Via hole structure, method for adjusting the impedance of signal via holes, printed circuit board and communication equipment
The via hole structure with capacitive terminals addresses impedance limitations by adjusting terminal size, overcoming CAF constraints and improving signal quality and speed in high-speed digital products.
Patent Information
- Application Number
- JP2025574983
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-06-30
- Filing Date
- 2024-05-09
- Publication Date
- 2026-07-13
AI Technical Summary
Conventional methods for adjusting the impedance of via holes in printed circuit boards are limited by the Conductive Anodic Filament (CAF) effect and processing constraints, restricting the ability to reduce impedance through distance and anti-pad size adjustments, which affects signal speed in high-speed digital products.
A via hole structure with capacitive terminals electrically connected to signal via holes, allowing impedance adjustment by varying terminal size, overcoming CAF limitations and reducing the equivalent distance between via holes.
The capacitive terminals enable effective impedance adjustment, reducing via hole impedance and improving signal quality without altering anti-pad size, thus enhancing signal speed and continuity.
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Abstract
Description
Technical Field
[0001] This application claims the priority of a Chinese patent application filed with the China National Intellectual Property Administration on June 30, 2023, with an application number of 202310802851.7 and an application title of "Via Hole Structure, Impedance Adjustment Method for Signal Via Holes, and Printed Circuit Board", and the entire content of the application is incorporated herein by reference.
[0002] This application belongs to the technical field of communications, and specifically relates to a via hole structure, an impedance adjustment method for signal via holes, and a printed circuit board.
Background Art
[0003] With the advent of the big data era, in order to meet the large-scale data communication interactions, the signal speed of a single channel of digital chips has been continuously increased. However, the higher the signal speed, the larger the channel bandwidth required for its transmission. The signal bandwidth can be understood as the difference between the highest frequency and the lowest frequency of the signal in the signal spectrum map, and it can also be said that the signal bandwidth is the frequency range that the signal has.
[0004] Via holes are an essential component in current communication products. In order to improve the signal speed, the current mainstream method is to reduce the impedance of the via holes by adjusting the distance between differential via holes, the distance between the ground via and the differential via holes, and the size of the anti-pad of the differential via holes.
[0005] However, due to the Conductive Anodic Filament (CAF) effect, the distance between via holes of different networks must not be less than a certain value. In the current process, the distance between hole walls needs to be greater than 0.5 mm. Therefore, there are limitations to adjusting the impedance by adjusting the distance between via holes.
[0006] On the other hand, the size of the anti-pad is limited by the processing capabilities and cannot be made sufficiently small, so there are certain limitations to adjusting the impedance by the size of the anti-pad of the differential via hole. As can be seen from the above, in related technologies, when the impedance of the differential via hole is high, the impedance adjustment capability of the via hole in conventional technology is limited, which affects the signal speed. [Overview of the Initiative] [Problems that the invention aims to solve]
[0007] The present invention aims to provide a via-hole structure, a method for adjusting the impedance of signal via-holes, and a printed circuit board that can solve the problem of high impedance in via-holes of printed circuit boards (PCBs) for high-speed digital products. [Means for solving the problem]
[0008] In a first aspect, an embodiment of the present application provides a via hole structure comprising at least one signal via hole and at least one terminal, wherein one of the terminals is electrically connected to one of the signal via holes.
[0009] In one embodiment of the first aspect, a single signal via hole is electrically connected to at least one terminal.
[0010] In one embodiment of the first aspect, a plurality of the signal via holes are electrically connected to at least one terminal, and one of the terminals is electrically connected to one of the signal via holes.
[0011] In one embodiment of the first aspect, the one signal via hole is electrically connected to a plurality of terminals.
[0012] In one embodiment of the first aspect, the multiple terminals are insulated from each other.
[0013] In one embodiment of the first aspect, the multiple terminals are electrically connected as a whole.
[0014] In one embodiment of the first aspect, the terminal has a circular structure.
[0015] In one embodiment of the first aspect, the terminal is fixedly connected to the outer wall of the signal via hole.
[0016] In a second aspect, an embodiment of the present application provides a method for adjusting the impedance of a signal via hole applied to a via hole structure described in the first aspect, comprising the steps of: determining a target size of the terminals of the via hole structure based on a target impedance value; and adjusting the size of the terminals of the via hole structure to the target size in accordance with the target size, thereby causing the impedance value of the via hole structure to reach the target impedance value.
