A method, device and electronic equipment for thermal reflection microscopic thermal imaging expansion compensation

Abstract

The present invention provides a method, device and electronic device for thermal reflection microscopic thermal imaging expansion compensation. The method comprises: obtaining an initial image of a device under test under current environmental conditions. Calculating a scaling factor of the initial image relative to a standard image of the device under test, wherein the standard image is an image obtained by a microscope system under the condition that the image distance is the focal length of an imaging lens and the object distance is the focal length of an objective lens. Determine a target image distance and a target object distance that match the current environmental conditions according to the scaling factor. Set the image distance of the microscope system to the target image distance and the object distance to the target object distance to obtain a thermal reflection microscopic thermal imaging image of the device under test after expansion compensation. The present invention can adjust the image distance and the object distance of the microscope system according to the scaling factor of the image before and after the thermal expansion of the device under test, so as to achieve a magnification equal to the initial magnification divided by the scaling factor, and correspondingly adjust the image size of the thermal imaging of the device under test, thereby achieving thermal imaging expansion compensation and reducing the thermal imaging temperature measurement error caused by the thermal expansion of the device under test.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature detection of microelectronic devices, and in particular to a method, a device and an electronic device for thermal reflection micro thermal imaging expansion compensation. Background Art

[0002] Thermal reflection temperature measurement technology is a non-contact temperature measurement technology based on the phenomenon of thermal reflection. The basic characteristic of the thermal reflection phenomenon is that the reflectivity of an object changes with the temperature of the object. The basic principle of thermal reflection temperature measurement is to deduce the temperature change ΔT by measuring the relative change ΔR / R0 of the reflectivity R. Thermal reflection microscopic thermal imaging temperature measurement can be achieved by utilizing the above-mentioned thermal reflection phenomenon in combination with a reflective microscope optical system. Under the premise of constant incident light intensity, the relative change ΔR / R0 of the reflectivity can be replaced by the relative change Δc / c0 of the camera grayscale value reading.

[0003] The core temperature measurement process is mainly divided into two steps: light and heat reflection coefficient C TR Calibration and temperature testing. Based on the results of the research on the principle of photothermal reflection, the intrinsic photothermal reflection characteristics of materials, and the research on influencing factors, the accurate photothermal reflection coefficient C is obtained. TR It is the key to achieve temperature measurement. Thermal reflection micro-thermography temperature measurement usually performs pixel-by-pixel C TR Calibrate, then keep the light source, objective lens, and position of the device under test unchanged, heat the device under test or energize it and measure the temperature.

[0004] Thermal reflection temperature measurement requires image acquisition at different temperatures. In theory, the position of the device under test should remain completely consistent during each image acquisition to ensure that the corresponding relationship between each pixel of the acquired image and the position of the surface under test remains unchanged, so that the temperature change ΔT can be calculated using the relative change Δc / c0 of the camera grayscale value reading at each pixel. However, during the test process, it is necessary to acquire images of the device under test at different temperatures. The temperature change of the device under test will cause thermal expansion, resulting in slight changes in the size of the device under test, thereby destroying the corresponding relationship between each pixel in each image and the surface under test, resulting in measurement errors. Summary of the invention

[0005] The embodiments of the present invention provide a method, device and electronic equipment for thermal reflection microscopic thermal imaging expansion compensation to solve the problem of how to reduce the thermal imaging temperature measurement error caused by thermal expansion of a device under test.

[0006] In a first aspect, an embodiment of the present invention provides a method for thermal reflection microscopy thermal imaging expansion compensation, which is applied to an infinity-corrected optical microscopy system, wherein the infinity-corrected optical microscopy system collects an image of a device under test through an objective lens, an imaging lens, and a thermal imaging camera, and the method comprises:

[0007] Get an initial image of the device under test under the current environmental conditions.

[0008] The scaling factor of the initial image relative to the standard image of the device under test is calculated, wherein the standard image of the device under test is an image acquired by the microscope system under the parameter setting conditions that the image distance is the focal length of the imaging lens and the object distance is the focal length of the objective lens.

[0009] The target image distance and the target object distance matching the current environmental conditions are determined according to the scaling factor.

[0010] The image distance of the microscope system is set to the target image distance, and the object distance is set to the target object distance, so as to obtain a thermal reflection microscope thermal imaging image of the device under test after expansion compensation.

[0011] In a possible implementation manner, determining the target image distance and the target object distance matching the current environmental conditions according to the scaling factor includes:

[0012] calculate As the target image distance, where f T is the focal length of the imaging lens, and α is the scaling factor.

[0013] calculate As the target object distance, where f L is the focal length of the objective lens.

