Common Causes of Film Capacitor Failure

Film capacitors are widely used as fundamental components in electronic devices, and their stability directly affects the reliability of the entire circuit. However, in practical applications, these capacitors often fail due to various reasons, primarily including voltage abnormalities, excessive temperature, and inherent product quality issues.

First, excessive voltage is one of the main causes of film capacitor failure. Each film capacitor has its rated operating voltage. If the circuit voltage exceeds its tolerance range, it may cause partial discharge inside the dielectric material, or even breakdown. Furthermore, some unscrupulous manufacturers in the market sell low withstand-voltage products as high-voltage models, making these capacitors prone to breakdown even under normal operating conditions.

Secondly, high temperature also significantly impacts capacitor lifespan. Film capacitors typically have a specified operating temperature; for instance, CBB capacitors generally withstand up to 105°C, while CL capacitors can endure up to 120°C. Prolonged operation in high-temperature environments accelerates the thermal aging of the dielectric material, shortening the capacitor's service life. Therefore, proper attention to ventilation and heat dissipation during installation is essential to ensure the capacitor operates within a safe temperature range.

Finally, inferior product quality is another critical factor that cannot be overlooked. In the fierce market competition, some manufacturers cut costs by using poor-quality materials and simplified production processes. This results in capacitors with unstable internal structures and poor insulation performance, severely shortening their service life and potentially causing failures within just one year of operation.

In summary, selecting genuine film capacitors that meet specifications, along with proper circuit design and adequate heat dissipation, is crucial for ensuring the long-term and stable operation of these components.