Methods, systems, devices, and media for improving signal integrity of flexible circuit boards

Abstract

This invention provides a method, system, device, and medium for improving signal integrity on flexible circuit boards, comprising: determining the number of segments included in a trace, wherein there is an angle change between adjacent segments; after determining the number of segments, setting the angle of the grid according to the trace, including: determining whether the angle change between adjacent segments of the trace exceeds a preset angle value; if not, determining the longest segment of the trace, and setting the angle of the grid within the reference area of ​​the trace according to the angle of that segment; if so, setting the angle of the grid according to the relationship between the length of the trace and the preset length, and the trace itself; wherein setting the angle of the grid according to the angle of the segment specifically means: ensuring that the extension direction of one diagonal of the grid is consistent with the extension direction of the segment. The technical solution of this invention considers manufacturing tolerances and sets the grid angle according to bending without affecting signal integrity, making the grid setting simple and convenient.

Description

Technical Field

[0001] This invention relates to the field of flexible circuit board technology, and in particular to a method, system, device and medium for improving signal integrity of flexible circuit boards. Background Technology

[0002] The purpose of impedance control on flexible circuit boards is to ensure stable current transmission in the circuit and reduce signal reflection and interference. Impedance mismatch can lead to problems such as signal loss, clock skew, and signal overlap, and even affect the stability and reliability of the entire system. Therefore, impedance control is particularly important for circuits that require high-speed signal transmission or high frequency.

[0003] For impedance control purposes, a grid ground is typically used as the reference ground in flexible circuit boards. This helps control the impedance of signal lines and ensures the quality of signal transmission. Furthermore, a grid ground allows for greater flexibility in circuit design and assembly. However, for the grid ground impedance model, whether single-ended or differential traces, they should be routed as close as possible to the central intersection of the grid ground diamond structure and maintain strict symmetry.

[0004] In practical engineering applications, to avoid the effects of stress, the traces are routed according to the FPC's outline. Therefore, when the FPC outline has multiple bending areas, the FPC traces will also have multiple bends. With such bends in the traces, if the ground plane remains at a constant angle, the impedance will no longer match, resulting in poor signal transmission quality. Summary of the Invention

[0005] This invention provides a method, system, device, and medium for improving signal integrity on flexible circuit boards, in order to solve the problem of impedance mismatch in the ground plane when the traces are bent in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0007] According to a first aspect of the present invention, a method for improving signal integrity of a flexible circuit board is provided, the flexible circuit board comprising: a grid ground layer and a trace layer distributed longitudinally; the trace layer includes at least one trace; the grid ground layer includes a plurality of first copper lines and a plurality of second copper lines, the plurality of first copper lines being parallel to each other in a first direction, the plurality of second copper lines being parallel to each other in a second direction, and the plurality of first copper lines and the plurality of second copper lines intersecting to form a plurality of grids;

[0008] The method includes:

[0009] Determine the number of segments included in the routing, with angular changes between adjacent segments;

[0010] Once the number of segments is determined, the angle of the grid is set according to the routing, specifically including:

[0011] Determine whether the angle change between adjacent segments of the trace exceeds a preset angle value;

[0012] If not, determine the longest segment of the trace, and set the angle of the grid within the reference area of ​​the trace based on the angle of that segment;

[0013] If so, the angle of the grid is set according to the relationship between the length of the trace and the preset length, as well as the trace itself;

[0014] Specifically, setting the angle of the grid according to the angle of the segment means making the extension direction of one diagonal of the grid consistent with the extension direction of the segment.

[0015] Optionally, the angle of the grid can be set based on the relationship between the length of the trace and a preset length, as well as the trace itself. Specifically, this includes:

[0016] If the length of the trace is less than the preset length, then the longest segment of the trace is determined, and the angle of the grid in the reference area of ​​the trace is set according to the angle of that segment;

[0017] If the length of the trace is greater than or equal to the preset length, then it includes:

[0018] The longest segment of the trace is determined, and the angle of the grid within its reference area is set based on the angle of that segment.

[0019] Calculate the remaining length of the trace and determine whether it exceeds the preset length. If it does, continue to execute: determine the longest segment of the trace, and set the angle of the grid in the reference area according to the angle of the segment until the remaining trace length is less than the preset length or the trace has a remaining segment. At this time, set the angle of the grid in the remaining reference area according to the angle of the longest segment or the remaining segment of the remaining trace.

[0020] Optionally, after the number of segments is determined, the angle between the grid set according to the routing is further included:

[0021] Starting from one end of the trace, each segment is judged one by one to determine whether the angle change between it and the next segment exceeds a preset angle value. For consecutive segments whose angle change between each other does not exceed the preset angle value, they are named as a segment of the same type.

[0022] The specific steps to determine the longest segment of the routing are as follows: determine the same type of segment of the routing and the longest segment among the segments; when the longest segment is of the same type, the specific steps to set the angle of the grid in the reference area of ​​the same type of segment based on the angle of the segment are as follows: determine the longest segment of the same type of segment, and set the angle of the grid in the reference area of ​​the same type of segment based on the angle of the segment.

[0023] The process continues until the remaining trace length is less than the preset length or until a segment of the trace remains. Specifically, this means: until the remaining trace length is less than the preset length, or until a segment of the trace remains, or until a segment of the same type remains. When a segment of the same type remains, the angle of the grid within the remaining reference area is set based on the angle of the longest segment of the remaining segment of the same type.

