LTE-A Module Series
EG12 Hardware Design
EG12_Hardware_Design 91 / 97
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 should be 0.13mm~0.15mm. For more details, please refer to
document [4]
.
It is suggested that the peak reflow temperature is 238ºC ~ 245ºC (for SnAg3.0Cu0.5 alloy). The absolute
max 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. Recommended reflow soldering thermal profile is shown below:
Temp. (°C)
Reflow Zone
Soak Zone
245
200
220
238
C
D
B
A
150
100
Max slope: 1~3°C/sec
Cooling down
slope: 1~4°C/sec
Max slope:
2~3°C/sec
Figure 49: Reflow Soldering Thermal Profile
Table 48: Recommended Thermal Profile Parameters
Factor
Recommendation
Soak Zone
Max slope
1 to 3°C/sec
Soak time (between A and B: 150°C and 200°C)
60 to 120 sec
