A large-size silicon wafer strength testing device and testing method

Abstract

This invention belongs to the field of silicon wafer strength testing technology, and discloses a large-size silicon wafer strength testing device and method, including a test support assembly, a lifting test mechanism, a clamping mechanism, and a control platform. Different clamping components are separated vertically, allowing for quick assembly and disassembly to adapt to different testing requirements of silicon wafers. The four-point contact clamps have adjustable contact points and are equipped with scales to achieve uniform force application, ensuring the silicon wafer's stress state is close to ideal bending, and facilitating rapid reset to ensure experimental consistency. Under the control of the control platform, the lifting assembly precisely applies a controllable and uniform bending load along the Z-axis and collects reaction force data in real time. A protective cover fully covers the support frame, improving experimental safety. The control platform centrally manages the lifting motion and mechanical data acquisition, achieving automated testing and improving data accuracy, repeatability, and comparability. This device and method can be used for quality assessment and production process optimization of large-size silicon wafers, providing a scientific and reliable technical means for testing the bending strength of silicon wafers.

Description

Technical Field

[0001] This invention relates to the field of silicon wafer strength testing technology, and in particular to a large-size silicon wafer strength testing device and testing method. Background Technology

[0002] Generally, monocrystalline silicon wafers with a diameter greater than 200 mm and a relatively thin thickness are referred to as large-size silicon wafers, which have important applications in the semiconductor and photovoltaic industries. However, silicon wafers are brittle materials, prone to microcracks or grain boundary defects, and easily break under bending or localized stress. Therefore, strength testing is essential to determine the maximum allowable load or deflection during polishing, cutting, handling, and packaging, and to assess the overall quality and resistance to breakage of the silicon wafer, serving as an important indicator for quality control.

[0003] However, strength testing of large-size silicon wafers presents several challenges: due to their large area and thinness, traditional small fixtures are prone to localized stress concentrations during testing, leading to inaccurate failure modes and deviations in strength measurements; simultaneously, high precision is required for force control and displacement during testing, otherwise, uneven loading or premature or delayed failure may occur; furthermore, there is a safety hazard of fragmentation when the silicon wafer breaks; in addition, strength is affected by size effects and defect distribution, making it difficult for single-wafer measurements to fully reflect actual performance, and samples of different sizes and thicknesses make traditional fixtures unsuitable. Summary of the Invention

[0004] The purpose of this invention is to provide a large-size silicon wafer strength testing device and method, which applies a uniform and controllable bending load to the large-size silicon wafer to accurately reflect its bending strength, making the stress field during the test as close as possible to the ideal bending state, thereby improving the accuracy of the test data. At the same time, it can also evaluate the overall quality and resistance to damage of the silicon wafer as an important indicator of quality control; effectively improve the safety of the experimental process, ensure the reliable testing of large-size silicon wafers, and make the test results scientific and comparable.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A large-size silicon wafer strength testing device includes:

[0007] The test support assembly includes a base, a support frame, and a protective cover. The support frame is disposed on the base, and the protective cover is disposed on the outside of the support frame to prevent silicon wafer fragments from splashing during the test.

[0008] The lifting test mechanism includes a lifting component and a loading test component connected to its lower end. The lifting component can lift relative to the base along the Z-axis direction to drive the loading test component to apply a loading force to the silicon wafer and detect the reaction force data in real time.

[0009] The clamping mechanism includes a four-point contact clamping assembly and a ring-pressure clamping assembly, both of which are upper and lower separable clamping assemblies. They are detachably mounted on the base and the loading test assembly, respectively, and are located inside the protective cover, so that different clamping assemblies can be replaced according to test requirements to clamp the silicon wafer; wherein the position of each contact point of the four-point contact clamping assembly is adjustable and is provided with a readable scale for displaying the distance between each contact point;

[0010] The control platform is electrically connected to the lifting test mechanism and is used to control the motion parameters of the lifting test mechanism and collect the mechanical data output by the loading test component.

[0011] Among them, the X-axis, Y-axis and Z-axis are mutually perpendicular.

[0012] In some alternative embodiments, the four-point contact clamp assembly includes a first lower clamp and a first upper clamp; the ring-pressure clamp assembly includes a second lower clamp and a second upper clamp; the base is provided with a first quick-release connector, which is detachably connected to the first lower clamp or the second lower clamp; the loading test assembly is provided with a second quick-release connector, which is detachably connected to the first upper clamp or the second upper clamp, and both the first upper clamp and the second upper clamp are movable along the Z-axis towards the corresponding lower clamp to apply a loading force to the silicon wafer during loading testing.

[0013] In some optional embodiments, the first lower clamp includes a first adjustment knob, a first slide rail, two support contact rods, and a first scale. The two support contact rods are arranged parallel to each other along the Y-axis, and their axial direction is perpendicular to the first slide rail. The first slide rail and the first scale are arranged parallel to each other along the X-axis. The two support contact rods are mounted on a first mounting base on the first slide rail and can move relative to each other along the X-axis. The first adjustment knob can drive the first mounting base to move relative to each other to adjust the distance between the two support contact rods. The first scale is used to display the distance value.

