Wafer trimming equipment

Abstract

The utility model provides wafer trimming and trimming equipment, which comprises a main process area and a control system, and is characterized in that the main process area comprises a wafer bearing workbench, a driving main shaft and a cutting blade connected with the driving main shaft; the control system controls the driving main shaft and the wafer bearing workbench; the cutting blade comprises a main body part and a plurality of sharpening particles, the main body part is a cylinder with a preset diameter and a preset length, and the sharpening particles are distributed on the side surface of the cylindrical main body part; the driving main shaft is connected with a central shaft of the cylindrical main body part; during working, the cylindrical main body part is parallel to a wafer placed on the wafer bearing workbench, and the control system controls the overlapping length of the cutting blade connected with the driving main shaft and the edge of the wafer and the depth of the cutting blade during rotary cutting and controls the wafer bearing workbench to rotate at a preset rotating speed. And completing the girdling of the edge of the wafer.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor manufacturing, in particular to a wafer edge trimming device. Background Art

[0002] In the MEMS (micro-electro-mechanical system) process, for example, the wafer needs to be trimmed in the process after wafer bonding to prevent the wafer from being broken during subsequent thinning or other manufacturing processes. The edge of the wafer needs to be trimmed. In other semiconductor processes, the edge trimming process is also usually required. It should be noted that some of the edge trimming processes do not require the entire wafer thickness to be completely removed.

[0003] The blade of the current wafer trimming main equipment can only trim 1mm width at a time. For wafer edges with a circular cutting width exceeding 1mm, multiple circular cutting is required. This directly results in an increase in the time consumption of this trimming process, affecting the production capacity of the machine. At the same time, multiple circular cuttings have different precisions between different times, which can easily lead to uneven surface of the wafer edge after circular cutting. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a wafer trimming and trimming device, including a main process area and a control system, wherein the main process area includes: a wafer carrying worktable, a driving spindle and a cutting blade connected to the driving spindle; the control system controls the driving spindle and the wafer carrying worktable; the cutting blade includes a main body part and a plurality of grinding grains, the main body part is a cylinder with a preset diameter and a preset length, and the plurality of grinding grains are distributed on the side surface of the cylindrical main body part; the driving spindle is connected to the central axis of the cylindrical main body part;

[0005] During operation, the cylindrical main body is parallel to the wafer placed on the wafer carrying workbench, and the control system controls the length of overlap between the cutting blade connected to the driving spindle and the edge of the wafer and the depth of the cutting blade when rotating and cutting, and controls the wafer carrying workbench to rotate at a preset speed to complete the circular cutting of the wafer edge.

[0006] Preferably, the preset length of the main body portion of the cutting blade is not less than 5 mm.

[0007] Preferably, the preset diameter of the main body portion of the cutting blade is greater than 1 mm.

[0008] Preferably, the main process area also includes: a trimming width measurement sensor, which is arranged in the main process area on the side of the wafer supporting workbench; the trimming width measurement is communicatively connected to the control system, and in a working state, the trimming width of the measured wafer is fed back to the control system.

[0009] Preferably, the main process area also includes: a trimming depth measurement sensor, which is arranged in the main process area vertically above the edge portion of the wafer supporting workbench; the trimming depth measurement sensor is communicatively connected to the control system, and in a working state, the measured trimming depth of the wafer is fed back to the control system.

[0010] Preferably, the trimming width measurement sensor or the trimming depth measurement sensor is a laser ranging sensor.

[0011] Preferably, the abrasive particles are diamond particles.

[0012] Compared with the prior art, the utility model has the following technical effects:

[0013] The utility model controls the overlapping length of the cutting blade and the edge of the wafer through a control system, and can complete the cutting of the edges of wafers of different widths at one time, adapting to the needs of different cutting processes, and at the same time can improve the production capacity of the machine and the flatness of the edge surface of the wafer after cutting. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0015] Figure 1 It is a structural diagram of a wafer edge trimming device provided by an embodiment of the utility model;

[0016] Figure 2 This is a front view of a cutting blade provided by an embodiment of the utility model;

[0017] Figure 3 It is a side view of a cutting blade provided by an embodiment of the utility model;

[0018] Figure 4a-4d This is a schematic diagram of the structure of the edge trimming process of a wafer edge trimming device provided by an embodiment of the utility model;

[0019] Figure 5is a structural diagram of a wafer edge trimming device provided by another embodiment of the utility model;

[0020] Figure 6a-6d It is a structural schematic diagram of the edge trimming working process of a wafer edge trimming device provided by another embodiment of the utility model.

