JP3231350B2 - Capacitor network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor network mainly used as a noise filter for a high-frequency circuit.

[0002]

2. Description of the Related Art In recent years, capacitor networks are frequently used as high frequency noise absorbing elements in high-speed digital circuits.

A conventional thick film capacitor network will be described below.

As shown in FIGS. 13 and 14, a barium titanate-based ceramic capacitor powder is formed into a strip shape under pressure and fired at a high temperature of about 1300 ° C. on a ceramic capacitor substrate 12. A silver-based thick film paste is printed and fired so that the ceramic electrode substrate 13 and the common electrode 13 are opposed to each other with the ceramic capacitor substrate 12 interposed therebetween. Furthermore, after soldering the lead terminals 15, the insulating paint 16 is covered to complete the capacitor network.

[0005] This conventional capacitor network has three
It is a composite of 3 to 12 capacitors having a capacitance of 0 pF to 10 nF in one component, and is widely used particularly as a high frequency noise absorbing element in an input / output unit of a microcomputer.

[0006]

However, in the above-mentioned conventional configuration, since it is a lead type and has a high height,
It cannot be used for a device which is required to be thin and small. In addition, a crosstalk of a signal between adjacent terminals due to a stray capacitance generated between the electrodes 14 and a resonance due to a residual inductance generated by the lead terminal 15. The problem is that it cannot be used for high-speed digital circuits due to the decrease in frequency, and furthermore, the mechanical strength of the ceramic capacitor substrate 12 itself is weak, so that not only can the thickness of the ceramic capacitor substrate 12 be reduced, but also the sheet-shaped sintered body can be used in chocolate. -There was a problem that the manufacturing method of breaking into individual pieces could not be adopted and mass productivity was poor.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a capacitor network having excellent mountability, noise absorption characteristics, and good mass productivity.

[0008]

In order to achieve the above object, a capacitor network according to the present invention comprises a strip-shaped ceramic substrate having electrical insulation, a plurality of independent through electrodes formed on the ceramic substrate , And the through current
A common electrode facing through a thick-film dielectric layer is included so that the area facing the poles is constant, and a networked capacitor element on the ceramic substrate is formed on an end face of the ceramic substrate. , A plurality of end face electrode pairs respectively connected to the plurality of independent through electrodes and the common electrode, wherein the thick film dielectric layer comprises:
Formed so as to cover the through electrode, leaving a part of both ends of
It is a thing.

[0009]

According to this structure, a ceramic fired in advance is used.
Since the thick-film conductor paste is printed and fired directly on the end face of the substrate to provide the end face electrode, the adhesion is good and the strength of the end face electrode is increased. In addition, since the end surface electrodes provided only on the end surface of the ceramic substrate can be directly soldered to the circuit board, they can be mounted at a low profile and at a high density, and unnecessary inductors are not generated due to leadless, and mass production is possible. Will be higher.

[0010]

EXAMPLES For the Examples 1 (Example 1) Hereinafter the present invention will be described with reference to the drawings.

As shown in FIGS. 1 to 4 , an electrically insulating alumina-based ceramic substrate 1a on which a plurality of independent through electrodes 3a are formed is formed through a thick dielectric layer 4a.
a and a plurality of end face electrode pairs 8 facing
A method for manufacturing a capacitor network having a configuration in which the capacitors a and 9a are provided will be described with reference to FIG.

As shown in FIG. 5 (a), the primary division groove 6 and the secondary division groove 7 are machined vertically and horizontally so that one piece after division becomes a rectangular ceramic substrate 1a of 2.5 mm × 7 mm. A plurality of independent through-electrodes 3a are formed by screen-printing a silver-paradium-based thick-film conductor paste on one side of the sheet-shaped ceramic substrate 2a and baking it at 850 ° C. for 1 hour. Next, as shown in FIG. 5B, a part of both ends of the through electrode 3a is left so as to cover the through electrode 3a.
Thick film dielectric paste 4a is screen-printed and baked at 850 ° C. for 1 hour.
To form Next, as shown in FIG. 5 (c), the common electrode 5a has a constant area facing each through electrode 3a.
Is formed by screen printing a silver palladium-based thick film conductor paste and baking it at 850 ° C. for 1 hour to form a capacitor element. Next, as shown in FIG. 5D, after the sheet-like ceramic substrate 2a is divided along the primary division grooves 6, the divided end faces are connected to the through electrodes 3a as shown in FIG. 5E. End electrode pair 9a for signal
And an end face electrode pair 8 for a ground terminal connected to the common electrode 5a
a is coated with a silver-palladium thick conductor paste
It is formed by firing at 0 ° C. for one hour, and finally, as shown in FIG. 5 (f), is divided along the secondary division grooves 7 to complete the capacitor network.

