Jacking force measuring device and fragment prevention method

Abstract

The invention discloses a jacking force measuring device and an anti-fragment method. The jacking force measuring device comprises a load part, a force measuring part and a lead screw module which are connected from top to bottom. The top of the load part is fixed below an ejector pin supporting plate and is used for bearing jacking force transmitted by the ejector pin supporting plate; the side surface of the load part is connected with a first guide rail in the vertical direction, can move up and down along the first guide rail, and only transmits stress in the vertical direction to the force measuring part; the upper part of the force measuring part is connected with the load part; the lower part of the force measuring part is connected with the lead screw module; a pressure sensor of the force measuring part is located between the first part and the second part, and the first part and the second part independently move up and down.

Description

Technical Field

[0001] The present invention relates to semiconductor process equipment, in particular to a wafer lifting force measuring device in a vacuum environment and a fragment prevention method. Background Art

[0002] In the prior art, when the electrostatic adsorption function in semiconductor process equipment, such as CVD equipment, is executed, there is a situation where the attraction of the electrostatic chuck (ESC) to the wafer cannot be completely eliminated. When the wafer is lifted mechanically, if the force used to lift the wafer is too great, it may cause the wafer to break. It is necessary to implement a method to detect the force used to lift the wafer. Currently, there are no similar PECVD products on the market that directly measure the support force of the ejector pins lifting the wafer.

[0003] Existing techniques can only indirectly measure the presence of the ejector pins supporting the wafer. For example, the magnitude of the electrostatic attraction force can be indirectly determined by measuring the torque between the lead screw and the motor. Because the measured data includes factors such as motor torque and the friction inherent in the system, the desired force cannot be effectively separated from the measurement results.

[0004] In addition, in the prior art, when both tension and pressure exist in the force transmission rod, only the pressure can be measured, and the tension cannot be measured using a pressure sensor.

[0005] Therefore, there is an urgent need for a measuring device that can accurately measure the lifting force of the pin on the wafer. Summary of the Invention

[0006] In order to overcome the defects of the prior art, the present invention provides a wafer lifting force measurement device in a vacuum environment and an anti-fragmentation method.

[0007] The lifting force measuring device comprises: a load part, a force measuring part and a screw module connected from top to bottom.

[0008] The top of the load-bearing part is fixed under a pin support plate to bear the lifting force transmitted by the pin support plate; the side of the load-bearing part is connected to a first vertical guide rail and can move up and down along the first guide rail, only transmitting the vertical force to the force-measuring part;

[0009] The upper part of the force measuring part is connected to the load part; the lower part of the force measuring part is connected to the screw module; the pressure sensor of the force measuring part is located between the first part and the second part, and the first part and the second part move up and down independently.

[0010] In one embodiment, the load-bearing portion is connected to a vertical support plate, and the first guide rail is located on the vertical support plate.

[0011] In one embodiment, the side surface of the load-bearing portion is connected to the first guide rail via a guide rail force transmission rod, so that the bending moment from the ejector support plate is borne by the first guide rail.

[0012] In one embodiment, the force measuring part includes an upper force transmission rod, the pressure sensor, a pressure regulator, a lower force transmission rod, and a vacuum force regulator; the upper force transmission rod is the upper part; the pressure regulator and the lower force transmission rod are the lower part.

[0013] In one embodiment, the upper end of the upper force transmission rod is fixed below the load part; the pressure sensor is located between the lower end of the upper force transmission rod and the upper end of the pressure regulator; the lower end of the pressure regulator is embedded in and fixed in the lower force transmission rod; the vacuum force regulator is sleeved on the lower end of the upper force transmission rod and the outer periphery of the pressure sensor; the lower part of the vacuum force regulator is provided with a threaded hole, the upper end of the pressure regulator is provided with a thread, and the pressure regulator is connected to the lower thread of the vacuum force regulator; wherein, the pressure regulator is adjusted by rotating the length entering the vacuum force regulator so as to apply a pre-tightening force to the pressure sensor, so that the pressure sensor is supported by the lower end of the upper force transmission rod to offset the upward vacuum force.

