A mirror preparation method based on micro-channel heat dissipation

Abstract

The application belongs to the technical field of reflectors, and specifically discloses a reflector preparation method based on micro-flow channel heat dissipation, which comprises the following steps: obtaining first and second mirror bodies and plating a reflecting film on one side of each mirror body; performing micro-flow channel parameterization design according to three-dimensional data of the mirror bodies, establishing an optimization model with only geometric parameters as independent variables, outputting performance evaluation indexes through coupling heat transfer-fluid-structure simulation, and iteratively updating the geometric parameters based on the evaluation results; generating processing parameters, forming micro-flow channels by adopting picosecond laser etching, and polishing the channel walls by adopting femtosecond laser; sequentially performing deionized water flushing, cerium oxide grinding, sodium bicarbonate cleaning, and secondary flushing; and bonding the two mirror bodies into a mirror surface. The method realizes the comprehensive optimization of low temperature rise, low surface shape change and low pressure drop of the mirror surface under the constraints of processing, tolerance and operation boundary, and improves the optical stability and reliability under high-power application.

Description

Technical Field

[0001] This invention belongs to the field of reflector technology, specifically relating to a method for fabricating a reflector based on microchannel heat dissipation. Background Technology

[0002] 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 reflectors. A typical galvanometer system consists of a servo motor, a reflector assembly, a heat dissipation module, and a control circuit. The material properties of the reflectors directly determine the system's power handling capacity and dynamic response capability. 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.

[0003] The thermal management capability of the mirror in the laser beam transmission path is a crucial factor limiting the improvement of system performance. To reduce the mirror surface temperature rise caused by laser irradiation, various mirror designs with integrated cooling structures have been proposed in the prior art.

[0004] Existing technology, such as the patent with publication number CN216850730U, discloses a reflective unit and a high-power laser system, including a reflector and a cooling structure disposed on its back. The cooling structure has a cooling cavity, and multiple fluid channels for cooling fluid are arranged inside the cavity. These channels are typically defined by multiple protruding isolation walls, extending along the long axis of the reflector and arranged in an arc shape. The entire structure is sealed by a cover to form a cooling channel, and fluid inlets and outlets are provided to achieve liquid cooling.

[0005] Although the above solutions improve the heat dissipation capacity of the reflector to some extent, the following significant problems still exist: The design of the cooling channel structure is unreasonable and the fluid flow path is restricted: In the existing technology, the channel layout is mostly a simple parallel linear arrangement with a single topology, which makes it difficult to achieve uniform distribution of cooling medium and efficient heat exchange, and easily leads to local hot spots and heat dissipation blind spots. The cooling chamber cover structure is prone to adhesive gaps and has a large interface thermal resistance: the method of mechanically aligning and bonding the cover to seal the cooling chamber often results in loose bonding during the manufacturing process, leading to a decrease in cooling efficiency. Summary of the Invention

[0006] This invention addresses the problems in the prior art by providing a method for fabricating a reflector based on microchannel heat dissipation, thereby solving the problem of loose bonding and reduced cooling efficiency caused by assembly accuracy issues when fixing a cooling device externally to the reflector in the aforementioned background art.

[0007] The technical solution adopted in this invention is as follows: In a first aspect, this application provides a method for fabricating a reflector based on microchannel heat dissipation, comprising 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.

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

[0009] Furthermore, in step S2, the microfluidic channel is modeled parametrically, with the cross-section of one end of the microfluidic channel being one of a rectangle, trapezoid, or arc shape, and the cross-section of the other end of the microfluidic channel being a semi-circle.

[0010] Furthermore, in step S2, the parameter acquisition process is executed, 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.

[0011] Furthermore, the process of optimizing the 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.

[0012] Furthermore, in step S3, the microfluidic grooves are etched using a picosecond laser and the walls of the microfluidic grooves are polished using a femtosecond laser.

[0013] Furthermore, 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.

[0014] Furthermore, in step S5, the bonding method is one of the following: adhesive solution and thermosetting, hydroxyl bonding, or laser-assisted anodic bonding.

[0015] Furthermore, the bonding method adopts laser-assisted anodic bonding, and 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.

[0016] Furthermore, 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.

