Ceramic PCB presents a more decisive competitive edge over their counterparts in the PCB manufacturing world. If you plan to use a circuit board in high pressure, insulation and temperatures, and low volume machines, then Ceramic circuit boards should top your PCB list.
Ceramic PCBs display super thermal conductivity and low expansion coefficient (CTE). Additionally, they are highly versatile, less complicated, and provide better performance compared to standard PCBs.
Do you want to learn more about ceramic circuit boards and how they can positively impact your firm's general system performance? This article contains everything you need to know about ceramic PCBs, from classifications to properties to applications.
Welcome to the ultimate customization guide of Ceramic PCBs.
1. What is Ceramic PCB?
Ceramic PCB contains a thermally transitive ceramic residue and a binder. The first point to remember is to prepare the heat transmission, organic ceramic boards, at a heat transmission of between 9 to 20W/m. With this in mind, we can define a ceramic PCB as a board containing ceramic base materials.
The materials are good conductors of heat, like alumina and aluminum nitride. Remember, you should use high thermal conductivity materials to bring immediate impacts by conducting heat away from hot spots and dispersing it over the entire surface.
Besides the highly conductive base materials, you should manufacture ceramic PCBs using the LAM technique- a laser express galvanization strategy. While ceramic PCBs are highly versatile, they require a less complicated production with advanced performance.
Remember to print the conductive pathways in ceramic baseboards to raise the performance aspect of your board. The ceramic you will use here is not the regular one used in floors; instead, it is a particular type of material known as "fine ceramic."
1.1 Types of Ceramic PCB
Alumina- you can also call it A1203 or metal baseboard. It is a type of board that has dielectric thermal properties and electrically insulated components between aluminum and copper substrates. It would be best if you used Alumina ceramic boards for heat dissipation purposes and general temperature maintenance and regulation.
Alumina assemblies consist of three primary layers:
- The first one is a circuit layer containing copper of about 1-10 oz wide.
- Secondly, there is an insulating layer consisting of a thermally transitive and electrically insulating substrate.
- The third layer comprises copper aluminum material.
AIN- you can also call it Aluminium Nitride. AIN is a modern commercial ceramic material. It contains elements that are reproducible and regulated in the past 20 years. AIN is an excellent alternative to alumina due to its dielectric capacities, less thermal expansion coefficient, and sound thermal transmission. Besides, it does not react with most semiconductor manufacturing chemicals.
You can use AIN boards in heat sinks, microwaves, molten metal processing machines, electronic package substrates, insulators, and others.
2. Why are Ceramic PCB so Popular?
2.1 High Thermal Expansion
The first reason why ceramic boards are so popular in the electronics sector is their excellent thermal coefficient expansion. It is good to note that the ceramic base heat transmission almost matches that of silicon and can act as a connection material. Besides, you can use it as an isolator. Therefore, there is maximum use for the thermal properties of ceramic boards, even in adverse conditions.
The application of ceramic brings a stable dielectric capacity, and you can modify the balance into a partial radiofrequency loss to increase your device's power. Still, despite the surface toughness, ceramic materials come with an inherent resistance against chemical erosion. Ceramic's chemical resistance can change to resistance against liquids and moisture.
You can create several use cases to integrate a metal core board with a high thermal expansion. Besides, you can still turn the metal core into reliable conductors using the sintering technique. Therefore, the application of ceramic PCB is beneficial because of its high processing temperatures.
The ceramic board fabrication process creates durability through the use of unique properties, such as toughness. That prevents your PCB from wear and tear. So you can be confident that you will not change your PCB soon because of its slow aging capacity. Also, the high thermal resistance of ceramic PCB makes it assume a decelerated decomposition process.
Lastly, the use of metal cores can serve as inflexible carriers that offer mechanical stiffness. This property makes it easier to use ceramic PCBs in any state of matter because of the high resistance to corrosion and normal wear and tear.
3. Ceramic PCB Classifications
3.1 High-Temperature Co-fired Ceramic (HTCC) PCB
You can create high-temperature co-firing by concocting aluminum oxide, plasticizer, lubricant, and solvent. Then it would help if you perform roll forming, the curtain covering, and circuit tracing on refractory surfaces, such as tungsten. After that, cut and laminate your PCB, put it in a high-temperature oven of 16000C- 17000C, and bake for 32-48 hours.
