A wiring structure of a PCB impedance coplanar line
By adjusting the angle between the wiring direction of the PCB impedance lines and the fiberglass cloth to 4-6°, the problem of impedance fluctuation was solved, resulting in more stable impedance control and a higher product qualification rate.
Patent Information
- Application Number
- CN202521603274.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2026-06-19
- Estimated Expiration
- 2035-07-30
AI Technical Summary
The existing PCB impedance wires from Kebang are perpendicular or parallel to the warp and weft directions of the PP fiberglass cloth, causing the impedance value to be greatly affected by the fluctuation of the dielectric constant, making them prone to failure.
Set the angle between the routing direction of the PCB impedance lines and the warp or weft bundles of the fiberglass cloth in the PP insulation layer to 4-6° to avoid the impedance lines overlapping with the warp and weft of the fiberglass cloth or falling into gaps, and adopt a straight design.
It improves the stability and accuracy of impedance values, reduces the impact of glass fiber effect, increases impedance pass rate, and maintains production efficiency and cost control without changing the panel design or increasing costs.
Smart Images
Figure CN224385781U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of PCB (printed circuit board) manufacturing and processing technology, specifically to a wiring structure for PCB impedance lines. Background Technology
[0002] PCB impedance lines (also known as impedance traces) are an important component of the CAM (Computer-Aided Manufacturing) process in PCB production, primarily used for impedance control within the PCB board. The routing structure of the PCB impedance lines directly affects the accuracy of the impedance values within the PCB board.
[0003] In existing technologies, PP is used as an insulating layer above or below the impedance lines on PCBs. These impedance lines are typically designed as straight lines, and their routing direction is perpendicular or parallel to the warp and weft directions of the fiberglass cloth within the PP. PP is composed of a mixture of resin and fiberglass cloth, with the fiberglass cloth having a dielectric constant DK of 4.5-6 and the resin having a dielectric constant DK of 2-3.5, showing a significant difference between the two. Because PP is a mixture of resin and fiberglass cloth, it is difficult to obtain an accurate and effective dielectric constant DK value, which leads to a decrease in impedance simulation accuracy.
[0004] Furthermore, the impedance line in a conventional straight-line design is significantly affected by the distribution of warp and weft yarns in the fiberglass cloth: when the impedance line coincides with the warp and weft yarns (i.e., warp or weft bundles) of the fiberglass cloth in PP, the effective dielectric constant DK is relatively large, resulting in a higher impedance value; when the impedance line falls in the gaps between warp and weft yarns (i.e., between two adjacent warp bundles or two adjacent weft bundles), the effective dielectric constant DK is relatively small, resulting in a lower impedance value. The different positions of the same impedance line and the fiberglass cloth in PP directly cause fluctuations in the impedance value of the Kobond device. Depending on the different layering designs, this can affect the impedance value by up to 8%, and in severe cases, it can cause impedance failure. Utility Model Content
[0005] In order to overcome the problem that the impedance value of the PCB impedance wire is greatly affected by the fluctuation of dielectric constant and is prone to failure because it is perpendicular or parallel to the warp and weft directions of the PP fiberglass cloth, the present invention provides a wiring structure for the PCB impedance wire.
[0006] The technical solution of this utility model is as follows:
[0007] A wiring structure for PCB impedance lines includes a PP insulating layer and several PCB impedance lines uniformly arranged on the PP insulating layer. The PCB impedance lines are straight lines, and the angle between the wiring direction of the PCB impedance lines and the warp or weft yarn bundles of the fiberglass cloth of the PP insulating layer is 4-6°.
[0008] As a preferred embodiment of this utility model, the angle between the wiring direction of the PCB impedance Kobon impedance line and the warp or weft bundle of the fiberglass cloth is 5°.
[0009] As a preferred embodiment of this utility model, the angle between the wiring direction of the PCB impedance Kobon impedance line and the warp or weft bundle of the fiberglass cloth is 4°.
[0010] As a preferred embodiment of this utility model, the angle between the wiring direction of the PCB impedance Kobon impedance line and the warp or weft bundle of the fiberglass cloth is 6°.
[0011] As a preferred embodiment of this utility model, the fiberglass cloth has warp and weft bundles that are perpendicular to each other, and the warp and weft bundles are woven to form a uniform grid.
