Flexible PCB Cost Optimization Guide
In the modern electronics field, rigid PCB, due to its affordability and sufficient rigidity, is the most common choice. However, with the growing demand for miniaturization and portability, flexible PCB plays a crucial role in adapting to special scenarios in three-dimensional space. The application of flexible technology not only enables device miniaturization but also provides greater flexibility for electronic products.
While flexible PCB offers significant advantages in meeting specific requirements, it’s essential to recognize that its manufacturing complexity and relatively higher material costs contribute to an overall increase in project costs. Therefore, FS Technology is here to provide you with a Flexible PCB Cost Optimization Guide, aiming to assist customers in achieving technological innovation while maximizing cost-effectiveness for their project.
Why Are Flexible PCB Priced Higher
When comparing the costs of flexible PCB and rigid PCB, we observe that the cost of flexible PCB is typically between 5–10 times that of rigid PCB. This price difference is primarily attributed to several factors:
Firstly, the choice of substrate materials. Traditional rigid PCB typically use the more cost-effective FR4 as the substrate material, while flexible PCB primarily use high-performance polyimide. This material not only withstands chemical corrosion and high temperatures but also exhibits excellent electrical insulation properties, ensuring outstanding circuit performance in various environments.
Secondly, the proficiency in manufacturing technology. Rigid PCB have a long history, and manufacturers are highly proficient in their production processes. In contrast, flexible PCB began gaining popularity after the year 2000, and the manufacturing technology is relatively new, with lower proficiency among manufacturers. This results in additional costs due to potential failures in flexible PCB manufacturing, ultimately passed on to the customers.
Additionally, flexible PCB manufacturing requires more effort. Since flexible PCB are lighter and thinner, manufacturers need to exert more effort during the production process, facing additional challenges in fixation, for example. For more intricate flexible circuits, traditional CNC machining has certain limitations, requiring factories to invest in more expensive laser equipment. In some extreme environments, additional support structures such as reinforcement ribs or support layers may be needed to maintain performance, contributing to the overall increased costs.
Lastly, the manufacturing of multi-layer flexible PCB is relatively challenging. The impact of multiple layers on PCB manufacturing difficulty is evident, and you will find that the manufacturing of multi-layer flexible PCB has its limitations, with most manufacturers limiting production to 10 layers or fewer. Ultimately, scarcity adds to the value, leaving you with limited options.
Certainly, the additional investment in flexible PCB is often considered reasonable and worthwhile. Through careful configuration, flexible circuits can reduce the number of wires in devices, eliminate connectors used in rigid PCB, simplifying assembly, and reducing wiring errors and other issues.
How to Reduce the Cost of Flexible PCB
The size of flexible PCB panels has a profound impact on manufacturing costs. It’s not a simple mathematical calculation but a crucial factor in large-scale factory production. Typically, dozens or even hundreds of PCB are laid out on a large panel, and then cut into individual PCB. This production method not only efficiently saves raw materials but also reduces production batches, creating favorable conditions for mass production, ensuring rapid production of industrial-grade products with excellent quality.
In the commonly used standard rectangular panel sizes by manufacturers, 12” x 24” and 18” x 24” are common specifications. If there’s a need to further expand panel sizes, equipment and materials need to be updated. Equipment updates are self-explanatory, while material updates aim to better “nest” PCB. The edge rules of the panel determine the tooling “keep-out” area, and the spacing required between adjacent circuits directly affects nesting density. As the order quantity increases, combined with the advantages of panel production, labor costs are spread across each flexible PCB, ultimately becoming negligible.
However, during the assembly stage, panelized production is no longer applicable. Each subset of flexible PCB needs to be cut from the panel, then individually assembled and soldered. Therefore, the cost-saving advantages of panelized production end when manufacturing is completed and cannot extend to the assembly stage of flexible PCB.
Simplifying Circuit Structures
Firstly, consider double-sided design. As mentioned earlier regarding the number of layers, with an increase in layers such as 6, 8, or 16, product losses become more severe because additional steps are required, potentially reducing the success rate from 99.00% to 90.00%. The same applies to double-sided flexible PCB. While allowing components to be soldered on both sides of the board significantly improves the utilization of surface area, the cost is approximately 1.5-2 times that of a single-sided structure.
Secondly, pay attention to the arrangement of PCB vias. Although through-hole technology is commonly used due to its economic pricing, it may not be flexible enough in certain situations. Therefore, it may be necessary to introduce some advanced holes, such as blind vias or buried vias, leading to potential cost increases. In the early stages of flexible circuit design, it is essential to assess whether these advanced features are required.
