侧光平板式导光板散射网点设计及仿真分析

导光板是LCD背光模组里的一个重要组件,而底面散射网点的设计是设计导光板的一项关键技术。本文通过对冷阴极荧光灯(CCFL)作光源的侧光平板式导光板中光传输过程的分析得到了这种导光板散射网点的一种排布公式和设计方法,并用ASAP软件进行模拟仿真,比较了这种网点分布公式和设计方法与其他一些网点设计方法的优劣,验证了这种网点设计方法的可行性。通过这种网点设计方法获得了均匀性很好的输出亮度分布结果。     

TFT-LCD背光模组光学膜关键件的开发研究

背光模组关键件包括导光板、扩散膜、增光膜等，其技术实质是大型微细结构光学元件，即利用光学微细结构和散射微粒等实现对光能的重新分布，并达到特定的使用目的。背光模组关键件的设计与制造涉及光学、高分子材料、精密模具（含模具机床）和精密成型工艺与设备等多学科的交叉技术，我国虽然研究开发背光模组的单位较多，但由于受基础工业的限制，因此无法形成产业。成都菲斯特科技有限公司长期致力于微细结构光学元件的研究开发和量产．以光学型投影显示器件为代表产品，所形成的技术体系具有自主性、完整性和基础性三大特点，足以支撑背光模组光学膜关键件项目的发展。     

激光加工散射网点火山口对导光板光学的影响

针对激光加工导光板散射网点周围存在环状熔融物(火山口)对导光板光学影响的问题,进行了网点加工实验和光学仿真研究。采用CO₂激光在PMMA上进行打点实验,观察测量火山口的三维形貌尺寸,分析在不同能量参数下火山口的特征变化。为了提高激光导光板的光学性能,按照散射网点密度正比于其所在位置距光源距离的网点密度分布理论,在UG和TracePro软件中建立模型,仿真分析了火山口宽度和高度变化对导光板光学的影响,通过多次仿真得知,火山口在一定程度上提升了出光平均值,但随着火山口高度和宽度的增加出光平均值的增加减弱;另外火山口参数变化对导光板均匀度的影响较小,均匀度均可维持在88%以上。     

大尺寸改性聚苯醚绝缘垫片注塑工艺的研究

介绍了一种压缩气体绝缘传输线(CGIT)用大尺寸改性聚苯醚(MPPO)绝缘垫片的注塑成型工艺。该绝缘垫片厚度为26mm,外径为240mm,根据该尺寸设计了注塑成型模具,并通过超声波无损探伤技术对绝缘垫片内部缺陷进行了检测,结果表明绝缘垫片内部缺陷普遍存在于厚度12mm处。因此,对注塑模具和工艺参数采取了改进措施,如增加模具排气孔,增大浇口、流道和喷嘴的尺寸,调整熔融温度、射胶速度、注射压力和保压时间等。工艺改进后,绝缘垫片试样经逐层解剖,内部无肉眼可见缺陷。     

一种具有波形槽微结构的导光板设计

导光板是背光模组的关键组件,决定了出光效率以及出光均匀性。针对目前导光板的均匀性差和亮度低的问题,通过光学工程软件LightTools对导光板进行了设计,提出了一种新型的具有波形槽微结构的侧光平板式导光板的设计方法,并对微结构的分布方式和其参数进行了设计。结果表明,当矩形分布下的微结构按照规律在导光板上形成波形槽后,能够得到均匀性在80%以上的高性能导光板。相对微结构呈点阵式矩形分布下的导光板的均匀性只有60%～70%而言,这种高性能导光板的均匀性有了很大的提高,且该导光板尺寸在40～60mm范围内变动时,导光板的均匀性均能达到80%以上。     

718塑料模具钢激光合金化与氮化组织性能的比较

在718钢表面进行了超细碳化钨(WC)激光合金化的实验,利用金相显微镜、维氏硬度计等设备检测了合金化层的组织和性能.通过与氮化试样的比较,表明激光合金化可以得到晶粒细化,深度大,硬度高,与基体结合牢固的表面强化层.塑料注射成型模具大量使用718钢作为型芯、型腔等零部件的成型材料.上述成型零部件在磨损、侵蚀和注塑压力的共...     

精雕软件在角花注塑模具中的应用

本文主要介绍了精雕软件造型功能和曲面功能在角花注塑模具设计中的应用,通过精雕软件与Pro/E软件的结合,解决了模具型腔精细化、复杂化的问题,顺利实现了工艺品用注塑作业生产的工艺过程。     

塑料模具设计与制造 第七讲 型腔加工工艺和模具的装配工艺

第七讲型腔加工工艺和模具的装配工艺三、型腔的冷挤压型腔的冷挤压是利用淬硬的挤压冲头,在室温条件下,以很大的压力缓缓地挤入具有一定塑性的坯料,获得与冲头形状相同、凸凹相反的型腔的一种加工方法。冷挤压型腔过程简单、迅速,生产率高;型腔表面粗糙度可达R_a=0.32～0.08μm;由于材料纤维未被切断,故型腔强度高。冷挤压工艺适用干塑性较好的坯料成型,尤其适合于难以机械加工的复杂型腔、浮雕花纹、字母及多型腔模具的加工。 (一)冷挤压成型方法     

基于图像处理技术的激光直写导光板网点设计

为了快速高效地设计出输出表面照度均匀的导光板,采用了基于灰度图像处理技术的导光板网点设计方法,并利用TracePro光学模拟软件对2个LED单边入射的模型进行了理论分析和模拟验证,取得了模拟导光板表面照度值.结果表明,此方法设计的导光板输出照度均匀度可达86.7%,符合国际照明委员会(CIE)标准,经局部修改后均匀度可进一步提高到91.9%.该方法能够有效地设计出表面照度均匀的导光板.     

LCD导光板自由曲面微型槽结构设计与优化

为满足液晶显示器对于背光模组亮度高、发光均匀、厚度小的要求,提出一种侧入式背光模组的新型组合导光板结构设计方法。即在理想Lambertian光源侧向入射时,为满足导光板亮度均匀性的要求,提出并确定了一种基于自由曲面函数的导光板底部微型槽结构。借助于TracePro光学软件对该导光板进行了建模,并通过合理设置微型槽镀膜和组合反射板的光学属性,实现了导光板照明效果的仿真。仿真结果显示,基于该微型槽的导光板符合工程上的亮度均匀性和超薄设计要求。     

Sub‐20 nm Magnetic Dots with Perpendicular Magnetic Anisotropy

A new and simple method for the preparation of magnetic dot arrays is introduced. Diblock copolymer micelles with a silica core are used as template for the generation of nanostructure arrays. The silica cores are utilized as mask for ion milling preparation. The morphology and size of the silica and magnetic dot arrays are discussed. The magnetic dots are made from Co/Pt multilayer films. Ferromagnetic dots with a diameter well below 20 nm and perpendicular easy axis of magnetization are created. The switching behavior changes from domain wall motion, dominant in the film, to single domain particle switching in the dots. The magneto‐optic saturation signals and the evolution of magnetic anisotropy are discussed.     

半导体封装中的可视化技术

树脂传递模封装是广泛使用的可靠性量产性均好的半导体封装方法。但随着封装体（PACKAGE）尺寸的日益薄型化和多腿化,不可避免地会发生与树脂在模腔中流动状态有关的空隙等使制品失效的不良模式。这样,通过观察树脂流动状态及对空隙的分布进行研究,对于研究空隙发生机理从而抑制空隙发生具有重要意义。本文将着重介绍两种新的研究实验方法：（1）应用玻璃嵌入式新型可视化模具观察树脂在模腔中的流动状态;（2）采用超声波探查图像装置（简称SAT）进行树脂封装体内部的观察。     

基于Trace-Pro软件的LCD导光板网点分布仿真与研究

针对目前背光模组的均匀度差和亮度低的问题,利用Trace-Pro光学仿真软件对印刷式导光板的网点分布进行模拟分析,着重提高光输出的均匀度。采取分块优化来简化设计,通过与网点面积密度比的关联,利用网点密度比、网点半径和间距三者的关系,进行相互转化,拟合出间距的整体性最佳化曲线,从而避免了重复建模和光线追迹。通过这种网点设计方法获得了高照度下均匀度大于90%的导光板的网点分布。将优化结果与实际导光板尺寸比较对比可知,间距平均值偏差1.6μm以下,半径平均值偏差±2.7μm以下。实验结果与计算分析结果吻合得较好,对实际生产有一定的指导意义。     

Role of thermal ejection of carriers in the burning of spatial holes in quantum dot lasers

The role of thermal carrier ejection from quantum dots and free carrier diffusion in the burning of spatial holes in semiconductor quantum dot lasers is analyzed. The balance of the spatially inhomogeneous population inversion in the longitudinal direction of the cavity is shown to be controlled by thermal ejection from quantum dots. Because of this circumstance, hole burning in quantum dot lasers can show up more strongly and the threshold for multimode lasing can be lower than in semiconductor lasers with three-dimensional active regions or quantum-well lasers. The threshold for multimode lasing is determined as a function of the dispersion in the quantum dot size, cavity length, and temperature for structures that have been optimized to minimize the threshold current density of the fundamental mode. Fiz. Tekh. Poluprovodn. 33, 1076–1079 (September 1999)     

Generation and Concentration of Terahertz Radiation in a Microcavity with an Open Quantum Dot

A scheme to generate terahertz radiation by an array of quantum dots localized at the center of a semiconducting heterostructure is developed. Electrons are injected into the active part due to the source and drain Fermi energy difference induced by a dc electric field. The structure is placed inside a microcavity stimulating the electronic transition in the quantum dots accompanied by the emission of a photon to the cavity mode. This process is optimized using the filters formed by the quantum wells, which facilitate the electron density concentration in a quantum dot. The electromagnetic field radiated by the cavity in the waveguide can be used for a local effect on the charge qubits. The parameters of such a source depend on the working characteristics of the quantum dots and cavity.     

