Manufacturing method of spraying type inductor

Abstract

The invention relates to a manufacturing method of a spraying type inductor, and aims to improve the performance and the production efficiency of the inductor. The method comprises the following steps: winding a square coil by adopting a flat copper wire of which the surface is coated with insulating paint, and stripping the insulating paint at a leading-out end. The magnetic coating containing flaky iron-silicon-chromium magnetic powder, polyimide resin and a solvent is prepared after being immersed in a silane coupling agent for treatment, and it is ensured that the materials are evenly mixed. Then, a spray gun is used for spraying magnetic paint on the surface of the coil from multiple angles, and after air drying, baking treatment is conducted in an oven protected by nitrogen; and finally, bending the pin, pressing the pin into the coating, and carrying out electroplating treatment to obtain a finished inductor. The inductor has the beneficial effects that the short circuit risk is reduced, and the reliability of the inductor is improved; the filling efficiency of the magnetic material is improved through the spraying process, and material waste is reduced; the production process is simplified, the production time is shortened, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of inductor manufacturing, and in particular to a method for manufacturing a spray-coated inductor. Background Art

[0002] In modern electronic devices, inductors, as an important passive component, are widely used in power filtering, signal processing, energy storage and other fields. With the rapid development of electronic technology, the design and manufacture of inductors are also constantly improving. Among them, one-piece molded inductors, as an emerging type of inductor, have gradually become a hot spot for research and application due to their unique structure and performance.

[0003] The one-piece molded inductor is mainly composed of magnetic materials and coils. Its design features the use of alloy powder as magnetic material, combined with the coil for integrated pressing. Compared with traditional inductors, the core advantages of one-piece molded inductors are their compact structure, small size, stable performance, especially in terms of electromagnetic interference suppression and leakage magnetic characteristics. In traditional inductors, the coil is usually wound separately and then assembled with the magnetic core. This assembly method is prone to leakage magnetic, short circuit and other problems during use, which reduces the overall performance of the inductor.

[0004] Currently, there are two main ways to manufacture one-piece molded inductors: one is to use round copper wire as the coil, wind it into a hollow coil and weld it on the lead frame, then place the lead frame in the mold cavity and inject magnetic particles for pressing; the other is to use a flat copper wire design, first wind the flat copper wire into a hollow coil, then put it on a prefabricated T-shaped core column for pressing. Although these two methods have improved the performance of the inductor to a certain extent, there are still some problems that need to be solved.

[0005] First, during the pressing process, the mutual extrusion and friction between the copper wires will damage the insulating paint on the surface, causing a short circuit between two adjacent turns, thus affecting the reliability of the inductor. This situation is particularly prominent in high-temperature and high-frequency applications, and it is very easy to cause equipment failure or damage. In addition, traditional pressing processes often require complex molds, which have high production costs, and the wear and maintenance of the molds will increase the production cycle and cost.

[0006] Secondly, when filling magnetic materials, the inductors in the prior art may have uneven particle filling, resulting in unstable performance of the magnetic materials. For example, in the design using flat copper wire as the electrode, the fluidity of the powder is hindered due to the limitation of the electrode shape, resulting in insufficient filling and even exposure of the electrode coil, which will seriously affect the performance and reliability of the inductor. Therefore, improving the filling efficiency and uniformity of magnetic materials has become a key technical issue in the design and manufacture of one-piece molded inductors.

[0007] In addition, current inductor design focuses on improving its static performance, such as inductance and quality factor, but there is relatively little research on dynamic performance and long-term stability. Especially in practical applications, factors such as current fluctuations, temperature changes, and external electromagnetic interference that the inductor is subjected to will have a significant impact on the performance of the inductor. Therefore, how to design an inductor that can meet both static performance and good dynamic response has become a topic that needs to be solved urgently.

[0008] With the rise of emerging applications such as electric vehicles, smart homes, and 5G communications, the performance requirements for inductors are also increasing. Future inductors need to not only have efficient energy transmission capabilities, but also have good heat dissipation performance, anti-interference capabilities, and long-term stability. Therefore, research and development of new inductor design and manufacturing processes, especially the innovation of integrated molded inductors, will provide strong support for the development of the electronics industry.

[0009] In this context, the present invention proposes a new method for manufacturing a spray-coated inductor, aiming to address the deficiencies in the prior art. By not using the traditional pressing process, the friction between the copper wire and the magnetic particles is avoided, and the risk of failure of the insulating protective layer is reduced, thereby improving the reliability and production efficiency of the inductor. In addition, the present invention adopts a spraying process to make the filling of the magnetic material more uniform, thereby improving the overall performance of the inductor. This innovative manufacturing method not only simplifies the production process, but also significantly reduces the production cost, making the one-piece molded inductor have a broader application prospect in future electronic products.

[0010] In summary, as the importance of inductors in various applications continues to rise, innovative design and manufacturing methods will be the key to improving inductor performance and reducing production costs. The research and application of this invention aims to provide new technical support for the development of one-piece molded inductors and promote inductor technology to a higher level. Summary of the invention

[0011] The purpose of the present invention is to provide a method for manufacturing a spray-coated inductor in view of the shortcomings of the prior art, so as to solve the problems raised in the background technology.

[0012] To achieve the above object, the present invention provides the following technical solution: a method for manufacturing a spray-coated inductor, comprising the following steps: S1: Flat copper wire coated with insulating paint is wound into a square coil; S2: strip the insulating paint off the lead-out part of the square coil obtained in S1; S3: removing the insulating paint from the lead-out end of the coil obtained in S2, immersing the lead-out end portion in a silane coupling agent and then air-drying the portion; S4: Prepare magnetic material coating: the coating ratio is: 50-60% of surface insulation treated flaky iron silicon chromium magnetic powder, 10-20% of polyimide resin or silicone resin, 20-40% of solvent, and 1% of dibutyl phthalate as plasticizer; S5: Use a spray gun to spray S4 on the coil surface after S3 is air-dried from multiple angles to prepare magnetic material, and then air-dry; S6: Hang the coil air-dried in S5 in an oven for baking; S7: Bend the inductor pins and press them into the magnetic coating using a heated press head, and finally perform solder electroplating on the pins to obtain an inductor.

[0013] As a preferred technical solution of the present invention, the particle size of the flaky iron-silicon-chromium magnetic powder is D50=4-10 μm, and the thickness is 2-4 μm.

[0014] As a preferred technical solution of the present invention, the solvent of the magnetic material coating is xylene or acetone, and polyimide resin, silicone resin, or epoxy acrylic resin is used as the binder.

[0015] As a preferred technical solution of the present invention, the coating thickness of the S5 paint after spraying is between 250-300 μm.

[0016] As a preferred technical solution of the present invention, the S6 baking process is carried out in a nitrogen-protected thermostatic box, the baking temperature is 160-200° C., preferably 180° C., and the time is 30-90 minutes.

[0017] As a preferred technical solution of the present invention, the temperature of the heating press head of S7 is controlled between 180-200° C., and the pin pressing time is controlled between 10-20 seconds.

[0018] As a preferred technical solution of the present invention, the thickness of the solder layer of the pin in the S7 electroplating process is 0.8-15 μm.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The spray-coated inductor manufacturing method of the present invention has significant beneficial effects. First, by not using the traditional pressing process, the friction between the copper wire and the magnetic particles is reduced, and the risk of insulation layer damage is reduced. This improvement significantly reduces the risk of short circuits, and the probability of short circuits in traditional processes is reduced to less than 1 / 10, thereby improving the reliability of the inductor and ensuring its stability in harsh environments such as high temperature and high frequency.

[0020] Secondly, the present invention introduces a spraying process into the production process, which improves the filling efficiency and uniformity of the magnetic material. This method ensures that the magnetic material is more evenly distributed in the inductor, thereby improving the overall performance and magnetic characteristics of the inductor. Compared with the traditional filling method, the present invention reduces material waste, reduces the consumption of raw materials to 1 / 4 of the original, and has good economic benefits.

[0021] Finally, the simplified production process and reduced mold requirements not only shortened production time by more than 20%, but also reduced the investment cost of production equipment to 1 / 2 of the original. This efficient manufacturing method has enhanced the competitiveness of one-piece molded inductors in the market, further promoted the miniaturization and performance improvement of electronic products, and provided strong support for the sustainable development of related industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A square coil of a method for manufacturing a spray-coated inductor proposed by the present invention; Figure 2 A method for manufacturing a spray-coated inductor proposed by the present invention is a diagram in which a magnetic material is coated on the surface of a square coil; Figure 3 A method for manufacturing a spray-coated inductor proposed by the present invention is a diagram after bending the pins. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings and multiple embodiments. Example 1

[0025] See also Figure 1-Figure 3 , a method for manufacturing a spray-coated inductor, specifically comprising the following steps: Preparation of coil: Use a flat copper wire coated with insulating paint on the surface and wind it into a square coil. The coil meets the number of turns and size required by the design. Then, strip the insulating paint from the lead-out part of the coil (i.e. the wire part at both ends) for subsequent processing.

[0026] Coil treatment: remove the lead-out end of the coil and immerse it in the pre-configured silane coupling agent for 5 minutes, then take out the coil and hang it to air dry so that its surface is evenly covered with a thin film. This treatment helps to improve the adhesion of the magnetic material in the subsequent steps.

[0027] Preparation of magnetic material coating: The magnetic material coating is prepared by mixing 50% of surface insulation treated flaky iron silicon chromium magnetic powder, 15% of polyimide resin, 30% of xylene and 1% of dibutyl phthalate. The mixture is stirred evenly in a stirrer to ensure uniformity of the coating.

[0028] Spraying process: Use a spray gun to spray the prepared magnetic material coating on the air-dried coil surface from multiple angles. Make sure the spraying is uniform and the coating thickness after spraying is controlled at 250-300μm. After spraying, hang the coil to air dry again, and the air drying time is about 30 minutes.

[0029] Baking treatment: The air-dried coil is hung in a nitrogen-protected oven for baking. The baking temperature is controlled at 180°C and the baking time is 60 minutes to ensure the curing of the magnetic coating. The nitrogen protection in this process can prevent oxidation of the coil lead end.

