Coupler and method for making the same

Abstract

The present invention provides a coupler and a manufacturing method thereof. The coupler comprises: a top core board layer, an intermediate layer and a bottom core board layer, wherein the intermediate layer is respectively superimposed with the top core board layer and the bottom core board layer through corresponding dielectric layers; the intermediate layer is a multi-layer structure, comprising a first inner core board layer and a second inner core board layer, the first inner core board layer comprises a first signal line and a second signal line arranged on two opposite surfaces, and the second inner core board layer comprises a third signal line and a fourth signal line arranged on two opposite surfaces; wherein the first signal line is connected to the third signal line to form a first coupling line, and the second signal line is connected to the fourth signal line to form a second coupling line; an isolation layer is provided between the first inner core board layer and the second inner core board layer to isolate signals between signal lines of different layers on the same coupling line, thereby improving performance indicators of the coupler.

Description

Technical Field

[0001] The invention relates to the technical field of coupler design, and in particular to a coupler with a stacked structure. Background Art

[0002] As a commonly used passive device in communication systems, couplers, especially 3dB couplers, are widely used in RF, microwave circuits and communication systems. Couplers are a common microwave / millimeter wave component that can be used for signal separation and synthesis. 3dB couplers can continuously sample the transmission power along a certain direction of the transmission line, and can divide an input signal into two signals of equal amplitude and 90° phase difference. They can also be used for multi-signal synthesis to improve the utilization rate of output signals. 3dB couplers can also be used in power amplifiers, low noise amplifiers, adjustable phase shifters and adjustable attenuators. Its core indicators mainly include: return loss, insertion loss, coupling, isolation, coupling flatness, and amplitude flatness.

[0003] With the increasing expansion of communication frequency bands, the design frequency bands of 3dB couplers are also constantly changing, even including the design of unequal power distribution ratios and the miniaturization of coupler volumes. At present, in order to achieve the miniaturization of coupler volumes, stacked structures are often used: that is, a coupling line uses multi-layer wiring, but this method will cause mutual interference between signals, thereby affecting the coupling index. Summary of the invention

[0004] The present invention mainly provides a coupler with a laminated structure, which is used to realize a small volume design of the coupler and ensure the performance index of the coupler.

[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0006] Provided is a coupler, comprising: a top core board layer, an intermediate layer and a bottom core board layer, wherein the intermediate layer is respectively superimposed on the top core board layer and the bottom core board layer through corresponding dielectric layers;

[0007] Wherein, the intermediate layer comprises a first inner core layer and a second inner core layer stacked together, the first inner core layer is provided with a first signal line and a second signal line on two opposite surfaces thereof, and the second inner core layer is provided with a third signal line and a fourth signal line on two opposite surfaces thereof;

[0008] Wherein, the first signal line is connected to the third signal line to form a first coupling line, and the second signal line is connected to the fourth signal line to form a second coupling line;

[0009] An isolation layer is provided between the first inner core board layer and the second inner core board layer to isolate electrical signals between signal lines of different layers on the same coupling line.

[0010] In order to solve the above technical problems, another technical solution adopted by the present invention is: to provide a method for manufacturing a coupler, comprising:

[0011] Providing a top core layer, a first dielectric layer, a first inner core layer, a second dielectric layer, an isolation layer, a third dielectric layer, a second inner core layer, a fourth dielectric layer and a bottom core layer;

[0012] A first signal line and a second signal line are respectively arranged on two surfaces of the first inner core layer, and a third signal line and a fourth signal line are respectively arranged on two surfaces of the second inner core layer;

[0013] The first inner core plate layer, the second dielectric layer, the isolation layer, the third dielectric layer, and the second inner core plate layer are sequentially stacked and laminated to obtain a first assembly;

[0014] On the first assembly, the first signal line is connected to the third signal line to form a first coupling line, and the second signal line is connected to the fourth signal line to form a second coupling line, so as to obtain a second assembly;

[0015] The top core board layer, the first dielectric layer, the second assembly, the fourth dielectric layer and the bottom core board are stacked and laminated in sequence to obtain the coupler.

