A method and system for x-ray measurement of temperature distribution in a heating system

Abstract

The present application relates to a kind of X-ray measurement method and system of internal temperature distribution of heat generating system, provide a kind of heat generating system structure with temperature response measurement layer, the temperature response measurement layer is based on temperature response probe material composition, the material can form ordered structure with small angle X-ray diffraction signal, its cell parameter can be calibrated change with temperature, can be used as heat generating system internal temperature measurement probe, make the heat generating system while keeping original function, can read internal temperature information by external X-ray diffraction, further can be in the state of packaging or assembly, by X-ray diffraction reading the cell parameter of internal temperature response measurement layer, and reconstructs internal two-dimensional temperature distribution, to solve the problem that current contact type temperature measurement is difficult to obtain continuous internal temperature distribution, optical non-contact temperature measurement is difficult to penetrate package, electrical parameter temperature measurement is difficult to directly obtain spatial distribution.

Description

Technical Field

[0001] This invention relates to the field of temperature measurement technology, and in particular to an X-ray measurement method and system for the internal temperature distribution of a heating system. Background Technology

[0002] With the development of integrated circuits, power semiconductor devices, radio frequency devices, light-emitting devices, high-density electronic packaging, mechanical transmission systems, and energy storage devices, heat-generating systems, represented by packaged electronic devices, are increasingly operating under high power density, high integration, or complex heat dissipation boundary conditions. During operation, factors such as current concentration, localized resistive heating, carrier recombination, switching losses, mechanical friction, charge-discharge reactions, non-uniform thermal interfaces, and discontinuous heat dissipation paths can all lead to non-uniform temperature distributions within the system. For packaged electronic devices, localized hot spots often appear in the active region, gate edge, current-crowded regions, metal interconnects, solder joints, thermal interface materials, and locations where heat dissipation structures are discontinuous. For mechanical components, batteries, or other heat-generating systems, localized hot spots may appear at friction contact interfaces, electrode regions, interface layers, or localized heat transfer bottlenecks.

[0003] The internal temperature distribution of a heat-generating system directly affects its performance, reliability, and safe operating range. Taking electronic devices as an example, local overheating may lead to problems such as threshold voltage drift, increased on-resistance, increased leakage current, decreased luminous efficiency, accelerated electromigration, delamination of the package, solder fatigue, gate oxide degradation, and thermal runaway. Taking energy storage devices as an example, uneven internal temperature may induce local aging, capacity decay, and even safety risks. Therefore, accurately obtaining the internal temperature distribution of a heat-generating system under operating conditions, especially the hot spot location, peak temperature, and temperature change trend, is an important technical foundation for device design, packaging design, heat dissipation design, fault analysis, and reliability assessment. A review of literature in the field of power semiconductor device temperature measurement points out that junction temperature and thermal distribution information are of great significance for device thermal management, lifetime assessment, and failure analysis [1].

[0004] Existing methods for measuring the temperature distribution of heating systems can be broadly classified into three categories: contact temperature measurement, optical non-contact temperature measurement, and electrical parameter temperature measurement. Contact temperature measurement obtains the local temperature of the device surface, packaging structure, or several locations inside the system by directly or indirectly contacting the object under test with thermocouples, thermistors, thin-film resistance temperature detectors, temperature sensor arrays, flexible temperature sensors, or embedded fiber optic sensors. Optical non-contact temperature measurement obtains temperature information through optical signals such as infrared thermal radiation, reflectivity changes, Raman spectral changes, and fluorescence or phosphorescence signal changes. Electrical parameter temperature measurement uses temperature-sensitive electrical parameters in the heating system itself or the test structure, such as diode forward voltage drop, threshold voltage, on-resistance, leakage current, switching time, and voltage change slope, to deduce the temperature or equivalent junction temperature [1-9].

[0005] Each of the aforementioned methods has its applicable scope, but significant difficulties remain in measuring the internal temperature distribution under packaged or assembled conditions. Contact methods typically have limited measurement points, and sensor installation may alter local thermal boundary conditions; optical non-contact methods generally rely on surface optical signals, making it difficult to penetrate the package layer or opaque structures to directly read the internal temperature; electrical parameter methods can be used for online junction temperature estimation, but usually only provide single-point or equivalent temperature information, making it difficult to directly provide a complete two-dimensional internal temperature distribution. Therefore, how to obtain the internal two-dimensional temperature distribution of the heating system without opening or damaging its packaged / assembled state remains a problem that existing technologies need to solve.

[0006] Contact temperature measurement solution Contact temperature measurement solutions refer to directly attaching, pressing, soldering, embedding, or placing temperature-sensitive elements on heating systems, packages, circuit boards, heat dissipation structures, or test chips, obtaining temperature information through the electrical or optical response of the temperature-sensitive elements. Common contact temperature measurement elements include thermocouples, thermistors, platinum resistance thermometers, thin-film resistance temperature detectors, on-chip temperature sensor arrays, flexible temperature sensors, and fiber optic temperature sensors.

[0007] A typical approach involves attaching thermocouples or thermistors to the package housing, heat sink, printed circuit board (PCB), or critical areas. Thermocouples measure temperature by utilizing the relationship between the thermoelectric potential between different metal junctions and temperature; thermistors and platinum resistance thermometers measure temperature by utilizing the relationship between the resistance of materials and temperature. This method is simple in structure, low in cost, and uses universal testing equipment, making it suitable for engineering debugging, reliability testing, ambient temperature monitoring, and thermal structure evaluation. Its disadvantages are that the sensors can only measure the local temperature near their placement location, making it difficult to directly obtain a continuous temperature distribution; furthermore, the sensors, wires, adhesives, or solder joints themselves may alter the local heat conduction path, leading to deviations between the measured temperature and the actual internal temperature.

[0008] Another typical approach is to integrate a temperature sensor array into the test chip or package structure. This method can arrange resistive, diode, transistor or frequency-based temperature sensing units at multiple locations on the chip or substrate to obtain the temperature distribution of the device or package structure through multi-point temperature readings. Patent US6190040B1 discloses a sensor structure for semiconductor processing or temperature monitoring, which sets multiple temperature sensors, such as resistance temperature detectors, thermocouples or fiber optic sensors, on the substrate to obtain temperature information at different locations on the substrate

[10] . Patent US6180867B1 also discloses a thermal sensor array that can realize temperature detection through multiple sensing units and their interconnection structure

[11] .

[0009] For integrated circuits or system chips, on-chip sensor arrays can also be arranged inside the chip. Patent US7800879B2 discloses an on-chip sensor array for integrated circuit temperature management, which monitors the temperature status of different areas of the chip through multiple sensors and uses the measured temperature information for power management and thermal control

[12] . This type of solution can obtain local temperature information in real time during chip operation, which is suitable for dynamic thermal management and thermal protection; however, the number and position of sensors are fixed in the chip design stage, which cannot cover all potential hot spots, and the sensors themselves occupy chip area and wiring resources.

[0010] Overall, contact temperature measurement solutions are simple to implement, low in cost, and highly applicable to engineering, and can monitor temperature long-term within packages, PCBs, or heat dissipation structures. However, their main drawbacks are the limited number of measurement points, the contact thermal resistance between the sensor and the object being measured, the potential alteration of local heat dissipation conditions during installation, and the difficulty in directly obtaining the complete temperature distribution of critical areas within the heat-generating system.

[0011] Optical non-contact temperature measurement solution Optical non-contact temperature measurement refers to obtaining temperature information without direct contact with the heated system being measured. Instead, it involves collecting data on changes in the system's emitted thermal radiation, reflected light, scattered spectrum, or emission signals. Common methods include infrared thermography, thermal reflection microscopy, Raman spectroscopy, and fluorescence / phosphorescence thermography.

[0012] Infrared thermal imaging is one of the most widely used optical non-contact temperature measurement methods. Its basic principle is that the infrared radiation intensity of the surface of the object being measured is related to the temperature. The infrared thermal imager detects the infrared radiation on the target surface and, in combination with the target emissivity, ambient temperature and system calibration parameters, converts the infrared signal into a temperature image. This method is suitable for measuring the surface temperature distribution of objects such as PCBs, packaged devices, power modules, heat sinks, and LED modules. Usamentiaga et al. gave a systematic review of infrared thermal imaging technology and pointed out that infrared thermal imaging is a non-contact temperature measurement and non-destructive testing method, but its quantitative measurement needs to consider factors such as emissivity, environmental reflection and system calibration [2].

[0013] For heating systems, the emissivity of areas such as metal electrodes, pads, packaging materials and passivation layers varies greatly, so infrared thermography often requires emissivity correction. Vellvehi et al. studied the problem of infrared thermography emissivity correction in electronic applications and pointed out that when the surface being measured cannot deposit a coating with a known emissivity, emissivity correction will become a key factor limiting the accuracy of temperature measurement [3]. Patent WO2004097389A3 discloses a quantitative thermal imaging system, which sets a reference source with a known temperature and a known emissivity in the field of view of the thermal imager and uses the reference source to generate a calibration temperature map, which reflects the technical route of correction by reference source in infrared quantitative thermography

[13] .

