First of all, talk about the high Tg refers to the high heat resistance. With the rapid development of electronic industry, especially on behalf of computer electronic products toward the high function, high-rise development, require higher PCB material heat resistance as an important guarantee. With SMT, CMT represented by the emergence of high-density mounting technology and development, and the PCB in the small hole size, fine lines, thinner, the more inseparable from the support substrate with high heat resistance.

PCB materials under high temperature, not only produce softening, deformation, melting and other phenomena, but also in the mechanical, electrical characteristics of the sharp decline (I think we do not want to see their products occurred).

So the general high-Tg FR-4 and the difference between the FR-4: In the thermal state, especially in the heat after absorption, its materials, mechanical strength, dimensional stability, adhesion, water absorption, thermal decomposition , thermal expansion differences in various situations, high Tg products significantly better than the common PCB materials. This is why to use the high Tg PCB material.