Application Note
[Page 17]
Design Considerations of EMW3239
4.
SMT
Stencils
4.1
Stencils thickness is suggested as 0.12mm (0.1~0.15mm) with Laser grinding. Recommended solder paste:
No lead SAC305.
Stencils size is shown in figure 4.1, pad holes extend 0.15mm in order to improving solder wicking. If there
is no AOI testing, check module by eye is available to reduce the Pseudo Soldering.
Figure 4.1 Stencils size
Temperature Curve of Secondary Reflow
4.2
Pseudo soldering could be reduced by control the furnace with temperature curve of secondary reflow, as
shown in figure 4.2.
Secondary reflow times less than 2
Peak temperature: 250
℃
Figure 4.2 Temperature Curve of Secondary Reflow