[0021] Description of reference numerals:

[0022] 1- Wafer carrying table;

[0023] 2- Wafer;

[0024] 3- cutting blade;

[0025] 31-Main body;

[0026] 32- sharpening grains;

[0027] 4-driving spindle;

[0028] 5- Cutting depth measurement sensor;

[0029] 6- Cutting edge width measurement sensor. DETAILED DESCRIPTION

[0030] As described in the background technology, in the MEMS (micro-electro-mechanical system) process, for example, in the process after wafer bonding, it is necessary to trim the wafer to prevent the wafer from being broken during subsequent thinning or other manufacturing processes after bonding. It is necessary to trim the edge of the wafer. In other semiconductor processes, a trimming process is also usually required. However, the cutting width of the blade of the main equipment for wafer trimming is 1mm, so it can only complete the trimming of 1mm width at a time. For the crystal edge with a ring cutting width exceeding 1mm, it is necessary to perform ring cutting multiple times. Such a direct result is likely to lead to an increase in the time consumption of this trimming process, affecting the production capacity of the machine. At the same time, multiple ring cuttings and the difference in the precision of ring cutting between different times are likely to lead to the unevenness of the edge surface of the wafer after ring cutting.

[0031] In order to solve the above problems, the utility model provides a wafer trimming device, please refer to Figure 1 , including a wafer carrying worktable 1, a driving spindle 4 and a cutting blade 3 connected to the driving spindle 4; a control system controls the driving spindle 4 and the wafer carrying worktable 1; the cutting blade 3 includes a main body 31 and a plurality of grinding grains 32, the main body 31 is a cylinder with a preset diameter and a preset length, and the plurality of grinding grains 32 are distributed on the side surface of the cylindrical main body 31; the driving spindle 4 is connected to the central axis of the cylindrical main body 31.

[0032] During operation, the cylindrical main body 31 is parallel to the wafer 2 placed on the wafer supporting workbench 1. The control system controls the length of overlap between the cutting blade 3 connected to the driving spindle 4 and the edge of the wafer 2 and the depth of the cutting blade 3 when rotating and cutting, and controls the wafer supporting workbench 1 to rotate at a preset speed to complete the circular cutting of the wafer edge.

[0033] In the above technical solution provided by the utility model, the control system controls the overlapping length of the cutting blade and the edge of the wafer according to the width of the edge of the wafer to be cut, so that the cutting of the wafer edge can be completed with a one-time circular cutting without multiple circular cutting. For the edges of wafers to be cut of different widths, the utility model controls the overlapping length of the cutting blade and the edge of the wafer through the control system, and can complete the cutting of the edges of wafers of different widths at one time, which can meet the needs of different cutting processes, and at the same time can improve the production capacity of the machine, as well as the flatness of the edge surface of the wafer after cutting. Therefore, the above technical problems are solved.

[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0035] Please refer to Figure 1 An embodiment of the utility model provides a wafer trimming device, including a wafer carrying worktable 1, a driving spindle 4 and a cutting blade 3 connected to the driving spindle 4, and a control system controls the driving spindle 4 and the wafer carrying worktable 1.

[0036] In order to trim the wafer edge in one step, in one embodiment, the wafer carrying worktable 1 is used to carry the wafer 2, and the wafer carrying worktable 1 can be controlled by a control system to perform rotational motion, and the wafer carrying worktable 1 will drive the wafer 2 thereon to rotate together.

[0037] In one embodiment, the control system can control the first rotation driving device. The first rotation driving device is drivingly connected to the wafer carrying table 1. When the first rotation driving device is in operation, the wafer carrying table 1 is driven to rotate, and the wafer carrying table 1 drives the wafer 2 thereon to rotate together.