[0017] In one embodiment of the second aspect, after adjusting the size of the terminals of the via hole structure to the target size, the method further includes the step of adjusting the impedance value of the via hole structure to the target impedance value if, after adjusting the size of the terminals of the via hole structure, the impedance value of the via hole structure has not reached the target impedance value, by adjusting at least one of the first distance between two signal differential vias of the via hole structure, the second distance between the ground via and the signal via hole of the via hole structure, and the size of the antipad of the via hole structure.
[0018] In a third aspect, an embodiment of the present application provides a printed circuit board including the via-hole structure described in the first aspect.
[0019] In a fourth aspect, an embodiment of the present application provides a communication device including a printed circuit board as described in the third aspect.
[0020] In the embodiment of the present application, a via hole structure is provided. The via hole structure includes at least one signal via hole and at least one terminal. One of the terminals is electrically connected to one of the signal via holes. By adjusting the size and number of the terminals, etc., the impedance of the signal via hole can be adjusted, and there is no need to adjust the size of the anti-pad of the differential via hole. Thereby, the problem that the adjustment ability of the impedance of the via hole is limited when the impedance of the differential via is high can be solved.
Brief Description of the Drawings
[0021] [Figure 1a] It is a structural schematic diagram of a via hole structure in the related art. [Figure 1b] It is a structural schematic diagram of another via hole structure in the related art. [Figure 2] It is a structural schematic diagram of a via hole structure according to an embodiment of the present application. [Figure 3a] It is a structural schematic diagram of another via hole structure according to an embodiment of the present application. [Figure 3b] It is a structural schematic diagram of yet another via hole structure according to an embodiment of the present application. [Figure 4a] It is a structural schematic diagram of yet another via hole structure according to an embodiment of the present application. [Figure 4b] It is a structural schematic diagram of yet another via hole structure according to an embodiment of the present application. [Figure 5] It is a flowchart of a method for adjusting the impedance of a signal via hole according to an embodiment of the present application. [Figure 6] It is a comparative curve diagram of the impedance after simulation between the via hole structure provided in the embodiment of the present application and the via hole structure provided in the prior art.
Modes for Carrying Out the Invention
[0022] The technical solutions of the embodiments of this application will be described clearly and completely below with reference to the drawings of the embodiments of this application, and it will be clear that the embodiments described are some, but not all, embodiments of this application. All other embodiments that a person skilled in the art can obtain without creative work based on the embodiments of this application are within the scope of protection of this application.
[0023] The terms “first,” “second,” etc., in the specification and claims of this application are used to distinguish similar objects and are not intended to describe a specific order or sequence. The data used in this manner is interchangeable where appropriate so that the embodiments of this application can be carried out in an order other than that illustrated or described herein, and it should be understood that the objects distinguished as “first,” “second,” etc., are usually of the same kind and do not limit the number of objects; for example, there may be one first object or more. Furthermore, “and / or” in the specification and claims indicates at least one of the connected objects, and the letter “ / ” generally indicates that the preceding and following related objects are in an “or” relationship.
[0024] In related technologies, impedance adjustment of differential via holes may be performed not only by adjusting the distance between two differential vias as shown in Figure 1a, but also by adjusting the distance between the ground via and the differential via, and the size of the anti-pad of the differential via, as shown in Figure 1b. As signal speeds continue to increase, the dielectric constant of the sheet metal used in high-speed products becomes increasingly low, resulting in increasingly high impedance of signal vias. To reduce the impedance of via holes, it is necessary to reduce the distance between signal vias and between signal vias and ground vias, and to reduce the anti-pad of the signal vias. However, due to the CAF effect, the distance between via holes in different networks must not be less than a predetermined value. In current processes, the spacing between hole walls must be greater than 0.5 mm. Therefore, there are limitations to adjusting the impedance by adjusting the distance between via holes. On the other hand, the size of the anti-pad cannot be made sufficiently small due to processing limitations. Therefore, when the impedance of differential vias is high, the impedance adjustment capability of conventional via holes is limited. To address this problem, embodiments of the present application provide an improved via hole structure in which, in addition to the signal via hole, terminals are added to the signal via hole, and the terminals exhibit capacitiveness, thus reducing the impedance of the via hole. Furthermore, capacitive terminals overcome the limitations of CAF, reduce the equivalent distance between two signal vias, and lower the impedance of the via hole.
