From the perspective of manufacturing process, there are four main types of chip inductors, including winding, lamination, weaving and film chip inductors. Commonly used are coil type and laminated type. The former is the product of miniaturization of traditional coil patch inductor, while the latter is made by multilayer printing technology and lamination production technology, which is smaller than coil patch inductor, and is a key product developed in inductor field.
The characteristics of SMD inductor are wide inductance range (mH~H), high inductance precision, small loss (i.e. large Q), large allowable current, strong inheritance of manufacturing process, simplicity, low cost, etc., but the disadvantage is further miniaturization. Ceramic-centered winding-type patch inductor can maintain stable inductance and high Q value at such high frequency, so it occupies a position in high frequency circuit.
Compared with wound inductor, chip inductor has many advantages: small size, which is beneficial to miniaturization of circuit, closed magnetic circuit, no interference with surrounding components, no interference from nearby components, and high density installation of components; Integrated structure, high reliability; Good heat resistance and weldability; Regular shape, suitable for automatic surface installation and production. TDK MLK inductor has small size, good weldability, magnetic screen, high density design, monolithic structure, high reliability, small MLG inductor and high frequency ceramics. It is suitable for high frequency circuits. MLK inductor has a working frequency of 12GHz, high Q and low inductance value (1n~22nh)
Patch inductor has the characteristics of keeping high Q, high precision, high stability and small volume in microwave band. The internal electrodes are concentrated at the same level, and the magnetic field distribution is concentrated. After installation, the equipment parameters change little, and it shows good frequency characteristics above 100MHz.
TDK brand NL series inductance is wound type, 0.01~100uH, accuracy 5%, QQ, which can meet NL series inductance, NL series inductance and 300mA;; NLV type has high q value and environmental protection (plastic); Type NL, suitable for power cord.
Patch inductor has magnetic shielding, sintering density and good mechanical strength. The disadvantages are low lattice ratio, low cost, good magnetic shielding and high sintering density. Disadvantages are three commonly used sheet elements: good sheet elements and good sheet elements.
The main specifications and sizes of SMD inductors are divided into 1005, 1608, 2012, 3216, 3225, 4516, 4532 and so on according to metric standards.