Thinning control method, system and thinning equipment

Abstract

The present invention discloses a thinning control method, system and thinning equipment, wherein the thinning control method includes the following process: S1, when the suction cup of the loading manipulator moves down to the designated material picking position to suck the workpiece after centering, obtain the first pressure value measured by the detection sensor; S2, determine the thickness value of the workpiece according to the first pressure value; S3, calculate the difference between the thickness value of the workpiece determined in S2 and the standard thickness value; S4, calculate the speed reduction point position of the spindle for grinding the workpiece on the wafer table according to the determined difference; S5, after the spindle is controlled to move down to the speed reduction point position of the spindle determined in S4, grind the workpiece according to a predetermined process. The present invention can compare the calculated workpiece thickness with the standard thickness value, and adjust the speed reduction point position according to the comparison result, so that the adjusted speed reduction point position can effectively adapt to the processing needs of the actual workpiece, avoiding the problem of collision or reduced efficiency.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor device processing, and in particular to a thinning control method, system and thinning equipment. Background Art

[0002] Thinning is an important process in the processing of semiconductor devices such as wafers.

[0003] The thinning device is a special device for thinning. Patent documents with application publication number CN115338717A and authorization announcement number CN218639240U disclose two available thinning devices.

[0004] In both structures, a robot arm takes the wafer from the material box and transfers it to a centering mechanism for centering. After centering, the robot arm moves the wafer at the centering mechanism to a wafer stage, and then a grinding mechanism grinds the wafer on the wafer stage.

[0005] When the grinding mechanism is grinding, the spindle will first move down to the deceleration point at a faster speed. After the spindle moves down to the deceleration point, the spindle needs to be switched to a slower downward speed to make the grinding wheel contact the wafer at a low speed, thereby protecting the grinding wheel and the wafer.

[0006] In the existing thinning process, the corresponding standard deceleration point position is determined according to the standard thickness value of each wafer. However, due to the existence of processing errors, even for the same type of wafer, their thickness will be different. If the actual thickness of a wafer is greater than the standard thickness value of this wafer and its top surface is not lower than the standard deceleration point position corresponding to this wafer when it is placed on the wafer stage, then the grinding wheel at the lower end of the spindle will contact the wafer at a faster speed, increasing the risk of damage to the grinding wheel and wafer. There is even a situation where the thickness of the wafer exceeds the range of the thickness measuring mechanism, which further increases the risk of failure of the thickness measuring mechanism. On the contrary, if the actual thickness of a wafer is less than the standard thickness value of this wafer, then when the wafer is placed on the wafer stage, its top surface position will be lower than the standard deceleration point position, which will cause the spindle to reduce the downward speed at the standard deceleration point. It will take a longer time for the grinding wheel at the lower end of the spindle to contact the wafer, which will result in reduced efficiency and greater idle travel. Summary of the invention

[0007] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a thinning control method, system and thinning equipment.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] The thinning control method includes the following steps:

[0010] S1, after the workpiece is centered on the centering mechanism, the workpiece on the centering mechanism is grabbed by a loading robot and transferred to a wafer table, the centering mechanism includes a carrier for carrying the workpiece, the bottom of the carrier is connected to a detection sensor for detecting the axial pressure on the top of the carrier; when the suction cup coaxial with the centered workpiece in the loading robot moves down to a specified material picking height, a first pressure value measured by the detection sensor is obtained;

[0011] S2, determining a thickness value of the workpiece according to the first pressure value;

[0012] S3, calculating the difference between the thickness value of the workpiece determined in S2 and the standard thickness value;

[0013] S4, determining the speed reduction point position of the spindle for grinding the workpiece on the wafer stage according to the difference;

[0014] S5, after controlling the main shaft to move down to the speed reduction point position of the main shaft determined in S4, the workpiece is ground according to a predetermined process.

[0015] Preferably, after the workpiece is placed on the carrier, a second pressure value measured by the detection sensor is obtained,

[0016] When determining the thickness value of the workpiece according to the first pressure value, the pressure difference value is obtained by subtracting the second pressure value from the first pressure value, and the pressure difference value is substituted into the linear relationship between the pressure difference value and the workpiece thickness value to calculate the thickness value of the workpiece.

