Reflector preparation method based on micro-channel heat dissipation

Abstract

The invention belongs to the technical field of reflectors, and particularly discloses a reflector preparation method based on micro-channel heat dissipation, and the method comprises the steps: obtaining a first mirror body and a second mirror body, and plating a reflecting film on one side of the first mirror body and one side of the second mirror body; the method comprises the following steps: performing micro-fluidic groove parameterization design according to three-dimensional data of a lens body, establishing an optimization model which only takes geometric parameters as independent variables, outputting performance evaluation indexes through coupling heat transfer-fluid-structure simulation, and performing iterative updating on the geometric parameters based on an evaluation result; processing parameters are generated, a micro-flow groove is formed through picosecond laser etching, and the groove wall is polished through femtosecond laser; deionized water washing, cerium oxide grinding, sodium bicarbonate cleaning and secondary washing are sequentially carried out; and bonding the two mirror bodies into a mirror surface. According to the method, under the condition that processing, tolerance and operation boundary constraints are met, comprehensive optimization of low temperature rise, low surface shape change and low pressure drop of the mirror surface is achieved, and the optical stability and reliability under high-power application are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mirrors, and particularly relates to a mirror preparation method based on micro-flow channel heat dissipation. BACKGROUND

[0002] A scanning galvanometer is a high-precision and high-speed laser beam control device, which is widely used in many fields such as laser cutting, laser welding, laser additive manufacturing, and the like. As a core execution unit of a laser processing system, the core function of the scanning galvanometer is to realize two-dimensional / three-dimensional dynamic deflection of a laser beam through electromagnetic driving of a mirror piece. A typical scanning galvanometer system is composed of a servo motor, a mirror assembly, a heat dissipation module, and a control circuit. The material performance of the mirror piece directly determines the upper limit of the power bearing and the dynamic response capability of the system. The mirror is a core element of the scanning galvanometer system, and its performance directly determines the application boundary of the laser processing system in the fields of cutting, welding, additive manufacturing, and the like.

[0003] The heat management capability of the mirror in the laser beam transmission path becomes an important factor limiting the performance improvement of the system. In order to reduce the temperature rise of the mirror surface caused by laser irradiation, various mirror design schemes with integrated cooling structures are proposed in the prior art.

[0004] The patent with the publication number CN216850730U discloses a reflecting unit and a high-power laser system, which includes a mirror and a cooling structure arranged on the back surface of the mirror. The cooling structure has a cooling cavity, and a plurality of fluid flow channels for the flow of cooling fluid are arranged inside the cavity. The flow channels are usually formed by a plurality of protruding partition walls, extend along the long axis direction of the mirror, and are arranged in an arc shape. The overall cooling channel is formed by a cover, and a fluid inlet and outlet are arranged to realize liquid cooling.

[0005] Although the above scheme improves the heat dissipation capability of the mirror to some extent, there are still the following significant problems: The cooling flow channel structure design is unreasonable, and the fluid flow path is limited: the flow channel layout in the prior art is usually a simple parallel linear arrangement, and the topological structure is single, so it is difficult to realize uniform distribution and efficient heat exchange of the cooling medium, and local hot spots and heat dissipation blind areas are prone to occur; The cooling cavity cover structure is prone to bonding gaps, and the interface thermal resistance is large: the cooling cavity is closed by mechanically aligning and bonding the cover, and during the manufacturing process, the bonding is often not tight, resulting in a decrease in cooling efficiency. SUMMARY

[0006] The present application provides a mirror preparation method based on micro-flow channel heat dissipation to solve the problem of tight bonding and low cooling efficiency caused by assembly precision when the cooling device is fixed outside the mirror in the prior art.

[0007] The technical scheme adopted by the present application is as follows: In a first aspect, the present application provides a mirror preparation method based on micro-channel heat dissipation, comprising the following steps: Step S1, two mirror bodies are obtained, the two mirror bodies are a first mirror body and a second mirror body respectively, and three-dimensional data of the mirror bodies are obtained, and a reflective film is plated on a coating surface of the first mirror body and the second mirror body; Step S2, the shape of the micro-channel is designed according to the three-dimensional data of the mirror body, and the size of the micro-channel is calculated, and the processing parameters are output based on the shape of the micro-channel and the size of the micro-channel; Step S3, the processing surface of the first mirror body and the second mirror body is etched according to the processing parameters in step S2; Step S4, the processing surface of the first mirror body and the second mirror body which has completed the micro-channel etching is polished and cleaned; Step S5, the first mirror and the second mirror are bonded to form a mirror, and the micro-channel in the mirror is formed after the micro-channel is bonded.

[0008] Further, in step S1, a reflective film is plated on a coating surface of the first mirror body and the second mirror body by physical vapor deposition or chemical vapor deposition.

[0009] Further, in step S2, the micro-channel is modeled by parameterization, the cross section of one end of the micro-channel is one of a rectangle, a trapezoid or a circular arc, and the cross section of the other end of the micro-channel is a semicircle.

[0010] Further, in step S2, a parameter acquisition process is performed, including: A micro-channel parameter optimization model is established, and the geometric parameters of the micro-channel are input into the micro-channel parameter optimization model as initial parameters; The performance evaluation index is output by coupling heat transfer, fluid and structure simulation calculation; The performance evaluation index includes at least one of the peak value of the surface temperature rise of the mirror, the surface temperature distribution uniformity, the flow pressure drop and the surface shape change amount; The geometric parameters are optimized based on the performance evaluation index.

[0011] Further, the optimization process of the geometric parameters includes: An optimization criterion for determining the pros and cons is set, and the optimization criterion includes at least one of threshold judgment, weighted scoring or non-dominated sorting based on the performance evaluation index; The comprehensive evaluation value of the current geometric parameters is calculated according to the optimization criterion, and the optimization direction is determined; The optimization direction is obtained by at least one of the following methods: weighted gradient, derivative-free search or parameter selection strategy based on acquisition function; The candidate update parameter is generated according to the step strategy and the candidate update parameter is checked for feasibility; The feasibility check at least includes constraints of geometric boundaries, machining tolerances and operating boundaries; Among the candidate update parameters that pass the feasibility check, the parameter with a comprehensive evaluation value better than the current geometric parameter is selected as the update parameter for geometric parameter optimization.

[0012] Further, in step S3, the micro flow groove is etched by adopting a picosecond laser processing mode, and the micro flow groove wall is polished by adopting a femtosecond laser.

[0013] Further, step S4 includes the following steps: Step S4-1, using deionized water to flush the processing surface of the first mirror and the second mirror once; Step S4-2, using cerium oxide to polish the processing surface of the first mirror and the second mirror; Step S4-3, using sodium bicarbonate to clean the cerium oxide on the processing surface of the first mirror and the second mirror; Step S4-4, using deionized water to flush the processing surface of the first mirror and the second mirror twice.

[0014] Further, in step S5, the bonding method adopts one of a bonding solution and a heat curing method, a hydroxyl bonding method or a laser-assisted anodic bonding method.

[0015] Further, the bonding method adopts a laser-assisted anodic bonding method, a 200nm-thick silicon nitride transition layer is deposited at the bonding interface, and the 200nm-thick silicon nitride transition layer is arranged in the bonding ring area and maintains a distance not less than a preset gap from the nearest micro flow channel edge.

[0016] Further, in step S5, the first mirror and the second mirror are bonded by a frame, the frame is a ring structure, the frame is sleeved on the outer circumferential surface of the first mirror and the second mirror, the tank body is provided with a first through hole and a second through hole, and the first through hole and the second through hole are respectively communicated with two ends of the micro flow channel.

[0017] As can be seen from the above technical solutions, the advantages of the present application are: By designing the micro flow groove shape according to the mirror three-dimensional data and performing laser etching based on parameterized modeling, the layout precision and fitting degree of the micro flow channel structure are effectively improved, and the problems of unreasonable micro flow channel setting and low utilization rate of the cooling channel in the prior art are avoided; The grinding-cleaning-high-reliability bonding process combination ensures the uniformity of the micro flow groove alignment between the first mirror and the second mirror and the integrity of the bonding interface, significantly reduces the risk of a large gap formed by traditional cover and mirror bonding, and improves the micro flow channel sealing performance and structural stability. Attached Figure Description

[0018] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Fig. 1 This is a flowchart of the microchannel-based heat dissipation method for fabricating a reflector in the embodiment; Fig. 2 This is an exploded view of the reflector structure in the embodiment; Fig. 3 This is a partial structural perspective view of the reflector in the embodiment.

