Research On LCM Hot-pressing Process And Electrical Properties

LCD Module （LCM,Liquid Crystal Module） hot pressing process foranisotropic conductive film（ACF，Anisotropic Conductive Film）has a directimpact on the reliability of the connection.The reliability of the connection in theconnection resistance,connect power and conductive adhesive curingrate,pressing process is one of the direct factors that affect the reliability of theconnection.This article will be pressing process to make the connectionreliability factors affecting quantitative research.This paper reviews the history of ACF,based on LCM application andconnection reliability ACF research status at home and abroad on the use of themethod DOE（Design Of Experiments）and statistical analysis,the compressionratio by the group into the thousands of correspondence between the connectionresistance data,the connection resistance and studied the relationship between thepressure pad of the conductive particles,to determine the compression ratio of theconductive particles in the pad between40%to80%,the average number ofconductive particles on the pad is more than6,the connection resistance will beless than10Ω,deciving the fail rate over90%. It meets production needs.Using cross-comparison test method,carried out different types ofACF,different FPC（Flexible Printed Circuit）shape and material,sealing gluedispensing different types,and whether the impact of the protective tape tensionon the connection,the protective layer FPC polyimide amine and metal electrodewidth ratio greater than1:1,while supporting the use of UV glue dispensing,inthe case of the use of protective tape,pulling more than meet the productionrequirements10N/mm.According to the temperature of the curing rate and a strong correlationbetween the temperature and the effects of different positions below the curingratio IC,derived on the basis of the temperature,the higher the cure rate ofACF,but the high temperature will produce a springback phenomenon binding thesituation easily lead to the occurrence of the glue bond breaking,the temperaturecan not be higher than320℃,select the length and width dimensions close to theIC ACF length and width dimensions,help to improve the curing effect of ACFconclusion. Using a process of elimination,through different batches ACF,ACFvalidation of different models hot bubbles of reasons for the differences in thethickness of ACF and ACF established a selection of the thickness of themathematical model.According FOG （Film On Glass）short circuit,investigated the relationshipbetween the polyimide LCD steps from the pressing position and pressing theshort-circuit,and the experimental results show that the polyimide is not less thanthe distance on the LCD stand0.3mm,keep hot head from the edge of theLCD,which can effectively control the occurrence of hot short circuit conditions.