What Role Do Flexible Circuit Boards Play

Printed circuit boards (PCBs) play a critical role in many aerospace applications. Whether it’s aircraft, satellites, or military hardware, PCBs are often used to power these devices and connect them with the rest of the system. They’re also used in life support systems and flight control systems to ensure that equipment continues to function when needed. This is especially important in harsh environments where the equipment must perform on demand and cannot fail.

These factors are why many manufacturers use flexible circuit board for aerospace products, despite the fact that they have a higher manufacturing cost and lower yield than other PCB solutions. Fortunately, there are ways to mitigate these costs and improve your yield by understanding how rigid-flex boards are built.

Rigid-flex PCBs are constructed using a mix of materials, including copper foil and epoxy. These layers are stacked together, and the finished PCB includes a coverlay that protects the exposed conductors from corrosion and damage. In addition, rigid-flex PCBs feature a stiffener to help support different parts of the board. It’s essential to understand how these components work together so that you can design your rigid-flex circuit with the right specifications and tolerances.

What Role Do Flexible Circuit Boards Play in Aerospace Applications?

The base material for a rigid-flex PCB is a flexible epoxy or woven glass impregnated with epoxy resin. These substrates are often combined with a thin layer of a conductive material like silver or gold. This layer is known as the interconnection layer, and it’s what allows your device to flex and bend without damaging the copper.

During the fabrication process, the fabricator uses heat and pressure to melt the epoxy resin and bond it to the conductive layer. They’ll then add a layer of solder mask and a final protective film. The solder mask and other layers protect the conductive layer from damage, corrosion, and oxidation. This helps to ensure that the device can withstand the environmental conditions and harsh chemicals found in aerospace environments.

The biggest benefit of a flex circuit for an aerospace application is that it takes up less space than a traditional PCB with a similar layout. This is an important consideration because rockets and their payloads experience significant gravity during the liftoff phase. A flex circuit board’s reduced mass helps reduce the overall weight of the rocket, which means more fuel can be used for a faster and longer flight.

Moreover, a flex circuit board’s low thermal resistance up to 200degC is important for aerospace applications. This flexibility helps the board to operate reliably even when it’s subjected to intense heat from jet engine turbines. It’s also an important characteristic for wearable military gear such as night-vision goggles, where a flex circuit can integrate electronics conformally around the user without adding too much bulk or weight. This versatility also helps reduce the number of individual components, lowering the complexity and improving operational safety. Additionally, a flex circuit’s dynamic flexibility enables the device to move as the soldier moves, keeping it functional in the most challenging of scenarios.