[0020] In the figure: 1. First mirror body; 2. Second mirror body; 3. Microfluidic channel; 4. Microchannel; 5. Frame. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] A scanning galvanometer is a high-precision, high-speed laser beam control device widely used in laser cutting, laser welding, laser additive manufacturing, and other fields. As the core execution unit of a laser processing system, the core function of the scanning galvanometer is to achieve two-dimensional / three-dimensional dynamic deflection of the laser beam through electromagnetically driven reflective mirrors. Control accuracy can reach ±5μrad, and positioning speed exceeds 10m / s. A typical galvanometer system consists of a servo motor (including an angle sensor), a reflector assembly, a heat dissipation module, and control circuitry. The material properties of the reflector directly determine the system's power handling capacity (currently 500-3000W) and dynamic response capability (resonant frequency 10-50kHz). The reflector is the core component of the scanning galvanometer system, and its performance directly determines the application boundaries of the laser processing system in cutting, welding, additive manufacturing, and other fields.

[0023] Traditional reflective lenses generally use solid glass or fused quartz and other materials, and the high density characteristics of the materials cause the rotational inertia of the lenses to increase significantly. The large rotational inertia of the reflective mirror brings redundant load to the motor, and the high-frequency scanning performance is difficult to further improve. Taking a fused quartz lens with a diameter of 30 mm and a thickness of 5 mm as an example, the mass of the lens can reach about 8.5 g. At a scanning frequency of more than 2000 times per second, the inertial torque that the motor needs to overcome is as high as 0.15 N·m, which not only causes a driving energy loss of up to 20%, but also limits the possibility of breaking through the scanning frequency to the order of magnitude of 10 kHz.

[0024] In addition, after part of the energy of a high-energy laser is absorbed by the scanning galvanometer, the energy is converted into heat, causing local temperature rise and beam wavefront distortion, which degrades the performance of the optical system. For example, in the precision machining scene, the galvanometer needs to meet the stringent requirements of beam pointing repeatability error < 0.1 mrad and angular resolution < 1 μrad. Taking a traditional reflective mirror with a diameter of 20 mm as an example, when the laser power reaches 1 kW, 2% of the energy (about 20 W) absorbed by the mirror cannot be dissipated in time, which will cause the mirror surface temperature to rise by more than 50℃, causing thermal expansion deformation of 0.5-1.5 μm, and the spot diameter to increase by more than 30%, which seriously affects the process quality of micro-hole machining (hole diameter tolerance needs to be < 5 μm) and thin plate welding (fusion depth consistency requirement ± 3%). This is mainly due to the fact that the thermal conductivity of quartz material is only 1.38 W / (m·K), and under the action of kilowatt-level laser, the local temperature gradient of the mirror can reach 80℃ / cm 2 , which causes the thermal stress deformation to exceed λ / 4 (λ = 1,064 nm), and the wavefront distortion causes the focal point to shift by ± 25 μm, and the spot energy density to decrease by 40%.

[0025] The prior art such as the patent with publication number CN216850730U discloses a reflective unit and a high-power laser system, which includes a reflective mirror and a cooling structure arranged on the back surface of the reflective mirror. The cooling structure has a cooling cavity, and a plurality of fluid flow channels for the flow of cooling fluid are arranged inside the cavity. The flow channels are usually defined by a plurality of protruding partition walls, extend along the long axis of the reflective mirror, and are arranged in an arc shape. The cooling channels are formed by a cover, and fluid inlets and outlets are arranged to realize liquid cooling.

