《Low-Melting-Temperature-Pb-free-solder-paste-Evaluation-StudyPPT优秀课件》由会员分享，可在线阅读，更多相关《Low-Melting-Temperature-Pb-free-solder-paste-Evaluation-StudyPPT优秀课件（24页珍藏版）》请在装配图网上搜索。
1、Low Melting Temperature Pb-Free Solder Paste Evaluation ReportSurface Mount Advanced Engineering September 30,2011 Background Objectives Team Member Evaluation Flow Paper Study Machine and Materials Data and Results SummaryContentsBackgroundThe application of low-temperature solders in surface mount
2、assembly processes for products that do not experience harshtemperature environment is technically feasible.Increasing component complexity as well as the need for lower energy consumption will be a driver for advances in new solder materials.Objectives To study the impact of low melting temperature
3、 solder in reflow power consumption.To understand basic knowledge on solder joint strength comparison between SAC305 and low melting temperature lead free bismuth-based solder paste.(Note:This study focus on ENIG PCB pad finish)SMAE Joseph Escasura MingLiang Luo Francis Fernandez EDC LAB ShuangYang
4、Dong Zheng Xu Wang LeiTeam MemberEvaluation FlowSMTSolder Joint Reliability TestPaper StudyBrand NameModel NumberAlloy CompositionMelting PointCost ALPHA CVP-52042Sn/57.6Bi/0.4Ag139￥520/KG QUALITEK DSP 96842Sn/57Bi/1.0Ag139￥495/KG SENJU M705-GRN360 96.5Sn/3.0Ag/0.5Cu217￥520/KGSolder Paste Informatio
5、nPaper StudyRemark:Melting temperature of SnBiAg solder paste is 35%lower than SAC305.-High melting temperature-Low melting temperatureSolder Paste Reflow Profile RequirementPaper StudyParameterALPHA CVP-520QIALITEK DSP 968SENJU M705-GRN360Peak Temperature155C180C155C175C235C245CPre-heat time30sec12
6、0sec 80C110C69sec120sec 100138C70sec110sec 150180CReflow time30sec90sec 138C60sec80sec 139C30sec60sec 220CFigure1.Kaifa Test Board Use Resmed L3 SMT line Solder Paste ALPHA CVP-520 QUALITEK DSP 968 SENJU M705-GRN360 PCB:ENIG pad finish 54 PCBs for reliability test(18pcs for each solder paste)Compone
7、nts 0603 chip resistor:45pcs for each PCBA 0402 chip resistor:45pcs for each PCBAMachine and Materials0603&0402 chip resistorData and ResultReflow Profile(All profile meet the solder paste requirement)Figure2.SnBiAg Reflow Profile Figure3.SAC305 Reflow Profile Figure4.SnBiAg Reflow Oven Setting Figu
8、re5.SAC305 Reflow Oven SettingAlloy CompositionReflow Power Consumption 42Sn/57.6Bi/0.4Ag(ALPHA)3.77 KW/hr42Sn/57Bi/1.0Ag(QUALITEK)96.5Sn/3.0Ag/0.5Cu(SENJU)6.20 KW/hrReflow Oven Power ConsumptionData and Result BTU Power consumption measured for 10 minutes Reflow oven consume more electrical power w
9、hen using SAC305.Reflow power consumption for SAC305 is 40%higher than SnBiAg alloy.Test Condition Test temperature:-40-85,40 min/cycle Temperature conversion time:15s Test stages:0 cycles,100cycles,200c,400c&500c Samples:PCBA 1pcs/stage Evaluation criterion:Solder joint defects(crack)&shear strengt
10、h of chip resistorsReference:JESD22-A106B Thermal shock I.Thermal Shock TestData and ResultT TS S-5 50 00 0C CT TS S-4 40 00 0C CT TS S-2 20 00 0C CT TS S-1 10 00 0C CA As s-R Re ef fl lo ow w654321S Sh he ea ar r F Fo or rc ce e(K Kg gf f)AlphaQualitekSenjup pa as st te e t ty yp pe e2.263.223.222.
