JP5891344B2 - Surface mount electronic components - Google Patents

Description

  The present invention relates to a surface mount electronic component used in various electronic devices.

  In recent years, electronic control of automobile drive systems and control systems has been increasingly advanced, and a large number of electronic control devices have been installed in a single automobile, and further downsizing and higher reliability of electronic control devices are desired. It is rare.

  In addition, electronic components used in these electronic control devices are also required to have high reliability that can be surface-mounted for miniaturization and are required for in-vehicle components.

  Next, an example in which a coil element is used as a circuit element for such a conventional surface-mount type electronic component will be described with reference to the drawings.

  11 is a plan view of a conventional surface mount electronic component, FIG. 12 is a cross-sectional view taken along line AA of FIG. 11, and FIG. 12 shows a state where the surface mount electronic component is mounted on a mounting substrate.

  As shown in FIG. 11 and FIG. 12, the conventional surface-mount type electronic component forms a coil element 1 by winding a copper wire with an insulating film, and the coil element 1 is made of a metal magnetic powder and a thermosetting resin. The body 2 is formed by embedding in a mixed powder with a binder and press-molding, and the lead wires 3 at both ends of the coil element 1 protruding from the side surface of the body 2 are crushed into a flat plate shape and the body 2 The surface mounting type terminals 4 were formed by bending the side mountings from the side surface to the bottom surface, and thus the surface mounting type electronic components were configured.

  And this surface mount type electronic component was mounted with the solder 7 on the land 6 of the mounting board | substrate 5 using the reflow solder tank.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP 2009-123927 A

  In recent years, the mounting positions of electronic control devices for automobiles are increasing from outside the engine room to the inside of the engine room, and it is desired to further improve the vibration resistance.

  However, since the conventional surface mount type electronic component described above has a configuration in which the terminal 4 is bent from the side surface of the body 2 toward the bottom surface, there is a gap 8 between the terminal 4 and the body 2 due to the spring back of the bent portion. It sometimes occurred.

  When the gap 8 is generated, when the vibration of the vehicle is transmitted to the body 2 through the mounting substrate 5, the terminal 4 is bent by the size of the gap 8, and this is alternately repeated by the reciprocating motion. Causes vibration.

  As a result of repetition of this vibration, the stress is concentrated with the bent portion 9 of the terminal 4 or the boundary portion 10 between the terminal 4 and the fillet of the solder 7 as a fulcrum, and eventually the metal fatigues and breaks. There has been a problem that parts may be disconnected.

  An object of the present invention is to provide a highly reliable surface-mount electronic component as a vehicle-mounted component by preventing breakage of a terminal due to vibration.

In order to solve the above-described problems, the present invention includes a substantially square pillar-shaped body having a circuit element therein and a pair of plate-shaped terminals connected to the circuit element, and the terminals are respectively provided on opposite sides of the body. In a surface-mounted electronic component in which one end is fixed and the terminal is bent from the side to the bottom, and the other end of the terminal is placed on the bottom of the body, the range facing the corner of the other end of the terminal on the bottom of the body In addition, a rectangular parallelepiped concave notch is formed by dropping from the bottom surface of the body toward the side closer to the side orthogonal to the side to which one end of the terminal is fixed, and the corner of the terminal is recessed. The corners of the terminals are locked to the bottom surface of the body by bending along two inner walls perpendicular to each other .

  With the above configuration, when the corner of the terminal is bent along the inner wall of the recess, the terminal on the side of the body is pulled toward the body due to the stress that bends the corner of the terminal. After that, since the corner portion of the terminal is locked to the body, the spring back does not occur. As a result, the terminal can be fixed in contact with the side of the body and the inner wall of the recess, and the body generated by the gap between the body and the terminal will not vibrate like a pendulum, preventing the terminal from breaking can do.

  As described above, according to the present invention, it is possible to obtain the effect of preventing the breakage of the terminal due to the vibration and improving the reliability of the surface mount electronic component.

1 is a bottom perspective view of a surface mount electronic component according to an embodiment of the present invention. BB sectional view of FIG. CC sectional view of FIG. DD sectional view of FIG. The side view which shows the state mounted in the mounting substrate of the surface mount type electronic component in one embodiment of this invention The figure explaining the manufacturing process of the surface mount type electronic component in one embodiment of this invention The figure explaining the manufacturing process of the surface mount type electronic component in one embodiment of this invention The figure explaining the manufacturing process of the surface mount type electronic component in one embodiment of this invention The figure explaining the manufacturing process of the surface mount type electronic component in one embodiment of this invention The figure explaining the manufacturing process of the surface mount type electronic component in one embodiment of this invention Plan view of conventional surface mount electronic components Sectional view of the AA line of FIG.

