Differences between Rigid-flex Boards and FPC with FR4 Stiffeners

A rigid-flex PCB is a special circuit board structure that combines a rigid board with a flexible circuit board. It is created by combining a rigid board and a flexible board through a special connection. The flexible part is usually used in areas that need to be bent or folded, while the rigid part is used to support electronic components and connector sections. The rigid-flex board design gives engineers greater flexibility to adapt to complex three-dimensional spatial layouts and compact electronic device designs. By reducing the number of connectors, rigid-flex boards can increase reliability while saving space and weight.
On the other hand, an FPC with FR4 stiffeners is a flexible printed circuit board to which FR4 material is added as a reinforcement layer on the surface of the flexible circuit board.FR4 is a glass fibre reinforced epoxy resin commonly used in traditional rigid circuit boards. By adding an FR4 stiffener layer to a flexible circuit board, the mechanical strength and rigidity of the board can be increased, thereby improving durability and providing better physical support. FPCs with FR4 stiffeners are used in scenarios where a flexible board is required but high mechanical strength is needed, such as applications that require frequent bending or twisting. The reinforcement layer provides additional protection and reduces the risk of damage to the flexible circuit board during use.
Rigid-flex boards and FPCs with FR4 stiffeners differ significantly in their construction and use. Rigid-flex boards offer flexible wiring and space-optimized solutions by combining rigid and flexible boards. FPCs with FR4 stiffeners, on the other hand, achieve increased mechanical strength and rigidity by adding a reinforcement layer to the flexible board. Choosing the right structure depends on specific design requirements and application scenarios to meet the performance and reliability needs of electronic products. As circuit board supplier, Sienta need to decide which structure to use based on the actual situation and needs, and ensure that we design a reliable and effective circuit board. If there are any demands, please feel free contact Sienta for an answer or offer.