JPH0311879Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a capacitor that can be easily placed on a printed circuit board.

Conventionally, there is a capacitor shown in FIG. 1 that is disposed on a printed circuit board. A capacitor 1 shown in FIG. 1 is a disk-insulated fixed ceramic capacitor, and lead wires 2 are electrically connected to electrode layers formed on both sides of a ceramic disk (not shown) by soldering or the like. The entire structure is molded with resin so that the ends of the wires 2, 2 are exposed. In the capacitor 1 having the above structure, after the lead wires 2, 2 are inserted into the installation holes of the printed circuit board 3, the conductive layers 4, 4 of the printed circuit board 3 and the lead wires 2, 2 are connected to each other by soldering or the like. It is arranged on the printed circuit board 3 by connecting it to the printed circuit board 3.

However, as shown in FIG. 2, the capacitor 1 having the above structure has an inductance L due to the lead wires 2, 2, and therefore has the disadvantage that a capacitor having a capacitance C has poor frequency characteristics.

In order to avoid the inductance L caused by the lead wires 2, 2, there is also a magnetic capacitor as shown in FIG. This ceramic capacitor 5 is an electrode-exposed ceramic capacitor for mounting on a printed circuit board, and as shown in FIG. A porcelain plate 6 and an electrode layer 7 on each of its surfaces.
A (in the figure, the electrode layer 7B formed on the back surface of the magnetic plate 6 is not shown in the figure). Insert the rectangular plate-like portion 6B of No. 6 into the installation hole of the printed circuit board 3 until the chord of the meniscus-like portion 6A contacts the printed circuit board 3, and then insert the electrode layer 7A,
7B and the conductive layers 4, 4 of the printed circuit board 3 are electrically connected by soldering or the like, and arranged on the printed circuit board 3.

However, the magnetic capacitor 5 of the above structure
Since electrodes 7A and 7B are exposed, electrode 7
Workability is poor because extreme care must be taken in handling to avoid staining or damaging A and 7B. In addition, electrodes 7A, 7
If B gets dirty or scratched, its electrical characteristics will deteriorate and cause voltage breakdown. Furthermore, since the porcelain plate 6 is exposed, chipping, cracking, etc. of the porcelain plate 6 is likely to occur. Furthermore, if a large number of ceramic capacitors with the above structure are stored in one place, the ceramic capacitors will rub against each other, causing damage to the ceramic plate or peeling off of the electrode layer. During installation, metal streaks from the tweezers are left on the magnetic capacitor, which deteriorates the insulation properties of the magnetic capacitor. Therefore, the ceramic capacitor 5 could not be used for medium to high voltage (DC 500V or higher).

This idea was made in view of the above circumstances, and is easy to handle when mounted on a printed circuit board, without deterioration of characteristics due to inductance due to lead wires, can be used for medium and high voltage applications, and has excellent frequency characteristics. The purpose of this invention is to provide a good capacitor for mounting on a printed circuit board.

Next, an embodiment of this invention will be described with reference to the drawings.

Fig. 4 is an exploded perspective view showing an embodiment of this invention, Fig. 5 is a schematic sectional view showing an embodiment of this invention, and Fig. 6(A) is a printed circuit board layout showing an embodiment of this invention. FIG. 3 is a schematic top view showing a state in which the installation capacitor is arranged on a printed circuit board.

A ceramic capacitor 10 for mounting on a printed circuit board, which is an embodiment of this invention, includes at least a capacitor container 11, a ceramic plate 12, and an electrode lead 13.

