On May 3, Osram, the German lighting manufacturer, released its second-quarter results for the fiscal year 2017. From January to March 2017, it achieved revenue of 1.05 billion euros (equivalent to RMB 7.897 billion), an increase over the same period of the previous year. It is 10%. In today's rapid development of semiconductor lighting, LED's key problem - heat dissipation, will become a big problem, then how can we achieve the most efficient heat dissipation? Today we will talk about the key point of LED cooling - chip.
Nowadays, the manufacture of chips can be described as diverse, and LED chips are no exception. The thermal conductivity of the chip will directly affect the heat dissipation. Of course, as a chip, it is not possible to see the heat dissipation, as well as the dielectric constant and thermal expansion coefficient. Today, a comparison is made between a widely used aluminum substrate on the market and a ceramic substrate that has been relatively low-key.
Aluminum substrate - common in LED lighting products. There are two sides on the front and back sides. The white side is soldered to the LED pin, and the other side is in the form of aluminum. Generally, the thermal conductive paste is applied and the heat conductive portion is contacted.
The aluminum-based plates commonly used for aluminum substrates are mainly 1000 series, 5000 series and 6000 series. The basic characteristics of these three series aluminum materials are as follows:
1, 1000 series Representative 1050, 1060, 1070, 1000 series aluminum plate is also called pure aluminum plate. In all series, 1000 series belongs to the most aluminum content, and the purity can reach above 99.00%. Because it does not contain other technical elements, the production process is relatively simple and the price is relatively cheap. It is the most commonly used series in the conventional industry.
2, 5000 series represents 5052, 5005, 5083, 5A05 series. 5000 series aluminum plate belongs to the more common alloy aluminum plate series. The main element is magnesium, and the magnesium content is between 3-5%. It is also called aluminum-magnesium alloy. The main features are low density, high tensile strength and high elongation. The weight of aluminum-magnesium alloy is lower than other series under the same area, so it is commonly used in aviation, such as aircraft fuel tanks.
3, 6000 series Representative 6061 mainly contains magnesium and silicon two elements, so the advantages of 4000 series and 5000 series are concentrated. 6061 is a cold-processed aluminum forged product, which is suitable for applications with high corrosive and oxidizing requirements. Good usability, excellent interface characteristics, easy coating and good processability.
The thermal conductivity of the 5000-type aluminum substrate is about 135 W/(m·K), the 6000 system is about 150 W/(m·K), and the 1000 system is about 220 W/(m·K).
Next, let's take a look at the ceramic substrate.
国产自拍在线观看Ceramic substrate - refers to a special process board in which copper foil is directly bonded to the surface of aluminum oxide (Al2O3) or aluminum nitride (AlN) ceramic substrate (single or double sided) at high temperature. The ultra-thin composite substrate produced has excellent electrical insulation properties, high thermal conductivity, excellent solderability and high adhesion strength, and can etch various patterns like a PCB board, and has a large current carrying current. ability.
Ceramic circuit boards have the following characteristics:
国产自拍在线观看◆ Strong mechanical stress, stable shape; high strength, high thermal conductivity, high insulation; strong bonding, anti-corrosion.
国产自拍在线观看◆ Excellent thermal cycle performance, the number of cycles is up to 50,000 times, and the reliability is high.
国产自拍在线观看◆It can etch various graphic structures like PCB board (or IMS substrate); it is non-polluting and pollution-free.
◆The use temperature is wide -55 °C ~ 850 °C; the thermal expansion coefficient is close to silicon, simplifying the production process of power modules. It can save transition layer Mo film, save labor, material and reduce cost;
◆Reduce the solder layer, reduce the thermal resistance, reduce the void, and improve the yield;
国产自拍在线观看◆ The line width of 0.3mm thick copper foil is only 10% of ordinary printed circuit board under the same current carrying capacity;
国产自拍在线观看◆ Excellent thermal conductivity, which makes the chip package very compact, which greatly increases the power density and improves the reliability of the system and device;
◆ Ultra-thin (0.25mm) ceramic substrate can replace BeO, no environmental toxicity problem;
◆The current carrying capacity is large, 100A current continuously passes through the 1mm wide and 0.3mm thick copper body, and the temperature rise is about 17°C; the 100A current continuously passes through the 2mm wide and 0.3mm thick copper body, and the temperature rise is only about 5°C;
国产自拍在线观看◆The thermal resistance is low, the thermal resistance of the 10×10mm ceramic substrate is 0.63mm, the thermal resistance of the ceramic substrate is 0.31K/W, and the thermal resistance of the 0.38mm thick ceramic substrate is 0.19K/W, 0.25mm. The thermal resistance of the thickness ceramic substrate is 0.14 K/W.
◆ High insulation withstand voltage to ensure personal safety and equipment protection.
◆ New packaging and assembly methods can be implemented to make the product highly integrated and compact.
国产自拍在线观看The AIN ceramic plate has an extremely high thermal conductivity. The theoretical thermal conductivity at room temperature is 319 W/(m·K), and it has good insulation. The resistivity at 25 ° C is greater than 1014 Ω·cm.
国产自拍在线观看The introduction of ceramic substrate products has opened up the development of heat dissipation application industry. Due to the heat dissipation characteristics of ceramic substrates, ceramic substrates have the advantages of high heat dissipation, low thermal resistance, long life and voltage resistance. With the improvement of production technology and equipment, the product price is accelerated and rationalized. In order to expand the application areas of the LED industry, such as the indicator lights of home appliances, car lights, street lights and outdoor large billboards. The successful development of ceramic substrates will become a service for indoor lighting and outdoor lighting products, making the LED industry a broader market in the future.
After comparison, I believe that everyone has a certain understanding of the substrate of the two materials. With the update of the technology, new and better products will replace the old technology. The market has always been the survival of the fittest, as a manufacturer. We should be benign in competition and make our products better and better, so as to drive the progress and take-off of the entire industry.