Flex PCBs Handle Moisture and Humidity

When you design a flex circuit board, you need to consider how it will handle moisture and humidity. This will affect the functionality and durability of your product. In addition, it will impact the cost. This is because flex PCBs are more complex to produce than rigid ones, so they require more material and human interaction.

The best way to keep a flex pcbs from suffering damage from the effects of moisture is by keeping it in a controlled environment. This means storing it in a clean area and maintaining strict pest control in the factory. You also need to make sure that all the people working with the board are wearing anti-static clothing and wristbands. This will prevent the builder from damaging the circuit by accidentally touching it with metal objects or other electrostatic materials.

One way to minimize the risk of damage from moisture is by using a pre-baking process. This is a procedure where the parts are baked at a high temperature for 2-10 hours. This will ensure that all of the parts are dry before assembly. If you are assembling a complex flex PCB with many layers and ribs, this process may be needed more than once.

How Do Flex PCBs Handle Moisture and Humidity?

Another way to protect a flex circuit from damage is by choosing the right type of copper foil. For example, a rolled and annealed copper foil will be more durable than an un-annealed one. This is because it will be able to stretch more before fatigue cracking occurs. A rolled and annealed foil will also be more springy in the Z deflection direction, which is important for a flex PCB that will be bending and creasing all the time.

You can also use stiffeners on a flex PCB to protect it from damage. These are small rigid pieces that are laminated to the flex circuit. PCBWay offers several types of stiffeners, including FR4 and metal (not specified what type of metal). Stiffeners can help stabilize the flex circuit and reduce vibrations. They are especially useful for high-speed boards and those in harsh environments.

Flex circuits are used in a wide range of applications, from heads-up displays for aircraft piloting to wearable technology and minuscule devices for medical care. They can be molded into complex three-dimensional shapes, and they offer advantages over traditional wiring harnesses and ribbon connectors.

The physical flexibility and tensile strength of a flex circuit can make it easier to route wires through difficult-to-reach areas, and they can provide a much more compact and lightweight product. In fact, a flex circuit can replace an entire wire harness and its associated components in certain contexts.

When designing a flex PCB, you will need to choose between single-sided and double-sided flex circuits. Single-sided flex circuits have a single conductor layer on a flexible dielectric film, and they are printed on one side. Double-sided flex circuits have conductor layers on both sides of the dielectric film and are connected by plated through holes. This provides increased power handling capacity and circuit density, but it can increase the manufacturing cost.