[0014] In one embodiment, after the length of the pressure regulator entering the vacuum force regulator is determined, it is fixed by a nut.

[0015] In one embodiment, the screw module includes a screw, a slider and a second guide rail; the pressure regulator is fixed to the upper end of the lower force transmission rod, and the main body of the lower force transmission rod is fixedly connected to the slider, so that the lower force transmission rod can move up and down along the second guide rail.

[0016] In one embodiment, the second guide rail is independent of the first guide rail and the two are arranged in parallel. The pressure sensor is located between the first guide rail and the second guide rail. The up and down movement of the upper force transmission rod is limited by the first guide rail, and the up and down movement of the pressure regulator is limited by the second guide rail and the number of rotations of the thread.

[0017] In one embodiment, the lifting force reflects the electrostatic adsorption force of the wafer; the lifting force is the sum of the lifting forces of all ejector pins.

[0018] The present invention also provides a fragment prevention method, using the aforementioned lifting force measuring device, the method comprising:

[0019] Setting a preset allowable force, the preset allowable force being the maximum value allowed to prevent wafer breakage;

[0020] When the lifting force is measured to be less than or equal to the preset allowable force, the wafer is lifted normally;

[0021] When the lifting force is measured to be greater than the preset allowable force, the lifting is stopped, and the wafer is lifted again after the electrostatic adsorption force is eliminated, and the cycle is repeated multiple times until the lifting force is less than the preset allowable force.

[0022] The lift force measurement device and method provided by the present invention can accurately and directly separate the electrostatic adsorption force acting on the wafer. If the electrostatic adsorption force is too large, it is fed back to the system, and the electrostatic adsorption force elimination action is performed again to prevent fragmentation. In addition, the structure has the function of simultaneously measuring forces in two directions, which is achieved by applying a preload force through a pressure regulator. In addition, a separate guide rail is provided on the load portion to offset the bending moment generated by the wafer being eccentric to the pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above summary of the invention and the following detailed description of the present invention will be better understood when read in conjunction with the accompanying drawings. It should be noted that the drawings are only examples of the invention claimed. In the drawings, the same reference numerals represent the same or similar elements.

[0024] Figure 1A A semiconductor processing apparatus according to an embodiment of the present invention is shown;

[0025] Figure 1B Shows an overall schematic diagram of a lifting force measuring device according to an embodiment of the present invention;

[0026] Figure 2 A partial schematic diagram of a semiconductor device according to an embodiment of the present invention is shown;

[0027] Figure 3 A schematic diagram of a lifting force measuring device according to an embodiment of the present invention is shown;

[0028] Figure 4 A side view showing a lifting force measuring device according to an embodiment of the present invention;

[0029] Figure 5 A schematic diagram showing an upper dowel rod according to an embodiment of the present invention;

[0030] Figure 6 A schematic diagram showing a vacuum force regulator according to an embodiment of the present invention;

[0031] Figure 7 A schematic diagram showing the bending moment experienced by a lifting force measuring device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0032] The detailed features and advantages of the present invention are described in detail below in the specific embodiments. The content is sufficient for any person skilled in the art to understand the technical content of the present invention and implement it accordingly, and based on the description, claims and drawings disclosed in this specification, those skilled in the art can easily understand the relevant purposes and advantages of the present invention. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide an in-depth understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0033] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0034] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood to refer to the orientations depicted in that section and the accompanying drawings. These relative terms are used solely for convenience of description and do not necessarily imply that the devices described herein must be manufactured or operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0035] It is understood that although the terms "first," "second," "third," etc. may be used herein to describe various components, channels, assemblies, regions, layers, and / or portions, these components, channels, assemblies, regions, layers, and / or portions should not be limited by these terms, and these terms are merely used to distinguish different components, channels, assemblies, regions, layers, and / or portions. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0036] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0037] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0038] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0039] Figure 1A FIG1 shows a semiconductor processing device according to an embodiment of the present invention. The semiconductor processing device includes a heater 101, a plurality of ejector pins 102, a plurality of weights 103, a vertical support plate 106 (not shown in FIG1, but can be seen in FIG1). Figure 2 ), lifting force measuring device 105.