11、563.142.802.543.053.142.553.0332.273.194.150 06 60 03 3 R Re es si is st te er r S Sh he ea ar r F Fo or rc ce e o of f t th he e S So ol ld de er r J Jo oi in nt t a af ft te er r T Th he er rm ma al l S Sh ho oc ck k T TS S-5 50 00 0C CT TS S-4 40 00 0C CT TS S-2 20 00 0C CT TS S-1 10 00 0C CA As
12、s-r re ef fl lo ow we ed d3.02.52.01.51.00.5S Sh he ea ar r F Fo or rc ce e(K Kg gf f)AlphaQualitekSenjup pa as st te e t ty yp pe e1.512.132.381.301.911.941.402.251.961.452.421.861.362.172.030 04 40 02 2 R Re es si is st te er r S Sh he ea ar r F Fo or rc ce e o of f t th he e S So ol ld de er r J
13、Jo oi in nt t a af ft te er r T Th he er rm ma al l S Sh ho oc ck kFigure6.0603 chip resistors shear test Figure7.0402 chip resistors shear test Shear test results after thermal shock The shear strength of SnBiAg solders were higher than that of SnAgCu one.Thin IMC in SnBiAg solders Bi-rich phase in
14、 SnBiAg solders,Dispersion intensify SnAgCu shear force value kept stable after thermal shock.Data and Result50Xno crack50Xno crackSenju -500cno crack Cross-section result after thermal shock Solder joint were inspected through cross-section image.The results shown no crack in three samples after th
15、ermal shock.Data and Result100Xno crackFigure8.ALPHA -500C Figure9.QUALITEK -500C Figure10.SENJU -500C Test Condition Test temperature:125 Test stages:0h,24h,100h,225h,400h,600h,1000h Samples:PCBA 1pc/stage Evaluation criterion:Solder joint microstructure(IMC composition,IMC morphology,IMC thickness
16、,defects)&shear strengthReference:JESD22-A103C High Temperature Storage LifeData and ResultII.Isothermal Aging Test Shear test results after isothermal aging The shear strength of Qualitek and Alpha solder paste decreased after aging 1000h.The Alpha decreased quickly.However,the shear strength of Sn
17、AgCu solder kept stable after aging.Shear force of SnBiAg solders was near to that of SnAgCu after aging 1000h.Figure11.0603 chip resistors shear test Figure12.0402 chip resistors shear test Data and Result SEM/EDX results for Isothermal aging test IMC layers became thick after aging 1000h.IMC thick
18、ness increased with different rate after aging.AlphaQualitekSenjuQualitekAlphaSenjuFigure14.Isothermal-1000hData and ResultFigure13.After Reflow IMC thickness measurement after isothermal aging IMC layer thickness=IMC section area/Length The growth rate of IMC layers were different in aging phase,an
19、d the growth rate of Alpha and Qualitek pastes are the largest,Which is the reason that caused the shear strength decreasing quickly.IMC section areaLengthIMC layer thickness measurement methods Aging-0hAging-225hAging-400hAging-600hAging-1000h01234567 IMC thickness(m)isothermal aging time(h)Alpha Q
20、ualitek SenjuQualitek with higher growth rateData and Result EDX results for aging 225h The composition of IMC which was near the Ni(P)pad should be Ni3Sn4 phase,and that was near the solder should be consist of Ni3Sn4 and Au6Sn.Alpha-225h agingNi:10.42%Sn:61.92%Au：6.75%Ni:22.79%Sn:32.67%Bi-richNi(P
21、)padIMCData and ResultNi:9.62%Sn:50.20%Au：2.71%Bi:4.53%Ni:30.10%Sn:43.35%Bi-richNi(P)padAlpha-600h aging EDX results for aging 600h IMCs composition was the same with that of aging 225h.There was little Bi element that should belong to Sn-rich phase which came from solder.Data and ResultNi:7.30%Sn:5
22、7.45%Ag：4.57%Au：6.06%Ni:22.32%Sn:40.52%Ag：5.32%Senju-1000h aging EDX results for aging 1000h The compositions of IMCs which was near the Ni(P)pad should be Ag3Sn and Ni3Sn4,and that of which was near the solder should be Au6Sn,Ag3Sn and Ni3Sn4.Ni(P)padData and ResultSummary Existing reflow power con
23、sumption can reduce by 40%when using the alternate low melting temperature lead free solder paste.Based on reliability test result,the following were observed:The shear strength of SnBiAg solder was higher than SnAgCu before and after reliability test.Shear strength of SnBiAg solder was decreased af
24、ter aging of 1000h,but SnAgCu solder kept stable.Shear force of SnBiAg solders was near to that of SnAgCu after 1000h aging.IMC growth rate of SnBiAg is larger than SnAgCu after aging thus,resulting to degradation in shear strength.This evaluation study can be used as reference and benchmark in future products with low melting temperature Pb-free solder requirement.The End个人观点供参考，欢迎讨论
Low-Melting-Temperature-Pb-free-solder-paste-Evaluation-StudyPPT优秀课件
