JPH1167300A - Terminal board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the unnecessary radiation or leakage of an electromagnetic wave in a terminal board for connecting a cable to a PC board used in electronic equipment or to a device by constituting an insulator with a composite magnetic body containing soft magnetic body powder and an organic binder. SOLUTION: A terminal board 1 has a base insulator 2 made of a composite magnetic body formed by kneading, dispersing soft magnetic body powder in an organic binder, and a screw 3 for fixing an electric wire from the outside through a terminal, and the screw 3 is connected by screwing in a screw hole formed in a flat plate of a base part embedded in the base insulator 2 of a pin terminal 4 to be connected to a printed board. The adjacent screw 3 and the base part 4a of the pin terminal 4 are integrally formed with the base insulator 2, and partitioned with a barrier rib 5 vertically formed in the base insulator 2. The barrier rib 5 is also made of the composite magnetic body formed by kneading, dispersing the soft magnetic body powder in the organic binder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PC board used for an electronic device and a terminal block used for wiring cables between the devices.

[0002]

2. Description of the Related Art In recent years, electronic devices using high frequencies, such as digital electronic devices, have become widespread. In particular, mobile communication devices using a quasi-microwave band or a microwave band have been remarkably spread. In such mobile communication devices typified by mobile phones, demands for downsizing and weight reduction are remarkable, and high-density mounting of electronic components has become the biggest technical problem. Therefore, densely mounted electronic components, printed wiring or wiring between modules, etc., are extremely close to each other, and furthermore, the signal processing speed has been increased, so that electrostatic coupling and / or electromagnetic Coupling causes an increase in line-to-line coupling and interference due to radiated noise, etc., and there are not a few cases where normal operation of devices is hindered.

Conventionally, countermeasures against such a so-called high-frequency electromagnetic interference have been made mainly by providing a conductor shield.

[0004]

However, since the conductor shield is an electromagnetic interference countermeasure that utilizes the reflection of electromagnetic waves due to impedance mismatch with the space, even if the shielding effect is obtained, the shield from unnecessary radiation sources can be obtained. There is a disadvantage that electromagnetic coupling by reflection is promoted. In order to solve the drawback, it is considered that suppression of unnecessary radiation using the magnetic loss of the magnetic material, that is, the imaginary part permeability μ ″ is effective as a secondary electromagnetic interference countermeasure. Here, the absorption efficiency of unnecessary radiation is μ '
It is known that in the frequency range of ＞> μ´, it increases in proportion to the size of μ ″. Therefore, in order to obtain a large magnetic loss in the microwave band, the real part magnetic permeability must be VHF band (30 MHz to 300 MHz), quasi microwave band (300 MHz to 3 GHz) or lower frequency side of the microwave band (3 GHz to 3 GHz). It is necessary to realize a characteristic of being attenuated by magnetic resonance at about 10 GHz).

Furthermore, there are unnecessary radiations of electromagnetic waves from PC boards used in electronic devices and terminal blocks used for cable wiring between devices, and measures for suppressing electromagnetic interference have not been perfect.

Accordingly, a technical object of the present invention is to provide a terminal board for connecting to a PC board used in an electronic device or a cable wiring between the devices, which can prevent unnecessary radiation and leakage of electromagnetic waves. Is to provide.

[0007]

According to the present invention, there are provided a PC (printed circuit) board used in an electronic device and a cable wiring between the devices, comprising a conductive terminal and an insulator for fixing the terminal. In the terminal block used,
A terminal block is obtained in which the insulator is composed of a composite magnetic material containing a soft magnetic material powder and an organic binder.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a terminal block according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the terminal block of FIG. Referring to FIGS. 1 and 2, the terminal block 1 is
A base insulator 2 made of a composite magnetic material in which a soft magnetic material powder is kneaded and dispersed in an organic binder, and a screw 3 for fixing an external electric wire via a terminal are provided. The screw 3 is a printed circuit board (not shown). The pin terminal 4 is connected to the pin terminal 4 by tightening a screw 3 into a screw hole 4b provided in a flat plate of a base 4a embedded in the base insulator 2. Also, the adjacent screw 3 and the base 4a of the pin terminal
Are formed integrally with the base insulator 2 and are partitioned by a partition wall 5 erected on the base insulator 2. Like the base insulator 2, the partition walls 5 are also made of a composite magnetic material in which a soft magnetic material powder is kneaded and dispersed in an organic binder. Reference numeral 2a denotes a through hole 2 for a screw 3.
a.

