LED heat dissipation: Which is more efficient for aluminum and ceramic substrates?

In the rapid development of semiconductor lighting, LED's key problem - cooling, will become a big problem, so in the end how can the highest efficiency of heat it? Today we come to talk about the focus of LED heat - chip.

The manufacture of chips can now be varied, and LED chips are no exception. The thermal conductivity of the chip will directly affect the heat dissipation. Of course, as the chip can not only look at the heat dissipation, but also the dielectric constant, thermal expansion coefficient and so on. Today, aluminum substrates that are widely used in the market are compared with ceramic substrates that have been relatively low-key.

Aluminum plate:

Aluminum substrates are common in LED lighting products. There are positive and negative sides, the white side is the welding of the LED pin, the other side of the aluminum color, generally coated with conductive paste after contact with the thermal part.

The aluminum-based plates commonly used in aluminum substrates are mainly 1000-series, 5000-series, and 6000-series. The basic characteristics of these three-system aluminum materials are as follows:

1, 1000 series represents 1050, 1060, 1070, 1000 series aluminum plate, also known as pure aluminum plate, in all series 1000 series belong to the most aluminum content, the purity can reach more than 99.00%. Because it does not contain other technical elements, the production process is relatively single and the price is relatively cheap. It is the most commonly used series in the current industry.

2, 5000 series represents 5052, 5005, 5083, 5A05 series. 5000 series aluminum plate belongs to the more commonly used alloy aluminum plate series, the main element is magnesium, the magnesium content is between 3-5%, which is also called aluminum-magnesium alloy. The main features are low density, high tensile strength, and high elongation. In the same area, the weight of aluminum-magnesium alloy is lower than other series, so it is commonly used in aviation, such as aircraft fuel tank.

3, 6000 series represents 6061 mainly contains two elements of magnesium and silicon, so the advantages of the 4000 series and 5000 series are concentrated, 6061 is a cold-forged aluminum forging products, suitable for applications with high corrosion resistance, high oxidation resistance. Good usability, excellent interface features, easy coating, and good processability.

The thermal conductivity of the 5000 series aluminum substrate is about 135 W/(m·K), and the 6000 series is about 150 W/(m·K) and the 1000 series is about 220 W/(m·K).

Ceramic substrate

Ceramic substrate—refers to a special process plate in which copper foil is bonded directly to the surface of aluminum oxide (Al2O3) or aluminum nitride (AlN) ceramic substrates (on one or both sides) at high temperatures. The resulting ultra-thin composite substrate has excellent electrical insulation properties, high thermal conductivity properties, excellent solderability and high adhesion strength, and can etch a variety of patterns like a PCB board, with a large carrier current ability.

Ceramic circuit boards have the following features:

â—† strong mechanical stress, shape stability; high strength, high thermal conductivity, high insulation; strong bonding, anti-corrosion.

â—† Excellent thermal cycle performance, cycle times up to 50,000 times, high reliability.

â—† As with the PCB board (or IMS substrate), various patterns can be etched; no pollution, no pollution.

◆ Wide operating temperature - 55 °C -850 °C; thermal expansion coefficient close to silicon, simplified power module production process. Can save the transition layer Mo film, save labor, save materials, reduce costs;

â—†Reduce the solder layer, reduce thermal resistance, reduce voids, and increase yield;

â—† 0.3mm thick copper foil line width is only 10% of common printed circuit board at the same current carrying capacity;

â—† Excellent thermal conductivity, the chip package is very compact, so that the power density is greatly improved, and improve the reliability of the system and the device;

â—† Ultra-thin (0.25mm) ceramic substrate can replace BeO, no environmental toxicity issues;

◆ Large current carrying capacity, 100A current continuously passes copper body of 1mm width and 0.3mm thick, temperature rises about 17°C; 100A current continuously passes copper body of 2mm width and 0.3mm thick, temperature rise is only about 5°C;

◆Low thermal resistance, thermal resistance of 10×10mm ceramic substrate 0.63mm thickness The thermal resistance of ceramic substrate is 0.31K/W, thermal resistance of 0.38mm thickness ceramic substrate is 0.19K/W, 0.25mm The thickness of the ceramic substrate is 0.14 K/W.

â—† High insulation pressure, guarantee personal safety and equipment protection.

â—† New packaging and assembly methods can be realized to make the product highly integrated and the volume reduced.

The AIN ceramic plate has an extremely high thermal conductivity, a theoretical thermal conductivity of 319 W/(m·K) at room temperature, and good insulation properties, and resistivity greater than 1014 Ω·cm at 25°C.

Ceramic substrate products come out and open the development of heat-dissipation application industry. Due to the ceramic substrate heat dissipation characteristics and the ceramic substrate has the advantages of high heat dissipation, low thermal resistance, long life, voltage resistance, etc., with the improvement of production technology and equipment, the product price is accelerated and rationalized , and further expand the application of LED industry, such as home appliances, lights, car lights, street lights and large outdoor signage. The successful development of ceramic substrates will also provide services for indoor lighting and outdoor lighting products, making the LED industry a broader market area in the future.

After comparison, I believe that everyone has a certain understanding of the substrate of the two materials. With the update of technology, new and better products will surely replace the old technology. The market has always been the survival of the fittest as a manufacturer. , Should be healthy competition, make their products better and better, so as to promote the progress and take-off of the entire industry.