[0016] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention provides a coupler and a method for manufacturing the coupler, the coupler comprising a top core board layer, a first inner core board layer, a second inner core board layer, and a bottom core board layer, a first signal line and a second signal line are arranged on both surfaces of the first inner core board layer, and a third signal line and a fourth signal line are arranged on both surfaces of the second inner core board layer; the first signal line connects the third signal line to form a first coupling line, and the second signal line connects the fourth signal line to form a second coupling line; and an isolation layer is provided between the first inner core board layer and the second inner core board layer to isolate the electrical signals between signal lines of different layers on the same coupling line. The present application designs a coupling line in layers through a stacked structure to realize a long winding structure of a small-volume coupler, and isolates the signals between signal lines of different layers on the same coupling line through an isolation layer to prevent signals from interfering with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the coupler of the present invention;

[0018] Figure 2a-2b is a schematic diagram of the planar structure of a first embodiment of a coupler of the present invention;

[0019] Figure 3a-Figure 3b is a schematic diagram of the planar structure of a second embodiment of a coupler of the present invention;

[0020] Figure 4 is a structural schematic diagram of a first embodiment of a method for manufacturing a coupler of the present invention;

[0021] Figure 5 It is a structural schematic diagram of a second embodiment of the method for manufacturing a coupler of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] The terms "first", "second", "third", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] See also Figure 1 , which is a schematic diagram of the three-dimensional structure of the coupler of the present invention, the coupler 100 is used to achieve a low-frequency band, small-size design, and is easy to process, while ensuring the performance indicators of the coupler 100 to meet industry needs. Specifically, the coupler 100 includes: a plurality of core board layers 101 and a plurality of dielectric layers 102, wherein a corresponding dielectric layer 102 is arranged between any two adjacent core board layers 101 to stack the plurality of core board layers 101 together; wherein each core board layer 101 includes a substrate board and at least one signal line arranged on at least one surface of the substrate board, the signal line on at least one core board layer 101 is connected to the signal line on another core board layer 101 to form a coupling line, and an isolation layer is arranged between the core board layers to isolate the signals between signal lines of different layers on the same coupling line.

[0026] Specifically, see Figure 2a-2b, which is a schematic diagram of the planar structure of the first embodiment of the coupler of the present invention. The plurality of core board layers 101 include: a top core board layer 11, an intermediate layer and a bottom core board layer 17, and the intermediate layer is respectively superimposed with the top core board layer 11 and the bottom core board layer 17 through the corresponding dielectric layers 12 and 16.

[0027] Among them, the top core board layer 11 includes a substrate board 111 and a metal layer arranged on the substrate board 111 away from the middle layer; the bottom core board layer 17 includes a substrate board 171 and a metal layer arranged on the substrate board 171 away from the middle layer. In this embodiment, the top core board layer 11 and the bottom core board layer 17 both have a metal layer, and the surfaces with the metal layer are away from the middle layer.

[0028] A first circuit layer 112 is disposed on the metal layer on the surface of the top core layer 11 away from the middle layer, and a second circuit layer 172 is disposed on the metal layer on the surface of the bottom core layer 17 away from the middle layer. The first circuit layer 112 in the top core layer 11 is connected to the second circuit layer 172 in the bottom core layer 17. In one embodiment, the thickness of the first circuit layer 112 and the second circuit layer 172 is not less than 1 ounce.

[0029] Specifically, the first circuit layer 112 in the top core layer 11 is connected to the second circuit layer 172 in the bottom core layer 17 through the conductive via 19 , and the conductive via 19 runs through the top core layer 11 , the middle layer and the bottom core layer 17 .

