JP2014067787A - Pulse transformer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily allow a pulse transformer to have higher breakdown voltage suppressing the occurrence of surface discharge between lead terminals and to easily achieve microminiaturization of the pulse transformer in line with miniaturization of a communication device.SOLUTION: A pulse transformer device is formed with a pulse transformer 11 which contains multiple transformer elements and leads out a lot of lead terminals 14 in 180° opposite directions from both side surfaces 13 of a rectangular-parallelepiped housing part 12 being surface mounted by connecting electrically the pulse transformer 11 with wiring patterns 7, 8 of the printed circuit board 6 within a communication device. A protrusion wall part 16 extending in the lead terminal lead-out directions from both side surfaces 13 of the housing part 12 of the pulse transformer 11 is placed standing on the printed circuit board 6 at both sides of the lead terminals 14. The protrusion wall part 16 is integrally formed at the ends of both side surfaces 13 of the housing part 12 of the pulse transformer 11.

Description

  The present invention relates to a pulse transformer device that is incorporated in various communication devices installed in a high-speed LAN line and mounts a pulse transformer including a plurality of transformer elements on a printed circuit board.

  In recent years, communication lines have been increased in speed, and their line configurations are interconnected between information devices by Ethernet (registered trademark) LAN. Various devices installed on this type of high-speed LAN line include communication devices such as optical network units installed in offices, hubs, routers, remote sensing devices connected to the communication devices with cables, etc. There is no information equipment. A communication device used in such a high-speed LAN line incorporates a pulse transformer in order to efficiently transmit a high-frequency pulse signal.

  A pulse transformer incorporated in a communication device has a structure in which a transformer element in which a primary side winding and a secondary side winding are wound around an annular magnetic core is built in a resin molded casing. . This pulse transformer incorporates a plurality of transformer elements in accordance with a communication method of a high-speed LAN line connected to a communication device.

  In addition, this type of pulse transformer includes a surface mount type in which a large number of lead terminals are led out in opposite directions by 180 ° from both side surfaces of a resin-molded casing (see, for example, Patent Document 1). This surface-mount type pulse transformer is assembled to a printed circuit board by electrically connecting the tip portions of a large number of lead terminals extending from both side surfaces of the housing to a wiring pattern of the printed circuit board by soldering.

JP 2000-353713 A

  By the way, when the cable to which the information device is connected becomes long, it is easy to be affected by the induced lightning, and the lightning surge generated in the information device easily flows back to the communication device. When a surge caused by such an induced lightning enters a communication device, the circuit element in the communication device is burned out, so that countermeasures are required. Since the communication device used in the high-speed LAN line described above incorporates a pulse transformer, the pulse transformer can insulate the input and output to suppress surge intrusion. However, when an enameled wire is used as a winding used for a transformer element in a pulse transformer, dielectric breakdown occurs even at a low voltage. Therefore, it is preferable to use an insulation-coated electric wire.

  However, creeping discharge may be caused when the distance between the input-side lead terminal and the output-side lead terminal in the pulse transformer is not long. When such creeping discharge occurs, a conduction state is established between the input lead terminal and the output lead terminal of the pulse transformer, and subsequent circuit elements are destroyed. Since communication equipment incorporating this pulse transformer is downsized, the distance between the input-side lead terminal and output-side lead terminal becomes even shorter when a small-sized pulse transformer is used. Is more likely to occur.

  In order to increase the withstand voltage against lightning surge, it is necessary to increase the withstand voltage of the pulse transformer and to suppress the occurrence of creeping discharge between the lead terminals. In order to increase the withstand voltage of this pulse transformer, high-insulation coated electric wires will be used as the primary and secondary windings wound around the magnetic core constituting the transformer element. In that case, the outer diameter of the high-insulation coated electric wire becomes thick, and it becomes difficult to make the transformer element very small.

  Therefore, the present invention is proposed in view of the above-described problems, and the object of the present invention is to provide a pulse transformer device that can easily realize ultra-miniaturization of a pulse transformer in response to miniaturization of communication equipment. And providing a high withstand voltage by suppressing the occurrence of creeping discharge between the lead terminals.

  As a technical means for achieving the above-described object, the present invention provides a pulse transformer in which a large number of lead terminals are led out in opposite directions by 180 ° from both side surfaces of a rectangular parallelepiped housing portion incorporating a plurality of transformer elements. Is a pulse transformer device that is surface-mounted on a printed circuit board by electrically connecting to the wiring pattern of the printed circuit board in the communication device, and extends from both side surfaces of the casing portion of the pulse transformer in the lead terminal lead-out direction. The protruding wall portion is erected on the printed circuit board on both sides of the lead terminal.

