JPH03219605A - Laminated-type inductance element - Google Patents

Abstract

PURPOSE:To obtain a small-sized inductance element in which the electric resistance of a coil is small and whose Q value is high by a method wherein a recessed part is formed in the conductor-line formation part of a magnetic- substance layer and a conductor line is formed inside the recessed part. CONSTITUTION:A recessed part 3 is formed in advance in a conductor-line formation part on the surface of a magnetic-substance green sheet 2 such as an Ni-Zn-based ferrite or the like which has been formed in a sheet shape. A conductor paste is printed to be thick inside the recessed part 3 by a screen- printing method or the like to form a conductor line 1. A plurality of magnetic- substance green sheets 2 are laminated; conductor lines 1 at upper parts and lower parts of the magnetic-substance green sheets 2 are connected electrically via through holes 4 made at end parts of the conductor lines 1 to form a coil. In addition, the laminated magnetic-substance green sheets 2 are compression- bonded mutually; after that, the magnetic-substance green sheets 2 and the conductor lines 1 are baked and united; they are made electrically conductive to extraction parts 5 at both ends of the coil to form external electrodes at the outer face of a laminated-body block; a laminated-type inductance element is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chip-type multilayer inductance element used in various electronic circuits.

BACKGROUND TECHNOLOGY] In recent years, with the miniaturization, higher integration, and higher frequency of electronic circuits, there has been an increasing demand for chip-type multilayer inductance elements that are small and capable of surface mounting.

Conventionally, as this type of inductance element, for example,
As described in Japanese Patent Publication No. 57-39i521, the lamination of magnetic green sheets and the printing of conductor lines (conductive paste) are performed alternately, and the conductor lines formed on the end faces of the magnetic green sheets are used to connect each layer. A laminated inductance element (not shown) is known in which a coil is formed by connecting conductor lines, a magnetic green sheet is crimped, and then the magnetic green sheet and the conductor line are fired.

In addition, as described in Utility Model Application Publication No. 59-145009, a conductor line (conductive paste) is printed on each magnetic green sheet in advance, and the magnetic green sheets on which the conductor line is printed are laminated. The magnetic green sheets were then crimped, and the conductor lines were electrically connected between the upper and lower layers through the through holes provided in the magnetic green sheets to form a coil, and the laminated magnetic green sheets and conductor lines were fired. Stacked inductance elements (not shown) are known.

[Problems to be Solved by the Invention] However, in any of the conventional multilayer inductance elements, the conductor line 11 is printed on the flat surface 13 of the magnetic green sheet 12, as shown in FIG. Therefore, it was not possible to increase the cross-sectional area of the conductor line, and therefore it was difficult to reduce the electrical resistance of the coil. That is, the conductor line 11 is generally formed by thick-film printing a conductive paste on the surface 13 of the magnetic green sheet 12 by screen printing or the like.
In such a method of forming a conductor line, it is difficult to freely obtain a large film thickness by controlling the printed film thickness. Therefore, in order to increase the cross-sectional area of the conductor line 11,
The line width of the conductor line 11 must be increased, but if the line width of the conductor line 11 is increased, the external dimensions of the inductance element become larger, which poses a problem in miniaturizing electronic circuit components. Ta.

This result 1. In conventional inductance elements, the electrical resistance of the coil becomes large and the Q value (ie, the reciprocal of loss) becomes low, which is an obstacle when applied to electronic circuits.

The present invention has been made in view of the problems of the conventional example of slanting, and its purpose is to provide a small multilayer inductance element whose coil has low electric resistance and therefore has a high Q value. It is in.

[Means for Solving the Problems] Therefore, in the multilayer inductance element of the present invention, in an inductance element in which a plurality of magnetic layers each having a conductor line formed thereon are laminated and fixed, the conductor line of the magnetic layer is It is characterized in that a recess is formed in the formed portion, and a conductor line is provided within this recess.

[Function] In the present invention, since a concave portion is formed in the conductor line forming portion of the magnetic layer, when a conductive paste is printed on this conductor line forming portion to form a conductor line, the conductive paste forms a conductor line. It is filled in the recess of the forming part, and the cross-sectional area of the conductor line can be increased by the cross-sectional area of the recess.

