Printed Circuit Boards (PCB) Fr4 Material
First, it is important to understand what FR-4 materials are. Fr stands for “flame retardant”, which is suitable for glass fiber reinforced epoxy laminate, making it an ideal substrate for electronic components on printed circuit boards. Glass fiber provides a more rigid and flame retardant rigid structure made of epoxy resin.
Most printed circuit boards are made from glass reinforced epoxy laminates. Although there are various laminates on the market, FR-4 is widely used and widely accepted as the standard material for PCB manufacturing. FR-4 is a good electrical insulator with good strength to weight ratio and flame retardancy.
FR-4 is the common name of glass fiber and epoxy resin matrix, which is currently used in most occasions. PC substrate. It has a variety of standard thicknesses and can be selected according to the size, deflection and stiffness requirements of the board. The FR-4 name is now also a common term used by many engineers for any glass fiber epoxy PC board, even if it is not FR-4 in the sense of the formal standard, because there are many substrates similar to FR-4, but do not comply with the formal specification.
The standard single weight thickness is 0.031 inch (0.78 mm), and the subsequent double and triple thickness are 0.062 inch (1.57 mm) and 0.093 inch (2.36 mm), respectively; thinner ones are also acceptable. The table in reference 1 lists about 30% of the nominal electrical and mechanical properties of the FR-4; they are essential for stable performance and the ability to use raw plates from different sources and manufacture. FR-4 is usually green, but sometimes other colors, such as blue, are used. There is no standard PC length or width, and the circuit board does not have to be rectangular. It can be round, it can have a cut or something else. In many ways, the green PC board is the defining image of modern electronic circuits (Figure 1).
The reason why FR-4 material is so popular is that it has many wonderful qualities that can benefit printed circuit boards. In addition to being cheap and easy to use, it is also an electrical insulator with high insulation strength. In addition, it is durable, moisture-proof, temperature resistant and light weight. You can use the FR-4 PCB in almost any electronic application.