What is a high-TG PCB?
“TG” means the glass transition temperature of the printed circuit board(PCB); it is the temperature point when the PCB material starts to change. The circuit board will pass from solid into a rubbery state if the working temperature exceeds the specified TG value, and the performance of PCBs will be adversely affected.
Usually, standard PCBs are made of materials with a TG value of 140 °C and can withstand an operating temperature of 110 °C. These PCB materials will get soft, melt, even deform when at high temperatures, which will reduce the mechanical and electrical properties of overall products. Therefore, this ordinary PCB may not suitable for extreme temperature situations that are common in applications such as industrial electronics, automotive, and high-temperature electronics.
High-TG PCBs refer to the TG value of PCB materials is greater than 170 °C. The higher the TG value, the better the performance of the PCB heat durability, chemical resistance, and stability.
When does the high-TG PCB is necessary?
With the rapid development of the electronics industry, the represented products such as computers are developing towards high performance and high-density. PCB materials with higher heat resistance are the guarantee to meet development demands.
In general, the TG value of PCB should be at least 10-20 °C higher than the operating temperature of the product. If the TG value is 130 °C, the operating temperature should be lower than 110 °C; if the TG value is 170 °C, the operating temperature should be lower than 150 °C. High heat is terrible for unprotected PCBs, the dielectric and conductor will be damaged, and mechanical stresses will be created due to the differences in thermal expansion rates, which will result in performance instable, even complete failure.
High-TG PCB is likely the only answer in the PCB fabrication if you are working with high power density designs, or need a lead-free PCB assembly manufacturing process. The more heat you need to deal with, the greater the impact on PCB design. Adding the radiators and fans may increase the weight, size, and cost of products; reducing the power density may limit the effectiveness of overall outcomes. In this case, high-TG materials may be the right choice to be a part of the whole thermal control solution.
What are the high-TG materials in PCB manufacturing?
FR-4 is the grade name of flame-retardant fiberglass reinforced epoxy material. The PCBs manufactured with FR-4 material has a higher heat resistance than standard PCBs. Generally, the TG value of FR-4 material is 120-180 °C. And you also can choose the Ceramic, Polyimide, or PTFE materials if you have the demands of TG at least 200 °C.
NextPCB is an experienced PCB prototype and PCB assembly manufacturer, which offers high-TG PCBs that are fabricated using FR-4 with high heat resistance as the substrate material, and other materials are also available. Many customers from military, national defense, power, nuclear, electric power, automotive, and other industries regard NextPCB as a great partner in their PCB design and manufacturing. The experts in NextPCB will provide ideal solutions for you if you have any plan in your PCB projects.