[0026] Although the above scheme improves the heat dissipation capacity of the reflective mirror to some extent, the following problems still exist: The cooling flow channel structure design is unreasonable, and the fluid flow path is limited: the flow channel layout in the prior art is usually a simple parallel linear arrangement, and the topological structure is single, which makes it difficult to achieve uniform distribution and efficient heat exchange of the cooling medium, and local hot spots and heat dissipation blind areas are prone to occur; The cooling cavity cover structure is prone to bonding gaps, and the interface thermal resistance is large: in the manufacturing process, the bonding is not tight, which leads to the decrease of cooling efficiency.

[0027] Referring to Figs. 1-3 As shown in the drawings, the embodiment provides a mirror preparation method based on micro-channel heat dissipation.

[0028] Specifically, the application provides a mirror preparation method based on micro-channel heat dissipation, comprising the following steps: Step S1, obtaining two mirror bodies, the two mirror bodies being a first mirror body and a second mirror body, and obtaining three-dimensional data of the mirror bodies, and coating a reflective film on a coating surface of the first mirror body and the second mirror body; The reflective film is coated on the coating surface of the first mirror body and the second mirror body by physical vapor deposition or chemical vapor deposition; Step S2, designing the shape of the micro-flow groove according to the three-dimensional data of the mirror body and calculating the size of the micro-flow groove, and outputting the machining parameters based on the shape of the micro-flow groove and the size of the micro-flow groove; In step S2, the micro-flow groove is modeled by parameterization, the cross section of one end of the micro-flow groove is one of a rectangle, a trapezoid or a circular arc, and the cross section of the other end of the micro-flow groove is a semicircle.

[0029] In step S2, a parameter acquisition process is performed, including: A micro-flow groove parameter optimization model is established, and the geometric parameters of the micro-flow groove are input into the micro-flow groove parameter optimization model as initial parameters; The performance evaluation index is output by coupling heat transfer, fluid and structure simulation calculation; The performance evaluation index includes at least one of the peak value of the surface temperature rise of the mirror, the uniformity of the surface temperature distribution, the flow pressure drop and the face shape change amount; The geometric parameters are optimized based on the performance evaluation index; Step S3, etching the micro-flow channel on the machining surface of the first mirror body and the second mirror body according to the machining parameters of step S2; Step S4, grinding and cleaning the machining surface of the first mirror body and the second mirror body after the micro-flow channel etching; Step S4-1: using deionized water to perform initial washing on the machining surface of the first mirror body and the second mirror body to remove surface-attached dust and part of soluble impurities; Step S4-2: using cerium oxide to perform grinding treatment on the above machining surface to improve the surface flatness and remove residual particles or shallow defects in the etching process; Step S4-3: clean the ground processing surface using sodium bicarbonate, mainly to remove cerium oxide residues to avoid affecting the subsequent bonding interface; Step S4-4: flush the processing surface again with deionized water to completely remove impurities and solution residues generated during the cleaning process, ensuring that the surface cleanliness meets the requirements of the subsequent bonding process; Step S5, bond the first lens and the second lens to form a mirror, and the micro flow groove is bonded to form a micro flow channel in the mirror.

[0030] The above structure can form a closed cooling channel inside the lens through the symmetrical arrangement of the double mirror body and the complementary cooperation of the micro flow groove 3. The medium is introduced through the inlet, flows through the micro flow channel 4, and is discharged from the outlet, realizing effective heat dissipation of the entire mirror. The mirror body adopts a symmetrical structure design, which is beneficial to processing alignment and thermal field balance, and the micro flow channel 4 can be arranged according to the thermal load distribution. This structure not only ensures the temperature uniformity of the optical surface, but also improves the stability and life of the mirror in a high-power laser or high-speed scanning environment.

[0031] The above micro flow channel 4 can be realized by processing matching micro flow grooves 3 on the bonding surfaces of the first mirror body 1 and the second mirror body 2, and the complete closed flow path is formed after bonding. Each medium flow channel is independently formed and does not cross or communicate with each other, which is beneficial to control the path and distribution of the medium flow, improve the heat exchange efficiency and avoid the influence of fluid disturbance on the heat exchange stability of adjacent channels. This kind of single-in and single-out structure is particularly suitable for thermal control systems that use parallel cooling mode, and can further realize uniform distribution and collection of multiple flow channels by designing the inlet and outlet manifold structure, and enhance the overall thermal load carrying capacity.

