Integration Manual

SARA-R4/N4 series - System Integration Manual
UBX-16029218 - R11 Handling and soldering Page 124 of 157
☞ The modules must not be soldered with a damp heat process.
3.3.3 Optical inspection
After soldering the module, inspect it optically to verify that it is correctly aligned and centered.
3.3.4 Cleaning
Cleaning the modules is not recommended. Residues underneath the modules cannot be easily removed
with a washing process.
 Cleaning with water will lead to capillary effects where water is absorbed in the gap between the
baseboard and the module. The combination of residues of soldering flux and encapsulated water leads
to short circuits or resistor-like interconnections between neighboring pads. Water will also damage the
sticker and the ink-jet printed text.
 Cleaning with alcohol or other organic solvents can result in soldering flux residues flooding into the
two housings, areas that are not accessible for post-wash inspections. The solvent will also damage the
sticker and the ink-jet printed text.
 Ultrasonic cleaning will permanently damage the module, in particular the quartz oscillators.
For best results, use a "no clean" soldering paste and eliminate the cleaning step after the soldering.
3.3.5 Repeated reflow soldering
Repeated reflow soldering processes and soldering the module upside-down are not recommended.
Boards with components on both sides may require two reflow cycles. In this case, the module should
always be placed on the side of the board that is submitted into the last reflow cycle. The reason for this
(besides others) is the risk of the module falling off due to the significantly higher weight in relation to
other components.
☞ u-blox gives no warranty against damages to the SARA-R4/N4 series modules caused by performing
more than a total of two reflow soldering processes (one reflow soldering process to mount the SARA-
R4/N4 series module, plus one reflow soldering process to mount other parts).
3.3.6 Wave soldering
SARA-R4/N4 series LGA modules must not be soldered with a wave soldering process.
Boards with combined through-hole technology (THT) components and surface-mount technology (SMT)
devices require wave soldering to solder the THT components. No more than one wave soldering process
is allowed for a board with a SARA-R4/N4 series module already populated on it.
⚠ Performing a wave soldering process on the module can result in severe damage to the device!