Flexible PCB
Flex PCB

Flexible PCB

FPC - flexible circuit with benign folding ability

Flexible PCB is also known as FPC or flex circuit, the most commonly used circuit board after rigid PCBs are flex PCBs, which are used in many different electronic devices and projects. Unlike rigid ones, flexible PCBs are foldable and are therefore used by electronics manufacturers to improve the size of electronic products. Many times we have to use or rely on it, such as wearable electronic devices. In most cases, flexible boards are combined with rigid boards to form a rigid flex PCB with the advantages of both boards.

Why choose FS Technology Flexible PCB Boards?

Currently, this board type is frequently accessible and can be used in any project. Through the services of FS Technology, you can be assured that you will get top quality and more affordable flexible PCB boards due to our vast manufacturing capabilities, as follows:

  • Specialists in manufacturing flexible PCBs between 1–6 layers and with a maximum acceptable size of 610×1650 mm. If your project has additional needs, we will try our best to suit them.
  • Our provided surface treatment services include HASL, lead-free HASL, immersion gold, immersion tin, immersion silver, plated gold, OSP, carbon ink, ENEPIG and gold fingers.
  • FS Technology has an independent production and assembly workshop, which can provide cheaper flexible printed circuit boards (PCBA) for your project without MOQ requirements.
  • 13Our fast turnaround flex PCB manufacturing service can provide you with an expedited package to complete PCB prototyping in as fast as 1–2 days.
  • To order your flexible boards, we require and accept most Gerber file formats, such as POWERPCB, PROTEL, PADS2000, CAD, AUTOCAD, ORCAD, P-CAD, CAM-350, CAM2000 etc.

Flexible PCB sample display

Flexible PCBA Manufacturing Capability

Available materialsPolyimide, high Tg polyimide
Material thickness25 µm-50 µm
Copper thickness18 µm-35 µm
Minimum hole diameter0.004”
Drill Aspect Ratio35:1
Minimum trace/space0.003”/0.003”
Drilling technologyBlind/Buried vias and Micro vias
Impedance controlYes (10% tolerance)

Flex PCB Manufacturing Capability

FS Technology uses subtractive, additive or semi-additive FPC manufacturing processes to fulfill customer orders.

In a subtractive process, a turnkey manufacturer selectively removes unwanted copper foil from the surface of a copper clad laminate to establish a circuit image. Because it can reduce costs, and the process is mature and reliable, it is respected by PCB manufacturers and has become mainstream.

The additive process of flexible PCB refers to the method of electroless plating by the manufacturer to electroplate the circuit diagram on the PCB substrate that originally had no circuit pattern. FS Technology uses this process in flexible circuit boards with higher circuit density, but because this method is “additive”, the cost is high and the technology is immature, so it is not commonly used.

The semi-additive method is another form of additive process. This PCB manufacturing process uses ultraviolet light to cure the film, and uses electroplating technology to increase the copper thickness of the line to the thickness required by the customer. Finally, the excess copper layer under the photoresist is removed by flash etching to obtain the desired circuit pattern. It’s a new way to keep up with the evolution of electronic devices. Using this method, the copper thickness is not affected by the width of the line, and a flexible board with a minimum line width/line spacing of 14 μm/14 μm and a minimum aperture of 55 μm is produced.

Flex PCB Finishing Capability

The manufacturing of the FPC is only the first step in a turnkey service. Surface preparation is usually required for fragile circuit boards to ensure that the circuit boards are in an acceptable assembly condition. Immersion gold, immersion tin and immersion silver are not the only options in surface treatment services as we offer a much greater range of other surface treatment services (HASL, lead-free HASL, plated gold, etc). In addition to technical advantages, the provision of free conformal paint service in small-batch prototype manufacturing orders is one of the primary factors that FS Technology has received well.

The combination of electronic components and assembly techniques enables endless possibilities for your flexible projects and FS Technology has the capabilities to support your project needs. FS Technology not only provides traditional SMT assembly and through-hole assembly but also flip-chip technology that inverts the chip and connects directly to the substrate.

Additionally, FS Technology has a complete quality management system and involving PCBA testing in the assembly process is a critical part of the overall factory process, which includes free PCB manual inspections and AOI inspection. Accompanying these basic tests on flexible PCBA boards, ICT, flying probe testing and X-ray testing are additional compulsory tests that are required and performed during the manufacturing process of your electronic projects.

The Benefits of Buying Flexible PCBs for Electronics Projects

The technology used for flexible boards, also known as FPC or flexible printed circuit boards, are widely utilized in various fields and industries, which include consumer electronics, wearables, telecommunications, aviation, etc. Normally, flexible PCBAs exist in the form of single-layer boards and higher-density boards such as 8-layer, 10-layer or even 16-layer flexible boards, which are typically produced according to the needs of a project. If you choose FS Technology as your turnkey FPC supplier, we are capable of supplying all types of flexible PCBs that follow these characteristics:

  • Smaller and lighter substrates are used for flexible circuit board creation, measuring approximately 0.004 inches. Considering a minimalistic space and area, it is more suitable for complex circuits in a smaller footprint compared to other ordinary boards.
  • With a unique pressure processing function, when the assembled flexible PCB is subjected to external force, the components on the board will not shift.
  • If flexible boards are combined with rigid boards, the resulting boards, called rigid-flex boards, offer a combination of the features from both board types. That is to say, rigid-flex boards not only make up for the lower tensile strength (weakness) of flexible boards but also make up for the inflexibility of rigid boards.
  • Compared to other boards, High-end flexible PCB boards can reduce the risk of construction errors and repairs as well as provide protection for the advancement of the project.
  • Our flexible PCB come with the feature of easy airflow that cools the circuitry of the board.
  • The modifications in the structure of flexible multilayer PCB ensure that the construction of complicated structures and designs has adaptable features to make strong connections at the board corners.

Advantages of Flexible PCB​

The price advantage of flexible PCBA

Price of flexible PCB

The price drivers of PCBA include material, size, structure, purchase volume, etc. Regarding retail, this may mean that the finished product seller may increase the profit of the project through these aspects. Under the same conditions, the price of circuit board types are in the order of rigid < flexible < rigid-flex, but from the perspective of the use of PCB materials, FPC boards use fewer materials and components. In terms of manufacturing materials, more manufacturers choose to use polyimide materials that are less expensive and are key materials in flexible PCB production. In terms of PCBA components, due to the recent global pandemic, the major downturn and shortage of component supply have skyrocketed the price of chip components so by using flexible PCBs, you may be able to save more on this aspect. On top of that, in regard to the personnel needed for production, flexible circuit boards can be built with the fewest number of technicians.

Applications of flexible circuits

Facing the environment of high-voltage and high-temperature circuits, customers often will choose IMS PCB due to its high thermal management performance, but circuit boards with metal layers as inner layers obviously cannot meet many customers’ needs for complex circuits. As a result, flexible circuits are mainly brought up as their first choice. In some severe cases, circuit boards with poor heat dissipation may release harmful chemicals when misused but premium flexible PCB boards offer that needed resistance. Flexible PCBs are made of polyamide or polyester film as the base material, which greatly increases their thermal stability and performance. Be sure to keep in mind that when electronic products face the threat of high temperatures, although rare, the physical phenomenon of thermal expansion and contraction may occur, causing a drop in overall performance. Subsequently, these flexible boards have features to operate on any type of connector used in electronics, especially compatibility with ZIP connectors.

Application scenarios of FPCB
Flexible PCB saves space for circuits

Size of flexible PCB

As foldable circuit boards, flexible PCBs can not only provide three-dimensional space design freedom for projects but also improve space utilisation and weight efficiency in equipment. These boards require less area and lighter weight, and the use of a smaller footprint allows them to provide better functionality in full-featured large-scale projects. In small, reliable and consistent circuits or projects, flexible boards can also be installed in places where rigid circuit boards cannot because flexible PCBs utilize much fewer connectors and interconnects.

Applicable Fields of Customized Flexible PCBA

Flexible printed circuit boards (FPC) are considered to be an integral part of any electronic device as they can be applied to a vast variety of electronic products, such as computers, keyboards, cameras, mobile phone circuitry, etc. FS Technology has been active in the FPC manufacturing and assembly industry for ten years and within this timeframe, we have worked with many customers from a massive range of industries who use our flex PCB services for the computer and medical industries. The use of flexible PCBA is not limited to this though as the possible applications are very extensive, some of which we will introduce to you now.

Flexible PCBs are created for a diverse scope of manufacturing projects in several industries, including robotics, which commonly uses this type of PCB. HMI machine layout is also configured over these boards and machines that are commonly found in shopping malls (e.g. bar code readers) contain these boards with processing devices integrated with flexible PCBs.

Plus, these flexible printed circuit boards are commonly used in GPS systems within vehicles as the control systems that have been engineered in automobiles are usually manufactured over these boards. Currently, in new vehicles, most of the latest breaking systems that are installed (e.g. antilock brake system) make great use of these boards in manufacturing, in addition to airbag deployment systems.

Over in the medical industry, state-of-the-art hearing instruments and heartbeat sensors are created around flex medical PCBs.

Moreover, different types of electric components, such as active and passive devices, are designed through the use of flexible boards, like high towers, light circuits, etc. Other applications of these boards include the likes of satellite stations & communication grid circuitry, where application-specific resistors and capacitors are created to use these boards for different circuit types, including ripple and filter circuits.

Flex PCB vs Rigid PCB

In order to facilitate your selection of a suitable PCB type, we will make a simple comparison between flexible and rigid PCBs but for further details, please read “Rigid vs Flex PCB”.

  • High reliability and small footprint
  • Better thermal management
  • Easy to repair
  • The flexible PCB is used for high-speed operation where rigid is not used

Disadvantages of flexible boards compared to rigid boards:

  • The flexible PCB manufacturing process is more complex and requires a longer manufacturing time than rigid PCBs.
  • Price comparison under the same conditions: Rigid-flex PCB > Flexible PCB > Rigid PCB


In conclusion, FS Technology’s flexible PCB manufacturing capabilities have been demonstrated and simply put, choosing FS Technology will ensure that you get PCBA boards at a lower price that can easily be modified, reshaped and electrically altered to suit your project. As a leading turnkey PCBA company in China, FS Technology aims to meet the needs of flexible PCB assembly manufacturing customers using the latest materials and technologies, unswervingly adhering to customer quality and certification standards. If your electronic project needs our service, please get your flexible PCB price list by email below.

Get a Flexible PCB Quote