LED light generated when the heat can not be derived, will make the LED junction temperature is too high, affecting the product life cycle, luminous efficiency, stability.
LED heat dissipation:
According to different packaging technology, cooling methods are different, and a variety of LED cooling method can be the next schematic:
Cooling Path Description:
(1) Heat from the air
(2). Heat is exported directly from Systemcircuitboard
(3). Derived heat from the gold wire
(4). If eutectic and Flipchip process, thermal energy will be through the through-hole to the system circuit board and export
LED die (Die) to gold, eutectic or flip chip connected to its substrate (SubstrateofLEDDie) to form a LED chip (chip), and then the LED chip fixed to the system board (Systemcircuitboard). Therefore, the possible cooling path of the LED is to heat directly from the air, or through the LED crystal substrate to the system circuit board and then to the atmospheric environment. The rate of heat dissipation from the system board to the atmospheric environment depends on the design of the entire luminous fixture or system.
At this stage of the entire system of thermal bottlenecks, most of the heat from the LED grain conduction to its substrate and then to the system circuit board. This part of the possible cooling path: one is directly through the crystal substrate cooling to the system circuit board, in this cooling path, the LED grain substrate material thermal capacity is a very important parameter. On the other hand, the heat generated by the LED will also be through the electrode metal wire to the system circuit board, in general, the use of gold wire to do the electrode joint, the heat dissipation by the metal wire itself is more elongated geometric shape and limited; , The recent Eutectic or Flipchip bonding, this design significantly reduces the length of the wire and significantly increases the wire cross-sectional area, so that the thermal efficiency of the LED circuit leads to the system board will be effective Ascension.
Through the above cooling way to explain the choice of cooling substrate material and its LED grain packaging in the LED heat dispersion management accounted for a very important part.