Method, device, equipment and medium for detecting stress of back sealing substrate

Abstract

The invention provides a method, a device, equipment and a medium for detecting stress of a back sealing substrate. The method comprises the following steps: acquiring a first bending moment caused by residual stress in a substrate according to morphology changes before and after back sealing; at any sampling point on the surface of the back-sealed substrate, detecting the Young modulus of the sampling point along the depth direction; acquiring a second bending moment of a back sealing layer of the back-sealed substrate at the sampling point according to the Young modulus of the sampling point along the depth direction; based on the property of bending moment balance, stress distribution of the back sealing layer at the sampling point in the depth direction is obtained through the first bending moment and the second bending moment; and according to the stress distribution of the back sealing layer at the sampling point along the depth direction, obtaining the stress of a transition region between the back sealing layer at the sampling point and the substrate along the depth direction.

Description

Technical Field

[0001] The present disclosure relates to the technical field of semiconductor parameter measurement, and in particular to a method, device, equipment and medium for detecting stress of a back-sealing substrate. Background Art

[0002] In the semiconductor manufacturing process, in order to prevent the self-doping phenomenon of single-crystal silicon wafers (also called substrates or single-crystal substrates) during the epitaxial growth stage, the silicon wafers are usually back-sealed. Silicon wafer back-sealing technology is a commonly used method to prevent self-doping. It deposits a back-sealing layer such as a silicon dioxide film on the back of the silicon wafer to seal the dopant atoms inside the silicon wafer, thereby effectively inhibiting the dopant from diffusing outward.

[0003] The substrate has residual stress after back-sealing with silicon dioxide film. The detection scheme for this stress is currently usually to calculate the residual stress generated in the back-sealing process using the Stoney formula based on the change in the curvature of the silicon wafer before and after the back-sealing, assuming that the stress of the back-sealing layer is uniform. This residual stress is for the entire back-sealing layer. However, in the specific implementation process, there is a transition region between the back-sealing layer and the substrate. The material properties of this transition region are different from both the back-sealing layer and the substrate, resulting in uneven stress in the back-sealing layer.

[0004] Therefore, the accuracy of the results obtained by the current detection scheme for the stress of the back sealing layer is relatively low. Summary of the invention

[0005] The present invention provides a method, device, equipment and medium for detecting stress of a back sealing substrate, which can improve the accuracy of stress detection of a back sealing layer.

[0006] The technical solution of the present disclosure is achieved as follows: In a first aspect, the present disclosure provides a method for detecting stress of a back sealing substrate, the method comprising: Obtaining a first bending moment caused by residual stress in the substrate according to the morphology change before and after back sealing; At any sampling point on the surface of the substrate after back sealing, detecting the Young's modulus along the depth direction at the sampling point; According to the Young's modulus along the depth direction at the sampling point, obtaining the second bending moment of the back-sealing layer of the back-sealed substrate at the sampling point; Based on the property of bending moment balance, the stress distribution of the back sealing layer along the depth direction at the sampling point is obtained through the first bending moment and the second bending moment; According to the stress distribution of the back sealing layer at the sampling point along the depth direction, the stress of the transition area between the back sealing layer and the substrate at the sampling point along the depth direction is obtained.

[0007] In a second aspect, the present disclosure provides a device for detecting stress of a back sealing substrate, the device comprising: a first acquisition unit, a detection unit, a second acquisition unit, a third acquisition unit and a fourth acquisition unit; wherein, The first acquisition unit is configured to acquire a first bending moment caused by residual stress in the substrate according to a morphological change before and after back sealing; The detection unit is configured to detect the Young's modulus along the depth direction at any sampling point on the surface of the substrate after back sealing; The second acquisition unit is configured to acquire a second bending moment of the back-sealing layer of the back-sealed substrate at the sampling point according to the Young's modulus along the depth direction at the sampling point; The third acquisition unit is configured to acquire the stress distribution of the back cover layer along the depth direction at the sampling point through the first bending moment and the second bending moment based on the property of the bending moment balance; The fourth acquisition unit is configured to acquire the stress distribution in the depth direction of the transition region between the back sealing layer and the substrate at the sampling point according to the stress distribution in the depth direction of the back sealing layer at the sampling point.

