A method and device for testing the fracture strength of nanofilm

Abstract

The present application provides a method and device for testing the fracture strength of a nano film, and relates to the field of thin film testing technology. The method comprises: recording the thickness t of the nano film, fixing the nano film, and making the nano film cover the test hole. The test hole is vacuumed to break the nano film; the pressure difference between the inside and outside of the test hole is recorded when the test hole is broken, and the fracture pressure difference P is obtained. The displacement of the nano film into the test hole when the test hole is broken is recorded, and the fracture displacement w is obtained. The diameter D of the test hole is used as a line segment, and the distance of the fracture displacement w offset downward from the midpoint of the line segment is used as the fracture point, and the fracture point and the two end points of the line segment are used as a circle. The radius of the circle is measured to obtain the fracture radius R. The angle α between the tangent line of the end point of the circle and the line segment is measured, and the sine value sinα is calculated. The fracture strength σ is calculated by the formula. The device comprises a base, a vacuum assembly, a pressure detection unit, and a displacement measurement unit. The method can quickly and conveniently measure the fracture strength of the nano film.

Description

Technical Field

[0001] The present application relates to the technical field of thin film testing, and in particular to a method and device for testing the fracture strength of a nanofilm. Background Art

[0002] The fracture strength of nanofilms is difficult to test using traditional tensile gauges. Currently, the fracture strength test of nanofilms is based on nanoindentation testing or AFM (Atomic Force Microscope), but this method has high requirements for film size and requires the film to be transferred to micron-scale holes. The sample preparation is very difficult and the substrate processing is difficult. It can only test the fracture strength of nanofilms in the micron range. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a method for testing the fracture strength of a nanofilm, which aims to improve the difficulty in testing the fracture strength of a nanofilm in the related art.

[0004] The embodiment of the present application provides a method for testing the fracture strength of a nanomembrane, which includes: fixing the nanomembrane: recording the thickness t of the nanomembrane, placing the nanomembrane on a base with a test hole, so that the nanomembrane covers the test hole, keeping the surface of the nanomembrane flat, and fixing the nanomembrane to the base. Measuring the fracture displacement w and fracture pressure difference P of the nanomembrane: evacuating the test hole until the nanomembrane breaks, recording the pressure difference between the inside and outside of the test hole when the nanomembrane breaks, and obtaining the fracture pressure difference P. Recording the displacement of the nanomembrane concave into the test hole when the nanomembrane breaks, and obtaining the fracture displacement w. Establishing a fracture strength calculation model: using the diameter D of the test hole as a line segment, using the midpoint of the line segment as the distance of the fracture displacement w offset downward as the fracture point, and using the fracture point and the two endpoints of the line segment as three points to make a circle. Measuring the fracture radius R: measuring the radius of the circle to obtain the fracture radius R. Calculate the sine value of the fracture angle α: measure the angle α between the tangent line of the circle at the end point of the line segment and the fracture point, obtain the fracture angle α, and calculate the sine value of the fracture angle α. Calculate the fracture strength of the nanofilm: use the formula Calculate the fracture strength σ of the nanofilm. This nanofilm fracture strength test method only requires the construction of a simple device to quickly and easily test the fracture strength of the nanofilm. Compared with the nanoindenter and AFM tests, it eliminates the need for processing of highly difficult substrates and can test the fracture strength of nanofilms with sizes above the millimeter level.

[0005] As an optional technical solution of the embodiment of the present application, in the step of calculating the sine value sinα of the fracture angle α, the formula The test of the length quantity such as the fracture displacement w and the diameter D of the test hole is relatively simple and accurate. The sine value sinα of the fracture angle α is calculated with higher accuracy using the fracture displacement w and the diameter D of the test hole.

[0006] As an optional technical solution of the embodiment of the present application, in the step of measuring the fracture displacement w and the fracture pressure difference P of the nanomembrane, a differential pressure gauge is provided, and the differential pressure gauge is configured to detect the pressure difference inside the test hole and outside the test hole. The reading of the differential pressure gauge is read to obtain the fracture pressure difference P. By providing the differential pressure gauge, the reading of the differential pressure gauge is directly read, the step of calculating the pressure difference is omitted, the measurement process is simplified, and the measurement efficiency is improved.

