There are many types of SMD capacitors, which can be classified in various ways. The following are several main classification perspectives and their common types:
The phenomenon of low capacitance of surface mount capacitors (especially MLCC) when tested directly with a capacity of over 1uF is usually caused by the following key factors:
The storage time of capacitors is significantly affected by the type, storage conditions, and packaging process, with significant differences among different types. The following is a storage guide that integrates the characteristics of various capacitors:
Capacitor breakage is a common problem in electronic production, especially in ceramic capacitors (MLCC), which can lead to early product failure or reduced reliability. Preventing and controlling capacitor breakage requires comprehensive management from multiple aspects such as design, materials, processes, equipment, operation, and environment. Here are some key prevention and control measures:
Surface mount capacitors (especially multi-layer ceramic capacitors - MLCC) are prone to breakage or terminal detachment, mainly due to their own structure, material properties, and the combined effect of external stress. The following are the main reasons:
Leakage of surface mount capacitors (i.e., a decrease in insulation resistance causing unexpected current to pass through the dielectric) is a common failure mode, typically caused by multiple factors acting alone or in combination. Its essence lies in the destruction of the insulation performance of the dielectric:
It is a normal physical phenomenon for surface mount capacitors (especially the most commonly used multilayer ceramic capacitors MLCC) to have extremely small leakage currents, but the leakage currents must be within the allowable range specified in the manufacturer's specifications. Leakage current exceeding the specifications is considered a fault or abnormal phenomenon, indicating that the capacitor may be damaged or its performance may deteriorate.
The polarity of surface mount capacitors depends on their type and cannot be generalized. It is mainly divided into two categories:
The leakage current of MLCC (multi-layer ceramic chip capacitor) is the core indicator for evaluating its insulation performance, and its normal range shows significant differentiation due to differences in dielectric type, operating voltage, temperature, capacity, and manufacturing process. The reasonable range of MLCC leakage current is systematically analyzed from four dimensions: technical principles, influencing factors, testing standards, and selection suggestions, combined with typical data and cases:
Fracture of surface mount capacitors (MLCC) is a common and serious failure mode in electronic assembly and use. The essence of its fracture is that the mechanical or thermal stress borne by the brittle ceramic body (dielectric layer) exceeds the material strength limit. The following is a systematic analysis of the reasons:
