The substrate, or base of the ceramic board, is made using different inorganic materials, so it is known as ceramic PCB. The structure of the ceramic board has a base of ceramic materials, insulating layers, and other components connected to the board for making circuits for various projects.
These ceramic printed circuit boards come with low CTE (coefficient of thermal expansion) and are preferred for projects that need a low CTE. Their good thermal conductivity helps to be used for applications where thermal conductivity is the main factor. Aluminum nitride, alumina, and beryllium are commonly used types of ceramic substrates. They provide high electrical insulation used in integrated circuit substrates as insulators.
Understanding Ceramic PCB
Ceramic circuit boards are best to use for applications where you need electrical insulation, high temperature, and high-pressure applications. These boards come with features to handle all these parameters in an effective way as compared to other boards without any damage. Their low coefficient of thermal expansion and high thermal conductivity make them more prominent than conventional boards and also provide better functionality in harsh conditions.
These ceramic PCBs use materials like alumina or aluminum nitride as substrates which are good conductors of materials that provide high conductivity for these boards.
Types of Ceramic PCB Materials
There are different types of materials used for ceramic PCB boards, and each material has its features and applications that are explained follow in detail.
Aluminum Oxide (Al2O₃)
Aluminum oxide or alumina has oxygen and aluminum in its composition, and it is normally white. It is an inorganic material and comes in powder form. It is a timeless material and does not have water-soluble features. The electrical resistivity of alumina is 1*1014 Ω·cm. and has good electrical insulator features. The CTE value is 4.5 to 10.9 *10.6/K and 25 W/(mK) thermal conductivity.
Aluminum Nitride (AIN)
Aluminum oxide or alumina has oxygen and aluminum in its composition, and it is normally white. It is an inorganic material and comes in powder form. It is a timeless material and does not have water-soluble features. The electrical resistivity of alumina is 1*1014 Ω·cm. and has good electrical insulator features. The CTE value is 4.5 to 10.9 *10.6/K and 25 W/(mK) thermal conductivity.
Beryllium Oxid
It was called beryllium oxide and is now also known as beryllia. It also has good electrical features like thermal conductivity and insulation. Its melting point is 2506.85°C to 2575°C, and CTE is 7.4 to 8.9 *10-6/K. Its dimensions have rigid bonds like a diamond structure and comes with a white color.
Silicon carbide(SiC)
This ceramic material not only provides good strength for high temperatures and can easily handle temperature values of about 1500°C but also has high resistance and thermal conductivity features. Because of its high thermal resistance value, it can handle 1000 degrees easily, so it is used where high temperatures are involved, like in laser applications. However, its limitation is that boards that use these ceramic PCB materials as substrates are expensive.
Boron nitride (BN)
It can be used in solid as well as powder form since it has a synthetic nature. These materials provide ceramic circuit boards with good dielectric strength with a low dielectric constant.
Ceramic PCB vs. FR-4 PCBs
Ceramic PCBs and FR4 PCBs are the main parts of our electronics industry, and their importance cannot be denied for the creation of projects and devices. To use them, we must have knowledge of their basic differences that help us to know for which applications we need FR4 or ceramic. Let's discuss their basic differences.
Good Thermal Conductivity
Ceramic PCBs come with a higher thermal conductivity as compared to FR4 PCB boards. Ceramic PCB boards are used for LED lights where high heat is produced since these boards have high heat dissipation features. While FR4 boards use heat sinks for heat dissipation, for projects where high heat is involved, ceramic circuit boards are preferred.
Mechanical Strength
The mechanical features of ceramic circuit boards are low and can easily break if high pressure or shock is applied. But can easily handle high-temperature effects. FR4 can easily handle pressure, vibration, and shock since it comes with good mechanical strength.
Electrical Features
Ceramic PCBs are used in circuits where microwaves and high frequency are involved since they have good insulation, while FR4 has low features and is not good to use for high frequency and RF circuits.
Moisture Resistance
Ceramic PCB boards are used in outdoor circuits and devices since they easily handle moisture and other environmental conditions, while FR4 has good moisture resistance but not as much as ceramic PCB materials. In a harsh environment, FR4 uses any protection to avoid effect.
Substrate Materials
Aluminum oxide, or alumina, is used as a ceramic substrate, and FR4 is made with epoxy resin that has flame-retardant features.
Ceramic PCB Types
Like conventional PCB boards, ceramic circuits also come with different types that are explained here one by one.
LAM PCB
LAM PCB (Laser Activation Metallization PCB), is more used than other types of ceramic board. The ionization process is used for the creation of LAM board ceramic materials and metallic components with the use of a laser drill process that provides high energy. The smooth surface is obtained through the strong connection of ceramic and metallic parts.
DPC PCB
DPC PCB (Direct Plate Copper PCB), is a new type used for substrate and involves the use of etching and copper layers printed on a ceramic substrate. The DPC boards are made with the use of different techniques such as the sputtering process, vapor deposition, and vacuum. The high pressure and temperature involved in this process provide a strong connection between the substrate and copper. 10 μm to 140 μm is the range for copper thickness.
DBC PCB
DBC PCB (Direct Bonded Copper PCB), this board creation involves the addition of oxygen between ceramic and copper during deposition. The DBC board normally has a thickness range of 140 μm to 350 μm.
