Axial three-dimensional spiral inductor based on glass substrate and manufacturing method thereof

Abstract

The invention relates to the technical field of semiconductors, and discloses an axial three-dimensional spiral inductor based on a glass substrate and a manufacturing method thereof.The axial vertical spiral inductor comprises an upper surface layer, the glass substrate and a lower surface layer, and the upper surface layer comprises a plurality of first metal connecting wires; the lower surface layer comprises a plurality of second metal connecting wires and a plurality of third metal connecting wires, the glass substrate comprises a first glass through hole group and a second glass through hole group, and the first metal connecting wires and the second metal connecting wires are connected through the first glass through hole group or the second glass through hole group; the third metal connecting lines are located below the second metal connecting lines, the third metal connecting lines are parallel to the second metal connecting lines, one sides of the third metal connecting lines are electrically connected with the adjacent second metal connecting lines, and the other sides of the third metal connecting lines are grounded; the distance between the third metal connecting line and the adjacent second metal connecting line is larger than 20 microns. According to the technical scheme, the quality factor of the spiral inductor can be improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and particularly to an axial three-dimensional spiral inductor based on a glass substrate and a manufacturing method thereof. Background Art

[0002] With the rapid development of wireless communication technology, the performance requirements for passive devices in radio frequency integrated circuits are getting higher and higher. Among them, as the core passive device of radio frequency integrated circuits, the loss degree and quality factor of inductors are crucial for the performance of integrated circuits.

[0003] In related technologies, the coil of the traditional spiral inductor has a large loss. In the case of high frequencies, the strong coupling between the coil and the substrate will cause a large substrate loss, the quality factor of the spiral inductor is low, and a large parasitic capacitance is likely to be generated between the coil and the reference ground, further reducing the quality factor of the spiral inductor, and the performance of the spiral inductor is poor. Summary of the Invention

[0004] This application provides an axial three-dimensional spiral inductor based on a glass substrate and a manufacturing method thereof, which can improve the quality factor of the spiral inductor.

[0005] In a first aspect of this application, an axial three-dimensional spiral inductor based on a glass substrate is provided. The axial vertical spiral inductor includes an upper surface layer, a glass substrate, and a lower surface layer. The upper surface layer includes a plurality of first metal connection lines, the lower surface layer includes a plurality of second metal connection lines and a plurality of third metal connection lines, and the glass substrate includes a first glass via hole group and a second glass via hole group, where: the first metal connection line is connected to the second metal connection line through the first glass via hole group or the second glass via hole group; the third metal connection line is located below the second metal connection line, the third metal connection line is parallel to the second metal connection line, one side of the third metal connection line is electrically connected to the adjacent second metal connection line, and the other side of the third metal connection line is grounded; the distance between the third metal connection line and the adjacent second metal connection line is greater than 20 um.

[0006] In a possible implementation manner, the first glass via hole group includes a plurality of first glass via holes, and the second glass via hole group includes a plurality of second glass via holes; where: the first glass via hole group and the second glass via hole group are arranged along a first direction. Among them, a plurality of the first glass via holes are arranged along a second direction, a plurality of the second glass via holes are arranged along the second direction, and the first direction is perpendicular to the second direction; for adjacent first glass via holes and second glass via holes, they are connected through the first metal connection line on the upper surface layer and connected through the second metal connection line on the lower surface layer.

[0007] In a possible implementation, the first glass via group or the second glass via group further includes a plurality of copper cores; each of the copper cores is disposed in a corresponding first glass via or second glass via.

[0008] In a possible implementation, the upper surface layer further includes a first dielectric layer, and the lower surface layer further includes a second dielectric layer; the first dielectric layer wraps the first metal connection line, the first dielectric layer is in contact with the glass substrate, the second dielectric layer wraps the second metal connection line, and the second dielectric layer is in contact with the third metal connection line; the materials of the first dielectric layer and the second dielectric layer are both polyimide.

[0009] In a possible implementation, the thicknesses of the first metal connection line, the second metal connection line, and the third metal connection line are all 5 μm, the line widths of the first metal connection line, the second metal connection line, and the third metal connection line are all 80 μm, and the spacing between each of the first metal connection lines and the spacing between each of the second metal connection lines are both 5 μm.

[0010] In a possible implementation, the upper surface layer further includes an input end and an output end; the input end is located at one end of the upper surface layer, the output end is located at the other end of the upper surface layer, and the input end and the output end are on the same horizontal line.

