JP3136760B2 - Chip type three-terminal capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type three-terminal capacitor.

[0002]

2. Description of the Related Art As one of countermeasures against noise in electronic circuits, particularly digital circuits, there is a method of connecting a bypass capacitor between a signal conductor line and a ground conductor to release high frequency component noise to the ground conductor and remove it. Are known. As a bypass capacitor, a three-terminal capacitor is often used.
With the surface mounting, chip type three-terminal capacitors have been receiving attention.

Hereinafter, a conventional chip type three-terminal capacitor will be described. FIGS. 6A and 6B are a perspective view and an equivalent circuit diagram of a conventional chip type three-terminal capacitor, respectively. In this chip type three-terminal capacitor, a signal conductor line is provided inside a multilayer chip capacitor 1 and connected to signal line electrodes 2 and 3 provided at opposite ends of the chip capacitor. The ground electrode 4 is provided on the end surface of the multilayer chip capacitor 1 where no capacitor is formed so as to form a capacitor between itself and the internal signal conductor line.

[0004]

The chip type three-terminal capacitor constructed as shown in FIG. 3 is made of barium titanate or the like as a base material, and therefore is brittle and has a complicated shape having a concave portion or a convex portion at the edge of the substrate. I can't take it. Therefore, when forming the end surface electrodes in three directions of the edge of the rectangular substrate,
Simple end-face electrode forming methods, such as through-hole printing and roller printing, used in multiple chip resistors cannot be used due to short-circuit failure, and require other complicated manufacturing steps. In addition, there are also problems such as cracks during mounting and peeling of electrodes due to the brittleness of the base.

The present invention solves the above problems,
By forming a capacitor made of a thick film dielectric on an insulating substrate with excellent mechanical strength such as alumina, and providing a concave or convex portion at the edge of this insulating substrate, through-hole printing similar to multiple chip resistors , And the end face electrode can be formed by a simple method such as roller printing, and the matrix strength,
It is another object of the present invention to provide a chip-type three-terminal capacitor having a large end face electrode strength.

[0006]

In order to achieve the above object, a chip-type three-terminal capacitor according to the present invention comprises: a rectangular insulating substrate having a plurality of concave portions or convex portions at opposite end edges;
A plurality of terminal electrodes formed from a concave portion or a convex portion at both end edges of the insulating substrate to an upper surface of the insulating substrate, and a thick film dielectric formed so as to overlap with other terminal electrodes except for at least one of the plurality of terminal electrodes. with the body and an upper electrode formed so as to be connected to the terminal electrode and thick film dielectric thick film dielectric does not overlap with one of the terminal electrodes, and a protective layer covering the thick film dielectric , Among the terminal electrodes
The electrode on which the conductors overlap is the terminal electrode for the signal line.
And the terminal electrode where the thick film dielectric is not formed to overlap.
The pole is a terminal electrode for ground, and the upper electrode is
A terminal electrode for the signal line is covered with a thick film dielectric.
Is what it is.

[0007]

According to this structure, the terminal electrode having the thick film dielectric formed thereon functions as a signal line electrode having both ends of the substrate IN and OUT, while the terminal electrode connected to the upper electrode functions as a ground electrode. A chip type three-terminal capacitor can be obtained. The terminal electrodes are provided in the concave portions or the convex portions at both ends of the insulating substrate, and a simple end face electrode forming method similar to the multiple chip resistor can be employed. Since an insulating substrate having high mechanical strength, such as alumina, can be used as a base, a chip type three-terminal capacitor having high mounting reliability with almost no cracking or electrode peeling during mounting can be provided.

[0008]

(Embodiment 1) Hereinafter, a chip type three-terminal capacitor according to an embodiment of the present invention will be described with reference to the drawings. FIGS. 1A, 1B and 1C are a plan view, a sectional view and an equivalent circuit diagram of a chip type three-terminal capacitor according to a first embodiment of the present invention, respectively.
In FIG. 1, reference numeral 11 denotes an insulating substrate made of alumina or the like, which has a plurality of concave portions at opposite end edges. A signal line terminal electrode 12 and a ground terminal electrode 13 are formed from the concave portion to the upper surface of the insulating substrate. Reference numeral 14 denotes a thick film dielectric, 15 denotes an upper electrode overlapping the thick film dielectric 14 and the ground terminal electrode 13, 16 denotes crystallized glass, and 17 denotes amorphous glass.