  Hereinafter, an example in which a coil element is used as a circuit element of a surface-mount type electronic component according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a bottom perspective view of a surface-mounted electronic component according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line BB in FIG. 1, and FIG. 3 is a cross-sectional view taken along line CC in FIG. 4 is a cross-sectional view taken along the line DD of FIG. 1, and FIG. 5 is a side view showing a state in which the surface-mounted electronic component according to the embodiment of the present invention is mounted on a mounting board.

  As shown in FIGS. 1 to 5, the surface-mounted electronic component according to the present invention includes a substantially rectangular columnar body 22 having a coil element 21 therein as a circuit element, and a plate-like terminal 23 connected to the coil element 21. And.

  The terminals 23 are fixed to the opposite side surfaces of the body 22 and are bent from the side surface toward the bottom surface. The other end of the terminal 23 is a surface mount type terminal 23 arranged on the bottom surface of the body 22. .

  The body 22 is made of a magnetic material obtained by mixing a metal magnetic powder containing iron as a main component with a binder made of a thermosetting resin such as epoxy and granulating the binder, and the magnetic material is coiled. One end of the element 21 and the terminal 23 is embedded.

  The coil element 21 embedded in the body 22 is formed by spirally winding an insulating coated copper wire with a fusion layer to form an air-core coil. In this embodiment, the thickness of the copper wire is 0. A 28 mm copper wire was used, the shaft core diameter was 2.8 mm, 40 turns were wound, the lead wires 24 at both ends were drawn in opposite directions, and the fusion layer was cured to maintain the shape. is there.

  The terminal 23 is made of a metal flat plate. In this embodiment, a phosphor bronze plate having a thickness of 0.2 mm is used to electrically connect the lead wire 24 of the coil element 21, and one end thereof is connected to a katakana connector. The U-shaped protrusion 25 is embedded in the body 22.

  The connection between the terminal 23 and the lead wire 24 may be performed by forming a connection portion in the protruding portion 25 inside the body 22 or may be connected to the terminal 23 adjacent to the protruding portion 25 outside the body 22. In the embodiment, the storage groove 26 is formed by pressing in the center in the direction in which the terminal 23 extends, and the lead wire 24 is stored in the storage groove 26 and is electrically connected integrally using electric welding such as resistance welding. ing.

  By arranging the lead wire 24 in the storage groove 26 in this way, when the terminal 23 is bent from the side surface of the body 22 toward the bottom surface, the lead wire 24 is also arranged on the bottom surface of the body 22 and the thickness of the copper wire is reduced. Even with a thin copper wire of about 0.28 mm, the terminal 23 serves as a holding member, and the shape of the lead wire 24 can be maintained and the lead wire 24 and the land 35 of the mounting substrate 34 can be directly connected. As compared with the case where wiring is performed inside the terminal or connected to the terminal 23 adjacent to the projecting portion 25, there is no problem such as disconnection of the connecting portion between the terminal 23 and the lead wire 24, thereby improving reliability. it can.

  Furthermore, when the lead wire 24 is housed in the housing groove 26 as described above, when the diameter of the lead wire 24 is large and protrudes from the housing groove 26, when the plate is pressed flat in advance or is electrically welded, It is desirable to make the height of the lead wire 24 equal to the surface height of the terminal 23 using an electrode (not shown). By doing so, the flatness of the terminal 23 is improved and the connectivity of the mounting substrate 34 to the land 35 can be improved.

  Further, it is preferable to provide through holes 27 at positions corresponding to the ridges on the side surface and bottom surface of the body 22, so that when the terminals 23 are bent, the through holes 27 become escape portions. Thus, the lead line 24 is not stretched, and the reliability can be further improved.

  In this way, the projecting portion 25 which is one end of the coil element 21 and the terminal 23 is embedded in the magnetic material, and is pressure-molded using a mold. In this embodiment, the outer dimensions are 8.0 × 8. A body 22 of 0 × 5.4 mm is formed.

