A stacked structure, a non-reciprocal component, and a method for fabricating the same.

Abstract

This application discloses a stacked structure, a non-reciprocal element, and a processing method thereof. The stacked structure includes a first cover plate, a waveguide plate, and a magnetic plate stacked sequentially and connected by wafer bonding. The waveguide plate has at least two first through-holes for accommodating ferrite. This application employs a pre-packaging and then dicing method to fabricate the non-reciprocal element. Specifically, the required structures for multiple non-reciprocal elements are pre-packaged uniformly at the wafer level, allowing the first cover plate, waveguide plate, and magnetic plate to use the same specifications as conventional wafers, achieving high wafer-level flatness. Based on this, the three components can achieve high-precision alignment and parallelism control using equipment such as wafer bonding machines. This wafer-level packaging process ensures the uniformity and consistency of the bonding interface, thereby significantly improving the yield and performance consistency of the components after dividing the stacked structure into multiple independent non-reciprocal elements, which is significantly superior to traditional packaging methods.

Description

Technical Field

[0001] This application relates to the field of microwave component manufacturing technology, and in particular to a stacked structure, a non-reciprocal component, and a method for processing the same. Background Technology

[0002] MEMS circulators / isolators are a common type of non-reciprocal component, widely used in communication transceiver systems, radar TR components, and other fields. Currently, MEMS circulators are primarily packaged using chip-level packaging, which involves fabricating the circulator chip structure on a silicon wafer using MEMS fabrication processes, then dicing the silicon wafer into individual chips. These individual chips are then eutectic bonded at high temperatures using solder pads to weld the back of the circulator chip to a nickel-iron alloy. Finally, a ferromagnetic material is glued to the front of the circulator chip to obtain the final device.

[0003] In actual manufacturing, it was found that when the iron-nickel alloy metal sheet at the bottom of the circulator is individually connected to the circulator chip via gold-tin eutectic bonding, it is generally manually assembled using a bonding jig and a reflow oven as the bonding equipment. However, due to the limited positional accuracy of the bonding jig (typical mechanical jigs have a positioning accuracy of 100 to 300 μm), and the possibility of an angle between the plane of the iron-nickel alloy metal sheet and the plane of the circulator, resulting in non-parallelism, this process affects the circulator packaging yield. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a stacked structure, a non-reciprocal component, and a method for processing the same, in order to solve the problem of low yield of non-reciprocal components.

[0005] In a first aspect, this application provides a stacked structure comprising a first cover plate, a waveguide plate, and a magnetically conductive plate stacked sequentially and connected by wafer bonding; the waveguide plate has at least two first through-holes for accommodating ferrites; the first cover plate has a first metal layer on its side facing the waveguide plate; in a bonded state, the first metal layer covers all the first through-holes and is attached to the surface of each ferrite; at least two ferromagnets are mounted on the side of the first cover plate away from the waveguide plate, each ferromagnet for providing a constant magnetic field to at least one ferrite; the magnetically conductive plate has a second metal layer on its side facing the waveguide plate, the second metal layer being bonded to the surface metal layer of the waveguide plate; the stacked structure has at least four receiving structures, each receiving structure communicating with the surface metal layer of the waveguide plate and used to receive electrical connection material to electrically connect the signal transmission structure within the waveguide plate to external components; at least one of the two opposing outer surfaces of the stacked structure has a ground connection layer, the two opposing outer surfaces being the outermost surfaces of all wafer-bonded layers in the stacked structure in the stacking direction.

[0006] Based on the aforementioned stacked structure, this application enables the fabrication of non-reciprocal components using a pre-packaging and post-dicing approach. This involves pre-packaging the required structures for multiple non-reciprocal components at the wafer level, allowing the first cover plate, waveguide plate, and magnetic conductor plate to utilize the same dimensions and specifications as conventional wafers, achieving high wafer-level flatness. Consequently, these three components can be precisely aligned and parallelized using equipment such as wafer bonding machines. This wafer-level packaging process ensures the uniformity and consistency of the bonding interface, significantly improving component yield and performance consistency after dividing the stacked structure into multiple independent non-reciprocal components, demonstrating a significant advantage over traditional packaging methods.

[0007] In one or more embodiments of the above-described stacked structure, the first metal layer comprises at least two stacked metal layers, and at least one metal layer has a preset static permeability, wherein the preset static permeability is greater than 70.

[0008] Furthermore, based on the aforementioned first metal layer, the ferrite magnetic field distribution in the non-reciprocal element can be made more uniform.

[0009] In one or more embodiments of the above-described stacked structure, the ground connection layer is disposed on the side of the magnetic sheet away from the waveguide sheet, and the ground connection layer includes at least one first metal pattern layer, the first metal pattern layer including a scribe groove structure communicating with the magnetic sheet, the scribe groove structure being used to guide chemical liquid to etch the magnetic sheet.

[0010] Furthermore, based on the aforementioned dicing groove structure, combined with wet etching and dicing blade segmentation, the difficulty of segmenting the stacked structure can be significantly reduced, and processing efficiency can be improved.

[0011] In one or more embodiments of the above-described stacked structure, the magnetic sheet facing the waveguide sheet has at least two annular grooves, each annular groove corresponding to each ferrite. In the bonding state, the annular grooves are arranged along the outer periphery of the ferrite, and a constant distance is maintained between the annular grooves and the ferrite.

[0012] In one or more embodiments of the above-described stacked structure, the depth of the annular groove ranges from 3 μm to 10 μm, and the width ranges from 5 μm to 50 μm.

[0013] In one or more embodiments of the above-described stacked structure, the receiving structure is a second through hole penetrating the first cover plate or the magnetic sheet, the second through hole being used to introduce a bonding wire electrically connected to an external component; or, the receiving structure is a sixth through hole penetrating the waveguide sheet, the surface of the sixth through hole being provided with a conductive connection layer, and the conductive connection layer being connected to the surface metal layer of the waveguide sheet, and being used to introduce solder electrically connected to an external component.

[0014] In one or more embodiments of the above-described stacked structure, the stacked structure further includes a second cover plate and a cavity plate connected by wafer bonding. The cavity plate is disposed above the first cover plate along the stacking direction and is connected to the first cover plate by wafer bonding. The cavity plate is provided with at least two third through holes for placing the ferromagnetic material.

[0015] In one or more embodiments of the above-described stacked structure, the receiving structure includes a fourth through hole penetrating the second cover plate, a fifth through hole penetrating the cavity plate, and a second through hole penetrating the first cover plate. In the bonding state, the corresponding second through hole, the fourth through hole, and the fifth through hole are interconnected to introduce a bonding wire for electrical connection to the outside.