[0014] Thermal reflection microscopy is another important type of optical non-contact temperature measurement method. This method utilizes the property that the reflectivity of a material changes with temperature, and obtains the temperature change by measuring the change in the intensity of reflected light on the surface. Its basic relationship can be expressed as ΔR / R = C_TR·ΔT, where R is the reflectivity, ΔR is the reflectivity change, C_TR is the thermal reflection coefficient, and ΔT is the temperature change. Yuan et al. reviewed the application of thermal reflection technology in the temperature characterization of wide bandgap semiconductor materials and devices, and pointed out that thermal reflection thermal imaging has become an important means of thermal characterization of semiconductor devices [4]. Patent US7173245B2 discloses an AC-coupled thermal reflection imaging method that can be used for thermal detection of integrated circuits [5]; Patent US10139284B2 discloses a device and method for obtaining the temperature distribution of a sample through reflection signal, bias modulation and frequency domain analysis [6].

[0015] Raman spectroscopy thermometry utilizes the relationship between the Raman peak position, peak width, or Stokes / anti-Stokes peak intensity ratio of a material and temperature. For materials with distinct Raman characteristic peaks, such as Si, GaN, SiC, Ga2O3, diamond, and two-dimensional materials, Raman thermometry can be used to obtain the local temperature of the material. Xu et al. reviewed Raman-based micro-nano scale thermal transport characterization methods, pointing out that Raman peak position, peak width, and intensity can all be used as temperature detection indicators, but issues such as laser self-heating, material absorption, and temperature coefficient calibration need to be considered [7]. Boussekri et al. further pointed out that Raman thermometry is suitable for thermal characterization of semiconductor power devices, but if the active region is covered by metal or is optically inaccessible, traditional Raman methods will be limited [8].

[0016] Fluorescence or phosphorescence thermometry utilizes the characteristics of temperature-sensitive luminescent materials, such as the intensity, lifetime, peak position, or intensity ratio of the light emission, to measure the temperature. For light-emitting devices such as LEDs, the temperature can be estimated by utilizing the changes in the emission spectrum of the device itself. For non-luminescent and heat-generating systems, temperature-sensitive fluorescent or phosphorescent materials can be coated on the surface, and the emission images can be acquired by a camera and converted into temperature distribution. Patent US20220214221A1 discloses a phosphorescence thermometry imaging system that performs two-dimensional thermal imaging of the phosphorescent coating surface using an illumination system and a high-speed camera [9]. This type of method can obtain surface temperature maps, but usually requires the introduction of a temperature-sensitive coating, which may change the thermal boundary conditions of the measured surface.

[0017] In general, optical non-contact temperature measurement solutions eliminate the need for contact sensors at the measurement location, reducing the disturbance to the thermal state caused by sensor installation and providing temperature images of surfaces or localized areas. However, most optical methods can only measure the temperature of optically visible areas or surfaces; infrared thermometry is significantly affected by emissivity, thermal reflection thermometry requires thermal reflectance calibration, Raman thermometry is limited by the Raman signal of the material and metal obstruction, and fluorescence / phosphorescence thermometry typically requires additional coatings. Therefore, for hot spots inside packages or obscured by opaque structures, optical non-contact methods often struggle to directly obtain the true internal temperature.

[0018] Electrical parameter temperature measurement scheme Electrical parameter temperature measurement schemes refer to using temperature-sensitive electrical parameters in the heating system itself or in a specially tested structure to estimate the temperature. This type of method is particularly suitable for estimating junction temperature in power semiconductor devices, packaged devices and actual working circuits. Commonly used temperature-sensitive electrical parameters include forward voltage drop of PN junction or body diode, base-emitter voltage of BJT, threshold voltage of MOSFET, on-resistance, saturation voltage drop, leakage current, gate resistance, switching delay time, rate of change of current, rate of change of voltage, etc. Avenas et al. systematically reviewed the temperature-sensitive electrical parameter measurement methods for power semiconductor devices, pointing out that different electrical parameters have differences in sensitivity, linearity, measurability, applicable device types and calibration requirements [1].

[0019] A typical approach is to use the forward voltage drop of a diode to measure the junction temperature. Under a certain forward current, the forward voltage drop of a PN junction decreases as the temperature increases. Therefore, the junction temperature can be deduced from the forward voltage drop in actual testing by pre-calibrating the relationship between the forward voltage drop and the temperature. Patent US20130257329A1 discloses a power MOSFET junction temperature measurement scheme, in which the MOSFET and the diode used to measure the junction temperature are disposed on the same semiconductor substrate. The MOSFET junction temperature can be determined by applying a constant forward current to the diode and measuring the forward voltage, or by keeping the forward voltage constant and measuring the forward current

[14] .

[0020] Another typical approach is to measure the temperature by utilizing the characteristics of the threshold voltage, on-resistance, or saturation voltage drop of a MOSFET or IGBT as a function of temperature. For example, the on-resistance of a MOSFET usually increases with temperature. The on-resistance can be calculated by measuring the voltage and current in the on-state, and then the device temperature can be estimated by combining the calibration curve. For IGBTs, the junction temperature can be estimated by using the relationship between the collector-emitter saturation voltage drop and temperature. The advantage of this method is that it can be measured using the device's own electrical characteristics without the need for additional optical channels or external temperature sensors; however, its electrical parameters are affected by current, voltage, aging, parasitic parameters, and driving conditions, and usually require strict calibration and compensation [1].

[0021] Another approach is to estimate the junction temperature using transient switching parameters during device operation. Patent US10890493B2 discloses a system and method for measuring junction temperature during transistor operation, which determines the transistor junction temperature by measuring the load current and the voltage transition slope during transistor turn-off by a processing unit

[15] . This type of method is beneficial for online temperature monitoring under actual switching conditions, but it requires accurate extraction of temperature-related parameters from complex circuit waveforms and elimination of interference from factors such as parasitic inductance, capacitance, driving conditions, and load changes.

[0022] In order to obtain temperature distribution from finite electrical measurement information, existing technologies often combine thermal models, finite element calculations, thermal resistance networks, or inversion algorithms. Patent US20080026493A1 discloses a method for predicting the temperature and power map of an integrated circuit, which uses the thermal diffusion function to convolve with the power matrix to calculate the steady-state or transient temperature distribution on the surface of the integrated circuit

[16] . Patent CN103852181A discloses a method for measuring the peak junction temperature distribution of a MOSFET device, which collects temperature-sensitive parameters corresponding to multiple constant current pulses, establishes a family of three-dimensional curves of current-temperature-sensitive parameters-temperature, and thus obtains junction temperature information corresponding to different effective areas

[17] . This type of scheme shows that electrical parameter temperature measurement itself usually obtains local or equivalent temperature information. To obtain a more complete temperature distribution, it is often necessary to combine it with model inversion.

[0023] In general, electrical parameter temperature measurement methods are suitable for packaged devices, actual operating circuits, and online monitoring scenarios, as they do not require opening the package or establishing an optical path. They are particularly suitable for junction temperature estimation and thermal protection control of power devices. However, their shortcomings are that electrical parameters are usually not only affected by temperature, but also by operating current, voltage, device aging, batch differences, and circuit parasitic parameters. At the same time, electrical parameter methods usually obtain junction temperature, average temperature, or a few equivalent temperature information. To obtain a complete temperature distribution, it is still necessary to rely on multiple measurement points, specialized test structures, or thermal model inversion.

[0024] Existing techniques for temperature characterization based on X-ray diffraction Besides contact temperature measurement, optical non-contact temperature measurement, and electrical parameter temperature measurement, existing technologies also include methods for temperature characterization or temperature-dependent structural characterization using X-ray diffraction. The basic principle of these methods is that the lattice parameters, interplanar spacing, diffraction peak positions, or diffraction peak shapes of crystalline materials may change with temperature. Therefore, by measuring the material's structural parameters using X-ray diffraction and combining this with known thermal expansion relationships, lattice parameter-temperature calibration curves, or temperature-induced structural changes, the material's current temperature or the highest temperature it has experienced can be inferred.

[0025] For example, patent US5636258A discloses a method for in-situ non-contact temperature measurement using X-ray diffraction, which is mainly used for single-crystal semiconductor substrates such as Si, Ge or GaAs wafers. This method measures the lattice constant of the single-crystal semiconductor wafer and obtains the wafer temperature by utilizing the relationship between the lattice constant and temperature. Its core object is the lattice parameters of the semiconductor wafer itself, rather than setting additional temperature response probe materials inside the packaging or assembly structure; its measurement target is mainly the temperature of the wafer or substrate, rather than the two-dimensional temperature distribution inside the complex heating system

[18] .

[0026] For example, patent WO2018063788A1 discloses a method for measuring temperature in a high-temperature and high-pressure process or inside a high-pressure cavity. This method uses at least two material compounds to form a sample and performs high-temperature measurement based on the changes in diffraction patterns caused by the changes in the lattice parameters of the materials with temperature. This method shows that in environments where it is difficult to place conventional temperature sensors directly, temperature can be indirectly measured by changes in the lattice parameters of materials; however, its application scenarios are mainly for temperature measurement in high-temperature and high-pressure processes or inside high-pressure cavities, and not for two-dimensional scanning temperature measurement after pre-coating a temperature response layer inside heat-generating systems such as packaged electronic devices, mechanical components, or batteries

[19] .

