What is the difference between ceramic PCB and FR4?

In the current PCB industry, both ceramic PCB substrates and FR4 PCB substrates are commonly used.FR4 substrates are widely applied due to their low cost, while ceramic PCB substrates are more high-end with relatively higher costs. Many customers are still unfamiliar with ceramic PCBs, so in this article, we will compare ceramic PCBs and FR4 PCBs from several aspects including materials, performance, manufacturing processes, and applications.

What is a Ceramic PCB?

A ceramic PCB (Printed Circuit Board) is a type of circuit board manufactured using ceramic materials as the base. Unlike conventional substrates made from glass fiber-reinforced epoxy (FR4), ceramic PCBs offer superior thermal stability, mechanical strength, dielectric properties, and longer service life.
They are primarily used in high-temperature, high-frequency, and high-power applications—such as LED lighting, power amplifiers, semiconductor lasers, RF transceivers, sensors, and microwave devices.

What is an FR4 PCB?

FR4 is a composite material made primarily of woven fiberglass cloth and epoxy resin, compressed into multiple layers. It is one of the most widely used substrate materials for printed circuit boards (PCBs).
FR4 is favored for its excellent insulation, mechanical strength, low cost, and ease of processing. Its key properties include a low dielectric constant, high temperature resistance, good flame retardancy, strong mechanical performance, and outstanding chemical stability. These characteristics make FR4 the most commonly used PCB base material in a wide range of electronic products.

What Is the Difference Between Ceramic PCB and FR4?

1. Different Base Materials Lead to Different Properties

Ceramic PCBs use ceramic substrates such as alumina (Al₂O₃), aluminum nitride (AlN), or silicon nitride (Si₃N₄), which offer excellent thermal conductivity and insulation. In contrast, FR4 boards are made of fiberglass-reinforced epoxy laminate, which has relatively poor thermal conductivity and lacks inherent insulation performance.

2. Significant Differences in Thermal Conductivity and Insulation

Ceramic PCBs feature thermal conductivity ranging from 25 W/m·K to 230 W/m·K, depending on the material:

Alumina: 25–30 W/m·K
Aluminum nitride: 170 W/m·K or higher
Silicon nitride: 80–95 W/m·K

By contrast, FR4 PCBs typically offer thermal conductivity of only a few W/m·K. Moreover, FR4 boards require an additional insulation layer to help dissipate heat, whereas ceramic PCBs are inherently excellent insulators, with insulation resistance reaching ≥10¹⁴ Ω·cm.

3. Differences in Cost and Production Lead Time

Ceramic PCBs are significantly more expensive and have longer lead times compared to FR4 boards. While an FR4 prototype may cost only a few hundred RMB and be completed within 24 hours, a ceramic PCB prototype could cost several thousand RMB and typically takes 10–15 days for production.

ceramic PCB

4. Differences in Performance Advantages

Advantages of Ceramic PCBs:

High-Frequency, High-Speed Performance:
Very low dielectric constant (<10) and dielectric loss (<0.001), ensuring fast signal transmission and low latency—ideal for 5G communications and radar systems.
Superior Heat Dissipation:
High thermal conductivity helps quickly dissipate heat, reducing thermal stress on power devices and extending lifespan—for example, in LED lighting and automotive ECUs.
Environmental Resilience:
Operates reliably under harsh conditions: wide temperature range (-55°C to 850°C), radiation resistance, and vibration resistance—suitable for aerospace and military applications.
High Integration Capability:
Compatible with LTCC/HTCC technologies for 3D integration, reducing size in semiconductor modules and intelligent power components.

Advantages of FR4 PCBs:

Cost-Effective:
Material costs are about one-third that of ceramic PCBs, making them ideal for mass production.
Mature Manufacturing Processes:
Well-established SMT support and short turnaround times—double-sided boards can be produced in just a few days.
Stable Electrical Performance:
Dielectric constant of 4.0–4.7 and dielectric loss of 0.01–0.03, suitable for low- to mid-frequency applications such as consumer electronics and telecom devices.

5. Different Manufacturing Processes

Ceramic PCB manufacturing involves several complex processes such as DPC, DBC, thin-film, thick-film, HTCC, and LTCC technologies—each with unique requirements. In contrast, FR4 PCB production is simpler and more standardized. For multilayer ceramic PCBs, the process becomes even more complex and technically demanding compared to multilayer FR4 boards, resulting in higher cost and difficulty.

6. Different Market Applications

Thanks to their high thermal conductivity, excellent insulation, high-frequency capability, and resistance to extreme conditions, ceramic PCBs are widely used in:

High-power applications
High-current circuits
High-frequency systems
Environments requiring high thermal stability and insulation

On the other hand, FR4 PCBs are more broadly adopted across various industries due to their lower cost, shorter production cycle, and high demand—making them the go-to choice for consumer electronics, telecommunications, and general-purpose electronics.

Ceramic PCB vs FR4 PCB

Feature	Ceramic PCB	FR4 PCB
Material	Ceramic (AlN, Al₂O₃, BeO)	Fiberglass + epoxy (FR4)
Thermal Conductivity	High	Low
Heat Resistance	Very High	Moderate
Mechanical Strength	Brittle	Tough/Flexible
Cost	High	Low
Applications	High-power, high-temp	General electronics

Comparison and Selection Guide for Ceramic PCBs and FR4 PCBs

Selection Criteria	Ceramic PCBs	FR4 PCBs
Performance Priorities	High-frequency and high-speed performance, thermal management, high-temperature resistance, radiation hardness	Cost-effectiveness, manufacturing maturity, electrical stability for mid/low-frequency applications
Cost Sensitivity	High (material and processing costs exceed FR4 by 3x or more)	Low (ideal for mass production)
Typical Application Scenarios	Aerospace, 5G communications, automotive electronics (high-power modules)	Consumer electronics, communication devices, industrial controls
Reliability Requirements	High (requires CTE-matched designs)	Moderate (conventional UL94 V-0 flame-retardant standards)

Future Trends and Decision-Making Guidance

Technological Evolution

Ceramic PCBs: With the growing maturity of LTCC/HTCC processes, ceramic PCBs are expected to see wider adoption in 5G base stations, electric vehicle battery management systems (BMS), and other high-performance applications.
FR4 PCBs: By incorporating high-frequency materials (e.g., PTFE composites) and eco-friendly technologies (e.g., lead-free processes), FR4 PCBs continue evolving to meet new market demands.

Selection Decision Tree

High-frequency, high-speed requirements →
Choose ceramic PCB or high-frequency FR4 materials (e.g., Rogers RO4003).
High-power thermal management needs →
Choose ceramic PCB or aluminum-based PCB.
Cost-sensitive projects →
Choose FR4, ideally with 96% alumina hybrid designs for better thermal performance at lower cost.
Extreme environments (high temperature/radiation) →
Choose ceramic PCB, particularly aluminum nitride (AlN) substrates.

Conclusion

The core difference between PCB ceramic substrate and FR4 substrate lies in material properties and application direction. Ceramic substrate is based on ceramic materials such as alumina and aluminum nitride, with high thermal conductivity, excellent electrical insulation and outstanding high temperature resistance, suitable for power electronics, LED lighting, radio frequency communication and other fields with extremely high requirements for heat dissipation and stability; while FR4 substrate is composed of glass fiber cloth and epoxy resin, with good mechanical strength and processability, low cost, and is the first choice for most common electronic products such as consumer electronics, computers and industrial control.