A process for producing a non-solidified inductor

Abstract

The present application relates to the technical field of inductance, especially to the IPC H01F41 field, more particularly to a production process of non-solidified inductance. The process comprises the following steps: step 1: cold pressing powders into flat-core, U-core and R-bar respectively; step 2: winding coils; step 3: folding the corners of the coils and assembling them on the flat-core; step 4: assembling the R-bar in the middle of the coils and placing it in the U-core to expose the lead wires, obtaining a U-core combination; step 5: hot pressing the U-core combination; and step 6: stripping paint, brushing tin paste and spraying water-based paint on the exposed lead wires in sequence. The powders are cold pressed into flat-core, U-core and R-bar respectively, and then assembled and hot pressed, so that the high-temperature stability and inductance characteristics of the inductance can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inductance, in particular to the IPC H01F41 field, and more particularly to a production process of non-solidified inductance. BACKGROUND

[0002] Inductance elements are widely used in electronic circuit industry. Traditional inductors mainly wind enameled wire outside the magnetic conductor to form a wire-wound inductor, but have defects of low inductance value and poor DC saturation resistance. The traditional inductors have been gradually replaced by one-piece inductors with low DC impedance, good noise reduction effect and excellent magnetic shielding effect. However, the existing one-piece inductors are difficult to solve the problems of conductor coil deformation and electrode lifting, and cannot meet the application requirements.

[0003] CN114388249A provides a high-performance T-core process one-piece inductor and a preparation method thereof. The preparation method of the one-piece inductor is as follows: (1) a servo powder forming machine is used to form a T-core by beating the magnetic powder, the formed T-core is baked, and then a winding machine is used for winding; (2) the T-core after winding is put into a powder filling and hot pressing integrated machine for powder filling and hot pressing forming to obtain a formed inductor product; (3) the formed inductor product of step (2) is sequentially baked, ground and sprayed; (4) the formed inductor product of step (3) is subjected to laser treatment and electroplating, and the one-piece inductor is obtained. The inductor provided by the application still maintains excellent temperature rise characteristics and high Q value and other inductance characteristics in complex environments, but the one-piece structure has the defects of uneven heating and powder density uniformity in the hot pressing forming process, which affects the high temperature stability of the inductor to some extent. SUMMARY

[0004] In order to overcome the defects in the background art, the present application provides a split type inductance production process. The required parts are produced by cold pressing process before hot pressing, which effectively improves the inductance value and reduces the decay value of the saturation current. At the same time, the prepared inductor has good high temperature resistance and salt spray resistance.

[0005] In order to achieve the purpose of the present application, the present application provides a production process of non-solidified inductance, comprising the following steps:

[0006] Step 1: cold pressing the powder into a flat-Core (flat type component), a U-core (U type component) and an R stick (core material) respectively;

[0007] Step 2: winding the coil;

[0008] Step 3: folding the corners of the coil and assembling on the flat-Core;

[0009] Step 4: assemble R bar in the middle of the coil, place in the U-core, expose the lead, get the U-core combination;

[0010] Step 5: hot-press the U-core combination;

[0011] Step 6: expose the lead, in turn, paint stripping, brush tin paste, spray water-based paint, and get it.

[0012] The applicant found that the high-temperature stability and inductance characteristics of the inductor can be improved by first cold-pressing the powder into a flat-core, a U-core, and an R bar, and then assembling and hot-pressing. The existing integrated structure has the defects of uneven heating and uneven density of the powder during hot-pressing, which affects the high-temperature stability of the inductor to some extent. It is possible that the uneven stress between the layers causes deformation at high temperature, and at the same time, the coil may displace, resulting in a decrease in inductance. Further research found that by adjusting the cold-pressing pressure of different components, the cold-pressing pressure of the flat-core is 0.8-1.5T / cm 2 , the pressure of the U-core is 0.2-0.7T / cm 2 , and the pressure of the R bar is 0.9-1.7T / cm 2 , which can further improve the high-temperature stability and inductance characteristics of the inductor. It is possible that the uneven heating caused by the temperature difference between the inner and outer layers of the inductor during hot-pressing is improved.

[0013] The composition of the powder includes FeNi powder 30-50 parts, carbonyl iron powder 10-20 parts, FeSiCr powder 20-40 parts, and silane coupling agent 0.5-2 parts by weight.

[0014] Preferably, the particle size of the powder is 100-500 mesh.

[0015] Preferably, the powder includes FeNi powder 32 parts, carbonyl iron powder 12 parts, FeSiCr powder 20 parts, and silane coupling agent 0.8 parts by weight.

