Introductions1.doc

I. Materials Preparing LCD materials include ITO Glass, Polarizer, Spacers, Seals, LCD Fluid, and other chemical solutions. (I) ITO Glasses1. The makeup of ITO glass： Ca-Na glass （Bi-Si glass ）mother glass coated with SiO2 (to prevent the Na expanding into the LC fluid in the cell, thickness: 200250 （1 =0.0001mm） ) and then, ITO layer (thickness:2502000 ). The reason to coat ITO, namely Indium Tin Oxide, is because the Indium Oxide is highly transimissive, while the Tin Oxide is highly conductive. 2. Categories of ITO Glasses(1) Dimensions: 14*14 14*16 20*24Basically RIFDA uses 14x16 glasses.(2) Surface Resistance High Resistance: 150 500 Regular: 60 150 Low Resistance: 85%，彩色片的偏光效率相对较低，一般在80%以下。目前最好的偏振片偏振度可达99%以上 透过率：实际偏光片的透光率值都略低于50%。 色相：指偏光片颜色所对应的色坐标值 有效厚度：偏光板的总厚度，包括基板厚度，胶厚度及保护膜厚度。 Storing and Handling of polarizer The storage condition of polarizer is:temperature-2015、humidity- 65%20%RH，far away from progeny。 Be care for the usage of polarizer, avoiding rubbing, bending and striking。 The surface of polarizer should be clean, do not touch the surface, and protect from smudginess (without protecting coat）。 Carefully peel off the protective film before assembling the LCD. (III) LC Fluid液晶分类1. 物理条件分：热致液晶、溶致液晶 2. According to structure, there are four categories of Liquid Crystal Fluids: Neumatic, Cholesteric、Smectic、DiskDISKCHOLESTERICSMECTICNEMATIC液晶的主要技术参数：*相变温度特性：熔点至清亮点之间的温度区间 *粘度：响应时间*介电各向异性：阈值电压和响应速度 *光学各向异性n ：nd/2 n小则视角大 *弹性常数：陡度*液晶电阻率：液晶纯度 *扭曲能力Liquid Fluid is very sensitive to the humidity and luminance, therefore it should be stored in where there is facilitated with dehydrating system and blue lighting. (IV) Other Materials 光刻胶、PI材料、钝化膜、黑膜、紫外硬化性树脂（封边胶、封口胶、封PIN胶）、导电胶（丝印用、上PIN用）、玻璃纤维、垫片、金粉、镍粉、全息膜、匀光片、金属引线LCD上游材料日本厂商材料项目厂商日本占有率玻璃基板日本康宁(Corning)、旭硝子(AGC)、日本电器硝子(NEG)、NHT、日本板硝子及中央硝子65%彩色滤光片凸版印刷、大日本印刷、东丽、STI、ACTI、Micro、Canon、LCD大厂80%驱动ICSharp、Seiko-Epson、日本TI、NEC、Toshiba、日立85%背光板Stanley、茶谷产业、日本Denso、富士通化成、Enplas、多摩电气88%偏光板日东电工、住友化学、三立、Polatechno97%II. Manufacturing of ITO glass(I) Surface and PI handlingCleaningPR coatingCuringExposuredevelopingCuring EtchStriping1. Cleaning & Curing1) Clean with alkaline cleaner (碱性清洗液)and super sonic disposal2) Clean with DI (De-ionize 去离子) water3) Super sonic + spraying/showing clean4) Dehydrated with wind blade5) Dehydrated with curing6) UV cure to get rid of bacteria2. PR CoatingPR (photo-resistant) glues will be coated onto the clean surface of the ITO glass. We use the rolling tubes to evenly apply the glue, which is already missed with dilution solvents. There are 2 kinds of PR glues, positive and negative. Negative glues can be dissolved in some oxide solvents, such as acetone (丙酮), ether (乙醚), diethyl ether (环乙醚); but would not be dissolved in the alkaline (碱性) solvents. When exposed, it then would have photo-synthesis reactions (光聚作用), which would make it not dissolvent in those oxide solvent, but dissolvent in the alkaline solvents. During the etching process, the layers of glues would have an image exactly reverse to that of the etching model. This is why it is called Negative. Vise versa is positive glues. 2 characteristics would be critical here:(1) Distinctiveness rate: It symbolizes the accuracy of etching. If the pitch wide is W, then the Distinctiveness ratio is 1/W; for example, if W=0.5um, the D/R = 2000lines/mm. (2) Sensitization Rate: Is indicates the sensitiveness of the PR glue to the lights. The higher the S/R is, the shorter the exposure time will be. 3. PR CurveBasically its functions are to evaporate the dilutions in the glue, and to enhance the adhesiveness of the glue to the surface of glass. 