A wafer grinding and polishing process adjustment method based on pressure sensing

Abstract

The present invention relates to the field of wafer processing technology, and specifically discloses a wafer grinding and polishing processing adjustment method based on pressure sensing, the method comprising: S1: measuring the current initial thickness of a wafer to be processed, determining a target thickness of the wafer to be processed, and bonding the wafer to a substrate, and by real-time collecting and analyzing state parameter data of a grinding device and a wafer during a grinding operation, the grinding state of the wafer at different time points can be determined, and when a grinding disc is severely worn, the feed distance of a grinding push rod can be adjusted in real time according to the grinding state of the wafer at different time points, so as to ensure that the grinding disc and the wafer have good contact during the entire grinding process, and to ensure the efficiency and effect of the grinding, and by analyzing the state of the wafer after the processing is completed, it can be judged whether the grinding disc needs to be replaced, so as to avoid a severely worn grinding disc increasing the load of the grinding equipment and accelerating the wear and aging of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing, and specifically to a method for adjusting wafer grinding and polishing processing based on pressure sensing. Background Art

[0002] A wafer refers to a silicon wafer used to fabricate silicon semiconductor circuits. Its raw material is silicon. Before being put into use, the surface of the wafer to be processed needs to be polished according to a preset control strategy to ensure good flatness and smoothness of the wafer after processing, so as to meet the requirements of subsequent processes.

[0003] Conventional methods for adjusting wafer grinding and polishing processing usually first fix the wafer on a grinding table, and then adjust the initial feeding distance of the grinding push rod according to a preset control strategy. After that, the wafer can be ground. During the grinding process, the grinding push rod will gradually move towards the wafer through the preset feeding distance to ensure good contact between the grinding disc and the wafer, thereby ensuring the grinding and polishing effect of the wafer.

[0004] In the prior art, during the grinding process, the grinding push rod gradually moves towards the wafer through the preset feeding distance. However, during the use of the grinding disc, its grinding surface will wear, resulting in a decrease in grinding efficiency. If the feeding of the grinding push rod is always controlled according to the established feeding distance, when the wear of the grinding disc is relatively high, the pressure exerted by the grinding disc on the wafer will gradually decrease, thereby affecting the grinding efficiency and grinding effect. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for adjusting wafer grinding and polishing processing based on pressure sensing, and solve the following technical problems:

[0006] How to dynamically adjust the distance of the grinding push rod in real time to ensure the grinding efficiency.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A method for adjusting wafer grinding and polishing processing based on pressure sensing, the method includes:

[0009] S1: Measure the current initial thickness of the wafer to be processed, determine the target thickness of the wafer to be processed, and bond the wafer to the substrate;

[0010] S2: Adjust the initial feeding distance of the grinding push rod according to the preset control strategy to make the pressure between the grinding disc and the wafer to be processed reach the size corresponding to the preset control strategy;

[0011] S3: Perform the grinding operation at the grinding wheel rotation speed in the preset strategy, and collect and analyze the status parameter data of the grinding equipment and the wafer in real time to determine the grinding status of the wafer at different time points, and adjust the feeding distance of the grinding push rod in real time according to the grinding status of the wafer at different time points;

[0012] S4: When the wafer is ground to the target thickness, analyze the status of the processed wafer to determine whether the grinding wheel needs to be replaced. If not, complete the wafer grinding operation. If so, proceed to step S5:

[0013] S5: When it is determined that the grinding wheel needs to be replaced, give a warning and automatically stop the wafer grinding operation, waiting for the grinding wheel to be replaced.

[0014] Further, the process of adjusting the feeding distance of the grinding push rod in S3 includes:

[0015] S31: First, collect the status data of the wafer during grinding, including the surface temperature, thickness, and color depth of the grinding slurry of the wafer during the grinding process;

[0016] S32: By collecting the pressure change between the grinding wheel and the wafer to be processed and the rotation speed change of the grinding wheel, and combining the data collected in S31, calculate the grinding status influence coefficient of the wafer at different time points;

[0017] S33: By comparing the grinding status influence coefficient of the wafer at different time points with the preset influence coefficient, and judging whether to adjust the feeding distance of the grinding push rod according to the comparison result. If not, do nothing. If so, proceed to step S34;

[0018] S34: Adjust the feeding distance of the grinding push rod by combining the grinding status influence coefficient of the wafer at different time points and the drive motor equipment parameters of the grinding push rod.