[0024] Optionally, the method for determining the reference region is as follows:

[0025] One end of the trace and the point where the angle of the outline of the flexible circuit board changes near the end of the trace form one boundary of the reference area; the other end of the trace and the point where the angle of the outline of the flexible circuit board changes near the end of the trace form another boundary of the reference area, and the area between the two boundaries forms the reference area of ​​the trace.

[0026] Wherein, when one of the endpoints of the trace is the start or end point of the trace, the boundary corresponding to the endpoint is formed by the outline points of the two sides of the flexible circuit board that are laterally corresponding to the endpoint.

[0027] Optionally, before determining the number of segments included in the trace, the method further includes: determining a reference trace, specifically including:

[0028] Determine the number of the traces; if the number of the traces is one, then determine that the trace is a reference trace.

[0029] If the number of the traces is greater than one, it is determined whether differential signal lines are included. If so, the differential signal lines are determined as reference traces; otherwise, the trace with the fastest signal transmission speed is determined as the reference trace.

[0030] Correspondingly, determining the number of segments included in the trace specifically involves determining the number of segments included in the reference trace;

[0031] The angle of the grid is set according to the routing, specifically: the angle of the grid is set according to the reference routing.

[0032] Optionally, when the differential signal line is determined to be a reference trace, the method is executed for one of the differential signal lines;

[0033] Specifically, when the angle change between adjacent segments of the trace does not exceed a preset angle value, and the length of the trace is greater than or equal to the preset length, the reference area is determined using two differential signal lines, specifically including:

[0034] The endpoints on the same side of the traces corresponding to the two differential signal lines each form a boundary of the reference area with a point on the flexible circuit board near that endpoint and located on one side of the differential signal line where the angle of the outline changes; the endpoints on the other side of the traces corresponding to the two differential signal lines each form another boundary of the reference area with a point on the flexible circuit board near that endpoint and located on one side of the differential signal line where the angle of the outline changes.

[0035] Optionally, after setting the angle of the grid according to the reference trace, the method further includes: setting the position of the grid according to the reference trace, specifically including:

[0036] If the reference trace is a differential signal line, the vertical projection of one diagonal of the grid coincides with the extension direction of the intermediate axis of the differential signal line; otherwise, the vertical projection of one diagonal of the grid coincides with the extension direction of the reference trace.

[0037] Optionally, the preset length is determined by the speed of signal transmission in the trace and the rise time of the transmitted signal.

[0038] Optionally, determining the number of segments included in the trace specifically includes: taking one end of the trace as the starting point, and based on the change in the trace direction, determining that the segments before and after the direction change are different segments of the trace.

[0039] Optionally, after setting the angle of the grid according to the routing, the method further includes:

[0040] On the grid layer, a third copper wire is set in the reference area corresponding to the segment of the trace located in the corner area of ​​the flexible circuit board, and the vertical projection of the third copper wire coincides with the segment of the trace.

[0041] Optionally, the first direction is perpendicular to the second direction.

[0042] Optionally, the trace layer includes a copper mesh that avoids the trace.

[0043] Optionally, the position and direction of the grid copper are consistent with the position and direction of the grid formed by the intersection of the first copper line and the second copper line at the perpendicular corresponding position.

[0044] According to a second aspect of the present invention, a system for improving signal integrity of a flexible circuit board is provided, the flexible circuit board comprising: a grid ground layer and a trace layer distributed longitudinally; the trace layer comprising at least one trace; the grid ground layer comprising a plurality of first copper lines and a plurality of second copper lines, the plurality of first copper lines being parallel to each other in a first direction, the plurality of second copper lines being parallel to each other in a second direction, and the plurality of first copper lines and the plurality of second copper lines intersecting to form a plurality of grids;

[0045] The system includes:

[0046] The segment quantity determination module is used to determine the number of segments included in the routing, where there is an angle change between adjacent segments;

[0047] A grid angle setting module, used to set the angle of the grid according to the trace; specifically including:

[0048] The preset angle value judgment module is used to determine whether the angle change between adjacent segments of the trace exceeds the preset angle value.

[0049] The first setting module is used to determine the longest segment of the routing line when the angle change between adjacent segments of the routing line does not exceed a preset angle value, and set the angle of the grid in the reference area of ​​the routing line according to the angle of the segment.

[0050] The second setting module is used to set the angle of the grid according to the relationship between the length of the trace and the preset length, when the angle change between adjacent segments of the trace exceeds a preset angle value;

[0051] Specifically, setting the angle of the grid according to the angle of the segment means making the extension direction of one diagonal of the grid consistent with the extension direction of the segment.

[0052] According to a third aspect of the present invention, an electronic device is provided, comprising:

[0053] processor;

[0054] And, memory used to store processor-executable instructions;

[0055] The processor implements the steps in the method described above by running the executable instructions.

