Multilayer material measurement method, device and storage medium

Abstract

The present invention discloses a multilayer material measurement method, device and storage medium, which are applied to the field of thermal property measurement. The multilayer material measurement method includes: obtaining a thermal signal, and controlling the thermal signal to pass through the multilayer material along a first direction, wherein the multilayer material is provided with a plurality of sublayers arranged in a stacked manner; obtaining the temperature-propagation depth change relationship and the temperature-time change relationship of the multilayer material in the first direction; calculating the thermal resistance-propagation depth change relationship according to the thermal signal, the temperature-propagation depth change relationship and the temperature-time change relationship; calculating the thermal wave transfer characteristic-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship; obtaining the interface thermal resistance of the multilayer material and the transfer characteristics of the thermal wave at the interface of the multilayer material according to the thermal resistance-propagation depth change relationship and the thermal wave transfer characteristic-propagation depth change relationship. The method enables users to better understand the relevant parameters of the multilayer material and facilitates the application of the multilayer material.

Description

Technical Field

[0001] The invention relates to the field of thermal property measurement, and in particular to a multilayer material measurement method and device. Background Art

[0002] With the increasing development of multilayer materials, they have been used in more and more applications. At the same time, with the development of microelectronics technology, electronic components are changing towards thin, light, small and multifunctional, and the assembly density of components is getting higher and higher. The heat dissipation of power devices has become a prominent problem. Multilayer materials have become a key link in solving the heat dissipation problem of electronic devices in the future. When researchers synthesize multilayer materials, how to accurately measure the relevant parameters of multilayer materials is crucial.

[0003] In the related technologies, the measurement research of related parameters of multilayer materials is mainly based on theoretical and simulation research, and there is almost no related experimental research. In addition, the interface thermal resistance measurement method of multilayer materials and the transmission mechanism of heat waves between multilayer materials are unclear, and there is no effective measurement equipment. It is difficult to accurately obtain the interface thermal resistance of multilayer materials and the transmission characteristics of heat waves at the interface of multilayer materials. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the embodiments of the present application provide a multilayer material measurement method, device and storage medium, which can simultaneously measure the interfacial thermal resistance of the multilayer material and the transmission characteristics of the heat wave at the interface of the multilayer material, so as to facilitate the application of the multilayer material in the later stage.

[0005] In a first aspect, the present invention provides a method for measuring a multilayer material, comprising:

[0006] Acquire a thermal signal, and control the thermal signal to pass through the multilayer material along a first direction, wherein the multilayer material is provided with a plurality of sublayers arranged in a stacked manner;

[0007] Acquire the temperature-propagation depth variation relationship and the temperature-time variation relationship of the multilayer material in the first direction;

[0008] Calculating a thermal resistance-propagation depth change relationship according to the thermal signal, the temperature-propagation depth change relationship, and the temperature-time change relationship;

[0009] Calculating the thermal wave transfer characteristic-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship;

[0010] According to the relationship between thermal resistance and propagation depth variation and the relationship between thermal wave transfer characteristics and propagation depth variation, the interface thermal resistance of the multilayer material and the transfer characteristics of the thermal wave at the interface of the multilayer material are obtained.

[0011] The multilayer material measurement method provided in accordance with the first aspect of the present invention has at least the following beneficial effects: the multilayer material measurement method controls the thermal signal to pass through the multilayer material along the first direction, so that the temperature of the multilayer material changes, obtains the temperature-propagation depth change relationship and the temperature-time change relationship of the multilayer material in the first direction, and further calculates the thermal resistance-propagation depth change relationship and the heat transfer characteristic-propagation depth change relationship respectively through the thermal signal and the temperature change relationship with the propagation depth and time, thereby obtaining the thermal resistance and the transfer characteristics of the heat wave in the multilayer material, and obtaining the interface thermal resistance of the multilayer material and the transfer characteristics of the heat wave at the interface of the multilayer material in one step, so that the user can better understand the relevant parameters of the multilayer material, which is convenient for the later application of the multilayer material.

[0012] According to some embodiments of the present invention, calculating the thermal resistance-propagation depth variation relationship according to the thermal signal, the temperature-propagation depth variation relationship and the temperature-time variation relationship includes:

[0013] According to the temperature-propagation depth variation relationship, a temperature difference between any two adjacent positions of the multilayer material in the first direction is obtained;

[0014] According to the thermal signal and the temperature-time variation relationship, a thermal signal amplitude corresponding to the temperature variation trend is obtained;

[0015] Calculating the quotient of each temperature difference and the corresponding thermal signal amplitude to obtain a thermal resistance corresponding to each first position, wherein the first position is a middle point between the two adjacent position points corresponding to the temperature difference;

[0016] According to the plurality of thermal resistances and the corresponding first positions, a relationship between thermal resistance and propagation depth of the multilayer material in the first direction is obtained.

[0017] According to some embodiments of the present invention, the thermal wave transfer characteristics include at least one of the following thermal wave transfer characteristics: thermal wave amplitude, thermal wave phase, thermal wave temperature DC component, and thermal wave velocity.

[0018] According to some embodiments of the present invention, the calculating the thermal wave amplitude-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship includes:

[0019] According to the temperature-propagation depth variation relationship and the temperature-time variation relationship, the relationship formula of the heat wave is obtained, wherein the relationship formula of the heat wave is:

[0020]

[0021] Wherein, T(·) represents the thermal wave, x is the propagation depth of the thermal wave in the multilayer material, t is the propagation time of the thermal wave in the multilayer material, j0 is the initial amplitude of the thermal signal, ω is the angular frequency of the thermal signal, C v is the constant heat capacity of the multilayer material, α is the sample thermal diffusivity of the multilayer material, and

[0022] According to the relationship of the thermal wave, the relationship between the thermal wave amplitude and the propagation depth is obtained, wherein the relationship between the thermal wave amplitude and the propagation depth can be expressed as:

[0023]

[0024] Wherein, A(·) represents the thermal wave amplitude.

