Distinguishing High Tg PCBs from Conventional Tg PCBs
Distinguishing High Tg PCBs from Conventional Tg PCBs
In the realm of PCBs (Printed Circuit Boards), Tg value typically refers to the Glass Transition Temperature, denoting the temperature at which the resin substrate transitions from a glassy to a rubbery state, exhibiting significant changes in properties with temperature variations. Tg serves as a critical indicator of high-frequency PCB performance, widely utilized in industries such as defense, communication, and computing. In recent years, with the rise of technologies like 5G and AI, the demand for high-performance PCBs has surged, driving the elevation of Tg values once again.
Overview of High Tg and Conventional Tg PCBs:
Conventional Tg PCBs typically refer to FR4 substrates with Tg values below 130°C, while High Tg PCBs boast Tg values above 170°C, primarily catering to high-speed transmission and high-frequency communication fields.
Key Differences between High Tg and Conventional Tg PCBs:
a. Temperature Control:
High Tg PCB fabrication necessitates tighter temperature control and higher processing temperatures exceeding 180°C to ensure superior high-temperature performance.
b. Mechanical Strength:
High Tg PCBs exhibit enhanced mechanical strength, maintaining specified mechanical properties even at elevated temperatures.
c. Thermal Stability:
High Tg PCBs demonstrate exceptional high-temperature thermal stability, low thermal expansion coefficient, high glass transition temperature, and minimal water absorption, surpassing conventional PCBs, ensuring minimal impact on circuitry during thermal expansion deformation.
d. High-Frequency Performance:
As active device frequencies increase, the demand for higher Tg values escalates. High Tg correlates significantly with high-frequency performance, manifesting in reduced vertical voltage standing wave ratio (VSWR), lower signal loss due to dielectric loss, and decreased signal delay.
Advantages of High Tg PCBs in Applications:
a. Higher Applicable Frequency Bands:
High Tg PCBs excel in 5G communication and high-speed data transmission domains, offering stable and reliable performance.
b. Enhanced PCB Processing Adaptability:
High Tg PCBs exhibit superior processing maintainability, reliability, and compatibility with other materials in manufacturing, stacking, multilayer board design, and layer stackup design.
c. Compliance with Environmental Standards:
High Tg PCBs not only deliver high performance but also comply with environmental protection requirements, making them the preferred solution in complex multilayer board applications.
In conclusion, the escalating demand for high-performance PCB materials in high-speed transmission, high-frequency communication, and 5G applications has propelled the widespread adoption of High Tg PCBs. Their superior high-temperature stability, thermal expansion coefficient stability, and environmental compliance enhance PCB transmission performance significantly, making them indispensable in modern technology landscapes.