[0008] In a third aspect, the present disclosure provides a computing device, comprising a processor and a memory; the processor is used to execute instructions stored in the memory to implement the method for detecting back seal substrate stress as described in the first aspect.

[0009] In a fourth aspect, the present disclosure provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the method for detecting back seal substrate stress as described in the first aspect.

[0010] The present invention provides a method, device, equipment and medium for detecting stress of a back-sealing substrate; after obtaining the stress of the back-sealing layer through the bending moment of the substrate and the back-sealing layer based on the bending moment balance property, the stress distribution of the back-sealing layer along the depth direction is obtained according to the stress of the back-sealing layer using the Young's modulus along the depth at the sampling point, and the stress distribution of the transition area along the depth direction is obtained from the stress distribution of the back-sealing layer along the depth direction. The accuracy of stress detection of the back-sealing layer is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic cross-sectional view of a substrate with a backing layer deposited thereon provided in the present disclosure.

[0012] Figure 2 A schematic flow chart of a method for detecting stress of a back-sealing substrate provided in the present invention.

[0013] Figure 3A schematic diagram of the Young's modulus measurement results along the depth direction provided by the present disclosure.

[0014] Figure 4 Schematic diagram of substrate bending provided for the present disclosure.

[0015] Figure 5 A schematic diagram of the radial distribution of the morphology of the silicon wafer before back sealing provided in the present disclosure.

[0016] Figure 6 A schematic diagram of the radial distribution of the morphology of the back-sealed substrate provided in the present invention.

[0017] Figure 7 A schematic diagram of the difference in morphology of the substrate before and after back sealing provided in the present invention.

[0018] Figure 8 A schematic diagram of the stress distribution along the depth direction provided in the present disclosure.

[0019] Fig. 9 A schematic diagram of the composition of a device for detecting stress of a back sealing substrate provided by the present invention.

[0020] Fig.10 A schematic diagram of the structure of a computing device provided by the present disclosure. DETAILED DESCRIPTION

[0021] The technical solutions in the present disclosure will be described clearly and completely below in conjunction with the accompanying drawings in the present disclosure.

[0022] by Figure 1 As an example, the back cover substrate shown in FIG. Figure 1 In the figure, the back side of the single crystal substrate faces upward, and from bottom to top are the single crystal substrate, the transition area between the single crystal substrate and the back sealing layer, and the back sealing layer. In the present disclosure, the back side of the single crystal substrate is the surface for depositing the oxide film, and the surface opposite to the back side is the front side of the single crystal substrate. Usually, in the semiconductor device manufacturing process, the front side of the single crystal substrate is used for patterning to form a device. Figure 1 In the transition region, due to the mixture of single crystal silicon and silicon oxide, its material is quite different from that of the single crystal substrate and the backing layer. Such a difference will cause the mechanical properties of the material, such as Young's modulus, to change compared with the single crystal substrate and the backing layer. This change will cause the residual stress in this region to change, and then there will be stress concentration or unreasonable distribution, resulting in defects such as slip on the backing layer. Therefore, if the stress distribution in the transition region can be detected, the stress detection accuracy of the backing layer will be improved.

[0023] Based on this, the present disclosure hopes to provide a solution that can detect the stress of the back cover substrate along the depth direction, detect the stress distribution of the above transition area, and improve the accuracy of the stress detection of the back cover layer. Figure 2 , which shows a method for detecting stress of a back sealing substrate provided by the present disclosure, the method comprising steps S201 to S205.

[0024] In step S201, a first bending moment caused by residual stress in the substrate is obtained according to the morphology change before and after the back sealing.

[0025] In the present disclosure, the substrate will change its morphology before and after back-sealing due to the residual stress of the back-sealing layer. For a single crystal substrate, since its Young's modulus will not change during the back-sealing process, the first bending moment caused by the residual stress of the single crystal substrate in the process of causing the morphology change is only related to the amount of morphology change. Therefore, the present disclosure can calculate the first bending moment caused by the residual stress in the substrate by using the morphology change before and after back-sealing.

[0026] It should be noted that, since the Young's modulus of the substrate does not change during the back-sealing process, the first bending moment of any sampling point on the surface of the substrate where the back-sealing layer is deposited is the same.

[0027] In step S202, at any sampling point on the surface of the back-sealed substrate, the Young's modulus along the depth direction at the sampling point is detected.

[0028] In the present disclosure, Figure 1 Due to the existence of the transition region, the stress of the back-sealing layer is not uniform, but is unevenly distributed along the depth direction. Therefore, for the sampling points on the surface of the substrate on which the back-sealing layer is deposited, the stress of the back-sealing layer along the depth distribution at each sampling point is also different. In order to obtain the stress of the back-sealing layer along the depth distribution at all sampling points, multiple sampling points can be set on the surface of the substrate on which the back-sealing layer is deposited, and the technical solution of the present disclosure can be performed on each sampling point, so as to obtain the stress of the back-sealing layer along the depth distribution on the complete substrate surface.

[0029] In some examples, the Young's modulus along the depth direction at the sampling point can be measured using the continuous stiffness method of nanoindentation at the sampling point. For example, the back-sealed substrate is placed and fixed on the test platform of the nanoindentation instrument, and the test parameters of the test platform are adjusted as follows: loading speed: 50 nN / s, continuous stiffness measurement (Continuous Stiffness Measurement, CSM) vibration frequency: 45 Hz, vibration amplitude: 20 nm, maximum indentation depth: 600nm, unloading rate: 0.1 mN / s, holding time is 10 seconds, and the Young's modulus within 600 nanometers along the depth direction of the sampling point is measured. The measured Young's modulus along the depth direction is as follows: Figure 3 As shown, from Figure 3 It can be seen that in the range of about 400nm to 430nm, the Young's modulus changes significantly, so this range can be considered as a transition region and this range is Figure 3 The width shown in is the width of the transition region.

[0030] In some examples, before measuring the Young's modulus along the depth direction at the sampling point by the continuous stiffness method based on nanoindentation, the back-sealed substrate can be etched to reduce the thickness of the back-sealing layer. Specifically, since the depth of the nanoindentation measurement does not exceed 2 to 3 microns, such as the aforementioned 600 nanometers, etching operations are required for thicker back-sealing layers (such as back-sealing layers with a thickness of more than 600 nanometers). For example, HF with a concentration of 6% is used to etch the back-sealing layer to reduce the thickness of the back-sealing layer. It can be understood that thinner back-sealing layers (such as back-sealing layers with a thickness of less than 400 nanometers) do not need to be etched.

[0031] In step S203, the second bending moment of the back-sealing layer of the back-sealed substrate at the sampling point is obtained according to the Young's modulus along the depth direction at the sampling point.

[0032] In the present disclosure, since the stress of the back sealing layer is uneven along the depth direction, at the sampling point, the second bending moment caused by the stress of the back sealing layer during the morphological change of the substrate is related to the Young's modulus along the depth direction at the sampling point. Based on the Young's modulus along the depth direction obtained in the above step S202, the present disclosure can obtain the means for obtaining the second bending moment.

[0033] In step S204, based on the property of the bending moment balance, the stress distribution of the back cover layer along the depth direction at the sampling point is obtained through the first bending moment and the second bending moment.

