Void Reduction in Bottom Terminated Components Using Vacuum Assisted Reflow - 第18页
• Single lot of in house voiding test vehicle was used. • 6 Were finished with an OSP, 6 With Immersion Silver, 6 with Immersion Tin, 6 with ENIG within a da y or two o f each o ther . • Paste applied using a 100 µ thick…
Introduction
■ Several well known reflow profile process based techniques to reduce voiding
– Reflow Profile
– Peak Temperature
– Time Above Liquidus
■ None of them eliminate voiding
■ Study performed with Vacuum during reflow
■ High voiding paste/powder
■ 4 Surface Finishes, 2 vacuum pressures, 2 dwell times
■ Full factorial DOE using X-Ray inspection as response
• Single lot of in house voiding test vehicle was used.
• 6 Were finished with an OSP, 6 With Immersion Silver, 6 with
Immersion Tin, 6 with ENIG within a day or two of each other.
•
Paste applied using a 100 µ thick uncoated SS stencil
, BGA 256s, and LGA 228s
MLF-100
DPAK TO-252
MLF-52
BGA 256
BGA 228
5 Components/Board