[0014] In a possible implementation manner, determining the target image distance and the target object distance matching the current environmental conditions according to the scaling factor includes:

[0015] It is determined whether the scaling factor is greater than a preset threshold.

[0016] When the zoom factor is greater than a preset threshold, the target image distance and the target object distance matching the current environmental conditions are determined according to the zoom factor.

[0017] In a possible implementation, when the zoom factor is greater than a preset threshold, determining a target image distance and a target object distance that match the current environmental conditions according to the zoom factor includes:

[0018] Reduce the image distance Among them, α is the current scaling factor, f T is the focal length of the objective lens.

[0019] Reduce the object distance Among them, l O is the current object distance, f L is the focal length of the imaging lens.

[0020] A first initial image of the device under test is acquired through the microscope system under the setting conditions of the current image distance and the current object distance parameters.

[0021] A first scaling factor of the first initial image relative to the standard image of the device under test is calculated.

[0022] It is determined whether the first scaling factor is greater than a preset threshold.

[0023] If the first zoom factor is greater than a preset threshold, the first zoom factor is used as a current zoom factor, and the image distance and the object distance are reduced until the first zoom factor is less than or equal to the preset threshold.

[0024] In a possible implementation manner, after determining whether the scaling factor is greater than a preset threshold, the method further includes:

[0025] When the scaling factor is less than or equal to a preset threshold, the current image distance is used as the target image distance, and the current object distance is used as the target object distance.

[0026] In a second aspect, an embodiment of the present invention provides a thermal reflection microscopy thermal imaging expansion compensation device, which is applied to an infinity-corrected optical microscopy system. The infinity-corrected optical microscopy system collects an image of a device under test through an objective lens, an imaging lens, and a thermal imaging camera. The device includes:

[0027] The initial image acquisition module is used to acquire the initial image of the device under test under current environmental conditions.

[0028] A scaling factor calculation module is used to calculate the scaling factor of the initial image relative to the standard image of the device under test, wherein the standard image of the device under test is an image obtained by the microscope system under the parameter setting conditions that the image distance is the focal length of the imaging lens and the object distance is the focal length of the objective lens.

[0029] The target image distance and object distance acquisition module is used to determine the target image distance and target object distance that match the current environmental conditions according to the scaling factor.

[0030] The compensation image acquisition module is used to set the image distance of the microscope system to the target image distance and the object distance to the target object distance, so as to obtain a thermal reflection microscope thermal imaging image of the device under test after expansion compensation.

[0031] In a possible implementation, the target image distance and object distance acquisition module includes:

[0032] Target image distance acquisition unit, used to calculate As the target image distance, where f T is the focal length of the imaging lens, and α is the scaling factor.

[0033] Target distance acquisition unit, used to calculate As the target object distance, where f L is the focal length of the objective lens.

[0034] In a possible implementation manner, the device further includes:

[0035] The judging module is used to judge whether the scaling factor is greater than a preset threshold.

[0036] Correspondingly, the target image distance and object distance obtaining module is specifically configured to determine the target image distance and target object distance that match the current environmental conditions according to the zoom factor when the zoom factor is greater than a preset threshold.

[0037] In a possible implementation, the target image distance and object distance acquisition module includes:

[0038] Image distance adjustment unit, used to reduce the image distance Among them, α is the current scaling factor, f T is the focal length of the objective lens.

[0039] Object distance adjustment unit, used to reduce the object distance Among them, l O is the current object distance, f L is the focal length of the imaging lens.

[0040] The first initial image acquisition unit is used to acquire a first initial image of the device under test through a microscope system under the setting conditions of current image distance and current object distance parameters.

[0041] The first scaling factor calculation unit is used to calculate a first scaling factor of the first initial image relative to the standard image of the device under test.

[0042] A judging unit is used to judge whether the first scaling factor is greater than a preset threshold.

[0043] If the first zoom factor is greater than a preset threshold, the first zoom factor is used as a current zoom factor, and the image distance and the object distance are reduced until the first zoom factor is less than or equal to the preset threshold.

[0044] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the thermal reflection microscopy thermal imaging expansion compensation method as described in the first aspect or any possible implementation of the first aspect are implemented.

[0045] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the thermal reflection microscopy thermal imaging expansion compensation method as described in the first aspect or any possible implementation method of the first aspect are implemented.

[0046] The embodiment of the present invention provides a method, device and electronic device for thermal reflection microscopic thermal imaging expansion compensation, which are applied to an infinity-corrected optical microscopic system. The infinity-corrected optical microscopic system collects an image of a device under test through an objective lens, an imaging lens and a thermal imaging camera. The method includes: obtaining an initial image of the device under test under current environmental conditions. Calculating the scaling factor of the initial image relative to a standard image of the device under test, wherein the standard image of the device under test is an image obtained by the microscopic system under parameter setting conditions in which the image distance is the focal length of the imaging lens and the object distance is the focal length of the objective lens. Determine the target image distance and the target object distance that match the current environmental conditions according to the scaling factor. Set the image distance of the microscopic system to the target image distance and the object distance to the target object distance to obtain a thermal reflection microscopic thermal imaging image after expansion compensation of the device under test. According to the scaling factor of the image before and after the thermal expansion of the device under test, the image distance and the object distance of the microscopic system are adjusted accordingly relative to the initial magnification, so as to achieve a magnification equal to the initial magnification divided by the scaling factor, and correspondingly adjust the image size of the thermal imaging of the device under test, thereby achieving thermal imaging expansion compensation and reducing the thermal imaging temperature measurement error caused by the thermal expansion of the device under test. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0048] Figure 1 It is the C of different materials in the prior art TR Variation with wavelength;

[0049] Figure 2 It is a typical structural schematic diagram of a heat reflection microthermal imaging device in the prior art;

[0050] Figure 3 It is a schematic diagram of the optical path of a microscope of a thermal reflection micro thermal imaging device in the prior art;

[0051] Figure 4 is a flow chart for implementing the thermal reflection microscopic thermal imaging expansion compensation method provided by an embodiment of the present invention;

[0052] Figure 5 is a schematic structural diagram of a thermal reflection microscopic thermal imaging expansion compensation device provided in an embodiment of the present invention;

[0053] Figure 6 is a schematic structural diagram of a thermal reflection microscopic thermal imaging device provided in an embodiment of the present invention;

[0054] Figure 7is a schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0056] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0057] The embodiments of the present invention can be applied to a variety of application scenarios, which involve thermal reflection microscopic thermal imaging expansion compensation, and the specific application scenarios are not limited here. Exemplarily, in one application scenario, the thermal reflection microscopic thermal imaging expansion compensation method provided by the embodiment of the present invention is applied to thermal reflection temperature measurement.

[0058] Thermal reflection temperature measurement technology is a non-contact temperature measurement technology based on the phenomenon of thermal reflection. The basic characteristic of the thermal reflection phenomenon is that the reflectivity of an object changes with the temperature of the object. In the prior art, the change of reflectivity with temperature can be considered linear, so it can be characterized by a change rate coefficient, usually called the thermal reflection coefficient or thermal reflection calibration coefficient, denoted by C TR To express, the definition formula is:

[0059]

[0060] Among them, C TR is the thermal reflectance coefficient, R is the reflectivity, and T is the temperature. It is very difficult to measure the reflectivity with high accuracy, but it is relatively easy to measure the relative change of reflectivity. In practical applications, the formula (2) is used, that is, a linear approximation is made near a certain reflectivity R0, and it is assumed that C TR Does not vary with temperature:

[0061]

[0062] Then, given that C TR Under the condition of , the temperature change can be deduced by measuring the relative change of reflectivity. This is the basic formula for thermal reflection temperature measurement:

[0063]

[0064] Assuming that the incident light intensity is constant, the relative change in reflectivity ΔR / R0 can be replaced by the relative change in the camera grayscale value reading Δc / c0, then the above formula (3) can be rewritten into the following more operational form:

[0065]

[0066] It should be noted that C TR The changes are significant, so it is necessary to select an appropriate detection light wavelength according to the material being tested.

[0067] Figure 1 It is the C of different materials in the prior art TR Variation with wavelength; see Figure 1 : The horizontal axis is wavelength in nanometers, and the vertical axis is C TR From the above formula, we can see that under the same temperature change, C TR The larger the absolute value, the more obvious the relative change of reflectivity. TR If the reflectivity is zero, the method will not change. For example, for Au materials, a narrow spectrum light source with a central wavelength of 470nm or 520nm is usually selected, and the corresponding C TR The absolute value is usually (2×10 -4 ~4×10 -4 )℃ -1 level to avoid the failure of the above methods.

