The variation of resistance value of thick film resistors under temperature changes is mainly influenced by their temperature coefficient (TCR). The following is a detailed explanation of the resistance value changes of thick film resistors under temperature changes:
1. Temperature coefficient (TCR):
The temperature coefficient of thick film resistors is usually high, which means that their resistance value fluctuates greatly with temperature changes. According to the search results, the temperature coefficient of thick film resistors is generally between 50ppm and 200ppm/K. The temperature coefficient within this range indicates a high sensitivity of the resistance value to temperature changes.
2. The impact of temperature changes on resistance values:
In high temperature environments, the resistance value of thick film resistors may experience an increase or decrease, mainly due to changes in the thermal expansion coefficient of the resistor patch material. When the coefficient of thermal expansion is relatively small, the magnitude of the change is small.
In high temperature environments, the temperature coefficient of thick film resistors usually decreases, which means that when the temperature changes, the rate of change in resistance value will decrease.
In high temperature environments, the electrical power of resistors usually increases, mainly due to the decrease in resistance caused by temperature rise, resulting in an increase in current. This may cause the resistor to overheat, affecting the normal operation of the circuit.
3. Effects in high humidity environments:
In high humidity environments, the electrical performance of thick film resistors is mainly reflected in changes in resistance values and electro oxidation phenomena. Electrooxidation usually occurs at the end of a conductor, which may cause leakage and failure.
In summary, the resistance value of thick film resistors varies relatively greatly under temperature changes, especially in high temperature and high humidity environments. Therefore, when designing circuits, if there are high requirements for temperature stability, it may be necessary to consider using resistors with lower temperature coefficients or taking some temperature compensation measures to reduce the impact of temperature changes on circuit performance.
