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Ceramic PCB: The Ultimate Customization Guide in 2024

Ceramic PCB presents a more decisive competitive edge over their counterparts in the PCB manufacturing world. Ceramic circuit boards should top your PCB list if you plan to use a circuit board in high pressure, insulation and temperatures, and low volume machines.

Ceramic PCBs display superthermal 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 about ceramic PCBs, from classifications to properties to applications.

Welcome to the ultimate customization guide for Ceramic PCBs.

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What is a 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.

In addition to 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 on floors; instead, it is a type of material known as "fine ceramic."

Why is Ceramic PCB so Popular?

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 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.

Stability

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 roughness, ceramic materials come with an inherent resistance against chemical erosion. Ceramic's chemical resistance can change to resistance against liquids and moisture.

Versatility

Integrated metal core boards with high thermal expansion can be used for several applications. Using the sintering technique, the metal core can still be turned into a reliable conductor. Therefore, ceramic PCBs' high processing temperatures make them beneficial.

Durability

The ceramic board fabrication process creates durability through unique properties, such as toughness. That prevents your PCB from wear and tear.

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 PCBs makes it assume a decelerated decomposition process.

Adaptability

Lastly, 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.

 

Materials Used in a Ceramic PCB

Ceramic is not a single material; it is a group of hard, brittle, corrosion-resistant, and heat-resistant materials that PCB manufacturers can use as the base material.

These fabricators usually pick these ceramics while considering the CTE and thermal conductivity properties, and the most typical ones include the following.

Aluminum Oxide or Alumina

Unlike aluminum, alumina(Al2O3) is a crystalline powder material with high electrical resistivity (about 1 x 1014Ω.cm ).

The common purity of the material ranges from 94% to 99%, with alpha-phase alumina (over 95% purity) being the strongest and stiffest.

96% alumina is the most common in this range because it is affordable and has a CTE of 4.5 to 10.9 x 10-6/K thermal conductivity of 25 W/(m.k).

Aluminum oxide or alumina in a petri dish

Aluminum oxide or alumina in a petri dish

Aluminum Nitride

This non-oxide semiconductor has a hexagonal crystal structure and a bluish-white color when 100% pure, but it can be white, gray, or pale yellow when impure.

Aluminum nitride (AlN) is the best substrate material for ceramic PCBs because its thermal conductivity can be as high as 300W/(m.k).

Its electrical resistivity is also better than alumina's because it ranges from 10 to 16 Ω.m. But it is expensive.

Beryllium Oxide

Except diamond, beryllium oxide (BeO) has one of the highest thermal conductivity values of all nonmetals (ranges from 209 to 330W/(m.k)).

Additionally, it has strong, rigid bonds between its atoms that raise its melting and boiling points to 2575°C and 3905°C, while its CTE ranges from 7.4 to 8.9 x 10-6/K. These properties make it valuable in various electronics and other industries.

Beryllium oxide packaged in a bottle

Types of Ceramic PCBs

When you consider the manufacturing process, there are several ceramic PCB types, including thin-film, DPC, DBC, and more.

Direct Plate Copper (DPC) PCB

These PCBs undergo a manufacturing process where copper etching or printing is done using thin copper then this layer is plated to the ceramic substrate. This processing requires physical vapor deposition and sputtering in a vacuum.

Direct Bonded Copper (DBC) PCB

Direct copper bonding involves bonding the copper foil to the ceramic substrate at high temperatures to create a thin board with fine solderability, reliable electrical isolation, high thermal conductivity and high bonding strength.

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.

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. By making some changes to the thick film pasting, you can complete circuit board baking and improve the product accuracy and shrinking capacity of your board.

Thick Film Ceramic PCB

You can repeat a thick layer of 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 due to 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.

Thin-Film Ceramic PCB

To create a thin-film ceramic board, deposit thin layers of conductive and insulating materials on the ceramic base. This deposition creates boards with precise electrical properties that are ideal for RF applications.

A set of thin PCBs

A set of thin PCBs

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.

