U-shaped coil inductor and production method thereof

Abstract

The invention discloses a U-shaped coil inductor and a production method thereof, and the method comprises the following steps: S1, cutting a copper sheet into a required size through a punching machine, and bending the copper sheet into a U-shaped coil; s2, the U-shaped coil is placed on a lower punching die with the opening facing downwards, and an electrode of the U-shaped coil is placed in a groove of the lower punching die; s3, feeding the alloy powder into a mold, and applying pressure to press the alloy powder and the U-shaped coil into an inductor; s4, putting the inductor into an oven for baking; s5, uniformly covering the inductor with an organic coating through spraying equipment to form a protective layer; and S6, stripping the protective layer of the exposed electrode of the inductor by using laser, and plating a tin layer on the electrode through electroplating. The U-shaped coil has the beneficial effects that the U-shaped coil is formed by bending the copper sheet, the structure is simple, automatic generation and processing are facilitated, and the production efficiency is improved; the U-shaped coil and the magnetic powder block are pressed and integrally formed, the volume is small, the magnetic powder block can be easily integrated into a circuit, the design of the circuit is more compact, and the requirement for high integration of components is met.

Description

Technical Field

[0001] The invention relates to the technical field of electronic devices, and in particular to a U-shaped coil inductor and a production method thereof. Background Art

[0002] An inductor is a component that can convert electrical energy into magnetic energy and store it. It is a property of a closed loop. When the current through a closed loop changes, an electromotive force will appear to resist the change in current. This phenomenon is called self-inductance, which is a manifestation of electromagnetic induction. When an alternating current is added to the inductor coil, the change in its own current will cause a change in its own magnetic flux, thereby generating an induced electromotive force. The direction of this induced electromotive force always hinders the change in current that causes it. Therefore, the inductor presents a very small resistance to direct current (similar to a short circuit), but a higher impedance to alternating current, and the higher the frequency of the alternating current, the greater the hindering effect of the inductor on it.

[0003] In the prior art, the inductor is mainly composed of a skeleton, a winding, a magnetic core, etc., wherein the skeleton is used to support and fix the winding, the winding is an electromagnetic induction element wound with an insulated wire, and the magnetic core is used to enhance the magnetic field of the inductor. It is usually large in size and is not suitable for the needs of highly integrated components. In addition, it is troublesome to wind the winding with an insulated wire, and the efficiency of automated production and processing is low. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present application proposes a U-shaped coil inductor and a production method thereof. The U-shaped coil is formed by bending a copper sheet. The structure is simple and convenient for automated production and processing, thereby improving production efficiency. The U-shaped coil and a magnetic powder block are pressed together and formed into an integral part. The inductor has a small size and is easy to be integrated into a circuit, making the circuit design more compact and meeting the requirements of highly integrated components.

[0005] The following is a technical solution of the present invention, a method for producing a U-shaped coil inductor, comprising the following steps: S1. Cut the copper sheet into required size by punching machine and bend the copper sheet into U-shaped coil; S2, placing the U-shaped coil with its opening facing downward on the lower punch die, so that the electrode of the U-shaped coil is placed in the groove of the lower punch die; S3, feeding the alloy powder into the mold, and applying pressure to press the alloy powder and the U-shaped coil into an inductor; S4, placing the inductor into an oven for baking; S5. Use a spraying device to evenly cover the inductor with an organic coating to form a protective layer; S6. Use laser to strip off the protective layer of the exposed electrode of the inductor, and plate the electrode with a tin layer by electroplating.

[0006] As a preferred solution of the present invention, in S1, the ratio of the length, width and thickness of the copper sheet is 20:5:1, and the ratio of the coil length, the bending length and the electrode length of the U-shaped coil is 10:3:2.

[0007] As a preferred solution of the present invention, in S3, the pressing pressure of the molding machine is 3.5 to 5 , pressing time 2 seconds.

[0008] As a preferred solution of the present invention, in S4, the oven temperature is set to 120°C and the baking time is 30 minutes.

[0009] As a preferred solution of the present invention, in S5, the organic coating is water-based insulating paint or epoxy resin paint, the spraying speed of the spraying equipment is 10m / min to 12m / min, the spraying pressure is 0.3MPa to 0.5MPa, and the distance between the spray gun and the inductor is 13cm to 17cm.

