CHIP DEVICE, MULTI-LAYERED CHIP DEVICE AND METHOD OF PRODUCING THE SAME

There is provided a multi-layered chip device, including: a multi-layered body in which a plurality of inner magnetic layers are stacked; an inner electrode layer formed within the multi-layered body; an outer magnetic layer stacked on at least one of an upper surface and a lower surface of the multi-layered body; and external electrodes formed on outside of the multi-layered body and the outer magnetic layer and electrically connected to the inner electrode layer, wherein a length of the outer magnetic layer is shorter than the inner magnetic layer.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In addition, singular forms used in the specification are intended to include plural forms unless the context clearly indicates otherwise. In the specification, it is to be noted that the terms “comprising” or “including”, and the like, are not to be construed as necessarily including several components or several steps described in the specification, and some of the above components or steps may not be included or additional components or steps are construed as being further included.

Terms used in the specification, ‘first’, ‘second’, etc. can be used to describe various components, but the components are not to be construed as being limited to the terms. The terms are used to distinguish one component from another component. For example, the ‘first’ component may be named the ‘second’ component and the ‘second’ component may also be similarly named the ‘first’ component, without departing from the scope of the present invention.

A chip device according to an embodiment of the present invention may be appropriately applied as a chip inductor in which conductive patterns are formed on magnetic layers, a power inductor, chip beads, a chip filter, and the like.

Hereinafter, embodiments of the present invention will be described with reference to a multi-layered chip inductor.

FIG. 1is a partially cutaway perspective view of a multi-layered chip inductor according to an embodiment of the present invention andFIG. 2is a schematically exploded perspective view of a stacked appearance of the multi-layered chip inductor ofFIG. 1.

FIG. 3is a schematic plan view showing an appearance of conductive patterns formed on magnetic layers ofFIG. 1.

Referring toFIGS. 1 to 3, a multi-layered chip inductor10may include a multi-layered body15, conductive patterns40, a magnetic layer62, outer magnetic layers100-1and100-2, and external electrodes20. The magnetic layer62may be generally referred to as an inner magnetic layer.

In addition, according to another embodiment of the present invention, the multi-layered chip inductor10may further include an additional magnetic layer64. However, the multi-layered chip inductor10does not necessarily include the magnetic layer64as an essential component.

The multi-layered body15may be manufactured by printing the conductive patterns40on magnetic green sheets and stacking and sintering the magnetic green sheets on which the conductive patterns40have been formed.

The multi-layered body15may have a hexahedral shape. When the magnetic green sheets are stacked and sintered as a chip, the multi-layered body15may not be formed to have a hexahedral shape having a complete straight line due to a sintering shrinkage of ceramic powders. However, the multi-layered body15may be substantially formed to have a hexahedral shape.

When defining a hexahedral direction in order to clearly describe embodiments of the present invention, L, W, and T shown inFIG. 1each represent a length direction, a width direction, and a thickness direction. Here, the thickness direction may be used as the same concept as a direction in which the magnetic layers are stacked.

According to the embodiment ofFIG. 1, the multi-layered chip inductor10has a rectangular parallelepiped shape in which the length is larger than the width or thickness.

Meanwhile, a size of the multi-layered chip inductor10according to an embodiment of the present invention may have a length and a width within a range of 2.5±0.1 mm and 2.0±0.1 mm (2520 size), or may also be formed to have 2520 size or below, or2520size or more, including the external electrodes20.

The magnetic layer62may be formed of a Ni—Cu—Zn-based material, a Ni—Cu—Zn—Mg-based material, a Mn—Zn and ferrite-based material, but the embodiment of the present invention is not limited thereto.

Referring toFIG. 1, the outer magnetic layer100-1may be stacked on an upper surface of the multi-layered body15. In addition, the outer magnetic layer100-2may be stacked on a lower surface of the multi-layered body15.

A length of the outer magnetic layer100-1may be shorter than that of the inner magnetic layer62. The reason is that when the outer magnetic layer100-1is stacked on the upper surface of the multi-layered body15, the external electrodes need to be formed around the upper surface of the multi-layered body15that is not covered by the outer magnetic layer100-1. In addition, the reason is that when the outer magnetic layer100-2is stacked on the lower surface of the multi-layered body15, the external electrodes20need to be formed around the lower surface of the multi-layered body15that is not covered by the outer magnetic layer100-2.

