Preparation method of anti-cracking mould pressing inductor

Abstract

The invention discloses a preparation method of an anti-cracking mould pressing inductor, which is characterized by comprising the following preparation steps: S1, mixing an organic resin adhesive, a nanoscale material, a solvent and a soft magnetic material to prepare a soft magnetic composite material; and S2, granulating the soft magnetic composite material, and drying to remove the solvent to obtain the required finished product soft magnetic composite powder. The method has the beneficial effects that the product performance can be considered, and the technical problem of appearance cracking of the cold pressing sample of the product can be effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inductance, in particular to a preparation method of a crack-proof molded inductance. BACKGROUND

[0002] The integrally formed inductance is formed by embedding a coil in soft magnetic composite powder and pressing. The mainstream pressing methods in the industry are cold pressing and hot pressing. Cold pressing is directly pressed at room temperature.

[0003] In the prior art, the following is disclosed: CN115692006A discloses a molded inductance and a preparation method. The preparation method comprises sequentially filling first magnetic powder and second magnetic powder into a first mold cavity for molding to obtain a magnetic core seat, sleeving a preset coil conductor on the middle column, folding the two ends of the coil conductor to the side of the bottom plate away from the middle column, and performing post-processing on the two ends of the coil conductor to form electrodes, then placing the magnetic core seat sleeved with the coil conductor into a second mold cavity, filling preset magnetic core cover magnetic powder into the second mold cavity, and performing hot pressing to obtain a molded inductance. The process flow of the preparation method is simple, and the inductance value of the obtained molded inductance is high and the direct current resistance is low.

[0004] At present, the cold pressing process is used to prepare the molded inductance, especially the high inductance product (with multiple coil layers and thin product wall thickness). After demolding, cracks will appear on the demolding surface (especially the electrode surface) of the product, which limits the preparation of high-performance products by the cold pressing process. The current solutions in the industry are roughly divided into two aspects: 1. The size of the middle column of the inner shrinkage coil is left to the wall thickness of the product, and the saturation characteristics of the product are sacrificed. 2. Adjust the powder grading, improve the strength of the finished powder before baking by increasing the bite force between the powders. Both of these solutions have problems such as sacrificing product performance and increasing product cost. For the solution that cannot sacrifice performance, the industry can only sacrifice yield to prepare samples. In summary, it is an urgent problem to consider product performance and solve the appearance cracking of cold-pressed samples. SUMMARY

[0005] In order to solve the problems in the prior art, the purpose of the present application is to provide a preparation method of a crack-proof molded inductance, which can consider product performance and effectively solve the technical problem of appearance cracking of cold-pressed samples.

[0006] A preparation method of a crack-proof molded inductance comprises the following preparation steps: S1 mixes the organic resin adhesive, the nanoscale material, the solvent and the soft magnetic material to prepare a soft magnetic composite material; and S2 performs granulation and drying treatment on the soft magnetic composite material to remove the solvent, so as to obtain a finished soft magnetic composite powder.

[0007] As a further improvement of the present solution, the organic resin adhesive comprises any one or more of an epoxy resin adhesive, a phenolic resin adhesive, a cyanate ester adhesive, a silicone resin adhesive, an aromatic polyamine adhesive, an acid anhydride adhesive, a dicyandiamide adhesive and a hydrazide adhesive.

[0008] As a further improvement of the present solution, the nanoscale material comprises any one or several of nanoscale silicon dioxide, nanoscale aluminum oxide, nanoscale magnesium oxide and nanoscale cerium oxide.

[0009] As a further improvement of the present solution, the soft magnetic material comprises one or several of carbonyl iron powder, iron-silicon-chromium powder, amorphous iron powder and nanocrystalline iron powder.

[0010] As a further improvement of the present solution, the soft magnetic material is a mixture of Fe92Si3.5Cr4.5 with D50=10 μm and carbonyl iron powder with D50=6 μm in a ratio of 8:2, and both of the soft magnetic powders are passivated by 0.2% phosphoric acid.

[0011] As a further improvement of the present solution, the adhesive is a mixture of an epoxy resin adhesive and a cyanate ester adhesive.

[0012] As a further improvement of the present solution, the nanoscale material is any one or more of 100 nm silicon dioxide, 500 nm silicon dioxide and 500 nm aluminum oxide.

[0013] The present application has the following advantages: 1) The causes of cracking in the cold-pressing process of the prior art are as follows: (1) The pressing force in the cold-pressing process reaches 7-8 T / cm^2, which results in a large demolding force received by the product, and the overall bonding strength of the product cannot resist the demolding force. (2) In order to pursue product performance, the coil column is designed to be large, and the product wall thickness is thin.

[0014] In view of the above, the present application fills nanoscale materials in the glue to improve the strength of the glue before curing, thereby improving the pre-baking strength of the soft magnetic composite material, and then improving the overall strength of the product after the sample product is prepared, thereby effectively improving the cracking phenomenon in the cold-pressing process of the product and improving the appearance straight-through rate of the product.

[0015] 2) By filling the glue with nanomaterials, the pre-baking collapse strength of the soft magnetic composite powder is greatly improved without changing the overall formula of the powder material and the overall electromagnetic performance, thereby improving the overall strength of the cold-pressed sample product, resisting the tearing of the product electrode surface and C surface by the demolding force, improving the appearance of the cold-pressed sample product, and improving the appearance of the cold-pressed sample product. 3) The addition amount of the nanomaterial is relatively low, and the overall cost of the soft magnetic composite powder material is not greatly improved, and the cost is within a controllable range.

[0016] FIG. Figure 1 The inductance structure diagram in the application; 10-C surface demolding surface; 20-electrode surface demolding surface; Figure 2 The inductance demolding surface cracking mode in the application is electrode surface cracking; Figure 3 The inductance demolding surface cracking mode in the application is electrode surface cracking; Figure 4 The inductance demolding surface cracking mode in the application is electrode surface cracking. DETAILED DESCRIPTION

[0017] The application will be further described in combination with the following specific examples and drawings. The process, conditions, experimental methods, etc. for implementing the application are the general knowledge and common sense in the art, and the application does not have special restrictions.

[0018] The soft magnetic material powder used in the following examples and comparative examples is Fe92Si3.5Cr4.5 with D50=10pm and carbonyl iron powder with D50=6pm=8:2. Both kinds of soft magnetic powder are passivated with 0.2% phosphoric acid. The above powder material is mixed with the mixed adhesive, nanomaterial and acetone solvent and fully stirred to obtain a soft magnetic composite material. The obtained soft magnetic composite material is placed in an oven at 60°C for 60 minutes for drying treatment to obtain a final product powder. The adhesive includes: 1, epoxy resin adhesive; 2, cyanate ester adhesive; The nanomaterial includes: 1, 100nm silicon dioxide; 2, 500nm silicon dioxide; 3, 500nm aluminum oxide; The appearance of the cold-pressed sample product is tested by adjusting the mass ratio of the adhesive to the nanomaterial. The following product sample machine type is 0420-180.

[0019] Example 1 The soft magnetic material powder, (epoxy resin: 100 nm silicon dioxide), and acetone are mixed in a mass ratio of 100:5 (100:2):12, stirred uniformly, granulated to form a soft magnetic composite material, and the prepared soft magnetic composite material is placed in an oven for baking, with a baking temperature of 60°C and a baking time of 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare sample 0420-180 products, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding.

[0020] The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare sample 0420-180 products, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding.

[0021] Example 2 The soft magnetic material powder, (epoxy resin: 100 nm silicon dioxide), and acetone are mixed in a mass ratio of 100:5 (100:2):12, stirred uniformly, granulated to form a soft magnetic composite material, and the prepared soft magnetic composite material is placed in an oven for baking, with a baking temperature of 60°C and a baking time of 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare sample 0420-180 products, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding.

[0022] Example 3 The soft magnetic material powder, (epoxy resin: 100 nm silicon dioxide), and acetone are mixed in a mass ratio of 100:5 (100:2):12, stirred uniformly, granulated to form a soft magnetic composite material, and the prepared soft magnetic composite material is placed in an oven for baking, with a baking temperature of 60°C and a baking time of 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare sample 0420-180 products, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding. The soft magnetic material powder, (epoxy resin: 100 nm silicon dioxide), and acetone are mixed in a mass ratio of 100:5 (100:2):12, stirred uniformly, granulated to form a soft magnetic composite material, and the prepared soft magnetic composite material is placed in an oven for baking, with a baking temperature of 60°C and a baking time of 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare sample 0420-180 products, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding.

[0023] Example 5 The soft magnetic material powder, (cyanate ester resin: 500 nm silicon dioxide), and acetone are mixed in a mass ratio of 100:5 (100:2): 12, stirred uniformly, granulated to form a soft magnetic composite material, and the prepared soft magnetic composite material is placed in an oven for baking, with a baking temperature of 60°C and a baking time of 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare a sample 0420-180 product, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding.

[0024] Example 6 The soft magnetic material powder, (cyanate ester resin: 500 nm silicon dioxide), and acetone are mixed in a mass ratio of 100:5 (100:2): 12, stirred uniformly, granulated to form a soft magnetic composite material, and the prepared soft magnetic composite material is placed in an oven for baking, with a baking temperature of 60°C and a baking time of 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare a sample 0420-180 product, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding.

