Dielectric constant test product with multilayer high-speed soft and hard combined structure

Abstract

The utility model discloses a multilayer high-speed rigid-flex structure dielectric constant test product, which comprises a high-speed board, a bonding sheet and at least two sub-boards, the high-speed board is provided with a resonant ring and feeder lines distributed on two sides of the resonant ring, one of the sub-boards is provided with a lead, and one end of the lead is provided with a test interface; the high-speed board, the bonding sheet and each daughter board are stacked to form a multi-layer high-speed soft and hard combined structure; the multilayer high-speed soft and hard combined structure is provided with a via hole, and the lead is communicated with the feeder line through the via hole. In the embodiment of the invention, the test instrument is connected to the test interface to test the dielectric constant of the multi-layer high-speed soft-hard combined structure, the dielectric constant of the multi-layer high-speed soft-hard combined structure can be tested, and the problem that a traditional resonant ring method cannot be used for measuring the dielectric constant of a multi-layer product is effectively solved.

Description

Technical Field

[0001] This application relates to the technical field of PCB (Printed Circuit Board), and particularly to a dielectric constant test product for a multi-layer high-speed rigid-flexible combined structure. Background Art

[0002] In the related art, the dielectric constant is an important parameter of high-frequency boards. Accurately measuring the dielectric constant of high-frequency boards is very important for the application of the boards.

[0003] Currently, when testing the dielectric constant of high-frequency materials, a double-layer board structure is usually used for testing. In a multi-layer structure, there is no introduction in the industry on how to test the dielectric constant of high-frequency materials. Summary of the Invention

[0004] This application aims to at least solve one of the technical problems existing in the prior art. For this purpose, this application proposes a dielectric constant test product for a multi-layer high-speed rigid-flexible combined structure, which can be used to measure the dielectric constant of a multi-layer high-speed rigid-flexible combined structure.

[0005] The dielectric constant test product for a multi-layer high-speed rigid-flexible combined structure according to an embodiment of this application includes:

[0006] A high-speed board, a bonding sheet, and at least two sub-boards. The high-speed board is provided with a resonant ring and feed lines distributed on both sides of the resonant ring. One of the sub-boards is provided with a lead, and a test interface is provided at one end of the lead;

[0007] The high-speed board, the bonding sheet, and each of the sub-boards are stacked to form a multi-layer high-speed rigid-flexible combined structure. Among them, at least one of the sub-boards is provided on both sides of the high-speed board. The sub-board provided with the lead is located on the outermost layer of the multi-layer high-speed rigid-flexible combined structure. A bonding sheet is provided between the high-speed board and the adjacent sub-board, and a bonding sheet is also provided between adjacent two sub-boards;

[0008] A via hole is provided on the multi-layer high-speed rigid-flexible combined structure, and the other end of the lead is connected to the feed line through the via hole.

[0009] Further, the effective dielectric constant of the multi-layer high-speed rigid-flexible combined structure is ε eff , satisfying: Where f0 is the resonant frequency, r is the average radius of the resonant ring, and c is the speed of light.

[0010] Further, one surface of the high-speed board is provided with the resonant ring and the feed lines, and the other area of this surface except the resonant ring and the feed lines is the base material area.

[0011] Further, each of the sub-boards has two relatively arranged surfaces. A copper foil is laid on the surface of the sub-board where no lead is provided, and the position corresponding to the via on the surface of the sub-board where no lead is provided is set as a base material area.

[0012] Further, the high-speed board is provided with a process edge, and a copper bar is provided in the base material area of the process edge.

[0013] Further, the distance from the copper bar to the unit pattern on the high-speed board is 0.075 mm to 0.1 mm.

[0014] Further, the diameter of the via is 0.2 mm.

[0015] Further, the length L of the base material area around the via is 0.6 to 0.7 mm.

[0016] Further, the radius L1 of the solder ring of the via is 4 to 6 mil.

[0017] Further, the dielectric thickness between the resonant ring and the copper foil of the adjacent sub-board on the same side is uniform.

