JPH04360594A - Noise suppressing element and noise suppressing printed board - Google Patents

Abstract

PURPOSE:To effectively suppress noise and to reduce in size by providing an amorphous plate having a hole for passing leads of an electronic component to be mounted. CONSTITUTION:In a noise suppressing element 10 for an IC, an amorphous plate 14 having holes 13 of the same number as that of pins 12 of an IC, is laminated. The element 10 for the IC is mounted on a printed board 15 while inserting it into the pins 12 of the IC 11 so as to equivalently provide that inductors 16 are inserted to the pins 12 of the IC. If a current is small, the amorphous exhibits an extremely high inductance. For example, when a signal containing noise component is sent to the IC 11, since the amorphous of the element has an inductance component, noise of high frequency component is removed, and input to the IC 11. Thus, an erroneous operation of the IC 11 due to the noise component can be prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise suppressing element and printed circuit board for suppressing noise in electronic equipment such as computers.

0002

2. Description of the Related Art Electronic devices such as computers are used in many places such as office processing and automatic control equipment in factories. These electronic devices often use CPUs that operate based on clock signals of several MHz, and rapid changes in current or voltage at such high frequencies can generate noise called unnecessary radiation. It causes Such noise not only causes malfunctions in the electronic circuit itself, but may also induce malfunctions in other electronic devices, and suppressing noise is an important factor for the normal operation of electronic devices.

FIG. 9 is a diagram showing a case of suppressing noise that enters from a conventional input/output cable or is emitted from an electronic device.

As shown in the figure, a ring-shaped ferrite core 3 is provided around a cable 2 that connects a digital device 1 such as a computer and a peripheral device (not shown) to substantially increase the inductance component of the cable. noise was suppressed.

FIG. 10 is a diagram showing a noise suppressing element provided in an IC socket, a connector, or the like.

As shown in the figure, a so-called multi-hole ferrite 6 having the same number of holes 5 as the number of pins of the connector or IC has been used for an IC socket, connector, etc. 4 . Furthermore, as shown in FIG. 11, pin 8 of IC7
It was also practiced to insert ferrite beads 9 into the.

However, conventional noise suppressing elements have a limited noise suppressing effect, and there has been a desire for a noise suppressing element that can suppress noise more effectively and can be adapted to mass production.

[0008]

[Problems to be Solved by the Invention] As mentioned above, there are limits to the noise suppressing effect of conventional noise suppressing elements.
There has been a desire for a noise suppression element that can suppress noise more effectively and that can be miniaturized.

The present invention was devised to solve the above problems, and an object of the present invention is to provide a noise suppressing element that can suppress noise more effectively and can be miniaturized.

0010

[Means for Solving the Problems] In order to achieve the above-mentioned object, a first invention is a noise suppression element comprising an amorphous plate having a hole for passing a lead wire of an electronic component to be mounted. A second invention is a noise suppressing printed circuit board comprising an insulating substrate having printed wiring and an amorphous layer provided on at least one surface of the insulating substrate.

[0011]

[Function] The noise suppressing element and the noise suppressing printed circuit board of the present invention can effectively remove noise by using an amorphous inductance, and since an amorphous layer is provided on the printed circuit board, they are suitable for mass production and automation.

0012

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an IC (IN) which is an embodiment of the present invention.
FIG. 2 is a perspective view showing the configuration of a noise suppression element for TEGRATED CIRCUIT.

As shown in the figure, this noise suppressing element 10 for an IC is made up of laminated amorphous plates 14 provided with the same number of holes at the same pitch as the pins 12 of the IC 11. The thickness of one amorphous plate 14 is approximately 20 μm. Amorphous materials can be easily manufactured into thin plate shapes, and it is possible to reduce heat generation by stacking these thin amorphous plates. This is because the eddy current is proportional to the square of the thickness, so the thinner the sheet, the less the eddy current. Further, it is desirable that the surface of the IC noise suppression element 10 be coated with an insulating paint in order to insulate between the pins 12 of the IC 11.

Then, as shown in FIG.
5, the IC noise suppression element 10 is inserted into the pin 12 of the IC 11 and mounted.

By mounting in this manner, it becomes equivalent to inserting an inductor 16 into each pin of the IC as shown in FIG.