[0011] In a possible implementation, the input end is connected to the first glass via group through the first metal connection line, and the output end is connected to the second glass via group through the first metal connection line.

[0012] In a possible implementation, the materials of the first metal connection line, the second metal connection line, and the third metal connection line are copper.

[0013] The second aspect of the present application provides a method for manufacturing an axially vertical spiral inductor based on a glass substrate. The method includes: etching a plurality of glass through-holes on the glass substrate, depositing metallic copper on the upper surfaces of the plurality of glass through-holes and the glass substrate to form copper cores penetrating through each of the glass through-holes and a first metal layer covering the upper surface of the glass substrate, etching the first metal layer to obtain a plurality of first metal connection lines through etching, and coating a first dielectric layer on the upper surface of the glass substrate; rotating the glass substrate and depositing metallic copper on the lower surface of the glass substrate to form a second metal layer covering the lower surface of the glass substrate, etching the second metal layer to obtain a plurality of second metal connection lines through etching, and coating a second dielectric layer on the lower surface of the glass substrate; etching a plurality of dielectric through-holes connecting the second metal connection lines on the second dielectric layer, depositing metallic copper on the etched second dielectric layer to form a third metal layer covering the surface of the second dielectric layer, and the third metal layer penetrates through each of the dielectric through-holes to be connected to each of the second metal connection lines; etching the third metal layer to obtain a plurality of third metal connection lines through etching to form an axially three-dimensional spiral inductor.

[0014] In a possible implementation manner, the thickness of the second dielectric layer is greater than 20 um.

[0015] The technical solution provided by one or more embodiments of the present application optimizes the spatial layout of the spiral inductor in the glass substrate, thereby improving the quality factor of the spiral inductor. Specifically, by adjusting the thickness of the dielectric layer to control the distance between the spiral coil and the reference ground, parasitic capacitance between each metal connection line is avoided, the distribution of the electromagnetic field is optimized, and the skin effect loss of the spiral coil is reduced to improve the quality factor of the spiral coil.

[0016] It can be seen that the technical solution provided by the present application can effectively reduce the substrate loss and skin effect loss of the spiral inductor, thereby improving the quality factor of the spiral inductor. At the same time, the performance of the spiral inductor can also be ensured under high-frequency signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 FIG. is a schematic structural diagram of an axially three-dimensional spiral inductor based on a glass substrate provided by an embodiment of the present application;

[0019] Figure 2 A linear relationship diagram of pitch and inductance Q value at a frequency of 3.6 Hz provided by an embodiment of the present application;

[0020] Figure 3 A schematic diagram of the composition of an axial three-dimensional spiral inductor based on a glass substrate provided by an embodiment of the present application;

[0021] Figure 4 A schematic diagram of the positions of an input end and an output end provided by an embodiment of the present application;

[0022] Figure 5 A schematic structural diagram of an axial three-dimensional spiral inductor with a dielectric layer provided by an embodiment of the present application;

[0023] Figure 6 A schematic diagram of a manufacturing method of an axial three-dimensional spiral inductor based on a glass substrate provided by an embodiment of the present application.

[0024] Description of reference numerals

[0025] 10 - upper surface layer, 20 - glass substrate, 30 - lower surface layer, 11 - first metal connection line, 21 - first glass via hole group, 21 - second glass via hole group, 31 - second metal connection line, 32 - third metal connection line, 211 - first glass via hole, 221 - second glass via hole, 12 - first dielectric layer, 33 - second dielectric layer, 101 - input end, 102 - output end. Detailed implementation manners

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0027] In addition, the descriptions involving "first", "second", etc. in the present application are only for descriptive purposes and cannot be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the embodiments of the present application, unless otherwise stated, the meaning of "a plurality" is two or more. In addition, the use of "based on" or "according to" means open and inclusive, because a process, step, calculation, or other action "based on" or "according to" one or more of the stated conditions or values may in practice be based on additional conditions or values beyond the stated ones.

[0028] Traditional spiral inductors usually have a planar spiral winding structure and are fabricated using a resin substrate laminate process. The metal layer of the inductor coil is relatively thin, making it prone to the skin effect, which causes coil losses and weakens the inductance of the coil. According to Ohm's law and where Q is the quality factor of the inductor, L is the inductance, and R is the resistance value. Since the metal layer of the inductor coil is relatively thin and the cross-sectional area of the metal layer is small, the DC resistance of the coil increases, thereby reducing the quality factor of the spiral inductor.

[0029] At the same time, traditional spiral inductors usually use a silicon substrate. At high frequencies, the coil is prone to strong coupling with the silicon substrate, generating parasitic capacitance, which weakens the inductance and causes substrate losses, further reducing the quality factor of the spiral inductor.

[0030] In related technologies, in order to improve the quality factor of the inductor, a suspended structure spiral inductor with a hollowed-out inductor structure has emerged, but this method has a relatively complex process. In recent years, with the booming development of the glass via technology, a spiral structure inductor using glass as a substrate has emerged. Since glass has low dielectric loss and high insulation strength, it can optimize the electromagnetic field distribution of the inductor coil, reducing coil losses and substrate losses. However, since a relatively large parasitic capacitance is easily generated when the inductor coil is too close to the reference ground, the inductance will be further weakened, thereby reducing the quality factor of the inductor. In addition, when the inductor coil is too far from the reference ground, it will lead to greater process difficulty and insufficient reliability.

[0031] In view of this, one or more embodiments of the present application provide an axial three-dimensional spiral inductor based on a glass substrate and a manufacturing method thereof, which can solve the above problems and improve the quality factor of the spiral inductor.

[0032] Please refer to Figure 1 , one embodiment of the present application provides an axial three-dimensional spiral inductor based on a glass substrate. The axial vertical spiral inductor includes an upper surface layer 10, a glass substrate 20, and a lower surface layer 30. The upper surface layer 10 includes a plurality of first metal connection lines 11, the lower surface layer 30 includes a plurality of second metal connection lines 31 and a plurality of third metal connection lines 32, and the glass substrate 20 includes a first glass via group 21 and a second glass via group 22, wherein:

[0033] The first metal connecting line 11 and the second metal connecting line 31 are connected through the first glass via hole group 21 or the second glass via hole group 22; the third metal connecting line 32 is located below the second metal connecting line 31, the third metal connecting line 32 is parallel to the second metal connecting line 31, one side of the third metal connecting line 32 is electrically connected to the adjacent second metal connecting line 31, and the other side of the third metal connecting line 32 is grounded; the distance between the third metal connecting line 32 and the adjacent second metal connecting line 31 is greater than 20um.

[0034] Specifically, the above-mentioned multiple first metal connecting lines 11 are parallel to each other, the above-mentioned multiple second metal connecting lines 31 are parallel to each other, and the above-mentioned multiple first metal connecting lines 11, multiple second metal connecting lines 31, first glass via hole group 21 and second glass via hole group 22 are interconnected to form a multi-turn inductance coil. Among them, directly below each second metal connecting line 31, there is a third metal connecting line 32 connected thereto, and the third metal connecting line 32 and the second metal connecting line 31 are in the same plane. One side of the above-mentioned third metal connecting line 32 is connected to the second metal connecting line 31, and the other side is connected to the ground wire to serve as a reference ground plane.

[0035] The above-mentioned multiple third metal connecting lines 32 can provide electrical reference and electromagnetic shielding for the spiral inductor, improving the reliability and stability of the circuit. Specifically, the third metal connecting line 32 provides a stable electrical reference point for the inductor by connecting to the ground wire, and at the same time helps to shield electromagnetic interference, protecting the inductor from the influence of external electromagnetic fields, which is crucial for reducing noise and improving signal integrity. In addition, the third metal connecting line 32 can also conduct the heat generated during the operation of the inductor and provide physical support for the vertical spiral structure of the inductor, thereby improving the reliability and stability of the circuit.

[0036] In this embodiment, by controlling the distance between the second metal connecting line 31 and the third metal connecting line 32, the quality factor of the inductor can be improved. Among them, when the distance between the second metal connecting line 31 and the third metal connecting line 32 is small, a large parasitic capacitance will be generated and the skin effect is likely to occur, resulting in energy loss and a decrease in the quality factor of the inductor. On the contrary, when the distance between the second metal connecting line 31 and the third metal connecting line 32 is large, it is not conducive to the miniaturization and integrated design of the integrated circuit, increasing the process difficulty, and the increase in the distance may affect thermal management. In view of this, by reasonably controlling the distance between the second metal connecting line 31 and the third metal connecting line 32, while ensuring the reasonable structure of the inductor, the energy loss caused by parasitic capacitance and skin effect can be reduced, thereby improving the quality factor of the inductor.