FIG. 6 shows the insertion loss characteristics of one capacitor element of each of the capacitor network according to the first embodiment and the conventional capacitor network.
In both cases, the capacitance value was 2200 pF, and the circuit impedance was measured at 50Ω.

As is clear from FIG. 6, the capacitor network according to the present invention has an excellent effect in terms of high frequency noise absorption.

According to the first embodiment described above, the ceramic substrate 1a of the thin and long, be on the ceramic substrate 1a
Network and a plurality of independent through electrodes 3
a and the area facing the through electrode 3a becomes constant.
As described above, the common electrode 5 opposed via the thick film dielectric layer 4a
a , and a through electrode 3a and a common electrode 5a formed only on the end face of the ceramic substrate 1a.
By providing a plurality of end face electrode pairs 8a and 9a connected to the above , the noise elimination property and the mountability can be improved.

[0016] (Example 2) will be described with reference to the following with the second embodiment of the present invention with reference to the accompanying drawings.

7 to 10 , 2b is an alumina-based sheet ceramic substrate, 1b is a ceramic substrate,
8b and 9b are end face electrode pairs, 3b is a through electrode, 4b is a thick film dielectric layer, 5b is a common electrode, 6 is a primary division groove, 7 is a secondary division groove, and the above is the same as the configuration of the first embodiment. Things. And different from the configuration example 1, the through electrode 3b penetrates the central portion in the thickness direction of the thick film dielectric layer 4b, and a point having a lower surface common electrode 11 on the lower surface of the thick film dielectric layer 4b ,
The end face electrode pair 9b for signal connected to the through electrode 3b is
A point formed in the concave portion on the long side end surface of the lamic substrate 1b is connected to an arc connected to the common electrode 5b and the lower surface common electrode 11 .
This is the point that an end face electrode pair 8b for the terminal is formed on the short side end face of the ceramic substrate 1b.

A method of manufacturing the capacitor network configured as described above will be described with reference to FIG. First, as shown in FIG. 10 (a), a silver palladium-based thickness is formed in a round hole 10 of a sheet-shaped ceramic substrate 2b in which round holes 10 having a diameter of 4 mm are provided at equal pitches along the secondary dividing groove 7. The film conductor paste is subjected to through-hole printing using a screen printer, and baked at 850 ° C. for 1 hour, thereby forming a plurality of end face electrode pairs 9 b and a lower face common electrode 11. Next, as shown in FIG. 10B, a magne-niobate-based thick film capacitor paste was screen-printed so as to cover the lower surface common electrode 11, and as shown in FIG. After printing a plurality of through electrodes 3b, FIG.
As shown in (d), a thick film capacitor paste is further printed and baked at 850 ° C. for 1 hour to form a thick film dielectric layer 4. Thereafter, as shown in FIG. 10E, the common electrode 5a is provided by screen-printing a silver palladium-based thick film conductor paste and firing at 850 ° C. for 1 hour.
Form a capacitor element. Further, as shown in FIG. 10 (f), after dividing the primary division groove 6 of the sheet-shaped ceramic substrate 2b, the divided surface corresponding to the short side end surface of the ceramic substrate 1b is connected to the common electrode 5b, and The end face electrode pairs 8b facing each other are formed by applying a silver-paradium-based thick-film conductor paste and firing the paste.
Se Finally, by dividing along the secondary dividing groove 7
A capacitor network is completed by using the individual pieces made of the lamic substrate 1b .

The insertion loss characteristics of the capacitor network thus obtained were measured in the same manner as in Example 1. As a result, the insertion loss at 100 MHz was as large as 2 dB, and an excellent effect in terms of high frequency noise absorption was obtained. Can be

As described above , according to the second embodiment, the thick dielectric layers 4b, 4 sandwiched between the two common electrodes 5b, 11 are formed.
By disposing the through electrode 3b in the inside, the shielding effect of the capacitor can be strengthened and the high frequency characteristics can be further improved.

[0021] will be described with reference to the drawings attached to the third embodiment (Embodiment 3) The following present invention. As shown in FIG. 11, a difference from the configuration of the first embodiment is that a pair of end face electrodes 9c for signals connected to the through electrodes 3c is provided.
Is formed on the protruding portion of the end face on the long side of the ceramic substrate 1c, and the end face voltage for the ground terminal connected to the common electrode 5c is formed.
The point is that the pole pair 8c is formed on the end face on the short side of the ceramic substrate 1c.

The method of manufacturing the capacitor network of the third embodiment is basically the same as that of the first embodiment, except that a square hole having a side of 4 mm is formed along the secondary division groove 7 and along the primary division groove 6. The point is that a sheet-like ceramic substrate 1c in which rectangular holes are provided at equal pitches is used, and an end face electrode pair 8c for a ground terminal is provided after primary division. The capacitor network of Example 3 had excellent noise absorption characteristics.