[0040] The heater 101 includes a heating plate 107 and a heating plate base 108 located below the heating plate and supporting the heating plate 107 .

[0041] The heating plate base 108 and the lifting force measuring device 105 are connected to the vertical support plate 106. The vertical support plate 106 is arranged vertically.

[0042] The heating plate 107 is used to heat the wafer 109. The heating plate 107 has a plurality of through holes corresponding to the number of ejector pins.

[0043] The ejector pin 102 is inserted into the through hole. The upper end of the ejector pin 102 supports the wafer 109. The outer diameter of the upper end of the ejector pin 102 is larger than the minimum inner diameter of the through hole, so that the upper end of the ejector pin 102 is stuck on the upper surface of the heating plate 107 and does not fall off.

[0044] Each weight 103 is sleeved on the outer periphery of the lower end portion of each ejector pin 102 .

[0045] In one embodiment, the number of ejector pins is three, and the three ejector pins are evenly distributed along the circumference.

[0046] Figure 1B FIG2 is a schematic diagram of a lifting force measurement device according to an embodiment of the present invention. The lifting force measurement device includes a main body portion 110. In one embodiment, the lifting force measurement device may also include a pin support plate 104 fixedly connected to the active portion 110.

[0047] Combine Figure 1A and Figure 1B The ejector pin support plate 104 is disposed below the weight 103 to support the weight 103. When the ejector pin support plate 104 rises, it pushes the weight 103 upward and drives the ejector pins 102 to rise, thereby lifting the wafer 109.

[0048] The main body 110 of the lift force measurement device 105 of the present invention is located below the ejector support plate 104 and is used to measure the sum of the lift forces of multiple ejector pins (the force exerted by the ejector pins to lift the wafer). If the measured lift force is less than or equal to a preset allowable force, the wafer is lifted normally. If the measured lift force is greater than the preset allowable force, the lifting process is stopped, and the electrostatic adsorption force is eliminated again before the wafer is lifted again. This cycle is repeated multiple times until the lift force is less than the preset allowable force. The preset allowable force is the maximum value allowed to prevent debris.

[0049] Figure 2 FIG. 1 is a partial schematic diagram of a semiconductor device according to an embodiment of the present invention. During the process, an electrostatic adsorption force F is generated between the wafer 109 and the heating plate 107. 静电吸附 At the end of the process, the ejector pins need to lift the wafer 109 to separate it from the heating plate 107. Therefore, the ejector pins need to overcome the electrostatic adsorption force F 静电吸附 , the lifting force F through the lifting action pin The wafer is lifted up due to the electrostatic adsorption force F 静电吸附 The existence of the lifting force F pin In fact, it reflects the electrostatic adsorption force F 静电吸附 Therefore, in order for the wafer to be smoothly separated from the heating plate 107, it is necessary to eliminate the electrostatic adsorption force before lifting the wafer 109. If the electrostatic adsorption force is not completely eliminated, debris will easily be generated when the wafer is lifted. Therefore, the desired approach is to accurately measure the lifting force of the ejector pin to lift the wafer, and when the measured lifting force is greater than a preset allowable force, it means that the electrostatic adsorption force is very large. At this time, the lifting is stopped, and the electrostatic adsorption force needs to be eliminated again before lifting again until the lifting force is less than the anti-fragmentation allowable value.

[0050] However, existing measurement devices measure system torque, which includes system friction, acceleration and deceleration torque, and other factors. They cannot separate the torque from the electrostatic adsorption force, nor can they accurately separate the lifting force of the ejector pin. Therefore, the lifting force cannot be accurately measured.

