The development history of smd inductor

The latest smd inductor for the three major electronic components

Among the three major electronic components of electronic circuits, resistors, capacitors, and inductors, the inductor is the latest one to start smd development.

This is determined by its own nature, because in order to obtain a smd inductor with good stability, inductance that can meet the circuit requirements, and high Q value, many contradictions and difficulties will be encountered in the manufacturing process.

E.g:

1. When reducing the size of an inductor in order to reduce its volume, the inductance will also decrease.

2. When reducing the cross-sectional area of the conductor and the spacing width between the conductors in order to make up for the above-mentioned deficiency, the minimum cross-sectional area of the conductor and the minimum conductor spacing width are restricted by the process conditions.

3. The parasitic resistance of the inductor after miniaturization is large, which will inevitably lead to a decrease in the Q value.

4. Film inductors made by thick film technology (screen printing and firing) or thin film technology (vacuum evaporation coating or sputtering coating) are prone to cause large electromagnetic leakage, which will cause contact with other conductors or electronic components Parasitic coupling.

5.Although the use of magnetic materials with a permeability greater than 1, can increase inductance, reduce electromagnetic leakage, weaken parasitic coupling, and improve Q value, but these advantages are often caused by the difficulties in the structure of the smd inductor and the process. The difficulty, the limitation of frequency characteristics, the loss of magnetic materials and the nonlinearity of inductance are offset by factors.

Development details

For these reasons, for a long period of time, people have tried their best to avoid using inductors in integrated circuit electrical schematics and surface mount technology. In recent years, with the improvement of material technology and manufacturing technology, these contradictions have been partially resolved or alleviated, so that the smd inductor has entered a period of rapid development. Of course, it still has no smd resistors and stickers. smd capacitors develop so fast, but their output, quality and variety are showing an upward trend year by year. Like electronic components such as smd resistor and smd capacitor, China has also entered the world in the research, production, and application of smd inductor.