集成微热管的LED硅基板研制
发布时间：2018-08-19 16:46
【摘要】：全球能源短缺的忧虑再度加剧,节能减排是我们面临的重要问题。发光二级管(LED)作为一种新型半导体固态冷光源在照明领域逐步推广,并以其节能、环保的优势为大家熟知。然而,在现有研究水平下,只有15-30%的输入功率转化为光能,其余均转化为热量,造成LED芯片的结温升高,使得发光谱线漂移、光衰提早、寿命缩短。因此提高散热效率并实现结温稳定控制,是大功率LED器件设计和制造中的关键问题。硅的导热系数较高且加工工艺成熟,是目前LED模组基板材料的发展趋势之一。微热管采用相变传热的原理具有很高的导热系数,因此本文中集成热管的LED硅基板模组探索了一种高效散热新方法以减小从芯片到环境的热阻,将平板槽道微热管和蒸汽腔微热管集成于硅基板上,减少了热界面。本文针对3-10W不同功率的LED模组,采用MEMS加工工艺在硅基板两面分别加工微槽道和LED电极,与具有蒸汽腔的Pyrex7740玻璃盖板或铝翅片键合形成集成微热管的LED硅基板本体结构。对微热管抽真空后灌注一定量除气后的去离子水作为工质后,采用导电银浆将1W的LED芯片固晶到LED硅基板的基座上,并采用超声引线的方法,用金线实现芯片和电极连接。对研制的硅基板分别在真空绝热环境中和大气环境中进行导热性能测试,实验表明集成微热管的LED硅基板均能实现有效散热,梯形结构平板槽道微热管导热系数较硅提高5.65倍。为研究微槽道结构尺寸和表面能对平板槽道微热管性能的影响,改变硅基微槽道形状,设计了梯形和侧壁二级结构。接触角测量表明,采用两种结构微槽道比平行槽道更亲水,导热性能测试表明两种结构槽道微热管与同尺寸平行槽道微热管的当量导热系数分别提升了18.52.151.83%和7.71-9.62%。采用电铸铜柱和沉积石墨烯改性硅微槽道特性。其中,电铸铜柱提高了槽道的亲水性,电喷雾沉积的片状石墨烯使槽道疏水。导热性能测试发现铜柱改性后的平板槽道微热管以蒸汽腔方式工作,而石墨烯改性后的平板槽道微热管比同尺寸未改性微热管的稳定温度降低了4.87%。此外,电铸工艺在硅基板上加工的铜微槽道比同尺寸硅微槽道更亲水,使当量导热系数提升了约17%。以上对平板槽道微热管改性方法可以改善微槽道亲疏水性,改变毛细牵引力,使管内工质循环更有效,从而提升微热管性能。综上,本文针对大功率LED器件,设计并制作了集成微热管的LED硅基板,对其槽道结构和表面特性进行了优化,结果表明研制的基板有效提高了热量传输能力,研究结果对大功率LED器件的高效热输运和结温的稳定控制具有指导和借鉴意义。
[Abstract]:Global energy shortage concerns are growing again, energy conservation and emission reduction is an important problem we face. As a new type of semiconductor solid-state cold light source, the light-emitting secondary transistor (LED) has been gradually popularized in the field of lighting, and is well known for its advantages of energy saving and environmental protection. However, at the present research level, only 15-30% of the input power is converted to light energy, while the rest is converted into heat, which results in the rise of junction temperature of LED chip, the drift of luminescence spectrum line, the early light decay and the shortening of the lifetime. Therefore, it is a key problem in the design and manufacture of high power LED devices to improve the efficiency of heat dissipation and to realize the stable control of junction temperature. Silicon has high thermal conductivity and mature processing technology, which is one of the development trends of LED module material. The principle of phase change heat transfer in micro-heat pipe has high thermal conductivity. Therefore, the LED silicon substrate module integrated with heat pipe in this paper has explored a new method of high efficiency heat dissipation in order to reduce the thermal resistance from chip to environment. The thermal interface is reduced by integrating the flat groove micro-heat pipe and the steam cavity micro-heat pipe on the silicon substrate. In this paper, for 3-10W LED modules with different power, microchannel and LED electrode are machined on both sides of silicon substrate by MEMS process. The bulk structure of LED silicon substrate integrated microheat pipe is formed by bonding with Pyrex7740 glass cover plate with steam cavity or aluminum fin. After a certain amount of deionized water was poured into the microheat pipe after vacuum, the 1W LED chip was immobilized onto the base of the LED silicon substrate by conducting silver paste, and the connection between the chip and the electrode was realized by the method of ultrasonic lead and gold wire. The thermal conductivity of the fabricated silicon substrate in vacuum adiabatic environment and atmospheric environment is tested. The experimental results show that the LED silicon substrate integrated with micro-heat pipe can effectively dissipate heat, and the thermal conductivity of trapezoidal flat channel microheat pipe is 5.65 times higher than that of silicon. In order to study the effect of the structure size and surface energy of microchannel on the performance of microheat pipe with flat groove channel, the trapezoidal and lateral secondary structures were designed to change the shape of microgroove channel on silicon substrate. The measurement of contact angle shows that the microchannel with two structures is more hydrophilic than the parallel channel. The thermal conductivity tests show that the equivalent thermal conductivity of the micro-heat pipe with the same size and the same size increases by 18.52.151.83% and 7.71-9.62, respectively. The characteristics of silicon microchannel were modified by electroforming copper column and graphene deposition. Electroforming copper column improved the hydrophilicity of the channel, and the electrospray deposited flake graphene made the channel hydrophobic. The results of thermal conductivity test show that the copper column modified flat channel micro-heat pipe works in a steam chamber, while the graphene modified flat groove channel micro-heat pipe has a lower stable temperature of 4.87 than that of the same size unmodified micro-heat pipe. In addition, the copper microchannel fabricated on silicon substrate by electroforming process is more hydrophilic than that of silicon microchannel of the same size, which increases the equivalent thermal conductivity by about 17%. The above methods can improve the hydrophobicity of the microchannel, change the capillary tractive force, make the working fluid circulation more effective, and improve the performance of the micro-heat pipe. In summary, the LED silicon substrate integrated with microheat pipe is designed and fabricated for high power LED devices. The structure and surface characteristics of the channel are optimized. The results show that the developed substrate can effectively improve the heat transfer capacity. The results can be used as guidance and reference for high efficiency thermal transport and stability control of junction temperature for high power LED devices.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN312.8
