How Do You Terminate Components on a Flex PCB?

Components on a Flex PCB

When designing a flex pcb, it’s crucial to lock down the connector termination choice early on. This will ensure that the design is a complete system that fits all of your interconnect needs and save you re-design time when assembly and parts procurement occur. Most flex PCB manufacturers offer a range of interconnect technologies for your design, but the most popular are ZIF, unreinforced flex fingers, and crimped contacts or displacement connectors. Each has unique benefits, drawbacks and specific design considerations to be aware of.

ZIFs are a great choice for a number of reasons; they provide a low profile, have a high tolerance for bending and offer robust electrical performance. They are available in a variety of male and female mating pitches, including standard through-hole and surface mount types. There are also a variety of centerline housings that can be used to encapsulate the connector and add additional mechanical support.

Typically, the pins are made from nickel-copper with tin finishing and gold covering. This provides a good combination of durability and corrosion resistance, which is essential for a flex pcb. The connectors are also rated for a wide temperature range, which is a key attribute in any flex circuit application.

How Do You Terminate Components on a Flex PCB?

Another type of connector is the unreinforced flex finger termination, which consists of thin copper fingers that are attached to the flex circuit conductors. The conductors are positioned so that they can be easily bent or angled to match a specific layout or installation requirement. These flex fingers are then insulated with either a thin layer of base material or a solder mask to prevent shorting or accidental contact with other traces and components.

The first thing to consider when choosing a termination method is whether or not the flex circuit will be subjected to continuous bending. If the flex circuit will only be bent once during the assembly process and then left in place, you can be more generous in your layers, copper thickness, etc. However, if the flex will be constantly moving and bending, then it is recommended that you reduce the layers to minimize the amount of copper used.

During the PCB manufacturing process, copper is printed on the substrate layer and then photochemically etched to create a pattern of conductors. The traces are then plated with copper, which connects the individual layers of the board. Once the traces are plated, they are then covered with a protective solder mask and silk screen to protect the copper from oxidation during the assembly process.

One way to improve the flex PCB’s ability to handle dynamic bending is to stagger the placement of conductors across a bend area. This helps to distribute the strain evenly and avoid stress concentration points. Additionally, it is important to avoid 90deg bends, as this can cause the flex to fail due to compression and stress. It’s recommended to use a gradual curve and a large radius where possible.

Leave a Reply

Your email address will not be published. Required fields are marked *