Nichia STSE-CW2159A (4) Soldering Conditions Nichia LED leadframes are comprised of a silver plated copper alloy. This substance has a low thermal coefficient (easily conducts heat). Careful attention should be paid during soldering. Solder the LED no closer than 3mm from the base of the epoxy bulb. Soldering beyond the base of the tie bar is recommended. Recommended soldering conditions Pre-Heat Pre-Heat Time Solder Bath Temperature Dipping Time Dipping Position Dip Soldering 100°C Max. 60 seconds Max. 260°C Max. Temperature Soldering Time Position Soldering 300°C Max. 3 seconds Max. No closer than 3 mm from the base of the epoxy bulb. 10 seconds Max. No lower than 3 mm from the base of the epoxy bulb. Do not apply any stress to the lead particularly when heated. The LEDs must not be repositioned after soldering. After soldering the LEDs, the epoxy bulb should be protected from mechanical shock or vibration until the LEDs return to room temperature. Direct soldering onto a PC board should be avoided. Mechanical stress to the resin may be caused from warping of the PC board or from the clinching and cutting of the leadframes. When it is absolutely necessary, the LEDs may be mounted in this fashion but the User will assume responsibility for any problems. Direct soldering should only be done after testing has confirmed that no damage, such as wire bond failure or resin deterioration, will occur. Nichia’s LEDs should not be soldered directly to double sided PC boards because the heat will deteriorate the epoxy resin. When it is necessary to clamp the LEDs to prevent soldering failure, it is important to minimize the mechanical stress on the LEDs. Cut the LED leadframes at room temperature. Cutting the leadframes at high temperatures may cause failure of the LEDs. (5) Heat Generation Thermal design of the end product is of paramount importance. Please consider the heat generation of the LED when making the system design. The coefficient of temperature increase per input electric power is affected by the thermal resistance of the circuit board and density of LED placement on the board, as well as other components. It is necessary to avoid intense heat generation and operate within the maximum ratings given in this specification. The operating current should be decided after considering the ambient maximum temperature of LEDs. (6) Cleaning It is recommended that isopropyl alcohol be used as a solvent for cleaning the LEDs. When using other solvents, it should be confirmed beforehand whether the solvents will dissolve the resin or not. Freon solvents should not be used to clean the LEDs because of worldwide regulations. Do not clean the LEDs by the ultrasonic. When it is absolutely necessary, the influence of ultrasonic cleaning on the LEDs depends on factors such as ultrasonic power and the assembled condition. Before cleaning, a pre-test should be done to confirm whether any damage to the LEDs will occur. -5-