Telit Wireless Solutions ME910G1, Руководство по конструкции

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ME910G1 Hardware Design Guide
1VV0301593 Rev.12
Page 68 of 93 2021-09-24
Not Subject to NDA
Recommendations for PCB Pad Dimensions
It is not recommended to place vias or micro-vias not covered by solder resist in an area
of 0,3 mm around the pads unless they are transmitting the same signal of the pad itself
Figure 29: Pad dimensions recommendations
Holes in pad are allowed only allowed for blind holes and not for through holes.
Recommendations for PCB pad surfaces:
Finish Layer Thickness (um) Properties
Electro-less Ni /
Immersion Au
3 – 7 / 0.05 – 0.15 good solder ability protection, high shear force values
Table 35: Recommendations for PCB pad surfaces
The PCB must be able to withstand the higher temperatures that occur during the lead-
free process. This issue should be discussed with the PCB-supplier. In general, the
wettability of the tin-lead solder paste on the described surface plating is better than the
the lead-free solder paste.
It is not necessary to panel the PCB of the application, however in that case it is
recommended to use milled contours and predrilled board breakouts; scoring or v-cut
solutions are not recommended.
Thermal Performance
FR4 is one of the most commonly used PCB materials, it is a flame retardant composite
material, composed by fiberglass-reinforced and epoxy laminate. One of the features of
the FR4 is that it has a very low thermal conductivity. An inexpensive way to improve
Inhibit area for micro-via