Composite material for manufacturing an inductor, inductor, and method for manufacturing an inductor

Abstract

To provide a composite material for manufacturing an inductor, an inductor, and a method for manufacturing an inductor.SOLUTION: The present invention provides a composite material for manufacturing an inductor, an inductor, and a manufacturing method thereof. The composite material includes the following components in mass percentage: 70 to 75% carbonyl iron powder, 20 to 25% amorphous powder, 2 to 5% epoxy resin, 0.3 to 0.5% coupling agent, and 0.1 to 1.5% zinc stearate. The composite material according to the present invention can be combined with a specific inductor manufacturing process to produce an inductor with excellent performance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the technical field of inductors, and specifically to a composite material for the manufacture of inductors, an inductor, and a method for manufacturing the same.

Background Art

[0002] An inductor is a device that can convert electrical power into magnetic force and store it. The structure of an inductor is similar to that of a transformer, but it has only one winding. An inductor has a certain inductance and only inhibits the change of current. When the circuit is connected in a state where no current is passing through, the inductor tries to inhibit the current flowing there, and when the circuit is disconnected in a state where no current is passing through, the inductor tries to maintain the current without changing it. An inductor is also called a choke, reactor, or dynamic reactor.

[0003] The integrally molded inductor in the prior art includes a compression-molded metal magnetic powder block and a coil. The coil includes a coil body and two terminals. The coil body is made of a metal-coated wire and is embedded in the metal magnetic powder block. The terminals are located on both sides of the metal magnetic powder block, and the coil body has a bidirectional spiral structure.

[0004] The currently integrally molded inductors have the following several different structures. As shown in Figure 2, for the A-series inductor, first the coil is wound, then the coil is placed in a mold, and a uniform composite material is filled and cold press molded at once. As shown in Figure 4, for the B-series inductor, first the coil is wound, then the coil is placed in a mold, and a uniform composite material is filled and hot press molded at once. As shown in Figure 4, for the C-series inductor, first the T-core is cold press molded, then the coil is wound around the boss of the T-core, and then it is placed in a mold, and a uniform composite material is filled and hot press molded at once.

[0005] The above-mentioned inductors of Series A and B are affected by the coil. The molding density at the center of the coil is low. During press molding, the coil is compressed and easily deformed, which affects the magnetic induction effect and thus the performance of the inductor. In the above-mentioned inductor of Series C, the center of the coil is a boss structure of a T-core. Although the density is not low, the density outside the T-core is not high. During press molding, the coil is still compressed and deformed, which affects the magnetic induction effect and thus the performance of the inductor.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Based on the above technical problems existing in the prior art, the present invention provides a composite material for manufacturing an inductor. The inductor manufactured by combining the material with a specific process has excellent performance.

Means for Solving the Problems

[0008] To achieve the above object, the technical solution of the present invention is as follows. A composite material for manufacturing an inductor, comprising the following components based on mass percentage. Carbonyl iron powder 70 - 75% Amorphous powder 20 - 25% Epoxy resin 2 - 5% Coupling agent 0.3 - 0.5% Zinc stearate 0.1 - 1.5%

[0009] In some embodiments, the amorphous powder includes the following components. Si 1.8 - 3.8% B 2 - 4% C 0.2 - 1.0% P 0.02 - 0.2% S 0.01 - 0.03% The balance is Fe.

[0010] Furthermore, the present invention further provides a method for manufacturing an inductor, and the method includes the following steps. S1. Coil manufacturing: Use a winding machine to wind a flat copper wire to obtain a coil having two parallel lead wires in the horizontal direction, bend the two lead wires in the same direction to be perpendicular to the winding part, and strip the lead wire part. S2. Use the composite material according to claim 1 or 2 to manufacture a T-core and a U-core respectively. Specifically, it includes the following steps. Add the epoxy resin and the coupling agent to a solvent to obtain a first mixture. Next, add the carbonyl iron powder and the amorphous powder to the first mixture and mix uniformly to obtain a second mixture. Granulate the second mixture to form particles. Add the zinc stearate to the particles and mix uniformly to obtain a third mixture. Fill the third mixture into a mold and perform cold press molding to obtain a T-core and a U-core respectively. The T-core includes a base and a convex portion disposed on the base, and the convex portion conforms to the space of the coil. A concave groove is provided inside the U-core, and the concave groove conforms to the coil. S3. Place the coil obtained in step S1 in the concave groove of the U-core and extend the lead wire outside the concave groove. S4. Place the T-core in the space of the coil, cover the base over the concave groove opening, and bend the lead wire. S5. Hot press form the assembled U-core, coil, and T-core to obtain a formed member. S6. Bake the formed member. S7. Perform roll spraying and paint stripping on the baked formed member to obtain an inductor. S8. Surface treatment: Electroplate a composite layer on the paint stripping position on the surface of the inductor and two side surfaces parallel to the lead wire of the inductor. The composite layer is laminated in the order of a copper layer, a nickel layer, and a tin layer from the inside to the outside to obtain the final inductor product.

[0011] In some embodiments, in step S2, the forming pressure is 3.5 - 4.0 T / cm 2 is.

[0012] In some embodiments, in step S2, the cold press time is 1 - 2 s.

[0013] In some embodiments, in step S4, the bending angle of the lead wire is 45 - 90°, and more preferably, in step S4, the bending angle of the lead wire is 55 - 60°. The lead wire forms an angle of 30 - 35° with the surface of the base, facilitating hot press forming in step S5 and further bending the lead wire onto the surface of the base.

[0014] In some embodiments, in step S5, the hot press temperature is 160 - 180 °C.

[0015] In some embodiments, in step S5, the hot press pressure is 5.0 - 6.0 T / cm 2 is.

[0016] In some embodiments, in step S5, the hot press time is 50 - 80 s.

[0017] In some embodiments, in step S6, the firing process first raises the temperature step by step for firing and then lowers the temperature step by step for firing. Specifically, it is as follows. The first stage, firing temperature 80 ± 5 °C, firing time 30 ± 3 min; The second stage, firing temperature 100 ± 5 °C, firing time 30 ± 3 min; The third stage, firing temperature 120 ± 5 °C, firing time 30 ± 3 min; The fourth stage, firing temperature 140 ± 5 °C, firing time 30 ± 3 min; The fifth stage, firing temperature 160 ± 5 °C, firing time 120 ± 3 min; The sixth stage, firing temperature 140 ± 5 °C, firing time 15 ± 3 min; The seventh stage, firing temperature 120 ± 5 °C, firing time 15 ± 3 min; The eighth stage, firing temperature 100 ± 5 °C, firing time 15 ± 3 min.

[0018] In some embodiments, in step S7, the roll spray evenly applies an insulating paint to the surface of the molding member.

[0019] In some embodiments, in step S7, the paint stripping performs a paint stripping treatment on the copper wire of the lead wire portion of the molding member after roll spraying to expose the copper wire on the surface.

[0020] In some embodiments, in step S8, the thickness of the copper layer is 2 - 4 μm, the thickness of the nickel layer is 1 - 3 μm, and the thickness of the tin layer is 6 - 8 μm.

[0021] In some embodiments, the position where the composite layer is plated on the side surface is at the position 1 / 6 from top to bottom from the upper surface to the side surface of the inductor.

[0022] In some embodiments, the solvent is acetone and / or ethanol.

[0023] The present invention further provides an inductor obtained by the manufacturing method of any of the above embodiments.

[0024] In some embodiments, the inductor includes a formed member formed from a U-core, a coil, and a T-core. The U-core has a concave groove adapted to the coil. The T-core includes a base and a convex portion disposed on the base. The convex portion is adapted to the inner diameter of the coil. Two parallel lead wires are provided on the coil. The coil is disposed in the concave groove, and the lead wires are located outside the concave groove. The convex portion of the T-core is disposed in the space of the coil. The base is adapted to the opening of the concave groove. The lead wires are bent on the surface of the base. An insulating paint layer is applied to the portion of the surface of the formed member other than the lead wires. A copper layer, a nickel layer, and a tin layer are sequentially applied to the surface of the lead wires from the inside to the outside.

[0025] In some embodiments, two corners of the base of the T-core are provided with notches, and the lead wires of the coil pass through the notches.

Advantages of the Invention

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows. The present invention can obtain an inductor with excellent inductance performance by manufacturing a magnetic body using a specific composite material and manufacturing an inductor by combining specific processes. Specifically, a specific composite material is used, and a specific cold pressing forming process is used to manufacture a T-core and a U-core with a specific structure. Next, a coil is arranged in the concave groove of the U-core, the T-core is arranged in the space of the coil, the base directly covers the concave groove opening of the U-core, and a forming member is manufactured using a specific hot pressing forming process. Thereby, the problems of low powder density, deterioration of inductance performance due to coil deformation, and high loss of conventional inductors are effectively solved. The inductor manufactured by the present invention has a high forming density, is difficult for the coil to deform, has excellent inductance performance, high conversion efficiency, and low loss. In addition, the present invention adopts peak baking (step-by-step baking) to effectively reduce the risk of product cracking and alleviate the problem of thermal expansion caused by rapid high-temperature solidification.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0028] Hereinafter, specific embodiments of the present invention will be combined to clearly and completely explain the technical solutions in the embodiments of the present invention. However, the embodiments described here are only some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained on the premise that those skilled in the art do not require creative labor all belong to the protection scope of the present invention.

[0029] In the following examples and comparative examples, the following materials are used. Epoxy resin: It is an epoxy resin with model number NF552 manufactured by Yongkang Chemical Co., Ltd. Coupling agent: It is a silane coupling agent, specifically the silane coupling agent with model number KH-550 manufactured by Tianwei Co., Ltd. Zinc stearate: It is a product of Senoba New Materials Co., Ltd.

[0030] In the following examples and comparative examples, the dimensions of the coils used are the same. The inductors are all manufactured in two sizes, which are as follows respectively. Size 1: length × width × height is 5.1 mm × 5.3 mm × 3.0 mm; Size 2: length × width × height is 6.0 mm × 6.0 mm × 3.1 mm. In Comparative Examples 4 to 6, due to the difference in structure, the dimensions are adjusted. The height remains unchanged, and the length and width each increase by 0.3 mm.

[0031] Example 1: As shown in Figure 1, the manufacturing method of the inductor includes the following steps. S1. Coil production: Use a winding machine to wind a copper flat wire to obtain a coil (3) having two parallel lead wires (31) in the horizontal direction. Bend the two lead wires (31) in the same direction to be perpendicular to the winding part, and perform three-directional paint peeling on the lead wire (31) part using a laser device.

