JP2982561B2 - Chip-through capacitors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a through- chip capacitor incorporated in various electronic circuits and used as a noise filter or the like.

[0002]

2. Description of the Related Art As shown in FIG.
The feedthrough capacitor 31 includes a dielectric sheet 34 provided with a through internal conductor 36 on its surface, a dielectric sheet 34 provided with a ground internal conductor 38 on its surface, and a dielectric sheet 34 as a protective layer. After stacking these dielectric sheets 34, they are press-bonded and fired to obtain the through- chip capacitors 31 shown in FIG. Input / output external electrodes 42 and 43 are formed on the side portions on the far side and near side of the chip penetration capacitor 31, and ground external electrodes 45 and 46 are formed on both ends. The penetrating internal conductor 36 is electrically connected to the input / output external electrodes 42 and 43, and the ground internal conductor 38 is electrically connected to the ground external electrodes 45 and 46.

FIG. 8 is an electric equivalent circuit diagram of the feedthrough chip capacitor 31. The penetrating internal conductor 36 and the ground internal conductor 38 form a penetrating capacitor element. By the way, the ground inner conductor 3 of this feedthrough capacitor element
When the through- chip capacitor 31 is used in a high-frequency band, the residual inductance generated in 8 cannot be ignored. Therefore, the through internal conductor 36
Therefore, high-frequency signals such as noise once bypassed by the ground inner conductor 38 easily return to the penetrating inner conductor 36 again. As a result, there is a problem that the insertion loss characteristic in the high-frequency band of the through- chip capacitor 31 deteriorates.

It is an object of the present invention to provide a through- chip capacitor having a small residual inductance generated on the ground side and having excellent insertion loss characteristics in a high frequency band.

[0005]

In order to solve the above problems, a feed- through capacitor according to the present invention comprises: (a) a ground inner conductor and a signal inner conductor which are stacked so as to face each other with a dielectric interposed therebetween. (B) providing a ground external electrode on a mounting surface of the laminate that is perpendicular to the ground internal conductor, the signal internal conductor, and the dielectric; and connecting the ground internal conductor to the ground external electrode. (C) providing a signal external electrode on a surface facing the mounting surface of the laminate, and connecting the ground external electrode and the signal external electrode to each other.
The signal inner conductor is electrically connected to the signal external electrode, and (d) a through terminal is electrically connected to the surface of the signal external electrode. Here, the through terminal is a signal
It is pulled out from the external electrode in two directions.

[0006] When the feedthrough chip capacitor having the above configuration is mounted on, for example, a printed wiring board or the like, the ground external electrode is in direct contact with and electrically connected to a ground circuit conductor provided on the printed wiring board or the like. Therefore, the distance between the ground circuit conductor of the ground inner conductor and printed circuit board or the like of the chip through capacitor <br/> capacitors becomes short, residual inductance generated to the ground side of the chip through the capacitor becomes small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a feedthrough capacitor according to the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the feed- through capacitor 1 includes a dielectric sheet 2 having a ground inner conductor 4 provided on a surface thereof, a signal inner conductor 5
And a dielectric sheet 2 having no conductor on the front and back surfaces. Each dielectric sheet 2 is made of, for example, a ceramic material.

The ends of the internal conductors 4 and 5 are
It is exposed at the edge. The internal conductors 4 and 5 are formed by applying a conductive paste to the surface of the dielectric sheet 2 by printing or the like and drying the paste. As the conductive paste, A
A metal powder such as g or Ag-Pd is kneaded with a binder and a solvent. A plurality of dielectric sheets 2 each having the inner conductors 4 and 5 provided on the surface are alternately laminated, and if necessary, the dielectric sheets 2 having no conductors are laminated on the front and back surfaces, and then press-bonded and fired to be laminated. Body.

As shown in FIG. 2, a signal external electrode 8 and a ground external electrode 9 are formed on the upper surface and the mounting surface of the laminate, respectively. One end of each of the through terminals 10 and 11 is fixed to the surface of the signal external electrode 8 by means such as soldering and is electrically connected. As shown in FIG. 3, the dielectric sheet 2 and the internal conductors 4 and 5 are arranged perpendicular to the mounting surface. The internal ground conductor 4 is electrically connected to the external ground electrode 9, and the internal signal conductor 5 is electrically connected to the external signal electrode 8. A capacitance is generated between the ground inner conductor 4 and the signal inner conductor 5 to form a feedthrough capacitor element.

