JPH11262171A - Electrical component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical component which has both functions of an EMI filter and a surge absorber, enables reduction of the manufacturing cost and management cost, and requires very small attachment space. SOLUTION: An electrical component 1 is constituted of a 3-terminal electromagnetic interference eliminating filter 2 and a surge absorber 3 in a metal case which is integrally bonded to the filter 2 via an adhesive layer 4 therebetween. The 3-terminal EMI filter 2 has three terminals (an input terminal 2a, an output terminal 2b and a ground terminal 2c) and the surge absorber 3 is equipped with two terminals 3a and 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric component, and more particularly, to an electric component having both functions of a filter for removing electromagnetic interference and a surge absorber.

[0002]

2. Description of the Related Art Electromagnetic interference (EMI) generated in electronic devices and circuits is propagated through conductive wires and the air, causing noise in peripheral devices and circuits to cause malfunction. Therefore, an electromagnetic interference removal filter (EMI filter) for removing an electromagnetic interference by separating or attenuating a noise component and an effective component to remove the noise component is widely used.

Further, by absorbing surge voltage generated by external lightning surge caused by natural phenomena and internal lightning surge caused by transient phenomenon of electric circuit system, dielectric breakdown of electronic equipment and electronic circuit caused by surge voltage, Surge absorbers that prevent functional stoppage, malfunction, and deterioration are also widely used.

In recent years, in order to guarantee the stable operation of an electronic device (electronic circuit), the number of EMI filters and surge absorbers used in one electronic device (electronic circuit) is increasing.

[0005]

Conventionally, an EMI filter and a surge absorber have been used as separate parts. Therefore, there were the following problems. (1) Since the EMI filter and the surge absorber need to be separately attached to the electronic device (electronic circuit), particularly when a large number of EMI filters and surge absorbers are used in one electronic device (electronic circuit). Since the number of components constituting the electronic device (electronic circuit) increases, the manufacturing process becomes complicated and the manufacturing cost increases.

(2) Since the mounting space for the EMI filter and the surge absorber is required separately,
In particular, when a large number of EMI filters and surge absorbers are used in one electronic device, it is difficult to reduce the size of the electronic device. (3) Since it is necessary to separately order and manage the EMI filter and the surge absorber, it takes time and effort to order parts and manage inventory, thereby increasing management costs.

An object of the present invention is to provide an electric component capable of solving the above problems.

[0008]

Means for Solving the Problems According to the first aspect of the present invention, which has been made to achieve the above object, an electromagnetic interference removing filter (EMI filter) and a surge absorber in a metal case are integrated. That is the gist.

Therefore, according to the present invention, it is possible to obtain an electric component having both functions of an EMI filter and a surge absorber. Then, only by attaching one electric component to the electronic device (electronic circuit), the attachment of the EMI filter and the surge absorber is completed at the same time. Therefore, in particular, a large number of EMIs are required for one electronic device (electronic circuit).
When a filter and a surge absorber are used, the number of components constituting the electronic device (electronic circuit) can be reduced, so that the manufacturing process can be simplified and the manufacturing cost can be reduced. Also, compared to the case where the EMI filter and the surge absorber are separately mounted, the space for mounting the electric components can be reduced, so that
In particular, when a large number of EMI filters and surge absorbers are used in one electronic device, the size of the electronic device can be easily reduced. In addition, compared to the case where the EMI filter and the surge absorber are separately ordered and managed,
Since only one electrical component needs to be ordered and managed, management costs can be reduced by eliminating the time required for ordering components and managing inventory. Also, since the surge absorber is contained in a metal case, when integrating it with an EMI filter,
There is no risk of the surge absorber being damaged, and the adhesive can be securely bonded and integrated. In addition, since it is contained in a metal case, the size of the surge absorber can be reduced. Since the surge absorber is contained in a metal case, there is no possibility that the surge absorber will be damaged even when the electric components are automatically mounted.

[0010] In the electric component according to the first aspect, a three-terminal type may be used as the filter for removing electromagnetic interference, as in the second aspect. Since the three-terminal EMI filter has various excellent features as compared with the two-terminal type, an effective countermeasure against electromagnetic interference can be taken.