[0012] As a preferred embodiment of this utility model, the resin of the PP insulating layer is filled in the mesh and on the surface of the fiberglass cloth.
[0013] As a preferred embodiment of this utility model, the dielectric constant DK of the fiberglass cloth is 4.5-6.
[0014] As a preferred embodiment of this utility model, the dielectric constant DK of the resin is 2-3.5.
[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0016] This utility model provides a wiring structure for PCB impedance lines. By setting the angle between the wiring direction of the PCB impedance lines and the warp or weft bundles of the fiberglass cloth in the PP insulation layer to 4-6°, it avoids the impedance lines overlapping with the warp and weft yarns of the fiberglass cloth, as well as the impedance lines falling into the gaps between the warp and weft yarns of the fiberglass cloth. This reduces the influence of the fiberglass cloth warp and weft yarns (i.e., the fiberglass effect) on the impedance of the impedance lines, improves the impedance qualification rate, and can accurately represent the impedance value of the impedance lines within the PCB board. At the same time, without changing the PCB panel design or increasing production costs, it can replace the existing solution simply by adjusting the angle of the impedance lines, ensuring production efficiency and cost control, and has strong practical application value. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the wiring structure of the PCB impedance line in the prior art.
[0019] Figure 2 This is a schematic diagram of the wiring structure of the PCB impedance Kobon impedance line in one embodiment of this utility model.
[0020] In the diagram,
[0021] 1. PP insulation layer; 11. Fiberglass cloth; 111. Warp bundle; 112. Weft bundle; 2. PCB impedance Kobon impedance wire. Detailed Implementation
[0022] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. It is also declared that the embodiments described below are only for explaining this utility model and are not intended to limit this utility model.
[0023] It should be noted that the terms "installation," "setting," "connection," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Indications of orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used in the application's product, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. "Several" means one or more, unless otherwise explicitly defined.
[0024] Please see Figure 1In existing technology, PP is used as an insulating layer above or below the PCB impedance line 2. The PCB impedance line 2 is usually designed as a straight line, and its routing direction is perpendicular or parallel to the warp and weft directions of the fiberglass cloth 11 in the PP. However, this conventional straight-line design of the PCB impedance line 2 is significantly affected by the distribution of the warp and weft of the fiberglass cloth 11: when the impedance line coincides with the warp and weft of the fiberglass cloth 11 in the PP (i.e., warp bundle 111 or weft bundle 112), the effective dielectric constant DK is relatively large, resulting in a larger impedance value; when the impedance line falls in the gap between the warp and weft (i.e., between two adjacent warp bundles 111 or two adjacent weft bundles 112), the effective dielectric constant DK is relatively small, resulting in a smaller impedance value. The different positional distribution of the same impedance line and the fiberglass cloth 11 in the PP directly causes fluctuations in the impedance value. Depending on the different stack-up designs, this can affect the impedance value by up to 8%, and in severe cases, it can cause impedance failure.
[0025] Please see Figure 2 To address the aforementioned issues, embodiments of this utility model provide a wiring structure for PCB impedance lines, comprising a PP insulating layer 1 and several PCB impedance lines 2 uniformly distributed on the PP insulating layer 1. The PCB impedance lines 2 are straight lines, and the angle between the wiring direction of the PCB impedance lines 2 and the warp bundles 111 or weft bundles 112 of the fiberglass cloth 11 of the PP insulating layer 1 is 4-6°. By setting the angle between the routing direction of the PCB impedance line 2 and the warp bundle 111 or weft bundle 112 of the PP insulation layer 1 to 4-6°, the overlap of the impedance line with the warp and weft yarns of the fiberglass cloth 11 (i.e., warp bundle 111 or weft bundle 112) and the impedance line falling in the gaps between the warp and weft yarns of the fiberglass cloth 11 (i.e., between two adjacent warp bundles 111 or two adjacent weft bundles 112) are avoided. This reduces the drastic change in the effective dielectric constant DK, significantly reduces the impact of the fiberglass effect on impedance, and reduces impedance value fluctuation from the maximum of 8% in the prior art to a more stable range, thus avoiding impedance failure. Because the effective dielectric constant sensed by the impedance line is more uniform, its impedance value can more accurately represent the impedance value of the actual impedance line in the PCB board, improving the accuracy of impedance control and thus improving the product qualification rate. At the same time, without changing the PCB panel design or increasing production costs, the existing solution can be replaced simply by adjusting the angle of the impedance line, ensuring production efficiency and cost control, and has strong practical application value.
