NB-IoT Module Series
BC66 Hardware Design
BC66_Hardware_Design 46 / 50
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
so as 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 0.2mm. For more details, please refer to
document [4]
.
It is suggested that peak reflow temperature is from 235ºC to 245ºC (for SnAg3.0Cu0.5 alloy). The
absolute maximum reflow temperature is 260ºC. To avoid damage to the module caused by repeated
heating, it is suggested that the module should be mounted after reflow soldering for the other side of
PCB has been completed. Recommended reflow soldering thermal profile is shown below:
Time
50
100
150
200
250
300
50
100
150
200
250
160ºC
200ºC
217
0
70s~120s
40s~60s
Between 1~3ºC/s
Preheat
Heating
Cooling
ºC
s
Liquids Temperature
T
em
pe
ra
tu
re
Figure 31: Reflow Soldering Thermal Profile
7.3. Packaging
The modules are stored in a vacuum-sealed bag which is ESD protected. The bag should not be opened
until the devices are ready to be soldered onto the application.
