LEA-M8S / LEA-M8T - Hardware integration manual
UBX-15030060 - R06 Product handling Page 23 of 33
Production information
Cooling phase
A controlled cooling avoids negative metallurgical effects of the solder (the solder becomes more
brittle) and possible mechanical tensions in the products. Controlled cooling helps to achieve bright
solder fillets with good shape and low contact angle.
Temperature fall rate: max 4 °C/s
☞ To avoid falling off, place the u-blox M8 GNSS module on the topside of the motherboard during
soldering.
The final soldering temperature chosen at the factory depends on additional external factors such as
choice of soldering paste, size, thickness and properties of the baseboard. Exceeding the maximum
soldering temperature in the recommended soldering profile may permanently damage the module.
Figure 14: Recommended soldering profile
☞ u-blox M8 modules must not be soldered with a damp heat process.
Optical inspection
After soldering the u-blox M8 module, consider an optical inspection step to check whether:
The module is properly aligned and centered over the pads.
All pads are properly soldered.
No excess solder has created contacts to neighboring pads, or possibly to pad stacks and vias
nearby.
Cleaning
In general, cleaning the populated modules is strongly discouraged. Residues underneath the
modules cannot be easily removed with a washing process.
Cleaning with water will lead to capillary effects where water is absorbed into 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.
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.
The best approach is to use a “no clean” soldering paste and eliminate the cleaning step after the
soldering.
To Next Page
Loading...
Need help?
General
