The base material FR-4: What the Tg value says and what it doesn't stand for!

The base material FR-4: What the Tg value says and what it doesn’t stand for!

On this TechThursday we highlight one of the crucial and often misunderstood parameters in PCB and assembly design, the Tg value of FR-4, the most commonly used base material. 🛠️
This parameter is important for engineers and PCB designers because the material changes its properties at this point. FR-4 usually has a Tg value of around 130°C.

💡The common description of “Tg” as “glass transition temperature” can be misleading. In fact, the epoxy resin structure becomes soft and elastic above this temperature, which results in considerable expansion in the Z-axis. This expansion can cause serious defects: Cracks in plated-through holes, detachment of internal copper tracks or delamination of the material composite.

🌡It is essential that engineers keep the environment temperature of the electronic device, including a tolerance, below a certain threshold to ensure the mechanical integrity of the PCB.

🚨However, the Tg value is not an indicator of thermal performance or endurance of the PCB!

Our blog “FR4: Used by many, known by few” explains the correlations and what you should know about FR-4. In addition to a deeper insight, there are practical tips that can make PCB designs more reliable and right the first time.

👉 Click here for the article!

#eurocircuits #electronic #PCB #pcbdesign #pcbmanufacturing #fr4