[0038] The control system can control the rotation of the wafer carrying table 1 and the movement of the driving spindle 4. In one embodiment, the control system can also control the second rotary drive device and the mobile drive device. The mobile drive device is arranged in the driving spindle 4 to control the movement of the driving spindle 4. The mobile drive device is connected to the second rotary drive device for driving and controlling the second rotary drive device and the driving spindle 4 to move together. As for the mobile drive device is a multi-axis drive device, this embodiment does not make specific restrictions on this, and can be set according to actual use requirements. In this embodiment, the preferred mobile drive device is a two-axis drive device, which can control the driving spindle 4 to move along the XZ axis respectively. In this embodiment, the mobile drive device only needs to be adjusted in the X direction, that is, the length direction of the overlap between the cutting blade and the edge of the wafer, and the thickness direction of the wafer, that is, the Z direction. The second rotary drive device is arranged in the spindle, which can drive the cutting blade to perform rotary cutting according to a preset speed. Of course, the speed of this cutting blade can be different according to the setting of the control system. In actual application examples, the speed of the cutting blade can be reasonably set according to the material and size of the cut wafer and the size of the required trimming.

[0039] Of course, the above is only one embodiment of the control system. Since the control system is a mature technology in this field, technicians in this field can also choose control systems with different structures according to actual use requirements. The utility model does not make specific restrictions on this. However, as long as the movement of the driving spindle 4 and the wafer carrying worktable 1 is controlled by the control system, it belongs to the protection scope of the utility model.

[0040] Please refer to Figure 2 and Figure 3 The cutting blade 3 includes a main body 31 and a plurality of sharpening grains 32. The main body 31 is a cylindrical structure with a preset diameter and a preset length. The plurality of sharpening grains 32 are distributed on the side surface of the cylindrical main body 31, that is, the outer peripheral surface of the cylindrical main body 31. The driving spindle 4 is connected to the central axis of the cylindrical main body 31 to achieve coaxial fixation of the driving spindle 4 and the cylindrical main body 31.

[0041] When the wafer trimming equipment is working, the cylindrical main body 31 of the cutting blade 3 is parallel to the wafer 2 placed on the wafer supporting workbench 1, and the control system controls the length of the overlap between the cutting blade 3 and the edge of the wafer 2 and the depth of the cutting blade 3 when rotating and cutting, and controls the wafer supporting workbench 1 to rotate at a preset speed to complete the circular cutting of the edge of the wafer 2.

[0042] The main body 31 is cylindrical with a preset length so that it can completely overlap with the edge of the wafer, so as to complete the circumferential cutting of the wafer edge in one go. In one embodiment, the preset length of the cylindrical main body 31 of the cutting blade 3 is not less than the width of the edge to be cut of the wafer 2, so as to ensure that the cutting blade 3 can complete the circumferential cutting of the edge of the wafer 2 in one go when cutting. In the currently more common MEMS processes and other semiconductor processes, the width of the edge to be cut of the wafer generally does not exceed 5mm. Therefore, in order to be able to cut edges of different sizes, the preset length of the cylindrical main body 31 of the cutting blade 3 is not less than 5mm. Of course, the preset length of the cylindrical main body 31 of the cutting blade 3 is not limited to this and can be set according to actual use requirements.

[0043] The utility model presets the diameter of the main part 31 of the cutting blade 3 to be greater than 1 mm. In the present embodiment, the diameter of the cylindrical main part 31 of the cutting blade 3 is generally greater than the thickness of a conventional wafer. In the current MEMS process and some other semiconductor processes, the cutting depth of the edge of the wafer 2 is generally less than or equal to the thickness of a conventional wafer. Therefore, in this embodiment, the preset diameter of the main part of the cutting blade 3 is greater than 1 mm, the purpose is to perform the cutting at the edge of the wafer, and the rotating cutting blade is partially exposed on the surface of the wafer to be cut, so that the thickness cutting can be completed in one go.

[0044] In order to improve the cutting effect, grinding grains 32 are arranged on the side surface of the main body 31 of the cutting blade 3. The present invention does not specifically limit the material of the grinding grains 32. In order to reduce material loss, it is preferred to use grains with higher hardness, such as diamond grains, which can greatly improve the wear resistance of the cutting blade 3.

[0045] The wafer edge trimming equipment's edge trimming process is as follows:

[0046] First, please refer to Figure 4a , place the wafer 2 on the wafer carrying table 1, and the cutting blade 3 is controlled by the control system to approach the wafer 2 and stop on the upper surface of the edge to be cut. At this time, the length of the overlap between the cutting blade 3 and the edge of the wafer 2 is the width of the edge to be cut. Please refer to Figure 4b .

[0047] Then, please refer to Figure 4c The control system controls the cutting blade 3 to rotate and controls the cutting blade 3 to move downward (in the cutting edge depth direction) to a preset initial depth position.