[0023] In the above Examples 1-3, all thick film conductor pastes using silver palladium was calcined in air, it may be fired in non-oxidizing atmosphere using a copper-based paste . Further, in Examples 1 to 3, the thick film was used.
Although the dielectric layers 4, 4a, 4b are formed only on one side of the ceramic substrate, they may be formed on both sides of the ceramic substrate. Further, as shown in FIG. 12, the end face electrode pair 8 is provided on the ceramic substrate 1d .
A protective coat layer 17 of, for example, a glass layer for the purpose of protecting the capacitor element provided with d and 9d may be provided. Furthermore, the thick dielectric layers 4, 4a, 4
In the case of b, these thick film pastes are provided by screen printing, but may be formed by other methods such as bonding a green sheet .

[0024]

As described above, the present invention provides a rectangular ceramic substrate, a plurality of independent through-electrodes formed on the ceramic substrate , and a constant area of opposition to the through-electrode . Common facing through thick dielectric layer
A capacitor element that includes an electrode and is networked on the ceramic substrate; and a plurality of end face electrode pairs formed on an end face of the ceramic substrate and connected to the plurality of independent through electrodes and the common electrode, respectively. Bei the door
The thick-film dielectric layer is formed by forming a part of both ends of the through electrode.
This is formed so as to cover the through electrode while leaving
According to the configuration, in order to improve the adhesion strength between the end surface electrode and the ceramic substrate, in which has excellent mountability and noise absorption properties, it can realize a good capacitor network mass productivity.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a capacitor network according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ of FIG. 1;

FIG. 3 is a sectional view taken along line BB ′ of FIG. 1;

FIG. 4 is a circuit diagram of the capacitor network.

FIG. 5 is a schematic plan view of a ceramic substrate in main manufacturing steps of the capacitor network.

FIG. 6 is a comparison diagram of the insertion loss characteristics of the capacitor network and a conventional capacitor network.

FIG. 7 is a front sectional view of a capacitor network according to a second embodiment of the present invention.

FIG. 8 is a side sectional view of the capacitor network.

FIG. 9 is a circuit diagram of the capacitor network.

FIG. 10 is a schematic plan view of a ceramic substrate in main manufacturing steps of the capacitor network.

FIG. 11 is an external perspective view of a capacitor network according to a third embodiment of the present invention.

FIG. 12 is an external perspective view of a capacitor network according to another embodiment of the present invention.

FIG. 13 is a cutaway view of a part of a conventional capacitor network.
External perspective view of the can

FIG. 14 is a circuit diagram of a conventional capacitor network.

[Explanation of symbols]

1a Ceramic substrate 3a Through electrode 4a Thick film dielectric layer 5a Common electrode 6 Primary division groove 7 Secondary division groove 8a End face electrode pair 9a End face electrode pair

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-33908 (JP, A) JP-A-57-206016 (JP, A) JP-A-56-104429 (JP, A) 45623 (JP, U)

Claims (4)

(57) [Claims] 1. A strip-shaped ceramic substrate exhibiting electrical insulation, a plurality of independent through electrodes formed on the ceramic substrate , and a thick-film dielectric so that an area facing the through electrode is constant. The common electrode facing through the body layer
Wherein a capacitor element that is networked be on the ceramic substrate, wherein formed on the end face of the ceramic substrate, and a plurality of independent through electrode and the common electrode and a plurality of end surface electrode pairs respectively connected to Prepared, said
The thick-film dielectric layer is formed by leaving a part of both ends of the through electrode.
A capacitor network formed to cover the through electrode . 2. A strip-shaped ceramic substrate having electrical insulation properties.
Plate and a lower common electrode formed on the ceramic substrate.
Pole, a thick dielectric layer formed on the lower common electrode,
Through the center of the thick dielectric layer in the thickness direction.
Standing through electrode, and position only above this through electrode
Formed on the upper surface of the thick dielectric layer via the thick dielectric layer
Including the common electrode,
Networked capacitor element and the ceramic
The plurality of independent through electrodes formed on the end face of the substrate;
Connected to the lower surface common electrode and the common electrode, respectively.
A plurality of end face electrode pairs, wherein the thick film dielectric layer is
The through-electrode is covered except a part of both ends of the through-electrode.
Formed capacitor network. 3. The capacitor network according to claim 1, wherein the ceramic substrate has regular irregularities on an end face, and a pair of end face electrodes is provided on either a concave part or a convex part on the end face of the ceramic substrate. 4. A signal end face electrode pair connected to a through electrode on a long side end face of a ceramic substrate ,
A common electrode or a short-side end face of the ceramic substrate
The capacitor network according to claim 1, further comprising a lower surface common electrode and an end face electrode pair for a ground terminal connected to the common electrode .