Multilayer Ceramic PCB

Before you buy multilayer ceramic PCBs, there are critical aspects you must know such as material quality, features, performance criteria, layer thickness, fabrication process to applications, amongst others.

With this knowledge, you can choose a suitable ceramic PCB for your application.

Keep reading to be an expert in these types of PCBs.

• What is a Multilayer Ceramic PCB?
• What are the Qualities of the Multilayer Ceramic PCB?
• What is the Thickness for a Multilayer Ceramic PCB?
• What are the Uses of the Multilayer Ceramic PCB?
• Are the Ground and Power Planes important in a Multilayer Ceramic PCB?
• Can the High Temperature Co-fired Ceramic PCB be made in Multiple Layers?
• How are Multilayer Ceramic PCBs Packaged?
• What Substrates are Employed in Multilayer Ceramic PCBs?
• How is the Low-temperature Co-fired Ceramic PCB Furnished as a Multilayer?
• Do Hot Spots occur in Multilayer Ceramic PCBs?
• Is there Via Failure in Multilayer Ceramic PCBs?
• How do Multilayer Ceramic PCBs Dissipate Heat?
• Are Multilayer Ceramic PCBs used in Extreme Environments?
• What Technologies are used for Packing Components on a Multilayer Ceramic PCB?
• Can you Directly Integrate Components into the Inner Layers of a Multilayer Ceramic PCB?
• What are the Features of Drilled Holes on Multilayer Ceramic PCBs?
• What Test is Carried out on the Multilayer Ceramic PCB?
• What is Ceramic Electroplated Copper in a Multilayer Ceramic PCB?
• Can the Multilayer Ceramic PCB be used for a Power LED?
• Do Electronic Control Units use Multilayer Ceramic PCBs?

What is a Multilayer Ceramic PCB?

This is a ceramic PCB type that is furnished in more than two layers.

The increased layer count is useful in enhancing the signal transfer planes and as a result the board circuitry.

Additionally, it allows for a denser population.

Single layer ceramic PCB

The layer count is always even and as such you find four layers, six layers, eight layers, and so forth.

Multilayer ceramic PCBs can be made up to thirty layers.

The layers are held together by prepreg adhesives in between the substrate and conductive layers.

Multi-layer ceramic PCB

What are the Qualities of the Multilayer Ceramic PCB?

The multilayer ceramic PCB has several exceptional attributes that favor its use over other ceramic board types.

These properties include:

• Multilayer ceramic PCBs offer exemplary heat conduction while possessing a diminished coefficient of thermal expansion.

As a result, they offer reliable performance for high power circuitry.

• The multilayer ceramic PCB is exceptionally nifty finding given its simple design and elevated performance level.

Consequently, it can be substituted for long-established ceramic circuit boards.

• You find many uses for the multilayer ceramic PCB without performance difficulties.

This type of ceramic PCB configuration can be used in circuitry with large power needs.

It can also be employed for modules that are fashioned as chips that are mounted on the board surface.

• Furthermore, you find multilayer ceramic PCBs can function normally at increased temperature conditions over 300 °C.

Therefore, the board can tolerate external temperature fluctuations without hampering the circuit board’s performance.

• By fabricating ceramic circuit boards in multilayers, you find they can be made smaller and still functionally reliable.

With a small circuit board system, appliances can be made smaller allowing for high mobility and portability.

• The frequency performance achieved with the multilayer ceramic PCB is admirable. In such a set-up, there is reduced signal interference during transmission due to dedicated signal planes.
• Fabricating a multilayer ceramic PCB is generally cost-effective than fabricating single layer boards of the same layer count.

With a multilayer PCB design, you can have a denser bundle with a layer stack up.

• You also find that you can enclose multilayer ceramic PCBs in airtight casings preventing infiltration of water and moisture content. This prevents an infringement on the circuit board’s dielectric properties.

What is the Thickness for a Multilayer Ceramic PCB?

