5
Requirements on PCB Layout
The thickness of PCB is more than 1.0 mm (1.2 mm recommended) to reduce the
deformation caused by high temperature welding.
The minimum distance between the LGA module and the PCB edge is 1.5 mm. Other
devices must be located more than 1 mm away from the LGA module (more than 3 mm
recommended if rework is considered).
When the PCB layout is double sided, it is recommended that the LGA module be
placed on the second side for assembly.
Design of Solder Mask
The PCB pad design can be solder mask defined (SMD), or non-solder mask defined
(NSMD).NSMD is recommended. In addition, the solder mask of the NSMD pad design
is larger than the pad so the reliability of the solder joint can be improved.
The solder mask must be 100 µm to150 µm larger than the pad, that is, the single side
of the solder mask must be 50 µm to 75 µm larger than the pad. The specific size
depends on the processing capability of the PCB manufacturer.
Assembly
Stencil Design
It is recommended that the stencil for the LGA module be 0.15 mm in thickness. For the
stencil design, see the following figure
: