Rigid flex PCB are rigid boards that use a combination of flexible and rigid board technology in one application. Most rigid flex boards consist of multiple layers of flexible circuit substrate attached to one or more rigid external and / or internal boards, depending on the design of the application. The flexible substrate is designed to be in a continuous flex state and is often formed into curves during manufacturing or installation.
Rigid flex design is more challenging than the design of a typical rigid board environment; these boards are designed in a 3D space, but also provide greater space efficiency. By being able to design three-dimensional rigid flex designs that can rotate, fold and roll the flexible board substrates to achieve their desired shape for the final application’s package.
Cutting→Mechanical drilling→Plating through hole→filming→exposure→developing→etching→peeling→false bonding→hot pressing→surface treatment→processing combination→test→punching→inspection→packaging
Unloading→Pre-bake→Inner layer pattern transfer→Inner layer pattern etching→AOI detection→Laminated inner layer wiring layer→punching positioning hole→multilayer lamination→drilling through hole→plasma decontamination→metallized hole→ Graphic plating → outer layer transfer → etched outer layer pattern → AOI inspection → laminated outer cover layer or coated protective layer → surface coating → electrical property test → shape processing → inspection → packaging
Production Process of Rigid Flexe PCB
Whether manufacturing a prototype or producing rigid flex quantities requires large-scale rigid flex PCB fabrication and PCB assembly, this technology is well proven and reliable. The PCB flex part is especially good in fixing space and weight problems with spatial freedom.
Careful consideration of rigid flexible solutions and proper evaluation of the options available at an early stage in the rigid flex PCB design stage will return significant benefits. It is important that the PCB fabricator flex rigidity gets involved early in the design process to ensure the fab design and part are both coordinated and to account for final product variations.
The rigid flex PCB production stages are also complex and take more time than rigid ship fabrication. All flexible components of rigid flex boards have completely different processing, engraving and welding processes compared to rigid FR4 board.
Rigid flexible PCBs offer a wide array of applications, from weapon systems and military aerospace to mobile digital cameras and phones. Increasingly, rigid flex boards fabricated have been used in medical devices such as pacemakers with their space and weight reduction capabilities. The same advantages for using rigid flex PCB can be applied to military weapon and weapon control systems.
In consumer products, rigid flex not only maximizes space and weight but significantly improves reliability, eliminating much need for solder joints and delicate, fragile wire prone to problems. This is just one example, but rigid flex PCBs can be used to benefit almost all advanced electrical applications including test equipment, tools and cars.
Not sure what technology needs to be used for your projects? Call our experts and we can help you find out if you need flex, flex PCB or rigid HDI technology.
The rigid flex PCB is small in size and light in weight. The flexible circuit board was originally designed to replace larger belts. On current connected electronics connection boards, flexible boards are often the only solution for miniaturization and mobility requirements.
Material Description of Rigid Flex PCB
Flexible circuits (sometimes called flexible wires) are etched on the polymer base material on a printed copper or polymer film circuit. For thin and light devices with compact and complex construction, the design solution includes a single path for three-dimensional assembly of a multi-layered complex. The total flexible assembly weight and volume is 70% lower than that of traditional wire rope. Flexible panels can also enhance their strength by using a reinforcement material or a liner for additional mechanical stability.
Flexible PCB with higher assembly reliability and flexible circuit board reduces the hardware required for Nellian, such as common solder joints, body, wiring and cables in traditional electronic packages, allowing Flexible panels provide higher assembly reliability and throughput. Because complex systems include traditionally connected hardware in assemblies, a component’s movement rate is highly visible.
Future of Flexible Circuit Boards
Although the flexible circuit board’s future is brightly printed, it also faces the dilemma of the current Chinese economy. The feed industry faces unprecedented competitive pressure due to rising labor costs, overload, outdated production and technology, poor research and innovation capabilities. Low productivity and management efficiency.
Many small-scale rigid flex PCB manufacturers are unable to reverse profit and loss patterns, closing down some. Only by actively seeking transformation, increasing investment in research and development and innovation, and trying to reduce costs, improve management and production efficiency is the basic way out.
The Flexibility of the Rigid PCB
Due to the poor thermal capacity of a flexible PCB (compared to a rigid PCB), adequate wire widths must be provided. When several conductors with large currents are facing each other or are close together, maximum width or clearance is required when considering the temperature issue.
The rectangle should be preferred wherever possible, because it can better store the base materials. There should be enough free margins near the edge, depending on the possible excess space of the substrate. In shape, the inner corner should look rounded, and the sharp inner angle can cause the sheet tear.
Wire widths are smaller and spacing should be minimized as much as possible. If geometrical space allows, well arranged fine strings should be converted to wide strings. The wire terminated at the plated hole or the part mounting hole should be smoothly searched into the solder tray. As a general standard, any change from a straight line to a corner or another line should be as smooth as possible. Sharp corners cause tension to focus naturally, lead the conductor to malfunction.
Rigid PCB vs Rigid Flex PCB
In the mass rigid flex PCB production of small electronics (such as small computers), flexible PCBs combined with rigid laminates have become commonplace and cost-optimized. The flexible PCB is equipped with a rigid sheet (such as layer G-10) with a suitable groove position to facilitate later separation.
After assembling the parts and the welded wave, the rigid sheet is divided into different sections by cutting it so that it folds into the desired shape.