[0032] Experimental data show that the heat dissipation heat flux density can be increased to 1500W / cm 2 , meeting the heat dissipation requirements of large energy transmission galvanometer. In addition, the mass of the same volume of gas is about 1 / 800 of that of liquid (water), and the calculation is as follows: ρ (air) = 1.2 kg / m 3 , ρ (water) = 1000 kg / m 3 , according to the Reynolds number formula: Re = μρvL, where: ρ: fluid density (kg / m 3 ), v: flow rate (m / s), L: characteristic length (m, such as pipe diameter or object size), μ: dynamic viscosity (Pa·s).

[0033] Under the same flow rate (v) and the same characteristic length (L), the degree of mechanical disturbance mainly depends on the Reynolds number: the smaller the Reynolds number, the more the flow tends to be laminar, and the lower the mechanical disturbance (such as turbulent noise or resistance).

[0034] Under standard conditions: the dynamic viscosity of water is about 1.000 mPa·s, and the dynamic viscosity of air is 0.018 mPa·s, so under the same flow rate, the Reynolds number of air is about 15 times that of water, and compared with water cooling, air cooling can reduce the vibration disturbance to 1 / 15 under the same flow rate.

[0035] Therefore, the mechanical vibration caused by air cooling can be ignored compared with traditional liquid cooling.

[0036] In some embodiments, a plurality of micro flow grooves are provided, and the plurality of micro flow grooves are independent of each other; The micro flow groove 3 is constructed by using a quartic Bezier curve, which is defined by five control points. For the i-th medium flow channel 7, the five control points are in turn a first control point , a second control point , a third control point , a fourth control point , and a fifth control point , and the coordinates of the control points in the two-dimensional plane are respectively:

[0037] wherein, , are the starting and ending horizontal coordinates of the micro flow channel 4, respectively; is the unified vertical coordinate baseline of the starting point and the ending point; is the middle offset coefficient; is the end offset coefficient, ; is the proportionality coefficient; is the horizontal offset length of the control point; The above construction method realizes fine control of the curvature, path length and spatial distribution of each micro flow channel 4 by accurately setting the control point coordinates of the Bezier curve, and adapts to the heat dissipation requirements of different regional heat flux distribution. Compared with a cubic curve, a quartic Bezier curve has higher degrees of freedom in terms of control point distribution and curvature change, which is convenient for constructing a flow channel profile with smooth transition and controllable flow resistance, and improves the flow stability and heat exchange efficiency of the fluid in the channel.

[0038] In some embodiments, the distribution mode of different middle micro flow channels 4 is set as one of symmetrically increasing, sinusoidal distribution or hyperbolic tangent function distribution by the middle offset coefficient ; In this embodiment, the middle offset coefficient is set according to the following sinusoidal function distribution:

[0039] wherein, i is the number of the medium flow channel 7, and the value range is 1≤i≤N, N is the total number of the medium flow channel 7, For a preset maximum offset value, the middle part of each medium flow channel 7 has an offset coefficient respectively acting on the third control point of the corresponding Bezier curve The longitudinal coordinate offset of the micro-flow channel 4 is determined by the offset coefficient.

[0040] In some embodiments, the mirror further comprises a frame 5, which is a ring structure, and is sleeved on the outer circumferential surface of the first mirror body 1 and the second mirror body 2. The frame 5 is provided with a first through hole and a second through hole which respectively communicate with the medium inlet and the medium outlet.

[0041] The frame 5 structure can be used as an external limiting and protection member, which provides mechanical support and constraint on one hand to prevent the first mirror body 1 and the second mirror body 2 from being misaligned or warped during installation, transportation or operation, and on the other hand can be used for external fastening after the mirror body is bonded and forms an axial closed support. The frame 5 is preferably made of metal or high-strength composite material to balance the thermal stability and structural strength. The sleeving form can be interference fit or detachable buckle structure, which is determined according to the system assembly mode.

[0042] In some embodiments, the first mirror body 1 is provided with a first limiting member, and the second mirror body 2 is provided with a second limiting member. The first limiting member and the second limiting member are correspondingly arranged. The inner circumferential surface of the frame 5 is provided with a first limiting groove and a second limiting groove. The first limiting member is slidably arranged in the first limiting groove, and the second limiting member is slidably arranged in the second limiting groove.

