Hardware design

SPSGRF

12/23

DocID027664 Rev 5

5

Hardware design

The SPSGRF module supports SPI hardware interfaces.

Note:

- All unused pins should be left floating; do not ground.

- All GND pins must be well grounded.

- The area around the module should be free of any ground planes, power planes, trace

routings, or metal for 6 mm from the module antenna position, in all directions.

- Traces should not be routed underneath the module

5.1

Reflow soldering

The SPSGRF is a surface mount sub-1 GHz transceiver module supplied on an 11 pin, 4-

layer PCB. The final assembly recommended reflow profiles are indicated below.

The soldering phase must be executed with care. In order to avoid an undesired melting

phenomenon, particular attention should be given to the setup of the peak temperature.

Table 10 provides suggestions for the temperature profile based on IPC/JEDEC J-STD-

020C, July 2004 recommendations.

Table 10. Soldering recommendations

Profile feature

PB-free assembly

3°C/ sec max

Preheat

150 °C

200 °C

60-100 sec

Time maintained above:

217 °C

60-70 sec

10-20 sec

Ramp down rate

6 °C/sec

Time from 25 °C to peak temperature

8 minutes max