[0034] In the present disclosure, since the bending moment is balanced, the first bending moment and the second bending moment should be equal. Based on this equal property, the stress of the back cover layer can be obtained by combining the first bending moment and the second bending moment. In addition, corresponding to the aforementioned Young's modulus along the depth direction, the stress distribution of the back cover layer along the depth direction can be obtained from the stress of the back cover layer.

[0035] In step S205, according to the stress distribution of the back sealing layer at the sampling point along the depth direction, the stress distribution of the transition area between the back sealing layer and the substrate at the sampling point along the depth direction is obtained.

[0036] In the present disclosure, the material of the transition region of the back-sealing layer is different from that of the oxide film. Therefore, in the stress distribution of the back-sealing layer along the depth direction, there will be a stress distribution region that is significantly different from the stress distribution corresponding to the material of the oxide film. The stress distribution region and its corresponding stress distribution can be considered as the stress distribution of the transition region along the depth direction. Specifically, the stress corresponding to the material of the oxide film can be set as a threshold. When a stress distribution region less than the threshold appears in the stress distribution of the back-sealing layer in the depth direction at the sampling point, the stress distribution region can be determined as a transition region. Correspondingly, the depth of the stress distribution region is the depth of the transition region, and the stress distribution in the stress distribution region can be expressed as the stress distribution of the transition region.

[0037] It should be noted that the above technical solution can be applied to each of all sampling points on the substrate surface where the back-sealing layer is deposited. After executing the technical solution of the present disclosure on each sampling point, the stress distribution of the back-sealing layer and the transition region along the depth direction at each sampling point can be obtained, and then the stress distribution of the back-sealing layer and the transition region along the depth direction on the complete substrate surface can be summarized.

[0038] Through the above technical solution, the present invention obtains the stress of the back sealing layer through the bending moment of the substrate and the back sealing layer based on the bending moment balance property, obtains the stress distribution of the back sealing layer along the depth direction according to the stress of the back sealing layer using the Young's modulus along the depth at the sampling point, and obtains the stress distribution of the transition area along the depth direction from the stress distribution of the back sealing layer along the depth direction, thereby improving the accuracy of stress detection of the back sealing layer.

[0039] for Figure 2 In some possible implementations of the technical solution shown, obtaining the first bending moment caused by the residual stress in the substrate according to the morphology change before and after the back seal includes: Providing a backing substrate; Acquire a first curvature of the substrate before the back seal according to the geometrical morphology of the substrate before the back seal; Back-sealing the substrate through a thin film deposition process to obtain a back-sealed substrate; Acquire a second curvature of the back-sealed substrate according to the geometrical morphology of the back-sealed substrate; A first bending moment caused by residual stress in the substrate is obtained according to the first curvature and the second curvature.

[0040] For the above implementation, specifically, Figure 4 The schematic diagram of the substrate bending is shown, and the front side of the substrate (i.e. Figure 4 The upper surface of the substrate (i.e. Figure 4 The lower surface in the middle receives tensile stress and produces tensile strain. The curvature of the front side is , the curvature of the back side is , Figure 4 The back side (i.e., the lower surface) shown in FIG is deposited with a back-sealing layer, and the radius of the neutral surface is (R1+R2) / 2. Figure 4 In the bending case shown in , the strain on the surface Z away from the neutral plane in the thickness direction is as shown in Equation 1: (1) Considering that the substrate is in a biaxial stress state, the stress at the Z position is expressed as Equation 2: (2) in, , represents the Young's modulus and Poisson's ratio of the substrate at the Z position.

[0041] Based on the above formula 1 and formula 2, before depositing the back-sealing layer, the geometric shape measuring instrument of the substrate can be used to measure the radial distribution of the morphology of the substrate before the back-sealing, as shown in FIG. Figure 5 As shown. Figure 5 In the figure, the horizontal axis represents the radial coordinate with the center of the substrate as the zero point, and the vertical axis represents the height (Height, unit nm). It should be noted that Figure 5 The measurement result is obtained after the edge removal of the substrate is completed, and the edge removal (EE, Edge Exclusion) amount is 5mm.

