High TG PCBs (Printed Circuit Boards), where TG stands for Glass Transition Temperature, are PCBs made from materials with a relatively high glass transition temperature. The glass transition temperature is the point at which a polymer - based material changes from a rigid, glassy state to a more flexible, rubbery state. High TG PCBs are designed to withstand higher temperatures during manufacturing processes and in operational environments, making them suitable for a variety of demanding applications.

The materials used in high TG PCBs typically have a TG value of 170°C or higher, compared to standard PCBs made from materials like FR - 4, which usually have a TG around 130°C. Common materials for high TG PCBs include modified epoxy resins, polyphenylene ether (PPE), and other high - performance polymers. These materials offer enhanced thermal stability, mechanical strength, and chemical resistance, allowing the PCBs to maintain their structural integrity and electrical performance under high - temperature conditions.

During the manufacturing process of PCBs, especially in processes such as surface mount technology (SMT) soldering and through - hole soldering, high temperatures are involved. High TG PCBs can withstand these elevated temperatures without warping, delaminating, or experiencing significant changes in their electrical properties. This is crucial for ensuring the reliability and quality of the assembled PCBs, as any deformation or degradation during manufacturing can lead to component failures and reduced product lifespan.

In terms of applications, high TG PCBs are widely used in industries where high - temperature operation is a norm. In the automotive industry, they are used in engine control units, power electronics, and other components that are exposed to high temperatures under the hood. The ability of high TG PCBs to maintain their performance in such harsh environments is essential for ensuring the safety and reliability of vehicles. In the aerospace and defense sectors, high TG PCBs are used in avionics systems, where they need to withstand the extreme temperature variations experienced during flight, from the cold of high altitudes to the heat generated by electronic components.

High TG PCBs are also important in the industrial automation field, where they are used in control systems, motor drives, and other equipment that may operate in high - temperature industrial environments. Additionally, in power supply units and high - power electronic devices, high TG PCBs are preferred as they can handle the heat generated by high - power components more effectively. As the demand for more powerful and compact electronic devices continues to grow, the use of high TG PCBs is expected to increase, as they provide the necessary thermal and mechanical stability to support the operation of these advanced systems.