What Is Polyimide PCB

Although FR4 boards still dominate the traditional PCB market, recently polyimide PCB has made its mark in the industry with its versatility, and multipurpose usage. So, it’s not surprising that many manufacturers have developed a keen interest in polyimide PCB.

So, many electronics, as well as military weapon makers, ask, “What is polyimide PCB?”

To put it shortly, these boards are made with plastics that are built with incredible temperature endurance and strength. The manufacturing, however, requires the use of a variety of materials which affects its types and application.

And today, in our PCB discussion, we will know the real definition of polyimide PCB along with its types, applications and lastly, the difference with the conventional FR4 printed circuit boards.

So, are you ready?

Table of Contents

Our Recommended Polyimide PCB

flex PCB 2

FPCBs have a flexible, thin base. Such boards are mainly used as connectors between conventional, rigid boards, as part of an electronic product. In this capacity, FPCs (Flexible Printed Circuit Boards) is an alternative to cable connections. Also, flexible boards are used in the manufacture of antennas, inductors, etc.

Flexible boards have a number of advantages over printed circuit boards on a rigid base: reduced size and weight, reduced assembly costs, fewer interconnections, improved electrical performance and heat transfer, and the ability to arrange blocks in three dimensions.

In serial production, a wide selection of materials is available, which makes it possible to reduce the cost of the final product. The company’s specialists will help you choose the best option for your product.

What Is Polyimide PCB?

To understand the real meaning of polyimide PCB, at first, you will have to know about the ‘polyimide’ properly.

The word polyimide consists of two sub-phrases that includes, ‘poly’ which typically refers to polymers and ‘imide’ which refers to the advanced imide monomers. Together they create a diverse polymer group.

Moreover, the polymer group is manufactured using either natural or synthetic process. However, for now, forget about the natural polymers and focus on the synthetically manufactured polyimides. These polyimides are used to build the PCBs, hence the name polyimide PCB.

The synthetic polyimide used in manufacturing PCBs is resourced from different chemicals with imide structures. This manufacturing process is known as polymerizing to us. These polyimides are then used in making PCBs.

Different Types of Polyimide PCBs

Likewise, metal PCB and ceramic PCB, the polyimide made printed circuit boards also have multiple types. These classification has been made by determining the material used in synthesizing the amide polymer or polyimide.

The most common polyimide PCBs are:

Pure Polyimide or 2nd Generation Polyimide:

This is the simplest PCBs and lacks additional features such as brominated flame retardants. While the word ‘lacking’ is used negatively for most materials, pure polyimide has used it positively. The lack of flame retardants makes it extremely stable while still being flexible enough to use in different electrical and communicating devices. The polyimide is also occasionally called as polyimide flex PCB, mainly because of its useful flexibility.

Although it is the oldest of all polyimide PCB types, pure polyimides have widespread use. It is made possible thanks to the extreme endurance against temperature change and thermal stability during challenging situations.

3rd Generation Polyimide:

It is an updated version of pure polyimides. Also, it has additional additives which effectively make it more flammability resistance. The flammability resistance is crucial because it comes forward in stopping accidental electric fires.

However, the 3rd generation polyimide lacks the thermal stability of pure polyamides which can be a disadvantage for it. On the contrary, it is easy to manufacture, which propels the production line faster than any other polyimide flexible PCB.

So, you can manufacture the 3rd generation polyimide in bulk which lies in its vast favour.

Filled Polyimide:

This type of polyimide is similar to multilayer PCBs since it comes with more than one filler materials. The additional filler lowers the resin shrinkage.

The resin shrinkage resistance is vital since due to the shrinkage, many printed circuit boards become frail and cracks down during the drilling and curing proceedings. Also, the shrinkage resistance helps the filled polyimide maximize its long-term usage.

Low-Flow Polyimides:

The low-flow polyimides are made without the flexibility of the standard PCBs. So, sometimes people also refer to it as the rigid polyimide PCB.

The rigidity of the low-flow PCB comes useful when PCBs require stiffness to stay strong during the challenging conditions. So, when the traditional flexible PCBs fail, the low-flow polyimides come forward to solve the tough situations.