[0030] Among them, the middle layer is a multilayer structure, specifically including a first inner core plate layer 13 and a second inner core plate layer 15. It should be noted that the first inner core plate layer 13 and the second inner core plate layer 15 are also stacked by corresponding dielectric layers. The first inner core plate layer 13 and the second inner core plate layer 15 are the same as the top core plate layer 11 and the bottom core plate layer 17, and both include a substrate plate and a metal layer arranged on at least one surface of the substrate plate. In this embodiment, both surfaces of the first inner core plate layer 13 and the second inner core plate layer 15 have a metal layer. The first inner core board layer 13 includes a substrate board 131 and a first signal line 132 and a second signal line 133 located on metal layers on two opposite surfaces of the substrate board 131, and the second inner core board layer 15 includes a substrate board 151 and a third signal line 152 and a fourth signal line 153 located on metal layers on two opposite surfaces of the substrate board 151; wherein the first signal line 132 of the first inner core board layer 13 is connected to the third signal line 152 of the second inner core board layer 15 to form a first coupling line; the second signal line 133 of the first inner core board layer 13 is connected to the fourth signal line 153 of the second inner core board layer 15 to form a second coupling line.

[0031] Among them, an isolation layer 141 is also provided between the first inner core board layer 13 and the second inner core board layer 15, and the isolation layer 141 is respectively superimposed with the first inner core board layer 13 and the second inner core board layer 15 through the corresponding dielectric layers 142 and 143. The dielectric layers 142 and 143 are both semi-cured sheets. The isolation layer 141 is connected to the top core board layer 11 and the bottom core board layer 17 through conductive vias 19, and is used to shield the signals between different layers of the circuit layers on the same coupling line. Specifically, grounding wires are provided on the top core board layer 11 and the bottom core board layer 17, and the isolation layer 141 is connected to the grounding wires on the top core board layer 11 and the bottom core board layer 17 through conductive vias 19, thereby achieving the purpose of shielding the signals between different layers of the circuit layers on the same coupling line.

[0032] The middle layer is provided with a first conductive buried via 181 and a second conductive buried via 182, wherein the first signal line 132 of the first inner core board layer 13 is connected to the third signal line 152 of the second inner core board layer 15 through the first conductive buried via 181; the second signal line 133 of the first inner core board layer 13 is connected to the fourth signal line 153 of the second inner core board layer 15 through the second conductive buried via 182. For details, please refer to Figure 2a The first conductive buried via 181 penetrates from the first signal line 132 of the first inner core layer 13 to the third signal line 152 of the second inner core layer 15 , and the second conductive buried via 182 penetrates from the second signal line 133 of the first inner core layer 13 to the fourth signal line 153 of the second inner core layer 15 .

[0033] It should be noted that the inner walls of the conductive through hole 19 and the first conductive buried via 181 and the second conductive buried via 182 have a metal layer to achieve electrical connection, and the thickness of the metal layer is 20-25 microns.

[0034] In the above embodiment, the first signal line 132 connected to the third signal line 152 and the second signal line 133 connected to the fourth signal line 153 are cross-designed. In another embodiment, the first signal line 132 connected to the third signal line 152 can be located outside the second signal line 133 connected to the fourth signal line 153, such as Figure 2b shown.

[0035] In the present application, the top core board layer 11, the first inner core board layer 13, the second inner core board layer 15 and the bottom core board layer 17 are all copper clad laminates, which are the basic materials for making circuit boards, including a substrate board and copper foil covered on the substrate. The substrate board is made of a paper substrate, a glass fiber cloth substrate, a synthetic fiber cloth substrate, a non-woven fabric substrate, a composite substrate and other materials impregnated with resin to form a bonding sheet, which is made by combining multiple bonding sheets. The prepared substrate board is covered with copper foil on one or both sides, and then hot-pressed and cured to form a copper clad laminate.

[0036] In this embodiment, the top core board layer 11 and the bottom core board layer 17 can be copper clad laminates covered with copper foil on one side, the first circuit layer 112 and the second circuit layer 172 are both arranged on the copper foil, the first inner core board layer 13 and the second inner core board layer 15 are copper clad laminates covered with copper foil on both sides, and the first signal line 132, the second signal line 133, the third signal line 152 and the fourth signal line 153 are all arranged on the copper foil.

