回焊炉温度设定.ppt

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1、迴焊爐溫度設定廠務處劉年桂2013/Nov/07Contents爐膛設計Profile四個區間說明融錫狀態PWI高溫影響CTE測溫線埋設爐溫升溫圖型說明速度與爐膛加熱計算模擬InsideofOven(加熱爐膛內部)HeatingIntheovenUseVitronicsXPM21030ReflowprofileAngle-chipforCapacitortc1–smallSMDΔT:thesmallerthemass,thehotteritgets!tc1–mediumSMDtc3–largeSMDTimeTemp.230°C250°Ctc1–sm

2、allSMDtc1–mediumSMDtc3–largeSMD20°C20°CSmallSnAgCuProcessWindowTooHot!TooCold!Peak:230–250°Ctc1–255Ctc2–235°Ctc3–225°CHighTemperatureProfilesforleadfreereflowsolderingHightemp.reflowprofilesareoftenrecommendedtosolderleadfreeassemblies.Peaktemperaturesupto260°Carewritteninthel

3、iterature.Thisextremehightemperaturesmaydamagecomponents,PCBlaminateandinfluencesolderjointreliabilityandshape.SnPbSnAgCuSnAgCuTmax215°CTmax235°CTmax260°CComponent:ChipC1206AgPdBoard:NiAuPictures:Zollner,ZandtLeadFreeReflowProcessConcernsLeadFreeReflowProcessConcerns:Component

4、Damage225ºC250ºCVaporpressureinELCOPictures:PhilipsLFPeak:230°C–250°C??LeadFreeReflowProcessConcerns:ComponentDamage225ºC255ºCPictures:PhilipsLFPeak:230°C–250°C??240ºC270ºCDeformationofthermo-plasticcomponentbodiesLeadFreeReflowProcessConcerns:ComponentDamagePictures:JabilLFPe

5、ak:230°C–250°C??LeadFreeReflowProcessConcerns:OpenorNearOpenJointsResultofboardwarpageandcomponentbulgingduetohightemperaturePicture:PhilipsTheriskofmicrocracksincreasewiththedistancetothecenter.Ashigherthetemperature,ashighertheexpansionthermalexpansion(CTE)Highertemperaturei

6、ncreasesmechanicalstressonsolderjointsFailuretoproperlymountTCswillresultinanunwantedT!ReflowMachineProfiling–TheMostImportantStep!X??SurfacemeasurementBGAballmeasurementClassicalTemperatureProfileofaHotflow2/24GradientsdeltaTPCBPBGASpeed:1m/minT=5,8°C!ThermalManagement:F

7、lexibleProfiling–ClassicalSoak(1)HighPlateauTemperaturemaydamagePCBlaminateThermalManagement:FlexibleProfiling–ClassicalSoak(2)ClassicalTemperatureProfileofaHotflow2/24GradientsdeltaTPCBPBGASpeed:1m/minT=4,5°C!RaisingPreheattempcanreduceTLinearTemperatureProfileofaHotflow2

8、/24GradientsdeltaTPCBPBGARunningjustalinearprofileonsuchahi