[0042] After the back-sealing layer is deposited on the substrate, the geometric shape measuring instrument of the substrate can also be used to measure the radial distribution of the morphology of the back-sealed substrate. Figure 6 As shown, in Figure 6 In the figure, the horizontal axis represents the radial coordinate with the center of the substrate as the zero point, and the vertical axis represents the height (Height, unit nm). Figure 6 and Figure 5 Subtract the height values ​​under the corresponding horizontal axis to get the height difference as Figure 7 Based on Figure 7 By fitting a circle, we can get the curvature change as ,in, , They respectively represent the first curvature radius of the substrate before back-sealing and the second curvature radius of the substrate after back-sealing. It can be understood that , They are respectively the radius of the neutral plane of the substrate before back-sealing and the radius of the neutral plane of the substrate after back-sealing.

[0043] After obtaining the first radius of curvature and the second radius of curvature, due to the Young's modulus of the single crystal substrate Poisson's ratio will not change, that is, , Based on this, the first bending moment caused by the residual stress in the substrate As shown in formula 3 below: (3) in, Indicates the diameter of the silicon wafer.

[0044] It should be noted that for bending moment, the first bending moment and the second bending moment for Figure 2 In some possible implementations of the technical solution shown, obtaining the second bending moment of the back-sealing layer of the back-sealed substrate at the sampling point according to the Young's modulus along the depth direction at the sampling point includes: Numerically integrating the Young's modulus at the sampling point along the depth direction to obtain an integral value of the Young's modulus; The second bending moment is obtained according to the integrated value of the Young's modulus, the curvature radii of the front and back surfaces of the back-sealed substrate, and the thickness of the substrate.

[0045] For the above example, specifically, according to Stoney's formula, that is, The thickness of the back sealing layer is usually set to be much lower than that of the single crystal substrate and the stress of the back sealing layer is evenly distributed in the back sealing layer. In this case, the second bending moment of the back sealing layer is As shown in the following equation 4, combined with the properties of moment equilibrium, we have , Formula 4 is: (4) In formula 4, represents the stress of the backing layer, represents the thickness of the single crystal substrate, Indicates the thickness of the backing layer.

[0046] In the present disclosure, in combination with the above-mentioned solution, the back sealing layer is not uniformly distributed. Considering the existence of the transition area, based on Formula 4, the stress of the back sealing layer should be as shown in Formula 5 below: (5) In formula 5, It represents the Young's modulus in the backing layer.

[0047] In addition, since the Young's modulus of the transition region is different from that of the backing layer and the single crystal substrate, considering the non-uniformity of the stress distribution of the backing layer, based on the above equations 4 and 5, the second bending moment of the backing layer is As shown in Formula 6 below: (6) for Figure 2 In some possible implementations of the technical solution shown, the stress distribution of the back cover layer along the depth direction at the sampling point is obtained through the first bending moment and the second bending moment based on the property of the bending moment balance, including: Based on the property of the moment balance, setting the first bending moment to be equal to the second bending moment; Obtaining the stress of the back cover layer according to the equality of the first bending moment and the second bending moment; According to the Young's modulus along the depth direction at the sampling point and the stress of the back sealing layer, the stress distribution of the back sealing layer along the depth direction at the sampling point is obtained.

[0048] For the above example, since the bending moment is balanced, then we have , combining the above formula 3 and formula 6 with this property, we can get: In the case of the distribution along the depth direction, we can get Distribution along the depth direction.

[0049] The Young's modulus along the depth direction at the sampling point is measured by the aforementioned step S202. The continuous curve integral shown in Formula 6 can be expressed by the integral of discrete data as shown in Formula 7 below: (7) in, Indicates the depth interval divided along the depth direction.

