What is a ceramic circuit board?Following are the china pcb manufacture to learn more:
It is the circuit board that makes line above ceramic board, ceramic thermal conductivity is high, dimensional stability is good.
Suitable for high power circuit design applications
Why use ceramic electric roadbed board?
Common PCB is usually made of copper foil bonded with the substrate, and the substrate material is mostly glass fiber (fr-4), phenolic resin (fr-3) materials, adhesives are usually phenolic, epoxy, etc.Due to thermal stress, chemical factors, improper production process and other reasons in the process of PCB processing, or due to asymmetry of copper coating on both sides in the design process, it is easy to cause different degrees of bending of PCB board.
And another kind of PCB substrate – ceramic substrate, due to the heat dissipation performance, current carrying capacity, insulation, thermal expansion coefficient, etc., are much better than the ordinary glass fiber PCB plate, so it is widely used in high-power power electronics module, aerospace, military electronics and other products.
It USES adhesive to bond copper foil and substrate together with common PCB. Ceramic PCB is used to bond copper foil and ceramic substrate together under high temperature environment. With strong binding force, copper foil will not fall off, high reliability and stable performance under high temperature and high humidity environment.
The main material of ceramic substrate?
Alumina is the most commonly used substrate material in ceramic substrates, because of its mechanical, thermal and electrical properties, high strength and chemical stability compared with most other oxide ceramics, and the rich source of raw materials, suitable for a variety of manufacturing techniques and different shapes.According to the percentage of alumina (Al2O3) can be divided into: 75 porcelain, 96 porcelain, 99.5 porcelain.The electrical properties of alumina are almost unaffected by the content of alumina, but the mechanical properties and thermal conductivity vary greatly.The substrate with low purity has more glass and larger surface roughness.The higher the purity of the substrate, the more clean, dense, medium loss is lower, but the higher the price.
Beryllium oxide (BeO)
It has a higher thermal conductivity than the metal aluminum, and it is applied to the occasions where high thermal conductivity is needed. After the temperature exceeds 300℃, it rapidly decreases, but its development is limited due to its toxicity.
Aluminum nitride (AlN)
Aluminum nitride ceramics are ceramics with aluminum nitride powder as the main crystal phase.Compared with alumina ceramic substrate, insulation resistance, insulation voltage higher, dielectric constant lower.Its thermal conductivity is 7 to 10 times that of Al2O3, and the coefficient of thermal expansion (CTE) is approximately matched to the silicon wafer, which is crucial for high-power semiconductor chips.In the production process, AlN thermal conductivity is greatly affected by the content of residual oxygen impurities.At present, it is no problem for the thermal conductivity of the process production level to reach above 170W/(m·K).
Based on the above reasons, it can be known that alumina ceramics are still in a leading position in the fields of microelectronics, power electronics, hybrid microelectronics and power modules due to their superior comprehensive performance.
Advantages and disadvantages of ceramic PCB?
With a large carrying capacity, 100A current continuously passes through 1mm0.3mm thick copper body, with a temperature rise of about 17℃;The 100A current continuously passes through 2mm0.3mm thick copper body, and the temperature rises only about 5℃.
Better heat dissipation performance, low thermal expansion coefficient, stable shape, not easy to warp.
Good insulation, high voltage, ensure personal safety and equipment.
Strong binding force, the adoption of bonding technology, copper foil will not fall off.
High reliability, stable performance under high temperature and high humidity
Fragile, this is a major disadvantage, which leads to only a small area of the circuit board.
The price is expensive, electronic products more and more requirements rules, ceramic circuit board is still used in some more high-end products, low-end products will not be used.
USES of ceramic PCB:
High-power power electronics module, solar panel module, etc
High frequency switching power supply, solid state relay
Automotive electronics, aerospace, military electronic products
High power LED lighting products
Communication antenna, car igniter
Post time: Apr-25-2020