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FR-4 Tg

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    What is 'Tg' of an FR-4 PCB?

    Tg is a measurement that's used to determine the glass-transition temperature of FR-4, which is the temperature at which the dielectric constant (εr) of the laminate increases by 0.1 after 30 minutes. Tg is measured under specific conditions and can be useful for determining whether or not your PCB will have problems similar to those seen in early electronic devices made from other materials such as polystyrene or polypropylene.

    Tg is the glass transition temperature of the laminate, measured under a set of specific conditions.

    Tg is the glass transition temperature of the laminate, measured under a set of specific conditions. This temperature defines when you can touch your PCB on top and feel it, but not when you can't.

    It's important to know what your board will do at this point, because once it gets to that point all bets are off for how well it will hold up over time and what kind of damage may occur if left unchecked.

    This is defined as the temperature at which the dielectric constant (εr) of the material increases by 0.1 after 30 minutes

    The glass transition temperature is the temperature at which a material changes from a hard, brittle material to a soft, rubbery material.

    The first step in this process is when heat is applied to the polymer sample and it begins to deform. When this happens, it becomes less viscous and more pliable at room temperature: if you could touch it with your fingers (or even better—your tongue), you would feel that it was softer than before. This can happen over time as well; for example, if you were making chocolate sauce by heating milk on stovetop until it thickens into hot chocolate pudding with lots of marshmallows floating around in there—that would also happen gradually due to thermal expansion of ingredients during cooking process!

    This temperature defines the point where the PCB laminate begins to soften and becomes vulnerable to damage

    The point at which the PCB laminate begins to soften and become vulnerable to damage is defined by the temperature at which it starts to change its properties. This temperature can be calculated using this equation:

    Damage may be in the form of deformation or loss of properties such as εr or CTE

    Damage may be in the form of deformation or loss of properties such as εr or CTE. The reason for this is that temperature affects both the mechanical and electrical properties of a PCB, which includes its conductivity and dielectric constant (εr). If you want to know more about how this works, check out our article on how heat affects your electronics.

    There are two main issues when it comes to keeping your FR-4 Tg boards at proper temperatures: overheating them too quickly (too much heat can damage them) or cooling them too slowly (they'll develop cracks). If you're not sure if your board is damaged yet, try checking its resistance between 0V and 10V with an ohmmeter—if there's no reading at all then it's probably fine!

    The Tg defines the minimum operating temperature for a PCB.

    The Tg defines the minimum operating temperature for a PCB. It is the glass transition temperature of the laminate, measured under a set of specific conditions (see below). The temperature at which this happens is called room-temperature cure or RTc; it may also be called short-time cure or STC if it takes place during fabrication and not in an ambient environment.

    The term “room temperature” means 20°C (68°F) but can vary depending on supplier and model number.

    Conclusion

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