TSV-based tunable inductor structure and tuning method thereof

Abstract

The invention discloses a TSV-based tunable inductor structure and a tuning method thereof, the tunable inductor structure comprises a primary side inductor and an auxiliary inductor, the primary side inductor is nested in the auxiliary inductor to form a nested tunable inductor structure; wherein the auxiliary inductor is connected with the modulation source, and the primary inductor is connected with an actual application circuit, so that a voltage difference between a voltage V1 between two ports of the primary inductor and a voltage V2 between two ports of the auxiliary inductor is regulated and controlled through the modulation source, and the primary inductor and the auxiliary inductor are mutually coupled under the action of the voltage V1 and the voltage V2; and the inductance tuning of the primary side inductor is realized. According to the TSV tunable inductor, the TSV tunable inductor structure which is small in tuning range, large in area and high-frequency performance degradation of a traditional tunable inductor is converted into a TSV tunable inductor structure which is based on the magnetic coupling technology, is small in area and wide in tuning range and can be continuously tuned.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuits, and in particular relates to a TSV-based tunable inductor structure and a tuning method thereof. Background Art

[0002] With the rapid development of the new generation of wireless communication systems, compact tunable devices are needed to achieve frequency agility to meet the needs of RF systems for multi-band reconstruction capabilities. As a key component of the reconfigurable filter, the tunable inductor can realize dynamic signal selection; as the core part of the impedance matching network, it can dynamically adjust the impedance matching between the power amplifier and the antenna to achieve the maximum efficiency output of the signal. As the core of the tunable device, the tunable inductor can realize dynamic tuning of the frequency band, impedance matching and filter tuning during system operation without increasing the chip area.

[0003] Currently available tunable inductors can be divided into the following categories:

[0004] The first is to adjust the inductor combination by switches to achieve inductance tuning. Jaehun Lee et al. published "Millimeter-Wave Frequency Reconfigurable Dual-Band CMOS Power Amplifier for 5G Communication Radios" and proposed a method of adjusting the inductance value by switching the electrical connection relationship of the inductor through a MOS switch, but it has the disadvantages of large area, inability to tune continuously, and high MOS switch loss. The tunable inductor based on MEMS switches can also adjust the connection relationship of the inductor to achieve inductance tuning, and the tunable inductor based on MEMS switches has good RF performance, mature preparation technology and a wide tuning range, but has the disadvantages of slow switching speed, large area and high driving voltage. In addition, the tunable inductor based on memristors can also adjust the connection relationship of the inductor to achieve inductance tuning, and the tunable inductor based on memristors has the advantages of high integration, low power consumption and fast response speed, but has the disadvantages of narrow tuning range, high sensitivity to temperature changes and is not suitable for high-power RF system applications.

[0005] The second type is active inductor. Aysu Belen et al. published a paper titled "Design and Realization of BroadbandActive Inductor Based Band Pass Filter" and proposed an active inductor using a gyrator. The load capacitance is equivalent to the inductance through the capacitance-inductance gyration characteristics of the gyrator, thereby achieving inductance tuning. Tunable inductors based on active devices have a high degree of integration and tuning range, but when using capacitors as loads, the self-resonant frequency decreases and the quality factor decreases in high-frequency applications, resulting in serious degradation of high-frequency performance.

[0006] In summary, the existing tunable inductor structure has the problems of limited tuning range, large area, and high-frequency performance degradation. Therefore, the application of tunable inductors with high frequency band, wide tuning range, continuous adjustment, and miniaturization is of great significance to promote the multifunctional reconstruction and miniaturization of RF systems. Summary of the invention

[0007] In order to solve the above problems existing in the prior art, the present invention provides a tunable inductor structure based on TSV and a tuning method thereof. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0008] In a first aspect, an embodiment of the present invention provides a TSV-based tunable inductor structure, wherein the tunable inductor structure includes a primary inductor and an auxiliary inductor, wherein the primary inductor is nested in the auxiliary inductor to form a nested tunable inductor structure; wherein:

[0009] The auxiliary inductor is connected to a modulation source, and the primary inductor is connected to an actual application circuit, so that the voltage difference between the two-port voltage V1 of the primary inductor and the two-port voltage V2 of the auxiliary inductor can be regulated by the modulation source, so that the primary inductor and the auxiliary inductor are coupled with each other under the action of the voltage V1 and the voltage V2, thereby realizing the inductance tuning of the primary inductor.

