Diamond Heat Sink Substrates: The Core Solution for High-Efficiency Heat Dissipation in High-Power LED Lamps

Diamond boasts excellent properties such as a wide band gap, high thermal conductivity, high temperature resistance, acid and alkali resistance, corrosion resistance and radiation resistance. It plays a crucial role in high-power, high-frequency and high-temperature fields, and is regarded as one of the most promising wide band gap semiconductor materials at present.

At present, high-power LED tubes are generally plagued by practical problems including excessively high junction temperature under high power, bulky traditional heat dissipation structures, mismatched thermal expansion, bottlenecks in heat dissipation efficiency and limited power density improvement. If an LED lamp suffers from poor heat dissipation during operation, the heat will accumulate near the chip, leading to a rise in junction temperature, which in turn directly impairs the lamp's performance. Relying on its outstanding characteristics, diamond heat sink substrates play a vital role in four aspects: rapidly conducting heat to reduce junction temperature, improving luminous efficiency and light decay stability, significantly extending LED service life, and reducing thermal stress to enhance reliability.

Practical Application Schemes of Diamond Heat Sink Substrates in LED Tubes

(1) Diamond Substrates

There are two main technical routes. First, growing the LED epitaxial layer directly on a single crystal diamond, which features the lowest thermal resistance and is suitable for ultra-high voltage and ultra-high power LEDs. Second, bonding the GaN surface to a metallized single crystal diamond via wafer bonding technology, then laser stripping the original sapphire substrate to finally form a bonding layer, which is mainly applied in high-power LED tubes and UV devices.

(2) Diamond Heat Sink Substrates + Flip-Chip LED Chips

Eutectically solder flip-chip LED chips onto diamond heat sinks, metallize the back of the diamond, then solder it to an aluminum or copper substrate, and finally attach it to the aluminum profile housing of the tube for heat dissipation. This method features the shortest heat transfer path, highest efficiency and high light extraction efficiency, making it suitable for customers in the production of high-end commercial/industrial tubes.

(3) Diamond Film-Coated Copper Substrates

The main method is to composite a diamond film with a copper layer, using diamond as an insulating heat dissipation layer and fabricating copper circuits directly on its surface, with LED chips mounted directly on it, thus eliminating an additional heat sink layer. It integrates high thermal conductivity, insulation and wiring capabilities, serving as a modular heat dissipation substrate for LED tubes. This scheme is suitable for customers engaged in the standardized mass production of LED tubes.

Huazhe Jidian (Xiamen) Semiconductor Technology Co., Ltd., a national high-tech enterprise specializing in the R&D, production and sales of wide band gap semiconductor materials, can provide high-quality CVD diamond heat sink substrates with customized sizes, thicknesses and shapes, and is committed to delivering high-quality and efficient semiconductor material solutions to customers at home and abroad.