[0068] According to the results of the research on the principle of photothermal reflection, the intrinsic photothermal reflection characteristics of materials and the influencing factors, the accurate photothermal reflection coefficient C is obtained. TR It is the key to achieve temperature measurement. Many factors such as the material being tested, the wavelength of the test light, and the incident angle of the test light will affect the C TR In addition, the temperature measurement object is a microwave power device, whose surface material and structure are relatively complex, and there is no feasible means to obtain the C TR Therefore, thermal reflection microthermography usually performs pixel-by-pixel C TR Calibrate, then keep the light source, objective lens and the position of the device under test unchanged, apply excitation to the device under test and measure the temperature. The core temperature measurement process is mainly divided into two steps: C TR Calibration and temperature testing. C TR Calibration is to obtain pixel-by-pixel C values ​​of the device under test under specific test conditions. TR Information for temperature calculation. C TR The calibration is based on the formula:

[0069]

[0070] In formula (5), T1 and T2 are the set temperatures of the temperature control platform, and c1 and c2 are the grayscale value readings of the camera obtained by collecting images at the corresponding set temperatures. Note that only two temperature points are used here. Some literature uses multiple temperature points and then performs linear fitting to obtain C TR , but considering C TR The magnitude and stability of the device, especially the existence of light source intensity drift, takes a long time to measure multiple temperature points and is easily affected by drift. The solution adopted here is to test only at two temperature points, and then repeat the measurement multiple times to observe each set of measurements to obtain C TR The average value of one or several groups of data after stabilization is selected as C TR The advantages of the above method are that, on the one hand, each set of measurements has only two temperature points, which can minimize the impact of drift, and on the other hand, averaging multiple sets of data can also achieve a noise suppression effect similar to linear fitting after multi-temperature measurement.

[0071] Get C TR After that, you can start temperature measurement, according to the formula:

[0072]

[0073] In formula (6), T r The reference temperature set for the temperature control station; c r is the grayscale value reading of the camera obtained by capturing an image at the reference temperature when the device is not powered on; T m is the temperature to be measured; c m The camera grayscale value readings are taken from an image acquired at the temperature to be tested after powering up the device.

[0074] In summary, the core steps of thermal reflection micro-thermal imaging temperature measurement can be summarized as follows:

[0075]

[0076] Table 1: Core steps of thermal reflection microthermography temperature measurement

[0077] There are two points that need to be supplemented here: first, the gray value reading c obtained by each image acquisition can be obtained by averaging multiple frames of images, and the specific number of frames is determined according to the test target and test conditions; second, the above calculation is performed for each pixel of the image. The following is explained in the form of a single pixel.

[0078] Figure 2 It is a typical structural diagram of thermal reflection micro-thermal imaging equipment in the prior art; Figure 2:The typical structure of thermal reflection micro-thermal imaging equipment includes a microscope body, a microscope, a camera, an LED light source, a programmable hot and cold stage, a three-axis nano-displacement stage and an optical platform. The LED light source is used as the lighting source. The programmable hot and cold stage is used as a temperature control stage to achieve precise temperature control. The optical platform is used to isolate vibrations. The microscope is combined with an appropriate wavelength lighting source and a scientific research-level camera. The relative change in the reflectivity of the device under test is obtained through the relative change in the grayscale value of the camera, and the thermal reflection phenomenon is used for micro-thermal imaging. The precision temperature control stage provides a temperature environment for the device under test, as a C TR A means of adjusting the temperature of the device under test during the calibration process. The nano-stage is used to correct the position drift of the device under test to ensure that the position correspondence of each pixel in the multiple images collected during the test process is not destroyed. The entire set of equipment is placed on an optical platform to reduce the impact of environmental vibration.

[0079] The basic principle of thermal reflection temperature measurement is to deduce the temperature change ΔT by measuring the relative change ΔR / R0 of the reflectivity R. By utilizing the above-mentioned thermal reflection phenomenon and combining it with a reflective microscopic optical system, thermal reflection microscopic thermal imaging temperature measurement can be achieved.

[0080] Thermal reflection temperature measurement requires image acquisition at different temperatures. In theory, the position of the device under test should remain completely consistent during each image acquisition to ensure that the corresponding relationship between the position of each pixel in the acquired image and the surface under test remains unchanged, so that the temperature change ΔT can be calculated using the relative change Δc / c0 of the camera grayscale value reading at each pixel. However, during the test, it is necessary to acquire images of the device under test at different temperatures. The temperature change of the device under test will cause thermal expansion, resulting in slight changes in the size of the device under test, thereby destroying the corresponding relationship between each pixel in each image and the surface under test, resulting in measurement errors. Especially at the junction of different materials, the difference in the reading values ​​of adjacent pixels is often significantly greater than C TR level, where even dimensional changes caused by thermal expansion at the sub-pixel level can have a noticeable effect.

[0081] Figure 3 It is a schematic diagram of the optical path of a microscope of a thermal reflection micro-thermal imaging device in the prior art; Figure 3 :Using epi-illumination and infinity-corrected microscopy system, the diffuser is used to improve the uniformity of illumination. The infinity-corrected optical microscopy system collects images of the device under test through the objective lens, imaging lens and thermal imaging camera.

