LEA-M8F - Hardware Integration Manual
UBX-14000034 - R03
Early Production
Information
Design
Page 12 of 30
2
Design
2.1
Layout: Footprint and paste mask
This section describes the footprint and provides recommendations for the paste mask for the u-blox M8F LCC
module.
These are recommendations only and not specifications. Note that the copper and solder masks have the same
size and position.
To improve the wetting of the half vias, reduce the amount of solder paste under the module and increase the
volume outside of the module by defining the dimensions of the paste mask to form a T-shape (or equivalent)
extending beyond the copper mask. For the stencil thickness, see section 4.2.
Consider the paste mask outline when defining the minimal distance to the next component. The exact
geometry, distances, stencil thicknesses and solder paste volumes must be adapted to the specific
production processes (e.g. soldering) of the customer.
17.0 mm [669 mil]
22.
4 m
m
[881
.9 m
il]
1.0 mm
[39 mil]
0.
8 mm
[3
1.
5 m
il]
2.
45 m
m
[9
6.
5 m
il]
1.
1 mm
[43 m
il]
3.
0 mm
[11
8 m
il]
2.
15 m
m
[84
.5 m
il]
0.8 mm
[31.5 mil]
Stencil: 150
µ
m
15.7 mm [618 mil]
17.0 mm [669 mil]
20.8 mm [819 mil]
0
.8
mm
[31.
5
mi
l]
0
.6
mm
[23.
5
mi
l]
Figure 4: LEA-M8F footprint
Figure 5: LEA-M8F paste mask
2.1.1
Placement
A very important factor in achieving maximum performance is the placement of the receiver on the PCB. The
connection to the antenna must be as short as possible to avoid jamming into the very sensitive RF section.
Make sure that RF critical circuits are clearly separated from any other digital circuits on the system board. To
achieve this, position the receiver digital part towards your digital section of the system PCB. Care must also be
exercised with placing the receiver in proximity to circuitry that can emit heat. The RF part of the receiver is very
sensitive to temperature and sudden changes can have an adverse impact on performance.
The RF part of the receiver is a temperature sensitive component. Avoid high temperature drift
and air vents near the receiver.
