Thermal conductivity measurement device, system and method

Abstract

The invention relates to the technical field of thermal conductivity measurement equipment, and provides a thermal conductivity measurement device, system and method. The thermal conductivity measurement device comprises a laser generator, an optical path component, an incoherent light source, an incident optical fiber, a receiving optical fiber and a photoelectric detector. The laser generator projects a heating laser to a micro-nano thin film material through the optical path component and forms a first light spot on the micro-nano thin film material. The incoherent light source projects a detection light to the micro-nano thin film material through the incident optical fiber and forms a second light spot on the micro-nano thin film material that overlaps with the first light spot. The detection light is reflected by the micro-nano thin film material to form a first reflected light. The photoelectric detector receives the first reflected light through the receiving optical fiber. Since the detection light is incoherent light, the interference effect of the detection light is effectively avoided, and the measurement accuracy of the thermal conductivity measurement device is effectively improved. The detection light is projected and the first reflected light is received by the incident optical fiber and the receiving optical fiber respectively, so that the optical path structure is effectively simplified and the operability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal conductivity measurement equipment, and in particular to a thermal conductivity measurement device, system and method. Background Art

[0002] In recent years, as the size of materials and devices continues to shrink, the energy transport and conversion process of materials and devices has expanded towards the nanometer / femtosecond direction in the space / time scale, bringing many challenges to the fields of physics, chemistry, materials, electronics, etc. Among them, the thermal conductivity parameters of micro-nano materials have an increasingly greater impact on structural properties. The measurement of thermal conductivity parameters of micro-nano materials has become an important measurement technology in the micro-nano technology industry that is extremely challenging but urgently needs to be industrialized.

[0003] At present, there are many types of measuring devices on the market for measuring the thermal conductivity parameters of micro-nano materials according to different working principles, such as thermal conductivity measuring devices based on laser flash method, thermal conductivity measuring devices based on modulated photothermal reflection method, thermal conductivity measuring devices based on transient photothermal reflection method, etc. Among them, the thermal conductivity measuring devices based on transient photothermal reflection method have low measurement accuracy requirements and have the advantages of wide application range, low manufacturing cost, and high integration, making them a more suitable thermal conductivity measuring device for popularization and application. However, the traditional thermal conductivity measuring devices based on transient photothermal reflection method have large measurement errors and require the construction of complex optical paths to realize light projection and reception, with complex structures and low operability. Summary of the invention

[0004] The object of the present invention is to provide a thermal conductivity measurement device, system and method, aiming to solve the technical problems of large measurement error, complex structure and low operability of existing thermal conductivity measurement devices.

[0005] To achieve the above-mentioned purpose, the technical solution adopted in the embodiment of the present invention is: a thermal conductivity measuring device, including a laser generator, an optical path component, an incoherent light source, an incident optical fiber, a receiving optical fiber and a photodetector, wherein the laser generator projects a heating laser to the micro-nano thin film material through the optical path component and forms a first light spot on the micro-nano thin film material, the incoherent light source projects a detection light to the micro-nano thin film material through the incident optical fiber and forms a second light spot on the micro-nano thin film material that overlaps with the first light spot, the detection light is reflected by the micro-nano thin film material to form a first reflected light, and the photodetector receives the first reflected light through the receiving optical fiber.

[0006] The thermal conductivity measuring device provided by the present invention has at least the following beneficial effects: the thermal conductivity measuring device is implemented based on the transient photothermal reflection method, by using a laser generator to project a heating laser to a micro-nano thin film material to locally heat the micro-nano thin film material, and by using an incoherent light source to project a detection light to the heating position of the micro-nano thin film material, the detection light is reflected by the micro-nano thin film material to form a first reflected light, the first reflected light enters the photodetector through a receiving optical fiber, the photodetector converts the first reflected light into an electrical signal, and transmits the electrical signal to an analysis device, the analysis device analyzes the electrical signal to obtain the thermal conductivity parameter of the micro-nano thin film material; since the detection light is incoherent light, the interference effect of the detection light is effectively avoided to cause measurement errors, thereby effectively improving the measurement accuracy of the thermal conductivity measuring device; in addition, the thermal conductivity measuring device uses an incident optical fiber and a receiving optical fiber to respectively realize the projection of the detection light and the reception of the first reflected light, effectively simplifying the optical path structure, and the incident optical fiber and the receiving optical fiber can be bent in different directions according to work needs, effectively improving the operability of the thermal conductivity measuring device.