[0043] The above-mentioned limiting structure can be realized by radial embedding or axial guide groove structure to realize matching connection, which provides initial positioning and auxiliary alignment function during mirror body bonding process, and provides reliable limiting support under the action of heat or vibration load to avoid the risk of leakage caused by misplacement of micro-flow channel 4 or misalignment of sealing surface. The limiting member can be a boss, a tooth, a pin, etc., and the limiting groove can be a corresponding groove or slide rail, which is preferably symmetrically arranged at the bonding edge to ensure the structural integrity and mirror symmetry after assembly.

[0044] In some embodiments, the micro-flow channel is parameterized modeled, the cross section of one end of the micro-flow channel is one of rectangular, trapezoidal or circular arc, and the cross section of the other end of the micro-flow channel is semicircular.

[0045] In this embodiment, the micro-flow channel 4 is etched on the lens by femtosecond laser to form a three-dimensional micro-flow channel 3, and the femtosecond laser is used to polish the groove wall of the micro-flow channel 3. The cross-sectional shape of the flow channel is gradually changed and transitioned from the trapezoidal shape at the inlet end to the circular shape at the outlet end through parameterized modeling. The upper side length of the trapezoidal shape at the inlet end is 150 μm, the lower side length is 200 μm, and the diameter of the circular shape at the outlet end is 180 μm. This can increase the turbulence intensity of the cooling working medium (such as supercritical CO2) by 40%, and the heat exchange coefficient reaches 380 W / (m 2 ·K).

[0046] The cross-section change design helps to form a larger flow cross-section when the cooling medium enters the initial section of the micro-channel 4, so as to reduce the inlet flow resistance and improve the initial distribution uniformity. The trapezoidal or circular arc cross-section optimizes the boundary layer development and cooling coverage while ensuring the flow rate. The outlet section is set to a semicircular cross-section, which can effectively guide the fluid to converge and discharge, and reduce the vortex and backflow phenomenon caused by the sharp change of the cross-section, further improving the overall flow stability. The above cross-section shape can be formed by micron-level etching, laser processing or MEMS process, and the specific cross-section size can be accurately designed according to the flow demand and pressure drop tolerance of the target cooling medium.

[0047] In some embodiments, the bonding method of the fixed and attached connection between the first mirror body 1 and the second mirror body 2 adopts one of the following methods: adhesive solution and heat curing method, hydroxyl bonding method, or laser-assisted anodic bonding method.

[0048] Laser-assisted anodic bonding (Laser-Assisted Anodic Bonding) is a high-strength, low-pollution micro-connection technology suitable for glass-glass or glass-silicon material packaging. This method applies a certain voltage to the bonding interface and locally heats it with a laser, causing mobile ions in the glass to migrate to the interface under the action of the electric field, forming a permanent bond. This connection method has the advantages of controllable processing temperature, high interface cleanliness, and suitability for high-precision alignment, and is particularly suitable for scenarios where there are microstructures (such as micro-channels 3) inside the mirror body and high requirements for flatness and sealing. Using this connection method can effectively avoid the problems of mirror body thermal stress accumulation or deformation caused by traditional gluing or hot pressing methods, further improving the thermal stability and reliability of the product.

[0049] Under the premise of ensuring the integrity of the structure, the lens mass is reduced to 3.2g, and the moment of inertia is reduced by 62%. Finite element analysis shows that when subjected to a 200W laser power input, the maximum temperature rise on the lens surface is controlled within 18℃, and the thermal-induced surface error is less than λ / 20 (λ is the processing laser wavelength), which is 5 times better than the traditional structure. More importantly, the micro-channel 4 network forms a multi-stage stress buffer structure through topology optimization, and under a 3kg impact load, the von Mises stress peak value of the lens base is reduced from 850MPa in the traditional design to 210MPa, and the bending stiffness is increased to 1.8×104N·mm 2 , which can ensure that the angular positioning accuracy is maintained at ±5μrad after 107 scanning cycles.

