Inductor and preparation method thereof, filter

Abstract

The present disclosure provides an inductor and a preparation method thereof, and a filter, which belong to the technical field of passive devices. The inductor disclosed in the present disclosure comprises: a dielectric substrate having a connecting via hole penetrating along the thickness direction thereof; the dielectric substrate comprising a first surface and a second surface arranged opposite to each other along the thickness direction thereof; a first conductive structure arranged on the first surface; a second conductive structure arranged on the second surface, and the first conductive structure and the second conductive structure are electrically connected through a connecting electrode located in the connecting via hole to form a coil structure of the inductor; wherein at least one of the first conductive structure and the second conductive structure has a hollow pattern.

Description

Technical Field

[0001] The present invention belongs to the technical field of passive devices, and in particular relates to an inductor and a preparation method thereof, and a filter. Background Art

[0002] In the contemporary era, the consumer electronics industry is developing rapidly. Mobile communication terminals represented by mobile phones, especially 5G mobile phones, are developing rapidly. Mobile phones need to process more and more signal frequency bands, and the number of RF chips required is also rising. The mobile phone forms that are popular with consumers are constantly developing towards miniaturization, lightness, and long battery life. In traditional mobile phones, there are a large number of discrete devices such as resistors, capacitors, inductors, filters, etc. on the RF PCB board. They have the disadvantages of large size, high power consumption, many solder joints, and large changes in parasitic parameters, which are difficult to meet future needs. The interconnection and matching between RF chips require integrated passive devices with small area, high performance, and good consistency. The integrated passive devices on the market are mainly based on Si (silicon) substrates and GaAs (gallium arsenide) substrates. Si-based integrated passive devices have the advantage of low price, but Si itself has trace impurities (poor insulation), which leads to high microwave loss of the device and general performance; GaAs-based integrated passive devices have the advantage of excellent performance, but are expensive. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides an inductor and a preparation method thereof, and a filter.

[0004] In a first aspect, an embodiment of the present disclosure provides an inductor, comprising:

[0005] A dielectric substrate having a connecting via extending through the dielectric substrate in a thickness direction thereof; the dielectric substrate comprising a first surface and a second surface arranged opposite to each other in a thickness direction thereof;

[0006] A first conductive structure is disposed on the first surface;

[0007] The second conductive structure is disposed on the second surface, and the first conductive structure and the second conductive structure are electrically connected via a connecting electrode located in the connecting via hole to form a coil structure of the inductor; wherein,

[0008] At least one of the first conductive structure and the second conductive structure has a hollow pattern.

[0009] Wherein, when the first conductive structure has the hollow pattern, the hollow pattern includes a first opening extending along an extending direction of the first conductive structure;

[0010] When the second conductive structure has the hollow pattern, the hollow pattern includes a second opening extending along an extending direction of the second conductive structure.

[0011] Wherein, when the first conductive structure has the hollow pattern, the first opening has a first side and a second side that are arranged opposite to each other along the length direction of the first conductive structure; the orthographic projections of the first side and the second side on the plane where the first surface is located respectively fall on the contours of the orthographic projections of the two connecting vias on the plane where the first surface is located;

[0012] When the second conductive structure has the hollow pattern, the second opening has a third side and a fourth side that are relatively arranged along the length direction of the second conductive structure; the orthographic projections of the third side and the fourth side on the plane where the first surface is located respectively fall on the contours of the two connecting vias on the plane where the first surface is located.

[0013] Wherein, when the first conductive structure has the hollow pattern, for one of the first conductive structures and the two connecting vias covering it, the orthographic projection of the first opening of the first conductive structure on the plane where the first surface is located does not overlap with the orthographic projections of the two connecting vias on the plane where the first surface is located;

[0014] When the second conductive structure has the hollow pattern, the hollow pattern includes a second opening extending along the extension direction of the second conductive structure; for one second conductive structure and two connecting vias covering it, the orthographic projection of the second opening of the second conductive structure on the plane where the first surface is located has no overlap with the orthographic projection of the two connecting vias on the plane where the first surface is located.

