A high-Q power inductor

Abstract

This invention discloses a high-Q power inductor. A first magnetic adhesive covers the winding, and a second magnetic adhesive covers the area excluding the electrodes. Due to the higher content of a second resin in the first magnetic adhesive, the second resin can better encapsulate the winding, preventing voids, reducing losses, and ensuring magnetic performance. The adhesive in the second magnetic adhesive is similar to that in the first magnetic adhesive, resulting in good adhesion between the two, further preventing voids, reducing losses, and ensuring magnetic performance. The combination of the first and second magnetic adhesives effectively prevents void formation. Furthermore, due to the different concentrations of the second resin, the induced eddy currents in the first and second magnetic adhesives differ. The permeability of the first magnetic adhesive, which is in direct contact with the winding, is lower than the induced eddy current of the second magnetic adhesive, thus fully meeting the requirements for low losses and improving the Q value of the device.

Description

Technical Field

[0001] This invention relates to the field of inductor technology, and more particularly to a high-Q power inductor. Background Technology

[0002] With the continuous increase in global data volume, data processing and storage have become booming industries, and distributed base stations and AI servers are poised for explosive growth. Both servers and terminal devices are placing higher demands on power consumption. The losses of inductor components are directly related to their Q value; increasing the Q value can effectively reduce losses. However, current inductors, due to high power requirements, often use alloy materials, which have significant eddy current losses and thus lower Q values. Furthermore, the surface-mount structure of these components results in uneven magnetic field distribution. Areas with high magnetic field density often experience large eddy currents due to high induced current, further contributing to a lower overall Q value and failing to meet current application requirements for low losses.

[0003] Therefore, existing technologies have shortcomings and need to be improved. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a power inductor with a high Q value to meet the requirement of low loss.

[0005] The technical solution of the present invention is as follows: A high-Q power inductor is provided, comprising: a magnet, a winding, a first magnetic adhesive, a second magnetic adhesive, and electrodes. The winding is wound around the magnet, and the electrodes are attached to the magnet. The leads of the winding are connected to the electrodes. The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the non-electrode surfaces of the first magnetic adhesive and the magnet. The magnet is composed of: 94 wt%-98 wt% magnetic alloy powder, 2 wt%-6 wt% magnetic alloy powder, and other components. The first magnetic adhesive and the second magnetic adhesive are both composed of composite magnetic powder and the second resin, with the first magnetic adhesive containing 11wt% to 20wt% of the second resin and the second magnetic adhesive containing 5wt% to 10wt% of the second resin. The composite magnetic powder includes Fe-based nanocrystals and other powders, wherein the other powders are at least one of carbonyl iron powder, FeSiCr, and FeSiAl. The Fe-based nanocrystals account for 50wt% to 75wt% of the composite magnetic powder, and the composition of the Fe-based nanocrystals is 54.5wt% to 75wt% Fe, 15wt% to 25wt% Co, 7wt% to 12wt% Ni, 1wt% to 3.5wt% Al, and 2wt% to 5.0wt% Si. The other powders account for 25wt% to 50wt% of the composite magnetic powder. The particle size of the Fe-based nanocrystals is 1 to 4 μm, and the particle size of the composite magnetic powder is 1 to 10 μm.

[0006] Fe-based nanocrystals are mainly composed of FeCo and FeNi composite nanocrystals, which can effectively improve the magnetic permeability of the material while reducing material loss and improving the Q value. Furthermore, by designing a material with low eddy current loss (i.e., the area around the winding) in the region with high magnetic field density (i.e., around the winding), the Q value of the device is improved. Simultaneously, by using a material with high magnetic permeability (and a second magnetic adhesive) in the region with low magnetic field density (i.e., the area outside the winding) to reduce the number of winding turns and lower the DC resistance of the copper wire, the device achieves low loss at both low and high power densities, thus meeting the application requirements for low-loss devices.

[0007] The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the area excluding the electrodes. Because the first magnetic adhesive has a higher content of the second resin, the second resin can better encapsulate the winding, preventing voids, reducing losses, and ensuring magnetic performance. The adhesive in the second magnetic adhesive is similar to that in the first magnetic adhesive, resulting in good adhesion between them, further preventing voids, reducing losses, and ensuring magnetic performance. The combination of the first and second magnetic adhesives effectively prevents void formation. Furthermore, due to the different concentrations of the second resin, the first and second magnetic adhesives have different permeabilities. The first magnetic adhesive, which is in direct contact with the winding, has a lower permeability than the second magnetic adhesive, fully meeting the low-loss requirements and improving the Q value of the device.

