基于大功率LED散热的陶瓷覆铜板研究

发布时间：2018-07-04 22:57

  本文选题：LED封装基板 + 氧化铝陶瓷　； 参考：《浙江大学》2017年硕士论文

【摘要】：大功率LED是目前世界上大力发展的一项新的绿色照明技术,根据《2017全球蓝宝石与LED芯片市场报告》指出,2016年全球LED芯片市场规模已经超过了 447亿人民币。然而,随着LED的不断大功率化,其散热问题成为了困扰整个行业的重大问题,阻碍了 LED照明技术的发展脚步。目前,解决其散热问题的很大一个方面就是寻找合适的材料作为散热基板。氧化铝陶瓷是目前使用最广泛的陶瓷基板材料,同时氮化铝陶瓷有着超高的热导率、低介电常数、优秀的化学性能等优势,有望在将来成为主流的基板材料。本课题的主要目标是在现有的磁控溅射金属化方式基础上,提出新的工艺思路,为氧化铝陶瓷寻找了一种新的金属化工艺,同时对氮化铝陶瓷的金属化工艺技术进行了研究和探讨。本课题取得了以下成果:(1)理论上分析了大功率LED的结构特征与散热通道,并对LED建立了散热模型,同时使用大型有限元分析软件ANSYS进行了热学稳态仿真。从理论上论证了氮化铝陶瓷基板相对于氧化铝陶瓷基板、环氧树脂基板有着非常明显的散热优势,同时氧化铝陶瓷基板在中小功率的LED下也具有着一定的使用价值。(2)提出了一种制备氧化铝陶瓷覆铜板的新工艺:先低气压高能量的溅射沉积底铜层,再高气压溅射沉积加厚铜层。XPS等分析测试表明,初始沉积的底铜层与陶瓷界面存在明显的电子交换,形成了一层氧化铜的过渡层,正是这层过渡层匹配了金属与陶瓷,极大地提高了铜层与陶瓷的结合强度,同时,高气压所沉积的铜层晶粒细小排列致密,电阻率低。测试结果显示,该种工艺制备的氧化铝陶瓷覆铜板,其热阻为1.38℃/W,拉脱强度为6.2MPa,均优于购买的直接覆铜陶瓷板的1.88℃/W和2.4MPa。光刻线条清晰,能兼容常规光刻工艺。这一工艺为陶瓷覆铜板的制备提出了一种新的方法,具有很大的使用价值和产业化前景。(3)氮化铝陶瓷具有导热系数高、化学稳定性好等特出的优点,是未来高导热陶瓷覆铜板理想的材料,但是其金属化难题一直没有解决,严重制约了它的应用。本文系统地研究了氮化铝陶瓷金属化工艺,提出了一种采用激光活化表面再金属化的新工艺并已经成功了申请了相关专利。测试结果,该种工艺下的氧化铝陶瓷覆铜板,其热阻仅为0.25℃/W,铜层的拉脱强度为4.2MPa,并且能够采用常规光刻工艺而不需要进行二次光刻制备微细线条,这为氮化铝陶瓷覆铜板在高导热领域的全面推广应用打下了良好的基础。
[Abstract]:High-power LED is a new green lighting technology in the world. According to < 2017 Global Sapphire and LED Chip Market report, the scale of global LED chip market has exceeded 44.7 billion RMB in 2016. However, with the continuous high power of LED, its heat dissipation has become a major problem that puzzles the whole industry, which hinders the development of LED lighting technology. At present, one of the most important aspects to solve the heat dissipation problem is to find suitable materials as the heat dissipation substrate. Alumina ceramic is the most widely used ceramic substrate material at present. At the same time, aluminum nitride ceramic has the advantages of high thermal conductivity, low dielectric constant and excellent chemical properties, which is expected to become the mainstream substrate material in the future. On the basis of the existing metallization mode of magnetron sputtering, the main goal of this project is to put forward a new technological idea to find a new metallization process for alumina ceramics. At the same time, the metallization technology of aluminum nitride ceramics was studied and discussed. The main achievements of this paper are as follows: (1) the structure characteristics and heat dissipation channel of high-power LED are analyzed theoretically, and the heat dissipation model of LED is established. At the same time, the thermal steady-state simulation is carried out by using the large-scale finite element analysis software ANSYS. It is theoretically demonstrated that aluminum nitride ceramic substrates have obvious heat dissipation advantages over alumina ceramic substrates. At the same time, the alumina ceramic substrate also has certain use value under the medium and small power LED. (2) A new process of preparing the alumina ceramic clad plate is proposed. The analysis and measurement of thickened copper layer. XPS show that there is obvious electron exchange between the initial deposited bottom copper layer and the ceramic interface, which forms a transition layer of copper oxide, which matches metal and ceramics. The bonding strength between the copper layer and the ceramics is greatly improved. At the same time, the grain size of the copper layer deposited by high pressure is fine and compact, and the resistivity is low. The test results show that the thermal resistance and the pull-out strength of the alumina ceramic clad plate prepared by this process are 1.38 鈩，

本文编号：2097809