N58 Hardware User Guide
Chapter 9 Assembly
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9.4 Solder Paste
The solder paste volume and the PCB flatness play key roles in the production yield.
Do not use solder pastes with lead that use a module technique that is different from Neoway module
technique.
The melting temperature of solder pastes with lead is 35°C lower than that of solder pastes
without lead. The temperature in the reflow process parameters is also lower than that of solder
pastes without lead, and less time is consumed correspondingly. It is easy to cause the
LCC/LGA in the module to be in the semi-melted state after the second reflow soldering,
resulting in poor soldering.
If users must use solder pastes with lead, ensure that the reflow temperature is kept at 220°C for
more than 45 seconds and the peak temperature reaches 240°C.
9.5 SMT Furnace Temperature Curve
Neoway will not provide a warranty for thermal component exceptions caused by improper temperature control.
Thin or long PCB might bend during SMT. Therefore, use loading tools during the SMT and reflow
soldering process to avoid poor solder joint caused by PCB bending.
Figure 9-3 SMT furnace temperature curve