Sapphire wafer grinding device and method

Abstract

The invention discloses a sapphire wafer grinding device and a sapphire wafer grinding method, belongs to the technical field of sapphire double-sided grinding processing, and aims to solve the problem that the subsequent processing quality of a sapphire wafer is influenced due to the fact that the flatness of a disc surface of a grinding disc is changed due to the fact that the flow of grinding liquid is unstable during double-sided grinding of the existing sapphire wafer. According to the sapphire double-sided grinding machine, the grinding fluid supplementing unit, the grinding fluid conveying unit and the grinding fluid recycling unit are additionally arranged on the basis of a traditional double-sided grinding machine, the working flow of grinding fluid can be stabilized in the roughing grinding process, and the removal rate and roughness stability of the sapphire double-sided grinding machine are improved; meanwhile, timely supplement can be carried out when the grinding liquid is insufficient in the roughing grinding process, secondary grinding is carried out by utilizing the grinding liquid used in the roughing grinding process in the lower thickness grinding process, and the lower thickness grinding liquid is quantified, so that the removal rates of the sapphire wafers in each batch are the same, the quality of the sapphire wafers is stabilized, and the quality of the sapphire wafers is improved. The sapphire wafer grinding device is used for grinding sapphire wafers.

Description

Technical Field

[0001] The invention belongs to the technical field of sapphire double-sided grinding and processing, and in particular relates to a sapphire wafer grinding device and a grinding method. Background Art

[0002] As an important basic material for modern industry, sapphire single crystal material has superior properties in chemistry, electricity, mechanics, optics, surface properties, thermodynamics and durability. Sapphire has mature production technology, good device quality, good chemical stability, can be used in high-temperature growth processes, high mechanical strength, easy to handle and clean, and good transmittance in ultraviolet, infrared, visible light and microwave bands. Therefore, sapphire crystal materials are widely used in LED substrate materials, various consumer electronic products, high-intensity lasers, smart wearable devices, aerospace and large-scale integrated circuits.

[0003] In recent years, due to the emergence of display technologies such as OLED, QLED, Mini LED and Micro LED, integrated circuit chip packaging technology has developed towards smaller size, higher density, higher performance and more functions, and the corresponding wafer quality requirements have also increased. Therefore, the development of high-quality processing technology for sapphire wafers has become a necessary task for current development.

[0004] The double-sided grinding technology of sapphire wafers is mainly aimed at removing the surface line marks and damaged layers of the cutting disc, and trimming the flatness and warpage of the wafer, laying a good foundation for the subsequent double-sided chemical polishing of the sapphire wafer. After the double-sided grinding process, due to the unstable flow of the grinding liquid, the surface flatness of the grinding disc changes due to the pressure, speed, etc. through the wafer, which affects the subsequent processing quality of the sapphire wafer. Summary of the invention

[0005] The present invention aims to solve the problem that when the existing sapphire wafer is double-sided ground, the flow rate of the grinding liquid is unstable, resulting in a change in the flatness of the grinding disc surface, which affects the subsequent processing quality of the sapphire wafer. A sapphire wafer grinding device and a grinding method are provided.

[0006] A sapphire wafer grinding device, the grinding device comprises a double-sided grinding machine body, and also comprises a grinding liquid replenishing unit, a grinding liquid conveying unit and a grinding liquid recovery unit, the grinding liquid replenishing unit is arranged outside the double-sided grinding machine body, and the liquid outlet end of the grinding liquid replenishing unit is connected with the liquid inlet end of the grinding liquid conveying unit, the grinding liquid conveying unit is installed on the upper part of the double-sided grinding machine body, and the liquid outlet end of the grinding liquid conveying unit is connected with the liquid inlet end of the double-sided grinding machine body, the grinding liquid recovery unit is installed on the lower part of the double-sided grinding machine body, and the liquid inlet end of the grinding liquid recovery unit is connected with the liquid outlet end of the double-sided grinding machine body, and the liquid outlet end of the grinding liquid recovery unit is connected with the grinding liquid reflux end of the double-sided grinding machine body;

