NB-IoT Module Series
BC65 Hardware Design
BC65_Hardware_Design 50 / 55
1.
1)
This floor life is only applicable when the environment conforms to
IPC/JEDEC J-STD-033
.
2. To avoid blistering, layer separation and other soldering issues, it is forbidden to expose the modules
to the air for a long time. If the temperature and moisture do not conform to
IPC/JEDEC J-STD-033
or
the relative moisture is over 60 %, it is recommended to start the solder reflow process within 24
hours after the package is removed. And do not remove the packages of tremendous modules if they
are not ready for soldering.
3. Take the module out of the packaging and put it on high-temperature resistant fixtures before the
baking. If shorter baking time is desired, see
IPC/JEDEC J-STD-033
for baking procedure.
7.2. Manufacturing and Soldering
Push the squeegee to apply the solder paste on the surface of stencil, thus making the paste fill the
stencil openings and then penetrate to the PCB. The force on the squeegee should be adjusted properly
to produce a clean stencil surface on a single pass. To ensure the module soldering quality, the thickness
of stencil for the module is recommended to be 0.15
–0.18 mm. For more details, see
Document [4]
.
It is suggested that the peak reflow temperature be 238 ºC to 246 ºC, and the absolute maximum reflow
temperature be 246 ºC. To avoid damage to the module caused by repeated heating, it is strongly
recommended that the module should be mounted after reflow soldering for the other side of PCB has
been completed. The recommended reflow soldering thermal profile (lead-free reflow soldering) and
related parameters are shown below.
Temp. (
°C
)
Reflow Zone
Soak Zone
246
200
220
238
C
D
B
A
150
100
Max slope: 1 to 3
°C
/s
Cooling down slope:
-1.5 to -3
°C
/s
Max slope:
2 to 3
°C
/s
Figure 36: Recommended Reflow Soldering Thermal Profile
NOTES