[0016] In one or more embodiments of the above-described stacked structure, the side of the second cover away from the cavity sheet is provided with a shielding sheet covering all the ferromagnets, the shielding sheet being used to provide magnetic shielding for the ferromagnets; the shielding sheet is provided with at least four clearance structures, and in the bonding state, the clearance structures are configured one-to-one with the receiving structures.

[0017] In one or more embodiments of the above-described stacked structure, the thickness of the cavity sheet is at most 500 μm greater than the thickness of the ferromagnetic body; and / or, the maximum distance between the inner side of the third through hole and the outer side of the ferromagnetic body is 100 μm.

[0018] In a second aspect, this application provides a non-reciprocal element employing the stacking structure described above, wherein the non-reciprocal element is cut from the stacking structure.

[0019] In a third aspect, this application provides a method for fabricating non-reciprocal components, comprising: determining the specifications and materials of each layer connected by wafer bonding in a stacked structure according to the required number of non-reciprocal components to be manufactured, and fabricating a waveguide sheet using a TSV process based on the number of non-reciprocal components contained in a single stacked structure; forming a first metal layer on one side surface of a first cover sheet, forming a second metal layer on one side surface of a magnetic sheet, and forming a ground connection layer on the other side surface of the first cover sheet or the other side surface of the magnetic sheet; fabricating at least four receiving structures on the first cover sheet, the waveguide sheet, or the magnetic sheet, the receiving structures being used to accommodate electrical connection materials; fabricating at least two first through holes on the waveguide sheet, the first through holes being used to accommodate ferrite; bonding the first cover sheet to the waveguide sheet and installing the ferrite in the corresponding first through hole; bonding the waveguide sheet to the magnetic sheet and installing the ferrite on the side of the first cover sheet opposite to the waveguide sheet to form a stacked structure; and cutting the stacked structure into at least two non-reciprocal components.

[0020] In one or more embodiments of the above processing method, the method further includes: selecting a second cover plate and a cavity plate with the same size and specifications as the first cover plate; forming through holes on the second cover plate, the cavity plate, and the first cover plate to form a receiving structure in a bonded state; forming at least two third through holes on the cavity plate, the third through holes being used to accommodate ferromagnetic materials; sequentially connecting the second cover plate, the cavity plate, the first cover plate, and the waveguide plate through wafer bonding, and installing the ferromagnetic material in the third through holes and the ferrite material in the first through holes; connecting the waveguide plate and the magnetic conductive plate through wafer bonding to form a stacked structure; and cutting the stacked structure into at least two non-reciprocal elements.

[0021] In one or more embodiments of the above processing method, the ground connection layer is disposed on the side of the magnetic sheet away from the waveguide sheet, and the ground connection layer includes at least one first metal pattern layer. The first metal pattern layer includes a scribe groove structure communicating with the magnetic sheet. The scribe groove structure is used to guide the chemical liquid to etch the magnetic sheet. The step of cutting the stacked structure into at least two non-reciprocal elements includes: The magnetic sheet is etched and divided along the dicing groove structure on the first metal pattern layer by wet etching.

[0022] The above-described one or more embodiments of this application have at least one or more of the following beneficial effects: This application employs a bonding-then-dicing method to fabricate non-reciprocal components. This involves pre-bonding the required structures for multiple non-reciprocal components at the wafer level, ensuring that the first cover plate, waveguide plate, and magnetic conductor plate can all utilize the same specifications as conventional wafers, achieving high wafer-level flatness. Based on this, the three components can achieve high-precision alignment and parallelism control using equipment such as wafer bonding machines. This wafer-level packaging process guarantees the uniformity and consistency of the bonding interface, thereby significantly improving component yield and performance consistency after dividing the stacked structure into multiple independent non-reciprocal components, demonstrating a significant advantage over traditional packaging methods.

[0023] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0024] The disclosure of this application will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Furthermore, similar numbers in the drawings are used to denote similar components, wherein: Figure 1 This is a schematic diagram illustrating a stacked structure and the relationship between non-reciprocal components, provided in an embodiment of this application. Figure 2 This is a schematic diagram of a non-reciprocal element provided in an embodiment of this application for demonstration purposes; Figure 3 This is another structural schematic diagram provided in this application embodiment for illustrating a non-reciprocal element; Figure 4 This is a schematic diagram of a structure provided in an embodiment of this application for showing the back side of a stacked structure; Figure 5 This is a schematic diagram illustrating the structure of the sixth through hole provided in an embodiment of this application; Figure 6 This is a schematic diagram of a structure for showing a second cover plate provided in an embodiment of this application; Figure 7 This is a schematic diagram of a cavity sheet provided in an embodiment of this application; Figure 8 This is a schematic diagram of a structure for showing a first cover plate provided in an embodiment of this application; Figure 9 This is a schematic diagram illustrating the structure of a waveguide sheet provided in an embodiment of this application; Figure 10 This is a schematic diagram illustrating the structure of a magnetically conductive sheet provided in an embodiment of this application; Figure 11This application provides a simulation diagram of the magnetic field distribution of a non-reciprocal element in the absence of a high-permeability metal and in the presence of a high-permeability metal. Figure 12 This is a comparison diagram provided in an embodiment of this application for illustrating the distribution of a magnetic field; Figure 13 This is a schematic diagram illustrating a non-reciprocal element provided in an embodiment of this application; Figure 14 This is a flowchart provided in an embodiment of the present application to illustrate a method for processing non-reciprocal components.

[0025] Explanation of reference numerals in the attached figures: 1. Second cover plate; 11. Alignment mark; 12. Receiving structure; 121. Fourth through hole; 13. Shielding plate; 2. Cavity plate; 21. Third through hole; 22. Ferromagnetic material; 23. Fifth through hole; 3. First cover plate; 31. First metal layer; 32. Second through hole; 4. Waveguide plate; 41. First through hole; 42. Ferrite; 43. Sixth through hole; 431. Solder; 44. Via; 5. Magnetic conductive plate; 51. Second metal layer; 52. Ground connection layer; 521. Scribing groove structure; 53. Annular groove; 6. Stacked structure; 61. Non-reciprocal component; 7. PCB board. Detailed Implementation

[0026] Some embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.

[0027] Currently, traditional circulator or isolator packaging is mainly based on chip-level packaging. However, due to the limited positional accuracy of the bonding fixture and the possibility that the plane of the iron-nickel alloy metal sheet and the plane of the circulator are at an angle and the two planes are not parallel, this process will affect the circulator packaging yield.