[0017] As can be seen from the above technical solutions, the advantages of the present invention are: By designing the shape of the microchannel based on the three-dimensional data of the mirror body and performing laser etching based on parametric modeling, the layout accuracy and fitting degree of the microchannel structure are effectively improved, avoiding the problems of unreasonable microchannel setting and low cooling channel utilization in the existing technology. By employing a combination of grinding, cleaning, and high-reliability bonding processes, the uniformity of microchannel alignment and the integrity of the bonding interface between the first and second mirror bodies are ensured. This significantly reduces the risk of large gaps forming when the cover and mirror body are bonded together, and improves the sealing performance and structural stability of the microchannels. 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] Figure 1 This is a flowchart of the microchannel-based heat dissipation method for fabricating a reflector in the embodiment; Figure 2 This is an exploded view of the reflector structure in the embodiment; Figure 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 mirrors are generally made of solid glass or fused silica, whose high density results in a significant increase in rotational inertia. This large rotational inertia places a redundant load on the motor, hindering further improvements in high-frequency scanning performance. For example, a fused silica mirror with a diameter of 30mm and a thickness of 5mm weighs approximately 8.5g. At a scanning frequency exceeding 2000 scans per second, the motor needs to overcome an inertial torque as high as 0.15 N·m. This not only causes a drive energy loss of up to 20% but also limits the possibility of breaking through the scanning frequency range above 10kHz.

[0024] Furthermore, after a portion of the energy from a high-energy laser is absorbed by the scanning galvanometer, it is converted into heat, leading to a localized temperature increase, causing beam wavefront distortion, and degrading the performance of the optical system. For example, in precision machining scenarios, the galvanometer must meet stringent requirements such as beam pointing repeatability error <0.1 mrad and angular resolution <1 μrad. Taking a traditional 20 mm diameter mirror as an example, when the laser power reaches 1 kW, if the absorbed 2% energy (approximately 20 W) cannot dissipate in time, it will cause the mirror surface temperature to rise by more than 50 °C, inducing thermal expansion deformation of 0.5-1.5 μm, resulting in a spot diameter increase of more than 30%, severely affecting the process quality of micro-hole machining (hole diameter tolerance must be <5 μm) and thin plate welding (weld penetration consistency requirement ±3%). This is mainly because the thermal conductivity of quartz material is only 1.38 W / (m·K), and under the action of a kilowatt-level laser, the local temperature gradient of the lens can reach 80 °C / cm. 2 This results in thermal stress deformation exceeding λ / 4 (λ=1,064nm), wavefront distortion causing a focal point shift of ±25μm, and a 40% decrease in spot energy density.

[0025] Existing technology, such as the patent with publication number CN216850730U, discloses a reflective unit and a high-power laser system, including a reflector and a cooling structure disposed on its back. The cooling structure has a cooling cavity, and multiple fluid channels for cooling fluid are arranged inside the cavity. These channels are typically defined by multiple protruding isolation walls, extending along the long axis of the reflector and arranged in an arc shape. The entire structure is sealed by a cover to form a cooling channel, and fluid inlets and outlets are provided to achieve liquid cooling.

[0026] Although the above solutions improve the heat dissipation capacity of the reflector to some extent, the following significant problems still exist: The design of the cooling channel structure is unreasonable and the fluid flow path is restricted: In the existing technology, the channel layout is mostly a simple parallel linear arrangement with a single topology, which makes it difficult to achieve uniform distribution of cooling medium and efficient heat exchange, and easily leads to local hot spots and heat dissipation blind spots. The cooling chamber cover structure is prone to adhesive gaps and has a large interface thermal resistance: the method of mechanically aligning and bonding the cover to seal the cooling chamber often results in loose bonding during the manufacturing process, leading to a decrease in cooling efficiency.

[0027] Please see Figures 1-3 As shown, this embodiment provides a method for fabricating a mirror based on microchannel heat dissipation. The fabricated mirror is suitable for applications in high-heat-load optical systems with high requirements for thermal control and deformation suppression.

[0028] Specifically, this application provides a method for fabricating a reflector based on microchannel heat dissipation, comprising 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. A reflective coating is applied to one of the coating surfaces of the first and second mirrors by physical vapor deposition or chemical vapor deposition. 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; 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.