[0027] Chinese patent CN109030544B discloses a method for measuring the highest temperature based on the change of lattice parameters of microcrystals. The method uses X-ray single crystal diffraction to detect the lattice parameters of microcrystals and obtains the highest temperature experienced by the object under test through temperature calibration curve. This technical route also utilizes the relationship between lattice parameters and temperature, but it is more inclined to record the highest temperature or characterize the temperature history, rather than reconstructing the in-situ two-dimensional temperature distribution under the working state of the heating system

[20] .

[0028] Chinese patent CN101598606B discloses a temperature measurement method using a neutron-irradiated silicon carbide crystal as a sensor. This method uses a neutron-irradiated 6H-SiC crystal as a temperature measuring crystal. After isochronous annealing, the full width at half maximum (FWHM) of the X-ray diffraction peaks is measured to establish the relationship between the FWHM and the temperature for temperature measurement. This method belongs to the crystal temperature sensor scheme, but it relies on the neutron-irradiated crystal and the change in diffraction peak shape after annealing. It mainly measures the temperature information experienced by a specific sensing crystal and does not involve reading the internal soft matter ordered structure coating using small-angle X-ray diffraction, nor does it involve the reconstruction of the two-dimensional temperature field in the packaged or assembled state

[21] .

[0029] There are also some existing technologies that mainly use X-ray diffraction for structural characterization of materials at different temperatures. For example, CN104730097B discloses an in-situ characterization method for the high-temperature lattice constant of ferrisite, which determines the lattice constant of ferrisite at high temperature by high-temperature in-situ X-ray diffraction characterization and data processing. This type of technology demonstrates that X-ray diffraction can be used to determine the high-temperature lattice constant and thermal expansion behavior of materials, but its purpose is mainly to characterize the structural parameters of materials, rather than to pre-set ordered structural materials as temperature response probes inside the heating system and measure the internal temperature distribution

[22] .

[0030] In summary, existing X-ray diffraction-based temperature characterization techniques have proven the fundamental principle that "lattice parameters or diffraction peak characteristics can be used for temperature characterization." However, existing methods typically measure the material being measured or the crystal itself, such as single-crystal semiconductor wafers, high-voltage cavity crystal materials, SiC thermometric crystals, or high-temperature structural materials. Most methods obtain information on single-point temperatures, average temperatures, maximum temperatures, or material structure changes with temperature, rather than the two-dimensional temperature distribution within the heating system. Existing methods generally do not involve pre-coating a temperature-responsive measurement layer on the area to be measured inside the heating system before packaging or assembly, nor do they utilize soft matter or organic molecules with self-assembled ordered structures, especially temperature-responsive probe materials with small-angle X-ray diffraction signals, to achieve internal temperature reconstruction in the packaged or assembled state.

[0031] The disadvantages of existing technologies are as follows: Existing contact, optical non-contact, and electrical parameter temperature measurement methods generally suffer from the problem of not being able to directly obtain the internal two-dimensional temperature distribution in the packaged or assembled state for internal heat-generating systems such as packaged electronic devices, mechanical components, and batteries. Contact temperature measurement solutions include thermocouples, thermistors, thin-film resistance temperature detectors, on-chip sensor arrays, and embedded sensors. These solutions can obtain temperature information at several locations on the system surface, package structure, or inside the chip, and have advantages such as simple implementation, low cost, and suitability for long-term monitoring [10-12]. However, their shortcomings are that the number of measurement points is limited, making it difficult to directly obtain a continuous temperature distribution; sensor installation may change local heat dissipation conditions; and for hot spots or active area junction temperatures inside the package, contact sensors often can only provide indirect information.

[0032] Optical non-contact temperature measurement methods include infrared thermography, thermal reflection microscopy, Raman spectroscopy, and fluorescence / phosphorescence thermography. These methods can obtain surface or local temperature information without direct contact with the heating system, making them suitable for hotspot localization, surface thermal mapping analysis, and bare die thermal characterization [2-9,13]. However, their shortcomings include the fact that most optical methods are greatly affected by surface conditions and material optical properties; infrared thermography requires emissivity correction, thermal reflection requires thermal reflectance coefficient calibration, Raman thermography depends on the material's Raman signal, and fluorescence / phosphorescence thermography usually requires a temperature-sensitive coating; for areas that are encapsulated, covered by metal layers, or optically inaccessible, optical methods cannot directly obtain the true internal temperature.

[0033] Electrical parameter temperature measurement schemes include diode forward voltage drop method, threshold voltage method, on-resistance method, saturation voltage drop method, leakage current method, gate resistance method, switching transient parameter method, and electrical inversion method based on thermal model. These schemes can estimate the temperature in the operating state using the system's own electrical characteristics or on-chip test structure, and are suitable for packaged power devices and online thermal management [1,14-17]. However, their shortcomings are that the measured temperature is usually the junction temperature, average temperature, or equivalent temperature, which may not correspond to the actual local hot spot; electrical parameters are easily affected by non-temperature factors; if the temperature distribution is required, it is necessary to combine multi-point measurement, structural model, or inversion algorithm.

[0034] Existing temperature characterization methods based on X-ray diffraction can infer temperature by utilizing changes in lattice parameters, but they are usually targeted at the crystal being measured, specific crystal sensing materials, or high-temperature and high-pressure environments, and mainly obtain information on single-point temperature, average temperature, or maximum temperature; they do not pre-set a temperature response measurement layer inside the heating system, nor do they reconstruct the internal two-dimensional temperature distribution under the packaging or assembly state by scanning point by point [18-22].

[0035] Therefore, existing technologies still struggle to simultaneously meet the requirements of packaging / assembly status, non-contact reading, two-dimensional distribution reconstruction, internal hotspot location, and material signal distinguishability in measuring the internal temperature distribution of heating systems. Consequently, it is necessary to propose an improved method for measuring the internal temperature distribution of heating systems to enhance the accuracy, applicability, and engineering feasibility of internal temperature distribution acquisition.

[0036] The following are the references and patent documents mentioned above: [1] Avenas Y, Dupont L, Khatir Z. Temperature Measurement of PowerSemiconductor Devices by Thermo-Sensitive Electrical Parameters—A Review[J]. IEEE Transactions on Power Electronics, 2012, 27(6): 3081–3092. [2] Usamentiaga R, Venegas P, Guerediaga J, et al. InfraredThermography for Temperature Measurement and Non-Destructive Testing[J]. Sensors, 2014, 14(7): 12305–12348. [3] Vellvehi M, Perpiñà X, León J, et al. Irradiance-based emissivity correction in infrared thermography for electronic applications[J]. Review ofScientific Instruments, 2011, 82: 114901. [4] Yuan C, Hanus R, Graham S. A review of thermoreflectancetechniques for characterizing wide bandgap semiconductors' thermal properties and devices' temperatures[J]. Journal of Applied Physics, 2022, 132: 220701. [5] Tessier G, Holé S, Fournier D, et al. Submicron thermal imagingmethod and enhanced resolution AC-coupled imaging for thermal inspection ofintegrated circuits: US7173245B2[P]. 2007-02-06. [6] Korea Advanced Institute of Science and Technology. Temperaturedistribution measuring apparatus and method: US10139284B2[P]. 2018-11-27. [7] Xu S, Fan A, Wang H, et al. Raman-based nanoscale thermaltransport characterization: A critical review[J]. International Journal ofHeat and Mass Transfer, 2020, 154: 119751. [8] Boussekri M, et al. Two-Dimensional Materials for RamanThermometry on Power Electronic Devices[J]. Nanomaterials, 2025, 15(17):1344. [9] Glezer B, et al. Phosphor Thermometry Imaging System and ControlSystem: US20220214221A1[P]. 2022-07-07.

[10] Sensarray Corporation. Temperature sensor array: US6190040B1[P].2001-02-20.

[11] Sensarray Corporation. Thermal sensor array and method of makingsame: US6180867B1[P]. 2001-01-30.

[12] International Business Machines Corporation. On-chip sensor array for temperature management in integrated circuits: US7800879B2[P].2010-09-21.

[13] Thermal imaging system and method: WO2004097389A3[P]. 2004-11-11.

[14] TRW Automotive GmbH. Junction temperature measurement of a powerMOSFET: US20130257329A1[P]. 2013-10-03.

[15] Infineon Technologies AG. Systems and methods for measuring transistor junction temperature while operating: US10890493B2[P]. 2021-01-12.

[16] University of California, Santa Cruz. Efficient method to predict integrated circuit temperature and power maps: US20080026493A1[P].2008-01-31.

[17] Institute of Microelectronics, Chinese Academy of Sciences. A method for measuring the peak junction temperature distribution of MOSFET devices: CN103852181A[P]. 2014-06-11.

[18] International Business Machines Corporation. In-situ temperature measurement using X-ray diffraction: US5636258A[P]. 1997-06-03.

[19] Determining temperature inside a high pressure cell by X-raydiffraction: WO2018063788A1[P]. 2018-04-05.

[20] Institute of Overall Engineering, China Academy of Engineering Physics. A method for measuring the highest temperature based on the variation of microcrystal lattice parameters: CN109030544B[P]. 2020-11-03.

[21] Institute of Modern Physics, Chinese Academy of Sciences. A temperature measurement method using neutron-irradiated silicon carbide crystal as a sensor: CN101598606B[P]. 2011-01-05.

[22] Wuhan University of Science and Technology. An in-situ characterization method for the high-temperature lattice constant of ferruginous ore: CN104730097B[P]. 2016-08-24. Summary of the Invention

[0037] The purpose of this invention is to at least address one of the shortcomings of the prior art by providing an X-ray measurement method for the internal temperature distribution of a heating system.

[0038] To achieve the above objectives, the present invention adopts the following technical solution: Specifically, an X-ray measurement method for the internal temperature distribution of a heating system is proposed, including the following: Step 110: Set a temperature response measurement layer on the surface of the area to be tested of the target heating system. The temperature response measurement layer includes an ordered structural material whose cell parameters can be calibrated and changed with temperature. The ordered structural material has a small-angle X-ray diffraction signal. Step 120: Complete the packaging, assembly, or repackaging of the target heating system; Step 130: Put the target heating system into working state, power-on state, charging / discharging state, mechanical operation state, or external heating state; Step 140: Scan the temperature response measurement layer point by point to obtain small-angle X-ray diffraction patterns and transmission intensity signals; Step 150: Index the diffraction peaks based on the small-angle X-ray diffraction pattern and calculate the unit cell parameters at each scanning position; Step 160: Based on the cell parameter-temperature relationship or the cell parameter change rate, convert the cell parameters into temperature to obtain the temperature at each scanning position, and then reconstruct the two-dimensional temperature distribution map inside the target heating system.

[0039] Furthermore, specifically, the temperature response measurement layer is constructed based on an ordered structure formed by the self-assembly of temperature response probe molecules. These temperature response probe molecules can self-assemble into micelles and further arrange themselves in an ordered manner to form a low-symmetry soft matter ordered structure or a micelle superlattice.

[0040] Furthermore, specifically, the temperature-responsive probe molecule is an amphiphilic molecule, and the general formula of the amphiphilic molecule is: hydrophilic / polar head group—linking group—hydrophobic segment, wherein the hydrophilic / polar head group includes ionic groups and polar nonionic functional groups; the ionic groups include carboxylates, sulfonates, quaternary ammonium salts, and metal coordination groups, and the polar nonionic functional groups include carboxyl groups, amino groups, hydroxyl groups, or amides; the hydrophobic segment includes alkyl chains, aromatic groups, fluorinated segments, or other hydrophobic structures, and its chain length, volume fraction, and molecular geometry can be used to regulate the type of ordered structure formed by self-assembly and the temperature response behavior of the unit cell parameters.

[0041] Furthermore, specifically, the temperature response measurement layer can be configured to continuously cover the entire surface of the area to be measured or, as needed, cover one or more key areas.

[0042] Furthermore, the method also includes, After completing step 120, the initial cell parameters of each scanning position are obtained by performing a reference scan at room temperature without power. Then, the scan is performed again in the powered-on working state or the state under heat to be measured, and the two-dimensional temperature distribution map inside the target heating system is calculated based on the changes in cell parameters.

[0043] Furthermore, specifically, the temperature response measurement layer is a continuous solid or semi-solid coating and has good thermal contact with the surface of the area to be measured.

[0044] This invention also proposes an X-ray measurement system for the internal temperature distribution of a heating system, comprising, An X-ray source used to generate X-rays; Collimation / focusing components are used to adjust the direction, spot size, and divergence angle of the X-ray beam generated by the X-ray source. The XY scanning stage is used to place a target heating system with a temperature response measurement layer on the surface of the area to be measured, and to move the target heating system in the XY plane to achieve point-by-point scanning. A two-dimensional X-ray detector is used to acquire small-angle X-ray diffraction patterns of the temperature response measurement layer; The transmission intensity signal acquisition unit is used to acquire the intensity of the transmission beam that has not been scattered to obtain the transmission intensity signal, or to obtain the transmission intensity signal by utilizing the intensity of the direct light region, the central region, or the attenuated main beam intensity in the two-dimensional X-ray detector. The data processing module is used to process the small-angle X-ray diffraction pattern to obtain the cell parameters and reconstruct the two-dimensional temperature distribution map inside the target heating system.

[0045] Furthermore, specifically, the process by which the data processing module processes the small-angle X-ray diffraction pattern to obtain unit cell parameters and reconstruct a two-dimensional temperature distribution map inside the target heating system includes: S1. Perform background subtraction on the small-angle X-ray diffraction pattern to obtain the first image; S2. The first image is calibrated with a q value to obtain the second image; S3. Perform a two-dimensional diffraction pattern ring integral on the second image to obtain a one-dimensional small-angle X-ray scattering intensity curve I(q); S4. Peak position identification of I(q) yields the q values ​​of one or more experimental diffraction peaks; S5. Based on the pre-determined lattice model of the temperature response measurement layer material and the q value, the diffraction peak indexes are obtained to obtain the indexed diffraction peaks and their corresponding crystal plane indices. S6. The unit cell parameters are obtained by calculating the unit cell parameters using the indexed diffraction peaks and their corresponding crystal plane indices. S7. Perform temperature conversion on the cell parameters to obtain the temperature value; S8. Generate a two-dimensional temperature distribution map based on the temperature value and position coordinates corresponding to each scanning position.

[0046] Furthermore, specifically, in the process of indexing diffraction peaks, one or more small-angle diffraction peaks are indexed based on the known or candidate lattice model of the temperature response probe material. Then, based on the space group to which the material belongs or the candidate space group and the diffraction peak index results, multiple diffraction peaks are jointly fitted to obtain the cell parameters, and the local temperature is deduced based on the cell parameter-temperature relationship.

[0047] Furthermore, specifically, the temperature conversion process includes two methods. First, the cell parameter-temperature calibration curve method, which involves substituting the cell parameters obtained at each scanning position into a pre-established cell parameter-temperature calibration relationship to obtain the temperature at the corresponding position. Second, the cell parameter change rate method, which involves obtaining cell parameters in both the reference state and the state to be measured, and calculating the temperature change or actual temperature at the corresponding position based on the change in cell parameters between the two states and the pre-obtained cell parameter temperature change rate.

[0048] The beneficial effects of this invention are as follows: This invention proposes an X-ray measurement method and system for the internal temperature distribution of a heating system. First, it can obtain the two-dimensional temperature distribution inside the heating system in its packaged or assembled state, applicable to heating systems such as electronic devices, mechanical components, and batteries that are transmissible to X-rays. Second, the reading process is non-contact; measurement does not require reopening the device or contacting the internal measurement layer, only small-angle X-ray diffraction measurement from the outside. Third, it helps reduce interference from common packaging and device materials on the temperature measurement signal; since this invention mainly reads the diffraction signal of the temperature response probe material in the small-angle region, and common metals, polymer packaging materials, and inorganic media typically do not produce the same characteristic diffraction signals in the same small-angle region, it is beneficial to extract the temperature response signal from complex packaging or assembly structures. Fourth, reliability can be improved through multi-peak indexing and cell parameter fitting; in particular, low-symmetry soft matter ordered structures can provide multiple small-angle diffraction peaks, each of which can serve as a source of information for cell parameter measurement, thereby reducing random errors. Attached Figure Description

[0049] The above and other features of this disclosure will become more apparent from the detailed description of the embodiments illustrated in conjunction with the accompanying drawings. In the accompanying drawings, the same reference numerals denote the same or similar elements. Obviously, the drawings described below are merely some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort. In the drawings: Figure 1 The diagram shows the general design of temperature-responsive probe molecules and their self-assembly to form an ordered structure. Figure 2 The diagram shows a schematic of a temperature response measurement layer disposed inside a packaged electronic device. Figure 3 The diagram shows an X-ray measurement system for the internal temperature distribution of a heating system proposed in this invention. Figure 4 The diagram shows the data processing flowchart for reconstructing the internal two-dimensional temperature distribution based on changes in unit cell parameters. Figure 5 The diagram shows the structure, scanning area, and temperature distribution results of an example of the heating resistor used in this invention. Figure 6 The diagram shows a flowchart of an X-ray measurement method for the internal temperature distribution of a heating system proposed in this invention. Detailed Implementation

[0050] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The same reference numerals used throughout the accompanying drawings indicate the same or similar parts.

[0051] The following is an explanation of the elements involved in this invention: Heating system: refers to a device, component or system that can generate heat and form a temperature distribution during operation, testing, power supply, charging and discharging, mechanical movement or external excitation, including but not limited to packaged electronic devices, power devices, integrated circuits, circuit board assemblies, mechanical transmission assemblies, batteries and energy storage devices, etc.; and at least part of the system can be transmitted by X-rays.

[0052] Temperature response probe material: refers to a material that can form a temperature response measurement layer inside a heating system. It contains an ordered structure with small-angle X-ray diffraction signals. The cell parameters of this ordered structure change calibrably with temperature, so it can be used as a probe to obtain cell parameters and reconstruct the internal temperature through small-angle X-ray diffraction.