[0007] Furthermore, the grinding liquid replenishing unit includes a grinding liquid pre-storage barrel and a No. 1 liquid pump, the grinding liquid pre-storage barrel is arranged outside the double-sided grinder body, and a sufficient amount of grinding liquid is contained in the grinding liquid pre-storage barrel, the No. 1 liquid pump is arranged on the grinding liquid pre-storage barrel, and the liquid inlet end of the No. 1 liquid pump is connected with the grinding liquid pre-storage barrel through a liquid infusion tube, and the liquid outlet end of the No. 1 liquid pump is connected with the liquid inlet end of the grinding liquid delivery unit through a liquid infusion tube;

[0008] Furthermore, the grinding liquid delivery unit includes a grinding liquid delivery barrel and a peristaltic pump, both of which are installed on the upper part of the double-sided grinder body, the liquid outlet end of the No. 1 liquid pump is connected to the liquid inlet end of the grinding liquid delivery barrel through an infusion tube, and the liquid outlet end of the grinding liquid delivery barrel is connected to the liquid inlet end of the double-sided grinder body through the peristaltic pump;

[0009] Furthermore, the installation height of the grinding liquid delivery barrel is higher than the installation height of the peristaltic pump;

[0010] Further, the peristaltic pump has a length of 259 mm, a width of 157 mm, a height of 237 mm, 3-6 pump heads, a speed range of 0-150 rpm, and a flow range of 0-645 ml / min;

[0011] Further, the grinding liquid recovery unit includes a grinding liquid recovery barrel and a second liquid pump, the grinding liquid recovery barrel and the second liquid pump are both installed at the lower part of the double-sided grinder body, and the liquid inlet end of the grinding liquid recovery barrel is connected with the liquid outlet end of the double-sided grinder body, the liquid outlet end of the grinding liquid recovery barrel is connected with the liquid inlet end of the second liquid pump through an infusion tube, and the liquid outlet end of the second liquid pump is connected with the grinding liquid reflux end of the double-sided grinder body through an infusion tube;

[0012] A sapphire wafer grinding method, the grinding method is achieved by the following steps:

[0013] Step 1: Place the sapphire wafer to be ground on the lower grinding disc in the grinder, press and shake it by hand, and after confirming that the wafer is properly placed, lower the upper grinding disc;

[0014] Step 2: Perform a lower thickness grinding process on the sapphire wafer placed in step 1;

[0015] Step 3: Use a micrometer to measure the thickness of the sapphire wafer after the lower thick grinding in step 2. If the size meets the lower thick grinding requirement, there is no need to move the ground sapphire wafer, and the subsequent rough grinding process is directly performed. If the size does not meet the lower thick grinding requirement, readjust the parameters and continue to grind the sapphire wafer until the lower thick grinding requirement is met, and then the subsequent rough grinding process is performed;

[0016] Step 4: Perform rough grinding on the sapphire wafer whose thickness meets the standard in step 3;

[0017] Step 5: Use a micrometer to measure the thickness of the sapphire wafer after rough grinding in step 4. If the size meets the rough grinding requirement, pick out the ground sapphire wafer, clean it, perform a roughness test, and perform other numerical tests on it. If the size does not meet the lower thickness grinding requirement, readjust the parameters and continue to grind the sapphire wafer until it meets the rough grinding requirement. Then pick out the ground sapphire wafer, clean it, perform a roughness test, and perform other numerical tests on it.

[0018] Step 6: After finishing grinding one batch of wafers, continue to repeat the operations of Step 1 to Step 5 to grind the subsequent batches of sapphire wafers;

[0019] Furthermore, the specific steps of performing the lower thickness grinding process on the sapphire wafer placed in step 1 in step 2 are as follows:

[0020] Step 21: Start the second liquid pump to introduce the grinding liquid in the grinding liquid recovery bucket into the double-sided grinder body from the grinding liquid return end in the double-sided grinder body, and the liquid pumping amount of the second liquid pump is 30L / min;

