LEA-M8S / LEA-M8T - Hardware integration manual
UBX-15030060 - R06
Product handling
Page 24 of 33
Production information
Repeated reflow soldering
Only single reflow soldering processes are recommended for boards populated with u-blox M8
modules. To avoid upside down orientation during the second reflow cycle, the M8 modules should not
be submitted to two reflow cycles on a board populated with components on both sides. In such a
case, the module should always be placed on that side of the board which is submitted into the last
reflow cycle. This is because of the risk of the module falling off due to the significantly higher weight
in relation to other components.
You can consider two reflow cycles by excluding the above described upside down scenario and taking
into account the rework conditions described in section 4.
☞
Repeated reflow soldering processes and soldering the module upside down are not
recommended.
Wave soldering
Baseboards with combined through-hole technology (THT) components and surface-mount
technology (SMT) devices require wave soldering to solder the THT components. Only a single wave
soldering process is encouraged for boards populated with u-blox M8 modules.
Hand soldering
Hand soldering is allowed. Use a soldering iron temperature-setting equivalent to 350 °C. Place the
module precisely on the pads. Start with a cross-diagonal fixture soldering (for example, pins 1 and
15), and continue from left to right.
Rework
The u-blox M8 module can be unsoldered from the baseboard using a hot air gun. When using a hot
air gun for unsoldering the module, a maximum of one reflow cycle is allowed. Using a hot air gun is
not recommended because it is an uncontrolled process and might damage the module.
⚠
Attention: use of a hot air gun can lead to overheating and severely damage the module. Always
avoid overheating the module.
After the module is removed, clean the pads before placing and hand soldering a new module.
⚠
Never attempt a rework on the module itself, for example, by replacing individual components.
Such actions immediately terminate the warranty.
In addition to the two reflow cycles, manual rework on particular pins by using a soldering iron is
allowed. Manual rework steps on the module can be done several times.
Conformal coating
Certain applications employ a conformal coating of the PCB using HumiSeal
®
or other related coating
products. These materials affect the HF properties of the GNSS module and it is important to prevent
them from flowing into the module. The RF shields do not provide 100% protection for the module
from coating liquids with low viscosity; therefore, take care when applying the coating.
☞
Conformal coating of the module will void the warranty.
Casting
If casting is required, use viscose or another type of silicon pottant. The OEM is strongly advised to
qualify such processes in combination with the u-blox M8 module before implementing it in the
production.
☞
Casting will void the warranty.