[0053] Temperature response measurement layer: refers to a continuous solid or semi-solid coating pre-set on the surface of the area to be measured inside the heating system. This coating contains an ordered structural material with temperature-responsive cell parameters; at different temperatures, the position of its small-angle X-ray diffraction peak changes measurably, which can be used to deduce the temperature at that position.

[0054] Unit cell parameters: These are structural parameters calculated from the positions of small-angle X-ray diffraction peaks of temperature-responsive ordered structures. For ordered structures formed by the self-assembly of soft matter or organic molecules, the unit cell parameters include the lattice constant, cell edge length, cell angle, or other structural parameters that can be obtained from diffraction peak indices; their values ​​change calibrably with temperature.

[0055] Small-angle X-ray diffraction (SAXD) refers to a method for characterizing the mesoscopic ordered structure of materials using X-ray diffraction / scattering signals in small-angle regions. In this invention, the term includes diffraction peaks, scattering peaks, or correlation peaks generated by soft matter ordered structures in small-angle X-ray patterns, as long as the signal can be used for indexing and calculating unit cell parameters.

[0056] Low-symmetry soft matter ordered structures refer to mesoscopic ordered structures with relatively low lattice symmetry, formed by the self-assembly of soft matter or organic molecules. These structures typically exhibit multiple identifiable diffraction peaks in small-angle X-ray diffraction patterns, which can be used for the common indexing of multiple diffraction peaks and fitting of unit cell parameters. Examples include, but are not limited to, micellar superlattices, liquid crystal ordered structures, and self-assembled ordered structures of block copolymers.

[0057] Micellar superlattices refer to ordered soft matter structures formed by the self-assembly of amphiphilic molecules into micelles, which then further arrange themselves in an orderly manner as mesoscopic structural units. This structure can produce identifiable diffraction peaks in small-angle X-ray diffraction patterns, and its cell parameters change calibrably with temperature, making it a preferred form of the temperature-responsive probe material of this invention.

[0058] Transmission intensity signal: This refers to the intensity of the transmitted beam after X-rays pass through the heating system, packaging structure, and internal materials during small-angle X-ray diffraction, without scattering and propagating along the transmission direction. By comparing the transmitted beam intensity with the incident X-ray intensity, the degree of X-ray absorption after passing through the measured material can be obtained. Since metal circuits, metal electrodes, or other heavy element regions have strong absorption of X-rays, the transmission intensity at their corresponding locations is relatively reduced. Therefore, the transmission intensity signal can be used to assist in identifying high-absorption structures inside the heating system and for registering temperature measurement coordinates with internal structure coordinates.

[0059] Example 1, referring to Figure 6 This invention proposes an X-ray measurement method for the internal temperature distribution of a heating system, comprising the following:

[0060] Step 110: Set a temperature response measurement layer on the surface of the area to be tested of the target heating system. The temperature response measurement layer includes an ordered structural material whose cell parameters can be calibrated and changed with temperature. The ordered structural material has a small-angle X-ray diffraction signal. Preferably, the ordered structural material is a soft matter or an organic molecule self-assembled ordered structural material.

[0061] Step 120: Complete the packaging, assembly, or repackaging of the target heating system; this step may include two paths: First, before packaging or assembling, place the temperature response measurement layer on the surface of the area to be measured inside the heating system, and then complete the packaging or assembly; Second, for already packaged or assembled devices / systems, first remove the packaging or partially disassemble to expose the area to be measured, apply the temperature response measurement layer, and then repackage or reassemble.

[0062] Step 130: Put the target heating system into working state, power-on state, charging / discharging state, mechanical operation state, or external heating state; wherein, after the heating system is equipped with a temperature response measurement layer and completed encapsulation, assembly, or re-encapsulation, it should still maintain its original functions; for example, electronic devices can still be powered on and work normally, mechanical transmission components can still operate normally, and batteries or energy storage devices can still be charged and discharged normally.

[0063] Step 140: Scan the temperature response measurement layer point by point to obtain small-angle X-ray diffraction patterns and transmission intensity signals. While keeping the X-ray beam position constant, the heating system is moved via the XY scanning stage to sequentially irradiate different positions on the temperature response measurement layer with the X-ray beam, thus achieving point-by-point scanning. During point-by-point scanning, small-angle X-ray diffraction patterns and transmission intensity signals are acquired simultaneously. The small-angle X-ray diffraction patterns are used for cell parameter calculation and temperature inversion, while the transmission intensity signals are used to identify internal high-absorption structures or metal circuits and can assist in coordinate registration.

[0064] Step 150: Index the diffraction peaks based on the small-angle X-ray diffraction pattern and calculate the unit cell parameters at each scanning position; wherein, according to the known or candidate lattice model of the temperature response probe material, index one or more small-angle diffraction peaks; preferably, index multiple small-angle diffraction peaks together and perform multi-peak fitting to obtain the unit cell parameters at each scanning position.

[0065] Step 160: Based on the cell parameter-temperature relationship or the cell parameter change rate, convert the cell parameters into temperature to obtain the temperature at each scanning position. This allows for the reconstruction of a two-dimensional temperature distribution map within the target heating system. Furthermore, the transmission intensity signal can be used to identify internal high-absorption structures or metal circuits and registered with the temperature measurement coordinates, ensuring that each temperature value corresponds to a specific structural region, heat source region, or functional unit within the heating system. The temperature conversion can be performed using the cell parameter-temperature calibration curve method, or by using the change in cell parameters between the reference state and the state to be measured, combined with the cell parameter temperature change rate.

[0066] In this embodiment 1, a heating system structure is provided with a temperature response measurement layer (the temperature response measurement layer is based on a temperature response probe material, which can form an ordered structure with small-angle X-ray diffraction signals, and its cell parameters can be calibrated and changed with temperature, and can be used as a temperature measurement probe inside the heating system). This allows the heating system to maintain its original function while reading internal temperature information through external X-ray diffraction. In this way, the cell parameters of the internal temperature response measurement layer can be read through X-ray diffraction in the packaged or assembled state, and the internal two-dimensional temperature distribution can be reconstructed. This solves the problems of existing contact temperature measurement which is difficult to obtain a continuous internal temperature distribution, optical non-contact temperature measurement which is difficult to penetrate the package, and electrical parameter temperature measurement which is difficult to directly obtain the spatial distribution.

[0067] Compared to existing techniques for temperature characterization based on X-ray diffraction readings of lattice parameters, this invention does not merely measure the lattice parameters of the crystal under test or a specific inorganic crystal sensing material, but rather pre-sets a temperature response measurement layer inside the heating system. Through this measurement layer, packaged electronic devices, mechanical components, batteries, or other heating systems that originally lacked suitable diffraction temperature measurement signals can also have their internal temperature information read via X-ray diffraction. Therefore, this invention expands X-ray lattice parameter temperature measurement from "characterizing the temperature of the crystal under test itself" to "measuring the internal temperature distribution after setting a temperature response probe layer inside the heating system."

[0068] Furthermore, existing X-ray thermometry techniques are mostly used to characterize single-point temperature, average temperature, maximum temperature, or the temperature-dependent changes in material structure. This invention, however, obtains the two-dimensional temperature distribution within the heating system through point-by-point scanning, enabling the display of hotspot locations and temperature gradients. Moreover, this invention preferably employs soft matter or self-assembled ordered structures of organic molecules as temperature response probe materials, whose small-angle X-ray diffraction signals are beneficial for identification and extraction from complex encapsulation or assembly structures. When using low-symmetry soft matter ordered structures, multiple diffraction peaks can be used together for cell parameter fitting, thereby improving the reliability of temperature reconstruction.

[0069] In a preferred embodiment of the present invention, the temperature response measurement layer is specifically constructed based on an ordered structure formed by the self-assembly of temperature response probe molecules. The temperature response probe molecules can self-assemble into micelles and further arrange themselves in an ordered manner to form a low-symmetry soft matter ordered structure or a micelle superlattice.

[0070] In this preferred embodiment, refer to Figure 1 , Figure 1The diagram shows an amphiphilic molecule composed of a hydrophilic / polar head group 2, a linker group 3, and a hydrophobic segment 4. This temperature-responsive probe molecule 1 can self-assemble to form micelles 5, and further arrange themselves in an ordered manner to form a low-symmetry soft matter ordered structure or a micelle superlattice 6. This ordered structure has a small-angle X-ray diffraction signal 7, and its cell parameters change calibrably with temperature, allowing the establishment of a cell parameter-temperature calibration relationship 8.

[0071] Besides micellar superlattices, temperature-responsive probe materials can also be other soft matter or organic molecule self-assembled ordered structures with small-angle X-ray diffraction signals and temperature-calibrated cell parameters, such as liquid crystal materials and block copolymer self-assembled ordered structures. Low-symmetry structures are preferred, but not the only available structures.

[0072] Specifically, the temperature-responsive probe molecule is an amphiphilic molecule, and the general formula of the amphiphilic molecule is: hydrophilic / polar head group—linking group—hydrophobic segment, wherein the hydrophilic / polar head group includes ionic groups and polar nonionic functional groups; the ionic groups include carboxylates, sulfonates, quaternary ammonium salts, and metal coordination groups, and the polar nonionic functional groups include carboxyl groups, amino groups, hydroxyl groups, or amides; the hydrophobic segment includes alkyl chains, aromatic groups, fluorinated segments, or other hydrophobic structures, and its chain length, volume fraction, and molecular geometry can be used to regulate the type of ordered structure formed by self-assembly and the temperature response behavior of the unit cell parameters.