[0015] Wherein, when the first conductive structure has the hollow pattern, the first opening includes a fifth side and a sixth side extending along the length direction of the first connecting structure and arranged opposite to each other; the fifth side and the sixth side are straight line segments or broken line segments;

[0016] When the second conductive structure has the hollow pattern, the second opening includes a seventh side and an eighth side extending along the length direction of the second connection structure and arranged opposite to each other; the seventh side and the eighth side are straight line segments or broken line segments.

[0017] Wherein, when the first conductive structure has the hollow pattern, the center of the orthographic projection of the outer contour of the first conductive structure on the plane where the first surface is located is the first center, the center of the orthographic projection of the first opening on the plane where the first surface is located is the second center, and the first center and the second center coincide with each other;

[0018] When the second conductive structure has the hollow pattern, the center of the orthographic projection of the outer contour of the second conductive structure on the plane where the first surface is located is the third center, the center of the orthographic projection of the first opening on the plane where the first surface is located is the fourth center, and the third center coincides with the fourth center.

[0019] Wherein, when the first conductive structure has the hollow pattern, the hollow pattern includes a plurality of the first openings, and the plurality of the first openings all extend along the length direction of the first conductive structure and are arranged side by side in the width direction of the first conductive structure;

[0020] When the second conductive structure has the hollow pattern, the hollow pattern includes a plurality of second openings, and the plurality of second openings all extend along the length direction of the second conductive structure and are arranged side by side in the width direction of the second conductive structure.

[0021] Wherein, the film thickness of the first conductive structure and the second conductive structure are both greater than 1 μm.

[0022] Wherein, when the first conductive structure has the hollow pattern, the width of the first opening is greater than 10 μm, and when the second conductive structure has the hollow pattern, the width of the second opening is greater than 10 μm.

[0023] In a second aspect, an embodiment of the present disclosure provides a method for preparing an inductor, which includes:

[0024] A dielectric substrate is provided, wherein the dielectric substrate has a connecting via hole penetrating along the thickness direction thereof; the dielectric substrate comprises a first surface and a second surface arranged opposite to each other along the thickness direction thereof;

[0025] A connecting electrode is formed in the connecting via hole of the dielectric substrate, a first conductive structure is formed on the first surface, and a second conductive structure is formed on the second surface. The first conductive structure and the second conductive structure are electrically connected through the connecting electrode located in the connecting via hole to form a coil structure of the inductor; wherein,

[0026] The first conductive structure formed has a hollow pattern, and / or the second conductive structure formed has a hollow pattern.

[0027] Wherein, the method for preparing the inductor further includes: forming a first protective layer on a side of the first conductive structure away from the first surface; and forming a second protective layer on a side of the second conductive structure away from the second surface.

[0028] In a third aspect, an embodiment of the present disclosure provides a filter, comprising any of the inductors described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the structure of an exemplary inductor.

[0030] Figure 2 is a cross-sectional view of an exemplary inductor.

[0031] Figure 3 A schematic diagram of an inductor according to an embodiment of the present disclosure.

[0032] Figure 4 for Figure 1 A parameter identification diagram of the inductance principle of a first conductive structure of the inductor shown.

[0033] Figure 5 for Figure 2 A parameter identification diagram of the inductance principle of a first conductive structure of the inductor shown.

[0034] Figure 6 FIG. 4 is another schematic diagram of an inductor according to an embodiment of the present disclosure.

[0035] Figure 7 FIG. 4 is another schematic diagram of an inductor according to an embodiment of the present disclosure.

[0036] Figure 8 FIG. 4 is another schematic diagram of an inductor according to an embodiment of the present disclosure.

[0037] Fig. 9 FIG. 4 is another schematic diagram of an inductor according to an embodiment of the present disclosure.

