends.

[0011] In a second aspect, an embodiment of the present invention provides a method for dressing a grinding wheel, wherein the method is performed by using the apparatus according to the first aspect.

[0012] An embodiment of the present invention provides a device and method for dressing a grinding wheel; the device includes a distance sensor for sensing the feed distance of the grinding wheel relative to the circumferential surface of the dressing part. During the dressing process, the grinding wheel will continuously feed into the dressing part and the feed distance of the grinding wheel can represent the amount of dressing of the grinding wheel by the dressing part. Based on this, the actual feeding distance of the grinding wheel can be controlled to control the actual amount of dressing of the grinding wheel so as to make it consistent with the target dressing amount. Therefore, it can not only avoid the situation where the dressing amount of a single grinding wheel is insufficient or excessive, but also it is beneficial to control the consistency of multiple dressed grinding wheels during batch dressing, so as to achieve the purpose of controlling the quality consistency of the ground silicon wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of a conventional device for dressing a grinding wheel;

[0014] Figure 2 A schematic diagram of a device for dressing a grinding wheel provided in an embodiment of the present invention;

[0015] Figure 3 A schematic diagram of a device for dressing a grinding wheel provided in accordance with another embodiment of the present invention;

[0016] Figure 4 A schematic diagram of a device for dressing a grinding wheel provided in accordance with another embodiment of the present invention;

[0017] Figure 5 A schematic diagram of a device for dressing a grinding wheel provided according to yet another embodiment of the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0019] See also Figure 1 , which shows an embodiment of a conventional dressing device 1 for dressing a grinding wheel W, the dressing device 1 includes a substantially disc-shaped dressing portion 2 and a support shaft 3 that supports the dressing portion 2 from below and can drive the dressing portion 2 to rotate around its own rotation axis, wherein the dressing device dresses the grinding teeth T of the grinding wheel W through its circumferential surface while rotating around its own central axis.

[0020] At present, when the dressing device 1 is used to dress the grinding wheel, the operator first manually controls the alignment of the grinding teeth T of the grinding wheel W with the circumferential surface of the dressing part 2 based on visual observation. After the alignment, while the dressing device is rotating, the operator manually moves the grinding wheel W toward the dressing device 1 to dress the grinding teeth T of the grinding wheel W through the circumferential surface of the dressing part 2. In this process, the dressing amount of the grinding wheel is determined by the operator through visual observation and combined with operating experience. It is difficult to control the dressing amount of the grinding wheel to exactly reach the predetermined dressing amount in this way. Therefore, when multiple grinding wheels need to be dressed, it is basically impossible to ensure the consistency of the dimensions of the multiple grinding wheels after dressing, such as the tooth height and roughness of the grinding teeth. If these grinding wheels with poor consistency are used to produce silicon wafers, the roughness of the obtained silicon wafers is also difficult to achieve consistency.

[0021] To solve the above problems, see Figure 2 The embodiment of the present invention provides a device 100 for dressing a grinding wheel, the device 100 comprising: a columnar dressing portion 101, the dressing portion 101 being configured to rotate around its own central axis X so as to dress the grinding teeth T of the grinding wheel W through the circumferential surface 1011 of the dressing portion 101; a distance sensor 102, the distance sensor 102 being used to sense the feed distance of the grinding wheel W relative to the circumferential surface 1011 of the dressing portion 101; wherein, when the distance sensor 102 senses that the feed distance of the grinding wheel W relative to the circumferential surface 1011 of the dressing portion 101 reaches a first predetermined distance, the dressing operation ends. Figure 2 The examples shown are described in detail.

[0022] like Figure 2 As shown, the device 100 includes a dressing portion 101 and a distance sensor 102. When the device 100 is used to dress the grinding wheel W, the end of the grinding tooth T of the grinding wheel W is aligned toward the circumferential surface 1011 of the device 100 and moves toward the device 100. During the movement, the distance sensor 102 always senses the feeding distance of the grinding wheel W relative to the device 100. Figure 2In the example shown, the distance sensor 102 is configured to sense the distance between the surface of the grinding wheel W provided with the grinding teeth T and the circumferential surface 1011 of the dressing part 101, that is, the feed distance D1 of the grinding wheel W. When the grinding wheel W moves to contact the circumferential surface 1011 of the device 100, the device 100 starts to dress the grinding teeth T from the end of the grinding teeth T of the grinding wheel W through the circumferential surface 1011 by rotating around the central axis X. Once the feed distance D1 of the distance sensor 102 reaches a predetermined distance, the dressing operation ends. It should be noted that the predetermined distance corresponds to the amount of grinding teeth to be removed by dressing, and the amount of grinding teeth to be removed by dressing can be determined according to, for example, the actual wear of the grinding wheel, the grinding accuracy requirements, and the universality requirements during mass production. Therefore, performing the dressing operation based on the feed distance D1 can accurately achieve the target dressing amount, so that the dressed grinding wheel can meet the predetermined requirements.