  The pressure-molded body 22 is heat treated to cure the binder made of thermosetting resin, one end of the terminal 23 is fixed to the side surface of the body 22, the body 22 is heat treated, and then the terminal 23 is moved from the side surface. The other end of the terminal 23 is arranged on the bottom surface of the body 22 by bending toward the bottom surface.

  On the side surface and bottom surface of the body 22, there are formed storage recesses 29 for storing the projections 28 protruding to the opposite side of the storage grooves 26 formed by pressing the terminals 23 when forming the body 22. The convex portion 28 is accommodated in the concave portion 29, and the flat portion of the terminal 23 is bent along the side surface of the body 22.

  Next, fixing of the other end of the terminal 23 and the bottom surface of the body 22 which is a characteristic part of the present invention will be described.

  First, the bottom surface of the body 22 includes a range facing the corner portion 30 at the other end of the terminal 23 disposed on the bottom surface side, and a side surface closer to the side surface orthogonal to the side surface to which one end of the terminal 23 is fixed. A concave notch 31 is formed by being depressed from the bottom surface of the body 22.

  Then, by bending the corner portion 30 of the terminal 23 along the inner wall of the recess 31, the corner portion 30 of the terminal 23 is locked to the bottom surface of the body 22, and the other end of the terminal 23 is connected to the bottom surface of the body 22. It is fixed to.

  By doing so, even if the terminal 23 is bent from the side surface toward the bottom surface, a springback occurs in the bent portion of the side surface portion of the terminal 23, and a gap is generated between the body 22 and the terminal 23. In response to the stress that bends the corner 30 of the terminal 23 along the inner wall of the recess 31, the terminal 23 located on the side of the body 22 across the gap is drawn toward the body 22, It can be brought into contact with the side surface of the body 22.

  Furthermore, since the corner portion 30 side of the terminal 23 is also bent and locked along the inner wall of the recessed portion 31, no springback occurs after the corner portion 30 of the terminal 23 is locked. 23 can be fixed in contact with the side surface of the body 22 and the inner wall of the recess 31.

  As a result, even if the surface mount type electronic component of the present embodiment is mounted on the mounting substrate 34 and subjected to stress due to vibration of an automobile or the like, the body 22 and the terminal 23 are in contact and the terminal 23 is not bent. The body 22 does not vibrate like a pendulum, and the terminal 23 can be prevented from breaking.

  Here, including the range facing the corner 30 at the other end of the terminal 23 of the recessed portion 31 means including not only the range facing the corner 30 but also the outer edge portion of the corner 30. In this way, the corner portion 30 of the terminal 23 can be easily bent along the inner wall of the recessed portion 31, and the productivity can be improved.

  In this case, in particular, it is desirable to provide the recessed portion 31 integrally between the corner portions 30 of the opposing terminals 23, and more desirably, the closer side of the side surfaces orthogonal to the side surface of the body 22 to which one end of the terminal 23 is fixed. It is desirable to provide up to the side.

  By doing so, the space between the corner portions 30 of the terminals 23 facing each other is greatly cut out. Therefore, when the surface mount type electronic component is reflow-soldered to the mounting substrate 34, Accordingly, hot air is easily applied to the corners 30 of the terminals 23 bent together, and the solder fillets 32 can be formed also on the corners 30 of the terminals 23 bent as shown in FIG.

  The solder fillet 32 becomes a large back fillet 33, and the vibration resistance can be further improved by a synergistic effect with the solder fillet 32 formed on the terminal 23 on the side surface side of the body 22.

  The dimension for bending the corner portion 30 of the terminal 23 along the inner wall of the recessed portion 31 is preferably at least three times the thickness of the terminal 23, so that the terminal portion can be more accurately connected to the recessed portion 31. 23 corner portions 30 can be locked, and solder fillets 32 can be formed.

  In the present embodiment, the body 22 constitutes the closed magnetic path magnetic core of the coil element 21. However, since the recessed portion 31 is located on the side surface side of the body 22, there is no influence on the magnetic efficiency and the characteristics. The vibration resistance can be improved without deterioration.

  Further, the recess 31 is formed in a rectangular parallelepiped shape, and the corner 30 of the terminal 23 is bent along two orthogonal inner walls of the recess 31 so that the corner 30 of the terminal 23 is formed on the bottom surface of the body 22. It is preferable to lock.