[0037] In the present application, the dielectric layers (12, 14, 16) are all semi-cured sheets, which serve as interlayer bonding layers during lamination. Specifically, the semi-cured sheets are mainly composed of resin and reinforcing materials. When making multi-layer circuit boards, glass fiber cloth is usually used as the reinforcing material, which is impregnated with resin glue and then pre-baked by heat treatment to form a thin sheet. It will soften under heating and pressure, and will solidify after cooling. It has viscosity and can bond two adjacent layers during high-temperature pressing.

[0038] In one embodiment, the top core board layer, the first inner core board layer, the second inner core board layer and the bottom core board layer are all high-frequency board materials.

[0039] In this embodiment, the isolation layer 141 is a single-layer structure, which can be a conductive shielding layer, such as a copper layer, which is respectively superimposed on the first inner core board layer 13 and the second inner core board layer 15 through dielectric layers 142 and 143. Figure 2a As shown. It can also be a core board with copper foil on one side, and the core board is a copper clad board. Figure 2b As shown, the isolation layer 141 includes a substrate plate 1441 and a conductive shielding layer 145 (ie, copper foil) disposed on the substrate plate 1441 .

[0040] See also Figure 3a-Figure 3b , is a schematic diagram of the structure of the third embodiment of the coupler of the present invention. Compared with the second embodiment, the difference is that the isolation layer 141 is a multi-layer structure. In one embodiment, Figure 3a As shown, the isolation layer 141 includes a plurality of conductive shielding layers 145 and 146 stacked in layers, and a connecting layer 144 is sandwiched between the conductive shielding layers 145 and 146; in one embodiment, the connecting layer 144 is a dielectric layer, specifically a prepreg; in another embodiment, the connecting layer 144 is a core board, that is, a copper-clad board, that is, including a first substrate board and a metal layer arranged on both surfaces of the first substrate board, and the metal layer is the conductive shielding layer. Or in another embodiment, the connecting layer 144 can also be a combined layer, that is, a combination of a core board and a dielectric layer.

[0041] like Figure 3bAs shown, the isolation layer 141 includes a first isolation layer 147, a dielectric layer 149 and a second isolation layer 148 which are stacked in sequence from top to bottom. Specifically, the first isolation layer 147 includes a second substrate plate 1472 and a first conductive shielding layer 1471 covering the second substrate plate 1472 and close to the second isolation layer 148, and the second isolation layer 148 includes a third substrate plate 1481 and a second conductive shielding layer 1482 covering the third substrate plate 1481 and close to the first isolation layer 147. Both the first conductive shielding layer 1471 and the second conductive shielding layer 1482 are metal layers, i.e., copper layers.

[0042] In one embodiment, the materials of the top core board layer 11, the first inner core board layer 13, the second inner core board layer 15 and the bottom core board layer 17 of the present application are all high-frequency boards, and the coupler is a 3dB coupler.

[0043] See also Figure 4 , is a schematic structural diagram of a first embodiment of a method for manufacturing a coupler of the present invention. It comprises:

[0044] Step S41: providing a top core board layer, a first dielectric layer, a first inner core board layer, a second dielectric layer, an isolation layer, a third dielectric layer, a second inner core board layer, a fourth dielectric layer and a bottom core board layer.

[0045] The top core board layer, the first inner core board layer, the second inner core board layer and the bottom core board layer are all high-frequency boards, specifically, the materials are copper-clad boards, i.e., the basic materials for making circuit boards, mainly composed of a substrate board and copper foil covering the substrate board, the substrate board is made of a paper substrate, a glass fiber cloth substrate, a synthetic fiber cloth substrate, a non-woven fabric substrate, a composite substrate and other materials impregnated with resin to form a bonding sheet, which is made of a combination of multiple bonding sheets. Copper foil is coated on both surfaces of the substrate board, and high-temperature pressing is performed to form a copper-clad board.

[0046] Among them, the multiple core boards include core boards with a metal layer on one surface and core boards with metal layers on both surfaces. Specifically, when making copper clad boards, copper foil can be set on one surface of the substrate board, or copper foil can be set on both surfaces of the substrate board. When in use, the copper foil on one surface can be removed.