[0008] The magnetic alloy powder is at least one of FeSi, FeSiCr, and FeSiAl, wherein the Si content in the magnetic alloy powder is greater than 5.5 wt%, and the particle size of the magnetic alloy powder is 2 μm to 15 μm.

[0009] The first resin is one or at least two of epoxy resin, phenolic resin, and polyester resin.

[0010] The second resin is one or at least two of epoxy resin, phenolic resin, and polyester resin.

[0011] The magnet includes: a first support plate, a central column connected to the first support plate, and a second support plate connected to the central column; the winding is wound on the central column.

[0012] The electrode is welded to the lead wire of the winding.

[0013] Using the above scheme, the present invention provides a high-Q power inductor. A first magnetic adhesive covers the winding, and a second magnetic adhesive covers the area excluding the electrodes. Because the first magnetic adhesive has a higher content of a second resin, the second resin can better encapsulate the winding, preventing voids, reducing losses, and ensuring magnetic performance. The adhesive in the second magnetic adhesive is similar to that in the first magnetic adhesive, resulting in good adhesion between the two, further preventing voids, reducing losses, and ensuring magnetic performance. The combination of the first and second magnetic adhesives effectively prevents void formation. Furthermore, due to the different concentrations of the second resin, the induced eddy currents in the first and second magnetic adhesives differ. The permeability of the first magnetic adhesive, which is in direct contact with the winding, is lower than the induced eddy current of the second magnetic adhesive, thus fully meeting the low-loss requirement and improving the Q value of the device. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0016] Please see Figure 1 This invention provides a high-Q power inductor, comprising: a magnet, a winding 10, a first magnetic adhesive 11, a second magnetic adhesive 12, and an electrode 13. The winding 10 is wound around the magnet, and the electrode 13 is attached to the magnet. The leads of the winding 10 are connected to the electrode 13. The first magnetic adhesive 11 covers the winding 10, and the second magnetic adhesive 12 covers the first magnetic adhesive 11 and the non-electrode 13 surface of the magnet. The magnet is composed of: 94 wt%-98 wt% magnetic alloy powder, 2... The first magnetic adhesive is composed of wt%-6wt% of a first resin; both the first and second magnetic adhesives are composed of composite magnetic powder and a second resin, wherein the content of the second resin in the first magnetic adhesive is 11wt%~20wt%, and the content of the second resin in the second magnetic adhesive is 5wt%~10wt%; the composite magnetic powder includes: Fe-based nanocrystals and other powders, wherein the other powders are at least one of carbonyl iron powder, FeSiCr, and FeSiAl; the Fe-based nanocrystals account for 50wt%~75wt% of the composite magnetic powder, and the composition of the Fe-based nanocrystals is 54.5wt%~75wt% Fe, 15wt%~25wt% Co, 7wt%~12wt% Ni, 1wt%~3.5wt% Al, and 2wt%~5.0wt% Si; the other powders account for 25wt%~50wt% of the composite magnetic powder; the particle size of the Fe-based nanocrystals is 1~4µm, and the particle size of the composite magnetic powder is 1~10µm.

[0017] The magnetic alloy powder is at least one of FeSi, FeSiCr, and FeSiAl, wherein the Si content in the magnetic alloy powder is greater than 5.5 wt%, and the particle size of the magnetic alloy powder is 2 μm to 15 μm.

[0018] The first resin is one or at least two of epoxy resin, phenolic resin, and polyester resin.

[0019] The second resin is one or at least two of epoxy resin, phenolic resin, and polyester resin.

[0020] The magnet includes: a first support plate 14, a central column 15 connected to the first support plate 14, and a second support plate 16 connected to the central column 15; the winding 10 is wound on the central column 15.

[0021] The electrode 13 is welded to the lead wire of the winding 10.

