thermal conductivity

High Thermal Conductivity PCB: Materials & Design

Friday, May 15th, 2026

What Is a High Thermal Conductivity PCB?

High thermal conductivity PCBs are special circuit boards that move heat away from electronic parts quickly. Regular FR-4 boards only conduct 0.3-0.5 W/m·K of heat, but these boards use metal or ceramic cores to do 2-100 times better. They work as both a circuit board and a heat spreader, so you often don’t need big separate heatsinks.

Aluminum PCBs are the most popular type, making up over 85% of the market. They are cheap and work well for most power products. Other types include copper core, IMS, and ceramic PCBs for more demanding uses.

Why Is High Thermal Conductivity Important in PCB Design?

Good heat conduction makes electronics last longer and work better. A 10°C drop in component temperature can double the life of semiconductors. Bad heat dissipation makes LEDs lose 70% of their brightness in 3 years and causes power parts to fail suddenly.

In cars, thermal stability keeps safety systems working from -40°C to 125°C. Without high thermal conductivity PCBs, modern small, high-power devices like EV chargers and 5G phones would overheat and break.

What Materials Are Used in High Thermal Conductivity PCBs?

High thermal conductivity PCBs use three main layers: a copper circuit layer, a thermally conductive dielectric layer, and a core base. The dielectric layer is the most important because it causes 70-90% of the total heat resistance

High thermal conductivity PCBs layer consture

Core Material Performance Comparison

Material Type	Thermal Conductivity (W/m·K)	Max Temperature (°C)	Cost Index	Best For
Aluminum 6061	150-205	130	1.0	General power products
Pure Copper	385-400	150	3.5	High-current modules
Alumina Ceramic	18-36	1000+	2.5	Sensors and industrial parts
Aluminum Nitride	150-230	1000+	8.0	Medical and aerospace

Aluminum PCB, Copper Core PCB, IMS PCB, and Ceramic PCB: What Is the Difference?

Each type has its own strengths for different jobs. Aluminum PCBs are the cheapest and most common. Copper core PCBs conduct heat better for high-power uses. IMS PCBs have better insulation, and ceramic PCBs work in extreme temperatures.

PCB Type Comparison

PCB Type	Overall Heat Conductivity (W/m·K)	Insulation Voltage	Cost	Best Use
Aluminum PCB	1-5	1-3 kV	Low	LED lights, small power supplies
Copper Core PCB	3-10	1-3 kV	Medium	Motor controls, EV chargers
IMS PCB	1-9	Up to 5 kV	Medium	Power converters, car electronics
Ceramic PCB	18-230	>15 kV/mm	High	RF devices, medical lasers

How to Choose the Right Thermal Conductivity Rating?

The right rating depends on how much power your device uses. Too low and it overheats; too high and you waste money. A simple rule: add 0.5 W/m·K for every extra 10W of power.

For small LED bulbs under 50W, 1.0-1.5 W/m·K works fine. For street lights (50-150W), use 2.0-3.0 W/m·K. For industrial converters over 300W, you need 5.0+ W/m·K or a copper core PCB.

Thermal Conductivity vs Thermal Resistance: What Should Designers Know?

Thermal conductivity is how well a material moves heat. Thermal resistance is how hard it is for heat to pass through a whole structure. Many people mix these up, which leads to bad designs.

The formula is simple: Thermal Resistance = Thickness ÷ (Conductivity × Area). This means a thin, high-conductivity layer with a big area works best. For example, a 100μm thick 3 W/m·K dielectric is the same as a 200μm thick 6 W/m·K one.

How Does Copper Thickness Affect Thermal Performance?

Thicker copper carries more current and spreads heat better. It reduces resistive heating and moves heat away from hot parts faster. Increasing copper from 1 oz to 2 oz can lower component temperature by 5-10°C.

Copper Thickness Guide

Copper Weight	Thickness (μm)	Current per 1mm Width	Typical Use
1 oz	35	3-5 A	General circuits
2 oz	70	6-10 A	Power supplies, LED drivers
3 oz	105	10-15 A	High-current boards
4 oz+	140+	15-25 A+	Heavy power modules

How to Improve Heat Dissipation in PCB Layout?

Layout choices often matter more than material selection. Even the best material won’t work if heat can’t flow to the cooling system. Follow these simple rules for better results.

