CN201364804Y - Inductor and core thereof - Google Patents

Abstract

The utility model relates to an inductor and core thereof, the core contains recess and wire winding portion, the recess passes through in the direction of spool wire winding portion, wherein the core perpendicular to the cross section of spool wire winding portion, the sectional area of recess occupies about one third to half of the area of cross section.

Description

Inductor and its core

technical field

The utility model relates to an inductor and its core, in particular to a core suitable for high-frequency and low-frequency applications and an inductor using the core.

Background technique

Inductors consist of a conductive material surrounding a core. Generally, the conductive material is copper wire, and the core can be made of ferromagnetic material. In addition, the core can further be an air core, and the conductive material and the core are combined into an air core coil. Compared with the air-core coil, the core made of ferromagnetic material can effectively confine the magnetic force lines close to the core, thereby increasing the inductance, so as to manufacture an inductor with small size and high inductance.

Increasing the operating frequency to reduce the size of the inductor is a well-known technique, which can be used to manufacture inductors that meet the needs of increasingly compact electronic products. However, when the frequency of use increases, the core made of ferromagnetic materials will produce significant iron loss (iron loss), and most ferromagnetic materials will produce considerable loss when the frequency exceeds 100MHz, so increasing the frequency brings The loss limits the extent of its volume reduction.

Under the same inductance, the air-core coil needs larger and/or more coil turns, which will increase the volume of the air-core coil. However, in addition to no iron loss at high frequencies, the air-core part also has a better quality factor (Q factor; Q) and higher efficiency, and the air-core coil can be designed to operate at frequencies up to 1GHz. Therefore, under the condition of high frequency and no high inductance, the air core coil is usually the first choice for design.

In the face of high-frequency requirements, most of the research and development of inductors are focused on improving the characteristics of ferromagnetic materials, so that they can reduce eddy current losses in high-frequency applications, so that they can increase the range of their frequency of use, and In this way, the volume of the inductor is further reduced. However, these attempts to improve ferromagnetic materials have so far met with limited success. So far, there is still no inductor using a ferromagnetic material as the core that can have the excellent characteristics of no core loss at high frequencies like the air-core coil.

To sum up, since the core of the inductor will produce significant iron loss at high frequency, and there is still no effective solution to the problem, so far there is still no inductor that can simultaneously have high inductance at low frequency operation, And it has the characteristics of low loss and high Q value when operating at high frequency.

Utility model content

The utility model discloses a core and an inductor using the core. The core includes a hollow core, so that the core has a higher inductance when operating at a low frequency, and because the hollow core Therefore, the core can have low loss performance when operating at high frequency.

An embodiment of the utility model discloses a core part, the core part includes a groove and a winding part, the groove passes through the winding part in the direction of the winding axis, wherein the core part is perpendicular to the The cross-section of the winding shaft, the cross-sectional area of the groove accounts for about one-third to one-half of the area of the cross-section.

An embodiment of the present invention discloses an inductor, which includes the aforementioned core and a coil, wherein the coil is disposed on a winding portion of the core.

Description of drawings

Fig. 1 is a three-dimensional schematic diagram of an inductor according to an embodiment of the present invention;

Fig. 2 is a three-dimensional schematic view of the core of an embodiment of the present invention;

Fig. 3 is a schematic sectional view of Fig. 2 along the A-A section line;

Fig. 4 is a three-dimensional schematic view of the core of another embodiment of the present invention; and

Fig. 5 is a three-dimensional schematic view of the core of another embodiment of the present invention.

Detailed ways

FIG. 1 is a three-dimensional schematic diagram of an inductor 10 according to an embodiment of the present invention. The inductor 10 disclosed in the present invention includes a core 11 , a coil 12 and a shield 13 . A coil 12 is wound on the core 11 , and a shield 13 for providing shielding and concentrating the magnetic field is disposed around the coil 12 . The inductor 10 can be fixed by surface mount technology (SurfaceMount Technology; SMT), so one surface 17 of the inductor 10 can be provided with a recess 18 for accommodating the coil 12 . The coil 12 can be fixed on the circuit substrate without interfering with the inductor 10 by using the concave portion 18 . On the same surface 17, a plurality of solder pads 16 for surface mounting can be provided. The end portions of the coil 12 are connected to corresponding pads 16 whereby an external power source drives the inductor 10 .

FIG. 2 is a schematic perspective view of the core 11 according to an embodiment of the present invention. Referring to FIG. 1 and FIG. 2 , the core part 11 disclosed by the utility model includes a winding part 14 and a groove 15 . The winding portion 14 is where the coil 12 wraps around the core 11 , and the groove 15 passes through the winding portion 14 along the direction of the winding axis 19 . The length L ₂ of the groove 15 is longer than the length L ₁ of the winding portion 14 along the winding shaft 19, which can ensure that when the coil 12 surrounds the core 11, it can surround the hollow portion in the groove 15, thereby making all The hollow portion becomes a part of the core 11 around which the coil 12 surrounds. In an embodiment of the present invention, the groove 15 may be disposed on the opposite surface to the surface 17 having the solder pad 16 . The groove 15 can extend to two opposite ends 20 of the core 11 in the direction of the winding axis 19 as shown in FIG. 2 .