[0050] In some embodiments, at the level of the manufacturing process, the present solution adopts an innovative architecture of double-mirror bonding: first, a 532 nm picosecond laser is used to etch a microfluid channel structure with a depth of 400 μm on two groups of single-crystal silicon substrates with a thickness of 0.5 mm. The microfluid channel patterns of the two groups of mirrors are strictly mirror-symmetrically designed, and a laser-assisted anodic bonding technique is used to realize atomic-level interface fusion under the condition of 350 ℃ and 1500 V bias voltage, forming an integrated flow structure with a total thickness of 1 mm. This process ensures that the flow path of the cooling medium in the flow channel is completely symmetrical, effectively eliminating the temperature gradient caused by traditional single-sided cooling, and making the thermal distribution uniformity of the mirror working surface reach ±1.2 ℃. To enhance the structural reliability, a 200 nm thick silicon nitride transition layer is deposited at the bonding interface, which has a high matching coefficient of thermal expansion (2.3×10-6 / ℃) with silicon material (2.6×10-6 / ℃), and after 1000 thermal cycle tests from -196 ℃ to 300 ℃, the interface shear strength remains above 85 MPa. Experimental data show that the angle repeatability of the composite mirror reaches ±2 μrad at a scanning frequency of 20 kHz, which is 4 times higher than that of the traditional design, and the laser-induced wavefront distortion is controlled within λ / 50, providing hardware support for the development of high-power laser processing systems towards higher precision and faster speed.

[0051] In some embodiments, the present application provides a test method based on a microfluid channel heat dissipation mirror, comprising the following steps: Step a, introducing supercritical carbon dioxide working medium into the microfluid channel 4 of the mirror, so that it circulates and flows continuously in the microfluid channel 4, the supercritical carbon dioxide is delivered by a working medium system, and the flow control is carried out under the condition of maintaining it in a supercritical state; Step b, applying a heat source on one coated surface of the mirror to simulate the thermal load condition under working condition, the heat source can be a planar heat source, a radiation heat source or other forms of controllable heating device; Step c, during the set test period, the supercritical carbon dioxide continuously circulates, and the mirror temperature, fluid outlet temperature and pressure and other parameters are recorded by a sensing system, the measurement data can include the temperature distribution of the mirror surface, the temperature difference between the inlet and outlet, the fluid pressure fluctuation, etc.; The test period in this embodiment is 100 h; Step d, based on the data collected during the test, the thermal response behavior of the mirror is analyzed, and the thermal stability, structural integrity and aging trend of the mirror under the action of supercritical working medium are evaluated.

[0052] Through the test method provided by the present embodiment, the performance of the mirror can be quantitatively and qualitatively evaluated under conditions close to the actual working conditions, providing experimental basis for the application adaptability and reliability verification of the mirror.

[0053] The terminology used in this description is for the purpose of describing particular embodiments only and is not intended to be limiting of one or more embodiments described in this description. As used in this description and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or," as used herein, refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0054] It will be understood that, although the terms first, second, third, etc. can be used herein to describe various information, the information should not be limited to these terms. These terms are used only to distinguish one piece of information from another. For example, a first information could be termed a second information "without departing from the scope of one or more embodiments. As used herein, the term "if' can be construed to mean "when" or "upon" or "in response to determining" depending on the context.

[0055] The foregoing is merely illustrative of the principles of one or more embodiments described herein and various modifications can be made to the embodiments described without departing from the scope of the disclosure. For example, the above-described embodiments (and / or aspects thereof) can be used in combination with each other as is deemed suitable by the user or person of ordinary skill in the art. Other embodiments are set forth within the following claims.

Claims

1. A method for fabricating a reflector based on microchannel heat dissipation, characterized in that, Includes the following steps: Step S1: Obtain two mirror bodies, namely the first mirror body and the second mirror body, and obtain the three-dimensional data of the mirror bodies. Apply a reflective coating to one coating surface of the first mirror body and the second mirror body respectively. Step S2: Design the shape of the microfluidic channel and calculate its size based on the three-dimensional data of the mirror body, and output the processing parameters based on the shape and size of the microfluidic channel; Step S3: Perform microchannel etching on the machining surfaces of the first mirror body and the second mirror body according to the machining parameters in step S2; Step S4: Grind and clean the machining surfaces of the first and second mirror bodies after microchannel etching; Step S5: Bond the first lens and the second lens to form a reflector. At the same time, the microchannels are bonded together to form microchannels in the reflector.

