JP2000030176A - Lightning resistance type transmitting device and terminal network controller mounting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of insulating property between the input and output of a whole unit. SOLUTION: A photocoupler 1 constituted only of an inter-chip mold by a translucent electricity insulating resin 5 is mounted on a printed substrate 11. Besides, an electricity insulating seal agent 16 with light shielding property is coated and hardened in order to perfectly cover the photocoupler 1 and the connected copper leaf 14 of the printed substrate 11. Moreover, it is enclosed by a mold frame 15 for stabilizing quality, the seal agent 16 is coated and hardened inside and, then, unit conversion is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning-resistant transmission device used for a gas meter communication device by connecting a gas meter for each home and an automatic meter reading device of a central control center, and a terminal network control device equipped with the same. It is about.

[0002]

2. Description of the Related Art Conventionally, a lightning-resistant transmission device used for equipment which is required to have high lightning resistance and is connected to a telephone line, such as a terminal network controller, requires lightning resistance as shown in FIGS. A semi-transparent electrically insulating resin 35 (often an epoxy type) is primarily molded as a chip-to-chip mold for electrical insulation on a printed circuit board of the device. Next, in order to shield external light and prevent malfunction, and to secure heat resistance during soldering and the like, a secondary mold is formed of an opaque electrically insulating resin 37 (often epoxy) so as to cover the primary mold. Done 2
The heavy-molded photocoupler 31 has been mounted and soldered. Then, after forming the circuit, a molding frame 15 made of an insulating material having a necessary and sufficient height on all sides so as to surround the optical communication circuit portion formed of the double-molded photocoupler 31 and the copper foil 14 on the printed circuit board 11. Is fixed to the printed circuit board 11, and a silicone-based or urethane-based sealing agent 36 having electrical insulation is applied and cured in the molding frame 15 so that the inside of the frame has an insulating structure.

[0003]

However, in such a conventional lightning proof type transmission device, the double mold photocoupler 31 has a primary mold 35 made of a semi-transparent electric insulating resin and a primary mold 35 made of an opaque electric insulating resin. Next mold 37
In the interface 38, the adhesion may be deteriorated due to the variation in the production process. Also, at this interface, the input-output becomes degraded in withstand voltage, and there is a problem that the insulation between the input and the output of the entire unit is reduced even if the inside of the molding frame 15 is made to be an insulating structure by the electrically insulating sealing agent 36 as described above. Was.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to mount a photocoupler consisting only of a chip-to-chip mold made of a semi-transparent electrically insulating resin on a printed circuit board, and to form a light-shielding electrically insulating resin. A unit is formed by applying and curing a conductive sealing agent so that the photocoupler and the copper foil of the printed circuit board to be connected are completely covered.

[0005] According to the above invention, there is no interface between the primary mold and the secondary mold such as a double-molded photocoupler, and the light-shielding electrical insulation is performed without considering the withstand voltage degradation inside the photocoupler. The sealing agent can be adhered to the printed circuit board or photocoupler and applied and cured to the required range and thickness.
It is possible to prevent the insulation performance of the entire lightning-resistant transmission device from being lowered due to the deterioration of the withstand voltage of the photocoupler.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A lightning-resistant transmission device according to the present invention has a light-shielding electrically insulating sealant in which a photocoupler composed only of a chip-to-chip mold made of translucent electrically insulating resin is mounted on a printed circuit board. Is applied and cured so as to completely cover the photocoupler and the copper foil of the printed circuit board to be connected to make a unit.

A terminal network control device in which the lightning resistant type transmission device is mounted on a communication circuit unit for controlling communication by connecting to a meter reading meter via a transmission line and electrically insulating the communication circuit unit. Is realized.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a lightning-resistant transmission apparatus according to the present invention and a terminal network control apparatus equipped with the same;

(Embodiment 1) FIGS. 1 (a) and 1 (b) are an external view and a perspective view of a photocoupler composed only of a chip-to-chip mold made of a translucent electrically insulating resin used in Embodiment 1 of the present invention. It is sectional drawing. In the figure, reference numeral 1 denotes a photocoupler comprising a light emitting diode chip 2 and a phototransistor chip 3, and 4 denotes a light emitting diode chip 2 and a phototransistor chip 3 for mounting and connecting with a gold wire 6 and mounting and connecting to a printed circuit board or the like. It is a lead frame. Numeral 5 is a translucent electrically insulating resin for enabling optical communication between the light emitting diode 2 and the phototransistor 3, and also a resin for molding the components into a required shape.

FIG. 2 shows a photocoupler mounted on a printed circuit board of the lightning-resistant transmission device according to the first embodiment of the present invention and composed of a photocoupler composed of only a chip-to-chip mold and a copper foil of the printed circuit board connected to the photocoupler. The circuit part is in a range that provides the required insulation distance.The four sides are made of an insulating material that is sufficiently higher than the optical communication circuit part. FIG.

FIG. 3 shows a light-shielding electrically insulating sealant 5 applied to the inside of the molding frame of the first embodiment so as to completely cover the photocoupler 1 so as to have a sufficient thickness for light-shielding. It is sectional drawing which looked at the hardened place from the side.