[0030] Pin processing and electroplating: After baking, use a heated press head to bend the inductor pin part and press it into the magnetic coating. The press head temperature is controlled at 190℃ and the pressing time is 15 seconds. Finally, the bent pin is subjected to solder electroplating, and the thickness of the electroplating layer is controlled at 0.8-15μm.

[0031] The one-piece molded inductor produced by this method has a good magnetic shielding effect, reduces magnetic leakage, and effectively reduces the friction between the copper wire and the magnetic powder through the spraying process, reducing the risk of short circuit. Example 2

[0032] Improvements are made on the basis of Example 1, specifically as follows: See also Figure 1-Figure 3 , Selection and processing of coils: Flat copper wire with a thickness of 0.2 mm is used for winding, and the processing method of the lead-out end of the wound square coil is the same as that of Example 1.

[0033] Improvement of magnetic coating: The formula of magnetic coating is: 60% flaky iron silicon chromium magnetic powder (D50=4μm, thickness is 2μm), 20% polyimide resin, 19% acetone as solvent, 1% dibutyl phthalate as plasticizer. The formulated coating is vacuum defoamed to ensure that there are no bubbles in the coating.

[0034] Spraying thickness control: During spraying, the spraying angle and pressure of the spray gun are controlled to ensure that the coating thickness after each spraying is 280μm and the total spraying thickness does not exceed 300μm.

[0035] Adjustment of baking temperature: Under nitrogen protection, the baking temperature of the air-dried coil was adjusted to 200°C and the baking time was extended to 90 minutes to further enhance the hardness and heat resistance of the coating.

[0036] The inductors produced through this improved solution have better stability and reliability in high temperature and high frequency application scenarios. Example 3

[0037] See also Figure 1-Figure 3 In view of the requirements of inductors of different sizes, Embodiment 3 provides a method for manufacturing a small-sized inductor: Production of small-size coils: Use flat copper wire with a thickness of 0.1mm to wind a square coil with a coil size of 10mm x 10mm and 20 turns.

[0038] Adjustment of magnetic coating: The coating ratio is: 55% flaky iron silicon chromium magnetic powder (D50=8μm, thickness is 3μm), 15% silicone resin, 28% xylene, and 2% dibutyl phthalate.

[0039] Optimization of spraying process: Small-sized inductors have higher requirements for spraying process, so automated equipment is used in the spraying process to ensure that the coating thickness is uniformly controlled at around 270μm. The spraying process is carried out layer by layer, and each layer is air-dried for 5 minutes after spraying, and the final air-drying time is controlled to 40 minutes.

[0040] High-precision baking: Use a precision constant temperature box for baking, the baking temperature is 160°C and the time is 45 minutes.

[0041] The inductor produced by this embodiment is suitable for low-power, high-precision electronic devices, and its small size design makes it advantageous in applications such as mobile devices and wearable devices.

[0042] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a spray-coated inductor, It is characterized in that The following steps are involved: S1: Flat copper wire coated with insulating paint is wound into a square coil; S2: strip the insulating paint off the lead-out part of the square coil obtained in S1; S3: removing the insulating paint from the lead-out end of the coil obtained in S2, immersing the lead-out end portion in a silane coupling agent and then air-drying the portion; S4: prepare magnetic material coating, the coating ratio is: 50-60% of surface insulation treated flaky iron silicon chromium magnetic powder, 10-20% of polyimide resin or silicone resin, 20-40% of solvent, and 1% of dibutyl phthalate as plasticizer; S5: Use a spray gun to spray S4 on the coil surface after S3 is air-dried from multiple angles to prepare magnetic material, and then air-dry; S6: Hang the coil air-dried in S5 in an oven for baking; S7: Bend the inductor pins and press them into the magnetic coating using a heated press head, and finally perform solder electroplating on the pins to obtain an inductor.

2. A method for manufacturing a spray-coated inductor according to claim 1, It is characterized in that The particle size of the flaky iron-silicon-chromium magnetic powder is D50=4-10 μm, and the thickness is 2-4 μm.

3. The method for manufacturing a spray-coated inductor according to claim 1, It is characterized in that The solvent of the magnetic material coating is xylene or acetone, and polyimide resin, silicone resin, or epoxy acrylic resin is used as a binder.

4. The method for manufacturing a spray-coated inductor according to claim 1, It is characterized in that The coating thickness of the S5 coating after spraying is between 250-300 μm.

5. The method for manufacturing a spray-coated inductor according to claim 1, It is characterized in that The S6 baking process is carried out in a nitrogen-protected thermostatic box at a temperature of 160-200° C., preferably 180° C., for 30-90 minutes.

6. The method for manufacturing a spray-coated inductor according to claim 1, It is characterized in that The temperature of the heating press head of the S7 is controlled between 180-200° C., and the pin pressing time is controlled between 10-20 seconds.

7. The method for manufacturing a spray-coated inductor according to claim 1, It is characterized in that The thickness of the solder layer of the pins during the S7 electroplating process is 0.8-15 μm.

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