A thin-film power inductor

Abstract

The present invention discloses a thin-film type power inductor. The thin-film type power inductor includes: a magnet, a first port electrode, and a second port electrode; when the number of coils of the thin-film type power inductor is not less than 2, the magnet includes at least one first sub-structure, and the first sub-structure includes a first upper functional layer, a first upper coil, a first upper glue layer, a first insulating layer, a first lower glue layer, a first lower coil, and a first lower functional layer which are sequentially stacked; the first upper coil and the first lower coil respectively have a first end and a second end; the first end of the first upper coil and the first end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the first port electrode; the second end of the first upper coil and the second end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the second port electrode. The thin-film type power inductor provided by the present invention has the advantages of simple structure, large inductance, small DC resistance, and convenient miniaturization, etc.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of electronic devices, and particularly to a thin-film power inductor. Background Art

[0002] An inductor (also known as a choke, a reactor, a dynamic reactor) is a component that can convert electrical energy into magnetic energy and store it. Power inductors are usually used in power supply circuits or intelligent electronic devices. Power inductors can be divided into three categories: stacked power inductors, thin-film power inductors, and wound power inductors.

[0003] According to the development trend of high frequency, miniaturization, and large current of intelligent devices, the size requirements of power inductors are getting smaller and the rated current requirements are getting higher. Stacked power inductors have poor anti-saturation performance, and it is difficult to reduce the thickness of wound power inductors. Therefore, thin-film power inductors with low DC resistance, high self-resonant frequency, large current-carrying capacity, and easy miniaturization and thinning have become the development trend of current power inductors.

[0004] In existing thin-film power inductors, holes need to be drilled or misaligned between coils, resulting in a complex structure of the thin-film power inductor and being difficult to manufacture. Summary of the Invention

[0005] The present invention provides a thin-film power inductor, which has the advantages of simple structure, large inductance, small DC resistance, and easy miniaturization.

[0006] In a first aspect, embodiments of the present invention provide a thin-film power inductor, including: a magnet, a first port electrode, and a second port electrode, and the first port electrode and the second port electrode are respectively arranged on the outer surface of the magnet;

[0007] When the number of coils of the thin-film power inductor is not less than 2, the magnet includes at least one first sub-structure, and the first sub-structure includes a first upper functional layer, a first upper coil, a first upper glue layer, a first insulating layer, a first lower glue layer, a first lower coil, and a first lower functional layer which are sequentially stacked;

[0008] The first upper coil and the first lower coil respectively have a first end and a second end; the first end of the first upper coil and the first end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the first port electrode; the second end of the first upper coil and the second end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the second port electrode.

[0009] Optionally, when the number of coils of the thin-film power inductor is 2n, the magnet includes n first sub-structures stacked, and n is a positive integer.

[0010] Optionally, when the number of coils of the thin-film power inductor is 2n + 1, the magnet includes one second sub-structure and n first sub-structures arranged in a stacked manner, where n is a positive integer;

[0011] The second sub-structure includes a second functional layer, a second coil, a second adhesive layer, and a second insulating layer arranged in a stacked manner in sequence;

[0012] The second coil has a first end and a second end; the first end of the second coil, the first end of the first upper coil, and the first end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the first port electrode; the second end of the second coil, the second end of the first upper coil, and the second end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the second port electrode.

[0013] Optionally, when the number of coils of the thin-film power inductor is 1, the magnet includes one third sub-structure;

[0014] The third sub-structure includes a third upper functional layer, a third coil, a third adhesive layer, a third insulating layer, and a third lower functional layer arranged in a stacked manner in sequence;

[0015] The third coil has a first end and a second end; the first end of the third coil is exposed to the surface of the magnet and is electrically connected to the first port electrode; the second end of the third coil is exposed to the surface of the magnet and is electrically connected to the second port electrode.

[0016] Optionally, when the number of coils of the thin-film power inductor is not less than 2, the coils are coupled to each other pairwise and have the same shape.

[0017] Optionally, when the number of coils of the thin-film power inductor is not less than 2, the thin-film power inductor is a common-mode power inductor or a differential-mode power inductor.

