JPH0897661A - Filter - Google Patents

Abstract

PURPOSE: To obtain a small filter with high performance and high reliability having an excellent filter effect by forming a dielectric material, a resistor, a ferrite and a conductor electrode as layers on a ceramic board by a printing method to form the filter comprising at least two kinds of the printed layers. CONSTITUTION: The filter is formed by printing, drying and baking ferrite layers 5, 5', a conductor electrode layer (lower electrodes 2, 2' and an upper electrode 4), a dielectric layer 3, a resistor layer 6, and a protective glass layer 7 onto a ceramic board 1. The lower electrode 2, the dielectric layer 3 and the upper electrode 4 form a capacitor 10. The upper electrode 4 is covered by the ferrite layers 5, 5', the resistor layer 6 is formed between the lower electrode 2' and the upper electrode 4, and the capacitor 10, the ferrite layers 5, 5', the resistor layer 6, and the upper electrode 4 and part of the lower electrode are covered by the protective glass layer 7.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter which is required to be compact and have high performance in electronic parts.

[0002]

2. Description of the Related Art Conventionally, a large number of individual capacitors, individual ferrites, individual resistors, etc. are aligned and mounted on a substrate, a printed wiring board, etc. and used as a filter function. Further, JP-A-6-85485 proposes an LC substrate which is a porcelain substrate which has a through hole for inserting a lead wire and is integrally formed with a ferrite layer and a capacitor portion. Further, Japanese Patent Laid-Open Publication No. 50-70856 proposes a thick film capacitor formed by printing and firing electrodes and a dielectric in a laminated form on a ceramic substrate.

[0003]

The individual capacitors, the individual ferrites, the individual resistors, and the like, which are mounted as described above,
The handling of such items requires a large number of parts and a large number of assembling steps, resulting in high price and reliability. Further, in the LC substrate in which the lead wire is inserted as described in JP-A-6-85485, the route of the ferrite layer with respect to the lead wire is short and a sufficient filter effect cannot be obtained. Further, the thick film capacitor described in Japanese Patent Laid-Open No. 50-70856 has only a capacitor as a filter element and the filter effect is not sufficient, and its application is limited.

Therefore, an object of the present invention is to integrally form a filter function composed of a combination of a capacitor, a resistor, and a ferrite in a layered manner by a printing method, have an excellent filter effect, have a wide range of applications, and be small in size, low in price and high in price. It is to provide a filter having high performance and high reliability.

[0005]

The present invention comprises at least two kinds of a layered dielectric, a resistor and a ferrite body formed by a printing method on a ceramic substrate, and a conductor electrode, and has a filter effect. It is a filter that is excellent, has a wide range of uses, and is small in size, low in price, and has high performance and high reliability.

The filter according to the present invention will be described in detail below. 1A and 1B are drawings showing an embodiment of a filter according to the present invention. In addition, FIG.
It is sectional drawing which followed the JJ 'line of (A).

The filter according to the present invention comprises a ceramic substrate 1, a ferrite layer 5, 5 ', a conductor electrode layer (lower electrode 2,
2 ', the upper electrode 4), the dielectric layer 3, the resistor layer 6, and the protective glass layer 7 are printed, dried and fired. More specifically, the conductor electrode layer (the lower electrode 2,
2 ', upper electrode 4), dielectric layer 3, ferrite layer 5
5 ', the resistor layer 6 and the protective glass layer 7 are formed in layers, the lower electrode 2, the dielectric layer 3 and the upper electrode 4 constitute a capacitor 10, and the upper electrode 4 is a ferrite layer 5.5'.
A resistor layer 6 is formed between the lower electrode 2 ′ and the upper electrode 4 and surrounded by the capacitor 10, the ferrite layer 5,
5 ′, the resistor layer 6, the upper electrode 4 and part of the lower electrode are covered with the protective glass layer 7.

