Application method of a molded inductor release agent

Abstract

This invention discloses a method for applying a mold release agent for molded inductors, belonging to the technical field of mold release agents for molded inductors. The method includes the following steps: mixing magnetic powder and the mold release agent, sieving to obtain a powder; molding the powder and curing it. The mold release agent is graphene oxide, and the magnetic powder is iron-silicon-chromium alloy powder; the mass ratio of magnetic powder to mold release agent is 1000:2~4. This invention's application method is simple, compatible with existing mass production lines, and significantly improves product appearance yield while ensuring that the original inductance, magnetic saturation, and other core electrical properties of the molded inductor are not affected.

Description

Technical Field

[0001] This invention belongs to the technical field of molded inductor release agents, specifically a method for applying a molded inductor release agent. Background Technology

[0002] Integrated molded inductors are a new type of inductor component. Due to their advantages such as small size and high current withstand capability, they are widely used in consumer electronics and other fields. Magnetic powder molding is a key step in the production of molded inductors. During the molding process, the use of release agents plays a crucial role in protecting the appearance of the molded inductor during molding, pressing, and subsequent demolding.

[0003] During the molding process, the magnetic powder particles adhere tightly to the mold. During the demolding process after molding, excessive tensile force is exerted on the inductor body. In severe cases, this can lead to cracking of the molded inductor body, which seriously affects the appearance. This is very detrimental to the mass production yield of molded inductors. Summary of the Invention

[0004] To overcome the aforementioned technical problems, this invention provides a method for applying a mold release agent to molded inductors. This invention features a simple process, is compatible with existing mass production lines, and significantly improves product appearance yield while ensuring that the original inductance, magnetic saturation, and other core electrical properties of the molded inductor remain unaffected.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0006] This invention discloses a method for applying a molded inductor release agent, comprising the following steps: mixing magnetic powder and release agent, sieving to obtain powder; molding the powder and curing it.

[0007] According to some embodiments of the present invention, the release agent is graphene oxide.

[0008] According to some embodiments of the present invention, the graphene oxide has a particle size of 0.5-5 μm and an oxygen content of 30-40%.

[0009] According to some embodiments of the present invention, the magnetic powder is an iron-silicon-chromium alloy powder.

[0010] According to some embodiments of the present invention, the mass ratio of the magnetic powder to the mold release agent is 1000:2~4; wherein, if the proportion of the mold release agent is too low, the demolding effect will be insignificant during the production demolding process, resulting in a large number of inductor body cracks; if the proportion is too high, it will be difficult to guarantee the electrical characteristics level of the molded inductor.

[0011] In some preferred embodiments, the mass ratio of the magnetic powder to the release agent is 1000:3.

[0012] According to some embodiments of the present invention, the mixing time is 8 to 15 minutes, for example, 10 minutes.

[0013] According to some embodiments of the present invention, the sieving is to retain powder with a particle size between 50 and 150 mesh; wherein, powder with too large a particle size will block the powder flow holes, resulting in insufficient powder filling during the molding process, causing the inductor to lack powder, while fine powder with too small a particle size will be adsorbed on the mold surface, causing the fine powder to adhere to the metal electrode surface of the inductor during the molding process, resulting in poor appearance of the inductor.

[0014] According to some embodiments of the present invention, the sieving time is 3 to 7 minutes, preferably 5 minutes.

[0015] According to some embodiments of the present invention, the compression molding is performed by holding the pressure at 400~650MPa for 1~5s.

[0016] According to some embodiments of the present invention, the curing is performed by holding at 150~170°C for 5~9 hours, preferably by holding at 160°C for 7 hours.

[0017] According to some embodiments of the present invention, the measured inductance of the molded inductor obtained by the application method is 9.7~10.15 μH, preferably 9.95~10.10 μH.

[0018] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0019] Compared with the prior art, the beneficial effects of the present invention are: This invention uses graphene oxide as a release agent for molded inductors to eliminate product cracking defects caused by demolding tension. By limiting the precise ratio of magnetic powder and graphene oxide and the sieving process, it avoids the problem of surface spots on the product caused by graphene dispersion and agglomeration, and removes excessively large coarse powder and ultrafine powder, thus eliminating process drawbacks such as insufficient powder filling and electrode adhesion.

[0020] Compared to conventional processes without release agents, this solution can significantly improve the appearance yield of molded inductors while ensuring that electrical parameters such as inductance and saturation current remain at the original levels. Attached Figure Description

[0021] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 The image shows the appearance of the molded inductor sample prepared in Example 1.