[0037] Optionally, the spacing between the second metal connection line 31 and the third metal connection line 32 described above can be set to be 20 um or more. Specifically, please refer to Figure 2 , Figure 2 which is a linear relationship diagram of the above spacing and the inductance Q value (quality factor of the inductor) at a frequency of 3.6 Hz. When the above spacing is less than 20 um, the parasitic capacitance between the metal connection lines is relatively large, and skin effect loss is likely to occur, resulting in a relatively low quality factor of the inductor and poor performance. When the above spacing is greater than or equal to 20 um, the quality factor of the inductor is relatively high, and the performance of the inductor is better. However, the higher the spacing between the second metal connection line 31 and the third metal connection line 32, the more complex the inductor process, which is not conducive to the application of integrated circuits with limited space. Preferably, the spacing between the second metal connection line 31 and the third metal connection line 32 can be controlled to be 20 um.

[0038] In this embodiment, by using a glass substrate 20, the first metal connection line 11 and the second metal connection line 31 are connected through the first glass via group 21 and the second glass via group 22 to form a complete spiral coil. In the above spiral coil, the current circulates multiple times according to the spiral structure, and each circulation forms one turn of the inductor to form a complete current loop. It should be noted that the number of turns of the inductor is not limited in this application, and the actual number of turns can be adjusted according to design requirements. Further, during the current flow, the spiral coil will generate an electromagnetic field. Due to the low-loss characteristic of the glass substrate, it helps to optimize the distribution of the high-frequency electromagnetic field and can improve the quality factor of the inductor.

[0039] In this embodiment, the above spiral inductor adopts a stacked structure in the glass substrate to form a spatial layout of a three-dimensional spiral inductor, optimize the electromagnetic field distribution, and thus improve the quality factor of the inductor. Specifically, through a three-dimensional vertical design of the spiral coil in the glass substrate, the limitation of traditional planar winding is broken through, the electromagnetic field of the spiral inductor is optimized, and glass vias are fabricated using glass via technology, reducing the process difficulty of the spiral inductor with a suspended structure in the related art, and at the same time reducing the coil loss and substrate loss, thereby improving the quality factor of the spiral inductor.

[0040] In one embodiment, please refer to Figure 3, the first glass via group 21 includes a plurality of first glass vias 211, and the second glass via group 22 includes a plurality of second glass vias 221; wherein: the first glass via group 21 and the second glass via group 22 are arranged along a first direction, wherein a plurality of the first glass vias 211 are arranged along a second direction, and a plurality of the second glass vias 221 are arranged along the second direction, and the first direction is perpendicular to the second direction; for adjacent first glass via 211 and second glass via 221, they are connected by the first metal connection line 11 on the upper surface layer and connected by the second metal connection line 31 on the lower surface layer.

[0041] It should be noted that the above first direction and the above second direction are in the same plane, and the above first direction, the above second direction and the through direction of each glass via are perpendicular to each other to form a three-dimensional spiral structure of the spiral coil.

[0042] In this embodiment, one turn of the coil includes a first metal connection line 11, a second metal connection line 31 and a corresponding third metal connection line 32, a first glass via 211 and a second glass via 221. Among them, one end of the first metal connection line 11 is connected to one end of the second metal connection line 31 through the first glass via 211, and the other end of the first metal connection line 11 is connected to the other end of the second metal connection line 31 through the second glass via 221. The number of the above first glass vias 211 is equal to the number of the above second glass vias 221, and the number of the above first glass vias 211 or second glass vias 221 reflects the number of turns of each coil. It should be noted that the number of turns of the inductor coil in this application is not limited, and the number of turns of the coil can be adjusted according to different application scenarios. In addition, the number and diameter of the through holes in each of the above interconnection via groups are adjustable, and this application does not limit this too much.

[0043] In this embodiment, each of the above first glass vias 211 and second glass vias 221 is a tapered via penetrating through the above glass substrate. Among them, when forming a tapered via on the glass substrate, a glass via process can be used to perform a perforation operation. Specifically, various glass perforation techniques such as sandblasting, photosensitive glass method, plasma etching method or laser-induced etching method can be used to fabricate each glass via. Further, metal filling, electroplating filling, etc. can also be used to fill the glass via. Optionally, unidirectional perforation can be used to form a tapered via during the perforation operation, or bidirectional vias can be used to form a double-tapered via.

[0044] In one embodiment, the first glass via group or the second glass via group further includes a plurality of copper cores, and each copper core is disposed in a corresponding first glass via or second glass via. The copper cores penetrate through the respective glass vias and are used for electrical connection between the first metal connection line and the second metal connection line. The top of the copper core is connected to the first metal connection line, and the bottom of the copper core is connected to the second metal connection line. Preferably, after glass drilling to form the glass vias, electroplating copper is used for each glass via to prepare the copper cores of the respective interconnected vias.