[0007] The embodiment of the present application also provides a nano-membrane fracture strength testing device, which includes a base, a vacuum assembly, a pressure detection unit and a displacement measurement unit. A test hole is provided on the base, and the top of the test hole is used to place the nano-membrane. The vacuum assembly is used to vacuum the test hole. The pressure detection unit is configured to detect the pressure inside and outside the test hole. The displacement measurement unit is configured to detect the displacement of the nano-membrane located in the middle of the test hole into the test hole. By using the nano-membrane fracture strength testing device, the above-mentioned nano-membrane fracture strength testing method can be conveniently implemented, and the test of the nano-membrane fracture strength can be completed conveniently and quickly.

[0008] As an optional technical solution of the embodiment of the present application, an air extraction hole is provided on the base, the air extraction hole is connected to the test hole, and the vacuum assembly is connected to the air extraction hole. By providing the air extraction hole on the base, the vacuum assembly can easily vacuum the test hole.

[0009] As an optional technical solution of the embodiment of the present application, the vacuum pump assembly includes a vacuum pump and a regulating valve. The output end of the vacuum pump is connected to the input end of the regulating valve, and the output end of the regulating valve is connected to the air extraction hole through a pipeline. The vacuum pump is used for vacuuming, and the regulating valve can adjust the size of the negative pressure, so as to accurately measure the pressure in the test hole when the nanofilm is broken.

[0010] As an optional technical solution of the embodiment of the present application, the pressure detection unit is a differential pressure gauge, one measuring end of the differential pressure gauge is connected to the pipeline, and the other measuring end of the differential pressure gauge is connected to the atmosphere. By setting up the differential pressure gauge, the reading of the differential pressure gauge can be directly read during testing, eliminating the step of calculating the pressure difference between the test hole and the test hole, simplifying the measurement process, and improving the measurement efficiency.

[0011] As an optional technical solution of the embodiment of the present application, the displacement measuring unit is a displacement meter, which is arranged above the test hole. By arranging the displacement meter above the test hole, it is convenient to accurately measure the displacement of the nanofilm located in the middle of the test hole into the test hole.

[0012] As an optional technical solution of the embodiment of the present application, the test hole is a circular hole. Setting the test hole as a circular hole facilitates accurate measurement of the displacement of the nanofilm located in the middle of the test hole into the test hole.

[0013] As an optional technical solution of the embodiment of the present application, the base has a fixing structure for fixing the nanofilm. By setting the fixing structure, the nanofilm is easily fixed to prevent the nanofilm from sliding into the test hole during the vacuuming process and from breaking. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 A schematic diagram of the structure of a nanofilm fracture strength testing device (before vacuuming) provided in an embodiment of the present application;

[0016] Figure 2 A schematic diagram of the structure of a nanofilm fracture strength testing device (when vacuuming) provided in an embodiment of the present application;

[0017] Figure 3 A fracture strength calculation model provided in an embodiment of the present application.

[0018] Icon: 10-nanomembrane breaking strength testing device; 100-base; 110-test hole; 120-exhaust hole; 200-vacuum assembly; 210-vacuum pump; 220-regulating valve; 230-pipeline; 300-pressure detection unit; 400-displacement measurement unit; 500-nanomembrane. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0022] In the description of the embodiments of the present application, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the application are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the 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 should not be understood as a limitation on the present application.

[0023] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0024] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0025] Example

[0026] This embodiment provides a method for testing the fracture strength of a nanofilm, and the method comprises:

[0027] Fixing the nanofilm 500 : recording the thickness t of the nanofilm 500 , placing the nanofilm 500 on the base 100 with the test hole 110 , making the nanofilm 500 cover the test hole 110 , keeping the surface of the nanofilm 500 flat, and fixing the nanofilm 500 on the base 100 .

[0028] Measure the fracture displacement w and fracture pressure difference P of the nanomembrane 500: evacuate the test hole 110 until the nanomembrane 500 fractures, record the pressure difference between the inside of the test hole 110 and the outside of the test hole 110 when the nanomembrane 500 fractures, and obtain the fracture pressure difference P. Record the displacement of the nanomembrane 500 located in the middle of the test hole 110 into the test hole 110 when the nanomembrane 500 fractures, and obtain the fracture displacement w.

[0029] A fracture strength calculation model is established: a line segment is made with the diameter D of the test hole 110, a fracture point is made by shifting the fracture displacement w downward from the midpoint of the line segment, and a circle is made with the fracture point and the two endpoints of the line segment.

[0030] Measuring the fracture radius R: Measure the radius of the circle to obtain the fracture radius R.