[0025] According to some embodiments of the present invention, calculating the thermal wave phase-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship includes:

[0026] According to the temperature-propagation depth variation relationship and the temperature-time variation relationship, a relational expression of the heat wave is obtained, wherein the relational expression of the heat wave is used to characterize the relationship between the heat wave and the propagation depth and time;

[0027] According to the relationship of the thermal wave, a plurality of thermal wave phases are obtained, wherein the thermal wave phases correspond to the propagation depths one by one;

[0028] According to the multiple thermal wave phases and the corresponding propagation depths, a thermal wave phase-propagation depth variation relationship is obtained.

[0029] According to some embodiments of the present invention, the calculating the thermal wave temperature DC sub-item-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship includes:

[0030] According to the temperature-propagation depth variation relationship and the temperature-time variation relationship, a relational expression of the heat wave is obtained, wherein the relational expression of the heat wave is used to characterize the relationship between the heat wave and the propagation depth and time;

[0031] According to the relationship of the thermal wave, a plurality of DC components of the thermal wave are obtained, wherein the DC components of the thermal wave correspond to the propagation depths one by one;

[0032] According to the DC components of the plurality of thermal waves and the corresponding propagation depths, a variation relationship between the DC component of the thermal wave temperature and the propagation depth is obtained.

[0033] According to some embodiments of the present invention, the calculating the thermal wave velocity-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship includes:

[0034] Obtaining the position distance between any two adjacent position points of the multilayer material in the first direction;

[0035] Obtaining the initial temperature response time difference corresponding to each of the position distances;

[0036] Calculate the quotient of each of the position distances and the initial response temperature time difference to obtain the thermal wave velocity corresponding to the second position, wherein the second position is the middle point between two adjacent position points corresponding to the corresponding position distance;

[0037] According to the plurality of thermal wave velocities and the corresponding second positions, a relationship between the thermal wave velocity and the propagation depth of the multilayer material in the first direction is obtained.

[0038] According to some embodiments of the present invention, the calculating the thermal wave velocity-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship includes:

[0039] According to the temperature-propagation depth variation relationship, a temperature gradient of the multilayer material in a first direction is obtained;

[0040] According to the temperature-propagation depth variation relationship, the temperature of any position point of the multilayer material in the first direction is obtained;

[0041] According to the temperature gradient of the multilayer material in the first direction and the temperature at any position, the thermal wave velocity of the multilayer material at the current position is calculated, wherein the thermal wave velocity can be expressed as:

[0042]

[0043] Where v is the thermal wave velocity, J T is the heat flux, Q v is the heat capacity density, λ is the thermal conductivity of the multilayer material, ρ is the density of the multilayer material, C v is the constant heat capacity of the multilayer material, α is the sample thermal diffusivity of the multilayer material, is the temperature gradient of the multilayer material in the first direction, T is the temperature of the current position point of the multilayer material in the first direction, and the thermal wave velocity corresponds one-to-one to the position point of the multilayer material in the first direction;

[0044] According to the thermal wave velocity, a relationship between the thermal wave velocity and the propagation depth of the multilayer material in the first direction is obtained.

[0045] In a second aspect, the present invention provides a multilayer material measuring device, comprising:

[0046] A heating unit, the heating unit is used to emit a heat signal and use the heat signal to heat the multilayer material;

[0047] A sample chamber unit, the sample chamber unit being used to place the multilayer material;

[0048] A measuring unit, the measuring unit is used to measure temperature data of the multilayer material in a first direction;

[0049] A control processing unit, wherein the control processing unit is connected to the heating unit and the measuring unit respectively, and is used to obtain the temperature-propagation depth change relationship and the temperature-time change relationship of the multilayer material in the first direction, and calculate the thermal resistance-propagation depth change relationship and the thermal wave transfer characteristic-propagation depth change relationship according to the thermal signal, the temperature-propagation depth change relationship and the temperature-time change relationship, so as to obtain the thermal physical property parameters of the multilayer material and its interface.

[0050] Since the multi-layer material measuring device of the second aspect can execute any multi-layer material measuring method of the first aspect, it has all the beneficial effects of the first aspect of the present invention.

[0051] In a third aspect, the present invention provides a computer storage medium, comprising computer executable instructions stored therein, wherein the computer executable instructions are used to execute the multilayer material measurement method as described in any one of the first aspects.

[0052] Since the computer storage medium of the third aspect can execute any of the multi-layer material measurement methods of the first aspect, it has all the beneficial effects of the first aspect of the present invention.

[0053] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0055] Figure 1 is a structural block diagram of a multilayer material measuring device provided in an embodiment of the present application;

[0056] Figure 2 It is a diagram of the main steps of the multilayer material measurement method provided in an embodiment of the present application;

[0057] Figure 3 It is a step diagram of calculating the relationship between thermal resistance and propagation depth change of the multilayer material measurement method provided in the embodiment of the present application;

[0058] Figure 4 It is a step diagram of calculating the relationship between the thermal wave amplitude and the propagation depth change of the multilayer material measurement method provided in the embodiment of the present application;

[0059] Figure 5 It is a step diagram of calculating the relationship between the thermal wave phase and the propagation depth change of the multilayer material measurement method provided in the embodiment of the present application;

[0060] Figure 6 It is a step diagram of the relationship between the DC sub-item of the thermal wave temperature and the propagation depth change of the multilayer material measurement method provided in the embodiment of the present application;

[0061] Figure 7 is a step diagram of the relationship between the thermal wave velocity and the propagation depth change of the multilayer material measurement method provided in an embodiment of the present application;

