JP4665603B2 - Coil parts - Google Patents

Description

  The present invention relates to a coil component used in various electronic devices, communication devices, and the like.

  Hereinafter, a conventional technique will be described with reference to the drawings.

  FIG. 5 is a block diagram showing the entire control system for controlling the fuel injection device of the automobile engine, FIG. 6 is a circuit diagram of a power supply unit in the control control unit of the control system, FIG. 7 is a sectional view of the coil components, and FIG. It is a perspective view of the coil component.

  In FIG. 5, in the control system for controlling the fuel injection device of the automobile engine, the control control unit 2 supplied with the driving current from the battery 1 controls the fuel injection device 3 of the engine. The control control unit 2 is provided with a CPU 4 that calculates and controls the injection amount and injection timing of the fuel injection device, and a power supply unit 5 that supplies current to the CPU 4.

  As shown in FIG. 6, the power supply unit 5 includes a filter unit 8 including a coil component 6 and a capacitor component 7, and a DC / DC converter circuit including a coil component 6, a capacitor component 7, an IC 9, and a switching component 10. The filter unit 8 is connected to the battery terminal 12 on the battery 1 side, and the DC / DC converter circuit unit 11 is connected to the CPU terminal 13 on the CPU 4 side. In particular, the coil component 6 used for the DC / DC converter circuit unit 11 is driven to be switched by the switching component 10. In the DC / DC converter circuit unit 11, the 12 V voltage of the battery 1 is about 1.5 to 5 V for the CPU 4. I have a pressure drop.

  As one of the coil components 6 used for such a DC / DC converter circuit section 11, as shown in FIGS. 7 and 8, a drum-shaped drum magnetic core 14 having hooks at both ends of a winding shaft section 13, and this A coil 15 wound around the winding shaft portion 13 of the drum magnetic core 14, a ring-shaped ring magnetic core 16 combined with the drum magnetic core 14 so as to cover the coil 15, and a terminal 17 electrically connected to the coil 15. There is something with. The coil 15 is formed by winding a conducting wire made of a round wire in a spiral shape, and the lead wire 18 is wound around one end of an L-shaped terminal 17.

  The drum magnetic core 14 and the ring magnetic core 16 are made of a ferrite material, and the drum magnetic core 14 and the ring magnetic core 16 are integrated by applying an adhesive 19.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2002-64024 A

  Since the conventional coil component is used in the DC / DC converter circuit unit 11 in the vicinity of the automobile engine, heat resistance is required. However, in the coil component, since the drum magnetic core 14 and the ring magnetic core 16 are integrated by applying the adhesive 19, the adhesive 19 melts depending on the heat resistant temperature of the adhesive 19 and the reliability deteriorates. It had the problem that.

  In order to solve the above problems, an object of the present invention is to provide a coil component with improved heat resistance so that it is not necessary to consider the heat resistance of an adhesive.

  In order to achieve the above object, the present invention has the following configuration.

In the present invention, a magnetic material is powdered, the surface is covered with an insulating coating, a binder is mixed and pressure-molded, a coil embedded in the magnetic core, and an end of the coil protrudes from the side surface of the magnetic core. A terminal formed by bending from the side surface toward the bottom surface, and a recess is provided on the side surface of the magnetic core at a position facing the terminal from the portion where the end of the coil protrudes toward the bottom surface, Of the terminals located on the side surface of the magnetic core, the terminal is provided with a wide portion extending to a width wider than the width of the opposing concave portion on the side protruding from the magnetic core, and the wide portion is disposed on the side surface of the magnetic core. And a space is formed between the inner wall surface of the recess and the terminal .

  With the above configuration, the coil is made of a magnetic material powder, covered with an insulating coating, and embedded in a magnetic core formed by pressing and mixing a binder, so that the magnetic core can be formed without using an adhesive, and heat resistance is improved. It can be improved.

In particular, a concave portion is provided on the side surface of the magnetic core at a position facing the terminal from the portion where the end of the coil protrudes toward the lower surface, and the terminal faces the side protruding from the magnetic core among the terminals positioned on the side surface of the magnetic core. Since the wide portion extended to a width wider than the width of the concave portion to be formed is adjacent to the side surface of the magnetic core and a space is formed between the inner wall surface of the concave portion and the terminal , the end of the coil Even if the portion is used as a terminal, it is possible to absorb the thermal stress applied to the terminal due to the difference in thermal expansion coefficient between the mounting substrate and the magnetic core during mounting. That is, the terminal by a wide wide part also Runode to form between air, together with the terminal can absorb the stress by the movable This space, than the width of the recess between the inner wall surface of the recess of the end portion and the magnetic core of the coil Since the position of the terminal is restricted, the terminal does not move more than necessary.

  In the following, embodiments of the present invention will be described with reference to the drawings.

  1 is a perspective view of a coil component according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a mounting state of the coil component, FIG. 3 is a perspective view of a coil of the coil component, and FIG. It is process drawing which shows a part of manufacturing process.

1 to 3, the coil component of the present invention is formed by magnetically powdering a magnetic material, covering the surface with an insulating film, mixing a binder, and press-molding the magnetic core 20, and winding a conductive wire in a spiral shape. , and a coil 22 embedded in the core 20, and a terminal 24 formed by bending from the side toward the lower surface projecting ends of the coil 22 from the side of the magnetic core 20.

  The terminal 24 is formed by bending the end of the coil 22 from the side surface of the magnetic core 20 toward the lower surface.