[0032] S2. Use a composite material to manufacture a T-core and a U-core respectively. The composite material contains the following components by mass percentage. Carbonyl iron powder: 70% Amorphous powder: 25% Epoxy resin: 4% Silane coupling agent: 0.3% Zinc stearate: 0.7% The elemental composition of the amorphous powder is as follows. Si 3.0% B 4.0% C 1.0% P 0.03% S 0.01% The balance is Fe

[0033] The specific manufacturing procedures for the U-core (1) and the T-core (2) are as follows. Add epoxy resin and coupling agent to ethanol to create a first mixture. Next, add carbonyl iron powder and amorphous powder to the first mixture and stir evenly to volatilize the ethanol, creating a gel-like second mixture. Put the second mixture into a granulator (screen mesh is 100 mesh) to granulate it into particles, heat it at 45 °C for 2 hours, then sieve it (screen mesh is 100 mesh), add zinc stearate to the fine particles, stir at a rotation speed of 100 r / min for 0.5 hour, mix the materials evenly, then put them into a mold and perform cold press molding to obtain the T-core (2) and the U-core (1). The T-core (2) includes a base (21) and a convex portion (22) installed on the base (21). The base (21) is square and has cutouts provided at two of its corners to facilitate the lead wire (31) of the coil (3) passing through the cutouts. The convex portion (22) conforms to the space of the coil (3). A concave groove (11) is provided inside the U-core (1), and the concave groove (11) conforms to the coil (3). Here, the cold press pressure is 3.5 T / cm 2and the cold pressing time is 2 s. The cold pressing is carried out under pressure at normal temperature. The addition amount of the solvent is 25% of the total mass of the epoxy resin, coupling agent, carbonyl iron powder, and amorphous powder.

[0034] S3. Place the coil (3) obtained in step S1 in the concave groove (11) of the U-core (1), and extend the lead wire (31) outside the concave groove.

[0035] S4. Place the T-core (2) in the space of the coil (3), cover the mouth of the concave groove (11) with the base (21), bend the lead wire (31) at 55°, and make the included angle between the lead wire and the surface of the base (21) 35°.

[0036] S5. Hot press and mold the assembled U-core (1), coil (3), and T-core (2) to obtain a molded member. The hot pressing temperature is 180°C, and the hot pressing pressure is 5.5 T / cm 2 and the hot pressing time is 50 s.

[0037] S6. Put the molded member into an oven, first heat it up step by step for baking, and then cool it down step by step for baking. Specifically, it is as follows. The first stage: baking temperature 80°C, baking time 30 min; The second stage: baking temperature 100°C, baking time 30 min; The third stage: baking temperature 120°C, baking time 30 min; The fourth stage: baking temperature 140°C, baking time 30 min; The fifth stage: baking temperature 160°C, baking time 120 min; The sixth stage: baking temperature 140°C, baking time 15 min; The seventh stage: baking temperature 120°C, baking time 15 min; The eighth stage: baking temperature 100°C, baking time 15 min.

[0038] S7. Perform roll spraying and paint stripping on the forming member to obtain an inductor. The roll spraying is specifically as follows. Evenly apply an insulating paint to the surface of the forming member. For paint stripping, perform paint stripping treatment on the copper wire of the lead wire portion of the forming member after roll spraying to expose the copper wire on the surface.

[0039] S8. Surface treatment: Electroplate a composite layer on the paint stripping position on the surface of the inductor and on two side surfaces parallel to the lead wire of the inductor. The composite layer is laminated in the order of a copper layer, a nickel layer, and a tin layer from the inside to the outside to obtain the final inductor product. The thickness of the copper layer is 3 μm, the thickness of the nickel layer is 2 μm, and the thickness of the tin layer is 7 μm. The position where the composite layer is electroplated on the side surface is at a position 1 / 6 from the top to the bottom from the surface of the inductor.

[0040] As shown in FIG. 1, the structure of the inductor obtained by the method of this embodiment is specifically as follows. The inductor includes a forming member composed of a U-shaped iron core (U-core) (1), a coil (3), and a T-shaped iron core (T-core) (2). The U-shaped iron core (U-core) (1) is provided with a concave groove (11) adapted to the coil (3). The T-shaped iron core (T-core) (2) includes a base (21) and a convex portion (22) installed on the base (21). The convex portion (22) is adapted to the space of the coil (3). The coil (3) is provided with two parallel lead wires (31). The coil (3) is arranged in the concave groove (11). The lead wires (31) are located outside the concave groove (11). The convex portion (22) of the T-shaped iron core (T-core) (2) is located in the space of the coil (3), and the base (21) is adapted to the concave groove opening. The lead wires (31) are bent on the surface of the base (21). An insulating paint is applied to other positions on the surface of the forming member except for the surface of the lead wire (31). The surface of the lead wire (31) is coated with a copper layer, a nickel layer, and a tin layer in sequence from the inside to the outside. The base (21) of the T-shaped iron core (T-core) (2) is provided with notches at two corners, and the lead wires (31) of the coil (3) can pass through the notches.

[0041] Example 2: As shown in FIG. 1, the method for manufacturing an inductor includes the following steps. S1. Coil manufacturing: Use a winding machine to wind a flat copper wire to obtain a coil (3) having two parallel lead wires (31) in the horizontal direction. Bend the two lead wires (31) in the same direction to be perpendicular to the winding part, and perform three-direction paint peeling on the lead wire (31) part using a laser device.

[0042] S2. Use a composite material to manufacture a T-core (2) and a U-core (1) respectively, and include the following components in terms of the mass percentage of the composite material. Carbonyl iron powder: 75% Amorphous powder: 20% Epoxy resin: 4% Silane coupling agent: 0.3% Zinc stearate: 0.7% The elemental composition of the amorphous powder is as follows. Si 3.0% B 4.0% C 1.0% P 0.03% S 0.01% The rest is Fe

[0043] The specific manufacturing procedures for the U-core (1) and the T-core (2) are as follows. Add epoxy resin and coupling agent to ethanol to create a first mixture. Next, add carbonyl iron powder and amorphous powder to the first mixture, stir evenly to volatilize ethanol, and create a gel-like second mixture. Put the second mixture into a granulator (screen mesh is 100 mesh) to granulate it into particles, heat it at 45 °C for 2 hours, then sieve it (screen mesh is 100 mesh), add zinc stearate to the fine particles, stir at a rotation speed of 100 r / min for 0.5 hour, mix the materials evenly, then put them into a mold and perform cold press molding to obtain a T-core (2) and a U-core (1). The T-core (2) includes a base (21) and a convex portion (22) installed on the base (21). The convex portion (22) conforms to the space of the coil (3). A concave groove (11) is provided inside the U-core (1), and the concave groove (11) conforms to the coil (3). Here, the cold press pressure is 3.5 T / cm 2 and the cold press time is 2 s. The cold press is controlled at room temperature. The addition amount of the solvent is 25% of the total mass of epoxy resin, coupling agent, carbonyl iron powder, and amorphous powder.