[0017] Preferably, after determining the thickness value of the workpiece, it is confirmed whether the thickness value of the workpiece exceeds the measuring range of the thickness measuring mechanism of the thinning device. If so, an alarm is issued and the thinning process is exited; if not, S3 is executed.

[0018] Preferably, after the workpiece is moved onto the wafer stage, the thickness value of the workpiece is determined by a thickness measuring mechanism;

[0019] Determine the thickness value of the workpiece determined by the thickness measuring mechanism, the thickness value of the workpiece determined in S2, and the standard thickness value;

[0020] If it is determined that one of the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 is greater than the standard thickness value, and the other is less than the standard thickness value, an alarm is issued and thinning is stopped;

[0021] If it is determined that the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 are both greater than the standard thickness value, determine whether the thickness value of the workpiece determined by the thickness measuring mechanism is greater than the thickness value of the workpiece determined in S2, if so, calculate the difference according to the thickness value of the workpiece determined by the thickness measuring mechanism, otherwise, calculate the difference according to the thickness value of the workpiece determined in S2;

[0022] If it is determined that the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 are both less than the standard thickness value, determine whether the thickness value of the workpiece determined by the thickness measuring mechanism is greater than the thickness value of the workpiece determined in S2; if so, calculate the difference based on the thickness value of the workpiece determined in S2; otherwise, calculate the difference based on the thickness value of the workpiece determined by the thickness measuring mechanism.

[0023] Preferably, when the thickness value of the workpiece is determined by a thickness measuring mechanism, a plurality of detection values ​​of the thickness measuring mechanism are acquired at intervals, and the thickness value of the workpiece is determined based on the plurality of detection values.

[0024] Preferably, after the thickness value of the workpiece is determined by the thickness measuring mechanism, it is judged whether the difference between the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 exceeds a difference threshold. If so, an alarm is given and thinning is stopped. If not, it is judged whether the thickness value of the workpiece determined by the thickness measuring mechanism, the thickness value of the workpiece determined in S2 and the standard thickness value are greater than or equal to the difference.

[0025] Preferably, when the determined thickness value of the workpiece is greater than the standard thickness value, the spindle speed reduction point position is above the standard speed reduction point position, and the height difference between the spindle speed reduction point position and the standard speed reduction point position is the absolute value of the difference; when the determined thickness value of the workpiece is less than the standard thickness value, the spindle speed reduction point position is below the standard speed reduction point position, and the height difference between the spindle speed reduction point position and the standard speed reduction point position is the absolute value of the difference.

[0026] Preferably, when the workpiece is ground according to a predetermined process, the grinding is performed in stages, and different grinding parameters are used in each stage to grind a set thickness.

[0027] Thinning control system, including:

[0028] The picking and pressure acquisition unit is used to grab the workpiece on the centering mechanism and transfer it to the wafer table through a loading robot after the workpiece is centered on the centering mechanism, the centering mechanism includes a carrier for carrying the workpiece, and the bottom of the carrier is connected to a detection sensor for detecting the axial pressure on the top of the carrier; when the suction cup coaxial with the centered workpiece in the loading robot moves down to a specified picking height, the first pressure value measured by the detection sensor is obtained;

[0029] a thickness calculation unit, used to determine a thickness value of the workpiece according to the first pressure value;

[0030] A difference calculation unit, used for calculating the difference between the thickness value of the workpiece determined by the thickness calculation unit and the standard thickness value;

[0031] A speed reduction point position determination unit, used to determine the speed reduction point position of the spindle for grinding the workpiece on the wafer stage according to the difference;

[0032] The thinning unit is used to control the main shaft to move down to the speed reduction point position of the main shaft determined by the speed reduction point position determination unit, and then grind the workpiece according to a predetermined process.

[0033] A thinning device comprises a processor and a memory, wherein the memory stores a program executable by the processor, and when the program is executed, any of the above-mentioned thinning control methods is implemented.

[0034] The advantages of the technical solution of the present invention are mainly reflected in:

[0035] The thinning control method of the present invention sets a detection sensor at the centering mechanism, which can measure the pressure values ​​corresponding to workpieces of different thicknesses when the loading robot takes the material and calculate the thickness of the workpiece based on the measured pressure value, so that the calculated workpiece thickness can be compared with the standard thickness value, and the speed reduction point position can be adjusted according to the comparison result, so that the adjusted speed reduction point position can effectively adapt to the actual processing needs of the workpiece and avoid collision or efficiency reduction.