[0028] Therefore, this application creatively proposes a stacked structure, a non-reciprocal element, and a processing method thereof. The stacked structure includes a first cover plate, a waveguide plate, and a magnetic plate stacked sequentially and connected by wafer bonding. The waveguide plate has at least two first through-holes for accommodating ferrite. The non-reciprocal element is cut from the stacked structure. This application uses a pre-packaging and post-cutting method to prepare the non-reciprocal element, that is, the required structure of multiple non-reciprocal elements is pre-packaged uniformly at the wafer level, so that the first cover plate, waveguide plate, and magnetic plate can all adopt the same specifications as conventional wafers and have high flatness at the wafer level. Based on this, the three can achieve high-precision alignment and parallelism control through equipment such as wafer bonding machines. This wafer-level packaging process ensures the uniformity and consistency of the bonding interface, thereby significantly improving the yield and performance consistency of the components after dividing the stacked structure into multiple independent non-reciprocal elements, which is significantly better than traditional packaging methods.

[0029] The present application will be described in detail below through specific embodiments.

[0030] Example 1 Reference Figures 1 to 13 As shown, this application embodiment provides a stacked structure 6, which includes a first cover plate 3, a waveguide plate 4, and a magnetic sheet 5 stacked sequentially and connected by wafer bonding; the waveguide plate 4 is provided with at least two first through holes 41 for accommodating ferrites 42; the side of the first cover plate 3 facing the waveguide plate 4 is provided with a first metal layer 31; in the bonding state, the first metal layer 31 covers the openings of all the first through holes 41 and is attached to the surface of each ferrite 42; at least two ferromagnets 22 are mounted on the side of the first cover plate 3 away from the waveguide plate 4, each ferromagnet 22 is used to provide a constant magnetic field for at least one ferrite 42; the side of the magnetic sheet 5 facing the waveguide plate 4 is provided with a second metal layer 51, the second metal layer 51 is used for bonding to the surface metal layer of the waveguide plate 4.

[0031] The stacked structure 6 has at least four receiving structures 12, each receiving structure 12 is connected to the surface metal layer of the waveguide sheet 4 and is used to receive electrical connection material to electrically connect the signal transmission structure in the waveguide sheet 4 to external components; at least one of the two opposite outer surfaces of the stacked structure 6 is provided with a ground connection layer 52, and the two opposite outer surfaces are the outermost surfaces of all the layers in the stacked structure 6 connected by wafer bonding in the stacking direction.

[0032] It should be noted that although the first cover plate 3, waveguide plate 4, and magnetic plate 5 can be circular, rectangular, or other arbitrary regular shapes, and there are semiconductor processing equipment capable of supporting the processing of non-circular wafers such as rectangular wafers, in this embodiment, in order to be compatible with mainstream semiconductor processing equipment, all the layers connected by wafer bonding in the stacked structure 6 are designed to be disk-shaped, and their specifications match those of standard circular wafers.

[0033] Furthermore, the stacked structure 6 can be cut into at least two non-reciprocal elements 61 according to manufacturing requirements. A non-reciprocal element 61 refers to a microwave device that operates based on the principle of non-reciprocity. The types of non-reciprocal elements 61 include at least circulators and isolators.

[0034] In this embodiment, for ease of design and manufacturing, typically one ferromagnetic material 22 corresponds to one ferrite material 42. That is, a single non-reciprocal element 61 generally includes one ferrite material 42 and one ferromagnetic material 22. It should be noted that in practical applications, to achieve higher isolation, a single non-reciprocal element 61 may also be provided with at least two first through holes 41 to accommodate multiple ferrite materials 42, but in essence, it is still equivalent to multiple single ferrite material 42 units connected in series. Therefore, unless otherwise specified, the non-reciprocal element 61 in this embodiment refers to the basic structure of a single ferrite material 42 and a single ferromagnetic material 22.

[0035] It should be noted that the first metal layer 31 has a dual function: on the one hand, it ensures that the side of the ferrite 42 close to the first cover plate 3 is covered by a metal layer; on the other hand, it enables the first cover plate 3 to achieve wafer bonding connection with the waveguide plate 4.

[0036] Similarly, the second metal layer 51 has two functions: first, it enables the magnetic sheet 5 to be connected to the waveguide sheet 4 through wafer bonding; second, by using a low melting point metal layer, the two can be bonded at a suitable low temperature, thereby avoiding the demagnetization problem of the ferromagnetic material 22 caused by the need for high-temperature bonding due to the absence of the second metal layer 51.

[0037] Understandably, in the field of non-reciprocal components 61, waveguide 4 typically employs a substrate-integrated waveguide structure, generally made of silicon, and implemented using a through-substrate via 44 process. A typical flow of this process is as follows: first, through-holes are formed on the wafer through deep silicon etching; then, metal is deposited on the inner walls of the through-holes using sputtering or electroplating to form the via 44; simultaneously, metal layers connected to the via 44 are deposited on the upper and lower surfaces of the wafer, thus forming a complete substrate-integrated waveguide structure. Therefore, waveguide 4 possesses microwave signal transmission and processing capabilities. Specifically, the signal transmission structure of waveguide 4 refers to the via 44 and the metal layers on its upper and lower surfaces.

[0038] In this embodiment, the multiple vias 44 used to form the same non-reciprocal element 61 are typically distributed along the periphery of the first via 41. Since there are multiple first vias 41, correspondingly, vias 44 are arranged around each first via 41 to ensure that after the stacked structure 6 is divided, each unit can still form an independent substrate integrated waveguide structure.

[0039] Specifically, this application employs a bonding-then-dicing method to fabricate the non-reciprocal components 61. This involves pre-bonding the required structures for multiple non-reciprocal components 61 at the wafer level, ensuring that the first cover plate 3, waveguide plate 4, and magnetic sheet 5 can all utilize the same specifications as conventional wafers, achieving high wafer-level flatness. Based on this, the three components can achieve high-precision alignment and parallelism control using equipment such as wafer bonding machines. This wafer-level packaging process guarantees the uniformity and consistency of the bonding interface, thereby significantly improving the component yield and performance consistency after dividing the stacked structure 6 into multiple independent non-reciprocal components 61, which is significantly superior to traditional packaging methods.

[0040] Furthermore, in some examples, refer to Figure 3 As shown, the first metal layer 31 includes at least two stacked metal layers, and at least one metal layer has a preset static magnetic permeability, and the preset static magnetic permeability is greater than 70.

[0041] By setting at least one metal layer with a preset static permeability, the magnetic field distribution in the non-reciprocal element 61 can be made more uniform.

[0042] In some examples, the metal layer with a preset static permeability in the first metal layer 31 is made of at least one of iron, nickel, and cobalt, such as iron, nickel, cobalt, iron-nickel alloy, iron-cobalt alloy, or iron-nickel-cobalt alloy. In this embodiment, taking the plane where the first metal layer 31 is located as a reference, the metal layer with the preset static permeability can be only partially set, that is, it does not need to cover the entire reference plane, but only needs to meet the functional requirement of making the magnetic field distribution inside the ferrite 42 more uniform.

[0043] In this embodiment, at least one layer of metal with a preset static permeability is bonded to the first cover plate 3. This positioning ensures that the metal layer with high static permeability is kept away from the bonding interface between the first cover plate 3 and the waveguide plate 4, thereby preventing the ferromagnetic material 22 from being affected by the high temperatures during bonding.

[0044] The first metal layer 31 contains a metal with a preset static magnetic permeability, which redirects the magnetic field originally concentrated on the surface of the ferrite 42 to the magnetic permeable layer, making the magnetic field inside the ferrite 42 more uniform. (Refer to...) Figure 11 As shown, Figure 11The figure shows the local magnetic field distribution of the circulator obtained through simulation software. (a) shows the magnetic field distribution without the high-permeability metal, and (b) shows the magnetic field distribution after adding the high-permeability metal. The arrows in the figure indicate the direction of the magnetic induction vector B, and the arrow size represents the relative amplitude of B. As can be seen from the figure, without the high-permeability metal, the magnetic field is slightly deflected outwards at the upper edge of the cylinder of ferrite 42, with a larger field strength at the edge. However, after adding the high-permeability metal, the magnetic field deflects outwards within the high-permeability metal and is uniformly distributed inside the ferrite 42. Simulations show that by adding this metal layer, the magnetic field non-uniformity on the upper surface of ferrite 42 can be reduced from 12% to 3%.

[0045] In some examples, the maximum distance between the outer peripheral surface of the ferrite 42 and the inner surface of the corresponding first through hole 41 is 50 μm.

[0046] It is understandable that ferrite 42 is generally cylindrical or similar in shape to ensure magnetic field uniformity and rotational symmetry. Of course, it can also be triangular, hexagonal, or other shapes, but the bias magnetic field design needs to be optimized accordingly.

[0047] In this embodiment, the ferrite 42 adopts a cylindrical structure, and correspondingly, the first through hole for accommodating the ferrite 42 is also set as a circular hole. The diameter of the circular hole is larger than the diameter of the ferrite 42, but does not exceed the diameter of the ferrite 42 + 50 μm, thereby ensuring that the gap between the two is controlled within a reasonable range, which facilitates the stable placement of the ferrite 42 into the chamber and effectively maintains the uniformity of the magnetic field inside the ferrite 42.

[0048] Similarly, the ferromagnet 22 can also be designed as a cylindrical structure.

[0049] It should be noted that the grounding connection layer 52 is only disposed on the layers of the stacked structure 6; in this embodiment, it is specifically disposed on the first cover plate 3 or the magnetic sheet 5, and not on non-layered structures such as the ferromagnetic material 22. Specifically, the grounding connection layer 52 is disposed on the side of the first cover plate 3 away from the waveguide sheet 4, or on the side of the magnetic sheet 5 away from the waveguide sheet 4.

[0050] In actual installation, the ground connection layer 52 of the stacked structure 6 is usually positioned facing external components (such as the PCB board 7 or the housing). In this embodiment, the ground connection layer 52 is arranged on the side of the magnetic sheet 5 away from the waveguide sheet 4. Compared to placing it on the side of the first cover plate 3 away from the waveguide sheet 4, this solution eliminates the need to create a cavity on the external component to accommodate the ferromagnetic material 22 during installation, thus achieving effective contact between the ground connection layer 52 and the external component. In this case, the non-reciprocal element 61 does not need to be embedded inside the external component, thereby avoiding adverse effects on microwave performance—the deeper the cavity on the external component, the more significant the degradation of the microwave performance of the non-reciprocal element 61.

[0051] Understandably, after the stacked structure 6 is connected, it needs to be cut to obtain the required non-reciprocal element 61. Cutting can be done from either the front or back of the stacked structure 6 using a dicing blade. For ease of description, this application defines the side of the magnetic sheet 5 furthest from the first cover plate 3 as the front side.

[0052] In some examples, the ground connection layer 52 includes at least one first metal pattern layer, which contains a scribe groove structure 521 communicating with the magnetic sheet 5. The scribe groove structure 521 is used to guide the chemical liquid to etch the magnetic sheet 5.

[0053] It should be noted that in the field of non-reciprocal components 61, the magnetic sheet 5 is typically made of an iron-nickel alloy, which has high hardness. If a conventional wafer dicing tool is used to cut it directly, it is difficult to penetrate the iron-nickel alloy, which has a certain thickness. To solve this problem, this application provides a first metal pattern layer on the surface of the magnetic sheet 5, forming an overall protection for the area of ​​the magnetic sheet 5 except for the dicing groove. This allows for the use of a wet etching process, where a chemical etching solution removes some of the metal from the exposed area of ​​the magnetic sheet 5. The area covered by the first metal pattern layer remains intact, while the dicing groove area is etched away, thus achieving the division of the magnetic sheet 5. After the etching is completed, a dicing tool is used to cut the remaining layers in the stacked structure 6, ultimately obtaining the independent non-reciprocal components 61.

[0054] It is understood that the dicing groove structure 521 includes two parts: virtual (dicing groove) and real (solid part around the dicing groove to define the range of the dicing groove). The aforementioned "dicing groove" refers to the part of the dicing groove structure 521 that exposes the magnetic sheet 5.

[0055] In this embodiment, the first metal pattern layer has two layers: a nickel layer closer to the magnetic sheet 5 and a gold layer farther away from the magnetic sheet 5. Since the chemical solution used in wet etching does not react with gold, the area not exposed by the dicing structure 521 is preserved due to the protection of the gold layer, and the corresponding portion of the magnetic sheet 5 is not etched.

[0056] In some examples, all layers connected by wafer bonding in the stacked structure 6 are provided with alignment marks 11. By setting the alignment marks 11, the alignment accuracy between adjacent layers or corresponding layers can be further improved during the bonding process.

[0057] In this embodiment, the alignment mark 11 can be formed by depositing a portion of metal through methods such as photolithography, sputtering, evaporation, or electroplating. Specifically, when depositing a metal layer on a sheet such as the first cover plate 3, the waveguide sheet 4, and the magnetic sheet 5 (for example, depositing a first metal layer 31 on the first cover plate 3), the pattern of the alignment mark 11 can be pre-designed in the metal layer, so that the alignment mark 11 is formed simultaneously after the metal layer is deposited.

[0058] Furthermore, in some examples, the magnetic sheet 5 has at least two annular grooves 53 on the side facing the waveguide sheet 4, each annular groove 53 is provided in a one-to-one correspondence with each ferrite 42, and in the bonding state, the annular grooves 53 are provided along the outer periphery of the ferrite 42, and a constant distance is maintained between the annular grooves 53 and the ferrite 42.

[0059] Understandably, the magnetic field in ferrite 42 is mainly concentrated at the edges, resulting in a higher magnetic field strength in the edge regions than in the central regions. This magnetic field inhomogeneity causes the operating points of different parts of ferrite 42 to be inconsistent (some regions do not reach saturation), which in turn can lead to multimode resonance or spin wave excitation, increasing the RF loss of ferrite 42.

[0060] In this embodiment, for ease of design and manufacturing, the ferrite 42 adopts a cylindrical structure, and correspondingly, the annular groove 53 is designed as an annular shape. During processing, the first through hole 41 and the annular groove 53 share the same machining axis, keeping them as coaxial as possible. This ensures that after the ferrite 42 is installed, a constant distance can be maintained between the ferrite 42 and the annular groove 53. The annular groove 53 effectively suppresses the magnetic field strength at the edge of the ferrite 42, thereby improving the uniformity of its internal magnetic field.

[0061] It should be noted that the placement and dimensional accuracy of the annular groove 53 have a significant impact on magnetic field uniformity and are extremely sensitive to assembly errors. If traditional packaging and processing methods are used, assembly errors can easily exceed permissible limits (e.g., 20 μm). In such cases, even with the annular groove 53, magnetic field uniformity not only fails to improve but may even worsen. However, this application, based on wafer-level packaging technology, employs optical alignment during bonding, utilizing alignment marks 11 to achieve precise alignment of adjacent layers. This minimizes assembly errors and ensures that the design effect of the annular groove 53 is fully realized.

[0062] Reference Figure 12 As shown, Figure 12The figure shows the local magnetic field distribution of the circulator obtained through simulation software. (a) shows the magnetic field distribution without the annular groove 53, and (b) shows the magnetic field distribution with the annular groove 53. The arrows in the figure indicate the direction of the magnetic induction intensity vector B, and the size of the arrows represents the relative amplitude of B. As can be seen from the figure, without the annular groove 53, the magnetic induction intensity is concentrated in the outer peripheral edge region of the ferrite 42. However, with the annular groove 53, the groove is located exactly at the outer peripheral edge of the ferrite 42. The groove is a cavity with a higher magnetic reluctance than that of the iron-nickel alloy, effectively preventing some of the magnetic field from entering the edge of the ferrite 42, thereby improving the uniformity of the magnetic induction intensity inside the ferrite 42. Simulation results show that by setting the annular groove 53, the magnetic field non-uniformity on the lower surface of the ferrite 42 is reduced from 8% to 2%.

[0063] Furthermore, refer to Figure 3 As shown, wr represents the width of the annular groove 53. In some examples, the depth of the annular groove 53 ranges from 3 μm to 10 μm, and the width ranges from 5 μm to 50 μm.

[0064] By limiting the size of the annular groove 53 to a certain range, the positive influence of the annular groove 53 on the magnetic field uniformity of the ferrite 42 can be effectively guaranteed.

[0065] In this embodiment, the width of the annular groove 53 ranges from 10 to 30 μm.

[0066] As an alternative example, the receiving structure 12 is a second through hole 32 penetrating the first cover plate 3 or the magnetic sheet 5, the second through hole 32 being used to introduce a bonding wire for electrical connection with an external component; To reduce the adverse effects of installation on the non-reciprocal component 61, the second through hole 32 is usually placed on the first cover plate 3.

[0067] As another alternative example, the receiving structure 12 is a sixth through hole 43 penetrating the waveguide 4. The surface of the sixth through hole 43 is provided with a conductive connection layer, which is connected to the surface metal layer of the waveguide 4 and is used to introduce solder 431 for electrical connection with external components.

[0068] It should be noted that, in order to save material used in a single non-reciprocal component 61 and to further facilitate the installation of bonding wires or the soldering of solder 431, the receiving structures 12 corresponding to two adjacent non-reciprocal components 61 can be combined into one, for example, into a single through-hole. After the stack structure 6 is divided, the through-hole is divided into two parts, so that the receiving structures on each non-reciprocal component 61 become open slot structures, thereby facilitating the introduction of bonding wires or the soldering of solder 431.

[0069] In some examples, refer to Figure 5As shown, the conductive connection layer is typically made of metal to bring the signal transmission structure inside the waveguide 4 to the outside. During the soldering process, some of the solder 431 melts and, under the action of surface tension, flows naturally into the gap between the waveguide 4 and the magnetic sheet 5, thereby further enhancing the reliability of the electrical connection.

[0070] In addition, bonding wires are generally made of gold or aluminum wire, while solder 431 can be made of tin-lead or tin-silver-copper materials, depending on the actual process requirements.

[0071] In some examples, the electrical connection material can also be a composite material such as conductive adhesive. Its specific form can be adjusted according to actual process requirements, as long as it satisfies the requirement of a stable electrical connection between the non-reciprocal component 61 and the external component.

[0072] Example 2 Corresponding to Embodiment 1 above, refer to Figures 1 to 13 As shown, this application embodiment also provides a stacked structure, which further includes a second cover plate 1 and a cavity plate 2 connected by wafer bonding. The cavity plate 2 is disposed above the first cover plate 3 along the stacking direction and is connected to the first cover plate 3 by wafer bonding. The cavity plate 2 is provided with at least two third through holes 21, which are used to place ferromagnetic materials 22.

[0073] In this embodiment, both the second cover plate 1 and the cavity plate 2 are cylindrical.

[0074] By placing the ferromagnetic material 22 within the cavity structure formed by the second cover plate 1, the cavity plate 2, and the first cover plate 3, the second cover plate 1 and the cavity plate 2 can effectively protect the ferromagnetic material 22 from external impacts or vibrations when the non-reciprocal element 61 is subjected to such impacts or vibrations, thus preventing it from falling off or failing.

[0075] Furthermore, in the bonded state, the first through-hole 41 and the third through-hole 21 are coaxially arranged to ensure that the axes of the ferromagnetic material 22 and the ferrite material 42 coincide. This application, combining wafer-level packaging technology and the alignment mechanism of the alignment mark 11, allows the coaxiality of the axes of the first through-hole 41 and the third through-hole 21 to be controlled within a manageable range, thereby controlling the assembly offset within 5 to 20 μm, further improving component yield and product consistency.

[0076] As an alternative example, the receiving structure 12 includes a fourth through hole 121 penetrating the second cover plate 1, a fifth through hole 23 penetrating the cavity plate 2, and a second through hole 32 penetrating the first cover plate 3. In the bonded state, the corresponding second through hole 32, fourth through hole 121 and fifth through hole 23 are interconnected to introduce a bonding wire for electrical connection to the outside.

