导光板注塑成型技术的研究
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摘要
背光源是液晶显示器的主要零件之一,它给液晶显示器提供了稳定的光源。导光板是背光源的主要部件,其作用就是控制光的散射方向,把冷阴极灯管的线光源转化为均匀面光源。导光板注塑成型技术是一种通过光学网点转移的方法成型导光板的先进技术。
本文首先简要介绍了导光板的原理和注塑成型技术,接着通过模流分析软件分析实验模型的注塑成型条件和注塑成型工艺参数如模具温度、熔体料温、浇口射速、成品射速、射出压力、冷却时间、保压压力、保压时间、保压切换位置等对导光板品质的影响,然后采用田口方法设计了注塑成型技术的工艺实验规划,并进行了实际注塑工艺实验。实验结果表明,较长的冷却时间可以减少导光板的翘曲量;升高塑料熔体的温度、增加保压压力和保压时间可以提高导光板辉度;升高塑料熔体的温度有利于导光板均齐度的提高,但过高的熔体温度会使注塑成型的光学网点产生不均匀体积收缩而使导光板的均齐度降低。最后优化确立了一组在实际生产中得到应用的工艺参数,采用此工艺生产,实践表明其良品率从原来的75%提高到90%左右,经济效益显著。
Back light is one of the main parts of Liquid Crystal Display (LCD) and it provide stable light source for LCD. Light Guide Plate (LGP) is the main part of Back Light. The main function of LGP is to control the scattering directions of incident light to transfer linear light source to surface light source, increase luminance and uniformity in displays. In addition, LGP molding technology is an optic dot transfer method by molding.
Firstly this thesis introduced LGP light principium and molding technology. Then LGP molding condition was analysed by mold flow soft for this test mold. And molding parameters such as cooling time, mold temperature, barrel temperature, injection rates, injection pressure, packing pressure, packing switching, and packing time were also analysed by mold flow soft. Those gave out effect result on LGP quality. Then Taguchi Quality Engineering Method was adopted for LGP molding experiment design. And actual test was done. The relationship between the qualities and processing parameters was assessed based on the final qualities via both experimental verifications and quality measurements. In conclusions, experimental results had shown that long cooling time could reduce the LGP warpage. High melt resin temperature and high packing pressure and time would increase LGP luminance. The melt temperature is most critical to uniformity of transmittance, but too high melt temperature will cause light dot unevenness shrinkage after molding and decrease uniformity of transmittance. Finally one set parameter was optimized for mass production and this process can improve molding yield from 75% to 90% in normal mass production. And that was good for production cost saving.
本文首先简要介绍了导光板的原理和注塑成型技术,接着通过模流分析软件分析实验模型的注塑成型条件和注塑成型工艺参数如模具温度、熔体料温、浇口射速、成品射速、射出压力、冷却时间、保压压力、保压时间、保压切换位置等对导光板品质的影响,然后采用田口方法设计了注塑成型技术的工艺实验规划,并进行了实际注塑工艺实验。实验结果表明,较长的冷却时间可以减少导光板的翘曲量;升高塑料熔体的温度、增加保压压力和保压时间可以提高导光板辉度;升高塑料熔体的温度有利于导光板均齐度的提高,但过高的熔体温度会使注塑成型的光学网点产生不均匀体积收缩而使导光板的均齐度降低。最后优化确立了一组在实际生产中得到应用的工艺参数,采用此工艺生产,实践表明其良品率从原来的75%提高到90%左右,经济效益显著。
Back light is one of the main parts of Liquid Crystal Display (LCD) and it provide stable light source for LCD. Light Guide Plate (LGP) is the main part of Back Light. The main function of LGP is to control the scattering directions of incident light to transfer linear light source to surface light source, increase luminance and uniformity in displays. In addition, LGP molding technology is an optic dot transfer method by molding.
Firstly this thesis introduced LGP light principium and molding technology. Then LGP molding condition was analysed by mold flow soft for this test mold. And molding parameters such as cooling time, mold temperature, barrel temperature, injection rates, injection pressure, packing pressure, packing switching, and packing time were also analysed by mold flow soft. Those gave out effect result on LGP quality. Then Taguchi Quality Engineering Method was adopted for LGP molding experiment design. And actual test was done. The relationship between the qualities and processing parameters was assessed based on the final qualities via both experimental verifications and quality measurements. In conclusions, experimental results had shown that long cooling time could reduce the LGP warpage. High melt resin temperature and high packing pressure and time would increase LGP luminance. The melt temperature is most critical to uniformity of transmittance, but too high melt temperature will cause light dot unevenness shrinkage after molding and decrease uniformity of transmittance. Finally one set parameter was optimized for mass production and this process can improve molding yield from 75% to 90% in normal mass production. And that was good for production cost saving.
