000000
NEO-M8L - Hardware integration manual
UBX-16010549 - R08
Product handling
Page 15 of 28
C1-Public
4
Product handling
4.1
Packaging, shipping, storage and moisture preconditioning
For information pertaining to reels and tapes, Moisture Sensitivity levels (MSL), shipment and
storage information, as well as drying for preconditioning, see the corresponding product data sheet
[1], [2], or [3] or the u-blox Package Information guide [5] in the Related documents section.
Population of modules
☞
When populating the modules, make sure that the pick and place machine is aligned to the copper
pins of the module and not on the module edge. Note that a MEMS device is present internally.
4.2
Soldering
Soldering paste
Use of "No Clean" soldering paste is highly recommended, as it does not require cleaning after the
soldering process has taken place. The paste listed in the example below meets these criteria.
Soldering paste:
OM338 SAC405 / Nr.143714 (Cookson Electronics)
Alloy specification:
Sn 95.5/ Ag 4/ Cu 0.5 (95.5% Tin/ 4% Silver/ 0.5% Copper)
Melting temperature:
217 °C
Stencil thickness:
see section 2.3
The final choice of the soldering paste depends on the approved manufacturing procedures.
The paste-mask geometry for applying soldering paste should meet the recommendations.
☞
The quality of the solder joints on the connectors (’half vias’) should meet the appropriate IPC
specification.
Reflow soldering
A convection type-soldering oven is highly recommended over the infrared type radiation oven.
Convection-heated ovens allow precise control of the temperature, and all parts will heat up evenly,
regardless of material properties, thickness of components and surface color.
As a reference for the professional grade NEO-M8L, see the IPC-7530 Guidelines for temperature
profiling for mass soldering (reflow and wave) processes, published in 2001. For the Automotive Grade
NEO-M8L-01A module, see the IPC/JEDEC J-STD-020E, December 2014.
Preheat phase
During the initial heating of component leads and balls, residual humidity will be dried out. Note that
this preheat phase will not replace prior baking procedures.
Temperature rise rate: max 3 °C/s. If the temperature rise is too rapid in the preheat phase it may
cause excessive slumping.
Time: 60 - 120 s. If the preheat is insufficient, rather large solder balls tend to be generated.
Conversely, if performed excessively, fine balls and large balls will be generated in clusters.
End temperature: 150 - 200 °C. If the temperature is too low, non-melting tends to be caused in
areas containing large heat capacity.
Heating/ Reflow phase
The temperature rises above the liquidus temperature of 217°C. Avoid a sudden rise in temperature
as the slump of the paste could become worse.
