Data Sheet

FSC-BT956B Datasheet
Shenzhen Feasycom Technology Co., Ltd www.feasycom.com
-22-
The soldering profile depends on various parameters necessitating a set up for each application. The data here is
given only for guidance on solder reflow.
210
217
℃
250
A
B C D
1 2
0
25
3 4 5 6
min
E
Figure 10: Typical Lead-free Re-flow
Pre-heat zone (A) — This zone raises the temperature at a controlled rate, typically 0.5 – 2 C/s. The purpose of this
zone is to preheat the PCB board and components to 120 ~ 150 C. This stage is required to distribute the heat
uniformly to the PCB board and completely remove solvent to reduce the heat shock to components.
Equilibrium Zone 1 (B) — In this stage the flux becomes soft and uniformly encapsulates solder particles and spread
over PCB board, preventing them from being re-oxidized. Also with elevation of temperature and liquefaction of flux,
each activator and rosin get activated and start eliminating oxide film formed on the surface of each solder particle and
PCB board. The temperature is recommended to be 150 to 210 for 60 to 120 second for this zone.
Equilibrium Zone 2 (C) (optional) — In order to resolve the upright component issue, it is recommended to keep the
temperature in 210 – 217  for about 20 to 30 second.
Reflow Zone (D) — The profile in the figure is designed for Sn/Ag3.0/Cu0.5. It can be a reference for other lead-free
solder. The peak temperature should be high enough to achieve good wetting but not so high as to cause component
discoloration or damage. Excessive soldering time can lead to intermetallic growth which can result in a brittle joint. The
recommended peak temperature (Tp) is 230 ~ 250 C. The soldering time should be 30 to 90 second when the
temperature is above 217 C.
Cooling Zone (E) — The cooling ate should be fast, to keep the solder grains small which will give a longer-lasting joint.
Typical cooling rate should be 4 C.