First, put high-power parts near the board edges or mounting holes. Use big copper pads under hot components and add copper pours around them. Use thermal vias (0.3mm diameter, 1mm apart) under exposed pads. Also, keep heat-sensitive parts at least 10mm away from hot areas.

What Applications Use High Thermal Conductivity PCBs?

High thermal conductivity PCBs are used everywhere heat is a problem. The biggest use is LED lighting, where they make bulbs last 3-5 times longer. They are also common in car electronics, power supplies, and 5G communication devices.

Other uses include motor controls, medical equipment, and aerospace parts. Any device that is small but uses a lot of power will benefit from a high thermal conductivity PCB.

How to Choose a Reliable High Thermal Conductivity PCB Manufacturer?

A good manufacturer has experience with all types of high thermal conductivity PCBs and can help with design. Look for one that uses high-quality materials and has strict quality control.

Key things to check: experience with aluminum, copper, and ceramic PCBs; ability to do thermal analysis; stable material supply; and compliance with IPC, RoHS, and REACH standards. Also, make sure they can support both prototypes and mass production.

Why Choose EBest Circuit for High Thermal Conductivity PCB Projects?

EBest Circuit offers complete high thermal conductivity PCB services, from design review to mass production. We have over 10 years of experience with all types of thermal PCBs and work with top material suppliers.

Our team can help you optimize your stackup, select the right materials, and fix thermal issues before production. We support fast prototypes and reliable mass production, so you can get your products to market quickly.

FAQs About High Thermal Conductivity PCB

Q1: Can high thermal conductivity PCBs be multilayer?

A1: Yes, but they are more expensive than single-layer ones. Most designs use 1-2 layers, with 4+ layers only for special high-density needs.

Q2: How much more do they cost than FR-4?

A2: They usually cost 2-3 times more than FR-4. But they often eliminate the need for separate heatsinks, saving total system cost.

Q3: What is the maximum voltage they can handle?

A3: Standard aluminum PCBs handle 1-3kV. Special high-voltage designs can go up to 5kV, and ceramic PCBs offer even higher insulation.

Q4: Can aluminum PCBs be bent?

A4: Yes, 5052 aluminum alloy bends well. This is useful for curved LED lights and other custom shapes.

Q5: How do I test the actual thermal conductivity?

A5: Ask your manufacturer for laser flash analysis (LFA) test data. Datasheet values are often higher than real-world performance.

What is the thermal conductivity value for copper?

The thermal conductivity of copper is about 401W/m·K. ‌

The thermal conductivity refers to the heat transferred through 1 square meter of area in 1 second under stable heat transfer conditions, with a temperature difference of 1 degree (K, ℃) on both sides of a 1 meter thick material. The unit is watt/meter·degree (W/(m·K)).

The thermal conductivity is a parameter to measure the thermal conductivity of a material. The larger the value, the better the thermal conductivity. Due to its high thermal conductivity, copper is often used to make radiators, heat conductors and other applications that require efficient heat transfer.

What is the thermal conductivity of copper at 25 C?

The thermal conductivity of copper is affected by many factors. On the one hand, temperature is an important influencing factor. Generally speaking, the thermal conductivity of copper decreases with increasing temperature.

At 25℃, the thermal conductivity of copper is about 401W/m.K, and at 100℃, the thermal conductivity of copper is 377W/m・K.

How do you measure thermal conductivity of copper?

The thermal conductivity of copper is usually measured by the steady-state method. ‌

The steady-state method is a classic method for measuring the thermal conductivity of thermal insulation materials. It uses the equilibrium state in which the heat transfer rate is equal to the heat dissipation rate during stable heat transfer.

This method has a simple and clear principle and high accuracy. Although the measurement time is long and the environmental conditions are high, it is suitable for measuring thermal conductivity materials at medium temperatures, especially for low thermal conductivity materials such as rock, plastic, rubber, glass, and thermal insulation materials.

In the steady-state method, commonly used methods include heat flow method, protected heat flow method, and protected hot plate method. The basic principles of these methods are similar, but some standards are formulated for different thermal insulation materials, and the test results are similar.

What metal has the highest thermal conductivity?

Silver has the highest thermal conductivity.