[0050] It can be seen from equation 7 that the second bending moment corresponds to the Young's modulus of the backing layer, and is also distributed along the depth. Based on this, the Young's modulus of the sampling point along the depth distribution can be measured, and the stress of the backing layer can be distributed according to the Young's modulus value corresponding to each depth, so as to obtain the distribution of the backing layer along the depth direction. In the distribution process, the Young's modulus of the backing layer can be numerically integrated along the depth to obtain Then, according to the Young's modulus value corresponding to each depth interval The ratio to the above numerical integral value determines the weight of the stress assigned to each depth interval.

[0051] After the weight corresponding to each depth interval is obtained, the stress of the back sealing layer can be distributed along the depth direction to obtain the stress distribution of the back sealing layer along the depth direction.

[0052] like Figure 8 As shown in FIG. 1 , it shows a schematic diagram of an exemplary stress distribution along the depth direction. It can be seen from the figure that in the range of 0 to 400 nm and in the range of approximately 430 nm to 600 nm, the stress is relatively balanced, while in the range of 400 nm to approximately 430 nm, the stress is distributed in a linearly decreasing manner, and in the range of 400 nm to approximately 430 nm, the stress is distributed in a linearly decreasing manner. Figure 3 The range of the transition region shown in is roughly the same, that is, the range from 400nm to about 430nm is the transition region, and from Figure 8 The stress distribution in this area can also be obtained.

[0053] Based on the same inventive concept as the above technical solution, see Fig. 9 , which shows a device 90 for detecting stress of a back-sealing substrate provided by the present disclosure, comprising: a first acquisition unit 901, a detection unit 902, a second acquisition unit 903, a third acquisition unit 904 and a fourth acquisition unit 905; wherein, The first acquisition unit 901 is configured to acquire a first bending moment caused by residual stress in the substrate according to the morphology change before and after the back seal; The detection unit 902 is configured to detect the Young's modulus along the depth direction at any sampling point on the surface of the back-sealed substrate; The second acquisition unit 903 is configured to acquire a second bending moment of the back-sealing layer of the back-sealed substrate at the sampling point according to the Young's modulus along the depth direction at the sampling point; The third acquisition unit 904 is configured to acquire the stress distribution of the back cover layer along the depth direction at the sampling point through the first bending moment and the second bending moment based on the property of the bending moment balance; The fourth acquisition unit 905 is configured to acquire the stress distribution in the depth direction of the transition region between the back sealing layer and the substrate at the sampling point according to the stress distribution in the depth direction of the back sealing layer at the sampling point.

[0054] In some examples, the first acquisition unit 901 is configured to: Providing a backing substrate; Acquire a first curvature of the substrate before the back seal according to the geometrical morphology of the substrate before the back seal; Back-sealing the substrate through a thin film deposition process to obtain a back-sealed substrate; Acquire a second curvature of the back-sealed substrate according to the geometrical morphology of the back-sealed substrate; A first bending moment caused by residual stress in the substrate is obtained according to the first curvature and the second curvature.

[0055] In some examples, the detection unit 902 is configured to: For any sampling point on the surface of the back-sealed substrate, the Young's modulus along the depth direction at the sampling point is measured based on the continuous stiffness method of nanoindentation.

[0056] In some examples, the detection unit 902 is further configured to etch the back-sealed substrate to reduce the thickness of the back-sealing layer before measuring the Young's modulus along the depth direction at the sampling point using the continuous stiffness method based on nanoindentation.

[0057] In some examples, the second acquisition unit 903 is configured to: Numerically integrating the Young's modulus at the sampling point along the depth direction to obtain an integral value of the Young's modulus; The second bending moment is obtained according to the integrated value of the Young's modulus, the curvature radii of the front and back surfaces of the back-sealed substrate, and the thickness of the substrate.

[0058] In some examples, the third acquisition unit 904 is configured to: Based on the property of the moment balance, setting the first bending moment to be equal to the second bending moment; Obtaining the stress of the back cover layer according to the equality of the first bending moment and the second bending moment; According to the Young's modulus along the depth direction at the sampling point and the stress of the back sealing layer, the stress distribution of the back sealing layer along the depth direction at the sampling point is obtained.

[0059] In some examples, the fourth acquisition unit 905 is configured to: In the stress distribution in the depth direction of the back cover layer at the sampling point, the depth of the transition area is determined according to the set stress threshold, and the stress distribution in the depth direction of the transition area is obtained.

[0060] Please refer to Fig.10, which shows a structural block diagram of a computing device provided by an exemplary embodiment of the present disclosure. In some examples, the computing device 100 may be at least one of a smart phone, a smart watch, a desktop computer, a laptop, a virtual reality terminal, an augmented reality terminal, a wireless terminal, and a laptop portable computer. The computing device 100 has a communication function and can access a wired network or a wireless network. The computing device 100 may generally refer to one of a plurality of terminals, and those skilled in the art may know that the number of the above terminals may be more or less. In some examples, the computing device 100 may receive data based on the wired network or wireless network to which it is connected. It can be understood that the computing device 100 undertakes the calculation and processing work of the technical solution of the present disclosure, and the present disclosure does not limit this.

[0061] like Fig.10 As shown, the computing device in the present disclosure may include one or more of the following components: a processor 1010 and a memory 1020 .

[0062] Optionally, the processor 1010 uses various interfaces and lines to connect various parts within the entire computing device, and executes various functions of the computing device and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory 1020, and calling data stored in the memory 1020. Optionally, the processor 1010 can be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), and programmable logic array (PLA). The processor 1010 can integrate one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), a neural network processor (NPU), and a baseband chip. Among them, the CPU mainly processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing the content that needs to be displayed on the touch display; the NPU is used to implement artificial intelligence (AI) functions; and the baseband chip is used to process wireless communications. It is understandable that the above-mentioned baseband chip may not be integrated into the processor 1010, but may be implemented by a separate chip.

[0063] The memory 1020 may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory 1020 includes a non-transitory computer-readable storage medium. The memory 1020 may be used to store instructions, programs, codes, code sets, or instruction sets. The memory 1020 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above various method embodiments, etc.; the data storage area may store data created according to the use of the computing device, etc.

[0064] In addition, those skilled in the art can understand that the structure of the computing device shown in the above drawings does not constitute a limitation on the computing device, and the computing device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently. For example, the computing device also includes a display screen, a camera assembly, a microphone, a speaker, a radio frequency circuit, an input unit, a sensor (such as an acceleration sensor, an angular velocity sensor, a light sensor, etc.), an audio circuit, a WiFi module, a power supply, a Bluetooth module and other components, which will not be described in detail here.

[0065] The present disclosure also provides a computer-readable storage medium storing at least one instruction, wherein the at least one instruction is used to be executed by a processor to implement the method for detecting stress of a back sealing substrate as described in the above embodiments.

[0066] The present disclosure also provides a computer program product, which includes computer instructions stored in a computer-readable storage medium; a processor of a computing device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computing device executes to implement the method of detecting back-sealing substrate stress described in the above-mentioned various embodiments.

[0067] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the present disclosure can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. Storage media can be any available media that can be accessed by a general or special-purpose computer.

[0068] It should be noted that the technical solutions described in the present disclosure can be combined arbitrarily without conflict.

[0069] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for detecting stress of a backing substrate, characterized in that: The method comprises: Obtaining a first bending moment caused by residual stress in the substrate according to the morphology change before and after back sealing; At any sampling point on the surface of the substrate after back sealing, detecting the Young's modulus along the depth direction at the sampling point; According to the Young's modulus along the depth direction at the sampling point, obtaining the second bending moment of the back-sealing layer of the back-sealed substrate at the sampling point; Based on the property of bending moment balance, the stress distribution of the back sealing layer along the depth direction at the sampling point is obtained through the first bending moment and the second bending moment; According to the stress distribution of the back sealing layer at the sampling point along the depth direction, the stress of the transition area between the back sealing layer and the substrate at the sampling point along the depth direction is obtained.

