Your Leading Multilayer Flex PCB Manufacturer in China

PCBMay is a professional Multilayer flex PCB supplier in China, and we can provide one-stop solution for your project.

  • Over 12 years multilayer flex PCB manufacturing experience
  • Up to 10 multilayer flex PCB manufacturing
  • EMI/RFI shielding
  • All multilayer flex PCBs meet IPC class II or III
  • 48h quick-turn service for your prototype Multilayer flex PCB
  • 7/24 sales and engineering tech support

For flexible PCB capabilities, please refer to the following form.

Number of Layers1 – 10layers
Order Quantity1pc – 10000+pcs
Board thickness(without stiffener)0.002-0.2inch
Min. Board Size0.2*0.4inch
Min. Board Size9*14 inch
Build Time2days – 5weeks
MaterialFCCL (adhesive) Shengyi SF305
FCCL (adhesiveness)Panasonic R-F775
Taiflex MHK
Dupont Pyralux AP
CoverlayShengyi SF305C
Taiflex FHK 1025&2035
AdhesiveTaiflex BT
PI stiffenerTaiflex MHK
OthersTolerance of single layer±0.05mm
Tolerance of double-layer (≤0.3mm)±0.05mm
Tolerance of multi-layer(<0.3mm)±0.05mm
Tolerance of multi-layer(0.3-0.8mm)±0.1mm
Impedance control toleranceSingle ended:±5Ω(≤50Ω);±10%(>50Ω)
Differential Pairs: ±5Ω (≤50Ω);±10%(>50Ω)
Min coverlay bridge8mil
Min bend radius of single layer3-6 times of board thickness
Min bend radius of double-layer6-10 times of board thickness
Min bend radius of multilayer10-15 times of board thickness
Min dynamic bend radius20-40 times of board thickness
Inner layerMin line width/spacing (12/18um copper)3.0/3.2mil (loop lines 6.0/6.2mil)
Min line width/spacing (35um copper)4.0/4.0mil (loop lines 8.0/8.0mil)
Min line width/spacing (70um copper)6.0/6.5mil (loop lines 10/10.5mil)
Max copper thickness2oz
Outer layerMin line width/spacing (18um copper)3/3.2mil (loop lines 6/6mil)
Min line width/spacing (35um copper)4/4.5mil (loop lines 6/6mil)
Min line width/spacing (70um copper)6/7mil (loop lines 6/6mil)
Min line width/spacing (105um copper)10/13mil (loop lines 6/6mil)
Max finished copper thickness3OZ
DrillingMin distance between via and conductors6mil (<4 layer)
8mil (4-6 layer)
12mil (7-8 layer)
Min mechanical drill hole6mil
Solder maskSolder mask colorGreen/White/Black/Yellow
and silkscreenCoverlayYellow、Black
Min solder dam (base copper ≤ 1OZ)4mil (green),8mil(solder dam on the large copper)
Min clearance3mil (part for 2.5mil)
Silk colorWhite, Yellow
Surface treatmentSurface treatmentHASL, ENIG, ENEPIG, Electrolytic Nickel Gold, Soft gold, Hard gold,
Immersion silver and OSP
Mixed surface treatmentENIG+OSP, ENIG+G/F
Gold thickness (ENIG)0.05-0.10um
Nickel thickness (ENIG)3-6um
Gold thickness (ENEPIG)0.05-0.10um
Palladium thickness (ENEPIG)0.05-0.15um
Nick thickness (ENEPIG)3-6um
Electrolytic nickel thickness3-6um
Electrolytic gold thickness0.05-0.10um
Hard gold thickness (including lead)0.1-1.5um
OSP thickness0.1-0.3um
Immersion silver thickness0.2-0.4um
RoutingLaser accuracy±0.05mm
Punch accuracy±0.05mm–±0.15mm
VPC Plating Line

Releted Some Other PCBs

Why Choose PCBMay for Your Multilayer Flex PCB

Multilayer flex PCBs have three or more flexible conductive layers. As one of your trusted flexible circuit board manufacturers, PCBMay can offer different types of multilayer flex PCBs for your projects.