[0036] After determining the thickness of the workpiece according to the measured pressure value, the present invention can judge whether it exceeds the measuring range of the thickness measuring mechanism, and then give an alarm and stop thinning, thereby effectively avoiding the problem of thickness measuring mechanism failure caused by continued thickness measurement.

[0037] When calculating the thickness of a workpiece according to the measured pressure value, the present invention effectively avoids the influence of the weight of workpieces of different thicknesses on the pressure, which is beneficial to improving the accuracy of calculating the thickness of the workpiece.

[0038] The present invention calculates the thickness of the workpiece according to the pressure value and further combines the thickness measuring mechanism to measure the thickness of the workpiece, which can effectively avoid the misjudgment of the measurement by a single mechanism. At the same time, the accuracy of compensation can be guaranteed as much as possible through multi-directional comparison. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a process schematic diagram of the thinning control method of the present invention;

[0040] Figure 2 It is a schematic diagram of a process of determining a thickness value of a workpiece according to a first pressure value and a second pressure value in a thinning control method of the present invention;

[0041] Figure 3 The thinning control method of the present invention is a schematic diagram of a process in which a thickness measuring mechanism measures a thickness value of a workpiece. DETAILED DESCRIPTION

[0042] The purpose, advantages and features of the present invention will be illustrated and explained by the non-limiting description of the following preferred embodiments. These embodiments are only typical examples of the application of the technical solution of the present invention, and any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection claimed by the present invention.

[0043] In the description of the scheme, it should be noted that the terms "center", "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience and simplification of description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0044] Example 1

[0045] The following is an explanation of the process of the thinning control method disclosed by the present invention in conjunction with the accompanying drawings. The thinning control method is based on a thinning device. The specific structure of the thinning device can refer to the structure of the patent document cited in the background technology. The difference from the above-mentioned existing thinning device is that:

[0046] The present invention improves the centering mechanism for centering the workpiece in the thinning device, that is, the present invention connects a detection sensor (not shown in the figure) for detecting the axial pressure on the top of the platform under the platform for carrying the workpiece of the centering mechanism, and the detection sensor can be a known pressure sensor. In addition, in order to improve the support, the diameter of the platform can be as large as possible, for example, equivalent to the diameter of the circle formed when a circle of positioning claws expands to the maximum position, and at the same time, a strip hole for each positioning claw to move is provided on the platform.

[0047] Correspondingly, as attached Figure 1 As shown, the thinning control method includes the following process:

[0048] S1, after the workpiece is centered on the centering mechanism, the workpiece on the centering mechanism is grabbed by a loading robot and transferred to a wafer table, and when a suction cup coaxial with the centered workpiece in the loading robot moves down to a specified material picking height, a first pressure value measured by the detection sensor is obtained;

[0049] S2, determining a thickness value of the workpiece according to the first pressure value;

[0050] S3, calculating the difference between the thickness value of the workpiece determined in S2 and the standard thickness value;

[0051] S4, determining the speed reduction point position of the spindle for grinding the workpiece on the wafer stage according to the difference;

[0052] S5, after controlling the main shaft to move down to the speed reduction point position of the main shaft determined in S4, the workpiece is ground according to a predetermined process.

[0053] The specific structure of the loading robot is a known technology and will not be elaborated here. When it grabs the workpiece on the centering mechanism, the suction cup is moved to be coaxial with the workpiece centered on the centering mechanism through the rotating mechanism, and then the loading robot drives the rotating mechanism to move downward as a whole so that the suction cup moves down to the specified material picking height. At this time, the suction cup applies pressure to the workpiece at the centering mechanism.

[0054] In S2, when determining the thickness value of the workpiece according to the first pressure value, the measured first pressure value is substituted into a predetermined calculation formula to obtain the thickness value, and the calculation formula can be determined by the following process:

[0055] Prepare several samples with different thicknesses and measure the thickness of each sample;

[0056] After placing several samples one by one on the centering mechanism for centering, the loading robot grabs the centered samples according to the set program, and the suction cup of the loading robot moves to the specified material picking height each time. At the specified material picking height, the suction cup can apply pressure to the sample, so that the pressure value of each sample grabbed by the loading robot is measured by the detection sensor. After obtaining the thickness value and the corresponding pressure value of each sample, the relationship between the thickness value and the pressure value can be calculated through feasible tools such as matlab as the calculation formula.