[0019] Further, the process of calculating the grinding status influence coefficient of the wafer at different time points in S32 includes:

[0020] Obtain the surface temperature dispersion coefficient of the wafer from the start of grinding to the i-th time point through the formula where i is a data acquisition at a fixed time interval after the start of grinding of the wafer, n is the total number of data acquisitions from the start of grinding of the wafer to the i-th time point, ;

[0021] where is the surface temperature at the i-th time point after the start of grinding of the wafer, is the average value of all , is the proportionality coefficient, set by empirical fitting, is the indoor temperature at the i-th time point after the wafer starts grinding, is the preset indoor temperature, is the indoor humidity at the i-th time point after the wafer starts grinding, is the preset indoor humidity.

[0022] Further, the process of calculating the grinding state influence coefficient of the wafer at different time points in S32 further includes:

[0023] Obtain the real-time rotation speed data of the grinding disc through real-time monitoring, and establish a real-time change curve of the grinding disc rotation speed ;

[0024] Through the formula Calculate the grinding state influence coefficient at the i-th time point since the wafer starts grinding ;

[0025] Among them, is the pressure value between the wafer and the grinding disc at the i-th time point since the wafer starts grinding, is the preset pressure value, is the grinding thickness of the wafer at the i-th time point since the wafer starts grinding, is the preset grinding thickness, is the error influence function, is the color depth of the grinding slurry at the i-th time of grinding since the wafer starts grinding, is the preset color depth of the grinding slurry, is the standard value of, is a defined function. If , then let , otherwise, let , is the time point of the first data acquisition after the wafer starts grinding, is the time point of the i-th data acquisition after the wafer starts grinding.

[0026] Further, the comparison process in S33 includes:

[0027] By comparing the grinding state influence coefficient at the i-th time point since the wafer starts grinding with the preset grinding state influence coefficient threshold ;

[0028] If , it is judged that the current grinding state influence is high, the grinding quality is reduced, and the feed distance of the grinding push rod needs to be adjusted;

[0029] If , it is determined that the influence of the current grinding state is low and the grinding quality is high, and there is no need to adjust the feeding distance of the grinding push rod.

[0030] Further, the process of adjusting the feeding distance of the grinding push rod in S34 includes:

[0031] Through the formula Calculate the adjusted feeding distance of the grinding push rod at the i-th time point since the start of wafer grinding ;

[0032] Among them, Is the preset feeding distance of the grinding push rod at the i-th time point, Is the voltage value of the grinding push rod drive motor at the i-th time point, Is all Standard value of, Is the current value of the grinding push rod drive motor at the i-th time point, Is the preset current value, Is the adjustment coefficient comparison table function, based on the influence of the Value range in the empirical data on the feeding distance of the grinding push rod obtained through testing.

[0033] Further, the process of determining whether to replace the grinding disc in S4 includes:

[0034] Through the formula Calculate the quality loss coefficient of the wafer finished product ;

[0035] Among them, Is the flatness of the wafer after grinding, Is the preset flatness, Is the smoothness of the wafer after grinding, Is the preset smoothness, Is the thickness of the wafer after grinding, Is the preset thickness, Is Standard value of, Is the total grinding time of the wafer, Is the preset grinding time, m is the total number of data acquisitions from the start to the end of wafer grinding.

[0036] Further, the process of determining whether to replace the grinding disc in S4 also includes;

[0037] By comparing the wafer grinding state influence coefficient With the preset wafer grinding state influence coefficient threshold For comparison;

[0038] If , if it is determined that the quality loss coefficient of the finished wafer is small, it indicates that the state and grinding effect of the wafer grinding process are good, and there is no need to replace the grinding disc;

[0039] If , if it is determined that the quality loss coefficient of the finished wafer is large, it indicates that the state and grinding effect of the wafer grinding process are poor, and the grinding disc needs to be replaced.