  By doing so, since the corner portion 30 of the terminal 23 is bent along the orthogonal inner wall of the recess portion 31, the corner portion 30 of the terminal 23 can be more accurately locked to the recess portion 31. Furthermore, the back fillet 33 is formed not only in one direction but also in a plurality of directions, so that the vibration resistance can be further improved.

  Further, in this case, since the corners 30 on both sides of the one terminal 23 are bent so as to pull each other, the flatness of the terminal 23 arranged on the bottom surface is impaired when the corner 30 of the terminal 23 is bent. It can be prevented.

  Next, a method for manufacturing a surface-mounted electronic component according to an embodiment of the present invention will be described with reference to FIGS.

  First, as shown in FIG. 6, an air-core coil element 21 is formed by spirally winding an insulating coated copper wire with a fusion layer.

  After winding a copper wire around a predetermined winding axis and pulling out the lead wires 24 at both ends in opposite directions, the fusion layer is cured and reacted by blowing hot air or dripping a solvent onto the winding portion. An air core coil element 21 is formed by maintaining the shape of the turning part and removing it from the winding shaft.

  Next, the lead wire 24 and the terminal 23 are connected as shown in FIG.

  The terminal 23 is made of a metal plate such as a phosphor bronze plate, and one end portion is formed in a U-shape of katakana and two projecting portions 25 are provided. A storage groove 26 for storing the lead wire 24 is formed at the center in the extending direction of the terminal 23, and a through hole 27 is provided at a position corresponding to the ridge between the side surface and the bottom surface of the body 22.

  Then, after peeling off the insulating film of the lead wire 24, the lead wire 24 is stored in the storage groove 26 of the terminal 23, and the terminal 23 and the lead wire 24 are integrated with each other using electric welding such as resistance welding. Connect electrically.

  When the diameter dimension of the lead wire 24 is larger than the depth of the storage groove 26, the resistance welding electrode is pressed, or the lead wire 24 is pressed in advance to crush the lead wire 24, and the height of the flat portion of the terminal 23 is set. The flatness of the surface of the terminal 23 is ensured so as to be equivalent.

  The terminals 23 may be connected individually as shown in FIG. 7, but productivity can be improved by making them into a continuous hoop shape (not shown).

  Next, as shown in FIG. 8, a magnetic material made of iron as a main component and a binder made of a thermosetting resin are mixed and granulated into a magnetic material, and the coil element 21. The body 22 is formed by inserting the protruding portion 25 of the terminal 23 into a mold (not shown) and performing pressure molding. In FIG. 8, the outline of the body 22 is indicated by a broken line.

  At this time, a mold is used for the body 22 to form an accommodation recess 29 for accommodating the projection 28 of the accommodation groove 26 on the back surface of the terminal 23 from the side surface to the bottom surface of the body 22.

  Further, the bottom surface of the body 22 includes a range facing the corner portion 30 at the other end of the terminal 23 disposed on the bottom surface of the body 22, and the side closer to the side surface orthogonal to the side surface to which the one end of the terminal 23 is fixed. A concave notch 31 is formed by being depressed from the bottom surface of the body 22 toward the side surface. The recess 31 is integrally formed in a rectangular parallelepiped shape between the corners 30 of the terminals 23 facing each other.

  The pressure-molded body 22 is heat-treated to thermally cure the binder made of a thermosetting resin, thereby firmly fixing the protruding portion 25 of the terminal 23 to the side surface of the body 22.

  After the heat treatment, in order to improve the mountability on the mounting substrate 34, it is preferable to perform solder plating on the surface of the terminal 23 by immersing the terminal 23 in molten solder.

  Next, as shown in FIG. 9, the terminal 23 is bent from the side surface to the bottom surface of the body 22.

  First, the surplus portion on the other end side of the terminal 23 is cut, and the position corresponding to the ridge portion between the side surface and the bottom surface of the body 22 is bent (FIG. 9A).

  Then, the portion protruding from the side surface of the body 22 is bent in the bottom direction. At this time, the convex portion 28 on the back surface of the storage groove 26 of the terminal 23 is stored in the storage concave portion 29 formed in the body 22, and the flat portion of the terminal 23 is bent along the body 22 (FIG. 9B). ).

  Finally, the corner portion 30 of the terminal 23 is bent along two orthogonal inner walls of the recessed portion 31 formed in a rectangular parallelepiped shape, and the terminal 23 is locked to the recessed portion 31.

