What is high Tg PCB material?
When the temperature of a high Tg circuit board rises to a certain area, the substrate will change from the "glass state" to the "rubber state". The temperature at this time is called the glass transition temperature (Tg) of the board. That is, Tg is the highest temperature (°C) at which the base material maintains rigidity. That is to say, ordinary PCB substrate materials not only produce softening, deformation, melting and other phenomena at high temperatures, but also show a sharp decline in mechanical and electrical characteristics (I think you don't want to see this in your own products).
Generally, the Tg of the board is above 130 degrees, the high Tg is generally greater than 170 degrees, and the medium Tg is about greater than 150 degrees.
Usually PCB circuit boards with Tg ≥ 170°C are called high Tg circuit boards.
The Tg of the substrate is increased, and the characteristics of the circuit board such as heat resistance, moisture resistance, chemical resistance, and stability will be improved and improved. The higher the TG value, the better the temperature resistance of the board. Especially in the lead-free process, high Tg applications are more common.
High Tg refers to high heat resistance. With the rapid development of the electronics industry, especially the electronic products represented by computers, the development of high functionality and high multilayers requires higher heat resistance of PCB substrate materials as an important guarantee. The emergence and development of high-density mounting technologies represented by Surface-Mount (SMT) & BGA Assembly and CMT have made HDI PCBs more and more inseparable from the high heat resistance of the substrate in terms of small aperture, fine circuit and thinner. support.
Therefore, the difference between general FR-4 and high Tg FR-4 is the mechanical strength, dimensional stability, adhesion, water absorption, thermal decomposition, There are differences in various conditions such as thermal expansion, and high Tg products are obviously better than ordinary PCB substrate materials. In recent years, the number of customers requiring high Tg circuit boards has increased year by year.