The capacitor container 11, as shown in FIG.
It has a cylindrical shape with a bottom as a whole, and its opening 11A
A part of the peripheral end surface has a pair of substantially radially expanding flanges 11B, and a peripheral end surface not having the flanges 11B has a pair of opposing notches 11C cut out toward the peripheral surface. have. This pair of collar parts 11
B serves as a locking portion for the printed circuit board 14 to prevent the capacitor container 11 from falling out of the mounting hole of the printed circuit board 14 when the capacitor container 11 is inserted into the mounting hole of the printed circuit board 14. Conductive layer 14A formed on 14
It also serves as an electrode lead for electrical connection to. The notch 11C is for preventing the electrode lead 13, which will be described later, from being connected to the capacitor container 11, and therefore, it may have any shape as long as it is not connected. However, since the resin 15 is cast and solidified into the capacitor container 11 as described later, it is necessary to adjust the depth of the notch 11 to such an extent that a predetermined amount of the resin 15 does not overflow.

Note that the notch 11C and the flange 11B are a pair of flange 11, considering the stability when the capacitor container 11 is installed in the installation hole of the printed circuit board 14.
Preferably, B and the pair of notches 11C are in a positional relationship such that they are perpendicular to each other.

The porcelain plate 12 has a disc shape with a diameter that can be placed in the capacitor container 11 and a predetermined thickness so as to have a predetermined capacitance C, and electrode layers 12 having a diameter slightly smaller than the disc are provided on each of both sides.
A, 12B.

The electrode lead 13 includes an annular plate portion 33A and an annular plate portion 13A for connection to the electrode layer 12A.
A pair of substantially doglegged plates 13B, 13 extending in directions away from each other from opposing positions on the outer periphery of the
It has B. This electrode lead 13 is connected to the electrode layer 12 of the porcelain plate 12 placed inside the capacitor container 11.
It electrically connects A and the conductive layer 14A on the printed circuit board 14, and also serves as a holding member for fixing the ceramic plate 12.

As shown in FIGS. 4 and 5, a capacitor 10 for mounting on a printed circuit board, which is an embodiment of this invention, has a porcelain plate placed inside the capacitor container 11 described above.
The bottom surface of the capacitor container 11 and the electrode layer 12B of the ceramic plate 12 are electrically connected by soldering or the like, and then the electrode leads 13 are placed on the ceramic plate 12.
The electrode layer 12A and the annular plate 13A of the electrode lead 13 are electrically connected on the ceramic plate 12 by soldering or the like, and then a suitable resin 15, for example, a thermosetting resin, is placed in the capacitor container 11. It can be manufactured by pouring and filling and solidifying the ceramic plate 12 having the double-sided electrode layer and the plate-shaped portion 13A of the electrode lead 13 together.

Capacitor 10 for mounting on a printed circuit board with the above configuration
As shown in FIG. 6A, the capacitor container 11 is attached to the printed circuit board 14 by inserting the bottom part of the capacitor container 11 into the installation hole of the printed circuit board 14 and locking the collar part 11B to the surface of the printed circuit board 14. Part 11B
and the electrode leads 13 respectively on the printed circuit board 1.
By electrically connecting to predetermined conductive layers 14A, 14A on 4, it can be mounted on the printed circuit board 14.

Capacitor 10 for mounting on a printed circuit board with the above configuration
As shown in the equivalent circuit shown in FIG. 6B, by having an inductance L in the pair of approximately doglegged plates 13B, 13B, a T-shaped low-pass filter is formed by the capacitor formed by the electrode layers 12A, 12B and the electrode lead 13. is formed, so it can be used as a capacitor with improved high frequency characteristics, and
Since the capacitor container 11 can be installed on the printed circuit board 14 by fitting it into the installation hole of the printed circuit board 14, it is most suitable for the chip mount concept.

Although one embodiment of this invention has been described in detail above, this invention is not limited to the above embodiment, and it goes without saying that it can be implemented with appropriate modifications within the scope of the gist of this invention. Nor.

For example, the capacitor container 11 is not limited to the cylindrical shape with a bottom as in the above embodiment, but may be in the shape of a rectangular cylinder with a bottom. Note that the flange portion 11B does not have to have a substantially radial shape as in the embodiments described above, since it is sufficient to perform both the functions of an electrode lead and a locking portion.