[0025] The via hole structure, signal via hole impedance adjustment method, printed circuit board, and communication equipment according to the embodiment of this application will be described below with reference to the drawings, with specific examples and their application scenarios.
[0026] Figure 2 is a schematic diagram of the via hole structure according to an embodiment of the present invention.
[0027] As shown in Figure 2, an embodiment of the present invention provides a via hole structure comprising at least one signal via hole 201 and at least one terminal 101, wherein one of the terminals 101 is electrically connected to one of the signal via holes 201.
[0028] Since terminal 101 of the via hole structure exhibits capacitive properties, the impedance of the signal via hole 201 can be reduced. Specifically, the overall impedance of the signal via hole 201 can be adjusted by adjusting the size of terminal 101, eliminating the need to adjust the size of the anti-pad of the signal via hole. Furthermore, terminal 101 can overcome the CAF limit, reducing the equivalent distance between the two signal via holes 201, thereby reducing the impedance of the signal via hole 201.
[0029] In the embodiments of this application, the shape of the terminal 101 is not limited.
[0030] In the embodiments of the present invention, as shown in Figure 2, the via hole structure may further include a conductive layer 301 and a transmission wiring 401.
[0031] In embodiments of the present invention, a via-hole structure is provided, which includes at least one signal via-hole 201 and at least one terminal 101, wherein one of the terminals 101 is electrically connected to one of the signal via-holes 201. This allows the impedance of the entire signal via-hole 201 to be adjusted by adjusting the size of the terminal 101, and the terminal 101 can overcome the CAF limit, thereby reducing the equivalent distance between the two signal via-holes 201 and thereby reducing the impedance of the signal via-hole 201.
[0032] Figure 3a is a schematic diagram of another via hole structure according to an embodiment of the present invention.
[0033] As shown in Figure 3a, an embodiment of the present invention provides a via hole structure in which a single signal via hole 201 is electrically connected to at least one terminal 101.
[0034] In the embodiments of the present invention, it can be seen that in the via hole structure, only one signal via hole 201 is electrically connected to at least one terminal 101, and the other signal via holes 201 are not electrically connected to terminal 101.
[0035] In one implementation of this embodiment, as shown in Figure 3a, specifically, one signal via hole 201 is electrically connected to one terminal 101, while the other signal via hole 201 is not electrically connected to terminal 101.
[0036] In another implementation of this embodiment, one signal via hole 201 is electrically connected to two or more terminals 101, while the other signal via hole 201 is not electrically connected to terminal 101.
[0037] Figure 3b is a schematic diagram of yet another via hole structure according to an embodiment of the present invention.
[0038] As shown in Figure 3b, an embodiment of the present invention provides a via hole structure in which a plurality of signal via holes 201 are electrically connected to at least one terminal 101, and one terminal 101 is electrically connected to one of the signal via holes 201.
[0039] In the embodiment of the present application, as shown in Figure 3b, in the via hole structure, a plurality of signal via holes 201 are electrically connected to at least one terminal 101, and one terminal 101 is electrically connected to one signal via hole 201. In other words, one terminal 101 can only be electrically connected to one signal via hole 201, and one signal via hole 201 can be electrically connected to at least one terminal 101. A plurality of signal via holes 201 may be electrically connected to terminal 101.
[0040] In one implementation of this embodiment, as shown in Figure 3b, the via hole structure may consist of two signal via holes 201 and three terminals 101. Specifically, one signal via hole 201 is electrically connected to the two terminals 101, and the other signal via hole 201 is electrically connected to the other signal via hole 201.
[0041] In another implementation of this embodiment, as shown in Figure 2, the via hole structure may consist of two signal via holes 201 and two terminals 101, specifically, one signal via hole 201 is electrically connected to one terminal 101, and the other signal via hole 201 is electrically connected to the other signal via hole 201.
[0042] In addition to ensuring that one terminal 101 is electrically connected to one signal via hole 201 in the embodiments of this application, the other signal via holes 201 are electrically connected to at least one terminal 101, which may be electrically connected to one terminal 101 as shown in Figure 2, or to two terminals 101 as shown in Figure 3b. Similarly, a signal via hole 201 may be electrically connected to three, four or more terminals 101, and is not limited to the embodiments of this application.
