JPH0541334A - Surface mount capacitor assembly - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a surface-mounting capacitor assembly which is surface-mounting and has excellent insertion loss characteristics even in a high frequency band of 500 MHz or more. [Structure] An insulating substrate 11 and a lower conductor film 12 on the surface of the insulating substrate 11 and serving as a ground for a plurality of signal lines.
And a dielectric film 13 formed on the lower conductor film 12,
An element substrate provided with an upper conductor film 14 serving as a signal line formed facing the lower conductor film 12 via the dielectric film 13, a plurality of input / output terminal portions 15 and a lower portion of the element substrate. A lead terminal 17 connected to the electrode terminal portion 16,
The lead terminal 17 is in the shape of a clip for holding a board, and has a soldering portion at the tip thereof for vertically mounting an element board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount capacitor assembly for bypassing noise generation of an electronic device using a surface mount substrate to the ground.

[0002]

2. Description of the Related Art With the spread of electronic devices, measures against radiation noise generated by digital devices and noise immunity have become social demands. A three-terminal capacitor or an LC noise filter is used for the purpose of bypassing noise to the ground.

Further, there is used a feedthrough capacitor for high frequency bypass, which functions as a capacitor up to UHF band and higher frequencies. this is,
The metal case terminal serves as the ground, which is very effective for the purpose of passing signal lines from inside a metal body such as a chassis or panel.

A conventional feedthrough capacitor will be described below. FIG. 3 is a perspective view of a conventional feedthrough capacitor. As shown in FIG. 3, the feedthrough capacitor has a disk-shaped dielectric 31 with a lead terminal 32 penetrating therethrough, a metal case 33 covering the dielectric 31, and the dielectric 31 being an electrode film. Lead terminal 32 and metal case 33
Connected to. Therefore, the mounting on the printed board is lead insertion, and the ground is limited to the chassis, the panel, and the like.

[0005]

On the other hand, in recent years, the surface mounting rate of components has been rapidly increasing due to the weight reduction of electronic devices.
All passive and active components are going to be surface mounted. At the same time, compounding of the parts is also required. Therefore, surface mount components have been developed for noise filters that use capacitors, but they have excellent frequency impedance characteristics and can function as capacitors up to UHF band and higher frequencies, and can be used for high frequency bypass. Surface mount components, which have the same insertion loss characteristics as feedthrough capacitors, have not yet been realized. As shown in FIG. 4A, the three-terminal capacitor and the feedthrough capacitor have different characteristics.

An object of the present invention is to solve the above-mentioned conventional problems, and an object thereof is to provide a surface-mounting type capacitor assembly which is surface-mounting type and has excellent insertion loss characteristics even in a high frequency band of 500 MHz or more.

[0007]

To achieve the above object, the present invention provides a plurality of lower electrodes formed on a substrate at regular intervals and a dielectric provided so as to overlap the lower electrodes. A film, a plurality of upper electrodes formed on the dielectric film so as to face the lower electrodes and having input / output terminal portions at both ends, and electrically connected to the lower electrodes and the input / output terminal portions. A plurality of clip-shaped lead terminals sandwiched and held from one end surface side of the board, and a resin mold for covering the whole, and the board is erected on the wiring board to be mounted and the lead terminals are provided. It is mounted at the end of.

Further, according to the present invention, a plurality of lower electrodes formed on the substrate at regular intervals, a dielectric film provided so as to overlap the lower electrodes, and a dielectric film provided so as to overlap the lower electrodes. A body film, a plurality of upper electrodes formed on the dielectric film so as to face the lower electrodes and having input / output terminal portions at both ends, and electrically connected to the lower electrodes and the input / output terminal portions. Thus, a plurality of end face electrodes formed on the end face of the substrate are provided.

[0009]

According to the present invention, it is possible to realize a surface mountable chip type capacitor having excellent frequency impedance characteristics and exhibiting a function as a capacitor up to UHF band and higher frequencies.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A surface mount capacitor assembly according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view of a surface mounting capacitor assembly according to a first embodiment of the present invention. The surface mount capacitor assembly according to the first embodiment is shown in FIG.
As shown in (a), (b) and (c), a lower conductor film 12 serving as a ground for a plurality of signal lines is formed on the surface of a rectangular insulating substrate 11 such as ceramics, and is formed on the lower conductor film 12. A thick dielectric film 13 having a high dielectric constant (PbO-MgO-NbO-based perovskite structure), and an upper conductor film 14 serving as a signal line formed so as to face the lower conductor film 12 via the dielectric film 13. Are sequentially formed to form an element substrate. The clip-shaped lead terminal 17 sandwiched and held so as to be electrically connected to the lower electrode terminal portion 16 which is the terminal portion of the lower conductor film 12 and the input / output terminal portion which is the terminal portion of the upper conductor film 14 is an element body. Substrate surface, body substrate back surface,
It is provided with a clip-shaped substrate holding portion for holding the base substrate from three directions of the end face of the base substrate and a soldering portion for vertically mounting the base substrate. Further, the element substrate is a resin mold 18
It is molded with. An equivalent circuit diagram of this embodiment is shown in FIG.

