| 摘要: | 本研究主要在探討奈米氧化鋯與環氧樹脂及矽膠組成之奈米複合材料之合成方式，以及其於LED封裝材料上之應用。使用之樹脂主體材料主要分兩大部分，首先為選用商用環氧樹脂中黏度較低的脂環族環氧樹脂ERL-4221與表面改質過後之氧化鋯奈米粒子於乙酸乙酯溶劑中進行混合，將溶劑去除後得到氧化鋯/環氧樹脂複合封裝膠材。其次為參考文獻作法，自行合成具有低黏度，高折射率之矽膠原料後，重複第一部分複合材料做法，即可得到氧化鋯/環氧樹脂複合封裝膠材。
經由X光繞射儀(XRD)、粒徑分析儀(DLS)、小角度散射(SAXS)、熱重分析(TGA)、紫外光可見光光譜儀 (UV/Vis Spectrometer)、穿透式電子顯微鏡(TEM)、矽-29液態核磁共振光譜(Si29 NMR)、硬度計、黏度計及折射率儀進行性質分析，研究結果顯示對於自行合成矽膠之低黏度、高折射率、硬度及耐候性之要求均可達到。將奈米氧化鋯粒子與商用環氧樹脂及自製矽膠混合後製作之複合封裝膠，分別可提升折射率從1.5001 到1.5368 及1.5413 到1.5941。
將所製作的複合封裝膠材實際應用於商用LED封裝中並測試其出光功率及高溫(85 oC)高濕(85%相對溼度)點燈耐候試驗後，我們驗證出添加奈米氧化鋯於環氧樹脂或矽膠中確實可以因折射率及散熱性提升而增加出光率。總結本研究結果，我們可得到高性能之氧化鋯/矽膠複合封裝材，其於粒子添加量24vol%時折射率為1.59並於相同輸入電流時比商用高折射率封裝矽膠(OE-6630)表現出大於13%之出光功率。高溫高濕耐候測試結果也顯示此複合氧化鋯/矽膠封裝材與商用封裝矽膠材壽命相近，此氧化鋯/矽膠複合封裝材應極具發展成為LED封裝膠產品之潛力。
This thesis studies two kinds of zirconia composite system for LED encapsulation. The low viscosity cycloaliphatic epoxy/anhydride has been choose to be the matrix resin of zirconia/epoxy system in the former, and matrix resin of zirconia/silicone system was a home-made silicone of low viscosity and high R.I. in the latter. In both systems, the composite was prepared by dispersion of surface modified zirconia in a common solvent with the matrix resin. The composite encapsulant was obtained after removing solvents.
Physical & chemical characteristics of composite has been analyzed by X-ray diffraction(XRD), dynamic Light Scattering(DLS), small-angle X-ray scattering(SAXS), thermal gravimetric analysis(TGA), ultraviolet-visible spectroscopy(UV/Vis Spectrometer), transmission electron microscopy(TEM), silicon -29 liquid nuclear magnetic resonance spectroscopy(Si29 NMR), hardness tester, viscometer and refractometer. The results show that the composite resin, that satisfies the requirements of low viscosity, high refractive index, reasonable flexibility and good thermal/humidity durability, can be achieved. Maximum loading of filler for a workable encapsulant with either epoxy or silicone is 24vol%, and led to an increase of index from 1.5001 to 1.5368 in the former case, and from 1.5413 to 1.5941 in the latter.
To evaluate the performance of encapsulants, we have tested the composite encapsulants directly in working LED package. The light output power and it decay under 85oC/85% humidity operation condition was selected as the most important characteristics for an encapsulant. We can conclude that the incorporation of zirconia filler in either epoxy or silicone resin is beneficial for the application as LED encapsulant. Finally, we have obtained a zirconia/silicone composite with 24vol% filler content showing 13% better light extraction efficiency compared to the commercial high-n silicone encapsulant (OE-6630), with a comparable durability. This zirconia/silicone composite encapsulant should have potential to become a popular encapsulation material for LED packages. |