[0010] The thus obtained chip feed-through capacitor 1
Is mounted on the printed wiring board 15 when used as a noise filter, for example. That is, the ground external electrode 9 is electrically connected to the ground circuit conductor 16 provided on the surface of the printed wiring board 15 by soldering and fixed. Then, high-frequency noise transmitted through the through terminal 10 or 11 is removed from the signal external electrode 8 to the ground via the signal internal conductor 5, the ground internal conductor 4 and the ground external electrode 9. Since the ground external electrode 9 is in direct contact with and electrically connected to the ground circuit conductor 16, the distance between the ground internal conductor 4 and the ground circuit conductor 16 is reduced, and the ground external electrode 9 is generated on the ground side of the feed- through capacitor 1. The residual inductance becomes smaller. As a result,
The through- chip capacitor 1 has excellent insertion loss characteristics in a high frequency band. FIG. 4 shows a feed- through capacitor 1
3 is an electrical equivalent circuit diagram of FIG.

The through- chip capacitor according to the present invention is not limited to the above embodiment, but can be variously modified within the scope of the invention. The shape of the penetrating terminal is arbitrary, and as shown in FIG. 5, one lead wire 20 may be electrically connected to the signal external electrode 8. In the above-described embodiment, the dielectric sheets on which the internal conductors are formed are stacked and then integrally fired. However, the present invention is not necessarily limited to this. For example, a through- chip capacitor may be manufactured by a manufacturing method described below. A paste-like dielectric material is applied by printing or the like and dried to form a dielectric film. Then, a paste-like conductive material is applied to the surface of the dielectric film and dried to form an arbitrary internal conductor. I do. Next, a paste-like dielectric material is applied from above the conductor and dried to form a dielectric film. In this manner, a chip penetrating capacitor having a laminated structure can be obtained by successively applying layers.

[0012]

As is apparent from the above description, according to the present invention, since the ground external electrode is provided on the mounting surface, for example, when this chip through capacitor is mounted on a printed wiring board or the like, the ground external electrode is provided. Are directly in contact with and electrically connected to the ground circuit conductor provided on the printed wiring board or the like. Accordingly, the distance between the ground inner conductor of the feed- through capacitor and the ground circuit conductor such as the printed wiring board is shortened, and the residual inductance generated on the ground side of the feed- through capacitor can be suppressed.

As a result, a through- chip capacitor having a small residual inductance generated on the ground side and having excellent insertion loss characteristics in a high frequency band can be obtained.

[Brief description of the drawings]

FIG. 1 is an assembled perspective view showing one embodiment of a feedthrough chip capacitor according to the present invention.

FIG. 2 is a perspective view showing the appearance of the feed- through capacitor shown in FIG. 1;

FIG. 3 is a sectional view of the feed- through capacitor shown in FIG. 2;

FIG. 4 is an electric equivalent circuit diagram of the through- chip capacitor shown in FIG. 2;

FIG. 5 is a perspective view showing another embodiment.

FIG. 6 is an assembled perspective view showing a conventional example.

FIG. 7 is a perspective view showing the appearance of the conventional example shown in FIG. 6;

8 is an electric equivalent circuit diagram of the conventional example shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Chip penetration capacitor 2 ... Dielectric sheet 4 ... Ground internal conductor 5 ... Signal internal conductor 8 ... Signal external electrode 9 ... Ground external electrode 10, 11 ... Through terminal 20 ... Lead wire (through terminal)

Claims (2)

(57) [Claims] 1. A ground inner conductor and a signal inner conductor are stacked so as to face each other with a dielectric interposed therebetween to form a laminate, and the ground inner conductor, the signal inner conductor, and a plane perpendicular to the dielectric are formed. A ground external electrode is provided on the mounting surface of the laminate, the ground inner conductor is electrically connected to the ground external electrode, and a signal external electrode is provided on a surface facing the mounting surface of the laminate.
The ground external electrode and the signal external electrode
Re different surfaces disposed in said signal an inner conductor electrically connected to said signal external electrodes, the through terminal electrically connected to the surface of the signal external electrodes, the chip through the capacitor, characterized in that. (2) The through terminal is connected to the signal external electrode.
2. The device according to claim 1, wherein the device is drawn in two directions.
On-chip capacitor.