[0018] The multi-layer high-speed rigid-flexible combined structure dielectric constant test product of the embodiment of the present application has at least the following beneficial effects: In the embodiment of the present application, a resonant ring and a feeder are provided on the high-speed board. Leads are provided on the outermost sub-board. One end of the lead is connected to the test interface, and the other end is electrically connected to the feeder located in the inner layer through a via. Thus, the dielectric constant of the multi-layer high-speed rigid-flexible combined structure can be measured by connecting a test instrument to the test interface, and the dielectric constant of the multi-layer high-speed rigid-flexible combined structure can be obtained. That is to say, the embodiment of the present application solves the problem that the traditional resonant ring method cannot be used to measure the dielectric constant of multi-layer products.

[0019] The additional aspects and advantages of the present application will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following will further describe the present application in conjunction with the drawings and embodiments, where:

[0021] Figure 1 is a schematic structural diagram of a resonant ring in an embodiment of the present application;

[0022] Figure 2 is a schematic structural diagram of a multi-layer high-speed rigid-flexible combined structure dielectric constant test product in an embodiment of the present application;

[0023] Figure 3Schematic diagram of the structures of each layer of a multi-layer high-speed flexible-rigid combined structure test product in an embodiment of the present application;

[0024] Figure 4 Schematic diagram of the structural comparison between a common flexible board core board and the high-speed board material in an embodiment of the present application;

[0025] Figure 5 Schematic diagram of the interlayer dielectric thickness of the resonant ring of the high-speed board material in an embodiment of the present application;

[0026] Figure 6 Schematic diagram of the stacking process of the high-speed board material, adhesive sheet, daughter board and rigid buffer layer in an embodiment of the present application;

[0027] Figure 7 Schematic diagram of the structure of a dielectric constant test product in an embodiment of the present application.

[0028] Reference numerals:

[0029] 1. Flexible board core board;

[0030] 110. Resonant ring; 120. Feeder; 130. Lead; 140. Via; 150. Test interface;

[0031] 210. High-speed board material; 211. Process edge substrate area; 212. Copper strip; 220. Daughter board; 221. Substrate; 222. Copper foil; 230. Adhesive sheet; 240. Dielectric thickness; 250. Rigid buffer layer. Detailed implementation manners

[0032] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and should not be construed as a limitation to the present application.

[0033] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0034] In the description of this application, the meaning of "several" is more than one, the meaning of "multiple" is more than two, "greater than", "less than", "exceeding", etc. are understood to exclude the corresponding number, and "above", "below", "within", etc. are understood to include the corresponding number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0035] In the description of this application, unless otherwise clearly defined, terms such as "set", "install", "connect", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in this application in combination with the specific content of the technical solution.

[0036] In the description of this application, the description referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0037] Currently, when testing the dielectric constant of high-frequency materials, it is usually tested using a double-layer board structure. During the test, the resonance ring method can be used for testing. However, in the traditional resonance ring method, the resonance ring is usually arranged on a double-sided board structure and cannot be applied to multi-layer structures.

[0038] In view of this, the embodiments of this application propose a dielectric constant test product for a multi-layer high-speed rigid-flexible combined structure to effectively solve the foregoing problems.

[0039] See Figure 1 and Figure 2 As shown in and, the dielectric constant test product for the multi-layer high-speed rigid-flexible combined structure of the embodiments of this application includes high-speed boards, bonding sheets, and at least two sub-boards. The high-speed boards are provided with resonance rings and feed lines distributed on both sides of the resonance rings. One of the sub-boards is provided with leads, and one end of the leads is provided with test interfaces; the high-speed boards, bonding sheets, and each sub-board are stacked to form a multi-layer high-speed rigid-flexible combined structure. Among them, at least one sub-board is provided on both sides of the high-speed boards. The sub-board provided with leads is located on the outermost layer of the multi-layer high-speed rigid-flexible combined structure. Bonding sheets are provided between the high-speed boards and the adjacent sub-boards, and bonding sheets are also provided between adjacent two sub-boards; vias are provided on the multi-layer high-speed rigid-flexible combined structure, and the other end of the leads is connected to the feed lines through the vias.

[0040] In the embodiments of the present application, a resonant ring and a feeder are provided on a high-speed board, and leads are provided on the outermost daughter board. One end of the lead is connected to a test interface, and the other end is electrically connected to the feeder located on the inner layer through a via. In this way, a test instrument can be connected to the test interface to measure the dielectric constant of a multi-layer high-speed rigid-flexible combined structure, thereby obtaining the dielectric constant of the multi-layer high-speed rigid-flexible combined structure. That is to say, the embodiments of the present application solve the problem that the traditional resonant ring method cannot be used to measure the dielectric constant of multi-layer products.