Furthermore, a concave portion 25 is provided on the side surface of the magnetic core 20 at a position facing the terminal 24 from the portion where the end portion of the coil 22 protrudes toward the lower surface, and the terminal 24 includes the terminal 24 positioned on the side surface of the magnetic core 20. A wide portion 26 is provided which extends wider than the width of the concave portion 25 facing the side protruding from the magnetic core 20. The wide portion 26 is adjacent to the side surface of the magnetic core 20, and the inner wall surface 27 of the concave portion 25 and the coil 22 are provided. A space 28 is formed between the two ends.

  Then, the position below the wide portion 26 formed on the terminal 24 is used as a solder joint portion 29, solder 30 is applied to the terminal 24, and the coil component is mounted on the mounting substrate 32.

  The manufacturing method of the said coil components is as follows.

  FIG. 4A is a process diagram showing a state where re-press molding is performed with a mold so that a coil is sandwiched between two green compacts, and FIG. 4B is a state where re-press molding is completed with the same mold. It is process drawing shown. As shown in FIGS. 4 (a) and 4 (b), the magnetic core 20 is in a non-heated state in which the thermosetting resin does not completely cure the binder containing the thermosetting resin and the magnetic powder powdered from the magnetic material. The two green compacts 34 mixed and pressure-molded in step 2 are re-press-molded with a mold 36 so that the coil 22 is sandwiched, and the coil 22 is covered with the green compact 34 and the thermosetting resin is completely formed. It is molded by heating to cure.

At this time, the pressing force at the time of re-pressing molding is larger than the pressing force at the time of pressure molding, and the pressing force at the time of pressing molding the green compact 34 is about 0.5 to ¹ ton / cm ^2. Thus, the pressure applied at the time of re-pressure molding for molding the magnetic core 20 from the green compact 34 is about 3 to 5 ton / cm ² .

  With the above configuration, the coil 22 is made of a magnetic material, covered with an insulating coating, embedded in a magnetic core 20 formed by pressing a binder and mixed, so that the magnetic core can be formed without using an adhesive, Can be improved.

Further , a concave portion 25 is provided on the side surface of the magnetic core 20 at a position facing the terminal 24 bent from the portion where the end of the coil 22 protrudes, and the terminal 24 has a terminal 24 located on the side surface of the magnetic core 20. A wide portion 26 is provided which extends wider than the width of the concave portion 25 facing the side protruding from the magnetic core 20. The wide portion 26 is adjacent to the side surface of the magnetic core 20, and the inner wall surface 27 of the concave portion 25 and the coil 22 are provided. Since the space 28 is formed between the end portion of the coil 22 and the end portion of the coil 22, even if the end portion of the coil 22 is used as the terminal 24, the terminal 24 caused by the difference in thermal expansion coefficient between the mounting substrate 32 and the magnetic core 20 at the time of mounting. Can absorb thermal stress on That is, Runode form a spatial 28 between the inner wall surface 27 of the recess 25 of the end portion and the magnetic core 20 of the coil 22, together with pin 24 can absorb the stress by the movable This space 28, recess 25 of Since the position of the terminal 24 is regulated by the wide portion 26 wider than the width, the terminal does not move more than necessary.

  Further, the magnetic core 20 includes a plurality of green compacts obtained by pressing and molding a binder containing a thermosetting resin and a magnetic powder obtained by powdering a magnetic material in a non-heated state where the thermosetting resin is not completely cured. 34 is re-press-molded so as to sandwich the coil 22, the coil 22 is covered with the green compact 34, and the thermosetting resin is heated and molded so as to be completely cured. Between the coil 22 and the coil 22 without gaps, the magnetic gap can be reduced and the magnetic efficiency can be improved. In particular, since the pressing force at the time of re-pressing molding is larger than the pressing force at the time of pressure molding, not only the gap between the green compact 34 and the coil 22 but also the green compact 34 itself is formed. It is possible to densely form the entire magnetic core 20 in which the coil 22 is embedded, with the gaps in the gap being densely filled.

  As described above, the coil component according to the present invention improves the heat resistance so that it is not necessary to consider the heat resistance of the adhesive, and thus can be applied to various electronic devices and communication devices.

The perspective view of the coil components in one embodiment of this invention Cross-sectional view of the coil component mounted state Coil perspective view of the coil component Process diagram showing a part of the manufacturing process of the coil component The block diagram which shows the whole control system which controls the fuel injection device of the automobile engine Circuit diagram of the power supply unit in the control unit of the control system Cross-sectional view of the coil component Perspective view of the coil component

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Magnetic core 22 Coil 24 Terminal 25 Recessed part 26 Wide part 27 Inner wall surface 28 Space 29 Solder joint part 30 Solder 32 Mounting board 34 Green compact 36 Mold

Claims (1)

Covering the surface with an insulating film and a magnetic material powder, and pressure molding the core by mixing a binder, a coil embedded in the magnetic core, the ends of the coil to the lower surface from the side to protrude from the side surface of said magnetic core A terminal formed by bending toward the terminal, and a concave portion is provided on a side surface of the magnetic core at a position facing the terminal from a portion where the end of the coil protrudes toward a lower surface. Of the terminals located on the side surface of the magnetic core, a wide portion extending to a width wider than the width of the opposing concave portion is provided on the side protruding from the magnetic core, and the wide portion is adjacent to the side surface of the magnetic core. A coil component in which a space is formed between the inner wall surface of the recess and the terminal .

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