[0077] Understandably, depending on the actual processing conditions, the cross-sectional shape of the accommodating structure 12 can be any shape, as long as it satisfies the stable introduction and fixation of the binding line.

[0078] In addition, alignment marks 11 are provided on both the second cover plate 1 and the cavity plate 2 to facilitate high-precision installation of adjacent layers.

[0079] Furthermore, in some examples, refer to Figure 13 As shown, the side of the second cover plate 1 away from the cavity plate 2 is provided with a shielding plate 13 covering all the ferromagnets 22. The shielding plate 13 is used to provide magnetic shielding for the ferromagnets 22. The shielding plate 13 is provided with at least four avoidance structures. In the bonding state, the avoidance structures are arranged in a one-to-one correspondence with the receiving structure 12.

[0080] In this embodiment, the shielding sheet 13 is made of iron-nickel alloy, which can provide better magnetic shielding and reduce the magnetic coupling of the magnetic field of the ferromagnetic body 22 with other components.

[0081] In some examples, the thickness of the cavity plate 2 is up to 500 μm greater than the thickness of the ferromagnetic material 22. By limiting the thickness relationship between the cavity plate 2 and the ferromagnetic material 22, it is possible to ensure both the uniformity and stability of the magnetic field of the ferromagnetic material 22 and its impact resistance.

[0082] In some examples, the maximum distance between the inner side of the third through-hole 21 and the outer side of the ferromagnetic material 22 is 100 μm. This limitation effectively ensures the impact resistance of the ferromagnetic material 22.

[0083] In this embodiment, the third through hole 21 is a circular hole.

[0084] Example 3 Corresponding to embodiments 1 and 2 above, refer to Figures 1 to 13 As shown, this application embodiment also provides a non-reciprocal element, which is cut from a stacked structure 6.

[0085] In this embodiment, the non-reciprocal element 61 can be a circulator or an isolator.

[0086] Similar to the design and manufacturing concept of the receiving structure 12, the avoidance structure adopts the same design and manufacturing method as the receiving structure 12 in order to introduce a binding line.

[0087] In this embodiment, the bottom surface of the cut magnetic sheet 5 is generally used as the mounting surface of the non-reciprocal element 61, and the magnetic sheet 5 is mounted on the external element.

[0088] Example 4 Corresponding to embodiments 1 to 3 above, refer to Figure 14As shown in the embodiment of this application, a method for processing a non-reciprocal component is provided, the method comprising: S100. Based on the number of non-reciprocal elements 61 to be manufactured, determine the specifications and materials of each layer connected by wafer bonding in the stacked structure 6, and fabricate the waveguide sheet 4 using the TSV process based on the number of non-reciprocal elements 61 contained in a single stacked structure 6.

[0089] To ensure compatibility with conventional wafer fabrication equipment, the dimensions of each layer in the stacked structure 6 are typically selected to be the same as those of a standard wafer, such as 6 inches or 8 inches.

[0090] Specifically, the specifications of each layer can be determined according to actual processing requirements. It is understandable that, in order to facilitate processing and manufacturing and reduce material waste, the layers connected by wafer bonding in the stacked structure 6 generally adopt the same specifications.

[0091] In addition, when determining the number of non-reciprocal elements 61 that can be divided from a single stacked structure 6, it is usually necessary to take into account factors such as the process capability of the wafer processing equipment, the selected wafer specifications, and the corresponding material utilization rate.

[0092] It is understandable that, in the microwave field, once those skilled in the art know that the stacked structure 6 is used to manufacture at least two non-reciprocal elements 61, they can undoubtedly conclude from the name of the waveguide 4 that the waveguide 4 contains at least two sets of perforations, each set of perforations being disposed on the periphery of a first through hole 41, so as to connect with the metal layers on the upper and lower surfaces of the waveguide 4 to form a substrate integrated waveguide structure.

[0093] It should be noted that, in order to facilitate bonding, the coefficients of thermal expansion of the materials used in each layer of the stacked structure 6 should be as close as possible.

[0094] S200, a first metal layer 31 is formed on one side surface of the first cover plate 3, a second metal layer 51 is formed on one side surface of the magnetic sheet 5, and a grounding connection layer 52 is formed on the other side surface of the first cover plate 3 or the other side surface of the magnetic sheet 5.

[0095] The first metal layer 31 and the second metal layer 51, which are respectively disposed on the first cover plate 3 and the magnetic conductive plate 5, are connected by metal bonding to achieve a fixed connection between the two.

[0096] Furthermore, the first metal layer 31 can include a layer of metal with a preset static permeability to optimize the magnetic field distribution inside the ferrite 42 in the non-reciprocal element 61 and improve its uniformity. Simultaneously, the presence of metal above the ferrite 42 ensures the performance of the non-reciprocal element 61.

[0097] After the stacked structure 6 is cut into independent non-reciprocal elements 61, a sheet with a ground connection layer 52 is usually used as the mounting surface to achieve ground connection with the outside.

[0098] S300, at least four receiving structures 12 are processed on the first cover plate 3, waveguide plate 4 or magnetic sheet 5, the receiving structures 12 being used to accommodate electrical connection materials.

[0099] In practical use, in order to reduce installation steps and avoid adverse effects on the performance of non-reciprocal components 61, a receiving structure 12 is usually set on the first cover plate 3 or waveguide plate 4.

[0100] S400. At least two first through holes 41 are processed on the waveguide sheet 4. The first through holes 41 are used to accommodate ferrite 42.

[0101] S500, the first cover plate 3 is bonded to the waveguide plate 4, and the ferrite 42 is installed in the corresponding first through hole 41.

[0102] S600, the waveguide sheet 4 and the magnetic sheet 5 are bonded together, and the ferromagnetic body 22 is installed on the side of the first cover sheet 3 away from the waveguide sheet 4 to form a stacked structure 6.

[0103] S700, the stacked structure 6 is cut into at least two non-reciprocal elements 61.

[0104] Furthermore, in some examples, the method also includes: Select a second cover 1 and a cavity sheet 2 with the same specifications as the first cover 3; Through holes are respectively made on the second cover plate 1, the cavity plate 2 and the first cover plate 3 to form the receiving structure 12 in the bonded state; At least two third through holes 21 are opened on the cavity plate 2, and the third through holes 21 are used to accommodate the ferromagnet 22. The second cover plate 1 and the cavity plate 2 are connected by wafer bonding, and the ferromagnet 22 is installed in the third through hole 21; The cavity plate 2, the first cover plate 3 and the waveguide plate 4 are connected in sequence by wafer bonding, and the ferrite 42 is installed in the first through hole 41. Understandably, all the layers in stacked structure 6 that are connected by wafer bonding have had their corresponding vias and slots opened before the bonding connection was completed, so that they can be used later.