[0062] Figure 8 is another step diagram of the relationship between the thermal wave velocity and the propagation depth change of the multilayer material measurement method provided in an embodiment of the present application;

[0063] Fig. 9 is a schematic structural diagram of a multilayer material measuring device provided in an embodiment of the present application;

[0064] Fig.10 is a schematic diagram of the relationship between thermal resistance and propagation depth provided in an embodiment of the present application;

[0065] Fig.11 It is a schematic diagram of the relationship between the thermal wave amplitude and the propagation depth provided in the embodiment of the present application;

[0066] Fig.12 It is a schematic diagram of the relationship between the thermal wave phase and the propagation depth provided in the embodiment of the present application;

[0067] Fig.13 It is a schematic diagram of the relationship between the DC sub-item of the thermal wave temperature and the propagation depth provided in the embodiment of the present application;

[0068] Fig.14 It is a schematic diagram of the relationship between thermal wave velocity and propagation depth provided in an embodiment of the present application. DETAILED DESCRIPTION

[0069] In the following description, specific details such as specific system structures, technologies, etc. are proposed for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the embodiments of the present application can also 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 hindering the description of the embodiments of the present application.

[0070] It should be noted that although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that in the flowchart. The terms "first", "second", etc. in the specification, claims and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0071] It should also be understood that the references to "one embodiment" or "some embodiments" described in the specification of the embodiments of the present application mean that one or more embodiments of the embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Thus, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0072] With the increasing development of multilayer materials, they have been used in more and more applications. At the same time, with the development of microelectronics technology, electronic components are changing towards thin, light, small and multifunctional, and the assembly density of components is getting higher and higher. The heat dissipation of power devices has become a prominent problem. Multilayer materials have become a key link in solving the heat dissipation problem of electronic devices in the future. When researchers synthesize multilayer materials, how to accurately measure the relevant parameters of multilayer materials is crucial.

[0073] In the related technologies, the measurement research of the related parameters of multilayer materials is mainly based on theoretical and simulation research, and there is almost no related experimental research. In addition, the interface thermal resistance measurement method of multilayer materials and the transmission mechanism of heat waves between multilayer materials are unclear, and there is no effective measurement equipment. It is difficult to accurately obtain the interface thermal resistance of multilayer materials and the transmission characteristics of heat waves at the interface of multilayer materials, which is not conducive to the later application of multilayer materials.

[0074] Based on this, the embodiments of the present application provide a multilayer material measurement method, device and storage medium. The embodiments of the present application study the amplitude, phase and DC temperature sub-item variation law of a given thermal signal in a multilayer material based on microscopic infrared imaging technology, and analyze the interfacial thermal resistance in the multilayer material and the transmission characteristics of the thermal wave at the interface of the multilayer material, wherein the thermal wave is an AC signal obtained when the thermal signal is transmitted in the multilayer material.

[0075] The embodiments of the present application are further described below in conjunction with the accompanying drawings.

[0076] Reference Figure 1 , Figure 1 : is a structural block diagram of a multilayer material measuring device provided in an embodiment of the present application. The multilayer material measuring device provided in an embodiment of the present application comprises a sample chamber unit, a heating unit, a measuring unit and a control processing unit.

[0077] The heating unit is in communication connection with the control processing unit. According to the control signal sent from the control processing unit, the heating unit transmits a heat signal to the multilayer material in the sample cavity unit and heats the upper surface of the multilayer material using the heat signal.

[0078] It should be noted that the heating unit includes a laser heater and a signal generator. The signal generator is used to transmit a signal, and the laser heater is used to heat the signal transmitted by the signal generator, so that the heating unit can transmit a heat signal.

[0079] The sample chamber unit is used to place multiple layers of material.

[0080] It should be noted that the sample chamber unit includes a vacuum chamber and a heat sink. The vacuum chamber is used to place the multilayer material, and the multilayer material is placed on the upper surface of the heat sink. The multilayer material is placed in the vacuum chamber, which can effectively avoid the measurement data error due to environmental influences. The temperature of the heat sink does not change with the amount of heat energy transferred to it, which means that the performance of the heat sink is stable and can keep the bottom surface temperature of the multilayer composite material constant to reduce the influence of the external ambient temperature.

[0081] It should be noted that the surface of the multi-layer material is treated with black paint to reduce measurement errors caused by problems such as light reflection.

[0082] The measuring unit is in communication connection with the control unit, and is used for measuring the temperature data of the multilayer material in the sample cavity in a first direction, and sending the relevant data to the control processing unit for processing.

[0083] It should be noted that the temperature data measured by the measuring unit includes the temperature-propagation depth variation relationship and the temperature-time variation relationship of the multi-layer material in the first direction.

[0084] It should be noted that the measuring unit includes an infrared probe, an optical power meter and a high-speed infrared thermal imager. The infrared probe, the optical power meter and the high-speed infrared thermal imager are combined with each other to measure the temperature of the multilayer material.

[0085] The control processing unit is communicatively connected with the heating unit and the measuring unit respectively. The control processing unit can control the heating unit to send a heat signal to pass through the multilayer material along a first direction, and process the temperature data from the measuring unit to obtain the interface thermal resistance of the multilayer material and the transmission characteristics of the heat wave at the interface of the multilayer material, and the heat wave is an AC signal obtained when the heat signal is transmitted in the multilayer material.