  In the present invention, the protruding wall portions extending in the lead terminal lead-out direction from the both side surfaces of the casing portion of the pulse transformer are erected on the printed circuit board on both sides of the lead terminal. The creepage distance between the lead terminals led in the direction can be secured, so even if a surge due to induced lightning enters the pulse transformer, the creeping discharge on the side of the housing between the lead terminals is suppressed. Can do. By suppressing the creeping discharge by the protruding wall portion, it is possible to cope with the miniaturization and the high withstand voltage of the communication device together with the high withstand voltage of the pulse transformer.

  The protruding wall portion in the present invention preferably has a structure arranged above the lead terminal. In this way, even when the casing is thin, creeping discharge above the casing can be suppressed between the lead terminals. By suppressing the creeping discharge by the protruding wall portion, it is possible to cope with the miniaturization and the high withstand voltage of the communication device together with the high withstand voltage of the pulse transformer.

  The protruding wall portion in the present invention preferably has a structure formed integrally with the end portions on both sides of the casing portion of the pulse transformer. In this way, the creeping distance between the lead terminals can be secured by the pulse transformer itself, which is an effective means when applied to a newly manufactured pulse transformer. Further, a structure in which a flexible and thick insulator film is attached to the bottom surfaces of the housing part and the protruding wall part is preferable. In this way, since the gap can be completely eliminated by closely contacting the casing portion and the protruding wall portion and the printed board with the insulating film, a discharge path passing through the bottom surface of the casing portion and the protruding wall portion is generated. Can not be.

  The protruding wall in the present invention preferably has a structure formed integrally with a cover fitted to the casing of the pulse transformer. In this way, the creepage distance between the lead terminals can be secured with the cover fitted to the casing of the pulse transformer, which is effective when retrofitting to an existing pulse transformer mounted on a printed circuit board. Means.

  The protruding wall portion in the present invention preferably has a structure extending to a position protruding in the lead terminal lead-out direction rather than the tip position of the lead terminal. In this way, a sufficient creeping distance between the lead terminals can be secured, and creeping discharge between the lead terminals can be reliably suppressed.

  The pulse transformer in the present invention preferably has a structure in which a magnetic shield curtain is interposed between the transformer elements when a plurality of transformer elements must be arranged in parallel in the casing. If a plurality of transformer elements are arranged in parallel in a vertical state in this way, the mounting space on the printed circuit board can be reduced as compared with the case where a plurality of transformer elements are arranged in parallel in a horizontal state. This is an effective means for reducing the size of the image. Further, by interposing the magnetic shield curtain between the vertically placed transformer elements, the magnetic coupling between the transformer elements can be shielded.

  The pulse transformer in the present invention includes a transformer element in which a primary side winding and a secondary side winding are wound around an annular magnetic core, and the secondary side winding is a primary for high withstand voltage into which lightning surge enters. A structure having a diameter smaller than that of the side winding may be used. In this way, the inner diameter of the magnetic core can be reduced by reducing the diameter of the winding, so that the transformer element can be easily miniaturized.

  According to the present invention, the protruding wall portions extending in the lead terminal lead-out direction from the both side surfaces of the casing portion of the pulse transformer are erected on the printed board on both sides of the lead terminal. Since the creepage distance between the lead terminals led in the opposite direction can be secured, the creeping discharge between the lead terminals can be suppressed even if a surge caused by induced lightning enters the pulse transformer. By suppressing the creeping discharge by the protruding wall portion, it is possible to cope with downsizing of the communication device without enlarging the housing portion. As a result, an ultra-small pulse transformer device with a high withstand voltage can be easily provided.

