As the surface mount technology (SMT) and chip components develops in the electronics industry, the traditional PCBs having their base materials as organic laminates, are developing towards high reliability, high precision, and high density.
Of course ceramic PCBs are still relatively new and have been used widely for years in the electronics industry. This option is more viable for designers of printed circuit boards. It is also seen as a great solution for accomplishing electronic assembly technology and modern electronics.
You will discover that ceramic printed circuit boards have an edge over the traditional types. Also, ceramic PCB offers more versatility, superior performance and it is less complex. All these are possible due to its minimal CTE (coefficient of thermal expansion) and high thermal conductivity.
What is Ceramic PCB?
The ceramic pcb can be described as an organic binder and ceramic powder that conducts heat. The thermal conductivity at which this PCB is prepared is between 9 to 20W/m.
To explain further, ceramic PCBs are printed circuit boards, with ceramic as its base material. This base material is highly thermally conductive like aluminum nitride, alumina, and beryllium oxide. These are very effective in the transfer of heat from hot spots and then dissipating this heat over the entire surface.
Asides from this, the fabrication of ceramic PCB is done with the LAM technology. This technology is a laser quick activation metallization type. Therefore, ceramic PCBs are highly versatile and can easily substitute the whole traditional PCBs. This PCB will achieve this with even more enhanced performance and involving less complicated construction.
Ceramic PCB Material
For ceramic PCBs, aluminum nitride boards are the best. This is because they offer high thermal conductivity, a value above 150 w/mK. Due to the expensive nature of aluminum boards, some may choose cheaper ceramic PCBs with aluminum boards offering around 18 – 36 w/mK. Both types will offer a higher thermal performance compared to printed circuit boards made of metal core. This is because you don’t need an electric layer forming between the circuits and the core.
You can even increase the thermal conductivity further by making use of silver for your printing traces, with glass covering it for protection. There are other ceramic options. These include silicon carbide, beryllium oxide, and boron nitride.
You cannot finish ceramic boards with HASL, OSP, and other traditional finishes due to the high temperatures required for the operation. However, you can choose ceramic PCBs having gold plating. This includes Electroless nickel electroless palladium immersion gold (ENEPIG) and Electroless nickel immersion gold (ENIG). This helps in protecting the pads which are exposed. This is useful when silver corrosion may cause problems, i.e. in environments containing high sulfur.
Multilayer Ceramic PCB
PCB design, development, assembly, and board fabrication has been trending towards more complex, smaller architectures for a while now. The cause of this trend is due to the huge demand for better functionality, as well as wider development options, most especially in locations that are more compact. For most part, the answer of the Rigid flex PCB industry has been focused on the miniaturization of laminate materials and traditional substrate and increased PCB stackup or layers.
However, issues like heat dissipation, coefficient of thermal expansion and removing excess from the board has resulted in searching for alternative materials, which will respond better to these issues. Ceramics is one great result to emerge.
Ceramic materials, for example beryllium oxide, aluminum nitride, and aluminum oxide, have exceeded the traditional board material’s performance like those of epoxy glass fiber, polystyrene, phenolics resin, and polyimide in erosion resistance, thermal conductivity, high-density trace routing, and CTE component compatibility.
These attributes have made the use of ceramic materials in multilayer boards very favorable. These can be grouped with respect to their fabrication
Multilayer Ceramic PCB Fabrication Methods
The fabrication methods here include:
- Thick film ceramic PCB
- High-temperature Co-fired ceramic PCB
- Low-temperature Co-fired ceramic PCB
Thick film ceramic PCB
Here, these boards are made up of dielectric paste and gold, which is printed on a base made of ceramic, and baked at a temperature slightly below 1000°C. This type may utilize copper or gold, with copper most frequently used because it is less expensive. The baking is done in nitrogen gas to avoid oxidation.
High-temperature Co-fired ceramic PCB
This method makes use of an adhesive, aluminum oxide, as well as a lubricator, solvent, and plasticizer. Circuit tracing could be metals like molybdenum and tungsten, and the temperature for baking could go as high as 1700°C. Using this method will be great for carrier circuits and small-scale boards.
Low-temperature Co-fired ceramic PCB
This method makes use of co-firing. Here, the materials, which are either glass crystal, glass composite, or non-glass, are simultaneously combusted. Usually, for high thermal conductivity, the traces are gold, while the baking of boards is done at 900°C.
Multilayer Ceramic PCB Uses
Multilayer Ceramic PCBs play their greatest role in high-power, high-speed circuit applications. Research has shown that these boards can reduce the parasitic capacitance by about 90% in contrast to the traditional board materials. Also, they have great future use promise in the medical devices, automotive, industrial, and aerospace industries.
The major benefit of multilayer ceramic pcbs can be seen in their thermal properties. Out of all, the most significant is thermal conductivity. This surpasses traditional materials greatly. These benefits reveal the continuous rise in using ceramic boards for high-power and high-speed applications, which are necessary for better functioning of smaller packages.
Ceramic PCB Substrate
According to the material used, ceramic PCB substrates are of three types: Aluminum Nitride (AIN) and Aluminum oxide (AI2O3), and BeO.
The Aluminum oxide type is white in color. This has a thermal conductivity that falls within 24 W/m.k and 30 W/m.k. The other ceramic PCB substrate, Aluminum Nitride, is brown in color. This has a thermal conductivity that falls between 275 W/m.k and 320 W/m.k. From this, it is clear that the latter has a better thermal conductivity.