[0048] Next, please refer to Figure 4d The control system controls the wafer carrying table 1 to rotate at a preset speed to cut the edge of the wafer.

[0049] During the cutting process, the control system controls the driving spindle 4, thereby driving the cutting blade 3 to move in the cutting edge depth Z direction until the preset cutting edge depth is reached. After the wafer edge circumcision operation is completed, the cutting blade 3 is controlled by the control system to move back to the initial position.

[0050] In order to improve the cutting accuracy of the wafer edge width, in one embodiment, please refer to Figure 5 , the main process area also includes a trimming width measurement sensor 6, which is arranged in the main process area on the side of the wafer carrying workbench 1; the trimming width measurement sensor 6 is connected to the control system in communication, and in a working state, the measured trimming width of the wafer is fed back to the control system. In this embodiment, the trimming width measurement sensor 6 is arranged on the side of the wafer carrying workbench 1, and the purpose is to monitor the trimming width of the wafer 2 in real time during the cutting process, and feed back the measured trimming width of the wafer 2 to the control system, and the control system fine-tunes the position of the cutting blade 3 in the trimming width direction according to the actual trimming width, such as: if the trimming width requirement is not met, the control system fine-tunes the cutting blade 3 to move toward the center of the wafer 2 as needed to meet the trimming width requirement; if the trimming width requirement is exceeded, the control system fine-tunes the cutting blade 3 to move outward from the wafer 2 as needed to meet the trimming width requirement; if the trimming width requirement is met, the control system does not need to fine-tune the position of the cutting blade 3 in the trimming width direction, and the cutting blade 3 still cuts according to the preset width cutting path.

[0051] The present embodiment does not limit the specific type of the trimming width measuring sensor 6, such as an ultrasonic distance measuring sensor, an infrared distance measuring sensor, and a laser distance measuring sensor, etc., and those skilled in the art can select it as needed. Different types of measuring sensors can be installed in suitable positions in the wafer trimming equipment according to actual needs, and are not limited to the installation positions exemplified in this embodiment.

[0052] In order to improve the cutting accuracy of the wafer edge depth, in one embodiment, please refer to Figure 5, the main process area also includes a trimming depth measurement sensor 5, which is arranged in the main process area above the edge of the vertical wafer carrying workbench 1. The trimming depth measurement sensor 5 is connected to the control system in communication, and in a working state, the measured trimming depth of the wafer is fed back to the control system. In this embodiment, the trimming depth measurement sensor 5 is arranged above the edge of the vertical wafer carrying workbench 1, and the purpose is to measure the trimming depth of the wafer 2 during the cutting process, and feed back the measured trimming depth of the wafer 2 to the control system, and the control system fine-tunes the position of the cutting blade 3 at the trimming depth according to the actual trimming depth. If the trimming depth requirement is not met, the control system fine-tunes the cutting blade 3 as needed to increase the depth of cutting; if the trimming depth requirement is exceeded, the control system fine-tunes the cutting blade 3 as needed to reduce the depth of cutting; if the trimming depth requirement is met, the control system does not need to fine-tune the position of the cutting blade 3 in the trimming depth direction, and the cutting blade 3 still cuts according to the preset depth cutting path.

[0053] This embodiment does not limit the specific type of the trimming depth measurement sensor 5, such as an ultrasonic distance measuring sensor, an infrared distance measuring sensor, and a laser distance measuring sensor, etc., and technicians in this field can choose as needed. Different types of measurement sensors can be installed in suitable locations in the wafer trimming equipment according to actual needs, and are not limited to the installation locations listed in this embodiment. Another embodiment of the utility model provides a wafer trimming equipment, please refer to Figure 5 , including the main process area and the control system described in the above embodiment, the main process area includes the wafer carrying worktable 1, the driving spindle 4, the cutting blade 3 connected to the driving spindle 4, the trimming width measurement sensor 6 and the trimming depth measurement sensor 5 described in the above embodiment, the control system controls the movement of the driving spindle 4 and the wafer carrying worktable 1, and the trimming width measurement sensor 6 and the trimming depth measurement sensor 5 are both connected to the control system for communication. The trimming process of the wafer trimming equipment is as follows:

[0054] First, please refer to Figure 6a , place the wafer 2 on the wafer carrying table 1, and the cutting blade 3 is controlled by the control system to approach the wafer 2 and stop on the upper surface of the edge to be cut. At this time, the length of the overlap between the cutting blade 3 and the edge of the wafer 2 is the width of the edge to be cut. Please refer to Figure 6b .