2. The method for fabricating a reflector based on microchannel heat dissipation according to claim 1, characterized in that, In step S1, a reflective coating is deposited on one coating surface of the first mirror and the second mirror by physical vapor deposition or chemical vapor deposition.

3. The method for fabricating a reflector based on microchannel heat dissipation according to claim 1, characterized in that, In step S2, the microfluidic channel is modeled parametrically. The cross-section of one end of the microfluidic channel is one of a rectangle, trapezoid, or arc, and the cross-section of the other end of the microfluidic channel is a semi-circle.

4. The method for fabricating a reflector based on microchannel heat dissipation according to claim 3, characterized in that, The parameter acquisition process is executed in step S2, including: A microfluidic channel parameter optimization model is established, and the geometric parameters of the microfluidic channel are used as initial parameters to input into the microfluidic channel parameter optimization model; Performance evaluation indicators are output through coupled heat transfer, fluid and structure simulation calculations. Performance evaluation indicators include at least one of the following: peak surface temperature rise of the mirror, uniformity of surface temperature distribution, flow pressure drop, and surface shape change; Geometric parameters are optimized based on performance evaluation metrics.

5. The method for fabricating a reflector based on microchannel heat dissipation according to claim 4, characterized in that, The process of optimizing geometric parameters includes: Establish optimization criteria for judging the merits of a product or service. The optimization criteria include at least one of threshold judgment based on performance evaluation indicators, weighted scoring, or non-dominated ranking. Calculate the comprehensive evaluation value of the current geometric parameters and determine the optimization direction based on the optimization criteria; The optimization direction is obtained through at least one of the following methods: weighted gradient, derivativeless search, or parameter selection strategy based on the acquisition function; Candidate update parameters are generated according to the step size strategy, and the feasibility of the candidate update parameters is verified. Feasibility verification should include at least the constraints of geometric boundaries, machining tolerances, and operational boundaries; Among the candidate update parameters that have passed the feasibility verification, the parameters with a comprehensive evaluation value that is better than the current geometric parameters are selected as update parameters for geometric parameter optimization.

6. The method for fabricating a reflector based on microchannel heat dissipation according to claim 1, characterized in that, In step S3, picosecond laser processing is used to etch the microfluidic grooves, and femtosecond laser is used to polish the walls of the microfluidic grooves.

7. The method for fabricating a reflector based on microchannel heat dissipation according to claim 1, characterized in that, Step S4 includes the following steps: Step S4-1: Rinse the machined surfaces of the first and second mirror bodies once with deionized water; Step S4-2: Grind the machined surfaces of the first mirror body and the second mirror body using cerium oxide; Step S4-3: Use sodium bicarbonate to clean the cerium oxide on the machined surfaces of the first and second mirror bodies; Step S4-4: Use deionized water to perform a second rinse on the machined surfaces of the first and second mirror bodies.

8. The method for fabricating a reflector based on microchannel heat dissipation according to claim 1, characterized in that, In step S5, the bonding method is one of the following: adhesive solution and thermosetting, hydroxyl bonding, or laser-assisted anodic bonding.

9. The method for fabricating a reflector based on microchannel heat dissipation according to claim 8, characterized in that, The bonding method adopts laser-assisted anodic bonding. A 200nm thick silicon nitride transition layer is deposited at the bonding interface. The 200nm silicon nitride transition layer is set in the bonding ring area and maintains a distance of not less than a preset gap from the edge of the nearest microchannel.

10. The method for fabricating a reflector based on microchannel heat dissipation according to claim 1, characterized in that, In step S5, the first mirror body and the second mirror body are bonded together by a frame. The frame is a ring structure and is fitted onto the outer circumferential surface of the first mirror body and the second mirror body. The can body is provided with a first through hole and a second through hole, which are respectively connected to the two ends of the microchannel.

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