PCB Tech - Performance advantages of ceramic substrates and iron substrates

Circuit board, also known as PCB board, aluminum substrate, high frequency board, thick copper board, impedance board, ceramic board, circuit board, etc., is the electrical connection or electrical insulation carrier between various electronic components. Optimization plays a vital role; currently commonly used substrate materials mainly include: ceramic substrates, resin substrates, and metal or metal matrix composite materials, among which ceramic substrates have excellent electrical insulation, stable chemical properties, and thermal conductivity., Mechanical strength, breakdown resistance, high temperature resistance and many other characteristics make ceramic substrates the preferred material for high-power electronic circuit substrates; the common ceramic substrate materials on the market mainly include: beryllium oxide ceramics, alumina ceramics and aluminum nitride ceramics.

1. Beryllium oxide (BeO) ceramic substrate: Its thermal conductivity is as high as 250W/(mK). It is a dielectric material with unique electrical, thermal and mechanical properties; but because its powder contains highly toxic, long-term inhalation It will cause life-threatening and serious environmental pollution, which is why the beryllium oxide ceramic substrate has not been widely used.
2. Aluminum nitride (AlN) ceramic substrate: Aluminum nitride ceramic is a high thermal conductivity ceramic material that is expected to partially replace beryllium oxide ceramics; its thermal conductivity is as high as 200W/(mk), and it has good thermal conductivity, mechanical strength and high temperature resistance. Due to the process and raw materials, the price is higher than that of alumina ceramics. This is why many manufacturers prefer to choose alumina ceramics with lower performance as substrates.
3. Alumina (Al2O3) ceramic substrate: Alumina ceramics has the advantages of low dielectric loss, high mechanical strength, and good chemical stability; although its thermal conductivity is only 28W/(m·K), the raw materials for alumina are obtained Abundant and mature processing technology, so it is easier to be accepted by manufacturers in terms of price.
Fourth, PCB iron substrates are widely used because of their good thermal conductivity, heat dissipation, electrical insulation properties and mechanical processing properties. In the production process of circuit board manufacturers, it is clear that the PCB iron substrate can be divided into three layers, namely the circuit layer (copper foil), the insulating layer and the metal base layer. PCB iron substrates are widely used in LEDs, air conditioners, automobiles, ovens, electronics, street lights, high power, etc. Why PCB iron substrate can be so widely used and used in high-tech products. The thermal expansion, dimensional stability, and heat dissipation properties of the PCB iron substrate make it meet more demanding products. Now we will introduce the relevant performance of PCB iron substrate.
Iron substrate
5. PCB iron substrate heat dissipation: At present, many double-sided and multi-layer boards have high density and high power, and it is difficult to dissipate heat. Conventional printed circuit board substrates such as FR4 and CEM3 are poor thermal conductors, with interlayer insulation, and heat cannot be dissipated. Local heating of electronic equipment cannot be ruled out, leading to high-temperature failure of electronic components, and the PCB iron substrate can solve this heat dissipation problem. In addition to the PCB iron substrate, the copper substrate has a particularly good heat dissipation, but the price is very expensive.
PCB iron substrate dimensional stability: aluminum-based printed boards, obviously the size is much more stable than printed boards of insulating materials. Aluminum-based printed boards and aluminum sandwich panels are heated from 30°C to 140~150°C, with a size change of 2.5~3.0%.

Thermal expansion of PCB iron substrate: Thermal expansion and contraction are the common nature of materials, and the thermal expansion coefficients of different materials are different. The aluminum-based printed board can effectively solve the heat dissipation problem, thereby alleviating the thermal expansion and contraction of different substances on the printed board, and improving the durability and reliability of the whole machine and electronic equipment. Especially to solve the problem of thermal expansion and contraction of SMT (Surface Mount Technology).
Other reasons for PCB iron substrate: PCB iron substrate has a shielding effect; replaces brittle ceramic substrates; rest assured to use surface mounting technology; reduces the real effective area of the printed board; replaces radiators and other components to improve product heat resistance and physical properties; Reduce production costs and labor.