Conical inductor and manufacturing method of them

Abstract

To achieve a conical inductor of which microminiaturization can be easily made, and which can be corresponded to a SMD.SOLUTION: A conical inductor 32 is formed by winding one lead wire 28 to a bobbin 10 having a truncated-cone part 12, a column type end part 14, a support leg part 16, and a prism shape end part 18. When the column type end part 14 and the prism shape end part 18 are mounted onto a flat surface 24, a shape and a dimension of the bobbin 10 are set so that a center line α of the truncated-cone part 12 is crossed at a required angle to the flat surface 24. A first tangling part 30 is formed by tangling a lead wire 28 to the column type end part 14. A truncated-cone coil part 34 is formed so as to be wound in a concentric circular along the truncated-cone part 12. By tangling and winding it to the prism shape end part 18, a second tangling part 36 is formed. By executing a solder dip to the first tangling part 30 and the second tangling part 36, a first terminal part 40 and a second terminal part 42 are formed.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a conical inductor, and more particularly to a conical inductor that can be made extremely compact so that it can be built into an optical communication module or the like. [Background technology]

[0002] Currently, chip inductors used as noise filters in communication devices such as smartphones have a fixed inductance value and only operate near a frequency known as the resonant frequency, which is generally set to less than 10 GHz. In contrast, for ultra-high-speed, large-capacity optical communications that handle large amounts of information, and for next-generation 6G communications, it will be necessary to operate in frequency bands of 10 GHz or higher.

[0003] On the other hand, conical inductors (conical coils) with a conical shape have the characteristic that they operate at low frequencies because the inductance value is large in the large diameter part, and operate at high frequencies because the inductance value is small at the apex of the cone with a small diameter, and have the advantage that they can operate seamlessly from low to high frequencies as a whole. Conical inductors also have the characteristic that they are easy to reduce parasitic capacitance (floating capacitance). For this reason, conical inductors are expected to be used in communication applications that require stable operation over a wide frequency band. [Patent Document 1] Patent Publication No. 4-137507 [Patent Document 2] Patent Publication No. 2008-047711 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conical inductors have a bulky conical shape, which makes it difficult to reduce the size of the inductor, and also makes it difficult to surface mount the inductor. In other words, to incorporate it into an optical communications module, the overall length of the conical inductor itself (the dimension from the apex to the base of the cone) needs to be kept to 1 mm or less; however, winding a very thin, flexible lead wire into a cone shape within this dimension and providing terminals on both ends is in itself a difficult task. Furthermore, in order to fully utilize its function as a conical inductor, it needs to be mounted at a specified angle to the circuit board, but it is not easy to connect both ends to the circuit board while accurately maintaining this angle.

[0005] For example, the following Non-Patent Document 1 discloses a wideband conical inductor, but even the shortest one (model number: CC20T44K240G5-C) has a total length of 1.524 mm (0.060 in) including the outer case, and the conical inductor alone is well over 1 mm, making it not only bulky overall, but also difficult to achieve a stable installation angle because the method involves creating an air-core conical inductor and then fixing lead wires of a specified length with a resin wall through molding. Additionally, because the air-core coil wire is not fixed, it must be said that it is also difficult to achieve a stable gap between the wires. [Non-Patent Document 1] Micro SMT Broadband Conical Inductors / Internet URL: https: / / www.piconics.com / wp-content / uploads / 2021 / 03 / Micro-SMT-Broadband-Conical-data-sheet.pdf / Retrieved on: June 30, 2023

[0006] The present invention has been devised in view of the above circumstances, and has as its object to provide a conical inductor that can be easily miniaturized and is also compatible with SMD. [Means for solving the problem]

[0007] In order to achieve the above object, the conical inductor described in claim 1 is a conical inductor formed by winding one lead wire around a bobbin having a truncated cone portion, a first installation end portion connected to the top surface of the truncated cone portion, a support leg portion connected to the bottom surface of the truncated cone portion, and a second installation end portion connected to the lower end of the support leg, wherein the shape and dimensions of the bobbin are set so that when the first installation end portion and the second installation end portion are placed on a flat surface, the center line of the truncated cone portion intersects with the flat surface at a required angle (for example, in the range of 30 to 60 degrees), the lead wire is wound around the first installation end portion to form a first winding portion, the lead wire is wound concentrically around the truncated cone portion to form a conical coil portion, the lead wire is wound around the second installation end portion to form a second winding portion, and the first terminal portion and the second terminal portion are formed by applying solder dipping to the first winding portion and the second winding portion.

[0008] The conical inductor of claim 2 is the conical inductor of claim 1, characterized in that the shape and dimensions of the bobbin are set so that the conical inductor can stand on its own when the first installation end and the second installation end are placed on a flat surface.

[0009] The conical inductor of claim 3 is the conical inductor of claim 1 or 2, characterized in that it comprises a cap that houses the conical coil portion, and the first terminal portion and the second terminal portion are exposed to an opening surface of the cap.

[0010] The conical inductor described in claim 4 is a conical inductor according to claim 1 or 2, characterized in that a flange portion is formed between the top surface of the truncated cone portion and the first installation end portion to prevent solder from flowing into the conical coil portion.

[0011] The conical inductor described in claim 5 is a conical inductor according to claim 1 or 2, characterized in that the dimension between the top and bottom surfaces of the truncated cone portion of the bobbin is 1 mm or less, and the diameter of the lead wire is 30 μm or less.

[0012] A method for producing a conical inductor according to claim 6 is a method for producing a conical inductor by winding one lead wire around a bobbin having a truncated cone portion, a first installation end portion connected to a top surface of the truncated cone portion, a support leg portion connected to a bottom surface of the truncated cone portion, and a second installation end portion connected to a lower end of the support leg, the bobbin having a shape and dimensions set so that when the first installation end portion and the second installation end portion are placed on a flat surface, the center line of the truncated cone portion intersects with the flat surface at a required angle. The method includes the steps of: forming a first entangled portion by entanglement of the lead wire at a first installation end; forming a conical coil portion by concentrically winding the lead wire around a truncated cone portion; forming a second entangled portion by entanglement of the lead wire at a second installation end; and forming a first terminal portion and a second terminal portion by applying solder dipping to the first entangled portion and the second entangled portion. Effect of the Invention

[0013] The conical inductor of the present invention has a structure in which, by simply winding a single lead wire around a bobbin as a core material having a first installation end, a truncated cone portion, a support leg portion, and a second installation end as an integral part, in addition to the conical coil portion, a first entangled portion and a second entangled portion that form the base of the terminal portion are formed, making it possible to easily realize an ultra-compact conical inductor using an extremely thin, flexible lead wire. In addition, the bobbin is configured so that when placed on a flat surface, the truncated cone portion forms the required angle with respect to the installation surface. This has the advantage that, simply by winding the lead wire and then placing it on the circuit board, a conical coil portion that is inclined at the required angle is naturally obtained. Furthermore, the first terminal portion and the second terminal portion can be formed simply by dipping the first and second winding portions in solder, thereby achieving compatibility with SMD (Surface Mount Device). [Brief description of the drawings]

[0014] [Figure 1] 1 is a perspective view showing the front side of a bobbin that serves as a core material of a conical inductor. [Diagram 2] FIG. 2 is a perspective view showing the rear side of the bobbin. [Diagram 3] FIG. [Figure 4] This is a photograph showing how a lead wire is wound around a bobbin using a flyer-type winding machine. [Diagram 5] This is a photograph showing how the winding method of the lead wire is changed to match the shape and angle of each part of the bobbin. [Figure 6] FIG. 2 is a side view showing a conical inductor immediately after winding. [Figure 7] 13 is a photograph showing a conical inductor with a terminal portion formed thereon. [Figure 8] FIG. 2 is a side view showing a state in which the conical inductor is connected to a circuit board. [Figure 9] 1 is a partial cross-sectional side view showing a state in which a conical inductor with a cap attached is connected to a circuit board. [Figure 10] 13 is a photograph showing the open surface of a conical inductor with a cap attached. BEST MODE FOR CARRYING OUT THEINVENTION

[0015] The configuration of a conical inductor according to the present invention will now be described with reference to the accompanying drawings. Figures 1 and 2 show a bobbin 10 which serves as the core material of a conical inductor, and which comprises a truncated cone portion 12, a cylindrical end portion 14 serving as a first installation end portion connected to the top surface of the truncated cone portion 12, a support leg portion 16 connected to the bottom surface of the truncated cone portion 12, a rectangular columnar end portion 18 serving as a second installation end portion connected to the lower end of the support leg portion 16, and a cylindrical rod portion 20 connected to the back surface of the support leg portion 16. A flat flange portion 22 is formed between the cylindrical end portion 14 and the truncated cone portion 12 .