PCBMay can also provide a turnkey solution for your demand. You will send the inquiry of PCB design & layout, PCB fabrication, and PCB assembly to us, we love to help you.

All of us are looking for a PCB supplier who can offer high quality and competitive prices. In fact, if need high quality, the price will not be lower.

In order to cut down the labor cost, we have brought many high-tech fully automatic production lines, including VCP plating lines, LDI exposure equipment, silkscreen printers, and automatic fixture E-testers.

If you need your project very quickly, PCBMay can help you. We can manufacture the sample of multilayer flex PCB within 48h, it can meet your production schedule.

The standard board thickness of multilayer flex PCB is 1/2mil to 3mil and the copper thickness is 1/3oz to 3oz.

We have full service for quick-turn jobs and state-of-the-art equipment. It can meet your complicated project deadlines and budgets.

There are many different applications for multilayer flex PCB, including automotive engine controls, GPS systems, satellites, bar code equipment, cameras, mobile phones, and avionics.

Multilayer flex PCB

Multilayer Flex PCB

Are you looking for a premier multilayer flex PCB manufacturer? PCBMay is your best choice. PCBMay has over 500 workers in our workshop and the monthly capacity is 40,000 square meters.

We will help you in the multilayer flex PCB industry, send your questions.

Multilayer Flex PCB: The Ultimate FAQ Guide

In this guide, we will discuss multilayer flex PCB. If you want to learn more, please start to read it.

What is Multilayer Flex PCB?

A multilayer flex PCB comprises many single-sided or double-sided circuits with complicated interconnections, insulation, and plated through-hole or surface-mounted technologies.

Throughout the manufacturing phase, the multilayers can be laminated continuously. However, continuous lamination can restrict the maximum flexibility range.

When faced with design problems such as crossovers, impedance matching, crosstalk, insulation, high density, and multilayer flexible circuits are ideal remedies.

How To Design Multilayer Flex PCB?

Multilayer Flex PCB is preferred when the circuit needs to fit inside a specific assembly, and a higher component density is required.

The single-sided flexible circuit often falls short of these features. Also, the multilayered flex PCB is optimum for ground and power plane applications, impedance-controlled design, and protection and shielding.

MultiLayer Flex PCBs frequently features up to 8 conductive layers, use resistive foils, boost flexibility by leaving some surface unbonded

These multilayer flex PCBs are built for better performance than their predecessors, as we described in the concept of multilayer flexible PCBs.

As a result, they have several advantages, particularly in terms of efficiency. Several double-layer PCBs’ outputs are combined into a single multilayer PCB.

This reduces the weight and improves mobility by eliminating the need for several connectors.

Smaller yet more efficient electronics are possible thanks to the potential to attain the output of several double-layer PCBs on a single PCB.

As a result, compact but advanced devices such as tablets and smartphones have emerged. Because of the many layers of insulation between the layers, multilayer flex PCBs are more robust.

Multilayer flex PCB

Multilayer flex PCB

This results in a single, somewhat tightly bonded PCB rather than multiple loose ones.

Compared to double-layer PCBs, these PCBs are more durable and of higher quality.

This is primarily due to the intricate and complicated preparation and fabrication needed.

The integration of a large density of layers into a single PCB allows the PCBs to work well.

The boards are more connective, with inherent electrical properties that result in increased speed, even on tiny PCBs.

Multilayer flex PCBs present a single attachment point since they are a single entity, making it simpler to build the final product.

Many end-users of electronic devices want to provide just one link stage, so the vendor has to have one. Multilayer flex PCBs are rapidly displacing double-layer flexible PCBs as a result of these advantages.

This is due to the high-performance but smaller and compact PCBs’ ability to conserve room and improve portability.

What Is The Layout Of Multilayer Flex PCB?

Modern electrical circuits depend heavily on Multilayer flex PCBs.

This is thanks to their sturdy construction, as well as their multi-functional and durable capacities.

The number of layers of conductive materials used in multilayer flex PCB layouts may be classified.