[0055] Then, please refer to Figure 6c The control system controls the cutting blade 3 to rotate, and controls the cutting blade 3 to move downward (in the cutting edge depth direction) to a preset initial depth position for positioning.

[0056] Next, please refer to Figure 6d, the control system controls the wafer carrying worktable 1 to rotate respectively to cut the edge of the wafer.

[0057] During the cutting process, the trimming width measuring sensor 6 and the trimming depth measuring sensor 5 work, and respectively monitor the trimming width and trimming depth information of the wafer 2 in real time, and transmit the monitoring information to the control system in real time. The control system controls whether to fine-tune the trimming width and trimming depth of the cutting blade 3 according to the specific situation: if the trimming width requirement is not met or exceeded, the control system fine-tunes the position of the cutting blade 3 in the trimming width direction as required; if the trimming width requirement is met, the control system does not need to fine-tune the position of the cutting blade 3 in the trimming width direction. If the trimming depth requirement is not met or exceeded, the control system fine-tunes the position of the cutting blade 3 in the trimming depth direction as required; if the trimming depth requirement is met, the control system does not need to fine-tune the position of the cutting blade 3 in the trimming depth direction.

[0058] During the cutting process, the control system controls the cutting blade 3 to move downward, that is, in the cutting edge depth direction, until the preset cutting edge depth is reached. After the wafer edge circumcision operation is completed, the cutting blade 3 is controlled by the control system to move back to the initial position.

[0059] In this embodiment, the wafer trimming equipment is provided with a trimming width measurement sensor 6 and a trimming depth measurement sensor 5 at the same time; the control system monitors the position of the driving spindle 5 in the X direction and the Z direction according to the measurement data of these two types of sensors, and can adjust and control the position of the cutting blade 3 on the driving spindle 4, thereby improving the accuracy of the wafer trimming equipment and the consistency and stability of the edge cutting of different batches of wafers by the wafer trimming equipment.

[0060] The utility model controls the overlapping length of the cutting blade and the edge of the wafer through a control system to complete the cutting of the wafer edge in one go without repeated cutting. Therefore, it can adapt to the needs of different cutting processes and at the same time improve the production capacity of the machine and the flatness of the edge surface of the wafer after cutting.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A wafer trimming device, comprising a main process area and a control system, characterized in that: The main process area includes: a wafer carrying worktable, a driving spindle and a cutting blade connected to the driving spindle; the control system controls the driving spindle and the wafer carrying worktable; the cutting blade includes a main body and a plurality of grinding grains, the main body is a cylinder with a preset diameter and a preset length, and the plurality of grinding grains are distributed on the side surface of the cylindrical main body; the driving spindle is connected to the central axis of the cylindrical main body; During operation, the cylindrical main body is parallel to the wafer placed on the wafer carrying workbench, and the control system controls the length of overlap between the cutting blade connected to the driving spindle and the edge of the wafer and the depth of the cutting blade when rotating and cutting, and controls the wafer carrying workbench to rotate at a preset speed to complete the circular cutting of the wafer edge.

2. The wafer trimming equipment according to claim 1, characterized in that: The preset length of the main body portion of the cutting blade is not less than 5 mm.

3. The wafer trimming equipment according to claim 1, characterized in that: The predetermined diameter of the main body portion of the cutting blade is greater than 1 mm.

4. The wafer trimming equipment according to claim 1, characterized in that: The main process area also includes: a trimming width measurement sensor, which is arranged in the main process area on the side of the wafer supporting workbench; the trimming width measurement sensor is communicatively connected to the control system, and in a working state, the measured trimming width of the wafer is fed back to the control system.

5. The wafer trimming equipment according to claim 1, characterized in that: The main process area also includes: a trimming depth measurement sensor, which is arranged in the main process area vertically above the edge portion of the wafer supporting workbench; the trimming depth measurement sensor is communicatively connected to the control system, and in a working state, the measured trimming depth of the wafer is fed back to the control system.

6. The wafer edge trimming equipment according to claim 4 or 5, characterized in that: The trimming width measurement sensor or the trimming depth measurement sensor is a laser distance measurement sensor.

7. The wafer trimming equipment according to claim 1, characterized in that: The grinding grains are diamond grains.

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