[0086] In some embodiments, reference Fig. 9 , Fig. 9 It is a structural schematic diagram of a multilayer material measuring device provided in an embodiment of the present application. The multilayer material measuring device provided in an embodiment of the present application includes a sample chamber unit, a heating unit, a measuring unit and a control processing unit, wherein the sample chamber unit includes a vacuum chamber and a heat sink, the multilayer material is placed on the heat sink in the vacuum chamber, the heating unit is arranged outside the sample chamber unit, and the heating unit is arranged directly above the multilayer material, so that the heat signal sent by the heating unit can pass through the multilayer material in a vertical direction, the measuring unit is also located outside the sample chamber unit, and the measuring unit is used to measure the temperature data of the multilayer material in the sample chamber in a first direction, that is, the temperature distribution information of the multilayer material. The control processing unit processes the temperature data from the measuring unit to obtain the interface thermal resistance of the multilayer material and the transmission characteristics of the heat wave at the interface of the multilayer material.

[0087] The devices and application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of the system architecture and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0088] It can be understood by those skilled in the art that Figure 1 The device structure shown in the figure does not constitute a limitation on the embodiments of the present application, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0089] exist Figure 1 In the device structure shown, each module can call its stored multi-layer material measurement program to execute a multi-layer material measurement method.

[0090] Based on the above device, various embodiments of the multilayer material measurement method of the embodiment of the present application are proposed.

[0091] Reference Figure 2 , Figure 2 The main steps of the multilayer material measurement method provided in the embodiment of the present application are shown in the figure. The multilayer material measurement method provided in the embodiment of the present application includes but is not limited to the following steps:

[0092] Step S100: Acquire a thermal signal, and control the thermal signal to pass through a multilayer material along a first direction, wherein the multilayer material has a plurality of sublayers stacked in a stacked arrangement.

[0093] It should be noted that the first direction is a direction perpendicular to the multilayer material, and the thermal signal passes through the multilayer material along the first direction, that is, the thermal signal passes through the multiple sublayers of the stacked arrangement in sequence along the direction perpendicular to the multilayer material.

[0094] It should be noted that the number of layers of the multilayer material can be two layers, three layers, etc., and the embodiment of the present application does not limit the number of sub-layers in the multilayer material.

[0095] It should be noted that the thermal signal is a signal emitted by the heating unit.

[0096] In some embodiments, two iron sheets with a size of 10 mm×10 mm×2 mm are used as the multilayer material, and the thermal conductivity of the multilayer material is 14.04 W / m·K. The thermal signal is a sinusoidal signal with an amplitude of 10.02 W and a frequency of 0.1 Hz. Then, the expression of the thermal signal is:

[0097] q=Asin(2πft)=10.02sin(0.2πt)

[0098] Among them, q is the thermal signal, A is the amplitude or magnitude of the thermal signal, f is the frequency of the thermal signal, π is pi, t is time, and the unit of time is second.

[0099] Step S200, obtaining a temperature-propagation depth variation relationship and a temperature-time variation relationship of a multilayer material in a first direction.

[0100] Step S300, calculating the thermal resistance-propagation depth change relationship according to the thermal signal, the temperature-propagation depth change relationship and the temperature-time change relationship.

[0101] Step S400, calculating the thermal wave transfer characteristic-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship.

[0102] It should be noted that the thermal wave is an AC signal obtained when a thermal signal is transmitted in a multilayer material.

[0103] Step S500, according to the relationship between thermal resistance and propagation depth change and the relationship between thermal wave transfer characteristics and propagation depth change, the interface thermal resistance of the multilayer material and the transfer characteristics of the thermal wave at the interface of the multilayer material are obtained.

[0104] It should be noted that the thermal wave is an AC signal obtained when a thermal signal is transmitted in a multilayer material.

[0105] In some embodiments, the interface thermal resistance between the multilayer materials is much greater than the thermal resistance of the sublayers on both sides thereof, and various characteristics of the thermal wave drop sharply at the interface of the multilayer materials, and the related data after the drop are maintained in the next sublayer material.

[0106] It should be noted that the multilayer material measurement method provided in the embodiment of the present application controls the thermal signal to pass through the multilayer material along the first direction, so that the temperature of the multilayer material changes, and obtains the temperature-propagation depth change relationship and the temperature-time change relationship of the multilayer material in the first direction, and further calculates the thermal resistance-propagation depth change relationship and the heat transfer characteristic-propagation depth change relationship through the temperature change relationship with the propagation depth and time. Based on this, the thermal resistance and the transfer characteristics of the heat wave in the multilayer material can be obtained, and the interface thermal resistance of the multilayer material and the transfer characteristics of the heat wave at the interface of the multilayer material can be obtained by one-step analysis, so that users can better understand the relevant parameters of the multilayer material, which is convenient for the later application of the multilayer material.

[0107] It is understandable that, referring to Figure 3 , Figure 3 1 is a step diagram of calculating the relationship between thermal resistance and propagation depth change of the multilayer material measurement method provided in the embodiment of the present application. Step S300 includes but is not limited to the following steps:

[0108] Step S310: Obtain the temperature difference between any two adjacent positions of the multilayer material in the first direction according to the temperature-propagation depth variation relationship.

[0109] It should be noted that the two adjacent positions of the multilayer material in the first direction are two position points of the multilayer material in the propagation direction.

[0110] It should be noted that when the distance between two adjacent position points is infinitely close to 0, the calculated thermal resistance of the middle point between the two adjacent position points is close to its actual thermal resistance value. Therefore, the above-mentioned arbitrary two adjacent position points represent two adjacent position points whose distance is infinitely close to 0.

[0111] It should be noted that the measuring device can obtain image or video data during the measuring process, and two adjacent position points of the multilayer material in the first direction can be obtained by selecting two adjacent pixel points in the image or video data.

[0112] Step S320: Obtain the thermal signal amplitude corresponding to the temperature change trend according to the thermal signal and the temperature-time change relationship.

[0113] Step S330, calculating the quotient of each temperature difference and the corresponding thermal signal amplitude to obtain a thermal resistance corresponding to a first position one by one, wherein the first position is a middle point between two adjacent position points corresponding to the temperature difference.