[0043] In the embodiment of the present invention, one signal via hole 201 is electrically connected to a plurality of terminals 101.
[0044] In one embodiment of the present invention, as shown in Figure 3b, the right-hand signal via hole 201 is electrically connected to the two terminals 101. Alternatively, as shown in Figure 4a, both signal via holes 201 are electrically connected to the two terminals 101.
[0045] In the embodiment of this application, as shown in Figure 4a, the direction of terminal 101 of the signal via hole 201 can be set arbitrarily.
[0046] In the embodiments of the present invention, if a single signal via hole 201 is optionally electrically connected to a plurality of terminals 101, the plurality of terminals 101 are insulated from each other, as shown in Figures 3b and 4a.
[0047] Alternatively, if a single signal via hole 201 is electrically connected to multiple terminals 101, the multiple terminals 101 may be electrically connected integrally, as shown in Figure 4b.
[0048] In the embodiments of the present application, the terminal 101 may have a circular structure. Optionally, the terminal 101 is fixedly connected to the outer wall of the signal via hole 201. For example, in Figures 2 to 4b, one terminal 101 may have a substantially circular structure, and each terminal 101 may be fixedly connected to the outer wall of the signal via hole 201 by plating.
[0049] In the embodiments of the present invention, the impedance of the entire signal via hole 201 can be adjusted by adjusting the size of terminal 101, and since terminal 101 can overcome the CAF limit, the equivalent distance between the two signal via holes 201 can be reduced, thereby reducing the impedance of the signal via hole 201 and improving signal quality.
[0050] Figure 5 is a flowchart of the impedance adjustment method for a signal via hole according to an embodiment of the present invention.
[0051] The method is applicable to any of the via hole structures described above, and as shown in Figure 5, the method mainly comprises the following steps.
[0052] S510: Based on the target impedance value, the target size of the terminals of the via hole structure is determined.
[0053] Embodiments of the present invention provide a method for adjusting the impedance of a signal via hole. To adjust the impedance of a signal via hole, first a target impedance value should be determined, and then, based on the obtained target impedance value, the target size of the terminals of the via hole structure should be determined.
[0054] Because terminals exhibit capacitive properties, they can reduce the impedance of the signal via hole. When the impedance is relatively large, i.e., when the target impedance value is relatively large, the target size of the terminals in the via hole structure provided is also relatively large. When the impedance is relatively small, i.e., when the target impedance value is relatively small, the target size of the terminals in the via hole structure provided is also relatively small.
[0055] In specific applications, the size of the terminals corresponding to each impedance value can be obtained through three-dimensional modeling simulation, establishing a correspondence between impedance values and terminal sizes. In actual use, the target size of the terminals of the via hole structure can be obtained according to the target impedance value.
[0056] S520: The impedance value of the via hole structure is made to reach the target impedance value by adjusting the size of the terminals of the via hole structure to the target size according to the target size.
[0057] In this embodiment, a method for adjusting the impedance of a signal via hole is provided. Since the terminals exhibit capacitive properties and can reduce the impedance of the signal via hole, providing terminals electrically connected to the signal via hole around it serves to adjust the impedance of the signal via hole.
[0058] Furthermore, the terminals provided can overcome the limitations of CAF, reducing the equivalent distance between the two signal via holes, thereby lowering the impedance of the signal via holes.
[0059] In embodiments of the present application, after adjusting the size of the terminals of the via hole structure to the target size, the method further includes the step of adjusting the impedance value of the via hole structure to the target impedance value if, after adjusting the size of the terminals of the via hole structure, the impedance value of the via hole structure has not reached the target impedance value, by adjusting at least one of the first distance between two signal differential vias of the via hole structure, the second distance between the ground via and the signal via hole of the via hole structure, and the size of the antipad of the via hole structure.
[0060] In embodiments of the present invention, a method for adjusting the impedance of signal via holes is provided, which can solve the problem of high impedance in via holes of PCBs of high-speed digital products, reduce the impedance of the via holes, and improve signal quality.