[0045] In this embodiment, the materials of the first metal connection line, the second metal connection line, and the third metal connection line are also copper.

[0046] In this embodiment, by adjusting the aspect ratio and sidewall roughness of the copper cores, the skin effect loss in the high-frequency case can be reduced, and thus the quality factor of the spiral inductor can be improved. Specifically, since high-frequency current is mainly concentrated on the surface of the conductor, when the conductor roughness is too large, it will cause the current path to extend and electromagnetic wave scattering, resulting in additional losses. And when the diameter of the copper core increases, the surface area of the conductor increases and the skin effect loss decreases. When the depth of the copper core increases, the current path extends and the skin effect loss will increase. Therefore, by reasonably adjusting the aspect ratio and sidewall roughness of the copper cores, the performance of the balun can be improved to a certain extent. It should be noted that the above aspect ratio is the ratio of the depth of the copper core to the maximum diameter of the copper core. Preferably, the aspect ratio is 3.64:1.

[0047] In one embodiment, the metal thickness, line width, and the spacing between the respective metal connection lines of the spiral inductor can be adjusted. In high-frequency application scenarios, the current distribution inside the conductor is uneven, and the current is mainly concentrated on the surface of the conductor. As the frequency increases, the intensified skin effect will cause the current to tend to flow on the surface of the conductor. An overly narrow line width will cause the skin effect of the coil to be more obvious, the AC resistance to further increase, and the quality factor of the inductor to decrease. At the same time, an overly narrow spacing will cause the parasitic capacitance to cause an additional current path at high frequencies, thus affecting the electromagnetic field distribution of the inductor and further reducing the quality factor of the inductor. Therefore, selecting appropriate metal thickness, line width, and the spacing between the respective metal connection lines can further optimize the quality factor of the inductor.

[0048] Preferably, the thicknesses of the first metal connection line, the second metal connection line, and the third metal connection line are all 5um, the line widths of the first metal connection line, the second metal connection line, and the third metal connection line are all 80um, and the spacing between each of the first metal connection lines and the spacing between each of the second metal connection lines are both 5um.

[0049] Preferably, the thickness of the above-mentioned glass substrate can be set to 200 um. Specifically, an appropriate thickness helps to optimize the performance of the inductor, reduce parasitic capacitance and improve the quality factor. Among them, a too thin glass substrate has low mechanical strength and may increase parasitic capacitance and losses, while a too thick glass substrate increases the process cost and is not conducive to the thermal stability and reliability of the inductor. Co-optimizing the thickness of the glass substrate, the parameters of the various metal connection lines of the inductor, and the thickness of the dielectric layer can reduce the generation of parasitic capacitance and skin effect losses, and thus optimize the quality factor of the inductor.

[0050] Please refer to Figure 4 , in one embodiment, the upper surface layer 10 further includes an input end 101 and an output end 102; the input end 101 is located at one end of the upper surface layer, the output end 102 is located at the other end of the upper surface layer, and the input end 101 and the output end 102 are on the same horizontal line. The input end 101 is connected to the first glass via group 21 through the first metal connection line 11, and the output end 102 is connected to the second glass via group 22 through the first metal connection line 11.

[0051] In this embodiment, the above-mentioned input end 101 and the above-mentioned output end 102 are located on the diagonal of the upper surface layer, and are respectively connected to the first glass via 211 and the second glass via 221 with the farthest straight-line distance. The above-mentioned input end 101 is used to receive the signal current from the upstream of the circuit. The above-mentioned signal current is transmitted to the output end 102 through the spiral coil, and the above-mentioned output end 102 transmits the signal processed by the inductor to the downstream of the circuit. Among them, the electrical length between the input end 101 and the output end 102 will affect the operating frequency and impedance characteristics of the inductor. Preferably, the input end 101 and the output end 102 are arranged at both ends of the spiral inductor to achieve the best signal transmission and the smallest parasitic effect, thereby further optimizing the performance of the inductor.

[0052] In one embodiment, please refer to Figure 5 , the upper surface layer further includes a first dielectric layer 12, and the lower surface layer further includes a second dielectric layer 33; the first dielectric layer 12 wraps the first metal connection line 11, the first dielectric layer 12 is in contact with the glass substrate 20, the second dielectric layer 33 wraps the second metal connection line 31, and the second dielectric layer 33 is in contact with the third metal connection line 32; the materials of the first dielectric layer 12 and the second dielectric layer 33 are both polyimide.

[0053] In this embodiment, the first dielectric layer 12 and the second dielectric layer 33 can provide electrical insulation to prevent current leakage between different metal wires. Specifically, the first dielectric layer 12 is located below each first metal connection line 11 to provide insulation and support for the first metal connection line 11. The second dielectric layer 22 is located below each second metal connection line 31 and above the third metal connection line 32 to provide insulation and support for the second metal connection line 31 and the third metal connection line 32. The first metal connection line 11 and the second metal connection line 31 are connected through the first glass through-hole 211 or the second glass through-hole 221 in the glass substrate 20.

[0054] Meanwhile, by adjusting the thickness and material properties of the dielectric layer, the performance of the spiral inductor can be further optimized. By adjusting the thickness of the second dielectric layer, the spacing between the second metal connection line and the third metal connection line can be controlled. Separating the second metal connection line and the third metal connection line and appropriately adjusting the spacing between them can reduce the generation of parasitic capacitance between different metal connection lines, optimize the high-frequency electromagnetic field distribution, and thus improve the quality factor of the inductor.

[0055] Optionally, the above dielectric thickness can be set to be more than 25 μm. Specifically, the thicknesses of the first metal connection line, the second metal connection line, and the third metal connection line are all 5 μm. At this time, the spacing from the second metal connection line to the third metal connection line is more than 20 μm. When the dielectric thickness is lower than 25 μm, the parasitic capacitance between the metal connection lines is relatively large, and skin effect loss is likely to occur, resulting in a relatively low quality factor of the inductor and poor performance. When the dielectric thickness is higher than or equal to 25 μm, the quality factor of the inductor can reach more than 70, and the performance of the inductor is better. However, the higher the dielectric thickness, the more complex the process of the inductor, which is not conducive to the application of integrated circuits with limited space. At the same time, too high a dielectric thickness may affect the heat dissipation performance of the inductor, resulting in a reduction in the reliability of the inductor in a high-temperature environment. Preferably, the above dielectric thickness can be controlled to be 25 μm.

[0056] Preferably, polyimide can be used as the material of the dielectric layer. Polyimide has a very high insulation strength, and at the same time has high strength and flexibility, which is suitable for complex circuit layouts and three-dimensional structures, and is conducive to the stable operation of the inductor. Optionally, other dielectric layer materials such as polytetrafluoroethylene and epoxy resin can also be used.

[0057] A kind of axial three-dimensional spiral inductor based on a glass substrate provided by the technical solutions of multiple embodiments of the present application has a quality factor of more than 70 at a frequency of 3.6 GHz. As an important parameter for measuring the performance of an inductor, the quality factor reflects the ratio of the energy stored in the inductor to the energy consumed. The higher the quality factor, the smaller the energy loss of the inductor at the current frequency and the higher the performance. At the same time, the three-dimensional vertical spiral structure can greatly improve the chip integration, and the use of a glass substrate can reduce the substrate loss and still maintain high performance under high-frequency signals. In the application of a power amplification module, it can effectively avoid the loss of the filter, thereby improving the power added power and the maximum linear output power of the power amplification module, and is suitable for high-frequency high-power application scenarios.

[0058] The technical solutions provided by one or more embodiments of the present application optimize the spatial layout of the spiral inductor in the glass substrate, thereby improving the quality factor of the spiral inductor. Specifically, by adjusting the thickness of the dielectric layer to control the spacing between the spiral coil and the reference ground, parasitic capacitance between each metal connection line is avoided, the electromagnetic field distribution is optimized, and the skin effect loss of the spiral coil is reduced to improve the quality factor of the spiral coil.

[0059] In addition, by using a glass substrate and constructing a stacked structure, while meeting the smaller space limitation, the substrate loss and skin effect loss of the spiral inductor can be effectively reduced under high-frequency signals, further improving the quality factor of the spiral inductor and ensuring the performance of the spiral inductor under the working conditions of high-frequency signals.