Paper phenolic laminates can be divided into different grades, most can be used at temperatures up to 70 ~ 105, and working for long periods at temperatures above this range may lead to some Performance degraded.
And overheating can cause fouls, and in the affected areas the insulation resistance may drop to a very low value. In a high humidity environment, the insulation resistance of the surface will significantly decrease, however, when the humidity decreases, the insulation resistance will increase.
Rigid PCB Manufacturing Process
Production of printed circuit boards of a wide range of materials, according to the main material and auxiliary materials applications of two main types. Main material: Become a part of raw materials, such as copper clad laminate, weld resistant ink, marking ink, also known as physical and chemical materials.
Sub-materials: Materials used in the manufacturing process, such as optical dry film, bleach solution, electroplating solution, chemical cleaning agent, drill pad, etc., also known as non-material substance and chemistry.
What are the Design Elements of Rigid Flex PCB?
Most of the rigid flex PCB design elements of rigid printed circuit boards have been applied to the design of flexible printed circuit boards. However, there are new factors that need attention. Because the thermal capacity of the flexible printed circuit board is poor (compared to the rigid printed circuit board), adequate wire width should be provided.
The principle of line width selection is given when the current exceeds 1A. When several conductors carrying large currents are facing each other or are close together, there is a need for wire width or spacing when considering the temperature concentration issue. Static PCB: should be preferred where possible with a rectangular shape as it can better retain the base material. There should be enough free margins near the edge, depending on the possible excess space of the substrate.
Wire widths are smaller and spacing should be minimized as much as possible. If geometrical space allows, well arranged fine strings should be converted to wide strings.
As a general standard, the bending radius should be designed as large as possible. The use of thinner sheets (eg 50μm aluminum foil instead of 125μm copper foil) and the wider wire can improve the ability to bend more cyclic. For a large number of bending cycles, a flexible printed circuit board side usually shows better performance.
Rigid PCB Design and Flexible PCB Design Considerations are different
Conductor load capacity: due to the poor thermal capacity of the flexible PCB (compared to the rigid PCB), sufficient wire width should be provided. When several conductors carrying large currents are facing each other or are close together, additional wire width or spacing is required when considering the temperature concentration issue.
Shape:Wherever possible, the rectangle should be preferred, because it can better store the base materials. There should be enough free margins near the edge, depending on the possible excess space of the substrate. In shape, the inner corner should look rounded, and the sharp inner corner can cause the sheet tear. Conductor width is smaller and spacing should be minimized. If geometrical space allows, well-arranged fine strings should be converted to wide strings.
The wire terminated at the plating hole or the part mounting hole should be smoothly searched into the solder tray. As a general standard, any change from a straight line to a corner or another line should be as smooth as possible. Sharp corners cause tension to focus naturally, lead the conductor to malfunction.
Flexibility:As a general standard, the bending radius should be designed as large as possible. The use of thinner sheets like 50μm copper foil instead of 125μm copper foil and the wider wire can improve resistance to cyclic bending. For a large number of bending cycles, a flexible single sided PCB usually shows better performance.
Pad:In the padding area of the pad, there is a variation from flexible material to rigid material. This area is more prone to breakage than the conductor. Therefore, the pad should avoid appearing in areas prone to bending. The general shape of the pad should resemble a tear, and the coating should be able to cover the seams of the pad seam.
Rigid Sheets:In the mass production of small electronics (such as small computers), the rigid flex PCB combined with rigid laminated laminates has become very popular and is cost-optimized. The flexible PCBs are equipped with a rigid sheet (such as grade G-10) with a suitable groove position to facilitate later separation. After assembling the parts and the welded wave, the flex sheet is divided into different sections by cutting it so that it folds into the desired shape.
What is the Difference between Drawing A flex PCB and a Rigid-flex PCB Layer?
With the increase in the production of flex PCB and the application and advertisement of rigid PCBs, it is now more common to say that PCB with flex, rigid or rigid to say it is a few layers of PCB.
In general, a PCB is made of a flexible insulating substrate called a flex PCB or a flexible PCB. It is suitable for today’s electronic products with high density and high reliability, miniaturization, light direction of development needs, but also to meet strict economic requirements and competitive market demands.
In foreign countries, the flexiable PCB has been widely used in the early sixties. China, in the sixties began to produce and apply. In recent years, with the introduction of global economic integration and the introduction of technology to promote the use of technology continues to grow, a small number of small and medium rigid PCB factories aim at this opportunity to use The existing equipment of the tooling and process improvement processes the PCB production is flexible and adaptable to the growing demand for flex PCBs.
Capabilities of rigid flex PCB manufacturing
Drill to copper – Outer layers: 6 mil
Drill to copper – Inner layers: 8 mil
Copper Thickness: 0.5 oz – 5 oz
Minimum Hole Size: 0.005″
Minimum Trace/Space: 0.003″/0.003″
Minimum Pitch: 0.5 mm
Copper to board edge: 0.007″
Coverlay Opening: 0.003″
Coverlay Web (Kapton): 0.006″
PCBSKY is an industry leader in PCB manufacturing
with more than 10 years experience. We process single, double-sided, Multi-Layer, and Rigid Flex circuits.If you need any of them, welcome to contact us for the price and datasheet.
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