[0114] Step S340: Obtain a relationship between thermal resistance and propagation depth of the multilayer material in the first direction according to the multiple thermal resistances and the corresponding first positions.

[0115] It should be noted that by calculating the thermal resistance of all positions of the multilayer material in the first direction, the thermal resistance-propagation depth variation relationship of the multilayer material in the first direction is obtained. When more positions are obtained for the multilayer material in the first direction, the obtained thermal resistance-propagation depth variation relationship is closer to the actual variation relationship.

[0116] It should be noted that, to calculate the relationship between the thermal resistance and the propagation depth of the multilayer material in the first direction, the relationship between the temperature difference between two adjacent positions and the depth can be calculated first, and then the thermal resistance and the propagation depth can be obtained by calculating the quotient of the temperature difference and the thermal signal amplitude.

[0117] It should be noted that, to calculate the relationship between the thermal resistance and the propagation depth of the multilayer material in the first direction, the thermal resistance corresponding to each position point of the multilayer material in the first direction may be calculated first, so as to fit the relationship between the thermal resistance and the propagation depth.

[0118] It should be noted that the calculation relationship of the thermal resistance of the multilayer material in the first direction is:

[0119]

[0120] Wherein, R is thermal resistance, ΔT is the temperature difference between two adjacent points of the multilayer material in the first direction, and |q| is the amplitude of the thermal signal applied to the multilayer material, and its unit is W.

[0121] It should be noted that, refer to Fig.10 , Fig.10 The figure is a schematic diagram of the relationship between thermal resistance and propagation depth provided in the embodiment of the present application. The horizontal axis of the coordinate in the thermal resistance-propagation depth change relationship diagram is the propagation depth, whose unit is mm, and the vertical axis is the thermal resistance, whose unit is k·m. 2 / W. According to the schematic diagram of the relationship between thermal resistance and propagation depth, it can be obtained that for a multilayer material with two iron sheets of 10mm×10mm×2mm in size, the thermal resistance of each sub-layer remains basically unchanged with the propagation depth, and the thermal resistance of the first sub-layer is 5.81×10 -6 k·m 2 / W, the thermal resistance of the second sub-layer is 6.00×10 -6 k·m 2 / W, the thermal resistance at the interface of the multilayer material increases sharply, and its thermal resistance increases by 244.84% compared with the first sub-layer. In addition, the interface thermal resistance of the multilayer material is calculated to be 5.19×10 -5 k·m 2 / W.

[0122] It should be noted that according to the multilayer material testing method of the embodiment of the present application, the interfacial thermal resistance of the multilayer material is greater than the thermal resistance of each sublayer in the multilayer material. The properties of the interfacial thermal resistance of the multilayer material obtained can provide a deeper understanding of the multilayer material and facilitate the application of the multilayer material.

[0123] It can be understood that the thermal wave transfer characteristics include at least one of the following thermal wave transfer characteristics: thermal wave amplitude, thermal wave phase, thermal wave temperature DC component, and thermal wave velocity.

[0124] It is understandable that, referring to Figure 4 , Figure 4 1 is a diagram of the steps of calculating the relationship between the thermal wave amplitude and the propagation depth change of the multilayer material measurement method provided in the embodiment of the present application. The method of calculating the relationship between the thermal wave amplitude and the propagation depth change includes but is not limited to the following steps:

[0125] Step S411, according to the temperature-propagation depth change relationship and the temperature-time change relationship, the thermal wave relationship is obtained, wherein the thermal wave relationship is:

[0126]

[0127] Where T(·) represents the thermal wave, x is the propagation depth of the thermal wave in the multilayer material, t is the propagation time of the thermal wave in the multilayer material, j0 is the initial amplitude of the thermal signal, ω is the angular frequency of the thermal signal, and C v is the constant heat capacity of the multilayer material, α is the sample thermal diffusivity of the multilayer material, and

[0128] Step S412: According to the relationship of thermal waves, the relationship between the thermal wave amplitude and the propagation depth is obtained, wherein the relationship between the thermal wave amplitude and the propagation depth can be expressed as:

[0129]

[0130] Where A(·) represents the thermal wave amplitude.

[0131] It should be noted that, refer to Fig.11 , Fig.11 : is a schematic diagram of the relationship between the thermal wave amplitude and the propagation depth provided by the embodiment of the present application. The horizontal axis of the coordinate axis of the schematic diagram of the relationship between the thermal wave amplitude and the propagation depth is the propagation depth, and its unit is mm, and the vertical axis of the coordinate axis is the thermal wave amplitude, and the unit of the thermal wave amplitude is W. Fig.11 It can be seen that the thermal wave amplitude decays with the increase of propagation depth and finally tends to be stable. After the thermal wave passes through the interface of the multilayer material, the thermal wave amplitude decays sharply, and the attenuation ratio is 45.69%.

[0132] It is understandable that, referring to Figure 5 , Figure 5 1 is a diagram of the steps of calculating the relationship between the phase of a thermal wave and the change in the propagation depth of a multilayer material measurement method provided in an embodiment of the present application. The method of calculating the relationship between the phase of a thermal wave and the change in the propagation depth includes but is not limited to the following steps:

[0133] Step S421, obtaining a thermal wave relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship, wherein the thermal wave relationship is used to characterize the relationship between the thermal wave and the propagation depth and time.

[0134] It should be noted that the relationship between popularity can be expressed as:

[0135]

[0136] Where T(·) represents the thermal wave, x is the propagation depth of the thermal wave in the multilayer material, t is the propagation time of the thermal wave in the multilayer material, j0 is the initial amplitude of the thermal signal, ω is the angular frequency of the thermal signal, and C v is the constant heat capacity of the multilayer material, α is the sample thermal diffusivity of the multilayer material, and

[0137] Step S422: Obtain multiple thermal wave phases according to the thermal wave relationship, wherein the thermal wave phases correspond to the propagation depths one by one.