[0060] Please refer to Figure 6 , the present application also provides a manufacturing method of an axial three-dimensional spiral inductor based on a glass substrate, characterized in that the method includes the following steps:

[0061] S1: Etch a plurality of glass vias on the glass substrate, deposit metallic copper on the upper surfaces of the plurality of glass vias and the glass substrate to form copper cores penetrating through each of the glass vias and a first metal layer covering the upper surface of the glass substrate, etch the first metal layer, and after etching, obtain a plurality of first metal connection lines, and coat a first dielectric layer on the upper surface of the glass substrate;

[0062] S3: Rotate the glass substrate, and deposit metallic copper on the lower surface of the glass substrate to form a second metal layer covering the lower surface of the glass substrate, etch the second metal layer, and after etching, obtain a plurality of second metal connection lines, and coat a second dielectric layer on the lower surface of the glass substrate;

[0063] S5: Etch a plurality of dielectric vias connecting the second metal connecting lines on the second dielectric layer, and deposit copper metal on the etched second dielectric layer to form a third metal layer covering the surface of the second dielectric layer. The third metal layer penetrates through each of the dielectric vias and is connected to each of the second metal connecting lines;

[0064] S7: Etch the third metal layer. After etching, a plurality of third metal connecting lines are obtained to form an axial three-dimensional spiral inductor.

[0065] In this embodiment, a plurality of glass vias are etched on the glass substrate. The glass via process can be adopted, and glass perforation is performed by laser-induced etching. Specifically, after cleaning the glass substrate to remove surface contaminants, a high-power laser is used to irradiate the glass surface so that a plurality of denatured regions are generated in the irradiated areas of the glass material, and a plurality of glass vias vertically penetrating the glass substrate are formed by dry etching or wet etching. Among them, the glass vias obtained by laser-induced etching are tapered vias.

[0066] Further, copper is sputtered on the upper surface of the glass substrate to form a conductive first metal layer, and the glass vias are filled with copper by electroplating to form copper cores penetrating through each of the glass vias. Then, photoresist is spin-coated on the first metal layer, and after exposure and development, a photoresist layer defining a pattern with a plurality of first metal connecting lines is defined. The first metal layer covered with the photoresist layer is etched to form a plurality of first metal connecting lines. Further, polyimide is spin-coated on the upper surface of the glass substrate to form a first dielectric layer.

[0067] Further, invert the glass substrate so that the lower surface of the glass substrate is placed on the top. Deposit copper metal on the lower surface of the glass substrate to form a second metal layer. Spin-coat photoresist on the second metal layer, and after exposure and development, a photoresist layer defining a pattern with a plurality of second metal connecting lines is defined. The second metal layer covered with the photoresist layer is etched to form a plurality of second metal connecting lines. Further, polyimide is spin-coated on the lower surface of the glass substrate twice to form a second dielectric layer.

[0068] Further, in one embodiment, the second dielectric layer can be etched by dry etching or wet etching. Similarly, a layer of photoresist is coated on the surface of the second dielectric layer to make a photoresist layer with a plurality of dielectric via patterns through a photolithography process, and then the second dielectric layer is etched to obtain a plurality of dielectric vias that penetrate the second dielectric layer and are connected to the second metal connecting lines.

[0069] Further, deposit metallic copper on the second dielectric layer having a plurality of dielectric vias to form a third metal layer. Spin coat photoresist on the third metal layer, and after exposure and development, define a photoresist layer having a pattern of a plurality of third metal connection lines. The positions of the patterns of the third metal connection lines correspond to the positions of the plurality of second metal connection lines. Etch the third metal layer coated with the photoresist layer to form the third metal connection lines. Completion of the etching of the third metal connection lines indicates the formation of the above-mentioned axial vertical spiral inductor based on a glass substrate.

[0070] In one embodiment, after forming the metal connection lines of each layer, post-processing such as polishing, cleaning, and surface treatment is also required for the formed metal lines to improve the inductance performance and reliability.

[0071] In one embodiment, after manufacturing the inductor, performance tests can be performed on the inductor, such as the quality factor and frequency response. Necessary structural and material adjustments can be made according to the test results to optimize the inductance performance. Further, necessary packaging is performed on the inductor to protect the inductor and facilitate integration into a circuit.

[0072] This application also provides an integrated chip that applies the above-mentioned axial three-dimensional spiral inductor based on a glass substrate. The axial three-dimensional spiral inductor based on a glass substrate has significant advantages in an integrated chip. For example, in the fields of radio frequency chips and high-density system integration, the above-mentioned spiral inductor can greatly improve the chip integration degree and improve the electrical interconnection performance.

[0073] The chip clarified above can be implemented by a product having a certain function. A typical implementation device is a computer. Specifically, the computer can be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0074] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0075] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. For the relevant parts, reference can be made to the descriptions of other embodiments.