[0016] As shown in Figure 3, when the bobbin 10 is placed on a plane 24, the lower end surface of the cylindrical end portion 14, the lower end surface of the flange portion 22, and the lower end surface of the rectangular columnar end portion 18 are flush with each other, and a predetermined gap G is formed between the bottom surface of the truncated cone portion 12 and the plane 24. At this point, a predetermined angle X (for example, 40 degrees) is formed between the center line α of the truncated cone portion 12 (a straight line passing through the center point of the top surface and the center point of the bottom surface of the truncated cone portion 12) and the plane 24.

[0017] In order to achieve such a posture of the bobbin 10, the angle Y between the cylindrical end 14 and the truncated cone portion 12, the angle Z between the support leg 16 and the rectangular columnar end 18, and the length dimension of the support leg 16 are set.

[0018] As described above, the lower end surface of flange portion 22 is flush with the lower end surface of cylindrical end portion 14 and the lower end surface of rectangular columnar end portion 18, but the shape and dimensions are set so that the upper end surface protrudes above the upper end surface of cylindrical end portion 14.

[0019] The bobbin 10 is molded as a single unit by injecting a resin material such as a liquid crystal polymer into a mold, so that the shapes, dimensions, and angles of the above-mentioned components can be stably reproduced during mass production.

[0020] An extremely fine lead wire (for example, a polyurethane copper wire having a diameter of 20 μm) is wound around this bobbin 10 using a flyer-type winding machine. That is, as shown in FIG. 4, rod portion 20 of bobbin 10 is fitted and fixed into jig 27 made of a stainless steel pipe, and then while nozzle 26 of the winding machine is rotated around bobbin 10, one lead wire 28 unwound from the tip is continuously wound around cylindrical end 14, truncated cone portion 12, support leg 16, and rectangular columnar end 18 of bobbin 10.

[0021] At this time, as shown in FIG. 5, the winding machine changes the winding method of the lead wire 28 in accordance with the shape and angle of each part of the bobbin 10. That is, when winding the lead wire 28 around the cylindrical end portion 14 where the winding begins (FIG. 5(a)), the first entangled portion 30 is formed by winding the subsequent lead wire 28 in a cross shape so as to overlap the previously wound lead wire 28. Next, the lead wire 28 is wound concentrically around the truncated cone portion 12 of the bobbin 10 (FIG. 5(b)), thereby forming the conical coil portion 34 of the conical inductor 32. Next, when the lead wire 28 is wound around the rectangular columnar end 18 via the support leg 16 of the bobbin 10 (Figure 5(c)), the subsequent lead wire 28 is also wound crosswise so as to overlap the previously wound lead wire 28, thereby forming a second entangled portion 36.

[0022] The winding direction of nozzle 26 of the winding machine can be changed back and forth and left and right by operating an XY stage (not shown), and the angle of jig 27 can also be changed as needed, so that the winding method of lead wire 28 can be changed according to the shape, dimensions, and angle of each part of bobbin 10, as described above. Since it is only necessary to wind a single lead wire 28 around the bobbin 10 as a core material having the cylindrical end 14, the conical truncated cone portion 12, the support leg 16, and the rectangular columnar end 18 as an integral part, it is possible to form the conical inductor 32 using an extremely thin lead wire 28 that has no stiffness and lacks shape stability (when the lead wire diameter is 30 μm or less, the wire itself loses stiffness, so that in an air-core coil, even if it can be wound into a coil shape, it becomes difficult to maintain the coil shape).

[0023] FIG. 6 shows a conical inductor 32 immediately after winding, with a first entangled portion 30 formed at the cylindrical end 14 at the front end, a conical coil portion 34 formed in the truncated cone portion 12, and a second entangled portion 36 formed at the rectangular columnar end 18 at the rear end. In this way, the first entanglement portion 30 and the second entanglement portion 36 are formed at both ends of the conical inductor 32, and the lead wire 28 is firmly fastened to the bobbin 10, thereby effectively preventing the lead wire 28 from coming undone during use.

[0024] As shown in FIG. 7, the first terminal portion 40 and the second terminal portion 42 are easily formed by applying solder dipping to the first entangled portion 30 and the second entangled portion 36. At this time, the flange portion 22 functions as a barrier to prevent the solder from coming into contact with the conical coil portion 34 .

