What are and should be the thermal conductivity of ceramic PCBs?

The high thermal conductivity of ceramic PCBAs is probably the main reason more industries are turning to ceramics in their PCBs and packages, as this substrate offers significant advantages over traditional materials in this regard. Better CTE matching and sealing will only add to the attractiveness of these materials.

The challenge is that ceramic substrates and the boards your PCBA manufacturer makes from them are much more expensive than the materials used in traditional PCBs, which can be significantly more expensive to produce during high-volume jobs. However, the benefits of ceramic boards and the need for improved thermal conductivity are so great that any company that can afford to use them will likely do so out of necessity.

How to Estimate Thermal Conductivity Levels

At MCL, we can estimate thermal conductivity levels for the major types of ceramic plates, but the final values will vary depending on the manufacturing process, grain size, and composition. While we may not know the exact value of the plate, check out the range of values agreed upon by experts below:

Aluminum Nitride: One of the most popular but expensive ceramics-aluminum nitride-has a thermal conductivity considered by many to be over 150 W/MK, and usually around 180 W/MK. However, studies have found values ranging from 80 W/MK to 200 W/MK at room temperature, with values dropping by more than a third as they approach 100 degrees Celsius.

Alumina: Alumina, another primary ceramic, has a thermal conductivity range of 18 to 36 W/MK at room temperature.

OTHER MATERIAL TEMPERATURE RANGES: Other temperature ranges we can determine at room temperature include 184 to 300 for beryllium oxide, 15 to 600 for boron nitride, and 70-210 W/MK for silicon carbide.

With so much variation, it is difficult to determine the actual thermal conductivity. Your best bet is to perform your own tests, record the values you obtain and use them in future calculations.

Ceramic PCB Applications

Industries that require higher frequency connections and good heat resistance can benefit from ceramic PCBs. Some of the major industries that ceramic PCBs can serve include: aerospace, automotive, medical devices, heavy machinery, and electronics.

Depending on your design and manufacturing needs, ceramic PCB prototyping can be very useful and efficient for printed circuit boards in these and many other industries.