[0021] Step 22: Start the double-sided grinder body, so that the upper grinding disc and the lower grinding disc in the double-sided grinder body rotate simultaneously to grind the sapphire wafer at the bottom thickness, the rotation speed of the upper grinding disc is 5 to 10 rpm, the rotation speed of the lower grinding disc is 20 to 30 rpm, and the grinding time is 60 to 100 minutes;

[0022] Step 23: After the grinding is completed, the grinding liquid in the double-sided grinding machine body flows into the grinding liquid recovery bucket through the liquid outlet, and then the staff empties the grinding liquid in the grinding liquid recovery bucket after the lower thickness grinding;

[0023] Furthermore, in step 4, the specific steps of rough grinding the sapphire wafer after the thickness dimension reaches the standard in step 3 are as follows:

[0024] Step 41: Start the peristaltic pump to introduce the grinding liquid in the grinding liquid delivery barrel into the double-sided grinder body from the liquid inlet end in the double-sided grinder body, the working speed of the peristaltic pump is 20r / min, and the delivery volume of the peristaltic pump is 75-85ml / min per tube;

[0025] Step 42: Start the double-sided grinder body, so that the upper grinding disc and the lower grinding disc in the double-sided grinder body rotate simultaneously to perform rough grinding on the sapphire wafer, the rotation speed of the upper grinding disc is 5 to 10 rpm, the rotation speed of the lower grinding disc is 20 to 30 rpm, and the grinding time is 10 to 15 minutes;

[0026] Step 43: The grinding liquid after the rough grinding flows into the grinding liquid recovery bucket through the liquid outlet to be used for the next batch of sapphire wafers to be ground thicker;

[0027] Furthermore, when the grinding liquid in the grinding liquid delivery barrel is used up in step 41, liquid pump No. 1 starts to work to introduce a sufficient amount of grinding liquid in the grinding liquid pre-storage barrel into the grinding liquid delivery barrel and replenish the grinding liquid in the grinding liquid delivery barrel. The liquid pumping volume of liquid pump No. 1 is 30L / min.

[0028] The beneficial effects of this application compared to the prior art are as follows:

[0029] 1. A sapphire wafer grinding device provided in the present application utilizes the stability of the peristaltic pump flow rate to improve the stability of the removal rate and roughness of the sapphire double-sided grinder, which can help ensure that the change in the surface of the grinding disk becomes smaller with grinding time, and is beneficial to controlling grinding costs and improving grinding quality.

[0030] 2. A sapphire wafer grinding device provided in the present application optimizes the supply method of the grinding liquid through the double-sided grinding process requirements. Based on the grinding characteristics that the rough grinding will not cause too much influence on the particle size of the particles in the grinding liquid, the grinding liquid after the rough grinding is effectively collected and used for the next batch of thick grinding. This greatly improves the use efficiency of the grinding liquid and reduces the cost of grinding work.

[0031] 3. The present application provides a sapphire wafer grinding method, which effectively combines the lower thick grinding with the rough grinding, which can simplify the operation. The thickness of adjacent wafers is similar to the value, and the quality of the sapphire wafer is stabilized during the rough grinding. At the same time, the removal rate of each disk is the same through quantitative control of the grinding sand in the lower thick grinding process, so that the quality of the sapphire wafer is stabilized under the same conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of the sapphire wafer grinding device described in this application;

[0033] In the figure, 1 is a grinding liquid pre-storage barrel, 2 is a No. 1 liquid pump, 3 is a grinding liquid delivery barrel, 4 is a peristaltic pump, 5 is a grinding liquid recovery barrel and 6 is a No. 2 liquid pump. DETAILED DESCRIPTION

[0034] Specific implementation method 1: Combination Figure 1 To explain this embodiment, a sapphire wafer grinding device is provided in this embodiment, and the grinding device includes a double-sided grinder body, and also includes a grinding liquid replenishing unit, a grinding liquid delivery unit and a grinding liquid recovery unit. The grinding liquid replenishing unit is arranged on the outside of the double-sided grinder body, and the liquid outlet end of the grinding liquid replenishing unit is connected to the liquid inlet end of the grinding liquid delivery unit. The grinding liquid delivery unit is installed on the upper part of the double-sided grinder body, and the liquid outlet end of the grinding liquid delivery unit is connected to the liquid inlet end of the double-sided grinder body. The grinding liquid recovery unit is installed on the lower part of the double-sided grinder body, and the liquid inlet end of the grinding liquid recovery unit is connected to the liquid outlet end of the double-sided grinder body, and the liquid outlet end of the grinding liquid recovery unit is connected to the grinding liquid reflux end of the double-sided grinder body.