[0010] In one embodiment of the present invention, the auxiliary inductor includes a first TSV structure, a first micro-bump, a second micro-bump, a first metal RDL and a second metal RDL; wherein,

[0011] Each first TSV structure is located in the silicon substrate;

[0012] The first micro-bumps distributed in N rows and 2 columns are located in the first insulating layer on the upper surface of the silicon substrate, where N is an integer greater than 1; a plurality of first metal RDLs are located in the second insulating layer on the upper surface of the first insulating layer, and two ends of each first metal RDL are respectively connected to two first micro-bumps in the nth row and the second column and in the n+1th row and the first column, where n=1, 2, ..., N-1; the port leading out of the first micro-bump in the first row and the first column and the port leading out of the first micro-bump in the Nth row and the second column are used as two ports of the auxiliary inductor;

[0013] The second micro-bumps distributed in N rows and 2 columns are located in the third insulating layer on the lower surface of the silicon substrate, the second micro-bumps correspond to the first micro-bumps one-to-one, and the first TSV structure is connected between the corresponding second micro-bumps and the first micro-bumps; a plurality of second metal RDLs are located in the fourth insulating layer on the lower surface of the third insulating layer, and the two ends of each second metal RDL are respectively connected to the two second micro-bumps in the same row.

[0014] In one embodiment of the present invention, the primary inductor includes a second TSV structure, a third micro-bump, a fourth micro-bump, a third metal RDL and a fourth metal RDL; wherein,

[0015] Each second TSV structure is located in the silicon substrate;

[0016] The third micro-bumps distributed in N rows and 2 columns are located in the first insulating layer on the upper surface of the silicon substrate, where N is an integer greater than 1; a plurality of third metal RDLs are located in the first insulating layer, and two ends of the nth third metal RDL are respectively connected to two first micro-bumps in the nth row and 2nd column and in the n+1th row and 1st column, where n=1, 2, ..., N-1; a port led out of the third micro-bump in the 1st row and 1st column and a port led out of the third micro-bump in the Nth row and 2nd column are used as two ports of the primary inductor;

[0017] The fourth micro-bumps distributed in N rows and 2 columns are located in the third insulating layer, the fourth micro-bumps correspond to the third micro-bumps one-to-one, and a second TSV structure is connected between the corresponding fourth micro-bumps and the third micro-bumps; a plurality of fourth metal RDLs are located in the third insulating layer, and both ends of each fourth metal RDL are respectively connected to two fourth micro-bumps in the same row, and the length of the fourth metal RDL in the same row is less than the length of the second metal RDL.

[0018] In one embodiment of the present invention, the first TSV structure and the second TSV structure have the same structure; each first TSV structure includes a TSV through hole, a TSV insulating layer, and a TSV metal, the TSV insulating layer is located on the inner surface of the TSV through hole, and the TSV metal fully fills the TSV through hole.

[0019] In one embodiment of the present invention, the aperture sizes of the first to fourth micro-bumps are all equal; the aperture size of the first micro-bump is larger than the aperture size of the TSV through hole.

[0020] In one embodiment of the present invention, the thickness of the first micro-bump is equal to that of the second micro-bump, and the thickness of the third micro-bump is equal to that of the fourth micro-bump; the thickness of the first micro-bump is greater than that of the third micro-bump.

[0021] In one embodiment of the present invention, the thicknesses of the first insulating layer and the third insulating layer are equal; the thicknesses of the second insulating layer and the fourth insulating layer are equal; and the thickness of the first insulating layer is greater than that of the second insulating layer.

[0022] In one embodiment of the present invention, the first to fourth metal RDLs have the same thickness.