[0014] The second lower clamp includes a second adjustment knob, a second slide rail, two loading contact bars, and a second scale. The two loading contact bars are arranged parallel to each other along the Y-axis, with their axes perpendicular to the second slide rail, and are arranged opposite to the two support contact bars along the Z-axis. The second slide rail and the second scale are arranged parallel to each other along the X-axis. The two loading contact bars are mounted on a second mounting base on the second slide rail and can move relative to each other along the X-axis. The second adjustment knob can drive the second mounting base to move relative to each other to adjust the distance between the two loading contact bars. The second scale is used to display the distance value.

[0015] In some optional embodiments, the second lower clamp includes a fixed base, an annular support base, and positioning limiting members. The annular support base is disposed on the fixed base, and the fixed base is detachably connected to the base. The upper surface of the annular support base has an annular support protrusion along its inner edge to support the silicon wafer. The inner edge of the fixed base is provided with a plurality of positioning limiting members along the Z-axis direction to limit the radial placement position of the silicon wafer.

[0016] The second upper clamp includes an annular loading ring and a loading bracket. The upper end of the loading bracket is detachably connected to the loading test component, and the annular loading ring is installed at the lower end of the loading bracket and is disposed opposite to the annular support base. In the loading state, the lower surface of the annular loading ring contacts the silicon wafer to apply a loading force to the silicon wafer.

[0017] In some alternative embodiments, the two support contact rods, the two loading contact rods, the annular support protrusion of the annular support seat, and the annular loading ring are all provided with flexible pads on the side that contacts the silicon wafer.

[0018] In some alternative embodiments, the lifting assembly includes a drive motor, a lifting plate, and a lead screw. The lifting plate is arranged parallel to the base, and the lead screw is arranged on the support frame along the Z-axis. The output end of the lead screw is connected to the lifting plate. The drive motor is fixedly installed on the support frame, and the output end of the drive motor is connected to the lead screw to drive the lead screw to rotate and drive the lifting plate to rise and fall along the Z-axis.

[0019] In some alternative embodiments, the lifting assembly further includes a limiting member disposed on one side of the support frame to limit the lifting displacement of the lifting plate.

[0020] In some optional embodiments, the loading test assembly includes a loading drive and a pressure sensor. The loading drive is mounted on the lower end of the lifting plate, and its output end is arranged towards the silicon wafer along the Z-axis. The pressure sensor is disposed on the loading drive and is used to detect the loading force output by the loading drive to the silicon wafer. The second quick-release connector is disposed on the lower end of the loading drive and is used to detachably connect with the clamping mechanism.

[0021] In some alternative embodiments, the lower surface of the base is provided with a plurality of height-adjustable support legs.

[0022] A method for testing the strength of large-size silicon wafers, using the large-size silicon wafer strength testing apparatus as described in any of the above-mentioned methods, includes the following steps:

[0023] S1: Install the test support assembly on the platform, confirm that the base is level and the protective cover is in the open state; select and install the four-point contact fixture assembly or the ring-pressure fixture assembly according to the specifications and test requirements of the silicon wafer to be tested, and calibrate the contact point spacing and position;

[0024] S2: Place the silicon wafer to be tested on the lower clamping assembly. If the four-point contact clamping assembly is selected, the position of each contact point can be adjusted. Then close the protective cover and start the control platform. By adjusting the lifting assembly, slowly lower the loading test assembly so that the upper clamping assembly makes slight contact with the upper surface of the silicon wafer to form a stable clamp.

[0025] S3: The control platform is used to perform origin calibration on the lifting test mechanism and clear the mechanical sensing data of the loading test component; test parameters such as loading rate, loading range, sampling frequency and stopping conditions are set.

[0026] S4: Control the lifting assembly to descend at a constant speed in the vertical direction, so that the loading test assembly applies a gradually increasing loading force to the silicon wafer; the control platform collects loading force and displacement data in real time until the silicon wafer breaks or reaches the preset maximum load; during the loading process, the control platform synchronously records loading force, displacement and time data, automatically plots the load-displacement curve, and saves it to the database;

[0027] S5: After the test is completed, raise the lifting assembly to release the clamp, open the protective cover, and clean the base and debris inside the protective cover to ensure safety for the next test.

[0028] The beneficial effects of this invention are:

[0029] This invention provides a large-size silicon wafer strength testing device and method, including a test support assembly, a lifting test mechanism, a clamping mechanism, and a control platform. Different clamping assemblies (four-point contact clamping assembly and ring-pressure clamping assembly) employ a separate upper and lower design, with the upper and lower clamps detachably mounted on the base and loading test assembly respectively. This facilitates quick switching between the four-point contact clamping and ring-pressure clamping, making it suitable for large-size silicon wafers of different specifications and testing requirements. Furthermore, the four-point contact clamp has adjustable contact points and a scale, allowing for free adjustment of the support and loading point positions according to the silicon wafer size. This is suitable for silicon wafers of various specifications, achieving uniform force loading and avoiding the problems of uneven force or inability to clamp when using fixed-spacing clamps. It also ensures that the silicon wafer's stress state is close to ideal bending, accurately reflecting its bending strength. The scale visually displays the spacing of each contact point, facilitating operator recording of test configurations. The spacing can be quickly adjusted to the same level before each test, ensuring consistent experimental conditions and improving the comparability and repeatability of test data. Under the control of the control platform, the lifting assembly and loading test assembly precisely control the loading rate and loading force along the Z-axis to achieve controllable and uniform application of bending loads and collect reaction force data in real time. The protective cover fully covers the support frame to prevent fragments from flying when the silicon wafer breaks, improving experimental safety. The control platform centrally controls the motion parameters of the lifting mechanism and collects mechanical data to achieve automated testing, improve data accuracy and repeatability, and the test results can be used for silicon wafer quality assessment and production process optimization, enhancing comparability and scientific rigor. Attached Figure Description