[0040] Advantages of the present invention:

[0041] (1) By analyzing the state parameter data of the grinding equipment and the wafer in the grinding operation in real time, the present invention can determine the grinding state of the wafer at different time points. When the grinding disc is severely worn, the feeding distance of the grinding push rod can be adjusted in real time according to the grinding state of the wafer at different time points, so as to ensure good contact between the grinding disc and the wafer throughout the grinding process, ensure the grinding efficiency and effect, and by analyzing the state of the wafer after processing, it can be judged whether the grinding disc needs to be replaced, thus avoiding the severely worn grinding disc from increasing the load of the grinding equipment and accelerating the wear and aging of the equipment.

[0042] (2) By combining the state data of the wafer during grinding with the pressure change between the grinding disc and the wafer to be processed and the rotational speed change parameter of the grinding disc, the present invention can calculate the grinding state influence coefficient of the wafer at different time points. This data reflects the grinding state of the wafer at different time points. Therefore, by comparing the grinding state influence coefficient of the wafer at different time points with the preset influence coefficient, it can be judged whether to adjust the feeding distance of the grinding push rod, and the feeding distance of the grinding push rod can be adjusted in time in combination with this data, so as to ensure that the grinding disc applies sufficient pressure to the wafer and improve the grinding efficiency and effect.

[0043] (3) By combining the state data of the wafer in the grinding operation, the data information of the grinding equipment, and the surface temperature discrete coefficient of the wafer from the start of grinding to the i-th time point and other data, the diversified data improves the accuracy and reliability of the calculation result of the grinding state influence coefficient of the wafer at the i-th time point from the start of grinding, and provides accurate and reliable data support for the subsequent adjustment of the feeding distance of the grinding push rod, ensuring the accuracy of the adjustment result of the feeding distance of the grinding push rod.

[0044] (4) By comparing the grinding state influence coefficient of the wafer at the i-th time point from the start of grinding with the preset grinding state influence coefficient threshold By comparing, the grinding quality can be judged by combining the influence of the grinding state at the current time point. When judging the grinding quality, it means that if the feeding of the grinding push rod is still controlled according to the established feeding distance, the grinding efficiency and grinding effect will be greatly reduced. The feeding distance of the grinding push rod needs to be adjusted, thereby realizing the real-time dynamic adjustment of the distance of the grinding push rod to ensure the grinding efficiency.

[0045] (5) The present invention reduces the influence coefficient of wafer polishing state by With the preset grinding state influence coefficient threshold Compare the wafers. Through this comparison, the state of the wafer polishing process and the polishing effect can be analyzed and judged according to the mass loss coefficient of the finished wafer. Based on the analysis results, it is decided whether the polishing disc needs to be replaced, thereby avoiding the situation where the polishing efficiency is reduced due to excessive wear of the polishing disc and improving the polishing effect of the wafer. Brief Description of the Figures

[0046] The present invention will be further described below in conjunction with the accompanying drawings.

[0047] Figure 1 It is a flow chart of a wafer grinding and polishing adjustment method based on pressure sensing in the present invention;

[0048] Figure 2 This is a flow chart of the process of adjusting the feed distance of the grinding push rod in the present invention. Specific implementation method

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Please refer to Figure 1 As shown, in one embodiment, the present application provides a wafer grinding and polishing processing adjustment method based on pressure sensing, the method comprising:

[0051] S1: Measure the current initial thickness of the wafer to be processed, determine the target thickness of the wafer to be processed, and bond the wafer to the substrate;

[0052] S2: Adjust the initial feed distance of the grinding push rod according to the preset control strategy, so that the pressure between the grinding disc and the wafer to be processed reaches the size corresponding to the preset control strategy;

[0053] ​S3: Perform the grinding operation at the grinding wheel rotation speed in the preset strategy, and collect and analyze the status parameter data of the grinding equipment and the wafer in real time to determine the grinding status of the wafer at different time points, and adjust the feeding distance of the grinding push rod in real time according to the grinding status of the wafer at different time points;