[0031] Calculate the sine value sinα of the fracture angle α: measure the angle α between the tangent line of the circle at the endpoint of the line segment toward the fracture point and the line segment to obtain the fracture angle α, and calculate the sine value sinα of the fracture angle α.

[0032] Calculate the breaking strength of the nanofilm 500: The fracture strength σ of the nanofilm 500 is calculated.

[0033] By adopting the nanofilm fracture strength test method, only a simple device needs to be built to conveniently and quickly test the fracture strength of the nanofilm 500. Compared with the nanoindenter and AFM tests, it eliminates the need for processing of difficult substrates, and can test the fracture strength of nanofilms 500 with a size range above the millimeter level.

[0034] Please refer to Figure 1 , with reference Figure 2 In the step of fixing the nanomembrane 500, first, the thickness t of the nanomembrane 500 is recorded. Multiple measurements can be performed on different positions of the nanomembrane 500, and an average value is taken. Afterwards, the nanomembrane 500 is placed on a base 100 with a test hole 110, so that the nanomembrane 500 covers the test hole 110, and the portion of the nanomembrane 500 located at the periphery of the test hole 110 is fixed to the base 100. When fixing the nanomembrane 500, it is necessary to keep the portion of the nanomembrane 500 located above the test hole 110 flat and free of wrinkles. Optionally, an airtightness test is performed on the test hole 110 to ensure that the nanomembrane 500 covers the test hole 110 without air leakage.

[0035] After ensuring that the nanomembrane 500 is properly fixed, start to evacuate the test hole 110 until the nanomembrane 500 breaks. During the evacuation process, the power of evacuation can be large at first and then small, especially when the nanomembrane 500 is about to break, it is necessary to evacuate with a smaller power, so as to accurately record the pressure difference between the inside and outside of the test hole 110 when the nanomembrane 500 breaks, and obtain the rupture pressure difference P. In addition, when the nanomembrane 500 is about to break, evacuating with a smaller power can also accurately measure the displacement of the nanomembrane 500 located in the middle of the test hole 110 into the test hole 110 when the nanomembrane 500 breaks, and obtain the rupture displacement w.

[0036] In this embodiment, in the step of measuring the fracture displacement w and the fracture pressure difference P of the nanofilm 500, a differential pressure gauge is provided, and the differential pressure gauge is configured to detect the pressure difference between the inside of the test hole 110 and the outside of the test hole 110. The reading of the differential pressure gauge is read to obtain the fracture pressure difference P. By providing the differential pressure gauge, the reading of the differential pressure gauge is directly read, the step of calculating the pressure difference is omitted, the measurement process is simplified, and the measurement efficiency is improved.

[0037] In an optional embodiment, only the pressure inside the test hole 110 is recorded, and then the atmospheric pressure is compared with the pressure inside the test hole 110 recorded when the nanomembrane 500 is broken, so as to obtain the pressure difference between the inside and outside of the test hole 110 .

[0038] Please refer to Figure 3 After the fracture displacement w is obtained, a fracture strength calculation model can be established according to the fracture displacement w and the diameter D of the test hole 110. Specifically, a line segment is made with the length of the diameter D of the test hole 110, a fracture point is made at the midpoint of the line segment offset downward by the fracture displacement w, and a circle is made with the fracture point and the two endpoints of the line segment. The line segment represents the state of the nano film 500 when it is fixed on the base 100, and the arc represents the state of the nano film 500 when it is about to break.

[0039] After establishing the fracture strength calculation model, the radius of the circle can be measured to obtain the fracture radius R. The angle α between the tangent line at the end point of the line segment and the line segment can also be measured to obtain the fracture angle α, and the sine value sinα of the fracture angle α can be calculated. It should be noted that the "tangent line at the end point of the line segment toward the fracture point" here does not mean that the tangent line will pass through the fracture point, but that this tangent line is relatively close to the fracture point compared to the other tangent line away from the fracture point.

[0040] In this embodiment, the sine value sinα of the fracture angle α can be calculated by measuring the fracture angle α. This embodiment also provides another method for calculating the sine value sinα of the fracture angle α, that is, in the step of calculating the sine value sinα of the fracture angle α, the formula The test of the length quantity such as the fracture displacement w and the diameter D of the test hole 110 is relatively simple and accurate. The sine value sinα of the fracture angle α is calculated with higher accuracy by using the fracture displacement w and the diameter D of the test hole 110 .