In the chip-type three-terminal capacitor configured as described above, each terminal electrode can be formed by printing and firing a through-hole of a thick film conductor paste in the same manner as a multiple chip resistor. In addition, since the capacitor is formed of a thick film dielectric on a base substrate such as alumina, the mechanical strength of the chip and the strength of the terminal electrode can be increased, and cracking and peeling of the electrode during mounting can be almost eliminated. . In addition, since surface mounting can be performed using the same solder lands as the multiple chip resistors, there is also an advantage that the circuit pattern can be easily designed when used in combination.

The protective layer of the thick-film dielectric has a double structure of the crystallized glass 16 and the amorphous glass 17 having excellent plating resistance. This is because the amorphous glass penetrates into the dielectric material 14 and impairs the capacitor characteristics, and the crystallized glass 16 alone does not completely seal the interface with the substrate, and impairs the capacitor characteristics during terminal electrode plating. .

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a plan view of a chip type three-terminal capacitor showing a second embodiment of the present invention. 2, each unit is the same as the configuration in FIG. The difference from FIG. 1 is that the signal line electrode terminals 12
Are provided.

As described above, the signal line terminal electrode 12
Are provided, a chip-type three-terminal capacitor assembly can be easily manufactured by the same electrode forming method as that of the multiple chip resistor.

In the first and second embodiments, the terminal electrodes 12 and 13 are concave terminal electrodes formed by printing through holes in concave portions at the edges of the substrate. A convex terminal electrode may be used. In the second embodiment, the present invention can be applied to a case in which a plurality of ground terminal electrodes 13 are provided. Also, the signal line electrode terminal 1
Although 2 is provided linearly from both concave portions, it may be expanded or recessed toward the ground terminal electrode 13 in order to match the capacitance value.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a plan view of a chip-type three-terminal capacitor array according to a third embodiment of the present invention. 3, each part is the same as the structure of FIG. The difference from FIG. 2 is that the ground terminal electrodes 13 are provided at opposite ends of the insulating substrate 11 in the short side direction.

As described above, by providing the ground terminal electrodes 13 on the opposite end edges in the short side direction of the insulating substrate 11, the length can be shortened in the long side direction, and the chip can be further downsized. Further, since soldering is performed not only in the long side direction but also in the short side direction of the chip, there is an advantage that the soldering strength to the printed circuit board is increased.

In the third embodiment, the terminal electrode 1
The reference numerals 2 and 13 are concave terminal electrodes formed by printing through holes in the concave portions of the substrate edge. However, convex portions may be provided on the substrate edge to form convex terminal electrodes by roller printing, and the capacitance value is controlled. In order to allow the pattern to have a margin, it is formed non-linearly by swelling or depressing from the concave portion to the pair of concave portions at the opposite edge, but may be linearly formed if not necessary.

(Embodiment 4) Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 4 (a),
(B) is a plan view of a chip type three-terminal capacitor showing a fourth embodiment of the present invention. In FIG. 4, each part is shown in FIG.
Is similar to that of the above. The difference from FIG. 3 is that a plurality of resistors 18 are provided between the signal line terminal electrodes 12.

As described above, the signal line terminal electrode 12
By providing a resistor between them, multiple components of a resistor and a capacitor can be easily formed.

FIG. 5 shows an example of an application circuit of the fourth embodiment of the present invention. The portion surrounded by a dashed line is the capacitor of the present invention. FIG. 5A shows a series termination for reducing noise by connecting a resistor in series to the bus line. FIG. 5B shows an AC termination in which one resistor and one capacitor are connected in series from the bus line to the ground. FIG. 5 (c)
This is a combination of a pull-up / pull-down resistor and a capacitor. As described above, according to the present embodiment, all of the above circuits can be used.

[0020]

As described above, according to the present invention, the end face electrodes can be formed by the same simple method as the multiple chip resistor, and a base having high mechanical strength such as alumina can be used. The present invention can provide and realize a chip-type three-terminal capacitor having high mounting reliability without cracking or electrode peeling.