Benefits of Polyimide PCB

Since the polyimide PCB is a particular type of printed circuit boards, it is mainly used on special occasions. So, it would help if you understood when to use the polyimide PCB and when not to. Use the polyimide made PCBs when you need either one or all of the following characteristics:

  • Stable flexibility: The greatest benefit of the polyimide PCBs is its extreme stability and flexibility at the same time. It is a perfect combination of rigidity and flexibility which regular PCBs lack.
  • Tensile strength: Polyimide PCBs have excellent resistance against warping. It is made possible thanks to the flexibility of the polyimide materials. So, if you want durability for the PCB applications, the superior tensile strength and durability will be beneficial for you.
  • Thermal stability: Polyimide materials are known for having superior thermal endurance and resilience. So, the polyimide made PCBs are capable of working even at 260° temperature. Furthermore, thermal conduciveness prevents thermal damage during manufacturing and repairing jobs.
  • Extreme durability: Polyimide has resistance against various chemicals and temperature. So, it enjoys enhanced durability. The durability is essential to endure extreme physical stress which is a necessary benefit for PCBs.

Versatile Usage of Polyimide PCB

Both the rigid polyimide PCB and polyimide flexible PCBs are widely used in different industries. The most common applications of the polyimide PCBs are:

Computer and Laptops:

Modern-day laptops and computers suffer from heavy-duty usage and go through the extreme thermal rise of the components. Thus, the thermal conduciveness of the polyimide PCBs is beneficial for laptops and PCs.

Also, the flexibility and rigidity of these circuit boards come forward to enhance the overall durability of the computers.

Automotive Electronics:

Out of all electronic components, automotive electronics face the most challenging conditions. They need to function both in extreme cold and summer along with continuous jostling f multiple components.

Naturally, these automotive components ask for a durable PCB, which only the polyimide can supply.

Military and Aerospace:

Both the aerospace and military industry uses the most advanced electronics for their superior performance and safety requirements. Also, in both industry electronics component operates in the most hostile environment.

So, the durability and thermal stability of polyimide made PCB is essential to safeguard these components, which can be the ardent difference between life and death of millions.

Medical Industry:

Various medical treatments and diagnosis such as advanced imaging, implants and prosthetics require high-efficiency applications. This useful and high-performing efficiency will only come from the polyimide PCBs.

Differences Between FR4 and Polyimide PCB

When you know the factual distinctions between polyimide PCB and FR4, you will be able to pick the perfect printed circuit board for your desired jobs.

FR4 circuit boards are made of epoxy glass resin and laminated copper. So, it is rigid and not as flexible as the polyimide material. Also, polyimide is lightweight and more durable. Besides, polyimide also has better chemical and heat resistance compared to the FR4.

Last but not least, polyimide boards are more expensive the FR4. But its durability and widespread usage balance the overpricing to a greater extent.

The following table will help you understand the differences better between the FR4 PCB and polyimide PCBs-

Consideration Facts FR4 PCB Polyimide PCB
Tensile Strength
It has 231MPa which is more than 3X than FR4
Above-average to good
Extreme durability
Operating range
From -50°C to 110°C
From -200°C to 300°C
Thermal cycling
Quite a good cycling facility
The cycling facility is impressive
Resistance to chemical
Quite good
Quite good

Polyimide PCB with its great flexibility and extreme resistance to heat and chemicals is preferred in the aerospace industry. In fact, it has changed the aerospace industry quite brilliantly.

Who makes the best Polyimide PCB?

Many companies build polyimide PCBs and serve them in the market. But, not all of them are reliable. Hence, you must pick the right polyimide circuit board manufacturer for your works.

An ideal polyimide manufacturer will work with the highest-quality polymer plastics for the best flexibility and thermal resistance of the boards. Also, it should be able to offer you different types of polyimide circuit boards so you can easily get the right circuit boards.

FX PCB can be a reliable source in this regard. FX PCB with 10+ years of experience in manufacturing different types of PCBs will offer you tailored offers and the highest-quality PCBs. We manufacture both polyimide and FR4 circuit boards.

Also, FX PCB excels in building customized polyimide circuit boards for the aerospace and defense industry. It is a rare feature that most PCB builders won’t offer you.

The Bottom Line

We conclude the discussion on what is polyimide PCB with a high hope that you have a clear idea on the definition, usage and benefits of the polyimide PCBs. We built and supplied high-quality polyimide PCB that you can use in high-performing automotive, aerospace, military and daily electronics usage.

Also, polyimide PCBs are surely more durable and flexible than the standard FR4 ones. Its use in critical areas such as aerospace and defense technology is overwhelmingly massive. We are committed to serving you with the best polyimide PCBs for both sectors plus others as well.

Peter Gong
Peter Gong

I am Peter Gong. I have been working in PCB and PCBA industry for 15+ years now. I have been a part of the PCB revolution with my dedication to circuit board technologies and creative ideas. I write in FX PCB to impart my knowledge on PCB and PCBA for all circuit board lovers, manufacturers, and users.