[0029] 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; Optimize geometric parameters based on performance evaluation metrics; 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 S4-1: Use deionized water to perform an initial rinse on the machined surfaces of the first and second mirror bodies to remove surface dust and some soluble impurities. Step S4-2: The above-mentioned processed surface is ground with cerium oxide to improve the surface flatness and remove residual particles or shallow defects from the etching process. Step S4-3: Clean the machined surface after grinding with sodium bicarbonate, mainly to remove cerium oxide residue and avoid its impact on the subsequent bonding interface; Step S4-4: Rinse the processed surface again with deionized water to thoroughly remove impurities and solution residues generated during the cleaning process, and ensure 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 reflector. At the same time, the microchannels are bonded together to form microchannels in the reflector.

[0030] The aforementioned structure, through the symmetrical arrangement of the two mirror bodies and the complementary cooperation of the microchannels 3, can form a closed cooling channel inside the mirror. The medium is introduced through the inlet, flows through the microchannels 4, and is discharged from the outlet, achieving effective heat dissipation for the entire mirror. The mirror body adopts a symmetrical structural design, which is beneficial for processing alignment and thermal field equalization, while the microchannels 4 can be customized according to the heat load distribution. This structure not only ensures the temperature uniformity of the optical surface but also improves the stability and lifespan of the mirror under high-power laser or high-speed scanning environments.

[0031] The aforementioned microchannels 4 can be realized by machining matching microgrooves 3 on the mating surfaces of the first mirror 1 and the second mirror 2, forming a complete closed flow path after mating. Each medium flow channel is independently formed, without intersection or connection with each other, which is beneficial for controlling the path and distribution of medium flow, improving heat exchange efficiency, and avoiding the impact of fluid disturbance on the heat exchange stability of adjacent channels. This type of single-inlet single-outlet structure is particularly suitable for thermal control systems using parallel cooling methods. By designing the inlet and outlet manifold structure, the uniform distribution and collection of multiple channels can be further achieved, enhancing the overall heat load carrying capacity.

[0032] Experimental data show that the heat flux density can be increased to 1500 W / cm². 2 This meets the heat dissipation requirements of high-energy transmission galvanometers. Furthermore, the mass of a gas of the same volume is approximately 1 / 800 that of a liquid (water), calculated based on the following: ρ (air) = 1.2 kg / m³. 3 ρ(water) = 1000 kg / m³ 3 According to the Reynolds number formula: Re = ρvLμRe = μρvL, where: ρ: fluid density (kg / m³) 3 v: flow velocity (m / s), L: characteristic length (m, such as pipe diameter or object size), μ: dynamic viscosity (Pa·s).

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

[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. Therefore, at the same flow rate, the Reynolds number of air is about 15 times that of water. At the same flow rate, air cooling can reduce vibration disturbances to 1 / 15 compared to water cooling.

[0035] Therefore, the mechanical vibration caused by air cooling is negligible compared to that caused by traditional liquid cooling.

[0036] In some embodiments, multiple microchannels are provided, and the multiple microchannels are independent of each other; The microchannel 3 is constructed using a quartic Bézier curve, which is defined by five control points. For the i-th medium flow channel 7, the five control points are, in order, the first control point. Second control point Third control point Fourth control point With the fifth control point The coordinates of the control points in the two-dimensional plane are as follows:

[0037] in, , The x-coordinates are the starting and ending points of the microchannel, respectively. Establish a unified vertical coordinate baseline for the start and end points; This is the center offset coefficient; This is the end offset coefficient. ; This is the proportionality coefficient; The lateral offset length of the control point; The aforementioned construction method achieves precise control over the curvature, path length, and spatial distribution of each microchannel by accurately setting the coordinates of the control points of the Bézier curve, thus adapting to the heat dissipation requirements of different regions with varying heat flux distributions. Compared to cubic curves, quartic Bézier curves offer greater freedom in terms of the adjustability of control point distribution and curvature changes, facilitating the construction of channel profiles with smooth transitions and controllable flow resistance, thereby improving the flow stability and heat exchange efficiency of the fluid within the channel.

[0038] In some embodiments, the distribution pattern of different mid-section microchannels 4 is determined by the mid-section offset coefficient. It is set to one of the following: symmetrical increasing, sinusoidal distribution, or hyperbolic tangent function distribution; In this embodiment, the center offset coefficient The following sine function distribution is set:

[0039] Where i is the number of medium flow channel 7, and its value ranges from 1 to i to N, and N is the total number of medium flow channels 7. The maximum preset offset value is set as the mid-center offset coefficient for each medium flow channel 7. Each is applied to the third control point of its corresponding Bézier curve. The offset of the vertical axis.

