环氧树脂基复合材料热界面（TIM）的研究

发布时间：2018-05-19 15:14

本文选题：导热绝缘材料 + 多尺度热导率模型　；参考：《重庆大学》2015年硕士论文

【摘要】：大功率LED芯片在工作时产生的热量,不能快速有效的散失掉,将会严重影响大功率LED的发光强度及使用寿命。随着节能减排、发展低碳经济政策的推行,人们对于绿色照明光源的需求与日俱增,使得大功率LED在照明领域的应用越来越广泛,其散热问题是固态照明领域必须攻克的一道难关。在大功率LED的多层结构中,其层间粘接材料的低热导率及界面处理情况成为改善其散热问题的一个突破点。层间粘接材料需要具有较高的热导率、粘接强度,较好的绝缘性能以及与被粘接材料相匹配的热膨胀系数,才能有效地改善大功率LED整体的散热。本文在分析和总结绝缘导热粘接材料发展现状的基础上,根据现有的研究,采用硅烷偶联剂及水浴加热法来改善导热微粉及层间材料的微观与宏观两种界面,制备了碳化硼/环氧树脂、二氧化硅/环氧树脂、氮化硼/环氧树脂复合材料。并分别用OLYMPUS_BX53光学显微镜、SEM、FTIR、粘接强度测试、热导率测试、热膨胀系数测试、介电常数测试等对制备的复合材料进行了表征与分析。在有效介质均匀分布理论及傅里叶导热理论的基础上,运用Pal模型与Lewis-Nielsen模型计算理论热导率值,结合热导率实验结果与SEM图分析了范德瓦尔斯力对于复合材料热导率的影响。在此基础上,将制备的氮化硼/环氧树脂粘接材料与基板材料一起,制备环氧树脂多层复合材料,实验测试并研究了表面处理对于多层复合材料热导率、粘接强度、界面耐温性能及温度对耐久性能的影响。得到的主要结果如下:①在应用Pal模型与Lewis-Nielsen模型计算制备的碳化硼/环氧树脂、二氧化硅/环氧树脂复合材料热导率时发现:随着导热微粉质量分数的增加,导热微粉之间的距离减小,范德瓦耳斯力的作用增强,实验中二氧化硅/环氧树脂复合材料和碳化硼/环氧树脂复合材料的热导率也相继增加。通过对二氧化硅/环氧树脂复合材料的SEM图进行分析,证实了我们对于复合材料热导率机理的推断是正确的。②通过多次实验与性能测试,确定下来最佳的导热微粉表面处理方案。并用这种处理方法处理氮化硼导热微粉。实验结果表明:经表面处理后的氮化硼制备的氮化硼/环氧树脂复合材料热导率要远高于未经过表面处理的氮化硼/环氧树脂复合材料的热导率。与此同时,经过表面处理的氮化硼/环氧树脂复合材料的粘接强度要优于没有经过表面处理的氮化硼/环氧树脂复合材料。③经过表面处理的氮化硼/环氧树脂复合材料作为粘接剂,与基板材料一起制备的三层复合材料,其热导率远高于未经过表面处理的氮化硼/环氧树脂复合材料、基板材料组成的三层复合材料的热导率。在光学显微镜下观察氮化硼/环氧树脂三层复合材料宏观表面发现(俯视图与侧视图),未经过表面处理的氮化硼/环氧树脂复合材料表面出现了明显的热膨胀,材料被破坏。而经过表面处理的氮化硼/环氧树脂复合材料的表面,在温度升高时,表面未有明显变化,耐温性增强。对制备的三层复合材料进行相同时长,相同温度的热处理,发现经过表面处理的三层复合材料耐久性更好。
[Abstract]:The heat generated in the high power LED chip can not be lost quickly and effectively, which will seriously affect the luminous intensity and service life of high power LED. With the energy saving and emission reduction, the development of low carbon economic policy, the demand for green lighting is increasing day by day, making the application of high-power LED more and more widely in the field of lighting. The problem of heat dissipation is a difficult problem to be overcome in the field of solid-state lighting. In the multi-layer structure of high power LED, the low thermal conductivity and interface treatment of the interlayer bonding material become a breakthrough point to improve the heat dissipation. The interlayer adhesive needs to have high thermal conductivity, bonding strength, good insulation performance and the ability to improve the heat dissipation. The thermal expansion coefficient matched by the bonding material can effectively improve the heat dissipation of the high power LED. On the basis of the analysis and summary of the current development of the insulation and heat conduction adhesive materials, according to the existing research, the silane coupling agent and water bath heating method are used to improve the micro and macro two interfaces of the heat conduction micro powder and interlayer materials, and the preparation of the materials is prepared. Boron carbide / epoxy resin, silica / epoxy resin, boron nitride / epoxy resin composites were used to characterize and analyze the composite materials prepared by OLYMPUS_BX53 optical microscope, SEM, FTIR, bonding strength test, thermal conductivity test, thermal expansion coefficient test, dielectric constant test and so on. On the basis of Fu Liye's thermal conductivity theory, the Pal model and Lewis-Nielsen model are used to calculate the theoretical thermal conductivity, and the thermal conductivity test results and the SEM diagram are used to analyze the influence of Vander Vauls Ley on the thermal conductivity of the composites. On this basis, the prepared boron nitride / epoxy resin bonding material is prepared with the substrate, and the epoxy resin is prepared. The effects of surface treatment on the thermal conductivity, bonding strength, interfacial temperature resistance and temperature on durability of multilayer composites are tested and studied. The main results are as follows: (1) boron carbide / epoxy resin, silica / epoxy resin composites prepared by using Pal model and Lewis-Nielsen model are obtained. The thermal conductivity shows that with the increase of the mass fraction of the heat conduction powder, the distance between the heat conduction micropowders decreases, and the role of van der Waals is enhanced. The thermal conductivity of the silica / epoxy resin composite and the boron carbide / epoxy resin composites are also increased in the experiment. The SEM diagram of the silica / epoxy resin composites is obtained. A row analysis confirms that the inference of the thermal conductivity mechanism of the composite is correct. 2. By several experiments and performance tests, the best surface treatment scheme for the heat conduction micro powder is determined. And this treatment is used to treat the boron nitride thermal conductive powder. The experimental results show that boron nitride / epoxy tree is prepared by the surface treated boron nitride. The thermal conductivity of the composite material is much higher than that of the boron nitride / epoxy resin composite without surface treatment. At the same time, the bonding strength of the surface treated boron nitride / epoxy resin composite is better than that of the boron nitride / epoxy resin composite without surface treatment. 3. The surface treated boron nitride / ring has been used. The oxygen resin composite material is a three layer composite made with the substrate material. The thermal conductivity of the composite is much higher than that of the boron nitride / epoxy resin composite without surface treatment. The thermal conductivity of the three layer composite material of the substrate material is observed. Under the optical microscope, the macroscopic surface of the boron nitride / epoxy resin three layer composite material is observed under the optical microscope. It is found that the surface of the boron nitride / epoxy resin composite surface without surface treatment has obvious thermal expansion, and the material is destroyed. The surface of the surface treated boron nitride / epoxy resin composite is not obviously changed at the temperature, and the temperature resistance is enhanced. The three layer composite materials are prepared. At the same time, the heat treatment at the same temperature showed that the surface treated three layer composite material had better durability.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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