What are the disadvantages of thin-film power resistors

Although thin-film power resistors have many advantages, they also have some disadvantages. The following is a summary of the main drawbacks of thin-film power resistors:

High temperature coefficient:
The resistance value of thin film resistors may change with the variation of operating temperature, that is, their temperature coefficient is relatively large. This may have adverse effects on some high demand application scenarios, especially in situations where precise control of resistance values is required.
Relatively poor reliability:
The connection method of thin film resistors is mostly welding, and the welding interface is easily affected by mechanical and thermal stresses, which may lead to a decrease in the reliability of the resistor. Under long-term use or harsh environmental conditions, welding points may become loose or broken, which can affect the stability and performance of the circuit.
High cost:
Due to the relatively complex manufacturing process of thin film resistors and the need for high-precision materials and equipment, their production costs are usually high. This may limit the use of thin-film resistors in some low-cost applications.
Restricted resistance range:
The resistance range of thin film resistors is limited by the thickness and material of their resistance layer. Specific film materials can only produce resistors within a certain range of resistance values, which may limit the applicability of thin film resistors in certain specific applications.
Sensitive to humidity:
The resistance layer of thin film resistors is relatively thin and easily affected by humid environments. When water vapor passes through resistor encapsulation, it may introduce impurities and cause chemical corrosion, resulting in changes in resistance values and performance degradation. Therefore, special attention should be paid to protective measures when using in humid environments.
In summary, although thin-film power resistors have advantages such as high precision and stability, they also have disadvantages such as high temperature coefficient, poor reliability, high cost, limited resistance range, and sensitivity to humidity. When choosing resistors, it is necessary to weigh and consider specific application scenarios and requirements.