LED有机硅封装材料的研究进展

综述了高、中、低三种折射率LED有机硅封装材料的研究进展,分析了各种产品的优缺点,指出LED有机硅封装材料由低折射率向高折射率快速发展的方向。     

瓦克新的照明工业用有机硅封装材料简介

正新的照明工业用有机硅封装材料(如LUMISIL~?590591、LUMISIL~?740770和LUMISIL~?LR7601)是瓦克为LED(初级光学器件)封装、光学透镜及耦合元件(次级光学器件)生产而开发的新产品。LUMISIL~?590591是高透明的加成交联型LED有机硅封装材料,可固化成折射率为1.53的弹性体,属高折射率(HRI)封装材料,故其光输出量也极为理想。这些高透明有机硅还能让可见光(波长400~700 nm)几乎完全通过,在辐射强度高的情况下也不会黄变。此     

LED封装用改性环氧树脂研究进展

传统的LED环氧树脂封装材料存在脆性大、耐冲击性差、容易老化、透光率低、折射率低等缺陷,限制了其在LED封装产业中的应用,通过环氧树脂改性可弥补其作为LED封装材料的缺陷。本文综述了近年来LED环氧树脂封装材料在高折射率、光稳定、抗黄变、有机硅改性方面的研究进展,并展望了LED改性环氧树脂封装材料的发展前景。     

功率型LED封装用有机硅材料的研究进展

概述了有机硅材料的特性及作为功率型LED封装用材料的发展,主要从高折射率、高导热性、高透光率三方面综述了近几年有机硅材料的研究进展,并指出了制约有机硅封装材料发展的问题。     

功率型LED封装用有机硅材料的研究进展

概述了有机硅材料的特性及作为功率型LED封装用材料的发展,主要从高折射率、高导热性、高透光率三方面综述了近几年有机硅材料的研究进展,并指出了制约有机硅封装材料发展的问题。     

有机硅LED封装材料的最新研究进展

综述了近年来LED封装用有机硅材料(包括苯基有机硅、环己烷基有机硅、含氟有机硅、含环氧基有机硅)以及有机硅复合材料(有机硅/无机纳米粒子复合材料、有机硅/环氧树脂复合材料)的研究进展,并对有机硅LED封装材料未来的研究方向进行了展望。     

LED封装用有机硅材料的研究进展

介绍了发光二极管(LED)的特点及对封装材料的性能要求,指出了现有LED封装材料环氧树脂的不足,综述了近年来有机硅改性环氧树脂LED封装材料、有机硅LED封装材料的研究进展.     

功率型LED封装用有机硅材料的研究进展

介绍了发光二极管(LED)的特点、封装形式的发展及对封装材料的性能要求,指出了现有LED封装材料环氧树脂的缺陷,分析了有机硅封装材料的特点,综述了功率型LED封装用有机硅材料的研究进展。     

高功率型LED封装新材料的研究进展

随着发光二极管(LED)功率和亮度的不断提高,封装材料已成为制约LED进入照明领域的关键技术之一。综述了改性环氧树脂和有机硅LED封装材料的研究进展,并展望了改性环氧树脂和有机硅LED封装材料的发展前景。     

瓦克推出全新LED 用高折射率有机硅

正瓦克最近开发出了适用于发光二极管(LED)和光学部件的新型封装胶。该产品由透明度和折射率极高的有机硅弹性体制成,可承受高工作温度和强光辐射,而且不发生黄变,因此非常适合用于制造具有高发光效率的LED。此外,该产品还能保护LED芯片免受腐蚀性气体的侵蚀,从而大大延长了芯片的使用寿命。这种有机硅封装胶可以通过点胶等工业计量工艺进行加工。     

Transparent dispensible high‐refractive index ZrO2/epoxy nanocomposites for LED encapsulation

In this study, we report a facile ex situ approach to preparing transparent dispensible high‐refractive index ZrO₂/epoxy nanocomposites for LED encapsulation. Highly crystalline, near monodisperse ZrO₂ nanoparticles (NPs) were synthesized by a nonaqueous approach using benzyl alcohol as the coordinating solvent. The synthesized particles were then modified by (3‐glycidyloxypropyl)trimethoxysilane (GMS) ligand. It was found that, with tiny amount of surface‐treating ligand, the modified ZrO₂ NPs were able to be easily dispersed in a commercial epoxy matrix because of the epoxy compatible surface chemistry design as well as the small matrix molecular weight favoring mixing. Transparent thick (1 mm) ZrO₂/epoxy nanocomposites with a particle core content as high as 50 wt % and an optical transparency of 90% in the visible light range were successfully prepared. The refractive index of the prepared composites increased from 1.51 for neat epoxy to 1.65 for 50 wt % (20 vol %) ZrO₂ loading and maintained the same high‐Abbe number as the neat epoxy matrix. Compared with the neat epoxy encapsulant, an increase of 13.2% in light output power of red LEDs was achieved with the 50 wt % ZrO₂/epoxy nanocomposite as the novel encapsulant material. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3785–3793, 2013     

高折射率LED封装胶耐高低温冲击性的研究

以苯基乙烯基硅树脂、苯基乙烯基硅油、含氢硅油、增粘剂等为原料,制成了双组分加成型高折射率LED封装胶。研究了原料对其耐高低温冲击性能的影响。结果表明：在苯基乙烯基硅树脂中引入5％的γ-环氧丙氧基丙基三甲氧基硅烷、配胶时将黏度为5000mPa·s和300mPa·S的苯基乙烯基硅油按10：2的质量比混合使用、交联剂采用活性氢质量分数为0．43％的苯基含氢硅油、增粘剂含环氧基和氢基的预聚物的质量分数为1％,按此配方配成的LED封装胶用于5050、5730灯架进行测试,完全固化后先过3次回流焊,然后在-40-＋100℃的冷热冲击测试试验机中进行测试,经过500个循环后,封装胶无裂胶、胶脱底和胶片脱落、死灯等现象。     

LED封装用甲基苯基含氢硅油的制备

以甲基苯基环四硅氧烷（D4^ph）为单体,含氢双封头（MMH）为封端剂,酸性阳离子交换树脂为催化剂,通过开环聚合的方法制备了LED封装用甲基苯基含氢硅油。研究了反应温度、反应时间对含氢硅油黏度的影响,及甲基苯基环四硅氧烷含量对含氢硅油折射率和黏度的影响。进行了^1H—NMR、红外光谱性能表征。结果表明,反应温度、反应时间能显著影响硅油的黏度;苯基摩尔分数越高,折射率也越大。最佳反应温度110℃,反应时间10h。以此方法合成的含氢硅油为主要原料,制备了折射率1．54,透光率95％的LED灌封胶,适合用于LED封装。     

Light‐diffusing materials for LED illumination applications: Comparing the effectiveness of two typical light‐diffusing agents

Light‐diffusing materials (LDMs) are the primary lampshade materials used for indoor light‐emitting diode (LED) illumination. In this work, two varieties of typical LDMs filled with acrylic or silicone diffusing agents were fabricated via a twin‐screw extruder, and the influences of the particle size, refractive index and light‐diffusing surface area of the light‐diffusing agents on the properties of the LDMs, including their light‐diffusing properties, thermal stability and mechanical properties, were explored in depth. The results indicated that both acrylic and silicone light‐diffusing agents can be dispersed evenly in a polycarbonate (PC) matrix. The light‐diffusing surface area and refractive index are the main factors that influence the diffusing properties of LDMs. Compared with the silicone LDM, the acrylic LDM exhibited higher transmittance but poorer thermal stability and impact strength, making this material suitable for a rapid injection molding process to form half‐sphere covers that combine high haze and transmittance for LED light bulbs. Silicone LDMs exhibit good stability and impact strength, favoring a slow single‐screw extrusion molding process to prepare tubular or panel covers for tubular LED lamps and panel lamps. In this study, a method for producing LDMs with both high transmittance and high haze is reported. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42923.     