A PCB with more than two layers of conductive copper foil layers is known as a Multilayer flex PCB. Under layers of heat-protective insulation fabrics, these boards are laminated and fused together.

A PCB with three or more layers of conductive material falls under this group. Consequently, a multilayer flex PCB incorporates two or more double-layer PCBs or a blend of double- and single-layer circuit boards.

The most common explanation for this is to maximize the surface area available for wiring.

What Is The Stack-Up Of Multilayer Flex PCB?

Via the different PCB panel layers, PCB stack-up helps you have more circuitry on a single board.

On high-speed PCB layouts, stack-up will help you mitigate the circuit’s susceptibility to external noise, minimize radiation, and reduce crosstalk issues.

An adequately designed PCB substrate with a low inductance power delivery network will efficiently minimize electromagnetic emissions and increase signal integrity.

PCBs are becoming more complicated as more functions and circuits are squeezed into a single surface.

Multilayer flex PCBs will increase the device’s pace and flexibility, resulting in a more functional board.

Combining copper and insulating layers that make up a PCB is referred to as a PCB stack-up. Multilayer flex PCBs are made up of at least three conductive layers at their most simple level.

The insulation board forms the bottom sheet, and each circuit board is attached to the next. Internal layers may be protected from external noise with layer stacks, rendering them less susceptible to disruption from the outside.

PCB Layer Stack-ups is used to include more functionality in a narrower room.

A PCB Stack is designed to shield against external noise damage and to produce a functional unit that is more prone to wear and tear.

The PCB Stack-up is a tool that will assist you in making the best show decisions for your product.

To make the product more aesthetically appealing, the stack-up helps make the most use of any piece of equipment you have, from televisions to tablets to smartwatches.

It’s a platform for showing consumers how good the product is viewed and improving the display’s accuracy.

Multilayer flex PCB stacks are meticulously constructed to satisfy specific design requirements.

By putting several circuits on a single surface, good layer PCB stack-ups will help achieve lower-cost manufacturing.

Only 8-layer PCBs are capable of performing these five goals. When stacking sheets, delamination in the form of misaligning is expected, so use pads with an epoxy plate to prevent it.

Offsetting, key fabrics, and mounting layers on top of each other are both items to worry about.

Multilayer flex PCBs can use core and prepreg components from the same vendor.

If copper is spread unevenly in multilayer stack-ups, bow and twist issues can occur. Two-layer, four-layer, six-layer, eight-layer, and ten-layer PCB layer stack-ups are available.

The size of the circuit, the size of the PCB, and the board’s EMC specifications both influence how many layers you need.

Multilayer flex PCB

Multilayer flex PCB

What Are The Benefits Of Multilayer Flex PCB?

Routing, packaging, and soldering wires are all very expensive.

Flex circuits reduce these costs. Compared to conventional cabling and rigid boards, multilayer flexible PCBs give the following advantages:

Multilayer Flex PCBs remove human mistakes previously present in hand-built wire harnesses, thanks to precise prototypes and automated manufacturing.

Multilayer flex circuits need fewer physical labor and limit manufacturing defects, reducing assembly time and costs.

Multilayer flex PCBs may be built to suit perhaps the most unusual and complicated setups. In designs of rotating pieces, it can flex up to 500 million times without failing.

Multilayer flex PCB

Multilayer flex PCB

Polyimide’s extraordinary thermal tolerance often enables the circuit to survive high-temperature applications. Surface mount electronics are directly attached to the circuit on flexible PCBs, simplifying the overall configuration.

Flexible circuits allow for creating intricate designs that would be almost impossible to accomplish on rigid boards.

The thinnest dielectric substrates are used on multilayer flexible PCBs.

Because of the extra thinness, a more compact configuration is possible, removing the need for heavy rigid boards.

The elasticity and durability of the material make for a smaller package size.

Weight reduction makes flex circuits efficient in the face of ever-increasing demands in the electronics industry.

Insulators within the layers of multilayer flexible PCBs are rigid or flexible insulation materials. Multilayer Flexible PCBs follow the IPC 6013 – Type 3 norm.