[0047] In this embodiment, the first inner core board layer and the second inner core board layer are copper clad boards with copper foil on both sides, and the top core board layer and the bottom core board layer are copper clad boards with copper foil on one side.

[0048] The first dielectric layer, the second dielectric layer, the third dielectric layer and the fourth dielectric layer are all prepregs. They serve as interlayer bonding layers during lamination. Specifically, the prepregs are mainly composed of resin and reinforcing materials. When making multi-layer circuit boards, glass fiber cloth is usually used as reinforcing material, which is impregnated with resin glue and then pre-baked into thin sheets through heat treatment. It softens under heating and pressure, solidifies after cooling, and has stickiness, which can bond two adjacent layers during high-temperature pressing.

[0049] The isolation layer is a conductive shielding layer, which can be a single layer or multiple layers. In one embodiment, when the isolation layer is a single layer, it can be a metal layer, or a copper clad laminate with a metal layer on one side. In another embodiment, when the isolation layer is multiple layers, it can be a copper clad laminate with metal layers on both sides, or two layers of copper clad laminates with metal layers on one side, or a combination of a metal layer and a copper clad laminate.

[0050] Step S42: Disposing a first signal line and a second signal line on two surfaces of the first inner core board layer respectively, and disposing a third signal line and a fourth signal line on two surfaces of the second inner core board layer respectively.

[0051] In this embodiment, the first signal line and the second signal line are respectively arranged on both surfaces of the first inner core layer by etching or the like, and the third signal line and the fourth signal line are respectively arranged on both surfaces of the second inner core layer.

[0052] Step S43: stacking and laminating the first inner core board layer, the second dielectric layer, the isolation layer, the third dielectric layer, and the second inner core board layer in sequence to obtain a first assembly.

[0053] An isolation layer is provided between the first inner core plate layer and the second inner core plate layer, wherein the isolation layer may be a single layer structure (such as Figure 2a and Figure 2b As shown), it can also be a multi-layer structure (such as Figure 3a and Figure 3b shown).

[0054] The isolation layer is pressed together with the first inner core board layer and the second inner core board layer. Specifically, a second dielectric layer is arranged between the first inner core board layer and the isolation layer, and a third dielectric layer is arranged between the second inner core board layer and the isolation layer, and high-temperature pressing is performed to melt the second dielectric layer and the third dielectric layer to bond the isolation layer to the first inner core board layer and the second inner core board layer to form a first assembly.

[0055] Step S44: On the first assembly, the first signal line is connected to the third signal line to form a first coupling line, and the second signal line is connected to the fourth signal line to form a second coupling line, so as to obtain a second assembly.

[0056] The first coupling line and the second coupling line can be designed to cross (such as Figure 2a ), or they may not cross (as shown in Figure 2b shown).

[0057] Specifically, Figure 5 shown.

[0058] Step S441 : providing a first conductive buried via connected from the first signal line to the third signal line, and providing a second conductive buried via connected from the second signal line to the fourth signal line.

[0059] A first conductive buried via and a second conductive buried via are provided on the first inner core layer and the second inner core layer, wherein the first conductive buried via connects the first signal line and the third signal line, and the second conductive buried via connects the second signal line and the fourth signal line.

[0060] In one embodiment, the sidewalls of the first conductive buried via and the second conductive buried via have a metal layer, and the thickness of the metal layer is 20-25 microns.

[0061] The isolation layer is used to isolate signals between different layers of the same coupling line, specifically, to isolate signals between the first signal line and the third signal line on the first coupling line, or to isolate signals between the second signal line and the fourth signal line on the second coupling line.

[0062] Step S45: stacking and laminating the top core board layer, the first dielectric layer, the second assembly, the fourth dielectric layer and the bottom core board in sequence to obtain the coupler.

[0063] Specifically, the second assembly is bonded to the top core board layer through the first dielectric layer, and bonded to the bottom core board layer through the fourth dielectric layer.