FIG. 3 is a schematic cross-sectional view of FIG. 2 along the cut plane line AA. Referring to Fig. 2 and Fig. 3, in the scope of the length L of winding part ₁₄ , perpendicular to the cross section 24 of winding shaft 19, the cross-sectional area of groove 15 accounts for about 1/3rd to two of the area of cross section 24. Therefore, the core 11 disclosed in the present invention can be regarded as a composite core combining high magnetic permeability and low magnetic permeability. Since the winding part 14 is made of magnetically permeable material, the magnetic field lines generated by the coil 12 can be concentrated, thereby increasing the inductance of the inductor 10 . And the coil 12 also surrounds the air core (aircore) formed by the groove 15 at the same time, so that the inductor 10 also has the good high-frequency performance that the air-core coil possesses, so the core 11 disclosed by the utility model can operate at low frequencies. Operates with high inductance and low loss and high Q at high frequency operation. In this embodiment, the magnetic permeability of the winding portion 14 may be between 60 and 400. The winding portion 14 can be made of ferrites, nickel-zinc ferrite, molybdenum-beryllium molybdenum powdered iron core, manganese-zinc ferrite or nickel-copper-zinc ferrite. In this case embodiment, although the shape of the cross-section 24 of the core 11 is square, the technology disclosed in the utility model is not limited thereto, and the shape of the cross-section 24 of the core 11 can also be a polygon, a circle or an ellipse wait. In this embodiment, although the cross-sectional shape of the groove 15 is also square, it can also be in other shapes, such as polygonal, circular or elliptical. The shape of the cross-section 24 of the core 11 and the cross-sectional shape of the groove 15 may be the same as shown in FIG. 3 , or they may be different. For example, the shape of the cross-section 24 of the core 11 is a square, and the shape of the cross-section of the groove 15 is a circle and other different combinations.

Fig. 4 is a schematic perspective view of a core 11' according to another embodiment of the present invention. Referring to Fig. 1 and Fig. 4, the core part 11' includes the winding part 14 and the groove 15'. The winding portion 14 is where the coil 12 wraps around the core portion 11'. The groove 15 ′ passes through the winding portion 14 in the direction of the winding axis 19 . The length L ₂ of the groove 15' is longer than the length L ₁ of the winding part 14 along the winding shaft 19, so that when the coil 12 surrounds the core 11', it can also surround the hollow part in the groove 15', And make the hollow part a part surrounded by the coil 12 . On the two side walls 21 of the groove 15', a recess 22 can be provided near the opening, whereby the 15' can surround the magnetic field in the direction of the winding shaft 19 in the core 11'. The groove 15' can pass through two opposite ends 20 of the core 11' through two channels 23 according to the direction of the winding shaft 19.

Fig. 5 is a three-dimensional schematic diagram of a core 11" according to another embodiment of the present invention. Referring to Fig. 1 and Fig. 5, the core 11" includes a winding portion 14 and a groove 15'. The winding portion 14 is where the coil 12 surrounds the core 11″, and the groove 15′ passes through the winding portion ₁₄ in the direction of the winding shaft 19. The length L of the groove 15′ is the same as that of the winding portion 14 along the winding shaft 19. The length L ₁ is relatively large, so that when the coil 12 surrounds the core 11 ″, it can also surround the hollow part in the groove 15 ′, and make the hollow part become a part surrounded by the coil 12 .

The utility model utilizes an air core with a cross-sectional area of about one-third to one-half in the core, so that the core has a wider application frequency, thereby extending the use of the inductor using the core scope.

The technical content and technical features of the present utility model have been disclosed above, but those skilled in the art may still make various replacements and modifications based on the teaching and disclosure of the present utility model without departing from the spirit of the present utility model. Therefore, the protection scope of the utility model should not be limited to the contents disclosed in the embodiments, but should include various replacements and modifications that do not depart from the utility model, and are covered by the appended claims.

Claims (12)

1. A core comprising a groove and a winding portion, characterized in that the groove passes through the winding portion in the direction of the winding axis, wherein the core is perpendicular to the winding In the cross-section of the bobbin, the cross-sectional area of the groove accounts for about one-third to one-half of the cross-sectional area. 2. The core according to claim 1, wherein said groove extends to two opposite ends of said core in the direction of said winding axis. 3 . The core according to claim 1 , wherein the groove passes through two opposite ends of the core in two channels in the direction of the winding axis. 4 . 4. The core according to any one of claims 1 to 3, wherein the magnetic permeability of the winding part is between 60 and 400. 5. The core according to claim 1, characterized in that it further comprises a plurality of solder pads for surface mount technology, said solder pads being provided on the surface with recesses for accommodating wound coils. 6. The core according to claim 1, wherein the length of the groove along the direction of the winding axis and between two opposite ends of the core is longer than that of the winding portion along The length in the direction of the winding axis. 7. An inductor, characterized in that it comprises: a core, the core comprising a groove and a winding portion, the groove passing through the winding portion in the direction of the winding axis, wherein the core is perpendicular to the cross-section of the winding axis, the groove the groove has a cross-sectional area between about one-third and one-half of the cross-sectional area; and The coil is arranged on the winding part. 8. The inductor according to claim 7, wherein said groove extends to two opposite ends of said core in the direction of said winding axis. 9 . The inductor according to claim 7 , wherein the groove passes through two opposite ends of the core in two channels in the direction of the winding axis. 10. The inductor according to any one of claims 7 to 9, wherein the magnetic permeability of the winding part is between 60 and 400. 11. The inductor according to claim 7, characterized in that it further comprises a plurality of soldering pads for surface mount technology, said soldering pads being provided on the surface having a recess for accommodating said coil. 12. The inductor according to claim 7, wherein the length of the groove along the direction of the winding axis and between the two opposite ends of the core is greater than that of the winding portion along The length in the direction of the winding axis.

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