[0105] The cavity structure formed by the second cover plate 1, the cavity plate 2, and the first cover plate 3 can effectively protect the ferromagnetic material 22 and enhance its impact resistance.

[0106] Furthermore, in some examples, alignment marks 11 are formed on all layers connected by wafer bonding in the stacked structure 6; The processing methods also include: During bonding, align the alignment marks 11 between the two corresponding layers.

[0107] It is understandable that, based on the characteristics of the wafer processing equipment and actual needs, during bonding, the alignment marks 11 of adjacent wafer layers can be aligned, or the alignment marks 11 between two corresponding wafer layers can be aligned.

[0108] Furthermore, in some examples, cutting the stacked structure into at least two non-reciprocal elements includes: The magnetic sheet 5 is etched and divided along the dicing groove structure 521 on the first metal pattern layer by wet etching.

[0109] The first metal pattern layer has two layers: a nickel layer closer to the magnetic sheet 5 and a gold layer further away. Since the chemical solution used in wet etching does not react with gold, the areas not exposed by the dicing structure 521 are preserved due to the protection of the gold layer, and the corresponding portions of the magnetic sheet 5 are not etched.

[0110] See, as an example rather than a limitation. Figure 3 As shown, firstly, the material of the second cover plate 1 is set to silicon, and the material of the cavity plate 2 is set to silicon dioxide-based glass, and the coefficient of thermal expansion of the glass should be as close as possible to that of silicon. Subsequently, a patterned metal layer is deposited on the side of the second cover plate 1 away from the cavity plate 2 by means of photolithography, sputtering, evaporation or electroplating, and the metal layer contains alignment marks 11 for subsequent bonding.

[0111] Next, using photolithography and etching processes, vertical through-holes are fabricated on the second cover plate 1 to serve as partial receiving structures 12 for introducing bonding lines. Simultaneously, using laser and wet etching processes, two types of through-holes are formed on the cavity plate 2: one is a third through-hole 21 for accommodating the ferromagnetic material 22; the other serves as partial receiving structures 12 for introducing bonding lines. The through-holes serving as partial receiving structures 12 on the second cover plate 1 and the cavity plate 2 maintain the same shape and size.

[0112] Then, the second cover plate 1 is bonded to the cavity plate 2 using an anodic bonding process. After that, adhesive is applied to one axial end of the ferromagnetic body 22, the ferromagnetic body 22 is placed in the third through hole 21, and the adhesive is cured at high temperature, thereby achieving a fixed connection between the ferromagnetic body 22 and the wafer.

[0113] The first cover plate 3 is made of silicon, and multiple layers of metal are deposited on its side facing the waveguide plate 4 using methods such as photolithography, sputtering, evaporation, or electroplating to form a first metal layer 31. The first metal layer 31 includes at least two metal layers, and at least one layer is made of a material with high magnetic permeability in a static magnetic field (referred to as a magnetically conductive layer), such as iron (Fe), nickel (Ni), cobalt (Co), or alloys thereof. In this embodiment, the magnetically conductive layer is disposed on the side closest to the substrate of the first cover plate 3. The waveguide plate 4 is made of silicon and is fabricated using a through-substrate via (TSV) process. Subsequently, the first cover plate 3 and the waveguide plate 4 are connected using metal bonding methods (such as gold-tin bonding, gold-gold thermoforming bonding, etc.). After bonding is completed, ferrite 42 is inserted into the first through-hole 41 of the waveguide plate 4.

[0114] The material for the magnetic sheet 5 is set to be an iron-nickel alloy. After polishing the upper and lower surfaces of the magnetic sheet 5, a second metal layer 51 (usually a low-melting-point metal, such as tin or indium) is deposited on the upper surface by means of photolithography, sputtering, evaporation, or electroplating. Then, an annular groove 53 of a predetermined depth is formed by photolithography and etching processes. Subsequently, a grounding connection layer 52 is deposited on the lower surface of the magnetic sheet 5 by means of photolithography, sputtering, evaporation, or electroplating. This layer adopts a double-layer metal structure, with nickel and gold as the materials in sequence, and its pattern includes a dicing groove structure 521 that communicates with the magnetic sheet 5.

[0115] A high-temperature resistant adhesive (such as polyimide) is coated onto the surface of the cavity sheet 2 after the ferromagnet 22 is installed. The second cover plate 1, cavity sheet 2, first cover plate 3, and waveguide sheet 4 are placed sequentially along the stacking direction, and the layers are connected by wafer bonding to form a stacked wafer. During bonding, optical alignment can be performed using the alignment marks 11 on the second cover plate 1 and the waveguide sheet 4 to improve positional accuracy. Care must be taken to control the bonding temperature to avoid demagnetization of the ferromagnet 22 due to excessive temperature. Some adhesives (such as polyimide) require curing after bonding, for example, by long-term treatment in a nitrogen atmosphere at a low temperature (such as 200°C).

[0116] Next, the stacked wafers and the magnetic sheet 5 are bonded together to form the final stacked structure 6. The bonding is achieved by the first metal layer 31 and the second metal layer 51. Low-melting-point metals can be used to support eutectic bonding or solid-liquid inter-expansion bonding (SLID), thereby completing the bonding at a lower process temperature and avoiding affecting the magnetism of the ferromagnetic material 22. In this embodiment, solid-liquid inter-expansion bonding is selected, using gold (Au) and tin (Sn) to form an alloy. By controlling the thickness of the bonding metal layers, the atomic ratio of gold to tin during the bonding process is made to reach 5:1, forming a high-melting-point Au5Sn1 alloy with a melting point of about 700°C. The process temperature of solid-liquid inter-expansion bonding is about 250°C, which can effectively prevent the ferromagnetic material 22 from demagnetizing due to high temperature during the bonding process. During bonding, the alignment mark 11 above the second cover plate 1 can be optically aligned with the alignment mark 11 below the magnetic sheet 5, further improving the bonding accuracy.

[0117] Finally, the stacked structure 6 is flipped so that the side of the magnetic sheet 5 away from the waveguide sheet 4 faces upward. A wet etching process is used to remove the iron-nickel alloy within the scribe line structure 521 using a chemical etching solution. Since the etching solution does not react with gold, the iron-nickel alloy in the non-scribe line structure 521 region is preserved due to the protection of the gold layer of the grounding connection layer 52. In some examples, a shielding sheet 13, made of iron-nickel alloy, can also be glued to the side of the second cover sheet 1 away from the cavity sheet 2. Finally, the stacked structure 6 is diced into individual chips along the scribe line structure 521 by wafer dicing to obtain the desired non-reciprocal element 61.

