JPH04242309A - Noise filter - Google Patents

Abstract

PURPOSE:To attain noise elimination without distortion and to allow the filter to sufficiently cope with even a miniaturization requirement by means of multi- arrangement. CONSTITUTION:The noise filter 10 is provided with a rectangular dielectric board 1, on which resistor patterns 2... and a ground pattern 3 are provided. The plural resistor patterns 2... are formed on one side 1a of the dielectric board 1 and arranged thereon almost in parallel with an end face at the short side of the dielectric board 1. The ground pattern 3 is formed in the inside of the dielectric board 1 in parallel with the side 1a while being slightly lower than the surface of the side 1a, and the ground pattern 3 and each of the resistor patterns 2... are arranged opposite to each other while being parted somewhat from each other. Thus, the noise filter comprising RC composite components consisting of a distributed capacitance caused between the resistor patterns 2... and the ground pattern 3 and each of the resistor patterns 2... is formed. Moreover, multi-arrangement of the noise filters is attained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise filter.

0002

2. Description of the Related Art Conventionally, a noise filter has generally been constructed of an LC composite component consisting of an inductor L and a capacitor C, as shown in the equivalent circuit diagram of FIG. 8, for example.

0003

[Problems to be Solved by the Invention] However, in conventional noise filters, phenomena such as resonance occur between the inductor L and the capacitor C, which distorts the effective signal component and distorts the resulting distorted waveform component. There was a problem that secondary radiation occurred due to the

The present invention has been made in view of the above-mentioned problems, and provides a noise filter that is capable of removing noise without distortion and that can also sufficiently meet the recent demands for miniaturization of electronic components. is intended to provide.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a resistor pattern, a ground pattern, and a dielectric substrate, and a plurality of resistor patterns are provided and arranged in parallel with each other. , a noise filter was constructed by forming a resistance pattern and a ground pattern facing each other via a dielectric substrate.

[0006]

According to the above structure, a noise filter made of an RC composite component is formed by the distributed capacitance generated between the resistor pattern and the ground pattern, and each resistor pattern. Since RC composite parts do not have an inductance component,
No resonance phenomenon or secondary radiation phenomenon occurs in this noise filter.

[0007] Since a noise filter is constructed from a plurality of resistor patterns formed in parallel and a ground pattern placed opposite to the resistor patterns, it is possible to construct multiple noise filters, and it is also possible to use multiple noise filters. It becomes possible to form them at narrow pitches on a single dielectric substrate.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on embodiments shown in the drawings. FIG. 1 is a perspective view of an embodiment of the present invention, and FIGS. 2 and 3 are cross-sectional views taken along the lines AA and BB in FIG. 1.

This noise filter 10 includes a rectangular dielectric substrate 1, and the dielectric substrate 1 is provided with resistance patterns 2... and a ground pattern 3.

A plurality of resistor patterns 2 are formed on one surface 1a of the dielectric substrate 1. The resistance patterns 2 are formed into thin films by sputtering or vapor deposition, and are arranged in parallel with each other and substantially parallel to the short side end surfaces 1b and 1c of the dielectric substrate 1. Both ends of each resistance pattern 2 reach long side end surfaces 1d and 1e. Long side end surface 1d, 1
Input/output electrodes 4A..., 4B... are formed on e,
Each resistance pattern 2... is connected to input/output electrodes 4A, 4B, respectively. The input/output electrodes 4A and 4B are formed to extend to the back side. Then, the dielectric substrate surface 1a
The entire structure is covered with an insulating film 5, and the surfaces of the resistor patterns 2 are covered with this insulating film 5.

The ground pattern 3 is buried inside the dielectric substrate 1, as shown in the cross-sectional views of FIGS. 2 and 3. That is, the ground pattern 3 is buried inside the dielectric substrate 1 parallel to the surface 1a and slightly closer to the surface 1a, and the ground pattern 3 and each resistor pattern 2 are connected to each other through the dielectric substrate 1 by a little distance. They are placed facing each other at a distance. The ground pattern 3 has a size that covers the entire formation area of the resistor pattern 2. Also,
Both ends 3a and 3b of the ground pattern 3 reach short side end surfaces 1b and 1c of the dielectric substrate 1, and these end surfaces 1b
, 1c. Ground electrodes 6 and 7 are formed on the short side end surfaces 1b and 1c, respectively, and the ground pattern 3 is connected to these ground electrodes 6 and 7.

Noise filter 10 formed in this way
A distributed capacitance C is generated between each resistor pattern 2 and the ground pattern 3, forming a multiple RC composite component as shown in the equivalent circuit diagram of FIG. Therefore, EMI
When a high-frequency signal that requires countermeasures is input to each resistor pattern 2, the impedance on the input side is reduced by the generated distributed capacitance C, and noise in the signal is removed. that time,
Since there are no inductance components in these circuits, distortion of signal waveforms such as ringing and secondary radiation do not occur.

Furthermore, the formation pitch of the RC composite component formed in multiple series can be easily changed by changing the formation interval of the resistor patterns 2 formed in parallel. Therefore, it is relatively easy to form multiple noise filters 10 with a narrower pitch.

By the way, in the above embodiment, the resistor pattern 2... is formed in a long rectangular shape extending between the long side end surfaces 1d and 1e, but it is not limited to this, and may be formed in a spiral shape as shown in FIG. It may be a meander shape as shown in FIG. 6, or even a zigzag shape as shown in FIG.

Further, in the above embodiment, the ground pattern 3 is formed on almost the entire surface of the inside of the dielectric substrate 1, but the invention is not limited to this, and the ground pattern 2 may be divided into two or more parts in the longitudinal direction.

[0016]

As described above, according to the present invention, since the inductance component is eliminated from the components of the noise filter, inconvenient phenomena that lead to signal distortion, such as resonance phenomena and secondary radiation phenomena, do not occur, and distortion It is now possible to remove noise without noise.

Furthermore, since the noise filter is constructed from the resistor pattern formed in parallel and the ground pattern formed opposite to this through the dielectric substrate, it is possible to connect multiple noise filters, and It has become possible to form connected noise filters at narrow pitches on a single dielectric substrate. Therefore, it has become possible to downsize the noise filter.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the invention.

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

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

FIG. 4 is an equivalent circuit diagram of the embodiment.

FIG. 5 is a first modification example of a resistance pattern.

FIG. 6 is a second modification example of the resistance pattern.

FIG. 7 is a third modification example of the resistance pattern.

FIG. 8 is an equivalent circuit diagram of a conventional example.

[Explanation of symbols]

1 Dielectric substrate 2 Resistance pattern 3. Ground pattern

Claims (1)

[Claims] 1. A resistor pattern (2), a ground pattern (3), and a dielectric substrate (1) are provided. 2) and a ground pattern (3) are formed to face each other with a dielectric substrate (1) interposed therebetween.