Thickness of multilayer PCB

Multilayer ceramic PCBs have different thickness requirements depending on the circuit design.

Additionally, the thickness of a multilayer circuit board can be customized to a client’s requirement for prototyping purposes.

For instance, you find the minimum thickness of the ceramic substrate used in multilayer ceramic circuit boards at 0.07 mm.

However, larger or lower thicknesses can be provided for the ceramic substrates as customization.

This is besides the conductor thickness which is determined by the weight of the conductor and the PCB’s intended use.

What are the Uses of the Multilayer Ceramic PCB?

You find several uses of the multilayer PCB considering its increased circuitry and board space for the populates.

Some common multilayer ceramic PCB applications include:

• The multilayer ceramic PCB is used in memory modules.

These modules can be produced in a four-layer set-up with an agglomeration of connected integrated circuit chips.

The multilayer ceramic PCBs used in these devices offer for increased density and impressive performance.

• You would expect a multilayer ceramic PCB in aerospace developments such as satellite telecommunications and space-mobiles.

This is in addition to military weaponry such as missiles.

In these applications, the multilayer ceramic PCB is favored for its able performance in difficult environments.

You find that a multilayer PCB has impressive endurance to applied shocks, high temperatures, and vibrations.

• Multilayer ceramic PCBs are employed in miniaturized appliances such as electronic gadgets.

They find use because a multilayer configuration can allow for the attachment of a higher count of electronic components.

Gadget performance is duly improved by this implementation.

• Another modular application of the multilayer ceramic PCB is in the transceiver module. In this regard, you find the multilayer ceramic PCB used especially for radio detection and ranging communication.

The module is used for the transmission and reception of RF signals.

For this instance, the ceramic base is made of aluminium nitride due to its higher heat conduction ability than alumina.

Furthermore, it has a lower CTE offering an ideal communication transfer path without interference.

• Multilayer ceramic PCBs are utilized in the development of analog and/or digital circuitry.

Consequently, this has led to a decline in the manifestation of capacitance related to parasitic traits greatly.

Besides, the overall printed circuit board size and weight have been considerably reduced.

Additionally, interference signals such as crosstalk on the conductive path have been eliminated to a greater extent.

Are the Ground and Power Planes important in a Multilayer Ceramic PCB?

A ground plane is usually furnished as an independent layer with a circuit connected to a ground terminal.

You find the ground plane offers a path back for current flow through connected board components.

A power plane is presented as a stand-alone conductive layer through which current from a power source flows for board operation.

As in any multilayer circuit board configuration, the power and ground plane are pivotal in reducing the emission of electromagnetic interference.

These planes are useful in improving the traces’ signal on a multilayer ceramic circuit board.

Furthermore, you find it offers easier component connection compared to routing separate tracks alongside the conductive traces.

You find different arrangements of the power and ground planes amongst the conductive tier system of a multilayer ceramic PCB.

You find more signal clarity when the tiers dedicated to the VCC and ground are stack close to the signal planes.

The VCC and ground can be located as the outermost layers or as the innermost layers.

Multilayer ceramic PCB

Can the High Temperature Co-fired Ceramic PCB be made in Multiple Layers?

Yes, the high-temperature co-fired ceramic PCB can be produced in multiple layers.

Co-firing at high-temperature value is a time-honored process that is carried out by sintering mixed compounds.

You find this ceramic board type is only suited for small volumes or slave boards.

Making high-temperature co-fired multilayer ceramic PCBs is a difficult process.

This board type easily succumbs to warping and has low resistance to shrinking.

Additionally, the recalcitrant metals offer high resistance to tracing efforts.

For the high-temperature, co-fired ceramics, material combinations of alumina, lubricants, active solutions, and adhesives are performed.

The result is the formation of a fine ceramic compound that is rolled and blanketed before the application of a conductive track pattern.

Also, the conductive track is laid on metals with a recalcitrant property such as tungsten.

The formation is then undertaken through a sintering procedure in an oven at high temperatures of about 1650 °C.

The process is maintained steadily for about two days.

