Issue link: https://iconnect007.uberflip.com/i/1323994
52 SMT007 MAGAZINE I JANUARY 2021 Results • No influence on accuracy due to wet material • All 256 placements within +/-25 microns specification Reflow Profile To test curing time, we ran the board through a reflow process. The results below show a typ- ical ramp to spike profile, SAC 305, air atmo- sphere. Results • Cure transition is below liquidous phase of solder paste, eliminating LED movement from self-centering effects of surface tension. Accuracy Results—After Reflow Placement test/analysis "on wet panel" post reflow • Capability on wet paste and adhesive • 5.5 µm repeatability, all placements with 18 µm • 32 samples per panel Adhesive dispense: • Maintains LED position from surface tension effects during reflow • Proximity shall not contaminate pad • Only a single dot under LED body sufficient • Proximity nearest to pad and body Accuracy Results—Before Reflow Baseline placement test/analysis "on wet panel" • Capability on wet paste and adhesive • 5 µm repeatability, all placements with 18 µm • 32 samples per panel Figure 13: Test results. Figure 15: Accuracy measurement locations. Figure 14: X, Y accuracy data.