[0035] A sapphire wafer grinding device is provided in the present embodiment. Compared with the traditional double-sided grinder, a grinding liquid replenishing unit, a grinding liquid delivery unit and a grinding liquid recovery unit are added, which can achieve a stable working flow of the grinding liquid during the rough grinding process, improve the removal rate and roughness stability of the sapphire double-sided grinder, and control the grinding cost. At the same time, when the grinding liquid is insufficient during the rough grinding process, it can be replenished in time, and the grinding liquid used in the rough grinding is used for secondary grinding during the thick grinding process. The thick grinding liquid is quantified to make the removal rate of each batch of sapphire wafers the same. Under the same conditions, it is beneficial to stabilize the quality of sapphire wafers.

[0036] Specific implementation method 2: Combination Figure 1 This embodiment is described. The difference between this embodiment and the first embodiment is that the grinding liquid replenishing unit includes a grinding liquid pre-storage barrel 1 and a first liquid pump 2. The grinding liquid pre-storage barrel 1 is arranged outside the double-sided grinder body, and the grinding liquid pre-storage barrel 1 contains a sufficient amount of grinding liquid. The first liquid pump 2 is arranged on the grinding liquid pre-storage barrel 1, and the liquid inlet end of the first liquid pump 2 is connected to the grinding liquid pre-storage barrel 1 through an infusion tube, and the liquid outlet end of the first liquid pump 2 is connected to the liquid inlet end of the grinding liquid delivery unit through an infusion tube. Other components and connection methods are the same as those of the first embodiment.

[0037] In this embodiment, the grinding liquid replenishing unit is mainly used to store the prepared grinding liquid and to replenish the grinding liquid delivery unit in time when the grinding liquid is insufficient during the rough grinding process.

[0038] Specific implementation method three: Combination Figure 1This embodiment is described. The difference between this embodiment and the second embodiment is that the grinding liquid delivery unit includes a grinding liquid delivery barrel 3 and a peristaltic pump 4. The grinding liquid delivery barrel 3 and the peristaltic pump 4 are both installed on the upper part of the double-sided grinder body. The liquid outlet of the first liquid pump 2 is connected to the liquid inlet of the grinding liquid delivery barrel 3 through a liquid infusion tube, and the liquid outlet of the grinding liquid delivery barrel 3 is connected to the liquid inlet of the double-sided grinder body through the peristaltic pump 4. Other components and connection methods are the same as those of the second embodiment.

[0039] In this embodiment, the polishing liquid delivery unit mainly utilizes the flow stability of the peristaltic pump 4 to evenly deliver the polishing liquid to the double-sided grinder, thereby improving the removal rate and roughness stability of the sapphire double-sided grinder and controlling the grinding cost.

[0040] Specific implementation method four: Combination Figure 1 This embodiment is described. The difference between this embodiment and the third embodiment is that the installation height of the grinding liquid delivery barrel 3 is higher than the installation height of the peristaltic pump 4. The other components and connection methods are the same as those of the third embodiment.

[0041] Such an arrangement is used to ensure that the grinding liquid in the grinding liquid delivery barrel 3 can be stably delivered to the double-sided grinding machine body through the peristaltic pump 4.

[0042] Specific implementation method five: Combination Figure 1 This embodiment is described. This embodiment is different from the fourth embodiment in that the peristaltic pump 4 has a length of 259 mm, a width of 157 mm, a height of 237 mm, 3 to 6 pump heads, a speed range of 0 to 150 rpm, and a flow range of 0 to 645 ml / min. Other components and connection methods are the same as those of the fourth embodiment.

[0043] Specific implementation method six: Combination Figure 1 This embodiment is described. The difference between this embodiment and the fifth embodiment is that the grinding liquid recovery unit includes a grinding liquid recovery barrel 5 and a second liquid pump 6. The grinding liquid recovery barrel 5 and the second liquid pump 6 are both installed at the lower part of the double-sided grinder body, and the liquid inlet end of the grinding liquid recovery barrel 5 is connected with the liquid outlet end of the double-sided grinder body, the liquid outlet end of the grinding liquid recovery barrel 5 is connected with the liquid inlet end of the second liquid pump 6 through an infusion tube, and the liquid outlet end of the second liquid pump 6 is connected with the grinding liquid reflux end of the double-sided grinder body through an infusion tube. Other components and connection methods are the same as those of the fifth embodiment.

[0044] In this embodiment, the grinding liquid recovery unit has two functions. First, it is used to provide grinding liquid for the lower thick grinding work. The grinding liquid enters the double-sided grinding machine body from the grinding liquid recovery barrel 5 through the No. 2 liquid pump 6. Second, it is used to collect the grinding liquid after the rough grinding work, and store the grinding liquid and reuse it in the lower thick grinding process of the next batch of sapphire wafers. The advantage of this design is that the grinding liquid can be reused through recycling. On the premise of saving the cost of using the grinding liquid, it is also beneficial to quantify the grinding liquid when the sapphire wafers are undergoing lower thick grinding. The amount of rough grinding liquid used in this batch is the same as the amount of lower thick grinding liquid used in the next batch, so that the removal rate of each batch is the same. Under the same conditions, it is beneficial to stabilize the grinding quality of sapphire wafers.

[0045] Specific implementation method seven: Combination Figure 1 This embodiment describes a sapphire wafer grinding method, which is implemented by the following steps:

[0046] Step 1: Place the sapphire wafer to be ground on the lower grinding disc in the grinder, press and shake it by hand, and after confirming that the wafer is properly placed, lower the upper grinding disc;

[0047] Step 2: Perform a lower thickness grinding process on the sapphire wafer placed in step 1;

[0048] Step 3: Use a micrometer to measure the thickness of the sapphire wafer after the lower thick grinding in step 2. If the size meets the lower thick grinding requirement, there is no need to move the ground sapphire wafer, and the subsequent rough grinding process is directly performed. If the size does not meet the lower thick grinding requirement, readjust the parameters and continue to grind the sapphire wafer until the lower thick grinding requirement is met, and then the subsequent rough grinding process is performed;

[0049] Step 4: Perform rough grinding on the sapphire wafer whose thickness meets the standard in step 3;

[0050] Step 5: Use a micrometer to measure the thickness of the sapphire wafer after rough grinding in step 4. If the size meets the rough grinding requirement, pick out the ground sapphire wafer, clean it, perform a roughness test, and perform other numerical tests on it. If the size does not meet the lower thickness grinding requirement, readjust the parameters and continue to grind the sapphire wafer until it meets the rough grinding requirement. Then pick out the ground sapphire wafer, clean it, perform a roughness test, and perform other numerical tests on it.

[0051] Step 6: After finishing grinding one batch of wafers, continue to repeat steps 1 to 5 to grind subsequent batches of sapphire wafers.

[0052] A sapphire wafer grinding method provided in this embodiment uses a peristaltic pump to quantify the amount of grinding liquid for each batch of sapphire wafers. The grinding of the sapphire surface roughness and the grinding of the sapphire bottom thickness are two parts of the operation process, which are combined in the same machine for processing. The peristaltic pump is used to provide the grinding liquid for the rough grinding, which can ensure the stability of the liquid flow per minute. The processing time of each batch of sapphire wafers is the same, so that the sapphire surface roughness is stable;

[0053] After rough grinding, the grinding liquid flows into the grinding liquid recovery unit for subsequent thick grinding of sapphire wafers. Since the sapphire wafers have the same thickness, the same amount of sand, and the same amount of sand wear, the thick removal rate is the same. After the thick grinding is completed, the grinding liquid recovery unit (with a built-in 7L grinding liquid barrel) is emptied and the rough grinding operation is performed. This operation method can avoid the situation where one barrel of standard grinding liquid (30L) is used for multiple discs, the removal rate of each disc is unstable, and the grinding value increases batch by batch;

