指導教授：邱文英臺灣大學：化學工程學研究所雷以安Lei, I-AnnI-AnnLei2014-11-252018-06-282014-11-252018-06-282014http://ntur.lib.ntu.edu.tw//handle/246246/261168此博士研究主要針對環保節能相關材料之開發，論文主要為新型發光二極體(Light emitting diode, LED)封裝膠材之開發以及其應用。 第一部分利用利用水解縮合法，直接於商用矽樹脂封裝材料中合成高折射率二氧化鈦無機顆粒，藉由醋酸之螯合作用，得到高折射率之透明二氧化鈦/矽樹脂光學材料(TiO2/AB)，並應用於LED封裝材料，量測其封裝後之流明亮度。 第二部分利用水解縮合法，直接於商用矽樹脂封裝材料中合成高折射率二氧化鋯無機顆粒，同時藉由醋酸之螯合作用，使二氧化鋯顆粒於此商用矽樹脂封裝材中能穩定均勻分散，得到兼具高透明度以及高折射率之新型二氧化鋯/矽樹脂複合材料(ZrO2/AB)；並將此ZrO2/AB做為LED原件之封裝材料，使發光二極體藉由封裝材料折射率的提升，以得到較佳之出光亮度。由流明量測之結果顯示，以原本商用矽樹脂封裝之LED亮度為3.97 lm，而將此ZrO2/AB做為封裝材後，其亮度可增加至4.35 lm，顯示藉由導入二氧化鋯以提升封裝材之折射率，可有效改進LED之出光亮度，顯示此二氧化鋯/矽樹脂複合材料具有應用於LED封裝之潛力。 第三部分則是利用水解縮合法，在商用矽樹脂封裝材料B劑以及GMA( glycidyl methacrylate)單體中，合成二氧化鋯顆粒，除了利用醋酸對二氧化鋯之螯合作用外，GMA的加入可有效防止二氧化鋯在反應過程中之顆粒聚集，並利用其雙鍵參與商用矽樹脂之聚合反應，以增加此無機二氧化鋯顆粒與矽樹脂之相容性，以得到高透明度之高折射率二氧化鋯及具環氧基高分子/矽樹脂複合材料(ZrO2/ABG)，並將此ZrO2/ABG做為封裝材料，使LED得到較高之出光亮度。此外，我們利用光學基礎理論設計出簡易的光學模型，根據LED之晶片結構，模擬封裝材料以及passivation layer之折射率對於LED出光率之影響；最後，根據光學模型計算之結果，得到封裝材料以及passivation layer之最適折射率值，使LED可到達最佳之亮度。 第四部分目的為改進商用矽樹脂封裝材料於高低溫差異性極大的環境下，其應力釋放劇烈造成封裝可靠性不足之問題，本研究首先利用2-mercaptoethanol做為鏈轉移劑，合成PBA 寡聚物；藉由PBA寡聚物鏈段對無機顆粒之吸附作用，以原位水解縮合方式，將二氧化鋯顆粒直接生成於此PBA寡聚物鏈段上，形成二氧化鋯-寡聚物複合顆粒(ZrO2-PBA composite particle.)。並與商用矽樹脂均勻混合後，獲得含二氧化鋯-PBA寡聚物之矽樹脂複合材料，藉由其高折射率及高透明度之性質，做為LED封裝材料，並有效提升LED之發光亮度，除探討材料之穿透度、折射率、耐熱性以及其吸水性質之外，更著重於此複合封裝材料對於LED於高低溫差異性極大的環境下，對其信賴度之影響，以期改善原本商用矽樹脂封裝材料，因高低溫差產生之高應力，使得封裝可靠性不足的問題。In our research, development of encapsulating material of light emitting diodes (LEDs) is the mainly purpose. In the first part (Chapter 2), optical hybrid materials with high refractive index were synthesis by in-situ production of titanium dioxide (TiO2) directly in a commercial-grade silicone resin via a sol-gel reaction. The optical transparency of the prepared TiO2/silicone hybrid film was investigated by UV-visible spectroscopy. These hybrid films with various TiO2 contents exhibited different refractive indices; the refractive index could reach 1.66 for the hybrid with 30 wt% of the TiO2. In addition, refractive index, thermal stability of the cured hybrid materials was also investigated. In the second part (Chapter 3), novel ZrO2/silicone hybrid materials (ZrO2/AB) useful for the encapsulation of light-emitting diodes (LEDs) are synthesized by an in situ sol-gel reaction of zirconium propoxide directly in a commercial-grade silicone resin by an in situ sol-gel reaction. By the chelation of the acetic acid, the ZrO2/AB hybrids exhibit high transparency owing to the well-dispersed ZrO2 particles in the silicone material, and their refractive index value also increased with increasing weight percentage of the ZrO2 in the hybrid. These high-refractive-index ZrO2/AB hybrids were then used as encapsulating materials to improve the luminous flux of the LEDs. From the results of the luminous flux measurement, the LED encapsulated with the pure silicone material has luminous flux of 3.97 lm. After encapsulated with the ZrO2/AB hybrid, the luminous flux of the LED was enhanced to a value of 4.35, which revealing that the increase in the refractive index of the encapsulating material by the incorporation of the ZrO2 could effectively improved the luminous flux of the LED, and these novel ZrO2/AB hybrids could also be considered as a suitable candidate as the encapsulating material for the LED. In the third part (Chapter 4), ZrO2 particles are synthesized directly in a commercial-grade silicone resin (AB) with the addition of a vinyl monomer (glycidyl methacrylate, GMA) by an in situ sol-gel reaction to obtain the silicone hybrid material (ZrO2/ABG). In addition to use the acetic acid as chelating agent, the addition of the GMA is able to retard the gelation rate of the metal alkoxide compound as well as the growing rate of ZrO2 during the sol-gel reaction, and also enhance the interfacial strength of the inorganic fillers with the silicone matrix by reacting with the silicone resin through a hydrosilation reaction via its vinyl group. The ZrO2/ABG hybrids thus exhibit excellent transparency and high refractive index. These ZrO2/ABG hybrids were then used as encapsulating materials to help the LEDs reach a higher luminous flux. Furthermore, according to the optical theory and the structure of the high-power LEDs, a simple simulation model was developed to estimate the luminous flux of the LEDs encapsulated with the ZrO2/ABG hybrids and the influence of the refractive index of the passivation layer on the luminous flux of the LEDs. Finally, with the help of this simulation model, an optimum combination of the encapsulating material and the passivation layer with appropriate refractive index values was obtained for achieving the highest luminous flux of LED. In the fourth part (Chapter 5), the purpose is to improve thermal mechanical property of the encapsulating materials in a very large temperature difference condition., thus decreasing the influence of the encapsulation on the reliability performance of the LED. The PBA(polybutylacrylate) oliogomer was firstly synthesized by a telomerization using 2-mercaptoethanol as a chain transfer agent. By the absorption to the inorganic particles and the carbonyl groups, the ZrO2 particles were produced on the oligomer chains of the PBA via an in situ sol-gel reaction to obtain the ZrO2-PBA composite particles, and subsequently mixed with a commercial-grade silicone resin to obtain the ZrO2-PBA/silicone hybrid materials (ZrO2-PBA/AB). The well-dispersed ZrO2-PBA domains lead to a high transparency and high refractive index of the ZrO2-PBA/AB hybrids, resulting in a higher luminous flux than the pristine silicone material. In addition to discuss the transmittance, refractive index, thermal resistance, and the water uptake of the ZrO2-PBA/AB hybrids, thermal stress evaluation of the LEDs encapsulated with the ZrO2-PBA/AB hybrids was also carried out in a thermal shock experiment with a temperature change from -35 °C to 125 °C within 15 mins. The results show that these ZrO2-PBA/AB hybrids have a lower thermal stress and exhibit a better mechnical resistance against the thermal shock, and the reliability performance of the LEDs are also greatly improved as encapsulated with the ZrO2-PBA/AB hybrids.摘要 I Abstract III Contents ..............................................................................................................................VI Table contents ...................................................................................................................X Scheme contents ............................................................................................................. XII Figure contents ................................................................................................................XIII Chapter 1 Introduction 1 1.1 Introduction of light emitting diode (LED) 1 1.1.1 LED chip 2 1.1.2 LED encapsulation 3 1.2 Silicone-based encapsulating materials 5 1.3 Sol-gel process 7 1.3.1 The Partial Charge Model 8 1.3.2 Equilibrium species in aqueous solution of the metal alkoxide 10 1.3.3 Particle growth and aggregation 11 1.4 Direct methanol fuel cell 13 1.4.1 Main cell components and Materials 13 1.4.2 Methanol oxidation and poisoning of Pt by carbon oxide 17 1.5 Purpose of this work 19 1. 6 Flow chart of this work 21 Development of Novel Encapsulating material of Light Emitting Diodes (LEDs): Preparation of ZrO2/silicone material. 26 Chapter 2 Preparation of TiO2/silicone hybrids by an in situ sol-gel 26 2.2 Experiment 29 2.3 Characterizations 31 2.4 Results and Discussion 32 2.4.1 Size domain of TiO2 particles in the TiO2/AB resins before and after cure 32 2.4.2 Thermal stability of the TiO2/AB hybrid materials 34 2.4.3 Refractive index of the TiO2/AB hybrid films 36 2.4.4 Transmittance of the TiO2/AB hybrid films 37 2.4.5 Luminous flux of LEDs encapsulated with the TiO2/AB hybrid materials 37 2.5 Conclusion 39 Chapter 3 ZrO2/silicone hybrid materials useful for the encapsulation of light-emitting diodes 51 3.1 Introduction 51 3.2 Experimental 54 3.3 Characterizations 56 3.4 Results and Discussion 57 3.4.1 Particle size of ZrO2 in the ZrO2/AB hybrids 57 3.4.2 Transmittance of the ZrO2/AB hybrid materials 60 3.4.3 Thermal degradation and stability of the ZrO2/AB hybrid materials 62 3.4.4 Refractive index of the ZrO2/AB hybrid materials 65 3.4.5 Luminous flux of LEDs encapsulated with the ZrO2/AB hybrid materials 65 3.5 Conclusions 67 Chapter 4 Preparation and optical simulation of the light emitting diodes encapsulated with the ZrO2/silicone hybrid materials 81 4.1 Introduction 81 4.2 Experimental 84 4.3 Characterizations 86 4.4 Simulation model 87 4.5 Results and Discussion 91 4.5.1 Synthesis and properties of the silicone hybrid materials 91 4.5.2 Optical properties the ZrO2/ABG hybrid materials 93 4.5.3 Luminous flux of LEDs encapsulated with the ZrO2/ABG hybrid materials 94 4.5.4 Luminous flux of the encapsulated LEDs estimated from the simulation model 96 4.5.5 The influence of the refractive index of the passivation layer on the luminous flux 98 4.6 Conclusion 100 Chapter 5 ZrO2/silicone and ZrO2-PBA/silicone hybrid materials with Improved Thermomechanical properties useful for the LED Encapsulation 117 5.1 Introduction 117 5.2 Experimental 120 5.3 Characterizations 123 5.4 Results and Discussion 127 5.4.1 Synthesis of the ZrO2 particles in the ZrO2/B resin, and the ZrO2-PBA particles in the ZrO2-PBA/B resins 127 5.4.2 Transmittance of the ZrO2/AB and ZrO2-PBA/AB hybrid materials 129 5.4.3 Refractive index of the ZrO2/AB and ZrO2-PBA/AB hybrid materials 130 5.4.4 Thermal mechanical properties of the ZrO2/AB and ZrO2-PBA/AB hybrid materials. 