[0022] Example 1

[0023] This embodiment provides a high-Q power inductor, comprising: a magnet, a winding, a first magnetic adhesive, a second magnetic adhesive, and electrodes. The winding is wound around the magnet, and the electrodes are attached to the magnet. The leads of the winding are connected to the electrodes. The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the non-electrode surfaces of the first magnetic adhesive and the magnet. The magnet is composed of 95 wt% magnetic alloy powder and 5 wt% first resin. The first magnetic adhesive is composed of Fe-based nanocrystals, FeSiCr, and 20 wt% second resin. The Fe-based nanocrystals and FeSiCr form a composite magnetic powder, with the Fe-based nanocrystals comprising the majority of the composite magnetic powder. The final 75 wt% of the composite magnetic powder consists of Fe-based nanocrystals, FeSiCr, and 5 wt% of a second resin; the composite magnetic powder is composed of Fe-based nanocrystals and FeSiCr, with the Fe-based nanocrystals comprising 75 wt% of the composite magnetic powder, the Fe-based nanocrystals having a composition of 75 wt% Fe, 15 wt% Co, 7 wt% Ni, 1 wt% Al, and 2 wt% Si; the FeSiCr comprising 25 wt% of the composite magnetic powder; the particle size of the Fe-based nanocrystals being 1~4 μm, and the particle size of the FeSiCr being 1~10 μm.

[0024] The magnetic alloy powder is FeSiCr, the Si content in the magnetic alloy powder is greater than 6.0 wt%, and the particle size of the magnetic alloy powder is 2 μm to 15 μm.

[0025] The first resin is epoxy resin. The second resin is epoxy resin.

[0026] The magnet includes: a first support plate, a central column connected to the first support plate, and a second support plate connected to the central column; the winding is wound on the central column.

[0027] The electrode is welded to the lead wire of the winding.

[0028] Example 2

[0029] This embodiment provides a high-Q power inductor, comprising: a magnet, a winding, a first magnetic adhesive, a second magnetic adhesive, and electrodes. The winding is wound around the magnet, and the electrodes are attached to the magnet. The leads of the winding are connected to the electrodes. The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the non-electrode surfaces of the first magnetic adhesive and the magnet. The magnet is composed of 95 wt% magnetic alloy powder and 5 wt% first resin. The first magnetic adhesive is composed of Fe-based nanocrystals, FeSiCr, and 16 wt% second resin. The Fe-based nanocrystals and FeSiCr form a composite magnetic powder, with the Fe-based nanocrystals accounting for 65 wt% and the FeSiCr accounting for 35 wt%. The second magnetic adhesive is composed of Fe-based nanocrystals, FeSiCr, and 8 wt% second resin. The Fe-based nanocrystals and FeSiCr form a composite magnetic powder, with the Fe-based nanocrystals accounting for 60 wt% of the composite magnetic powder. The composition of the Fe-based nanocrystals is 64 wt% Fe, 20 wt% Co, 10 wt% Ni, 2.5 wt% Al, and 3.5 wt% Fe. wt% Si; the FeSiCr accounts for 40wt% of the composite magnetic powder; the particle size of the Fe-based nanocrystals is 1~4µm, and the particle size of the FeSiCr is 1~10µm.

[0030] The magnetic alloy powder is FeSiAl, the Si content in the magnetic alloy powder is greater than 8.5wt%, and the particle size of the magnetic alloy powder is 2um~15um.

[0031] The first resin is a combination of epoxy resin and phenolic resin, with a mass ratio of epoxy resin to phenolic resin of 1.5:1.

[0032] The second resin is a combination of epoxy resin and phenolic resin, with a mass ratio of epoxy resin to phenolic resin of 1.5:1.

[0033] The magnet includes: a first support plate, a central column connected to the first support plate, and a second support plate connected to the central column; the winding is wound on the central column.

[0034] The electrode is welded to the lead wire of the winding.

[0035] Example 3

[0036] This embodiment provides a high-Q power inductor, comprising: a magnet, a winding, a first magnetic adhesive, a second magnetic adhesive, and electrodes. The winding is wound around the magnet, and the electrodes are attached to the magnet. The leads of the winding are connected to the electrodes. The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the non-electrode surfaces of the first magnetic adhesive and the magnet. The magnet is composed of 95 wt% magnetic alloy powder and 5 wt% first resin. The first magnetic adhesive is composed of Fe-based nanocrystals, carbonyl iron powder, and 11 wt% second resin. The Fe-based nanocrystals and carbonyl iron powder form a composite magnetic powder, with the Fe-based nanocrystals and carbonyl iron powder each accounting for 50 wt% of the composite magnetic powder. The second magnetic adhesive is composed of Fe-based nanocrystals, carbonyl iron powder, and 10 wt% second resin. The Fe-based nanocrystals and carbonyl iron powder form a composite magnetic powder, with the Fe-based nanocrystals accounting for 50 wt% of the composite magnetic powder. The Fe-based nanocrystals have a composition of 54.5 wt% Fe, 25 wt% Co, and 12 wt% Ni. 3.5wt%Al, 5.0wt%Si; the carbonyl iron powder accounts for 50wt% of the composite magnetic powder; the particle size of the Fe-based nanocrystals is 1~4µm, and the particle size of the carbonyl iron powder is 1~10µm.