[0076] The above are only the embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

[0077] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. An axial vertical spiral inductor based on a glass substrate, characterized in that, The axial vertical spiral inductor includes an upper surface layer, a glass substrate, and a lower surface layer. The upper surface layer includes a plurality of first metal connection lines. The lower surface layer includes a plurality of second metal connection lines and a plurality of third metal connection lines. The glass substrate includes a first glass via hole group and a second glass via hole group, where: The first metal connection line is connected to the second metal connection line through the first glass via hole group or the second glass via hole group; The third metal connection line is located below the second metal connection line. The third metal connection line is parallel to the second metal connection line. One side of the third metal connection line is electrically connected to the adjacent second metal connection line, and the other side of the third metal connection line is grounded; The distance between the third metal connection line and the adjacent second metal connection line is greater than 20um.

2. The axial vertical spiral inductor based on a glass substrate according to claim 1, wherein The first glass via hole group includes a plurality of first glass via holes, and the second glass via hole group includes a plurality of second glass via holes; where: The first glass via hole group and the second glass via hole group are arranged along a first direction. Among them, a plurality of the first glass via holes are arranged along a second direction, and a plurality of the second glass via holes are arranged along the second direction. The first direction is perpendicular to the second direction; For adjacent first glass via hole and second glass via hole, they are connected through the first metal connection line on the upper surface layer and through the second metal connection line on the lower surface layer.

3. The axial vertical spiral inductor based on a glass substrate according to claim 2, wherein The first glass via hole group or the second glass via hole group further includes a plurality of copper cores; each copper core is arranged in the corresponding first glass via hole or second glass via hole.

4. The axial vertical spiral inductor based on a glass substrate according to claim 1, wherein The upper surface layer further includes a first dielectric layer, and the lower surface layer further includes a second dielectric layer; the first dielectric layer wraps the first metal connection line, the first dielectric layer is in contact with the glass substrate, the second dielectric layer wraps the second metal connection line, and the second dielectric layer is in contact with the third metal connection line; the materials of the first dielectric layer and the second dielectric layer are both polyimide.

5. The axial vertical spiral inductor based on a glass substrate according to claim 1, wherein, The thicknesses of the first metal connection line, the second metal connection line, and the third metal connection line are all 5um, the line widths of the first metal connection line, the second metal connection line, and the third metal connection line are all 80um, and the distances between the first metal connection lines and the distances between the second metal connection lines are all 5um.

6. The axial vertical spiral inductor based on a glass substrate according to claim 1, wherein The upper surface layer further includes an input end and an output end; the input end is located at one end of the upper surface layer, the output end is located at the other end of the upper surface layer, and the input end and the output end are on the same horizontal line.

7. The axially vertical spiral inductor based on a glass substrate according to claim 6, characterized in that, The input end is connected to the first glass via hole group through the first metal connection line, and the output end is connected to the second glass via hole group through the first metal connection line.

8. The axial vertical spiral inductor based on a glass substrate according to claim 1, wherein The materials of the first metal connection line, the second metal connection line, and the third metal connection line are copper.

9. A manufacturing method of an axial three-dimensional spiral inductor based on a glass substrate, characterized in that, The method includes: Etch a plurality of glass vias in a glass substrate, deposit metallic copper on the upper surfaces of the plurality of glass vias and the glass substrate to form copper cores penetrating through each of the glass vias and a first metal layer covering the upper surface of the glass substrate, etch the first metal layer, and obtain a plurality of first metal connection lines after etching, and coat a first dielectric layer on the upper surface of the glass substrate; Rotate the glass substrate, and deposit metallic copper on the lower surface of the glass substrate to form a second metal layer covering the lower surface of the glass substrate, etch the second metal layer, and obtain a plurality of second metal connection lines after etching, and coat a second dielectric layer on the lower surface of the glass substrate; Etch a plurality of dielectric vias connecting the second metal connection lines on the second dielectric layer, deposit metallic copper on the etched second dielectric layer to form a third metal layer covering the surface of the second dielectric layer, and the third metal layer penetrates through each of the dielectric vias and is connected to each of the second metal connection lines; Etch the third metal layer, and obtain a plurality of third metal connection lines after etching to form an axial three-dimensional spiral inductor.

10. The method according to claim 9, characterized in that, The thickness of the second dielectric layer is greater than 20 μm.

11. An integrated chip, characterized in that, The integrated chip applies an axial three-dimensional spiral inductor based on a glass substrate as described in any one of claims 1 to 8.

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