131 5.4.5 Thermal expansion coefficient of the ZrO2/AB and ZrO2-PBA/AB hybrid materials. 133 5.4.6 Reliability test of the LEDs encapsulated with the ZrO2/AB and ZrO2-PBA/AB hybrid materials. 134 5.4.7 Luminous flux of LEDs encapsulated with the ZrO2/AB and ZrO2-PBA/AB hybrid materials. 136 5.5 Conclusion 139 Chapter 6 Conclusions 159 Appendix I- Preparation of Aniline/Nafion composite membrane. 163 Appendix II- Stablized monomer dispersion contain inorganic oxide nanoparticles with high refractive index and it preparation. 202 Appendix III- ZrO2 morphologies of the ZrO2/silicone hybrids. 221 Table contents Table 1.1 Moisture and Oxygen permeability of silicone materials. 6 Table 1.2 Effects of the formal charge of the metal ion (z), the coordination number (N) and the electronegativity of the metal ( ) on the metal precursors. 11 Table 2.1. The recipes of TiO2 /AB with different TiO2 contents and the particle size of TiO2 in silicone resin 43 Table 2.2The properties of pure silicone material and TiO2/AB hybrids. 44 Table 3.1 Recipes for synthesizing the ZrO2/AB with different ZrO2 contents 71 Table 3.2 Observation of the reaction solution after sol-gel reaction when using various kinds solvent and mix solvent into the synthesis. 72 Table 3.3 The reaction heats of the AB and the ZrO2/AB resins. 72 Table 3.4 Thermal and optical properties of the cured AB and ZrO2/AB films 72 Table 3.5 The shore hardness of the pure AB silicone material and the ZrO2/AB hybrids 73 Table 4.1 Recipes for synthesizing the ZrO2/BG with different ZrO2 contents 104 Table 4.2 The parameters used for calculation in the simulation model. 105 Table 4.3 Optical properties of the cured AB and ZrO2/ABG films 106 Table 4.4 Luminous flux values of the LED chip ( ), the light reaching the encapsulating material ( ), the light passing through the encapsulating material ( ) and the light entering air ( ) from the simulation model, along with the experimental luminous flux from the in-device test (LA,exp). 107 Table 5.1 Recipes for preparing the PBA oligomers (PBA) with different molecular weight. 144 Table 5.2 Recipes for preparing the ZrO2 /B resins with different ZrO2 contents. 144 Table 5.3 Recipes for preparing the ZrO2-PBA /B resins with different ZrO2 contents. 145 Table 5.4 Optical properties of the pure AB silicone material, the ZrO2/AB, and the ZrO2-PBA/AB hybrids. 146 Table 5.5 Thermal mechanical properties of the pure AB silicone material, the ZrO2/AB, and the ZrO2-PBA/AB hybrids. 147 Table 5.6 Reliability test of the LEDs encapsulated with the pure AB silicone material, the ZrO2/AB, and the ZrO2-PBA/AB hybrids. (-35~125 °C; Dwell time=15 min.) 148 Scheme contents Scheme 1.1 associative nucleophilic substitution. 9 Scheme 5.1：Mechanism of the radical telomerization for preparing PBAoligomer using AIBN and 2-Mercaptoethanol as chain transfer agent. 149 Scheme 5.2 The overall synthetic procedure of the ZrO2-PBA/B resin 150 Figure contents Figure 1.1 versatility of the LEDs in the application of the light resources. 