Ceramic PCBs Handle Thermal Cycling

When it comes to constructing PCBs, designers must choose the right material. The choice of material is critical, as it impacts the board’s durability, performance, and longevity. PCBs are made from different materials, including FR-4, LTCC, and ceramic. Each has unique thermal and electrical properties. Ceramic PCBs are ideal for applications that require a long lifespan and high thermal conductivity. These circuits are capable of withstanding extreme temperatures, making them perfect for electronics used in the field.

Compared to FR-4, ceramic pcb board offer superior thermal management. Their thermal conductivity allows heat to travel quickly through the entire board, thereby dissipating it into the environment. This prevents overheating and the subsequent failure of components, extending the life of the board. In addition, the ceramic layer’s low coefficient of expansion helps reduce mechanical stress caused by temperature fluctuations.

The ceramic layer’s low CTE and high thermal conductivity also make it an excellent substrate for copper and silver traces. These metals are the most durable materials used in modern technology and are highly compatible with the ceramic layer’s low CTE. This makes the ceramic a perfect platform for soldering and other connections. As an added benefit, the ceramic’s chemical inertness makes it resistant to a wide range of harsh chemicals. This ensures that the circuits will remain functional under extreme conditions, from the scorching heat of an automotive engine to the freezing vacuum of outer space.

How Do Ceramic PCBs Handle Thermal Cycling?

Ceramic PCBs can be fabricated using several methods, including liquid crystal co-firing (LCCC) and laser-assisted micromachining (LAM). In the former, the ceramic is melted into a glass matrix by applying a high temperature to the surface. Then, the ceramic is cured in an oven. It is important to bake the board in a minimized gas, like hydrogen, to avoid oxidizing the tungsten and molybdenum. The process is very fast, allowing the ceramic to be cured in less than 48 hours.

Moreover, a ceramic circuit board’s thermal resistance is lower than that of FR-4. Hence, it can be fabricated with much thinner layers of insulation and conductive metal. This can significantly reduce the weight of the finished product and improve its performance. In contrast, FR-4 PCBs require thermal vias, metal planes on the inner layers, and thermal landings to transport heat away from hot parts. These elements can be costly and inefficient. In comparison, a ceramic PCB can efficiently disperse heat to an active cooling device or its packaging.

The ceramic layer’s insulating and conductive properties also enable it to resist chemical erosion, even under high temperature. These characteristics make it a great material for high-speed signal transmission. Furthermore, the ceramic’s tensile strength and abrasion-resistance make it an excellent choice for rugged environments. Hence, the ceramic enables a wide range of industries to implement their products in the field without worrying about their safety.