[Brief description of the drawings]

FIG. 1A is a plan view of a chip type three-terminal capacitor according to a first embodiment of the present invention; FIG. 1B is a cross-sectional view of the chip type three-terminal capacitor according to the embodiment; FIG. Circuit diagram of type 3 terminal capacitor

FIG. 2 is a plan view of a chip type three-terminal capacitor according to a second embodiment of the present invention.

FIG. 3 is a plan view of a chip-type three-terminal capacitor according to a third embodiment of the present invention.

FIG. 4A is a plan view of a chip type three-terminal capacitor according to a fourth embodiment of the present invention, and FIG. 4B is an equivalent circuit diagram of the chip type three-terminal capacitor according to the same embodiment.

FIGS. 5A to 5C are circuit diagrams showing examples of applied circuits according to a fourth embodiment of the present invention;

6A is a perspective view of a conventional chip type three-terminal capacitor, and FIG. 6B is an equivalent circuit diagram of a conventional chip type three-terminal capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Insulation substrate 12 Signal line terminal electrode 13 Ground terminal electrode 14 Thick film dielectric 15 Upper electrode 16 Crystallized glass 17 Amorphous glass 18 Thick film resistor

──────────────────────────────────────────────────続 き Continued on the front page (72) Minoru Soba, Inventor 1006 Kazuma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-50-80467 (JP, A) JP-A Sho57 JP-A-3-159105 (JP, A) JP-A-60-83234 (JP, U) JP-A-54-124161 (JP, U) JP-A-50-10511 (JP, Y1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01G 4/00-4/40 H01G 13/00-13/06

Claims (4)

(57) [Claims] 1. A rectangular insulating substrate having a plurality of concave portions or convex portions at opposite ends, a plurality of terminal electrodes formed from the concave portions or convex portions at both ends of the insulating substrate to the upper surface of the insulating substrate, A thick-film dielectric formed so as to overlap other terminal electrodes except at least one of the plurality of terminal electrodes; a terminal electrode and a thick-film dielectric which are not formed by overlapping the thick-film dielectric among the terminal electrodes; An upper electrode formed so as to be connected to a protective layer covering the thick film dielectric.
The terminal electrode of which the dielectric is overlapped is
A terminal electrode for a signal line, wherein the thick film dielectric is overlapped.
Terminal electrodes that are not formed are ground terminal electrodes
And the upper electrode is connected to the signal through the thick film dielectric.
Chip type three-terminal capacitor covering the terminal electrode for the No. line . 2. A rectangular insulating substrate having a plurality of pairs of recesses or protrusions at opposite end edges in the long side direction and a pair of recesses or protrusions at opposite end edges in the short side direction; A plurality of signal line terminal electrodes formed from the concave or convex portion to a pair of concave or convex portions on the opposite edge, and a thickness formed so as to overlap except for both end portions of the plurality of signal line terminal electrodes. A film dielectric, a pair of ground terminal electrodes formed in a concave portion or a convex portion in the short side direction, and a pair of ground terminals on the opposite edge from the ground terminal electrode on the thick film dielectric. An upper electrode formed over the electrode, and a protective film that covers the thick film dielectric ,
The upper electrode is connected to the plurality of signal lines through the thick film dielectric.
Chip-type three-terminal capacitor covering the electrodes for 3. A rectangular insulating substrate having a plurality of pairs of recesses or protrusions at opposite end edges in the long side direction and a pair of recesses or protrusions at opposite end edges in the short side direction; A plurality of signal line terminals formed from the concave or convex portions to a pair of concave or convex portions on the opposite edge, and a plurality of resistors connected in series on a signal path between the signal line terminal electrodes; A thick-film dielectric formed so as to overlap with both end edges of the plurality of signal line terminal electrodes except for the resistor portion, and a pair of ground terminal electrodes formed in a concave portion or a convex portion in a short side direction. , comprising an upper electrode formed over the grounding terminal electrode pairs on opposite edges from the grounding terminal electrode through the thick film dielectric, and a protective layer covering the thick film dielectric, said upper electrode the thick film dielectric of
A chip-type three-terminal capacitor that covers the plurality of signal line electrodes via a plurality of signal line electrodes . 4. The chip-type three-terminal capacitor according to claim 1, wherein the protective film has a double structure of crystallized glass and non-crystallized glass.