[0041] After obtaining the above data, we can use the formula Calculate the fracture strength σ of the nanofilm 500. In this formula, the circumference π, the fracture radius R, the thickness t of the nanofilm 500, the sine value sinα of the fracture angle α, the diameter D of the test hole 110 and the fracture pressure difference P are all known quantities, and only the fracture strength σ is an unknown quantity. Therefore, the fracture strength σ of the nanofilm 500 can be calculated.

[0042] By adopting the nanofilm fracture strength test method, the fracture strength of the nanofilm 500 can be tested conveniently and quickly, eliminating the need for processing a highly difficult substrate, and the fracture strength of the nanofilm 500 with a size in the millimeter range or above can be tested.

[0043] Please refer to Figure 1 , with reference Figure 2 The present embodiment further provides a nano-membrane fracture strength testing device 10, which includes a base 100, a vacuum assembly 200, a pressure detection unit 300, and a displacement measurement unit 400. A test hole 110 is provided on the base 100, and the upper part of the test hole 110 is used to place a nano-membrane 500. The vacuum assembly 200 is used to vacuum the test hole 110. The pressure detection unit 300 is configured to detect the pressure inside and outside the test hole 110. The displacement measurement unit 400 is configured to detect the displacement of the nano-membrane 500 located in the middle of the test hole 110 into the test hole 110. By using the nano-membrane fracture strength testing device 10, the above-mentioned nano-membrane fracture strength testing method can be conveniently implemented, and the test of the fracture strength of the nano-membrane 500 can be completed conveniently and quickly.

[0044] Please refer to Figure 1 , with reference Figure 2 In this embodiment, a test hole 110 is provided on the base 100, and the nanofilm 500 is placed above the test hole 110, and the test hole 110 is a circular hole. The test hole 110 is set as a circular hole, which is convenient for accurately measuring the displacement of the nanofilm 500 located in the middle of the test hole 110 into the test hole 110. Optionally, the test hole 110 can also be other regular holes, for example, a polygonal hole. An air extraction hole 120 is provided on the base 100, and the air extraction hole 120 is connected to the test hole 110, and the vacuum assembly 200 is connected to the air extraction hole 120. By providing the air extraction hole 120 on the base 100, it is convenient for the vacuum assembly 200 to vacuum the test hole 110. In an optional embodiment, the vacuum assembly 200 is attached to the inner wall of the test hole 110 and extends into the test hole 110 to vacuum the test hole 110. In another optional implementation, the vacuum assembly 200 is located in the test hole 110 , and the air in the test hole 110 is sucked into a container for storage, thereby reducing the air pressure in the test hole 110 .

[0045] It should be noted that the base 100 has a fixed structure (not shown in the figure) for fixing the nano film 500. By setting the fixed structure, it is convenient to fix the nano film 500, prevent the nano film 500 from sliding into the test hole 110 during the vacuuming process, and cannot break. In an optional embodiment, the fixed structure includes a squeeze plate and a locking member, the squeeze plate is rotatably connected to the base 100, and the locking member is connected to the squeeze plate. When the nano film 500 is to be fixed, the locking member is first loosened so that the squeeze plate rotates relative to the base 100, and then the nano film 500 is placed and turned back to the squeeze plate. The squeeze plate squeezes and fixes the nano film 500 on the base 100. In order to avoid the squeeze plate from moving during the test, it is necessary to lock the locking member. Optionally, the locking member is a screw, and the locking member passes through the squeeze plate to fix the squeeze plate on the base 100.

[0046] Please refer to Figure 1 , with reference Figure 2 In this embodiment, the vacuum pumping assembly 200 includes a vacuum pump 210 and a regulating valve 220. The output end of the vacuum pump 210 is connected to the input end of the regulating valve 220, and the output end of the regulating valve 220 is connected to the air extraction hole 120 through a pipe 230. The vacuum pump 210 is used for vacuuming, and the regulating valve 220 can adjust the size of the negative pressure, or in other words, adjust the rate of change of the negative pressure in the test hole 110, so as to accurately measure the pressure in the test hole 110 when the nano membrane 500 breaks. For example, at the beginning of the test, the nano membrane 500 will deform under the negative pressure, but will not break so quickly. At the beginning of the test, the opening of the regulating valve 220 can be increased to quickly reduce the negative pressure in the test hole 110. Afterwards, the nano membrane 500 gradually tightens and is on the verge of breaking. In this process, the opening of the regulating valve 220 can be reduced to accurately determine the fracture pressure difference P when the nano membrane 500 breaks. In an optional embodiment, the vacuum assembly 200 includes a vacuum pump 210 and a controller, and the vacuum pump 210 is electrically connected to the controller. The controller can control the power of the vacuum pump 210 according to manual control or preset instructions to adjust the rate of change of the negative pressure in the test hole 110.

