JP5673874B2 - Periodic structure and wiring board - Google Patents

Description

  The present invention relates to a periodic structure and a wiring board.

  In Patent Document 1, a sheet-like shield conductor and an insulator are stacked, and in the insulator, a shield ground line connected to the shield conductor, an independent ground line not connected to the shield conductor, and a high-speed signal line are parallel. A flexible cable is described in which the shield ground line and the ground line are adjacent to each other, and the high-speed signal line is adjacent to the ground line and not adjacent to the shield ground line.

  In Patent Document 2, when a shield film is wound around a substrate body, an overlapping region near the end of the shield film is obliquely intersected with a portion arranged in parallel with the signal wiring, and each signal wiring is overlapped. A wiring board that crosses the region diagonally is described.

  In Patent Document 3, when two grounds arranged adjacent to each other on the same board surface cannot be directly connected in a printed circuit board due to a characteristic difference, a resistance element, a capacitor, and an inductor are connected between the two grounds. A printed circuit board structure is described which is connected via any one of the circuit elements.

JP 2002-117726 A JP 2007-035787 A JP 2008-130484 A

  The present invention is a signal subject to suppression of transmission compared to a periodic structure in which a plurality of first conductors are arranged in the first direction and the second direction intersecting the first direction so that the sides are adjacent to each other. It is an object of the present invention to provide a periodic structure and a wiring board that can reduce the radiation of electromagnetic waves caused by.

The periodic structure according to claim 1 is a pair of corners arranged to face each other in a first direction and a pair of corners arranged to face each other in a second direction intersecting the first direction. A plurality of conductors arranged in the first direction and the second direction so that the corners are adjacent to each other, and the conductors arranged along the first direction. A plurality of second conductors smaller than the first conductor connecting each of the adjacent corners of the first conductor, and the adjacent corners of the first conductor arranged along the second direction a of said first third smaller plurality than conductors of conductors connecting each, a, a pre-Symbol second direction, extending Zaikata direction of the plurality of signal lines arranged outside the signal layer It is set to.

  According to a second aspect of the present invention, in the periodic structure according to the first aspect, each of the first conductor and the second conductor is provided in each of the regions surrounded by the four first conductors arranged adjacent to each other. And a fourth conductor that is not connected to any of the third conductors.

  The invention according to claim 3 is the periodic structure according to claim 2, wherein each of the fourth conductors is provided with at least one connection hole for electrically connecting to a grounded connection object. is there.

  A wiring board according to a fourth aspect of the present invention is a signal layer in which at least one signal line is disposed, the signal layer adjacent to the signal layer, and the periodic structure according to any one of the first to third aspects. And a power supply layer.

  According to a fifth aspect of the present invention, there is provided a wiring board having at least one signal line, a power supply layer adjacent to the signal layer and having the periodic structure according to the third aspect, and the connection hole. And a ground layer connected to the fourth conductor via the first conductor.

  According to the invention described in claim 1, compared to the periodic structure in which a plurality of first conductors are arranged in the first direction and the second direction intersecting the first direction so that the sides are adjacent to each other, It is possible to reduce the emission of electromagnetic waves caused by a signal that is subject to transmission suppression. Further, crosstalk between a plurality of signal lines can be reduced.

  According to the second aspect of the present invention, it is possible to further reduce the radiation of the electromagnetic wave caused by the signal as compared with the configuration in which the fourth conductor is not provided.

  According to the third aspect of the present invention, it is possible to further reduce the radiation of the electromagnetic wave caused by the signal as compared with the configuration in which the connection hole is not provided in the fourth conductor.

  According to the invention of claim 4, the periodic structure in which a plurality of first conductors are arranged in the first direction and the second direction intersecting the first direction so that the sides are adjacent to each other is provided in the power supply layer. Compared with the case of being arranged, it is possible to reduce the radiation of electromagnetic waves caused by the signal that is the object of transmission suppression propagating through the signal line arranged in the signal layer.

  According to the fifth aspect of the present invention, the power supply layer includes a periodic structure in which a plurality of first conductors are arranged in the first direction and the second direction intersecting the first direction so that the sides are adjacent to each other. Compared with the case of being arranged, it is possible to reduce the radiation of electromagnetic waves caused by the signal that is the object of transmission suppression propagating through the signal line arranged in the signal layer.

It is an upper surface schematic diagram of the wiring board which concerns on embodiment. It is a cross-sectional schematic diagram of the wiring board which concerns on embodiment. It is a top view which shows an example of the periodic structure which concerns on embodiment. It is the figure which expanded a part of periodic structure shown in FIG. It is a top view which shows the other example of the periodic structure which concerns on embodiment. It is a top view which shows the other example of the periodic structure which concerns on embodiment. It is an enlarged view of the 4th conductor shown in FIG. It is a top view which shows an example of the conventional periodic structure. FIG. 8 is a diagram illustrating an example of a measurement result of a change in radiated electric field intensity with respect to a frequency when a signal is propagated from measurement point 1 to measurement point 2 in each periodic structure shown in FIGS. 2, 4, 5, and 7. is there. It is a figure which shows an example of the electric field distribution in the surface near the z direction of the electric field of the x direction measured about the conventional periodic structure shown in FIG. It is a figure which shows an example of the electric field distribution in the surface near the z direction of the electric field of the x direction measured about the periodic structure shown in FIG. It is a figure which shows an example of the electric field distribution in the surface near the z direction of the electric field of the y direction measured about the conventional periodic structure shown in FIG. It is a figure which shows an example of the electric field distribution in the surface near the z direction of the electric field of the y direction measured about the periodic structure shown in FIG. It is a figure which shows an example of the electric field distribution in the surface near the z direction of the electric field of the z direction measured about the conventional periodic structure shown in FIG. It is a figure which shows an example of the electric field distribution in the surface near the z direction of the electric field of the z direction measured about the periodic structure shown in FIG. It is a figure which shows an example of the electric field distribution in the near surface of the z direction of the absolute value which carried out the vector synthesis | combination of each electric field of the x direction, y direction, and z direction measured about the conventional periodic structure shown in FIG. It is a figure which shows an example of the electric field distribution in the near surface of the z direction of the absolute value which carried out vector composition of each electric field of the x direction, y direction, and z direction measured about the periodic structure shown in FIG. An example of a measurement result of a change in transmission amount (S21) with respect to a frequency when a signal is propagated from measurement point 1 to measurement point 2 in each periodic structure shown in FIGS. 2, 4, 5, and 7 is shown. FIG. It is a figure which shows the state which has arrange | positioned the two signal lines extended along the y direction on the upper layer of this area | region with respect to the area | region in which the single conductor was provided spaced apart in the x direction. FIG. 3 is a diagram showing a state in which two signal lines extending along the y direction are arranged in the upper layer of the region and separated from each other in the x direction with respect to the region where the periodic structure shown in FIG. 2 is provided. . FIG. 5 is a diagram showing a state in which two signal lines extending along the y direction are arranged in the upper layer of the region and separated from each other in the x direction with respect to the region where the periodic structure shown in FIG. 4 is provided. . FIG. 6 is a diagram showing a state in which two signal lines extending along the y direction are arranged in the upper layer of the region and separated from each other in the x direction with respect to the region where the periodic structure shown in FIG. 5 is provided. . It is a figure which shows an example of the measurement result of the permeation | transmission amount change to each measurement point with respect to the frequency in the conductor shown to FIG. 14A. It is a figure which shows an example of the measurement result of the change of the permeation | transmission amount to each measurement point with respect to the frequency in the periodic structure shown to FIG. 14B. It is a figure which shows an example of the measurement result of the permeation | transmission amount to each measurement point with respect to the frequency in the periodic structure shown to FIG. 14C. It is a figure which shows an example of the measurement result of the permeation | transmission amount to each measurement point with respect to the frequency in the periodic structure shown to FIG. 14D. It is the figure which extracted and showed the measurement result of S41 from each of FIGS. FIG. 14B is a diagram showing a state in which two signal lines are inclined with respect to the x direction by 71.4 degrees with respect to the periodic structure shown in FIG. 14B. FIG. 14B is a diagram showing a state in which two signal lines are inclined with respect to the x direction by 56.1 degrees with respect to the periodic structure shown in FIG. 14B. FIG. 14B is a diagram showing a state where two signal lines are inclined with respect to the x direction by 44.7 degrees with respect to the periodic structure shown in FIG. 14B. An example of the measurement result of S41 when a signal is propagated from measurement point 1 to measurement point 2 when two signal lines are arranged as shown in FIGS. 20A to 20C with respect to the periodic structure shown in FIG. 14B. FIG. FIG. 14B is a diagram showing a state in which two signal lines are inclined by 71.4 degrees in the x direction with respect to the conductor shown in FIG. 14A. FIG. 14B is a diagram showing a state in which two signal lines are inclined with respect to the conductor shown in FIG. 14A by 56.1 degrees in the x direction. FIG. 14B is a diagram showing a state in which two signal lines are inclined by 44.7 degrees in the x direction with respect to the conductor shown in FIG. 14A. FIG. 14A shows an example of the measurement result of S41 when a signal is propagated from measurement point 1 to measurement point 2 when two signal lines are arranged as shown in FIGS. 22A to 22C with respect to the conductor shown in FIG. 14A. It is a figure. It is a figure which shows the other example of the periodic structure body by which the connection hole was provided in the 4th conductor. It is a figure which shows the other example of the periodic structure body by which the connection hole was provided in the 4th conductor. It is a figure which shows the other example of the periodic structure body by which the connection hole was provided in the 4th conductor. It is a figure which shows the other example of the periodic structure body by which the connection hole was provided in the 4th conductor. In each of the periodic structure having no connection hole and the periodic structure having the connection hole shown in FIGS. 24A to 24D and FIG. 5, the frequency with respect to the frequency when the signal is propagated from the measurement point 1 to the measurement point 2 It is a figure which shows an example of the measurement result of the change of radiation electric field strength. In each of the periodic structure having no connection hole and the periodic structure having the connection hole shown in FIGS. 24A to 24D and FIG. 5, the frequency with respect to the frequency when the signal is propagated from the measurement point 1 to the measurement point 2 is shown. It is a figure which shows an example of the measurement result of the change of S21. It is the figure which extracted and showed the measurement result in the 6.5-8.5 GHz frequency band from the measurement result shown in FIG. It is the figure which extracted and showed the measurement result in a 9-11 GHz frequency band from the measurement result shown in FIG. It is the figure which extracted and showed the measurement result in a 12-14 GHz frequency band from the measurement result shown in FIG. It is the figure which extracted and showed the measurement result in the 14-16 GHz frequency band from the measurement result shown in FIG. It is the figure which extracted and showed the measurement result in the frequency band of 17-19 GHz from the measurement result shown in FIG.

