Users Manual

GSM/GPRS Module Series
M66 Hardware Design
M66_Hardware_Design Confidential / Released 80 / 82
7.2. 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 at the hole of the module pads should be 0.2 mm for M66. For more details, please
refer to document [12].
It is suggested that peak reflow temperature is from 235ºC to 245ºC (for SnAg3.0Cu0.5 alloy). The
absolute max reflow temperature is 260ºC. To avoid damage to the module caused by repeated 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(s)
50
100
150 200 250 300
50
100
150
200
250
160℃
200℃
217
0
70s~120s
40s~60s
Between 1~3℃/S
Preheat Heating Cooling
℃
s
Liquids
Temperature
Figure 47: Reflow Soldering Thermal Profile