摘录——助焊剂常见问题.doc

摘录——助焊剂常见问题.doc摘录一一助焊剂常见问题First,afterwe1ding,PCBsurfaceresidueismore,lessclean:beforeweldingwithoutpreheatingandpreheatingtemperatureistoolow(dip,shorttime)・(notfullyvolatileflux)・furnacetemperatureisnotenough・・(KongTaida)thatcausesthefluxtorise・theuseoffluxintheprocess,:,thewavefurnaceitselfhasnowindknife,resultinginexcessivecoatingamountofflux,preheatingdropstotheheatingtube・(unevencoatingofthefluxonthePCB).(pletelyvolatile,FLUXdrop)ortooslow(causedbyhotplatetemperatureistoohigh).(PCBsheetisbadandheatingpipeistooclosetoPCB).Three,thecorrosion(ponents,blackspot)1\isnotfullypreheated(preheatingtemperatureislow,equalspeed)causedbyresidualflux,harmfulresiduetoomuch)・2\usefluxthatneedscleaning,,powerflow,easyleakage(badinsulation)PCBdesignisunreasonable,wiringistooclose,etc・・PCBsoldercoatingisofpoorqualityandeasytoconduct・Five,leakagewelding,weld,・PCBwiringisunreasonable(partsarenotdistributedproperly)・foampipeblocked,unevenfoaming,resultinginunevenFLUXcoatingonthePCB・Improperhandlingmethodfor