FIG. 5 is an exploded perspective view showing a state before the pulse transformer is assembled to the printed board in the embodiment of the present invention in which a projecting wall portion is provided on the casing of the pulse transformer. FIG. 2 is an assembled perspective view showing a state after the pulse transformer of FIG. 1 is assembled to a printed board. FIG. 3 is a plan view of FIG. 2. It is sectional drawing which follows the AA line of FIG. FIG. 5 is an exploded perspective view showing a state before a pulse transformer is assembled to a printed board in another embodiment of the present invention. FIG. 6 is an assembled perspective view showing a state after the pulse transformer of FIG. 5 is assembled to a printed circuit board. FIG. 7 is a plan view of FIG. 6. It is sectional drawing which follows the BB line of FIG. FIG. 5 is an exploded perspective view showing a state before the pulse transformer and the cover are assembled to the printed board in the embodiment of the present invention in which the protruding wall portion is provided on the cover. FIG. 10 is an assembled perspective view illustrating a state after the pulse transformer and the cover of FIG. 9 are assembled to the printed circuit board. It is a top view of FIG. It is sectional drawing which follows the CC line of FIG. FIG. 5 is a plan sectional view showing a pulse transformer in which a transformer element is arranged in a vertical state in a casing. It is sectional drawing which follows the DD line | wire of FIG. It is sectional drawing which follows the EE line | wire of FIG. It is a perspective view which shows the trans | transformer element which wound the primary side coil | winding and the secondary side coil | winding around the magnetic body core. It is a block diagram which shows the optical network unit incorporating a pulse transformer.

  Embodiments of a pulse transformer device according to the present invention will be described in detail below. In the following embodiment, as shown in FIG. 17, an optical fiber 1 drawn into an office or the like is connected to a cable 3 extending from various information devices 2 such as a hub and a router installed at a remote location. The case where it applies to the pulse transformer 11 integrated in the optical network unit 4 which is a communication apparatus is illustrated.

  The pulse transformer 11 according to the embodiment shown in FIGS. 1 to 4 has a number of lead terminals 14 and 15 that are 180 ° from both side surfaces 13 of a rectangular parallelepiped housing portion 12 containing a plurality of transformer elements (not shown). It has a structure derived in the opposite direction. In FIG. 4, the inside of the housing 12 (transformer element) is not shown and is hatched. The casing 12 of the pulse transformer 11 has a structure formed by, for example, resin molding or a structure made of a resin case. The lead terminals 14 and 15 are led out from the side surface 13 of the housing portion 12 in a state of being arranged in a straight line along the width direction, and have a surface mounting type structure by bending the tip portion thereof.

  In the pulse transformer 11 of this embodiment, a protruding wall portion 16 extending in the lead terminal lead-out direction from the end portions of both side surfaces 13 of the housing portion 12 is formed integrally with the housing portion 12. The protruding wall portion 16 extends to a position that protrudes in the lead terminal lead-out direction from the position of the tip of the lead terminals 14 and 15. Such a structure contributes to suppressing the occurrence of creeping discharge by ensuring the creeping distance between the input side lead terminal 14 and the output side lead terminal 15.

  In this surface mount type pulse transformer 11, the leading ends of a large number of lead terminals 14 and 15 extending from both side surfaces 13 of the housing 12 are electrically connected to the wiring patterns 7 and 8 of the printed circuit board 6 by soldering. Thus, the printed circuit board 6 in the optical network unit 4 (see FIG. 17) is assembled. In this way, the pulse transformer 11 is configured by assembling the pulse transformer 11 to the printed circuit board 6. A resist film 9 for protecting the wiring pattern is formed on the surface of the printed circuit board 6, and the resist film 9 is opened only by the wiring patterns 7 and 8 to which the leading ends of the lead terminals 14 and 15 are connected.

  At this time, in order to fix the casing 12 in a state of being closely adhered to the printed circuit board 6, a shape that matches the mounting surface of the casing 12 is formed between the printed circuit board 6 and the casing 12. An adhesive sheet 17 that is an insulating film is interposed. This adhesive sheet 17 is made of an elastic material. Further, instead of the adhesive sheet 17, an insulating adhesive may be applied to the entire attachment surface of the housing portion 12 and the protruding wall portion 16. Such a close contact structure between the casing portion 12 and the protruding wall portion 16 and the printed circuit board 6 prevents creeping discharge by not forming a gap between the casing portion 12 and the protruding wall portion 16 and the printed circuit board 6. Contributes to suppression.

  By the way, as shown in FIG. 17, in the optical network unit 4 used in the high-speed LAN line, if the cable 3 connecting the information device 2 becomes long, it is easily affected by induced lightning, and the lightning surge generated in the information device 2 Easily flows back to the optical network unit 4. As shown by broken line arrows in the figure, when a surge caused by induced lightning enters a pulse transformer 11 (see FIGS. 1 to 4) incorporated in the optical network unit 4, the input side lead terminal 14 and the output side of the pulse transformer 11 are shown. Creeping discharge may occur between the lead terminals 15, that is, between the input-side lead terminals 14 and the output-side lead terminals 15 located on the outermost side in the lead terminal arrangement direction.