[0007] In one embodiment, a fiber collimator is provided at one end of the incident optical fiber close to the micro-nano thin film material.

[0008] In one embodiment, the thermal conductivity measuring device further comprises an optical coupler disposed on the incident optical fiber, the receiving optical fiber is connected between the optical coupler and the photodetector, and the projection direction of the detection light is perpendicular to the surface of the micro-nano thin film material.

[0009] In one embodiment, a projection direction of the heating laser and a projection direction of the detection light are arranged to intersect.

[0010] In one embodiment, the optical path component includes a beam expander and a focusing lens, and the heating laser is sequentially projected onto the micro-nano thin film material through the beam expander and the focusing lens.

[0011] In one embodiment, the optical path component further includes a plurality of total reflectors, and the heating laser is sequentially projected onto the micro-nano thin film material through the beam expander, each of the total reflectors and the focusing objective lens.

[0012] In one embodiment, the thermal conductivity measuring device further comprises a camera, and a working end of the camera is arranged opposite to a surface of the micro-nano thin film material close to the incident optical fiber.

[0013] In one embodiment, the incoherent light source is a monochromatic LED light source.

[0014] A thermal conductivity measurement system comprises an analysis device and the thermal conductivity measurement device, wherein the photoelectric detector of the thermal conductivity measurement device is electrically connected to the analysis device.

[0015] Since the above thermal conductivity measurement system adopts all the embodiments of the above thermal conductivity measurement device, it has at least all the beneficial effects of the above embodiments, which will not be described one by one here.

[0016] A thermal conductivity measurement method comprises the following steps:

[0017] The laser generator projects a heating laser to the micro-nano thin film material through an optical path component and forms a first light spot on the micro-nano thin film material to locally heat the micro-nano thin film material;

[0018] An incoherent light source projects a detection light to the micro-nano thin film material through an incident optical fiber and forms a second light spot on the micro-nano thin film material that overlaps with the first light spot;

[0019] The detection light is reflected by the micro-nano thin film material to form a first reflected light, and the first reflected light enters the photoelectric detector through the receiving optical fiber;

[0020] The photoelectric detector converts the first reflected light into an electrical signal, and transmits the electrical signal to an analysis device;

[0021] The analysis device analyzes the electrical signal to obtain the thermal conductivity parameter of the micro-nano thin film material.

[0022] Since the thermal conductivity measurement method adopts all the embodiments of the thermal conductivity measurement system, it has at least all the beneficial effects of the above embodiments, which will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the structure of a thermal conductivity measurement system provided by an embodiment of the present invention;

[0025] Figure 2 This is a flow chart of a thermal conductivity measurement method provided by an embodiment of the present invention.

[0026] Among them, the reference numerals in the figure are:

[0027] 10. Thermal conductivity measurement system, 11. Thermal conductivity measurement device, 111. Laser generator, 112. Optical path component, 1121. Beam expander, 1122. Focusing objective lens, 1123. Total reflector, 113. Incoherent light source, 114. Incident optical fiber, 1141. Optical fiber collimator, 115. Receiving optical fiber, 116. Photodetector, 117. Optical coupler, 118. Camera, 119. Translation stage, 12. Analysis equipment. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The thermal conductivity measurement device 11, system and method provided in the embodiment of the present invention are described in detail below by taking a micro-nano thin film material covered with a metal transduction layer as a sample to be measured as an example, wherein the metal transduction layer is an Au transduction layer, an Al transduction layer, etc., and the Au transduction layer is used as an example for description below.

[0033] Please combine Figure 1As shown, a thermal conductivity measuring device 11 includes a laser generator 111, an optical path component 112, an incoherent light source 113, an incident optical fiber 114, a receiving optical fiber 115 and a photodetector 116. The laser generator 111 projects a heating laser to the Au transducer layer of the micro-nano thin film material through the optical path component 112 and forms a first light spot on the Au transducer layer of the micro-nano thin film material. The incoherent light source 113 projects a detection light to the Au transducer layer of the micro-nano thin film material through the incident optical fiber 114 and forms a second light spot on the Au transducer layer of the micro-nano thin film material that overlaps with the first light spot. The detection light is reflected by the Au transducer layer of the micro-nano thin film material to form a first reflected light. The photodetector 116 receives the first reflected light through the receiving optical fiber 115.