The organic binder of the insulator comprising the partition wall 5 and the base insulator 2 includes epoxy resin, diallyl phthalate resin, melamine resin, phenol resin, silicone resin, unsaturated polyester resin, urea resin, polyurethane, and amide. Thermosetting resins such as resins and imide resins can be used.

Examples of the soft magnetic material powder of the insulator include iron aluminum silicon alloy (Sendust (registered trademark)) and iron nickel alloy (Permalloy) having high high-frequency magnetic permeability as typical materials. This soft magnetic material powder is finely powdered and its surface is oxidized for use.

Next, the terminal block according to the embodiment of the present invention will be described more specifically.

Table 1 below shows the soft magnetic powder and the organic binder used for the insulator of the terminal block.

[0014]

[Table 1]

The sendust alloy powder has an oxygen partial pressure of 20%
Was oxidized in a nitrogen-oxygen mixed gas atmosphere, and an oxide film was formed on the surface. These were heated, kneaded and pressed to obtain a molded body. The volume resistance of the composite magnetic material was measured and found to be 1 × 10 ¹⁰ Ω · cm.

A terminal block made of a composite magnetic material having the above composition was molded under pressure to obtain a sample of the present invention. The terminal pitch of this terminal block was 7.62 mm, and the number of poles was 6 pins with a row of screw terminals.

For comparison, a commercially available terminal block molded using only an epoxy resin was prepared.
This comparative sample has the same shape as the above embodiment,
The rating was 250V-10A.

For comparison between the sample of the present invention and a comparative sample,
The electric field strength of each sample was measured using the evaluation jig shown in FIG. As shown in FIG. 3, the jig for evaluation 10 has the terminal block 1 as a sample of the present invention and a comparative sample attached to a test electronic device 12 in a shield box 11 made of aluminum, and is provided at the upper center of the shield box 11. The measurement was performed with only the terminal block 1 protruding outward from the opening 13 for taking out the terminal block. The frame ground of the test electronic device 12 was grounded to the shield box 11. The measurement was performed using a spectrum analyzer (not shown) in an anechoic chamber (not shown). The measurement results are shown in FIGS. 4 and 5, respectively. FIG. 4 shows the case of using the sample of the present invention, while FIG. 5 shows the case of a terminal block of only a commercially available epoxy resin used as a comparative sample. From the comparison between FIG. 4 and FIG.
At MHz, it was found that the sample of the present invention had a maximum 8 dB lower electromagnetic field strength than the comparative sample.

[0019]

As described above, according to the present invention,
A terminal block for connecting a cable capable of preventing unnecessary radiation and leakage of an electromagnetic wave to a device or the like can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a terminal block according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the terminal block of FIG.

FIG. 3 is a perspective view showing an evaluation jig for evaluating characteristics.

FIG. 4 is a diagram showing characteristics of the sample of the present invention, showing a relationship between a measurement frequency and an electric field intensity.

FIG. 5 is a diagram showing characteristics of a comparative sample, showing a relationship between a measurement frequency and an electric field intensity.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Terminal block 2 Base insulator 2a Through hole 3 Screw 4 Pin terminal 4a Base 4b Screw hole 5 Partition wall 10 Evaluation jig 11 Shield box 12 Test electronic device 13 Opening hole

Claims (1)

[Claims] 1. A terminal board comprising a conductive terminal and an insulator for fixing the terminal, the terminal board being used for a PC board used in an electronic device or a cable wiring between the devices, wherein the insulator comprises a soft magnetic powder and an organic material. A terminal block comprising a composite magnetic body containing a binder.