Power type package

LED chips and packages are developing towards high power, which can generate a high power ratio under high current Φ The 5mm LED is 10-20 times larger than the luminous flux, which must be effective

Power Packaging Technology

The heat dissipation and non deteriorating packaging materials solve the problem of light attenuation. Therefore, the shell and packaging are also its key technologies. LED packaging that can withstand several watts of power has emerged. 5W series white, green, blue-green and blue power LEDs have been supplied since the beginning of 2003. The light output of white LED has reached 1871lm, and the light efficiency is 44.31lm/W. The problem of green light attenuation has been solved. The LED that can withstand 10W power and large area tube have been developed; Dagger size is 2.5 × 2.5mm, can work under 5A current, and the light output reaches 2001lm. As a solid light source, it has great development space.

Luxeon series power LED is to flip weld the A1GalnN power flip chip on the silicon carrier with solder bumps, and then put the silicon carrier with flip chip welding into the heat sink and shell, and bond the leads for packaging. This kind of package is the best for the design of light extraction efficiency, heat dissipation performance and increased working current density. Its main features: low thermal resistance, generally only 14 ℃/W, only 1/10 of the conventional LED; High reliability. The package is filled with stable flexible gel. In the range of - 40-120 ℃, the internal stress caused by sudden temperature change will not disconnect the gold wire from the lead frame, and prevent the epoxy resin lens from yellowing. The lead frame will not be stained by oxidation; The optimal design of the reflector cup and lens makes the radiation pattern controllable and the optical efficiency highest. In addition, its excellent output light power, external quantum efficiency and other properties will develop LED solid state light source to a new level.

The packaging structure of Norlux series power LED is a multi chip combination with hexagonal aluminum plate as the base (making it non-conductive). The diameter of the base is 31.75mm, and the luminous area is located in its center, with a diameter of about (0.375 × 25.4) mm, which can accommodate 40 LED tube cores, and the aluminum plate serves as the heat sink at the same time. The bonding lead of the tube core is connected with the positive and negative electrodes through two contact points made on the base, and the number of tube cores arranged on the base is determined according to the required output light power. The ultra-high brightness AlGaInN and AlGaInP tube cores can be assembled for packaging, and the emitted light is monochrome, color or synthetic white respectively. Finally, the high refractive index material is used for packaging according to the optical design shape. This kind of package adopts conventional die high-density combination package, which has high light extraction efficiency, low thermal resistance, better protection of the die and bonding lead, high optical output power under high current, and is also a promising LED solid light source.

In application, the packaged products can be assembled on a metal core PCB board with an aluminum interlayer to form a power density LED. The PCB board is used as the wiring for device electrode connection, and the aluminum core interlayer can be used as a heat sink to obtain high luminous flux and photoelectric conversion efficiency. In addition, the packaged SMD LEDs are small in size and can be flexibly combined to form colorful lighting sources such as module type, light guide plate type, spotlight type and reflective type.

The thermal characteristics of power LED directly affect the working temperature, luminous efficiency, luminous wavelength and service life of LED. Therefore, the packaging design and manufacturing technology of power LED chips are particularly important.