JPH1117304A - Printed wiring board carrying inductance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively exclude noise produced from the electronic device of each circuit formed on a printed wiring board and, at the same time, to prevent the size increase of the board itself by constituting an inductance network forming a grid-like pattern in the middle of a power line or a ground line. SOLUTION: A conductive pattern 2 formed on the surface of a printed wiring board 1 made of a phenol resin, etc., contains a grid-like pattern 4 for forming an inductance component between input and output terminal sections 3 and 4 as part of a power line or a ground line. The grid-like pattern has an inductance on the side constituting each grid as an equivalent circuit and forms a grid-like network. Since the resultant inductance value of the network becomes a large value and the resultant inductance becomes a large impedance against a high-frequency component and effectively blocks unnecessary radiation, the need for mounting special parts on the board 1 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board having an inductance, and more particularly, to a printed wiring board having a power supply or a ground pattern formed with an inductance for preventing noise and unnecessary radiation.

[0002]

2. Description of the Related Art A printed wiring board includes a power supply pattern for forming a power supply line for supplying power to semiconductors and electronic components and an earth pattern for forming an earth line. If these power supply patterns and ground patterns are used as a common circuit for the entire device, if the noise generated by the electronic device of each circuit is transmitted to other circuit blocks,
Such a problem had arisen.

For this reason, in an audio device or the like in which noise on a signal is directly transmitted to the auditory sense, a power supply pattern or a ground pattern is applied to each circuit independently of a smoothing capacitor at the last stage of the power supply circuit, Means are provided independently for each circuit. However, since the power supply pattern and the earth pattern of the printed wiring board are formed by a continuous wide pattern commonly called a solid pattern, drawing this wide pattern for each circuit makes the printed wiring board itself large. This is not suitable for downsizing the device.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a printed wiring which can effectively prevent noise without providing a power supply pattern or a ground pattern for each circuit without providing a power supply circuit for each circuit. To provide a substrate.

[0005]

According to a first aspect of the present invention, there is provided a printed wiring board on which an inductance is formed, wherein a grid-like pattern is formed in the middle of a power supply line or an earth line on the substrate. Blocks noise.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial plan view of a printed wiring board on which an inductance according to the present invention is formed. The printed wiring board has a conductive pattern 2 formed on a surface of a substrate 1 made of phenol resin, glass epoxy resin, or the like by electroplating or the like. Is shown.

In the present invention, the conductor pattern 2 is a part of a power supply line or a ground line, and the input / output terminal portions 3a,
A grid-like pattern 4 is provided between 3b to form an inductance component. The lattice-shaped pattern 4 has an inductance L on each side constituting each lattice as shown in FIG. 2 as an equivalent circuit, and forms a lattice-like circuit network. The composite inductance value of this lattice-like circuit network becomes a large value, becomes a large impedance with respect to a high frequency component, and effectively acts to prevent unnecessary radiation.

FIG. 3 shows an application example in which a grid-like pattern 4 is connected to power supply lines 6 of devices 5a and 5b such as ICs. The device 5a is connected between a power supply terminal 7a and a ground terminal 8a. A decoupling capacitor 10 a is connected between the grounds 9. The lattice pattern 4 is inserted in the middle of the power supply line 6.
The composite inductance component of the lattice pattern 4 has a large impedance, and therefore has a low impedance for the DC component and a relatively high impedance for the high-frequency noise component. This makes it difficult for high-frequency noise to be transmitted as compared with the conventional solid power supply line pattern. Decoupling capacitors 10a, 1
Since 0b has a low impedance with respect to the high-frequency component, it acts to release the high-frequency component to the ground.

FIGS. 4 and 5 are plan views of a modified example of the printed wiring board on which the inductance according to the present invention is formed. FIG. 4 is a view showing the input / output terminals 3a and 3 of the printed wiring board of the embodiment shown in FIG.
b is the diagonal position of the lattice pattern 4. The composite inductance value is based on the printed wiring board shown in FIG.
It has the advantage of being larger.

FIG. 5 shows a grid-shaped pattern 4 having a circular outer shape.
Equivalent values are obtained.

[0011]

According to the printed wiring board having the inductance of the present invention, it is not necessary to mount a special component in order to prevent unnecessary radiation.

[Brief description of the drawings]

FIG. 1 is a plan view of a printed wiring board on which an inductance according to the present invention is formed.

FIG. 2 is an equivalent circuit diagram of a lattice pattern of a printed wiring board on which an inductance according to the present invention is formed.

FIG. 3 is a circuit block diagram showing an application example of a printed wiring board having an inductance according to the present invention.

FIG. 4 is a plan view of a modified example of the printed wiring board on which the inductance of the present invention is formed.

FIG. 5 is a plan view of another modification of the printed wiring board on which the inductance of the present invention is formed.

[Description of Signs] 1 ... substrate, 2 ... conductor pattern, 3a, 3b ... input / output terminal, 4 ... lattice pattern, 5a, 5b ... device, 6 ...
Power supply lines, 7a, 7b: power supply terminals, 8a, 8b: ground terminals, 9: ground, 10a, 10b: decoupling capacitors

Claims (2)

[Claims] 1. A printed wiring board having an inductance in which a grid-like pattern is formed in the middle of a power supply line or an earth line on a substrate. 2. The inductance according to claim 1, wherein an input / output terminal connected to the power supply line or the ground line is provided on the grid-like pattern, and a decoupling capacitor is connected to the input / output terminal. Printed wiring board formed.