In FIG. 1, reference numeral 11 denotes a printed circuit formed by mounting and soldering a photocoupler 1 composed of only a chip-to-chip mold made of a semi-transparent electrically insulating resin together with other electronic components 13 and forming a circuit with a copper foil 14. A substrate 15 surrounds an optical communication circuit section composed of a copper foil 14 connected to a photocoupler 1 formed only by a chip-to-chip mold made of a translucent electrically insulating resin mounted on a printed board 11. This is a molded frame made of an electrically insulating material inserted and fixed to the printed circuit board 11. 16 is the printed circuit board 11
Is a light-shielding electrically insulating sealant applied and cured inside the molding frame 15 inserted and fixed into the molding frame 15.

Next, the operation will be described. As described above, mounting on the printed circuit board 1 that requires electrical
A molded frame 15 made of an electrically insulating material is used to form an optical communication circuit portion made of an electrically insulating material and formed of a copper foil 14 connected to a photocoupler 1 composed only of a chip-to-chip mold made of soldered translucent electrically insulating resin. 11 and cover it. Next, a light-shielding electric insulating sealant 16 is applied and cured to a height completely covering the photocoupler 1 formed only by a chip-to-chip mold made of a semi-transparent electric insulating resin inside the molding frame 15, and the lightning-resistant transmission is performed. Configure the device.

(Embodiment 2) FIG. 4 is an external view of a terminal network control apparatus equipped with a lightning-resistant transmission body described in Embodiment 1.

In FIG. 1, reference numeral 20 denotes a lightning-resistant transmission device, and reference numeral 21 denotes a printed circuit board of a terminal network control device on which the transmission device is mounted. A terminal block 22 is connected to the printed circuit board 21 of the terminal network control device by mounting and soldering, and is connected to a meter for meter reading via a transmission line, and to an external device such as a center automatic meter reading device via a telephone line. Reference numeral 23 denotes a case which accommodates and fixes the printed circuit board 21 of the terminal network control device to constitute the terminal network control device. Reference numeral 24 denotes a case attached to the case 23 and connected to an external device by a connecting wire to the terminal block 22. It is a case lid for covering a part.

Next, the operation will be described. As described above, the photocoupler 1 composed of only the terminal block 22 and the mold between the chips made of translucent electrically insulating resin is mounted and soldered on the printed circuit board 21 of the terminal network control device together with other components.

Next, the optical communication circuit section comprising the photocoupler 2 on the printed circuit board 21 is surrounded by an electrically insulating molded frame 15 as in the first embodiment, and a light-shielding electrically insulating sealant 16 is applied inside. By curing, the lightning-resistant transmission device 20 is obtained.

Next, the printed circuit board 21 of the terminal network control device on which the lightning-resistant type transmission device 20 is mounted is housed and fixed in the case 23. Further, after connecting the terminal block 22 to an external device by a connection wire, the case cover 24 is attached and fixed to the case 23.

[0019]

As apparent from the above description, the following effects can be obtained according to the lightning-resistant transmission device of the present invention.

A photocoupler consisting of only a chip-to-chip mold made of a semi-transparent electric insulating resin is mounted on a printed circuit board, and a light-shielding electric insulating sealant is attached to one photocoupler and a copper foil of the printed circuit board to be connected. Is coated and cured so as to be completely covered, so that there is no problem such as malfunction due to external light and the like.
It is possible to eliminate the problem that the interface between the next molds is present and the mold has poor adhesiveness at the interface, resulting in a gap or deterioration of the pressure resistance inside the photocoupler. Then, a light-shielding electrically insulating sealant is brought into close contact with a printed circuit board or a photocoupler composed of only a chip-to-chip mold made of a semi-transparent electrically insulating resin, and is applied and cured to a required range and thickness. Since the required withstand voltage can be ensured, it is possible to prevent the insulation of the entire lightning-resistant transmission device from deteriorating due to deterioration of the withstand voltage of the photocoupler.

Also, by adopting the lightning-resistant transmission device in the optical communication circuit mounted on the printed circuit board of the terminal network control device, the terminal network control device having high lightning resistance performance requires a relatively large-scale change. And can be realized at low cost.

[Brief description of the drawings]

FIG. 1A is an external view of a photocoupler in a lightning-resistant transmission device according to a first embodiment of the present invention.

FIG. 2 is an external view showing a state where the apparatus is mounted on a printed circuit board.

FIG. 3 is a cross-sectional view showing a state where a sealant is cured inside a molding frame in the apparatus.

FIG. 4 is an external view of a terminal network control device equipped with a lightning-resistant transmission device according to a second embodiment of the present invention.

FIG. 5 (a) External view of a conventional lightning-resistant transmission device (b) Cross-sectional view of the same device

FIG. 6 is an external view showing a state in which the apparatus has a double-molded photocoupler and is mounted on a printed circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photocoupler 5 Electric insulating resin 11 Printed circuit board 14 Copper foil 16 Electric insulating sealant

Claims (2)

[Claims] 1. A photocoupler composed of only a chip-to-chip mold made of a translucent electrically insulating resin is mounted on a printed circuit board, and the photocoupler and the copper foil of the printed circuit board are sealed with a light-shielding electric insulating seal. A lightning-resistant transmission device that is applied and cured so that it is completely covered by the agent and is unitized. 2. A terminal network control device in which the lightning-resistant transmission device according to claim 1 is mounted, one end of which is connected to a meter reading meter, and the other end of which is connected to a center automatic meter reading device.