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Care has been taken to ensure that ECOPACK™ components are solderable
using both current Lead and Lead-free PCB assembly processes. This ensures
that our ECOPACK™ components can be integrated regardless of whether
the assembly processes have already been converted to Lead-free or not.
However BGA type components will require a higher soldering temperature
than Leaded equivalents.
The main difference between Pb and Pb-free soldering process is the
temperature range : Pb–soldering (215°C-240°C) vs Pb–free soldering
(235°C-260°C).
a. Backward compatibility
NiPdAu and Sn products are compatible with a Pb containing soldering
process (See Application Note AN 2034 about Soldering Compatibility).
As a consequence, our customer assembly lines will not be af-fected
by the use ECOPACK™ products and all stocks will be compatible with
the various soldering processes. Therefore ST will implement its conversion
schedule, as per the attached roadmap. For SnAgCu finishing (BGA) the
compatibility is not fully guaranteed (soldering below 230° is critical).
b. Forward compatibility
Most of our packages are compatible with Lead-free soldering processes.
Nevertheless when customers convert their production line to Pb-free
before Pb-free products availability, due to the higher reflow temperature
(235°C-260°C), a few devices containing Pb may not be qualified for
such a temperature range (higher moisture sensitivity). It is the customer’s
duty to make sure that our current Pb-devices are qualified with their
new soldering process. It is important to note that the maximum temperature
is mentioned on the Inner box label.
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