[0138] It should be noted that the calculation of the thermal wave phase of the multilayer material at any point in the first direction can be expressed by the following formula:

[0139]

[0140] in, Expressed as the thermal wave phase.

[0141] Step S423: Obtain a thermal wave phase-propagation depth variation relationship according to a plurality of thermal wave phases and corresponding propagation depths.

[0142] It should be noted that, refer to Fig.12 , Fig.12 Schematic diagram of the relationship between the thermal wave phase and the propagation depth provided by the embodiment of the present application. The horizontal axis of the coordinate diagram of the relationship between the thermal wave phase and the propagation depth is the propagation depth, and its unit is mm, and the vertical axis is the thermal wave phase, and the thermal wave phase unit is °. Fig.12It can be seen that the thermal wave phase decays with the increase of propagation depth, and after the thermal wave passes through the interface of the multilayer material, the thermal wave phase decays sharply, with an attenuation ratio of 6.06%.

[0143] It is understandable that, referring to Figure 6 , Figure 6 The method for calculating the relationship between the DC sub-item of the thermal wave temperature and the change in the propagation depth of the multilayer material measurement method provided in the embodiment of the present application includes but is not limited to the following steps:

[0144] Step S431, obtaining a thermal wave relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship, wherein the thermal wave relationship is used to characterize the relationship between the thermal wave and the propagation depth and time.

[0145] It should be noted that the relationship between popularity can be expressed as:

[0146]

[0147] Where T(·) represents the thermal wave, x is the propagation depth of the thermal wave in the multilayer material, t is the propagation time of the thermal wave in the multilayer material, j0 is the initial amplitude of the thermal signal, ω is the angular frequency of the thermal signal, and C v is the constant heat capacity of the multilayer material, α is the sample thermal diffusivity of the multilayer material, and

[0148] Step S432: obtaining a plurality of direct current components of the thermal waves according to the relationship between the thermal waves, wherein the direct current components of the thermal waves correspond one to one with the propagation depths.

[0149] It should be noted that the DC component of the thermal wave is the average value of the thermal wave. The calculation of the DC component of the thermal wave at any point in the first direction of the multilayer material can be expressed by the following formula:

[0150]

[0151] Among them, f D is the DC component of the thermal wave, T is time, and T(t) is the relationship between the thermal wave and time at the current position of the multilayer material in the first direction.

[0152] Step S433: obtaining a thermal wave temperature DC component-propagation depth variation relationship according to the DC components of the plurality of thermal waves and the corresponding propagation depths.

[0153] It should be noted that, refer to Fig.13 , Fig.13: This is a schematic diagram of the relationship between the thermal wave temperature DC sub-item and the propagation depth provided by the embodiment of the present application. The horizontal axis of the schematic diagram of the relationship between the thermal wave phase and the thermal wave temperature DC sub-item is the propagation depth, the unit is mm, and the vertical axis is the thermal wave temperature DC sub-item, and the thermal wave phase unit is °C. Fig.13 It can be seen that the DC component of the thermal wave temperature decays with the increase of the propagation depth, and after the thermal wave passes through the interface of the multilayer material, the DC component of the thermal wave temperature decays sharply, with an attenuation ratio of 7.3%.

[0154] It is understandable that, referring to Figure 7 , Figure 7 The following is a step diagram of the relationship between the thermal wave velocity and the propagation depth of a multilayer material measurement method provided in an embodiment of the present application. The method steps for calculating the relationship between the thermal wave velocity and the propagation depth include but are not limited to the following steps:

[0155] Step S441, obtaining the position distance between any two adjacent position points of the multilayer material in the first direction.

[0156] It should be noted that the two adjacent positions of the multilayer material in the first direction are two position points of the multilayer material in the propagation direction.

[0157] It should be noted that when the distance between two adjacent position points is infinitely close to 0, the calculated thermal resistance of the middle point between the two adjacent position points is close to its actual thermal resistance value. Therefore, the above-mentioned arbitrary two adjacent position points represent two adjacent position points whose distance is infinitely close to 0.

[0158] It should be noted that the measuring device can obtain image or video data during the measuring process, and two adjacent position points of the multilayer material in the first direction can be obtained by selecting two adjacent pixel points in the image or video data.

[0159] Step S442: Obtain the initial temperature response time difference corresponding to each position distance.

[0160] It should be noted that the initial temperature response time difference is the time difference between the temperatures of two adjacent points corresponding to the position distance that change for the first time due to the transmission of the heat wave.

[0161] Step S443, calculating the quotient of each position distance and the initial response temperature time difference to obtain the thermal wave velocity corresponding to the second position, wherein the second position is the middle point between two adjacent position points corresponding to the corresponding position distance.

[0162] Step S444: Obtain a thermal wave velocity-propagation depth variation relationship of the multilayer material in the first direction according to the multiple thermal wave velocities and the corresponding second positions.

[0163] It should be noted that the calculation relationship of the thermal wave velocity of the midpoint between two adjacent positions is as follows:

[0164]

[0165] Among them, v is the thermal wave velocity, L is the distance between two adjacent positions of the multilayer material in the first direction, the unit is mm, and Δt is the initial temperature response time difference between the two adjacent positions at present, the unit is s.

[0166] It is understandable that, referring to Figure 8 , Figure 8 This is another step diagram of the relationship between the thermal wave velocity and the propagation depth of the multilayer material measurement method provided in the embodiment of the present application. The method steps for calculating the relationship between the thermal wave velocity and the propagation depth include but are not limited to the following steps:

[0167] Step S451, obtaining the temperature gradient of the multilayer material in the first direction according to the temperature-propagation depth variation relationship.