[0041] In some embodiments of the present application, when manufacturing the dielectric constant test product of the multi-layer high-speed rigid-flexible combined structure of the embodiments of the present application, the following steps are included:

[0042] S110: Provide a high-speed board 210, a bonding sheet 230, and at least two daughter boards 220. The high-speed board 210 is provided with a resonant ring 110 and feeders 120 distributed on both sides of the resonant ring 110. A lead 130 is provided on one of the daughter boards 220, and a test interface 150 is provided at one end of the lead 130;

[0043] S120: Stack and press the high-speed board 210, the bonding sheet 230, and each daughter board 220 to form a multi-layer high-speed rigid-flexible combined structure. Among them, at least one daughter board 220 is provided on both sides of the high-speed board 210. The daughter board 220 provided with the lead 130 is located on the outermost layer of the multi-layer high-speed rigid-flexible combined structure, and the lead 130 is located on the side of the daughter board 220 away from the high-speed board 210. A bonding sheet 230 is provided between the high-speed board 210 and the adjacent daughter board 220, and a bonding sheet 230 is also provided between two adjacent daughter boards 220;

[0044] S130: Process a via 140 on the multi-layer high-speed rigid-flexible combined structure so that the lead 130 is connected to the feeder 120 through the via 140.

[0045] It is worth mentioning that there are many methods for testing the dielectric constant of high-speed high-frequency boards. One of the methods is the resonant ring method. The resonant ring method has broadband characteristics, high accuracy, and simple operation. However, in the traditional resonant ring method, the resonant ring 110 pattern is set on a double-sided board structure to measure the dielectric constant of the double-sided board structure, and it cannot be applied to multi-layer products.

[0046] In the embodiments of the present application, the circuit structure of the resonant ring 110 is as Figure 1 and Figure 2 shown. Among them, the resonant ring 110 pattern is made by etching a high-speed high-frequency substrate. Feeders 120 are used as transmission lines on both sides of the resonant ring 110 to weakly couple with the resonant ring 110 to make the resonant ring 110 resonate. Figure 1 and Figure 2Where, r is the average radius of the resonant ring 110, Wr is the ring width of the resonant ring 110, g is the distance between the coupled transmission line (i.e., the feeder 120) and the ring (hereinafter referred to as the coupling gap), and W0 is the line width of the transmission line.

[0047] The test principle is as follows:

[0048] At a certain resonant frequency, the dielectric constant measurement by the resonant ring method is based on the following formula:

[0049] 2πR = nλ g , n = 1, 2, 3,...

[0050] It should be understood that the average circumference of the resonant ring 110 is equal to an integer multiple of the waveguide wavelength λg in the medium. In the above formula, r is the average radius of the resonant ring 110, n is the resonance number, and λ g is the waveguide wavelength.

[0051] The waveguide wavelength λ of the resonant ring 110 g is calculated as follows. λ g is a function of the resonant frequency f0:

[0052]

[0053] Where, c is the speed of light, ε eff is the effective dielectric constant, and f0 is the resonant frequency.

[0054] Furthermore, In the above formula, ε r is the relative dielectric constant, and h is the thickness of the plate. The effective dielectric constant corresponding to the resonant frequency can be obtained. That is, by inputting different resonant frequencies to the resonant ring 110 through an instrument, the effective dielectric constant of the material can be obtained.

[0055] Therefore, in some embodiments of the present application, the effective dielectric constant of the multi-layer high-speed rigid-flexible combined structure is ε eff , satisfying:

[0056]

[0057] Where, f0 is the resonant frequency, r is the average radius of the resonant ring 110, and c is the speed of light.

[0058] Furthermore, refer to Figure 2, one surface of the high-speed board 210 is provided with a resonant ring 110 and a feeder 120, and the other areas of this surface except the resonant ring and the feeder are set as the base material area. Specifically, the core board of the high-speed board 210 includes a base material area and copper-clad layers arranged on both sides of the base material area, and both the resonant ring 110 and the feeder 120 are processed from the copper-clad layers on the high-speed board 210. That is to say, in the high-speed board 210, except for the resonant ring 110 and the feeder 120, there is no copper-clad layer in other areas of the surface where the resonant ring 110 is located. In this way, it is convenient to use the resonant ring method to test the dielectric constant of the board.

