In the field of PCBA patch processing, PCB base material selection is a key link. FR-4 board is a commonly used material for PCB multilayer boards, and it is widely used in the field of electronic engineering.
This article will delve into why FR-4 board is so popular in PCB multilayer board manufacturing and what advantages it has.
Table of Contents
- What is FR-4 board?
- Why choose FR-4 board for PCB multilayer board?
- Application areas of FR-4 boards
- FR-4 VS other materials
- Conclusion
What is FR-4 board?
FR-4 is a fiberglass-reinforced epoxy resin material. The “FR” in its name stands for “Flame Retardant” and the number “4” represents its flame retardant grade.

The material is self-extinguishing when heated, making it compliant with many electronics safety standards.
Why choose FR-4 board for PCB multilayer board?
- Excellent mechanical properties: FR4 PCB has high strength and stiffness, and can withstand various mechanical and thermal stresses during the PCB manufacturing process, ensuring the stability and reliability of multi-layer boards.
- Good electrical properties: FR-4 has excellent insulation properties and stable dielectric constant, which can ensure stable signal transmission in multi-layer boards and reduce signal distortion and crosstalk.
- Excellent thermal stability: FR-4 board has a low coefficient of thermal expansion and can maintain dimensional stability over a wide temperature range, which is crucial for electronic equipment that needs to withstand high-temperature welding and long-term operation.
- Easy to process: FR-4 material is easy to cut, drill and etch, suitable for various complex PCB processing processes, and can meet the high-precision and high-density manufacturing requirements of multi-layer boards.
- Cost-effectiveness: Although the price of the FR-4 board is not the lowest, considering its comprehensive performance and wide range of applications, it is a more cost-effective option.
- Environmental compliance: With the increasing awareness of environmental protection, FR-4 materials are constantly improving, and many manufacturers have been able to provide FR-4 boards that comply with environmental standards such as RoHS.
Application areas of FR-4 boards
Due to the excellent performance of FR-4 boards, they are widely used in various multilayer PCBs, especially high-end electronic products such as mobile phones, tablets, laptops, servers, communication equipment, and automotive electronics.
These fields have extremely high requirements on PCB performance and reliability. FR-4 boards can meet these requirements and ensure the stable operation of electronic equipment.
FR-4 VS other materials
In addition to FR-4, there are other materials used in PCB manufacturing such as CEM-1, CEM-3 and aluminum substrates.

However, compared with these materials, FR-4 has more balanced performance in terms of mechanical strength, electrical properties, thermal stability and processing performance. Although CEM-1 and CEM-3 are lower in cost, their performance is poor in high-temperature and high-humidity environments; although aluminum substrates have good heat dissipation performance, they are costly and difficult to process.
Therefore, FR-4 is still the mainstream choice for multilayer board manufacturing.
Conclusion
FR-4 boards occupy a dominant position in PCB multilayer board manufacturing due to their excellent mechanical properties, good electrical properties, excellent thermal stability, easy processing and high cost-effectiveness.
As the electronics industry continues to develop, the requirements for PCB performance are getting higher and higher, and FR-4 materials are constantly being improved and optimized to adapt to these new challenges and needs.
For engineers and technicians engaged in PCBA SMT processing, understanding the characteristics and advantages of FR-4 boards is of great significance for selecting appropriate PCB substrates and ensuring the quality and reliability of electronic products.