[0082] Figure 4 is a flow chart of the implementation of the thermal reflection microscopic thermal imaging expansion compensation method provided by an embodiment of the present invention; Figure 4 :

[0083] The embodiment of the present invention provides a thermal reflection microscopy thermal imaging expansion compensation method, which is applied to an infinity-corrected optical microscopy system. The infinity-corrected optical microscopy system collects an image of a device under test through an objective lens, an imaging lens, and a thermal imaging camera. The method includes:

[0084] In step S1, an initial image of the device under test under current environmental conditions is acquired.

[0085] Exemplary environmental conditions include whether the device under test is powered on. Exemplary environmental conditions include whether the device under test is heated. Exemplary environmental conditions include heating the device under test to different temperatures. Referring to Table 1, the thermal reflection microscopic thermography temperature measurement process requires multiple acquisitions of images of the device under test at different device states and different temperature control temperatures. In a certain temperature measurement step, an initial image of the device under test is acquired by the microscope system under the current environmental conditions.

[0086] In step S2, the scaling factor of the initial image relative to the standard image of the device under test is calculated, wherein the standard image of the device under test is an image acquired by the microscope system under the parameter setting conditions that the image distance is the focal length of the imaging lens and the object distance is the focal length of the objective lens.

[0087] Using the standard image as a reference, the image registration algorithm of the prior art is used to calculate the scaling factor of the initial image relative to the standard image of the device under test. For example, the coordinate system of the initial image and the standard image is transformed into a logarithmic coordinate system, and the scaling information of the image is calculated in the logarithmic coordinate system by the translation information of the image to obtain the scaling factors of the rows and columns. For example, in the process of thermal reflection microthermography temperature measurement, the standard image can be C TR The first image acquired during a calibration or temperature test process.

[0088] In step S3, the target image distance and the target object distance matching the current environmental conditions are determined according to the scaling factor.

[0089] The target image distance and the target object distance that match the current environmental conditions, that is, keep the current environmental conditions unchanged, adjust the image distance and the object distance, so that the target image distance and the target object distance meet the condition: the ratio of the target image distance to the target object distance is equal to the ratio of the focal length of the imaging lens to the focal length of the objective lens divided by the zoom factor. The ratio of the target image distance to the target object distance is the target magnification. The ratio of the focal length of the imaging lens to the focal length of the objective lens is the initial magnification of the microscope system. The initial magnification is the magnification when the standard image is acquired. That is, adjust the image distance and the object distance so that the target magnification is equal to the initial magnification divided by the zoom factor. Based on the initial magnification and the zoom factor, the target magnification of the microscope system is adjusted accordingly, and the size of the thermal imaging of the device under test is adjusted accordingly.

[0090] Exemplarily, the device under test thermally expands, the initial image is magnified relative to the standard image, the zoom factor is greater than 1, the magnification of the corresponding microscope system is reduced, the imaging is reduced, and further an image after expansion compensation is obtained at a target magnification.

[0091] In step S4, the image distance of the microscope system is set to the target image distance, and the object distance is set to the target object distance, so as to obtain a thermal reflection microscope thermal imaging image after expansion compensation of the device under test.

[0092] The embodiment provided by the present invention adjusts the image distance and object distance of the microscope system accordingly relative to the initial magnification according to the zoom factor of the image before and after the thermal expansion of the device under test, so as to achieve a target magnification equal to the initial magnification divided by the zoom factor, and correspondingly adjusts the image size of the thermal imaging of the device under test, thereby achieving thermal imaging expansion compensation and reducing the thermal imaging temperature measurement error caused by the thermal expansion of the device under test.

[0093] In a possible implementation, determining a target image distance and a target object distance that match the current environmental conditions according to the scaling factor includes:

[0094] calculate As the target image distance, where f T is the focal length of the imaging lens, and α is the scaling factor.

[0095] calculate As the target object distance, where f L is the focal length of the objective lens.

[0096] In the infinity-corrected microscope optical path, there is parallel light between the objective lens and the imaging lens. The device under test is located on the front focal plane of the objective lens, and the camera sensor is located on the back focal plane of the imaging lens. The magnification of the system is:

[0097]

[0098] In formula (7), M is the magnification, f T is the focal length of the imaging lens, f L is the focal length of the objective lens.

[0099] When the device under test is not in the front focal plane of the objective lens, the magnification of the system can be calculated using a more general formula:

[0100]

[0101] In formula (8), l I is the image distance, l O is the object distance, regardless of direction, and is always positive.

[0102] According to Newton's optical formula, when the image is clear:

[0103] l O lI =f T f L (9)

[0104] Substituting formula (9) into formula (8) yields the following solution:

[0105]

[0106] The meaning of the above formula is that for a certain microscope optical system, f T 、f L The image distance and the object distance must be adjusted accordingly to keep the image clear.