[0064] It should be noted that, in this process, the surfaces of the top core board layer and the bottom core board layer having the metal layer need to be arranged on the outside.

[0065] Among them, Figure 5 As shown, after step S45, the following steps are also included:

[0066] Step S451: a first circuit layer is arranged on a surface of the top core board layer away from the bottom core board layer, and a second circuit layer is arranged on a surface of the bottom core board layer away from the top core board layer.

[0067] The first circuit layer is arranged on the surface of the top core board layer away from the bottom core board layer by etching or other methods, and the second circuit layer is arranged on the surface of the bottom core board layer away from the top core board layer. Both the first circuit layer and the second circuit layer are arranged on the metal layer.

[0068] In one embodiment, after the first circuit layer and the second circuit layer are manufactured, they need to be electroplated to increase the thickness to no less than 1 ounce.

[0069] In one embodiment, when manufacturing the first circuit layer and the second circuit layer, a ground line needs to be fabricated so that the isolation layer is connected to the ground line to achieve the purpose of shielding the electrical signals of different signal lines on the same coupling line.

[0070] Step S452: Disposing a conductive via connecting the first circuit layer through the isolation layer to the second circuit layer.

[0071] It should be noted that the isolation layer is electrically connected to the ground wires on the top core board layer and the bottom core board layer through conductive through holes, so that the isolation layer can play an isolation role, thereby isolating different circuit layers on the same coupling line to prevent signal interference.

[0072] In this embodiment, the coupler only describes part of the relevant structure, and the other structures are the same as those of the coupler in the prior art, which will not be described in detail here.

[0073] The coupler provided by the present invention includes a top core board layer, a first inner core board layer, a second inner core board layer and a bottom core board layer, and the first inner core board layer includes a first signal line and a second signal line, and the second inner core board layer includes a third signal line and a fourth signal line, the first signal line of the first inner core board layer is connected to the third signal line of the second inner core board layer to form a first coupling line, and the second signal line of the first inner core board layer is connected to the fourth signal line of the second inner core board layer to form a second coupling line, and an isolation layer is also provided between the first inner core board layer and the second inner core board layer, and the isolation layer is connected to the top core board layer and the bottom core board layer to shield the signals between different layers of the same coupling line. In this way, a coupling line is designed in layers to achieve a long winding structure of a small-volume coupler, and the isolation layer is used to prevent interference of multiple coupling line signals.

[0074] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A coupler, characterized in that: The coupler comprises: a top core board layer, an intermediate layer and a bottom core board layer, wherein the intermediate layer is respectively superimposed on the top core board layer and the bottom core board layer through corresponding dielectric layers; Wherein, the intermediate layer comprises a first inner core layer and a second inner core layer stacked together, the first inner core layer is provided with a first signal line and a second signal line on two opposite surfaces thereof, and the second inner core layer is provided with a third signal line and a fourth signal line on two opposite surfaces thereof; Wherein, the first signal line is connected to the third signal line to form a first coupling line, and the second signal line is connected to the fourth signal line to form a second coupling line; An isolation layer is provided between the first inner core board layer and the second inner core board layer, and the isolation layer is respectively superimposed on the first inner core board layer and the second inner core board layer through the corresponding dielectric layer; a grounding wire is provided on one side of the top core board layer and the bottom core board layer, and a conductive through hole connecting the grounding wire of the top core board layer and / or the bottom core board layer is provided in the coupler, and the isolation layer is connected to the top core board layer and / or the bottom core board layer through the conductive through hole to isolate the electrical signals between signal lines of different layers on the same coupling line.

2. The coupler according to claim 1, characterized in that The conductive via penetrates the top core board layer, the middle layer and the bottom core board layer, and the inner wall of the conductive via has a metal layer.

3. The coupler according to claim 1, characterized in that: The coupler is provided with a first conductive buried via connecting the first signal line and the third signal line to form a first coupling line; and The second signal line and the fourth signal line are connected to form a second conductive buried via of a second coupling line.