[0056] According to a fourth aspect of the present invention, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0057] The method, system, device, and medium for improving signal integrity of flexible circuit boards provided by this invention compare the angle change between adjacent segments of the trace with a preset angle value, which takes manufacturing tolerances into account. If no angle exceeds the preset value, the grid angle is set based on the angle of the longest segment. If an angle exceeds the preset value, it indicates a significant bend in the trace; in this case, the relationship between the trace length and a preset length is determined to establish the grid angle. The preset length takes into account the impact of trace length on signal integrity. In summary, this method considers the impact of manufacturing tolerances on trace angles and comprehensively considers both trace bends and trace lengths to set the grid angle. It sets the grid angle based on bends without affecting signal integrity, making the grid angle setting simple and convenient, and ensuring controllable impedance changes in the traces, thus guaranteeing signal integrity. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 This is a partial top view of the wiring layer of a flexible circuit board according to an embodiment of the present invention;

[0060] Figure 2 This is a partial top view of the lower network layer of a flexible circuit board according to an embodiment of the present invention;

[0061] Figure 3 This is a partial top perspective view of a flexible circuit board according to an embodiment of the present invention;

[0062] Figure 4 This is a flowchart of a method for improving signal integrity on a flexible circuit board according to an embodiment of the present invention;

[0063] Figure 5 This is a schematic diagram of the segment division of a trace according to an embodiment of the present invention;

[0064] Figure 6 This is a schematic diagram of the segmentation of a trace according to another embodiment of the present invention;

[0065] Figure 7 This is a naming diagram of similar segments according to an embodiment of the present invention;

[0066] Figure 8 This is a schematic diagram showing the division of the reference area for the routing of a trace according to an embodiment of the present invention;

[0067] Figure 9 This is a schematic diagram showing the division of the reference area for the routing of a trace according to another embodiment of the present invention;

[0068] Figure 10 This is a schematic diagram of the routing and mesh positions according to another embodiment of the present invention;

[0069] Figure 11 This is a schematic diagram of the mesh copper arrangement on the trace layer according to another embodiment of the present invention;

[0070] Figure 12 This is a schematic diagram of a system for improving signal integrity on a flexible circuit board according to an embodiment of the present invention;

[0071] Figure 13 This is a schematic diagram of an electronic device according to an embodiment of the present invention;

[0072] Explanation of reference numerals in the attached figures:

[0073] 1-Flexible circuit board;

[0074] 11-Tracking layer;

[0075] 111 - Wiring;

[0076] 112 - First Boundary;

[0077] 113 - Second Boundary;

[0078] 114 - Third Boundary;

[0079] 115 - Fourth Boundary;

[0080] 116 - Fifth Boundary;

[0081] 117-Mesh Copper;

[0082] 12-Network Strata;

[0083] 121 - First copper wire;

[0084] 122 - Second copper wire;

[0085] Module for determining the number of segments 21;

[0086] 22-Grid Angle Setting Module;

[0087] 221-Preset Angle Value Judgment Module;

[0088] 222 - First Setup Module;

[0089] 223 - Second Settings Module;

[0090] 31-processor,

[0091] 32-Internal bus,

[0092] 33-Network interface,

[0093] 34-Memory,

[0094] 35 - Memory. Detailed Implementation

[0095] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0096] In the description of this invention, it should be understood that the terms "upper part", "lower part", "upper end", "lower end", "lower surface", "upper surface", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element 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 of the invention.

[0097] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0098] In the description of this invention, "a plurality of" means multiple, such as two, three, four, etc., unless otherwise explicitly specified.

[0099] In the description of this invention, unless otherwise explicitly specified and limited, the term "connection" and other such terms should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the components; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0100] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0101] In one embodiment, a method for improving signal integrity on a flexible circuit board is provided. Please refer to [reference needed]. Figure 1 The flexible circuit board 1 includes, along its longitudinal direction, a grid ground layer and a trace layer. Figure 1 This is a top view of the wiring layer portion of a flexible circuit board. Figure 2 This is a top view of the grid-like ground plane portion of the flexible circuit board. Figure 3 This is a partial top perspective view of the flexible circuit board; the positional relationship between the ground plane and the trace layer is not shown. The trace layer includes at least one trace 111, such as... Figure 1 As shown; the grid stratum includes multiple first copper wires 121 and multiple second copper wires 122. The multiple first copper wires 121 are parallel to each other in a first direction, and the multiple second copper wires 122 are parallel to each other in a second direction. The multiple first copper wires and multiple second copper wires intersect to form several grids, such as... Figure 2 As shown.

[0102] Please refer to Figure 4 The method includes:

[0103] S11: Determine the number of segments included in the routing, with angle changes between adjacent segments.

[0104] Specifically, based on the change in the routing direction, it is determined that the segments before and after the change in direction are different segments of the routing.

[0105] As one implementation method, the number of segments included in the trace can be determined after the trace is drawn. Starting from one end of the trace, the direction of the trace is detected. When the direction of the trace changes, the segment before the position of change is defined as a segment. Then the detection is continued until the other end of the trace.

[0106] As another implementation, the number of segments included in the trace can also be determined during the trace drawing process. At the beginning of the trace drawing, the number of segments included in the trace is 1. During the trace drawing process, when the direction of the drawn trace changes, the number of segments included in the trace is increased by 1 until the trace drawing is completed.

[0107] Please refer to Figures 5-6 ,like Figure 5 or Figure 6 The trace shown includes 5 segments, starting from one end of the trace and ending at the other, namely: ①, ②, ③, ④, and ⑤.

[0108] S12: After the number of segments is determined, the grid angle is set according to the routing, specifically including:

[0109] S121: Determine whether the angle change between adjacent segments of the trace exceeds the preset angle value.

[0110] As one implementation method, the preset angle value can be any value between 0° and 20°, such as 10°, and the preset angle value is determined based on manufacturing tolerances.

[0111] As an example, please continue to refer to Figure 5 ,like Figure 5 In the routing shown, the angle values ​​between ① and ②, between ② and ③, between ③ and ④, and between ④ and ⑤ are all less than the preset angle value. That is, the angle change value between adjacent segments of the routing does not exceed the preset angle value, then proceed to S122.