[0044] S3. Place the coil obtained in step S1 in the concave groove (11) of the U-core (1), and extend the lead wire (31) outside the concave groove.

[0045] S4. Place the T-core (2) in the space of the coil (3), cover the base (21) over the opening of the concave groove (11), bend the lead wire (31) at 55°, and make the included angle between the lead wire and the surface of the base (21) 35°.

[0046] S5. Hot press form the assembled U-core (1), coil (3), and T-core (2) to obtain a formed member. The hot press temperature is 180°C, and the hot press pressure is 5.5 T / cm 2 and the hot press time is 50 s.

[0047] S6. Place the formed member in an oven, first heat it step by step for baking, and then cool it step by step for baking. Specifically, it is as follows. First stage: Baking temperature 80°C, baking time 30 min; Second stage: Baking temperature 100°C, baking time 30 min; Third stage: Baking temperature 120°C, baking time 30 min; Fourth stage: Baking temperature 140°C, baking time 30 min; Fifth stage: Baking temperature 160°C, baking time 120 min; Sixth stage: Baking temperature 140°C, baking time 15 min; Seventh stage: Baking temperature 120°C, baking time 15 min; Eighth stage: Baking temperature 100°C, baking time 15 min.

[0048] S7. Perform roll spraying and paint stripping treatment on the formed member to obtain an inductor. The roll spraying is specifically as follows. Evenly apply an insulating paint on the surface of the formed member. For paint stripping, perform paint stripping treatment on the copper wire of the lead wire part of the formed member after roll spraying to expose the copper wire on the surface.

[0049] S8. Surface treatment: Electroplate a composite layer on the paint stripping position on the surface of the inductor and two side surfaces parallel to the lead wire of the inductor. The composite layer is laminated in the order of a copper layer, a nickel layer, and a tin layer from the inside to the outside to obtain the final inductor product. The thickness of the copper layer is 3 μm, the thickness of the nickel layer is 2 μm, and the thickness of the tin layer is 7 μm. The position for electroplating the composite layer on the side surface is at 1 / 6 position from the top to the bottom of the surface of the inductor.

[0050] The structure of the inductor in this embodiment is the same as that in Embodiment 1.

[0051] Example 3: As shown in FIG. 1, the method for manufacturing an inductor includes the following steps. S1. Coil production: Use a winding machine to wind a flat copper wire to obtain a coil (3) having two parallel lead wires (31) in the horizontal direction, bend the two lead wires (31) in the same direction to be perpendicular to the winding part, and perform three-direction paint peeling on the lead wire (31) part using a laser device.

[0052] S2. Use a composite material to manufacture a T-core (2) and a U-core (1) respectively, and include the following components in terms of the mass percentage of the composite material. Carbonyl iron powder: 73% Amorphous powder: 23% Epoxy resin: 3% Silane coupling agent: 0.3% Zinc stearate: 0.7% The elemental composition of the amorphous powder is as follows. Si 3.0% B 4.0% C 1.0% P 0.03% S 0.01% The rest is Fe

[0053] The specific manufacturing procedures for the U-core (1) and the T-core (2) are as follows. Add epoxy resin and coupling agent to ethanol to create a first mixture. Next, add carbonyl iron powder and amorphous powder to the first mixture, stir evenly to volatilize ethanol, and create a gel-like second mixture. Put the second mixture into a granulator (screen mesh is 100 mesh) to granulate it into particles, heat it at 45 °C for 2 hours, then sieve it (screen mesh is 100 mesh), add zinc stearate to the fine particles, stir at a rotation speed of 100 r / min for 0.5 hour, mix the materials evenly, then put them into a mold and perform cold pressing molding to obtain a T-core (2) and a U-core (1). The T-core (2) includes a base (21) and a convex portion (22) installed on the base (21). The convex portion (22) conforms to the space of the coil (3). A concave groove (11) is provided inside the U-core (1), and the concave groove (11) conforms to the coil (3). Here, the cold pressing pressure is 3.5 T / cm 2 and the cold pressing time is 2 s. The cold pressing is controlled at room temperature. The addition amount of the solvent is 25% of the total mass of epoxy resin, coupling agent, carbonyl iron powder, and amorphous powder.

[0054] S3. Place the coil (3) obtained in step S1 in the concave groove (11) of the U-core (1), and extend the lead wire (31) outside the concave groove.

[0055] S4. Place the T-core (2) in the space of the coil (3), cover the base (21) over the opening of the concave groove (11), bend the lead wire (31) at 55°, and make the included angle between the lead wire and the surface of the base (21) 35°.

[0056] S5. Hot press form the assembled U-core (1), coil (3), and T-core (2) to obtain a formed member. The hot press temperature is 180 °C, and the hot press pressure is 5.5 T / cm 2 and the hot press time is 50 s.

[0057] S6. Put the formed member into an oven, first raise the temperature step by step for baking, and then lower the temperature step by step for baking. Specifically, it is as follows. First stage: Baking temperature 80 °C, baking time 30 min; Second stage: Baking temperature 100 °C, baking time 30 min; Third stage: Baking temperature 120 °C, baking time 30 min; Fourth stage: Baking temperature 140 °C, baking time 30 min; Fifth stage: Baking temperature 160 °C, baking time 120 min; Sixth stage: Baking temperature 140 °C, baking time 15 min; Seventh stage: Baking temperature 120 °C, baking time 15 min; Eighth stage: Baking temperature 100 °C, baking time 15 min.