1 Figure. 1.2 Schematic illustrations of (B) the LED chip and (A) the cross-sections of a commercial-grade LED structure. 2 Figure 1.3 Dynamic mechanical analysis of the HRI and NRI silicone material 6 Figure 1.4 Schematic diagram of the direct methanol fuel cell. 14 Figure 1.5 Types of PEMs: (a) Monomer units of α,β,β-trifluorostyrene sulfonic acid (b) BAM3G (c) Nafion (d) Dow membrane (e) polysulfone (f) polyetherketone [45]. 15 1.4.1.2 Electrodes 16 Figure 1.6 Scheme of a double-layer GDL 16 Figure 1.7 Reaction mechanism of methanol oxidation on Pt electrode 18 Figure 2.1 Particle size distribution of the TiO2 in the TiO2/AB solution (10 wt.% in MEK): (a) TiO2 /AB1 ( =3.60 nm), (b) TiO2 /AB3 ( =13.5nm)(c) TiO2 /AB5 ( =21.0 nm), (d) TiO2/AB7 ( =18.0 nm)(e) TiO2 /AB10 ( =18.2 nm), (f) TiO2 /AB15 ( =8.70 nm), (g) TiO2 /AB30 ( =11.7 nm) 45 Figure 2.2 Surface morphology of the cured TiO2/AB films (A) TiO2/AB1 (B) TiO2/AB3 (C) TiO2/AB5 (D) TiO2/AB 7 (E) TiO2/AB 10 ( μm) (F) TiO2/AB 15 ( μm) (G) TiO2/AB 30 ( μm) 47 Figure 2.3 (A) Thermal degradation curves and (B) differential weight-loss curves of the cured AB and TiO2/AB hybrids: (a) AB, (b) TiO2/AB1, (c) TiO2/AB3, (d) TiO2/AB5, (e) TiO2/AB7, (f) TiO2/AB10, (g) TiO2/AB15, (h) TiO2/AB15 48 Figure 2.4 Refractive index of the cured AB and TiO2/AB films: (a) AB, (b) TiO2/AB1, (c) TiO2/AB3, (d) TiO2/AB5, (e) TiO2/AB7, (f) TiO2/AB10, (g) TiO2/AB15. 49 Figure 2.5 Transmittance of the cured AB and TiO2/AB films: (a) AB, (b) TiO2/AB1, (c) TiO2/AB3, (d) TiO2/AB5, (e) TiO2/AB7, (f) TiO2/AB10, (g) TiO2/AB15, (h) TiO2/AB30 49 Figure 2.6 The effect of TiO2 content in the TiO2/AB encapsulating material on the luminance of the LEDs. The luminous flux of the bare chip without any encapsulation was 3.849 lm 50 Figure 2.7 Absorbance of TiO2 : (a) TiO2 after the chelation of the acetic acid. (b) TiO2 particles. 50 Figure 3.1 UV absorbance of (a) ZrO2 particles after the chelation of the acetic acid, (b) ZrO2 particles, (c) TiO2 particles after the chelation of the acetic acid. 74 Figure 3.2 Surface morphology of the cured ZrO2/AB films 75 Figure 3.3 TEM images of the ZrO2/AB resins before cure. (A)ZrO2/AB3 ( =13~24 nm), (B)ZrO2/AB5 ( =17~28 nm). 76 Figure 3.4 DSC analysis of the reaction heats of the AB and the ZrO2/AB resins. (Heating from 50 °C to 300 °C with heating rate of 10°C/min ): (a) AB, (b) ZrO2/AB1, (c) ZrO2/AB3, (d) ZrO2/AB5, (e) ZrO2/AB7, (f) ZrO2/AB10, (g) ZrO2/AB15. 76 Figure 3.5 Transmittance of the AB and ZrO2/AB resins before cure ( path length= 1 mm) 77 Figure 3.6 Transmittance of the cured AB and ZrO2/AB films 77 Figure 3.7 The XRD analysis of the ZrO2/AB hybrids. (A)ZrO2/AB7, (B)ZrO2/AB15 78 Figure 3.8 Thermal degradation curves of the cured AB and ZrO2/AB resins 78 Figure 3.9 Thermal stability of the cured AB and ZrO2/AB resins at 260 °C 79 Figure 3.10 Refractive index of the cured AB and ZrO2/AB films 79 Figure 3.11 The effect of ZrO2 content in the ZrO2/AB encapsulating material on the luminous flux of the LEDs. 80 Figure 3.12 The photographs of the LEDs encapsulation with the ZrO2/AB1 and the ZrO2/AB3 hybrids, and the cured thin films of the ZrO2/AB1 and ZrO2/AB3 hybrids. 