High ceramic PCB thermal conductivity is probably the leading reason more industries are turning to ceramics in their printed circuit boards and packages, as this material has a clear edge over plastics in this regard. Better CTE matching and hermetic sealing only add to the appeal of these materials. The challenge is that these materials, and the boards your ceramic PCB manufacturer makes from them, are considerably more expensive than materials for traditional printed circuit boards, which can add up significantly over the length of a high-volume job. However, the benefits of ceramic boards and the need for heightened thermal conductivity is so great, any company in a relevant industry that can afford to use ceramic boards will probably do so out of necessity.
While we can have an estimate of the level of thermal conductivity each ceramic board can provide, the final values will vary depending upon the manufacturing process, in addition to grain size and composition. We can offer a range of values that experts seem to agree upon.
Thermal conductivity for one of the most popular, although expensive ceramics â?? aluminum nitride â?? is one that many identify as over 150 W/mK, usually around 180 W/mK. However, studies find values ranging all the way from 80 W/mK to 200 W/mK at room temperature, with values dropping by more than one-third as you approach 100 degrees Celsius. Other thermal ranges we can identify at room temperature include 18-36 W/mK for aluminum oxide, 184 to 300 for beryllium oxide, 15 to 600 for boron nitride and 70-210 for silicon carbide.
Because the variations are so wide, it is difficult to pin down actual thermal conductivity numbers. Your best approach will be to do your own testing, record the values you obtain and use those in your future calculations.
