论文总字数：28104字

摘 要

白光LED作为照明产品中的新起之秀，在各个领域都显示出了较高的应用价值。在LED的制备过程中，封装技术是其中不可或缺的一环。封装技术涉及到多个领域，包括材料、机械、电气等，其中封装材料、结构和工艺对LED器件性能的影响尤为重要。依照白光LED发光原理不同，器件的封装结构也不同。主要分为三类：多芯片组合发光、紫外/近紫外芯片和多种荧光粉组合、蓝光芯片和黄色荧光粉组合。考虑到价格以及封装效率等因素，当今主流的白光LED封装结构是黄色荧光粉 蓝光LED芯片。

随着白光LED逐渐大功率化，现有的封装技术已经无法满足器件的应用需求，因此本文基于黄色荧光粉和蓝光LED组合发光原理，提出一种新型的封装结构——使用粉浆法在芯片上涂覆黄色荧光粉胶（YAG：Ce），并采用三维陶瓷基板封装白光LED。为改善白光LED的光效和光品质不佳的弊端，本文还就荧光粉胶的浓度、厚度对白光LED性能的影响进行了研究探讨。结果表明，随着荧光粉浓度增大，白光LED的发光效率（LE）先增加后减小，而相对色温（CCT）则是呈现下降趋势。在荧光粉浓度为12.5wt%时，白光LED样品表现出最佳的显色性和较高的LE，此时CCT为5915 K，色度坐标为（0.3166，0.3345），LE为94.55 lm/W。通过理论分析研究，可知厚度对白光LED性能的影响主要是受荧光粉吸收蓝光的速率控制，荧光粉层越厚，器件的光提取效率越低，能量损耗越大，且更不易散热，而在荧光粉层较薄时，荧光粉对蓝光的吸收速率低，黄光无法完全平衡蓝光，器件光品质不佳。

除此之外，本文还测试了LED器件的光学一致性。较好的光学一致性说明器件具有大批量生产的潜力。通过对相同封装类型白光LED样品进行各种光学性能测试并计算其标准误差（STD）以及相对标准偏差（RSD），根据误差大小来评价白光LED的光学一致性是否优异。为了进一步说明器件的可靠程度，本研究中加入老化试验。将白光LED模组老化处理200 h，观察各性能指标的变化。最终得到结论：使用荧光粉胶涂覆、三维陶瓷封装的白光LED具有良好的光学一致性，器件可靠性高。

关键词：白光LED；荧光粉；三维陶瓷封装基板；光学一致性

Abstract

As a rising star in the field of products, white LED have showed good application value in many fields.

In the process of LED preparation, packaging technology is an indispensable part. Packaging technology involves many fields, including materials, machinery, electrical and so on. Among them, packaging materials, structures and processes have a great influence on the performances of LED devices. According to the different theories of white LED, the packaging structure of devices is also different. It is mainly divided into three categories: multi-chip combination luminescence, combination of UV/near UV chips and various phosphors, combination of blue chips and yellow phosphor. Considering the cost and packaging efficiency, the mainstream packaging structure of white LED is yellow phosphor blue LED chip.

With the increasing power of white LEDs, the existing packaging technologies have been unable to meet the application requirements of devices. Therefore, based on the combination of yellow phosphor and blue LED, a new packaging structure is proposed: coating yellow phosphor glue (YAG:Ce) on chips by slurry method, and packaging White LED with three-dimensional ceramic substrate. In order to improve the luminous efficiency of white LED and the disadvantage of poor light quality, the effect of the concentration and thickness of phosphor glue on the performance of white LED was also studied. The results show that as phosphor concentration increases, luminous efficiency(LE) of white LED increases first and then decreases, while correlated color temperature(CCT) shows a downward trend. When the phosphor concentration is 12.5wt%, white LED sample shows the best color rendering and higher LE. At this time, the CCT is 5915k, the chromaticity coordinate is (0.3166, 0.3345), and the LE is 94.55lm/w. Through theoretical analysis and research, it can be seen that the affect of phosphor thickness on the performances of white LED is mainly controlled by the absorption rate of blue light by phosphor. The thicker the phosphor layer is, the lower the light extraction efficiency, the greater the energy loss of the device, and it is more difficult to dissipate heat. And when the phosphor layer is thin, the absorption rate of the blue light by the phosphor is low, the yellow light cannot completely balance the blue light, and the light quality of the device is poor.

