JP3122320U - Wire wound inductor - Google Patents

Abstract

The present invention provides a wound inductor that does not deteriorate characteristics in a high frequency band.
A conductive wire 16 in which an insulating film 14 is formed on the surface of a copper wire 12 is wound around the outer peripheral surface of a winding portion 20 of a conical core 18 made of a magnetic material such as dielectric ceramic or ferrite. Further, a connection terminal 22 formed by exposing the copper wire 12 to both ends of the conductive wire 16 is provided, and a winding type inductor in which the tip of the connection terminal 22 is formed as a conductor contact portion 22a. The length of the lead wire 16 and the connection terminal 22 from the tip of the lead wire 16 wound around the wire portion 20 to the conductor contact portion 22a is set in a range of 0.4 mm to 0.6 mm. ing.
[Selection] Figure 1

Description

  The present invention relates to a wound inductor used as a choke coil or the like, and more particularly to a wound inductor excellent in broadband characteristics.

The applicant previously proposed Japanese Patent Application Laid-Open No. 2004-6695 as a wound inductor having excellent broadband characteristics.
As shown in FIGS. 8 to 10, the wound inductor 60 includes a conductor 66 in which an insulating film 64 made of a polymer insulating material such as polyester or polyurethane is formed on a surface of a copper wire 62. It is formed by winding around the outer peripheral surface of a winding part 70 of a conical core 68 made of a magnetic material such as.
Further, both ends of the conductive wire 66 are formed with terminal portions 72 by peeling the insulating coating 64 and exposing the copper wire 62.

  As shown in FIG. 8, the wire wound inductor 60 has a conductor 72 constituting a microstrip line for transmitting a high-frequency signal formed on a circuit board with a tip 72a of the terminal portion 72 formed by exposing a copper wire 62. The pattern 74 is used by being directly connected to the pattern 74 via the solder 76.

  The wound inductor 60 is formed in a conical shape in which the winding portion 70 of the core 68 gradually decreases in diameter from one end (the right end in FIG. 8) to the other end (the left end in FIG. 5). Therefore, the winding diameter of the conducting wire 66 wound around the winding portion 70 gradually decreases from one end (the right end in FIG. 8) to the other end (the left end in FIG. 8).

Thus, in the above-described wound inductor 60, the winding diameter of the conductive wire 66 wound around the winding portion 70 gradually increases from one end (the right end in FIG. 8) to the other end (the left end in FIG. 8). Since it becomes smaller, as shown in the graph of FIG. 11, it has a large number of different self-resonant frequencies continuously over a wide frequency band. It can be used.
JP 2004-6695 A

By the way, the lead wire 66 from the tip end portion of the core 68 on the small diameter side of the lead wire 66 wound around the winding portion 70 of the core 68 of the wire-wound inductor 60 to the tip end portion 72a directly connected to the conductor pattern 74 is provided. When the length L of the terminal portion 72 is small, the wound inductor 60 is deteriorated in characteristics in a high frequency band of 20 GHz or more. This is because the lead wire 66 and the terminal portion 72 of the lead wire 66 wound around the winding portion 70 of the core 68 from the tip end portion on the small diameter side of the core 68 to the tip end portion 72a directly connected to the conductor pattern 74 are arranged. If the length L is too small, the capacitance between the tip of the conductor 68 on the small diameter side of the core 68 and the conductor pattern 74 is increased, which is considered to be caused by a decrease in impedance in the high frequency band.
Further, the length of the conductor 66 and the terminal portion 72 from the tip of the conductor 68 wound around the winding portion 70 of the core 68 on the small diameter side of the core 68 to the tip of the terminal portion 72a directly connected to the conductor pattern 74. Even when the length L is large, the characteristics of the wound inductor 60 are deteriorated in the high frequency band. The reason is considered that the characteristic impedance of the conductor pattern 74 constituting the microstrip line is disturbed.

  The present invention has been devised in view of the above-described problems, and an object of the present invention is to realize a wound inductor that does not cause deterioration of characteristics in a high frequency band.

In order to achieve the above object, in the wound inductor according to the present invention, on the outer peripheral surface of the core having a winding portion formed in a conical shape or a pyramid shape, on the surface of the conductive wire. A wire wound inductor in which a conductive wire formed with an insulating film is wound, and a connection terminal formed by exposing the conductive wire material is provided at both ends of the conductive wire, and the tip of the connection terminal is a conductor contact portion In this case, the length of the lead wire and the connection terminal from the tip portion on the core small diameter side of the lead wire wound around the core winding portion to the conductor contact portion is set in the range of 0.4 mm to 0.6 mm. It is characterized by being.
The core can be made of a magnetic material such as ferrite.

  In the wire-wound inductor according to the present invention, the length of the conductive wire and the connecting terminal from the leading end portion on the small core side of the conductive wire wound around the winding portion of the core to the conductor contact portion is 0.4 mm to By setting it in the range of 0.6 mm, it is possible to realize a wound inductor that does not deteriorate characteristics in a high frequency band.

  As shown in FIGS. 1 to 3, a wound inductor 10 according to the present invention is made of a polymer insulating material such as polyester or polyurethane on the surface of a copper wire 12 (see FIGS. 2 and 3) as a conductive wire. A conductive wire 16 on which an insulating coating 14 is formed is wound around the outer peripheral surface of a winding portion 20 of a conical core 18 made of a magnetic material such as dielectric ceramic or ferrite.

