Manufacturing And Soldering - Quectel EC25-AUX Hardware Design

8.2. 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 0.18mm~0.20mm. For more details, please
refer to document [4].
It is suggested that the peak reflow temperature is 238ºC~245ºC, and the absolute maximum reflow
temperature is 245ºC. 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)
245
238
220
200
Soak Zone
150
100
Table 64: Recommended Thermal Profile Parameters
Factor
Soak Zone
Max slope
Soak time (between A and B: 150°C and 200°C)
Reflow Zone
EC25_Hardware_Design
A
Max slope: 1~3°C/sec
Figure 49: Reflow Soldering Thermal Profile
LTE Standard Module Series
EC25 Hardware Design
Reflow Zone
Max slope:
C
2~3°C/sec
B
D
Recommendation
1~3°C/sec
60~120sec
Cooling down
slope: 1~4°C/sec
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