JP2003209016A - Stacked inductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stacked inductor which is arranged so as to prevent conductive patterns of the uppermost and the lowermost layers constituting an inner coil of the inductor from having short circuit at through hole portions. <P>SOLUTION: Insulating layers 1m, 1n having lead-out conductor patterns 2i, 2j are provided as the lowermost and the uppermost layers, respectively, for constituting the coil. The patterns 2i, 2j are formed at the positions which do not align with the through holes 3a, 3f, respectively, for connecting coil conductor patterns 2a, 2g adjacent to the patterns 2i, 2j in the stacked direction, to coil conductor patterns 2b, 2f of the subsequent layers, respectively. The patterns 2i, 2j are led out to the sides of the stacked body and connected to terminal electrodes, respectively, disposed on the sides. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a laminated inductor manufactured by laminating green sheets, and more particularly to a coil for preventing short-circuiting at the beginning and end of winding. Regarding the structure. 2. Description of the Related Art The demand for laminated electronic components is rapidly increasing in response to recent demands for smaller and lighter sets. The laminating method for manufacturing a laminated electronic component is roughly classified into a printing method and a sheet method. The sheet method is excellent in accuracy, and is mainly used for small products. FIG. 3 is a perspective view showing a layer structure of a coil component of a conventional laminated inductor manufactured by a sheet method. 1a to 1g are insulating layers made of a magnetic material or a dielectric, and 2a to 2g are these insulating layers 1a to 1g.
Are conductor patterns for coils formed by printing or the like. 3a to 3f are the insulator layers 1a to 1 respectively.
f, the through holes provided in each of the through holes 3
a to 3f are provided in advance on a ceramic green sheet to be the insulator layers 1a to 1f by a laser or the like, and each of the through holes 3a to 3f is filled with a conductive paste in the printing or the like process. These through holes 3a to 3f connect end portions of the coil conductor patterns adjacent in the laminating direction. Of the coil conductor patterns 2a to 2g, the uppermost and lowermost coil conductor patterns 2a and 2g are provided with lead portions 4a and 4b as winding start and winding end portions, respectively. It is formed to be. When manufacturing a laminated inductor having this layer structure, as shown in FIG. 4A, the insulator layers 1a to 1g are formed by forming a plurality of coil conductor patterns 2a to 2g vertically and horizontally. The green sheets are sandwiched between the green sheets to be the cover insulating layers 1i and 1j on the upper surface and the cover insulating layer 1k on the lower surface, and are pressed from above by pressing (P) as shown in FIG. 4B. Then, after cutting into individual chips and baking, the terminal electrodes 5a and 5b are formed on the side surfaces by applying a conductive paste, baking, plating and the like. When the green sheets are laminated and pressed, the insulator layers 1a to 1k are crushed, but the conductors in the through holes 3a to 3f made of silver or silver alloy powder paste are crushed. The amount of shrinkage due to the compression of the part is relatively small. For this reason, the portions of the through holes 3a, 3c, 3e and 3b, 3d, 3f are portions that are hard to be compressed like columns. As a result, the uppermost and lowermost coil conductor patterns 2a and 2g become
4A and 4B, the portion facing e is compressed more strongly than the extraction portions 4a and 4b, and as shown in FIG. 4A, the portion where the conductor pattern is not formed (the portion serving as the side portion of the laminate) is not compressed. Since there is a gap g in FIG.
(B) The drawer portions 4a and 4b are bent downward and upward, respectively, and the drawer portions 4a and 4b and the through hole 3
The conductors b and 3e are close to each other at portions 6 and 7, respectively, which may cause a short circuit, which lowers the yield. The reason why the insulator layers 1a to 1g are crushed is that the green sheet is in a flexible state containing a certain amount of solvent in order to secure adhesion to other green sheets. The above-mentioned short-circuit becomes remarkable as the insulator layers 1a to 1k become thinner due to the demand for miniaturization and thinning of the multilayer electronic component. The present invention has been made in view of the above circumstances, and provides a laminated inductor having a structure capable of preventing a short circuit at a through hole portion of a conductor pattern of an uppermost layer and a lowermost layer constituting an internal coil for an inductor. Aim. The laminated inductor according to the present invention is obtained by laminating a plurality of green sheets on which a conductor pattern for a coil is formed together with upper and lower cover green sheets, compressing and sintering the green sheets. Manufactured and the coil conductor patterns adjacent in the stacking direction are connected via through holes,
A winding inductor in which the winding start and end portions are pulled out to the side surfaces of the laminated body and connected to the terminal electrodes on the side surfaces of the laminated body. An insulating layer having a conductor pattern for connection, connecting each of the conductor patterns for extraction to a coil conductor pattern adjacent in the laminating direction via a through-hole; The coil conductor pattern adjacent to the pattern is formed at a position that does not overlap with a formation position of a through hole connecting to the coil conductor pattern of the next layer. According to this structure, the lead conductor pattern on the insulator layer added to the uppermost layer and the lowermost layer of the coil component part is composed of the coil conductor pattern adjacent in the stacking direction and the coil of the next layer. Even if the lead-out part reaching the side face is bent in the stacking direction without facing the through hole connecting the conductor pattern for use, the top and bottom layer conductor patterns are prevented from short-circuiting with the adjacent pole conductor Is done. FIG. 1 is a perspective view showing a layer structure of a laminated inductor according to an embodiment of the present invention. 1, reference numerals 1a to 1g denote insulator layers 1a to 1g shown in FIG.
Is an insulator layer corresponding to. These insulator layers 1a to 1
g is formed as a sheet-like green sheet by mixing a magnetic powder or a dielectric powder, a binder, and a solvent at a stage before molding as a laminate. 2a-2g
Is an L-shaped coil conductor pattern formed on the insulator layers 1a to 1h by printing a silver (including alloy) paste. However, of these coil conductor patterns, the coil conductor patterns 2a and 2g do not have the lead portions 4a and 4b shown in FIG. 3a to 3f are the conductor patterns 2 for the coil.
It is a through-hole that connects the ends of adjacent ones of a to 2g. Reference numerals 1m and 1n denote insulating layers added above the insulating layer 1a, which is the uppermost layer of the coil component, and below the lowermost insulating layer 1g, respectively. Patterns 2i and 2j are formed on the upper surface. These conductor patterns 2i, 2j are connected to coil conductor patterns 2a, 2g adjacent in the laminating direction by through holes 3g, 3h provided in the insulator layers 1m, 1n, respectively. One of the lead conductor patterns 2i is a through hole 3 in which the coil conductor pattern 2a adjacent in the laminating direction is connected to the coil conductor pattern 2b of the next layer.
It is formed at a position that does not overlap with a. In addition, the other lead conductor pattern 2j also has a coil conductor pattern 2g adjacent to the coil conductor pattern 2g in the lamination direction.
It is formed at a position that does not overlap with the through-hole 3f connected to f. FIG. 2A shows the structure of the green sheets to be the insulator layers 1a to 1g by adding the green sheets to be the insulator layers 1m and 1n forming the lead conductor patterns 2i and 2j. The state before and after crimping is shown, in which the green sheets to be the upper and lower insulator layers 1i, 1j, and 1k are vertically arranged, and FIG. 2B shows the state after crimping. These green sheets are shown in Figure 2
After crimping as shown in (B), the chip is cut into individual chips as described above and fired, and then the terminal electrodes 5a and 5b connected to the lead-out conductor patterns 2i and 2j are attached to the side surfaces of the sintered body. , Conductive paste applied, baked and plated. As shown in FIG. 2B, in the present invention, the lead conductor patterns 2i and 2j are
Since the conductor patterns 2i and 2j are formed at positions that do not face the through holes 3a and 3f, they are prevented from being short-circuited to the through holes 3a and 3f. In the short prevention structure according to the present invention, the size of a product is about 1 mm × 0.5 mm × 0.5 mm, and the thickness of each of the insulator layers 1 a to 1 n in a green sheet state is 20 μm or less. This is particularly effective when the number of layers 1a to 1n is 20 or more, but can be applied to other specifications. The present invention is particularly effective when adopting an L-shaped coil conductor pattern in which the positions of the through holes are concentrated on the diagonal of the laminate, but the coil conductor pattern is a U-shaped conductor pattern. The case can also be applied. According to the present invention, in the laminated inductor, an insulating layer having a lead conductor pattern is added to the uppermost layer and the lowermost layer constituting the internal coil, and each of the lead conductor patterns is formed. The lead conductor pattern is configured not to face the through-holes connecting the coil conductor patterns adjacent to each other in the stacking direction to the coil conductor patterns of the respective next layers. A short circuit is prevented in a portion, and the yield is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a layer structure of an embodiment of a laminated inductor according to the present invention. 2A is a side view showing a laminated state of the laminated inductor of FIG. 1 before green sheet crimping, and FIG. 2B is a side perspective view showing a state of the laminated inductor after crimping. FIG. 3 is a perspective view showing a layer structure of a conventional laminated inductor. 4A is a side view showing a state of lamination of the laminated inductor of FIG. 3 before green sheet crimping, and FIG. 4B is a side perspective view showing a state of the laminated inductor after crimping. [Description of Signs] 1a to 1n: Insulator layer, 2a to 2g: Conductor pattern for coil, 2i, 2j: Conductor pattern for lead, 3a to 3
h: Through hole, 5a, 5b: Terminal electrode

Claims (1)

Claims 1. A plurality of green sheets on which a conductor pattern for a coil is formed are laminated together with upper and lower cover green sheets, compressed, sintered, and manufactured to be adjacent to each other in the laminating direction. The coil conductor pattern is connected through a through-hole, and is a laminated inductor connected to a terminal electrode on the side surface of the multilayer body by drawing out the winding start and end portions to the side surface of the multilayer body. An insulator layer having a conductor pattern for drawing out to the side surface of the laminate is added to the uppermost layer and the lowermost layer, and each of the conductor patterns for drawing is connected to a coil conductor pattern adjacent in the laminating direction via a through hole. Each of the lead conductor patterns has a shape of a through hole that connects the coil conductor pattern adjacent to each of the lead conductor patterns to a coil conductor pattern of the next layer. A multilayer inductor characterized in that it is formed at a position that does not overlap with a formed part.