[0037] The magnetic alloy powder is FeSi, the Si content in the magnetic alloy powder is greater than 6.5wt%, and the particle size of the magnetic alloy powder is 2um~15um.

[0038] The first resin is epoxy resin and polyester resin, wherein the mass ratio of epoxy resin to polyester resin is 1.2:1.

[0039] The second resin is epoxy resin and polyester resin, wherein the mass ratio of epoxy resin to polyester resin is 1.2:1.

[0040] The magnet includes: a first support plate, a central column connected to the first support plate, and a second support plate connected to the central column; the winding is wound on the central column.

[0041] The electrode is welded to the lead wire of the winding.

[0042] Comparative Example 1

[0043] This embodiment provides a power inductor, comprising: a magnet, a winding, a first magnetic adhesive, a second magnetic adhesive, and electrodes. The winding is wound around the magnet, and the electrodes are attached to the magnet. The leads of the winding are connected to the electrodes. The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the non-electrode surfaces of the first magnetic adhesive and the magnet. The magnet is composed of 95 wt% magnetic alloy powder and 5 wt% first resin. Both the first and second magnetic adhesives are composed of Fe-based nanocrystals, FeSiCr, and the second resin, wherein the content of the second resin is 20 wt%. The Fe-based nanocrystals and FeSiCr form a composite magnetic powder, with the Fe-based nanocrystals accounting for 75 wt% of the composite magnetic powder. The composition of the Fe-based nanocrystals is 75 wt% Fe, 15 wt% Co, 7 wt% Ni, 1 wt% Al, and 2 wt% Si. The FeSiCr accounts for 25 wt% of the composite magnetic powder. The particle size of the Fe-based nanocrystals is 1~4 μm, and the particle size of the FeSiCr is 1~10 μm.

[0044] The magnetic alloy powder is FeSiCr, the Si content in the magnetic alloy powder is greater than 6.0 wt%, and the particle size of the magnetic alloy powder is 2 μm to 15 μm.

[0045] The first resin is epoxy resin.

[0046] The second resin is epoxy resin.

[0047] The magnet includes: a first support plate, a central column connected to the first support plate, and a second support plate connected to the central column; the winding is wound on the central column.

[0048] The electrode is welded to the lead wire of the winding.

[0049] Comparative Example 2

[0050] This embodiment provides a power inductor, comprising: a magnet, a winding, a first magnetic adhesive, a second magnetic adhesive, and electrodes. The winding is wound around the magnet, and the electrodes are attached to the magnet. The leads of the winding are connected to the electrodes. The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the non-electrode surfaces of the first magnetic adhesive and the magnet. The magnet is composed of 95 wt% magnetic alloy powder and 5 wt% first resin. Both the first and second magnetic adhesives are composed of Fe-based nanocrystals, FeSiCr, and the second resin, wherein the content of the second resin is 5 wt%. The Fe-based nanocrystals and FeSiCr form a composite magnetic powder, with the Fe-based nanocrystals accounting for 75 wt% of the composite magnetic powder. The composition of the Fe-based nanocrystals is 75 wt% Fe, 15 wt% Co, 7 wt% Ni, 1 wt% Al, and 2 wt% Si. The FeSiCr accounts for 25 wt% of the composite magnetic powder. The particle size of the Fe-based nanocrystals is 1~4 μm, and the particle size of the FeSiCr is 1~10 μm.

[0051] The magnetic alloy powder is FeSiCr, the Si content in the magnetic alloy powder is greater than 6.0 wt%, and the particle size of the magnetic alloy powder is 2 μm to 15 μm.

[0052] The first resin is epoxy resin.

[0053] The second resin is epoxy resin.

[0054] The magnet includes: a first support plate, a central column connected to the first support plate, and a second support plate connected to the central column; the winding is wound on the central column.

[0055] The electrode is welded to the lead wire of the winding.

[0056] Comparative Example 3

[0057] This embodiment provides a power inductor, comprising: a magnet, a winding, a first magnetic adhesive, a second magnetic adhesive, and electrodes. The winding is wound around the magnet, and the electrodes are attached to the magnet. The leads of the winding are connected to the electrodes. The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the non-electrode surfaces of the first magnetic adhesive and the magnet. The magnet is composed of 95 wt% magnetic alloy powder and 5 wt% first resin. Both the first and second magnetic adhesives are composed of FeSiCr and the second resin, wherein the content of the second resin is 5 wt%. The particle size of the FeSiCr is 1~10 μm.

