14.Component Lifted-Spot Reflow( 零件浮起 )

                拒收                        良好r

缺c描述 :

Components have been lifted from its original intended position after spot reflow.

^完焊後零件自原砗附游恢酶∑

可能因素 :

• Conveyor vibration
• 出д
• Conveyor angle high
• 送в薪嵌炔
• Early removal of board
• 太早移影遄
• Component not seated right
• 零件未放置到定位
• Improper board handling
• 基板操作不

可行的A防方法 :

• Maintain the conveyor so as to prevent it from vibrating by removing debris
• So送П苊馊坼a後震
• Ensure that the conveyor angle is at the correct level 
• _保送o明@角度差
• Ensure that the board is placed evenly before soldering
• _保焊前是被平放置
• Correct preheating should reduce the thermal shock and also ensure a good joint
• 正_的A峥p少嵝nK形成良好接c
• Correct weight of placement should be ensured
• _好零件重量能抗衡ac染哿

重工注意事 :

• For multilead, fine-pitch component and IC :
  The footprint of the lifted gullwing legs is fluxed and the lifted leg is bent down with the help of a tweezer before the component is soldered back with a chisel-shaped soldering tip.

• For SMD : ( refer to the rework for Tombstone )

For through-hole component :
A desolder is used to remove the solder joint of the lifted leg.A tweezer is used to push the component lifted leg down until it is level and then it is resoldered back.A chisel-shaped soldering tip is used by placing it long enough against the joint such that the transfer of heat is sufficient enough before placing the solderwire close to the tip of the iron.