HW User Guide
1vv0301018 Rev. 15
Page
60
of
72
2019-01-07
It is not recommended to place via or micro-via not covered by solder resist in an area of
0.3 mm around the pads unless it carries the same signal of the pad itself (see following
figure).
Holes in pad are allowed only for blind holes and not for through holes.
Recommendations for PCB pad surfaces:
Finish
Layer thickness [µm]
Properties
Electro-less Ni / Immersion Au
3 –7 / 0.05 – 0.15
good solder ability protection,
high shear force values
The PCB must be able to resist the higher temperatures which are occurring at the lead-
free process. This issue should be discussed with the PCB-supplier. Generally, the
wettability of tin-lead solder paste on the described surface plating is better compared to
lead-free solder paste.
It is not necessary to panel the application PCB, however in that case it is suggested to
use milled contours and predrilled board breakouts; scoring or v-cut solutions are not
recommended.
Solder paste
Lead free
Solder paste
Sn/Ag/Cu
We recommend using only “no clean” solder paste in order to avoid the cleaning of the
modules after assembly.
Inhibit area for micro-via