[0034] Among them, the wavelength of the heating laser can be different values. The currently more commonly used heating laser wavelength is 1064nm. Of course, the wavelength of the heating laser can also be different values, such as 800nm, 405nm, etc., which are not specifically limited here; the wavelength of the detection light is related to the type of the metal transduction layer. For example, when the metal transduction layer is an Au transduction layer, the wavelength of the detection light is 532nm. In this way, the reflection sensitivity of the detection light to the Au transduction layer is effectively improved.

[0035] The thermal conductivity measuring device 11 is implemented based on the transient photothermal reflection method, by using a laser generator 111 to project a heating laser to the Au transducer layer of the micro-nano thin film material to locally heat the micro-nano thin film material, and by using an incoherent light source 113 to project a detection light to the heating position of the micro-nano thin film material, the detection light is reflected by the Au transducer layer of the micro-nano thin film material to form a first reflected light, the first reflected light enters the photodetector 116 through the receiving optical fiber 115, the photodetector 116 converts the first reflected light into an electrical signal, and transmits the electrical signal to the analysis device 12, the analysis device 12 analyzes the electrical signal to obtain the thermal conductivity parameters of the micro-nano thin film material; since the detection light is incoherent light, the interference effect of the detection light can be effectively avoided to cause measurement errors, thereby effectively improving the measurement accuracy of the thermal conductivity measurement device 11; in addition, the thermal conductivity measurement device 11 adopts the incident optical fiber 114 and the receiving optical fiber 115 to respectively realize the projection of the detection light and the reception of the first reflected light, effectively simplifying the optical path structure, and the incident optical fiber 114 and the receiving optical fiber 115 can be bent in different directions according to work needs, effectively improving the operability of the thermal conductivity measurement device 11.

[0036] In this embodiment, please combine Figure 1 As shown, a fiber collimator 1141 is provided at one end of the incident optical fiber 114 close to the micro-nano thin film material.

[0037] Specifically, the thermal conductivity measuring device 11 further includes a displacement stage 119, on which the micro-nano thin film material is horizontally placed, and the optical fiber collimator 1141 can make the second light spot reach a smaller size. By adjusting the displacement accuracy of the displacement stage 119 to match the size of the second light spot, the spatial resolution of the thermal conductivity measuring device 11 can be effectively improved.

[0038] For example, the optical fiber collimator 1141 adjusts the size of the second light spot to 0.5 μm, and by using the displacement stage 119 with a displacement accuracy of 0.5 μm, the spatial resolution of the thermal conductivity measurement device 11 can reach 0.5 μm.

[0039] In this embodiment, please combine Figure 1 As shown, the thermal conductivity measuring device 11 further includes an optical coupler 117 disposed on the incident optical fiber 114, and the receiving optical fiber 115 is connected between the optical coupler 117 and the photodetector 116, and the projection direction of the detection light is perpendicular to the surface of the Au transducer layer of the micro-nano thin film material. When the detection light reaches the surface of the Au transducer layer of the micro-nano thin film material, the detection light is reflected by the surface of the Au transducer layer of the micro-nano thin film material to form a first reflected light, and the first reflected light is also perpendicular to the surface of the Au transducer layer of the micro-nano thin film material and returns to the incident optical fiber 114, and then, the first reflected light enters the reflecting optical fiber through the optical coupler 117, and finally reaches the photodetector 116. By adopting the above technical solution, the design difficulty of the optical path of the above thermal conductivity measuring device 11 is effectively reduced, and the optical path structure of the above thermal conductivity measuring device 11 can be further simplified.

[0040] In this embodiment, please combine Figure 1 As shown, the projection direction of the heating laser is arranged to intersect with the projection direction of the detection light. After the heating laser reaches the surface of the Au transducer layer of the micro-nano thin film material, it is reflected to form a second reflected light. Since the projection direction of the heating laser is arranged to intersect with the projection direction of the detection light, the second reflected light does not overlap with the detection light. In this way, there is no need to set up an additional filter to filter the second reflected light, which can further simplify the optical path structure of the above-mentioned thermal conductivity measurement device 11.

