JP3873333B2 - Lightning surge protector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lightning surge protection device for electronic equipment, and more particularly to a lightning surge protection device electrically insulated by a photocoupler.
[0002]
[Prior art]
Conventionally, this type of lightning surge protection device uses a photodiode 16 and a phototransistor 17 individually as shown in FIG. 6, and a printed wiring board 19 mounted together with a drive circuit component 18 is cylindrically shielded from external light, There is a separate adapter type that is inserted and fixed from the front and rear of the mounting cover 20 having a facing optical transmission path with a ensured creepage distance, and that the photodiode 16 and the phototransistor 17 face each other with a creepage distance secured. is there.
[0003]
Also, as shown in FIG. 8 (A), compared with the conventional photocoupler 21, in order to increase the creepage distance, a photocoupler 22 that is enlarged as shown in FIG. 8 (B) is used to secure the creepage distance between the input and output terminals and to insulate. The breakdown voltage was improved.
[0004]
[Problems to be solved by the invention]
However, such a conventional lightning surge protection device has a problem that the electronic equipment becomes extremely large and the cost is greatly increased.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a terminal block having a surface mounting terminal provided with an encircling portion that extends and uses the resin portion of the terminal block, and when the terminal block is attached to a printed wiring board, the encircling portion Is formed so as to surround the exposed conductive portion from the surface mounting terminal of the terminal block through the copper foil of the printed wiring board to the terminal of the photocoupler in close contact with the printed wiring board.
[0006]
Further, the same configuration as described above can be realized by providing the surrounding portion separately and separately from the terminal block, and further providing a groove portion and a projecting portion on the opposing surfaces of the terminal block and the surrounding component to be fitted and fixed.
[0007]
Next, insulating resin is injected into the enclosed part in a horizontal state so that the conductive part is completely covered and sufficient insulation thickness is secured, and the terminal is connected to the external device and the photocoupler. This increases the insulation distance between other circuits to improve the insulation performance.
[0008]
According to the above invention, a part of the terminal block is extended / utilized, or a separate enclosure is provided to enclose the enclosure from the terminal portion of the terminal block to the terminal portion of the photocoupler, and the insulating resin is horizontally placed inside the enclosure. In addition, a large space is not required to inject and harden the resin. In addition, since the photocoupler itself can be used in an existing size, it is possible to prevent obstruction of the component mounting space and cost increase due to the adoption of a large-sized component.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a connection terminal having a conductive pin protruding from the bottom surface, a terminal block having a surface mounting terminal protruding from the side surface and bent and having a soldering surface in substantially the same surface as the bottom surface, and the front and back surfaces on which the carbon table is mounted. Double-sided printed wiring board having a dielectric strength between copper foils, a photocoupler for connecting the surface mounting terminal and one terminal via the copper foil of the printed wiring board, and an outer periphery of the conductive portion from the side surface of the terminal block to the photocoupler The resin enclosing portion and the terminal block are brought into close contact with the printed wiring board, and the insulating resin is injected and cured inside the enclosing portion so as to immerse the surface mounting terminal and the photocoupler. Since the inside of the enclosure has an insulating structure, it is possible to increase the insulating distance between the front and back insulating structures of the printed wiring board and the external connection terminals of the terminal block and the circuits after the photocoupler, thereby improving the insulating performance. Further, since the soldering fixing portion of the surface mounting terminal resists external force applied to the terminal in parallel with the surface mounting terminal, it is possible to prevent the peeling and breaking of the soldering fixing portion of the connection terminal.
[0010]
In addition, the enclosing portion by extending and using the terminal block is configured separately from the terminal block, and further has a resin part structured to be fitted and fixed by providing a groove and a protrusion on the opposing surface of the terminal block and the enclosing part. The same curing as described above can be obtained.
[0011]
Embodiments of the present invention will be described below with reference to the drawings.
Example 1
1 is an external view of a lightning surge protection device according to a first embodiment of the present invention before the terminal block is attached. FIG. 2 is an external view of the lightning surge protection device according to the first embodiment after the terminal block is attached. 3 is a cross-sectional view after the insulating resin is injected and cured in FIG. FIG. 4 is a schematic enlarged sectional view of the terminal block.
[0012]
In the figure, reference numeral 1 denotes a terminal block having surface mounting terminals 2, and a surrounding part 3 is formed on the terminal block 1 by extending and utilizing a resin part of the terminal block 1. 4 is a surface mount photocoupler that is electrically insulated by optical connection and transmits signals, 5 is an electronic circuit component that is connected to the photocoupler 4 and performs signal processing, and 6 is a double-sided printed wiring that has high withstand voltage between the front and back copper foils. The circuit board is configured by mounting and soldering the terminal block 1, the surface mount photocoupler 4, the electronic circuit component 5 and the like on the substrate. 7 is an insulating resin having high insulation characteristics after curing, 8 is a connection terminal in which a conductive pin protrudes from the bottom of the terminal block, and 9 is a screw-type external connection terminal connected to the surface mounting terminal 2. is there.