[0107] Assume that in the initial state, the object and image are located at the focal planes of the objective lens and imaging lens respectively, and the magnification is M0. The image scaling factor caused by thermal expansion is α. To compensate, the magnification should be adjusted to M x to meet:

[0108]

[0109] Combining formula (11) with formula (10), we get:

[0110]

[0111] In the formula, l x It represents the target image distance that needs to be adjusted for compensation. The solution is:

[0112]

[0113] According to formula (13), l x Adjust the image distance and refocus to achieve clear imaging, that is, adjust the object distance accordingly, to achieve expansion compensation. For example, the object distance is adjusted using the existing focusing algorithm to achieve clear imaging. For example, formula (13) is substituted into formula (9) to obtain the target object distance l that satisfies clear imaging. Ox for

[0114] The embodiment provided by the present invention adjusts the image distance according to the zoom factor to Object distance is The imaging expansion compensation is realized while clear imaging of the device under test is achieved.

[0115] In a possible implementation, determining a target image distance and a target object distance that match the current environmental conditions according to the scaling factor includes:

[0116] Determine whether the scaling factor is greater than a preset threshold.

[0117] When the zoom factor is greater than a preset threshold, the target image distance and the target object distance that match the current environmental conditions are determined according to the zoom factor.

[0118] Exemplarily, the temperature of the device under test when acquiring the standard image is lower than the temperature of the device under test when acquiring the initial image. Accordingly, the scaling factor of the initial image relative to the standard image is greater than 1. Exemplarily, in the process of thermal reflection microthermography temperature measurement, the standard image is acquired when the device under test is at room temperature.

[0119] In a possible implementation, when the zoom factor is greater than a preset threshold, determining a target image distance and a target object distance that match the current environmental conditions according to the zoom factor includes:

[0120] Reduce the image distance Among them, α is the current scaling factor, f T is the focal length of the objective lens.

[0121] Reduce the object distance Among them, l O is the current object distance, f L is the focal length of the imaging lens.

[0122] A first initial image of the device under test is acquired through the microscope system under the setting conditions of the current image distance and the current object distance parameters.

[0123] A first scaling factor of the first initial image relative to the standard image of the device under test is calculated.

[0124] It is determined whether the first scaling factor is greater than a preset threshold.

[0125] If the first zoom factor is greater than the preset threshold, the first zoom factor is used as the current zoom factor, and the image distance and the object distance are reduced until the first zoom factor is less than or equal to the preset threshold.

[0126] The method provided by the embodiment of the present invention introduces a closed-loop control mechanism, which gradually reduces the image distance and the object distance until the zoom factor is lower than the preset threshold, thereby improving the compensation accuracy and reducing the scaling factor α and the image distance l. x Control accuracy requirements. Ensure clear imaging while achieving compensation.

[0127] Some microscopes provide a fine adjustment mechanism for adjusting the image distance, but it is usually manual and there is no readout to determine the image distance value. T It is a known microscope parameter. Usually, products from the same manufacturer use the same f T For example, an electric adjustment mechanism is added between the camera and the imaging lens, which can be controlled by the method provided in the embodiment of the present invention to automatically adjust the image distance and the object distance according to the calculation results to achieve thermal reflection microscopic thermal imaging expansion compensation.

[0128] The following is the derivation of the adjustment amount of the image distance. The derivation is based on formula (10). I The derivative is:

[0129]

[0130]

[0131] In the thermal reflection micro-thermal imaging temperature test scenario, the dimensional change caused by thermal expansion is usually within 1%, that is,

[0132]

[0133]

[0134] The current expansion factor is α, and the current magnification is M s , the objective magnification adjusted for compensation is M x ,but

[0135]

[0136]

[0137] Combined with formula (15), since the change is small enough, the nominal magnification of the microscope M0 can be used instead of M x , f T Instead of l I ,thereby

[0138]

[0139] Substituting formula (20) into formula (9), we can get the adjustment amount of object distance:

[0140]

[0141] At this point, we can use Δl I As the adjustment amount of image distance, as the input of closed-loop control, and combined with PID control, expansion compensation is achieved.

[0142] In a possible implementation manner, after determining whether the scaling factor is greater than a preset threshold, the method further includes:

[0143] When the scaling factor is less than or equal to a preset threshold, the current image distance is used as the target image distance, and the current object distance is used as the target object distance.