[0016] Preferably, the particle size of the FeNi powder is 300 mesh, and the grade is FeNi50, which is purchased from Changsha Tianjiu Metal Material Co., Ltd.

[0017] Preferably, the particle size of the carbonyl iron powder is 300 mesh, which is purchased from Nangong Yintai Metal Material Co., Ltd.

[0018] Preferably, the particle size of the FeSiCr powder is 325 mesh, which is purchased from Quanzhou Tianzhi Alloy Material Technology Co., Ltd.

[0019] Preferably, the silane coupling agent is KH-563, which is purchased from Nanjing Quanxi Chemical Co., Ltd.

[0020] Preferably, the wire used in step 2 comprises a flat wire.

[0021] Further preferably, the thickness to width ratio of the flat wire is 1:(3-7).

[0022] More preferably, the thickness of the flat wire is 0.1-0.3mm.

[0023] Preferably, the gauge of the flat wire comprises one of 1.0x0.17mm (widthxthickness), 1.0x0.23mm.

[0024] The pressure of the flat-core cold press forming is 0.8-1.5T / cm 2 , the pressure of the U-core is 0.2-0.7T / cm 2 , the pressure of the R-bar is 0.9-1.7T / cm 2 .

[0025] Preferably, the pressure of the flat-core cold press forming is 1.0-1.5T / cm 2 , the pressure of the U-core is 0.4-0.6T / cm 2 , the pressure of the R-bar is 1.0-1.5T / cm 2 .

[0026] Further preferably, the pressure of the flat-core cold press forming is 1.2T / cm 2 , the pressure of the U-core is 0.5T / cm 2 , the pressure of the R-bar is 1.3T / cm 2 .

[0027] The preheating is performed before the hot press forming, the preheating temperature is 60-120℃, and the preheating time is 10-40s.

[0028] Preferably, the preheating is performed before the hot press forming, the preheating temperature is 80-110℃, and the preheating time is 20-30s.

[0029] The temperature of the hot press forming is 140-160℃.

[0030] Preferably, the temperature of the hot press forming is 145℃.

[0031] The pressure of the hot press forming is 0.4-0.8T / cm 2 , and the time is 20-60s.

[0032] Preferably, the pressure of the hot press forming is 0.5-0.6T / cm 2 , and the time is 30-50s.

[0033] The temperature of the solder paste is 240-250℃, and the thickness of the solder paste is 7-13μm.

[0034] Preferably, the temperature of the solder paste application is 245°C, and the thickness of the solder paste application is 9-13 μm.

[0035] The thickness of the water-based paint spray is 15-30 μm.

[0036] Preferably, the thickness of the water-based paint spray is 25 μm.

[0037] Preferably, the water-based paint is purchased from Xiamen Yingpai New Material Technology Co., Ltd., model: HY103.

[0038] Advantages:

[0039] 1. First, cold-press the powder into flat-core, U-core, and R-rod shapes, and then assemble and hot-press them to improve the high-temperature resistance and inductance characteristics of the inductor.

[0040] 2. The hot pressing temperature is 140-160℃. The forming pressure is 0.5-0.6T / cm. 2 The time is 30-50s, which can improve the inductance value of the inductor, achieve excellent saturation current, reduce losses, and improve the inductor's resistance to high temperature and high humidity.

[0041] 3. Preheating is performed before hot pressing. The preheating temperature is 60-120℃, and the preheating time is...

[0042] 10-40s can improve the inductor's resistance to high temperature and high humidity.

[0043] 4. The line used in step 2 includes a flat line, the thickness to width ratio of which is 1:(3-7), which can further improve the sensitivity. Attached Figure Description

[0044] Figure 1 The following is a simplified production process diagram for Example 1, where 1. Flat Core; 2. Winding; 3. Folded Line Combination; 4. U-core + R-bar; 5. Hot Pressing; 6. Laser Stripping; 7. Solder Paste Printing; 8. Test Packaging.

[0045] Figure 2 The electrode surface of the inductor prepared in Example 1.

[0046] Figure 3 The image shows a cross-sectional view of the inductor prepared in Example 1.

[0047] Figure 4 The image shows a cross-sectional view of the inductor prepared in Example 2.

[0048] Figure 5 The inductance characteristic measurement data of Example 1.