[0112] In different embodiments, if the number of trace segments is 1, this is also included in the case, and then proceed to S122.

[0113] As another example, please continue to refer to Figure 6 ,like Figure 6 In the routing shown, the angle values ​​between ① and ②, between ② and ③, between ③ and ④, and between ④ and ⑤ are all greater than the preset angle value. That is, the angle change value between adjacent segments of the routing exceeds the preset angle value, then proceed to S123.

[0114] Of course, in the above embodiments, the number of angle change values ​​between adjacent segments of the wiring that exceed the preset angle value exceeds one. In different embodiments, as long as the angle change value between any two adjacent segments exceeds the preset angle value, it is determined to be this situation, and then proceed to S123.

[0115] S122: If not, determine the longest segment of the trace and set the angle of the grid in the reference area of ​​the trace based on the angle of that segment.

[0116] Specifically, setting the angle of the grid according to the angle of the segment means making the extension direction of one diagonal of the grid consistent with the extension direction of the segment.

[0117] As an example, the first direction of the first copper wire is perpendicular to the second direction of the second copper wire, that is, the resulting grid is a square grid, such as... Figure 2 As shown; furthermore, the angles of the traces and the grid can both be referenced to the horizontal direction. That is, the angle of the trace is the angle between the direction of the trace and the horizontal direction, and the angle of the grid is the angle between the first copper line, the second copper line, and the horizontal direction. Therefore, the grid angle is set according to the angle of this segment as follows: if the angle of this trace segment is 'a', then the angle of the first copper line is 45°+a, and the angle of the second copper line is 135°+a.

[0118] In different embodiments, the first direction and the second direction may not be perpendicular, and the resulting mesh may be a rhomboid mesh.

[0119] Preferably, the spacing between adjacent first copper lines and the spacing between adjacent second copper lines are the same, and the spacing between the two is the same.

[0120] In the case of S122, if the direction of the trace changes very little (less than the preset angle value) or remains unchanged, the corresponding grid for that trace can be set to the same angle without affecting signal integrity. If the number of segments is greater than one, the angle of the longest segment is used as a reference to set the grid angle, ensuring that the grid angle matches the trace angle to the maximum extent.

[0121] Of course, the above S122 also includes the case where the number of segments is 1. In this case, the longest segment of the trace is the trace itself, and the angle of the grid in the reference area of ​​the trace is set according to the angle of the trace.

[0122] S123: If applicable, the angle of the grid is set according to the relationship between the length of the trace and the preset length, as well as the trace itself.

[0123] As one implementation method, the preset length is determined based on whether this length affects signal integrity. When the signal transmission delay in the trace is greater than 20% of the signal rise time, the signal waveform will be significantly affected, resulting in ringing, which will lead to a decrease in signal stability and reliability. Assuming the transmission speed of a signal is V (in / ns), the rise time is Tr (ns), the trace length is L (in), and the signal delay is TD (ns), Tr*20% ≤ TD = L / V, that is, when 0.2Tr·V ≤ L, the impact on signal integrity is relatively small, and vice versa.

[0124] In one embodiment, the preset length is determined by the speed of signal transmission in the trace and the rise time of the transmitted signal. For example, the preset length can be set to 0.2Tr·V.

[0125] In different implementations, in order to further improve signal integrity, the preset length can be set with a margin, that is, set to be smaller than 0.2Tr·V, such as Tr·V / 6.

[0126] Determine the relationship between the trace length and the preset length, and set the grid angle accordingly. This specifically includes:

[0127] S1231: If the length of the trace is less than the preset length, it means that although the trace is bent, the impact of this segment on signal integrity is relatively small. In this case, the angle of the grid corresponding to this segment of the trace does not need to be changed according to the angle of the trace, and the same angle can be used. In this case, you can refer to the angle setting method in S122, that is: determine the longest segment of the trace, and set the angle of the grid in the reference area of ​​the trace according to the angle of this segment.

[0128] S1232: If the length of the trace is greater than or equal to the preset length, it means that the trace has a significant impact on signal integrity. In this case, the angle of the grid needs to be changed according to the angle of the trace to ensure impedance matching, thereby reducing signal reflection and distortion and improving signal integrity.

[0129] If the trace length is greater than or equal to the preset length, the grid angle needs to be adjusted according to the trace angle, specifically including:

[0130] S12321: Determine the longest segment of the trace and set the angle of the grid within its reference area based on the angle of that segment.

[0131] As an example, please continue to refer to Figure 6 The trace consists of 5 segments, starting from one end: ①, ②, ③, ④, and ⑤. Assuming the trace length is greater than the preset length, and ① is the longest segment, the angle of the grid within the reference area of ​​① is set according to the angle of ①, so that the extension direction of one diagonal of the grid is the same as the extension direction of ①.

[0132] S12322: Calculate the remaining trace length and determine if it exceeds the preset length. If it does, continue execution: Determine the longest segment among the remaining trace segments and set the angle of the grid in its reference area based on the angle of that segment until the remaining trace length is less than the preset length or a trace segment remains. If the remaining trace length is less than the preset length, set the angle of the grid in the remaining reference area based on the longest segment among the remaining traces; if a trace segment remains, set the angle of the grid in the remaining reference area based on the angle of the remaining segment.

