unicore UM981, User Manual, Page: 23 / 27

UM981 User Manual
18 Production Requirement UC-00-M33 EN R1.0

The pads denoted as detail C are 1.79 mm longer than the module border.

The pad denoted as detail A is 0.50 mm longer than the module border. It is
relatively short as it is an RF pin pad, so we hope the trace on the surface is as
short as possible to reduce the impact of external interference on the RF signals.
4 Production Requirement
Recommended soldering temperature curve is as follows:
° C
250
217
200
150
100
50
0
Rising Cooling Reflux
Peak 245 ° C
40~60s
60~120s
Preheating
Max. 4° C/s
Max. 3° C/s
Time (s)
Figure 4-1 Soldering Temperature (Lead-free)
Temperature Rising Stage

Rising slope: Max. 3 °C/s

Rising temperature range: 50 °C ~ 150 ° C
Preheating Stage
 Preheating time: 60s ~ 120 s
 Preheating temperature range: 150 ° C ~ 180 °C
Reflux Stage
 Over melting temperature (217 °C) time: 40s ~ 60 s
 Peak temperature for soldering: no higher than 245 ° C