[0013]
Reference numeral 10 denotes solder A for electrically connecting the bottom protruding connection terminal 8 to the printed wiring board 6, reference numeral 11 denotes solder B for electrically connecting the surface mounting terminal 2 to the printed wiring board 6, and reference numeral 12 denotes the bottom protruding connection terminal 8. It is a copper foil for soldering.
[0014]
Next, the operation will be described. As described above, the terminal block 1 is mounted on the double-sided printed wiring board 6 together with other electronic circuit components 5 and after soldering, the insulating resin 7 is placed inside the enclosure 3 of the terminal block 1 and the surface mounting terminals 2 of the terminal block 1 are mounted. Then, the conductive portion such as the terminals of the photocoupler 4 is completely covered and injected to such a depth that a sufficient insulating thickness is ensured, and then cured.
[0015]
Therefore, as shown in FIG. 3, the insulation distance between the external connection terminal 9 and the other electronic circuit component 5 and the copper foil of the double-sided printed wiring board 6 is increased, and the external connection as shown in FIG. In the conventional case where there is no solder B11 with respect to the forces F1 and F2 applied to the terminal block 1 when the terminal is fastened with screws, the forces G1 and G2 for peeling the solder A10 from the copper foil 12 acted. However, since the solder B11 is added, it can be absorbed by the drags R1 and R2.
[0016]
(Example 2)
FIG. 5 is an external view of the lightning surge protection device according to the second embodiment of the present invention before the resin surrounding part 8 is attached. FIG. 6 is an external view after the resin surrounding part 13 of Example 2 is attached. In the figure, 1 is a terminal block having surface mounting terminals 2, and 4 to 6 are the same as in the first embodiment. Reference numeral 13 denotes a resin-enclosed part in which the encircling portion 3 of the terminal block 1 of the first embodiment is configured independently, and has a fixing projection 14. Reference numeral 15 denotes a groove provided in the terminal block 1 for fitting in and fixing to the fixing projection 14.
[0017]
Next, the operation will be described. As described above, the protrusion 14 of the resin enclosure 13 and the groove 15 of the terminal block 1 are fitted, and after mounting and fixing to the double-sided printed wiring board 6, the insulating resin is placed inside the enclosure of the resin enclosure 13 in a horizontal state. 7 is injected from the conductive portion to a depth that ensures a sufficient insulation thickness, as in Example 1, and then cured.
[0018]
Note that the cross-sectional view after injecting and drying the insulating resin 7 and the enlarged cross-sectional view of the terminal block are substantially the same as those in FIGS.
[0019]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
[0020]
Effectively utilizes the margin of protrusion of the terminal block on the printed wiring board, so that the surface mount photocoupler can be efficiently stored three-dimensionally, and the terminal pitch of the surface mount terminals that are electrically insulated by the terminal block and placed close to each other In addition, since the surface mounting terminals can be arranged on the printed wiring board, the surface mounting photocoupler can be rationally accommodated also in a plane. Further, since the surface mount photocoupler is arranged close to the terminal block, the side surface of the terminal block can be used as one surface of the surrounding portion, and when a separate surrounding portion is provided as in claim 2, it can also be used as a fixing surface of the surrounding portion. In addition, since the soldering fixing portion of the surface mounting terminal resists an external force applied to the terminal in parallel with the surface mounting terminal, it is possible to prevent peeling and breaking of the soldering fixing portion of the connection terminal.
[0021]
In addition, since an electronic component is mounted on the printed wiring board and the surrounding portion is mounted and fixed, there is an advantageous effect that there are few restrictions on the design of the printed wiring board.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a lightning surge protection device according to a first embodiment of the present invention before the terminal block is attached. FIG. 2 is an external perspective view of the same device after the terminal block is attached. 4 is a cross-sectional view of the lightning surge protection device after injecting and curing the insulation resin. FIG. 4 is a cross-sectional view of the terminal block of the device. FIG. FIG. 6 is a perspective view of an external appearance of a conventional adapter type lightning surge protection device. FIG. 8A is a photocoupler used in the device. Appearance perspective view (B) Appearance perspective view of photocoupler with increased creepage distance and improved withstand voltage [Description of symbols]
DESCRIPTION OF SYMBOLS 1 Terminal block 2 Surface mounting terminal 3 Surrounding part 4 Surface mounting photocoupler 6 Double-sided printed wiring board 7 Insulating resin 8 Connection terminal 9 External connection terminal 13 Resin surrounding part 14 Protrusion part 15 Groove part

Claims (2)

A lightning surge protection device in which a terminal block and a photocoupler are mounted on a double-sided printed wiring board having copper foil by soldering, wherein the terminal block includes a connection terminal protruding from a bottom surface, a protruding terminal protruding from a side surface, and a bent portion. A surface mounting terminal having a soldered surface on substantially the same surface, and the surface mounting terminal and one terminal of the photocoupler are connected via a copper foil of the double-sided printed wiring board, and The surface mounting terminal, the photocoupler, and a surrounding portion of the copper foil for connecting the photocoupler and the surface mounting terminal. An insulating resin is injected into the surrounding portion. Lightning surge protection device , characterized by being cured . The lightning surge according to claim 1, wherein a pair of grooves parallel to each other and extending in the height direction are formed on the side surfaces of the terminal block, and the surrounding portions have fitting portions that are slidably fitted into the grooves on both end surfaces. Protective device.

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