回焊炉温度设定.ppt

迴焊爐溫度設定,廠務處 劉年桂2013/Nov/07,Contents,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,Inside of Oven(加熱爐膛內部),HeatingIn the oven,Use Vitronics XPM21030,Reflow profile,Angle-chip for Capacitor,tc1 small SMD,T:the smaller the mass,the hotter it gets!,tc1 medium SMD,tc3 large SMD,Time,Temp.,230C,250C,tc1 small SMD,tc1 medium SMD,tc3 large SMD,20C,20C,Small SnAgCu Process Window,Peak:230 250C,tc1 255C,tc2 235C,tc3 225C,High Temperature Profiles for lead free reflow soldering,High temp.reflow profiles are often recommended to solder lead free assemblies.Peak temperatures up to 260 C are written in the literature.This extreme high temperatures may damage components,PCB laminate and influence solder joint reliability and shape.,Lead Free Reflow Process Concerns,Lead Free Reflow Process Concerns:Component Damage,225 C,250 C,Vapor pressure in ELCO,Pictures:Philips,LF Peak:230C 250C?,Lead Free Reflow Process Concerns:Component Damage,225 C,255 C,Pictures:Philips,LF Peak:230C 250C?,240 C,270 C,Deformation of thermo-plastic component bodies,Lead Free Reflow Process Concerns:Component Damage,Pictures:Jabil,LF Peak:230C 250C?,Lead Free Reflow Process Concerns:Open or Near Open Joints,Result of board warpage and component bulging due to high temperature,Picture:Philips,The risk of micro cracks increase with the distance to the center.As higher the temperature,as higher the expansion,thermal expansion(CTE),Higher temperature increases mechanical stress on solder joints,Failure to properly mount TCs will result in an unwanted T!,Reflow Machine Profiling The Most Important Step!,X,?,?,Surface measurement,BGA ball measurement,Classical Temperature Profile of a Hotflow 2/24,Gradientsdelta T,Speed:1m/min,T=5,8C!,Thermal Management:Flexible Profiling Classical Soak(1),High Plateau Temperature may damagePCB laminate,Thermal Management:Flexible Profiling Classical Soak(2),Classical Temperature Profile of a Hotflow 2/24,Gradientsdelta T,Speed:1m/min,T=4,5C!,Raising Preheat tempcan reduce T,Linear Temperature Profile of a Hotflow 2/24,Gradientsdelta T,Running just a linear profile on such ahigh sofisticated machine makes no sense!Delta T can be reduced by different setup.,T=9,3C!,Speed:1m/min,Thermal Management:Flexible Profiling Straight Line(1),Linear Temperature Profile of a Hotflow 2/24 with flat peak,Gradientsdelta T,Setting up a flat peak will reduce the delta T tremendously.,T=6,0C!,Speed:1m/min,Thermal Management:Flexible Profiling Straight Line(2),Flat peakcan reduce T,Linear Temp.Profile of a Hotflow 2/24 with flat peak/slow speed,Gradientsdelta T,Slightly Increasing the process time willreduce the delta T additionaly.,T=4,8C!,Speed:0,85m/min,Thermal Management:Flexible Profiling Straight Line(4),Flat peak&slower speedcan reduce T,爐膛長度與溫度設定,