[0054] Thickening and roughing are performed on the same machine, saving the time of picking up the wafer and placing it on the roughing machine, saving labor. Its characteristic is that there is no need to pick up and place the wafer during the roughing process. The wafer is still in the position of thickening. The adjacent wafers are close in thickness, value and surface shape. When roughing is performed, the value will not fluctuate too much, which improves the double-sided grinding quality of sapphire wafers.

[0055] Specific implementation method eight: Combination Figure 1 This embodiment is described. The difference between this embodiment and the seventh embodiment is that the specific steps of performing the lower thickness grinding process on the sapphire wafer placed in step 1 in step 2 are as follows:

[0056] Step 21: Start the second liquid pump 6 to introduce the grinding liquid in the grinding liquid recovery barrel 5 into the double-sided grinder body from the grinding liquid return end in the double-sided grinder body, and the liquid pumping amount of the second liquid pump 6 is 30L / min;

[0057] Step 22: Start the double-sided grinder body, so that the upper grinding disc and the lower grinding disc in the double-sided grinder body rotate simultaneously to grind the sapphire wafer at the bottom thickness, the rotation speed of the upper grinding disc is 5 to 10 rpm, the rotation speed of the lower grinding disc is 20 to 30 rpm, and the grinding time is 60 to 100 minutes;

[0058] Step 23: After the grinding is completed, the grinding liquid in the double-sided grinding machine body flows into the grinding liquid recovery barrel 5 through the liquid outlet, and then the staff empties the grinding liquid in the grinding liquid recovery barrel 5 after the lower thickness grinding.

[0059] The other components and connection methods are the same as those of the seventh embodiment.

[0060] In this embodiment, the grinding liquid used after rough grinding of the sapphire surface is used for thickening. Since the grinding liquid only flows through the disk surface once, the pressure is the same (the abrasiveness of the boron carbide particles is consistent), the processing time is the same as the peristaltic pump flow rate (grinding liquid quantity), and the removal rate per disk is the same. The sapphire is processed through the same process to stabilize the various grinding values ​​(warp, Bow, TTV, LTV).

[0061] Specific implementation method nine: Combination Figure 1 This embodiment is described. The difference between this embodiment and the eighth embodiment is that the specific steps of rough grinding the sapphire wafer after the thickness dimension reaches the standard in step 3 in step 4 are as follows:

[0062] Step 41: start the peristaltic pump 4 to introduce the grinding liquid in the grinding liquid delivery barrel 3 into the double-sided grinder body from the liquid inlet end in the double-sided grinder body, the working speed of the peristaltic pump 4 is 20r / min, and the delivery volume of the peristaltic pump 4 is 75-85ml / min per tube;

[0063] Step 42: Start the double-sided grinder body, so that the upper grinding disc and the lower grinding disc in the double-sided grinder body rotate simultaneously to perform rough grinding on the sapphire wafer, the rotation speed of the upper grinding disc is 5 to 10 rpm, the rotation speed of the lower grinding disc is 20 to 30 rpm, and the grinding time is 10 to 15 minutes;

[0064] Step 43: The grinding liquid after the rough grinding flows into the grinding liquid recovery barrel 5 through the liquid outlet to be used for the thick grinding of the next batch of sapphire wafers.

[0065] Other components and connection methods are the same as those in the eighth embodiment.

[0066] In this embodiment, the roughness is checked after the wafer reaches the standard thickness, and the peristaltic pump 4 is used for timing and quantity, and the processing time and flow rate are unified, so that the surface roughness of multiple batches of sapphires can achieve a uniform effect (the sand is not circulated).

