Inductor

Abstract

The utility model discloses an inductor which comprises a coil and a magnetic base, the magnetic base is used for fixing the coil, two ends of the coil are connected with pins, the inductor further comprises a magnetic covering layer, and the magnetic covering layer is located on the upper surface of the magnetic base and covers the coil located on the magnetic base. The magnetic base comprises a plane layer and at least one protruding layer, the protruding layer is used for wrapping a coil, the side end of the plane layer in the length direction is provided with a notch, the notch is used for enabling a pin to penetrate out, the arranged notch facilitates the pin to penetrate out, the die-cast magnetic base is easier to demould, and the cost of a mould is low.

Description

Technical Field

[0001] The utility model relates to the technical field of inductors, in particular to an inductor. Background Art

[0002] An inductor is an electronic component used to store energy and regulate current. It works on the principle of electromagnetic induction and stores electrical energy by generating a magnetic field in a conductor.

[0003] An inductor is a device used to store energy and regulate current, and works on the principle of electromagnetic induction. It plays a role in stabilizing current and filtering noise in the circuit, and is widely used in various electronic systems and circuits.

[0004] At present, the magnetic base in the inductor is generally formed by die-casting of magnetic powder. The magnetic base needs to reserve holes for the pins to facilitate the pins to pass through and connect with the terminals. However, the reserved holes lead to higher mold costs on the one hand, and on the other hand, the magnetic base is difficult to demold after die-casting. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides an inductor, including a coil and a magnetic base, wherein the magnetic base is used to fix the coil, and pins are connected to both ends of the coil. The utility model also includes a magnetic covering layer, which is located on the upper surface of the magnetic base and covers the coil located on the magnetic base. The magnetic base includes a planar layer and at least one raised layer, and the raised layer is used to wrap the coil. A notch is set at the side end of the planar layer along the length direction, and the notch is used to pass through the pin.

[0006] Preferably, it also includes a terminal, the terminal connecting the pins, and the terminal is attached to the lower surface of the magnetic base.

[0007] Preferably, the coil is spirally wound on the protrusion layer to form one or more layers of coils.

[0008] Preferably, the cross section of the coil is circular, rectangular, polygonal or irregular.

[0009] Preferably, the coil comprises a conductor and an isolation layer, the isolation layer is coated on the surface of the conductor, and the conductor is connected to the pin.

[0010] Preferably, the thickness of the isolation layer is T, and 0.002 mm≦T≦0.5 mm.

[0011] Preferably: the magnetic covering layer comprises a soft magnetic metal material, and the soft magnetic metal material is selected from one of iron-based powder, iron-based amorphous powder, iron-silicon-aluminum alloy powder, iron-silicon alloy powder, iron-nickel alloy powder, nanocrystalline alloy powder, or a combination of two or more of the above materials.

[0012] Preferably, the particle size distribution of the equivalent particle size of the metal particles of the soft magnetic metal material is X, and the corresponding particle size when the cumulative particle size distribution percentage reaches X% is Dx, and Dx≤2*T.

[0013] Preferably, the interval of the cumulative particle size distribution percentage X is 50≤X≤100.

[0014] Preferably, the isolation layer is made of an insulating flexible polymer material, and the insulating flexible polymer material is a polyamide, polyimide or polyether material.

[0015] Technical effects and advantages of the utility model:

[0016] In the utility model, the notch is provided to facilitate the pin to be passed out, the die-cast magnetic base is easier to demould, and the cost of the mold is also low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the structure of an inductor provided in Example 1 of the present application;

[0018] Figure 2 is a schematic diagram of the structure of the coil winding in the inductor provided in the first embodiment of the present application;

[0019] Figure 3 is a longitudinal cross-sectional view of a coil in an inductor provided in Embodiment 1 of the present application wound around a magnetic base;

[0020] Figure 4 is a longitudinal cross-sectional view of the portion of the coil wrapped around the magnetic base in the inductor provided in the first embodiment of the present application;

[0021] Figure 5 It is a front view of the magnetic base in the inductor provided in the first embodiment of the present application;

[0022] Figure 6 is a top view of the magnetic base in the inductor provided in the first embodiment of the present application;

[0023] Figure 7 is a schematic diagram of the structure of a coil in an inductor provided in Example 1 of the present application;

[0024] Figure 8 is a schematic diagram of soft magnetic metal material particles of the magnetic covering layer in the inductor provided in Example 1 of the present application;

[0025] Fig. 9 It is a schematic diagram of the inductor structure provided in Example 2 of the present application.

[0026] In the figure: 1, coil; 11, conductor; 12, isolation layer; 2, magnetic base; 21, plane layer; 22, notch; 23, raised layer; 3, magnetic covering layer; 4, terminal; 5, pin. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific purposes.

[0028] See also Figures 1-2 As shown, in this embodiment, an inductor is provided, including a coil 1 and a magnetic base 3, the magnetic base 3 is used to fix the coil 1, and pins 5 are also connected to both ends of the coil 1, the pins 5 are used to connect to terminals 4, and the terminals 4 are attached to the lower surface of the magnetic base 3. The inductor also includes a magnetic covering layer 3, which is located on the upper surface of the magnetic base 2 and covers the coil 1 located on the magnetic base 3.

[0029] For details, see Figures 3-4 As shown, the coil 1 is spirally wound on the raised layer 22 to form one or more layers of the coil 1. Preferably, the coil 1 is wrapped in two layers, and the height of the outer layer of the coil 1 is greater than the height of the inner layer of the coil 1, so that the coil 1 is wrapped more tightly. One end of the coil 1 is connected to a pin 5, and the other end of the coil 1 is connected to another pin 5. The two pins 5 pass through the notch 22 and are connected to the terminal 4. The magnetic covering layer 3 is then wrapped on the magnetic base 2 to cover the coil 1. When current passes through the coil 1, a magnetic field is generated. This magnetic field interacts with the magnetic base 2 to form an inductance effect.

[0030] In this embodiment, see Figures 5-6 As shown, the magnetic base 2 includes a planar layer 21 and at least one raised layer 22, the raised layer 22 is used to wrap the coil 1, and a notch 22 is set at the side end of the planar layer 21 along the length direction, the notch 22 is used to pass through the pin 5, and the number of the notches 22 is consistent with the number of the terminals 4. The set notch 22 is convenient for passing the pin 5 through, and compared with the design of the opening of the magnetic base 2 in the prior art, the die-cast magnetic base 2 is easier to demold, and the cost of the mold is also lower.

[0031] See also Figure 7 As shown, the coil 1 includes a conductor 11 and an isolation layer 12, the isolation layer 2 is coated on the surface of the conductor 11, the conductor 11 is connected to the pin 5, and the thickness of the isolation layer 12 is T.

[0032] The width of T is 0.002 mm≦T≦0.5 mm, preferably, 0.05 mm≦T≦0.2 mm.

[0033] Furthermore, the isolation layer 12 is made of an insulating flexible polymer material, such as polyamide, polyimide, polyether, etc. The material of the isolation layer 12 has no effect on the short circuit verification.

[0034] Furthermore, the magnetic base 2 is made of metal soft magnetic powder by die-casting. The metal soft magnetic powder material includes but is not limited to silicon steel, nickel-iron alloy, iron-nickel alloy and iron-aluminum alloy. The metal soft magnetic powder is a kind of metal magnetic material with the characteristics of high magnetization, stable magnetism, high temperature resistance and wide temperature range, corrosion resistance and the like.

[0035] Metal soft magnetic powder has high corrosion resistance and deformation resistance. Its physical properties are stronger than those of ordinary ferrosilicon and water iron wire materials, and it has relatively stable magnetism. In addition, it has high stability and mechanical stability, making the magnetism of the product more stable and reliable.

[0036] Furthermore, two terminals 4 are provided, one is an input terminal and the other is an output terminal. These two terminals are used to connect the inductor to other components in the circuit. The input terminal is a current input terminal, which receives a current signal from the circuit, and the output terminal is a current output terminal, which outputs a current signal passing through the inductor.

[0037] Furthermore, two pins 5 are provided, one is an input pin and the other is an output pin. The input pin is the current input end of the inductor, which receives the current signal from the circuit, and the output pin is the current output end of the inductor, which outputs the current signal passing through the inductor.

[0038] In this embodiment, see Figure 8 As shown, the magnetic covering layer includes a soft magnetic metal material, and the magnetic metal material reduces the risk of puncturing the coil isolation layer. The soft magnetic metal material is selected from one of iron-based powder, iron-based amorphous powder, iron-silicon-aluminum alloy powder, iron-silicon alloy powder, iron-nickel alloy powder, and nano-crystalline alloy powder, or a combination of two or more of the above materials.

[0039] Specifically, the particle size distribution of the equivalent particle size of the metal particles of the soft magnetic metal material is X, and the corresponding particle size when the cumulative particle size distribution percentage reaches X% is Dx, and Dx≤2*T.

[0040] Further, the interval of the cumulative particle size distribution percentage X is 50≤X≤100, preferably, 90≤X≤100.

[0041] See also Fig. 9 As shown, the cross section of the coil 1 is not limited to a circle, but may also be a rectangle, a polygon or an irregular shape.

[0042] The present application is further described in detail below with reference to the embodiments.

[0043] Example 1

[0044] The powder particle size of the magnetic covering layer is D70=0.035 mm, the thickness of the isolation layer coated on the conductor surface of the coil is T=0.02 mm, and the short circuit ratio of the product in the 200V waveform test is 2%.

[0045] Example 2

[0046] The powder particle size of the magnetic covering layer is D90=0.038 mm, the thickness of the isolation layer coated on the conductor surface of the coil is T=0.017 mm, and the short circuit ratio of the product in the 200V waveform test is 1%.

[0047] Example 3

[0048] The powder particle size of the magnetic covering layer is D97=0.038 mm, the thickness of the isolation layer coated on the conductor surface of the coil is T=0.017 mm, and the short circuit ratio of the product in the 200V waveform test is 0.5%.

[0049] Example 4

[0050] The powder particle size of the magnetic covering layer is D97=0.030 mm, the thickness of the isolation layer coated on the conductor surface of the coil is T=0.02 mm, and the short circuit ratio of the product in the 200V waveform test is 0.04%.

[0051] Example 5

[0052] The powder particle size of the magnetic covering layer is D99=0.032 mm, the thickness of the isolation layer coated on the conductor surface of the coil is T=0.02 mm, and the short circuit ratio of the product in the 200V waveform test is 0%.

[0053] Comparative Example 1

[0054] The powder particle size of the magnetic covering layer is D70=0.035 mm, the thickness of the isolation layer coated on the conductor surface of the coil is T=0.01 mm, and the short circuit ratio of the product in the 200V waveform test is 6.4%.

[0055] Table 1 Test results:

[0056]

[0057] Among them, the total number of samples is 18720, and the short circuit ratio = the number of samples with poor waveform / the total number of samples.

[0058] Waveform test: During the measurement, the same pulse as that used in the measurement of the standard inductor is applied to the inductor under test through capacitor discharge. Due to the inductance and Q value of the inductor, it will respond to a voltage decay waveform corresponding to the discharge pulse. By comparing certain features of the decay waveform, short circuits between turns and layers of the inductor and differences in the number of turns and magnetic materials can be detected. A 200V voltage pulse can be applied. When the waveform area of ​​the inductor under test is less than 80% of the area of ​​the standard inductor, that is, the inductor under test has a bad waveform, the inductor is judged to be short-circuited.

[0059] Combining Example 1 and Comparative Example 1 with Table 1, it can be seen that

[0060] In Example 1, the diameter of the powder particle size D70 is less than twice the thickness of the isolation layer (2T=0.04mm), and in Comparative Example 1, the diameter of the powder particle size D70 is greater than twice the thickness of the isolation layer (2T=0.02mm). In Example 1, the short-circuit ratio of the 200V waveform test is reduced from 6.4% in Comparative Example 1 to 2%, indicating that when the powder particle size is less than twice the thickness of the isolation layer, the short-circuit ratio caused by powder piercing the coil can be reduced.

[0061] Combining Example 2 and Example 3 with Table 1, it can be seen that

[0062] The powder particle size and the thickness of the isolation layer in Example 2 and Example 3 are the same. When the cumulative particle size distribution percentage increases, the short circuit ratio will be reduced.

[0063] It can be seen from Examples 1-5 and Table 1 that

[0064] When the diameter of the powder particles is less than twice the thickness of the isolation layer, the proportion of short circuits caused by the powder piercing the coil will be greatly reduced.

[0065] In another embodiment, a method for manufacturing an inductor is also provided. The method manufactures the inductor, wherein the inductor includes a magnetic covering layer and a coil isolation layer. The magnetic covering layer is made of a soft magnetic metal material, and the equivalent particle size of the metal particles of the soft magnetic metal material is less than or equal to twice the thickness of the coil isolation layer.

[0066] Specifically, the particle size distribution of the equivalent particle size of the metal particles in the soft magnetic metal material is X, and the corresponding particle size when the cumulative particle size distribution percentage reaches X% is Dx, and Dx≤2*T, where T is the thickness of the coil isolation layer in the inductor.

[0067] Furthermore, the magnetic metal material is selected from one of iron-based powder, iron-based amorphous powder, iron-silicon-aluminum alloy powder, iron-silicon alloy powder, iron-nickel alloy powder, and nanocrystalline alloy powder, or a combination of two or more of the above materials.

[0068] Further, the percentage of X is 50≤X≤100, preferably, 90≤X≤100, and the width of T is 0.002mm≦T≦0.5mm, preferably, 0.05mm≦T≦0.2mm.

[0069] When the powder particle size is less than twice the thickness of the isolation layer, the short circuit ratio caused by the powder piercing the coil can be reduced.

[0070] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. Structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to conventional means in the field unless otherwise specified and limited.

Claims

1. An inductor, comprising a coil and a magnetic base, wherein the magnetic base is used to fix the coil, and pins are connected to both ends of the coil, characterized in that: It also includes a magnetic covering layer, which is located on the upper surface of the magnetic base and covers the coil located on the magnetic base. The magnetic base includes a planar layer and at least one raised layer, the raised layer is used to wrap the coil, and a notch is set at the side end of the planar layer along the length direction, and the notch is used to pass through the pin.

2. The inductor according to claim 1, characterized in that: It also includes a terminal, which is connected to a pin and is attached to the lower surface of the magnetic base.

3. An inductor according to claim 2, characterized in that: The coil is spirally wound on the protrusion layer to form one or more layers of coils.

4. The inductor according to claim 3, characterized in that: The cross section of the coil is circular, rectangular or polygonal.

5. The inductor according to claim 1, characterized in that: The coil comprises a conductor and an isolation layer, wherein the isolation layer is coated on the surface of the conductor, and the conductor is connected to a pin.

6. The inductor according to claim 5, characterized in that: The thickness of the isolation layer is T, and 0.002 mm≦T≦0.5 mm.

7. The inductor according to claim 1, characterized in that: The magnetic covering layer comprises a soft magnetic metal material, and the soft magnetic metal material is selected from one of iron-based powder, iron-based amorphous powder, iron-silicon-aluminum alloy powder, iron-silicon alloy powder, iron-nickel alloy powder, and nano-crystalline alloy powder.

8. The inductor according to claim 7, characterized in that: The particle size distribution of the equivalent particle size of the metal particles of the soft magnetic metal material is X, and the corresponding particle size when the cumulative particle size distribution percentage reaches X% is Dx, and Dx≤2*T.

9. The inductor according to claim 8, characterized in that: The interval of the cumulative particle size distribution percentage X is 50≤X≤100.

10. The inductor according to claim 5, characterized in that: The isolation layer is made of an insulating flexible polymer material, and the insulating flexible polymer material is a polyamide, polyimide or polyether material.

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