Further, in the electric component according to the first or second aspect, as in the third aspect, a microgap type discharge element may be used as the surge absorber. Since the microgap type discharge element can obtain a quick response characteristic, the electronic device (electronic circuit) can be surely protected from a surge voltage.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of the electric component 1 of the present embodiment. The electric component 1 includes a three-terminal type electromagnetic interference removal filter (three-terminal EMI filter) 2,
The surge absorber 3 in the metal case and the adhesive layer 4
It is configured by being integrated by bonding through a. The three-terminal EMI filter 2 has three terminals (an input terminal 2a, an output terminal 2b, and a ground terminal 2c). Also,
The surge absorber 3 has two terminals 3a and 3b.

To use the three-terminal EMI filter 2, each terminal 2a, 2b is connected to a DC power supply line (DC line) of an electronic device (electronic circuit), and a ground terminal 2c is connected.
To the ground line. As a result, it is possible to reduce high-frequency noise components leaking from the electronic device (electronic circuit) to the DC power supply line and to reduce impulse noise entering the electronic device (electronic circuit) from the DC power supply line. In addition, radiation noise can be reduced.

Alternatively, the terminals 2a and 2b are connected to signal lines of an electronic device (electronic circuit), and the ground terminal 2c is connected to a ground line. As a result, it is possible to reduce the high-frequency component of the digital signal waveform and to reduce unnecessary high-frequency components of the analog signal, thereby reducing radiation noise.

Here, the three-terminal EMI filter 2 includes:
There are various types such as a three-terminal capacitor, a type combining an inductor and a capacitor, and a type combining a ferrite and a capacitor. In the present embodiment, any type may be used.

The three-terminal capacitor is such that the hot terminal of the capacitor is divided into two terminals, an input side and an output side, and the residual inductance generated in series with the capacitor on the hot side is eliminated, and the input and output sides on the hot side are eliminated. The noise removal effect is improved by positively utilizing the residual inductance generated at each of the terminals as a choke in the filter element.

The type in which an inductor and a capacitor are combined means that both ends of two inductors connected in series are used as an input terminal and an output terminal, respectively, and one electrode of the capacitor is connected to a node between the inductors and the other is connected. This electrode is used as a ground terminal to form a T-type filter, and the cutoff frequency and the characteristic impedance can be freely set by variously combining the constants of the inductor and the capacitor.

[0018] Further, the ferrite-capacitor combination type increases residual inductance generated at each terminal by inserting ferrite beads into hot-side input and output terminals of a three-terminal capacitor, respectively. The frequency band can be changed by changing the value of the capacitor.

FIG. 2 is a partial longitudinal sectional view showing an example of the surge absorber 3 in a metal case. A micro-gap type discharge element 12 is mounted in a cylindrical metal case 11. The micro gap discharge element 12
It comprises a cylindrical base resistor 13 made of silicon carbide (SiC) having a microgap 13a formed on the surface, and metal caps 14a and 14b provided on both ends of the base resistor 13. . Each cap 14 is connected to metal terminals 3a and 3b.

The terminal 3a is inserted through a ceramic insulating cap 15 inserted into one end of the metal case 11 and protrudes out of the metal case 11, and the terminal 3b is inserted into a hole 11a provided at the other end of the metal case 11. It is inserted and protrudes out of the metal case 11. Here, the terminal 3a and the insulating cap 1
5, the insulating cap 15 and the metal case 11, and the terminal 3b and the hole 11a of the metal case 11 are connected via a solder layer 16, respectively.

The surge absorber 3 configured as described above
Is used, one of the terminals 3a and 3b is connected to the ground of the electronic device (electronic circuit), and the other is connected to a required portion of the electronic device (electronic circuit). When a surge voltage is applied between the terminals 3a and 3b, field-discharge-type electrons are generated in the microgap 13a, and the electrons act as triggers to cause the caps 14 as shown by arrows A.
a, 14b, as shown by the arrow B, the caps 14a, 1
4b and the metal case 11, an arc discharge occurs between the base resistor 13 and the metal case 11 as shown by an arrow C, and a surge voltage is applied to the ground via the terminal 3a or the terminal 3b. To protect the connected electronic devices (electronic circuits).

