User's Manual

FLC-WFM301 Datasheet
Flaircomm Microelectronics Confidential
-25-
9. Recommended Reflow Profile
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 9: Recommended Reflow Profile
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.