FIG. 4 is a graph showing the current dependence of the inductance of a ferrite core having the same dimensions as an amorphous core. A shows the case of amorphous, and B shows the case of ferrite core.

As shown in the figure, when the current is relatively small, the amorphous material exhibits extremely high inductance. For this reason, the high inductance portion of the amorphous can be effectively used, especially for noise components in the micro current range.

For example, when a signal containing a noise component as shown in FIG. 5(a) is sent to the IC 11, the amorphous IC noise suppressing element has an inductance component, so that the signal as shown in FIG. 5(b) is transmitted to the IC 11. Then, high frequency component noise is removed and the signal is input to the IC 11. Therefore, it is possible to prevent malfunction of the IC 11 due to noise components.

Next, a noise suppressing printed circuit board according to another embodiment of the present invention will be described.

FIG. 6 shows a cross-sectional view of the noise suppression printed circuit board 17. As shown in the figure, a copper printed wiring 19 formed by etching or the like is provided on one surface of the epoxy board 18. and epoxy board 18
An amorphous layer 20 is provided on the other surface. This amorphous layer 20 may be constructed by laminating thin amorphous plates depending on the desired amount of inductance.

A hole 21 for the pin 12 of the IC 11 is made by drilling or the like in the epoxy plate 18 and the amorphous layer 20 all at once. After that, mount IC11 and pin 12
is fixed to the printed wiring 19 with solder 22 to obtain continuity.

In the noise suppressing printed circuit board 17 of this embodiment, the amorphous layer 2 is formed only on one side of the epoxy board 18.
0, however, amorphous layers 20a and 20b may be provided on both sides of the epoxy board 18, as shown in FIG. In the noise suppression printed circuit board shown in FIGS. 6 and 7,
An amorphous plate was provided on the entire surface of the epoxy plate 18.
As shown in FIG. 2, the amorphous layer 20c may be provided only around the pins or lead wires of an electronic component such as an IC. By doing so, it becomes possible to reduce the amount of amorphous to achieve weight reduction and cost reduction, and it also becomes possible to obtain an appropriate inductance for noise suppression. Also, although the noise suppression effect is reduced, the amorphous layers 20, 2
A ferrite core layer may be provided instead of 0a, 20b, and 20c.

Therefore, the above-described noise suppressing printed circuit board does not require the complicated work of inserting amorphous beads into each IC pin one by one, and is therefore suitable for mass production and automation.

[0025]

[Effects of the Invention] According to the noise suppressing element and the noise suppressing printed circuit board of the present invention, noise can be effectively removed using the amorphous inductance, and since an amorphous layer is provided on the printed circuit board, it is suitable for mass production and automation. .

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an IC noise suppression element according to the present embodiment.

FIG. 2 is a cross-sectional view of the IC noise suppressing element shown in FIG. 1 and the IC mounted on a printed circuit board.

FIG. 3 is a diagram showing an equivalent circuit of an IC when mounted as shown in FIG. 2;

FIG. 4 is a graph showing the current dependence of the inductance of a ferrite core having the same dimensions as an amorphous core.

FIG. 5 is a diagram showing signals input to an IC.

FIG. 6 is a sectional view showing the structure of a noise suppressing printed circuit board according to an embodiment of the present invention.

FIG. 7 is a sectional view showing the structure of a noise suppressing printed circuit board according to another embodiment of the present invention.

FIG. 8 is a plan view showing the configuration of a noise suppressing printed circuit board according to still another embodiment of the present invention.

FIG. 9 is a diagram showing a conventional case of suppressing noise entering or emitting from an input/output cable.

FIG. 10 is a diagram showing a conventional noise suppression element provided in an IC socket, connector, etc.

FIG. 11 is a diagram illustrating noise suppression by inserting ferrite beads into IC pins.

[Explanation of symbols]

10... IC noise suppression elements 13, 21... Holes 14... Amorphous board 15... Printed circuit board 17... Noise suppression printed circuit board 18... Epoxy board 19... Printed wiring 20, 20a, 20b, 20c... Amorphous layer 22...
solder

Claims (2)

[Claims] 1. A noise suppression element comprising an amorphous plate having a hole for passing a lead wire of an electronic component to be mounted. 2. A noise suppressing printed circuit board comprising an insulating substrate having printed wiring and an amorphous layer provided on at least one surface of the insulating substrate.