What are the common types of surface mount inductors?
There are several types of inductors available on the market. How can they be distinguished from each other, and what factors should be considered when choosing the appropriate inductor for a specific application?
A multilayer inductor consists of a substrate structure and a coil. The substrate structure includes a layer of insulation material that covers a substrate and a coil formed on top of the insulation material. The main feature of multilayer inductors is their high magnetic density, which allows for a larger inductance value. In addition, their simple structure results in relatively low manufacturing costs.
An unshielded coil refers to a coil that is not covered by metal shield material (such as a magnetic core or magnetic powder). They are typically used in electronic circuits for energy storage and electromagnetic interference suppression. Unshielded inductors have lower electromagnetic interference suppression capabilities, and may not be ideal for use in environments with strong electromagnetic interference. However, their manufacturing costs are lower, making them a viable option for some applications
A semi-shielded inductor uses magnetic powder to cover the coil, providing shielding effects that fall between those of unshielded and shielded inductors. Semi-shielded coils are typically used in electronic circuits for energy storage and electromagnetic interference suppression. Compared to unshielded coils, semi-shielded coils have better electromagnetic interference suppression capabilities, but their manufacturing costs are slightly higher.
A shielded coil refers to a coil that is covered by metal shield material such as a magnetic core. Shielded coils are typically used in electronic circuits for energy storage and electromagnetic interference suppression. Compared to unshielded and semi-shielded coils, shielded coils have better electromagnetic interference suppression capabilities and can effectively prevent external electromagnetic interference from affecting the circuit. However, due to the use of shield material, the manufacturing costs of shielded coils are the highest among the four types.