10
PCB Design Guidelines
The recommended WS1102 PCB Land pattern is shown
in Figure 14 and Figure 15. The substrate is coated with
solder mask between the I/O and conductive paddle to
protect the gold pads from short circuit that is caused by
solder bleeding/bridging.
Stencil Design Guidelines
A properly designed solder screen or stencil is required
to ensure optimum amount of solder paste is deposited
onto the PCB pads.
The recommended stencil layout is shown in Figure 16.
Reducing the stencil opening can potentially generate
more voids. On the other hand, stencil openings larger than
100% will lead to excessive solder paste smear or bridging
across the I/O pads or conductive paddle to adjacent I/O
pads. Considering the fact that solder paste thickness will
directly aect the quality of the solder joint, a good choice
is to use laser cut stencil composed of 0.100 mm (4 mils) or
0.127 mm (5mils) thick stainless steel which is capable of
producing the required ne stencil outline.
0.25
0.8
0.4
0.65 0.5
Ø 0.3mm
on 0.5mm pitch
1.4
0.8
0.5
0.75 0.55
1.325
1.1
0.8
0.4
0.65 0.5
1.05
Figure 14. Metallization.
Figure 15. Solder Mask Opening.
Figure 16. Solder Paste Stencil Aperture.
