Surface-mounted inductor and wafer-level manufacturing method thereof

Abstract

The invention relates to a surface-mounted inductor and a wafer-level manufacturing method thereof and belongs to the field of manufacturing of passive devices. The surface-mounted inductor comprises a substrate (110), more than one metal wiring layer (200) which form an inductance structure in a central inductance coil area, and electrodes (300) in electrode areas on two sides; the metal wiring layers (200) are electrically connected through dielectric layer through holes (401); a metal wiring layer I (210) and a metal wiring layer II (220) of the metal wiring layers (200) extend to the electrode areas on the two sides and are connected with the electrodes (300) which have the same height on the two sides; a surface protecting layer (500) covers the surface of the metal wiring layer (200) in the upper most layer. According to the invention, inductors, electrodes and other structures are manufactured on the surface of a wafer through a wafer-level re-wiring technology, so that the obtained surface-mounted inductor is higher in inductance precision, smaller in thickness, and higher in reliability, and can overcome the defect of upwarp of a single side in surface-mounting, and realize high-density surface-mount.

Description

technical field [0001] The invention relates to a surface-mounted inductance device and a wafer-level manufacturing method thereof, belonging to the field of passive device manufacturing. Background technique [0002] Inductors are essential components in electronic devices. With the miniaturization trend of electronic devices, especially handheld electronic devices such as mobile phones, the size of inductors is getting smaller and smaller. At present, the RF inductor models for wireless communication mainly have 0201 size and 0402 size (imperial system). Among them, the package length of the 0201 size model is between 500 microns and 700 microns, the width is between 250 microns and 350 microns, and the height is 250 microns. Microns to 350 microns; 0402 size models have packages with lengths between 900 microns and 1100 microns, widths between 400 microns and 600 microns, and heights between 450 microns and 550 microns. Traditional inductors are mainly made by multi-lay...

AI Technical Summary

Problems solved by technology

As shown in the right figure of Figure 2, with the inductance device It keeps shrinking, and its own weight is getting lighter and lighter. If the wetting force between the two electrodes of the inductor and the solder is unbalanced during the surface mount process, one end of the inductor will be lifted, resulting in poor assembly and greatly reducing the assembly yield.

In addition, since the solder will climb to the side wall of the electrode, if the two inductors are too close to each other during assembly, solder bridges will easily appear. Therefore, the distance between the two devices needs to be opened when designing the circuit board, which will lose The circuit board area cannot achieve high-density mounting

[0003] In the LTCC process, the metal circuit used to form the inductor coil is formed by printing and sintering. Due to the limitation of the printing process capacity, the dimensional accuracy of the metal circuit is not high. It is also impossible to achieve narrow-pitch circuit printing, so the precision of the inductors produced by this process is low, usually the precision of the inductors less than 4nH can only reach + / -0.3nH, which cannot meet the needs of high-efficiency radio frequency systems

In addition, as shown in Figure 3, the LTCC process Inductors are usually multi-layer structures, and the lines are distributed throughout the thickness of the inductor, so it is difficult to achieve ultra-thin packaging

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