High-power LED product application considerations-EEWORLD

Collect

During the application of high-power LED products and devices, heat dissipation, electrostatic protection and welding have a great impact on their characteristics, which need to be paid great attention by application-end customers.

　　1. Heat dissipation:

　　Due to the current limitations of semiconductor light-emitting diode chip technology, the photoelectric conversion efficiency of LEDs needs to be improved, especially for high-power LEDs. Because of their high power, more than 60% of the electrical energy will be converted into heat energy for release (with the development of semiconductor technology, the photoelectric conversion efficiency will gradually increase). This requires end customers to do a good job of heat dissipation when applying high-power LED products to ensure the normal operation of high-power LED products.

　　1. Heat sink requirements.

　　Appearance and material: If the sealing requirements of the finished product are not high, it can directly convect with the external air environment. It is recommended to use aluminum or copper heat sinks with fins.

　　2. Effective heat dissipation surface area:

　　For 1W high-power LED white light (other colors are basically the same), our company recommends that the total effective heat dissipation surface area of the heat sink is ≥50-60 square centimeters. For 3W products, it is recommended that the total effective heat dissipation surface area of the heat sink is ≥150 square centimeters. For higher power, it will be increased according to the situation and test results. Try to ensure that the heat sink temperature does not exceed 60℃.

　　3. Connection method:

　　When connecting the high-power LED substrate and the heat sink, please ensure that the two contact surfaces are flat and in good contact. To strengthen the bonding between the two contact surfaces, it is recommended to apply a layer of thermal grease (thermal conductivity of thermal grease ≥ 3.0W/mk) on the bottom of the LED substrate or the surface of the heat sink. The thermal grease should be applied evenly and in an appropriate amount, and then fixed with screws.

　　2. Electrostatic protection.

　　LED is a semiconductor device and is very sensitive to static electricity. Especially for white, green, blue and purple LEDs, it is necessary to prevent and eliminate static electricity. 　　1. Generation of static electricity:

　　① Friction: In daily life, static electricity can be generated when any two objects of different materials come into contact and then separate, and the most common way to generate static electricity is by friction. The better the insulation of a material, the easier it is to generate static electricity by friction. In addition, static electricity can also be generated when any two objects of different materials come into contact and then separate.

　　② Induction: For conductive materials, since electrons can flow freely on its surface, if it is placed in an electric field, positive and negative ions will be transferred due to like repulsion and opposite attraction, and charge will be generated on its surface.

　　③ Conduction: For conductive materials, since electrons can flow freely on its surface, if it comes into contact with a charged object, charge transfer will occur.

　　2. Hazards of static electricity to LED testers:

　　① Due to the heat generated by the instantaneous electric field or current, the LED is partially damaged, which is manifested as a rapid increase in leakage current. It can still work, but the brightness is reduced and the life is damaged.

　　② Due to the electric field or current destroying the insulation layer of the LED, the device cannot work (completely destroyed), which is manifested as a dead light.

　　3. Static electricity protection and elimination measures:

　　For the entire process (production, testing, packaging, etc.), all employees who have direct contact with LEDs must take measures to prevent and eliminate static electricity, mainly including:

　　1. The workshop is laid with anti-static flooring and grounded.

　　2. The workbench is an anti-static workbench, and the production machine is well grounded.

　　3. The operator wears anti-static clothing, anti-static wristbands, gloves or foot rings.

　　4. Use ion blowers.

　　5. The welding soldering iron is grounded.

　　6. The packaging is made of anti-static materials. 　3. Welding. 　　When welding, please note that it is best to choose a constant temperature soldering iron, the welding temperature is 260℃, and the soldering iron should not be in contact with the LED pad for more than 3S at a time.

　

Reference address：High-power LED product application considerations

Previous article：The difference between high frequency induction lamp and low frequency induction lamp
Next article：A brief discussion on high-efficiency drive solutions for all-round penetration of LED lighting

Popular Resources
Popular amplifiers