NB-IoT Module Series
BC95 Hardware Design
BC95_Hardware_Design Confidential / Released 46 / 51
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 0.15mm. For more details, please refer to
document [1]
.
It is suggested that the peak reflow temperature is 235 ~ 245ºC (for SnAg3.0Cu0.5 alloy). The absolute
max reflow temperature is 260ºC. To avoid damage to the module caused by repeatedly 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 29: Reflow Soldering Thermal Profile
Quectel
Confidential
