Discussion on aluminum substrate
Our commonly used PCB board is coated with copper on one or both sides of the insulating board surface As a specific form of PCB, this aluminum substrate is usually copper plated on one side with a thin insulation layer, and then an aluminum springboard is superimposed on the side without copper coating. That is, the so-called aluminum substrate is usually used for audio, power, communication electronic equipment, automobiles, computers, lamps and lighting, etc
So, what are the benefits of aluminum substrate?
Aluminum material
Good heat dissipation efficiency: the aluminum substrate can minimize the thermal resistance, has a smaller thermal resistance, and the thermal expansion coefficient is closer to the copper foil, so that the aluminum substrate has excellent thermal conductivity and heat dissipation efficiency, reduces the operating temperature of the module, and extends the service life.
High current carrying capacity: under the same thickness and line width, aluminum substrate can carry higher current.
Good machinability: It can replace ceramic substrate, with better mechanical durability. At the same time, it has high strength and toughness, and can realize large area PCB manufacturing and component installation.
Good electromagnetic wave mask: In order to ensure the efficiency of electronic circuits, some components in electronic products need to prevent electromagnetic wave radiation and interference. The aluminum substrate can be used as a mask to mask electromagnetic waves
Environmental protection: The raw material aluminum is non-toxic and can be recycled. Comply with ROHS requirements.
Light weight: aluminum is surprisingly light and convenient under the condition of good strength and elasticity.
However, from the perspective of process and selectivity, aluminum substrate still has some disadvantages in the existing market, such as:
High cost: compared with the commodity at par, the price of aluminum substrate accounts for more than 30%.
High process difficulty: at present, it is difficult to make double panel, and the process is complex. In the manufacturing process, withstand voltage and electric strength are also prone to problems.
The plates are not unified: CPCA industry standards, national standards, international standards, etc., and there is no unified data specification standard.
The commonly used aluminum substrates include 1000 series, 5000 series and 6000 series.
-1000 series
It represents 1050, 1060, 10701000 series aluminum plates, also known as pure aluminum plates. Among all series, 1000 series has the highest aluminum content, with purity of more than 99.00%. Because it does not contain other scientific and technological elements, the production process is relatively simple and the price is relatively cheap. It is currently the most commonly used series in conventional industries. At present, most of the circulation in the market is
1050 and 1060 series. The minimum aluminum content of 1000 series aluminum plate is determined according to the last two digits. For example, the last two digits of the 1050 series are 50. According to the international brand naming principle, the aluminum content must reach 99.5% or more before it is considered as qualified products. In china's scientific and technological standards for aluminum alloys (gb/t3880-2006), 1050 also clearly stipulates that the aluminum content should reach 99.5%.
Similarly, the aluminum content of 1060 series aluminum plates must be above 99.6%.
-5000 series
Represent 5052, 5005, 5083 and 5A05 series. 5000 series aluminum plates are a series of commonly used alloy aluminum plates. The main element is magnesium. The magnesium content is 3-5%, also known as aluminum magnesium alloy. Its main characteristics are low density, high tensile strength and high elongation. In the same area, the weight of aluminum magnesium alloy is lower than that of other series, which is often used in the aviation field, such as aircraft fuel tank. Another
It is also widely used in traditional industries. Its processing technology is continuous casting and rolling, belonging to the hot rolled aluminum plate series, which can be deeply oxidized. In China, 5000 series aluminum plate is one of the more mature aluminum plate series.
-6000 series
The typical 6061 mainly contains magnesium and silicon. It integrates the advantages of the 4000 series and 5000 series. 6061 is a cold treated aluminum forging product, suitable for applications requiring high corrosion resistance and oxidation resistance. It has good usability, excellent interface characteristics, easy coating and good processing efficiency. 6061's general characteristics: good interface characteristics, easy coating, high strength and good usability
Strong corrosion resistance. Typical uses of 6061 aluminum: aircraft parts, camera parts, couplers, ship accessories and hardware, electronic accessories and connectors.
Considering the texture, hardness, elongation, chemical efficiency and price of the data itself, the current aluminum base plate generally adopts 5052 alloy aluminum plate of 5000 series aluminum materials.
Insulating layer: The insulating layer is a layer of insulating material with low thermal resistance and heat conduction.
Base: A metal substrate, usually aluminum or optional copper Aluminum copper base copper clad laminate and traditional epoxy glass cloth laminate
Aluminum structure.jpg
Aluminum structure
Aluminum substrate is a kind of copper clad laminate based on aluminum, which has good heat dissipation efficiency. We usually use aluminum substrates for circuit boards that require good heat dissipation. In the application of LED lights, due to the high heat of LED, if the heat is not emitted in time, the brightness is easy to decline, or even burn the chip. Aluminum is a metal with good thermal conductivity. LED lamp beads can be installed on the aluminum substrate
Fast heat dissipation. The aluminum substrate is designed with an insulating layer, which will not conduct electricity. If it conducts electricity, there is no way to design circuits on it.
The technology is applied to the thermal insulation layer of high-performance aluminum substrate, so that it has extremely excellent thermal conductivity and high strength electrical insulation efficiency; The metal base is the supporting component of the aluminum substrate, which requires high thermal conductivity. Generally speaking, it is aluminum plate or copper plate (copper plate can provide better thermal conductivity), which is suitable for conventional processing, such as drilling, punching and cutting.
Compared with other materials, PCB has incomparable advantages. SMT public art suitable for surface mounting of power components. Without radiator, the volume is greatly reduced, the heat dissipation effect is excellent, and the insulation and mechanical properties are good.
Single sided aluminum substrate usually has 3 layers, including circuit layer (copper foil), insulation layer and aluminum metal base. There is an insulating layer between the circuit layer and the aluminum base, which will not cause short circuit. There is a circuit layer on both sides of the double-layer high-end aluminum substrate, of course, aluminum is in the middle. Multilayer aluminum substrates are rare.
In general, LED lamps use single-sided aluminum substrate, and the circuit layer is pasted with LED. The aluminum substrate on the back can be in good contact with the radiator for heat dissipation.
The insulating layer in the aluminum substrate is the most critical and core technology in the aluminum substrate. It should not only adhere to copper foil, but also have good thermal conductivity, because the insulating layer of aluminum substrate is the largest thermal barrier. If the heat of copper foil cannot be transferred to the aluminum substrate quickly, the aluminum substrate will lose its importance.
Characteristics of LED aluminum substrate
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1. Use Surface Mount Technology (SMT);
2. In the circuit design, the thermal diffusion is effectively treated;
3. Reduce the working temperature of the product, improve the power density and reliability of the product, and extend the service life of the product;
4. Reduce product volume, hardware and assembly costs;
5. Replace the fragile ceramic substrate for better mechanical durability.
Application of LED aluminum substrate
Purpose: Power hybrid integrated circuit.
1. Audio equipment: input/output amplifier, balance amplifier, audio amplifier, pre amplifier, power amplifier, etc.
2. Power supply equipment: switch regulator, DC/AC converter, sw regulator, etc.
3. Communication electronic equipment: high frequency amplifier ` filter apparatus ` sending circuit. 4. Office automation equipment: motor driver, etc.
5. Automobile: electronic regulator, igniter, power controller, etc.
6. Computer: CPU board, floppy disk drive, power supply equipment, etc.
7. Power module: inverter, solid-state relay, rectifier bridge, etc
The above is the explanation given by the editor of pcb circuit board company. If you want to know more about PCBA, you can go to our company's home page to learn about it. In addition, our company also sells various circuit boards,
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