When the temperature rises to a certain area, the substrate will change from "glass state" to "rubber state", and the temperature at this time is called the glass transition temperature (TG) of the PCBs. In other words, TG is the maximum temperature (℃) at which the substrate remains rigid. At high temperature, ordinary PCB substrate materials not only soften, deform and melt, but also show a sharp decline in mechanical and electrical properties. Our TG 150 printed circuit boards can maintain the rigidity of the substrate at 150 ℃.
With the increase of Tg of the substrate, the heat resistance, moisture resistance, chemical resistance and stability of the circuit board will be improved. The higher the TG value, the better the temperature resistance of the plate, especially in the lead-free process, high Tg application is more.
With the rapid development of electronic industry, especially the electronic products represented by computers are developing towards high functionality and high multi-layer, which requires higher heat resistance of PCB
substrate materials as an important guarantee. The emergence and development of high density mounting technology represented by SMT and CMT makes PCB more and more dependent on the support of high heat resistance of substrate in small aperture, fine circuit and thin shape. Therefore, the difference between the general FR-4 and the high Tg FR-4 is that under the thermal state, especially after moisture absorption, the material has different mechanical strength, dimensional stability, adhesion, water absorption, thermal decomposition, thermal expansion and other conditions. Our TG 150 printed circuit boards is obviously better than the ordinary PCB substrate material.