Dissipation factor and service life of smd capacitor

    The loss tangent of the smd capacitor is also called the dissipation factor; the power capacitor is a real capacitor, not an ideal capacitor. Under the action of an external AC voltage, in addition to outputting a certain capacity of reactive power Q, it is inside the capacitor A certain amount of active power loss P is generated in the medium, in the plate (aluminum foil) of the capacitor, in the conductor such as the lead, and the leakage current between the porcelain bottles. Usually the ratio of the active power P and the reactive power Q of the capacitor is called the loss tangent of the capacitor. Insulation resistance refers to the application of a DC voltage to the dielectric. After a certain period of polarization, the leakage current flowing through the dielectric corresponds to The resistance is called insulation resistance.

    The service life of a smd capacitor (also defined as service life and operating life) is defined as the achievable life of the capacitor without exceeding the specified failure rate. The service life is obtained by using experience and accelerated aging test. If the load is lower than the rated value, the service life can be extended (such as low operating voltage, current and ambient temperature), and proper heat dissipation measures can also extend the service life. In addition to the above electrical parameters, SMD electrodeless capacitor also have reliability items such as dielectric strength, bending strength, storage temperature, temperature and humidity cycles, and solderability.