高功率半导体激光器微通道热沉模拟优化及SLM制造

发布时间：2018-04-04 23:32

  本文选题：微通道热沉　切入点：散热性能　出处：《北京工业大学》2015年硕士论文

【摘要】：半导体激光器因其转换效率高、寿命长、体积小、重量轻、可靠性高、能直接调制且易与其他半导体器件集成等优点,广泛应用于工业加工、激光医疗、激光通讯、信息显示,航空航天等领域。高的光输出功率带来的高耗散热量如不及时消除会造成温升导致阈值电流升高,效率降低,激光波长发生温漂等影响光束质量。芯片温度的控制是半导体激光器发展中的一个重要的研究领域,微通道热沉作为半导体激光器主要的散热方式已成为其高性能工作的关键器件。依据计算流体力学和计算传热学理论,从实验影响物理量出发选择并确定控制方程,使用有限体积法对控制方程离散,基于一款微通道热沉确立物理和数学模型,对导入模型加载边界条件和初始参数,用可实现k-?模型作为湍流计算模型。利用FLUENT软件进行了微通道热沉内部通道流场温度场的数值计算和后处理。影响微通道热沉散热性能的主要结构因素是:进出口宽度、微通道宽度、间距、高度及通道脊长度。通过数值模拟分别研究了进水通道流量不均匀的原因;在微通道高度进出口宽度为固定值的条件下微通道宽度,间距,通道脊长度和壁面粗糙度4个因素分别对芯片表面温升和压降散热性能的影响规律两个方面。提出改进方案优化进水层通道结构使返水孔流量均匀化;表面温升随微通道间距、宽度、通道脊长度变小而降低但趋势放缓,压降随间距减小宽度增加而减小,随长度增加而增大;一定范围内,温升随壁面粗糙度增大而减小,压降随之增大而增大。数值计算获得特定外形尺寸下最优内通道结构尺寸参数,理论上验证了SLM工艺表面质量对热沉散热性能提升可行性。最优结构热沉热阻为0.34K/W,压降为0.9bar。利用EOS M270成型设备从工艺参数对成型件致密度和表面粗糙度的影响规律;纯镍微小结构成型质量;热沉摆放方式和支撑添加方法3个方面来研究采用SLM制造纯镍微通道热沉的工艺。得到成型质量最优的工艺参数、成型尺寸范围及成型摆放和支撑添加方法,并制造出经数值计算优化的微通道热沉。将成型的微通道热沉表面处理后与单bar输出功率80W的半导体芯片封装进行功率光谱等激光参数测试,经测量得在流量0.3L/min下芯片表面温升18℃,计算得此微通道热沉热阻0.39K/W,压降1.4bar,满足芯片散热要求,验证了优化方案的可行性。
[Abstract]:Semiconductor lasers are widely used in industrial processing, laser medical treatment, laser communication and information display because of their advantages such as high conversion efficiency, long life, small volume, light weight, high reliability, direct modulation and easy integration with other semiconductor devices.Aerospace and other fieldsIf the high heat dissipation caused by high optical output power is not eliminated in time, the threshold current will increase, the efficiency will decrease, and the laser wavelength temperature drift will affect the beam quality.The control of chip temperature is an important research field in the development of semiconductor lasers. As the main heat dissipation mode of semiconductor lasers, microchannel heat sink has become the key component of its high performance work.According to the theory of computational fluid dynamics and computational heat transfer, the governing equations are selected and determined from the experimental effects of physical quantities. The control equations are discretized by the finite volume method, and the physical and mathematical models are established based on a microchannel heat sink.For the import model to load boundary conditions and initial parameters, using the implementable k-?The model is used as turbulence calculation model.The numerical calculation and post-processing of the flow field temperature field in the microchannel heat sink are carried out by using FLUENT software.The main structural factors affecting the heat sink performance of microchannel are the width of inlet and outlet, the width of microchannel, the spacing, the height and the length of channel ridge.Through numerical simulation, the causes of the inhomogeneous flow in the inlet channel are studied respectively, and the width and spacing of the microchannel under the condition of fixed inlet and outlet width of the microchannel height are studied.The influence of channel ridge length and wall roughness on the performance of temperature rise and pressure drop on the chip surface is discussed in this paper.An improved scheme is proposed to optimize the structure of the influent layer channel so as to homogenize the flow rate of the backwater hole, and the surface temperature rise decreases with the distance between the microchannels, the width and the length of the channel ridge, but the trend slows down, and the pressure drop decreases with the decrease of the spacing width.The temperature rise decreases with the increase of the wall roughness and the pressure drop increases with the increase of the length.The optimal structural parameters of the inner channel are obtained by numerical calculation. It is proved theoretically that the surface quality of SLM process can improve the heat sink performance.The heat sink resistance of the optimal structure is 0.34 K / W and the pressure drop is 0.9bar.The effect of process parameters on density and surface roughness of molded parts was studied by using EOS M270 forming equipment.In this paper, the heat sink process of pure nickel microchannel made by SLM was studied in three aspects: heat sink arrangement and support addition method.The optimum process parameters, forming dimension range, forming arrangement and support adding method were obtained, and the heat sink of microchannel was fabricated by numerical calculation.The fabricated microchannel heat sink surface was treated with a semiconductor chip with a single bar output power of 80W. The laser parameters such as power spectrum were measured, and the temperature rise of the chip surface was measured at 18 鈩，

本文编号：1712220