[0018] Optionally, when the thin-film power inductor is a common-mode power inductor, the coils are designed in the same direction pairwise;

[0019] When the thin-film power inductor is a differential-mode power inductor, the coils are designed in the opposite direction pairwise.

[0020] Optionally, the functional layer of the thin-film power inductor is made of a magnetic material.

[0021] Optionally, the magnetic material is a soft magnetic alloy.

[0022] Optionally, the coil of the thin-film power inductor is made of a metal or a metal alloy.

[0023] The present invention provides a thin-film type power inductor, comprising: a magnet, a first port electrode, and a second port electrode, wherein the first port electrode and the second port electrode are respectively disposed on the outer surface of the magnet; when the number of coils of the thin-film type power inductor is not less than 2, the magnet comprises at least one first sub-structure, and the first sub-structure comprises a first upper functional layer, a first upper coil, a first upper glue layer, a first insulating layer, a first lower glue layer, a first lower coil, and a first lower functional layer which are sequentially stacked; the first upper coil and the first lower coil respectively have a first end and a second end; the first end of the first upper coil and the first end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the first port electrode; the second end of the first upper coil and the second end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the second port electrode. Since the two ends of the coil of the thin-film type power inductor are directly exposed to the magnet surface and are respectively electrically connected to the first port electrode and the second port electrode, rapid extraction of the electrodes is realized; in addition, there is no need to punch holes for connection between the coils and there is no via hole layer, which facilitates further miniaturization. Compared with the existing thin-film type power inductor, the thin-film type power inductor provided by the present invention makes full use of the three-dimensional multi-layer space, significantly reduces the required volume of the component, and has the advantages of simple structure, large inductance, small DC resistance, and easy miniaturization. Description of the Drawings

[0024] Figure 1 is a three-dimensional structural schematic diagram of a thin-film type power inductor provided by an embodiment of the present invention;

[0025] Figure 2 is a cross-sectional structural schematic diagram of a first sub-structure provided by an embodiment of the present invention;

[0026] Figure 3 is a cross-sectional structural schematic diagram of a second sub-structure provided by an embodiment of the present invention;

[0027] Figure 4 is a cross-sectional structural schematic diagram of a third sub-structure provided by an embodiment of the present invention;

[0028] Figure 5 is a three-dimensional structural perspective view of a magnet with 2 coils provided by an embodiment of the present invention;

[0029] Figure 6 is a three-dimensional structural perspective view of a thin-film type power inductor with 2 coils provided by an embodiment of the present invention;

[0030] Figure 7 is a cross-sectional structural schematic diagram of a magnet with 4 coils provided by an embodiment of the present invention;

[0031] Figure 8 is a cross-sectional structural schematic diagram of a magnet with 3 coils provided by an embodiment of the present invention;

[0032] Figure 9 is a perspective view of the three - dimensional structure of a thin - film power inductor with three turns provided by an embodiment of the present invention;

[0033] Figure 10 is a schematic cross - sectional view of a magnet with five turns provided by an embodiment of the present invention

[0034] Figure 11 is a perspective view of the three - dimensional structure of a thin - film power inductor with one turn provided by an embodiment of the present invention. Detailed implementation manners

[0035] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of convenience of description, only parts related to the present invention rather than all structures are shown in the drawings.

[0036] Meanwhile, the descriptions of the drawings and embodiments are illustrative rather than restrictive. The same reference numerals throughout the specification represent the same elements. Additionally, for the sake of understanding and easy description, the sizes of some structures, regions, etc. may be exaggerated in the drawings. Additionally, unless explicitly described to the contrary, the words "comprising" and variations such as "including" or "having" will be understood to imply including the element, but not excluding any other element.

[0037] In the embodiments of the present invention, "first", "second", etc. are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another. And, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are also intended to include the plural forms.

[0038] When a certain embodiment can be implemented differently, the specific process sequence can be executed differently from the described sequence. For example, two consecutively described processes can be executed substantially at the same time or in the reverse order of the described sequence.

