Multilayer coil component and method for manufacturing the same

Abstract

Provided is a highly reliable multilayer coil component wherein migration of Ag constituting an inner conductor is controlled, problem of internal stress is relaxed without forming an air gap between a magnetic ceramic layer and an inner conductor layer, DC resistance is lowered, and disconnection of an inner conductor due to a surge is prevented from occurring easily. A metal film (20) is distributed over the surface of an inner conductor (2), so that an air gap does not exist on the interface (A) of the inner conductor (2) including the metal film (20) and a magnetic ceramic (11) on the periphery of the inner conductor, and the interface (A) of the inner conductor (2) and the magnetic ceramic (11) is in a dissociative state. An acid solution containing a metal is infiltrated from the side surface of a magnetic ceramic element via a side gap portion, i.e. a region between the side portion of the inner conductor and the side surface of the magnetic ceramic element, so as to reach the interface of the inner conductor and the magnetic ceramic on the periphery thereof, and thus the metal is deposited on the surface of the inner conductor.

Description

technical field [0001] The present invention relates to a laminated coil component in which a helical coil formed by interposing an inner conductor layer mainly composed of Ag is arranged via a magnetic ceramic layer and connected to each other in a magnetic ceramic element, and a method for producing the same. Background technique [0002] In recent years, the demand for miniaturization of electronic components has increased, and the mainstream direction of coil components has gradually shifted to laminated coil components suitable for miniaturization. [0003] However, in a laminated coil component obtained by firing a magnetic ceramic and an inner conductor at the same time, internal stress due to the difference in thermal expansion coefficient between the magnetic ceramic layer and the inner conductor layer degrades the magnetic properties of the magnetic ceramic, causing the laminated coil to deteriorate. Problems such as the drop or deviation of the resistance value of...

AI Technical Summary

Problems solved by technology

[0005] However, in the multilayer resistive element of Patent Document 1, the magnetic ceramic element is immersed in a plating solution, and the plating solution is infiltrated from the portion of the internal conductor layer exposed on the surface of the magnetic ceramic element to the inside, thereby forming a plate on the magnetic ceramic layer. A discontinuous gap is formed between the inner conductor layer, therefore, an inner conductor layer and a gap are formed between the magnetic ceramic layers, resulting in a thinner inner conductor layer and a smaller ratio of the ceramic layers occupied by the inner conductor layer

[0006] Therefore, there is a problem that it is difficult to obtain products with low DC resistance

In particular, for small products such as products with a size of 1.0mm×0.5mm×0.5mm or products with a size of 0.6mm×0.3mm×0.3mm, it is necessary to make the magnetic ceramic layer thinner and provide an internal conductor between the magnetic ceramic layers. It is difficult to form both layers and voids and to make the inner conductor layer thicker. Therefore, not only the reduction of DC resistance cannot be achieved, but also the disconnection of the inner conductor is likely to occur due to surges, etc., and it is not possible to ensure The question of sufficient reliability

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