  The bending of the corner portion 30 of the terminal 23 will be described in more detail with reference to FIG.

  The corner portion 30 of the terminal 23 is bent by preparing a punch 36 that can be fitted in an approximate shape with the recessed portion 31 and pressing the punch 36 into the recessed portion 31 while contacting the corner portion 30 of the terminal 23.

  The dimension of the punch 36 is obtained by subtracting the thickness dimension of the terminal 23 from the planar dimension of the recess 31.

  By pushing such a punch 36 into the corner portion 30 of the terminal 23, the corner portion 30 of the terminal 23 can be crimped and bent to two orthogonal inner walls of the recess portion 31, and the recess 23 can be bent into the recess portion 31. The corner | angular part 30 can be latched exactly.

  Further, by simultaneously crimping and bending the four corners 30, the terminal 23 on the side surface of the body 22 is attracted toward the body 22 in a balanced manner, thereby eliminating a gap between the body 22 and the terminal 23. In addition, even between the corner portions 30 of one terminal 23, the terminals 23 act so as to be attracted to each other, and are not attracted to and tilted to either one, and the flatness of the terminal 23 on the bottom surface side is not impaired. The corner portion 30 can be bent.

  By doing so, the surface mount electronic component shown in FIG. 1 can be manufactured.

  In the present embodiment, the lead wire 24 of the coil element 21 has been described as being integrally electrically connected to a terminal made of a metal plate. However, the diameter of the copper wire of the coil element 21 is, for example, 0.8 mm or more. In the case of a thick copper wire, the lead wire 24 at both ends of the coil element 21 may be pressed into a flat plate shape to form the terminal 23, and the same effect as in the present embodiment can be obtained.

  The body 22 has been described as a pressure-molded magnetic material. However, the body 22 may be a plastic container filled with a circuit element and filled with resin. One end of the terminal is fixed to the side of the container, and the other end of the terminal is fixed. If the corner portion is bent and locked along the recessed portion formed on the bottom surface of the container, the same effect as the present embodiment can be obtained.

  Since the surface mount type electronic component according to the present invention can fix the terminal in contact with the side surface of the body and the inner wall of the recess, the surface mount type electronic component can be prevented from being broken by the pendulum-like vibration of the body. It is possible to increase the reliability and is industrially useful.

DESCRIPTION OF SYMBOLS 21 Coil element 22 Body 23 Terminal 24 Lead wire 25 Projection part 26 Storage groove 27 Through-hole 28 Projection part 29 Storage recess part 30 Corner part 31 Notch part 32 Solder fillet 33 Back fillet 34 Mounting board 35 Land 36 Punch

Claims (3)

A body having a substantially quadrangular prism shape having a circuit element inside, and a pair of plate-like terminals connected to the circuit element, and fixing one end of each of the terminals to opposite sides of the body; In the surface-mounted electronic component in which the other end of the terminal is arranged on the bottom surface of the body by bending from the side surface toward the bottom surface, the bottom surface of the body includes a range facing the corner of the other end of the terminal, A rectangular parallelepiped concave notch is formed by dropping from the bottom surface of the body toward a side surface closer to a side surface orthogonal to a side surface to which one end of the terminal is fixed, and the corner portion of the terminal is A surface-mount type electronic component in which the corner portion of the terminal is locked to the bottom surface of the body by being bent along two orthogonal inner walls of the recessed portion. 2. The surface-mount type electronic component according to claim 1, wherein the recessed portion is provided integrally between the corner portions of the opposing terminals. A body having a substantially quadrangular prism shape having a circuit element inside, and a pair of plate-like terminals connected to the circuit element, and fixing one end of each of the terminals to opposite sides of the body; In the surface-mounted electronic component in which the other end of the terminal is arranged on the bottom surface of the body by bending from the side surface to the bottom surface, from the range facing the outer edge portion of the corner portion of the other end of the terminal on the bottom surface of the body. And forming a notch that is notched down from the bottom of the body across a side surface that is orthogonal to a side surface that is orthogonal to the side surface to which one end of the terminal is fixed, and the recess portion has a plurality of continuous inner walls. The corner of the terminal is locked to the bottom surface of the body by bending the corner of the terminal along two adjacent inner walls of the recess. Surface mount type Child parts.

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