[0039] Next, the thin - film power inductor and its technical effects will be described in detail.

[0040] Figure 1 shows a schematic perspective view of a thin - film power inductor provided by an embodiment of the present invention. As Figure 1 shown, the thin - film power inductor includes: a magnet 10, a first port electrode 20, and a second port electrode 30. The first port electrode 20 and the second port electrode 30 are respectively disposed on the outer surface of the magnet 10.

[0041] In one embodiment, the first port electrode 20 is the input electrode IN of the thin-film power inductor, and the second port electrode 30 is the output electrode OUT of the thin-film power inductor; alternatively, the first port electrode 20 is the output electrode OUT of the thin-film power inductor, and the second port electrode 30 is the input electrode IN of the thin-film power inductor.

[0042] The first port electrode 20 and the second port electrode 30 can be formed by applying silver paste at the specified port positions of the magnet 10 and electroplating after low-temperature curing.

[0043] The number of coils (also known as inductance coils) included in the magnet 10 can be designed according to the inductance of the thin-film power inductor. Specifically, the number of coils can be any positive integer.

[0044] To describe in detail the structure of the magnet 10 with different numbers of coils, the first sub-structure, the second sub-structure, and the third sub-structure are introduced separately here.

[0045] Figure 2 FIG. shows a schematic cross-sectional structure diagram of a first sub-structure provided by an embodiment of the present invention. As Figure 2 shown, the first sub-structure includes a first upper functional layer A1, a first upper coil A2, a first glue layer A3, a first insulating layer A4, a first lower glue layer A5, a first lower coil A6, and a first lower functional layer A7 that are sequentially stacked.

[0046] Figure 3 FIG. shows a schematic cross-sectional structure diagram of a second sub-structure provided by an embodiment of the present invention. As Figure 3 shown, the second sub-structure includes a second functional layer B1, a second coil B2, a second glue layer B3, and a second insulating layer B4 that are sequentially stacked.

[0047] Figure 4 FIG. shows a schematic cross-sectional structure diagram of a third sub-structure provided by an embodiment of the present invention. As Figure 4 shown, the third sub-structure includes a third upper functional layer C1, a third coil C2, a third glue layer C3, a third insulating layer C4, and a third lower functional layer C5 that are sequentially stacked.

[0048] Combined with the above Figures 2 - 4It can be known that the functional layers can be: the first upper functional layer A1, the first lower functional layer A7, the second functional layer B1, the third upper functional layer C1, and the third lower functional layer C5. The functional layers can be made of the same material and the same manufacturing process, and here it is only used to distinguish the different positions of the functional layers. Similarly, the coils can be: the first upper coil A2, the first lower coil A6, the second coil B2, and the third coil C2; the adhesive layers can be: the first upper adhesive layer A3, the first lower adhesive layer A5, the second adhesive layer B3, and the third adhesive layer C3; the insulating layers can be: the first insulating layer A4, the second insulating layer B4, and the third insulating layer C4.

[0049] The functional layer is used to cover the coil to increase the inductance of the thin-film power inductor. The coil self-inductance generates inductance. The adhesive layer bonds the film layers on both sides of the adhesive layer together. The insulating layer is used to ensure insulation between the coils.

[0050] In the first possible implementation manner, when the number of coils of the thin-film power inductor is 2n (n is a positive integer), the magnet 10 includes n first sub-structures stacked on top of each other.

[0051] Exemplarily, when n = 1 (that is, the number of coils of the thin-film power inductor is 2), Figure 5 shows a perspective view of a three-dimensional structure of a magnet with 2 coils provided by an embodiment of the present invention; Figure 6 shows a perspective view of a three-dimensional structure of a thin-film power inductor with 2 coils provided by an embodiment of the present invention. As Figure 5 and Figure 6 shown, the first upper coil A2 and the first lower coil A6 respectively have a first end and a second end; the first end 111 of the first upper coil A2 and the first end 121 of the first lower coil A6 are exposed to the same surface of the magnet and are electrically connected to the first port electrode 20; the second end 112 of the first upper coil A2 and the second end 122 of the first lower coil A6 are exposed to the same surface of the magnet and are electrically connected to the second port electrode 30.