  Hereinafter, various embodiments will be described in detail with reference to the drawings.

[First Embodiment]

First, a configuration of a wiring board according to an embodiment will be described with reference to FIG.
FIG. 1A is a schematic top view of the wiring board 10 according to the present embodiment, and FIG. 1B is a schematic cross-sectional view of the wiring board 10.

  The wiring board 10 includes a signal layer 10a, a power supply layer 10b, and a ground layer 10c. Each of the signal layer 10a, the power supply layer 10b, and the ground layer 10c is laminated with an insulating layer interposed therebetween. Here, the wiring board 10 will be described as a multilayer wiring board in which each of the signal layer 10a, the power supply layer 10b, and the ground layer 10c is laminated one by one with an insulating layer in between. However, the present invention is not limited to such a structure. Alternatively, there may be a configuration without a ground layer, or there may be two or more signal layers, or there may be two or more power supply layers or ground layers. Further, the signal layer 10a may be provided between the power supply layer 10b and the ground layer 10c.

  The signal layer 10 a is provided with a memory 11, an LSI (Large Scale Integration) 12, and a plurality of signal lines 13 that connect the memory 11 and the LSI 12. Further, terminals 14 and 15 are provided in the signal layer 10a. The LSI 12 is connected to the terminal 14 through the signal line 16 and is connected to the terminal 15 through the signal line 17. The terminals 14 and 15 are connected to other wiring boards, and the LSI 12 exchanges signals with other wiring boards via the signal lines 16 and 17 and the terminals 14 and 15. Note that the wirings and circuits arranged in the signal layer 10a according to the present embodiment are examples, and the present invention is not limited to this.

  The power supply layer 10b is supplied with power from a power supply unit (not shown) to a power supply target. The ground layer 10c is grounded.

  A plurality of conductors having different sizes are periodically arranged in a region of the power supply layer 10b corresponding to a region where the signal lines 16 and 17 are disposed in the signal layer 10a (a region indicated by a thick broken line in FIGS. 1A and 1B). The connected periodic structures are arranged.

  FIG. 2 shows an example of the periodic structure. FIG. 3 is an enlarged view of a part of the periodic structure shown in FIG. The periodic structure 22 includes a first conductor including a pair of corner portions 31a and 31b disposed so as to face each other in the x direction and a pair of corner portions 31c and 31d disposed so as to face each other in the y direction. A conductor group 30 is provided in which a plurality of 31 are arranged in the x direction and the y direction so that the corners are adjacent to each other.