本文编号：2192240
[Abstract]:Global energy shortage concerns are growing again, energy conservation and emission reduction is an important problem we face. As a new type of semiconductor solid-state cold light source, the light-emitting secondary transistor (LED) has been gradually popularized in the field of lighting, and is well known for its advantages of energy saving and environmental protection. However, at the present research level, only 15-30% of the input power is converted to light energy, while the rest is converted into heat, which results in the rise of junction temperature of LED chip, the drift of luminescence spectrum line, the early light decay and the shortening of the lifetime. Therefore, it is a key problem in the design and manufacture of high power LED devices to improve the efficiency of heat dissipation and to realize the stable control of junction temperature. Silicon has high thermal conductivity and mature processing technology, which is one of the development trends of LED module material. The principle of phase change heat transfer in micro-heat pipe has high thermal conductivity. Therefore, the LED silicon substrate module integrated with heat pipe in this paper has explored a new method of high efficiency heat dissipation in order to reduce the thermal resistance from chip to environment. The thermal interface is reduced by integrating the flat groove micro-heat pipe and the steam cavity micro-heat pipe on the silicon substrate. In this paper, for 3-10W LED modules with different power, microchannel and LED electrode are machined on both sides of silicon substrate by MEMS process. The bulk structure of LED silicon substrate integrated microheat pipe is formed by bonding with Pyrex7740 glass cover plate with steam cavity or aluminum fin. After a certain amount of deionized water was poured into the microheat pipe after vacuum, the 1W LED chip was immobilized onto the base of the LED silicon substrate by conducting silver paste, and the connection between the chip and the electrode was realized by the method of ultrasonic lead and gold wire. The thermal conductivity of the fabricated silicon substrate in vacuum adiabatic environment and atmospheric environment is tested. The experimental results show that the LED silicon substrate integrated with micro-heat pipe can effectively dissipate heat, and the thermal conductivity of trapezoidal flat channel microheat pipe is 5.65 times higher than that of silicon. In order to study the effect of the structure size and surface energy of microchannel on the performance of microheat pipe with flat groove channel, the trapezoidal and lateral secondary structures were designed to change the shape of microgroove channel on silicon substrate. The measurement of contact angle shows that the microchannel with two structures is more hydrophilic than the parallel channel. The thermal conductivity tests show that the equivalent thermal conductivity of the micro-heat pipe with the same size and the same size increases by 18.52.151.83% and 7.71-9.62, respectively. The characteristics of silicon microchannel were modified by electroforming copper column and graphene deposition. Electroforming copper column improved the hydrophilicity of the channel, and the electrospray deposited flake graphene made the channel hydrophobic. The results of thermal conductivity test show that the copper column modified flat channel micro-heat pipe works in a steam chamber, while the graphene modified flat groove channel micro-heat pipe has a lower stable temperature of 4.87 than that of the same size unmodified micro-heat pipe. In addition, the copper microchannel fabricated on silicon substrate by electroforming process is more hydrophilic than that of silicon microchannel of the same size, which increases the equivalent thermal conductivity by about 17%. The above methods can improve the hydrophobicity of the microchannel, change the capillary tractive force, make the working fluid circulation more effective, and improve the performance of the micro-heat pipe. In summary, the LED silicon substrate integrated with microheat pipe is designed and fabricated for high power LED devices. The structure and surface characteristics of the channel are optimized. The results show that the developed substrate can effectively improve the heat transfer capacity. The results can be used as guidance and reference for high efficiency thermal transport and stability control of junction temperature for high power LED devices.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN312.8
【共引文献】
相关期刊论文 前2条
1 殷录桥;张金龙;宋朋;翁菲;张建华;;热界面材料对高功率LED热阻的影响[J];光电子.激光;2013年10期
2 张建新;牛萍娟;武志刚;王景祥;李红月;;大功率LED散热器性能的双目标优化[J];电工技术学报;2014年04期
相关博士学位论文 前3条
1 袁冬;LED光热结构优化设计[D];华南理工大学;2013年
2 高铁成;高效率LED汽车前照灯关键技术研究[D];天津大学;2014年
3 郑怀;大功率LED封装工艺中流动分析及其工程应用[D];华中科技大学;2014年
，本文编号：2192240
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