4. The coupler according to claim 1, characterized in that The dielectric layer is disposed on both sides of the isolation layer to bond the isolation layer to the first inner core board layer and the second inner core board layer.

5. The coupler according to claim 4, characterized in that: The isolation layer is specifically a conductive shielding layer.

6. The coupler according to claim 4, characterized in that The isolation layer includes a plurality of conductive shielding layers stacked in layers, and a connecting layer sandwiched between any two adjacent conductive shielding layers; Wherein, the connecting layer is a dielectric layer, a core board or a combined layer; wherein, the combined layer is any stacking combination between a dielectric layer and a core board, and the core board includes a first substrate board and a conductive shielding layer arranged on two opposite surfaces of the first substrate board.

7. The coupler according to claim 1, characterized in that: The isolation layer comprises a first isolation layer, a dielectric layer and a second isolation layer which are stacked in sequence from top to bottom; The first isolation layer includes a second substrate plate and a first conductive shielding layer covering the second substrate plate and close to the second isolation layer, and the second isolation layer includes a third substrate plate and a second conductive shielding layer covering the third substrate plate and close to the first isolation layer.

8. The coupler according to claim 2, characterized in that: The top core board layer includes a first circuit layer on a surface away from the middle layer; The bottom core layer includes a second wiring layer on a surface away from the intermediate layer.

9. The coupler according to claim 8, characterized in that The thickness of the first circuit layer and the second circuit layer is not less than 1 ounce.

10. The coupler according to claim 1, characterized in that The top core board layer, the first inner core board layer, the second inner core board layer and the bottom core board layer are all high-frequency board materials.

11. A method for manufacturing a coupler, characterized in that: include: Providing a top core board layer, a first dielectric layer, a first inner core board layer, a second dielectric layer, an isolation layer, a third dielectric layer, a second inner core board layer, a fourth dielectric layer and a bottom core board layer; a grounding wire is provided on one side of the top core board layer and the bottom core board layer; A first signal line and a second signal line are respectively arranged on two surfaces of the first inner core layer, and a third signal line and a fourth signal line are respectively arranged on two surfaces of the second inner core layer; The first inner core plate layer, the second dielectric layer, the isolation layer, the third dielectric layer, and the second inner core plate layer are sequentially stacked and laminated to obtain a first assembly; On the first assembly, the first signal line is connected to the third signal line to form a first coupling line, and the second signal line is connected to the fourth signal line to form a second coupling line, so as to obtain a second assembly; The top core board layer, the first dielectric layer, the second assembly, the third dielectric layer and the bottom core board layer are stacked and laminated in sequence, and conductive through holes are opened to connect the grounding wires of the top core board layer and / or the bottom core board layer, and the isolation layer is connected to the top core board layer and / or the bottom core board layer to obtain the coupler.

12. The method for manufacturing a coupler according to claim 11, characterized in that: The first signal line is connected with the third signal line to form a first coupling line, and the second signal line is connected with the fourth signal line to form a second coupling line on the first assembly to obtain a second assembly, specifically comprising: Provide a first conductive buried via connected from the first signal line to the third signal line, and provide a second conductive buried via connected from the second signal line to the fourth signal line; After the top core board layer, the first dielectric layer, the second assembly, the fourth dielectric layer and the bottom core board layer are stacked and laminated in sequence to obtain the coupler, the method further comprises: A first circuit layer is arranged on a surface of the top core board layer away from the bottom core board layer, and a second circuit layer is arranged on a surface of the bottom core board layer away from the top core board layer; A conductive via is provided which connects the first circuit layer through the isolation layer and connects to the second circuit layer.

13. The method for manufacturing a coupler according to claim 12, characterized in that: After the first circuit layer is arranged on the surface of the top core board layer away from the bottom core board layer, and the second circuit layer is arranged on the surface of the bottom core board layer away from the top core board layer, the method further comprises: The first circuit layer and the second circuit layer are electroplated so that the thickness of the first circuit layer and the second circuit layer is not less than 1 ounce.

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