[0030] Figure 1 This is a structural schematic diagram of the test support component and lifting test mechanism in this invention;

[0031] Figure 2 This is a schematic diagram of the structure of the four-point contact clamp assembly in this invention;

[0032] Figure 3 This is a schematic diagram of the ring-pressure clamp assembly in this invention;

[0033] Figure 4 This is a flowchart of the large-size silicon wafer strength testing method in this invention.

[0034] In the picture:

[0035] 100. Silicon wafers;

[0036] 1. Test support assembly; 11. Base; 12. Support frame; 13. Protective cover; 14. First quick-release connector; 15. Second quick-release connector; 16. Support leg; 17. Control button;

[0037] 2. Lifting test mechanism; 21. Lifting assembly; 211. Lifting plate; 212. Limiting component; 22. Loading test assembly; 221. Loading drive component; 222. Pressure sensor;

[0038] 3. Four-point contact clamp assembly; 31. First lower clamp; 311. First adjustment knob; 312. First slide rail; 313. Support contact bar; 314. First scale; 315. First mounting base; 32. First upper clamp; 321. Second adjustment knob; 322. Second slide rail; 323. Loading contact bar; 324. Second scale; 325. Second mounting base;

[0039] 4. Ring-type clamping fixture assembly; 41. Second lower clamp; 411. Fixed base; 412. Ring support base; 413. Positioning and limiting component; 42. Second upper clamp; 421. Ring loading ring; 422. Loading bracket. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0041] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0044] Please refer to Figures 1 to 3 As shown, this embodiment provides a large-size silicon wafer strength testing device, including a test support assembly 1, a lifting test mechanism 2, a clamping mechanism, and a control platform. The test support assembly 1 includes a base 11, a support frame 12, and a protective cover 13. The support frame 12 is disposed on the base 11, and the protective cover 13 is disposed on the outside of the support frame 12 to prevent silicon wafer fragments from flying during the test. The lifting test mechanism 2 includes a lifting component 21 and a loading test component 22 connected to its lower end. The lifting component 21 can move up and down relative to the base 11 along the Z-axis direction to drive the loading test component 22 to apply a loading force to the silicon wafer 100 and detect the reaction force data in real time. The clamping mechanism includes a four-point contact clamping assembly 3 and a ring-pressure clamping assembly 4, both of which are separate upper and lower clamping assemblies. They are detachably mounted on the base 11 and the loading test assembly 22, respectively, and are located inside the protective cover 13, so that different clamping assemblies can be replaced according to test requirements to clamp the silicon wafer 100. The position of each contact point of the four-point contact clamping assembly 3 is adjustable and is equipped with a readable scale to display the distance between each contact point. The control platform is electrically connected to the lifting test mechanism 2 and is used to control the motion parameters of the lifting test mechanism 2 and collect the mechanical data output by the loading test assembly 22. The X-axis, Y-axis and Z-axis directions are mutually perpendicular.

[0045] Different clamping assemblies (four-point contact clamping assembly 3 and ring-pressure clamping assembly 4) adopt an upper and lower separation design. The upper and lower clamps are detachably mounted on the base 11 and the loading test assembly 22, respectively, to facilitate quick switching between the four-point contact clamping and the ring-pressure clamping, which is suitable for large-size silicon wafers 100 of different specifications and test requirements. Among them, the four-point contact clamping assembly 3 is suitable for measuring the bending strength of silicon wafer 100. By applying force at four points, a constant bending moment area is formed in the middle, which effectively avoids local stress concentration and makes the failure of silicon wafer 100 reflect the true bending resistance. The ring-pressure clamping is suitable for measuring the local failure strength and overall load-bearing capacity of silicon wafer 100. The lower clamp is a ring support, and the silicon wafer 100 is placed on the ring. The upper clamp is a ring loading plate, which applies force evenly along the ring. When loading, the force is evenly distributed to the surface of silicon wafer 100 through the ring surface to achieve radial compression or uniform bending, which can reflect the strength of silicon wafer 100 under multi-directional force. It is suitable for testing the uniformity and damage resistance of round or large-size silicon wafers 100.

[0046] Furthermore, the four-point contact fixture features adjustable contact points and a scale, allowing for free adjustment of the support and loading point positions according to the size of the silicon wafer 100. It is suitable for silicon wafers of various sizes, achieving uniform force loading and avoiding the problems of uneven force or inability to clamp when using fixed-spacing fixtures. This ensures that the silicon wafer 100's stress state closely approximates ideal bending, accurately reflecting its bending strength. The scale visually displays the spacing of each contact point, facilitating operator recording of test configurations. The spacing can be quickly adjusted to the same level before each test, ensuring consistent experimental conditions and improving the comparability and repeatability of test data.

