JP2005310867A - Coil component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil component whose reliability is improved without integrating a drum core and a ring core with adhesive so that heat resistance of adhesive is not necessary to be considered and suppressing disconnection of lead wires of coils. <P>SOLUTION: The coil component is provided with a core 30 whose cross section is rectangular, coils 32 which are formed by spirally winding conductors and are embedded in the core 30 and terminals 34 which are electrically connected to the coils 32. The terminals 34 are provided with the lead-out wires 42 of the coils 32 projected from the core 30 and folded toward the base of sides of the core 30 and holders 44 which are overlapped with the lead-out wires 42 and hold positions and shapes of the lead-out wires 42. Powders of magnetic materials are not interposed between the adjacent conductors of the coils 32, and cross section shapes of the conductors 66 are made into almost honeycomb shapes so that the conductors 66 are closely brought into contact with each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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. 7 is a block diagram showing the entire control system for controlling the fuel injection device of the automobile engine, FIG. 8 is a circuit diagram of the power supply unit in the control control unit of the control system, FIG. 9 is a sectional view of the coil components, and FIG. It is a perspective view of the conventional coil components used for the power supply part.

  In FIG. 7, in the control system for controlling the fuel injection device of the automobile engine, the control control unit 2 to which the driving current is supplied 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. 8, the power supply unit includes a filter unit 8 including a coil component 6 and a capacitor component 7, and a DC / DC converter circuit unit including a coil component 6, a capacitor component 7, an IC 9, and a switching component 10. 11 are connected to each other, 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, and the DC / DC converter circuit unit 11 sets the 12 V voltage of the battery 1 to about 1.5 to 5 V for the CPU 4. I have a pressure drop.

  As one of the coil components used in such a DC / DC converter circuit section 11, as shown in FIGS. 9 and 10, a drum-shaped drum magnetic core 21 having hooks at both ends of the winding shaft section 20, and the drum A coil 22 wound around the winding shaft portion 20 of the magnetic core 21, a ring-shaped ring magnetic core 23 combined with the drum magnetic core 21 so as to cover the coil 22, and a terminal portion 24 electrically connected to the coil 22. There is something with. The coil 22 is formed by spirally winding a conducting wire made of a round wire, and the lead wire 25 is wound around one end 26 of the L-shaped terminal portion 24.

  The drum magnetic core 21 and the ring magnetic core 23 are made of a ferrite material, and the drum magnetic core 21 and the ring magnetic core 23 are integrated by applying an adhesive 27.

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 for 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 21 and the ring magnetic core 23 are integrated by applying the adhesive 27, the adhesive 27 melts depending on the heat-resistant temperature of the adhesive 27 and the reliability deteriorates. It had the problem that.

  Further, since the lead wire 25 of the coil 22 is entangled with the L-shaped terminal portion 24, tension is easily applied between the terminal portion 24 and the lead wire 25 of the coil 22 due to the vibration of the engine of the automobile. There was a problem that the wire 25 may be broken.

  In order to solve the above problems, the present invention does not integrate the drum magnetic core and the ring magnetic core with an adhesive so that it is not necessary to consider the heat resistance of the adhesive. It aims at providing the coil component which suppressed and improved the reliability.

  In order to solve the above problems, the present invention has the following configuration.

  The present invention comprises a magnetic material made of powdered powder, the surface is covered with an insulating film, a binder is mixed and pressure-molded, and a coil is formed by winding a conductive wire in a spiral, embedded in the magnetic core, And a terminal portion electrically connected to the coil, and the cross-sectional shape of the conductive wire is substantially set so that the conductive wire is brought into close contact with each other without interposing the powder of the magnetic material between the conductive wires adjacent to the coil. It is the structure made into the hexagon shape.

  With the above configuration, the terminal portion is composed of a coil lead wire that is bent from the magnetic core and a holding portion that overlaps the lead wire and holds the position and shape of the lead wire. The position and shape of the bent coil lead wire can be maintained, and the lead wire itself can be used as a terminal portion.

  As a result, there is no need to tie the lead wire to the terminal part, and the reliability of the lead wire can be suppressed by suppressing the disconnection of the lead wire, and the coil thickness is reduced or the coil wire diameter is increased in order to increase the number of coil turns. Even if the lead wire becomes thin or becomes difficult to bend or becomes independent, the disconnection of the lead wire of the coil can be suppressed and the reliability can be improved.

  In particular, between the adjacent conductors of the coil, the magnetic material powder is not interposed, and the cross-sectional shape of the conductors is substantially hexagonal so that the conductors are in close contact with each other, so that the magnetic flux circulates around each conductor. Can be suppressed, magnetic flux can be generated efficiently over the entire coil, inductance can be increased, and variation in inductance can be reduced.