Among metals, silver has a thermal conductivity of 411W/(m·K), which is the highest value among all metals. This property of silver makes it the metal with the best thermal conductivity.

In contrast, copper has a thermal conductivity of 401W/(m·K), which is also very high, but still slightly lower than silver. Other metals such as gold and aluminum have thermal conductivities of 315W/(m·K) and 237W/(m·K), respectively, which are lower than silver and copper. Therefore, from the perspective of thermal conductivity, silver is undoubtedly the metal with the best thermal conductivity.

In addition, although the thermal conductivity of copper is also very high, reaching 401W/(m·K), second only to silver, among pure metals, the thermal conductivity of silver is still the highest. However, in practical applications, copper is widely used because of its good conductivity and relatively low cost.

Which metal is the poorest conductor of heat?

The metal with the worst thermal conductivity is iron. ‌

Among metal materials, the thermal conductivity of iron is 0.163, while that of copper and silver is, and that of aluminum is 0.5. These data indicate that the thermal conductivity of iron is significantly lower than that of other common metals. Therefore, it can be concluded that iron is the metal with the worst thermal conductivity‌.

Why copper has highest thermal conductivity?

Copper has the highest thermal conductivity‌, mainly because of its unique physical and chemical properties. The superior thermal conductivity of copper is mainly attributed to its crystal structure and electronic properties.

Copper is a metal with good electrical and thermal conductivity, which is due to the presence of a large number of free electrons in the crystals of copper. These free electrons can effectively transfer heat when colliding with metal cations in the crystal, making copper extremely thermally conductive.

The thermal conductivity of copper is about 400 W/m·K, which means that copper transfers much more heat per unit time than most other materials. The high thermal conductivity allows copper to quickly transfer heat away, with efficient heat dissipation.

What happens to copper when it is heated?

When copper is heated, its volume increases, its mass remains unchanged, and its density decreases. ‌

When copper is heated, its volume increases due to the property of thermal expansion and contraction. This is because when the copper block is heated, the distance between atoms increases, resulting in an increase in volume. At the same time, the mass of copper is a property of matter, which is only related to the amount of matter contained, and has nothing to do with the position, state, shape, and temperature of the object. Therefore, the mass of copper remains unchanged after heating.

In addition, when copper is heated in the air, if it reacts with oxygen, black copper oxide (CuO) will be generated on the surface. This chemical change will cause the color of copper to change from red to black.

In summary, when copper is heated, not only will its volume increase, its mass remain unchanged, and its density decrease, but it will also react with oxygen to generate copper oxide when heated in the air, resulting in a change in surface color.

Why does copper turn green?

Copper turns green because it is oxidized in the air to form copper rust. The main component of this copper rust is basic copper carbonate, which is green in color. ‌

Copper will be oxidized in the air to form copper rust. This rusting process is the result of a combination of factors, including the reaction of copper with oxygen, water vapor and carbon dioxide in the air.

Specifically, when copper is exposed to oxygen, water and carbon dioxide in humid air for a long time, a chemical reaction will occur to generate basic copper carbonate (Cu2(OH)2CO3), a green inorganic compound, so a green rust layer will form on the copper surface.

This process not only occurs on the surface of copper, but also because the main component of copper rust is basic copper carbonate, the color of copper rust is green, which makes the appearance of copper products appear green.

Copper has become the preferred material for heat conduction in many fields due to its high thermal conductivity, good processing performance and stable thermal conductivity. With the continuous advancement of science and technology, it is believed that copper will continue to play an important role in future development.

What is thermal conductivity?

Thermal conductivity is a physical value signifies the capacity of a material to allow heat flow per unit area through it in a unit of time. A higher thermal conductivity indicates better heat conduction for the material. In the field of heat generation and thermal management products, thermal conductivity is a crucial parameter as it relates to the product’s heat dissipation capability and stability. In the structure of aluminum, the thermal conductivity layer is always stand between the copper circuit layer and base material, so that the heat generated by product can be transfer quickly to outside.

Significance of Thermal Conductivity in Aluminum PCBs

Aluminum substrates are commonly used materials in heat dissipation and thermal management products. Their thermal conductivity is a vital element evaluated heat dissipation properties typically in W/m·K. It can be understood as the material’s heat transfer rate, i.e., the amount of heat conducted per unit time. Specifically, assuming the same amount of heat is conducted in aluminum substrates and other materials, the conduction rate of aluminum substrate will be faster over a certain period. This implies that aluminum substrates can transfer heat more quickly from the heat source to the external environment, achieving efficient heat dissipation.