[0010] As a preferred solution of the present invention, in S6, the electrode is plated with a tin layer by electroplating, the current density of the electroplating equipment is 2A / cm² to 3A / cm², and the temperature of the electroplating solution is 40°C to 50°C.

[0011] A U-shaped coil inductor comprises a U-shaped coil and a magnetic powder block, wherein the coil part and the bending part of the U-shaped coil are located inside the magnetic powder block, and the electrode of the U-shaped coil is exposed from the magnetic powder block.

[0012] As a preferred solution of the present invention, the magnetic powder block is formed by pressing alloy powder, and the alloy powder is iron-based alloy powder.

[0013] As a preferred solution of the present invention, the composition and proportion of the iron-based alloy powder are as follows: Iron powder: 80%-90%; Nickel powder: 5%-10%; Silica powder: 0.5%-2%.

[0014] The beneficial effects of the present invention are as follows: the present invention bends a copper sheet into a U-shaped coil, which has a simple structure and is convenient for automated production and processing, thereby improving production efficiency; the U-shaped coil and the magnetic powder block are pressed together and integrally formed, which has a small size and is easy to integrate into the circuit, making the circuit design more compact and meeting the needs of highly integrated components; and the integrated inductor has a higher inductance and a smaller leakage inductance, as well as a lower DC resistance, thereby improving the conversion efficiency and stability of the circuit, and can withstand the impact of large currents, and can maintain excellent temperature rise current and saturation current characteristics in a high temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the U-shaped coil inductor of the present invention; Figure 2 It is a structural schematic diagram of the U-shaped coil of the present invention; Figure 3 is a schematic diagram of a copper sheet of the present invention; Figure 4 It is a schematic diagram of the lower punch die of the punching machine of the present invention; Figure 5 It is the assembly diagram of the U-shaped coil and the lower punch die of the present invention; Figure 6 It is a flow chart of the production method of the U-shaped coil inductor of the present invention; In the figure: 1, U-shaped coil; 11, coil part; 12, bending part; 13, electrode; 2, magnetic powder block; 3, lower punch die; 31, groove. DETAILED DESCRIPTION

[0016] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0017] like Figures 1 to 5 As shown, a U-shaped coil inductor includes: a U-shaped coil and a magnetic powder block, the coil portion and the bending portion of the U-shaped coil are located inside the magnetic powder block, and the electrodes of the U-shaped coil are exposed from the magnetic powder block.

[0018] In this embodiment, the U-shaped coil is formed by stamping and bending a copper sheet. The coil portion, the bending portion and the electrode are not physically separated, but are defined according to the relative position of the U-shaped coil in the magnetic powder block. The U-shaped coil is formed by cutting the copper sheet into the required size through a punching machine and bending the copper sheet into a U shape. The ratio of the length, width and thickness of the copper sheet is 20:5:1, and the ratio of the coil portion length, the bending portion length and the electrode length is 10:3:2. The U-shaped coil is placed on the lower punch die with the opening facing downward, the electrode portion is aligned with the groove of the lower punch die, alloy powder is fed into the die, and pressure is applied to the alloy powder by a forming machine, so that the coil portion and the bending portion are located in the magnetic powder block, and the electrode is exposed outside the magnetic powder block, which is convenient for connection through the electrode.

[0019] In this embodiment, the magnetic powder block is formed by pressing alloy powder, the alloy powder is iron-based alloy powder, and the composition and proportion of the iron-based alloy powder are as follows: iron powder: 80%-90%; nickel powder: 5%-10%; silicon powder: 0.5%-2%.

[0020] In this embodiment, the height of the magnetic powder block is greater than or equal to twice the length of the bent portion.

[0021] In this embodiment, the width of the magnetic powder block is greater than or equal to five times the width of the electrode.

[0022] like Figure 6 As shown, a method for producing a U-shaped coil inductor comprises the following steps: S1. Cut the copper sheet into required size by punching machine and bend the copper sheet into U-shaped coil; S2, placing the U-shaped coil with its opening facing downward on the lower punch die, so that the electrode of the U-shaped coil is placed in the groove of the lower punch die; S3, feeding the alloy powder into the mold, and applying pressure to press the alloy powder and the U-shaped coil into an inductor; S4, placing the inductor into an oven for baking; S5. Use a spraying device to evenly cover the inductor with an organic coating to form a protective layer; S6. Use laser to strip off the protective layer of the exposed electrode of the inductor, and plate the electrode with a tin layer by electroplating.