[0073] The temperature-responsive probe material of this invention is preferably an ordered structure material formed by the self-assembly of soft matter or organic molecules, including but not limited to micelle superlattice materials, liquid crystal materials, and block copolymer self-assembled ordered structures; among which, micelle superlattice materials are a preferred embodiment. The temperature-responsive probe material can form an ordered structure with small-angle X-ray diffraction signals, and the cell parameters of this ordered structure change calibrably with temperature.

[0074] In a preferred embodiment, the temperature-responsive probe material is formed by the self-assembly of amphiphilic molecules. The general formula of the amphiphilic molecules can be summarized as: hydrophilic / polar head group – linking group – hydrophobic segment. The hydrophilic / polar head group includes ionic groups and polar nonionic functional groups; ionic groups include carboxylates, sulfonates, quaternary ammonium salts, metal coordinating groups, etc., and polar nonionic functional groups include carboxyl groups, amino groups, hydroxyl groups, or amides, etc. The hydrophobic segment includes alkyl chains, aromatic groups, fluorinated segments, or other hydrophobic structures, and its chain length, volume fraction, and molecular geometry can be used to control the type of ordered structure and the temperature response behavior of the unit cell parameters formed by self-assembly.

[0075] The temperature-responsive probe material can form an ordered structure through factors such as hydrophobic interactions, ion interactions, metal coordination interactions, hydrogen bonding, π-π interactions, and molecular geometric constraints. These factors can be used to regulate the type of ordered structure, cell parameters, and the response behavior of cell parameters as a function of temperature. This invention does not limit the specific physical mechanism of cell parameter changes with temperature, but only requires that the cell parameters have a calibrable temperature response relationship within the target temperature range.

[0076] The temperature response measurement layer is a continuous solid or semi-solid coating disposed on the surface of the area to be measured inside the heating system. During device operation or testing, it maintains an ordered structural signal that can be read by small-angle X-ray diffraction. The ordered structure in the temperature response measurement layer can be randomly oriented or polycrystalline; as long as it produces identifiable and indexable diffraction peaks in the small-angle X-ray diffraction pattern, it can be used for cell parameter calculation and temperature reconstruction.

[0077] The thickness of the temperature response measurement layer can be adjusted according to the device structure, packaging space, X-ray transmission conditions, and diffraction signal intensity, for example, 1 μm–5 mm, preferably 10 μm–500 μm; in a specific embodiment, the thickness of the temperature response measurement layer is approximately 100 μm. The temperature response measurement material can be directly coated onto the chip surface, circuit surface, or surface of the heat source area to be measured, and a stable measurement layer is formed by relying on the film-forming or adhesion properties of the material itself, generally without the need for additional adhesive layers, interface layers, or undercoating layers.

[0078] The temperature response measurement layer can be selectively configured according to temperature measurement requirements. It can either continuously cover the entire surface under test inside the heating system to obtain the temperature distribution over a large area, or it can cover only one or more key areas under test, such as the active area of ​​power devices, local hot spots, metal interconnect areas, areas near solder joints, mechanical friction areas, local areas of the battery, or other locations where temperature monitoring is required.

[0079] Temperature response measurement layers can be prepared using processes that form thin films or coatings, such as drop coating, spin coating, blade coating, spray coating, screen printing, inkjet printing, and transfer printing. After coating, depending on the materials and solvent system used, continuous solid or semi-solid temperature response measurement layers can be formed by room temperature standing, solvent evaporation, heating and drying, vacuum drying, or curing.

[0080] When used for internal temperature measurement in electronic devices, the temperature response measurement layer is preferably an electrically insulating material to avoid affecting the electrical connections, signal transmission, and normal operation of the electronic device. The temperature response measurement layer preferably has good thermal contact or thermal coupling with the surface of the circuit under test, the chip surface, or the area of ​​the heat source to be measured, so that changes in the cell parameters of the measurement layer can reflect the local temperature at the corresponding location. The temperature response measurement layer preferably maintains structural and chemical stability within the predetermined operating temperature range of the device and under packaging process conditions, and does not undergo chemical reactions with the chip surface, circuit metal layers, dielectric layers, passivation layers, or packaging materials that would affect the normal operation of the device.

[0081] For different target temperature ranges, different types of temperature-responsive probe molecules or soft matter ordered structure materials can be selected to ensure they possess a stable ordered phase and calibrable cell parameter-temperature relationship within the corresponding temperature range. For example, general selection can be made according to low-temperature region, room temperature to medium-temperature region, and high-temperature region, but this division is not strictly limited; the specific operating temperature range is determined by the chemical structure of the probe molecules, their self-assembled phase state, and their cell parameter-temperature response relationship. The temperature-responsive measurement layer is suitable for operating or testing temperature ranges of heating systems, for example, from −40 ℃ to 300 ℃.

[0082] The temperature-response probe material may exhibit different ordered phases or undergo phase transitions under different temperature conditions. This invention does not require the material to maintain the same lattice type across the entire temperature range; in actual temperature measurement, one ordered phase that is stable within the target temperature range and exhibits identifiable small-angle X-ray diffraction peaks can be selected as the temperature-measuring phase, and temperature conversion can be performed based on the cell parameter-temperature relationship of this phase. The material generates identifiable diffraction peaks in the small-angle X-ray region, which is beneficial for distinguishing it from the main structural signals of common metals, polymer encapsulation materials, and inorganic media in heating systems.

[0083] As a preferred embodiment of the present invention, the temperature response measurement layer is configured to continuously cover the entire surface of the area to be measured or, as needed, cover one or more key areas.

[0084] In this preferred embodiment, refer to Figure 2 , Figure 2The diagram shows a heating system or packaged electronic device 9, which includes a heating circuit, a chip, or a heat source region 10 to be measured. A temperature response measurement layer 11 is disposed on the surface of the heat source region to be measured and is covered by a packaging layer 12. The temperature response measurement layer 11 can continuously cover the entire surface to be measured, or it can cover only one or more key areas as needed. The temperature response measurement layer can be set in the manner described above. In addition, the point-by-point scanning path is not particularly limited. It can be scanned line by line according to a two-dimensional grid, or other scanning paths can be selected according to the shape of the area to be measured, the location of hot spots, or the testing efficiency; as long as the small-angle X-ray diffraction signals of multiple coordinate points in the area to be measured can be obtained and the temperature distribution can be reconstructed. The X-ray spot size can generally be tens of micrometers to hundreds of micrometers; the spatial sampling interval or effective resolution scale of the temperature distribution map can be set according to the measurement requirements, spot size, scanning step size, and signal-to-noise ratio, for example, it can be tens of micrometers to several millimeters.

[0085] In a preferred embodiment of the present invention, the method further includes, After completing step 120, the initial cell parameters of each scanning position are obtained by performing a reference scan at room temperature without power. Then, the scan is performed again in the powered-on working state or the state under heat to be measured, and the two-dimensional temperature distribution map inside the target heating system is calculated based on the changes in cell parameters.

[0086] In this preferred embodiment, a reference scan can be performed at room temperature without power to obtain the initial unit cell parameters at each scan position; subsequently, a scan is performed again in the powered-on operating state or under the thermal condition to be measured, and the temperature distribution is calculated based on the changes in unit cell parameters. This reference state scan is a preferred step and is not a necessary limitation of the present invention.

[0087] Example 2: This invention also proposes an X-ray measurement system for the internal temperature distribution of a heating system, comprising: An X-ray source used to generate X-rays; Collimation / focusing components are used to adjust the direction, spot size, and divergence angle of the X-ray beam generated by the X-ray source. The XY scanning stage is used to place a target heating system with a temperature response measurement layer on the surface of the area to be measured, and to move the target heating system in the XY plane to achieve point-by-point scanning. A two-dimensional X-ray detector is used to acquire small-angle X-ray diffraction patterns of the temperature response measurement layer; The transmission intensity signal acquisition unit is used to acquire the intensity of the transmission beam that has not been scattered to obtain the transmission intensity signal, or to obtain the transmission intensity signal by utilizing the intensity of the direct light region, the central region, or the attenuated main beam intensity in the two-dimensional X-ray detector. The data processing module is used to process the small-angle X-ray diffraction pattern to obtain the cell parameters and reconstruct the two-dimensional temperature distribution map inside the target heating system.

[0088] The X-ray energy can be selected based on the packaging material, packaging thickness, and the X-ray transmission capability of the heating system; for example, it can be 5–100 keV. For low-absorption packaging materials such as polymers, resins, and silicone, X-rays of approximately 10 keV can be used; for metals, ceramics, or thicker packaging structures, X-rays of approximately 40 keV or higher energy can be used to ensure that transmission signals and small-angle X-ray diffraction signals can be effectively acquired.

[0089] Transmission intensity signals can be used to identify high-absorption structures or metal circuits within a heating system. Since metal circuits, metal electrodes, or other regions containing heavy elements strongly absorb X-rays, the transmission intensity at their corresponding locations is relatively reduced. Therefore, the spatial distribution of internal metal circuits or high-absorption structures can be reconstructed based on the transmission intensity distribution, and this information can be used for registration between temperature measurement coordinates and internal structure coordinates.

[0090] Reference Figure 3 , Figure 3 The diagram shows an X-ray source 13, a collimation / focusing assembly 14, a sample platform or XY scanning platform 15, a heating system or encapsulated electronics 9, a two-dimensional X-ray detector 16, and a data processing module 18. The X-ray beam position remains constant. By moving the heating system or encapsulated electronics 9 via the sample platform or XY scanning platform 15, X-rays sequentially irradiate different positions of the temperature response measurement layer 11, obtaining small-angle X-ray diffraction signals 7 and transmission intensity signals 17.

[0091] Reference Figure 4 In a preferred embodiment of the present invention, specifically, the process by which the data processing module processes the small-angle X-ray diffraction pattern to obtain unit cell parameters and reconstruct a two-dimensional temperature distribution map inside the target heating system includes: S1. Perform background subtraction on the small-angle X-ray diffraction pattern to obtain the first image; S2. The first image is calibrated with a q value to obtain the second image; S3. Perform a two-dimensional diffraction pattern ring integral on the second image to obtain a one-dimensional small-angle X-ray scattering intensity curve I(q); S4. Peak position identification of I(q) yields the q values ​​of one or more experimental diffraction peaks; S5. Based on the pre-determined lattice model of the temperature response measurement layer material and the q value, the diffraction peak indexes are obtained to obtain the indexed diffraction peaks and their corresponding crystal plane indices. S6. The unit cell parameters are obtained by calculating the unit cell parameters using the indexed diffraction peaks and their corresponding crystal plane indices. S7. Perform temperature conversion on the cell parameters to obtain the temperature value; S8. Generate a two-dimensional temperature distribution map based on the temperature value and position coordinates corresponding to each scanning position.

[0092] More specifically, the preferred implementation process of the above steps is as follows: S1. Background subtraction: The two-dimensional small-angle X-ray diffraction pattern obtained by the target heating system at each scanning position in the area to be tested is used as input, and the blank background pattern, dark field pattern or substrate pattern without temperature response measurement layer is used as background reference. The background subtraction is performed on the two-dimensional small-angle X-ray diffraction pattern, and the background subtraction two-dimensional small-angle X-ray diffraction pattern is output. S2. Scattering vector q-value calibration: Using the two-dimensional small-angle X-ray diffraction pattern of the standard sample and its known characteristic peak positions as input, determine the correspondence between the detector center, the distance from the sample to the detector, and the pixel position and the scattering vector q-value, and output the two-dimensional small-angle X-ray diffraction pattern after q-value calibration. S3. Two-dimensional diffraction pattern ring integration: Taking the two-dimensional small-angle X-ray diffraction pattern after background subtraction and q-value calibration as input, the two-dimensional small-angle X-ray diffraction pattern is integrated in a ring according to the same q-value or a preset azimuth angle range, and the one-dimensional small-angle X-ray scattering intensity curve I(q) is output. S4. Peak position identification: Taking the one-dimensional small-angle X-ray scattering intensity curve I(q) as input, smoothing, background baseline correction and local peak search are performed on it to identify the characteristic diffraction peak positions of the temperature response measurement layer and output the q value of one or more experimental diffraction peaks. S5. Diffraction Peak Indexing: Using the q value of the experimental diffraction peak and the known or candidate lattice model of the temperature response measurement layer material as input, the experimental diffraction peak is matched with the candidate crystal plane index, and the corresponding crystal plane index is selected according to the matching residual, and the indexed diffraction peak and its corresponding crystal plane index are output. S6. Calculation of unit cell parameters: Using the indexed diffraction peak q-value and its corresponding crystal plane index as input, and according to the relationship between the unit cell parameters and the diffraction peak q-value in the lattice model, one or more unit cell parameters are fitted and calculated, and the unit cell parameters at each scanning position of the region to be measured are output. S7. Temperature conversion: Using the cell parameters at each scanning position of the area to be measured as input, the cell parameters are converted into the local temperature at the corresponding scanning position according to the pre-established calibration relationship between cell parameters and temperature, and the temperature value at each scanning position of the area to be measured is output. S8. Generation of two-dimensional temperature distribution map: Taking the coordinates of each scanning position and the corresponding local temperature value recorded by the XY scanning stage as input, the local temperature values ​​at each scanning position are arranged, interpolated or gridded according to their spatial coordinates to output a two-dimensional temperature distribution map inside the target heating system.

[0093] Figure 4 The process, as shown, includes point-by-point scanning, acquisition of small-angle X-ray diffraction signal 7 and transmission intensity signal 17, background subtraction, q-value calibration, ring integration of the two-dimensional diffraction pattern, peak identification, diffraction peak indexing, cell parameter calculation, temperature conversion, and generation of a two-dimensional temperature distribution map 20. The transmission intensity signal 17 can be used to assist in identifying internal high-absorption structures or metal circuits 19, and for registering temperature measurement coordinates with internal structure coordinates.

[0094] In a preferred embodiment of the present invention, specifically, during the process of indexing diffraction peaks, one or more small-angle diffraction peaks are indexed according to the known or candidate lattice model of the temperature response probe material. Then, based on the space group to which the material belongs or the candidate space group and the diffraction peak index results, multiple diffraction peaks are jointly fitted to obtain the cell parameters, and the local temperature is deduced based on the cell parameter-temperature relationship.

[0095] In this preferred embodiment, during the diffraction peak indexing and cell parameter calculation steps, one or more small-angle diffraction peaks are indexed based on the known or candidate lattice model of the temperature response probe material. For high-symmetry lattices, such as cubic lattices, only one lattice constant 'a' can be used for temperature conversion; for low-symmetry soft matter ordered structures, multiple or all cell parameters, such as a, b, c, and one or more of α, β, γ, can be used to obtain temperature values ​​through multi-parameter fitting or joint inversion. Preferably, based on the space group to which the material belongs or the candidate space group and the diffraction peak index results, multiple diffraction peaks are jointly fitted to obtain cell parameters, and the local temperature is deduced based on the cell parameter-temperature relationship.

[0096] In a preferred embodiment of the present invention, the temperature conversion process includes two methods: First, the cell parameter-temperature calibration curve method, which involves substituting the cell parameters obtained at each scanning position into a pre-established cell parameter-temperature calibration relationship to obtain the temperature at the corresponding position; Second, the cell parameter change rate method, which involves obtaining cell parameters in both the reference state and the state to be measured, and calculating the temperature change or actual temperature at the corresponding position based on the change in cell parameters between the two states and in conjunction with the pre-obtained cell parameter temperature change rate.

[0097] The following are some application examples of this invention: Example 1: Measurement of two-dimensional temperature distribution inside a heating resistor In one specific embodiment, a heating resistor on a conventional PCB substrate is used as the heating system model. A temperature response measurement layer is coated on the surface of the heating resistor on the PCB substrate. The temperature response measurement layer comprises a low-symmetry micelle superlattice structure formed by the self-assembly of amphiphilic molecules, and the coating thickness is approximately 100 μm. Subsequently, a polyimide tape, such as Kapton tape, is used to cover the coated heating resistor to form a simulated encapsulation or shielding structure.

[0098] During measurement, a constant voltage of approximately 1.5 V was applied to the heating resistor to induce heating. While the heating resistor remained energized, transmission small-angle X-ray diffraction (SAXD) was performed using approximately 10 keV X-rays. Keeping the X-ray beam position constant, the sample platform was moved to scan the test area point by point. The scanning step size was 100 μm, and 10 × 10 point scans were performed within an area of ​​approximately 1 mm × 1 mm, resulting in a total of 100 small-angle X-ray diffraction patterns.

[0099] For each scanning point, the small-angle X-ray diffraction pattern undergoes background subtraction, q-value calibration, two-dimensional diffraction pattern ring integration, peak identification, diffraction peak indexing, and unit cell parameter calculation. Using a pre-established unit cell parameter-temperature calibration curve, the unit cell parameters fitted to each scanning point are converted into temperature values ​​at the corresponding locations.

[0100] Reference Figure 5 , Figure 5 The heating resistor on the PCB substrate, marked by the red frame, serves as a heating circuit, chip, or heat source to be measured. A temperature response measurement layer is coated on its surface and covered by polyimide tape as an encapsulation layer. By performing a 10 × 10 dot matrix scan on a 1 mm × 1 mm scanning area (red frame), the two-dimensional temperature distribution and transmission intensity distribution on the surface of the heating resistor can be obtained.

[0101] Through the above steps, a two-dimensional temperature distribution map is reconstructed within a 1 mm × 1 mm scanning area, with temperatures ranging from approximately 150 to 190 ℃. The temperature is highest in the central region of the heating resistor, at approximately 190 ℃, and gradually decreases towards the surrounding areas.