Remember to bake in a minimized gas, like hydrogen, to avoid oxidizing tungsten and molybdenum.
You can use ceramic circuit boards produced under high-temperature co-firing on small-scale PCBs and carrier circuits. It is impossible to use these methods in large-scale PCBs because of their low shrinking lenience, warpage, and moderately high tracing opposition of surfaces.
3.2 Low-Temperature Co-fired Ceramic (LTCC) Circuit Board
You can fabricate LTCC PCBs by mixing crystal glass, composite glass, and non-glass, adhesive materials. Then it would help if you carried out sheet generation and circuit tracing with a highly conductive gold paste.
LTCC creates a conduit to metal paste for circuit tracing. Besides, you can complete circuit board baking by making some changes to the thick film pasting. Also, you can improve the product accuracy and shrinking capacity of your board.
3.3 Thick Film Ceramic PCB
You can repeat a thick layer gold paste on print on your ceramic base. However, you should bake the layers at a temperature below 10000C. While this fabrication strategy is ideal for large-scale ceramic circuit board production, its use is limited because of the high gold prices.
Alternatively, you can create a multi-layered, highly concentrated copper circuit board. That is the most common ceramic circuit board in the PCB manufacturing industry right now.
Remember to bake your ceramic board in nitrogen gas to prevent the oxidation of copper. Apart from that, the dielectric paste produced by nitrogen gas is an essential ingredient of this technology.
4. Ceramic PCB Properties
Unlike standard boards that contain substrates made of epoxy glass fiber, polystyrene, and others, ceramic panels have unique properties that make them stand out from the rest. These properties include:
- Ceramic PCBs are good thermal conductors.
- Chemicals do not quickly erode ceramic circuit boards.
- Ceramic PCBs have excellent compatible mechanical intensity.
- Ceramic boards are easy to perform high-density tracing.
- Lastly, their CTA element compatibility is good.
5. Ceramic vs. FR4
If you want to use a PCB, you have two options to choose from: a standard FR4 board or a metal core PCB (MCPCB). Ceramic PCBs are metal core boards that you can use in devices with adverse conditions. They provide unique benefits compared to FR4 boards.
With the invention of cutting-edge electronics that apply miniaturization and high-speed, designers no longer prefer FR4 substrates in intensive power and smart use cases. The laser technique used in LAM aligns well with the high-density assembly of PCBs and fineness creation.
One significant difference between FR4 and ceramic boards is their heat transmission capacities. FR4 boards have an abysmally low heat transmission capacity compared to ceramic PCBs. From the metal topic in Chemistry, Aluminium oxide conducts heats 20 times better than FR4. Also, Aluminium nitride and silicon carbide transmit heat 100 times better than FR4.
FR4 circuit boards with high thermal requirements often pay off for their low heat transmission capacities using metal parts to conduct heat more effectively. Metal structures, such as thermal Vias, thermal landings, and cooling gadgets, are applied to distribute heat from surfaces. However, ceramic PCBs rarely require these structures, as they efficiently conduct heat to thermal landings, cooling gadgets, and device packages.
It is also important to note that good conductors of heat are also good electrical conductors. But ceramics go against this law, as they have low electrical conductivity, enabling them to fit well in circuit boards. Still, you can modify their electrical conductivity via doping- the process used to create ceramic resistors.
5.1 Multilayer Ceramic PCB
Ceramic PCBs have additional properties that are particularly essential in multilayer PCBs. The high heat transmission capacities prevent hot spot formation on surfaces and inner parts because ceramic distributes heat evenly throughout the PCB. Contrary, FR4 boards depend on metal structures and cooling gadgets to conduct heat from central points of the PCB.
Multilayer PCBs rely on Vias to reach the inner parts of a circuit. FR4 Vias are fragile and easily break during heat conduction because copper and FR4 have different thermal expansion coefficients.
The thermal conductivity of these PCBs generates stress throughout the Via barrel and put points. It would help if you made special design considerations for such surfaces to avoid Via failure.
Ceramic PCBs contain heat expansion coefficients that closely match with conductor structure values. That minimizes the stress that mounts up on these surfaces during thermal conduction. The excellent heat transmission throughout the PCB also ensures an even thermal expansion.
Generally, ceramics contain good mechanical strength and can tolerate high automatic weights, such as intense vibrations and shock. They pose lower Young's modulus than FR4, implying FR4 distorts more under similar circumstances.