[0040] In some embodiments, the reflector further includes a frame 5, which is an annular structure. The frame 5 is fitted onto the outer circumferential surface of the first mirror body 1 and the second mirror body 2. The frame 5 has a first through hole and a second through hole that are respectively connected to the medium inlet and the medium outlet.

[0041] The frame 5 structure serves as an external limiting and protective component. On one hand, it provides mechanical support and constraint to prevent misalignment or warping of the first mirror 1 and the second mirror 2 during installation, transportation, or operation. On the other hand, it can be used for external fastening after the mirrors are attached, forming an axially closed support. The frame 5 is preferably made of metal or high-strength composite material to balance thermal stability and structural strength. The fitting method can be an interference fit or a detachable snap-fit ​​structure, depending on the system assembly method.

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

[0043] The aforementioned limiting structure can be connected via radial embedding or axial guide groove structure. It provides initial positioning and auxiliary alignment during mirror assembly, and offers reliable limiting support under thermal or vibration loads on the mirror body, preventing leakage risks caused by misalignment of the microchannel 4 or sealing surface. The limiting component can be a boss, locking tooth, pin, etc., and the limiting groove can be a corresponding groove or slide rail, preferably symmetrically arranged at the mating edges to ensure the structural integrity and mirror symmetry after assembly.

[0044] In some embodiments, the microfluidic channel is modeled parametrically, with one end of the microfluidic channel having a cross-section that is rectangular, trapezoidal, or arc-shaped, and the other end having a semi-circular cross-section.

[0045] In this embodiment, the microchannel 4 uses a femtosecond laser to etch a three-dimensional microchannel 3 on the lens, and the wall of the microchannel 3 is polished using a femtosecond laser. Through parametric modeling, the cross-sectional shape of the channel gradually transitions from a trapezoid at the inlet end to a circle at the outlet end. The upper side length of the trapezoid at the inlet end is 150 μm, the lower side length is 200 μm, and the diameter of the circle at the outlet end is 180 μm. This can increase the turbulence intensity of the cooling medium (such as supercritical CO2) by 40%, achieving a heat transfer coefficient of 380 W / (m²). 2 ·K).

[0046] This cross-sectional variation design helps to create a larger flow cross-section when the cooling medium enters the initial section of the microchannel 4, reducing inlet flow resistance and improving initial distribution uniformity. Trapezoidal or arc-shaped cross-sections optimize boundary layer development and cooling coverage while ensuring flow rate. The semi-circular outlet section effectively guides fluid convergence and discharge, reducing vortices and backflow caused by abrupt cross-sectional changes, further enhancing overall flow stability. These cross-sectional shapes can be formed through micron-level etching, laser processing, or MEMS technology, and their specific dimensions can be precisely designed according to the flow rate requirements and pressure drop tolerance of the target cooling medium.

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

[0048] Laser-assisted anodic bonding (LAB) is a high-strength, low-pollution micro-connection technology suitable for encapsulation between glass-to-glass or glass-to-silicon materials. This method involves applying a voltage and localizing laser heating at the bonding interface, causing mobile ions in the glass to migrate to the interface under the influence of an electric field, forming a permanent bond. This connection method offers advantages such as controllable processing temperature, high interface cleanliness, and suitability for high-precision alignment. It is particularly suitable for scenarios where the internal structure of the mirror (such as microchannels) requires high flatness and sealing. Using this connection method effectively avoids the problems of thermal stress accumulation or uncontrolled deformation of the mirror body caused by traditional adhesive or hot-pressing methods, further improving the thermal stability and reliability of the product.

[0049] While maintaining structural integrity, the lens mass was reduced to 3.2g, and the moment of inertia was 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 thermally induced surface shape error is less than λ / 20 (λ is the processing laser wavelength), which is 5 times better than the traditional structure. More importantly, the microchannel 4 network forms a multi-level stress buffer structure through topology optimization. Under a 3kg impact load, the peak von Mises stress of the lens substrate is reduced from 850MPa in the traditional design to 210MPa, and the bending stiffness is increased to 1.8×10⁴ N·mm. 2 This ensures that the angular positioning accuracy remains at ±5 μrad after 107 scan cycles.