[0023] An embodiment of the present invention provides a device 100 for dressing a grinding wheel; the device 100 includes a distance sensor 102 for sensing the feed distance of the grinding wheel W relative to the circumferential surface 1011 of the dressing portion 101. During the dressing process, the grinding wheel W will continuously feed toward the dressing portion 101 and the feed distance of the grinding wheel can represent the dressing amount of the grinding wheel W by the dressing portion 101. Based on this, the actual dressing amount of the grinding wheel can be controlled by controlling the actual feed distance of the grinding wheel to make it consistent with the target dressing amount. Therefore, not only can insufficient or excessive dressing of a single grinding wheel be avoided, but also the consistency of multiple dressed grinding wheels can be controlled during batch dressing, thereby achieving the purpose of controlling the quality consistency of the ground silicon wafers.

[0024] According to a preferred embodiment of the present invention, see Figure 3 The device 100 further includes a controller 103 communicating with the distance sensor 102, and the controller 103 is configured to stop the trimming part 101 from rotating when the distance sensor 102 senses that the feeding distance D1 reaches the first predetermined distance, thereby ending the trimming operation.

[0025] In order to improve cost-effectiveness, the dressing part 101 can be made to start rotating only when it contacts the grinding wheel W. Alternatively, in order to ensure stability at the beginning of the dressing operation and avoid damage to the grinding teeth caused by sudden start-up of the dressing part 101, the dressing part 101 can be made to rotate when the grinding wheel W approaches. Based on this, preferably, the controller 103 is configured to make the dressing part 101 start rotating when the distance sensor 102 senses that the feed distance D1 reaches a second predetermined distance, wherein the second predetermined distance can be determined according to actual production requirements.

[0026] In order to enable the dressing portion 101 to dress the grinding wheel through its entire circumferential surface 1011, preferably, the dressing portion 101 is configured to be able to reciprocate along the central axis while rotating around the central axis, thereby expanding the contact range of each grinding tooth with the circumferential surface 1011, rather than always dressing the grinding wheel in a fixed local area, thereby improving the uniformity and efficiency of dressing.

[0027] According to another preferred embodiment of the present invention, the length of the dressing portion 101 along the central axis is greater than the diameter of the grinding wheel, so that the grinding wheel can be dressed in a larger area.

[0028] In order to ensure that the dressing part 101 can be stably supported and to ensure that the debris generated during the dressing operation leaves the dressing device and the grinding wheel as quickly as possible to avoid interfering with the subsequent dressing operation, preferably, see Figure 4 The device 100 is arranged so that the central axis X of the dressing part 101 is along the vertical direction, and the device 100 also includes a base 104 arranged below the dressing part 101 along the central axis X, and the base 104 has a convex shape along the central axis X, so that the material falling on the base 104 leaves the base along the surface of the top of the base 104, thereby preventing these debris from accumulating on the dressing part 101 and affecting the dressing effect, and also preventing the debris from contaminating the grinding wheel.

[0029] During the dressing process, the friction between the dressing part 101 and the grinding teeth T will generate a lot of heat, which will not only affect the dressing effect, but also accelerate the wear of the dressing part and the grinding teeth. In order to reduce the influence of heat on the device 1 and the grinding wheel W, preferably, see Figure 5 The device 100 further includes an injector 105, which is used to inject coolant toward the dressing part 101 and the grinding wheel W when the dressing part 101 performs a dressing operation.

[0030] As an illustrative and non-limiting example, the trimming portion is made of diamond and a ceramic binder.

[0031] An embodiment of the present invention provides a method for dressing a grinding wheel, wherein the method is performed by using the above-mentioned apparatus.

[0032] It should be noted that the technical solutions described in the embodiments of the present invention can be combined arbitrarily without conflict.

[0033] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A device for dressing a grinding wheel, characterized in that: The device comprises: A cylindrical dressing portion, the dressing portion being arranged to be rotatable about its own central axis so as to dress the grinding teeth of the grinding wheel through the circumferential surface of the dressing portion; a distance sensor, the distance sensor being used to sense a feed distance of the grinding wheel relative to the circumferential surface of the dressing portion, the feed distance being used to characterize a dressing amount of the grinding wheel by the dressing portion; When the distance sensor senses that the feeding distance of the grinding wheel relative to the circumferential surface of the dressing portion reaches a first predetermined distance, the dressing operation ends.

2. The device according to claim 1, characterized in that The device further comprises a controller in communication with the distance sensor, wherein the controller is configured to stop the trimming part from rotating when the distance sensor senses that the feeding distance reaches the first predetermined distance.

3. The device according to claim 2, characterized in that The controller is configured to cause the trimming part to start rotating when the distance sensor senses that the feeding distance reaches a second predetermined distance.

4. The device according to claim 1, characterized in that The trimming portion is provided so as to be capable of reciprocating along the central axis while rotating about the central axis.

5. The device according to claim 4, characterized in that The length of the dressing portion along the central axis is greater than the diameter of the grinding wheel.

6. The device according to any one of claims 1 to 5, characterized in that The device is arranged so that the central axis of the trimming part is along the vertical direction, and the device also includes a base arranged below the trimming part along the central axis, and the base has a convex shape along the central axis to facilitate the material falling on the base to leave the base along the surface of the top of the base.

7. The device according to claim 6, characterized in that The apparatus further includes an injector for injecting a coolant toward the dressing section and the grinding wheel when the dressing section performs a dressing operation.

8. The device according to any one of claims 1 to 5, characterized in that The trimming portion is made of diamond and a ceramic binder.

9. A method for dressing a grinding wheel, characterized in that: The method is performed by using an apparatus according to any one of claims 1 to 8.

Images