[0133] As an example, please continue to refer to Figure 6 After setting the angles of the grid within the reference area ①, calculate the length of the remaining traces, which is the total length of ②, ③, ④, and ⑤. Determine if it exceeds the preset length. If it does, identify the longest segment. Assuming ③ is the longest remaining trace segment, set the angle of the grid within the reference area of ​​③ based on the angle of ③, ensuring that the extension direction of one diagonal of the grid is the same as the extension direction of ③. Then, calculate the length of the remaining traces again, which is the total length of ②, ④, and ⑤, and determine if it exceeds the preset length. If it does not exceed the preset length, identify the longest segment. Assuming ② is the longest segment, set the angle of the grid within the remaining reference areas (i.e., the reference areas corresponding to ②, ④, and ⑤) based on the angle of ②.

[0134] The above Figure 6In the example shown, segments ② and ④ of the corner region are straight segments. In different embodiments, the segments of the corner region can also be arc-shaped segments. When the segment of the corner region is an arc-shaped segment, and the length of the arc-shaped segment is greater than a preset length, which affects signal integrity, preferably, the arc-shaped segment can be divided into N equal parts, and the angle of the grid in each equal part of the reference area can be set separately. The angle of the grid in each equal part of the reference area is based on the tangent direction of the arc-shaped segment.

[0135] In one embodiment, after the number of segments is determined, the relationship between this determination and the angle of the grid set according to the routing also includes:

[0136] S21: Starting from one end of the trace, each segment is judged one by one to determine whether the angle change between it and the next segment exceeds the preset angle value. For consecutive segments whose angle change between each other does not exceed the preset angle value, they are named as a segment of the same type.

[0137] Based on the settings in S21 above, the longest segment of the routing is determined by: determining the same type of routing segments and the longest segment among them; when the longest segment is of the same type, the angle of the grid in the reference area of ​​the same type of segment is set according to the angle of that segment, specifically by: determining the longest segment of the same type of segment and setting the angle of the grid in the reference area of ​​the same type of segment according to the angle of that segment.

[0138] The process continues until the remaining trace length is less than the preset length, or until a segment of the trace remains. Specifically, this means until the remaining trace length is less than the preset length, or until a segment of the trace remains, or until a segment of the same type remains. When a segment of the same type remains, the angle of the longest segment of that type is used to set the angle of the grid within the remaining reference area. For the grid angle setting when the remaining trace length is less than the preset length or when a segment of the trace remains, please refer to the description in S12322; it will not be repeated here.

[0139] As an example, please refer to Figure 7 The routing consists of 6 segments, numbered ①, ②, ③, ④, ⑤, and ⑥, starting from one end. Starting from side ①, each segment is evaluated individually. If the angle changes between ① and ②, and between ② and ③, do not exceed a preset angle value, then ①, ②, and ③ are named as a single segment (e.g., the first single segment). If the angle change between ③ and ④ exceeds the preset angle value, then no segment is named. If the angle change between ④ and ⑤ does not exceed the preset angle value, then ④ and ⑤ are named as another single segment (e.g., the second single segment). If the angle change between ⑤ and ⑥ exceeds the preset angle value, then no segment is named.

[0140] After naming segments of the same type, these segments can be treated as a whole for determining the angle settings of the mesh. The segment with the longest length among the determined routing segments or remaining routing segments will be selected. The routing segments or remaining routing segments may contain only segments of the same type, only segments of the same type, or both. In this case, the longest segment among the determined segments is the longest segment among the determined routing segments. Please continue to refer to [reference needed]. Figure 7 Assuming the trace length exceeds the preset length, the first step in determining the longest length is as follows: The trace includes both segments of the same type and segments of the same type. The judgment is then made between the longest segment of the same type and the longest segment of the same type. Assuming the longest segment of the same type is the first segment of the same type, the angle of the grid within the reference area corresponding to the first segment of the same type is set. This setting can be based on the angle of the longest segment of the first type of the same type. Assuming segment ① is the longest segment of the first type of the same type, the angle of the grid within the reference area of ​​the first segment of the same type is set based on the angle of segment ①. The principle for setting the grid in the reference area of ​​the remaining traces is similar and will not be elaborated here.

[0141] In the above embodiments, after naming the same type of segments, the angle settings of the grids of the same type of segments can be performed together without having to set them one by one, which further simplifies the angle setting of the grids.

[0142] In one embodiment, please refer to Figure 8 The method for determining the reference area is as follows:

[0143] One end of the trace and the points on either side of the flexible circuit board where the angle changes form a boundary of the reference area; the other end of the trace and the points on either side of the flexible circuit board where the angle changes form another boundary of the reference area. The area between these two boundaries forms the reference area for this trace, that is, the area enclosed by the two boundaries and the two sides of the flexible circuit board 1 is the reference area for this trace. Figure 8 Taking the second trace ② as an example, its two ends and the points where the angle of the outline of the flexible circuit board changes near the two ends respectively form the first boundary 112 and the second boundary 113 of the reference area. The first boundary 112, the second boundary 113 and the two sides of the flexible circuit board 1 enclose the reference area of ​​the trace.

[0144] When one end of the trace is the start or end point of the trace, such as Figure 8 The left endpoint of ① and the right endpoint of ③ shown are defined by the boundary points on both sides of the flexible circuit board corresponding to the endpoint in the horizontal direction. Figure 8 The third boundary 114 is shown in the figure.

[0145] In addition, once the boundaries of the reference areas of the two adjacent segments of the trace are determined, the reference area of ​​the trace is determined, which is the area between the two segments. At this point, it is no longer necessary to use boundary lines for determination.