BeO features a better thermal conductivity compared to metal aluminum. This is utilized in applications that require a higher thermal conductivity. However, after 300℃, the temperature falls quickly. One important point here is that its development is limited by toxicity.
It is very important that you choose the best substrates for your circuits. Different board types are available. However, ceramic pcbs are well known among users of circuit boards. This is due to its versatility.
This is why it is great to purchase the best boards from top-notch ceramic PCB manufacturers. These manufacturers offer the best solutions based on customer’s requirements for printed circuit boards.
One reason why you should choose the best solutions is because they work fine for all electronic circuit types having an increased thermal conductivity and minimal expansion coefficient. When there is more versatility, it shows as the best alternative to already available PCBs having minimal complex design and increased performance.
This ensures the effective functioning of ceramic pcbs on proximity sensors, high-power circuits, and chip-on-board modules.
Ceramic PCB Board
Ceramic PCB boards are of two types: Aluminum nitride and aluminum oxide
Aluminum Nitride Ceramic PCB Board
This is one of the well-known, but expensive ceramic PCB boards. The thermal conductivity is identified to fall within 151 W/mK and 180 W/mK.
Aluminum Oxide Ceramic PCB Board
Aluminum oxide is another of the major ceramics. At room temperature, this ceramic pcb board possesses a thermal conductivity that ranges between 18 – 36 W/mk.
Ceramic Circuit Boards
Ceramic circuit boards are composed of metal cores. It is advisable to choose aluminum nitride boards if you need a circuit board with a high thermal conductivity. For those searching for a less expensive alternative, you can choose aluminum oxide boards. This can be used for proximity sensors, chip-on-board modules, high-power circuits and more.
Ceramic PCB Manufacturer: Choosing the Right One for Your Ceramic PCB Production
Before going ahead to work with any ceramic PCB manufacturer, make sure that the manufacturer has better and superior processing. Also, the oxidation has to be controlled. This will offer a greater temperature resistance and maximum thermal conductivity.
Top manufacturers utilize the automatic processing method for their manufacturing. This allows the oxidation to be controlled and then eliminated.
Below are some of the qualities to watch out for before choosing your ceramic pcb manufacturer.
Design Rule Check
Any ceramic PCB manufacturer should rely on a DRC – Design Rule Check. This is to make sure that boards delivered have been properly optimized for space use. With their DRC software, they should make sure users get the optimal board layout.
Skilled manufacturing and engineering staff
Work with ceramic PCB manufacturers having expert staff. These staffs are always ready to ensure your get the best ceramic PCB to use for your products. By working with them, you will be rest assured that their staff has your needs at heart. Also, they have the required experience to deliver great and high-quality results.
Design for Manufacturability
Work with manufacturers that work with a process referred to as Design for Manufacturability. This process ensures the easy and successful manufacturing of your ceramic PCB to meet your quality expectations and product specifications.
Improvements in manufacturing design also helps in saving costs, increases the safety and compliance of your PCB, improves customer satisfaction, and hastens the time at which it reaches the market.
Work with ceramic PCB manufacturers having PCB quality assurance policy. This makes sure that you get just premium quality boards. These manufacturers will have a Quality Control Team that monitors all the stages involved in PCB production. All these are to ensure that all industry standards, as well as the requirements of customers are met.
Ceramic PCB Applications
Today, ceramic PCB has become widely used due to its many strengths. These include low coefficient of thermal expansion, high thermal conductivity, chemical erosion resistance, and low dielectric constant. The major industries that can be served by ceramic PCBs are automotive, aerospace, electronics, heavy machinery, and medical devices.
The importance and efficiency of ceramic PCBs can be found in other industries asides this. This depends on your manufacturing needs, as well as your design. Please let’s consider the applications of ceramic PCB.
Any ceramic PCB can have high-density assembly. This is why it can have about 4 IC chips. This is why it is very reliable when manufacturing memory modules.
Memory modules utilized in products for telecommunication can be utilized in very extreme environments. Asides from this, they are very resistant to shock and vibration.
Ceramic circuits are also utilized in the manufacturing of transmission and receiving modules for radars used in communication industries.
The reason for this is that aluminum nitride possesses low coefficient of thermal expansion (CTE) and higher thermal conductivity. This is what ensures the module is reliable and effective in transmission and receiving.
Multilayer Interconnect Board
The use of ceramic PCBs can be seen in the production of multilayer interconnect board. Ceramic circuit boards have the ability to hold components on one board area.
With this, you are sure of producing devices that are more sophisticated in smaller packages, in contrast to when you utilize FR4 boards.
Some companies have recently taken advantage of the Low-temperature Co-fired ceramic PCBs to manufacture digital/analog PCB boards. This was done to reduce parasitic capacitance by about nine tenths. This will not just overcome circuit tracing’s crosstalk interference, but reduces the weight and volume of the circuit.
Compared to other circuit boards, ceramic PCBs come with many benefits. This is especially due to the strength of its base material. Also, this leads to some differences in the process of manufacturing. Due to these advantages, ceramic PCBs usually come with better efficiency and stronger capabilities. Also, it is very important to choose the appropriate substrate. Then, make sure you work with the best ceramic PCB manufacturers and suppliers. This is necessary because these boards stand out and require handling by skilled professionals. If these boards are properly fabricated and well assembled, they will work perfectly.