[0057] Better, as attached Figure 2 As shown, after the workpiece is placed on the stage, the second pressure value measured by the detection sensor is obtained, and when determining the thickness value of the workpiece according to the first pressure value, the pressure difference value is first subtracted from the second pressure value by the first pressure value, and then the pressure difference value is substituted into the linear relationship between the pressure difference value and the workpiece thickness value to calculate the thickness value of the workpiece. This method can effectively avoid the influence of the weight of workpieces of different thicknesses on the pressure value, thereby making the calculation of the thickness value more accurate.

[0058] The linear relationship between the pressure difference and the workpiece thickness is determined based on the process of measuring the pressure value by grabbing the sample by the loading robot, that is, after each sample is placed on the carrier and centered, the pressure value measured by the detection sensor at this time is first obtained, and then the pressure value is measured when the loading robot grabs the sample, and the pressure value is measured. The pressure difference corresponding to each sample is subtracted from the pressure value measured when the sample is placed on the carrier from the pressure value measured when the sample is grabbed. After obtaining the thickness values ​​and corresponding pressure differences of several samples, the linear relationship between the thickness and the pressure difference can be calculated based on the above data through feasible tools such as matlab. The linear relationship is usually as follows: y=ax+b, where y is the pressure difference, x is the thickness of the workpiece, and a and b are determined constants.

[0059] As attached Figure 3 As shown, after determining the thickness value of the workpiece according to the first pressure value, confirm whether the thickness value of the workpiece exceeds the measuring range of the thickness measuring mechanism of the thinning equipment. If so, an alarm is issued and the thinning process is exited; if not, execute S3, which can effectively protect the thickness measuring mechanism.

[0060] Further, after the workpiece is moved onto the wafer table, if the thickness of the workpiece determined according to the first pressure value does not exceed the measuring range of the thickness measuring mechanism, the thickness of the workpiece is determined by the thickness measuring mechanism. The thickness measuring mechanism measures the thickness of the workpiece by placing its two measuring rods on the top surface of the workpiece and the top surface of the wafer table respectively. Its specific structure and thickness measurement principle are known technologies and will not be described in detail here.

[0061] In order to avoid errors in reading immediately after the thickness measuring mechanism is lowered into place due to the instability of the thickness measuring mechanism, when measuring the thickness of the workpiece by the thickness measuring mechanism, multiple detection values ​​of the thickness measuring mechanism are obtained at intervals, that is, after the two measuring rods are lowered into place, a detection value is obtained every predetermined time. The predetermined time and the specific number of multiple detection values ​​can be determined as needed, for example, the predetermined time is 10 milliseconds, 20 milliseconds, or 30 milliseconds, and the specific number is, for example, 3, 4, 5, etc., which are not limited here. When determining the thickness value of the workpiece based on multiple detection values, the average value of the multiple detection values ​​can be taken, or the average value can be taken after removing the maximum value and the minimum value.

[0062] Usually, the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 should be the same or similar, but it is inevitable that there are some abnormal situations that lead to misjudgment. Therefore, after the thickness measuring mechanism determines the thickness value of the workpiece, it can be determined whether the difference between the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 exceeds the difference threshold.

[0063] If so, an alarm is sounded and thinning is stopped;

[0064] If not, the thickness value of the workpiece determined by the thickness measuring mechanism, the thickness value of the workpiece determined in S2 and the standard thickness value are determined.

[0065] If it is determined that one of the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 is greater than the standard thickness value, and the other is less than the standard thickness value, an alarm is issued and thinning is stopped.

[0066] If it is determined that the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 are both greater than the standard thickness value, determine whether the thickness value of the workpiece determined by the thickness measuring mechanism is greater than the thickness value of the workpiece determined in S2; if so, calculate the difference based on the thickness value of the workpiece determined by the thickness measuring mechanism; otherwise, calculate the difference based on the thickness value of the workpiece determined in S2.

[0067] If it is determined that the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 are both less than the standard thickness value, determine whether the thickness value of the workpiece determined by the thickness measuring mechanism is greater than the thickness value of the workpiece determined in S2; if so, calculate the difference based on the thickness value of the workpiece determined in S2; otherwise, calculate the difference based on the thickness value of the workpiece determined by the thickness measuring mechanism.