[0146] In one embodiment, before determining the number of segments included in the trace, the method further includes: determining a reference trace, specifically including:

[0147] Determine the number of traces. If the number of traces is one, then determine the trace as the reference trace.

[0148] If the number of traces is greater than one, it is determined whether differential signal lines are included. If differential signal lines are included, they are generally the primary traces, and thus the differential signal lines are designated as the reference traces. If not, the trace with the fastest signal transmission speed is designated as the reference trace. Correspondingly, subsequent steps are performed on the reference trace.

[0149] In the above embodiments, a reference trace is determined, and the angle of the grid is set based on the reference trace, that is, the angle of the grid is based on the most important trace.

[0150] Specifically, determining the number of segments included in the trace involves: determining the number of segments included in the reference trace; setting the grid angle based on the trace involves: setting the grid angle based on the reference trace.

[0151] In one embodiment, when the reference trace is a differential signal line, the determination of the number of trace segments, whether the angle change between adjacent trace segments exceeds a preset angle value, and the relationship between the trace length and the preset length, as described in the above embodiments, can be performed on only one differential signal line when determining the longest segment among the trace segments, similar segments, or remaining trace segments. However, in this embodiment, when the angle change between adjacent trace segments exceeds a preset angle value, and the trace length is greater than or equal to the preset length, two differential signal lines are used when determining the reference area. Please refer to... Figure 9 Specifically: the endpoints on the same side of the traces corresponding to the two differential signal lines each form a boundary of a reference area with a point on the flexible circuit board near that endpoint and located on one side of the differential signal line where the outline changes angle (e.g., Figure 9 The fourth boundary 115); the other end of the trace corresponding to the two differential signal lines and the point on the flexible circuit board near the end and located on one side of the differential signal line where the outline changes angle form another boundary of the reference area (e.g., Figure 9 The fifth boundary (116) in the middle.

[0152] In the above embodiments, two differential signal lines are used to determine the reference area, which allows for more precise setting of the grid angle. Of course, in different embodiments, since the two differential signal lines are very close together, only one of the differential signal lines can be used to determine the reference area.

[0153] In another embodiment, after setting the grid angle according to the reference trace in S12, the method further includes:

[0154] S31: Set the grid position based on the reference trace, specifically including:

[0155] If the reference trace is a differential signal line, such that the perpendicular projection of one diagonal of the grid coincides with the extension direction of the intermediate axis of the differential signal line, then... Figure 3 As shown; otherwise, make the perpendicular projection of one diagonal of the mesh coincide with the extension direction of the reference trace, as shown. Figure 10 As shown in the figure, only part of the routing and part of the mesh are shown.

[0156] In one embodiment, after setting the grid angle according to the traces in step S12, the method further includes:

[0157] S41: On the grid ground layer, a third copper trace is placed within the reference area corresponding to the trace segment located in the corner region of the flexible circuit board. The vertical projection of the third copper trace coincides with the trace segment. That is, for the trace in the corner region, a copper trace perpendicular to the trace segment is drawn to achieve better impedance matching.

[0158] In another embodiment, the trace layer includes a mesh copper 117 that avoids the traces. Please refer to [reference needed]. Figure 11 The 117 copper mesh can be distributed on both sides of the trace. Laying copper mesh on the trace layer can improve the EMC immunity and signal quality of the flexible circuit board.

[0159] In one implementation, the position and direction of the grid copper are consistent with the position and direction of the grid formed by the intersection of the first copper line and the second copper line at their perpendicular corresponding positions.

[0160] In one embodiment, a system for improving signal integrity of a flexible circuit board is also provided. The flexible circuit board includes a grid ground layer and a trace layer distributed along the longitudinal direction. The trace layer includes at least one trace. The grid ground layer includes multiple first copper lines and multiple second copper lines. The multiple first copper lines are parallel to each other in a first direction, and the multiple second copper lines are parallel to each other in a second direction. The multiple first copper lines and the multiple second copper lines intersect to form a plurality of grids.

[0161] Please refer to Figure 12 The system includes:

[0162] The segment quantity determination module 21 is used to determine the number of segments included in the routing, where there is an angle change between adjacent segments;

[0163] Grid angle setting module 22, which is used to set the angle of the grid according to the trace; specifically includes:

[0164] The preset angle value judgment module 221 is used to determine whether the angle change between adjacent segments of the wiring exceeds the preset angle value.

[0165] The first setting module 222 is used to determine the longest segment of the trace when the angle change between adjacent segments of the trace does not exceed the preset angle value, and set the angle of the grid in the reference area of ​​the trace according to the angle of that segment.

[0166] The second setting module 223 is used to set the angle of the grid according to the relationship between the length of the trace and the preset length, when the angle change between adjacent segments of the trace exceeds the preset angle value.

[0167] Specifically, setting the angle of the grid according to the angle of the segment means making the extension direction of one diagonal of the grid consistent with the extension direction of the segment.

[0168] In one embodiment, the second setting module is specifically used for:

[0169] If the length of the trace is less than the preset length, the longest segment of the trace is determined, and the angle of the grid in the reference area of ​​the trace is set according to the angle of that segment.

[0170] If the trace length is greater than or equal to the preset length, then:

[0171] Determine the longest segment of the trace, and set the angle of the grid within its reference area based on the angle of that segment;

[0172] Calculate the remaining trace length and determine if it exceeds the preset length. If it does, continue: Determine the longest segment of the trace and set the angle of the grid in its reference area based on the angle of that segment until the remaining trace length is less than the preset length or a trace segment remains. At this point, set the angle of the grid in the remaining reference area based on the angle of the longest segment or the remaining segment.