Ceramic PCB Thermal Conductivity

Among nonmetals, ceramics have some of the highest thermal conductivity ratings and are more efficient than metal PCBs because they don’t need an insulation layer.

These materials also provide hermetic sealing and offer better CTE matching than traditional fiberglass substrates.

Electronic components mounted on a white PCB

Electronic components mounted on a white PCB

Ceramics are more expensive than traditional materials. However, if you can afford these costs or make the end product competitively priced in the market, the thermal conductivity benefit is worth it for high-performance PCBs.

This value varies depending on the ceramic material and the manufacturing process. Alumina’s thermal conductivity varies from 18 to 36 W/(m.k) at room temperature, while that of aluminum nitride varies from 80 to 200 W/(m.k) at room temperature with highs of 300 W/(m.k).

These values drop significantly as the material’s temperature increases (more than one-third as you approach 100°C).

Beryllium oxide and boron nitride have higher thermal conduction figures, but these figures vary among materials, which means it is better to do your own testing to obtain the actual value.

Ceramic PCB vs. Aluminum PCB

Aluminum is an electrically conductive material, so one key difference between ceramic and aluminum boards is that the latter must have an insulation layer between the metal base and the circuit. Plated through–holes must also have electrical insulation.

An aluminum PCB with SMD LEDs

The other important factor is thermal conductivity. Aluminum conducts at 237 W/(m.k), but the actual value for ceramics depends on the material and varies for each material.

For instance, it averages around 25 W/(m.k), which is significantly lower than that of aluminum.

However, the insulation layer in aluminum boards works against this benefit, giving ceramic an advantage. The value drops to 1 - 3 W/(m.k), which is way below what aluminum oxide offers.

And when you consider materials like aluminum nitride and beryllium oxide, aluminum doesn’t stand a chance. The only advantage of this metal PCB is its structural strength.

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Ceramic vs. FR4

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.

Multilayer Ceramic PCB

Multilayer Ceramic PCBs

 

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 the 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. To avoid Via failure, it would help if you made special design considerations for such surfaces.

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.

When Is It Ideal To Use Ceramic PCBs?

Ceramic has high thermal conductivity, low thermal expansion, resists corrosion, and can be made to have extremely thin layers. The thinner they are, the better the thermal conductivity and the lighter the board.

A batch of PCBs produced for automotive applications

A batch of PCBs produced for automotive applications

Even if you want to build a thick multilayer PCB, the ceramic’s thermal conductivity will be an asset to the structure because it will eliminate hotspots.

Therefore, these boards are ideal for applications where heat, weight, and size are critical. Think of automotive, communication, aerospace and other similar use cases.

The only downside is cost. Ceramic is even costlier than aluminum, so applications like LEDs are mounted on aluminum PCBs.

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.

Memory Modules

Memory Modules

One of the primary uses of ceramic boards is memory modules. These boards contain memory-incorporated circuits, which can be applied in DDR SDRAM manufacturing and other memory-based electronic parts. Computers' Random Access Memory (RAM) uses ceramic substrate circuit boards with incorporated memory modulus.

Transmission Modules

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.

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.

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.

Solar Panels

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.

Electrical Power Transmitter

ceramic PCB

Wireless power transmission and charging devices have become increasingly popular basic electronics. Due to their exclusive thermal elements and heat-transmission capacities, ceramic boards can be used to manufacture these gadgets.

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. These circuits mostly consist of ceramic board substrates.

Semiconductor Coolers

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 current semiconductor chips. However, the invention of ceramic semiconductor circuits has facilitated higher integration and ability in small circuit manufacturing. That is why we consider ceramic boards the future of the semiconductor industry.

High Power LED

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 efficiency.

Therefore, only ceramic circuits provide the thermal efficiency needed to create LED light. LEDs using ceramic circuits do not require thermal interface components, minimizing the necessary parts to create and maintain LED light.

Ceramic PCB: Pros and Cons

Pros and Cons

How to Manufacture Ceramic PCB

You can apply silver or gold conductive pastes to lay trace connections in all layers of 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.