Further, connection terminals 22 formed by peeling the insulating coating 14 by a predetermined length and exposing the copper wire 12 are provided at both ends of the conductive wire 16. The tip of the connection terminal 22 is formed as a conductor contact portion 22a that is directly connected via a solder 26 to a conductor pattern 24 constituting a microstrip line that transmits a high-frequency signal formed on a circuit board.
In the wound inductor 10 according to the present invention, the conductor 16 and the connection terminal 22 of the conductor 16 wound around the winding portion 20 of the core 18 from the tip of the core 18 on the small diameter side to the conductor contact portion 22a. The length L is set in the range of 0.4 mm to 0.6 mm. The length of the conductor contact portion 22a of the connection terminal 22 is about 0.2 mm.
Note that the dimensions of the wound inductor 10 of the present invention are, for example, that the maximum diameter of the winding portion 20 of the core 18 is 1 mm, the length is 2 mm, and the diameter of the conductor 16 is 0.05 mm.

  As described above, in the wound inductor 10 of the present invention, the diameter of the winding portion 20 of the core 18 gradually decreases from one end (the right end in FIG. 1) to the other end (the left end in FIG. 1). Since it has a conical shape, the winding diameter of the conducting wire 16 wound around the winding portion 20 also gradually decreases from one end (the right end in FIG. 1) to the other end (the left end in FIG. 1). To go.

  Thus, in the wound inductor 10 of the present invention, the winding diameter of the conducting wire 16 wound around the winding portion 20 is from one end (the right end in FIG. 1) to the other end (the left end in FIG. 1). Since it gradually decreases, as shown in the graph of FIG. 4, it has a number of different self-resonant frequencies continuously over a wide frequency band. It can be used in a wide band.

  Thus, in the above-described wound inductor 10 of the present invention, the lead wire 16 extending from the tip end portion on the small diameter side of the core 18 of the lead wire 16 wound around the winding portion 20 of the core 18 to the conductor contact portion 22a. And, by setting the length L of the connection terminal 22 in the range of 0.4 mm to 0.6 mm, it is possible to realize a wound inductor that does not cause characteristic deterioration in the high frequency band.

Results of experiments conducted by the inventors are shown in FIGS. FIG. 5 is a graph showing the isolation characteristics when the length L of the conductor 16 and the connection terminal 22 from the tip of the conductor 18 on the small diameter side of the core 18 to the conductor contact portion 22a is 0.2 mm, and FIG. FIG. 7 is a graph showing the isolation characteristics when the length L of the lead wire 16 and the connecting terminal 22 from the tip of the core 18 on the small diameter side to the conductor contact portion 22a is 1.0 mm. 6 is a graph showing the isolation characteristics when the length L of the lead wire 16 and the connection terminal 22 from the tip of the core 18 on the small diameter side to the conductor contact portion 22a is 0.5 mm.
As shown in the graph of FIG. 5, when L is 0.2 mm, the isolation characteristic deteriorates when the frequency exceeds 10 GHz, and -20 dB cannot be maintained. Further, as shown in the graph of FIG. 6, when L is 1.0 mm, the isolation characteristic deteriorates when the frequency exceeds 10 GHz, and -20 dB cannot be maintained.
On the other hand, when L is 0.5 mm as in the present invention, good isolation characteristics of about −20 dB can be obtained even when the frequency exceeds 40 GHz, as shown in the graph of FIG.

  Note that the shape of the winding portion 20 of the core 18 is not limited to the above-described conical shape, and may be a pyramid shape.

  When the core 18 is made of a magnetic material such as ferrite, the magnetic permeability increases, so that a large insertion loss is obtained, and frequency characteristics such as isolation characteristics are improved.

1 is a front view of a wire wound inductor according to the present invention. It is CC sectional drawing of FIG. It is DD expanded sectional drawing of FIG. It is a graph which shows the impedance characteristic of the winding type inductor of this invention. It is a graph which shows the isolation characteristic in case the length L of the conducting wire and connecting terminal from the front-end | tip part of the core small diameter side of a conducting wire to a conductor contact part is 0.2 mm. It is a graph which shows the isolation characteristic in case the length L of the conducting wire and connecting terminal from the front-end | tip part of the core small diameter side of a conducting wire to a conductor contact part is 1.0 mm. It is a graph which shows the isolation characteristic in case the length L of the conducting wire and connecting terminal from the front-end | tip part of the core small diameter side of a conducting wire to a conductor contact part is 0.5 mm. It is a front view of the conventional winding type inductor. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a graph which shows the impedance characteristic of the conventional winding type inductor.

Explanation of symbols

10 Wire wound inductor
12 Copper wire
14 Insulation coating
16 conductor
18 core
20 Winding part
22 Connection terminal
22a Conductor contact area
24 Conductor pattern

Claims (2)

  A conducting wire formed by forming an insulating film on the surface of a conductive wire is wound around the outer peripheral surface of a winding portion of a core having a conical or pyramidal winding portion, and the conductive wire is formed at both ends of the conducting wire. A wire-wound inductor having a connection terminal formed by exposing a conductive wire and having a conductor contact portion as a tip of the connection terminal, the tip on the core small-diameter side of a conducting wire wound around the core winding portion A wire-wound inductor characterized in that the length of the lead wires and connection terminals from the contact portion to the conductor contact portion is set in a range of 0.4 mm to 0.6 mm. The wound inductor according to claim 1, wherein the core is made of a magnetic material.

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