High Tg means high heat resistance. General Tg board for more than 130 degrees, high Tg PCB generally greater than 170 degrees, medium Tg is greater than 150 degrees. With the rapid development of electronic industry, especially electronic products represented by computer, the development towards high function and high multilayer requires higher heat resistance of PCB substrate material as an important guarantee.
The appearance and development of high density installation technology represented by SMT and CMT make PCB more and more inseparable from the support of high heat resistance of substrate in small aperture, fine wiring and thin type. The Tg of substrate is improved. The characteristics of PCB such as heat resistance, moisture resistance, chemical resistance and stability are improved. The higher the TG value, the better the temperature resistance. Therefore, high Tg is more widely used.
The higher the Tg point is, the higher the temperature requirement of the plate will be when it is pressed together. The pressed plate will also be hard and brittle, which will affect the quality of mechanical drilling (if any) in the later process and the electrical properties during use to some extent. Tg point is the maximum temperature at which the substrate remains rigid ("C "). That is to say, common PCB substrate materials not only produce softening, deformation, melting and other phenomena at High temperature, but also show a sharp decline in mechanical and electrical properties.
The general Tg plate is more than 130 degrees, the high-tg is generally greater than 170 degrees, and the medium Tg is about greater than 150 degrees. High tg PCB heat resistance, moisture resistance, chemical resistance, stability and other characteristics will be improved.