In the surge absorber 3 having the above structure, the microgap type discharge element 12 using the microgap 13a is employed, so that a quick response characteristic can be obtained. In addition, since silicon carbide is used for the base resistor 13, a stable operation with high durability against repeated surges can be realized. In addition, each terminal 3
Since the capacitance between a and 3b can be suppressed to several pF or less, there is no possibility of affecting the signal line even when connected to the signal line.

As described in detail above, in the electric component 1 of the present embodiment, the three-terminal EMI filter 2 and the surge absorber 3 are integrated and configured as one component. Therefore, only by attaching one electric component 1 to an electronic device (electronic circuit), the attachment of the three-terminal EMI filter 2 and the surge absorber 3 is completed at the same time.
Therefore, in particular, when a large number of EMI filters and surge absorbers are used in one electronic device (electronic circuit), the number of components constituting the electronic device (electronic circuit) can be reduced. Can be simplified and the manufacturing cost can be reduced. In addition, compared to a case where a three-terminal EMI filter and a surge absorber are separately mounted, the space for mounting the electric component 1 can be reduced.
When a filter and a surge absorber are used, the electronic device can be easily reduced in size. And EMI
In comparison with the case where the filter and the surge absorber are separately ordered and managed, according to the electric component 1, the management cost can be reduced by eliminating the time required for ordering the components and managing the inventory.

The surge absorber 3 is a metal case 1
Since the surge absorber 3 is used, the surge absorber 3 is not damaged when the EMI filter 2 and the three-terminal EMI filter 2 are bonded and integrated via the adhesive layer 4, and the EMI filter 2 can be reliably bonded and integrated. Incidentally, a surge absorber using a micro-gap type discharge element with a glass exterior has been conventionally marketed.
It could not be integrated with the terminal type EMI filter 2. Further, by using the metal case 11, the size of the surge absorber 3 can be reduced as compared with the case where a glass exterior is used. Since the surge absorber 3 uses the metal case 11, there is no possibility that the surge absorber 3 will be damaged even when the electric component 1 is automatically mounted.

The present invention is not limited to the above embodiment, but may be modified as follows. Even in such a case, the same operation and effect as the above embodiment can be obtained. [1] In the above embodiment, the three-terminal EMI filter 2 and the surge absorber 3 are bonded and integrated via the adhesive layer 4. However, the powder coating is applied to both the three-terminal EMI filter 2 and the surge absorber 3 to sinter the powder coating, and as shown in FIG. 2 and the surge absorber 3 may be integrated by covering them. FIG.
As shown in (3), the three-terminal EMI filter 2 and the surge absorber 3 may be integrated by molding with a resin layer 6. Even in these cases, the surge absorber 3
Since the metal case 11 is used, the surge absorber 3 is not likely to be damaged when integrated with the three-terminal EMI filter 2.

[2] In the above embodiment, the terminals 2a to 2c of the three-terminal EMI filter 2 and the terminals 3a and 3b of the surge absorber 3 are independent from each other, but as shown in FIG. Terminal 2 of type EMI filter 2
The terminal c may be connected to one of the terminals 3a and 3b of the surge absorber 3 in advance to form one terminal 1a.

[3] The three-terminal EMI filter 2 may be replaced with a two-terminal EMI filter composed of a capacitor and an inductor. [4] The present invention may be applied to any type of surge absorber 3 other than the micro-gap discharge element.

[Brief description of the drawings]

FIG. 1 is a front view of an electric component according to an embodiment of the invention.

FIG. 2 is a partial longitudinal sectional view showing an example of a surge absorber used in one embodiment.

FIG. 3 is an explanatory diagram for explaining an electric component according to another embodiment that embodies the present invention.

FIG. 4 is a front view of an electric component according to another embodiment embodying the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electric components 2 ... 3-terminal EMI filter 3 ... Surge absorber in a metal case 4 ... Adhesive layer 5 ... Paint layer 6 ... Resin layer

Claims (3)

[Claims] 1. An electric component, wherein an electromagnetic wave elimination filter and a surge absorber in a metal case are integrated with each other. 2. The electric component according to claim 1, wherein the filter for removing electromagnetic interference is a three-terminal type. 3. The electric component according to claim 1, wherein the surge absorber is a microgap type discharge element.