Both rigid and flexible printed circuit boards (PCBs) are used to connect electronic components in various consumer and non-consumer devices. As the name suggests, a rigid PCB is a circuit board built on a rigid base layer that cannot be bent, while a flexible PCB (also called a flex circuit) is built on a flexible foundation that can be bent, twisted, and folded.
Although traditional PCBs and flexible PCBs have the same basic purpose, it must be noted that there are many differences between them. Flexible circuits are not just bent PCBs. They are manufactured differently from rigid PCBs and have various performance advantages and disadvantages. Learn more about rigid and flexible PCBs below.
What is the difference between a rigid PCB and a flexible circuit?
Rigid PCB, usually referred to as PCB for short, is what most people think of when they imagine a circuit board. These boards use conductive tracks and other components arranged on a non-conductive substrate to connect electrical components. On rigid circuit boards, non-conductive substrates usually contain glass, which can reinforce the board's strength and give it strength and rigidity. The rigid circuit board provides good support for the components and provides good thermal resistance.
Although flexible PCBs also have conductive traces on non-conductive substrates, this type of circuit board uses a flexible substrate, such as polyimide. The flexible base enables the flexible circuit to withstand vibration, dissipate heat and fold into various shapes. Due to its structural advantages, flexible circuits are increasingly used in compact and innovative electronic products.
In addition to the material and rigidity of the base layer, the significant differences between PCBs and flexible circuits include:
l Conductive materials: Since flexible circuits must be bent, manufacturers may use softer rolled annealed copper instead of conductive copper.
l Manufacturing process: Flexible PCB manufacturers do not use solder mask, but use a process called overlay or overlay to protect the exposed circuit of the flexible PCB.
l Typical cost: The cost of flexible circuits is usually higher than that of rigid circuit boards. However, because the flexible circuit board can be installed in a compact space, engineers can reduce the size of their products, thereby indirectly saving costs.
How to choose between rigid and flexible PCB
Rigid and flexible circuit boards can be used in many different products, although some applications may benefit more from one type of circuit board. For example, rigid PCBs are meaningful in larger products (such as TVs and desktop computers), while more compact products (such as smartphones and wearable technology) require flexible circuits.
When choosing between rigid PCB and flexible PCB, please consider your application needs, the type of circuit board preferred by the industry, and the effects of using one or the other type may be profitable.
