SARA-G3 and SARA-U2 series - System Integration Manual 
UBX-13000995 - R26    Contents 
    Page 7 of 217 
2.9  Reserved pins (RSVD) ........................................................................................................................ 160 
2.10  Module placement ........................................................................................................................ 160 
2.11  Module footprint and paste mask ................................................................................................. 161 
2.12  Thermal guidelines ........................................................................................................................ 162 
2.13  ESD guidelines .............................................................................................................................. 164 
2.13.1  ESD immunity test overview ...................................................................................................... 164 
2.13.2  ESD immunity test of u-blox SARA-G3 and SARA-U2 reference designs ..................................... 164 
2.13.3  ESD application circuits .............................................................................................................. 165 
2.14  SARA-G3 /  SARA-U2 ATEX modules integration in  devices intended for use  in potentially explosive 
atmospheres ................................................................................................................................................ 167 
2.14.1  General guidelines ..................................................................................................................... 167 
2.14.2  Guidelines for VCC supply circuit design ................................................................................... 168 
2.14.3  Guidelines for antenna RF interface design ................................................................................ 170 
2.15  Schematic for SARA-G3 and SARA-U2 series module integration .................................................. 171 
2.15.1  Schematic for SARA-G300 / SARA-G310 modules integration ................................................... 171 
2.15.2  Schematic for SARA-G340 / SARA-G350 modules integration ................................................... 172 
2.15.3  Schematic for SARA-U2 series modules integration ................................................................... 173 
2.16  Design-in checklist ........................................................................................................................ 174 
2.16.1  Schematic checklist ................................................................................................................... 174 
2.16.2  Layout checklist ......................................................................................................................... 175 
2.16.3  Antenna checklist ...................................................................................................................... 175 
3  Handling and soldering ........................................................................................... 176 
3.1  Packaging, shipping, storage and moisture preconditioning ............................................................. 176 
3.2  Handling ........................................................................................................................................... 176 
3.3  Soldering .......................................................................................................................................... 177 
3.3.1  Soldering paste ......................................................................................................................... 177 
3.3.2  Reflow soldering ....................................................................................................................... 177 
3.3.3  Optical inspection ...................................................................................................................... 178 
3.3.4  Cleaning .................................................................................................................................... 178 
3.3.5  Repeated reflow soldering ......................................................................................................... 179 
3.3.6  Wave soldering ......................................................................................................................... 179 
3.3.7  Hand soldering .......................................................................................................................... 179 
3.3.8  Rework ...................................................................................................................................... 179 
3.3.9  Conformal coating .................................................................................................................... 179 
3.3.10  Casting ...................................................................................................................................... 179 
3.3.11  Grounding metal covers ............................................................................................................ 179 
3.3.12  Use of ultrasonic processes ........................................................................................................ 179 
4  Approvals .................................................................................................................. 180 
4.1  Product certification approval overview............................................................................................. 180 
4.2  US Federal Communications Commission notice ............................................................................... 181 
4.2.1  Safety warnings review the structure ......................................................................................... 181 
4.2.2  Declaration of conformity .......................................................................................................... 181 
4.2.3  Modifications ............................................................................................................................ 182