[0038] Fig.10 4 is a circuit diagram of a filter according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0040] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0041] In the first aspect, the embodiments of the present disclosure provide an inductor, which is a three-dimensional inductor structure, including a dielectric substrate 10, a connecting electrode, a first conductive structure 21, and a second conductive structure 22; wherein the dielectric substrate 10 has a plurality of connecting vias 11 penetrating along the thickness direction thereof, and each connecting via 11 is filled with a connecting electrode. The dielectric substrate 10 includes a first surface (upper surface) and a second surface (lower surface) arranged opposite to each other along the thickness direction thereof, the first conductive structure 21 is arranged on the first surface of the dielectric, and the second conductive structure 22 is arranged on the second surface of the dielectric substrate 10, and at this time, the first conductive structure 21 is electrically connected to the second conductive structure 22 through the connecting electrode located in the connecting via 11, so as to form a coil structure of the inductor.

[0042] Specifically, refer to Figure 1 and 2 , Figure 1 is a top view of an exemplary inductor; Figure 2: is a cross-sectional view of an exemplary inductor; each first conductive structure 21 of the inductor extends along the first direction and is arranged side by side along the second direction; each second conductive structure 22 of the inductor extends along the third direction and is arranged side by side along the second direction. The connecting vias 11 on the dielectric substrate 10 are divided into two groups arranged side by side along the first direction, and each group includes a plurality of vias arranged side by side along the second direction. Among them, the first direction, the second direction, and the third direction are all different directions. In the embodiment of the present disclosure, the first direction and the second direction are perpendicular to each other, and the first direction and the third direction intersect and are arranged non-perpendicularly as an example. Of course, the extension directions of the first conductive structure 21 and the second conductive structure 22 can also be interchanged, both within the protection scope of the embodiment of the present disclosure. In addition, in the present embodiment, the inductor includes N first conductive structures 21 and N-1 second conductive structures 22 as an example for explanation, wherein N≥2, and N is an integer. The first end and the second end of the first conductive structure 21 overlap at least partially with the positive projection of a connecting via 11 on the dielectric substrate 10, respectively. And the first end and the second end of one first conductive structure 21 correspond to different connecting vias 11, that is, the orthographic projections of one first conductive structure 21 and two connecting vias 11 on the dielectric substrate 10 at least partially overlap. At this time, the first end of the i-th second conductive structure 22 of the inductor is connected to the first end of the i-th first conductive structure 21 and the second end of the i+1-th first conductive structure 21 through the connecting electrode 11 in the connecting via 11, forming an inductor coil, wherein 1≤i≤N-1, and i is an integer.

[0043] Reference Figure 3 In the embodiment of the present disclosure, at least one of the first conductive structure 21 and the second conductive structure 22 has a hollow pattern. When the first conductive structure 21 has a hollow pattern, the stress of the first conductive pattern on the dielectric substrate 10 can be effectively reduced, and the risk of warping of the dielectric substrate 10 can be reduced; similarly, when the second conductive structure 22 has a hollow pattern, the stress of the second conductive pattern on the dielectric substrate 10 can be effectively reduced, and the risk of warping of the dielectric substrate 10 can also be reduced.

[0044] In some examples, when the first conductive structure 21 has a hollow pattern, the hollow pattern has at least one first opening 210 extending along the length direction of the first conductive structure 21 . Figure 3 For example, only one first opening 210 is provided on the first conductive structure 21. In this case, any first conductive structure 21 is equivalent to multiple first substructures connected in parallel, and the inductance between the first substructures of the first conductive structure 21 and the first substructures of the adjacent first conductive structures 21 increase the inductance value of the inductor, thereby improving the inductance density. Similarly, when the second conductive structure 22 has a hollow pattern, the hollow pattern has at least one second opening 220 extending along the length direction of the second conductive structure 22. Figure 6For example, only one second opening 220 is provided on the second conductive structure 22. In this case, any second conductive structure 22 is equivalent to a plurality of second substructures connected in parallel, and the inductance between the second substructures of the second conductive structure 22 and the inductance of the second substructures of the adjacent second conductive structure 22 increase the inductance value of the inductor, thereby improving the inductance density.

[0045] The specific principle of increasing the inductance value of the inductor by using the above structure is described below. The inductor of the first conductive structure 21 is used for illustration, wherein the first conductive structure 21 has a hollow pattern, which is a first opening 210 extending along the length direction of the first conductive structure 21, and the number of the first opening 210 is one, and each first conductive structure 21 is divided into two parallel first substructures by the first opening 210.

