Technical requirements for LED light emitting diode welding

When we see a shining LED , we don't see that the LED light-emitting diode requires many procedures and technical requirements when it is assembled on the production line. Let's talk about the technical requirements for welding. The technical requirements for the welding of white light LED diodes are very strict. Some tiny details will have a huge impact on the welding of LED diodes. Therefore, the following requirements must be strictly followed during the welding of LED light-emitting diodes:

　　1. Workers must wear anti-static gloves and anti-static wrists during production, and the soldering iron must be grounded. It is strictly forbidden to touch the two lead pins of the white light LED with bare hands. Because the anti-static rating of the white light LED is 100V, and when the humidity is 60%-90% on the workbench, the static electricity of the human body will damage the crystal layer of the light-emitting diode. After working for a period of time (such as 10 hours), the diode will fail (not light up). In severe cases, it will fail immediately.

　　2. The soldering temperature is 260℃ for 3 seconds. Too high temperature and too long time will burn the chip. In order to better protect the LED, the distance between the LED colloid and the PC board should be more than 2mm so that the soldering heat can be dissipated in the pin.

　　3. The normal operating current of LED is 20mA (30mA for Lumins 3014 SMD), and a small fluctuation in voltage (such as 0.1V) will cause a large fluctuation in current (10%-15%). Therefore, when designing the circuit, different current limiting resistors should be matched according to the voltage drop of the LED to ensure that the LED is in the best working state. If the current is too large, the life of the LED will be shortened, and if the current is too small, the required light intensity cannot be achieved. Generally, suppliers will separate the LED into different colors when supplying in batches, that is, the light intensity, voltage, and light color of the LEDs in the same package are consistent, and they are indicated on the color table.

　　1. Soldering with a soldering iron: The tip temperature of the soldering iron (maximum 30W) should not exceed 300°C; the soldering time should not exceed 3 seconds; the soldering position should be at least 2 mm away from the colloid.

　　2. Wave soldering: The maximum temperature of dip soldering is 260℃; the dip soldering time shall not exceed 5 seconds; the dip soldering position shall be at least 2 mm away from the colloid. LED welding curve pin forming method: 1. The bracket must be bent 2 mm away from the colloid. 2. The bracket forming must be done with a fixture or by professionals. 3. The bracket forming must ensure that the pins and spacing are consistent with those on the circuit board. 4. The bracket forming must be completed before welding.

　　Cleaning: Be especially careful when cleaning the colloid with chemicals, because some chemicals such as trichloroethylene and acetone can damage the surface of the colloid and cause discoloration. Ethanol can be used to wipe and immerse, and the time should not exceed 3 minutes at room temperature. Static electricity protection The sharp increase of static electricity and current will damage the LED. Please use anti-static equipment, such as protective belts and gloves, when using InGaN series products.