Rare-earth high-brightness high-power LED lighting fixtures for light efficiency and heat dissipation

April 24, 2023

Rare-earth high-brightness high-power LED lighting fixtures for light efficiency and heat dissipation

The continuous improvement of rare earth phosphors has benefited the overall lighting industry - metal halide lamps, high pressure sodium lamps, fluorescent tube energy-saving lamps and the latest high-power LED lamps.

In addition to structural simplification, rare earth high-power LED lamps integrate the following technologies: heat sink and lamp housing integrated heat dissipation structure, monolithic structure, so that the lamps are completely exposed in the ambient air, no regenerative cavity exists; rare earth alloy material production The heat conductivity of the radiator is high and the thermal resistance is low. The structure of the rare earth alloy uniform temperature plate makes the heat dissipation uniform and has no high temperature region; the precision matching technology between different heat conductive materials and the thermal deformation modulus matching technology make the contact tight and the thermal resistance is low; The use of high-efficiency heat-conducting dielectric materials reduces the thermal resistance of the contact surface; the aerodynamic and thermodynamic principles are used to design a perforated three-dimensional grid-like heat sink to form a “chimney-type” heat dissipation method to accelerate the air convection cycle, and the through-hole structure makes the dust have nowhere to be attached. The direct contact area between the heat sink and the air is ensured; the nano-thermal radiation coating increases the heat radiation capability of the lamp.

High-efficiency light source conversion enables high-power LED lamps to improve light efficiency and reduce heat consumption. The same power consumption can have higher brightness; if the brightness is equal, it is equal to the heat loss. This is naturally beneficial for LED chips that are afraid of heat. However, since the energy that is actually converted into light energy to emit the illuminant is only about 30%, most of the energy remains in the form of heat on the LED chip.

The substrate material and solid crystal mode of the LED chip itself are becoming more and more efficient and heat conduction:

1. US CREE 's unique silicon carbide substrate is the highest thermal conductivity LED chip substrate. The 40x40mil chip can withstand 1000MA current. As long as the subsequent heat dissipation does not have this rated 1W power chip, 3W is used. There are no concerns about burning.

2. The chip of the traditional sapphire substrate, not showing weakness, developed a method of flip chip mounting chip. The two electrodes on the surface are turned to the bottom surface and directly soldered to the metal heat conductive substrate with silver paste. This heat transfer is more straightforward than the conventional use of thermally conductive silver paste. In addition, high-power LED chips from recent days, South Korea and Taiwan also have a method of adding a metal plating layer on the sapphire substrate, so that silver paste can be used instead of silver glue to solidify the crystal. After the silver paste is cured, the thermal conductivity is close to that of pure silver, which is higher than the thermal conductivity of the silver paste.

Improvement of Thermal Conductive Copper Sheet --Diamond-Copper Composite

If the LED chip is not directly bonded to the circuit substrate by COB , a material with fast heat conduction is used as an intermediate medium for connecting the heat sink fins. Copper is a material that is only slightly inferior to silver in metal, and its price is lower, so copper is currently the most common thermal transfer material for high-power LED chips.

However, the coefficient of thermal expansion of copper ( about 19) is much larger than the coefficient of thermal expansion of the sapphire substrate (about 5). Therefore, the use of copper as a chip thermal carrier in the harsh environment, there is a risk of chip chipping. The chip size is limited. Nowadays, diamond-copper composite sheets have been developed in China. The thermal conductivity is higher than that of pure copper; the thermal expansion coefficient is lower than that of copper. It is expected that after mass production, the price can be accepted by manufacturers that produce high-power LED chip integrated blocks. The latest experimental report, using a 100W integrated module comparison, with a pure copper module at a chip temperature of 75 degrees Celsius, the module temperature of the diamond-copper composite chip is only 65 degrees Celsius.

If you need to purchase lamps in bulk, please contact us.WOSEN is a professional manufacturer and supplier of Led Flood Light, Led Street Light, Led Solar Light, etc. For more information, please visit https://www.wosenled.com/ or contact admin@wosenled.com or WhatsApp +86-13425434349

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