4. Exposure Covered with exposure covering plate, the ITO glass coated with PR glue would be placed under the UV lights to selectively expose the PR glue. Those parts of exposed glues would thus become not dissolvable by oxide solvents; while those which are not exposed would still be dissolvable. The exposure plate is designed by the Designing Dept., in accordance with customers requirements. Normally the exposure timing for TN glass is 1 2 seconds, while that for STN is at least 5 second. 5. DevelopmentUse developing solvent (which has 4% base碱) to take off those exposed parts of PI, and reserve those unexposed parts. It would protect the ITO during etching process. * There is another step called Top Coating, which would apply the SiO2 onto the surface of ITO glass, after the developed process. Its function is to fill into the dents between the developed and non-developed parts, thereby not only increasing the insulation, but also improving the viewing angles by efficiently removal of the electro shape under non display situation. For ordinary TN and STN LCD products, it is not required. 6. Main CurveThe ITO glass would be cured under high temperature of 140C in order to enhance the strength of PI coating, and meanwhile evaporate the leftover of the diluting solvents. 7. EtchUsing appropriate proportioned etching solvents to wear away the ITO coating of those parts whose PR coating is removed during development process. Those which still have PR coating would not react, and thus would shape as the ITO electro circuits. 8. StrippingUse high concentration NaOH solution as stripping solvent, erode the leftover of the PI glue, and structure the ITO outline which is exactly the same as the design of the exposure plate. 9. Cleaning and curing(1) Use highly pure water wears away the leftover of base碱solvents, PI glues, and other foreign substances. (2) Dry out the ITO glass So far the first step of ITO glass manufacturing process, surface and PI handling, is accomplished. Next we will go into PI buffing and alignment process. (II) PI Buffing1. PI PrintingApply the organic polymeric material (有机高分子材料), polyimide (聚酰亚胺, PI ) onto the surface of glass. PI is not conductive, and can stand high temperature. 2. Pre-CureSince the PI have some diluting solvents, so curing process would evaporate those solvent when it make the PI coating more even. But the major function would solidify the PI layer, whose hardness would affect the rubbing dents and angle. Thus its temperature is critical here. Normally TN required a curing temperature of 230C, while STN asks for 210C, and FSTN, 180C. 3. PI RubbingThe PI layer would be rubbed at a specific angle by fine-hair brush, and thus consist dents which the liquid crystal 分子 would ally to. This procedure would thus determine the twisting angle of LCD: TN 90 Degree, while STN 210 Degree. 4. CleaningSpecific procedure would remove the contaminations, such as leftover of the brush etc. (III) AlignmentParticle departurePre CuringSeal printing Aligning CuringAg printing 1. Seal Printing & Pre-curing1) Seal PrintingUse the tech of silk printing, the sealing glue would be applied to both upper and lower glass, along the edges of the LCD cell as designed. There are 2 kinds of sealing glue, heat-curing glue and UV-curing glue. Even the curing conditions are different, both are made of epoxy resin环氧树脂，环氧胶. It is highly non-conductive, but we can connect the electrode of upper and lower glass by adding some silver particles. 2) Pre-curing: Based on the characteristics of the materials of glue, we use heat or UV to cure the glue and the silver particles. 2. Ag(Cross-order) Printing & Spacer Spray1) Ag (cross-order) PrintingApply the cross order onto the surface of the glass. 2) Spacer SpraySpacer is made ball-shaped powder made of resin 树脂. The evenly spread spacer (several um ) would support the cell thickness. Normally we use 5.2um, 6.2um, 6.75um and 7.75um spacers. To prevent the pollution inside the LCD cell, the spacer cannot have 水分or other foreign substances. Steel wireOperating platformSpacer spraying gunSPACER Spacers SprayingSpacers under Microscope3. Aligning (Glass Assembly)Assemble the upper and lower glass in accordance with the positioning requirements of the design. The positioning marks and the direction of glass cannot be messed up. 4. CuringUnder high temperature of 160C, cure the glue of the sealing line to improve adhesiveness. Meanwhile, apply pressure onto the cell would make the cell thickness more even. But over-curing be UV would The cell thickness would directly affect the product display effects, especially for STN products. If the evenness of the cell thickness exceeds the tolerance of 0.2um, the elect-optical characteristics and color of display would have huge difference. Thus, cell thickness is critical for LCD products quality, and it is determined in this process. We now have walked through so-called front processes, and would introduce the backside process, which include fluid injection, end sealing, testing and polarizer assembling, etc. (IV) Backside Process 1End-sealLC fillingscribing Inspectionand test pasting packing1. Cell scribingThere are scribing symbols on 4 corners of the single LCD cell. Cut the whole glass into several strips of glass; expose the opening where the LC fluid will be injected into the cell. 2. LC InjectionLC injection Steps: (1) Place the empty cells into the hermetically sealed chamber, vacuum the air. Then pose the LC fluid to the opening. There are 2 ways of posing the fluid, one is needling for smaller openings, the other is saturating for either larger or small openings. (2) Instill dry noble gas (惰性气体) into the chamber to press the LC fluid into the cell. This process has high requirements on the circumstances since it easily can be contaminated by steam, grease or particles. 3. End SealingSeal the opening of the fluid-filled cell with sealing resin 树脂glue, to avoid external contaminations and to prevent fluid leakage. 4. CuringThe sealing glues can be cured by either heat or UV disposal.5. Break-offThe strips of the LCD cells have to be broken off into individual LCD cells. 6. Cleaning Use cleaning solutions to wash away the liquid crystal fluid and other particles attached to the exterior of the cells; then use water to wear away the cleaning solutions, and the use DI water (去离子水) and super-sonic waves to clean. 7. HeatingBy heating up for a period of time (80C for 30 seconds), we force the liquid crystalline molecules to follow the directions of the rubbing 8. Edge Grinding Grind the cracks of the edge of the glass (V) Backside Process 21. CleaningWipe off the dust left over from the Edge Grinding process with 酒精， 异丙醇, 氟利昂溶剂; dont use 丙酮或芳香族熔剂(如甲苯). 2. Visual InspectionVisual Inspection is accomplished under 2 pieces of polarizer. When the 光轴 of polarizer parallel to each other, they consist a transparent area; under which you can observe the possible foreign defects caused in the prior manufacturing process. Possible defects detected in this process: 1) Inside contaminations: foreign substances attached onto the surface of glass before cell-assembly; or the spacers not spread evenly. 2) Finger prints: Operators finger touched the ITO surface or the PI layers.3) Directing defaults: the clear/dark situation can not observed, or part of some characters appears; or the rubbing traces can be seen. The causes is the PI layer is not applied (or not stubbornly attached); or the rubbing force is not appropriate4) Seal-frame out of shape: the line is not even5) Rainbow: the unevenness of the cell thickness cause the circle/strips color differences. 6) Bubbles: inappropriate fluid injection causes that the cell is not fully filled. 7) Gas intruded: gas intrudes into the cell due to the not fully sealed opening. 8) Scribe defects: the scribing process cause some cut into the seal line, or cracks. 