JPH0946020A - Noise filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a noise filter which is not affected by a pattern design of a printed board whereon an electronic part is mounted, has a short pattern of a coil, an X capacitor and a Y capacitor and damps noises highly effectively. SOLUTION: The device comprises a bobbin 2 whereto a wiring 1 is applied, and a coil consisting of a core and a capacitor; a thick film pattern 3 is formed in a side surface of the bobbin 2; a lamination ceramic capacitor 4 is mounted on the thick film pattern 3; both ends of the thick film pattern 3 and the wiring 1 are connected to as terminal 5 buried in the bobbin 2; and a coil and a capacity are formed in one piece structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise filter used in various electronic devices and the like.

[0002]

2. Description of the Related Art A noise filter composed of a coil and a capacitor is an electronic component that attenuates both external noise and noise generated by electronic equipment. Therefore, the noise filter is indispensable for electronic equipment.

Conventionally, in this type of noise filter, as shown in the circuit diagram of FIG. 2, a capacitor called an X capacitor (X capacitor) 7 is arranged on the AC line side with respect to the coil 6, and Y is arranged on the electronic device side. Capacitor (Y capacitor)
It has a configuration in which capacitors called 8 are placed,
The coil 6, the X capacitor 7 and the Y capacitor 8 are
They were individually mounted on a printed circuit board on which other electronic components were mounted.

As shown in FIG. 3, the X capacitor 7 connected between the two AC lines absorbs normal mode noise 9 (noise existing as a noise source between the two AC lines). It is for.

Further, as shown in FIG. 4, a Y capacitor 8 connected in a Y shape between the two AC lines and the ground.
The coil 6 and the common mode noise 10 (the noise source is A
It serves to attenuate the noise existing between the C line and the ground.

[0006]

However, in the conventional noise filter, since the coil, the X capacitor, and the Y capacitor are individually provided, the method of designing the pattern of the printed circuit board on which the electronic parts of the electronic device itself are mounted is designed. Depending on the situation, the coil, the X capacitor, and the Y capacitor may be mounted at distant places, so the pattern connecting the coil, the X capacitor, and the Y capacitor becomes very long, and the pattern itself promotes the generation of noise. There was a problem of doing.

In order to solve the above problems, the object of the present invention is not affected by the pattern design of the printed circuit board on which electronic parts are mounted, and the pattern of the coil, the X capacitor and the Y capacitor is short, and the effect of attenuating noise is obtained. To obtain a high noise filter.

[0008]

According to the present invention, a thick film pattern is formed on the side surface of a wound bobbin, and a monolithic ceramic capacitor which is an X capacitor and a Y capacitor is mounted on the thick film pattern. By the coil,
A noise filter can be obtained in which the X capacitor and the Y capacitor are integrally structured, and both ends of the winding and the thick film pattern on which the laminated ceramic capacitor is mounted are respectively connected to the terminals embedded in the bobbin.

That is, the present invention is a noise filter comprising a bobbin having a winding, a coil consisting of a core, and a capacitor, wherein a thick film pattern is formed on the side surface of the bobbin and laminated on the thick film pattern. A noise filter in which a ceramic capacitor is mounted, both ends of the thick film pattern and the winding are connected to terminals embedded in a bobbin, and the coil and the capacitor are integrated.

[0010]

According to the present invention, a thick film pattern is formed on a side surface of a bobbin, and an X capacitor and a laminated ceramic capacitor, which is a Y capacitor, are mounted on the thick film pattern, and a coil, an X capacitor, and By forming the Y capacitor in an integrated structure, the pattern connecting the Y capacitors can be shortened. As a result, the inductance of the wiring and the printed circuit board pattern is reduced, and a noise filter that is sufficiently effective in reducing noise and that is not affected by the pattern design of the printed circuit board can be obtained.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of the noise filter of the present invention. In FIG. 1, a thick film pattern 3 having a thickness of several tens of μ is formed on the side surface of the bobbin 2 having the winding 1 by the MID technique.
Is formed on the thick film pattern 3, and an X capacitor (0.
1μF 250V and Y capacitor (4700pF 2
The laminated ceramic capacitor 4 of 50 V) is mounted.

Both ends of the winding 1 and the thick film pattern 3 on which the laminated ceramic capacitor 4 is mounted are respectively connected to the terminals 5 embedded in the bobbin 2, so that the winding 1, the X capacitor and the Y capacitor are integrated. .

[0014]

As described above, according to the present invention,
By integrally forming the coil and the capacitor, a noise filter having a high noise reduction effect and not affected by the printed circuit board design can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a noise filter according to the present invention.

FIG. 2 is a circuit diagram showing a configuration of a conventional noise filter.

FIG. 3 is a circuit diagram showing a flow of a normal mode noise current.

FIG. 4 is a circuit diagram showing the flow of common mode noise current.

[Explanation of symbols] 1 winding 2 bobbin 3 thick film pattern 4 multilayer ceramic capacitor 5 terminal 6 coil 7 X capacitor (X capacitor) 8 Y capacitor (Y capacitor) 9 normal mode noise 10 common mode noise

Claims (1)

[Claims] 1. A noise filter comprising a coil consisting of a wound bobbin, a core, and a capacitor, wherein a thick film pattern is formed on a side surface of the bobbin, and a multilayer ceramic capacitor is mounted on the thick film pattern. Then, the thick film pattern and both ends of the winding are connected to terminals embedded in the bobbin, and the coil and the capacitor have an integrated structure.