Meanwhile, the outer magnetic layers100-1and100-2may be formed of the same material as a material used to form the inner magnetic layer62.

The conductive patterns40may be formed by printing a conductive paste using silver (Ag) as a main component at a predetermined thickness. The conductive patterns40may be electrically connected to the external electrodes20that are formed at both longitudinal ends.

The external electrodes20are formed at both longitudinal ends of the ceramic body15and may be formed by electroplating an alloy selected from Cu, Ni, Sn, Ag, and Pd. However, the embodiment of the present invention is not limited to these materials.

The conductive patterns40may include leads that are electrically connected to the external electrodes20.

Referring toFIG. 2, a conductive pattern40aon a single multi-layered carrier60aincludes a conductive pattern42ain a length direction and a conductive pattern44ain a width direction. The conductive pattern40ais electrically connected to a conductive pattern40bon another multi-layered carrier60bhaving a magnetic layer62adisposed therebetween through via electrodes formed on the magnetic layer62ato thus form coil patterns in a multi-layered direction.

All the coil patterns according to the embodiment of the present invention have a turn number of 9.5 times, but the embodiment of the present invention is not limited thereto. In order for the coil patterns50to have a turn number of 9.5 times, thirteen multi-layered carriers60a,60b, . . . ,60min which conductive patterns40a,40b, . . . ,40mare formed are disposed between upper and lower magnetic layers80aand80bforming a cover layer.

The embodiment of the present invention discloses the conductive patterns42aand44brequiring two multi-layered carriers so as to form the coil pattern50having a turn number of one time, but is not limited thereto and therefore, may require different number of multi-layered carriers according to a shape of the conductive pattern.

Here, excellent DC bias characteristics may be provided within the limited multi-layered body15by reducing an interval between the magnetic layers between the upper conductive pattern40aand the lower conductive pattern40bthat face each other in the multi-layered direction, having the magnetic layer62atherebetween. When the interval between the magnetic layers can be reduced, the thickness of the conductive patterns42aand44ais increased and thus, the resistance of current flowing in a coil may be reduced.

Meanwhile, the outer magnetic layer100-1may be disposed on the magnetic layer80a. Further, the outer magnetic layer100-2may be disposed under the magnetic layer80b. In this case, the outer magnetic layers100-1and100-2may increase the inductance of the multi-layered inductor without increasing DC resistance. Also, as described above, the length of the outer magnetic layers100-1and100-2may be shorter than that of the inner magnetic layer.

In addition, the outer magnetic layer100-1may be disposed so that a center of the outer magnetic layer100-1corresponds to a center of the magnetic layer80a. Also, the outer magnetic layer100-2may be disposed so that a center of the outer magnetic layer100-2corresponds to a center of the magnetic layer80b.

Describing one-time turn of the coil pattern50with reference toFIG. 3, when a single via electrode72bis defined as 1 and another via electrode74bis defined as 2, in the conductive pattern40bformed on a single magnetic layer, a via electrode72cof the lower conductive pattern42cin the multi-layered direction, corresponding to the 2, is defined as 3, and an opposite point of the conductive pattern42cof a dielectric layer60c, facing the 1, is defined as 4; one-time turn (1→2→3→4) is formed counterclockwise from 1, which may be defined as one turn.

The multi-layered chip inductor ofFIG. 1is cut in a length direction L and a thickness direction T shown inFIGS. 4A and 4B.

Referring toFIGS. 4A and 4B, when the multi-layered chip inductor is viewed in the length direction L and the thickness direction T, leads48that are electrically connected to the external electrodes20are formed on top and bottom magnetic layers on which the conductive patterns40are formed. The leads48are exposed to ends Ws1and Ws2in a length direction of the ceramic body15and are electrically connected to the external electrodes20.

The conductive patterns40may be disposed to face each other within the multi-layered body15, having the magnetic layer62therebetween.

Meanwhile, the outer magnetic layer100-1may be stacked on the multi-layered body15. The outer magnetic layer100-1may be disposed between upper portions20-1of both external electrodes20. Further, both ends in the length direction L of the outer magnetic layer100-1may be in contact with the upper portions20-1of the external electrodes.