[0102] Example 2: Measurement of internal temperature distribution in packaged electronic devices In another embodiment, the present invention is applied to the measurement of internal temperature distribution in packaged electronic devices. First, a temperature response measurement layer 11 is coated onto the chip surface, circuit surface, or surface of the heat source region to be measured in the packaged electronic device. The temperature response measurement layer comprises an ordered structural material with small-angle X-ray diffraction signals and cell parameters that change with temperature, preferably a soft matter or organic molecule self-assembled ordered structural material.

[0103] Subsequently, encapsulation is completed using conventional processes, placing the temperature response measurement layer within the encapsulation layer. The encapsulation material and form are not particularly limited and can include polymer resin encapsulation, epoxy encapsulation, silicone encapsulation, ceramic encapsulation, glass encapsulation, metal encapsulation, chip-level encapsulation, power module encapsulation, etc. The temperature response measurement layer 11 has minimal impact on electronic devices and is preferably an electrically insulating layer. Furthermore, by controlling the coating thickness and coverage area, it is possible to avoid affecting circuit connections, signal transmission, and normal device operation.

[0104] During measurement, the packaged electronic device is kept in normal power-on operation. While maintaining the X-ray beam position, the device is moved using an XY scanning stage, allowing the fixed X-ray beam to irradiate different locations point by point. Small-angle X-ray diffraction patterns and transmission intensity signals are acquired at each location. Based on the indexing of small-angle X-ray diffraction peaks and the cell parameter-temperature relationship, the two-dimensional temperature distribution inside the packaged electronic device is reconstructed. Optionally, the transmission intensity signal can be used to identify internal metal circuitry or high-absorption structures, and coordinate registration can be performed.

[0105] Example 3: Dynamic measurement of internal temperature changes over time This invention can also be used for the dynamic measurement of temperature changes over time within a heating system. In one approach, a fixed X-ray beam is aimed at a target location inside the heating system, such as a hot spot, an active region of a chip, a localized area of ​​a battery, or a region experiencing mechanical frictional heating. During the operation of the heating system, small-angle X-ray diffraction patterns at this location are continuously or intermittently acquired, and the temperature-time curve at that location is obtained based on the changes in cell parameters over time. The acquisition interval can be selected based on the diffraction signal intensity of the temperature-responsive material, the X-ray source intensity, and the required signal-to-noise ratio, for example, from 0.5 seconds to 15 minutes.

[0106] In another approach, a two-dimensional point-by-point scan can be repeatedly performed at set time intervals when the heating system starts up, stops, changes power, charges or discharges, or other thermal processes occur, to obtain internal two-dimensional temperature distribution maps at multiple moments, thereby analyzing the evolution of the internal temperature field over time.

[0107] Although the description of the invention has been quite detailed and particularly of several described embodiments, it is not intended to limit it to any of these details or embodiments or any particular embodiment, but should be considered as providing a broad possible interpretation of the claims by referring to the appended claims and taking into account the prior art, thereby effectively covering the intended scope of the invention. Furthermore, the invention has been described above with respect to embodiments foreseeable by the inventors in order to provide a useful description, and non-substantial modifications to the invention that have not yet been foreseen may still represent equivalent modifications.

[0108] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. Any embodiment that achieves the technical effects of the present invention using the same means should fall within the protection scope of the present invention. Within the protection scope of the present invention, various modifications and variations can be made to the technical solutions and / or implementation methods.

Claims

1. An X-ray measurement method for the internal temperature distribution of a heating system, characterized in that, Including the following: Step 110: Set a temperature response measurement layer on the surface of the area to be tested of the target heating system. The temperature response measurement layer includes an ordered structural material whose cell parameters can be calibrated and changed with temperature. The ordered structural material has a small-angle X-ray diffraction signal. Step 120: Complete the packaging, assembly, or repackaging of the target heating system; Step 130: Put the target heating system into working state, power-on state, charging / discharging state, mechanical operation state, or external heating state; Step 140: Scan the temperature response measurement layer point by point to obtain small-angle X-ray diffraction patterns and transmission intensity signals; Step 150: Index the diffraction peaks based on the small-angle X-ray diffraction pattern and calculate the unit cell parameters at each scanning position; Step 160: Based on the cell parameter-temperature relationship or the cell parameter change rate, convert the cell parameters into temperature to obtain the temperature at each scanning position, and then reconstruct the two-dimensional temperature distribution map inside the target heating system. Specifically, the temperature response measurement layer is constructed based on an ordered structure formed by the self-assembly of temperature response probe molecules. The temperature response probe molecules can self-assemble into micelles and further arrange themselves in an ordered manner to form a low-symmetry soft matter ordered structure or a micelle superlattice. Specifically, the temperature-responsive probe molecule is an amphiphilic molecule, and the general formula of the amphiphilic molecule is: hydrophilic / polar head group—linking group—hydrophobic segment, wherein the hydrophilic / polar head group includes ionic groups and polar nonionic functional groups; the ionic groups include carboxylates, sulfonates, quaternary ammonium salts, and metal coordination groups, and the polar nonionic functional groups include carboxyl groups, amino groups, hydroxyl groups, or amides; the hydrophobic segment includes alkyl chains, aromatic groups, fluorinated segments, or other hydrophobic structures, and its chain length, volume fraction, and molecular geometry can be used to regulate the type of ordered structure formed by self-assembly and the temperature response behavior of the unit cell parameters; Specifically, the temperature response measurement layer is a continuous solid or semi-solid coating and has good thermal contact with the surface of the area to be measured.

2. The X-ray measurement method for the internal temperature distribution of a heating system according to claim 1, characterized in that, Specifically, the temperature response measurement layer can be configured to continuously cover the entire surface of the area to be measured or cover one or more key areas as needed.

3. The X-ray measurement method for the internal temperature distribution of a heating system according to claim 1, characterized in that, The method also includes, After completing step 120, the initial cell parameters at each scanning position are obtained by performing a reference scan at room temperature without power. Then, the system is scanned again under either the powered-on operating state or the thermal state to be measured, and the two-dimensional temperature distribution map inside the target heating system is calculated based on the changes in the unit cell parameters.

4. An X-ray measurement system for the internal temperature distribution of a heating system, characterized in that, The system comprising the steps of the method described in any one of claims 1-3, wherein the method is applied, An X-ray source used to generate X-rays; Collimation / focusing components are used to adjust the direction, spot size, and divergence angle of the X-ray beam generated by the X-ray source. The XY scanning stage is used to place a target heating system with a temperature response measurement layer on the surface of the area to be measured, and to move the target heating system in the XY plane to achieve point-by-point scanning. A two-dimensional X-ray detector is used to acquire small-angle X-ray diffraction patterns of the temperature response measurement layer; The transmission intensity signal acquisition unit is used to acquire the intensity of the transmission beam that has not been scattered to obtain the transmission intensity signal, or to obtain the transmission intensity signal by utilizing the intensity of the direct light region, the central region, or the attenuated main beam intensity in the two-dimensional X-ray detector. The data processing module is used to process the small-angle X-ray diffraction pattern to obtain the cell parameters and reconstruct the two-dimensional temperature distribution map inside the target heating system.

5. An X-ray measurement system for the internal temperature distribution of a heating system according to claim 4, characterized in that, Specifically, the data processing module processes the small-angle X-ray diffraction pattern to obtain unit cell parameters and reconstruct a two-dimensional temperature distribution map inside the target heating system, including: S1. Perform background subtraction on the small-angle X-ray diffraction pattern to obtain the first image; S2. The first image is calibrated with a q value to obtain the second image; S3. Perform a two-dimensional diffraction pattern ring integral on the second image to obtain a one-dimensional small-angle X-ray scattering intensity curve I(q); S4. Peak position identification of I(q) yields the q values ​​of one or more experimental diffraction peaks; S5. Based on the pre-determined lattice model of the temperature response measurement layer material and the q value, the diffraction peak indexes are obtained to obtain the indexed diffraction peaks and their corresponding crystal plane indices. S6. The unit cell parameters are obtained by calculating the unit cell parameters using the indexed diffraction peaks and their corresponding crystal plane indices. S7. Perform temperature conversion on the cell parameters to obtain the temperature value; S8. Generate a two-dimensional temperature distribution map based on the temperature value and position coordinates corresponding to each scanning position.

6. The X-ray measurement system for the internal temperature distribution of a heating system according to claim 5, characterized in that, Specifically, in the process of indexing diffraction peaks, one or more small-angle diffraction peaks are indexed based on the known or candidate lattice model of the temperature response probe material. Then, based on the space group to which the material belongs or the candidate space group and the diffraction peak index results, multiple diffraction peaks are fitted together to obtain the cell parameters, and the local temperature is deduced based on the cell parameter-temperature relationship.

7. An X-ray measurement system for the internal temperature distribution of a heating system according to claim 5, characterized in that, Specifically, the temperature conversion process includes two methods. First, the cell parameter-temperature calibration curve method, which involves substituting the cell parameters obtained at each scanning position into a pre-established cell parameter-temperature calibration relationship to obtain the temperature at the corresponding position. Second, the cell parameter change rate method, which involves obtaining cell parameters in both the reference state and the state to be measured, and calculating the temperature change or actual temperature at the corresponding position based on the change in cell parameters between the two states and the pre-obtained cell parameter temperature change rate.

Images