  In addition, the coil is made of powdered magnetic material, covered with an insulating film, embedded in a magnetic core that has been press-molded by mixing a binder, so the magnetic core can be formed without using an adhesive, and heat resistance is improved. It can be improved.

  Thus, according to the present invention, it is possible to provide a coil component with improved heat resistance and reliability.

  Hereinafter, the invention described in all claims of the present invention will be described using embodiments of the present invention.

  1 is an exploded perspective view of a coil component according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a magnetic core of the coil component, and FIG. 3 is an enlarged perspective view of a terminal portion connected to a coil of the coil component. 4 is a perspective view of the coil component, FIG. 5 is a sectional view of the coil component, and FIG. 6 is an enlarged sectional view of the coil of the coil component corresponding to part A in FIG.

  1 to 6, a coil component according to an embodiment of the present invention includes a magnetic core 30 having a rectangular cross-section in which a magnetic material is powdered, the surface is covered with an insulating film, and a binder is mixed and pressed. The coil portion 32 is formed by winding a conductive wire in a spiral shape and embedded in the magnetic core 30, and a terminal portion 34 electrically connected to the coil portion 32.

The magnetic core 30 is formed by mixing a binder containing a thermosetting resin and magnetic powder in a non-heated state in which the thermosetting resin is not completely cured, and press-molding at about 0.5 to 1 ton / cm ² . The green compact 36 is re-press-molded so as to sandwich the coil portion 32, and the green compact 36 is covered with the coil portion 32 and heated so that the thermosetting resin is completely cured. At this time, the re-pressure molding is performed at a pressure of about 3 to 5 ton / cm ² , which is larger than the pressure molding, and the thickness of the green compact 36 after the re-pressure molding than before the re-pressure molding. Is made thinner and the molding density is increased. In particular, there are two green compacts 36, one green compact 36 has a prismatic shape formed with a storage portion 38 that completely stores the coil portion 32, and the other green compact 36 is one green compact. The lead wire 42 of the coil portion 32 protrudes from the interface 40 of the two green compacts 36.

  The terminal portion 34 protrudes from the magnetic core 30 and is bent from the side surface to the bottom surface of the magnetic core 30. The terminal portion 34 overlaps the lead wire 42 and holds the position and shape of the lead wire 42. And a holding portion 44. The holding part 44 is made of a metal flat plate having a self-supporting property capable of supporting the shape of the holding part 44 independently. The self-supporting property here means that the shape of the holding portion 44 superimposed on the bent lead wire 42 is not easily deformed by an external force, and the position of the lead wire 42 with respect to the magnetic core 30 and the lead wire 42. It means having a rigidity that can hold the shape. The holding portion 44 has a rigidity that is at least greater than the rigidity of the lead wire 42.

  The holding portion 44 is provided with a groove portion 46 for housing the lead wire 42 of the coil portion 32 from the side surface to the bottom surface of the magnetic core 30 on the surface opposite to the magnetic core 30 side. In this groove portion 46, a through hole 50 is provided at a position facing the ridge portion 48 between the side surface and the bottom surface of the magnetic core 30, a lead wire 42 is disposed on the through hole 50, and the lead wire is placed on the through hole 50. 42 is bent from the side surface of the magnetic core 30 to the bottom surface.

  The width of the groove portion 46 is wider than the diameter of the lead wire 42, and the opening surface 52 of the groove portion 46 and the outer peripheral surface of the conducting wire are substantially flush with each other. The lead wire 42 is formed on the groove portion 46 by an adhesive. Glued and stored. This adhesion may be temporarily fixed, or may be connected to the land of the mounting substrate by soldering at the time of mounting.

  In addition, the shape of one end 53 of the holding portion 44 is a U-shape in which two protrusions 56 are formed on the end surface 54, and a corner 58 formed between the protrusion 56 and the end surface 54 is circular. The end portion 53 is embedded in the magnetic core 30 so as to surround the outer edge portion of the coil portion 32 with the end face 54 and the protruding portion 56. In particular, the protruding portion 56 is embedded on the upper surface side of the magnetic core 30 and is disposed at the corner portion 60 of the magnetic core 30, and the end surface 54 is embedded on the side surface side of the magnetic core 30. A notch 62 is provided at the center of the end face 54, and a protrusion 64 is provided in the protrusion 56 in a direction perpendicular to the embedding direction, and the lead wire 42 is bent at a position facing the notch 62.

  Furthermore, the cross-sectional shape of the conducting wire 66 is made substantially hexagonal so that the conducting wires 66 are brought into close contact with each other as shown in FIG. Each conductive wire 66 is a self-bonding wire.

