flex circuit assembly line
Generally speaking, a flex circuit assembly line is where all the work happens in terms of assembling flexible printed circuit boards. The process involves etching copper foils, putting them into a laminate, applying a polyimide or liquid photoimageable coverlay, and adding stiffeners as needed. These stiffeners are typically made of FR-4 or Kapton, and they protect components or connectors attached to the board from any excessive bending during use.
As you can imagine, there are many different flex circuit configurations that can be made, each with its own unique design requirements. The most important flex circuit specifications a designer should consider include the base material, coverlay and stiffener materials. Once these materials are chosen, the flex circuit assembly can begin.
When compared to traditional rigid circuit boards and hand-wired wire harnesses, flex circuits offer significant benefits. Reduced assembly errors due to their design accuracy and automation, for instance. Flex circuits only route to points called for by the plan’s schematic, net list or gerber files, eliminating the high cost of assembly mistakes associated with hand-built wire harnesses.
What is a flex circuit assembly line?
In addition to their reduced weight and size, flex circuits also have the ability to solve problems that would otherwise be difficult to address with rigid and hand-wired solutions. Examples of these challenges include flexing during installation, dynamic applications and high-density circuits.
The thinner design of flex circuits also allows for increased heat dissipation, which helps keep electronic components cooler and more efficient. This can be especially beneficial in dynamic or high-performance applications, such as mobile phones and laptops.
Another advantage of flex circuits is their flexibility during installation. Because of their design, they can be manipulated in three dimensions during installation and servicing, solving space and weight issues. This is especially useful for reducing point-to-point wire replacement costs.
Before a flex circuit assembly is shipped to a customer, it undergoes a baking process, which reduces the amount of moisture in the board. This is done to prevent the onset of any potential problems, such as corrosion or electrical failures, caused by excess moisture.
Once the baking process is complete, the flex circuit is optically inspected and electrically tested to ensure that it meets all the required standards. Once the flex circuit passes QC it is sent to packaging and warehousing. High-temperature adhesives, such as those based on polyimide or modified epoxy, can withstand the thermal stresses encountered during both manufacturing processes, such as solder reflow, and during actual operation in high-temperature environments.
The ability of the adhesive to maintain its bond strength and flexibility at elevated temperatures ensures the circuit’s reliability in demanding applications, such as automotive engine compartments, aerospace systems, or industrial automation equipment.
Sierra Circuits can produce a wide range of flex circuit assemblies, from single-layer to multi-layer rigid and rigid-flex circuits. Contact us to discuss your project, and we’ll help you determine the best flex circuit assembly options for your specific needs. Our engineers and technicians can bring your flex circuit designs to life! To learn more about our services, please request a quote. Alternatively, you can email us with any questions you may have. We look forward to hearing from you!