[0054] S4: When the wafer is ground to the target thickness, analyze the status of the processed wafer to determine whether the grinding wheel needs to be replaced. If the answer is no, complete the wafer grinding operation. If the answer is yes, proceed to step S5:

[0055] S5: When it is determined that the grinding wheel needs to be replaced, give a warning and automatically stop the wafer grinding operation, waiting for the grinding wheel to be replaced;

[0056] Through the above technical solution, this embodiment provides a method for adjusting wafer grinding and polishing based on pressure sensing. First, measure the current initial thickness of the wafer to be processed, determine the target thickness of the wafer to be processed, and bond the wafer to the substrate. Then, adjust the initial feeding distance of the grinding push rod according to the preset control strategy to make the pressure between the grinding wheel and the wafer to be processed reach the size corresponding to the preset control strategy. Subsequently, the grinding operation can be performed at the grinding wheel rotation speed in the preset strategy, and collect and analyze the status parameter data of the grinding equipment and the wafer in real time to determine the grinding status of the wafer at different time points, and adjust the feeding distance of the grinding push rod in real time according to the grinding status of the wafer at different time points; when the wafer is ground to the target thickness, analyze the status of the processed wafer to determine whether the grinding wheel needs to be replaced. If it is determined that the grinding wheel does not need to be replaced, directly complete the wafer grinding operation. If it is determined that the grinding wheel needs to be replaced, give a warning and automatically stop the wafer grinding operation, waiting for the grinding wheel to be replaced;

[0057] By setting like this, in this embodiment, by collecting and analyzing the status parameter data of the grinding equipment and the wafer in the grinding operation in real time, the grinding status of the wafer at different time points can be determined. When the grinding wheel is severely worn, the feeding distance of the grinding push rod can be adjusted in real time according to the grinding status of the wafer at different time points, so as to ensure good contact between the grinding wheel and the wafer during the whole grinding process, ensure the grinding efficiency and effect, and by analyzing the status of the processed wafer, it can be judged whether the grinding wheel needs to be replaced, thus avoiding the severely worn grinding wheel from increasing the load of the grinding equipment and accelerating the wear and aging of the equipment.

[0058] Please refer to Figure 2 As shown, the process of adjusting the feeding distance of the grinding push rod in S3 includes:

[0059] S31: First, collect the status data of the wafer during grinding, including the surface temperature, thickness and color depth of the grinding slurry of the wafer during the grinding process;

[0060] S32: Calculate the grinding state influence coefficient of the wafer at different time points by collecting the pressure change between the grinding disc and the wafer to be processed and the rotational speed change of the grinding disc, and combining the data collected in S31;

[0061] S33: Compare the grinding state influence coefficient of the wafer at different time points with a preset influence coefficient, and determine whether to adjust the feeding distance of the grinding push rod according to the comparison result. If the answer is no, no operation is performed. If the answer is yes, go to step S34;

[0062] S34: Adjust the feeding distance of the grinding push rod by combining the grinding state influence coefficient of the wafer at different time points and the driving motor equipment parameters of the grinding push rod;

[0063] Through the above technical solution, this embodiment provides a process for adjusting the feeding distance of the grinding push rod. First, collect the state data of the wafer during grinding, including the surface temperature, thickness, and color depth of the grinding slurry of the wafer during the grinding process. Then, the pressure change between the grinding disc and the wafer to be processed and the rotational speed change of the grinding disc can be collected, and combined with the state data of the wafer during grinding, the grinding state influence coefficient of the wafer at different time points can be calculated. Subsequently, compare the grinding state influence coefficient of the wafer at different time points with a preset influence coefficient, and determine whether to adjust the feeding distance of the grinding push rod according to the comparison result. When it is determined that the feeding distance of the grinding push rod needs to be adjusted, combine the grinding state influence coefficient of the wafer at different time points and the driving motor equipment parameters of the grinding push rod to adjust the feeding distance of the grinding push rod;

[0064] By setting like this, by combining the state data of the wafer during grinding with the pressure change between the grinding disc and the wafer to be processed and the rotational speed change parameters of the grinding disc, the grinding state influence coefficient of the wafer at different time points can be calculated. This data reflects the grinding state of the wafer at different time points. Therefore, by comparing the grinding state influence coefficient of the wafer at different time points with a preset influence coefficient, a judgment can be made on whether to adjust the feeding distance of the grinding push rod, and the feeding distance of the grinding push rod can be adjusted in a timely manner in combination with this data, so as to ensure that the grinding disc applies sufficient pressure to the wafer and improve the grinding efficiency and effect.