(Embodiment 2) Next, another embodiment of the present invention will be described. FIGS. 3A and 3B are perspective views of a surface mounting capacitor assembly according to a second embodiment of the present invention. In the surface-mounting capacitor assembly according to the second embodiment, a lower conductor film 22 serving as a ground for a plurality of signal lines is formed on the surface of the insulating substrate 21, and a high dielectric constant (formed on the lower conductor film 22 is PbO-MgO-NbO-based perovskite structure)
Thick dielectric film 23, and an upper conductor film 24 serving as a signal line which is formed so as to face the lower conductor film 22 via the dielectric film 23, and the end face of the insulating substrate 21 is A plurality of end face electrodes 25 are formed so as to be electrically connected to the lower conductor film 22 and the upper conductor film 24. An equivalent circuit diagram of this embodiment is shown in FIG.

In the case of the upper conductor film 24 having the shape shown in FIG. 3B, the circuit structure is as shown in FIG. 6A.

FIG. 2B shows the insertion loss characteristic of the surface mounting capacitor assembly having the above structure. Since it has a structure in which the signal line is adjacent to the dielectric film, it has excellent frequency impedance characteristics, and has the same impedance characteristics as an ideal capacitor, that is, it functions as a capacitor up to UHF band and higher frequencies. The characteristic which exhibits is obtained. Further, since it has the surface mounting structure and the network structure, the mounting area can be significantly reduced.

[0015]

As described above, according to the surface mounting capacitor assembly of the present invention, it is possible to obtain the characteristic of having the same impedance characteristic as an ideal capacitor, that is, the function of functioning as a capacitor up to UHF band and higher frequencies. Be done. In addition, since the shape is surface mounting and has a network structure, the mounting area can be greatly reduced, which is very effective for electronic devices that are required to be light, thin, short, and small.

[Brief description of drawings]

FIG. 1 is a perspective view in which a part of a surface mount capacitor assembly according to a first embodiment of the present invention is cut away.

2 (a), (b) and (c) are perspective views of an element substrate of a surface-mounted capacitor assembly, respectively.

3A and 3B are perspective views of a surface mounting capacitor assembly according to a second embodiment of the present invention.

4A is a characteristic diagram of insertion loss of a conventional feedthrough capacitor and a three-terminal capacitor, and FIG. 4B is a characteristic diagram of insertion loss of the capacitor element of the present invention and an ideal capacitor.

FIG. 5 is a perspective view of a conventional feedthrough capacitor.

6A and 6B are equivalent circuit diagrams of a surface mounting capacitor assembly according to an embodiment of the present invention.

[Explanation of symbols]

 11, 21 Insulating substrate 12, 22 Lower conductor film 13, 23 Dielectric film 14, 24 Upper conductor film 15 Input / output terminal portion 16 Lower electrode terminal portion 17 Lead terminal 18 Resin mold 25 End surface electrode

Claims (2)

[Claims] 1. A plurality of lower electrodes formed on a substrate at regular intervals, a dielectric film provided so as to overlap the lower electrodes, and a dielectric film on the dielectric film so as to face the lower electrodes. A plurality of upper electrodes formed and having input / output terminal portions at both ends, and a plurality of clip-shaped leads sandwiched and held from one end surface side of the substrate so as to be electrically connected to the lower electrodes and the input / output terminal portions. A surface-mounting capacitor assembly comprising terminals and a resin mold for covering the entire surface, wherein the board is erected on a wiring board to be mounted and mounted at the ends of the lead terminals. 2. A plurality of lower electrodes formed on a substrate at regular intervals, a dielectric film provided so as to overlap the lower electrodes, and a dielectric film provided so as to overlap the lower electrodes. A plurality of upper electrodes formed on the dielectric film so as to face the lower electrodes and having input / output terminal portions at both ends, and a substrate for electrically connecting to the lower electrodes and the input / output terminal portions. And a plurality of end surface electrodes formed on the end surface of the surface mounting capacitor assembly.