[0025] Thereafter, the bobbin 10 is removed from the jig 27 of the winding machine, thereby completing the conical inductor 32 as shown in FIG. The conical inductor 32 is electrically connected onto a circuit board 44 via a first terminal portion 40 and a second terminal portion 42 . Although the contact area between the cylindrical end 14 and the flange 22 and the circuit board 44 is relatively small, the contact area of ​​the rectangular columnar end 18 is ensured to be sufficiently wide, so that the conical inductor 32 can stand stably on the circuit board 44. This makes it possible to support high-density surface mounting.

[0026] As shown in FIG. 9, the conical inductor 32 can be fitted with a resin cap 46 . Reference numeral 48 in the drawing denotes a silicone adhesive interposed between the conical inductor 32 and the cap 46 .

[0027] FIG. 10 is an enlarged photograph (magnification: ×200.0) of the conical inductor 32 with the cap 46 attached, taken from the open side of the cap 46, showing that the first terminal portion 40 and the second terminal portion 42 of the conical inductor 32 are exposed. As shown in the figure, the dimensions of the cap 46 are only 0.8 mm in length and 1.2 mm in width, and the dimensions of the conical coil portion 34 of the conical inductor 32 are also approximately 0.6 mm, which is significantly less than 1 mm.

[0028] Since providing a larger diameter entanglement portion at the tip side (smaller diameter side) of the conical coil portion 34 of the conical inductor 32 can adversely affect the characteristics of the inductor, it is desirable to set the diameter of the cylindrical end portion 14 smaller than the diameter of the tip portion of the conical coil portion 34. However, the shape is not limited to a cylindrical shape, and a prismatic end may be provided in place of the cylindrical end 14, and the lead wire 28 may be wound around this to form the first winding portion 30.

[0029] The cross-sectional shape of the lead wire 28 is not limited to a perfect circle. For example, the wiring resistance can be reduced by using a lead wire having an elliptical or rectangular cross-sectional shape. [Explanation of symbols]

[0030] 10 Bobbin 12 Cone truncated part 14 Cylindrical End 16 Support legs 18 Prismatic End 20 Rod section 22 Flange 24 plane 26 Nozzles 27 Jig 28 Lead Wire 30 First entanglement 32 Conical inductor 34 Conical coil section 36 Second entanglement 40 First terminal part 42 Second terminal part 44 Circuit Board 46 Cap 48 Adhesive

Claims

1. A conical inductor formed by winding one lead wire around a bobbin having a truncated cone portion, a first installation end portion connected to a top surface of the truncated cone portion, a support leg portion connected to a bottom surface of the truncated cone portion, and a second installation end portion connected to a lower end of the support leg portion, The shape and dimensions of the bobbin are set so that, when the first installation end and the second installation end are placed on a plane, the center line of the truncated cone portion intersects with the plane at a required angle; The lead wire is wound around the first installation end to form a first winding portion, and wound concentrically around the truncated cone portion to form a conical coil portion, and wound around the second installation end to form a second winding portion, A conical inductor, comprising: a first terminal portion and a second terminal portion formed by applying solder dipping to a first intertwining portion and a second intertwining portion.

2. 2. The conical inductor according to claim 1, wherein the shape and dimensions of the bobbin are set so that the conical inductor is self-supporting when the first installation end and the second installation end are placed on a flat surface.

3. A cap is provided to house the conical coil portion, 3. The conical inductor according to claim 1, wherein the first terminal portion and the second terminal portion are exposed at an opening surface of the cap.

4. 3. A conical inductor as described in claim 1 or 2, characterized in that a flange portion is formed between the top surface of the truncated cone portion and the first installation end portion to prevent solder from flowing into the conical coil portion.

5. The dimension between the top and bottom surfaces of the truncated cone portion of the bobbin is 1 mm or less, 3. A conical inductor according to claim 1, wherein the diameter of the lead wire is 30 μm or less.

6. A method for manufacturing a conical inductor by winding one lead wire around a bobbin having a truncated cone portion, a first installation end portion connected to a top surface of the truncated cone portion, a support leg portion connected to a bottom surface of the truncated cone portion, and a second installation end portion connected to a lower end of the support leg, the bobbin having a shape and dimensions set so that when the first installation end portion and the second installation end portion are placed on a flat surface, the center line of the truncated cone portion intersects with the flat surface at a required angle, forming a first coil by coiling the lead wire at a first installation end; forming a conical coil portion by concentrically winding the lead wire around a truncated cone portion; forming a second coil by coiling the lead wire at a second installation end; forming a first terminal portion and a second terminal portion by performing solder dipping on the first and second entangled portions; A method for manufacturing a conical inductor comprising the steps of:

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