Epoxy Fiberglass Glass Fiber Laminate

With the rapid development of electronic technology, FR4 sheet is becoming more and more important in electronic manufacturing.

 

First of all, FR4 sheet is actually a kind of glass fiber epoxy resin copper-clad board, which is a substrate in the circuit board. Simply put, FR4 sheet can be divided into two types: ordinary FR4 and high TG FR4. When the temperature rises to a specific region, the substrate will change from “glassy” to “rubbery”, and this temperature is called the glass transition temperature (Tg). In other words, Tg is the maximum temperature at which a substrate can remain rigid. Ordinary PCB substrate materials will soften, deform and even melt at high temperatures, and the mechanical and electrical properties will also decrease dramatically.

 

Generally speaking, the Tg of ordinary FR4 boards is above 130 degrees, while the Tg of high TG FR4 boards is usually greater than 170 degrees, and the medium Tg is around 150 degrees. Those PCB printed circuit boards with Tg ≥ 170 degrees Celsius are called high Tg printed circuit boards. The higher the Tg of the substrate, the higher the heat resistance, humidity resistance, chemical resistance and stability of the printed circuit board. High Tg is especially widely used in lead-free processes.

 

Overall, FR4 sheet is an indispensable and important material in electronics manufacturing, and its features and performance make it excel in high-temperature, high-moisture, and high-chemical corrosion environments. Whether it is ordinary FR4 or high TG FR4, they are providing solid support for our electronic devices.