Further, the electrode lead 13 can electrically connect the electrode layer 12A on the ceramic plate 12 and the conductive layer 14A of the printed circuit board 14, and form a low-pass filter together with the electrode layers 12A and 12B forming the capacitor C. Therefore, it is not limited to the shape as in the above embodiment, but as shown in FIG. It may also be integrated. Alternatively, the electric wire 17 may only have a substantially U-shape formed by bending the tip portions away from each other and flattening the portion that contacts the electrode layer. Furthermore, electrode lead 1
3, as shown in FIG. 8, a magnetic sleeve 19 may be interposed except for the portions to be soldered to the electrode layer 12A and the conductive layer 14A of the printed circuit board 14. If the magnetic sleeve 19 is inserted,
The frequency characteristics of the capacitor according to this invention can be improved.

As detailed above, the capacitor for printed circuit board mounting according to this invention has a T-shaped low-pass filter formed by the electrode leads and the ceramic plate having the electrode layer, so it is a broadband capacitor with excellent high frequency characteristics. becomes. In addition, the capacitor container 11
The reason why no inductance L component is generated is that the contact area between the electrode layer 12B and the capacitor container 11 is large. In addition, a porcelain plate with electrode layers formed on both sides is housed in a capacitor container, and the periphery of the porcelain plate, including the electrode layer, is hardened with resin, so you can hold the capacitor for mounting on a printed circuit board with your bare hands. There is no risk of damaging the electrode layer, and handling is extremely easy. Moreover, since there is no risk of cracking or chipping of the electrode layer or the ceramic plate, in this respect as well, the printed circuit board mounted capacitor according to the present invention can be satisfactorily used as a medium-high voltage capacitor. In addition, the capacitor for mounting on a printed circuit board according to this invention has a structure in which only the flange of the capacitor container and the outwardly extending portions of a pair of electrode leads are slightly protruding from the surface of the printed circuit board, so that the capacitor can be used as a chip component. This is compatible with the chip mount concept because the protruding height of the mount can be minimized.

[Brief explanation of the drawing]

FIG. 1 is a cutaway perspective view showing a conventional ceramic capacitor arranged on a printed circuit board, FIG. 2 is a circuit diagram showing an equivalent circuit of the conventional ceramic capacitor,
Fig. 3 is a cutaway perspective view showing another conventional ceramic capacitor arranged on a printed circuit board, Fig. 4 is an exploded perspective view showing an embodiment of this invention, and Fig. 5 is an embodiment of this invention. 6A is a schematic top view showing a state in which a capacitor for mounting on a printed circuit board, which is an embodiment of this invention, is arranged on a printed circuit board, and FIG. 6B is an embodiment of this invention. FIGS. 7 and 8 are perspective views showing electrode leads in other embodiments of this invention. 10...Capacitor for printed circuit board placement, 11
...Capacitor container, 11A...Opening, 11B
...Trim part, 12...Porcelain plate, 12A, 12B...
Electrode layer, 13... Electrode lead, 14... Printed circuit board, 14A... Conductive layer.

Claims (1)

[Scope of utility model registration request] A bottomed cylindrical capacitor container having a flange and a pair of notches at the opening, and a porcelain ceramic having electrode layers on both sides, one electrode layer being electrically connected and disposed within the capacitor container. a plate, a plate-like part electrically connected to the other electrode of the ceramic plate, and a plate-like part extending in directions away from each other from the plate-like part, the tips of which are respectively externally connected through a notch provided in the capacitor container. A printed circuit board, comprising: an electrode lead consisting of a pair of dogleg-shaped portions protruding in the opposite direction; and a resin filled in the capacitor container including the ceramic plate, electrodes on both sides thereof, and the plate portion of the electrode lead. The capacitor container is inserted into a hole drilled in the hole, the flange is electrically connected to a predetermined conductive layer on the printed circuit board, and the electrode lead is electrically connected to another conductive layer on the printed circuit board. Capacitors for printed circuit board mounting.