[0041] In this embodiment, please combine Figure 1 As shown, the optical path component 112 includes a beam expander 1121 and a focusing lens 1122. The heating laser is sequentially projected onto the surface of the Au transducer layer of the micro-nano thin film material through the beam expander 1121 and the focusing lens 1122, wherein the beam expander 1121 may be a Keplerian laser beam expander 1121 or a Galilean laser beam expander 1121. Specifically, the heating laser is expanded and collimated by the beam expander 1121, and then focused onto the Au transducer layer of the micro-nano thin film material through the focusing lens 1122 to form a first light spot, thereby reducing the size of the first light spot.

[0042] Specifically, the radius size of the first light spot is controlled between 20μm and 50μm. It should be noted that, in order to facilitate the alignment and adjustment of the first light spot and the second light spot, the radius size of the first light spot is one order of magnitude larger than the radius size of the second light spot. For example, when the radius size of the first light spot is 50μm, the radius size of the second light spot is 0.5μm.

[0043] Specifically, please combine Figure 1 As shown, the optical path component 112 also includes a plurality of full reflectors 1123. The heating laser is sequentially projected onto the Au transducer layer of the micro-nano thin film material through the beam expander 1121, each full reflector 1123 and the focusing lens 1122. The number of full reflectors 1123 and the setting angle of each full reflector 1123 can be set according to the actual application scenario. For example, Figure 1 As shown, two total reflectors 1123 are provided, wherein one total reflector 1123 is provided at an angle of 45°, and the other total reflector 1123 is provided at an angle of 60°. The heating laser emitted from the laser generator 111 is horizontally projected onto the total reflector 1123 provided at an angle of 45°, and then vertically reflected onto the total reflector 1123 provided at an angle of 60°, and finally projected onto the surface of the Au transducer layer of the micro-nano thin film material at an angle of 30°.

[0044] In this embodiment, please combine Figure 1 As shown, the thermal conductivity measuring device 11 further includes a camera 118, and the working end of the camera 118 is arranged opposite to the Au transducer layer of the micro-nano thin film material. The camera 118 is a CCD (Charge Coupled Device) camera or a CMOS (Complementary Metal-Oxide-Semiconductor) camera. By setting the camera 118, the position of the first light spot and the position of the second light spot can be monitored in real time, so as to facilitate the adjustment of the position of the first light spot and the position of the second light spot to ensure that the first light spot and the second light spot coincide with each other.

[0045] In this embodiment, the incoherent light source 113 is a monochromatic LED light source.

[0046] Please combine Figure 1 As shown, a thermal conductivity measurement system 10 includes an analysis device 12 and the thermal conductivity measurement device 11, wherein the photodetector 116 of the thermal conductivity measurement device 11 is electrically connected to the analysis device 12. The analysis device 12 may be of various types, such as an oscilloscope, a computer with a digital conversion card, etc., which are not specifically limited here.

[0047] Since the thermal conductivity measurement system 10 adopts all the embodiments of the thermal conductivity measurement device 11, it has at least all the beneficial effects of the above embodiments, which will not be described one by one here.

[0048] Please combine Figure 2 As shown, a thermal conductivity measurement method comprises the following steps:

[0049] Step S100, placing the micro-nano thin film material horizontally on the displacement stage 119;

[0050] Step S200: The laser generator 111 projects a heating laser onto the Au transducer layer of the micro-nano thin film material through the optical path component 112 and forms a first light spot on the Au transducer layer of the micro-nano thin film material to locally heat the micro-nano thin film material.

[0051] Step S300: the incoherent light source 113 projects a detection light to the Au transducer layer of the micro-nano thin film material through the incident optical fiber 114 and forms a second light spot on the Au transducer layer of the micro-nano thin film material that overlaps with the first light spot;

[0052] Step S400: the detection light is reflected by the Au transducer layer of the micro-nano thin film material to form a first reflected light, and the first reflected light enters the photodetector 116 through the receiving optical fiber 115;

[0053] Step S500, the photodetector 116 converts the first reflected light into an electrical signal, and transmits the electrical signal to the analysis device 12;

[0054] Step S600: The analysis device 12 analyzes the electrical signal to obtain the thermal conductivity parameters of the micro-nano thin film material.

