Datasheet

LUXEON LED Assembly and Handling Application Brief AB32 20121217 32
5.6 Reflow Profile
LUXEON LEDs are compatible with surface mount technology and lead-free reflow. This greatly simplifies the manufacturing process by eliminating
the need for adhesives and epoxies. It has been said that the most important step in reflow soldering is the reflow itself. This occurs when the
boards move through the oven and the solder paste melts forming the solder joints. To form good solder joints, the time and temperature profile
throughout the reflow process must be well maintained.
A temperature profile consists of three primary phases (an example reflow profile is shown in Figure 40):
1. Preheat: the board enters the reflow oven and is warmed up to a temperature lower than the melting point of the solder alloy.
2. Reflow: the board is heated to a peak temperature above the melting point of the solder, but below the temperature that would damage
the components or the board.
3. Cooling down: the board is cooled down rapidly, allowing the solder to freeze, before the board exits the oven.
As a point of reference, the melting temperature for SAC 305 is 217°C, and the minimum peak reflow temperature is 235°C.
Philips Lumileds successfully utilized the reflow profile in Figure 40 for LUXEON LEDs on PCB.
Figure 40. Reflow profile of LUXEON LEDs using SAC-305 solder paste.