Printed circuit boards, even standard FR-4 PCBs, are incredibly resilient pieces of electronics. There are certain conditions for which these boards will not be appropriate. For example, PCBs for aerospace may be subjected to extreme temperatures, both very high and very low temperatures. For situations requiring PCBs that can handle extremely low-temperatures, also called cryogenic PCBs, special low-temperature PCB material may be necessary.
What Is the Minimum Temperature for FR-4 PCBs?
The typical FR-4 PCB should be able to withstand temperatures close to -50°C. At this point, you may start to find brittle cracks in the material. While this is quite cold, you will generally prefer your FR-4 PCBs not to get anywhere near this standard to minimize stress and lengthen the life of your PCB. Furthermore, in industries like the aerospace industry, where PCBs may end up in outer space, the board may be exposed to temperatures as low as negative 150°C, far below the recommended temperature level for FR-4 PCBs.
PCB Materials for Low-Temperature Applications
Fortunately, you can use many materials as a substitute to FR-4 when making PCBs that need to be resistant to extreme temperatures. Polyimide materials, for example, are highly resistant to temperature on both ends, standing up to temperatures not only cryogenic but as hot as 260 degrees Celsius, as well as being fire-resistant. Polyimide is susceptible to water, however, which is an important design consideration. A more expensive option is ceramic, where you have the best of both worlds. Ceramic PCB’s are no susceptible to water and can withstand extreme high and low temperature. The down side to cermaic PCB’s are their cost and design barriers. There are many differences and benefits between ceramic PCB, FR-4 boards, and MCPCB.
Another extremely useful material in cryogenic PCBs is aluminum, which can conduct at .5 Kelvin, or negative 272°C. The downside of aluminum is that it is extremely reactive, and so it requires unconventional methods when building circuit boards.
Finding the Right PCBs for Your Industry
One of the benefits of working with Millennium Circuits Limited for your PCBs is that we have worked across virtually every major industry that uses PCBs and know many of the specific needs of different sectors such as aerospace or defense when it comes to printed circuit boards. A board that can withstand very low temperatures may be one consideration. Some companies prefer ceramic boards due to their very high operating temperature capacity and low expansion coefficient. You may need a flexible or rigid-flexible board if your industry uses applications that require printed circuit boards that can fit into smaller or oddly-shaped devices.
The wrong type of printed circuit board can be disastrous for your production. While you should always look for cost-effective solutions, trying to cut costs by buying printed circuit boards that do not have all the qualities you need can be much more expensive in the long run. MCL can help you find the right circuit boards and provide them to you affordably in a timely fashion, whether you need a small batch or a large run. To learn more about our printed circuit board services or to order low-temperature PCBs or any kind of PCBs for your business, contact MCL now.