[0026] In a preferred embodiment, the PP insulating layer 1 is composed of a mixture of resin and fiberglass cloth 11. The fiberglass cloth 11 has mutually perpendicular warp bundles 111 and weft bundles 112, which are woven into a uniform mesh. The resin fills the mesh and the surface of the fiberglass cloth 11. The dielectric constant DK of the fiberglass cloth 11 is 4.5-6, and the dielectric constant DK of the resin is 2-3.5.
[0027] In a preferred embodiment, the wiring direction of the PCB impedance line 2 is at a 5° angle to the warp bundle 111 or weft bundle 112 of the fiberglass cloth 11. This angle design minimizes the overlap between the impedance line and the warp bundle 111 or weft bundle 112, while also preventing it from falling entirely into the gaps between the warp and weft yarns. This ensures that the impedance line is evenly distributed in the mixing area of the fiberglass cloth 11 and the resin, effectively balancing the difference in dielectric constant between the two, resulting in a more stable impedance value, improved impedance pass rate, and accurate representation of the actual impedance value of the impedance line within the PCB board. Furthermore, the small 5° angle offset does not change the PCB panel layout, does not affect production efficiency, and achieves a cost-free improvement.
[0028] In a suboptimal embodiment, the angle between the routing direction of the PCB impedance line 2 and the warp bundle 111 or weft bundle 112 of the fiberglass cloth 11 is 4° or 6°. While the 4° and 6° angles are not as effective as the 5° angle, they still prevent extreme overlap or complete gaps between the impedance line and the warp and weft bundles 112, reducing the impact of the fiberglass effect on impedance. Compared to the vertical or parallel designs in the prior art, these two angles effectively reduce impedance fluctuations, ensuring the impedance pass rate remains within acceptable limits. Furthermore, the smaller angles of 4° and 6° do not affect PCB panel utilization, require no additional cost, and can serve as an alternative to the 5° solution, improving the flexibility and applicability of the technical solution.
[0029] In a sub-preferred embodiment, the angle between the wiring direction of the PCB impedance line 2 and the warp bundle 111 or weft bundle 112 of the fiberglass cloth 11 is 6°.
[0030] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
[0031] The present utility model patent has been described above with reference to the accompanying drawings. Obviously, the implementation of the present utility model patent is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present utility model patent, or the direct application of the inventive concept and technical solution of the present utility model patent to other occasions without modification, are all within the protection scope of the present utility model.
Claims
1. A wiring structure for PCB impedance lines, characterized in that, It includes a PP insulating layer and several PCB impedance lines evenly distributed above or below the PP insulating layer. The PCB impedance lines are straight lines, and the angle between the routing direction of the PCB impedance lines and the warp or weft yarn bundles of the fiberglass cloth of the PP insulating layer is 4-6°.
2. The wiring structure of the PCB impedance Kobond impedance line according to claim 1, characterized in that, The angle between the wiring direction of the PCB impedance Kobon impedance line and the warp or weft bundle of the fiberglass cloth is 5°.
3. The wiring structure of the PCB impedance Kobond impedance line according to claim 1, characterized in that, The angle between the wiring direction of the PCB impedance Kobon impedance line and the warp or weft bundle of the fiberglass cloth is 4°.
4. The wiring structure of the PCB impedance Kobond impedance line according to claim 1, characterized in that, The angle between the wiring direction of the PCB impedance Kobon impedance line and the warp or weft bundle of the fiberglass cloth is 6°.
5. The wiring structure of the PCB impedance Kobond impedance line according to claim 1, characterized in that, The fiberglass cloth has warp and weft bundles that are perpendicular to each other, and the warp and weft bundles are woven together to form a uniform grid.
6. The wiring structure of the PCB impedance Kobond impedance line according to claim 5, characterized in that, The resin of the PP insulation layer fills the mesh and the surface of the fiberglass cloth.
7. The wiring structure of the PCB impedance Kobond impedance line according to claim 6, characterized in that, The dielectric constant DK of the fiberglass cloth is 4.5-6.
8. The wiring structure of the PCB impedance Kobond impedance line according to claim 6, characterized in that, The dielectric constant DK of the resin is 2-3.5.