Synthesis and characterization of a high refractive diglycidyl ether of thiodibenzenethiol epoxy resin

High refractive index of epoxy resins used as encapsulant in light-emitting diode (LED) is essential in improving the light extraction efficiency, reducing heat and prolonging the service life of LED packages. In this study, diglycidyl ether of thiodibenzenethiol (DGETDBT), an epoxy resin with high refractive index, was synthesized via a novel method and its chemical structure was characterized with Fourier-transform infrared (FTIR) spectrometer and ¹H NMR spectrometer. Using m-xylylenediamine (MXDA) as curing agent, the curing behavior of DGETDBT was studied by differential scanning calorimetry (DSC) and was compared with that of diglycidyl ether of bisphenol A (DGEBA), a generally used encapsulant in LED. The thermal behavior and optical performance of these two resins were investigated with thermogravimetric analyses, UV?CVis scanning spectrophotometer, and Abbe refractometer, respectively. The results showed that DGETDBT/MXDA resin demonstrated similar curing and thermal behavior to DGEBA/MXDA resin. But its refractive index reaches 1.698, which is significantly higher than that of DGEBA/MXDA resin (1.604). Comparatively, DGETDBT resin can be expected to be a more effective encapsulant of LED.     

高折光指数含硅环氧树脂的合成与性能研究

将二苯基二氯硅烷经过氢化铝锂还原为二苯基硅烷,再与4-乙烯基环氧环己烷进行硅氢加成后合成了1种新型含硅环氧树脂二[2-(3,4-环氧环己基)乙基]二苯基硅烷(EODPS)。该树脂的折光指数达到1.567,并具有较好的透明度。采用甲基六氢苯酐和乙酰丙酮铝-二苯基硅醇组合物分别对EODPS进行固化。通过红外光谱,DSC分析表征了EODPS的结构,研究了其固化活性,并对固化后产物的热稳定性、力学性能和吸水性进行了测试,且与脂环族环氧树脂CEL-2021P性能进行了比较。结果表明,与CEL-2021P相比,EODPS具有更高的热稳定性和更低的吸水率,可用于LED封装。     

Improvement of photon extraction efficiency of GaN-based LED using micro and nano complex polymer structures

A micro- and nanoscale complex structure made of a high refractive index polymer (n = 2.08) was formed on the ITO electrode layer of an edge-emitting type GaN blue light-emitting diode (LED), in order to improve the photon extraction efficiency by suppressing total internal reflection of photons. The nanoimprint lithography process was used to form the micro- and nanoscale complex structures, using a polymer resin with dispersed TiO2 nano-particles as an imprint resin. Plasma processing, such as reactive ion etching, was used to form the micro- and nano-scale complex structure; thus, plasma-induced damage to the LED device can be avoided. Due to the high refractive index polymeric micro- and nanostructure on the ITO layer, the electroluminescence emission was increased up to 20%, compared to an identical LED that was grown on a patterned sapphire substrate to improve photon extraction efficiency.     

LED非球面透镜注射压缩成型工艺稳健性优化分析

采用稳健设计方法,以发光二极管（LED）非球面透镜折射率变化为实验目标,以压缩距离、压缩速度、压缩力、保压压力、熔体温度、冷却时间、注射速率为影响因素,设计了L27(37)正交试验矩阵,并对透镜的注射压缩成型过程采用Moldflow2015软件模拟分析。结果表明,最优工艺参数组合为A3B1C2D3E3F2G2;熔体温度对透镜折射率的影响最大,注射速率次之,压缩距离、冷却时间、保压压力影响较小,压缩速度、压缩力影响最小;优化后采用更高的熔体温度和较快的注射速率,有利于减小透镜的体积收缩,改善透镜内部残余应力,折射率变化减小了45 %,翘曲变形量减小了4.3 %。     

Transparent red -emitting silicone resin for color conversion and encapsulation of NUV light-emitting diodes

Herein, a novel transparent phenyl vinyl silicone resin nanocomposite containing exfoliated fluorescent Eu-containing hydrotalcite-like compound (EFHSN) is developed to serve as a dual role of color conversion and encapsulation material. Excited by near-NUV light, the EFHSN emits a strong characteristic red light (614 nm). Meanwhile, the EFHSN shows not only excellent transparency (T > 95%) in the UV-Vis region and high refractive index (1.46) but also superior thermal stability, which could meet the need of commercial encapsulation materials and optical application. Therefore, the EFHSN is expected to be used in InGaN-based NUV light-emitting diodes and flexible optoelectronic device.