They are made up of three or more conductive flexible layers and flexible insulating layers within them, and additional insulating polyimide layers.

They often use high-speed operated impedances in a surface strapline or microstrip setup and plated through-holes that stretch through both the fluid and rigid layers.

Multilayer flex PCBs, in general, are a cost-effective way to minimize human error by eliminating the usage of hand-built wire harnesses by design precision and process automation.

Wrapping, soldering, and routing wires are also quite expensive. Their adaptability allows them to operate under the harshest conditions and in almost limitless applications.

What Are The Materials Of Multilayer Flex PCB?

Multilayer flex PCBs are made from a broad range of substances, including films, foils, and adhesives.

Although polyester and polyimide continue to dominate the base film industry, newer technologies such as PEN and LCP are being investigated and implemented.

Both of these materials may play a significant role in the future as a cost-effective intermediate in PEN and a higher-performance alternative in the case of LCP.

Similarly, as digital signaling progresses into the domain of RF speeds, thin reinforced PTFE materials can play an important role.

A wide variety of adhesives and even different kinds of metal foils may be used in base material manufacturing and the base materials.

The components to use are heavily influenced by how and when the circuit would be constructed and used in the center.

A careful assessment of the various materials’ relative merits might be needed to make the right option for a particular application

On flexible base laminates, other materials may have conductive (or resistive) pathways.

The PTF multilayer flex PCBs are a subclass of flexible circuits made of thick polymer film.

Among conductor compounds, the indium-tin-oxide is unusual in that it is translucent.

The PTF technology is also used to make various low-cost devices, including membrane switches, touchpads, and low-cost calculators.

A specially fabricated foil is used in a specialized construction process for creating flex circuits. It will have an efficient termination resistor solution, reducing assembly difficulty and weight. Plateable toner flexible circuits are a branch of the flexible circuit manufacturing method.

A flex circuit pattern was created directly on a multilayer flexible PCB substrate using a unique toner material that bonds to base films.

Multilayer flex PCB

Multilayer flex PCB

What Are The Applications Of Multilayer Flex PCB?

Multilayer flex PCBs have many advantages over single-layer PCBs.

As a result, multilayer flex PCBs have become common in several industries.

The flexibility and adaptability provided by flexible PCBs, in particular, are the driving forces behind this transition.

The two most essential characteristics of telecommunications equipment are durability and functionality.

As a result, multilayer PCBs are preferred for mobile devices and outdoor towers in this industry.

People worldwide are rapidly migrating to intelligent devices such as smartphones, which make multitasking much more accessible.

These devices must use multilayer PCBs to achieve this quality while remaining portable.

Durability is also a requirement for industrial equipment. Industrial equipment is occasionally subjected to rough handling that is too much for it to handle.

As a result, multilayer PCBs are commonly used in industrial controls that operate machinery.

Whether it’s for diagnosis or treatment, medical equipment’s mobility and functionality are critical.

As a result, multilayer flex PCBs are widely used in this industry, from heart monitors to CAT scan machines and beyond.

High-speed circuits and highly compact engineering design are critical in the military industry.

They must create electronics that can perform multiple functions while still allowing for easy movement. Multilayer PCBs are the best way to do this.

Multilayer flex PCBs are ideal for automobiles’ internal atmosphere because of their high heat tolerance, compact scale, and high efficiency.

As a result, they’re commonly found in onboard computers and engine sensors.

When it comes to weight, scale, longevity, and efficiency, this is one of the most delicate industries.

Multilayer flex PCBs are the safest for electronics like cockpit computers because of the mixture of these characteristics. Electronics for computers

Portability and consistency are so critical in the computing industry that they usually overshadow the expense consequences.

For example, laptops require both high performance and portability. As a result, they rely on multilayer PCBs for their motherboards and other components.


This guide aims to give you a solid foundation in multilayer flex PCBs.

The article tries to clarify all the definitions and procedures and helps you grasp them quickly. In this respect, the guide puts you in an excellent position to deal with any multilayer flex PCB problems.

With this knowledge, you will make informed decisions on all issues involving these kinds of PCBs.

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