9) Scratches: scratches on the surface of the screen10) Seal-opening contaminations: seal-opening glue interfere into the seal-frame; cause the pasty opening.11) Cracks 3. Electrical InspectionApply the voltage signals onto the LCD to test the actual display effects. The signal from the tester includes COM signals and SEG signals. COM signals would go through the silver point to the back electros, and SEG would go directly to the front electros. So, if a cross voltage applied onto a cross point of back electros and front electros (driving voltage) is higher than LCDs 阀值voltage, the character or graphics corresponding would show up. In this sense, the tester can also be used to judge and alert the big current (大电流) caused by shortcut or contaminations. Defects detected in this process:1) Line Missing2) Short Cut3) Non-Display4) Blurred wording5) “Fat” characters6) Half Characters7) Disrupting wording8) Black strip9) Whit dots10) Large power consumption 4. CleaningBefore applying the polarizer, the surface of the glass should be clean again. 5. Polarizer assembly- Cut the whole piece of polarizer in accordance with the directions of the long side (the 光轴s direction)- Assembly: assemble the well-cut polarizer onto the glass in accordance with the drawings positions. - 消泡: 碾压apply 46 kgs pressure onto the LCD cell to press out the bubbles between polarizer and the screen. - Inspectation: Possible defects includes:1) Assembly defaults: assembly in wrong directions, no-assembling, or wrongly assembled.2) Size is not in accordance with that of the drawings3) Deviated4) Contamination 5) No protective film6) Damaged polarizer or scratches7) Bubbles between the screen and polarizer- Adjust the color difference, normally adjust the face polarizer for Y/G STN displays; adjust the bottom polarizer for FSTN displays. 6. Pin assemblyPins would connect the electrodes of LCD to the driving circuits, which would apply the driving signals (COM and SEG) onto the corresponding LCD electrodes for display.- 点碳浆 highly conductive- Assemble the pins using UV glue- Cut the pins7. Electrical InspectionTesting, including visual and electrical inspects. 8. Final InspectionQC final inspects 9. Packaging Packaging the LCD screen into the box made of foam plastic泡沫塑料 , which is highly elastic 弹性, buffering capacitive, 缓冲性好，pressure resistant and shock-proof. 耐压力强防震。10. StockingStock into the warehouse.(VI) Silk-Printing Some products need silk-printing either on the top front of the screen, or onto the inside of the cell. III. LCM Manufacturing Processn 液晶显示模组(Liquid Crystal Display Module)，缩写为LCM或LCDM。n 模块结构分类 普通模块的核心部件就是LCD与集成板，故液晶显示器件的安装需要依靠其它的元件来连接。 故按显示器件（LCD）与驱动器板的连接方式与固定方式不同来区分。 连接方式： 导电胶条，是一种普通的连接方式。 热压连接（如FPC/导电纸等）。 直接集成连接（如金属PIN脚的连接）。 固定方式： 铁架（铁架扭脚嵌入PCB）。 胶架（用螺丝，定位销固定）。nn 结构流程：外部接口控制器CONTROLLER驱动器DIRVER显示器件LCD Panel连接方式固定方式n 常用的接口连接方式: 导电胶条:导电胶条是一层薄的导电橡胶与一层薄的绝缘橡胶热压成。其结构如下 :o PITCH有：0.04、0.05、0.10、0.18（单位：mm）。 LCD外引线至少与23条导电条正位接触。故LCD外引线PITCH及脚步宽越小则所需的电胶条的PITCH越小，LCD与PCB的对位越困难o 常用的类型：a）YS型、b）YP型、c）YL型、d）YI型； YS型两侧是较厚的绝缘层，其弹性与当中的导电橡胶样可以支撑较大的压力 YP型两侧是软多孔的绝缘胶，既能保护导电橡胶，又不会增加其硬度，弹性减小不会造成接触不良。当导电胶条的高度小于或等于宽度时，一般用此种 插座连接（Connecter）通常都是标准件, 选购的供应商如下： NAIS、MOLEX、HIROSE、 SAMTEC 、ELCO 排线（FFC） FFC（Flexible Flat Cable）为镀锡软铜箔夹于两层绝缘材料（PVCPET）之间的扁平线。尺寸及公差的定义和要求见参照图样 规范的的术语表达：o 导通接触面（Conductor）o 绝缘体（Insulation）o 补强板（Stiffener）o 导体厚（Conductor Thickness)有0.1、0.05、0.035mmo 此材料同FFC的柔韧性有关，0.1的较硬。o 尽量不要采用Pitch小于0.50mm设计用于焊接。 柔性线路板（FPC）FPC（Flexible Printed Circuits) 为一种铜质线路印制在PI聚酰亚胺（Polyimide） 或PE聚脂（Polyester）薄膜基材上, 具有o 可自由弯曲和可挠性o 纤薄轻巧、精密度高o 可以有多层线路，并于板上贴芯片或SMT 晶片o 装配方式：插接、焊接、ACF热压。o Materials: 基层 Base film： 12.5、25、50、75、125um（PIPE) 铜薄分Copper Foil：电解铜和压延铜 料厚有：18、35、70um 覆盖层Coverlay Film： 12.5、25、50、75、125um（PIPE) 补强板Stiffener ：0.2mm （PIPE)o 连接ZIF的接插件（Connecting with ZIF conn