Lastly, focus on surface finishes. ENIG, serving the dual purpose of preventing copper oxidation and providing a solderable surface, is the surface treatment method used in about 80% of circuit boards. If cost is not a significant concern, consider ENEPIG, which adds a layer to ENIG for enhanced performance. Additionally, there are various PCB surface finish services with noticeable differences in price and effectiveness. If you are struggling to reduce the cost of your flexible PCB, discussing with FS Technology’s engineers could provide valuable insights.
Consider whether a combination of rigid and flexible is necessary, or if a flexible PCB with reinforced ribs is sufficient. This is crucial as the cost of rigid-flex PCB is the highest. Then, choose the appropriate IPC grade based on project requirements. Grade 3 has stricter requirements compared to Grade 2, such as serialization and additional coupon validation, thereby increasing project costs.
Evaluate the need for high-density interconnects, which involve features like blind and buried vias, laser-drilled microvias, sequential layer lamination, and holes in solder pads. This increases the number of circuit layers, reduces trace width, tightens spacing, and makes routing more dense, ultimately raising the cost of flexible PCB. However, this technology facilitates faster connections while reducing project size and volume.
Before designing, determine the bend radius early to ensure the design can sustain necessary bends without damaging the copper. Depending on the application, flexible PCB can be categorized as static, infrequently bent (less than 100 times during the lifespan), or dynamic, regularly bent and potentially enduring tens of thousands of bends.
Currently, there are several manufacturers in the market that specialize in providing services for flexible PCB. However, most of them can only handle small batch projects, resulting in higher unit prices for the final PCB. To obtain a more cost-effective unit price, it is recommended to obtain flexible circuit solutions from large manufacturers like FS Technology.
Firstly, coming from China allows us to provide PCB manufacturing services at a lower labor cost for you. Secondly, our production facility is equipped with intelligent devices for automated mass production, catering to projects of various scales and helping you reduce costs through economies of scale. Additionally, our turnkey PCB service is a significant highlight, as we take care of everything from manufacturing to assembly, eliminating time waste in the project. Most importantly, what sets us apart from traditional manufacturers is our engineering assistance service. When we take on an order, our engineers intervene and provide services like design optimization and component substitution to help you reduce the cost of flexible circuits!
Hesitating Due to the Cost of Flexible PCB?
For those deliberating the investment in flexible PCB, specifically due to cost considerations, a comprehensive understanding of their intrinsic value is imperative. Flexible PCB, while appearing to carry a higher price point, present a cost-effective solution for designs emphasizing weight and space efficiency, coupled with the intricate demands of complex designs.
The distinct advantage of customizable routing paths within the printed circuit board of a flex circuit significantly enhances its reliability and trustworthiness. The materials employed in the construction of flexible PCB ensure their ability to withstand diverse gravitational forces and harsh conditions, ranging from everyday occurrences like phone drops to more extreme scenarios such as missile launches. Furthermore, their resilience in elevated temperatures renders them particularly suitable for critical industries such as aerospace, military, oil exploration, and medical applications.
The durability of flexible circuits enables them to endure numerous flexing cycles while efficiently transmitting signals and power without interruptions. The low mass and ductility of flex PCB allow them to withstand substantial strain or shape alterations without compromising strength, thus enduring high vibrations. By replacing extensive wiring and cables, flex PCB contribute to significant space savings and a reduction in package weight, making them particularly relevant in industries such as surgical tools, cell phones, equipment, and automobile components. Their inherent flexibility allows seamless adaptation to diverse spaces and applications.
Flex PCB prove particularly advantageous in high-speed digital signaling systems, where maintaining signal integrity is of paramount importance. The rapid rise times characteristic of high-speed systems necessitate effective management of factors that may impact the quality of square wave pulse signals. Through the seamless integration of form, fit, and function into a single circuit, flex PCB effectively reduce assembly costs and steps, consequently minimizing the potential for errors.
As electronic technologies continue to advance, the demand for flexible PCBs has witnessed a notable surge. The relationship between price and cost in this scenario can be delicate. The market segmentation by niche manufacturers is influenced by factors such as quantity, delivery timelines, market demands, and targeted customer penetration strategies. Hence, it becomes evident why significant price disparities exist among different suppliers. As consumers, it is imperative not only to focus on pricing but also to prioritize product quality.
Comprehensive Guide to Multilayer Flexible Circuits If you are seeking FPC solutions, FS Technology can assist you in the entire process from concept to finished product. We
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