  With the above configuration, the coil part 32 is made of powdered magnetic material, covered with an insulating film, embedded in the magnetic core 30 formed by mixing and bonding a binder, and therefore the magnetic core 30 can be formed without using an adhesive. It can form and can improve heat resistance.

  The terminal portion 34 includes a lead wire 42 of the coil portion 32 that is bent from the magnetic core 30 and a holding portion 44 that holds the position and shape of the lead wire 42 so as to overlap the lead wire 42. Therefore, the position and shape of the lead wire 42 of the coil portion 32 bent by the holding portion 44 can be held, and the lead wire 42 itself can be used as the terminal portion 34.

  As a result, it is not necessary to tie the lead wire 42 to the terminal portion 34, the disconnection of the lead wire 42 can be suppressed and the reliability can be improved, and the thickness of the coil portion 32 can be increased in order to increase the number of turns of the coil portion 32. Even if the wire diameter of the coil portion 32 is reduced or the wire diameter of the coil portion 32 is reduced, the lead wire 42 itself becomes easily bent or becomes independent, thereby suppressing the disconnection of the lead wire 42 of the coil portion 32 and improving reliability. it can.

  In particular, between the adjacent conductors 66 of the coil portion 32, the cross-sectional shape of the conductors 66 is made substantially hexagonal so that the conductors 66 are brought into close contact with each other without interposing a powder of magnetic material. It is possible to suppress the generation of magnetic flux so as to circulate, and to efficiently generate the magnetic flux over the entire coil portion 32, thereby increasing inductance and reducing variation in inductance. Since the conducting wire 66 of the coil portion 32 is a self-bonding wire, more effects can be obtained.

  Further, since one of the green compacts 36 forming the magnetic core 30 is formed with a storage portion 38 for storing the coil portion 32, when the green compact 36 is re-press molded, The applied pressure makes it difficult for the magnetic material powder to enter between the adjacent conductors 66 of the coil portion 32, and the conductors 66 can be brought into close contact with each other without interposing the magnetic material powder. One green compact 35 has a prismatic shape in which a storage portion 38 that completely stores the coil portion 32 is formed, and the other green compact 36 has a lid shape that covers one green compact 36. More effects can be obtained.

  Furthermore, if the lead wire 42 protrudes from the interface 40 of the two green compacts 36, it is possible to prevent the magnetic core 30 near the lead wire 42 from being cracked or chipped.

  As described above, since the coil component according to the present invention can improve heat resistance and reliability, it can be applied to various electronic devices and communication devices.

The disassembled perspective view of the coil components in one embodiment of this invention An exploded perspective view of the magnetic core of the coil component An enlarged perspective view of a terminal portion connected to a coil of the same coil component Perspective view of the coil component Cross-sectional view of the coil component The expanded sectional view of the coil of the same coil components equivalent to the A section of FIG. 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 A perspective view of a conventional coil component used for the power supply unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 Magnetic core 32 Coil part 34 Terminal part 36 Green compact 38 Storage part 40 Interface 42 Lead line 44 Holding part 46 Groove part 48 Ridge part 50 Through-hole 52 Opening surface 53 End part 54 End surface 56 Projection part 58 Corner part 60 Corner part 62 Notch Part 64 Convex part 66 Conductor

Claims (5)

Magnetic material is powdered, the surface is covered with an insulating film, a binder is mixed and pressure-molded, a magnetic core is formed by winding a conductive wire in a spiral, and the coil is embedded in the magnetic core. And the cross-sectional shape of the conductor is substantially hexagonal so that the conductors are in close contact with each other without interposing the powder of the magnetic material between the adjacent conductors of the coil. Coil parts. The coil component according to claim 1, wherein the conductive wire of the coil is a self-bonding wire. The magnetic core sandwiches the coil portion with a plurality of green compacts obtained by mixing and molding a binder containing a thermosetting resin and magnetic powder in a non-heated state where the thermosetting resin is not completely cured. In such a manner, the coil portion is covered with the green compact and heated so that the thermosetting resin is completely cured, and one of the green compacts includes: The coil component according to claim 1, wherein a storage portion for storing the coil is formed. The number of the green compacts is two, one green compact has a prismatic shape with a storage part for completely storing the coil, and the other green compact has a lid-like shape that covers one green compact. The coil component according to claim 3. The terminal portion includes a lead wire of the coil that is bent from the magnetic core and a holding portion that overlaps the lead wire and holds the position and shape of the lead wire. The coil component according to claim 4, wherein the coil component is protruded from an interface of the individual green compacts.

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