Differential transmission board sets and assemblies

Abstract

To improve a transmission characteristic of a substrate set for a differential transmission.SOLUTION: A substrate set 4 for a differential transmission is formed by combining: a mounting substrate 7 onto which a compression connector 5 is mounted; and a contact substrate 6 contacted to the compression connector 5. In the contact substrate 6, a second conductive layer 6CL2 is a ground layer, in which a penetration hole 55 is formed. The penetration hole 55 is formed so that a first signal pad 35 and a second signal pad 36 are together positioned inside of an inner peripheral edge 55A of the penetration hole 55. In the contact substrate 6, the penetration hole 55 is formed so as to overlap an outer side region 33Q of a first ground pad 33 and an outer side region 34Q of a second ground pad 34. In the mounting substrate 7, a penetration hole 85 is formed so as to be separated from a first ground pad 63 and a second ground pad 64 when viewed in a vertical direction.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a differential transmission board set and assembly. [Background technology]

[0002] Patent Document 1 discloses a paddle card substrate 1002, which is a multilayer substrate in which multiple conductor layers 1000 and multiple insulator layers 1001 are alternately stacked, as shown in FIG. 36 of the present application. The multiple conductor layers 1000 include a first conductor layer 1000A, a second conductor layer 1000B, a third conductor layer 1000C, and a fourth conductor layer 1000D. The multiple insulator layers 1001 include a first insulator layer 1001A, a second insulator layer 1001B, and a third insulator layer 1001C. From the surface layer side to the inner layer side of the paddle card substrate 1002, the first conductor layer 1000A, the first insulator layer 1001A, the second conductor layer 1000B, the second insulator layer 1001B, the third conductor layer 1000C, the third insulator layer 1001C, and the fourth conductor layer 1000D are arranged in this order.

[0003] The first conductor layer 1000A is formed with two cable connection pads 1003 to which two signal line conductors of a differential signal transmission cable are soldered, and two ground pads 1004 arranged on either side of the two cable connection pads 1003.

[0004] Furthermore, the second conductor layer 1000B and the third conductor layer 1000C are respectively formed with through holes 1005B and through holes 1005C that overlap with the two cable connection pads 1003 in the stacking direction, thereby suppressing capacitive coupling between the two cable connection pads 1003 and the second conductor layer 1000B, and thereby preventing a decrease in differential impedance at the two cable connection pads 1003. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-27721 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors of the present application have developed two differential transmission boards that are electrically connected to each other via a compression connector that includes multiple compression contacts, each of which includes a soldered portion and a spring portion, and a housing that holds the multiple compression contacts. The two differential transmission boards are combined to form a differential transmission board set.

[0007] An object of the present disclosure is to provide a technique for improving the transmission characteristics of a differential transmission board set. [Means for solving the problem]