  The periodic structure 22 includes a plurality of second conductors 32 that are smaller than the first conductors 31 that connect adjacent corners of the first conductors 31 that are arranged along the x direction. The periodic structure 22 includes a plurality of third conductors 33 that are smaller than the first conductors 31 connecting the adjacent corners of the first conductors 31 arranged along the y direction.

  In the example given here, the first conductor 31 has a square shape, and the second conductor 32 and the third conductor 33 have a rectangular shape. However, each conductor is not limited to this shape. The size and shape of the second conductor 32 and the third conductor 33 may be the same or different.

  FIG. 4 shows another example of the periodic structure according to the present embodiment. In addition to the structure of the periodic structure 22 shown in FIG. 2, the periodic structure 24 shown in FIG. 4 includes a first conductor in each of the regions surrounded by the four first conductors 31 arranged adjacent to each other. 31, a second conductor 32, and a fourth conductor 34 that is not connected to any of the third conductors 33 is disposed.

  Note that each of the fourth conductors 34 plays a role as a shield conductor, and is in an electrically floating state (a floating state that is not electrically connected to any potential point). In the example given here, the fourth conductor 34 has a square shape, but the fourth conductor 34 is not limited to this shape.

  FIG. 5 shows another example of the periodic structure according to the present embodiment. In addition to the structure of the periodic structure 22 shown in FIG. 2, the periodic structure 26 shown in FIG. 5 includes a first conductor in each of the regions surrounded by the four first conductors 31 arranged adjacent to each other. 31, a second conductor 32, and a fourth conductor 35 that is not connected to any of the third conductors 33 is disposed. FIG. 6 is an enlarged view of the fourth conductor 35. As shown in FIG. 6, the fourth conductor 35 of the periodic structure 26 is provided with 25 connection holes (also referred to as vias) 36 for electrical connection to the ground layer 10 c in a lattice shape. The fourth conductor 35 is electrically connected to the ground layer 10 c through the connection hole 36. In the present embodiment, the fourth conductor in which the connection hole 36 is not provided is denoted by reference numeral 34, and the fourth conductor in which the connection hole 36 is provided is identified by reference numeral 35. .

  Each of the fourth conductors 35 plays a role as a shield conductor. In the example given here, the fourth conductor 35 has a square shape, but the fourth conductor 35 is not limited to this shape. Further, the number of the connection holes 36 is not limited to the above as long as it is at least one, and the arrangement state of the connection holes 36 is not limited to the lattice shape.

  Next, the characteristics of the periodic structures 22, 24, and 26 shown in FIGS. 2, 4, and 5 will be described.

  First, a conventional periodic structure 28 as a comparative example for the periodic structures 22, 24, 26 will be described.

  The conventional periodic structure 28 shown in FIG. 7 includes a first conductor 41 having a pair of sides arranged so as to face each other in the x direction and a pair of sides arranged so as to face each other in the y direction. A plurality of conductor groups 40 arranged in the x direction and the y direction so as to be adjacent to each other and a plurality of conductors smaller than the first conductor 41 connecting each of the adjacent sides of the first conductors 41 arranged in the x direction. Second conductors 42 and a plurality of third conductors 43 smaller than the first conductors 41 connecting adjacent sides of the first conductors 41 arranged along the y direction. .

  FIG. 8 shows an example of the measurement result of the change in the intensity of the radiated electric field with respect to the frequency when the signal is propagated from the measurement point 1 to the measurement point 2 in each periodic structure shown in FIG. 2, FIG. 4, FIG. 5, and FIG. FIG. Here, (1) is the measurement result in the periodic structure 22, (2) is the measurement result in the periodic structure 24, (3) is the measurement result in the periodic structure 26, and (4) is in the conventional periodic structure 28. The measurement results are shown. Measurement conditions are as follows.

(A) Measurement conditions of the periodic structure 22 in FIG. 2 • Number of arrangements of the first conductors 31 in the x direction: 6 pieces • Number of arrangements of the first conductors 31 in the y direction: 3 pieces • of the first conductors 31 Shape and size: Square shape with a diagonal length of 15 mm. Shape and size of second conductor 32: Length of side not in contact with first conductor 31 is 0.5 mm and in contact with first conductor 31. Rectangular shape with side length of 1 mm / shape and size of third conductor 33: length of side not in contact with first conductor 31 is 0.5 mm, length of side in contact with first conductor 31 The overall size of the rectangular / periodic structure 22 with 1 mm of: 92.5 mm in the x direction and 46 mm in the y direction

(B) Measurement conditions for the periodic structure 24 in FIG. 4. Number of arrangement of the first conductors 31, shape and size of the first conductor 31, shape and size of the second conductor 32, and third conductor The shape and size of 33 and the size of the periodic structure 24 as a whole are the same as the measurement condition (a). Shape of the fourth conductor 34: square shape with a diagonal length of 13 mm

(C) Measurement conditions for the periodic structure 26 in FIG. 5-Number of first conductors 31 arranged, shape and size of the first conductor 31, shape and size of the second conductor 32, and third conductor The shape and size of 33 and the size of the entire periodic structure 26 are the same as the measurement condition (a). Shape and size of the fourth conductor 35: square shape with a diagonal length of 13 mm. Shape and size: Square shape with a side of 0.5 mm ・ Number and arrangement of connection holes 36: 25, lattice shape

(D) Measurement conditions of the conventional periodic structure 28 in FIG. 7 • Number of arrangements of the first conductors 41 in the x direction: 6 pieces • Number of arrangements of the first conductors 41 in the y direction: 3 pieces • First conductors 41 shape and size: square shape with a side length of 15 mm. Shape and size of second conductor 42: length of side not in contact with first conductor 41 is 0.5 mm. The shape and size of the rectangular shape / third conductor 43 with a side length of 1 mm in contact: the length of the side not in contact with the first conductor 41 is 0.5 mm, and the side in contact with the first conductor 41 Overall size of the rectangular / periodic structure 28 with a length of 1 mm: 92.5 mm in the x direction and 46 mm in the y direction

  The periodic structures 22, 24, and 26 in which a plurality of first conductors 31 are arranged in the x direction and the y direction so that the corners are adjacent to each other include the first conductor 41 in the x direction and the y direction so that the sides are adjacent to each other. The electrical coupling between the first conductors 41 is small as compared to the periodic structures 28 arranged in the direction.

  In FIG. 8, when the measurement results of (1) to (3) and the measurement result of (4) are compared, the radiated electric field intensity in the periodic structures 22, 24, and 26 in the frequency band other than 6.5 to 8 GHz is the conventional period. Lower than the structure 28, the radiation field characteristics are improved.

  Further, when the measurement result of the periodic structure 22 in (1) is compared with the measurement result of the periodic structure 24 in (2), the radiated electric field intensity in the periodic structure 24 is periodic in the frequency band of 6.5 GHz or higher. The radiation field strength is lower than the radiation field strength in the structure 22, and the radiation field characteristics are improved.

  Further, when the measurement result of the periodic structure 24 in (2) and the measurement result of the periodic structure 26 in (3) are compared, the radiated electric field intensity in the periodic structure 26 is periodic in the frequency band of 6.5 GHz or more. The radiation field characteristics are improved by being lower than the radiation field intensity in the structure 24.

  9 to 12 show each period measured by propagating a signal having a frequency of 5 GHz and a power of 1 W from the measurement point 1 to the measurement point 2 in the periodic structure 22 and the conventional periodic structure 28 under the same measurement conditions as described above. It is the figure which represented typically an example of the electric field distribution in a structure. The measurement conditions are the same as the measurement conditions (a) and (d). 9 to 12, the lower left portion corresponds to the measurement point 1 and the upper right portion corresponds to the measurement point 2.

  FIG. 9A is a diagram showing an example of an electric field distribution in the vicinity of the z-direction electric field measured for the conventional periodic structure 28, and FIG. 9B is an x-direction measured for the periodic structure 22. It is a figure which shows an example of the electric field distribution in the surface near the z direction of an electric field.

  FIG. 10A is a diagram illustrating an example of an electric field distribution in the vicinity of the z-direction of the electric field in the y direction measured for the conventional periodic structure 28, and FIG. It is a figure which shows an example of the electric field distribution in the surface near the z direction of an electric field.

  FIG. 11A is a diagram illustrating an example of an electric field distribution in the vicinity surface in the z direction of the electric field in the z direction measured for the conventional periodic structure 28, and FIG. 11B is a diagram in the z direction measured for the periodic structure 22. It is a figure which shows an example of the electric field distribution in the surface near the z direction of an electric field.

  FIG. 12A shows an absolute value obtained by vector synthesis of the electric fields in the x-direction, y-direction, and z-direction measured for the conventional periodic structure 28 shown in FIGS. 9A, 10A, and 11A in the vicinity surface in the z-direction. FIG. 12B is a diagram illustrating an example of the electric field distribution, and FIG. 12B is an absolute value obtained by vector synthesis of the electric fields in the x, y, and z directions measured for the periodic structure 22 shown in FIGS. 9B, 10B, and 11B. It is a figure which shows an example of the electric field distribution in the surface near the z direction of a value.

  As shown in FIGS. 9 to 12, in any measurement result, the periodic structure 22 has a smaller electric field spread from the measurement point 1 as the signal source than the conventional periodic structure 28.

  FIG. 13 shows the transmission amount with respect to the frequency when a signal is propagated from measurement point 1 to measurement point 2 in each periodic structure shown in FIGS. 2, 4, 5, and 7 (hereinafter referred to as S21). It is a figure which shows an example of the measurement result of a change. Here, (1) is the measurement result in the periodic structure 22, (2) is the measurement result in the periodic structure 24, (3) is the measurement result in the periodic structure 26, and (4) is in the conventional periodic structure 28. It is a measurement result. The measurement conditions are the same as the measurement conditions (a) to (d) for the radiation electric field intensity in FIG. In FIG. 13, the closer to 0, the smaller the attenuation amount (the larger the transmission amount).

  In FIG. 13, the measurement results for the periodic structure 22 of (1), the periodic structure 24 of (2), and the periodic structure 26 of (3), and the measurement of the conventional periodic structure 28 of (4). Comparing the results, in the high frequency band exceeding 2 GHz, the values of S21 of the periodic structures 22, 24, 26 are higher than those of the conventional periodic structure 28, but the periodic structures 22, 24, 26 are provided. In this case, a sufficiently small characteristic of S21 is obtained compared to S21 = 0. It should be noted that in the low frequency band of 2 GHz or less close to the direct current component, the attenuation amount is small in any of the periodic structures 22, 24, and 26, which is sufficient when the periodic structures 22, 24, and 26 are provided in the power supply layer 10b. Power supply performance can be obtained.

  Next, with respect to the characteristics related to crosstalk (signal leakage, interference) generated between a plurality of signal lines for the periodic structures 22, 24, and 26, a single conductor having the same external shape as the periodic structure 22 but having no periodic structure is used. 29 (see FIG. 14A).

  Here, as shown in FIGS. 14A to 14D, two signal lines 50 extending in the y direction are formed on the upper layer of each of the regions where the conductor 29 and the periodic structures 22, 24, 26 are provided. One of the two signal lines 50, 52 is set as a measurement point 1, the other end is set as a measurement point 2, and the other signal line 52 is connected to the other signal line 52. When one end is the measurement point 3 and the other end is the measurement point 4, the change in the transmission amount to each measurement point with respect to the frequency when the signal is propagated from the measurement point 1 to the measurement point 2 was measured.

  In this measurement, the measurement conditions for the periodic structures 22, 24, and 26 are the same as the measurement conditions (a), (b), and (c) of the radiated electric field intensity in FIG. In addition, the entire shape and size of the single conductor 29 given as a comparative example this time are the same as the entire shape and size of the periodic structure 22 (that is, the x direction is 92.5 mm and the y direction is 46 mm). . The conductor 29 and each of the periodic structures 22, 24, and 26 were measured with the distance between the two signal lines 50 and 52 in the x direction being 62 mm. Examples of measurement results are shown in FIGS.

  FIG. 15 is a diagram illustrating an example of a measurement result of a change in the amount of transmission to each measurement point with respect to the frequency in the conductor 29. FIG. 16 is a diagram illustrating an example of a measurement result of a change in the transmission amount to each measurement point with respect to the frequency in the periodic structure 22. FIG. 17 is a diagram illustrating an example of the measurement result of the change in the transmission amount to each measurement point with respect to the frequency in the periodic structure 24. FIG. 18 is a diagram illustrating an example of a measurement result of a change in the transmission amount to each measurement point with respect to the frequency in the periodic structure 26.

Here, each S parameter (S11, S21, S31, S41) which shows each measurement result in FIGS. 15-18 shows the following physical quantities.
S11: Reflection amount of signal propagated from measurement point 1 to return to measurement point 1. S21: Transmission amount of signal propagated from measurement point 1 to measurement point 2. S31: Propagation from measurement point 1 to measurement point 3. S41: Transmission amount of signal propagating from measurement point 1 to measurement point 4

  S31 is a parameter widely used as an evaluation index for near-end crosstalk, and S41 is a parameter widely used as an evaluation index for far-end crosstalk.