[0065] The process of calculating the grinding state influence coefficient of the wafer at different time points in S32 includes:

[0066] Through the formula Calculate the surface temperature discrete coefficient of the wafer from the start of grinding to the i-th time point ;

[0067] Wherein, i is a data acquisition of the wafer at a fixed time interval since the start of grinding, and n is the total number of data acquisitions of the wafer from the start of grinding to the i-th time point. is the surface temperature of the wafer at the i-th time point since the start of grinding. is for all average value, is the proportionality coefficient, which is set by empirical fitting. is the indoor temperature of the wafer at the i-th time point since the start of grinding. is the preset indoor temperature. is the indoor humidity of the wafer at the i-th time point since the start of grinding. is the preset indoor humidity;

[0068] Through the above technical solution, this embodiment provides the coefficient of variation of the surface temperature of the wafer from the start of grinding to the i-th time point , which can be obtained by the formula Obviously, when the surface temperature data at each data acquisition of the wafer at a fixed time interval since the start of grinding differ more, and the indoor temperature is higher and the humidity is lower, then the coefficient of variation of the surface temperature of the wafer from the start of grinding to the i-th time point is larger. On the contrary, when the surface temperature data at each data acquisition of the wafer at a fixed time interval since the start of grinding differ less, and the indoor temperature is lower and the humidity is higher, then the coefficient of variation of the surface temperature of the wafer from the start of grinding to the i-th time point is smaller;

[0069] By eliminating the influence of indoor temperature and humidity, when the surface temperature data at each data acquisition of the wafer at a fixed time interval since the start of grinding differ more, it indicates that the pressure exerted by the grinding disc on the wafer is continuously changing, that is, it represents that the grinding disc has a certain degree of wear. Through this calculation method, it can provide diversified data support for subsequent adjustment of the feed distance of the grinding push rod, thereby improving the accuracy and reliability of the adjustment result, and ensuring that the grinding disc can exert sufficient pressure on the wafer to ensure the grinding effect and efficiency after the adjustment of the grinding push rod is completed.

[0070] The process of calculating the influence coefficient of the grinding state of the wafer at different time points in S32 further includes:

[0071] Obtain the real-time rotational speed data of the grinding disc through real-time monitoring, and establish a real-time change curve of the rotational speed of the grinding disc ;

[0072] Through the formula Calculate the influence coefficient of the grinding state of the wafer at the i-th time point since the start of grinding ;

[0073] Wherein, is the pressure value between the wafer and the polishing pad at the i-th time point since the wafer started polishing, is the preset pressure value, is the polishing thickness of the wafer at the i-th time point since the wafer started polishing, is the preset polishing thickness, is the error influence function, is the color depth of the grinding slurry at the i-th time of grinding of the wafer since the wafer started polishing, is the preset color depth of the grinding slurry, is the standard value of, and the above standard value can be selected and set according to the allowable error in the empirical data, is the definition function. If , then let , otherwise, let , is the time point of the first data acquisition after the wafer started polishing, is the time point of the i-th data acquisition after the wafer started polishing;

[0074] Through the above technical solution, this embodiment provides the polishing state influence coefficient at the i-th time point since the wafer started polishing, which can be obtained by the formula . Among them, the formula can calculate the rotational speed change amount between the time point of the first data acquisition and the time point of the i-th data acquisition after the wafer started polishing. Obviously, when the rotational speed change amount is larger, and the polishing thickness, the color depth of the grinding slurry, and the pressure value between the wafer and the polishing pad at the i-th time point since the wafer started polishing are smaller, then the polishing state influence coefficient at the i-th time point since the wafer started polishing is larger, indicating that the polishing state influence on the wafer at the current time point is greater and the polishing effect is poorer. On the contrary, when the rotational speed change amount is smaller, and the polishing thickness, the color depth of the grinding slurry, and the pressure value between the wafer and the polishing pad at the i-th time point since the wafer started polishing are closer to the preset values, then the polishing state influence coefficient at the i-th time point since the wafer started polishing is smaller, indicating that the polishing state influence on the wafer at the current time point is smaller and the polishing effect is good;