[0173] In another embodiment, the system further includes:

[0174] The same-segment naming module is used to determine the segment number after starting from one end of the trace, and to judge each segment one by one to see if the angle change between it and the next segment exceeds a preset angle value. For consecutive segments whose angle change between each other does not exceed the preset angle value, they are named as the same-segment.

[0175] In another embodiment, the system further includes:

[0176] The reference routing determination module is used to determine reference routing before the number of segments is determined. Specifically, it is used for:

[0177] Determine the number of traces. If the number of traces is one, then determine the trace as the reference trace.

[0178] If the number of traces is greater than one, determine whether differential signal lines are included. If so, determine the differential signal lines as reference traces; otherwise, determine the trace with the fastest signal transmission speed as the reference trace.

[0179] In another embodiment, the system further includes:

[0180] The grid position setting module is used to set the grid position based on the reference trace after the grid angle is set. Specifically, it is used for:

[0181] If the reference trace is a differential signal line, the vertical projection of one diagonal of the grid coincides with the extension direction of the intermediate axis of the differential signal line; otherwise, the vertical projection of one diagonal of the grid coincides with the extension direction of the reference trace.

[0182] In one embodiment, the system further includes:

[0183] The third copper wire setting module is used to set a third copper wire in the reference area corresponding to the segment of the trace located in the corner area of ​​the flexible circuit board on the grid ground layer after the grid angle is set. The vertical projection of the third copper wire coincides with the segment of the trace.

[0184] In one embodiment, the system further includes:

[0185] The grid copper setting module is used to set grid copper on the trace layer after the grid angle is set, and the grid copper avoids the trace position.

[0186] In one embodiment, an electronic device is also provided, please refer to Figure 13At the hardware level, the device includes a processor 31, an internal bus 32, a network interface 33, memory 34, and a storage device 35, and may also include other hardware required for business operations. One or more embodiments of the present invention can be implemented in software, for example, the processor 31 reads the corresponding computer program from the storage device 35 into the storage device 34 and then runs it. Of course, in addition to software implementation, one or more embodiments of the present invention do not exclude other implementation methods, such as logic devices or a combination of hardware and software, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0187] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which can take the form of a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email sending and receiving device, game console, tablet computer, wearable device, or any combination of these devices.

[0188] In a typical configuration, a computer includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0189] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0190] Computer-readable media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0191] In summary, in the above embodiments of the present invention, firstly, the angle of the grid is set based on whether the angle change between adjacent segments of the trace exceeds a preset angle value. Considering the manufacturing tolerances in the production and processing of flexible circuit boards, angle changes that do not exceed the preset angle value are ignored, making the grid setting more convenient and simple. In addition, for angle changes that exceed the preset angle value, the relationship between the length of the trace and the preset length is considered, and the grid angle is set according to the bend without affecting signal integrity, further simplifying the setting of the grid angle.

[0192] The foregoing has described specific embodiments of the invention. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0193] In the description of this specification, the references to terms such as "an embodiment," "an example," "a specific implementation process," and "an example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0194] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for improving signal integrity on a flexible circuit board, characterized in that, The flexible circuit board includes a grid ground layer and a trace layer distributed along the longitudinal direction; the trace layer includes at least one trace; the grid ground layer includes multiple first copper lines and multiple second copper lines, the multiple first copper lines are parallel to each other in a first direction, the multiple second copper lines are parallel to each other in a second direction, and the multiple first copper lines and the multiple second copper lines intersect to form a plurality of grids; The method includes: Determine the number of segments included in the routing, with angular changes between adjacent segments; Once the number of segments is determined, the angle of the grid is set according to the routing, specifically including: Determine whether the angle change between adjacent segments of the trace exceeds a preset angle value; If not, determine the longest segment of the trace, and set the angle of the grid within the reference area of ​​the trace based on the angle of that segment; If so, the angle of the grid is set according to the relationship between the length of the trace and the preset length, as well as the trace itself; Specifically, setting the angle of the grid according to the angle of the segment means making the extension direction of one diagonal of the grid consistent with the extension direction of the segment.

2. The method according to claim 1, characterized in that, The angle of the grid is set based on the relationship between the length of the trace and the preset length, and the trace itself, specifically including: If the length of the trace is less than the preset length, then the longest segment of the trace is determined, and the angle of the grid in the reference area of ​​the trace is set according to the angle of that segment; If the length of the trace is greater than or equal to the preset length, then it includes: The longest segment of the trace is determined, and the angle of the grid within its reference area is set based on the angle of that segment. Calculate the remaining length of the trace and determine whether it exceeds the preset length. If it does, continue to execute: determine the longest segment of the trace, and set the angle of the grid in the reference area according to the angle of the segment until the remaining trace length is less than the preset length or the trace has a remaining segment. At this time, set the angle of the grid in the remaining reference area according to the angle of the longest segment or the remaining segment of the remaining trace.

