What is PCB material Tg mean?

Tg is a mechanical property that designates glass transition temperature, that is, the temperature at which the base material (polymer or glass) shifts from a glassy, ​​solid, rigid state to a rubbery state. When the Tg is exceeded, materials don’t melt but undergo structural change and become rubbery.

The Glass Transition Temperature (Tg) is one of the most important properties of any epoxy and is the temperature region where the polymer transitions from a hard, glassy material to a soft, rubbery material.

PCB Circuit board material must flame-resistant, it can’t be burned at a certain temperature and only be soften. The temperature point is called the glass transition temperature (Tg).

The higher Tg point means higher temperature requirement during lamination. And the boards will be hard and crisp, which will affect hole and the electrical properties.

Ordinary PCB materials at high temperatures, not only will be soften, deformation, melting and other phenomena, but also the mechanical and electrical properties decline sharply.

General fr4 Tg is 130-140 centigrade, moderate Tg is greater than 150-160 centigrade, High-Tg is greater than 170 degrees.

The higher of Tg, the better performance of PCB heat resistance, moisture resistance, chemical resistance, stability and other characteristics. 



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