[0118] Among them, the partial receiving structures 12 on the second cover plate 1, the cavity plate 2 and the first cover plate 3 are connected in a bonded state to form a receiving structure 12.

[0119] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0120] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0121] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A stacked structure, characterized in that, It includes a first cover plate, a waveguide plate, and a magnetic plate that are stacked sequentially and connected by wafer bonding; The waveguide sheet is provided with at least two first through holes for accommodating ferrite. The first cover plate has a first metal layer on the side facing the waveguide sheet; in the bonded state, the first metal layer covers all the first through holes and is attached to the surface of each of the ferrites; At least two ferromagnets are mounted on the side of the first cover plate away from the waveguide plate, each of the ferromagnets being used to provide a constant magnetic field for at least one of the ferrites; The magnetic conductive sheet has a second metal layer on the side facing the waveguide sheet, and the second metal layer is used to bond to the surface metal layer of the waveguide sheet; The stacked structure has at least four receiving structures, each of which is connected to the surface metal layer of the waveguide sheet and is used to receive electrical connection material to electrically connect the signal transmission structure inside the waveguide sheet to external components. At least one of the two opposing outer surfaces of the stacked structure is provided with a ground connection layer, and the two opposing outer surfaces are the outermost surfaces of all the wafer-bonded layers in the stacked structure in the stacking direction.

2. The stacking structure according to claim 1, characterized in that, The first metal layer comprises at least two stacked metal layers, and at least one metal layer has a preset static magnetic permeability, wherein the preset static magnetic permeability is greater than 70.

3. The stacking structure according to claim 1, characterized in that, The grounding connection layer is disposed on the side of the magnetic sheet away from the waveguide sheet. The grounding connection layer includes at least one first metal pattern layer. The first metal pattern layer includes a scribe groove structure communicating with the magnetic sheet. The scribe groove structure is used to guide the chemical liquid to etch the magnetic sheet.

4. The stacking structure according to claim 1, characterized in that, The magnetic conductive sheet has at least two annular grooves on the side facing the waveguide sheet. Each annular groove corresponds to each ferrite. In the bonding state, the annular groove is arranged along the outer periphery of the ferrite, and a constant distance is maintained between the annular groove and the ferrite.

5. The stacking structure according to claim 4, characterized in that, The depth of the annular groove ranges from 3 μm to 10 μm, and the width ranges from 5 μm to 50 μm.

6. The stacking structure according to claim 1, characterized in that, The receiving structure is a second through hole that penetrates the first cover plate or the magnetic sheet, and the second through hole is used to introduce a bonding wire that is electrically connected to an external component. or, The receiving structure is a sixth through hole penetrating the waveguide sheet. The surface of the sixth through hole is provided with a conductive connection layer, which is connected to the surface metal layer of the waveguide sheet and is used to introduce solder for electrical connection with external components.

7. The stacking structure according to any one of claims 1-6, characterized in that, The stacked structure further includes a second cover plate and a cavity plate connected by wafer bonding. The cavity plate is disposed above the first cover plate along the stacking direction and is connected to the first cover plate by wafer bonding. The cavity plate is provided with at least two third through holes, which are used to place the ferromagnet.

8. The stacking structure according to claim 7, characterized in that, The receiving structure includes a fourth through hole penetrating the second cover plate, a fifth through hole penetrating the cavity plate, and a second through hole penetrating the first cover plate. In the bonding state, the corresponding second through hole, the fourth through hole, and the fifth through hole are interconnected to introduce a bonding wire for electrical connection to the outside.

9. The stacking structure according to claim 7, characterized in that, The second cover plate has a shielding sheet on the side away from the cavity plate that covers all the ferromagnetic materials. The shielding sheet is used to provide magnetic shielding for the ferromagnetic materials. The shielding sheet has at least four clearance structures, and in the bonded state, the clearance structures are configured one-to-one with the receiving structures.

10. The stacking structure according to claim 7, characterized in that, The thickness of the cavity sheet is at most 500 μm greater than the thickness of the ferromagnetic material; And / or, The maximum distance between the inner side of the third through hole and the outer side of the ferromagnet is 100 μm.

11. A non-reciprocal element, characterized in that, The non-reciprocal element is cut from the stacked structure as described in any one of claims 1 to 10.

12. A method for processing a non-reciprocal component, characterized in that, The method includes: Based on the number of non-reciprocal components to be manufactured, determine the specifications and materials of each layer connected by wafer bonding in the stacked structure, and fabricate waveguide sheets using TSV process based on the number of non-reciprocal components contained in a single stacked structure. A first metal layer is formed on one side surface of the first cover plate, a second metal layer is formed on one side surface of the magnetic sheet, and a grounding connection layer is formed on the other side surface of the first cover plate or the other side surface of the magnetic sheet. At least four receiving structures are processed on the first cover plate, waveguide plate, or magnetic sheet, the receiving structures being used to accommodate electrical connection material; At least two first through holes are processed on the waveguide sheet, the first through holes being used to accommodate ferrite; The first cover plate is bonded to the waveguide plate, and the ferrite is installed in the corresponding first through hole; The waveguide sheet and the magnetic sheet are bonded together, and a ferromagnetic body is installed on the side of the first cover plate away from the waveguide sheet to form a stacked structure; The stacked structure is cut into at least two non-reciprocal elements.

13. The processing method according to claim 12, characterized in that, The method further includes: Select a second cover plate and a cavity plate with the same specifications as the first cover plate; Through holes are respectively formed on the second cover plate, the cavity plate and the first cover plate to form a receiving structure in the bonded state; At least two third through holes are formed on the cavity sheet, and the third through holes are used to accommodate ferromagnets; The second cover plate, cavity plate, first cover plate and waveguide plate are connected in sequence by wafer bonding, and the ferromagnet is installed in the third through hole and the ferrite is installed in the first through hole. Waveguide sheets and magnetic sheets are connected by wafer bonding to form a stacked structure; The stacked structure is cut into at least two non-reciprocal elements.

14. The processing method according to claim 12, characterized in that, The grounding connection layer is disposed on the side of the magnetic sheet away from the waveguide sheet. The grounding connection layer includes at least one first metal pattern layer. The first metal pattern layer includes a scribe groove structure communicating with the magnetic sheet. The scribe groove structure is used to guide the chemical liquid to etch the magnetic sheet. The step of cutting the stacked structure into at least two non-reciprocal elements includes: The magnetic sheet is etched and divided along the dicing groove structure on the first metal pattern layer by wet etching.

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