[0068] Of course, in other embodiments, the difference may be calculated by taking the average of the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2.

[0069] When the determined thickness value of the workpiece is greater than the standard thickness value, the spindle deceleration point position is located above the standard deceleration point position, and the height difference between the spindle deceleration point position and the standard deceleration point position is the absolute value of the difference; when the determined thickness value of the workpiece is less than the standard thickness value, the spindle deceleration point position is located below the standard deceleration point position, and the height difference between the spindle deceleration point position and the standard deceleration point position is the absolute value of the difference. That is, when the difference between the determined thickness value of the workpiece and the standard thickness value is greater than zero, it indicates that the top surface of the workpiece on the wafer stage is higher than the top surface of the workpiece with the standard thickness value placed on the wafer stage, therefore, it is necessary to adjust the standard deceleration point position upward, and the distance adjusted upward is the absolute value of the difference; when the determined thickness value of the workpiece is less than the standard thickness value, it indicates that the top surface of the workpiece on the wafer stage is lower than the top surface of the workpiece with the standard thickness value placed on the wafer stage, therefore, it is necessary to adjust the standard deceleration point position downward, and the distance adjusted downward is the absolute value of the difference.

[0070] In S5, when the workpiece is ground according to a predetermined process, the workpiece is ground in stages, and different grinding parameters are used in each stage to grind a set thickness. For example, the grinding is carried out in three stages, and the feed speed of the previous stage is greater than the feed speed of the next stage. The specific grinding parameters and the set thickness to be ground in each stage can be determined as needed and are not set here.

[0071] Example 2

[0072] This embodiment discloses a thinning control system, including:

[0073] The picking and pressure acquisition unit is used to grab the workpiece on the centering mechanism and transfer it to the wafer table through a loading robot after the workpiece is centered on the centering mechanism, the centering mechanism includes a carrier for carrying the workpiece, and the bottom of the carrier is connected to a detection sensor for detecting the axial pressure on the top of the carrier; when the suction cup coaxial with the centered workpiece in the loading robot moves down to a specified picking height, the first pressure value measured by the detection sensor is obtained;

[0074] a thickness calculation unit, used to determine a thickness value of the workpiece according to the first pressure value;

[0075] A difference calculation unit, used for calculating the difference between the thickness value of the workpiece determined by the thickness calculation unit and the standard thickness value;

[0076] A speed reduction point position determination unit, used to determine the speed reduction point position of the spindle for grinding the workpiece on the wafer stage according to the difference;

[0077] The thinning unit is used to control the main shaft to move down to the speed reduction point position of the main shaft determined by the speed reduction point position determination unit, and then grind the workpiece according to a predetermined process.

[0078] Example 3

[0079] This embodiment discloses a thinning device, including a processor and a memory, wherein the memory stores a program executable by the processor, and when the program is executed, any of the above-mentioned thinning control methods is implemented.

[0080] There are many implementation methods of the present invention, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A thinning control method, characterized in that: The process includes the following: S1, after the workpiece is centered on the centering mechanism, the workpiece on the centering mechanism is grabbed by a loading robot and transferred to a wafer table, the centering mechanism includes a carrier for carrying the workpiece, the bottom of the carrier is connected to a detection sensor for detecting the axial pressure on the top of the carrier; when the suction cup coaxial with the centered workpiece in the loading robot moves down to a specified material picking height, a first pressure value measured by the detection sensor is obtained; S2, determining a thickness value of the workpiece according to the first pressure value; S3, calculating the difference between the thickness value of the workpiece determined in S2 and the standard thickness value; S4, determining the speed reduction point position of the spindle for grinding the workpiece on the wafer stage according to the difference; S5, after controlling the spindle to move down to the spindle speed reduction point position determined in S4, grinding the workpiece according to a predetermined process; After the workpiece is placed on the carrier, a second pressure value measured by the detection sensor is obtained, When determining the thickness value of the workpiece according to the first pressure value, the pressure difference value is obtained by subtracting the second pressure value from the first pressure value, and the pressure difference value is substituted into the linear relationship between the pressure difference value and the workpiece thickness value to calculate the thickness value of the workpiece.