[0049] Figure 6 The inductance characteristic measurement data of Example 2. DETAILED DESCRIPTION

[0050] Example 1

[0051] A production process of non-solidified inductance, as shown in the following steps: Figure 1

[0052] Step 1: The powder is respectively cold-pressed into flat-Core (flat assembly), U-core (U-shaped assembly) and R stick (core material);

[0053] Step 2: winding the coil;

[0054] Step 3: folding the coil corner and assembling on the flat-Core;

[0055] Step 4: assembling the R stick in the middle of the coil and placing in the U-core, exposing the lead wire, to obtain the U-core combination;

[0056] Step 5: hot-pressing the U-core combination;

[0057] Step 6: stripping the paint, brushing the tin paste and spraying the water-based paint on the exposed lead wire in sequence, to obtain the inductance electrode surface, as shown in the following figure, and the cross-sectional view of the inductance, as shown in the following figure. Figure 2 Figure 3

[0058] The composition of the powder is: FeNi powder 32 parts, carbonyl iron powder 12 parts, FeSiCr powder 20 parts, silane coupling agent 0.8 parts by weight.

[0059] The FeNi powder has a particle size of 300 mesh, brand: FeNi50, purchased from Changsha Tianjiu Metal Material Co., Ltd.; the carbonyl iron powder has a particle size of 300 mesh, purchased from Nangong Yintai Metal Material Co., Ltd.; the FeSiCr powder has a particle size of 325 mesh, purchased from Quanzhou Tianzhi Alloy Material Technology Co., Ltd.; the silane coupling agent is KH-563, purchased from Nanjing Quanxi Chemical Co., Ltd.

[0060] The wire used in Step 2 is a flat wire, with a specification of 1.0×0.23mm, a middle column of 2.3mm, a number of turns of 5.75 turns, and a winding method of vertical winding.

[0061] The pressure for cold-pressing the flat-Core is 1.2T / cm 2 , the pressure for the U-core is 0.5T / cm 2 , and the pressure for the R stick is 1.3T / cm​​​2 .

[0062] The temperature of the cold-press forming is 25°C.

[0063] The preheating temperature is 100°C, and the preheating time is 20s.

[0064] The temperature of the hot-press forming is 145°C.

[0065] The pressure of the hot-press forming is 0.5T / cm 2 , and the time is 30s.

[0066] The temperature of the tin paste brushing is 245°C, and the thickness of the tin paste brushing is 12.6μm.

[0067] The thickness of the water-based paint spraying is 25μm.

[0068] The water-based paint is purchased from Xiamen Yingpai New Material Technology Co., Ltd., and the model is HY103.

[0069] Example 2

[0070] A production process of a non-solidified inductor includes the following steps:

[0071] Step 1: cold-press forming the powder into a flat-Core, a U-core, and an R rod, respectively;

[0072] Step 2: winding a coil;

[0073] Step 3: folding the corners of the coil and assembling on the flat-Core;

[0074] Step 4: assembling the R rod in the middle of the coil and placing in the U-core, exposing the lead wire, to obtain a U-core combination;

[0075] Step 5: hot-press forming the U-core combination;

[0076] Step 6: exposing the lead wire and sequentially performing paint stripping, tin paste brushing, and water-based paint spraying, to obtain the inductor, as shown in FIG. 5, which is a sectional view of the inductor. Figure 4

[0077] The powder includes, by weight: FeNi powder 32 parts, carbonyl iron powder 12 parts, FeSiCr powder 20 parts, and silane coupling agent 0.8 parts.

[0078] ​The FeNi powder particle size was 300 mesh, brand: FeNi50, purchased from Changsha Tianjiu Metal Material Co., Ltd.; the carbonyl iron powder particle size was 300 mesh, purchased from Nangong Yintai Metal Material Co., Ltd.; the FeSiCr powder particle size was 325 mesh, purchased from Quanzhou Tianzhi Alloy Material Technology Co., Ltd.; the silane coupling agent was KH-563, purchased from Nanjing Quanxi Chemical Co., Ltd.

[0079] The wire used in step 2 was a flat wire, the specification of which was 1.0*0.17 mm, the center column was 2.3 mm, the number of turns was 16.75 turns, and the winding method was vertical winding.

[0080] The pressure of the flat-core cold pressing forming was 1.2 T / cm 2 , the pressure of the U-core was 0.5 T / cm 2 , and the pressure of the R rod was 1.3 T / cm 2 .

[0081] The preheating temperature before hot pressing forming was 100°C, and the preheating time was 30 s.

[0082] The hot pressing forming temperature was 145°C.

[0083] The hot pressing forming pressure was 0.6 T / cm 2 , and the time was 50 s.

[0084] The temperature of the tin paste brushing was 245°C, and the thickness of the tin paste brushing was 9.2 μm.

