User's Manual

HE910 Hardware User Guide
1vv0300925 Rev.9 – 07-02-2012
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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.
Inhibit area for micro-via