2. The thinning control method according to claim 1, characterized in that: After determining the thickness value of the workpiece, confirm whether the thickness value of the workpiece exceeds the measuring range of the thickness measuring mechanism of the thinning device. If so, an alarm is issued and the thinning process is exited; if not, execute S3.

3. The thinning control method according to claim 1, characterized in that: After the workpiece is moved onto the wafer stage, the thickness value of the workpiece is determined by a thickness measuring mechanism; Determine the thickness value of the workpiece determined by the thickness measuring mechanism, the thickness value of the workpiece determined in S2, and the standard thickness value; If it is determined that one of the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 is greater than the standard thickness value, and the other is less than the standard thickness value, an alarm is issued and thinning is stopped; If it is determined that the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 are both greater than the standard thickness value, determine whether the thickness value of the workpiece determined by the thickness measuring mechanism is greater than the thickness value of the workpiece determined in S2, if so, calculate the difference according to the thickness value of the workpiece determined by the thickness measuring mechanism, otherwise, calculate the difference according to the thickness value of the workpiece determined in S2; If it is determined that the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 are both less than the standard thickness value, determine whether the thickness value of the workpiece determined by the thickness measuring mechanism is greater than the thickness value of the workpiece determined in S2; if so, calculate the difference based on the thickness value of the workpiece determined in S2; otherwise, calculate the difference based on the thickness value of the workpiece determined by the thickness measuring mechanism.

4. The thinning control method according to claim 3, characterized in that: When the thickness value of the workpiece is determined by the thickness measuring mechanism, a plurality of detection values ​​of the thickness measuring mechanism are acquired at intervals, and the thickness value of the workpiece is determined according to the plurality of detection values.

5. The thinning control method according to claim 3, characterized in that: After the thickness value of the workpiece is determined by the thickness measuring mechanism, it is determined whether the difference between the thickness value of the workpiece determined by the thickness measuring mechanism and the thickness value of the workpiece determined in S2 exceeds the difference threshold. If so, an alarm is issued and thinning is stopped. If not, the thickness value of the workpiece determined by the thickness measuring mechanism, the thickness value of the workpiece determined in S2 and the standard thickness value are determined.

6. The thinning control method according to claim 1, characterized in that: When the determined thickness value of the workpiece is greater than the standard thickness value, the spindle speed reduction point position is above the standard speed reduction point position, and the height difference between the spindle speed reduction point position and the standard speed reduction point position is the absolute value of the difference; when the determined thickness value of the workpiece is less than the standard thickness value, the spindle speed reduction point position is below the standard speed reduction point position, and the height difference between the spindle speed reduction point position and the standard speed reduction point position is the absolute value of the difference.

7. The thinning control method according to any one of claims 1 to 6, characterized in that: When the workpiece is ground according to a predetermined process, the grinding is performed in stages, and different grinding parameters are used in each stage to grind a set thickness.

8. Thinning control system, characterized in that, include: The picking and pressure acquisition unit is used to grab the workpiece on the centering mechanism and transfer it to the wafer table through a loading robot after the workpiece is centered on the centering mechanism, the centering mechanism includes a carrier for carrying the workpiece, and the bottom of the carrier is connected to a detection sensor for detecting the axial pressure on the top of the carrier; when the suction cup coaxial with the centered workpiece in the loading robot moves down to a specified picking height, the first pressure value measured by the detection sensor is obtained; a thickness calculation unit, used to determine a thickness value of the workpiece according to the first pressure value; A difference calculation unit, used for calculating the difference between the thickness value of the workpiece determined by the thickness calculation unit and the standard thickness value; A speed reduction point position determination unit, used to determine the speed reduction point position of the spindle for grinding the workpiece on the wafer stage according to the difference; A thinning unit, used for controlling the spindle to move down to the spindle speed reduction point position determined by the speed reduction point position determination unit, and then grinding the workpiece according to a predetermined process; After the workpiece is placed on the carrier, a second pressure value measured by the detection sensor is obtained, When determining the thickness value of the workpiece according to the first pressure value, the pressure difference value is obtained by subtracting the second pressure value from the first pressure value, and the pressure difference value is substituted into the linear relationship between the pressure difference value and the workpiece thickness value to calculate the thickness value of the workpiece.

9. A thinning device comprising a processor and a memory, wherein the memory stores a program executable by the processor, characterized in that: When the program is executed, the thinning control method according to any one of claims 1 to 7 is implemented.

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