[0047] Under the control of the control platform, the lifting assembly 21 and the loading test assembly 22 precisely control the loading rate and loading force along the Z-axis direction to achieve controllable and uniform application of bending load and collect reaction force data in real time. The protective cover 13 fully covers the support frame 12 to prevent fragments from flying when the silicon wafer 100 breaks, thereby improving experimental safety. The control platform centrally controls the motion parameters of the lifting mechanism and collects mechanical data to achieve automated testing, improve data accuracy and repeatability, and the test results can be used for silicon wafer 100 quality assessment and production process optimization, enhancing comparability and scientific rigor.

[0048] Optionally, the protective cover 13 is provided with an operation window, which can be selectively opened or closed to facilitate the operator to clean up the silicon wafer 100 fragments and place the silicon wafer 100 to be tested.

[0049] like Figure 1 As shown, specifically, the four-point contact clamp assembly 3 includes a first lower clamp 31 and a first upper clamp 32; the ring-pressure clamp assembly 4 includes a second lower clamp 41 and a second upper clamp 42; the base 11 is provided with a first quick-release connector 14, which is detachably connected to the first lower clamp 31 or the second lower clamp 41; the loading test assembly 22 is provided with a second quick-release connector 15, which is detachably connected to the first upper clamp 32 or the second upper clamp 42. Both the first upper clamp 32 and the second upper clamp 42 can move along the Z-axis towards the corresponding lower clamp to apply a loading force to the silicon wafer 100 during loading testing. The first quick-release connector 14 on the base 11 and the second quick-release connector 15 on the loading test assembly 22 allow operators to quickly switch clamp types to adapt to different testing needs or different specifications of silicon wafers 100 without complex tools or disassembly / assembly steps, improving experimental flexibility and efficiency.

[0050] The first quick-release connector 14 and the second quick-release connector 15 may, but are not limited to, use spring-loaded pin positioning components. A socket is provided at the center of the upper surface of the base 11, and a positioning hole is provided on the socket. The lower surfaces of the first lower clamp 31 and the second lower clamp 41 are equipped with pin bodies corresponding to the socket. The pin body is cylindrical and can be inserted into the socket. The cylindrical side has a spring-loaded protrusion along the circumference, which is used to automatically push into the positioning hole when the pin is inserted into the socket, so as to reliably fix the lower clamp. When it is necessary to disassemble the clamp, the protrusion can be pressed to disengage it from the positioning hole, so as to achieve quick disassembly.

[0051] In other embodiments, the first quick-release connector 14 and the second quick-release connector 15 may also adopt a fastener-type quick-release structure, which is not specifically limited here.

[0052] like Figure 2 As shown, the specific structure of the four-point contact clamp assembly 3 is as follows: the first lower clamp 31 includes a first adjustment knob 311, a first slide rail 312, two support contact rods 313, and a first scale 314. The two support contact rods 313 are arranged parallel to each other along the Y-axis, and their axial direction is perpendicular to the first slide rail 312. The first slide rail 312 and the first scale 314 are arranged parallel to each other along the X-axis. The two support contact rods 313 are mounted on a first mounting base 315 on the first slide rail 312 and can move relative to each other along the X-axis. The first adjustment knob 311 can drive the first mounting base 315 to move relative to each other to adjust the distance between the two support contact rods 313. The first scale 314 is used to display the distance value. The second clamp 41 includes a second adjustment knob 321, a second slide rail 322, two loading contact rods 323, and a second scale 324. The two loading contact rods 323 are arranged parallel to each other along the Y-axis, with their axes perpendicular to the second slide rail 322, and are arranged opposite to the two support contact rods 313 along the Z-axis. The second slide rail 322 and the second scale 324 are arranged parallel to each other along the X-axis. The two loading contact rods 323 are mounted on the second mounting base 325 on the second slide rail 322 and can move relative to each other along the X-axis. The second adjustment knob 321 can drive the second mounting base 325 to move relative to each other to adjust the distance between the two loading contact rods 323. The second scale 324 is used to display the distance value.

[0053] The first and second adjustment knobs 311 and 321 can adjust the spacing between the support contact rods 313 and the loading contact rods 323 according to the size of the silicon wafer 100, flexibly setting the position of the support or loading point. Both the two loading contact rods 323 and the two support contact rods 313 are arranged parallel to the Y-axis, with the axis perpendicular to the slide rail direction, ensuring that the force is distributed along the expected direction on the surface of the silicon wafer 100. Furthermore, they are arranged opposite each other in the Z-axis direction, so that the bending load is applied to the middle section of the silicon wafer 100, forming an ideal bending stress field. Operators can quickly change the spacing between the corresponding support contact rods 313 and loading contact rods 323 by rotating the first and second adjustment knobs 311 and 321, suitable for testing silicon wafers 100 of different sizes or multiple batches, improving experimental efficiency. The force applied by the four contact rods forms a constant bending moment region in the middle, effectively avoiding local stress concentration, allowing the failure of the silicon wafer 100 to reflect its true bending resistance.