[0023] In step S1, the copper sheet is cut into the required size by a punching machine, and the copper sheet is bent into a U-shaped coil. Specifically, according to the required size of the copper sheet, a suitable stamping die is designed and manufactured, the copper sheet is placed on the workbench of the punching machine, and a positioning device is used to ensure its accurate position. The copper sheet is fixed on the workbench with a clamp or a pressing plate to prevent movement or deformation during the punching process, and the punching machine is started to close the upper and lower dies to cut the copper sheet. The ratio of the length, width and thickness of the copper sheet is 20:5:1, and the ratio of the coil length, the bending length and the electrode length is 10:3:2.

[0024] In step S2, the U-shaped coil is placed on the lower punch die with its opening facing downward, so that the electrode of the U-shaped coil is placed in the groove of the lower punch die. Specifically, the U-shaped coil is placed on the lower punch die of the forming machine with its opening facing downward, and the lower punch die is provided with a groove adapted to the electrode of the U-shaped coil. The electrode is aligned with the groove of the lower punch die, and the electrode of the U-shaped coil is placed in the groove of the lower punch die. When the forming machine applies pressure to press the alloy powder and the U-shaped coil into an inductor, the electrode is exposed outside the magnetic powder block to improve applicability.

[0025] In step S3, the alloy powder is fed into the mold by a molding machine, and pressure is applied to press the alloy powder and the U-shaped coil into an inductor. After the U-shaped coil is placed with its opening facing downward on the lower punch mold of the molding machine, the alloy powder is fed into the mold by the molding machine. After the alloy powder is filled, the molding machine applies pressure to close the upper punch mold and the lower punch mold, and the alloy powder is pressed into a magnetic powder block under pressure. At the same time, since the U-shaped coil is placed with its opening facing downward on the lower punch mold of the molding machine, and the electrode of the U-shaped coil is placed in the groove of the lower punch mold, after the alloy powder is pressed into a magnetic powder block, the coil part and the bending part of the U-shaped coil are located inside the magnetic powder block, and the electrode of the U-shaped coil is exposed outside the magnetic powder block, that is, the electrode is located on the outer surface of the inductor. The pressing pressure of the molding machine is 3.5 to 5 , pressing time 2 seconds.

[0026] In step S4, the inductor is placed in an oven for baking. Specifically, the formed inductor is placed in an oven for baking. The inductor is baked in the oven to remove volatile substances and improve the strength of the inductor. The oven is set at a temperature of 120°C and the baking time is 30 minutes.

[0027] In step S5, the inductor is evenly covered with an organic coating by a spraying device to form a protective layer. Specifically, the inductor is pre-treated, such as cleaning, degreasing, etc., to ensure that the coating can be firmly attached to the surface of the inductor, and a suitable organic coating is selected to ensure that it has good insulation, corrosion resistance and adhesion. The inductor is placed in a fixture of the spraying device to ensure that the blank can rotate or move stably. The parameters of the spraying device, such as spraying speed, spraying pressure, the distance between the spray gun and the blank, etc., are set to ensure that the coating can be evenly covered on the surface of the inductor. The spraying device is started to spray the inductor and form a solid protective layer. The sprayed inductor is placed in a curing device, such as an oven or a curing furnace. Set a suitable curing temperature and time to ensure that the coating can be fully cured and form a solid protective layer. Among them, the organic coating can be a water-based insulating paint or an epoxy resin paint, the spraying speed is 10m / min to 12m / min, the spraying pressure is 0.3MPa to 0.5MPa, and the distance between the spray gun and the inductor is 13cm to 17cm.

[0028] In step S6, a laser is used to strip the protective layer of the exposed electrode of the inductor. Specifically, the position of the electrode where the protective layer needs to be stripped is determined and marked clearly. Select a suitable laser stripping device to ensure that it can accurately control the power, wavelength and focal point of the laser. Place the inductor on the workbench of the laser stripping device to ensure that the electrode position is aligned with the laser focal point. Start the laser stripping device and irradiate the electrode position with a laser. The laser energy will be absorbed by the protective layer and converted into heat energy, causing the protective layer to melt, vaporize and strip off quickly. During the stripping process, the depth and accuracy of the stripping can be controlled by adjusting the laser power and irradiation time.