[0075] That is because when the polishing thickness, the color depth of the grinding slurry, and the pressure value between the wafer and the polishing pad at the i-th time point since the wafer started polishing are smaller, it means that at this time point, the fitting effect between the polishing pad and the wafer becomes worse, which will lead to the polishing thickness being less than the preset thickness, and less dust resulting in a lighter color of the grinding slurry, and the pressure value between the wafer and the polishing pad being less than the preset value, that is, it represents that if the feeding distance of the polishing push rod is still controlled according to the established feeding distance at this time, the polishing efficiency and the polishing effect will be greatly reduced, and the feeding distance of the polishing push rod needs to be adjusted;

[0076] Through this calculation method, by combining the state data of the wafer during the grinding operation, the data information of the grinding equipment, and the surface temperature discrete coefficient of the wafer from the start of grinding to the i-th time point and other data, the diversified data improves the accuracy and reliability of the calculation result of the grinding state influence coefficient of the wafer at the i-th time point since the start of grinding, and provides accurate and reliable data support for subsequent adjustment of the feeding distance of the grinding push rod, ensuring the accuracy of the adjustment result of the feeding distance of the grinding push rod.

[0077] The comparison process in S33 includes:

[0078] By comparing the grinding state influence coefficient of the wafer at the i-th time point since the start of grinding with the preset threshold of the grinding state influence coefficient ;

[0079] If , it is determined that the current grinding state has a high influence and the grinding quality is reduced, and the feeding distance of the grinding push rod needs to be adjusted;

[0080] If , it is determined that the current grinding state has a low influence and the grinding quality is high, and the feeding distance of the grinding push rod does not need to be adjusted;

[0081] Through the above technical solution, in this embodiment, by comparing the grinding state influence coefficient of the wafer at the i-th time point since the start of grinding with the preset threshold of the grinding state influence coefficient , through this comparison method, the grinding quality can be judged by combining the high or low influence of the grinding state at the current time point. When it is judged that the grinding quality is low, it means that if the feeding of the grinding push rod is still controlled according to the established feeding distance at this time, the grinding efficiency and grinding effect will be greatly reduced, and the feeding distance of the grinding push rod needs to be adjusted, thereby realizing the dynamic adjustment of the distance of the grinding push rod in real time to ensure the grinding efficiency.

[0082] The process of adjusting the feeding distance of the grinding push rod in S34 includes:

[0083] By the formula calculate the adjusted feeding distance of the grinding push rod at the i-th time point since the start of grinding of the wafer ;

[0084] wherein, is the preset feeding distance of the grinding push rod at the i-th time point, is the voltage value of the driving motor of the grinding push rod at the i-th time point, is all standard value, is the current value of the polishing push rod driving motor at the i-th time point, is the preset current value, is the adjustment coefficient look-up table function, based on the influence of the value range of the numerical values in the empirical data on the feeding distance of the polishing push rod, obtained through testing;

[0085] Through the above technical solution, this embodiment provides the adjusted feeding distance of the polishing push rod at the i-th time point since the start of wafer polishing , through this calculation method, after combining the polishing state influence coefficient at the i-th time point since the start of wafer polishing with the voltage and current data of the polishing push rod driving motor, it can provide diversified data support for the calculation results of the adjusted feeding distance of the polishing push rod at different time points, thereby improving the accuracy of the calculation results, ensuring the real-time adjustment of the feeding distance of the polishing push rod, while improving the accuracy and reliability of the feeding distance adjustment, and ensuring the polishing efficiency and polishing effect.

