Manufacturing And Soldering - Quectel EG91 Series Hardware Design

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
properlyso as to produce a clean stencil surface on a single pass. To ensure the module soldering quality,
thethickness of stencil for the module is recommended to be 0.15mm~0.18mm. For more details, please
refer todocument [4].
It is suggested that the peak reflow temperature is 240ºC~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
240
220
200
Soak Zone
150
100
Table 45: Recommended Thermal Profile Parameters
Factor
Soak Zone
Max slope
Soak time (between A and B: 150°C and 200°C)
Reflow Zone
EG91_Hardware_Design

8.2. Manufacturing and Soldering

A
Max slope: 1~3°C/sec
Figure 46: Reflow Soldering Thermal Profile
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EG91 Hardware Design
Reflow Zone
Max slope:
C
2~3°C/sec
B
D
Recommendation
1 to 3°C/sec
60 to 120 sec
LTE Module Series
Cooling down
slope: 1~4°C/sec