欢迎来到天天文库
浏览记录
ID:40632045
大小:232.15 KB
页数:3页
时间:2019-08-05
《FlashSoldering_Diode_Laser》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、“FlashSoldering”–ANewOpportunityforDiodeLasersDavidW.SteinmeiermicroJoiningSolutionsBackground–Theelectronicsindustryeffectivelyusesmassreflowsolderingtechniquestobondthemajorityofthrough-holeandsurfacemountcomponentstotheirprintedcircuitboard(PCB)assemblies.However,somet
2、emperaturesensitiveelectroniccomponentscannottoleratethehightemperaturepeakof230°Cforoneminutethatistypicallyencounteredinthemassreflowsolderingprocesswithoutsufferingdamage.Thesecomponentsaresolderedoff-lineusinghandorothersemi-automatedsolderingtechniques.Thisprocessisc
3、ommonlyknownas“OddFormSoldering”or“SelectiveSoldering”andconstitutesasmuchas10%ofallelectronicassemblywork.Handsolderingisslowandhighlydependentonoperatorskillleveltoachieveagoodsolderjoint.Attemptstousesemi-automatedformsofselectivesolderinghavebeenpartiallysuccessful.Se
4、mi-automatedselectivesolderingtechniquesincludehotbar,thecommonsolderingiron,andmicro-flame.Allthreeheatsourcesrequireintimatecontactwiththecomponentstocreateasolderjoint.Theseheatsourcesaretypicallypairedwithasolderwirefeedsystemforcontrollingthewiresolderfeedrate.Hotbar
5、reflowsolderingutilizesatemperaturecontrolledmetalheatingelementthatcanbepulsedtothedesiredreflowsolderingtemperatureormaintainedataconstanttemperature.Hotbarreflowsolderingsuffersfromseveralmajordrawbackswhichincludemechanicaldeformationoftheelectroniccomponentsurfaceand
6、reducedthermaltransferduetowarpingandfluxbuildupontheheatingelementsurface.Insomecases,thehotbarcontactsurfacemustbecleanedasoftenasevery500to1,000cycles.Thesolderingironalsousesametalheatingelementforaconstanttemperatureheatsource.Solderintheformofsolderwireishandorsemi-
7、automaticallyfeedintothejointarea.Topreventareductioninheattransfer,thesolderingironheatingelementortipmustbeconstantlywipedbyamechanicalscrubbingmechanismtoremovefluxandsolderoxidebuildup.Thisrepeatedoxidationremovalprocesseventuallyresultsinthereplacementoftheheatingele
8、ment.Micro-flameheatingemploysaminiaturegasfeedflametocreatethenecessarysolderingheat.Micro-flam
此文档下载收益归作者所有
点击更多查看相关文章~~