Flex circuits Advantages of Flexible and Rigid-Flex PCB Circuits

Written by: Anaya Vardya on June 22, 2020

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Since their introduction, flexible and rigid-flex pcb boards have been steadily moving from the fringe of electronic interconnection towards its center. Today, flexible PCBx boards are found in countless products from the very simple to the highly complex. There are numerous reasons for this shift, as there are a multitude of advantages. An examination of the benefits will make this clear.

  1. They are a remedy to natural product packaging problems: Flexible PCB boards are often chosen because they help to solve problems related to getting electronics inside the product they serve. They are a true three-dimensional solution that allows electronic components and functional/operation elements (i.e., switches, displays, connectors and the like) to be placed in optimal locations within the product assuring ease of use by the consumer. They can be folded and formed around edges to fit the space allowed without breaking the assembly into discrete pieces.
  2. They help reduce assembly costs: Prior to the broad use of flexible PCBs, assemblies were commonly a collection of different circuits and connections. This resulted in the purchasing, kitting and assembly of many different parts. By using a custom pcb flex circuit design, the number of part numbers required for making circuit related interconnections is reduced to one.
  3. They eliminate potential for human error: Since the pcb design is an integrated circuit assembly with all interconnections controlled by the design artwork, the potential for human error in making interconnections is eliminated. This is especially true in the cases where discrete wires are used for interconnection.
  4. They can reduce both weight and volume requirements for a product: Flexible circuits are appreciably lighter than their rigid circuit counterparts. Depending on the components used and the exact structure of the assembly and final products, they can save as much as 60% of the weight and space for the end-product compared to a rigid circuit solution. Additionally, their lower profile can help a designer create a lower profile product than is possible with a nominal 1.5mm thick rigid board.
  5. They facilitate dynamic flexing: Nearly all flexible circuits are designed to be flexed or folded. In some unusual cases, even very thin rigid circuits have been able to serve to a limited degree. However, in the case where dynamic flexing of a circuit is required to meet the objectives of the design, flexible circuits have proven best. Modern disc drives, for example, require that the flexible circuit endure anywhere from tens to hundreds of millions of flexural cycles over the life of the product. Other products (laptop hinge circuits, for example) may only require thousands of cycles, but it is the dynamic actuation capability enabled by the flex circuit that is key to its operation.
  6. They improve thermal management and are well suited to high temp applications: High temperatures are experienced both in assembly with lead-free solder and in the operation of higher power and higher frequency digital circuits. Polyimide materials are well suited to the management of high heat applications. Not only can they handle the heat, their thinness allows them to dissipate heat better than other thicker and less thermally conductive dielectrics.
  7. They help improve product aesthetics: While aesthetics may seem a low order advantage, people are commonly influenced by visual impressions and frequently make judgements based on those first impressions. Flexible circuit materials and structures look impressive both to the seasoned engineer and the layperson. It can influence the decisions made in some applications, especially those where the user gets exposure to the functional elements of the product.
  8. They are intrinsically more reliable: Flexible circuits help to reduce the complexity of the assembly and can reduce the number of interconnections that might be otherwise required using solder. Reductions in complexity is a key objective of a reliable design. With respect to the minimization of the number of solder interconnections, reliability engineers know all too well that most failures in electronic systems occur at solder interconnections. It follows naturally that a reduction in the number of opportunities for failure should result in a corresponding increase in product reliability.

In summary, flex and rigid-flex pcb boards have significant advantages. There are many additional advantages which go beyond the short list provided here. What is important to remember is that most of the advantages stem from the versatility and unique integrative abilities these important members of the electronic interconnection family can offer. When looking for rigid flex PCB boards, American Standard Circuits, is your choice  and top PCB manufacturer in the US and around the globe.

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