What are High-TG PCBs? Where to Use & Advantages

High-Tg PCBs are ideal to use in high-temperature requirements (>170 degrees Celsius). Tg or Glass Transition Temperature defines the temperature limit for the proper working of PCB.

To put it simply, the working temperature of the PCB should always be less than the Tg(glass transition temperature) value of the substrate. Tg affects the molecular weight, crosslinks, and flexibility of the polymer used in the PCB board. High-Tg PCBs provide better stability and hassle-free operation at a higher temperature.

What happens when the temperature exceeds the Tg value for the PCB?

  • When the PCB temperature exceeds its Tg value for a considerable amount of time, the substrate undergoes a change from its glassy state to a rubbery state.
  • So the substrate doesn’t melt but becomes rubbery and undergoes structural change. With this, the PCB loses its mechanical and electrical properties.

Properties of High-Tg PCBs

Thermal expansion of FR-4 and FR-4 High-Tg with increasing temperature
Thermal expansion of FR-4 and FR-4 High-Tg with increasing temperature
  • While working on PCBs, the temperature is an important parameter to ensure reliability. Because as the temperature increases, the materials start expanding, and hence, their properties change.
  • So, to ensure that the PCB performs efficiently even at higher temperatures, High-Tg PCBs are used.
  • High-Tg materials have the following properties:

1. Lower thermal expansion.

High-Tg PCB undergoes lesser dimension changes at high temperatures. So, when the temperature lowers down, the chances of cracking or breaking the substrate reduces.

2. Better heat and moisture resistance.

High-Tg PCBs provide better mechanical and chemical resistance than Normal-FR4 PCBs. 


So, having discussed all this, you might have got the idea of using High-Tg PCBs in your projects. When it comes to high-temperature applications, you need to be sure that the PCBs will operate efficiently. PCBWay has all the experience and quality products to meet all your needs. So, visit PCBWay for all your PCB requirements.


Applications of High-Tg PCBs:

The High-Tg PCBs applications vary amongst various industries. Some of them are listed below:

1) Metal industries

  • Getting a proper metal shape requires cutting, grinding, welding, and melting of a metal piece. The temperature change in this process varies to a great extent. So, to keep the microcontroller of these machines flawless, High-Tg PCBs are required.
High-Tg PCB boards manufactured at PCBWay
High-Tg PCB boards manufactured at PCBWay

2) Engine controllers

Either it is the aerospace or automobile industry, both industries require reliable controllers to improve the engine’s efficiency. With greater RPM and longer running hours, the temperature of the unit rises significantly. So, the use of High-Tg PCB becomes necessary to withstand higher temperatures.

Advantages of High-Tg PCBs

1) Higher Stability

High-Tg PCBs have better heat, chemical, and moisture resistance. It improves the lifespan of the PCB board by reducing the short circuit and other PCB failures.

2) Ideal for Multi-layer PCBs

Multi-layer PCBs have complex and dense electronic circuits. With more electronic components placed in a confined space, the heat generation is way more than standard PCBs. So, an effective way to tackle this problem is to use substrate made of High-Tg material.

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