[0046] The inductance of any first conductive structure 21 includes three parts: self-inductance, in-phase mutual inductance between adjacent first conductive structures 21, and in-phase mutual inductance between second conductive structures 22 arranged opposite thereto. The inductance value of the self-inductance of the first conductive structure 21 can be evaluated by formula 1, which is related to the length and width of the first conductive structure 21. Within a unit length, the width decreases, and the self-inductance increases. The inductance value of the mutual inductance can be evaluated by formula 2, which is related to the length of the first conductive structure 21 and the center distance of the first conductive structure 21. Within a unit length, the smaller the wiring spacing, the greater the mutual inductance. In the calculation of the total inductance, the in-phase mutual inductance is added to the self-inductance, and the reverse mutual inductance is subtracted from the self-inductance.

[0047]

[0048] The total inductance of the trace = self-inductance + same-direction mutual inductance - opposite-direction mutual inductance.

[0049] Existing three-dimensional inductor structures such as Figure 4 As shown, the inductance L of the first conductive structure 21a is La+Mab-Mac, where La is the self-inductance of the first conductive structure 21a, Mab is the mutual inductance between the first conductive structure 21a and the second conductive structure 22b, and Mac is the mutual inductance between the first conductive structure 21a and the first conductive structure 21c.

[0050] Reference Figure 5For the first substructure a1 of the first conductive structure 21, the inductive mutual inductance increases from Mab to Ma1a2+Ma1b1+Ma1b2. Since the center distances between the first substructure a1 and the first substructure a2, and the center distances between the first substructure a1 and the first substructure b1 are less than the center distances between the first conductive structure 21a and the first conductive structure 21b in the existing inductor structure, the inductance of a1 is greatly improved. Of course, the total inductance value will be reduced after the inductance of the first substructure a1 and the first substructure a2 are connected in parallel, but the overall inductance value is still improved. Taking the first substructure with a line width of 80μm, the width of the first opening 210 on the first conductive structure 21 is 20μm, and the line length of the first conductive structure 21 is 200μm as an example, the calculation Figure 3 The inductance of the first conductive structure 21 in the inductor structure shown is about 0.1 nH. Figure 5 The inductance of the first conductive structure 21 in the inductor structure shown is about 0.12 nH, and the inductance value is increased by 20%. The increase in the inductance value varies with the size of the hollowing.

[0051] In the embodiment of the present disclosure, a hollow pattern may be provided only on the first conductive structure 21, that is, the first conductive structure 21 has a first opening 210, and the first opening 210 extends along the length direction of the first conductive structure 21; Figure 6 As shown, a hollow pattern may also be provided only on the second conductive structure 22, that is, the second conductive structure 22 has a second opening 220, and the second opening 220 extends along the length direction of the second conductive structure 22; Figure 7 As shown, the first conductive structure 21 can also be designed as a first conductive structure 21 having a first opening 210 , and the second conductive structure 22 can be designed as a second conductive structure 22 having a second opening 220 .

[0052] In some examples, when the first conductive structure 21 has a hollow pattern, the orthographic projection of the first opening 210 on the first surface of the dielectric substrate 10 has a first side and a second side that are oppositely arranged along the length direction of the first conductive structure 21. The orthographic projections of the first side and the second side on the plane where the first surface is located respectively fall on the contours of the orthographic projections of the two connecting vias 11 on the plane where the first surface is located. Similarly, when the second conductive structure 22 has a hollow pattern, the second opening 220 has a third side and a fourth side that are oppositely arranged along the length direction of the second conductive structure 22; the orthographic projections of the third side and the fourth side on the plane where the first surface is located respectively fall on the contours of the two connecting vias 11 on the plane where the first surface is located.

[0053] In some examples, reference Figure 8Considering the partial characteristics of the current in the connecting via 11, the current is generally concentrated in the connection direction between the connecting via 11 and the first conductive structure 21 / the second conductive structure 22. Therefore, when the first opening 210 is provided on the first conductive structure 21, the position of the first opening 210 should avoid the connecting via 11 where the connecting electrode connected thereto is located, that is, there is a certain distance between the first opening 210 and the connecting via 11, that is, for a first conductive structure 21 and two connecting vias 11 covering it, the orthographic projection of the first opening 210 of the first conductive structure 21 on the plane where the first surface is located does not overlap with the orthographic projections of the two connecting vias 11 on the plane where the first surface is located. Similarly, when a second opening 220 is provided on the second conductive structure 22, the position of the second opening 220 should avoid the connecting via 11 where the connecting electrode to which it is connected is located, that is, there should be a certain distance between the second opening 220 and the connecting via 11, that is, for a second conductive structure 22 and two connecting vias 11 covering it, the orthographic projection of the second opening 220 of the second conductive structure 22 on the plane where the first surface is located does not overlap with the orthographic projections of the two connecting vias 11 on the plane where the first surface is located.

[0054] In some examples, when the number of the first openings 210 on the first conductive structure 21 is one, the center of the orthographic projection of the outer contour of the first conductive structure 21 on the plane where the first surface is located is the first center, the center of the orthographic projection of the first opening 210 on the plane where the first surface is located is the second center, and the first center and the second center coincide with each other. In this way, the inductance of each first conductive structure 21 is uniform. Similarly, when the number of the second openings 220 on the second conductive structure 22 is one, the center of the orthographic projection of the outer contour of the second conductive structure 22 on the plane where the first surface is located is the third center, the center of the orthographic projection of the first opening 210 on the plane where the first surface is located is the fourth center, and the third center and the fourth center coincide with each other. In this way, the inductance of each second conductive structure 22 is uniform.

[0055] In some examples, when the first conductive structure 21 has a hollow pattern, the number of first openings 210 included in the hollow pattern may be multiple, and the multiple first openings 210 all extend along the length direction of the first conductive structure 21 and are evenly arranged side by side. When the number of first openings 210 is 2, the first conductive structure 21 is divided into 3 parallel first substructures; when the number of first openings 210 is 3, the first conductive structure 21 is divided into 4 parallel first substructures; when the number of first openings 210 is 4, the first conductive structure 21 is divided into 5 parallel first substructures. Similarly, when the second conductive structure 22 has a hollow pattern, the number of second openings 220 included in the hollow pattern may be multiple, and the multiple second openings 220 all extend along the length direction of the second conductive structure 22 and are evenly arranged side by side. When the number of the second openings 220 is 2, the second conductive structure 22 is divided into 3 parallel second substructures; when the number of the second openings 220 is 3, the second conductive structure 22 is divided into 4 parallel second substructures; when the number of the second openings 220 is 4, the second conductive structure 22 is divided into 5 parallel second substructures.

[0056] In some examples, the film thickness of the first conductive structure 21 and the second conductive structure 22 is greater than 1 μm. When the first conductive structure 21 has a first opening 210, the width of the first opening 210 is greater than 10 μm, and when the second conductive structure 22 has a second opening 220, the width of the second opening 220 is greater than 10 μm. It should be noted that the widths of the first opening 210 and the second opening 220 are related to the period of the connecting via 11. In the embodiment of the present disclosure, the period of the connecting via 11 is about 100 μm. The period of the connecting via 11 refers to the center distance between the two connecting vias 11 along the width direction of the first conductive structure 21.

[0057] In some examples, when the first conductive structure 21 has a first opening 210, when the first conductive structure 21 has a hollow pattern, the first opening 210 includes a fifth side and a sixth side extending along the length direction of the first connecting structure and arranged opposite to each other; the fifth side and the sixth side are straight line segments, such as Figure 3 As shown; or the fifth and sixth sides are broken line segments, such as Fig. 9 Similarly, when the second conductive structure 22 has a hollow pattern, the second opening 220 includes a seventh side and an eighth side extending along the length direction of the second connection structure and arranged opposite to each other; the seventh side and the eighth side are straight line segments or broken line segments. It should be noted that the specific styles of the fifth side and the sixth side of the first opening 210 are not limited in the embodiment of the present disclosure, and similarly, the specific styles of the seventh side and the eighth side of the second opening 220 are not limited.

[0058] In a second aspect, an embodiment of the present disclosure provides a method for preparing an inductor, which can be used to prepare any of the above-mentioned inductor structures. The method for preparing an inductor of an embodiment of the present disclosure comprises the following steps:

[0059] A dielectric substrate 10 is provided; the dielectric substrate 10 has a connecting via 11 penetrating along the thickness direction thereof; the dielectric substrate 10 includes a first surface and a second surface which are arranged opposite to each other along the thickness direction thereof.

[0060] A connecting electrode is formed in the connecting via 11 of the dielectric substrate 10, a first conductive structure 21 is formed on the first surface, and a second conductive structure 22 is formed on the second surface. The first conductive structure 21 is electrically connected to the second conductive structure 22 through the connecting electrode in the connecting via 11 to form an inductor coil structure.

[0061] Among them, at least one of the first conductive structure 21 and the second conductive structure 22 formed in the embodiment of the present disclosure has a hollow pattern. When the first conductive structure 21 has a hollow pattern, the stress of the first conductive pattern on the dielectric substrate 10 can be effectively reduced, and the risk of warping of the dielectric substrate 10 can be reduced; similarly, when the second conductive structure 22 has a hollow pattern, the stress of the second conductive pattern on the dielectric substrate 10 can be effectively reduced, and the risk of warping of the dielectric substrate 10 can also be reduced.

[0062] In order to make the preparation method of the inductor in the embodiment of the present disclosure clearer, the following is described with reference to a specific example. The preparation method of the inductor includes:

[0063] S11, providing a dielectric substrate 10; the dielectric substrate 10 comprises a first surface and a second surface which are arranged opposite to each other along a thickness direction thereof.

[0064] The dielectric substrate 10 includes but is not limited to a glass substrate.

[0065] S12 , forming a connecting via hole 11 penetrating the dielectric substrate 10 along the thickness of the dielectric substrate 10 .

[0066] In some examples, a variety of methods can be used to make the via-last / connection via 1111 on the dielectric substrate 1010. For example: sandblasting, photosensitive glass, focused discharge, plasma etching, laser ablation, electrochemical, laser induced etching, etc. Different methods have different advantages and disadvantages and scope of application. For example, for the sandblasting method, its advantage is that the process is simple, and the aperture of the connection via 11 made by this method is larger, and it is only suitable for the production of connection vias 11 with an aperture greater than 200 μm. The advantage of the photosensitive glass method is that the process is simple and high-density, high-aspect ratio connection vias 11 can be made. The advantage of the focused discharge method is that the hole-forming speed is fast. The side wall roughness of the connection via 11 prepared by the plasma etching method is small. The advantage of the laser ablation method is that it can make high-density, high-aspect ratio connection vias 11 with large roughness. The advantages of the electrochemical method are low cost, simple equipment, fast hole-forming rate, and large diameter of the connection via 11. The advantages of the laser induced etching method are that the hole-forming rate is fast, and high-density, high-aspect-ratio connecting vias 11 can be produced without damage inside the vias. The disadvantage is that the laser equipment is expensive. Here, laser induced etching is taken as an example, and the laser induced etching method is used to make a rear through hole on the back. First, a laser is used to induce laser modification of the position where the connecting via 11 is to be made, and then a wet etching method is used to make the through hole. Since the rear through hole can only be made by a single-sided etching method, the obtained hole can only be an inverted tapered hole. For the laser induced etching drilling method, this single-sided etched inverted tapered hole is a typical feature of the rear through hole on the back of the connecting via 11.

[0067] S13, forming a connection electrode in the connection via 11, forming a first conductive structure 21 on the first surface, forming a second conductive structure 22 on the second surface, and the first conductive structure 21 is electrically connected to the second conductive structure 22 through the connection electrode in the connection via 11 to form an inductor coil structure. At least one of the first conductive structure 21 and the second conductive structure 22 formed has a hollow pattern.

[0068] In some examples, in step S13, an auxiliary film layer is formed by a method including but not limited to magnetron sputtering, and then the first conductive film layer is continuously sputtered, and the first conductive film layer is used as a seed layer, and the first seed layer is electroplated. After the electroplating is completed, the excess electroplated copper on the first surface and the second surface is removed by a chemical mechanical polishing (CMP) method to form a connection electrode filling the connecting via 11. Next, the first conductive structure 21 and the second conductive structure 22 are formed on the first surface by a patterning process. The formation methods of the first conductive structure 21 and the second conductive structure 22 include but are not limited to magnetron sputtering, electroplating, printing and other processes to form a metal conductive layer, and then formed by a patterning process.

[0069] The above is a connection electrode formed by a subtractive method. Of course, the connection electrode can also be formed by an additive method.

[0070] The auxiliary film layer is used to increase the adhesion of the first conductive film layer. The material of the auxiliary film layer includes but is not limited to titanium Ti, and the material of the first conductive film layer includes but is not limited to Cu. The thickness of the auxiliary film layer is about 10nm to 300nm, and the thickness of the first conductive film layer is about 30nm to 100nm.

[0071] In some examples, the preparation method of the embodiment of the present disclosure may further include forming a first protective layer on a side of the first conductive structure 21 away from the dielectric substrate 10 after forming the first conductive structure 21, and forming a second protective layer on a side of the second conductive structure 22 away from the dielectric substrate 10 after forming the second conductive structure 22.

[0072] Among them, the first protective layer is used to prevent water and oxygen from corroding the structure formed on the first surface of the dielectric substrate 10, and the second protective layer is used to prevent water and oxygen from corroding the structure formed on the second surface of the dielectric substrate 10. The material of the first protective layer can be an inorganic insulating material. For example: the first protective layer can be an inorganic insulating layer formed by silicon nitride (SiNx), or an inorganic insulating layer formed by silicon oxide (SiO2), or a laminated composite film layer of several SiNx inorganic insulating layers and SiO2 inorganic insulating layers. Of course, the material of the first protective layer can also be an organic material, ABF material, etc. The material of the second protective layer can be selected from the same material as the first protective layer, so it will not be repeated here.

[0073] This completes the introduction of the method for preparing the inductor according to the embodiment of the present disclosure.

[0074] In a third aspect, an embodiment of the present disclosure provides a filter, which may include the above-mentioned inductor, and may also include a capacitor and a resistor.

[0075] Fig.10 is a circuit diagram of a filter; Fig.10 As shown, the filter circuit includes two inductors, a capacitor and a resistor. For ease of understanding, the two inductors are respectively referred to as the first inductor L1 and the second inductor L2. Figure 2 The first lead end of the first inductor L1 is connected to the first end of the resistor R, the second lead end of the first inductor is connected to the second plate of the capacitor C, the first lead end of the second inductor L2 is connected to the first end of the resistor R, and the second lead end of the second inductor L2 is connected to the first plate of the capacitor C.

[0076] It should be noted that the resistor R can be implemented by a wire, or a high-resistance material such as indium tin oxide (ITO) or nickel-chromium (NiCr) alloy. In the disclosed embodiment, the formation of the resistor R is not limited, and the following mainly introduces the capacitor and the inductor.

[0077] The first plate of the capacitor in the filter can be arranged in the same layer as the first conductive structure 21 of the inductor, the second plate of the capacitor is arranged on the side of the first plate away from the dielectric substrate 10, and a dielectric layer is arranged between the first plate and the second plate of the capacitor.

[0078] Since the filter includes the above-mentioned inductor, its inductance value is significantly improved, and the performance of the filter is significantly improved. It can be understood that the above embodiments are only exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An inductor, comprising: The dielectric substrate has a connecting via hole penetrating along the thickness direction thereof; The dielectric substrate comprises a first surface and a second surface which are arranged opposite to each other along the thickness direction thereof; A first conductive structure is disposed on the first surface; The second conductive structure is disposed on the second surface, and the first conductive structure and the second conductive structure are electrically connected via a connecting electrode located in the connecting via hole to form a coil structure of the inductor; wherein, At least one of the first conductive structure and the second conductive structure has a hollow pattern; When the first conductive structure has the hollow pattern, the hollow pattern includes a first opening extending along an extending direction of the first conductive structure; When the second conductive structure has the hollow pattern, the hollow pattern includes a second opening extending along an extending direction of the second conductive structure.