[0047] The pressure detection unit 300 is configured to detect the pressure difference between the inside of the test hole 110 and the outside of the test hole 110. In the present embodiment, the pressure detection unit 300 is a differential pressure gauge, one measuring end of the differential pressure gauge is connected to the pipe 230, and the other measuring end of the differential pressure gauge is connected to the atmosphere. By setting the differential pressure gauge, the reading of the differential pressure gauge can be directly read during the test, eliminating the step of calculating the pressure difference between the inside of the test hole 110 and the outside of the test hole 110, simplifying the measurement process, and improving the measurement efficiency. In an optional embodiment, the pressure detection unit 300 includes a pressure gauge, which is configured to measure the pressure inside the test hole 110. Afterwards, the atmospheric pressure is compared with the pressure inside the test hole 110 to obtain the pressure difference between the inside of the test hole 110 and the outside of the test hole 110.

[0048] Please refer to Figure 1 , with reference Figure 2 The displacement measuring unit 400 is configured to detect the displacement of the nano film 500 located in the middle of the test hole 110 that is sunken into the test hole 110, or to detect the deflection of the nano film 500. In this embodiment, the displacement measuring unit 400 is a displacement meter, and the displacement meter is arranged above the test hole 110. By arranging the displacement meter above the test hole 110, it is convenient to accurately measure the displacement of the nano film 500 located in the middle of the test hole 110 that is sunken into the test hole 110.

[0049] The present embodiment provides a nano film fracture strength test device 10, which includes a base 100, a vacuum assembly 200, a pressure detection unit 300 and a displacement measurement unit 400. A test hole 110 is provided on the base 100, and the upper part of the test hole 110 is used to place a nano film 500. The vacuum assembly 200 is used to vacuum the test hole 110. The pressure detection unit 300 is configured to detect the pressure inside and outside the test hole 110. The displacement measurement unit 400 is configured to detect the displacement of the nano film 500 located in the middle of the test hole 110 into the test hole 110. The nano film fracture strength test device 10 can be used to conveniently test the fracture strength of the nano film 500, especially the nano film 500 with a size above the millimeter level, without the need to transfer the nano film 500 to other substrates for testing, eliminating the influence of the substrate, and more directly reflecting the fracture strength performance of the nano film 500 itself.

[0050] The above-mentioned nanofilm fracture strength test method and device were used to test 10 groups of different nanofilms 500, and the test data are as follows:

[0051]

[0052]

[0053] The nanofilm fracture strength testing method and device provided in this embodiment can conveniently and quickly test the fracture strength of the nanofilm 500. Compared with nanoindenter and AFM testing, it eliminates the need for processing of highly difficult substrates and can test the fracture strength of nanofilms 500 with a size range of millimeters or above.

[0054] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for testing the fracture strength of a nanofilm, characterized in that: The nanofilm fracture strength testing method comprises: Providing a nanofilm, wherein the thickness of the nanofilm is t; Providing a base, the base having a test hole; Covering the test hole with the nanofilm, keeping the surface of the nanofilm flat, fixing the nanofilm on the base, and evacuating the test hole until the nanofilm breaks; Record the pressure difference between the inside and outside of the test hole when the nanomembrane is broken to obtain the fracture pressure difference P, and record the displacement of the nanomembrane concave into the test hole when the nanomembrane is broken to obtain the fracture displacement w; Establish a fracture strength calculation model, use the diameter D of the test hole as a line segment, use the midpoint of the line segment offset downward by the fracture displacement w as a fracture point, use the fracture point and the two endpoints of the line segment as three points to make a circle, measure the radius of the circle, and obtain the fracture radius R; Measuring an angle α between a tangent line of the circle at an end point of the line segment and the line segment to the breaking point, obtaining a breaking angle α, and calculating a sine value sinα of the breaking angle; By formula Calculate the fracture strength σ of the nanofilm; In the step of calculating the sine value sinα of the fracture angle α, the formula Calculated.

2. The nanofilm breaking strength testing method according to claim 1, characterized in that: In the step of measuring the fracture displacement w and fracture pressure difference P of the nanomembrane, a differential pressure gauge is provided, the differential pressure gauge is configured to detect the pressure difference between the inside and outside of the test hole, and the fracture pressure difference P is obtained by reading the reading of the differential pressure gauge.

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