[0058] S7. Perform roll spraying and paint stripping treatment on the formed member to obtain an inductor. The roll spraying is specifically as follows. Evenly apply an insulating paint on the surface of the formed member. For paint stripping, perform paint stripping treatment on the copper wire of the lead wire part of the formed member after roll spraying to expose the copper wire on the surface.

[0059] S8. Surface treatment: Electroplate a composite layer on the paint stripping position on the surface of the inductor and two side surfaces parallel to the lead wire of the inductor. The composite layer is laminated in the order of a copper layer, a nickel layer, and a tin layer from the inside to the outside to obtain the final inductor product. The thickness of the copper layer is 3 μm, the thickness of the nickel layer is 2 μm, and the thickness of the tin layer is 7 μm. The position for electroplating the composite layer on the side surface is at 1 / 6 position from the top to the bottom of the surface of the inductor.

[0060] The structure of the inductor in this embodiment is the same as that in Embodiment 1.

[0061] Comparative Example 1: As shown in FIG. 1, the method for manufacturing a coil includes the following steps. S1. Coil production: Using a winding machine to wind a flat copper wire to obtain a coil (3) having two parallel lead wires (31) in the horizontal direction, bending the two lead wires (31) in the same direction to be perpendicular to the winding portion, and performing three-directional paint peeling on the lead wire (31) portion using a laser device.

[0062] S2. Using a composite material to manufacture a T-core and a U-core respectively, and including the following components in terms of the mass percentage of the composite material. Carbonyl iron powder: 70% Amorphous powder: 25% Epoxy resin: 4% Silane coupling agent: 0.3% Zinc stearate: 0.7% The elemental composition of the amorphous powder is as follows. Si 3.0% B 4.0% C 1.0% P 0.03% S 0.01% The balance is Fe

[0063] The specific manufacturing procedures for the U-core (1) and the T-core (2) are as follows. Add epoxy resin and coupling agent to ethanol to form a first mixture. Next, add carbonyl iron powder and amorphous powder to the first mixture, stir evenly to volatilize ethanol, and form a gel-like second mixture. Put the second mixture into a granulator (screen mesh is 100 mesh) to granulate it into particles, heat it at 45 °C for 2 hours, then sieve it (screen mesh is 100 mesh), add zinc stearate to the fine particles, stir at a rotation speed of 100 r / min for 0.5 hour, mix the materials evenly, then put them into a mold and perform cold press molding to obtain a T-core (2) and a U-core (1). The T-core (2) includes a base (21) and a convex portion (22) installed on the base (21). The convex portion (22) conforms to the space of the coil (3). A concave groove (11) is provided inside the U-core (1), and the concave groove (11) conforms to the coil (3). Here, the cold press pressure is 3.5 T / cm 2 and the cold press time is 2 s. The cold press is controlled at normal temperature. The addition amount of the solvent is 25% of the total mass of the epoxy resin, coupling agent, carbonyl iron powder, and amorphous powder.

[0064] S3. Place the coil (3) obtained in step S1 in the concave groove (11) of the U-core (1), and extend the lead wire (31) outside the concave groove.

[0065] S4. Place the T-core (2) in the space of the coil (3), cover the base (21) over the opening of the concave groove (11), bend the lead wire (31) at 55°, and make the included angle between the lead wire and the surface of the base (21) 35°.

[0066] S5. Hot press form the assembled U-core (1), coil (3), and T-core (2) to obtain a formed member. The hot press temperature is 180 °C, and the hot press pressure is 5.5 T / cm 2 and the hot press time is 50 s.

[0067] S6. Put the formed member into an oven, first heat it up step by step for firing, and then cool it down step by step for firing. Specifically, it is as follows. The first stage: firing temperature 80 °C, firing time 30 min; The second stage: firing temperature 100 °C, firing time 30 min; The third stage: firing temperature 120 °C, firing time 30 min; The fourth stage: firing temperature 140 °C, firing time 30 min; The fifth stage: firing temperature 160 °C, firing time 120 min; The sixth stage: firing temperature 140 °C, firing time 15 min; The seventh stage: firing temperature 120 °C, firing time 15 min; The eighth stage: firing temperature 100 °C, firing time 15 min.

[0068] S7. Perform roll spraying and paint stripping treatment on the formed member to obtain an inductor. The roll spraying is specifically as follows. Evenly apply an insulating paint on the surface of the formed member. For paint stripping, perform paint stripping treatment on the copper wire of the lead wire part of the formed member after roll spraying to expose the copper wire on the surface.

[0069] S8. Surface treatment: Electroplate a composite layer on the paint stripping position on the surface of the inductor and on two side surfaces parallel to the lead wire of the inductor. The composite layer is laminated in the order of a copper layer, a nickel layer, and a tin layer from the inside to the outside to obtain the final inductor product. The thickness of the copper layer is 4 μm, the thickness of the nickel layer is 2 μm, and the thickness of the tin layer is 6 μm. The position for electroplating the composite layer on the side surface is at 1 / 6 position from the top to the bottom of the surface of the inductor.

[0070] The structure of the inductor in this comparative example is the same as that in Example 1.

[0071] Comparative Example 2: As shown in FIG. 1, the method for manufacturing an inductor includes the following steps.

[0072] S1. Coil production: Using a winding machine to wind a flat copper wire to obtain a coil (3) having two parallel lead wires (31) in the horizontal direction, bending the two lead wires (31) in the same direction to be perpendicular to the winding portion, and performing three-directional paint peeling on the lead wire (31) portion using a laser device.