[0050] In some embodiments, at the manufacturing process level, this solution employs an innovative dual-lens bonding architecture: First, a 532nm picosecond laser is used to etch microfluidic channel structures with a depth of 400μm onto two 0.5mm thick single-crystal silicon substrates. The microfluidic channel patterns of the two lenses are designed with strict mirror symmetry. Using laser-assisted anodic bonding technology, atomic-level interface fusion is achieved under a bias voltage of 1500V and a temperature of 350℃, forming an integrated flow channel structure with a total thickness of 1mm. This process ensures that the flow path of the cooling medium within the flow channel is completely symmetrical, effectively eliminating the temperature gradient caused by traditional unilateral cooling, and achieving a heat distribution uniformity of ±1.2℃ on the working surface of the lens. To enhance structural reliability, a 200nm thick silicon nitride transition layer is deposited at the bonding interface. Its coefficient of thermal expansion (2.3×10-6 / ℃) is highly matched with that of silicon (2.6×10-6 / ℃). After 1000 thermal cycles from -196℃ to 300℃, the interfacial shear strength remains above 85MPa. Experimental data show that the composite lens achieves an angular repeatability accuracy of ±2μrad at a scanning frequency of 20kHz, which is 4 times higher than that of the traditional design. At the same time, it controls the laser-induced wavefront distortion 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, this application provides a testing method based on a microchannel heat dissipation reflector, comprising the following steps: Step a: Introduce supercritical carbon dioxide working fluid into the microchannel 4 of the reflector, so that it continuously circulates in the microchannel 4. The supercritical carbon dioxide is transported by the working fluid supply system and its flow is controlled under the condition of maintaining it in a supercritical state. Step b: Apply a heat source to one of the coated surfaces of the reflector to simulate the heat load conditions under working conditions. The heat source can be a surface heat source, a radiant heat source, or other forms of controllable heating device. Step c: Within the set test cycle, supercritical carbon dioxide is continuously circulated, and parameters such as mirror temperature, fluid outlet temperature and pressure are recorded through a sensing system. The measurement data may include the temperature distribution on the surface of the mirror, the temperature difference between the inlet and outlet, and fluid pressure fluctuations. The testing period in this embodiment is 100 hours; Step d: Based on the data collected during the test, analyze the thermal response behavior of the reflector and evaluate its thermal stability, structural integrity and aging trend under the action of supercritical working fluid.

[0052] The testing method provided in this embodiment enables quantitative and qualitative evaluation of the performance of a reflector under near-real-world operating conditions, providing experimental evidence for verifying its application adaptability and reliability.

[0053] The terminology used in one or more embodiments of this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this specification. The singular forms “a,” “described,” and “the” as used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this embodiment refers to and includes any or all possible combinations of one or more associated listed items.

[0054] It should be understood that although the terms first, second, third, etc., may be used to describe various information in one or more embodiments of this specification, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of one or more embodiments of this specification, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "in response to a determination," or "when," or "in the event of a determination."

[0055] The above description is merely a preferred embodiment of one or more embodiments of this specification and is not intended to limit the scope of one or more embodiments of this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of this specification should be included within the protection scope of one or more embodiments of this specification.

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; The microfluidic channel is modeled parametrically and constructed using a fourth-order Bézier curve. The distribution of different mid-section microchannels is determined by the mid-section offset coefficient. Based on the distribution of the sine function: in This is the numbering of the medium flow channel. This represents the total number of media flow channels. This is the preset maximum offset value; 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; Picosecond lasers are used to etch three-dimensional microfluidic channels on a lens, and femtosecond lasers are used to polish the walls of the microfluidic channels, so that the cross-sectional shape of the channel gradually transitions from a trapezoid at the inlet end to a circle at the outlet end. The upper side of the trapezoid at the inlet end is 150μm long and the lower side is 200μm long, while the diameter of the circle at the outlet end is 180μm. 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, and at the same time, the microchannels are bonded to form microchannels in the reflector. 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. A certain voltage is applied to the bonding interface and local laser heating is performed, causing mobile ions in the glass to migrate to the interface under the action of an electric field, forming a permanent bond.

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, 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.

4. The method for fabricating a reflector based on microchannel heat dissipation according to claim 2, 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.

5. 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.

6. 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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