You find the baking process for the high-temperature co-fired ceramics is carried out in the presence of hydrogen or nitrogen gas.

These gases act as reducing agents preventing the oxidation of the refractory metal such as tungsten.

How are Multilayer Ceramic PCBs Packaged?

Packaging of multilayer ceramic PCBs is meant to achieve two major purposes.

You find the thermal performance of the multilayer ceramic PCB is influential in the packaging decision.

Also important is the reliability standard expected of the circuit board concerning hermeticity.

In achieving exemplary thermal performance, the multilayer ceramic PCB is attached to a heat sink fabricated of copper.

On the other hand, the reliability standard is established by testing for hermetic capability at extreme temperature ranges.

What Substrates are Employed in Multilayer Ceramic PCBs?

Substrates provide electrical isolation for the layers used in electrical charge transfer.

Isolation is useful in preventing signal interference between layers especially so for a multilayer configuration.

Ceramic substrates are formed from fine ceramic compounds and are valued for their excellent thermal properties compared to traditional substrates.

The common fine ceramic substrates used are alumina and aluminium nitride.

Other ceramic compounds utilized as substrates include beryllium oxide that is hampered by its toxicity.

Moreover, alumina can be used in different strains enabled through processes such as injection molding.

An example is an aluminium oxide compound reinforced with zirconia.

Ceramic substrate

· Alumina (Aluminium Oxide)

You find most multilayer ceramic PCBs employing alumina as the preferred ceramic compound for its substrate.

The use of alumina is time-honored with demonstrated performance qualities.

Additionally, alumina can be obtained at a lower cost amongst other options.

Some of the alumina’s qualities that promote its usage include its impressive mechanical strength and conduction of heat.

Also to be mentioned are its low dielectric properties and the ability to support high-value linkages for density.

· Aluminium Nitride

Aluminium nitride will offer you better thermal properties than alumina such as its high heat conductivity and low CTE.

Consequently, you will find its use in applications with large heat production where it offers exemplary performance at over 150 W/mK.

The low thermal expansion coefficient conforms easily to that of the semiconductor attachments.

To produce aluminium nitride a hot pressing technique is employed where close tolerances are applied.

You also find aluminium nitride to possess a good strength to weight ratio.

This allows its use especially in higher layer counts of the multilayer ceramic PCB.

In this case, through-vias are employed boring through the structure with surface terminations of high precision.

How is the Low-temperature Co-fired Ceramic PCB Furnished as a Multilayer?

The low-temperature co-fired ceramic PCB is made through the combination of glass-based compounds and derivatives with bonding agents.

The resulting formation is rolled out and a conductive layer deposited onto it using a gold-based goop.

Also, the formation is subsequently cut to size and baked in an oven at low sintering temperatures not exceeding 900 °C.

Besides, the resulting board has a conductive track patterned to it over the gold layer providing impressive conductive ability.

The layers are patterned according to the desired layer count before being stacked together and laminated.

Also, the multilayer set-up is precise with good resistance capability to shrinking.

Additionally, the board can be tweaked for better heat conduction performance and mechanical strength.

Do Hot Spots occur in Multilayer Ceramic PCBs?

Unlike multilayer PCBs utilizing FR – 4 substrates, hot spots are unlikely to be observed with the multilayer ceramic PCB.

Hot spots are pockets of heated air that form on the conductive surface layers as heat coalesces during conduction.

You find the low thermal conductivity of FR – 4 substrate causes hot spots due to the slow thermal dissipation process.

FR – 4 based boards involve the use of active structures to help in the conduction process.

This results in uneven heat dissipation resulting in hot spots.

On the other hand, ceramic-based substrates have excellent heat conductivity.

You find that the conduction of thermal energy is constant across the board.

This way, there is no chance for heat build-ups to create hotspots.

Is there Via Failure in Multilayer Ceramic PCBs?

Vias are plated through-holes in multilayer PCBs that provide interlayer connectivity.