[0168] Step S452: Obtain the temperature of any position point of the multilayer material in the first direction according to the temperature-propagation depth variation relationship.

[0169] Step S453: Calculate the thermal wave velocity of the multilayer material at the current position according to the temperature gradient of the multilayer material in the first direction and the temperature at any position, wherein the thermal wave velocity can be expressed as:

[0170]

[0171] Where v is the thermal wave velocity, J T is the heat flux, Q v is the heat capacity density, λ is the thermal conductivity of the multilayer material, ρ is the density of the multilayer material, C v is the constant heat capacity of the multilayer material, α is the sample thermal diffusivity of the multilayer material, is the temperature gradient of the multilayer material in the first direction, T is the temperature of the current position of the multilayer material in the first direction, and the thermal wave velocity corresponds one-to-one to the position of the multilayer material in the first direction.

[0172] Step S454: Obtain the relationship between the thermal wave velocity and the propagation depth of the multilayer material in the first direction according to the thermal wave velocity.

[0173] It should be noted that, refer to Fig.14 , Fig.14 This is a schematic diagram of the relationship between the thermal wave velocity and the propagation depth provided in the embodiment of the present application. The horizontal axis of the schematic diagram of the relationship between the thermal wave velocity and the thermal wave temperature DC sub-item is the propagation depth, the unit is mm, the vertical axis is the thermal wave velocity, and the thermal wave phase unit is mm / s. Fig.14 V-formula is the curve obtained by fitting the relationship between thermal wave velocity and propagation depth through steps S451 to S454, and V-real is the curve of thermal wave velocity and propagation depth obtained through steps S441 to S444. V-formula is closer to the data obtained through public fitting, while the processing of V-real related data is simpler and closer to the real data. Fig.14 It can be seen that the relationship between the thermal wave velocity and propagation depth obtained by the V-formula and V-real methods is not much different, and the two are quite consistent. In addition, the propagation speed of thermal waves at the interface of multilayer materials is faster than that in the sublayer.

[0174] The interfacial thermal resistance of the multilayer material obtained by the multilayer material measurement method provided in the embodiment of the present application is much higher than the thermal resistance of the sublayers on both sides. The heat wave is an AC signal, and its transmission characteristics at the interface of the multilayer material are: the amplitude, phase, and DC term temperature of the heat wave decay with the increase of the propagation depth; after passing through the interface, the amplitude, phase, and DC term temperature of the thermal signal are greatly attenuated. The propagation speed of the heat wave at the interface of the multilayer material is faster than the propagation speed in the sublayer, and the heat wave speeds obtained by the two methods of step S451 to step S454 and step S441 to step S444 are not much different.

[0175] In addition, the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the multilayer material measuring method of steps S100 to S500 is performed.

[0176] The processor and the memory may be connected via a bus or other means.

[0177] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0178] The non-transient software program and instructions required to implement the multi-layer material measurement method of the above embodiment are stored in the memory. When executed by the processor, the multi-layer material measurement method of the above embodiment is executed, for example, the above described multi-layer material measurement method is executed. Figure 2 Method steps S100 to S500 in.

[0179] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0180] In addition, one embodiment of the present application also provides a computer-readable storage medium, which stores computer-executable instructions. The computer-executable instructions are executed by a processor or a controller, so that the processor can execute the multilayer material measurement method in the above embodiment, for example, to execute the above described Figure 2 Steps S100 to S500 of the method, Figure 3 Steps S310 to S340 of the method, Figure 4 Steps S411 to S412 of the method, Figure 5 Steps S421 and S423 of the method, Figure 6 Steps S431 to S433 of the method, Figure 7 Steps S441 to S444 of the method, Figure 8 Method steps S451 to S454.

[0181] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed method above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0182] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for measuring multi-layer materials, characterized in that: include: Acquire a thermal signal, and control the thermal signal to pass through the multilayer material along a first direction, wherein the multilayer material is provided with a plurality of sublayers arranged in a stacked manner; Acquire the temperature-propagation depth variation relationship and the temperature-time variation relationship of the multilayer material in the first direction; Calculating a thermal resistance-propagation depth change relationship according to the thermal signal, the temperature-propagation depth change relationship, and the temperature-time change relationship; Calculating the thermal wave transfer characteristic-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship; According to the relationship between the thermal resistance and the propagation depth, and the relationship between the thermal wave transfer characteristics and the propagation depth, the interface thermal resistance of the multilayer material and the transfer characteristics of the thermal wave at the interface of the multilayer material are obtained; Wherein, the thermal wave transfer characteristics include at least one of the following thermal wave transfer characteristics: thermal wave amplitude, thermal wave phase, thermal wave temperature DC sub-item, thermal wave velocity; The calculating the thermal resistance-propagation depth change relationship according to the thermal signal, the temperature-propagation depth change relationship and the temperature-time change relationship comprises: According to the temperature-propagation depth variation relationship, a temperature difference between any two adjacent positions of the multilayer material in the first direction is obtained; According to the thermal signal and the temperature-time variation relationship, a thermal signal amplitude corresponding to the temperature variation trend is obtained; Calculating the quotient of each temperature difference and the corresponding thermal signal amplitude to obtain a thermal resistance corresponding to a first position one by one, wherein the first position is a middle point between the two adjacent position points corresponding to the temperature difference; According to the plurality of thermal resistances and the corresponding first positions, a relationship between thermal resistance and propagation depth of the multilayer material in the first direction is obtained.