2. The inductor according to claim 1, wherein: When the first conductive structure has the hollow pattern, the first opening has a first side and a second side that are oppositely arranged along a length direction of the first conductive structure; The orthographic projections of the first side and the second side on the plane where the first surface is located respectively fall on the contours of the orthographic projections of the two connecting vias on the plane where the first surface is located; When the second conductive structure has the hollow pattern, the second opening has a third side and a fourth side that are relatively arranged along the length direction of the second conductive structure; the orthographic projections of the third side and the fourth side on the plane where the first surface is located respectively fall on the contours of the two connecting vias on the plane where the first surface is located.

3. The inductor according to claim 1, wherein: When the first conductive structure has the hollow pattern, for one of the first conductive structures and the two connecting vias covering it, the orthographic projection of the first opening of the first conductive structure on the plane where the first surface is located does not overlap with the orthographic projections of the two connecting vias on the plane where the first surface is located; When the second conductive structure has the hollow pattern, the hollow pattern includes a second opening extending along the extension direction of the second conductive structure; for one second conductive structure and two connecting vias covering it, the orthographic projection of the second opening of the second conductive structure on the plane where the first surface is located has no overlap with the orthographic projection of the two connecting vias on the plane where the first surface is located.

4. The inductor according to claim 1, wherein: When the first conductive structure has the hollow pattern, the first opening includes a fifth side and a sixth side extending along the length direction of the first conductive structure and arranged opposite to each other; the fifth side and the sixth side are straight line segments or broken line segments; When the second conductive structure has the hollow pattern, the second opening includes a seventh side and an eighth side extending along the length direction of the second conductive structure and arranged opposite to each other; the seventh side and the eighth side are straight line segments or broken line segments.

5. The inductor according to claim 1, wherein: When the first conductive structure has the hollow pattern, the center of the orthographic projection of the outer contour of the first conductive structure on the plane where the first surface is located is the first center, the center of the orthographic projection of the first opening on the plane where the first surface is located is the second center, and the first center and the second center coincide with each other; When the second conductive structure has the hollow pattern, the center of the orthographic projection of the outer contour of the second conductive structure on the plane where the first surface is located is the third center, the center of the orthographic projection of the first opening on the plane where the first surface is located is the fourth center, and the third center coincides with the fourth center.

6. The inductor according to claim 1, wherein: When the first conductive structure has the hollow pattern, the hollow pattern includes a plurality of the first openings, and the plurality of the first openings all extend along the length direction of the first conductive structure and are arranged side by side in the width direction of the first conductive structure; When the second conductive structure has the hollow pattern, the hollow pattern includes a plurality of second openings, and the plurality of second openings all extend along the length direction of the second conductive structure and are arranged side by side in the width direction of the second conductive structure.

7. The inductor according to any one of claims 1 to 6, wherein: The thickness of the first conductive structure and the second conductive structure are both greater than 1 μm.

8. The inductor according to any one of claims 1 to 6, wherein: When the first conductive structure has the hollow pattern, the width of the first opening is greater than 10 μm, and when the second conductive structure has the hollow pattern, the width of the second opening is greater than 10 μm.

9. A method for preparing an inductor, comprising: Providing a dielectric substrate, wherein the dielectric substrate has a connecting via hole penetrating along a thickness direction thereof; The dielectric substrate comprises a first surface and a second surface which are arranged opposite to each other along the thickness direction thereof; A connecting electrode is formed in the connecting via hole of the dielectric substrate, a first conductive structure is formed on the first surface, and a second conductive structure is formed on the second surface. The first conductive structure and the second conductive structure are electrically connected through the connecting electrode located in the connecting via hole to form a coil structure of the inductor; wherein, The first conductive structure formed has a hollow pattern, and / or the second conductive structure formed has a hollow pattern.

10. The method for preparing an inductor according to claim 9, wherein: Also includes: forming a first protective layer on a side of the first conductive structure facing away from the first surface; A second protection layer is formed on a side of the second conductive structure facing away from the second surface.

11. A filter comprising the inductor according to any one of claims 1 to 8.

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