Plating of the holes is done through metallization by using a conductive material such as copper.

This connectivity is to allow heat conduction and electrical signal transfer between the conductive layers.

When made to facilitate heat conduction, vias are referred to as thermal vias.

Via failure, especially in FR – 4 based PCBs occurs due to the effects of thermal cycling.

In this case, the subjection of the vias to different temperature values makes them predisposed to structural damage through fracturing.

The fracturing of vias is exacerbated by the incongruity of the FR – 4’s CTE and the via plating.

You find that the different responses to temperature changes exert a strain on the via walls and linkages.

However, in multilayer ceramic PCBs, via-failure is hardly experienced due to the very low CTE of the fine ceramic substrate.

Thus, the response to thermal changes of the via construction and the ceramic substrate is similar preventing the occurrence of thermal strain.

How do Multilayer Ceramic PCBs Dissipate Heat?

Heat is dissipated in multilayer ceramic PCBs through connected thermal vias.

 Types of vias

These vias transfer heat across the multiple layers to the construction base where it is released to the external environment.

You find the low coefficient of thermal expansion of fine ceramics plays a pivotal role in the heat dissipation.

The low CTE allows for a corresponding response to thermal changes by the multilayer circuit board and the vias.

Consequently, there is no buildup of thermal-induced strain within the vias.

As such, heat is transferred from the layers across the conductive infrastructure to the common release point.

Additionally, you will find the excellent heat conduction quality of fine ceramics useful in the heat transfer process.

It allows heat to travel within the multilayer ceramic circuit board structure evenly and unimpeded.

As such, the conductive thermal path manifested by the via system experiences reduced external pressure that could otherwise cause fracturing.

Are Multilayer Ceramic PCBs used in Extreme Environments?

Yes, they are.

You find multilayer ceramic PCBs employed in harsh environmental conditions due to their structural competency.

Multilayer ceramic PCBs are mechanically sturdy with the ability to bear increased loads.

These ceramic PCBs can tolerate applied shocks and tremors.

Furthermore, you will find that multilayer ceramic PCBs have a low-value Young’s modulus that ensures it maintains its rigidity.

This way, the multilayer ceramic PCB cannot easily distort under force exertion.

Contrarily, you find multilayer boards based on FR – 4 substrates have a higher Young’s modulus which makes them susceptible to deformation.

What Technologies are used for Packing Components on a Multilayer Ceramic PCB?

There are two common packing technologies that you will find for the multilayer ceramic PCB; through-hole technology and surface mounted technology.

In through-hole technology, components boast metalized extensions used to offer board connection.

The components are attached on one side while the leads extend to the reverse side where they are fastened.

For surface mounted technology, the components are attached on the same board side that they are mounted on.

These components have their bottom surfaces patterned to adhere to the board surface eliminating the need for holes.

They are then affixed to the board through the use of solder paste and heat treatment.

Can you Directly Integrate Components into the Inner Layers of a Multilayer Ceramic PCB?

You find that directly incorporating components with passive capacities to a multilayer ceramic PCB’s internal layers is possible.

In making a multilayer ceramic circuit board, the conductive circuit path for every layer is furnished on gold or silver-based fixatives.

This is carried out thorough the screen printing of every individual layer in the board configuration.

To create a system of vias, unbaked planes are stamped through by applying concentrated mechanical forces.

Smaller vias are devised by incorporating laser-assisted drilling.

Subsequently, the individually prepared layers are arranged in a stack, secured, and ready for oven baking.

The baking process of the multilayer configuration is carried out at a low baking temperature.

The conditions in this baking process correspond to those at which the silver and gold-based fixatives are sintered.

As such, the materials combination occurs unwaveringly without any difficulties.

The ability to facilitate the low-temperature sintering procedure is what you find allows direct component integration.

This is unlike in FR – 4 based multilayer PCBs that succumb to the frailties of their different thermal properties.

Components are layered on the internal tiers allowing for the achievement of increased density.

Multilayer printed circuit board

What are the Features of Drilled Holes on Multilayer Ceramic PCBs?

The drilling process of holes in multilayer ceramic PCBs seeks to create a vias network and provide attachment for leaded components.

When boring through-holes on a multilayer ceramic PCB, consideration has to be taken for the hole dimensions.

These include the minimum size, hole clearance, and tolerance, and the maximum allowance.

Additionally, drilled through-holes can be plated or not plated depending on their role.

Plated through-holes are meant for conductivity purposes.

Electrical conductivity helps in connecting the different conductive tiers and establishing connections for leaded components.

Thermal conductivity is for the dissipation of generated heat between the board strata.

What Test is Carried out on the Multilayer Ceramic PCB?

A test is conducted on a multilayer ceramic PCB to unearth deficiencies and to determine its reliability in performance.

Tests are used to highlight the presence of errors and faults in multilayer ceramic circuit boards.

Errors could be related to board members and placements while faults could be a result of deficiencies in laying of circuitry.

The multilayer ceramic circuit board is electrically tested by the use of a flying probe.

This involves the use of a fixture that hovers above the board highlighting points and testing them for electrical signals.

With this test, you can successfully identify points that are electrically isolated when they should not.

Additionally, an electrical test can aid in determining board locations that are electrically connected when they should be isolated.

You would find the flying probe test executed when the board is yet to be assembled with components and after.

The scope of faults realized this where is narrower allowing for easier dealing.

What is Ceramic Electroplated Copper in a Multilayer Ceramic PCB?

Ceramic electroplated copper refers to a multilayer ceramic PCB with copper circuitry applied over the ceramic substrate below the conductive layer.

In this formation, the copper is of pure form offering impressive electrical capabilities.

It also forms a very strong bond with the ceramic substrate.

You find the bond formed is undisruptive to the thermal dissipation process facilitating the heat extraction process.

This way, the multilayer ceramic circuit board can perform at a high-efficiency level and offer increase performance stability.

Can the Multilayer Ceramic PCB be used for a Power LED?

Ceramic PCB for power LED

You can implement a power light-emitting diode on the base of a multilayer ceramic circuit board.

You would find such a light source with the ability to sustain continuous luminosity without functional difficulties.

Some of the features linked to the multilayer ceramic PCB that contribute to the impressive performance of such an LED include:

The module on which the semiconductor LED is fashioned possesses matching CTE with the ceramic substrate.

This ensures they are unaffected by changes in temperature offsetting the encumbrance to useful light and thus allowing stability of performance.

You find there is faster conduction of generated heat away from the light-emitting diode.

This is because it is precisely constructed on the fine ceramic substrate.

Moreover, the resistance to thermal conduction is very low with a silver overlay made through low-temperature oven baking.

The multilayer ceramic PCB provides a coherent facade for light reflection with a wide dispersion angle.

Consequently, the light generated by such an LED is uniform and mellow with a warm intensity.

Such a light possesses little danger to a naked eye finding uses as sport’s floodlight.

With a multilayer ceramic PCB, the light emitted by the power LED has increased incandescent efficiency.

Besides, light distortion is reduced through the elimination of heat buildup by effective conduction resulting in very low light degeneration.

Do Electronic Control Units use Multilayer Ceramic PCBs?

An electronic control unit (ECU) refers to an embedded vehicular system that controls and manages various electrical functions.

Such functions include the control modules for the engine, braking system, transmission system, and the fuel system.

Multilayer ceramic PCBs are integrated into electronic control units to aid in the support of the vehicle’s electrical system.

You find using multilayer ceramic PCBs in ECUs enables the use of elaborate circuitry while providing general dependability.

Additionally, the temperature performances of the ECUs inpunitive conditions are enviable while thermal conduction is highly reliable.

This way, overheating of components that could lead to systems’ failure is avoided.

At Venture Electronics, we can optimize the performance of your electronic products with our high quality multilayer ceramic PCBs.

For inquiries or questions, contact Venture Electronics now.