[0073] S2. Using a composite material to manufacture a T-core and a U-core respectively, and including the following components in terms of the mass percentage of the composite material. Carbonyl iron powder: 70% Amorphous powder: 25% Epoxy resin: 3% Silane coupling agent: 1% Zinc stearate: 1% The elemental composition of the amorphous powder is as follows. Si 3.0% B 4.0% C 1.0% P 0.03% S 0.01% The balance is Fe

[0074] The specific manufacturing procedures for the U-core (1) and the T-core (2) are as follows. Add epoxy resin and coupling agent to ethanol to create a first mixture. Next, add carbonyl iron powder and amorphous powder to the first mixture, stir evenly to volatilize ethanol, and create a gel-like second mixture. Put the second mixture into a granulator (screen mesh is 100 mesh) to granulate it into particles, heat it at 45 °C for 2 hours, then sieve it (screen mesh is 100 mesh), add zinc stearate to the fine particles, stir at a rotation speed of 100 r / min for 0.5 hour, mix the materials evenly, then put them into a mold and perform cold pressing molding to obtain a T-core (2) and a U-core (1). The T-core (2) includes a base (21) and a convex portion (22) installed on the base (21). The convex portion (22) conforms to the space of the coil (3). A concave groove (11) is provided inside the U-core (1), and the concave groove (11) conforms to the coil (3). Here, the cold pressing pressure is 3.5 T / cm 2 and the cold pressing time is 2 s. The cold pressing is controlled at room temperature. The addition amount of the solvent is 25% of the total mass of the epoxy resin, coupling agent, carbonyl iron powder, and amorphous powder.

[0075] S3. Place the coil (3) obtained in step S1 in the concave groove (11) of the U-core (1), and extend the lead wire (31) outside the concave groove.

[0076] S4. Place the T-core (2) in the space of the coil (3), cover the base (21) over the opening of the concave groove (11), bend the lead wire (31) at 55°, and make the included angle between the lead wire and the surface of the base (21) 35°.

[0077] S5. Hot press form the assembled U-core (1), coil (3), and T-core (2) to obtain a formed member. The hot press temperature is 180°C, and the hot press pressure is 5.5 T / cm 2 and the hot press time is 50 s.

[0078] S6. Put the formed member into an oven, first heat it up step by step for firing, and then cool it down step by step for firing. Specifically, it is as follows. The first stage: firing temperature 80°C, firing time 30 min; The second stage: firing temperature 100°C, firing time 30 min; The third stage: firing temperature 120°C, firing time 30 min; The fourth stage: firing temperature 140°C, firing time 30 min; The fifth stage: firing temperature 160°C, firing time 120 min; The sixth stage: firing temperature 140°C, firing time 15 min; The seventh stage: firing temperature 120°C, firing time 15 min; The eighth stage: firing temperature 100°C, firing time 15 min.

[0079] S7. Perform roll spraying and paint stripping treatment on the formed member to obtain an inductor. The roll spraying is specifically as follows. Evenly apply insulating paint to the surface of the formed member. For paint stripping, perform paint stripping treatment on the copper wire of the lead wire part of the formed member after roll spraying to expose the copper wire on the surface.

[0080] S8. Surface treatment: Electroplate a composite layer on the paint stripping position on the surface of the inductor and two side surfaces parallel to the lead wire of the inductor. The composite layer is laminated in the order of a copper layer, a nickel layer, and a tin layer from the inside to the outside to obtain the final inductor product. The thickness of the copper layer is 4 μm, the thickness of the nickel layer is 2 μm, and the thickness of the tin layer is 6 μm. The position for electroplating the composite layer on the side surface is at 1 / 6 position from the top to the bottom of the surface of the inductor.

[0081] The structure of the inductor in this comparative example is the same as that in Example 1.

[0082] Comparative Example 3: As shown in FIG. 1, the method for manufacturing an inductor includes the following steps. S1. Coil production: Using a winding machine to wind a flat copper wire to obtain a coil (3) having two parallel lead wires (31) in the horizontal direction, bending the two lead wires (31) in the same direction to be perpendicular to the winding portion, and performing three-direction paint peeling on the lead wire (31) portion using a laser device.

[0083] S2. Using a composite material to manufacture a T-core and a U-core respectively, and including the following components in terms of the mass percentage of the composite material. Carbonyl iron powder: 70% Amorphous powder: 25% Epoxy resin: 4% Silane coupling agent: 0.3% Zinc stearate: 0.7% The elemental composition of the amorphous powder is as follows. Si 3.0% B 4.0% C 1.0% P 0.03% S 0.01% The rest is Fe

[0084] The specific manufacturing procedures of the U-core (1) and the T-core (2) are as follows. Add epoxy resin and coupling agent to ethanol to create a first mixture. Next, add carbonyl iron powder and amorphous powder to the first mixture, stir evenly to volatilize the ethanol, and create a gel-like second mixture. Put the second mixture into a granulator (screen mesh is 100 mesh) to granulate it into particles, heat it at 45 °C for 2 hours, then sieve it (screen mesh is 100 mesh), add zinc stearate to the fine particles, stir at a rotation speed of 100 r / min for 0.5 hour, mix the materials evenly, then put them into a mold and perform cold press molding to obtain a T-core (2) and a U-core (1). The T-core (2) includes a base (21) and a convex portion (22) installed on the base (21). The convex portion (22) fits into the space of the coil (3). A concave groove (11) is provided inside the U-core (1), and the concave groove (11) fits the coil (3). Here, the cold press pressure is 3.5 T / cm 2 and the cold press time is 2 s. The cold press is controlled at normal temperature. The addition amount of the solvent is 25% of the total mass of the epoxy resin, coupling agent, carbonyl iron powder, and amorphous powder.

[0085] S3. Place the coil obtained in step S1 in the concave groove (11) of the U-core (1), and extend the lead wire (31) outside the concave groove.