[0144] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0145] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0146] Figure 5 is a schematic diagram of the structure of a thermal reflection microscopic thermal imaging expansion compensation device provided in an embodiment of the present invention. For ease of description, only the part related to the embodiment of the present invention is shown; Figure 5 :

[0147] The embodiment of the present invention provides a thermal reflection microscopic thermal imaging expansion compensation device 2, which is applied to an infinity-corrected optical microscopic system. The infinity-corrected optical microscopic system collects an image of a device under test through an objective lens, an imaging lens, and a thermal imaging camera. The thermal reflection microscopic thermal imaging expansion compensation device 2 includes:

[0148] The initial image acquisition module 21 is used to acquire an initial image of the device under test under current environmental conditions.

[0149] The scaling factor calculation module 22 is used to calculate the scaling factor of the initial image relative to the standard image of the device under test, wherein the standard image of the device under test is an image obtained by the microscope system under the parameter setting conditions that the image distance is the focal length of the imaging lens and the object distance is the focal length of the objective lens.

[0150] The target image distance and object distance obtaining module 23 is used to determine the target image distance and the target object distance that match the current environmental conditions according to the scaling factor.

[0151] The compensation image acquisition module 24 is used to set the image distance of the microscope system to the target image distance and the object distance to the target object distance, and obtain a thermal reflection microscope thermal imaging image after expansion compensation of the device under test.

[0152] The embodiment of the present invention adjusts the image distance and object distance of the microscope system accordingly relative to the initial magnification according to the zoom factor of the image before and after the thermal expansion of the device under test, so as to achieve a magnification equal to the initial magnification divided by the zoom factor, and accordingly adjusts the image size of the thermal imaging of the device under test, thereby achieving thermal imaging expansion compensation and reducing the thermal imaging temperature measurement error caused by the thermal expansion of the device under test.

[0153] In a possible implementation, the target image distance and object distance obtaining module 23 includes:

[0154] Target image distance acquisition unit, used to calculate As the target image distance, where f T is the focal length of the imaging lens, and α is the scaling factor.

[0155] Target distance acquisition unit, used to calculate As the target object distance, where f L is the focal length of the objective lens.

[0156] In a possible implementation, the device further includes:

[0157] The judging module is used to judge whether the scaling factor is greater than a preset threshold.

[0158] Correspondingly, the target image distance and object distance obtaining module 23 is specifically configured to determine the target image distance and target object distance that match the current environmental conditions according to the zoom factor when the zoom factor is greater than a preset threshold.

[0159] In a possible implementation, the target image distance and object distance obtaining module 23 includes:

[0160] Image distance adjustment unit, used to reduce the image distance Among them, α is the current scaling factor, f T is the focal length of the objective lens.

[0161] Object distance adjustment unit, used to reduce the object distance Among them, l O is the current object distance, f L is the focal length of the imaging lens.

[0162] The first initial image acquisition unit is used to acquire a first initial image of the device under test through a microscope system under the setting conditions of current image distance and current object distance parameters.

[0163] The first scaling factor calculation unit is used to calculate a first scaling factor of the first initial image relative to a standard image of the device under test.

[0164] The determination unit is used to determine whether the first scaling factor is greater than a preset threshold.

[0165] If the first zoom factor is greater than the preset threshold, the first zoom factor is used as the current zoom factor, and the image distance and the object distance are reduced until the first zoom factor is less than or equal to the preset threshold.

[0166] Figure 6 is a schematic diagram of the structure of a thermal reflection microscopic thermal imaging device provided in an embodiment of the present invention; Figure 6 The above-mentioned device collects the image of the device under test through an objective lens, an imaging lens and a thermal imaging camera. An electric adjustment mechanism is added between the camera and the imaging lens, and the thermal reflection microscopic thermal imaging expansion compensation method provided by the embodiment of the present invention is used to automatically adjust the image distance and the object distance according to the calculation results to achieve thermal reflection microscopic thermal imaging expansion compensation.

[0167] Figure 7 Schematic diagram of an electronic device provided by an embodiment of the present invention. Figure 7As shown, the electronic device 3 of this embodiment includes: a processor 30, a memory 31, and a computer program 32 stored in the memory 31 and executable on the processor 30. When the processor 30 executes the computer program 32, the steps in the above-mentioned thermal reflection microscopic thermal imaging expansion compensation method embodiments are implemented, for example Figure 4 Alternatively, when the processor 30 executes the computer program 32, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 5 The functions of modules 21 to 24 are shown.

[0168] Exemplarily, the computer program 32 may be divided into one or more modules / units, which are stored in the memory 31 and executed by the processor 30 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 32 in the electronic device 3. For example, the computer program 32 may be divided into Figure 5 Modules 21 to 24 are shown.

