Product Specs

Parameters of lead-free reflow soldering
Zone
Time
Heating Rate
Peak Temperature
Cooling Rate
Preheat zone(40～150℃)
60～150s
≤2.0℃/s
-
-
Soak zone(150～200℃)
60～120s
<1.0℃/s
-
-
Reflow zone(>217℃)
60～90s
-
230～260℃
-
Cooling zone(Tmax～180℃)
-
-
-
1.0℃/s≤Slope≤4.0℃/s
Note：
 Preheat zone: The temperate range is 40–150°C (104–302°F), the heating rate must be about 2.0°C/s
(36°F/s), and the zone duration must be 60–150s.
 Soak zone: The temperature range is 150–200°C (302–392°F), the heating rate must be less than 1.0°C/s
(34°F/s), and the zone duration must be 60–120s. Slow heating is required; otherwise, soldering is poor.
 Reflow zone: The zone temperature increases from 217°C (423°F) to Tmax and then decreases to 217°C
(423°F) again. The zone duration must be 60–90s.
 Cooling zone: The zone temperature decreases from Tmax to 180°C (356°F). The cooling rate cannot exceed
4.0°C/s (39°F/s).
 It should take no more than 6 minutes for the ambient temperature to increase from 25°C (77°F) to 250°C
(482°F).
 The thermal profile shown in the preceding figure provides recommended values. Customers need to
adjust the values based on actual production.
 Typically, the duration of the reflow zone is 60–90s. For the boards with great heat capacity, the duration
can be prolonged to 120s. For details about the requirements on package thermal resistance, see the
IPC/JEDEC J-STD-020D standard. For details about the method of measuring the package temperature, see
the JEP 140 standard.
Thermal resistance standard for the lead-free package
Package Thickness
Volume mm3
<350
Volume mm3
350～2000
Volume mm3
>2000
<1.6mm
260℃
260℃
260℃
1.6mm～2.5mm
260℃
250℃
245℃
>2.5mm
250℃
245℃
245℃
The component soldering terminals (such as the solder balls and pins) and external heat sinks are not
considered for volume calculation.
The method of measuring the reflow soldering thermal profile is as follows:
According to the JEP140 standard, to measure the package temperature, you are advised to place the
temperature probe of the thermocouple close to the chip surface if the chip package is thin, or to drill a hole on the
package surface and place the temperature probe of the thermocouple into the hole if the chip
package is thick. The second method is recommended based on the thickness of most chip packages. However,
this method is not applicable if the chip package is too thin to drill a hole.