High Power Lamp Beads Considerations

- Jan 16, 2019-

In the application process, high-power lamp bead products and devices have a great influence on heat dissipation, static electricity protection and soldering, and need to be highly valued by application customers.

Heat dissipation

Due to the limitations of current semiconductor light-emitting diode chip technology, the photoelectric conversion efficiency of LEDs needs to be improved, especially for high-power LEDs. Because of its high power, about 60% of the electrical energy will become thermal energy release (with the development of semiconductor technology). The photoelectric conversion efficiency will gradually increase), which requires the end customer to do the heat dissipation work when applying high-power LED products to ensure the high-power LED products work normally.

1. Heat sink requirements.

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

2. Effective heat dissipation surface area:

For 1W high power LED white light (other colors are basically the same), we recommend the total heat dissipation surface area of  the heat sink ≥ 50-60 square centimeters. For 3W products, it is recommended that the total heat dissipation surface area of  the heat sink be ≥150 square centimeters. The higher power depends on the situation and the test results. Try to ensure that the heat sink temperature does not exceed 60 °C.

3. connection method:

When connecting the high-power LED aluminum substrate to the heat sink, please ensure that the two contact surfaces are flat and the contact is good. To strengthen the bonding degree between the two contact surfaces, it is recommended to apply a layer of thermal grease (thermal grease) on the bottom of the LED aluminum substrate or the surface of the heat sink. Thermal conductivity ≥ 3.0W / mk), thermal grease required to apply uniform, appropriate amount, and then screwed and fixed.

Static Protection

LED is a semiconductor device, which is sensitive to static electricity. Especially for white, green, blue and purple LEDs, it is necessary to prevent static electricity generation and eliminate static electricity.

1. The generation of static electricity:

  • Friction: In daily life, any two objects of different materials can be separated after contact, and static electricity can be generated. The most common method of generating static electricity is frictional electricity generation. The better the insulation of the material, the easier it is to rub the electricity. In addition, static electricity can also be generated by the separation of any two different substances after contact.

  • Induction: For conductive materials, because electrons can flow freely on its surface, such as placing it in an electric field, due to homosexual repelling, the opposite sex attracts, positive and negative ions will transfer, and charges will be generated on the surface.

  • Conduction: For conductive materials, charge transfer occurs due to the free flow of electrons on its surface, such as contact with charged objects.

2. The harm of static electricity to LED:

The heat generated by the instantaneous electric field or current causes the LED to be partially injured. It shows that the leakage current increases rapidly and still works, but the brightness is lowered and the life is damaged. The electric field or current destroys the insulation layer of the LED, making the device inoperable (completely destroyed), which is a dead light.

Detailed Product Description

3. Electrostatic protection and elimination measures:

  • For the entire process (production, testing, packaging, etc.) all employees who are in direct contact with the LED must take measures to prevent and eliminate static electricity, mainly

  • Lay the anti-static floor and ground the workshop.

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

  • The operator wears an antistatic suit with an anti-static wrist strap, gloves or an ankle ring.

  • Apply an ion fan.

  • Soldering the soldering iron to make grounding measures.

  • the packaging uses anti-static materials.