[0052] Another exemplarily, when n = 2 (that is, the number of coils of the thin-film power inductor is 4), Figure 7 shows a schematic cross-sectional structure of a magnet with 4 coils provided by an embodiment of the present invention. As Figure 7 shown, 2 first sub-structures are stacked on top of each other. In one embodiment, the adjacent first upper functional layer A1 and the first lower functional layer A7 can be one film layer and are formed in the same process.

[0053] In the second possible implementation manner, when the number of coils of the thin-film power inductor is 2n + 1 (n is a positive integer), the magnet 10 includes a second sub-structure and n first sub-structures stacked on top of each other.

[0054] Exemplarily, when n = 1 (i.e., the number of turns of the thin-film power inductor is 3), Figure 8 Fig. shows a schematic cross-sectional structure of a magnet with 3 turns according to an embodiment of the present invention; Figure 9 Fig. shows a perspective view of a three-dimensional structure of a thin-film power inductor with 3 turns according to an embodiment of the present invention. As Figure 8 and Figure 9 shown, the magnet includes a second sub-structure and a first sub-structure stacked on each other

[0055] The first upper coil A2, the first lower coil A6, and the second coil B2 each have a first end and a second end; the first ends 111 of the first upper coil A2, the first ends 121 of the first lower coil A6, and the first ends 131 of the second coil B2 are exposed to the same surface of the magnet and are electrically connected to the first port electrode 20; the second ends 112 of the first upper coil A2, the second ends 122 of the first lower coil A6, and the second ends 132 of the second coil B2 are exposed to the same surface of the magnet and are electrically connected to the second port electrode 30.

[0056] Another exemplarily, when n = 2 (i.e., the number of turns of the thin-film power inductor is 5), Figure 10 Fig. shows a schematic cross-sectional structure of a magnet with 5 turns according to an embodiment of the present invention. As Figure 10 shown, 1 second sub-structure and 2 first sub-structures are stacked. In one embodiment, the adjacent first upper functional layer A1 and the first lower functional layer A7 can be a single film layer and are formed in the same process.

[0057] In a third possible implementation, when the number of turns of the thin-film power inductor is 1, the magnet 10 includes a third sub-structure. Figure 11 Fig. shows a perspective view of a three-dimensional structure of a thin-film power inductor with 1 turn according to an embodiment of the present invention. As Figure 11 shown, the third coil C2 has a first end 111 and a second end 121; the first end 111 of the third coil C2 is exposed to the surface of the magnet and is electrically connected to the first port electrode 20; the second end 121 of the third coil C2 is exposed to the surface of the magnet and is electrically connected to the second port electrode 30.

[0058] Optionally, when the number of turns of the thin-film power inductor is not less than 2, the coils are mutually coupled pairwise and have the same shape. Thus, the inductance of the thin-film power inductor can be increased.

[0059] Optionally, when the number of turns of the thin-film power inductor is not less than 2, the thin-film power inductor is a common-mode power inductor or a differential-mode power inductor.

[0060] Optionally, when the thin-film power inductor is a common-mode power inductor, the coils are designed in the same direction pairwise, so that the DC resistance is reduced and the inductance is increased;

[0061] When the thin-film power inductor is a differential-mode power inductor, the coils are designed in the opposite direction pairwise, so that the DC resistance is increased and the inductance is reduced.

[0062] Optionally, the functional layer of the thin-film power inductor is made of a magnetic material. The magnetic material for making the functional layer can be subjected to insulation treatment.

[0063] Optionally, the magnetic material is a soft magnetic alloy. A soft magnetic alloy is a magnetic material with a high saturation magnetic flux density, a low coercive force, and a high magnetic permeability.

[0064] Optionally, the coils of the thin-film power inductor are made of a metal or a metal alloy. Specifically, it can be made of a metal or a metal alloy with a low resistivity.