Challenges in Ceramic PCB Manufacturing and Solutions

If using ceramic substrates for your PCBs, you are likely to encounter these manufacturing challenges.

Different Slice Size After Laser Scribing

Once a large ceramic panel is processed, it must be split into individual boards to make the PCBs.

Manufacturers usually use laser scribing to create these separations, which cuts to about 50% of the board’s depth. The other half is left for cracking either before or after assembly.

A regular FR4 PCB panel with a V-scoring cut to separate the individual pieces

A regular FR4 PCB panel with a V-scoring cut to separate the individual pieces

The melting point difference of each point when laser scribing creates differences in the crack direction and ceramic substrate’s point of view.

Therefore, the PCBs might be unequal in size after splitting with a variation of 0.1 to 0.15mm.

Wire Bonding Damage

Wire bonding requires heat, and this thermal shock can cause defects in the ceramic substrate.

If this thermal stress exceeds the material’s strength on the defect areas caused by laser marking and cutting, it can damage the base.

Fortunately, you can avoid this damage by preheating the substrate over a wide area to eliminate significant temperature variation on one point that can cause cracks.

Advancements in Ceramic PCB Fabrication

Ceramic PCB fabrication has advanced in four areas, the first being material availability.

As more companies and businesses invest in material science, multiple varieties of ceramics for PCBs have emerged each with different thermal, resistive, and mechanical properties.

Manufacturers can use these varieties to customize the PCB for the specific application.

Considering thick and thin film technologies, this deposition allows manufacturers to precisely layer the insulative and conductive layers on the ceramic to build high-performance circuits.

Thick and thin film transistors

Thick and thin film transistors

Innovations in multilayer PCB designs like alignment precision, via-holes, and layer stacking have also made it possible to build dense multilayer boards in compact packages for tiny mobile devices.

The last advancement is miniaturization, where improvements in the fabrication processes have made it possible to etch fine traces and mount tiny components on ceramic boards.

Things To Consider When Buying Ceramic Circuit Boards

Specific Ceramic Material

Each ceramic material has different physical, thermal, and electrical properties and prices. Alumina is the cheapest of these materials but offers the lowest performance, although it is still better than aluminum.

Beryllium oxide and aluminum nitride are the high-performance ceramic materials you should consider for boards with high-heat-generating components.

Conductor Material

If you want to use the thin-film circuit board type, the ones with gold-palladium conductors are better than their silver-palladium counterparts because gold is more corrosion-resistant.

Silver is cheaper than gold, but you wouldn’t want to have performance or connectivity issues that increase repair or maintenance costs.

Ceramic Board Type

Each ceramic board type is better for a specific application. For instance, direct-bonded copper ceramic boards are suitable for etching different layouts, while thin-plate boards are ideal for compact devices.

Application

Ceramics are not viable for simple electronics; the materials are too costly to waste in applications that can run on regular FR4 substrate boards.

The type of material matters, too. For instance, alumina is the cheapest of these ceramic materials and is ideal for projects like high-power LED lighting that emits a lot of heat or circuits with multiple chips.

Regular LED lighting can function on aluminum metal PCBs.

Only use aluminum nitride and beryllium oxide to make thick multilayer PCBs that have hot components and RF transmission lines that can get hot.

Conclusion

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 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.

FAQs

1.  What is a signal trace?

In electronic devices, a signal trace on a PCB is equal to a wire for conducting signals. Each trace consists of a flat, narrow part of the copper foil that remains after etching.

2. What to consider in the PCB assembly process for electronic components?

In PCB assembly, you need to consider the PCB types. The type of PCB including Single-layer PCB, Double-layer PCB, etc.

Then the materials, like the base material, dielectric materials, Fr-4 substrate, dielectric layer, etc. Besides, you need to confirm the board layout, place the electronic component, the board size, impedance control, etc.

Also, the Surface mounts technology, like BGA, or the color of solder mask. Finally, check all the Circuit Board Parts that you need for the electronic equipment.

For more details, you are welcome to contact our technical team.

 

 

 

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