利用能量过滤TEM获取外延量子点的成分信息

半导体量子点应用于许多关键的现代科学技术中。量子点的尺寸和成分对决定量子点光电性质十分重要。由于量子点的尺寸很小,表征量子点的成分及其分布是一项很有挑战性的任务。本文综述了能量过滤透射电子显微术如何应用于量子点成分的研究。     

Characteristics of pH sensors fabricated by using protein-mediated CdSe/ZnS quantum dots

The pH sensors using protein-mediated CdSe/ZnS quantum dots in an electrolyte-insulator-semiconductor (EIS) structure have been investigated. The hydrophobic cylindrical cavity of the chaperonin (GroEL) protein template was used to trap CdSe/ZnS quantum dots on hydrophobically treated SiO₂ surface. The CdSe/ZnS quantum dot with a small diameter of 3.98 nm is observed by atomic force microscope. A fair pH response with a sensitivity of 39 mV/pH and a linearity of 99.48% are obtained by using CdSe/ZnS quantum dot based EIS sensor, while those values are found to be 53 mV/pH and 99.95% for bare SiO₂ based EIS pH sensors. The pH response and linearity of CdSe/ZnS based quantum dot sensors are inferior (slightly) as compared to the bare SiO₂ sensors owing to the initial negative charges of CdSe quantum dots membrane, which has been explained by energy band diagrams. It is expected that this kind of quantum dot membrane can be useful in future bio-molecule detections.     

Low-Cost Vacuum Molding Process for BGA Using a Large Area Substrate

We have developed a new ball grid array vacuum molding process using a large area substrate, called vacuum dip compression molding (VDCM), with the aim of reducing the substrate molding cost. The VDCM method imposes less of a burden on the environment because it enables efficient use of the substrate area for packaging, increasing the proportion of the effective area on the substrate. In contrast to the transfer molding method, VDCM does not generate cull or runner waste. VDCM also has the advantage of reducing the thickness of the mold resin. It can mold packages with various thicknesses using a single mold. Using VDCM equipment, we conducted a basic evaluation of molding performance. It was confirmed that no significant wire sweep occurred even when the wire length exceeded 3 mm, indicating that VDCM is less prone to wire sweep compared to transfer molding. The prototyped fine pitch ball grid arrays had a satisfactory level of moisture sensitivity.     

一种导光板网点分布懿计算方法与仿真

导光板网点的分布决定着背光源出光的亮度均匀度。文章通过对导光板中光的传输过程的分析,同时根据LED照度分布,推导出一种网点分布的计算方法,并对仿真结果进行了分析。     

1.3-μm CW lasing characteristics of self-assembled InGaAs-GaAsquantum dots

This paper presents the lasing properties and their temperature dependence for 1.3-μm semiconductor lasers involving self-assembled InGaAs-GaAs quantum dots as the active region. High-density 1.3-μm emission dots were successfully grown by the combination of low-rate growth and InGaAs-layer overgrowth using molecular beam epitaxy. 1.3-μm ground-level CW lasing occurring at a low threshold current of 5.4 mA at 25°C with a realistic cavity length of 300 μm and high-reflectivity coatings on both facets. The internal loss of the lasers was evaluated to be about 1.2 cm^-1 from the inclination of the plots between the external quantum efficiency and the cavity length. The ground-level modal gain per dot layer was evaluated to be 1.0 cm^-1, which closely agreed with the calculation taking into account the dot density, inhomogeneous broadening, and homogeneous broadening. The characteristic temperature of threshold currents T₀ was found to depend on cavity length and the number of dot layers in the active region of the lasers. A T₀ of 82 K was obtained near room temperature, and spontaneous emission intensity as a function of injection current indicated that the nonradiative channel degraded the temperature characteristics. A low-temperature study suggested that an infinite T₀ with a low threshold current (~1 mA) is available if the nonradiative recombination process is eliminated. The investigation in this paper asserted that the improvement in surface density and radiative efficiency of quantum dots is a key to the evolution of 1.3-μm quantum-dot lasers