[0051] In addition, after the chamber is vacuumed, the lifting force measuring device will be subjected to an upward pulling force, namely the vacuum force F 真空 , and the entire gravity G acting on the lifting force measuring device. When the vacuum force F 真空 When it is much larger than G, the overall resultant force of the lift force measuring device is upward, and the pressure sensor in the lift force measuring device cannot correctly measure the lift force.

[0052] The lifting force measuring device 105 of the present invention overcomes the above-mentioned drawbacks and is described in detail below.

[0053] Figure 3 A schematic diagram of a lifting force measuring device according to an embodiment of the present invention is shown.

[0054] The main body of the lifting force measuring device 105 includes but is not limited to a force measuring portion 301, a screw module 302, and a load portion 303. In one embodiment, the lifting force measuring device further includes an ejector pin support plate 104. The main body is fixed below the ejector pin support plate.

[0055] Ejector pin support plate 104 supports and propels weight 103 up and down. Ejector pins 102 on weight 103 are used to lift wafer 109. The lifting force, reflecting the electrostatic attraction on the wafer, is transmitted to force measurement unit 301 via ejector pin support plate 104 and load unit 303, thereby measuring the lifting force (i.e., electrostatic attraction) on the wafer.

[0056] The load part 303 is fixed below the ejector plate 104 and is used to bear the lifting force transmitted from the ejector plate 104 and transmit it to the force measuring part 301. The load part 303 is connected to the first guide rail ( Figure 3 Due to the viewing angle, it is not shown. Figure 4 ) connection, the load-bearing part 303 can move up and down along the guide rail. The load-bearing part 303 only transmits the vertical force to the force-measuring part 301.

[0057] The force measuring part 301 is connected below the load part 303 and is used to measure the pressure transmitted by the load part 303 .

[0058] The lead screw module 302 converts rotational motion into linear motion. It includes a lead screw, a slider, and a second guide rail. The lead screw's rotation drives the slider to move linearly along the second guide rail. The force measuring unit 301 is fixedly connected to the slider, allowing it to move up and down along the second guide rail of the lead screw module 302.

[0059] The lifting force measuring device 105 of the present invention further includes a driving device, which includes a coupling 304 and a motor 305 connected to the coupling. The coupling is connected to the screw module 302.

[0060] Figure 4 FIG. 4 is a schematic structural diagram of a force measuring unit according to an embodiment of the present invention, wherein the force measuring unit comprises an upper force transmission rod 401 , a pressure sensor 402 , a pressure regulator 403 , a lower force transmission rod 404 , and a vacuum force regulator 405 .

[0061] The upper end of the upper force transmission rod 401 is fixed below the load portion 303. The specific structure of the upper force transmission rod 401 is as follows: Figure 5 shown.

[0062] The pressure sensor 402 is located between the lower end of the upper force transmission rod 401 and the upper end of the pressure regulator 403 .

[0063] The lower end of the pressure regulator 403 is embedded in and fixed to the lower force transmission rod 404. The upper end of the pressure regulator 403 is threaded.

[0064] The vacuum force regulator 405 is sleeved on the lower end of the upper force transmission rod 401 and the outer periphery of the pressure sensor 402. At the same time, the lower part of the vacuum force regulator 405 has a threaded hole, and the threaded pressure regulator 403 is screwed into the threaded hole and connected to the lower part of the vacuum force regulator 405. The specific structure of the vacuum force regulator 405 is as follows: Figure 6 shown.

[0065] The pressure regulator 403 is adjusted by rotating the length of the pressure regulator 403 entering the vacuum force regulator 405, which is equivalent to applying a preload force to the pressure sensor 402 (i.e., setting an initial pressure for the pressure sensor). The pressure sensor 402 is pushed upward, increasing the pressure applied to the pressure sensor by the lower end of the upper force transmission rod 401, which can effectively offset the effect of the vacuum force. The purpose of this design is that after the vacuum is started, the pressure sensor 402 can still work normally even if the combined force of the vacuum force and the load gravity is in the upward direction. In other words, the lifting force measuring device of the present invention can meet the measurement function when the vacuum force is upward, and has a calibration function for different pressure values ​​when switching to the vacuum atmosphere.