[0054] Optionally, a first ball screw is also provided at the position of the first slide rail 312 of the first lower clamp 31. The first ball screw is parallel to the first slide rail 312. Each of the two first mounting seats 315 has a ball nut at its bottom, which engages with the first ball screw. The two ball nuts are designed to be either right-handed or left-handed, opposite to the thread direction of the first ball screw, so that when the first adjustment knob 311 rotates the first ball screw, the two first mounting seats 315 can move synchronously in opposite directions. Furthermore, a second ball screw is also provided at the position of the second slide rail 322 on the first upper clamp 32. The second ball screw is parallel to the second slide rail 322. Each of the two second mounting seats 325 has a ball nut at its bottom, which engages with the second ball screw. The two ball nuts are designed to be either right-handed or left-handed, opposite to the thread direction of the second ball screw, so that when the second adjustment knob 321 rotates the second ball screw, the two second mounting seats 325 can move synchronously in opposite directions.

[0055] like Figure 3As shown, the specific structure of the ring-type clamp assembly 4 is as follows: the second lower clamp 41 includes a fixed base 411, an annular support base 412, and positioning limiting members 413. The annular support base 412 is disposed on the fixed base 411, and the fixed base 411 is detachably connected to the base 11. The upper surface of the annular support base 412 has an annular support protrusion along its inner edge to support the silicon wafer 100. The inner edge of the fixed base 411 is provided with multiple positioning limiting members 413 along the Z-axis to limit the radial placement position of the silicon wafer 100. The second upper clamp 42 includes an annular loading ring 421 and a loading bracket 422. The upper end of the loading bracket 422 is detachably connected to the loading test assembly 22, and the lower end of the loading bracket 422 is equipped with the annular loading ring 421, which is disposed opposite to the annular support base 412. In the loading state, the lower surface of the annular loading ring 421 contacts the silicon wafer 100 to apply a loading force to the silicon wafer 100. Through the above design, the supporting protrusion of the annular support 412 can uniformly support the edge of the silicon wafer 100, reducing local stress concentration; multiple positioning and limiting elements 413 limit the radial position of the silicon wafer 100, making the silicon wafer 100 accurately placed and with good repeatability, avoiding uneven distribution of bending stress due to eccentric placement, thereby ensuring the consistency of test data. The annular loading ring 421 is arranged opposite to the annular support 412 to form a "ring-wafer-ring" clamping structure, so that the loading force is evenly distributed along the edge of the silicon wafer 100, close to the ideal bending state, improving the accuracy of bending strength testing. The lower surface of the loading ring is in direct contact with the silicon wafer 100, with a short force transmission path, reducing errors caused by intermediate links. By evenly distributing the force to the surface of the silicon wafer 100 through the ring surface, radial compression or uniform bending is achieved, which can reflect the strength of the silicon wafer 100 under multi-directional force, and is suitable for testing the uniformity and damage resistance of circular or large-size silicon wafers 100.

[0056] Since silicon wafer 100 is a highly brittle material, it is extremely sensitive to local stress when subjected to force. If rigid components such as loading rings and support rods are in direct contact with silicon wafer 100, even slight geometric deviations or surface roughness at the contact points can cause stress concentration. Once the stress in a local area exceeds the material limit, micro-cracks or breakage will occur prematurely, causing silicon wafer 100 to fracture not due to overall bending failure, but due to local damage. The resulting destructive stress value is too low and cannot accurately reflect the true bending strength of silicon wafer 100. To overcome the above problems, in some embodiments, flexible pads are provided on the side of the two support contact rods 313, the two loading contact rods 323, the annular support protrusion of the annular support seat 412, and the annular loading ring 421 that are in contact with silicon wafer 100. The pads can form a flexible transition layer between the loading or support contact surfaces, which can deform slightly, buffer local protrusions, and prevent local point damage, thereby smoothing the contact stress distribution and allowing silicon wafer 100 to fracture when it undergoes overall bending failure. This makes the stress on silicon wafer 100 closer to the ideal uniform bending state, thus obtaining true bending strength data.

[0057] In some optional embodiments, the lifting assembly 21 includes a drive motor, a lifting plate 211, and a lead screw. The lifting plate 211 is arranged parallel to the base 11. The lead screw is arranged on the support frame 12 along the Z-axis, and its output end is connected to the lifting plate 211. The drive motor is fixedly installed on the support frame 12, and its output end is connected to the lead screw drive to drive the lead screw to rotate and drive the lifting plate 211 to rise and fall along the Z-axis. The lead screw drive is a high-linearity transmission form that can accurately convert rotational motion into linear motion. Combined with the drive motor, it controls the displacement of the lifting plate 211 along the Z-axis by a small rotation angle. Furthermore, the lead screw drive has good self-locking and guiding properties, ensuring smooth lifting motion, and is particularly suitable for smooth loading tests of brittle materials such as silicon wafers 100. It is understood that the drive motor can be, but is not limited to, a servo motor or a stepper motor, and no specific limitation is made here.