[0059] Further, as shown in Figure 2 and Figure 3 , each daughter board 220 has two relatively arranged surfaces. The daughter board 220 includes a base material 221 and a copper foil 222. The surface of the daughter board 220 where the lead 130 is not provided is set as the copper foil 222, and the position corresponding to the via 140 on the surface of the daughter board 220 where the lead 130 is not provided is set as the base material area. Among them, the copper foil 222 can be used as a shielding layer for the resonant ring 110, which can reduce the interference caused by the outside or other layers to the resonant ring 110 and help improve the measurement accuracy of the dielectric constant.

[0060] It should be noted that the high-speed material is a fluorine-based material. When the thickness of the high-speed board 210 is small, its tear resistance is poor. However, in order to ensure the bending performance, the core board thickness of the high-speed board 210 is generally set to be less than or equal to 4 mil. In the high-temperature lamination state, the adhesive sheet 230 or the prepreg between the inner layers of the multi-layer high-speed rigid-flexible board combination structure will melt and exert an extrusion effect on the fluorine-based high-speed board 210, making the copper-free area of the high-speed board 210 prone to fracture.

[0061] As Figure 4 shown, the process edge of the ordinary flexible board core board 1 is usually set as the base material area, and there is no copper-clad layer in the base material area.

[0062] In some embodiments of the present application, as shown in Figure 4 , the high-speed board 210 is provided with a process edge, and the process edge has a process edge base material area 211. A copper bar 212 is locally laid in the process edge base material area 211 of the high-speed board 210. In this way, the copper bar 212 can be used to improve the tear resistance of the base material area of the high-speed board 210 and reduce the tearing risk of the high-speed board 210 during lamination.

[0063] In a possible implementation manner, as shown in Figure 4As shown, the high-speed board 210 is provided with a process edge. The substrate area 211 of the process edge is partially covered with copper bars 212 for treatment. The distance d between the laid copper bars and the unit pattern is 0.075 - 0.1 mm. In this way, not only can the copper bars be used to improve the tear resistance of the substrate area 211 of the process edge, but also a reasonable interval can be maintained between the copper bars and the unit pattern to avoid adverse effects of the copper bars 212 on the unit pattern.

[0064] See Figure 5 As shown, it is necessary to ensure that the dielectric layer thickness (i.e., dielectric thickness 240) between the resonant ring 110 and the shielding layer (copper foil of the adjacent sub-board) is uniform in order to minimize the impedance value fluctuations of the multi-layer high-speed rigid-flexible combined structure and obtain accurate measured dielectric constant.

[0065] Therefore, during the lamination process of the high-speed board 210 and each sub-board 220, a rigid buffer layer 250 is provided on the outside of the multi-layer high-speed rigid-flexible combined structure. By pressing the high-speed board 210, the adhesive sheet 230, and each sub-board 220 through the rigid buffer layer 250, the uniformity of the dielectric thickness between the resonant ring 110 and the shielding layer can be improved.

[0066] Among them, the rigid buffer layer 250 is a plate-like structure with relatively high rigidity, which can effectively reduce deformation during the lamination process. That is to say, the lamination force during the lamination process can act evenly on the multi-layer high-speed rigid-flexible combined structure, thereby improving the uniformity of the dielectric layer thickness between the resonant ring 110 and the shielding layer, and further improving the accuracy of the measured dielectric constant.

[0067] It should be understood that in the above embodiment, the shielding layer is the copper-clad layer (i.e., copper foil 222) on the side of the sub-board 220 adjacent to the high-speed board 210 and close to the resonant ring 110. The dielectric layer thickness (i.e., dielectric thickness 240) refers to the dielectric thickness between the shielding layer and the resonant ring 110. In this embodiment, the dielectric is specifically the adhesive sheet 230.

[0068] In a possible implementation manner, the rigid buffer layer 250 is provided on both sides of the multi-layer high-speed rigid-flexible combined structure. During lamination, the sub-board 220, the high-speed board 210, and the adhesive sheet 230 are laminated through the rigid buffer layer 250 to improve the uniformity of the lamination force, thereby ensuring the uniformity of the dielectric thickness 240 between the resonant ring 110 and the shielding layer.