Meanwhile, the outer magnetic layer100-2may be stacked on the lower surface of the multi-layered body15. The outer magnetic layer100-2may be disposed between lower portions20-2of both external electrodes20. Further, both ends in the length direction L of the outer magnetic layer100-2may be in contact with the lower portions20-2of the external electrodes20.

FIG. 4Bis an enlarged cross-sectional view of portion A ofFIG. 4A.

As shown inFIG. 4B, a thickness T1of the outer magnetic layer100-1may be determined based on a thickness T2of the upper portion20-1of the outer electrode. According to the embodiment of the present invention, the thickness T1of the outer magnetic layer100-1may be equal to the thickness T2of the upper portion of the external electrode. Also, the thickness T1of the outer magnetic layer100-1may be 0.9 to 1.1 times of the thickness T2of the upper portion of the external electrode.

Since a stacking height of the outer magnetic layer100-1is similar to the thickness T2of the upper portion of the external electrode, the inductance of the multi-layered inductor may be increased without increasing the entire chip height of the multi-layered inductor.

Meanwhile, the thickness of the outer magnetic layer100-2and the thickness of the lower portion20-2of the external electrode may satisfy the above relationship.

Meanwhile, the inductance of the multi-layered chip inductor having 2520 size was measured by adopting the configuration of the present invention. Reviewing simulation results, the multi-layered inductor adopting the outer magnetic layers100-1and100-2had inductance about 2% higher than in the configuration of the related art in which the outer magnetic layers100-1and100-2are not adopted.

That is, a product in which ferrite is formed at the same height as the external electrode may have improve initial inductance and DC bias characteristics as compare with the existing products. For example, when comparing the inductor according to the present invention with the inductor according to the related art at the same height, the inductor according the present invention shows the improved initial inductance and DC bias characteristics.

FIG. 5is a cross-sectional view of a multi-layered inductor according to another embodiment of the present invention.

Generally, in the multi-layered inductor, the magnetic layers and the conductive patterns are alternately stacked, and the conductor patterns may be formed of coil conductors electrically connected to each other between the layers.

However, the multi-layered inductor as described above may suddenly degrade the inductance due to the occurrence of magnetic saturation of the magnetic substance due to the increase in current when DC current is applied thereto.

That is, the multi-layered inductor as described above may have a defect of the deterioration in DC overlapping characteristics.

For this reason, the multi-layered inductor having a magnetic gap part in which a part of the magnetic layer is substituted into a non-magnetic substance. The multi-layered inductor including the magnetic gap part may suppress the magnetic saturation occurring when the DC current is applied thereto, thereby improving the DC current overlapping characteristics.

According to the embodiment of the present invention, the multi-layered inductor including a magnetic gap90may include the outer magnetic layers100-1and100-2.

The multi-layered inductor as described above suppresses the magnetic saturation, thereby improving the DC current overlapping characteristics and increasing the inductance.

FIG. 6A through 6Care diagrams illustrating a method of producing a multi-layered inductor according to an embodiment of the present invention.

According to the embodiment of the present invention, as shown inFIG. 6A, the multi-layered body15may be prepared. The multi-layered body15may be formed by the stacking method as shown inFIG. 2. In addition, the multi-layered body15may be formed by various methods in addition to the stacking method as shown inFIG. 2.

Referring toFIG. 6B, the outer magnetic layer100-1may be stacked on the upper surface of the multi-layered body15. Further, the outer magnetic layer100-2may be stacked on the lower surface of the multi-layered body15.

The length of the outer magnetic layer100-1may be determined based on the lengths of the outer magnetic layers100-1and100-2and the upper portions20-1of the external electrodes that are formed on external surfaces of the multi-layered body15. For example, the length of the outer magnetic layer100-1may be formed to be equal to a distance between ends of the upper portions20-1of both external electrodes. In addition, the length of the outer magnetic layer100-2may be determined based on the lengths of the outer magnetic layers100-2and100-2and the lower portions20-2of the external electrodes that are formed on external surfaces of the multi-layered body15.

As such, in the process of preparing the outer magnetic layers having the length as described above, there is no need to perform an additional process of cutting the outer magnetic layer, such that the multi-layered process time may be shortened.