In the filter according to the present invention, the structure of the filter is not limited to the above-described structure, but may be a structure / combination having at least two kinds of dielectrics, resistors and ferrites, and a conductive electrode having a filter function. I wish I had it. Further, insulating ceramics are preferable as the ceramic substrate. More preferably, it is an alumina ceramic. Further, the materials for forming the conductor electrode layer (lower electrode, upper electrode, signal electrode, ground electrode, etc.), ferrite layer, dielectric layer, resistor layer and protective glass layer can be printed by a printing method and fired. There is no particular limitation as long as it is possible. Preferably, the dielectric layer has a perovskite structure. More preferably, the dielectric layer is Pb (Mg _1/3 Nb _2/3 ) O ₃ , Pb (Zn _1/3 Nb
_2/3 ) at least one of O ₃ , PbTiO ₃ and Bi ₂ O ₃
A dielectric having a composition containing is preferable. The material of the conductor electrode layer is C
u, Ag-Pd, Ag-Pt, W, Mo-Mn, etc. are preferable. More preferably, Ag-Pd, Cu, Ag-P
t. Furthermore, the method of forming the conductor electrode layer, the ferrite layer, the dielectric layer, the resistor layer and the protective glass layer is
It is formed by firing. Preferably, it is formed by a thick film printing technique.

The capacitor has a sandwich structure of a dielectric and an electrode. In addition, the electrodes are surrounded by a dielectric, and further,
A through-type capacitor can be formed by surrounding and covering with a ground electrode.

The ferrite layer may be formed only on the lower surface or the upper surface of the electrode on the surface of the ceramic substrate, and preferably the electrode is surrounded by the ferrite layer on the surface of the ceramic substrate to form a through type or through hole. Is formed on the inner wall of the through hole of the ceramic substrate having a ferrite layer and an electrode layer or a lead frame in a through type. Further, the inside of the through hole may be filled with an electrode layer or a ferrite layer, and is preferably formed only on the wall surface.

Furthermore, the filter function of the filter is protected,
A protective layer for improving reliability is printed with glass paste,
In addition to forming the protective glass layer by drying and baking, resins may be printed, applied, dip, etc., and dried and cured.

The filter function is performed by the conductor electrode layer (lower electrode,
Upper electrode), a ferrite layer, a dielectric layer and a ferrite including a resistor, a capacitor and a resistor. A filter formed by forming a plurality of elements on a ceramic substrate may include a combination of the ferrite, the capacitor, and the resistor, and the filter function may be formed for each electrode. It may be formed only. The shape of the filter function is not particularly limited. The dielectric layer of the capacitor that constitutes the filter function may be formed in common with a plurality of electrodes, but it is preferable that each electrode has an independent dielectric layer. Further, the electrodes are not limited to those formed by printing, but may be combined with lead frames or the like.
Preferably, it is formed by a printing method.

Such a filter according to the present invention can be used in electronic equipment, computer peripherals, communication equipment, video equipment, game equipment, sales equipment, and the like. Further, the filter according to the present invention is structurally simple, can form a large number of filter elements at the same time, has a large degree of freedom in design, and is easy to manufacture. The filter according to the present invention,
It has an excellent filter effect, a wide range of applications, small size, low price, high performance and high reliability, and is also excellent as a surface mount type.

[0014]

Embodiments of the filter according to the present invention will be described below. The filter according to the present invention is not limited to the following embodiments.

(Embodiment 1) A plurality of break lines are formed on the ceramic substrate 1 using an alumina ceramic having a notch for determining the direction of the filter, and an Ag-Pd type conductive paste is screen-printed on the ceramic substrate 1 as shown in FIG. Then, it was dried and fired to form the lower electrodes 2.2 '.

Next, the dielectric paste was screen-printed on the lower electrode 2, dried and fired to form independent dielectric layers 3. Further, a ferrite paste was screen-printed on the upper surface of the ceramic substrate 1, dried and fired to form a ferrite layer 5.

Next, an Ag-Pd type conductive paste was screen-printed on the upper surface of the dielectric layer 3, the surface of the ceramic substrate 1 and the ferrite layer 5, dried and fired to form the upper electrode 4. The lower electrode 2, the dielectric layer 3 and the upper electrode 4 form a capacitor 10.

Next, a resistor paste was screen-printed between the lower electrode 2'and the upper electrode 4, dried and fired to form a resistor layer 6. Further, a ferrite paste was screen-printed on the upper electrode 4 on the ferrite layer 5, dried and fired to form a ferrite layer 5 '. The ferrite layers 5 and 5 ′ surround and cover the upper electrode 4. Further, a glass paste was screen-printed so as to cover the lower electrode, the upper electrode, the capacitor layer, the resistor layer, and the ferrite layer, dried and fired to form the protective glass layer 7, thereby forming a filter.