2. The method according to claim 1, characterized in that: The step of obtaining the first bending moment caused by the residual stress in the substrate according to the morphological changes before and after the back seal comprises: Providing a backing substrate; Acquire a first curvature of the substrate before the back seal according to the geometrical morphology of the substrate before the back seal; Back-sealing the substrate through a thin film deposition process to obtain a back-sealed substrate; Acquire a second curvature of the back-sealed substrate according to the geometrical morphology of the back-sealed substrate; A first bending moment caused by residual stress in the substrate is obtained according to the first curvature and the second curvature.

3. The method according to claim 1, characterized in that The method of detecting the Young's modulus along the depth direction at any sampling point on the surface of the substrate after back sealing comprises: For any sampling point on the surface of the back-sealed substrate, the Young's modulus along the depth direction at the sampling point is measured based on the continuous stiffness method of nanoindentation.

4. The method according to claim 3, characterized in that: Before measuring the Young's modulus along the depth direction at the sampling point by the continuous stiffness method based on nanoindentation, the method further comprises: The back-sealed substrate is etched to reduce the thickness of the back-sealing layer.

5. The method according to claim 1, characterized in that The step of obtaining the second bending moment of the back-sealing layer of the back-sealed substrate at the sampling point according to the Young's modulus along the depth direction at the sampling point comprises: Numerically integrating the Young's modulus at the sampling point along the depth direction to obtain an integral value of the Young's modulus; The second bending moment is obtained according to the integrated value of the Young's modulus, the curvature radii of the front and back surfaces of the back-sealed substrate, and the thickness of the substrate.

6. The method according to claim 1, characterized in that The method of obtaining the stress distribution of the back cover layer along the depth direction at the sampling point based on the property of the bending moment balance through the first bending moment and the second bending moment includes: Based on the property of the moment balance, setting the first bending moment to be equal to the second bending moment; Obtaining the stress of the back cover layer according to the equality of the first bending moment and the second bending moment; According to the Young's modulus along the depth direction at the sampling point and the stress of the back sealing layer, the stress distribution of the back sealing layer along the depth direction at the sampling point is obtained.

7. The method according to claim 1, characterized in that The step of obtaining the stress in the depth direction of the transition region between the back sealing layer and the substrate at the sampling point according to the stress distribution of the back sealing layer at the sampling point along the depth direction comprises: In the stress distribution in the depth direction of the back cover layer at the sampling point, the depth of the transition area is determined according to the set stress threshold, and the stress distribution in the depth direction of the transition area is obtained.

8. A device for detecting stress of a backing substrate, characterized in that: The device comprises: a first acquisition unit, a detection unit, a second acquisition unit, a third acquisition unit and a fourth acquisition unit; wherein, The first acquisition unit is configured to acquire a first bending moment caused by residual stress in the substrate according to a morphological change before and after back sealing; The detection unit is configured to detect the Young's modulus along the depth direction at any sampling point on the surface of the substrate after back sealing; The second acquisition unit is configured to acquire a second bending moment of the back-sealing layer of the back-sealed substrate at the sampling point according to the Young's modulus along the depth direction at the sampling point; The third acquisition unit is configured to acquire the stress distribution of the back cover layer along the depth direction at the sampling point through the first bending moment and the second bending moment based on the property of the bending moment balance; The fourth acquisition unit is configured to acquire the stress distribution in the depth direction of the transition region between the back sealing layer and the substrate at the sampling point according to the stress distribution in the depth direction of the back sealing layer at the sampling point.

9. A computing device, characterized in that The computing device comprises a processor and a memory; the processor is used to execute instructions stored in the memory to implement the method for detecting stress of a back seal substrate according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the method for detecting stress of a back seal substrate according to any one of claims 1 to 7.

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