[0085] The thickness of the water-based paint spraying was 25 μm.

[0086] The water-based paint was purchased from Xiamen Yingpai New Material Technology Co., Ltd., model: HY103.

[0087] Comparative Example 1

[0088] The specific implementation was the same as that of Example 1, except that the pressure of the flat-core cold pressing forming in Comparative Example 1 was 0.8 T / cm 2 , the pressure of the U-core was 0.8 T / cm 2 , and the pressure of the R rod was 0.8 T / cm 2 .

[0089] Comparative Example 2

[0090] The specific implementation was the same as that of Example 1, except that the hot pressing forming temperature in Comparative Example 2 was 135°C, the hot pressing forming pressure was 0.8 T / cm 2 , and the time was 15 s.

[0091] Performance test method

[0092] The inductance obtained in the examples and comparative examples was subjected to performance testing, and the test data is shown in Table 1.

[0093] 1. Salt spray resistance: The detection method refers to GB / T1771-2007. After 24 hours, the electrode surface rust area is less than 5%, which is qualified, otherwise unqualified;

[0094] 2. High temperature and high humidity test: The test environment temperature is 85℃, the humidity is 85%, after 24 hours, the electrode surface rust area is less than 2%, and the appearance does not appear warping deformation, which is qualified, otherwise unqualified;

[0095] 3. Inductance characteristic determination: including inductance value, direct current resistance, saturation current, according to GB / T 40853.1-2021 determination, the test results of example 2 are shown in Table 1. Figure 5 The inductance value is 6.667μh, the direct current resistance is 26.3mΩ, and the saturation current is 6.6A / 23.45%. The test results of example 1 are shown in Table 1. Figure 6 The inductance value is 0.989μh, the direct current resistance is 6.47mΩ, and the saturation current is 16.5A / 27.52%.

[0096] Performance test data

[0097] Table 1

[0098] Salt spray resistance High temperature and humidity resistance Inductance value DC resistance Saturation current Example 1 Pass Pass 0.99 μh 6.47 mΩ 16.5A / 27.52％ Example 2 Pass Pass 6.67 μh 26.3 mΩ 6.6A / 23.45％ Comparative Example 1 Pass Fail 0.90 μh 7.02 mΩ 16.5A / 29.32％ Comparative Example 2 Pass Fail 0.92 μh 6.84 mΩ 16.5A / 29.73％

Claims

1. A manufacturing process for a non-cured inductor, characterized in that, Includes the following steps: Step 1: Cold press the powder into flat-core, U-core, and R-rod shapes respectively; Step 2: Wind the coil; Step 3: Fold the coil at the corner and assemble it onto the flat core; Step 4: Assemble the R rod in the middle of the coil, place it in the U-core, exposing the leads, and obtain the U-core assembly; Step 5: Hot-press the U-core assembly; Step 6: Strip the exposed leads, apply solder paste, and spray water-based paint in sequence to obtain the powder composition by weight: 30-50 parts FeNi powder, 10-20 parts carbonyl iron powder, 20-40 parts FeSiCr powder, and 0.5-2 parts silane coupling agent. The pressure for the flat-core cold pressing is 0.8-1.5 T / cm. 2 The pressure of the U-core is 0.2-0.7 T / cm. 2 , The pressure on the R-bar is 0.9-1.7 T / cm. 2 ; Before hot pressing, the material is preheated at a temperature of 60-120°C for 10-40 seconds.

2. The manufacturing process for a non-cured inductor according to claim 1, characterized in that, The line used in step 2 includes a flat line, the thickness to width ratio of which is 1:(3-7).

3. The manufacturing process for a non-cured inductor according to claim 2, characterized in that, The thickness of the flat wire is 0.1-0.3 mm.

4. The manufacturing process for a non-cured inductor according to claim 3, characterized in that, The pressure for the flat-core cold pressing is 1.0-1.5T / cm. 2 The pressure of the U-core is 0.4-0.6 T / cm. 2 The pressure on the R-bar is 1.0-1.5 T / cm. 2 .

5. The manufacturing process for a non-cured inductor according to claim 4, characterized in that, The hot pressing temperature is 140-160℃.

6. The manufacturing process for a non-cured inductor according to claim 5, characterized in that, The pressure for hot pressing is 0.4-0.8 T / cm. 2 The hot pressing time is 20-60 seconds.

7. The manufacturing process for a non-cured inductor according to claim 1 or 6, characterized in that, The temperature of the solder paste is 240-250℃, and the thickness of the solder paste is 7-13μm.

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