  Therefore, in the pulse transformer 11 of this embodiment, the protruding wall portions 16 extending in the lead terminal lead-out direction from the both side surfaces 13 of the housing portion 12 are erected on the printed circuit board 6 on both sides of the lead terminals 14 and 15. The protruding wall portion 16 can secure a creepage distance on the side of the housing portion 12 between the input side lead terminal 14 and the output side lead terminal 15 located on the outermost side. As a result, even if a surge caused by induced lightning enters the pulse transformer 11, creeping discharge on the side of the housing portion 12 is suppressed between the input-side lead terminal 14 and the output-side lead terminal 15 located on the outermost side. Therefore, the connection between the input-side lead terminal 14 and the output-side lead terminal 15 is in a conductive state, so that it is possible to avoid destruction of electronic components connected after the pulse transformer 11. By suppressing the creeping discharge by the protruding wall portion 16, it is possible to increase the withstand voltage of the cable connecting portion including the pulse transformer 11.

  Since the optical network unit 4 in which the pulse transformer 11 is incorporated is miniaturized, when the ultra-small pulse transformer 11 is used, the separation distance between the input side lead terminal 14 and the output side lead terminal 15 is small. Due to the short side of the casing 12, the protruding wall 16 described above causes creeping on the side of the casing 12 between the outermost input side lead terminal 14 and the output side lead terminal 15. The effect of suppressing the creeping discharge by securing the distance is remarkably exhibited.

  In the embodiment shown in FIGS. 1 to 4, the case where the thickness a (see FIG. 1) of the housing portion 12 is thick has been described. However, in the embodiment shown in FIGS. 5 to 8, the thickness b (FIG. 5) of the housing portion 22. The case where reference is thin is illustrated (a> b). 5 to 8, the same or corresponding parts as those in FIGS.

  The pulse transformer 21 of the embodiment shown in FIGS. 5 to 8 includes a protruding wall portion 26 extending in the lead terminal lead-out direction from the side portions 23 of the housing portion 22 on both sides of the lead terminals 24 and 25. The protruding wall portion 28 that is provided integrally with the portion 22 and is erected on the printed circuit board 6 and extends in the lead terminal lead-out direction from the upper part of the both side surfaces 23 of the housing portion 22 is provided above the lead terminals 24 and 25. It is provided integrally with the body part 22.

  The pulse transformer 21 is formed by electrically connecting the tip portions of a large number of lead terminals 24 and 25 extending from both side surfaces 23 of the housing portion 22 to the wiring patterns 7 and 8 of the printed circuit board 6 by soldering. 6 is assembled. At this time, an insulating adhesive sheet 27 having a shape matched with the mounting surfaces of the casing portion 22 and the protruding wall portion 26 is interposed between the printed circuit board 6 and the casing portion 22. This adhesive sheet 27 is made of an elastic material. Further, instead of the adhesive sheet 27, an insulating adhesive may be applied to the entire attachment surface of the housing portion 22 and the protruding wall portion 26. Such a close contact structure between the housing portion 22 and the projecting wall portion 26 and the printed circuit board 6 prevents creeping discharge by not forming a gap between the housing portion 22 and the projecting wall portion 26 and the printed circuit board 6. Contributes to suppression.

  In the pulse transformer 21 of this embodiment, projecting wall portions 26 extending in the lead terminal lead-out direction from both side surfaces 23 of the housing portion 22 are provided on the side of the lead terminals 24 and 25, so that the outermost side in the lead arrangement direction. A creeping distance on the side of the housing portion 22 can be ensured between the input lead terminal 24 and the output lead terminal 25 located. In addition, by providing protruding wall portions 28 extending from both side surfaces 23 of the housing portion 22 in the lead terminal lead-out direction above the lead terminals 24 and 25, the input side lead terminals 24 positioned on the inner side in the lead arrangement direction A creeping distance above the housing portion 22 can be ensured between the output side lead terminal 25 and the output side lead terminal 25. As a result, even if a surge due to induced lightning enters the pulse transformer 21, the side wall of the housing 22 is located between the input-side lead terminal 24 and the output-side lead terminal 25 located at the outermost side by the protruding wall portion 26. Creeping discharge can be suppressed, and even if the thickness b of the casing portion 22 is thin, the protruding wall portion 28 allows the casing between the input-side lead terminal 24 and the output-side lead terminal 25 located inside. Creeping discharge above the body part 22 can be suppressed. By suppressing the creeping discharge by the protruding wall portions 26 and 28, it is possible to increase the withstand voltage of the cable connecting portion including the pulse transformer 21.

