TFTLCD返工IC端子腐蚀行为研究
2018-10-10高洪波
高洪波
摘要:TFT LCD端子区黏合玻璃芯片(COG)、柔性印刷电路板(FPC)时会出现显示异常,需要对集成电路(IC)进行返工并重新黏合,返工时异方性导电胶(ACF)去除液极易造成端子区腐蚀。实验对腐蚀位置进行扫描电子显微镜(SEM)表面像和断面像分析,确认了膜层结构与膜层厚度,验证了多种ACF去除液在不同时间的去除效率。实验表明,由于氧化铟锡(ITO)和M2刮伤,引起去除液渗透到各膜层,造成端子腐蚀,而采用G 430型去除液涂抹且静置1 min后再用丙酮去除的方法,则可有效去除ACF且无腐蚀现象。该方法返工效率高,且棉签代替竹签操作方便,减少刮伤隐患,间接增强了端子耐腐蚀性能。
关键词:TFT LCD; 端子腐蚀; 去除液; 膜层结构
中图分类号: TN 873.93 文献标志码: A doi: 10.3969/j.issn.1005 5630.2018.03.013
Abstract:When TFT LCD display becomes abnormal after terminal area bonding with chip on glass(COG),flexible printed circuit(FPC),it requires re bonding the integrated circuit(IC) and anisotropic conductive film(ACF) removal fluid can easily lead to corrosion of the terminal area.In the experiment,the scanning electronic microscopy(SEM) surface image and cross sectional image were used for the analysis of corrosion location,the film structure and thickness.The efficiency of various ACF removal fluids for different processing time was confirmed.The experimental results show that due to the scratch on indium tin oxide(ITO) & M2,removal fluid is easy to penetrate into the layers after scratching,causing corrosion on the terminal.After applying G 430 removal fluid for 1 min,acetone can be removed.It can effectively remove the glue without corrosion.The efficiency is greatly improved.It is easy to operate with cotton swab instead of bamboo sticks for reducing the risk of scratches and enhancing the performance for the corrosion proof.
Keywords:TFT LCD; terminal corrosion; cleaning fluid; film structure
引 言
薄膜晶體管液晶显示器(thin film transistor liquid crystal display,TFT LCD)凭借良好的性能、较低的功耗、时尚的外形已逐渐替代黑白阴极射线管(CRT)显示器[1]。目前国内主流的生产厂家有京东方、华星光电、天马微电子等,这些产品已开始慢慢打开国际市场[2]。随着时间的推移,TFT LCD技术日趋成熟,显示行业正朝着高性能、低功耗、低价格、高产能方向发展[3 5]。
在TFT LCD面板生产中,模组段一道工序为:制作好的显示屏需要异方性导电胶(anisotropic conductive film,ACF)黏合COG(chip on glass)、柔性印刷电路板(flexible printed circuit,FPC)。测试时若出现显示异常或发现显示屏缺陷,需要返工拆除集成电路(integrated circuit,IC)和FPC,并重新进行黏合直至显示效果正常才进入下一制程[6 9]。这一制程若发生异常情况,如黏合上异物,就需要大量显示屏返工IC、FPC,此阶段在清除ACF时极易破坏端子区而造成显示屏损坏,如:在返工IC时,使用ACF去除液去除黏合IC的ACF时可能造成显示屏端子区腐蚀。……
