LISA-U1 series - System Integration Manual
3G.G2-HW-10002-3
Preliminary
Handling and soldering
Page 117 of 125
4
Handling and soldering
No natural rubbers, no hygroscopic materials or materials containing asbestos are employed.
4.1
Packaging, shipping, storage and moisture preconditioning
For information pertaining to reels and tapes, Moisture Sensitivity levels (MSD), shipment and storage
information, as well as drying for preconditioning see the
LISA-U1 series
Data Sheet
The LISA-U1 series modules are Electro-Static Discharge (ESD) sensitive devices.
Ensure ESD precautions are implemented during handling of the module.
4.2
Soldering
4.2.1
Soldering paste
Use of "No Clean" soldering paste is strongly 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:
95.5% Sn / 3.9% Ag / 0.6% Cu (95.5% Tin / 3.9% Silver / 0.6% Copper)
95.5% Sn / 4.0% Ag / 0.5% Cu (95.5% Tin / 4.0% Silver / 0.5% Copper)
Melting Temperature: 217°C
Stencil Thickness:
120 µm for base boards
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 in section 2.2.2
The quality of the solder joints on the connectors (’half vias’) should meet the appropriate IPC
specification.
4.2.2
Reflow soldering
A convection type-soldering oven is strongly recommended
over the infrared type radiation oven.
Convection heated ovens allow precise control of the temperature and all parts will be heated up evenly,
regardless of material properties, thickness of components and surface color.
Consider the "IPC-7530 Guidelines for temperature profiling for mass soldering (reflow and wave) processes,
published 2001".
Preheat phase
Initial heating of component leads and balls. Residual humidity will be dried out. Please 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.