3. The method according to claim 2, characterized in that, After the number of segments is determined, the relationship between this number and the angle of the grid set according to the routing also includes: Starting from one end of the trace, each segment is judged one by one to determine whether the angle change between it and the next segment exceeds a preset angle value. For consecutive segments whose angle change between each other does not exceed the preset angle value, they are named as a segment of the same type. The specific steps to determine the longest segment of the routing are as follows: determine the same type of segment of the routing and the longest segment among the segments; when the longest segment is of the same type, the specific steps to set the angle of the grid in the reference area of ​​the same type of segment based on the angle of the segment are as follows: determine the longest segment of the same type of segment, and set the angle of the grid in the reference area of ​​the same type of segment based on the angle of the segment. The process continues until the remaining trace length is less than the preset length or until a segment of the trace remains. Specifically, this means: until the remaining trace length is less than the preset length, or until a segment of the trace remains, or until a segment of the same type remains. When a segment of the same type remains, the angle of the grid within the remaining reference area is set based on the angle of the longest segment of the remaining segment of the same type.

4. The method according to claim 2, characterized in that, The method for determining the reference region is as follows: One end of the trace and the point where the angle of the outline of the flexible circuit board changes near the end of the trace form one boundary of the reference area; the other end of the trace and the point where the angle of the outline of the flexible circuit board changes near the end of the trace form another boundary of the reference area, and the area between the two boundaries forms the reference area of ​​the trace. Wherein, when one of the endpoints of the trace is the start or end point of the trace, the boundary corresponding to the endpoint is formed by the outline points of the two sides of the flexible circuit board that are laterally corresponding to the endpoint.

5. The method according to claim 4, characterized in that, Before determining the number of segments included in the routing, the process further includes: determining a reference routing, specifically including: Determine the number of the traces; if the number of the traces is one, then determine that the trace is a reference trace. If the number of the traces is greater than one, it is determined whether differential signal lines are included. If so, the differential signal lines are determined as reference traces; otherwise, the trace with the fastest signal transmission speed is determined as the reference trace. Correspondingly, determining the number of segments included in the trace specifically involves determining the number of segments included in the reference trace; The angle of the grid is set according to the routing, specifically: the angle of the grid is set according to the reference routing.

6. The method according to claim 5, characterized in that, When the differential signal line is determined to be a reference trace, the method is executed for one of the differential signal lines. Specifically, when the angle change between adjacent segments of the trace does not exceed a preset angle value, and the length of the trace is greater than or equal to the preset length, the reference area is determined using two differential signal lines, specifically including: The endpoints on the same side of the traces corresponding to the two differential signal lines each form a boundary of the reference area with a point on the flexible circuit board near that endpoint and located on one side of the differential signal line where the angle of the outline changes; the endpoints on the other side of the traces corresponding to the two differential signal lines each form another boundary of the reference area with a point on the flexible circuit board near that endpoint and located on one side of the differential signal line where the angle of the outline changes.

7. The method according to claim 5, characterized in that, After setting the angle of the grid according to the reference trace, the method further includes: setting the position of the grid according to the reference trace, specifically including: If the reference trace is a differential signal line, the vertical projection of one diagonal of the grid coincides with the extension direction of the intermediate axis of the differential signal line; otherwise, the vertical projection of one diagonal of the grid coincides with the extension direction of the reference trace.

8. The method according to claim 1, characterized in that, The preset length is determined by the speed of signal transmission in the trace and the rise time of the transmitted signal.

9. The method according to claim 1, characterized in that, The determination of the number of segments included in the trace specifically includes: taking one end of the trace as the starting point, and based on the change in the trace direction, determining that the segments before and after the change in direction are different segments of the trace.

10. The method according to any one of claims 1 to 9, characterized in that, After setting the angle of the grid according to the routing, the method further includes: On the grid layer, a third copper wire is set in the reference area corresponding to the segment of the trace located in the corner area of ​​the flexible circuit board, and the vertical projection of the third copper wire coincides with the segment of the trace.

11. The method according to any one of claims 1 to 9, characterized in that, The first direction is perpendicular to the second direction.

12. The method according to any one of claims 1 to 9, characterized in that, The trace layer includes a copper grid that avoids the trace.

13. The method according to claim 12, characterized in that, The position and direction of the grid copper are consistent with the position and direction of the grid formed by the intersection of the first copper line and the second copper line at the corresponding perpendicular position.

14. A system for improving signal integrity on flexible circuit boards, characterized in that, The flexible circuit board includes a grid ground layer and a trace layer distributed along the longitudinal direction; the trace layer includes at least one trace; the grid ground layer includes multiple first copper lines and multiple second copper lines, the multiple first copper lines are parallel to each other in a first direction, the multiple second copper lines are parallel to each other in a second direction, and the multiple first copper lines and the multiple second copper lines intersect to form a plurality of grids; The system includes: The segment quantity determination module is used to determine the number of segments included in the routing, where there is an angle change between adjacent segments; A grid angle setting module, used to set the angle of the grid according to the trace; specifically including: The preset angle value judgment module is used to determine whether the angle change between adjacent segments of the trace exceeds the preset angle value. The first setting module is used to determine the longest segment of the routing line when the angle change between adjacent segments of the routing line does not exceed a preset angle value, and set the angle of the grid in the reference area of ​​the routing line according to the angle of the segment. The second setting module is used to set the angle of the grid according to the relationship between the length of the trace and the preset length, when the angle change between adjacent segments of the trace exceeds a preset angle value; Specifically, setting the angle of the grid according to the angle of the segment means making the extension direction of one diagonal of the grid consistent with the extension direction of the segment.

15. An electronic device, characterized in that, include: processor; And, memory used to store processor-executable instructions; The processor implements the steps of the method according to any one of claims 1-13 by running the executable instructions.

16. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1-13.

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