2019-BTU-web-Vacuum-reflow-Dimock.pdf - 第18页

Atmosphere Nitrogen Solder paste SAC 305 Board finish ENIG Profile R TS - 240 peak Pad Design Window pane Pump dow n rate Fixed Refill rate Fix ed Multiple V acuum levels Hold T imes Preliminary results from 3 MLFs 100, …

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Assembly Process
• Screen print solder paste
• 100 micron thick stencils
• Paste inspection
• Koh-Young 8030-3 & Optical
• Placement & Inspection
• Reflow soldering
• BTU Pyramax 125N (control – no vacuum)
• BTU Pyramax Vacuum Oven
• KIC SPS Profiler
• Post-Reflow Inspection
• Visual
• X-ray analysis (Dage XD7600)
Atmosphere Nitrogen
Solder paste SAC 305
Board finish ENIG
Profile RTS - 240 peak
Pad Design Window pane
Pump down rate Fixed
Refill rate Fixed
Multiple
Vacuum levels
Hold Times
Preliminary results from 3 MLFs 100, 52, & 16
MLF 16 no vac vs vac
MLF 100 no vac vs vac
Hold times % Voids @ 60 Torr
Torr Sec MLF100 MLF52 MLF16
760 0 38.54 27.81 20.37
60 10 9.3 4.2 3.0
60 20 8.0 3.4 1.7
60 30 6.1 2.6 2.5
60 40 6.2 2.5 2.2
20 5 7.3
20 10 3.65 2.49 1.18
20 20 3.35 1.24 1.14
20 30 1.93 0.72 1.04
20 40 1.99 1.13 0.66
> 10%
< 10%
< 3%
Hold times % Voids @ 20 Torr
Conclusions: