JP2607058Y2 - Multilayer chip inductor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer chip inductor having a closed magnetic circuit structure.

[0002]

2. Description of the Related Art As shown in FIGS. 4 and 5, a conventional multilayer chip inductor generally has a helical coil 4 provided inside a magnetic body 1 and an external terminal formed on the end face of the coil. An electrode 3 is provided with a lead portion 2 provided continuously with a spiral winding pattern constituting a coil.
(Formed by the same conductor as the coil conductor 4 ′), and in such a multilayer chip inductor, as shown in FIG. 6, a coil conductor pattern (coil conductor 4 ′) constituting a coil is formed. It is manufactured by laminating the sheet 6 on which the lead portion 2 is formed on the upper and lower sides of the formed magnetic green sheet 6. The arrows in FIGS. 4 and 5 are magnetic flux models.

[0003] When a laminated chip inductor having the above-described configuration has a closed magnetic circuit structure for concentrating a magnetic flux in the inductor element, a fixed margin is provided around an internally provided coil to provide a magnetic field in the chip. Road is secured.

[0004]

However, in the above-mentioned conventional multilayer chip inductor having a closed magnetic circuit structure, the substantial margin on the end face side on which the external terminal electrode is formed is reduced as shown in FIG.
(M) (the part obtained by subtracting the width of the lead-out part from the part from the coil to the end face of the external terminal electrode formation), the external dimensions of the chip were not effectively used. That is, when the magnetic flux of the coil is cut off by the lead portion made of a conductor, there is a problem that an eddy current is generated and the inductance value is reduced.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a multilayer chip inductor capable of increasing the inductance value with the same outer diameter.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has provided lead portions near the upper and lower surfaces of a chip separated from the coil in the stacking direction, and has provided the lead portion with the coil start end and The inventors have found that the above problems can be solved by electrically connecting the terminal to the terminal by through-hole connection, and arrived at the present invention.

That is, the present invention provides a multilayer chip inductor in which a spiral coil composed of a circulating pattern is provided inside a magnetic material, and a drawer for connecting the coil to an input / output external terminal electrode formed on a chip end face. The upper and lower surfaces of the chip are electrically conductively connected to the circling pattern through through holes in the magnetic sheet in which only a plurality of through holes are formed, and are sufficiently separated from the circulating pattern in the lamination direction of the magnetic sheets. In addition to being provided in the vicinity, the lead-out portion is provided without overlapping with the circulating pattern except for the connection portion by the through-hole, and the magnetic flux in the coil is not substantially blocked by the lead-out portion. A multilayer chip inductor is provided.

[0008]

The laminated chip inductor according to the present invention is a magnetic sheet (hereinafter referred to as a sheet A) on which a conductor pattern of each coil is formed by laminating and connecting through holes to form a helical coil. These sheets are composed of a magnetic sheet (sheet B) having a through hole formed therethrough and a magnetic sheet (sheet C) having a lead portion for electrically connecting the external electrode terminals and the coil. Are laminated as follows, and the obtained laminate is fired to form an external terminal electrode on the end face where the lead portion is exposed.

First, a plurality of sheets B are stacked on a sheet C, and a sheet A is stacked thereon in a predetermined order so as to form a helical coil, and a plurality of sheets B are stacked again. The sheet C is laminated thereon. Next, a green sheet in which a conductor and a through-hole are not formed as outermost layers is laminated on the upper and lower sides of the laminated sheet. The through hole in the sheet B is formed at a position where the end of the lead portion and the beginning and end of the coil are connected when they are stacked as described above, and the inside is filled with a conductor.

In the multilayer chip inductor of the present invention obtained as described above, as shown in FIG. 1, the lead portion 2 for electrically connecting the coil 4 and the external terminal electrode 3 is made of a magnetic material 1.
The lead portion 2 and the beginning and end of the coil are electrically connected to each other by through-holes 5 filled with a conductor therein. ing.

By providing the lead portion at such a position, the magnetic flux (arrow in the drawing) in the coil can be obtained without adding the area of the lead portion to a necessary margin between the coil and the end face of the external terminal electrode. Almost no blockage by the drawer. Therefore, the inductance value can be increased while being configured with the same external dimensions, number of coil turns, conductor thickness, firing temperature, and material as the conventional multilayer chip inductor.

Hereinafter, the present invention will be described in more detail with reference to embodiments. However, the scope of the present invention is not limited by the following embodiments.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The multilayer chip inductor of the present invention can be manufactured, for example, as follows. First, a magnetic green sheet 6 is manufactured using the same material as that of a conventional multilayer chip inductor, and a coil-shaped conductor pattern in which a helical coil is formed by laminating and connecting through holes on the sheet. To form Next, these sheets are laminated as shown in FIG.

That is, the sheet 6 on which the lead portion 2 is formed is laminated on the green sheet 6 on which the coil conductor 4 'and the through hole 5 are not formed, and the sheet 6 on which only the through hole 5 is formed. After laminating a plurality of sheets 6, the sheets 6 on which the coil conductors 4 ′ are formed are laminated in a predetermined order, and a plurality of sheets 6 on which only the through holes 5 are formed are laminated again. Finally, the green sheet 6 in which the coil conductor 4 ′ and the through hole 5 are not formed is stacked.

Next, after the obtained laminate is pressed, 900 ° C.
The external terminal electrode 3 is formed on the end face where the lead portion 2 is exposed, and a multilayer chip inductor having a spiral coil 4 provided inside the magnetic body 1 is obtained (FIGS. 1 and 2).
The external dimensions of the multilayer chip inductor manufactured in this example are length 3.2 × width 1.6 × thickness 0.7 mm, and the number of coil turns is 12 turns.

As described above, a large number of multilayer chip inductors of the present invention are manufactured, and 30 are randomly selected from among them.
L value and Q value were measured.

On the other hand, for comparison with the multilayer chip inductor of the present invention, the drawing is performed in the same manner as described above, except that a sheet having a lead portion is formed above and below a sheet on which the coil start and end are formed. A number of conventional multilayer chip inductors as shown in FIG.
The number of coil turns, the firing temperature, the material, the area of the lead portion, etc. are the same as those of the chip of the present invention described above), and 30 pieces were randomly selected from them, and the L value and the Q value were measured.

As a result, the multilayer chip inductor of the present invention had an L value of 32.1 μH and a Q value of 50.2, whereas the conventional multilayer chip inductor had an L value of 28.3 μH and a Q value of 50.2.
45.5, and both the L value and the Q value were significantly reduced.

[0019]

The multilayer chip inductor of the present invention has the same outer dimensions, number of coil turns, conductor thickness, firing temperature and material as the conventional multilayer chip inductor, but increases the L and Q values. be able to.

[Brief description of the drawings]

1A and 1B are views showing a multilayer chip inductor of the present invention, wherein FIG. 1A is a side sectional view of a chip cut in a stacking direction connecting external terminal electrodes, and FIG. 1B is a side sectional view of FIG. FIG. 4 is a partially enlarged view of FIG.

FIG. 2 is a cross-sectional view of the multilayer chip inductor according to the present invention, which is cut in a horizontal direction orthogonal to a stacking direction.

FIG. 3 is a perspective view showing a sheet laminating mode in a manufacturing process of the multilayer chip inductor of the present invention.

FIG. 4 is a sectional side view of a conventional multilayer chip inductor cut in a lamination direction connecting external terminal electrodes.

FIG. 5 is a cross-sectional view of an upper margin portion of a conventional multilayer chip inductor cut in a horizontal direction orthogonal to a stacking direction.

FIG. 6 is a perspective view showing a sheet laminating mode in a manufacturing process of a conventional multilayer chip inductor.

[Explanation of symbols]

 1 magnetic substance 2 lead part 3 external terminal electrode 4 coil 4 'coil conductor 5 through hole 6 magnetic green sheet M substantially Good margin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-54808 (JP, A) JP-A-62-61305 (JP, A) JP-A-3-219609 (JP, A) 88309 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 17/00, 17/06

Claims (1)

(57) [Scope of request for utility model registration] 1. A magnetic material formed by a circular pattern.
A multilayer chip inductor with a spiral coil inside
External ends for input and output formed on the coil and chip end faces
The lead-out section for connecting to the
Through the through holes in the magnetic sheet with only
The conductive pattern is electrically connected to the circuit pattern to
Of the chip sufficiently separated from the circling pattern in the layer direction
It is installed near the upper and lower surfaces, and the drawer is
Except for the connection part by the through hole,
And the magnetic flux in the coil is
It is noted that it is not substantially blocked by the drawer.
Multilayer chip inductor.