[0086] S4. Place the T-core (2) in the space of the coil (3), with the base (21) covering the opening of the concave groove (11), bend the lead wire (31) at 55°, and make the included angle between the lead wire and the surface of the base (21) 35°.

[0087] S5. Hot press form the assembled U-core (1), coil (3), and T-core (2) to obtain a formed member. The hot press temperature is 160°C, and the hot press pressure is 7.0 T / cm 2 and the hot press time is 80 s.

[0088] S6. Place the formed member in an oven, first raise the temperature step by step for firing, and then lower the temperature step by step for firing. Specifically, it is as follows. First stage: Firing temperature 80°C, firing time 30 min; Second stage: Firing temperature 100°C, firing time 30 min; Third stage: Firing temperature 120°C, firing time 30 min; Fourth stage: Firing temperature 140°C, firing time 30 min; Fifth stage: Firing temperature 160°C, firing time 120 min; Sixth stage: Firing temperature 140°C, firing time 15 min; Seventh stage: Firing temperature 120°C, firing time 15 min; Eighth stage: Firing temperature 100°C, firing time 15 min.

[0089] S7. Perform roll spraying and paint stripping treatment on the formed member to obtain an inductor. The roll spraying is specifically as follows. Evenly apply an insulating paint on the surface of the formed member. For paint stripping, perform paint stripping treatment on the copper wire of the lead wire part of the formed member after roll spraying to expose the copper wire on the surface.

[0090] S8. Surface treatment: Electroplate a composite layer on the paint stripping position on the surface of the inductor and two side surfaces parallel to the lead wire of the inductor. The composite layer is laminated in the order of a copper layer, a nickel layer, and a tin layer from the inside to the outside to obtain the final inductor product. The thickness of the copper layer is 4 μm, the thickness of the nickel layer is 2 μm, and the thickness of the tin layer is 6 μm. The position for electroplating the composite layer on the side surface is at 1 / 6 position from the top to the bottom of the inductor surface.

[0091] The structure of the inductor in this comparative example is the same as that in Example 1.

[0092] Comparative Example 4: In this comparative example, the raw material composition of the composite material used for manufacturing the magnet is as follows in terms of mass percentage. Alloy powder 95% Epoxy resin 4% Silane coupling agent 0.3% Zinc stearate 0.7% Here, the alloy powder is a normal commercially available product, for example, the FeSiCr-C soft magnetic alloy powder of Antai Co., Ltd.

[0093] The structure of the inductor in this comparative example is as shown in the structure of the A series inductor in Figure 2 and is manufactured by a conventional method. Specifically, it is as follows.

[0094] According to the method of Example 1, first, the composite material is uniformly mixed, then the coil is placed in a mold, the uniformly mixed composite material is filled, and cold pressing molding is performed at one time. The pressure of the cold pressing is 6.0 T / cm 2 and the time is 3 s.

[0095] Comparative Example 5: In this comparative example, the raw material composition of the composite material used for manufacturing the magnet is as follows in terms of mass percentage. Carbonyl iron powder 95% Epoxy resin 4% Silane coupling agent 0.3% Zinc stearate 0.7%

[0096] The structure of the inductor in this comparative example is as shown in the structure of the B series inductor in Figure 3 and is manufactured by a conventional method. Specifically, it is as follows.

[0097] According to the method of Example 1, the composite material was uniformly mixed. Next, the coil was placed in a mold, filled with the uniformly mixed composite material, and hot press molding was performed at one time. The temperature of the hot press was 160 °C / cm 2 The pressure was 5.0 T, and the time was 8 s.

[0098] Comparative Example 6: In this comparative example, the raw material composition of the composite material used to manufacture the magnet is as follows in mass percentage. Carbonyl iron powder 95% Epoxy resin 4% Silane coupling agent 0.3% Zinc stearate 0.7%

[0099] The inductor structure of this comparative example is as shown in the structure of the C series inductor in Figure 4 and is manufactured by a conventional method. Specifically, it is as follows.

[0100] According to the method of Example 1, first, the composite material was uniformly mixed, and a T-core was obtained by cold press molding. The temperature of the cold press was room temperature, the pressure was 4.0 T / cm 2 The time was 2 s. Next, a coil was wound around the convex part of the T-core, placed in a mold, filled with the uniformly mixed composite material, and hot press molding was performed at one time. The temperature of the hot press was 160 °C, and the pressure was 5.0 T / cm 2 The time was 60 s.

[0101] Related performance tests were carried out with reference to the inductors of Examples 1-3 and Comparative Examples 1-6. The specific measurement method is as follows.

[0102] Inductor, current measurement: Using an LCR tester, the sample was tested, and the parameters were set to a frequency of 1 MHz and a bias current (initial energization), and the inductance and current values were measured.

[0103] Loss: Using the CHROMA1810 tester, the test parameters were set to 100 mT and the frequency to 100 KHz.

[0104] The test results are as shown in Table 1. Table 1 Related performance test results of each inductor

Table 1

[0105] Each technical feature of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as these combinations of technical features do not conflict, they should all be considered to be included within the scope described in this specification.

[0106] The above embodiments are provided to illustrate the technical methods of the present invention and are not restrictive. The present invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any modification or equivalent replacement to the technical solution of the present invention shall be included within the protection scope of the present invention as long as it does not deviate from the spirit and scope of this technical solution.