[0086] The process of determining whether to replace the polishing disc in S4 includes:

[0087] By the formula calculate the quality loss coefficient of the wafer finished product ;

[0088] wherein, is the flatness of the wafer after polishing, is the preset flatness, is the smoothness of the wafer after polishing, is the preset smoothness, is the thickness of the wafer after polishing, is the preset thickness, is the standard value of, is the total polishing duration of the wafer, is the preset polishing duration, m is the total number of data acquisitions from the start to the end of wafer polishing;

[0089] Through the above technical solution, this embodiment provides the quality loss coefficient of the wafer finished product , which can be calculated by the formula Calculated, obviously, the higher the flatness and smoothness of the wafer after grinding, the less the thickness deviates from the preset value, and the shorter the grinding duration and the average feed distance adjusted by the grinding push rod during the grinding operation, the lower the quality loss coefficient of the wafer product, indicating that the quality of the wafer product is high and the wear of the grinding disc is low, and there is no need to replace it. On the contrary, the lower the flatness and smoothness of the wafer after grinding, the more the thickness deviates from the preset value, and the longer the grinding duration and the average feed distance adjusted by the grinding push rod during the grinding operation, the higher the quality loss coefficient of the wafer product, indicating that the quality of the wafer product is low and the wear of the grinding disc is high, and it needs to be replaced.

[0090] The process of determining whether to replace the grinding disc in S4 further includes;

[0091] By taking the wafer grinding state influence coefficient and comparing it with the preset grinding state influence coefficient threshold ;

[0092] If , it is determined that the quality loss coefficient of the wafer product is small, which means that the state and grinding effect of the wafer grinding process are good, and there is no need to replace the grinding disc;

[0093] If , it is determined that the quality loss coefficient of the wafer product is large, which means that the state and grinding effect of the wafer grinding process are poor, and the grinding disc needs to be replaced;

[0094] Through the above technical solution, in this embodiment, by comparing the wafer grinding state influence coefficient with the preset grinding state influence coefficient threshold , through this comparison method, the state and grinding effect of the wafer grinding process can be analyzed and judged according to the size of the quality loss coefficient of the wafer product, and whether to replace the grinding disc can be decided according to the analysis result, so as to avoid the situation that the grinding efficiency is reduced due to excessive wear of the grinding disc and improve the grinding effect of the wafer.

[0095] The above has described an embodiment of the present invention in detail, but the content described is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A wafer grinding and polishing adjustment method based on pressure sensing, characterized in that: The method comprises: S1: measuring the current initial thickness of the wafer to be processed, determining the target thickness of the wafer to be processed, and bonding the wafer to the substrate; S2: adjusting the initial feeding distance of the grinding push rod according to the preset control strategy so that the pressure between the grinding disk and the wafer to be processed reaches the value corresponding to the preset control strategy; S3: Perform grinding operation according to the grinding disc speed in the preset strategy, collect and analyze the status parameter data of the grinding equipment and the wafer in real time, determine the grinding status of the wafer at different time points, and adjust the feeding distance of the grinding push rod in real time according to the grinding status of the wafer at different time points; S4: When the wafer is ground to the target thickness, the wafer status after processing is analyzed to determine whether the grinding disc needs to be replaced. If not, the wafer grinding operation is completed. If yes, proceed to step S5: S5: When it is determined that the grinding disc needs to be replaced, a warning is issued and the wafer grinding operation is automatically stopped to wait for the grinding disc to be replaced; The process of adjusting the feeding distance of the grinding push rod in S3 includes: S31: firstly, collecting the state data of the wafer during grinding, including the surface temperature, thickness and color depth of the grinding slurry of the wafer during grinding; S32: calculating the influence coefficient of the grinding state of the wafer at different time points by collecting the pressure change between the grinding disk and the wafer to be processed and the rotation speed change of the grinding disk and combining the data collected in S31; S33: by comparing the grinding state influence coefficient of the wafer at different time points with the preset influence coefficient, and judging whether it is necessary to adjust the feeding distance of the grinding push rod according to the comparison result, if not, no operation is performed, if yes, proceed to step S34; S34: The feeding distance of the grinding push rod is adjusted by combining the grinding state influence coefficient of the wafer at different time points and the driving motor equipment parameters of the grinding push rod.