[0065] Optionally, the size of the thin-film power inductor provided by the embodiments of the present invention can be set according to actual needs. For example, the size of the thin-film power inductor can be 1.2 mm × 1.0 mm × 0.3 mm, the line width is 100 μm, and the line thickness is 30 μm.

[0066] The present invention provides a thin-film power inductor, including: a magnet, a first port electrode, and a second port electrode, the first port electrode and the second port electrode are respectively arranged on the outer surface of the magnet; when the number of coils of the thin-film power inductor is not less than 2, the magnet includes at least one first sub-structure, the first sub-structure includes a first upper functional layer, a first upper coil, a first glue layer, a first insulating layer, a first lower glue layer, a first lower coil, and a first lower functional layer which are sequentially stacked; the first upper coil and the first lower coil respectively have a first end and a second end; the first end of the first upper coil and the first end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the first port electrode; the second end of the first upper coil and the second end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the second port electrode. Since the two ends of the coils of the thin-film power inductor are directly exposed to the magnet surface and are respectively electrically connected to the first port electrode and the second port electrode, the rapid extraction of the electrodes is realized; in addition, there is no need to punch holes for connection between the coils, there is no via hole layer, and there is no electrical connection, which is convenient for further miniaturization. Compared with the existing thin-film power inductor, the thin-film power inductor provided by the present invention makes full use of the three-dimensional multi-layer space, significantly reduces the volume required for the component, and has the advantages of simple structure, large inductance, small DC resistance, and easy miniaturization.

[0067] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A thin-film type power inductor, characterized in that, it includes: a magnet, a first port electrode, and a second port electrode, wherein the first port electrode and the second port electrode are respectively arranged on the outer surface of the magnet; the first port electrode and the second port electrode are formed by applying silver paste at the port position of the magnet and electroplating after low-temperature curing; when the number of coils of the thin-film type power inductor is not less than 2, the magnet includes at least one first sub-structure, and the first sub-structure includes a first upper functional layer, a first upper coil, a first upper glue layer, a first insulating layer, a first lower glue layer, a first lower coil, and a first lower functional layer which are sequentially stacked; the first upper coil and the first lower coil respectively have a first end and a second end; the first end of the first upper coil and the first end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the first port electrode; the second end of the first upper coil and the second end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the second port electrode.

2. The thin-film type power inductor according to claim 1, characterized in that, when the number of coils of the thin-film type power inductor is 2n, the magnet includes n first sub-structures stacked, and n is a positive integer.

3. The thin-film type power inductor according to claim 1, characterized in that, when the number of coils of the thin-film type power inductor is 2n + 1, the magnet includes a second sub-structure and n first sub-structures stacked, and n is a positive integer; the second sub-structure includes a second functional layer, a second coil, a second glue layer, and a second insulating layer which are sequentially stacked; the second coil has a first end and a second end; the first end of the second coil, the first end of the first upper coil, and the first end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the first port electrode; the second end of the second coil, the second end of the first upper coil, and the second end of the first lower coil are exposed to the same surface of the magnet and are electrically connected to the second port electrode.

4. The thin-film type power inductor according to claim 1, characterized in that, when the number of coils of the thin-film type power inductor is not less than 2, the coils are coupled to each other pairwise and have the same shape.

5. The thin-film type power inductor according to claim 1, characterized in that, when the number of coils of the thin-film type power inductor is not less than 2, the thin-film type power inductor is a common-mode power inductor or a differential-mode power inductor.

6. The thin-film type power inductor according to claim 5, characterized in that, when the thin-film type power inductor is a common-mode power inductor, the coils are designed in the same direction pairwise; when the thin-film type power inductor is a differential-mode power inductor, the coils are designed in the opposite direction pairwise.

7. The thin-film type power inductor according to claim 1, characterized in that, the functional layer of the thin-film type power inductor is made of a magnetic material.

8. The thin-film power inductor according to claim 7, wherein, the magnetic material is a soft magnetic alloy.

9. The thin-film power inductor according to claim 1, wherein, the coil of the thin-film power inductor is made of metal or metal alloy.

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