FR4 circuit board is a PCB that we often use.FR4 is the most commonly used material for printed circuit boards. FR4 describes a class of flame retardant glass fiber epoxy laminates.Most PCBs are made of FR4 as the base material. While this choice may not lead to disaster, it may make your design far less optimized for its intended functionality.
Most electrical engineers and those involved in printed circuit boards are familiar with FR4 materials. FR4 is the basic material for most rigid circuit boards. However, many people don’t know what FR4 is, let alone why it is the most popular PCB foundation.
What is FR4 material?
FR4, also known as FR-4, is both a name and a grade. The name is applicable to glass fiber reinforced epoxy laminates used in printed circuit board manufacturing. “Fr” means the material is flame retardant, “4” means glass fiber reinforced epoxy resin. However, the name is also used as a rating for epoxy laminates. The name essentially indicates the basic quality of the laminate, indicating that all kinds of plates and designs are lower than FR4 grade. “Fr” in the name stands for flame retardant, while 4 is different from similar materials.
The material widely known as FR4 is a composite structure. The most basic layer of the material is glass fiber woven into a thin cloth. Glass fiber endows FR4 with necessary structural stability. Then, the innermost glass fiber layer is surrounded by flame retardant epoxy resin and bonded. In addition to other physical properties, the resin gives the material rigidity.