OEM Multilayer Flex PCB: The Ultimate Guide


Oakley Mae

Home » Blog » Flexible PCB » OEM Multilayer Flex PCB: The Ultimate Guide

An OEM multilayer flex PCB is an important part of modern-day electronics.

Trends predict that most devices will have multilayer flex PCBs soon.

However, as popular as they are, multilayer flexible PCBs are more challenging to manufacture than rigid PCBs. 

For this reason, many individuals outsource the process to OEMs.

So you may wonder why they do so. We have the information you need today. Let’s Let’s.

Table of Contents

What Are OEM Multilayer Flex PCBs

OEM multilayer flex PCBs are flexible circuit boards that an original equipment manufacturer produces for use by another company.

Additionally, they have more than two layers of copper foil in their structure with complex surface-mounted components. 

Going with an OEM multiflex PCB is a better option if you have a project requiring the circuit board to be flexible.

They are great for reducing crosstalk, providing exact impedance needs, and eliminating crossovers.

Benefits of OEM Multilayer Flex PCB

A flexible PCB connected to a rigid PCB

(A flexible PCB connected to a rigid PCB)

Generally, OEMs invest massive resources to produce multilayer flex PCBs.

Consequently, they make circuit boards more reliable and durable than appliance manufacturers. 

For example, electronic companies usually procure circuit boards from companies that deal with the boards exclusively.

Therefore, they reap the following benefits.

High Performance

Producing multilayer flex PCBs involves design, manufacturing, and assembly.

Therefore, companies that deal exclusively with circuit boards tend to produce boards that perform better. 

Additionally, multiplayer PCBs have high component density, meaning they are less prone to failure resulting from system overload.


Buying multilayer flex PCBs from OEMs is cheaper than manufacturing on your own.

Doing so saves you time and money that you would otherwise spend on design, manufacturing, and assembly.

Moreover, buying multilayer PCBs in bulk is more affordable, and you can get discounts from OEMs. 


OEMs’ OEMs’ation to producing high-quality multilayer PCBs ensures they manufacture durable circuit boards.

Furthermore, OEMs have the equipment to manufacture different types of multilayer PCBs.

In most cases, you can request unique designs they can deliver while ensuring you get durable circuit boards. 

High Density

Multilayer PCBs have a higher component density than single and double-sided circuit boards.

Consequently, they have a higher conductive area to mount more components.

Generally, high density is crucial for applications that lack space and need the board to be compact.


OEM multilayer PCBs have high density, making them more compact than most other boards.

Moreover, they have greater conductive area per volume, allowing them to be compact and accommodate more components.  

Applications of OEM Multilayer Flex PCB

An illustration of a robotic arm in a factory

(An illustration of a robotic arm in a factory)

The following are the applications of OEM multilayer flex PCBs

  • Manufacturing: Sensor equipment, processing machines, robotic arms
  • Electronics: Cameras, laptops, printer heads
  • Automotive: Antilock brakes, Airbag systems, engine controls
  • Medical: Exercise monitors, hearing aids, pacemakers
A man looking at his smart watch and phone

(A man looking at his smart watch and phone)

The future of OEM multilayer flexible PCBs is bright as the market demands better-performing electrical systems and appliances.

Here, we look at their future trends to unfold what tomorrow holds for multilayer flexible PCBs.

Miniaturization of Multilayer Flex PCBs

The market demands that manufacturers produce smaller and yet more capable devices.

Additionally, they want compact, high-speed devices that come cheaply. 

And when it comes to flexible PCBs, the more compact a board is, the smaller it gets.

Therefore, manufacturers are investing massively to reduce the sizes of their multilayer flex PCBs while ensuring they are powerful. 

More Use in Wearable Devices

Multilayer flexible PCBs are finding greater use in wearable devices since they are lightweight.

As time progresses, consumers demand lighter and more capable wearable devices. 

For instance, we see more capable smartwatches from electronics manufacturers like Samsung.

The watches continue being lighter as the manufacturers adopt less-weight materials for their multilayer flex PCBs.

Integration of Sensors

Sensors play an important role in modern electronics.

For instance, most smart devices have sensors that pick signals before relaying them to actuators for an action to happen.

Moreover, the sensors rely on multilayer flexible PCBs to pick and transform the signal into a meaningful message. 

5G Technology

Most circuit boards that you can find on 5G devices are multilayer flexible PCBs.

The reason is that they need lightweight PCBs for high-speed communication between devices.

Additionally, the flex PCBs can handle the heavy data traffic accompanying 5G technology. 

Advanced Materials

A trend that will transform the multilayer flex PCB industry is the adoption of advanced materials like flexible substrates and conductive inks.

Consequently, OEMs can manufacture better boards at a cheaper price. 

Materials Used in OEM Multilayer Flex PCBs

A copper wire cable

(A copper wire cable)


It is the substrate materials that differentiate rigid and flexible circuit boards.

For example, rigid PCBs have FR-4 as the substrate material making them rigid and not prone to bending or twisting. 

Conversely, flex PCBs have flexible polyimide or polyester as the substrate material, with the former being more popular.

Polyimide is tough, heat resistant, and very flexible allowing you to twist and bend the multilayer flex PCB as you wish. 


Copper is a popular conductor in multilayer flex PCBs due to its excellent electrical properties.

If you plan on bending your flex PCB during installation, you are better off with Electro-Deposited copper.

It is durable despite being cheaper than the Rolled Anneled copper foils for repeated twisting applications. 


Adhesives bond the polyimide to the copper foils during and after manufacturing.

Generally, manufacturers prefer them as they are cheaper to procure.

However, modern trends call for adhesiveness laminates as newer processes deposit conductive copper directly to the substrate.


What are the considerations while designing OEM multilayer flex PCBs?

First, consider a multilayer PCB’s PCB’snical flexibility to ensure it can withstand repeated bending without delaminating.

Second, use several layers that don’t the flex board’board’sbility.

Third, position components to minimize stress on the PCB during bending or twisting. 

Additionally, route traces in a manner that avoids sharp corners, guarding them against cracks.

Fourth, consider the operating environment to use materials that won’t won’t or lose their electrical properties. 

Fifth, your multilayer flex PCB must satisfy the electrical requirements of the application.

As such, consider its impedance, capacitance, and signal integrity.

Moreover, you must select the trace widths and materials to ensure your circuit board satisfies electrical needs.

How do you manufacture an OEM multilayer flex PCB?

The first step in manufacturing an OEM multilayer flex PCB is designing using a software tool like Altium.

At this stage, define the number of layers and how you will place components onto the circuit board. 

Second, select the best materials for your board depending on its applications.

Afterward, print the layers of multilayer flex PCB knot the substrate through photolithography.

Next, laminate the layers using heat and pressure to create a multilayer structure. 

Additionally, drill holes through the PCB, plate it with copper, and coat it with a solder mask to guard the copper traces.

Finally, test your multilayer flex PCB for insulation resistance and other performance parameters. 


Original equipment manufacturers (OEMs) produce excellent multilayer flexible PCBs in most industries.

Multilayer flex PCBs are lightweight and compact, with high component density. 

Consequently, they find use in many wearable devices and consumer electronics.

If you have a high-volume project, we recommend procuring your multilayer flex PCBs from a trusted OEM.

It will save you money and time,e and you will surely get high-quality circuit boards.