[0025] Example 7 The soft magnetic material powder, (epoxy resin: 500 nm aluminum oxide), and acetone are mixed in a mass ratio of 100:5 (100:2): 12, stirred uniformly, granulated to form a soft magnetic composite material, and the prepared soft magnetic composite material is placed in an oven for baking, with a baking temperature of 60°C and a baking time of 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare a sample 0420-180 product, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding.

[0026] Example 8 The soft magnetic material powder, (epoxy resin: 500 nm aluminum oxide), and acetone are mixed in a mass ratio of 100:5 (100:2): 12, stirred uniformly, granulated to form a soft magnetic composite material, and the prepared soft magnetic composite material is placed in an oven for baking, with a baking temperature of 60°C and a baking time of 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed in a 04 size cold pressing mold for pressing to prepare a sample 0420-180 product, with a pressure of 7.4 T / cm^2, and the product appearance is observed after demolding.

[0027] Comparative Example 1 The soft magnetic material powder, epoxy resin and acetone are mixed in a mass ratio of 100:5:12, granulated after uniform stirring, to form a soft magnetic composite material, the prepared soft magnetic composite material is placed into an oven for baking, the baking temperature is set to 60 DEG C, and the baking time is 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed into a 04 size cold pressing mold for pressing, to prepare a sample 0420-180 product, and the sample preparation conditions are: pressure 7.4 T / cm^2, and the product appearance is observed after demolding after pressing.

[0028] Comparative Example 2 The soft magnetic material powder, epoxy resin and acetone are mixed in a mass ratio of 100:5:12, granulated after uniform stirring, to form a soft magnetic composite material, the prepared soft magnetic composite material is placed into an oven for baking, the baking temperature is set to 60 DEG C, and the baking time is 60 min, to obtain a soft magnetic composite powder. The soft magnetic composite material is placed into a 04 size cold pressing mold for pressing, to prepare a sample 0420-180 product, and the sample preparation conditions are: pressure 7.4 T / cm^2, and the product appearance is observed after demolding after pressing. From the test results in Table 1 and Table 2, it can be known that: 1) through filling the nanomaterial in the glue, the pre-baking collapse strength of the soft magnetic composite powder is greatly improved without changing the overall formula of the powder material and the overall electromagnetic performance of the powder material, so that the overall strength of the cold-pressed sample product is improved, the tearing of the electrode surface and the C surface of the product by the demolding force is resisted, the appearance of the product after cold-pressed sample is improved, and the appearance direct pass rate of the cold-pressed sample product is improved; 2) the addition amount of the nanomaterial is relatively low, and the overall cost of the soft magnetic composite powder material is not greatly improved, and the cost is within a controllable range.

[0029] The protection scope of the present application is not limited to the above examples. Changes and advantages that can be thought of by those skilled in the art without departing from the spirit and scope of the present application are included in the present application, and are claimed in the appended claims.

Claims

1. A method for preparing a crack-proof molded inductor, characterized in that: The method comprises the following preparation steps: S1: mixing an organic resin adhesive, a nano-scale material, a solvent and a soft magnetic material to prepare a soft magnetic composite material; S2: granulating and drying the soft magnetic composite material to remove the solvent to obtain the desired finished soft magnetic composite powder.

2. The method for preparing the crack-proof molded inductor according to claim 1, wherein: The organic resin adhesive includes any one or more of epoxy resin adhesive, phenolic resin adhesive, cyanate adhesive, silicone resin adhesive, aromatic polyamine adhesive, acid anhydride adhesive, dicyandiamide adhesive and hydrazide adhesive.

3. The method for preparing the anti-cracking molded inductor according to claim 1 according to claim 2, characterized in that: The nano-scale material includes any one or more of nano-scale silicon dioxide, nano-scale aluminum oxide, nano-scale magnesium oxide, and nano-scale cerium oxide.

4. The method for preparing the anti-cracking molded inductor according to claim 1, characterized in that: The soft magnetic material includes one or a mixture of carbonyl iron powder, iron silicon chromium powder, amorphous iron powder, and nanocrystalline iron powder.

5. The method for preparing the anti-cracking molded inductor according to claim 1 according to claim 4, characterized in that: The soft magnetic material is Fe92Si3.5Cr4.5 with D50=10 μm and carbonyl iron powder with D50=6 μm in a ratio of 8:

2. Both soft magnetic powders are passivated with 0.2% phosphoric acid.

6. The method for preparing the anti-cracking molded inductor according to claim 1 according to claim 2, characterized in that: The adhesive is a mixture of an epoxy resin adhesive and a cyanate adhesive.

7. The method for preparing the anti-cracking molded inductor according to claim 1 according to claim 2, characterized in that: The nanomaterial is any one or more of 100nm silicon dioxide, 500nm silicon dioxide, and 500nm aluminum oxide.

Images