14
E
TERNA
LTP5901
AND
LTP5902
I
NTEGRATION
G
UIDE
2 Manufacturing
Guidelines
Reflow
Given that Eterna modules are assembled using either “SAC305”, "Alpha OM-338 CSP" or "
SMIC ECO M705-GRN360" No Clear Solder Paste, careful adherence to J-STD-020 to avoid
reflowing the modules during the assembly process is necessary. The solder joint quality of
the “castellations” where they contact the mating PCB should meet IPC-A-610 Acceptability of
Electronic Assemblies, section 8.2.4 Castellated Terminations.
Solder Paste/Cleaning
“No Clean” soldering paste is strongly recommended, as it does not require cleaning following
the soldering process. Cleaning the populated modules is strongly discouraged due to the
potential issues that may result. Residuals under the module are difficult to remove with any
cleaning process. Cleaning with water can lead to capillary effects where water is absorbed
into the gap between the host board and the module, potentially resulting in combination with
soldering flux residuals leading to short circuits between neighboring pads. Cleaning with
alcohol or a similar organic solvent will likely flood soldering flux residuals under the shield,
which is not accessible for post-washing inspection. Ultrasonic cleaning could damage the
module permanently.
Packaging
The LTP5901 and LTP5902 modules are MSL3, however baking is required when parts are
packaged in individual ESD bags.