[0058] The lifting plate 211 is driven by a lead screw to move up and down along the Z-axis. If the control program malfunctions or the motor misoperates, the lifting plate 211 may exceed its designed stroke, causing the upper and lower clamps to collide and crush the silicon wafer 100, or even damage the transmission mechanism. To prevent this, the lifting assembly 21 also includes a limiting member 212, located on one side of the support frame 12, to physically limit the stroke of the lifting plate 211, thereby effectively preventing excessive lifting and lowering and protecting the safe operation of the silicon wafer 100, the loading ring, and the lead screw transmission system. Furthermore, during actual testing, the limiting member 212 can also serve as a mechanical zero-position reference for the lifting mechanism, helping the control unit identify the upper and lower limit positions of the lifting plate 211, thus ensuring accurate reset of the initial lifting position. This design ensures that the starting position of the lifting plate 211 is consistent in each test, improving the repeatability accuracy of the loading displacement and loading force, and further enhancing the accuracy and reliability of the test results.

[0059] In this embodiment, the loading test component 22 includes a loading drive 221 and a pressure sensor 222. The loading drive 221 is installed at the lower end of the lifting plate 211, and its output end is arranged along the Z-axis towards the silicon wafer 100. The pressure sensor 222 is disposed on the loading drive 221 and is used to detect the loading force output by the loading drive 221 to the silicon wafer 100. The second quick-release connector 15 is disposed at the lower end of the loading drive 221 and is used to detachably connect with the clamping mechanism. During the test, the loading drive 221 controls the loading speed and loading amount according to the set program to realize a continuous and controllable bending loading process of different types of clamping components. The pressure sensor 222 is disposed between the loading drive 221 and the clamping mechanism to detect the actual force value transmitted by the loading drive 221 to the silicon wafer 100 in real time. The detection signal is fed back to the control unit for closed-loop adjustment of the loading drive force to ensure that the force value during the loading process is consistent with the set value.

[0060] Furthermore, the loading test component 22 is coaxially arranged with the lifting plate 211, so that the output end of the loading drive component 221 is aligned with the center of the silicon wafer 100 along the Z-axis. A displacement sensor is provided on the loading drive component 221 for real-time detection of loading displacement. The above design achieves linear and controllable loading motion through the loading drive component 221. Combined with the dual feedback of the pressure sensor 222 and the displacement sensor, flexible switching between force control mode and displacement control mode can be achieved, thereby ensuring that the load applied to the silicon wafer 100 is stable and linear, avoiding brittle fracture of the silicon wafer 100 or distortion of test data due to instantaneous impact. The pressure sensor 222 can accurately measure the destructive force value of the silicon wafer 100, thereby obtaining more realistic bending strength data. The coaxial arrangement of the loading drive component 221 and the lifting plate 211 makes the force transmission path shorter and the direction consistent, effectively reducing test errors caused by off-center loading.

[0061] It is understood that the loading drive unit 221 may, but is not limited to, electric cylinders or hydraulic cylinders, etc., and no specific limitation is made here.

[0062] In some optional embodiments, the lower surface of the base 11 is provided with multiple height-adjustable support legs 16 for horizontal adjustment and stable support of the entire testing device. By adjusting the height of each support leg 16, the device can be quickly leveled under different experimental platform or ground conditions, ensuring that the silicon wafer 100 is in a horizontal state and that the lifting assembly 21 and the loading direction are strictly aligned with the center of the silicon wafer 100 along the Z-axis, thereby ensuring the verticality of the loading force and the accuracy of the test data. In addition, the height-adjustable support legs 16 can also compensate for minor unevenness of the ground during installation, avoiding structural deformation caused by uneven force on the base 11, improving the overall stability and vibration resistance of the device, and preventing errors caused by minor shaking during testing. It is understood that the support leg 16 includes a connecting part and a support adjustment part. The connecting part is fixedly connected to the lower surface of the base 11, and the top end of the support adjustment part is threadedly connected to the connecting part. The height of the support leg 16 can be finely adjusted by rotating the support adjustment part, and its bottom end contacts the experimental platform or ground, thereby ensuring the stable placement of the testing device and the testing accuracy.

[0063] In some alternative embodiments, a control button 17 is provided on the base 11. The control button 17 is electrically connected to the control platform and is used to control the lifting assembly 21 to move up and down along the Z-axis, so as to realize the manual operation or adjustment of the test device.

[0064] Please refer to Figure 4 As shown, this embodiment also provides a method for testing the strength of large-size silicon wafers, employing the large-size silicon wafer strength testing device as described in any of the above embodiments, including the following steps:

[0065] S1: Install the test support assembly 1 on the platform, confirm that the base 11 is horizontal and the protective cover 13 is in the open state; according to the specifications and test requirements of the silicon wafer 100 to be tested, select and install the four-point contact fixture assembly 3 or the ring-pressure fixture assembly 4, and calibrate the contact point spacing and position.

[0066] S2: Place the silicon wafer 100 to be tested on the lower clamping assembly. If the four-point contact clamping assembly 3 is selected, the position of each contact point can be adjusted. Then close the protective cover 13 and start the control platform. By adjusting the lifting assembly 21, slowly lower the loading test assembly 22 so that the upper clamping assembly makes slight contact with the upper surface of the silicon wafer 100 to form a stable clamp.