[0069] Furthermore, the rigid buffer layer 250 can specifically be selected as an aluminum sheet with a certain thickness. Of course, the rigid buffer layer 250 can also be set as other hard metal plates.

[0070] Further, in order to ensure the uniformity of the dielectric layer thickness of the resonant ring 110 in the multi-layer high-speed rigid-flexible combined structure, when laminating the multi-layer high-speed rigid-flexible combined structure, the lamination pressure is set to 400 - 450 PSI; the transfer pressure temperature of the adhesive sheet 230 is 90°C - 100°C. In this way, the fluidity of the adhesive sheet 230 during lamination can be reduced, which is beneficial to making the dielectric thickness 240 uniform after lamination.

[0071] In some embodiments of the present application, the multi-layer high-speed rigid-flexible combined structure has n layers, and the resonant ring 110 is disposed on the L3 layer or the L4 layer, as Figure 3 and Figure 5 shown. That is to say, at least one daughter board 220 is disposed on both sides of the high-speed board 210, and the high-speed board 210 is located in the inner layer of the multi-layer high-speed rigid-flexible combined structure.

[0072] In a possible implementation manner, referring to Figure 3 shown, the multi-layer high-speed rigid-flexible combined structure has 8 layers, namely L1 layer, L2 layer, L3 layer, L4 layer, L5 layer, L6 layer, L7 layer and L8 layer.

[0073] Specifically, referring to Figure 3 shown:

[0074] L1 layer: Most of it is set as the base material area, only the test PAD (i.e., the test interface 150) and the lead 130 are retained. The lead 130 is a part of the length (5 mm) intercepted from both ends of the resonant ring 110 on the L4 layer and placed on the L1 layer. At the same time, the line width of the lead 130 is set to 18 mil. In addition, a via 140 is designed at the end of the lead 130 to connect to the feeder 120 on the inner layer L4 layer. Among them, the aperture of the via 140 is set to 0.2 mm, and the unilateral radius of the solder ring of the via 140 and the feeder 120 is set to 4 - 6 mil.

[0075] L2 layer: It is designed as a large copper foil 222. Note that in the selected area A of the L2 layer, no pads are set but directly a large copper foil 222 is set, and in the selected area B of the L2 layer, a base material circle is set, and the radius of the base material circle is 8 - 12 mil larger than the unilateral side of the via 140.

[0076] L3 layer: The same design as the L2 layer.

[0077] L4 layer: It is composed of the resonant ring 110, the feeder 120 (the line width is controlled within 4.8 mil) and the via 140, and the other positions are set as the base material area.

[0078] The designs of the L5, 6, 7, and 8 layers are the same as those of the L2 layer.

[0079] Next, referring to Figures 4 to 7The manufacturing method of a multi-layer high-speed rigid-flexible combined structure dielectric constant test product according to an embodiment of the present application is described in detail with a specific embodiment. It should be understood that the following embodiments are only exemplary descriptions and should not be construed as limitations on the embodiments of the present application.

[0080] 1) Make circuits on the rigid board core board and the high-speed board 210, and slot the bonding sheet 230.

[0081] 2) It should be noted that the high-speed material is a fluorine-based material. When the core board thickness is small, its tear resistance is poor. However, in order to ensure the bending performance, the core board thickness is generally ≤4 mil. At the high temperature state of lamination and pressing, the melting of the prepreg between layers will exert an extrusion effect on the fluorine-based high-speed material, and the copper-free area of the high-speed material is prone to breakage.

[0082] To reduce the tearing risk of the high-speed board 210 during pressing, the high-speed board 210 is locally laid with copper bars 212 in the substrate area 211 of the process edge, as Figure 4 shown, the distance d1 between the laid copper bar and the unit pattern in the high-speed board 210 is 0.075 - 0.1 mm.

[0083] 3) The high-speed board 210 is bonded and laminated with a cover film, and then pre-arranged and laminated together with the slotted bonding sheet 230 and the rigid board core board after circuit making.

[0084] It should be noted that the dielectric thickness 240 between the resonant ring 110 and the shielding layer is uniform and consistent, the impedance value fluctuation is small, and the measured dielectric constant is accurate.

