The advantages and disadvantages of the ceramic PCB circuit board were introduced above. One of the disadvantages is that the ceramic substrate is too expensive and fragile. Ordinary glass fiber PCB is not good for heat dissipation, ceramic PCB is relatively stable, and it is not easy to deform under high temperature and humidity environment, but the price is relatively expensive, and it is often used in advanced products. If my product is not that advanced, such as large-area and high-power LED light boards, which are relatively cheap, but require very good heat dissipation performance, is there a PCB substrate with cheap material and good heat dissipation?

　　 The answer is yes. That is the aluminum substrate PCB that this article will introduce. Everyone knows that aluminum is a metal and has conductivity. How can it be used as a PCB material?

　　 This is because the aluminum substrate is composed of three layers: copper foil, insulating layer and metal aluminum. Since there is an insulating layer, can the metal layer be made of other materials besides aluminum? Such as copper plate, stainless steel, iron plate, silicon steel plate and so on. What kind of material is used for the metal substrate, in addition to considering the heat dissipation performance, but also consider the thermal expansion coefficient, thermal conductivity, strength, hardness, weight, surface condition and cost of the metal substrate.

　　Under normal circumstances, considering the cost and technical performance, aluminum plate is an ideal choice. Available aluminum plates are 6061, 5052, 1060, etc. If there are higher thermal conductivity, mechanical properties, electrical properties and other special performance requirements, copper plates, stainless steel plates, iron plates and silicon steel plates can also be used.

　　 is common in LED lighting products. There are two sides, the white side is soldered with LED pins, and the other side is aluminum color. Generally, the thermal conductive paste is applied to contact with the thermal conductive part. Mainly used in LED lamps and audio equipment, power supply equipment, etc. The main advantages are fast heat conduction and good heat dissipation performance.

　　 Compared with the traditional FR-4, the aluminum substrate can reduce the thermal resistance to a lower level, so that the aluminum substrate has excellent thermal conductivity; compared with the ceramic substrate, its mechanical properties are extremely excellent.

　　 In addition to good heat dissipation performance, aluminum substrates also have the following advantages:

　　Comply with RoHS environmental protection requirements

　　 is more suitable for SMT process

　　 Higher current carrying capacity

　　In the circuit design scheme, the heat dissipation is extremely effective treatment, thereby reducing the operating temperature of the module, extending the service life, and improving the power density and reliability;

　　 Reduce the assembly of heat sinks and other hardware (including thermal interface materials), reduce product volume, reduce hardware and assembly costs; combine power circuits and control circuits;