[0029] The electrode is plated with a tin layer by electroplating. Specifically, a suitable electroplating solution and electroplating equipment are selected to ensure that they can provide good electroplating effect and stability. The electrode is pretreated, such as cleaning and activation, to ensure that the electroplating solution can be evenly attached to the electrode surface. The inductor is placed in the fixture of the electroplating equipment to ensure that the electrode can be completely immersed in the electroplating solution. The parameters of the electroplating equipment, such as current density, electroplating solution temperature, etc., are set. The electroplating equipment is started to electroplate the electrode. During the electroplating process, the tin ions will be reduced on the electrode surface and form a tin layer. After the electroplating is completed, the inductor is removed from the electroplating solution and cleaned to remove surface residues and impurities. The quality of the tinned electrode is checked to ensure that its coating is uniform, defect-free and has good adhesion. Among them, the current density of the electroplating equipment is 2A / cm² to 3A / cm², and the plating solution temperature is 40℃ to 50℃.

[0030] The present invention bends a copper sheet into a U-shaped coil, has a simple structure, and improves production efficiency; the U-shaped coil and the magnetic powder block are pressed and integrated into a small volume, and are easy to be integrated into the circuit, so that the circuit design is more compact and meets the needs of highly integrated components; and the integrated inductor has higher inductance and smaller leakage inductance, as well as lower DC resistance, thereby improving the conversion efficiency and stability of the circuit, and can withstand the impact of large currents, and can maintain excellent temperature rise current and saturation current characteristics in a high temperature environment.

[0031] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0032] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for producing a U-shaped coil inductor, characterized in that: The following steps are involved: S1. Cut the copper sheet into required size by punching machine and bend the copper sheet into U-shaped coil; S2, placing the U-shaped coil with its opening facing downward on the lower punch die, so that the electrode of the U-shaped coil is placed in the groove of the lower punch die; S3, feeding the alloy powder into the mold, and applying pressure to press the alloy powder and the U-shaped coil into an inductor; S4, placing the inductor into an oven for baking; S5. Use a spraying device to evenly cover the inductor with an organic coating to form a protective layer; S6. Use laser to strip off the protective layer of the exposed electrode of the inductor, and plate the electrode with a tin layer by electroplating.

2. The method for producing a U-shaped coil inductor according to claim 1, characterized in that: In S1, the ratio of the length, width and thickness of the copper sheet is 20:5:1, and the ratio of the coil length, the bending length and the electrode length of the U-shaped coil is 10:3:

2.

3. The method for producing a U-shaped coil inductor according to claim 1, characterized in that: In S3, the pressing pressure of the molding machine is 3.5 to 5 , pressing time 2 seconds.

4. The method for producing a U-shaped coil inductor according to claim 1, characterized in that: In S4, the oven temperature is set to 120°C and the baking time is 30 minutes.

5. The method for producing a U-shaped coil inductor according to claim 1, characterized in that: In S5, the organic coating is water-based insulating paint or epoxy resin paint, the spraying speed of the spraying equipment is 10m / min to 12m / min, the spraying pressure is 0.3MPa to 0.5MPa, and the distance between the spray gun and the inductor is 13cm to 17cm.

6. The method for producing a U-shaped coil inductor according to claim 1, characterized in that: In S6, the electrode is plated with a tin layer by electroplating, the current density of the electroplating equipment is 2A / cm² to 3A / cm², and the temperature of the electroplating solution is 40℃ to 50℃.

7. A U-shaped coil inductor, applicable to the method for producing a U-shaped coil inductor according to any one of claims 1 to 6, characterized in that: include: The U-shaped coil and the magnetic powder block, the coil part and the bent part of the U-shaped coil are located inside the magnetic powder block, and the electrodes of the U-shaped coil are exposed from the magnetic powder block.

8. A U-shaped coil inductor according to claim 7, characterized in that: The magnetic powder block is formed by pressing alloy powder, and the alloy powder is iron-based alloy powder.

9. A U-shaped coil inductor according to claim 8, characterized in that: The composition and proportion of the iron-based alloy powder are as follows: Iron powder: 80%-90%; Nickel powder: 5%-10%; Silica powder: 0.5%-2%.

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