[0066] In one embodiment, after the length of the pressure regulator 403 entering the vacuum force regulator 405 is determined, it can be fixed by a nut.

[0067] A pressure regulator 403 is fixed to the upper end of the lower force transmission rod 404 , and the main body of the lower force transmission rod 404 is fixedly connected to the slider of the screw module 302 , so that the lower force transmission rod 404 can move up and down along the second guide rail.

[0068] The side of the load part 303 is connected to the first guide rail 406 on the vertical support plate 106 through the guide rail force transmission rod. The load part 303 moves up and down along the first guide rail 406, and the ejector plate above the load part 303 moves synchronously. The upper force transmission rod 401 below the load part 303 also moves synchronously. The first guide rail 406 can offset the bending moment generated by the reaction force of the wafer eccentric to the pressure sensor acting on the hammer (i.e., the reaction force of the lifting force). That is, the present invention provides a separate guide rail (first guide rail) for the load part, so that the guide rail is subjected to bending moment, so that the load part only transmits vertical force to the pressure sensor 403.

[0069] Figure 7 FIG. 1 is a schematic diagram showing the bending moment of a lifting force measuring device according to an embodiment of the present invention. Figure 7 As shown in the figure, the lifting force is transmitted through three ejector pins and finally transmitted to the pressure sensor. Since the center of the measured force is not consistent with the center of the pressure sensor, a Figure 7 The bending moment M shown in the figure. Specifically, their effects on the guide rail force transmission rod 501 can be converted into an additional bending moment M1 for F1, an additional bending moment M2 for F2, and an additional bending moment M3 for F3. The side of the load-bearing unit is connected to the first guide rail, so that the bending moment is borne by the first guide rail. Therefore, the vertical force F1+F2+F3 transmitted to the pressure sensor is the only resultant force, so the lifting force measured by the force measuring unit is only in the vertical direction. Therefore, the lifting force measurement device of the present invention can offset the lateral force of the pressure sensor and achieve closed-loop control of the pressure sensor and motor torque.

[0070] It should be pointed out that the second guide rail of the screw module of the present invention is independent of the first guide rail on the vertical support plate, and the two are arranged in parallel. The pressure sensor is located between the two guide rails. The up and down movement of the upper force transmission rod above the pressure sensor is limited by the first guide rail, and the up and down movement of the pressure regulator below the pressure sensor is limited by the second guide rail. The independent up and down movement of the pressure regulator and the upper force transmission rod enables the extrusion force generated by the contact between the pressure sensor located between the two and the pressure regulator and the upper force transmission rod to be independently adjusted, thereby generating a preload force corresponding to the size of the vacuum force.

[0071] The present invention also provides a fragment prevention method, using the aforementioned lifting force measuring device, the method comprising:

[0072] Setting a preset allowable force, the preset allowable force being the maximum value allowed to prevent wafer breakage;

[0073] When the lifting force is measured to be less than or equal to the preset allowable force, the wafer is lifted normally;

[0074] When the lifting force is measured to be greater than the preset allowable force, the lifting is stopped, and the wafer is lifted again after the electrostatic adsorption force is eliminated, and the cycle is repeated multiple times until the lifting force is less than the preset allowable force.

[0075] The terms and expressions used above are for descriptive purposes only, and the present invention is not limited to these terms and expressions. The use of these terms and expressions is not intended to exclude any equivalent features shown and described (or portions thereof), and it should be recognized that various modifications that may exist are also intended to be included within the scope of the claims. Other modifications, variations, and substitutions are also possible. Accordingly, the claims should be deemed to cover all such equivalents.

[0076] Similarly, it should be noted that in order to simplify the description of the present disclosure and thus facilitate understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present disclosure sometimes combines multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of the present disclosure requires more features than those mentioned in the claims.