The filter manufactured in this manner has a resistance of
The filter function is formed by the ferrite, the capacitor, and the upper electrode that penetrates the ferrite, and it has excellent filter performance, is compact, low-priced, and highly reliable, and is extremely suitable for surface mounting as a leadless electronic component on a printed circuit board, etc. Was useful to.

(Example 2) A filter was obtained as shown in Fig. 2 by carrying out the same method as in Example 1. Ceramic substrate 11
Ground electrode 14 is formed on the surface of, dielectric layer 13 is formed, ferrite layer 15 is formed, signal electrode 12 is formed, ferrite layer 15 'is formed, dielectric layer 13' is formed, and ground is formed. The electrode 14 'was formed, the protective glass layer 17 was formed, and the filter was produced. The ground electrodes 14 and 14 ', the dielectric layers 13 and 13', and the signal electrode 12 form a through-type capacitor 20.

The filter manufactured in this manner forms a filter function by the signal electrode and the ground electrode penetrating the capacitor and a filter function by the ferrite, and has excellent filter performance, small size, low price, and high reliability, It is very useful as a leadless electronic component for surface mounting mounting on printed circuit boards and the like.

(Embodiment 3) As shown in FIG. 3, an alumina ceramic substrate 21 having holes is used, and a ferrite paste is screen-printed, dried and fired on the inner wall of the holes of the ceramic substrate 21 to form a ferrite layer 25. Formed. Next, the conductive paste was screen-printed, dried and fired to form the ground electrode 24. Next, the dielectric paste is screen-printed, dried, and fired to form the dielectric layer 2
Formed 3. Next, the conductive paste was screen-printed, dried, and baked to form the signal electrode 22. Next, the glass paste was screen-printed, dried and fired to form the protective glass layer 27. Next, the lead 28 is inserted into the hole, and the signal electrode 22 is contacted and fixed with the solder 29,
(The lead 28 'was brought into contact with the ground electrode.) The lead was homed to prepare a filter. Signal electrode 2
2, the dielectric layer 23 and the ground electrode 24 are capacitors 30
And the ferrite layer in which the lead 28 is inserted forms a through-type ferrite.

In the filter thus manufactured, the path of the filter effect of the ferrite layer 25 and the lead 28 is long,
It was excellent in the noise removing effect together with the capacitor 30. It was also suitable for surface mounting.

[0024]

The filter according to the present invention is formed on a ceramic substrate by a printing method, has excellent filter performance, is small in size, low in price, and highly reliable, and is extremely suitable for surface mounting on a printed circuit board or the like. It can be provided as a useful electronic component.

[0025]

[Brief description of drawings]

1A and 1B are a top view and a cross-sectional view showing an embodiment of a filter according to the present invention. (A) is
It is the figure seen from the upper surface, (B) is JJ 'of (A) figure.
It is sectional drawing which followed the line. (Example 1)

[0026]

2A and 2B are a top view and a cross-sectional view showing an embodiment of a filter according to the present invention. (A) is
It is the figure seen from the upper surface, (B) is KK 'of (A) figure.
It is sectional drawing which followed the line. (Example 2)

[0027]

3 (A) and 3 (B) are a diagram and a sectional view showing an embodiment of a filter according to the present invention. (A) is a perspective view, (B) is a vertical cross-sectional view of the lead 28 of (A). (Example 3)

[0028]

[Explanation of symbols]

 1.11.21 Ceramic substrate 2.2 'Lower electrode 3.13'13'23 Dielectric layer 4 Upper electrode 5.5'15.15'25 Ferrite layer 6 Resistor layer 7.17.27 Protection Glass layer 10/30 Capacitor 12/22 Signal electrode 14/14 '/ 24 Ground electrode 28/28' Lead 29 Solder 20 Through-type capacitor

Claims (3)

[Claims] 1. A filter comprising at least two kinds of layered dielectrics, resistors and ferrites formed by a printing method on a ceramic substrate, and a conductor electrode. 2. The filter according to claim 1, which is a surface mount type. 3. The filter according to claim 1, wherein the structure of the dielectric body and the conductor electrode and / or the structure of the ferrite body and the conductor electrode is a penetration type. [0001]