2. The multi-layer material measuring method according to claim 1, characterized in that: The calculating the relationship between the thermal wave amplitude and the propagation depth change according to the temperature-propagation depth change relationship and the temperature-time change relationship comprises: According to the temperature-propagation depth variation relationship and the temperature-time variation relationship, the relationship formula of the heat wave is obtained, wherein the relationship formula of the heat wave is: Wherein, T(·) represents the thermal wave, x is the propagation depth of the thermal wave in the multilayer material, t is the propagation time of the thermal wave in the multilayer material, j0 is the initial amplitude of the thermal signal, ω is the angular frequency of the thermal signal, C v is the constant heat capacity of the multilayer material, α is the sample thermal diffusivity of the multilayer material, and According to the relationship of the thermal wave, the relationship between the thermal wave amplitude and the propagation depth is obtained, wherein the relationship between the thermal wave amplitude and the propagation depth can be expressed as: Wherein, A(·) represents the thermal wave amplitude.

3. The multi-layer material measuring method according to claim 1, characterized in that: The calculating the thermal wave phase-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship comprises: According to the temperature-propagation depth variation relationship and the temperature-time variation relationship, a relational expression of the heat wave is obtained, wherein the relational expression of the heat wave is used to characterize the relationship between the heat wave and the propagation depth and time; According to the relationship of the thermal wave, a plurality of thermal wave phases are obtained, wherein the thermal wave phases correspond to the propagation depths one by one; According to the multiple thermal wave phases and the corresponding propagation depths, a thermal wave phase-propagation depth variation relationship is obtained.

4. The multi-layer material measuring method according to claim 1, characterized in that: The calculating the relationship between the thermal wave temperature DC sub-item and the propagation depth change according to the temperature-propagation depth change relationship and the temperature-time change relationship includes: According to the temperature-propagation depth variation relationship and the temperature-time variation relationship, a relational expression of the heat wave is obtained, wherein the relational expression of the heat wave is used to characterize the relationship between the heat wave and the propagation depth and time; According to the relationship of the thermal wave, a plurality of DC components of the thermal wave are obtained, wherein the DC components of the thermal wave correspond to the propagation depths one by one; According to the DC components of the plurality of thermal waves and the corresponding propagation depths, a variation relationship between the DC component of the thermal wave temperature and the propagation depth is obtained.

5. The multi-layer material measuring method according to claim 1, characterized in that: The calculating the thermal wave velocity-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship comprises: Obtaining the position distance between any two adjacent position points of the multilayer material in the first direction; Obtaining the initial temperature response time difference corresponding to each of the position distances; Calculate the quotient of each of the position distances and the initial response temperature time difference to obtain the thermal wave velocity corresponding to the second position, wherein the second position is the middle point between two adjacent position points corresponding to the corresponding position distance; According to the plurality of thermal wave velocities and the corresponding second positions, a relationship between the thermal wave velocity and the propagation depth of the multilayer material in the first direction is obtained.

6. The multi-layer material measuring method according to claim 1, characterized in that: The calculating the thermal wave velocity-propagation depth change relationship according to the temperature-propagation depth change relationship and the temperature-time change relationship comprises: According to the temperature-propagation depth variation relationship, a temperature gradient of the multilayer material in a first direction is obtained; According to the temperature-propagation depth variation relationship, the temperature of any position point of the multilayer material in the first direction is obtained; According to the temperature gradient of the multilayer material in the first direction and the temperature at any position, the thermal wave velocity of the multilayer material at the current position is calculated, wherein the thermal wave velocity can be expressed as: Where v is the thermal wave velocity, J T is the heat flux, Q v is the heat capacity density, λ is the thermal conductivity of the multilayer material, ρ is the density of the multilayer material, C v is the constant heat capacity of the multilayer material, α is the sample thermal diffusivity of the multilayer material, is the temperature gradient of the multilayer material in the first direction, T is the temperature of the current position point of the multilayer material in the first direction, and the thermal wave velocity corresponds one-to-one to the position point of the multilayer material in the first direction; According to the thermal wave velocity, a relationship between the thermal wave velocity and the propagation depth of the multilayer material in the first direction is obtained.

7. A multi-layer material measuring device, characterized in that: include: A heating unit, the heating unit is used to emit a heat signal and use the heat signal to heat the multilayer material; A sample chamber unit, the sample chamber unit being used to place the multilayer material; A measuring unit, the measuring unit is used to measure temperature data of the multilayer material in a first direction; a control processing unit, the control processing unit being connected to the heating unit and the measuring unit respectively, and being used to obtain the temperature-propagation depth variation relationship and the temperature-time variation relationship of the multilayer material in the first direction, and to calculate the thermal resistance-propagation depth variation relationship and the thermal wave transfer characteristic-propagation depth variation relationship according to the thermal signal, the temperature-propagation depth variation relationship and the temperature-time variation relationship, so as to obtain the thermal physical property parameters of the multilayer material and its interface; Wherein, the thermal wave transfer characteristics include at least one of the following thermal wave transfer characteristics: thermal wave amplitude, thermal wave phase, thermal wave temperature DC sub-item, thermal wave velocity; The calculating the thermal resistance-propagation depth change relationship according to the thermal signal, the temperature-propagation depth change relationship and the temperature-time change relationship comprises: According to the temperature-propagation depth variation relationship, a temperature difference between any two adjacent positions of the multilayer material in the first direction is obtained; According to the thermal signal and the temperature-time variation relationship, a thermal signal amplitude corresponding to the temperature variation trend is obtained; Calculating the quotient of each temperature difference and the corresponding thermal signal amplitude to obtain a thermal resistance corresponding to a first position one by one, wherein the first position is a middle point between the two adjacent position points corresponding to the temperature difference; According to the plurality of thermal resistances and the corresponding first positions, a relationship between thermal resistance and propagation depth of the multilayer material in the first direction is obtained.

8. A computer storage medium, characterized in that: The device comprises computer executable instructions stored therein, wherein the computer executable instructions are used to execute the multi-layer material measuring method according to any one of claims 1 to 6.

Images