In this way, by increasing the cross-sectional area of the conductor line, the electrical resistance of the coil can be reduced, and an inductance element with a high Q value can be manufactured. Moreover,
Since the line width of the conductor line does not increase even though the thickness of the conductor line increases, a small inductance element can be obtained.

[Example 1] Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 and 2.

What is shown in FIG. 1 is a schematic cross-sectional view of a magnetic green sheet 2 on which a conductor line 1 is formed. On the surface of a plate-shaped magnetic green sheet 2 made of Ni--Zn ferrite or the like, recesses 3 are formed in advance in areas where conductor lines are to be formed. The recess 3 is formed by a method such as pressing a mold onto the surface of the magnetic green sheet 2. A conductor line 1 is formed in the recess 3 by printing a thick film of conductive paste using a method such as screen printing. During this printing, the height h of the conductor line 1 exposed on the surface of the magnetic green sheet 2 is the same as the thickness of the conventional conductor line 11 formed by screen printing, etc. 1 is filled, the thickness t of the conductor line 1 increases, and the conductor line 1 having a large cross-sectional area is formed. That is, the cross-sectional area of the conductor line 1 increases by the cross-sectional area of the recess 3. Note that if the recess 3 is deep compared to the printed film thickness of the conductive paste and the conductor line 1 cannot be filled into the recess 8 due to -degree printing,
You may repeat printing several times.

FIG. 2 shows a stacked state of a plurality of magnetic green sheets 2 obtained as described above. A conductor line 1 with an L-shaped pattern is formed on the magnetic green sheet 2 provided with the coil take-out part 5, and a conductor line with an approximately 0.5 turn pattern is formed on the other magnetic green sheet 2. 1 is formed. A coil is formed by stacking a plurality of these magnetic green sheets 2 and electrically connecting the upper and lower conductor lines 1 of the magnetic green sheets 2 through the through holes 4 provided at the ends of the conductor lines 1. Form. Furthermore, after the laminated magnetic green sheets 2 are crimped together, the magnetic green sheets 2 and the conductor line 1 are fired and integrated, so that they are electrically connected to the take-out portion 5 of the open end of the coil. External electrodes (not shown) are formed on the outer surface of the laminate block to obtain a laminate inductance element.

Since the cross-sectional area of the coil of the inductance element thus obtained is larger than that of the conventional one, the resistance of the coil is reduced, and an inductance element with a high Q value can be obtained.

In the above embodiment, a green sheet laminated type inductance element has been described, but it goes without saying that the present invention can also be applied to a printed laminated type inductance element in which printing of conductor lines and lamination of green sheets are alternately repeated. be. Further, the configuration of the coil is not limited to a specific pattern.

[Effects of the Invention] According to the present invention, a conductor line with a large thickness can be obtained without being limited by the printed film thickness of the conductor line, and the cross-sectional area of the conductor line can be increased. Therefore, compared to conventional multilayer inductance elements, the electrical resistance of the coil can be significantly reduced, and an inductance element with a high Q value can be manufactured. Furthermore, since the line width of the conductor line does not become large, a compact multilayer inductance element can be obtained. Therefore, the field of application of the multilayer inductance element to electronic circuits can be greatly expanded.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the present invention, in which Figure 1 is a cross-sectional view showing a magnetic material Green Sea I in which a conductor line is printed in the concave part of the conductor line forming part, and Figure 2 is a cross-sectional view showing a magnetic material Green Sea I. A partially omitted perspective view showing a state in which magnetic green sheets are stacked;
FIG. 3 is a sectional view showing a magnetic green sheet on which conductor lines are formed in a conventional multilayer inductance element. 1... Conductor line 2... Magnetic green sheet 3... Recessed part 4... Through hole 5... Takeout part

Claims (1)

[Claims] (1) In an inductance element in which a plurality of magnetic layers each having a conductor line formed thereon are laminated and fixed, a recess is formed in the conductor line forming portion of the magnetic layer, and the conductor line is provided within the recess. A multilayer inductance element featuring: