Ceramics Used in Electronic Applications

Key Takeaways

• Ceramics, such as aluminum oxide, are crucial in multilayer ceramic capacitors (MLCCs) and resistors, providing insulation and dissipating energy as heat.

• Ceramics, such as aluminum oxide, are crucial in multilayer ceramic capacitors (MLCCs) and resistors, providing insulation and dissipating energy as heat.

• Ceramic substrates and packaging, including materials like aluminum oxide and beryllium oxide, offer low dielectric loss, high thermal conductivity, and chemical stability.

Ceramics used in electronics range from passive components to IC packaging solutions and more.

Ceramic materials play a foundational role in modern electronic systems, spanning everything from multilayer ceramic capacitors (MLCCs) and semiconductor packaging to RF substrates, sensors, and piezoelectric materials. Their electrical insulation capability, thermal conductivity, high temperature stability, and mechanical strength make them essential in applications where conventional polymer materials cannot meet performance or reliability requirements.

In semiconductor and electronic device manufacturing, ceramics are widely used in integrated circuits, power modules, chip packaging, and high-frequency communication systems where thermal management and dimensional stability are critical. Many modern multilayer ceramic capacitor dielectrics are based on barium titanate because its crystalline structure enables significantly higher capacitance values in compact package sizes.

Applications include ceramic substrates for high power electronics, quartz crystals used in timing circuits, and piezoelectric materials whose piezoelectric properties allow them to convert mechanical stress into electrical charge for sensing and control systems.

The table below highlights several common ceramic materials and their roles in modern electronic and semiconductor applications.

Let’s explore some common ways ceramics are used in electronics.

Ceramics Used in Electronics

Multilayer ceramic capacitors achieve high capacitance density by stacking extremely thin ceramic dielectric layers within a compact package structure. Most modern MLCCs use barium titanate-based dielectric formulations because their crystalline structure enables very high dielectric constants compared to traditional linear dielectric materials. This allows significantly higher capacitance values in smaller package sizes, though the tradeoff includes voltage-dependent capacitance behavior, dielectric aging, and increased sensitivity to temperature variation.

The manufacturing process used to produce multilayer ceramic devices requires precise control of ceramic particle size, layer thickness, sintering temperature, and electrode formation. Small variations in the process can directly affect capacitance stability, dielectric loss, and long-term reliability.

Ceramics Used in Passive Components

Ceramics are used in multiple ways for passive SMD components:

• Aluminum oxide, known for its low electrical conductivity, is essential in multilayer ceramic capacitors (MLCCs) to insulate different electrode layers and in resistors for energy dissipation as heat.  These capacitors work by using a ceramic dielectric to store electrical charges between metal layers.
• Ceramics are used in thermistors, inductors (where magnetically permeable ceramics generate magnetic fields), and circuit protection devices (using semiconducting ceramics to shield against voltage spikes).

Ceramics Used in Electronics - Piezo-Electrics

Ferroelectric ceramics, often synonymous with piezoelectric ceramics due to their piezoelectric properties, are primarily employed in the creation of piezoelectric devices, showcasing the significant application of these materials. Lead zirconate titanate (PZT) and barium titanate (BaTiO3) are favored in production for their high piezoelectric coefficients, piezoelectric properties, and strong mechanical performance.

Insulators

Ceramic products are widely used in consumer electronics:

• As insulators in various applications, including spark plugs, hermetic packaging, ceramic arc tubes, and protective elements like beads and tubing for bare wires and power lines. 
• As coil bobbins, electronic tube holders, band switches, and support brackets.

These electronic ceramics must meet several critical criteria: 

1. A low dielectric constant 
2. Low dielectric loss
3. High insulation resistivity
4. High breakdown strength
5. Optimal dielectric properties across different temperatures and frequencies. 
6. Superior mechanical strength and chemical stability to perform effectively in their roles as insulators.

Although ceramic materials provide excellent electrical and thermal performance, they are also more brittle than conventional PCB materials and can become susceptible to cracking under excessive mechanical stress or thermal shock conditions.

Ceramics Used in ICs and Semiconductors

IC Substrates

Ceramic substrates are thin and flat-fired materials that can be used in ICs. Three ceramic substrate materials are common:

• Aluminum oxide (Al2O3)
• Aluminum nitride (AlN)
• Beryllium oxide (BeO)

Ceramic substrates have the advantage of a low dielectric constant and dielectric loss, high thermal conductivity, and good chemical stability.

Compared to conventional FR-4 materials with thermal conductivity typically below 0.5 W/mK, ceramic substrates such as alumina and aluminum nitride can provide thermal conductivity ranging from approximately 20 W/mK to more than 170 W/mK depending on the material formulation. This makes them valuable in high power semiconductor and RF applications where thermal dissipation directly affects device reliability and performance.

IC Packaging

Integrated circuits, consisting of interconnected components on silicon chips, can use packages for electrical insulation and hermetic support. 

As semiconductor packages continue increasing in power density and interconnect complexity, ceramic materials are playing an increasingly important role in advanced packaging, RF modules, power electronics, and thermal management architectures.

Semiconductor Manufacturing

Fused silica is the the primary ceramic in the semiconductor sector. It is used in:

1. Crucibles for silicon ingots
2. Reactors for epitaxial silicon deposition
3. Wafer carriers
4. Single-wafer processing tools
5. Wet etch tanks

Alumina, known for its electrical and thermal insulation properties, is also heavily utilized in semiconductor wafer processing equipment. 

Electroceramics

Electroceramics extend beyond the commonly known types to include ferrite-based permanent magnets and circuit devices designed for high-reliability applications, such as low- and high-temperature co-fired ceramics and ceramic electronic substrates. Additionally, electronically conductive ceramics like indium tin oxide (ITO), lanthanum-doped strontium titanate (SLT), and yttrium-doped strontium titanate (SYT) are used in thin-film transistors.

Ceramic PCBs

Ceramics, known for their poor electrical conductivity, are excellent insulators that prevent the free flow of electrical current. Ceramic Printed Circuit Boards (PCBs) utilize ceramics as their substrate material. Applications include:

• High-frequency electronics like RF devices, microwave circuits, and radar systems, where ceramic PCBs' low signal loss and high dielectric constants are advantageous. 
• In LED lighting, ceramic PCBs underpin LED modules, enhancing heat dissipation to prolong LED lifespan and performance. 
• In power electronics, ceramic PCBs manage high temperatures and ensure thermal stability, crucial for efficient heat dissipation.

Glass Ceramics Used in Electronics

Glass also falls under the category of ceramics. 

• It is used for manufacturing display panels for televisions, computers, and mobile devices.
• Glass powder is incorporated into thick film paste for the metallization of electronic components.
• Glass seals are employed in applications to safeguard electronic devices from environmental factors. 
• The production of flexible glass is advancing, aimed at the development of flexible devices like organic light-emitting diodes (OLEDs).

As we’ve discovered, there are many different ceramics used in electronics. If you are using ceramics in your packaging designs, explore packaging solutions with Allegro X Advanced Package Designer. Unlock the full potential of your electronic packaging today!

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