We specialize in three types of ceramic substrates:
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Alumina (AlN) PCBs
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Aluminum Nitride Base
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Copper Clad
A ceramic printed circuit board (PCB) uses materials like aluminum oxide or aluminum nitride instead of traditional FR4 fiberglass. Here are key highlights about ceramic PCBs:
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Superior Performance: Ceramic PCBs offer enhanced heat resistance, superior electrical insulation, and exceptional dimensional stability compared to standard FR4 PCBs, allowing operation at high temperatures.
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Materials: Common ceramic choices include alumina (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), and low temperature co-fired ceramics (LTCC).
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Manufacturing Process: Produced through processes such as screen printing, lamination, laser drilling, and high-temperature sintering to form robust circuits.
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High Frequency Capabilities: Ideal for RF and microwave applications due to excellent high frequency characteristics and low loss tangents.
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High Voltage Support: Capable of handling higher voltage circuits with minimal thermal expansion.
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Complex Designs: Multilayer ceramic PCBs can incorporate buried vias or cavities to accommodate intricate layouts.
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Applications: Widely used in military, aerospace, automotive electronics, telecom infrastructure, medical devices, and other sectors where reliability in extreme conditions is crucial.
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Manufacturing Excellence: Leading ceramic PCB manufacturers offer comprehensive services including fabrication, assembly, and rigorous testing to ensure high-quality, reliable ceramic boards.
Ceramic Substrate Material | Thermal Conductivity |
|---|---|
Aluminum Nitride | 150 – 180 W/mK |
Aluminum Oxide | 18-36 W/mK |
Beryllium Oxide | 184-300 W/mK |
Boron Nitride | 15 – 600 W/mK |
Silicon Carbide | 70-210 W/mK |
Manufacturing process for ceramic printed circuit boards (PCBs):
Material Preparation: Ceramic materials, typically aluminum oxide or aluminum nitride powder, are mixed with binders and sintering aids. The resulting slurry is cast into sheets of "green tape."
Via Formation: Holes are punched in the green tape to create vias for interconnecting components. These vias are then filled with a conductive paste.
Conductive Layer Printing: Circuit patterns are formed by screen printing a conductive paste containing materials such as silver, gold, or copper onto the green tape.
Lamination: Multiple layers of circuitized green tape, along with non-circuitized dielectric layers, are stacked and laminated under pressure to form a multi-layer board.
Bisque Firing: The laminated board undergoes slow heating to burn off binders and organic compounds, leaving behind ceramic and metal particles.
Sintering: The bisque-fired board is sintered at high temperatures (up to 1600°C) to densify the ceramic structure and firmly bond the conductive layers.
Machining: Laser or mechanical drilling is used to create vias or cutouts in the fully sintered board. Additional finishing operations may also be performed.
Metallization: Conductive paths on the fired ceramic board are electroplated or coated to reduce resistivity.
Testing: Rigorous electrical, thermal, mechanical, and environmental tests are conducted to ensure the reliability of the board.
Assembly: Surface mount or leaded components are soldered onto the finished ceramic PCB. Further testing is performed post-assembly.
This comprehensive process enables the fabrication of complex, multi-layered ceramic circuit boards that offer high reliability and superior performance characteristics.
Alumina Ceramic Substrate
The alumina ceramic substrate has high mechanical strength, good insulation, and light resistance. It has been widely used in multilayer wiring ceramic substrates, electronic packaging, and high-density packaging substrates.
1. The Crystal Structure, Classification, and Performance of Alumina Ceramic Substrate
Alumina has many homogenous crystals, such as α-Al2o3, β-Al2o3, γ-Al2o3, etc. Among them, α-Al2o3 has higher stability. Its crystal structure is compact, physical and chemical properties are stable, and it has density and mechanical properties. The advantage of higher strength has more applications in the industry.
Alumina ceramics are classified by alumina purity. Alumina purity of “99% is called corundum porcelain, and alumina purity of 99%, 95%, and 90% is called 99 porcelain, 95 porcelain, and 90 porcelain, content” 85% of alumina ceramics are generally called high alumina ceramics. The bulk density of 99.5% alumina ceramics is 3.95g/cm3, the bending strength is 395MPa, the linear expansion coefficient is 8.1×10-6, the thermal conductivity is 32W/(m·K), and the insulation strength is 18KV/mm.
2. Manufacturing Process of Black Alumina Ceramic Substrate
Black alumina ceramic substrates are mostly used in semiconductor integrated circuits and electronic products. This is mainly due to the high photosensitivity of most electronic products. The packaging materials need to have strong light-shielding properties to ensure the clarity of the digital display. It is packaged with a black alumina ceramic substrate. With the continuous updating of modern electronic components, the demand for black alumina packaging substrates is also expanding. At present, research on the manufacturing process of black alumina ceramics is actively carried out at home and abroad.
Black alumina ceramic fiber board used in the electronic product packaging are based on the needs of their application fields. The selection of black coloring materials needs to combine the properties of ceramic raw materials. For example, it is necessary to consider that ceramic raw materials need to have better electrical insulation. Therefore, in addition to the ceramic substrate’s final coloration and mechanical strength, the black coloring material must also consider electrical insulation, heat insulation, and electronic properties. Other functions of packaging materials. In the ceramic coloring process, the low-temperature environment may affect the volatility of the coloring material and keep it warm for a certain period. During this process, the free coloring material may aggregate into spinel compounds, preventing the coloring material from continuing under high-temperature environments. Volatile to ensure the coloring effect.
3.The Process of Manufacturing Black Alumina Ceramic Substrate by Casting Method
The casting method refers to the manufacturing process of adding solvents, dispersants, binders, plasticizers, and other substances to the ceramic powder to make the slurry evenly distributed. Afterward, making the ceramic sheets of different specifications on the casting machine. It is called the scraper forming method. This process first appeared in the late 1940s and was used to produce ceramic chip capacitors. The advantages of this process are:
(1) The equipment is simple to operate, efficient in production, capable of continuous operation, and high in automation.
(2) The density of the embryo body and the elasticity of the diaphragm is greater.
(3) Mature technology.
(4) Controllable production specifications and a wide range.