[0067] S3: Through the control platform, perform origin calibration on the lifting test mechanism 2, clear the mechanical sensing data of the loading test component 22; set the test parameters for loading rate, loading range, sampling frequency and stopping conditions;

[0068] S4: Control the lifting assembly 21 to descend at a constant speed in the vertical direction, so that the loading test assembly 22 applies a gradually increasing loading force to the silicon wafer 100; the control platform collects loading force and displacement data in real time until the silicon wafer 100 breaks or reaches the preset maximum load; during the loading process, the control platform synchronously records loading force, displacement and time data, automatically plots the load-displacement curve, and saves it to the database;

[0069] S5: After the test is completed, lift the lifting assembly 21 to release the clamp, open the protective cover 13, and clean the debris inside the base 11 and the protective cover 13 to ensure safety for the next test.

[0070] Based on the size of the silicon wafer 100 and experimental requirements, suitable clamps can be selected and the contact point positions calibrated to ensure that silicon wafers 100 of different sizes can be clamped horizontally, guaranteeing uniform force on the silicon wafer 100. The lifting assembly 21 descends at a constant speed, gradually increasing the loading force to avoid brittle fracture of the silicon wafer 100 due to instantaneous impact, making its stress closer to the ideal bending state, thereby improving the authenticity of the test data. By calibrating the origin of the lifting test mechanism 2 and zeroing the sensor data through the control platform, the measurement accuracy of the mechanical sensor can be ensured; at the same time, the control platform can set parameters such as loading rate, loading range, and sampling frequency to achieve repeatable test conditions, providing a reliable basis for material performance analysis. The protective cover 13 can effectively prevent debris from flying and injuring people during device operation. After the test, the lifting assembly 21 is reset and debris is cleaned up, providing a safe environment for the next test, effectively reducing experimental risks and ensuring the safety of operators and the device.

[0071] This testing method achieves high precision, high repeatability, and high safety in testing large-size silicon wafers 100 at different strengths through precise clamping, gradual loading, and real-time data acquisition. Adjustable clamps and lifting mechanisms ensure uniform force distribution and stable loading on the silicon wafer 100, and can adapt to the testing needs of silicon wafers 100 of different specifications. Combined with synchronous data acquisition and automated management via a control platform, the experimental operation is simple, and the data is complete and reliable, providing a scientific basis for subsequent material performance evaluation and process research.

[0072] Furthermore, the loading test component 22 includes a pressure sensor 222 and a displacement sensor, both of which can acquire data in real time and be automatically managed by the control platform to accurately obtain the destructive force and displacement information of the silicon wafer 100. By introducing the ASTM (American Society for Testing and Materials) strength characterization standard for ceramic samples to calculate and analyze the flexural strength of the silicon wafer 100, the test results can be scientifically quantified, ensuring the standardization and comparability of the data, and providing a reliable basis for material performance evaluation, failure mechanism research, and process optimization.

[0073] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A large size silicon wafer strength testing apparatus, characterized by, include: The test support assembly (1) includes a base (11), a support frame (12) and a protective cover (13). The support frame (12) is disposed on the base (11), and the protective cover (13) is disposed on the outside of the support frame (12) to prevent silicon wafer (100) fragments from splashing during the test. The lifting test mechanism (2) includes a lifting component (21) and a loading test component (22) connected to its lower end. The lifting component (21) can lift relative to the base (11) along the Z-axis direction to drive the loading test component (22) to apply a loading force to the silicon wafer (100) and detect the reaction force data in real time. The clamping mechanism includes a four-point contact clamping assembly (3) and a ring-pressure clamping assembly (4), both of which are upper and lower separable clamping assemblies. They are respectively detachably installed on the base (11) and the loading test assembly (22) and located inside the protective cover (13) to replace different clamping assemblies according to test requirements to clamp the silicon wafer (100); wherein the position of each contact point of the four-point contact clamping assembly (3) is adjustable and is provided with a readable scale to display the distance between each contact point; The control platform is electrically connected to the lifting test mechanism (2) and is used to control the motion parameters of the lifting test mechanism (2) and collect the mechanical data output by the loading test component (22); The four-point contact clamp assembly (3) includes a first lower clamp (31) and a first upper clamp (32); the ring-pressure clamp assembly (4) includes a second lower clamp (41) and a second upper clamp (42); the base (11) is provided with a first quick-release connector (14), which is detachably connected to the first lower clamp (31) or the second lower clamp (41); the loading test assembly (22) is provided with a second quick-release connector (15), which is detachably connected to the first upper clamp (32) or the second upper clamp (42). Both the first upper clamp (32) and the second upper clamp (42) can move along the Z-axis towards the corresponding lower clamp to apply a loading force to the silicon wafer (100) during the loading test; The first lower clamp (31) includes a first adjustment knob (311), a first slide rail (312), two support contact rods (313), and a first scale (314). The two support contact rods (313) are arranged parallel to each other along the Y-axis, and their axial direction is perpendicular to the first slide rail (312). The first slide rail (312) and the first scale (314) are arranged parallel to each other along the X-axis. The two support contact rods (313) are mounted on a first mounting seat (315) on the first slide rail (312) and can move relative to each other along the X-axis. The first adjustment knob (311) can drive the first mounting seat (315) to move relative to each other to adjust the distance between the two support contact rods (313). The first scale (314) is used to display the distance value. The first upper clamp (32) includes a second adjustment knob (321), a second slide rail (322), two loading contact bars (323), and a second scale (324). The two loading contact bars (323) are arranged parallel to each other along the Y-axis, with their axial direction perpendicular to the second slide rail (322), and are arranged opposite to the two support contact bars (313) along the Z-axis. The second slide rail (322) and the second scale (324) are arranged parallel to each other along the X-axis. The two loading contact bars (323) are mounted on the second mounting base (325) on the second slide rail (322) and can move relative to each other along the X-axis. The second adjustment knob (321) can drive the second mounting base (325) to move relative to each other to adjust the distance between the two loading contact bars (323). The second scale (324) is used to display the distance value. Among them, the X-axis, Y-axis and Z-axis are mutually perpendicular.

