Flex PCBs Be Used in Electrochemical Sensors

A flex printed circuit board (FPC) is flexible and can be made from a variety of materials. Compared to rigid PCBs, it has better resistance to vibration and movement and can fit into shapes that would be impractical or impossible for a rigid design. It can also help save space and weight.

Despite these benefits, some designers are still reluctant to choose a flex design. They may think that a flex circuit board can’t be as robust or reliable, especially in harsh environments like those found in electrochemical sensors. Fortunately, recent advancements in flex technology have changed the perception of this type of product.

One of the key factors in determining whether a flex circuit is reliable is its construction. Often, flex pcbs are manufactured using a multilayer construction. They can also be single or double-sided. The choice of which to use depends on the application. During manufacture, the layers are bonded together through the use of adhesives. They are then interconnected by plated through holes (PTHs). A layer of polyimide is typically added to both sides of the construction to provide insulation.

Can Flex PCBs Be Used in Electrochemical Sensors?

The quality of a flex circuit board is determined by its base raw material and stack-up. The most common flex raw material is Polyimide. It can be either adhesive or non-adhesive, depending on the application. It can be laminated with copper foil or other conductive materials. It can be rolled or flat, and can be finished with silkscreen, solder mask, or other coatings to suit the application.

Other options that can be added to a flex circuit include the addition of tin or soft gold finishing. This is useful for covering exposed pads on the flex PCB, as well as providing an excellent surface for wire bonding. Other options are to add adhesive to specific areas of the flex, or to have it backed with a metallic shield for electromagnetic interference (EMI) protection.

A flex PCB’s durability and reliability depends on its material selection, design, and fabrication process. The material properties that are chosen must be able to handle the environmental conditions that the product will experience, such as heat, moisture, chemicals, shock and vibration, and radiation. Having accurate material properties in the initial design phase can reduce cost and lead to a more robust product.

It’s important to note that the failures observed with the flex circuits used in this study occurred at the trace-to-pad interfaces. There was no damage to the polyimide coverlay. Moreover, the failures were not caused by fatigue or stress on the traces as was originally suspected. This new data supports the use of flex circuits in medical applications such as electrochemical sensors. It will also help engineers make more informed decisions about how to design their future products.