80 Figure 4.1 (A) Schematic illustrations of (A) the cross-sections of a commercial-grade LED structure and (B) the LED chip. 108 Figure 4.2 (A) Schematic illustration of the layers that the light would pass from the emitting layer of the LED chip for construction of the optical simulation model. (B) SEM image of the cross-section of the LED chip. 109 Figure 4.3 (A) The pathway of the light emitted from the LED chip through the ITO and passivation layers. (B) The absorption of light in the encapsulating material. (C) The Fresnel loss of light due to the crossing from the encapsulating material to air. 110 Figure 4.4 The photographs of the overall synthetic procedure of the ZrO2/BG 111 Figure 4.5 SEM micrographs of the cured ZrO2/ABG films 112 Figure 4.6 FTIR spectra of the (a) silicone resin B, (b) glycidyl methacrylate (GMA), (c) the mixture of B silicone resin and GMA before cure, and (d) the mixture of B silicone resin and GMA after cure. 113 Figure 4.7 Transmittance of the AB and ZrO2/ABG cured resins: (a) AB, (b) ZrO2/ABG1, (c) ZrO2/ABG3, (d) ZrO2/ABG5, (e) ZrO2/ABG7. 114 Figure 4.8 The XRD analysis of the ZrO2/ABG hybrids. (A)ZrO2/ABG5, (B)ZrO2/ABG7. 114 Figure 4.9 Refractive index of the cured AB and ZrO2/ABG films: (a) AB, (b) ZrO2/ABG1, (c) ZrO2/ABG3, (d) ZrO2/ABG5, (e) ZrO2/ABG7. 115 Figure 4.10 Luminous flux of the LEDs encapsulated with the pure AB resin and the ZrO2/ABG hybrid materials 115 Figure 4.11 Effect of ZrO2 content in the ZrO2/ABG encapsulating material on the luminous flux of the LEDs. 116 Figure 4.12 Simulated luminous flux values of the encapsulated LEDs by changing the refractive index of the passivation layer. The LED encapsulated with the material:(a) AB, (b) ZrO2/ABG1, (c) ZrO2/ABG3, (d) ZrO2/ABG5, (e) ZrO2/ABG7. 116 Figure 5.1 TEM images of the (A)ZrO2 particles in the ZrO2/B resins: (A)-1 ZrO2/B1 ( =8~30 nm), (A)-2 ZrO2/B3( =15~35 nm), (A)-3 ZrO2/B5( =14~67 nm), (B) ZrO2-PBA 4000 composite particles ( =25~415 nm), and (C) ZrO2-PBA 2000 ( =14~300 nm)composite particles. 151 Figure 5.2 Transmittance of the (A) ZrO2/AB, (B) ZrO2-PBA 4000/AB, and (C) ZrO2-PBA 2000/AB hybrids 152 Figure 5.3 Refractive index of the (A) ZrO2/AB, (B) ZrO2-PBA 4000/AB, and (C) ZrO2-PBA 2000/AB hybrids 153 Figure 5.4 DMA curves of the pure AB silicone material, ZrO2/AB, ZrO2-PBA 4000/AB, and ZrO2-PBA 2000/AB hybrids. (A) Dynamic storage modulus (E*), (B) loss factor tan δ. 154 Figure 5.5 TMA curves of the (A) ZrO2/AB, (B) ZrO2-PBA 4000/AB, and (C) ZrO2-PBA 2000/AB hybrids 155 Figure 5.6 The effect of ZrO2 content in the (A) ZrO2/AB, (B) ZrO2-PBA 4000/AB, and (C) ZrO2-PBA 2000/AB as encapsulating materials on the luminous flux of the LEDs. 156 Figure 5.7 Transmittance of the (A) ZrO2/AB, (B) ZrO2-PBA 4000/AB, and (C) ZrO2-PBA 2000/AB hybrids 157 Figure 5.8 Photos of the LED housings encapsulated with (A) ZrO2-PBA 4000/AB, and (B) ZrO2-PBA 2000/AB hybrids after immersing in red ink for 1h at 100 °C. 1587910113 bytesapplication/pdf論文公開時間：2014/09/15論文使用權限：同意有償授權(權利金給回饋學校)發光二極體封裝膠材無機/有機複合材料二氧化鋯thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/261168/1/ntu-103-F96524008-1.pdf