[0058] The magnetic alloy powder is FeSiCr, the Si content in the magnetic alloy powder is greater than 6.0 wt%, and the particle size of the magnetic alloy powder is 2 μm to 15 μm.

[0059] The first resin is epoxy resin.

[0060] The second resin is epoxy resin.

[0061] The magnet includes: a first support plate, a central column connected to the first support plate, and a second support plate connected to the central column; the winding is wound on the central column.

[0062] The electrode is welded to the lead wire of the winding.

[0063] Performance tests were conducted on the products made in Examples 1-3 and Comparative Examples 1-3. The product dimensions were 1.6 mm (length) * 0.8 mm (width) * 0.8 mm (height). The inductance and Q value of the samples at the initial permeability μi (1V / 1MHz) were measured using a 3260B LCR meter. The test results are shown in Table 1.

[0064] Table 1. Performance comparison of Examples 1-3 and Comparative Examples 1-3

[0065]

[0066] When comparing the inductors of the same specifications prepared in the example and the comparative example, the Q value of the example is significantly higher than that of the comparative example, indicating that the optimization of material composition and product structure can significantly improve the Q value of the device, thereby benefiting the reduction of losses.

[0067] In summary, this invention provides a high-Q power inductor. A first magnetic adhesive covers the winding, and a second magnetic adhesive covers the area excluding the electrodes. Due to the higher content of the second resin in the first magnetic adhesive, the second resin can better encapsulate the winding, preventing voids, reducing losses, and ensuring magnetic performance. The adhesive in the second magnetic adhesive is similar to that in the first magnetic adhesive, resulting in good adhesion between the two, further preventing voids, reducing losses, and ensuring magnetic performance. The combination of the first and second magnetic adhesives effectively prevents void formation. Furthermore, due to the different concentrations of the second resin, the induced eddy currents in the first and second magnetic adhesives differ. The permeability of the first magnetic adhesive, which is in direct contact with the winding, is lower than the induced eddy current of the second magnetic adhesive, thus fully meeting the low-loss requirement and improving the Q value of the device.

[0068] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-Q power inductor, characterized in that, include: The system comprises a magnet, a winding, a first magnetic adhesive, a second magnetic adhesive, and electrodes. The winding is wound around the magnet, and the electrodes are attached to the magnet. The leads of the winding are connected to the electrodes. The first magnetic adhesive covers the winding, and the second magnetic adhesive covers the non-electrode surfaces of the first magnetic adhesive and the magnet. The magnet is composed of 94wt%-98wt% magnetic alloy powder and 2wt%-6wt% first resin. Both the first and second magnetic adhesives are composed of composite magnetic powder and second resin. The first magnetic adhesive contains 11wt%~20wt% of second resin, and the second magnetic adhesive contains 5wt% of second resin. The composite magnetic powder comprises 50 wt% to 10 wt% of Fe-based nanocrystals and other powders, wherein the other powders are at least one of carbonyl iron powder, FeSiCr, and FeSiAl; the Fe-based nanocrystals account for 50 wt% to 75 wt% of the composite magnetic powder, and the composition of the Fe-based nanocrystals is 54.5 wt% to 75 wt% Fe, 15 wt% to 25 wt% Co, 7 wt% to 12 wt% Ni, 1 wt% to 3.5 wt% Al, and 2 wt% to 5.0 wt% Si; the particle size of the Fe-based nanocrystals is 1 to 4 μm, and the particle size of the other powders is 1 to 10 μm.

2. The high-Q power inductor according to claim 1, characterized in that, The magnetic alloy powder is at least one of FeSi, FeSiCr, and FeSiAl, wherein the Si content in the magnetic alloy powder is greater than 5.5 wt%, and the particle size of the magnetic alloy powder is 2 μm to 15 μm.

3. A high-Q power inductor according to claim 1, characterized in that, The first resin is one or at least two of epoxy resin, phenolic resin, and polyester resin.

4. A high-Q power inductor according to claim 1, characterized in that, The second resin is one or at least two of epoxy resin, phenolic resin, and polyester resin.

5. A high-Q power inductor according to claim 1, characterized in that, The magnet includes: a first support plate, a central column connected to the first support plate, and a second support plate connected to the central column; the winding is wound on the central column.

6. A high-Q power inductor according to claim 1, characterized in that, The electrode is welded to the lead wire of the winding.

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