  In the embodiment shown in FIG. 1 to FIG. 8, the case where the protruding wall portions 16, 26, and 28 are formed integrally with the casing portions 12 and 22 of the pulse transformers 11 and 21 has been described. In the embodiment, the case where the protruding wall portions 46 and 48 are formed by the cover 41 separate from the housing portion 32 of the pulse transformer 31 is illustrated. 9 to 12, the same reference numerals are given to the same or corresponding parts as those in FIGS. 1 to 8, and redundant description is omitted.

  In the pulse transformer 31 of the embodiment shown in FIGS. 9 to 12, an insulating cover 41 is fitted on a rectangular parallelepiped housing portion 32, and projecting wall portions 46 and 48 are integrally formed on a part of the cover 41. Forming. The cover 46 is provided with a position restricting portion 43 for positioning with respect to the housing portion 32 by contacting both side surfaces 33 of the housing portion 32 of the pulse transformer 31. A portion of the cover 41 outside the position restricting portion 43 extends from the side portions of the side surfaces 33 of the housing portion 32 in the lead terminal lead-out direction and is erected on the printed circuit board 6 on both sides of the lead terminals 34 and 35. And a projecting wall portion 48 that extends in the lead terminal lead-out direction and is located above the lead terminals 34 and 35.

  The pulse transformer 31 is formed by electrically connecting the tip portions of a large number of lead terminals 34 and 35 extending from both side surfaces 33 of the housing portion 32 to the wiring patterns 7 and 8 of the printed circuit board 6 by soldering. 6 is assembled. At this time, an insulating adhesive sheet 37 having a shape matching the mounting surface of the housing part 32 is interposed between the printed circuit board 6 and the housing part 32. The adhesive sheet 37 is made of an elastic material. Further, instead of the adhesive sheet 37, an insulating adhesive may be applied to the entire mounting surface of the housing portion 32. The cover 41 is fixed in close contact with the printed circuit board 6 by an insulating adhesive applied to the entire bottom surface including the protruding wall portion 46. Such a close contact structure between the housing part 32 and the cover 41 and the printed circuit board 6 prevents the occurrence of creeping discharge by not forming a gap between the housing part 32 and the cover 41 and the printed circuit board 6. Contribute.

  In this embodiment, the protruding wall portion 46 of the cover 41 fitted to the housing portion 32 of the pulse transformer 31 is provided between the input-side lead terminal 34 and the output-side lead terminal 35 positioned on the outermost side in the lead arrangement direction. The creepage distances on both sides of the housing part 32 can be ensured, and the housing between the input-side lead terminal 34 and the output-side lead terminal 35 positioned inside in the lead arrangement direction by the protruding wall part 48. A creepage distance above the portion 32 can be secured. As a result, even if a surge caused by induced lightning enters the pulse transformer 31, both sides of the housing portion 32 are located between the input-side lead terminal 34 and the output-side lead terminal 35 located on the outermost side by the protruding wall portion 46. Creeping discharge at the upper side of the housing portion 32 can be suppressed between the input side lead terminal 34 and the output side lead terminal 35 located inside by the protruding wall portion 48. Can do. By suppressing the creeping discharge by the protruding wall portions 46 and 48, it is possible to increase the withstand voltage of the cable connecting portion including the pulse transformer.

  As in the embodiment shown in FIGS. 1 to 8, a structure is adopted in which projecting wall portions 16, 26, 28 are integrally formed on both side surfaces 13, 23 of the housing portions 12, 22 of the pulse transformers 11, 21. Accordingly, the creeping distance between the lead terminals can be secured by the pulse transformers 11 and 21 themselves, which is effective when applied to the newly manufactured pulse transformers 11 and 21. On the other hand, as in the embodiment shown in FIGS. 9 to 12, by adopting a structure in which projecting wall portions 46 and 48 are formed in a separate cover 41 fitted on the housing portion 32 of the pulse transformer 31, The cover 41 can ensure a creepage distance between the lead terminals, and is effective when retrofitting to an existing pulse transformer 31 mounted on the printed circuit board 6.