[0077] Similarly, it should be pointed out that although the present invention has been described with reference to the current specific embodiments, ordinary technicians in this technical field should realize that the above embodiments are only used to illustrate the present invention, and various equivalent changes or substitutions can be made without departing from the spirit of the present invention. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present invention, they will fall within the scope of the claims of this application.

Claims

1. A lifting force measuring device, characterized in that: include: The load part, force measuring part and screw module are connected from top to bottom; The top of the load-bearing part is fixed under a pin support plate to bear the lifting force transmitted by the pin support plate; the side of the load-bearing part is connected to a first vertical guide rail and can move up and down along the first guide rail, only transmitting the vertical force to the force-measuring part; The upper part of the force measuring part is connected to the load part; the lower part of the force measuring part is connected to the screw module; the pressure sensor of the force measuring part is located between the first part and the second part, and the first part and the second part move up and down independently.

2. The lifting force measuring device according to claim 1, characterized in that: The load-bearing portion is connected to a vertical support plate, and the first guide rail is located on the vertical support plate.

3. The lifting force measuring device according to claim 1, wherein: The side surface of the load-bearing portion is connected to the first guide rail through a guide rail force transmission rod, so that the bending moment from the ejector support plate is borne by the first guide rail.

4. The lifting force measuring device according to claim 1, wherein: The force measuring part includes an upper force transmission rod, the pressure sensor, a pressure regulator, a lower force transmission rod, and a vacuum force regulator; the upper force transmission rod is the upper part; the pressure regulator and the lower force transmission rod are the lower part.

5. The lifting force measuring device according to claim 4, characterized in that: The upper end of the upper force transmission rod is fixed below the load-bearing portion; The pressure sensor is located between the lower end of the upper force transmission rod and the upper end of the pressure regulator; The lower end of the pressure regulator is embedded in and fixed in the lower force transmission rod; The vacuum force regulator is sleeved on the lower end of the upper force transmission rod and the outer periphery of the pressure sensor; the lower part of the vacuum force regulator is provided with a threaded hole, the upper end of the pressure regulator is provided with a thread, and the pressure regulator is threadedly connected to the lower part of the vacuum force regulator; The pressure regulator is adjusted by rotating the length of the pressure regulator entering the vacuum force regulator so as to apply a pre-tightening force to the pressure sensor so that the pressure sensor is supported by the lower end of the upper force transmission rod to offset the upward vacuum force.

6. The lifting force measuring device according to claim 5, characterized in that: After the length of the pressure regulator entering the interior of the vacuum force regulator is determined, it is fixed by a nut.

7. The lifting force measuring device according to claim 5, characterized in that: The screw module includes a screw, a slider and a second guide rail; the pressure regulator is fixed to the upper end of the lower force transmission rod, and the main body of the lower force transmission rod is fixedly connected to the slider, so that the lower force transmission rod can move up and down along the second guide rail.

8. The lifting force measuring device according to claim 7, characterized in that: The second guide rail is independent of the first guide rail and the two are arranged in parallel. The pressure sensor is located between the first guide rail and the second guide rail. The up and down movement of the upper force transmission rod is limited by the first guide rail, and the up and down movement of the pressure regulator is limited by the second guide rail and the number of rotations of the thread.

9. The lifting force measuring device according to claim 1, wherein: The lifting force reflects the electrostatic adsorption force of the wafer; the lifting force is the sum of the lifting forces of all ejector pins.

10. A fragment prevention method, using the lifting force measurement device according to any one of claims 1 to 9, the method comprising: Setting a preset allowable force, the preset allowable force being the maximum value allowed to prevent wafer breakage; When the lifting force is measured to be less than or equal to the preset allowable force, the wafer is lifted normally; When the lifting force is measured to be greater than the preset allowable force, the lifting is stopped, and the wafer is lifted again after the electrostatic adsorption force is eliminated, and the cycle is repeated multiple times until the lifting force is less than the preset allowable force.

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