[0023] In one embodiment of the present invention, the thickness of the first micro bump and the second micro bump is 6 μm; the thickness of the third micro bump and the fourth micro bump is 2 μm; the thickness of the first insulating layer and the third insulating layer is 6 μm, and the thickness of the second insulating layer and the fourth insulating layer is 2 μm; the thickness of the first metal RDL to the fourth metal RDL is 2 μm.

[0024] In a second aspect, an embodiment of the present invention provides a tuning method for a tunable inductor structure based on TSV, the tuning method comprising:

[0025] Designing a TSV-based tunable inductor structure according to any one of the first aspects;

[0026] Connect the two ports of the auxiliary inductor to the modulation source and the ground respectively;

[0027] The modulation source is regulated to regulate the voltage difference between the two-port voltage V1 of the primary inductor and the two-port voltage V2 of the auxiliary inductor, so that the primary inductor and the auxiliary inductor are coupled with each other under the action of the voltages V1 and V2, the inductance value of the primary inductor is tuned, and the two ports of the primary inductor are connected to the actual application circuit.

[0028] Beneficial effects of the present invention:

[0029] The TSV-based tunable inductor structure proposed in the present invention nests the primary inductor and the auxiliary inductor, which can reduce the area of ​​the tunable inductor structure and is beneficial to improving the integration of the radio frequency system; since the self-resonant frequency of the primary inductor is higher than the self-resonant frequency of the auxiliary inductor, the primary inductor is connected to the actual circuit, and the auxiliary inductor is connected to the modulation source for regulation, so that the inductance value of the primary inductor can be continuously tuned within a wider range, which can be used to design inductors with higher self-resonant frequencies and improve the multi-band tuning capability of the radio frequency system; based on the proposed tunable inductor structure, the modulation source modulation method is used, the tuning is simple and flexible, and continuous tuning is possible, and by flexibly regulating the voltage V2 of the modulation source, a voltage difference is created between the voltage V1 and the voltage V2, thereby coupling the primary inductor and the auxiliary inductor with each other, thereby achieving the purpose of tuning the inductance value of the primary inductor. It can be seen that the tunable inductor structure proposed in the present invention improves the tunability of the inductor device, and realizes the transformation from the traditional tunable inductor with small tuning range, large area and high-frequency performance degradation to the TSV tunable inductor structure with smaller area, wider tuning range and continuous tuning based on magnetic coupling technology. It has the advantages of smaller volume, wider tuning range and continuous tuning, can improve the multi-band tuning capability of electronic systems, meet the design requirements of miniaturization and multi-functional reconstruction of RF microsystems, can be widely used in RF circuits such as filters and impedance matching networks, and has positive significance for promoting the development of miniaturized design and flexible configuration of RF electronic systems.

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of a TSV-based tunable inductor structure provided in an embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of a specific structure of a TSV-based tunable inductor structure provided in an embodiment of the present invention;

[0033] Figure 3 is a side view of a TSV-based tunable inductor structure provided by an embodiment of the present invention;

[0034] Figure 4 It is a schematic diagram comparing changes in equivalent inductance values ​​of the primary inductance in a non-modulation mode and a modulation mode provided by an embodiment of the present invention.

[0035] Figure 5 It is a schematic diagram of the change of the equivalent inductance value of the primary inductance when the modulation source voltage V2 takes different values ​​provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0037] First, see Figure 1 An embodiment of the present invention provides a TSV-based tunable inductor structure, which includes a primary inductor and an auxiliary inductor. The primary inductor is nested in the auxiliary inductor, and the physical size of the auxiliary inductor is larger than that of the primary inductor, so as to form a nested tunable inductor structure, thereby realizing area sharing between the primary inductor and the auxiliary inductor; wherein the auxiliary inductor is connected to a modulation source, and the primary inductor is connected to an actual application circuit, so as to regulate the voltage difference between the voltage V1 between the two ports of the primary inductor and the voltage V2 between the two ports of the auxiliary inductor through the modulation source, so that the primary inductor and the auxiliary inductor are coupled to each other under the action of the voltage V1 and the voltage V2, thereby realizing the inductance tuning of the primary inductor. Figure 1 The dotted line in the middle illustrates the structure of the primary inductor, and the solid line illustrates the structure of the auxiliary inductor. S1 and S3 are the two ports of the primary inductor, which are used to connect to the actual application circuit. S2 and G are the two ports of the auxiliary inductor. S2 is connected to the modulation source and G is grounded.

[0038] In the embodiment of the present invention, the auxiliary inductor is as follows: Figure 2 and Figure 3 As shown, it includes a first TSV structure, a first micro-bump, a second micro-bump, a first metal RDL (Redistribution Layer) and a second metal RDL; wherein,

[0039] Each first TSV (Through-Silicon Via) structure is located in the silicon substrate;

[0040] The first micro-bumps distributed in N rows and 2 columns are located in the first insulating layer on the upper surface of the silicon substrate, where N is an integer greater than 1; a plurality of first metal RDLs are located in the second insulating layer on the upper surface of the first insulating layer, and two ends of each first metal RDL are respectively connected to two first micro-bumps in the nth row and the second column and in the n+1th row and the first column, where n=1, 2, ..., N-1; the port leading out of the first micro-bump in the first row and the first column and the port leading out of the first micro-bump in the Nth row and the second column are used as two ports of the auxiliary inductor; Figure 2 and Figure 3 The case where N=3 is illustrated in FIG. 1 , where the rows and columns close to S1 and S2 can be defined as the starting points of the rows and columns.

[0041] The second micro-bumps distributed in N rows and 2 columns are located in the third insulating layer on the lower surface of the silicon substrate, the second micro-bumps correspond to the first micro-bumps one-to-one, and the first TSV structure is connected between the corresponding second micro-bumps and the first micro-bumps; a plurality of second metal RDLs are located in the fourth insulating layer on the lower surface of the third insulating layer, and the two ends of each second metal RDL are respectively connected to the two second micro-bumps in the same row.

[0042] In the embodiment of the present invention, the primary inductance is as follows: Figure 2 and Figure 3 As shown, it includes a second TSV structure, a third micro-bump, a fourth micro-bump, a third metal RDL and a fourth metal RDL; wherein,

[0043] Each second TSV structure is located in the silicon substrate;

[0044] The third micro-bumps distributed in N rows and 2 columns are located in the first insulating layer on the upper surface of the silicon substrate, where N is an integer greater than 1; a plurality of third metal RDLs are located in the first insulating layer, and two ends of the nth third metal RDL are respectively connected to two first micro-bumps in the nth row and 2nd column and in the n+1th row and 1st column, where n=1, 2, ..., N-1; a port led out of the third micro-bump in the 1st row and 1st column and a port led out of the third micro-bump in the Nth row and 2nd column are used as two ports of the primary inductor;

[0045] The fourth micro-bumps distributed in N rows and 2 columns are located in the third insulating layer, the fourth micro-bumps correspond to the third micro-bumps one by one, and the second TSV structure is connected between the corresponding fourth micro-bumps and the third micro-bumps; a plurality of fourth metal RDLs are located in the third insulating layer, and both ends of each fourth metal RDL are respectively connected to two fourth micro-bumps in the same row, and the length of the fourth metal RDL in the same row is less than the length of the second metal RDL; Figure 2 and Figure 3 The case where N=3 is shown in FIG.

[0046] The fourth micro-bumps distributed in N rows and 2 columns are located in the third insulating layer, the fourth micro-bumps correspond to the third micro-bumps one-to-one, and a second TSV structure is connected between the corresponding fourth micro-bumps and the third micro-bumps; a plurality of fourth metal RDLs are located in the third insulating layer, and each fourth metal RDL is connected through two fourth micro-bumps in the same row.

[0047] In the embodiment of the present invention, the first TSV structure and the second TSV structure have the same structure; each first TSV structure includes a TSV through hole, a TSV insulating layer, and a TSV metal, the TSV insulating layer is located on the inner surface of the TSV through hole, and the TSV metal is fully filled in the TSV through hole, and the filled TSV metal can be copper. The depth-to-width ratio of the first TSV structure and the second TSV structure is 10:1; the first TSV structure and the second TSV structure act as an inductive conductive coil in the present invention.

[0048] In the embodiment of the present invention, the aperture sizes of the first micro-bump to the fourth micro-bump are all equal; the aperture size of the first micro-bump is larger than the aperture size of the TSV through hole. The apertures of the first micro-bump to the fourth micro-bump are larger than the apertures of the TSV through holes in the first TSV structure and the second TSV structure, so that good electrical interconnection can be formed between the micro-bump and the TSV metal in the TSV through hole.

[0049] In the embodiment of the present invention, the thickness of the first micro-bump is equal to that of the second micro-bump, the thickness of the third micro-bump is equal to that of the fourth micro-bump, and the thickness of the first micro-bump is greater than that of the third micro-bump. The material of the first micro-bump to the fourth micro-bump can be copper.

[0050] In the embodiment of the present invention, the first insulating layer and the third insulating layer have the same thickness; the second insulating layer and the fourth insulating layer have the same thickness; the first insulating layer has a thickness greater than that of the second insulating layer. The material of the first to fourth insulating layers may be SiO2.

[0051] In the embodiment of the present invention, the thicknesses of the first metal RDL to the fourth metal RDL are equal. Both ports of the primary inductor and the auxiliary inductor are composed of metal RDL. The metal RDL can be copper. The first metal RDL of the auxiliary inductor is electrically connected to the TSV metal in the first TSV structure through the first micro-bump, and the second metal RDL of the auxiliary inductor is electrically connected to the TSV metal in the first TSV structure through the second micro-bump; the third metal RDL of the primary inductor is electrically connected to the TSV metal in the second TSV structure through the third micro-bump, and the fourth metal RDL of the primary inductor is electrically connected to the TSV metal in the second TSV structure through the fourth micro-bump.

[0052] In the embodiment of the present invention, the thickness of the first micro bump and the second micro bump is 6 μm; the thickness of the third micro bump and the fourth micro bump is 2 μm; the thickness of the first insulating layer and the third insulating layer is 6 μm, and the thickness of the second insulating layer and the fourth insulating layer is 2 μm; the thickness of the first metal RDL to the fourth metal RDL is 2 μm.

[0053] The embodiment of the present invention embeds the TSV structure into the silicon substrate, and uses through holes and micro-bumps to realize the electrical interconnection between the metal RDL and the TSV metal, which effectively utilizes the volume of the silicon substrate in the vertical direction, reduces the occupied area of ​​the inductor structure, and is conducive to the transition to a three-dimensional inductor structure with a larger scale, smaller volume and wider tuning range, thereby improving the integration scale of the system.

[0054] In summary, the TSV-based tunable inductor structure provided in the embodiment of the present invention nests the primary inductor and the auxiliary inductor, which can reduce the area of ​​the tunable inductor structure and is beneficial to improving the integration of the RF system; since the self-resonant frequency of the primary inductor is higher than the self-resonant frequency of the auxiliary inductor, the primary inductor is connected to the actual circuit, and the auxiliary inductor is connected to the modulation source for regulation, so that the inductance value of the primary inductor can be continuously tuned within a wider range, which can be used to design an inductor with a higher self-resonant frequency and improve the multi-band tuning capability of the RF system; based on the proposed tunable inductor structure, the modulation source modulation method is used, and the tuning is simple and flexible, and continuous tuning is possible. By flexibly regulating the voltage V2 of the modulation source, a voltage difference is created between the voltage V1 and the voltage V2, so that the primary inductor and the auxiliary inductor are coupled to each other, thereby achieving the purpose of tuning the inductance value of the primary inductor. It can be seen that the tunable inductor structure proposed in the embodiment of the present invention improves the tunability of the inductor device, and realizes the transformation from the traditional tunable inductor with a small tuning range, a large area, and high-frequency performance degradation to a TSV tunable inductor structure with a smaller area, a wider tuning range, and continuous tuning based on magnetic coupling technology. It has a smaller volume and a wider tuning range, can improve the multi-band tuning capability of the electronic system, meet the design requirements of miniaturization and multi-functional reconstruction of RF microsystems, can be widely used in RF circuits such as filters and impedance matching networks, and has positive significance for promoting the development of miniaturized design and flexible configuration of RF electronic systems.

[0055] In a second aspect, an embodiment of the present invention provides a tuning method of a tunable inductor structure based on TSV, the tuning method comprising:

[0056] Designing a TSV-based tunable inductor structure according to any one of the first aspects;

[0057] Connect the two ports of the auxiliary inductor to the modulation source and the ground respectively;

[0058] The modulation source is regulated to regulate the voltage difference between the voltage V1 between the two ports of the primary inductor and the voltage V2 between the two ports of the auxiliary inductor, so that the primary inductor and the auxiliary inductor are coupled with each other under the action of the voltages V1 and V2, the inductance value of the primary inductor is tuned, and the two ports of the primary inductor are connected to the actual application circuit.

[0059] The embodiment of the present invention verifies the TSV-based tunable inductor structure proposed in the first aspect as follows:

[0060] like Figure 4 As shown by the black line in the middle, when no modulation is performed, the equivalent inductance of the primary inductance is 2.52nH; Figure 4 As shown by the red line in the middle, when the modulation source voltage V2 is changed for modulation, the equivalent inductance value of the primary inductance can be changed to 5.14nH. Figure 4The horizontal axis represents the frequency in GHz, and the vertical axis represents the equivalent inductance in nH.

[0061] like Figure 5 In the modulation mode, the voltage V1 at the two ports of the primary inductor is set to 0.5V, and different voltages V2 are generated by adjusting the modulation source. Different voltage differences are generated between the voltages V1 and V2, and under the action of the magnetic coupling effect, the change in voltage causes the equivalent inductance of the primary inductor to change, thus achieving dynamic tuning of the inductance of the primary inductor. Figure 5 The horizontal axis represents the frequency in GHz, and the vertical axis represents the equivalent inductance in nH. Figure 5 The lines of different colors in the figure represent the changes in the equivalent inductance of the primary inductance under different voltage differences.

[0062] As for the method embodiment of the second aspect, since it is basically similar to the structural embodiment of the first aspect, the description is relatively simple, and the relevant parts may refer to the partial description of the structural embodiment of the first aspect.

[0063] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0064] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the specification and its drawings. In the specification, the word "comprising" does not exclude other components or steps, and "a" or "one" does not exclude multiple situations. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0065] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A tunable inductor structure based on TSV, characterized in that: The tunable inductor structure includes a primary inductor and an auxiliary inductor, wherein the primary inductor is nested in the auxiliary inductor to form a nested tunable inductor structure; wherein, The auxiliary inductor is connected to a modulation source, and the primary inductor is connected to an actual application circuit, so that the voltage difference between the voltage V1 between the two ports of the primary inductor and the voltage V2 between the two ports of the auxiliary inductor can be regulated by the modulation source, so that the primary inductor and the auxiliary inductor are coupled with each other under the action of the voltage V1 and the voltage V2, thereby realizing the inductance tuning of the primary inductor.

2. The TSV-based tunable inductor structure according to claim 1, characterized in that: The auxiliary inductor includes a first TSV structure, a first micro-bump, a second micro-bump, a first metal RDL and a second metal RDL; wherein, Each first TSV structure is located in the silicon substrate; The first micro-bumps distributed in N rows and 2 columns are located in the first insulating layer on the upper surface of the silicon substrate, where N is an integer greater than 1; a plurality of first metal RDLs are located in the second insulating layer on the upper surface of the first insulating layer, and two ends of each first metal RDL are respectively connected to two first micro-bumps in the nth row and the second column and in the n+1th row and the first column, where n=1, 2, ..., N-1; the port leading out of the first micro-bump in the first row and the first column and the port leading out of the first micro-bump in the Nth row and the second column are used as two ports of the auxiliary inductor; The second micro-bumps distributed in N rows and 2 columns are located in the third insulating layer on the lower surface of the silicon substrate, the second micro-bumps correspond to the first micro-bumps one-to-one, and the first TSV structure is connected between the corresponding second micro-bumps and the first micro-bumps; a plurality of second metal RDLs are located in the fourth insulating layer on the lower surface of the third insulating layer, and the two ends of each second metal RDL are respectively connected to the two second micro-bumps in the same row.

3. The TSV-based tunable inductor structure according to claim 2, characterized in that: The primary inductor includes a second TSV structure, a third micro-bump, a fourth micro-bump, a third metal RDL and a fourth metal RDL; wherein, Each second TSV structure is located in the silicon substrate; The third micro-bumps distributed in N rows and 2 columns are located in the first insulating layer on the upper surface of the silicon substrate, where N is an integer greater than 1; a plurality of third metal RDLs are located in the first insulating layer, and two ends of the nth third metal RDL are respectively connected to two first micro-bumps in the nth row and 2nd column and in the n+1th row and 1st column, where n=1, 2, ..., N-1; a port led out of the third micro-bump in the 1st row and 1st column and a port led out of the third micro-bump in the Nth row and 2nd column are used as two ports of the primary inductor; The fourth micro-bumps distributed in N rows and 2 columns are located in the third insulating layer, the fourth micro-bumps correspond to the third micro-bumps one-to-one, and a second TSV structure is connected between the corresponding fourth micro-bumps and the third micro-bumps; a plurality of fourth metal RDLs are located in the third insulating layer, and both ends of each fourth metal RDL are respectively connected to two fourth micro-bumps in the same row, and the length of the fourth metal RDL in the same row is less than the length of the second metal RDL.

4. The TSV-based tunable inductor structure according to claim 3, characterized in that: The first TSV structure and the second TSV structure have the same structure; each first TSV structure includes a TSV through hole, a TSV insulating layer, and a TSV metal, the TSV insulating layer is located on the inner surface of the TSV through hole, and the TSV metal fully fills the TSV through hole.

5. The TSV-based tunable inductor structure according to claim 4, characterized in that: The aperture sizes of the first micro-bump to the fourth micro-bump are all equal; the aperture size of the first micro-bump is larger than the aperture size of the TSV through hole.

6. The TSV-based tunable inductor structure according to claim 3, characterized in that: The thickness of the first micro-bump is equal to the thickness of the second micro-bump, and the thickness of the third micro-bump is equal to the thickness of the fourth micro-bump; the thickness of the first micro-bump is greater than the thickness of the third micro-bump.

7. The TSV-based tunable inductor structure according to claim 3, characterized in that: The thickness of the first insulating layer is equal to that of the third insulating layer; the thickness of the second insulating layer is equal to that of the fourth insulating layer; and the thickness of the first insulating layer is greater than that of the second insulating layer.

8. The TSV-based tunable inductor structure according to claim 3, characterized in that: The first to fourth metal RDLs have the same thickness.

9. The TSV-based tunable inductor structure according to claim 3, characterized in that: The thickness of the first micro bump and the second micro bump is 6 μm; the thickness of the third micro bump and the fourth micro bump is 2 μm; the thickness of the first insulating layer and the third insulating layer is 6 μm, and the thickness of the second insulating layer and the fourth insulating layer is 2 μm; the thickness of the first metal RDL to the fourth metal RDL is 2 μm.

10. A tuning method for a tunable inductor structure based on TSV, characterized in that: The tuning method comprises: Design a TSV-based tunable inductor structure as described in any one of claims 1 to 9; Connect the two ports of the auxiliary inductor to the modulation source and the ground respectively; The modulation source is regulated to regulate the voltage difference between the voltage V1 between the two ports of the primary inductor and the voltage V2 between the two ports of the auxiliary inductor, so that the primary inductor and the auxiliary inductor are coupled with each other under the action of the voltages V1 and V2, the inductance value of the primary inductor is tuned, and the two ports of the primary inductor are connected to the actual application circuit.

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