[0061] Furthermore, as shown in Figure 6, this is a comparison curve diagram of the simulated impedance of the via hole structure provided in the embodiment of the present application and the via hole structure provided in the prior art. In the curve diagram, the horizontal coordinate represents the signal transmission time in units of ns, and the vertical coordinate represents the impedance value in units of ohms. As is clear from Figure 6, the simulated impedance of the via hole structure provided in the embodiment of the present application (curve 2) shows better continuity compared to the simulated impedance of the via hole structure provided in the prior art (curve 1). The impedance of the prior art is too high, and the technology of the embodiment of the present application can reduce the impedance.
[0062] Furthermore, as is clear from Figure 6, the impedance adjustment interval simulated in the embodiment of the present invention is wider, and the impedance of via holes located in the dielectric layer, in addition to the conductor layer, can also be adjusted.
[0063] Embodiments of the present invention further provide a printed circuit board including any one of the above via-hole structures.
[0064] The embodiments of the present invention further provide a communication device including the printed circuit board described above.
[0065] In this specification, the terms “include,” “incorporate,” or any other variation thereof are intended to cover non-exclusive inclusion, thereby including not only those elements but also other elements not expressly enumerated, or elements specific to this process, method, article, or apparatus. Unless otherwise specified, an element limited by the phrase “includes one…” does not preclude the presence of another identical element in a process, method, article, or apparatus that includes that element. Furthermore, the scope of methods and apparatus in embodiments of this application is not limited to performing functions in the order shown or considered, but may further include performing functions substantially simultaneously or in reverse order depending on the function; for example, a described method may be performed in a different order than described, and various steps may be added, omitted, or combined. Also, features described with reference to some examples may be combined in other examples.
[0066] Through the above description of the embodiments, those skilled in the art will clearly understand that the methods of the above embodiments may be implemented by software and the necessary general-purpose hardware platform, or of course by hardware, but in many cases the former is a more preferred embodiment. Based on this understanding, the essence of the technical solution of the present application or the part that contributes to related technologies can be embodied in the form of a software product.
[0067] A person skilled in the art, by considering the specification and practicing the invention disclosed herein, will readily conceive of other means of implementation of the Application. The Application is intended to cover any variations, uses, or adaptive changes of the Application, which may include common or conventional means of the art known in the Application, in accordance with the general principles of the Application, and which are not disclosed herein. The Specification and Examples are to be considered merely illustrative, and the actual scope and intent of the Application are defined in the Claims.
[0068] It should be understood that this application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes can be made without exceeding its scope. The scope of this application is limited to the attached claims.
Claims
1. It has a beer hall structure, At least one signal via hall, A via hole structure comprising at least one terminal, wherein one of the terminals is electrically connected to one of the signal via holes.
2. The via hole structure according to claim 1, wherein the single signal via hole is electrically connected to the at least one terminal.
3. The via hole structure according to claim 1, wherein a plurality of signal via holes are electrically connected to at least one terminal, and one terminal is electrically connected to one of the signal via holes.
4. The via hole structure according to any one of claims 1 to 3, wherein the one signal via hole is electrically connected to a plurality of terminals.
5. The via hole structure according to claim 4, wherein the plurality of terminals are insulated from each other.
6. The via hole structure according to claim 4, wherein the plurality of terminals are electrically connected integrally.
7. The via hole structure according to any one of claims 1 to 3, wherein the terminal has a circular structure.
8. The via hole structure according to any one of claims 1 to 3, wherein the terminal is fixedly connected to the outer wall of the signal via hole.
9. A method for adjusting the impedance of a signal via hole, applicable to any one of claims 1 to 8, A step of determining the target size of the terminals of the via hole structure based on the target impedance value, A method for adjusting the impedance of a signal via hole, comprising the step of adjusting the size of the terminals of the via hole structure to the target size according to the target size, thereby causing the impedance value of the via hole structure to reach the target impedance value.
10. After adjusting the size of the terminals of the via hole structure to the target size, The method according to claim 9, further comprising the step of adjusting the size of the terminals of the via hole structure to the target size, and if the impedance value of the via hole structure has not reached the target impedance value, adjusting at least one of the first distance between two signal differential vias of the via hole structure, the second distance between the ground via and the signal via hole of the via hole structure, and the size of the antipad of the via hole structure to bring the impedance value of the via hole structure to the target impedance value.
11. A printed circuit board comprising the via hole structure described in any one of claims 1 to 8.
12. A communication device including a printed circuit board as described in claim 11.