[0169] The electronic device 3 may be a computing device such as a microscope system, a desktop computer, a notebook, a PDA, and a cloud server. The electronic device 3 may include, but is not limited to, a processor 30 and a memory 31. Those skilled in the art will understand that Figure 7 It is only an example of the electronic device 3 and does not constitute a limitation of the electronic device 3. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0170] The processor 30 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0171] The memory 31 may be an internal storage unit of the electronic device 3, such as a hard disk or memory of the electronic device 3. The memory 31 may also be an external storage device of the electronic device 3, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 3. Further, the memory 31 may also include both an internal storage unit and an external storage device of the electronic device 3. The memory 31 is used to store the computer program and other programs and data required by the electronic device. The memory 31 may also be used to temporarily store data that has been output or is to be output.

[0172] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0173] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0174] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0175] In the embodiments provided by the present invention, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0176] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0177] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0178] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned thermal reflection microscopic thermal imaging expansion compensation method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium.

[0179] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for thermal reflection microscopic thermal imaging expansion compensation, characterized in that: Applied to an infinity-corrected optical microscope system, the infinity-corrected optical microscope system collects an image of a device under test through an objective lens, an imaging lens, and a thermal imaging camera, the method comprising: Acquire an initial image of the device under test under current environmental conditions; Calculating a scaling factor of the initial image relative to a standard image of the device under test, wherein the standard image of the device under test is an image acquired by the microscope system under parameter setting conditions that an image distance is a focal length of an imaging lens and an object distance is a focal length of an objective lens; Determine whether the zoom factor is greater than a preset threshold; when the zoom factor is greater than the preset threshold, determine the target image distance and the target object distance that match the current environmental conditions according to the zoom factor; the determining the target image distance and the target object distance that match the current environmental conditions according to the zoom factor includes: reducing the image distance Among them, α is the current scaling factor, f Y is the focal length of the objective lens; reduces the object distance Among them, l O is the current object distance, f L is the focal length of the imaging lens; obtaining a first initial image of the device under test by the microscope system under the current image distance and current object distance parameter setting conditions; calculating a first scaling factor of the first initial image relative to the standard image of the device under test; determining whether the first scaling factor is greater than a preset threshold; if the first scaling factor is greater than the preset threshold, using the first scaling factor as the current scaling factor, reducing the image distance and the object distance until the first scaling factor is less than or equal to the preset threshold; The image distance of the microscope system is set to the target image distance, and the object distance is set to the target object distance, so as to obtain a thermal reflection microscope thermal imaging image of the device under test after expansion compensation.

2. The thermal reflection micro-thermal imaging expansion compensation method according to claim 1, characterized in that: After determining whether the scaling factor is greater than a preset threshold, the method further includes: When the scaling factor is less than or equal to a preset threshold, the current image distance is used as the target image distance, and the current object distance is used as the target object distance.

3. A heat reflection microscopic thermal imaging expansion compensation device, characterized in that: Applied to an infinity-corrected optical microscope system, the infinity-corrected optical microscope system collects images of the device under test through an objective lens, an imaging lens and a thermal imaging camera, and the device comprises: An initial image acquisition module is used to acquire an initial image of the device under test under current environmental conditions; a scaling factor calculation module, used to calculate the scaling factor of the initial image relative to the standard image of the device under test, wherein the standard image of the device under test is an image acquired by the microscope system under the parameter setting conditions that the image distance is the focal length of the imaging lens and the object distance is the focal length of the objective lens; The target image distance and object distance acquisition module is used to determine whether the zoom factor is greater than a preset threshold; when the zoom factor is greater than the preset threshold, determine the target image distance and target object distance that match the current environmental conditions according to the zoom factor; the determination of the target image distance and target object distance that match the current environmental conditions according to the zoom factor includes: reducing the image distance Among them, α is the current scaling factor, f T is the focal length of the objective lens; reduces the object distance Among them, l O is the current object distance, f L is the focal length of the imaging lens; obtaining a first initial image of the device under test by the microscope system under the current image distance and current object distance parameter setting conditions; calculating a first scaling factor of the first initial image relative to the standard image of the device under test; determining whether the first scaling factor is greater than a preset threshold; if the first scaling factor is greater than the preset threshold, using the first scaling factor as the current scaling factor, reducing the image distance and the object distance until the first scaling factor is less than or equal to the preset threshold; The compensation image acquisition module is used to set the image distance of the microscope system to the target image distance and the object distance to the target object distance, so as to obtain a thermal reflection microscope thermal imaging image of the device under test after expansion compensation.

4. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the thermal reflection microthermography expansion compensation method as described in any one of claims 1 to 2 are implemented.

5. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the thermal reflection microthermography expansion compensation method as described in any one of claims 1 to 2 are implemented.

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