Understanding the Benefits of Using FR4 Stiffeners in Design

FR4 stiffener

FR4 stiffeners are essential to many electronic designs. These materials strengthen and reinforce printed circuit boards (PCBs) and other electronic components. They provide structural support and additional protection from environmental elements. Furthermore, we use FR4 stiffeners in designing PCBs subject to frequent vibrations and extreme temperatures. By providing extra strength and support, artist 3D FR4 stiffeners can help protect electronic components and improve overall performance.

Definition of FR4 stiffener

FR4 stiffener is a type of stiffener material made of fiberglass-reinforced epoxy resin. It helps construct electronic components such as circuit boards and other electronic components. It is a robust and lightweight material resistant to temperature and chemicals. In addition, it is also flame retardant and provides good electrical insulation. FR4 stiffeners can also reinforce PCBs and provide extra support to components on the board.

Structure of an FR4 Stiffener

FR4 is a type of composite material applicable in manufacture of PCBs and other electronic components. It is a glass-reinforced epoxy laminate famous for its high strength and electrical insulation properties.

A stiffener is a structural element that provides additional support and stiffness to a structure or component. In the FR4context, a stiffener is typically a strip of material you attach to the surface of the FR4. It provides additional support and rigidity. This extra support is helpful when the FR4 must withstand higher loads, stresses or maintain its shape under certain conditions.

The FR4 stiffener structure can vary depending on its specific application and system’s requirements or component where you use it.

However, standard features of an FR4 stiffener may include the following:

  • A central core of FR4 material provides the stiffener’s strength and electrical insulation properties.
  • Glass fibers embedded in the FR4 material provide additional strength and stiffness.
  • Adhesive layers attach the stiffener to the surface of the FR4 or other substrate.

Design considerations for FR4 stiffener

Flex PCB FR4 stiffener
  1. Thickness:

FR4 stiffener should have an appropriate thickness for the application. For example, if the application requires a stiffener with more rigidity, it should comprise of with a thicker material.

  • Size:

In designing an FR4 stiffener, one should determine the size required basing on the application and size of the components.

  • Cost:

 Engineers should consider the cost of the FR4 stiffener when choosing the material and thickness. In addition, the price should also include the adhesive and finishing costs.

  • Cutouts:

When designing an FR4 stiffener, it is necessary to consider the shape and size of the cutouts. The cutouts size should be appropriate for the application and should not weaken the overall structure of the stiffener.

  • Reinforcement:

FR4 stiffener should consist of an appropriate reinforcement, such as ribs and webs. This reinforcement will help to provide additional rigidity and strength to the stiffener.

  • Adhesive:

It should be carefully selected if an adhesive attaches the stiffener to the substrate. The adhesive should withstand the application’s temperature and humidity and provide a strong bond between the stiffener and the substrate. 

  • Finish:

FR4 stiffener should have an appropriate finish, such as a matte or glossy finish. This finish can help to protect the stiffener from corrosion and wear.

Steps involved in FR4 stiffener

FPC FR4 stiffener

The steps involved in manufacturing an FR4 stiffener will depend on the specific design and requirements of the stiffener, as well as the manufacturing processes and equipment used. However, some general steps involved in the process could include the following:

  1. Design: When manufacturing an FR4 stiffener, design it to meet the application’s specific requirements. This step may involve determining the stiffener’s size, shape, thickness, and other features, such as reinforcing elements or adhesive layers.
  2. Cutting: Once the design of the FR4 stiffener is complete, the next step is to cut the material to the desired shape and size. This process may involve various techniques, such as laser, water jet, or die cutting.
  3. Layering: In some cases, the FR4 stiffener may consist of multiple laminated layers of material. If this is the case, the next step in the process will be to lay down the various layers of fabric and bond them together using adhesive or heat.
  4. Curing: After the layers of the FR4 stiffener have bonded together, the material will need to cure to fully set the adhesive and ensure that the stiffener has the desired strength and stiffness. Depending on the adhesive used, this may be easy to achieve using heat or UV light.
  5. Finishing: The FR4 stiffener may need finishing to prepare it for use. The finishing process may involve trimming excess material, applying additional coatings or finishes, or attaching other components, such as mounting holes or mounting brackets.

Advantages of FR4 stiffener

FR4 is a composite material commonly used to manufacture printed circuit boards (PCBs) and other electronic components due to its high strength and electrical insulation properties. Adding a stiffener to an FR4 component can provide several additional benefits, including:

  1. Increased stiffness and strength: The stiffener can help to improve the overall stiffness and stability of the component. This can be particularly useful in situations where the component needs to withstand higher loads or stresses or where it needs to maintain its shape under certain conditions.
  2. Improved dimensional stability: An FR4 stiffener prevents the component from warping or deforming under load, enhancing its overall dimensional stability. This can be important for ensuring that the component functions correctly and maintains its performance over time.
  3. Enhanced electrical insulation: FR4 is famous for its high electrical insulation properties. Adding a stiffener can help further improve these properties by providing additional insulation between different layers or components.
  4. Increased durability: An FR4 stiffener can help to improve the overall durability of the component by providing additional support and protection against damage or wear. This can be particularly important in applications where the component will undergo harsh conditions or frequent use.

Disadvantages of FR4 stiffener

Flexible PCB FR4 stiffener

There are a few potential disadvantages to using an FR4 stiffener in specific applications, including:

  1. Increased cost: Using an FR4 stiffener can add additional cost to the component or structure, as it requires supplementary material and manufacturing steps. The high price may make the feature more expensive to produce, which could be a disadvantage in cost-sensitive applications.
  2. Increased weight: An FR4 stiffener can also add additional weight to the component or structure, which could be a disadvantage in applications where weight is a critical factor.
  3. Limited flexibility: Depending on the design of the FR4 stiffener, it may also limit the flexibility of the component or structure to some extent. This could be a disadvantage in situations where the feature needs to be able to bend or flex to a certain degree.
  4. Limited customization: Using an FR4 stiffener may also limit the ability to customize the component or structure to fit specific requirements or needs. This could be a disadvantage when the component needs tailoring to a particular application or environment.


In conclusion, the Artist’s 3D’s FR4 stiffener is a structural element that provides additional support and stiffness to an FR4 component or structure. It is typically made up of an FR4 core material reinforced with glass fibers and may include adhesive layers and reinforcing elements such as ribs or grooves.

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