LTCC PCB
LTCC PCB (Low-Temperature Co-fired Ceramic PCB), board composition uses glass, or in some conditions not, normally ceramic and glass mixed in a ratio of 30 to 50. For mixing glass and ceramic materials, inorganic binders are used. Through hole process used or making hole drilling on the sheet where the mixture is applied. The screen printing process is used for circuit designing.
HTCC PCB
HTCC PCB (High-Temperature Co-fired Ceramic PCB), board uses raw substrate, and for gaseous conditions, its baking temperature range is 1600 to 1700 °C. That helps us in high-temperature conditions.
Thick Film Ceramic PCB
Thick film ceramic substrates are part of applications where high oxidation exists. Their baling temperature is 1000 degrees in nitrogen chambers, and it has a gold, silver, or dielectric coating on the base. Its connected electron components are easily changed due to oxidation resistance features.
Thin Film Ceramic PCB
The materials used for the creation of these thin film ceramic substrates are beryllium oxide or aluminum oxide and are mostly used in circuits where high frequency exists. For an accurate conductivity layer on board, uniform deposition sputtering and chemical vapor deposition processes are used.
Advantages of Ceramics PCB
There are many advantages of ceramic PCBs as compared to other boards that make them the best for certain applications.
Low CTE
They can handle high-temperature conditions since they have strong interatomic bonds and a solid nature. All these features make ceramic PCB boards stable in different harsh conditions.
Stability
These ceramic printed circuit boards have low-frequency effects and have a stable dielectric nature. It has moisture resistance and is also not affected by different chemicals.
Thermal Conductivity
It has good thermal conductivity since it uses different base materials, and each has its conductivity value that helps to work in different temperature conditions. Normally, its thermal conductivity value is 25 330 W/(m·K), which is higher than FR4 PCBs. So it can work well in higher temperature conditions.
High-Frequency
Applications where signal transmission and high-frequency use are used, such as in medical devices where ceramic circuit boards are used that do not have a high effect on HFs.
Thermal Insulation
High insulation features help to heat flow from substrate materials and do not affect board components.
Disadvantages of Ceramic PCBs
With the advantages of PCB ceramic, they also have some disadvantages or limitations. We needed to consider their practical uses. Some are listed here.
High Cost
The production of ceramic circuit boards uses costly materials, so the overall cost of these boards is higher than FR4, which uses low-cost materials.
Brittle Nature
These ceramic PCB boards do not handle high pressure due to their fragile structure. Break when high pressure is involved and also has an effect on the complete device or circuit.
Limited Design
Its design was not modified after creation since it needed an accurate and proper process for designing.
The Use of Ceramic Circuit
Ceramic boards are part of our different projects and devices, and with the advancement of technology, their use is growing. Some common uses of ceramic circuit boards are explained here.
When is it Best to Use Ceramic Circuits?
The use of ceramic boards is based on applications since they can be used for all applications, but one must check whether it is good for that project or not. Some features like weight, net expenses, and conductivity define where these ceramic PCB boards are needed. It will be used for projects where small sizes, low weight, and high heat transfer are needed based on high corrosion and low thermal expansion features of ceramic materials.
It can handle high-temperature conditions, so it is used in the automobile and aviation industries.
Different Applications of Ceramic PCB Board
High-Power Applications
For applications with high voltage and current, like vehicles, these ceramic circuit boards are the best option to use since they have insulation for the connected component to avoid high current-carrying parts.
LED Technology
High-brightness LED lights have high heat dissipation due to the use of ceramic boards since they are stable in thermal conditions.
Medical Devices
Different devices in the medical field, like X-ray machines and MRI scanners, are made with ceramic circuits for handling high frequencies during their work.
Ceramic PCB Manufacturing Process
- Manufacturing involves first of all the preparation of ceramic PCB material that makes sheets with a combination of binders. For components connected on board vias are made through the creation of thin holes on the surface. The silver or copper paste is applied to the sheet to make conductive layers. In the next step, the board was laminated, and binders and organic materials were removed with the use of heat.
- Board sintering is performed at a temperature of about 1600 °C for the connection of conductive layers vias drilled with the use of laser drilling. The board is electroplated to avoid resistivity, and in the last different tests were performed to find any faults on the board.
Design Considerations for Ceramic PCBs
Thermal Management
- To fulfill the demand of applications that needed high thermal management, a proper heat dissipation factor or ceramic substrate PCB was considered. There is consideration of vias, heat sinks, and component connections considered for board design.
Electrical Performance
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There is a need for proper impedance control in high-frequency PCBs, and the ceramic circuit board has controlled impedance for traces on the board. So selected materials of the board and design easily handle impedance effects to minimize the reflection of signal and distortion.
Mechanical Design
- PCBs made with ceramic materials can easily handle high stress and bending due to their high mechanical strength and rigid nature. So preferred for high-vibration projects.
Top Ceramic PCB Manufacturer in China - FC
The creation of ceramic PCB uses many types of materials such as alumina, beryllium oxide, silicon carbide, and aluminum nitride. The electronic connector is another name for ceramic circuit boards. They are the main part of projects where high temperature and high frequency are involved and are also used for the prevention of oxidation and chemical effects on board. High power density features help these boards to work as the main component in aviation and vehicles. There are many types of these boards that we covered.
Ceramic circuit boards offered by FC PCBA not only have quality features and work for the miniaturization of modern electronic circuits, but they are also used for different applications like LEDs, high-power semiconductors, and electrical and thermal features. Choose FC as the ceramic PCB supplier and get high-quality ceramic printed circuit boards now.