Besieds, the optical consistency of LED devices is tested. The good optical consistency shows that the device has the potential of mass production. By testing the optical properties of the same package type white LED and calculating its standard error (STD) and relative standard deviation (RSD), the optical consistency of white LED is evaluated according to the error. In order to further illustrate the reliability of the device, the aging experiment was added to this study. The white LED module was ages for 200 hours and the changes in various performance indicators was observed. Finally, it is concluded that the white LED encapsulated with phosphor glue and three-dimensional ceramic substrates has good optical consistency and device reliability is high.

Key words: white LED；phosphor；3D ceramic packaging substrate；optical consistency

目 录

第1章 绪论 1

1.1 半导体照明技术 1

1.2 白光LED 3

1.2.1 白光LED发光原理 3

1.2.2 白光LED关键技术 4

1.2.3 白光LED发展面临的挑战 4

1.3 LED封装技术 5

1.3.1 白光LED封装用荧光粉 5

1.3.2 白光LED封装基板 6

1.4 本论文的研究目的以及内容 7

1.4.1 研究目的 7

1.4.2 研究内容 8

第2章 白光LED模组封装设计 9

2.1 实验材料与仪器 9

2.1.1 实验材料 9

2.1.2 实验仪器 9

2.2 白光LED封装结构设计 9

2.3 荧光粉胶制备 10

2.3.1 荧光粉性能参数 10

2.3.2 荧光粉胶制备流程 11

2.4 白光LED封装基板制备 11

2.4.1 平面DPC基板制备 11

2.4.2 三维陶瓷基板制备 12

2.5 白光LED封装工艺 13

2.5.1 平面DPC基板封装工艺 13

2.5.2 三维陶瓷基板封装工艺 13

2.6 本章小结 14

第3章 白光LED性能测试 15

3.1 性能介绍 15

3.1.1 光通量 15

3.1.2 发光效率 15

3.1.3 色度坐标 15

3.1.4 相关色温 16

3.1.5 显色指数 16

3.2 白光LED性能测试方法 16

3.2.1 积分球 17

3.2.2 光谱仪 17

3.3 本章小结 18

第4章 结果分析 19

4.1 荧光粉浓度对白光LED性能影响 19

4.2 荧光粉厚度对白光LED光学性能影响 21

4.3 光学一致性测试结果分析 21

4.4 本章小结 24

第5章 总结与展望 25

5.1 全文总结 25

5.2 展望 26

参考文献 27

附录A 29

附录B 30

致 谢 31

第1章 绪论

当今现代科技高速发展，社会整体生活水平逐渐提高。照明作为人们生活中不可或缺的一环，已经经历了一百多年的演变。目前常用的三种照明光源技术如图1.1所示。

图1.1 现代照明光源技术

1879年，第一代光源白炽灯问世，白光照明开始走向人类的日常生活。传统白炽灯利用热辐射原理发光，其光效低（12-24 lm/W），寿命短（1000-3000小时），能耗大，大部分能量以热的形式散失，光电转换效率仅仅为10%左右。因其性能发展受限，白炽灯开始被社会所淘汰。1938年，荧光灯被发明出来。荧光灯基于光致发光原理，在灯管内壁涂覆荧光粉，利用紫外线激发荧光粉发光。其光效最高可达到80 lm/W，寿命较白炽灯也大幅度增加，约10000小时，但是荧光灯含汞、铅污染，为环境保护增添了负担。气体放电灯（HID）和超高压汞灯（UHP）的出现虽然使得照明产品的种类更加多样化，但是其适应性差、难以运输和保存，难以满足居民日常照明需求。

纵观照明技术的发展历程，每一个照明产品的出现都对应着人们的生活需要和社会在该阶段的生产需求。而在世界能源短缺、环境日益恶化的今天，传统照明技术的弊端逐渐显露，新型绿色照明光源的研究应运而生，即半导体照明技术。半导体照明技术提高了灯具发光效率，降低了生产成本和能源消耗，已经成为二十一世纪照明技术发展的主旋律。

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