A four-layer combination rigid flex circuit has four conductive copper layers. Typically, a four-layer has two flexible layers and two rigid layers.

There are many high level benefits to Rigid Flex circuits including:

Connection Reliability – Connecting rigid layers with flexible cables is the foundation for combination rigid flex circuits.

Lower Part Count – Compared to a traditional rigid board, combination rigid flex circuits require fewer parts and interconnections.

Flexible Design Options – At Flexible Circuit Technologies, we pride ourselves on taking on the most complex of design challenges. Rigid flex circuits can be designed to meet highly complex and unimaginable configurations while utilizing a rigid substrate. Rigid flex circuit designs could entail any of the following:

• Highly complex configurations
• Controlled Impedance
• Three to eight-layer combinations
• Reduced interconnections

High Density Applications – More often than not, the rigid component of a rigid flex circuit is utilized for high density device population. In addition, flexible circuits allow for minutely narrow lines giving way to high density device population. Denser device populations and lighter conductors can be designed into a product, freeing space for additional product features.

Package Size and Weight Reduction – Multiple systems in rigid boards create more weight and utilize more space. Combining rigid boards with flexible circuits allows for a more streamlined design thus reducing package size and weight.