  As is clear from the measurement results of FIGS. 15 to 18, the periodic structures 22, 24, and 26 have lower values of S 31 and S 41 than the single conductor 29.

  FIG. 19 is a diagram showing the measurement results of S41 of the conductor 29 and the periodic structures 22, 24, and 26 extracted from each of FIGS. In FIG. 19, (A) is a measurement result about the conductor 29, (B) is a measurement result about the periodic structure 22, (C) is a measurement result about the periodic structure 24, and (D) is about the periodic structure 26. The measurement results are shown.

  As is clear from this measurement result, in the frequency band of 2 GHz to 6 GHz, the value of S41 decreases in the order of the conductor 29, the periodic structure 22, the periodic structure 24, and the periodic structure 26.

  15 to 19, the measurement is performed when the extending direction of the signal lines 50 and 52 is the y direction (in other words, the inclination θ of the extending direction of the signal lines 50 and 52 with respect to the x direction is 90 degrees). The characteristics of the periodic structures 22, 24, and 26 have been described by taking the results as examples. Hereinafter, the characteristics of the periodic structures 22, 24, and 26 will be described by taking measurement results when θ = 90 as an example. To do. Since the periodic structure 22 has a basic configuration common to each of the three types of periodic structures 22, 24, and 26, representatively, S41 in the periodic structure 22 is measured, and the measurement result As an example, the characteristics of the periodic structures 22, 24, and 26 according to the present embodiment will be described.

  FIG. 21 shows that in the periodic structure 22, θ is θ = 90 (see FIG. 14B), θ = 71.4 (FIG. 20A), θ = 56.1 (see FIG. 20B), θ = 44.7 (see FIG. 20C) is a diagram illustrating an example of the measurement result of S41 when a signal is propagated from measurement point 1 to measurement point 2 in the four cases of FIG. In this measurement, the measurement conditions other than θ are equal to the measurement condition (a) of the radiated electric field intensity shown in FIG.

  As shown in FIG. 21, the value of S41 in the case of θ = 71.4, θ = 56.1, θ = 44.7 in which the signal lines 50 and 52 are tilted in the x direction is the case of θ = 90. It is higher than

  23, in the conductor 29, θ is θ = 90 (see FIG. 14A), θ = 71.4 (FIG. 22A), θ = 56.1 (see FIG. 22B), θ = 44.7 (see FIG. 22C). ) Is a diagram showing an example of the measurement result of S41 when a signal is propagated from measurement point 1 to measurement point 2. In this measurement, it is assumed that the overall shape and size of the conductor 29 are equal to the overall shape and size of the periodic structure 22 (that is, 92.5 mm in the x direction and 46 mm in the y direction).

  As shown in FIG. 23, in the case of the conductor 29, the value of S41 does not change greatly even if θ changes.

  Note that the periodic structure is not limited to the periodic structures 22, 24, and 26 exemplified above. For example, the arrangement and number of connection holes 36 provided in the fourth conductor 35 of the periodic structure 26 may be changed.

  For example, as shown in FIG. 24A, one connection hole 36 may be provided in the center of the fourth conductor 35. In addition, as shown in FIG. 24B, a total of five connection holes 36 may be provided, one at each of the central portions of the four sides of the fourth conductor 35 and one at the center of the fourth conductor 35. Good. In addition, as shown in FIG. 24C, a total of four connection holes 36 may be provided, one at each of the four corners of the fourth conductor 35. Further, as shown in FIG. 24D, nine connection holes 36 may be arranged in a lattice shape.

Below, the characteristic of the periodic structure according to the connection hole 36 is demonstrated.
Here, in order to distinguish the periodic structures according to the arrangement of the connection holes 36, the following reference numerals are given to the periodic structures for convenience.
-Periodic structure which has the 4th conductor 35 shown to FIG. 24A: Periodic structure 26a
-Periodic structure which has the 4th conductor 35 shown to FIG. 24B: Periodic structure 26b
-Periodic structure which has the 4th conductor 35 shown to FIG. 24C: Periodic structure 26c
-Periodic structure having the fourth conductor 35 shown in FIG. 24D: Periodic structure 26d
-Periodic structure which has the 4th conductor 35 shown in FIG. 5, FIG. 6: Periodic structure 26e

  FIG. 25 shows the radiation with respect to the frequency when the signal is propagated from the measurement point 1 to the measurement point 2 in each of the periodic structure 24 shown in FIG. 4 and the periodic structures 26a to 26e shown in FIG. It is a figure which shows an example of the measurement result of a change of electric field strength.

