LTE Standard Module Series
EC200U_Series_Hardware_Design 88 / 94
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 0.18
–
0.20 mm. For more details, please refer to
document [4]
It is suggested that the peak reflow temperature is 235
–
246 ºC, and the absolute maximum reflow
temperature is 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
217
235
C
D
B
A
150
100
Max slope: 1~3
°C
/s
Cooling down slope:
-1.5 ~ -3
°C
/s
Max slope:
2~3
°C
/s
Figure 42: Reflow Soldering Thermal Profile
1. To avoid blistering, layer separation and other soldering issues, extended exposure of the module to
the air is forbidden.
2. Take out the module from the package and put it on high-temperature-resistant fixtures before
baking. All modules must be soldered to PCB within 24 hours after the baking, otherwise put them
in the drying oven. If shorter baking time is desired, see
IPC/JEDEC J-STD-033
for the baking
procedure.
3. Pay attention to ESD protection, such as wearing anti-static gloves, when touching the modules.
NOTE