引文
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[4]蒋宗树.导光板导光设计之研究[D].中原大学,2003.
[5]方育斌.LCD背光模组之光学最佳化设计[D].国立成功大学,2004.
[6]勾治践,樊仲维,等.光学塑料透镜注射成型关键技术的研究[J].光学精密工程,2000,8(6):526-531.
[7]邹跃军,任丁.背光源结构分析及几种提高亮度的途径[J].液晶与显示,2002,17(6):465-470
[8]文放怀.田口方法[M].广东经济出版社,2006,8.
[9]陈进都.多段射出在导光板的应用与分析[D].国立中兴大学,2005,6.
[10]赖怀恩.导光板成型品质与射出成型制程参数之研究[D].国立清华大学,2004,6.
[11]林瑞璋.Moldflow软体应用[M].全威图书有限公司,PP.11.
[12]E Johannabar.Injection Molding Machines a User's Guide[M].Hanser/Gardner Publication,Inc,Cincinnati,pp.33-37,(1985).
[13]Tim A.Osswald.Material Science of Polymers for Engineers[M].Hanser Publishers,(1996).
[14]Di Feng.Novel integrated light-guide plates for liquid display backlight[J].Journal of optics,2005,7(3):111-17
[15]H.Yang,M.Y.Wu,W.T.Yi.Micro-tapered post array for new light-guide plate molding technology in liquid crystal displays[J].International Display Manufacturing Conference and Exhibition,IDMC'05,2005,561-564.
[16]C.J.Kuo,T.Su.Optimisation of precision injection moulding processing parameters and implementation of quality precision system for LCD light guide plate[J].Polymers and Ploymer Composites,2007,1(15):17-28.
[17]H.S.Lee.In-plane deformation analysis and design of experiment approach for injection molding of light guide plate for LCDs[J].International Journal of Precision Engineering and Manufacturing,2006,1(7):51-56.
[2]王贵恒.高分子材料成型加工原理[M].化学工业出版社,1998.3.
[3]蔡俊钦.导光板光学设计及制程之最佳化研究[D].国立高雄应用科技大学,2004.
[4]蒋宗树.导光板导光设计之研究[D].中原大学,2003.
[5]方育斌.LCD背光模组之光学最佳化设计[D].国立成功大学,2004.
[6]勾治践,樊仲维,等.光学塑料透镜注射成型关键技术的研究[J].光学精密工程,2000,8(6):526-531.
[7]邹跃军,任丁.背光源结构分析及几种提高亮度的途径[J].液晶与显示,2002,17(6):465-470
[8]文放怀.田口方法[M].广东经济出版社,2006,8.
[9]陈进都.多段射出在导光板的应用与分析[D].国立中兴大学,2005,6.
[10]赖怀恩.导光板成型品质与射出成型制程参数之研究[D].国立清华大学,2004,6.
[11]林瑞璋.Moldflow软体应用[M].全威图书有限公司,PP.11.
[12]E Johannabar.Injection Molding Machines a User's Guide[M].Hanser/Gardner Publication,Inc,Cincinnati,pp.33-37,(1985).
[13]Tim A.Osswald.Material Science of Polymers for Engineers[M].Hanser Publishers,(1996).
[14]Di Feng.Novel integrated light-guide plates for liquid display backlight[J].Journal of optics,2005,7(3):111-17
[15]H.Yang,M.Y.Wu,W.T.Yi.Micro-tapered post array for new light-guide plate molding technology in liquid crystal displays[J].International Display Manufacturing Conference and Exhibition,IDMC'05,2005,561-564.
[16]C.J.Kuo,T.Su.Optimisation of precision injection moulding processing parameters and implementation of quality precision system for LCD light guide plate[J].Polymers and Ploymer Composites,2007,1(15):17-28.
[17]H.S.Lee.In-plane deformation analysis and design of experiment approach for injection molding of light guide plate for LCDs[J].International Journal of Precision Engineering and Manufacturing,2006,1(7):51-56.