2. The apparatus for testing strength of a large size silicon wafer according to claim 1, wherein The second lower clamp (41) includes a fixed base (411), an annular support base (412), and positioning limiting members (413). The annular support base (412) is disposed on the fixed base (411), and the fixed base (411) is detachably connected to the base (11). The upper surface of the annular support base (412) has an annular support protrusion along its inner edge to support the silicon wafer (100). The inner edge of the fixed base (411) is provided with a plurality of positioning limiting members (413) along the Z-axis direction to limit the radial placement position of the silicon wafer (100). The second upper clamp (42) includes an annular loading ring (421) and a loading bracket (422). The upper end of the loading bracket (422) is detachably connected to the loading test assembly (22). The lower end of the loading bracket (422) is equipped with the annular loading ring (421) and is arranged opposite to the annular support base (412). In the loading state, the lower surface of the annular loading ring (421) contacts the silicon wafer (100) to apply a loading force to the silicon wafer (100).

3. The large-size silicon wafer strength testing device according to claim 2, characterized in that, The two support contact rods (313), the two loading contact rods (323), the annular support protrusion of the annular support base (412), and the annular loading ring (421) are all provided with flexible pads on the side that contacts the silicon wafer (100).

4. The large-size silicon wafer strength testing device according to claim 1, characterized in that, The lifting assembly (21) includes a drive motor, a lifting plate (211) and a lead screw. The lifting plate (211) is arranged parallel to the base (11). The lead screw is arranged on the support frame (12) along the Z-axis direction. The output end of the lead screw is connected to the lifting plate (211). The drive motor is fixedly installed on the support frame (12). The output end of the drive motor is connected to the lead screw to drive the lead screw to rotate and drive the lifting plate (211) to rise and fall along the Z-axis direction.

5. The large-size silicon wafer strength testing device according to claim 4, characterized in that, The lifting assembly (21) also includes a limiting member (212) located on one side of the support frame (12) for limiting the lifting displacement of the lifting plate (211).

6. The apparatus for testing strength of a large size silicon wafer according to claim 5, wherein The loading test assembly (22) includes a loading drive (221) and a pressure sensor (222). The loading drive (221) is installed at the lower end of the lifting plate (211), and its output end is arranged along the Z-axis towards the silicon wafer (100). The pressure sensor (222) is disposed on the loading drive (221) and is used to detect the loading force output by the loading drive (221) to the silicon wafer (100). The second quick-release connector (15) is disposed at the lower end of the loading drive (221) and is used to detachably connect with the clamping mechanism.

7. The apparatus for testing strength of large size silicon wafers as claimed in any one of claims 1 to 6, wherein The lower surface of the base (11) is provided with multiple height-adjustable support legs (16).

8. A method of testing the strength of a large size silicon wafer, characterized by, The large-size silicon wafer strength testing apparatus as described in any one of claims 1 to 7 includes the following steps: S1: Install the test support assembly (1) on the platform, confirm that the base (11) is horizontal and the protective cover (13) is in the open state; select and install the four-point contact fixture assembly (3) or the ring-pressure fixture assembly (4) according to the specifications and test requirements of the silicon wafer (100) to be tested, and calibrate the contact point spacing and position. S2: Place the silicon wafer (100) to be tested on the lower clamping assembly. If the four-point contact clamping assembly (3) is selected, the position of each contact point can be adjusted. Then close the protective cover (13), start the control platform, and slowly lower the loading test assembly (22) by adjusting the lifting assembly (21) so that the upper clamping assembly makes slight contact with the upper surface of the silicon wafer (100) to form a stable clamping. S3: Through the control platform, the lifting test mechanism (2) is calibrated at the origin and the mechanical sensing data of the loading test component (22) is cleared; test parameters such as loading rate, loading range, sampling frequency and stopping condition are set; S4: Control the lifting assembly (21) to descend at a constant speed in the vertical direction, so that the loading test assembly (22) applies a gradually increasing loading force to the silicon wafer (100); the control platform collects loading force and displacement data in real time until the silicon wafer (100) breaks or reaches the preset maximum load; during the loading process, the control platform synchronously records loading force, displacement and time data, automatically plots the load-displacement curve, and saves it to the database; S5: After the test is completed, lift the lifting component (21) to release the clamp, open the protective cover (13), and clean the debris inside the base (11) and the protective cover (13) to ensure safety for the next test.

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