Explanation of Reference Signs

[0107] 1 U-shaped iron core (U-core) 11 Groove 2 T-shaped iron core (T-core) 21 Base 22 Protrusion 3 Coil 31 Lead wire

Claims

1. In terms of mass percentage, 70 - 75% carbonyl iron powder, 20 - 25% amorphous powder, 2 - 5% epoxy resin, 0.3 - 0.5% coupling agent, 0.1 - 1.5% zinc stearate, comprising the components, wherein the amorphous powder, in terms of mass percentage, contains 1.8 - 3.8% Si, 2 - 4% B, 0.2 - 1.0% C, 0.02 - 0.20% P, 0.01 - 0.03% S, the balance being Fe, the composite material containing these components is used for manufacturing the T-core and U-core of an inductor. The conditions for manufacturing these cores are as follows: The conditions for cold press forming are that the cold press pressure is 3.5 - 4.0 T / cm² and / or the cold press time is 1 - 2 s. The conditions for hot press forming are that the hot press temperature is 160 - 180°C and / or the hot press pressure is 5.0 - 6.0 T / cm² and / or the hot press time is 50 - 80 s. The T-core and U-core are fired after hot press forming. The firing process is to first increase the temperature step by step for firing and then decrease the temperature step by step for firing. Specifically, The first stage: firing temperature 80 ± 5°C, firing time 30 ± 3 min; The second stage: firing temperature 100 ± 5°C, firing time 30 ± 3 min; The third stage: firing temperature 120 ± 5°C, firing time 30 ± 3 min; The fourth stage: firing temperature 140 ± 5°C, firing time 30 ± 3 min; The fifth stage: firing temperature 160 ± 5°C, firing time 120 ± 3 min; The sixth stage: firing temperature 140 ± 5°C, firing time 15 ± 3 min; The seventh stage: firing temperature 120 ± 5°C, firing time 15 ± 3 min; The eighth stage: firing temperature 100 ± 5°C, firing time 15 ± 3 min; A composite material for manufacturing an inductor, characterized in that.

2. A method for manufacturing an inductor, characterized by comprising the following steps: S1. Coil manufacturing: Using a winding machine to wind a copper flat wire to obtain a coil having two parallel lead wires in the horizontal direction, bending the two lead wires in the same direction to be perpendicular to the winding part, and peeling the lead wire part. S2. Use the composite material for manufacturing the inductor according to claim 1 to manufacture a T-core and a U-core respectively. Add the epoxy resin and the coupling agent to a solvent to obtain a first mixture. Next, add the carbonyl iron powder and the amorphous powder to the first mixture, mix them uniformly to obtain a second mixture. Granulate the second mixture to form particles. Add the zinc stearate to the particles and mix them uniformly to obtain a third mixture. Fill the third mixture into a mold and perform cold pressing and molding to obtain a T-core and a U-core respectively. The T-core includes a base and a convex portion disposed on the base. The convex portion is adapted to the space of the coil. A concave groove is provided inside the U-core, and the concave groove is adapted to the coil. S3. Place the coil obtained in step S1 in the concave groove of the U-core and extend the lead wire outside the concave groove. S4. Place the T-core in the space of the coil, cover the base over the opening of the concave groove, and bend the lead wire. S5. Hot press and mold the assembled U-core, coil, and T-core to obtain a molded member. S6. Bake the molded member. S7. Perform roll spraying and paint stripping treatment on the baked molded member to obtain an inductor. S8. Surface treatment: Electroplate a composite layer on the paint stripping position on the surface of the inductor and on two side surfaces parallel to the lead wire of the inductor. The composite layer is laminated in the order of a copper layer, a nickel layer, and a tin layer from the inside to the outside to obtain the final inductor product.

3. In step S5, the hot press temperature is 160 to 180 °C, and / or the hot press pressure is 5.0 to 6.0 T / cm ２ and / or the hot press time is 50 to 80 s, and the method for manufacturing an inductor according to claim 2, characterized in that.

4. In step S2, the pressure of the cold press is 3.5 to 4.0 T / cm ２ and / or the cold press time is 1 to 2 s, and the method for manufacturing an inductor according to claim 2 is characterized by this.

5. The method for manufacturing an inductor according to claim 2, wherein in step S8, the thickness of the copper layer is 2 - 4 μm, the thickness of the nickel layer is 1 - 3 μm, and the thickness of the tin layer is 6 - 8 μm.

6. In step S6, the baking process first raises the temperature step by step for baking and then lowers the temperature step by step for baking. Specifically, The first stage: The baking temperature is 80 ± 5 °C, and the baking time is 30 ± 3 min. The second stage: The baking temperature is 100 ± 5 °C, and the baking time is 30 ± 3 min. The third stage, firing temperature 120 ± 5 °C, firing time 30 ± 3 min; The fourth stage, firing temperature 140 ± 5 °C, firing time 30 ± 3 min; The fifth stage, firing temperature 160 ± 5 °C, firing time 120 ± 3 min; The sixth stage, firing temperature 140 ± 5 °C, firing time 15 ± 3 min; The seventh stage, firing temperature 120 ± 5 °C, firing time 15 ± 3 min; The eighth stage, firing temperature 100 ± 5 °C, firing time 15 ± 3 min; The method for manufacturing an inductor according to claim 2, characterized in that it is as described above.

7. An inductor manufactured by the manufacturing method according to any one of claims 2 to 6.

8. Including a molded member formed from a U-core, a coil, and a T-core, the U-core has a concave groove adapted to the coil, the T-core includes a base and a convex portion provided on the base, the convex portion is adapted to the inner diameter of the coil, two parallel lead wires are provided on the coil, the coil is disposed in the concave groove, and the lead wires are located outside the concave groove, the convex portion of the T-core is disposed in the space of the coil, the base is adapted to the mouth of the concave groove, the lead wires are bent on the surface of the base, an insulating paint layer is applied to the portion of the surface of the molded member other than the lead wires, and a copper layer, a nickel layer, and a tin layer are sequentially applied to the surface of the lead wires from the inside out. The inductor according to claim 7, characterized in that it is as described above.

9. The inductor according to claim 8, characterized in that the base of the T-core is provided with notches at two corners, and the lead wires of the coil pass through the notches.

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