[0055] Specifically, in step S200, the heating laser emitted from the laser generator 111 is expanded and collimated by the beam expander 1121, and then the total reflective mirrors 1123 cooperate with each other to change the optical path of the heating laser. The heating laser is finally focused by the focusing objective lens 1122 and projected onto the Au transduction layer of the micro-nano thin film material to form the above-mentioned first light spot.

[0056] Specifically, in step S600, the analysis device 12 forms a transient thermal reflection curve based on the received electrical signal, and imports the transient thermal reflection curve into the transient thermal conductivity model, wherein the change in the electrical signal after the first reflected light is converted by the photodetector 116 is proportional to the change in the surface temperature of the micro-nano thin film material. According to the transient change of the above electrical signal over time, the thermal conductivity parameters such as the thermal conductivity of the micro-nano thin film material, the interface thermal resistance between the Au transduction layer and the micro-nano thin film material, etc. can be analyzed and fitted.

[0057] The transient thermal conduction model includes but is not limited to the Au model, the interface thermal resistance layer model, the material layer model, and the substrate layer model.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermal conductivity measuring device, characterized in that: The thermal conductivity measuring device comprises a laser generator, an optical path component, an incoherent light source, an incident optical fiber, a receiving optical fiber and a photodetector, wherein the incoherent light source is a monochromatic LED light source, the laser generator projects a heating laser to the micro-nano thin film material through the optical path component and forms a first light spot on the micro-nano thin film material, the incoherent light source projects a detection light vertically to the micro-nano thin film material through the incident optical fiber and forms a second light spot on the micro-nano thin film material that overlaps with the first light spot, the detection light is vertically reflected by the micro-nano thin film material to form a first reflected light, and the photodetector receives the first reflected light through the receiving optical fiber; The projection direction of the heating laser is arranged to intersect with the projection direction of the detection light. After the heating laser reaches the surface of the micro-nano thin film material, it is reflected to form a second reflected light, and the second reflected light does not overlap with the detection light.

2. The thermal conductivity measuring device according to claim 1, characterized in that: An optical fiber collimator is arranged at one end of the incident optical fiber close to the micro-nano thin film material.

3. The thermal conductivity measuring device according to claim 1, characterized in that: The thermal conductivity measuring device further comprises an optical coupler arranged on the incident optical fiber, and the receiving optical fiber is connected between the optical coupler and the photoelectric detector.

4. The thermal conductivity measuring device according to claim 1, characterized in that: The optical path component includes a beam expander and a focusing lens, and the heating laser is sequentially projected onto the micro-nano thin film material through the beam expander and the focusing lens.

5. The thermal conductivity measuring device according to claim 4, characterized in that: The optical path component also includes a plurality of total reflectors, and the heating laser is sequentially projected onto the micro-nano thin film material through the beam expander, each of the total reflectors and the focusing objective lens.

6. The thermal conductivity measuring device according to claim 1, characterized in that: The thermal conductivity measuring device further comprises a camera, and a working end of the camera is arranged opposite to a surface of the micro-nano thin film material close to the incident optical fiber.

7. A thermal conductivity measurement system, characterized in that: The thermal conductivity measurement system comprises an analysis device and the thermal conductivity measurement apparatus according to any one of claims 1 to 6, wherein the photoelectric detector of the thermal conductivity measurement apparatus is electrically connected to the analysis device.

8. A thermal conductivity measurement method, characterized in that: Applied to the device according to any one of claims 1 to 6, the thermal conductivity measurement method comprises the following steps: The laser generator projects a heating laser to the micro-nano thin film material through an optical path component and forms a first light spot on the micro-nano thin film material to locally heat the micro-nano thin film material; An incoherent light source projects a detection light to the micro-nano thin film material through an incident optical fiber and forms a second light spot on the micro-nano thin film material that overlaps with the first light spot; The detection light is reflected by the micro-nano thin film material to form a first reflected light, and the first reflected light enters the photoelectric detector through the receiving optical fiber; The photoelectric detector converts the first reflected light into an electrical signal, and transmits the electrical signal to an analysis device; The analysis device analyzes the electrical signal to obtain the thermal conductivity parameter of the micro-nano thin film material.

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