[0067] Specific implementation method ten: Combination Figure 1 This embodiment is described. The difference between this embodiment and the ninth embodiment is that when the grinding liquid in the grinding liquid delivery barrel 3 is used up in step 41, the first liquid pump 2 starts to work to introduce a sufficient amount of grinding liquid in the grinding liquid pre-storage barrel 1 into the grinding liquid delivery barrel 3 and replenish the grinding liquid in the grinding liquid delivery barrel 3. The liquid pumping volume of the first liquid pump 2 is 30L / min. Other components and connection methods are the same as those of the ninth embodiment.

[0068] The present invention has been disclosed as above with preferred implementation cases, but it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent implementation cases with equivalent changes by using the above-disclosed structures and technical contents without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above implementation cases based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A sapphire wafer grinding device, the grinding device comprising a double-sided grinding machine body, characterized in that: It also includes a grinding liquid replenishing unit, a grinding liquid delivery unit and a grinding liquid recovery unit. The grinding liquid replenishing unit is arranged on the outside of the double-sided grinding machine body, and the liquid outlet end of the grinding liquid replenishing unit is connected to the liquid inlet end of the grinding liquid delivery unit. The grinding liquid delivery unit is installed on the upper part of the double-sided grinding machine body, and the liquid outlet end of the grinding liquid delivery unit is connected to the liquid inlet end of the double-sided grinding machine body. The grinding liquid recovery unit is installed on the lower part of the double-sided grinding machine body, and the liquid inlet end of the grinding liquid recovery unit is connected to the liquid outlet end of the double-sided grinding machine body. The liquid outlet end of the grinding liquid recovery unit is connected to the grinding liquid reflux end of the double-sided grinding machine body.

2. A sapphire wafer grinding device according to claim 1, characterized in that: The grinding liquid replenishing unit comprises a grinding liquid pre-storage barrel (1) and a first liquid pump (2); the grinding liquid pre-storage barrel (1) is arranged outside the double-sided grinding machine body, and a sufficient amount of grinding liquid is contained in the grinding liquid pre-storage barrel (1); the first liquid pump (2) is arranged on the grinding liquid pre-storage barrel (1), and the liquid inlet end of the first liquid pump (2) is connected to the grinding liquid pre-storage barrel (1) through a liquid infusion pipe, and the liquid outlet end of the first liquid pump (2) is connected to the liquid inlet end of the grinding liquid delivery unit through a liquid infusion pipe.

3. A sapphire wafer grinding device according to claim 2, characterized in that: The grinding liquid delivery unit comprises a grinding liquid delivery barrel (3) and a peristaltic pump (4), both of which are mounted on the upper part of the double-sided grinder body, the liquid outlet end of the first liquid pump (2) is connected to the liquid inlet end of the grinding liquid delivery barrel (3) through a liquid infusion tube, and the liquid outlet end of the grinding liquid delivery barrel (3) is connected to the liquid inlet end of the double-sided grinder body through the peristaltic pump (4).

4. A sapphire wafer grinding device according to claim 3, characterized in that: The installation height of the grinding liquid delivery barrel (3) is higher than the installation height of the peristaltic pump (4).

5. A sapphire wafer grinding device according to claim 4, characterized in that: The peristaltic pump (4) has a length of 259 mm, a width of 157 mm, a height of 237 mm, 3 to 6 pump heads, a rotation speed range of 0 to 150 rpm, and a flow rate range of 0 to 645 ml / min.

6. A sapphire wafer grinding device according to claim 5, characterized in that: The grinding liquid recovery unit comprises a grinding liquid recovery barrel (5) and a second liquid pump (6), the grinding liquid recovery barrel (5) and the second liquid pump (6) are both installed at the lower part of the double-sided grinding machine body, and the liquid inlet end of the grinding liquid recovery barrel (5) is connected to the liquid outlet end of the double-sided grinding machine body, the liquid outlet end of the grinding liquid recovery barrel (5) is connected to the liquid inlet end of the second liquid pump (6) through a liquid infusion pipe, and the liquid outlet end of the second liquid pump (6) is connected to the grinding liquid reflux end of the double-sided grinding machine body through a liquid infusion pipe.