Impact of Thermal Conductivity on Heat Dissipation Products

The primary function of thermal management products is to dissipate heat. How does thermal conductivity specifically affect them? Let us dive into from below aspects:

1. Thermal Conductivity Value

A higher thermal conductivity leads to better heat dissipation capability, as it can achieve faster transfer of heat from the heat source to the environment. Therefore, thermal conductivity of aluminum substrates plays a crucial role in the heat dissipation products, such as the LED lights, industrial power devices, automotives. At EBest Circuit (Best Technology), the thermal conductivity we used for aluminum PCB always is range from 1.0 to 3.0W (thickness=75-200um). Different thermal conductivity value has its own thickness.

2. Product Stability

The stability of a product also depends on its thermal conductivity. According to our 17+ manufacturing experience, insufficient thermal conductivity in heat dissipation products may result in overheating during prolonged operation, potentially shortening the product’s lifespan. Let me take a simple example, assume your mobile phone is under long time playing games, then it will generate many heats, finally causing the overheating phenomenon. And this will shorten its lifecycle if you always do like that.

When it comes to thermal conductivity selection, there is a big misunderstanding is that some may believe that higher thermal conductivity in aluminum substrates is always better. However, this is not entirely accurate. While higher thermal conductivity is generally favorable, it does not mean that aluminum substrates with the highest thermal conductivity are suitable for all heat dissipation applications. In specific use cases, it is essential to choose the appropriate thermal conductivity for aluminum substrates based on actual requirements to achieve the optimal heat dissipation effect.

By the way, if you want to choose higher thermal conductivity value, ceramic PCB is a better choice, which can achieve 24W or more. It mainly depends on its ceramic substrate material, like the Al2O3 thermal conductivity value is around 24W~28W/m-K, while AlN enable to reach 150W~240W/m-K.

Conclusion

All in all, to ensure optimal heat dissipation effects and stability, it is crucial to choose the right thermal conductivity for aluminum substrates based on actual needs. The careful consideration of thermal conductivity values in aluminum PCBs is integral to the longevity and performance of heat dissipation products, emphasizing the importance of informed selection in the pursuit of effective thermal management.

EBest Circuit (Best Technology) is an expert in metal core PCB manufacturing, we have strong R&D team and full-experienced employs that can provide with you the best metal core PCB solution. Welcome to contact us at sales@bestpcbs.com if you want to know more.

thermal conductivity

What Is a High Thermal Conductivity PCB?

Why Is High Thermal Conductivity Important in PCB Design?

What Materials Are Used in High Thermal Conductivity PCBs?

Core Material Performance Comparison

Aluminum PCB, Copper Core PCB, IMS PCB, and Ceramic PCB: What Is the Difference?

PCB Type Comparison

How to Choose the Right Thermal Conductivity Rating?

Thermal Conductivity vs Thermal Resistance: What Should Designers Know?

How Does Copper Thickness Affect Thermal Performance?

Copper Thickness Guide

How to Improve Heat Dissipation in PCB Layout?

What Applications Use High Thermal Conductivity PCBs?

How to Choose a Reliable High Thermal Conductivity PCB Manufacturer?

Why Choose EBest Circuit for High Thermal Conductivity PCB Projects?

FAQs About High Thermal Conductivity PCB

Q1: Can high thermal conductivity PCBs be multilayer?

Q2: How much more do they cost than FR-4?

Q3: What is the maximum voltage they can handle?

Q4: Can aluminum PCBs be bent?

Q5: How do I test the actual thermal conductivity?

You may also like

What is the thermal conductivity value for copper?

What is the thermal conductivity of copper at 25 C?

How do you measure thermal conductivity of copper?

What metal has the highest thermal conductivity?

Which metal is the poorest conductor of heat?

Why copper has highest thermal conductivity?

What happens to copper when it is heated?

Why does copper turn green?

You may also like

What is thermal conductivity?

Significance of Thermal Conductivity in Aluminum PCBs

Impact of Thermal Conductivity on Heat Dissipation Products

Conclusion

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