[0085] To ensure the uniformity of the dielectric thickness 240 between the resonant ring 110 layers of the high-speed board 210, in this embodiment, a buffer material with high rigidity (such as an aluminum sheet) is used for buffering, and appropriate lamination parameters are used. The lamination pressure is 400 - 450 PSI, and the transfer pressure temperature of the bonding sheet 230 is 90 - 100 °C, reducing the fluidity of the bonding sheet 230 during lamination, making the dielectric thickness 240 of the product uniform after lamination, as Figure 6 shown.

[0086] 4) Press, drill holes, electroplate, make outer layer circuits, make surface treatment, and shape according to the process, and the high-speed rigid-flexible combined structure dielectric constant test product according to the embodiment of the present application can be obtained, and then the product is tested for dielectric constant by an instrument.

[0087] In this embodiment, the high-speed board 210 is specifically a high-speed flexible board core board or a high-frequency high-speed copper clad laminate; the daughter board 220 can be a rigid board core board, a flexible board core board and other boards.

[0088] In the embodiment of the present application, the high-speed board 210 is specifically a high-frequency high-speed copper clad laminate.

[0089] The embodiments of the present application have been described in detail above in conjunction with the accompanying drawings. However, the present application is not limited to the above embodiments, and various changes can be made without departing from the gist of the present application within the scope of knowledge possessed by those of ordinary skill in the art to which the present application pertains. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A multi-layer high-speed soft-hard combination structure dielectric constant test product, characterized in that: include: A high-speed plate, a bonding sheet, and at least two sub-plates, wherein the high-speed plate is provided with a resonant ring and feed lines distributed on both sides of the resonant ring, one of the sub-plates is provided with a lead, and one end of the lead is provided with a test interface; The high-speed plate, the bonding sheet, and each of the sub-plates are stacked to form a multi-layer high-speed rigid-flexible structure, wherein at least one sub-plate is provided on both sides of the high-speed plate, the sub-plate provided with the leads is located on the outermost layer of the multi-layer high-speed rigid-flexible structure, the bonding sheet is provided between the high-speed plate and the adjacent sub-plate, and the bonding sheet is also provided between two adjacent sub-plates; The multi-layer high-speed rigid-flexible structure is provided with a via hole, and the other end of the lead is connected to the feed line through the via hole.

2. The multi-layer high-speed soft-hard combination structure dielectric constant test product according to claim 1, characterized in that: The effective dielectric constant of the multi-layer high-speed hard-soft combination structure is ε eff ,satisfy: Where f0 is the resonant frequency, r is the average radius of the resonant ring, and c is the speed of light.

3. The multi-layer high-speed soft-hard combination structure dielectric constant test product according to claim 1, characterized in that: The resonant ring and the feed line are arranged on one surface of the high-speed plate, and the other area of the surface except the resonant ring and the feed line is a substrate area.

4. The multi-layer high-speed soft-hard combination structure dielectric constant test product according to claim 1, characterized in that: Each of the daughter boards has two surfaces arranged opposite to each other. The surface of the daughter board where the leads are not arranged is provided with copper foil, and the surface of the daughter board where the leads are not arranged is provided with a substrate area corresponding to the position of the via hole.

5. The multi-layer high-speed hard-soft combination structure dielectric constant test product according to any one of claims 1 to 4, characterized in that: The high-speed plate is provided with a process edge, and a base material area of the process edge is paved with a copper strip.

6. The multi-layer high-speed soft-hard combination structure dielectric constant test product according to claim 5, characterized in that: The distance between the copper strip and the unit pattern on the high-speed plate is 0.075 mm to 0.1 mm.

7. The multi-layer high-speed hard-soft combination structure dielectric constant test product according to claim 1, characterized in that: The diameter of the via hole is 0.2 mm.

8. The multi-layer high-speed hard-soft combination structure dielectric constant test product according to claim 7, characterized in that: The length L of the substrate area around the via hole is 0.6-0.7 mm.

9. The multi-layer high-speed hard-soft combination structure dielectric constant test product according to claim 7, characterized in that: The radius L1 of the solder ring of the via hole is 4 to 6 mil.

10. The multi-layer high-speed hard-soft combination structure dielectric constant test product according to claim 1, characterized in that: The dielectric thickness between the resonant ring and the adjacent sub-plates on the same side is uniform.

Images