7. A grinding method implemented by a sapphire wafer grinding device according to any one of claims 1 to 7, characterized in that: The grinding method is achieved by the following steps: Step 1: Place the sapphire wafer to be ground on the lower grinding disc in the grinder, press and shake it by hand, and after confirming that the wafer is properly placed, lower the upper grinding disc; Step 2: Perform a lower thickness grinding process on the sapphire wafer placed in step 1; Step 3: Use a micrometer to measure the thickness of the sapphire wafer after the lower thick grinding in step 2. If the size meets the lower thick grinding requirement, there is no need to move the ground sapphire wafer, and the subsequent rough grinding process is directly performed. If the size does not meet the lower thick grinding requirement, readjust the parameters and continue to grind the sapphire wafer until the lower thick grinding requirement is met, and then the subsequent rough grinding process is performed; Step 4: Perform rough grinding on the sapphire wafer whose thickness meets the standard in step 3; Step 5: Use a micrometer to measure the thickness of the sapphire wafer after rough grinding in step 4. If the size meets the rough grinding requirement, pick out the ground sapphire wafer, clean it, perform a roughness test, and perform other numerical tests on it. If the size does not meet the lower thickness grinding requirement, readjust the parameters and continue to grind the sapphire wafer until it meets the rough grinding requirement. Then pick out the ground sapphire wafer, clean it, perform a roughness test, and perform other numerical tests on it. Step 6: After finishing grinding one batch of wafers, continue to repeat steps 1 to 5 to grind subsequent batches of sapphire wafers.

8. A sapphire wafer grinding method according to claim 7, characterized in that: The specific steps of performing the lower thickness grinding process on the sapphire wafer placed in step 1 in step 2 are as follows: Step 21: Start the second liquid pump (6) to introduce the grinding liquid in the grinding liquid recovery barrel (5) into the double-sided grinder body from the grinding liquid return end in the double-sided grinder body, and the liquid pumping volume of the second liquid pump (6) is 30L / min; Step 22: Start the double-sided grinder body, so that the upper grinding disc and the lower grinding disc in the double-sided grinder body rotate simultaneously to grind the sapphire wafer at the bottom thickness, the rotation speed of the upper grinding disc is 5 to 10 rpm, the rotation speed of the lower grinding disc is 20 to 30 rpm, and the grinding time is 60 to 100 minutes; Step 23: After the grinding is completed, the grinding liquid in the double-sided grinding machine body flows into the grinding liquid recovery bucket (5) through the liquid outlet, and then the staff empties the grinding liquid in the grinding liquid recovery bucket (5) after the lower thickness grinding.

9. A sapphire wafer grinding method according to claim 7, characterized in that: The specific steps of rough grinding the sapphire wafer after the thickness dimension reaches the standard in step 3 in step 4 are as follows: Step 41: Start the peristaltic pump (4) to introduce the grinding liquid in the grinding liquid delivery barrel (3) into the double-sided grinder body from the liquid inlet end in the double-sided grinder body, the operating speed of the peristaltic pump (4) is 20r / min, and the delivery volume of the peristaltic pump (4) is 75-85ml / min per tube; Step 42: Start the double-sided grinder body, so that the upper grinding disc and the lower grinding disc in the double-sided grinder body rotate simultaneously to perform rough grinding on the sapphire wafer, the rotation speed of the upper grinding disc is 5 to 10 rpm, the rotation speed of the lower grinding disc is 20 to 30 rpm, and the grinding time is 10 to 15 minutes; Step 43: The grinding liquid after the rough grinding flows into the grinding liquid recovery bucket (5) through the liquid outlet to be used for the next batch of sapphire wafers to be ground thicker.

10. A sapphire wafer grinding method according to claim 9, characterized in that: When the grinding liquid in the grinding liquid delivery barrel (3) is used up in step 41, the No. 1 liquid pump (2) starts to work to introduce a sufficient amount of grinding liquid in the grinding liquid pre-storage barrel (1) into the grinding liquid delivery barrel (3) and replenish the grinding liquid in the grinding liquid delivery barrel (3). The liquid pumping volume of the No. 1 liquid pump (2) is 30L / min.

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