[0023] Figure 2 The image shown is of the molded inductor sample prepared in Example 3. Detailed Implementation

[0024] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0025] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0026] The "range" disclosed in this invention is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be combined arbitrarily; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for specific parameters, it is understood that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this invention, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein; "0-5" is merely a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer greater than or equal to 2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0027] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0028] Unless otherwise specified, all technical features and optional technical features of this invention can be combined to form new technical solutions.

[0029] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0030] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0031] Unless otherwise specified, the term "or" is inclusive in this invention. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0032] The raw material information used in the following examples is as follows: The graphene oxide has a particle size of 3.2 μm and an oxygen content of 40%. The magnetic powder is an iron-silicon-chromium alloy powder, with the grade Yuean H325. This includes, but is not limited to, the models from the above manufacturers.

[0033] Example 1 The application method of the mold release agent for molded inductors in this embodiment is as follows: After mixing the magnetic powder and graphene oxide, stir for 10 minutes to mix them evenly, and then sieve for 5 minutes to remove coarse and fine powder. Only powder with a particle size between 50 and 150 mesh is retained after sieving. The mass ratio of magnetic powder to graphene oxide is 1000:1. The powder was filled into the molded inductor coil, and the powder was molded under a pressure of 500 MPa for 1.5 seconds, followed by curing at 160°C for 7 hours. The appearance of the resulting molded inductor sample is shown in the image below. Figure 1 It has several defects.

[0034] Example 2 The difference between this embodiment and Embodiment 1 is as follows: The mass ratio of magnetic powder to graphene oxide is 1000:2; The other raw materials, steps and parameters are the same as in Example 1.

[0035] Example 3 The difference between this embodiment and Embodiment 1 is as follows: The mass ratio of magnetic powder to graphene oxide is 1000:3; The other raw materials, steps and parameters are the same as in Example 1.

[0036] The appearance of the molded inductor sample prepared in this embodiment is shown in the figure below. Figure 2 It has a good appearance with no obvious defects.

[0037] Example 4 The difference between this embodiment and Embodiment 1 is as follows: The mass ratio of magnetic powder to graphene oxide is 1000:4; The other raw materials, steps and parameters are the same as in Example 1.

[0038] Example 5 The difference between this embodiment and Embodiment 1 is as follows: The mass ratio of magnetic powder to graphene oxide is 1000:5; The other raw materials, steps and parameters are the same as in Example 1.

[0039] Comparative Example 1 The difference between this comparative example and Example 1 is as follows: The mass ratio of magnetic powder to graphene oxide is 1000:0, meaning that graphene oxide is not used. The other raw materials, steps and parameters are the same as in Example 1.

[0040] Test case The electrical characteristics of the 06 series integrally molded inductors with an inductance of 10μH prepared in the above embodiments and comparative examples were tested, and the test results are shown in Table 1. Among them, the appearance yield requires inspection for defects such as cracks, defects, material loss, surface spots, powder adhesion, and unevenness, and the appearance yield is required to be ≥95% to be qualified.

[0041] Table 1

[0042] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this invention. It should be understood that the above descriptions are merely specific embodiments of this invention and are not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method of applying a compression inductor release agent, characterized in that, The process includes the following steps: mixing magnetic powder and release agent, sieving to obtain powder; The powder can be molded and cured.

2. The method of claim 1, wherein the molding inductance release agent is applied by a method comprising: The release agent is graphene oxide.

3. The method of claim 2, wherein the molding inductance release agent is applied by a method comprising: The graphene oxide has a particle size of 0.5-5 μm and an oxygen content of 30-40%.

4. The method of claim 1, wherein the molding inductance release agent is applied by a method comprising: The magnetic powder is an iron-silicon-chromium alloy powder.

5. The method of claim 1, wherein the molding inductance release agent is applied by a method comprising: The mass ratio of the magnetic powder to the release agent is 1000:2~4, preferably 1000:

3.

6. The method of claim 1, wherein the molding inductance release agent is applied by a method comprising: The mixing time is 8-15 minutes.

7. The method of claim 1 wherein the molding inductance release agent is applied by a die. The sieving process retains powder with a particle size between 50 and 150 mesh. And / or, the screening time is 3~7 minutes.

8. The method of claim 1, wherein the molding inductance release agent is applied by a method comprising: The compression molding process involves holding the pressure at 400-650 MPa for 1-5 seconds.

9. The method of claim 1, wherein the molding inductance release agent is applied by a method comprising: The curing process involves maintaining a temperature of 150-170℃ for 5-9 hours.

10. The method of claim 1-9, wherein, The measured inductance of the molded inductor prepared by the application method is 9.7~10.15 μH.

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