2. The wafer grinding and polishing adjustment method based on pressure sensing according to claim 1 is characterized in that: The process of calculating the influence coefficient of the grinding state of the wafer at different time points in S32 includes: By formula Calculate the surface temperature dispersion coefficient of the wafer from the beginning of grinding to the i-th time point ; Among them, i is a data collection at a fixed time interval since the start of wafer grinding, n is the total number of data collections from the start of wafer grinding to the i-th time point, is the surface temperature of the wafer at the i-th time point after the start of grinding, For all The average value of is the proportionality coefficient, which is set according to empirical fitting. is the room temperature at the i-th time point after the wafer starts to be polished, is the preset indoor temperature. is the indoor humidity at the i-th time point after the wafer starts to be polished, The preset indoor humidity.

3. The wafer grinding and polishing adjustment method based on pressure sensing according to claim 2 is characterized in that: The process of calculating the influence coefficient of the grinding state of the wafer at different time points in S32 also includes: The real-time rotation speed data of the grinding disc is obtained through real-time monitoring, and the real-time rotation speed change curve of the grinding disc is established. ; By formula Calculate the influence coefficient of the grinding state of the wafer at the i-th time point since the start of grinding ; in, is the pressure value between the wafer and the grinding disc at the i-th time point since the start of grinding, is the preset pressure value, is the grinding thickness of the wafer at the i-th time point since the start of grinding, is the preset grinding thickness, is the error influence function, is the color depth of the polishing slurry at the i-th time since the start of polishing of the wafer, is the preset grinding slurry color depth, for The standard value of To define a function, if , then let , otherwise, let , The time point when the first data is collected after the wafer starts to be polished. is the time point of the i-th data collection after the wafer starts to be polished.

4. The wafer grinding and polishing adjustment method based on pressure sensing according to claim 3 is characterized in that: The comparison process in S33 includes: By calculating the polishing state influence coefficient of the wafer at the i-th time point since the start of polishing The preset grinding state influence coefficient threshold Make a comparison; like , it is judged that the current grinding state has a high impact, the grinding quality is reduced, and the feeding distance of the grinding push rod needs to be adjusted; like , it is judged that the current grinding state has low impact and high grinding quality, and there is no need to adjust the feed distance of the grinding push rod.

5. The wafer grinding and polishing adjustment method based on pressure sensing according to claim 4 is characterized in that: The process of adjusting the feeding distance of the grinding push rod in S34 includes: By formula Calculate the adjusted grinding push rod feed distance of the wafer from the i-th time point since the start of grinding ; in, The preset feed distance of the grinding push rod at the i-th time point, is the voltage value of the grinding push rod driving motor at the i-th time point, For all The standard value of is the current value of the grinding push rod driving motor at the i-th time point, is the preset current value, To adjust the coefficient comparison table function, according to the empirical data The influence of the range of values ​​on the grinding push rod feed distance is obtained based on the test.

6. The wafer grinding and polishing adjustment method based on pressure sensing according to claim 5 is characterized in that: The process of determining whether the grinding disc needs to be replaced in S4 includes: By formula Calculate the mass loss coefficient of the finished wafer ; in, is the flatness of the wafer after grinding, For the preset flatness, is the smoothness of the wafer after grinding, is the preset smoothness, is the thickness of the wafer after grinding, is the preset thickness, for The standard value of is the total wafer grinding time, is the preset grinding time, and m is the total number of data collection times from the start to the end of wafer grinding.

7. The wafer grinding and polishing adjustment method based on pressure sensing according to claim 6 is characterized in that: The process of determining whether the grinding disc needs to be replaced in S4 also includes: By calculating the wafer grinding state influence coefficient The preset grinding state influence coefficient threshold Make a comparison; like , it is judged that the quality loss coefficient of the finished wafer is small, which means that the state of the wafer grinding process and the grinding effect are good, and there is no need to replace the grinding disc; like , it is judged that the quality loss coefficient of the finished wafer is large, which means that the state of the wafer grinding process and the grinding effect are poor, and the grinding disc needs to be replaced.

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