  FIG. 26 is a diagram illustrating an example of a measurement result of a change in S21 with respect to frequency when a signal is propagated from measurement point 1 to measurement point 2 in each of the periodic structure 24 and the periodic structures 26a to 26e. It is.

  In each of FIGS. 25 and 26, (1) is a measurement result in the periodic structure 24, (2) is a measurement result in the periodic structure 26a, (3) is a measurement result in the periodic structure 26b, and (4) is a period. The measurement result in the structure 26c, (5) shows the measurement result in the periodic structure 26d, and (6) shows the measurement result in the periodic structure 26e. The measurement conditions of the periodic structure 24 are the same as the measurement conditions (b) described above, and the measurement conditions of the periodic structure 26e are the same as the measurement conditions (c) described above. The measurement conditions for the periodic structures 26a to 26d are the same as the measurement conditions (c) described above except for the number and arrangement state of the connection holes 36.

  As shown in FIG. 25, the relationship between the number of connection holes 36 arranged and the radiated electric field strength differs depending on the frequency. For example, in the frequency band of 7.5 to 8.0 GHz, the radiation electric field strength increases as the number of connection holes 36 increases.

  Further, as shown in FIG. 26, the relationship between the number of connection holes 36 arranged and the value of S21 also differs depending on the frequency. For example, at a frequency of 6 GHz, the value of S21 decreases as the number of connection holes 36 increases.

  Here, the measurement result of the radiation electric field intensity shown in FIG. 25 will be examined in more detail. FIG. 27 is a diagram in which measurement results in the 6.5 to 8.5 GHz frequency band are extracted from the measurement results shown in FIG. FIG. 28 is a diagram showing the measurement results in the 9 to 11 GHz frequency band extracted from the measurement results shown in FIG. FIG. 29 is a diagram in which measurement results in the frequency band of 12 to 14 GHz are extracted from the measurement results shown in FIG. FIG. 30 is a diagram showing the measurement results in the frequency band of 14 to 16 GHz extracted from the measurement results shown in FIG. FIG. 31 is a diagram obtained by extracting measurement results in the frequency band of 17 to 19 GHz from the measurement results shown in FIG.

  In the measurement results shown in FIGS. 27 to 31, in a low frequency band (for example, 6.5 to 8.5 GHz), a periodic structure having a large number of connection holes 36 (two or more connection holes 36) has a small periodic structure ( The intensity of the radiated electric field is lower than that of the connection hole 36 or less. Further, in a high frequency band (for example, 12 to 19 GHz), the relationship between the number of connection holes 36 and the radiation electric field strength cannot be found.

DESCRIPTION OF SYMBOLS 10 Wiring board 10a Signal layer 10b Power supply layer 10c Ground layer 14, 15 Terminal 16, 17 Signal line 22, 24, 26 Periodic structure 31 1st conductor 31a, 31b, 31c, 31d Corner 32 2nd conductor 33 2nd 3 conductors 34, 35 4th conductor 36 Connection hole

Claims (5)

A first conductor having a pair of corners arranged to face each other in a first direction and a pair of corners arranged to face each other in a second direction intersecting the first direction; A conductor group arranged in the first direction and the second direction so that the corners are adjacent to each other;
A plurality of second conductors smaller than the first conductors connecting each of the adjacent corners of the first conductors arranged along the first direction;
A plurality of third conductors smaller than the first conductor connecting each of the adjacent corners of the first conductor arranged along the second direction,
Previous SL second direction, extending Zaikata direction and the periodic structure of the plurality of signal lines arranged outside the signal layer.   A fourth region that is not connected to any of the first conductor, the second conductor, and the third conductor in each of the regions surrounded by the four first conductors that are arranged adjacent to each other. The periodic structure according to claim 1, wherein a conductor is provided.   The periodic structure according to claim 2, wherein each of the fourth conductors is provided with at least one connection hole for electrically connecting to a grounded connection target. A signal layer provided with at least one signal line;
A power supply layer adjacent to the signal layer and having the periodic structure according to any one of claims 1 to 3,
Wiring board equipped with. A signal layer provided with at least one signal line;
A power supply layer adjacent to the signal layer and having the periodic structure according to claim 3,
A ground layer connected to the fourth conductor via the connection hole;
Wiring board equipped with.