  As shown in the embodiment shown in FIGS. 1 to 4, the pulse transformer 11 having a thick casing portion 12 has a plurality of transformer elements 51 (eight examples are shown in the figure) as shown in FIGS. 13 to 15. , 52 are arranged in parallel in the casing portion 12 in a vertically placed state, and a magnetic shield curtain 53 is interposed between the transformer elements 51, 52. In addition, in FIGS. 13-15, the housing | casing part 12 which consists of resin cases is illustrated. The eight transformer elements 51 and 52 are constituted by an insulating transformer element 51 having a non-small diameter and a noise removing transformer element 52 having a very small diameter. In this way, by arranging the plurality of transformer elements 51 and 52 in parallel in a vertically placed state, the mounting space on the printed circuit board 6 can be reduced as compared with the case where the plurality of transformer elements 51 and 52 are placed in parallel in a horizontally placed state. Therefore, the pulse transformer 11 can be easily miniaturized. Further, by interposing the magnetic shield curtain 53 between the vertically placed transformer elements 51 and 52, the magnetic coupling between the transformer elements 51 and 52 can be shielded. In a high-speed LAN line, a 4-to-8-core cable 3 (see FIG. 17) is used, so four circuit transformer elements 51 and 52 per line are, for example, h: 10 mm, w: 17 mm, d: 12 mm. It is necessary to accommodate in the casing 12 having a size, and the vertical arrangement structure of the transformer elements 51 and 52 described above is effective in this respect.

  In the case of the pulse transformers 11, 21, 31 described in the embodiment shown in FIGS. 1 to 12, the large-diameter insulating transformer element 51 is connected to the annular magnetic body (ferrite) core 54 as shown in FIG. 16. A structure in which the primary winding 55 and the secondary winding 56 having different diameters are wound by a predetermined number of turns is possible. Since the primary side winding 55 of the transformer element 51 is connected to the cable 3 (see FIG. 17) of the information device 2, there is a possibility of a lightning surge intrusion. A reinforced insulated wire having a large diameter of about 10 kV (outer diameter: about 0.29 mmφ) is used. On the other hand, when a high withstand voltage is not required, the secondary side winding 56 uses an insulated wire having a withstand voltage of about 1 kV and a smaller diameter (outer diameter: about 0.15 mmφ) than the primary side winding 55. You can also. In this way, by using a reinforced insulated wire with a large diameter and high withstand voltage for the primary side winding 55, it is possible to reliably suppress the intrusion of lightning surge and to connect the primary side winding 55 to the secondary side winding 56. It is possible to wind the primary side winding 55 and the secondary side winding 56 by a predetermined number of turns around the ultra-small magnetic core 54 by using an insulated wire having a smaller diameter and not for high withstand voltage. Thus, the transformer element 51 can be easily miniaturized.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

6 Printed circuit board 7, 8 Wiring pattern 11, 21, 31 Pulse transformer 12, 22, 32 Housing part 13, 23, 33 Side face 14, 15, 24, 25, 34, 35 Lead terminal 16, 26, 28, 46, 48 Projection Wall 41 Cover 51 Transformer Element 53 Magnetic Shield Screen 54 Magnetic Core 55 Primary Winding 56 Secondary Winding

Claims (7)

  A pulse transformer in which a large number of lead terminals are led out in opposite directions by 180 ° from both side surfaces of a rectangular parallelepiped housing having a plurality of transformer elements is electrically connected to a wiring pattern of a printed circuit board in a communication device. Accordingly, in the pulse transformer device surface-mounted on the printed board, protruding wall portions extending in the lead terminal lead-out direction from both side surfaces of the casing portion of the pulse transformer are disposed on both sides of the lead terminal. A pulse transformer device characterized by being arranged upright on the top.   The pulse transformer device according to claim 1, wherein the protruding wall portion is disposed above the lead terminal.   3. The pulse transformer device according to claim 1, wherein the projecting wall portion is integrally formed at ends of both side surfaces of the casing portion of the pulse transformer. 4.   3. The pulse transformer device according to claim 1, wherein the projecting wall portion is integrally formed with a cover fitted to a housing portion of the pulse transformer.   The pulse transformer device according to any one of claims 1 to 4, wherein the protruding wall portion extends to a position protruding in a lead terminal lead-out direction from a tip position of the lead terminal.   The pulse transformer device according to any one of claims 1 to 5, wherein the pulse transformer includes a plurality of transformer elements arranged in parallel in a vertically arranged state in a casing portion, and a magnetic shield curtain interposed between the transformer elements. .   The pulse transformer includes a transformer element in which a primary side winding and a secondary side winding are wound around an annular magnetic core, and the secondary side winding is a primary side for high withstand voltage into which lightning surge enters. The pulse transformer device according to any one of claims 1 to 6, wherein the pulse transformer device has a diameter smaller than that of the winding.