6. Applications of Ceramic PCB
Engineers and designers tend to use ceramic boards more than standard PCBs because of their high thermal transmission, minimal CTE, high chemical corrosion resistance, and reduced dielectric constant.
6.1 Memory Modules
One of the primary uses of ceramic boards is memory modules. These boards contain memory incorporated circuits, which you can apply in DDR SDRAM manufacturing and other memory-based electronic parts. The Random Access Memory (RAM) of computers use ceramic substrate circuit boards with incorporated memory modulus.
6.2 Transmission Modules
Ceramic circuit boards facilitate radar technology. Americans were the first people to use ceramic boards in the manufacturer of transmission modules. The technology is now widely used. It leverages multi-layered ceramic boards because of their excellent thermal conductivity and compatibility properties with CTE.
6.3 Multilayer Interconnect Board
One of the major strongholds of ceramic boards is that they contain a higher capacity than standard PCBs. To put it differently, ceramic panels hold more parts with the same surface area than regular circuit boards. For that reason, ceramic panels have a higher potential for use cases.
6.4 Analog/Digital PCB
Numerous computing companies have exploited low-temperature ceramic circuit (LTCC) PCBs to produce more significant analog and high circuit tracing boards. These companies currently use LTCCs to make lightweight circuits that minimize personal computers' overall weight and lessen crosstalk interference.
6.5 Solar Panels
You can apply both HTCCs and LTCCs to make solar panels and other photovoltaic (PV) panels. These devices use multi-layered ceramic PCB technology to achieve durability and enough thermal transmission.
6.6 Electrical Power Transmitter
Wireless power transmission and charging devices have become increasingly popular basic electronics. You can manufacture these gadgets using ceramic boards due to their exclusive thermal elements and heat-transmission capacities.
You can use ceramic PCBs to produce an electromagnetic field to conduct energy from a receiver to a transmitter. It would help if you also had induction coils to transport electricity from an electromagnetic field and transform it into electrical current, which the receiver circuit can readily use. Mostly, these circuits consist of ceramic board substrates.
6.7 Semiconductor Coolers
With the introduction of pocket-size gadgets, more and more electronic components are becoming miniaturized. Semiconductor chips, which are becoming smaller yearly, facilitate component miniaturization.
These chips employ micro-fabrication technology to enable better integration at advanced speeds while retaining maximum tracing abilities.
Standard boards cannot support the high number of circuit capacities required for the current semiconductor chips. But the invention of ceramic semiconductor circuits has facilitated higher integration and ability in small circuit manufacturing. That is why we consider ceramic boards as the future of the semiconductor industry.
6.8 High Power LED
Ceramic substrates offer a maximum sub-amount for superpower LED lights. Ceramic circuits utilize a dense film strategy to capitalize on efficiency. Consequently, the LED lights' heat does not affect the circuit's working efficiency.
Therefore, only ceramic circuits provide the thermal efficiency needed for LED light creation. LEDs using ceramic circuits do not require thermal interface components, minimizing the number of parts necessary to create and maintain LED light.
7. Ceramic PCB: Pros and Cons
8. How to Manufacture Ceramic PCB
You can apply silver or gold conductive pastes to lay trace connections in all layers in ceramic PCBs' production process. It would help if you placed these substrates in every layer with a layer-by-layer screen printing technique. Besides, it would help if you punched Vias within unfired layers.
Once you have printed and stacked the ceramic layers, you should fire the whole stack in an oven. Remember to use firing temperatures of less than 10000C to match the sintering temperature of the substrates.
The minimal temperature baking process facilitates the application of metal substrates, specifically gold and silver, in ceramic boards.
Multilayer boards' high baking and sintering will allow you to incorporate passive elements directly into the more in-depth section of a ceramic board.
However, this is impossible in FR4 panels. The hot baking and sintering will enable you to adjust the assembly density of the inner surfaces.
With the invention of chip technology in the electronics world, traditional PCBs integrated with organic base substrates evolve towards super density, good precision, and reliability. Ceramic circuit boards are a new breed of PCBs gaining popularity in the electronics space because of their unique properties.
Ceramic PCBs offer several benefits over the standard boards. Because of their excellent thermal conductivity and low expansion coefficient (CTE), ceramic PCBs are highly versatile, less complicated, and provide better performance than traditional circuit boards. Engineers consider these PCBs as the ideal solution for miniaturization purposes of cutting-edge electronic devices.