Thermal Guidelines - Ublox JODY-W1 Series System Integration Manual

Figure 10 describes the pad layout for the JODY-W1 series module. The proposed land pattern layout
reflects the pin layout of the module. Both Solder Mask Defined (SMD) and Non Solder Mask Defined
(NSMD) pads can be used with the following considerations:
• Pins from 1 to 60 should be NSMD
• Inner pads must have a good thermal bonding to PCB ground planes to help spreading the heat
generated by the module.
• If NSMD design is chosen for inner pads, thermal reliefs should be considered and 4 or 9 vias per
pad must be added for heat sink. Those vias may require copper capping.
• If SMD design is chosen for inner pads, the land pattern can be flooded on a ground plane beneath
the module and vias added around the pads for heat sinking.
The suggested stencil layout for the JODY-W1 series module follows exactly the copper outer pad
layout as described in
pattern.
Figure 11 shows a suggested stencil opening implementation with the following characteristics:
• Solder paste area should be split into several smaller parts, typically four to nine, depending on the
copper pad area.
• Total solder paste area should cover about 50% to 60% of copper thermal pad area.
• Total solder paste area must not exceed 65% of copper thermal pad area.
Missing to consider solder paste optimization may lead to poor soldering quality in production.
Figure 11: Stencil opening example for inner thermal pads (dimensions in µm)
⚠
The exact mask geometries, distances and stencil thicknesses must be adapted to the specific
production process of the customer.

2.7 Thermal guidelines

JODY-W1 series modules have been successfully tested from -40 °C to +85 °C ambient temperature.
The board generates heat during high loads that must be dissipated to sustain the lifetime of the
components.
The improvement of module's thermal dissipation decreases its internal temperature, which
increases the long-term reliability of the device for applications that operate at high ambient
temperature.
UBX-16012621 - R18
C1-Public
Figure 10. The central pads should be implemented with a special solder paste
JODY-W1 series - System integration manual
Design-in Page 34 of 72