In addition, in the process described above, inductor performance may be improved without being degraded therefor due to remnants generated during the cutting of the outer magnetic layer.

Meanwhile, the outer magnetic layers100-1and100-2may be stacked on the upper and lower surfaces of the multi-layered body15. In addition, the outer magnetic layer may be stacked only on one surface of the upper and lower surfaces of the multi-layered body15as needed.

As shown inFIG. 6C, the external electrodes20may be formed on outside of the multi-layered outer magnetic layers100-1and100-2and the multi-layered body.

FIGS. 7A through 7Dare diagrams illustrating a method of producing a multi-layered inductor according to another embodiment of the present invention.

According to the embodiment of the present invention, as shown inFIG. 7A, the multi-layered body15may be prepared. The multi-layered body15may be formed by the stacking method as shown inFIG. 2. In addition, the multi-layered body15may be formed by various methods in addition to the stacking method shown inFIG. 2.

Referring toFIG. 7B, the outer magnetic layer100-1may be stacked on the upper surface of the multi-layered body15. Also, the outer magnetic layer100-2may be stacked on the lower surface of the multi-layered body15.

In this case, the length of the outer magnetic layers stacked on the upper surface and/or the lower surface of the multi-layered body15may be equal to the length of the inner magnetic layer configuring the multi-layered body15.

In this case, since the magnetic substance used to form the multi-layered body15may be used for forming the outer magnetic layer, the process may not require a process of separately preparing the outer magnetic substance.

Referring toFIG. 7C, portions of both ends of the outer magnetic layers100-1and100-2stacked on the upper surface and/or the lower surface of the multi-layered body15may be cut based on the lengths of the upper and lower portions of the external electrodes.

The lengths of the cut outer magnetic layer100-1and100-2may be determined based on the lengths of the outer magnetic layers100-1and100-2and the lengths of the upper and lower portions of the external electrodes that are formed on external surfaces of the multi-layered body15.

For example, the length of the cut outer magnetic layer may be equal to the length between the ends of the upper portions of both external electrodes and the length between the ends of the lower portions of both external electrodes.

Referring toFIG. 7C, the external electrodes20may be formed on outside of the multi-layered outer magnetic layers100-1and100-2and the multi-layered body.

FIGS. 8A through 8Care diagrams showing an inductor according to another embodiment of the present invention.

The configuration of the outer magnetic layer as described above may be applied to the plane inductor.

Referring toFIG. 8A, a coil241may be formed on an upper surface of a support substrate216. In addition, a coil212may be formed on a bottom surface of the support substrate216.

Referring toFIG. 8B, a magnetic body210may be formed to include the support substrate216and the coils212and214. In addition, the magnetic body210may be formed of a magnetic substance.

Referring toFIG. 8C, the respective external electrodes220-1and220-2may be formed so as to contact one end of the coil.

The plane inductor ofFIGS. 8A to 8Cis cut in a length direction L and a thickness direction T shown inFIG. 9.

Referring toFIG. 9, when the plane inductor is viewed in the length direction L and the thickness direction T, the coil214may be electrically connected to the external electrode220-1and the coil212may be electrically connected to the external electrode220-2.

Meanwhile, an outer magnetic layer230-1may be stacked on the upper surface of the multi-layered body210. The outer magnetic layer230-1may be disposed between upper portions220-1of both external electrodes220. Further, both ends of the outer magnetic layer230-1in the length direction L thereof may be in contact with the upper portion220-1of the external electrode.

Meanwhile, an outer magnetic layer230-2may be stacked on the lower surface of the multi-layered body210. The outer magnetic layer230-2may be disposed between bottom portions220-2of both external electrodes220. In addition, both ends of the outer magnetic layer230-2in the length direction L thereof may be in contact with the bottom portion220-2of the external electrode.

As shown inFIG. 9, the length of the outer magnetic layers230-1and230-2is shorter than that of the magnetic body210.

As described above, the configuration of the outer magnetic layer according to the embodiment of the present invention may be applied to various inductors, regardless of the shape of the body.

As set forth above, according to embodiments of the present invention, the chip device with excellent electrical characteristics while being miniaturized, and the method of producing the same, may be provided to users.

Further, the chip device with excellent inductance characteristics while being easily mass-produced and the method of producing the same may be provided to users.