[0008] According to a first aspect of the present disclosure, there is provided a differential transmission board set comprising two differential transmission boards electrically connected to each other via a compression connector, the compression connector comprising four compression contacts each including a soldering portion and a spring portion and arranged in a row, and a housing for holding the four compression contacts, the two differential transmission boards including a mounting board on which the compression connector is mounted and a contact board to be brought into contact with the compression connector, and both the mounting board and the contact board each including a plurality of A multilayer board is formed by alternately stacking conductor layers and a plurality of insulator layers, and in both the mounting board and the contact board, the plurality of conductor layers include, in order from the compression connector side, a first conductor layer and a second conductor layer, and in both the mounting board and the contact board, the first conductor layer has four electrode pads corresponding to the four compression contacts, and the four electrode pads include a first signal pad, a second signal pad, a first ground pad, and a second ground pad, and the first ground pad, the first signal pad, the front the second signal pad and the second ground pad are arranged in this order along a first direction; on the mounting board, the soldering portions of the four compression contacts can be soldered to the first ground pad, the first signal pad, the second signal pad, and the second ground pad, respectively; on the contact board, the spring portions of the four compression contacts can be brought into contact with the first ground pad, the first signal pad, the second signal pad, and the second ground pad, respectively; in both the mounting board and the contact board, the second conductor layer is a ground layer and has a through hole formed therein; in both the mounting board and the contact board, the through hole is formed so that both the first signal pad and the second signal pad are located inside an inner periphery of the through hole when viewed from the stacking direction; and in both the mounting board and the contact board, the first ground pad has an inner region closer to the first signal pad than a bisector that bisects a pad area of ​​the first ground pad in the first direction;and an outer region farther from the first signal pad than the bisector, and in both the mounting board and the contact board, the second ground pad includes an inner region closer to the second signal pad than the bisector that bisects the pad area of ​​the second ground pad in the first direction, and an outer region farther from the second signal pad than the bisector, and in the contact board, the through hole is formed so as to overlap the outer region of the first ground pad and the outer region of the second ground pad when viewed along the stacking direction, and in the mounting board, the through hole is formed away from the first ground pad and the second ground pad when viewed along the stacking direction. In both the mounting board and the contact board, the plurality of conductor layers further includes a third conductor layer, and the first conductor layer, the second conductor layer, and the third conductor layer are stacked in this order, starting from the compression connector side, and in both the mounting board and the contact board, the third conductor layer may be a ground layer and overlap with the first signal pad and the second signal pad in the stacking direction. In both the mounting board and the contact board, the plurality of conductor layers further includes a third conductor layer, a fourth conductor layer, and a fifth conductor layer, and the first conductor layer, the second conductor layer, the third conductor layer, the fourth conductor layer, and the fifth conductor layer are stacked in this order starting from the compression connector side. In both the mounting board and the contact board, the third conductor layer and the fourth conductor layer are ground layers and have through holes formed therein. In both the mounting board and the contact board, the through holes in the third conductor layer and the fourth conductor layer are both formed so that the first signal pad and the second signal pad are both located inside the inner periphery of the through hole when viewed from the stacking direction. In both the mounting board and the contact board, the fifth conductor layer may be a ground layer and overlap with the first signal pad and the second signal pad in the stacking direction. The differential transmission board may be formed by combining two differential transmission boards electrically connected to each other via a compression connector in which a plurality of compression contact groups each consisting of four compression contacts aligned in a row are arranged. In at least one of the mounting board and the contact board, the multiple conductor layers include, from the compression connector side, the first conductor layer, the second conductor layer,...(N-1)th conductor layer, and Nth conductor layer (where N is a natural number greater than or equal to 4), in this order, the Nth conductor layer includes a first signal pad and a second signal pad electrically connected to the first signal pad and the second signal pad of the first conductor layer, respectively, and the (N-1)th conductor layer may be a ground layer and overlap with the first signal pad and the second signal pad of the Nth conductor layer in the stacking direction. An assembly is provided that includes the above-described differential transmission board set and the compression connector. [Effects of the Invention]

[0009] According to the present disclosure, the transmission characteristics of a differential transmission board set can be improved. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view of an information processing device (first embodiment). [Figure 2] 1 is an exploded perspective view of the information processing device as seen from another angle (first embodiment). [Figure 3] 1 is a cross-sectional view of a differential transmission assembly (first embodiment). [Figure 4] 1 is a partial bottom view of a first conductor layer of a contact substrate (first embodiment). [Figure 5] 10 is a partial bottom view of the second conductor layer of the contact substrate (first embodiment). [Figure 6] 10 is a partial bottom view of the third conductor layer of the contact substrate (first embodiment). [Figure 7] 10 is a partial bottom view of the fourth conductor layer of the contact substrate (first embodiment). [Figure 8] 10 is a partial bottom view of the fifth conductor layer of the contact substrate (first embodiment). [Figure 9] 10 is a partial bottom view of the sixth conductor layer of the contact substrate (first embodiment). [Figure 10] 1 is a projection view of a plurality of conductor layers of a contact substrate (first embodiment). [Figure 11] 1 is a partial plan view of a first conductor layer of a mounting board (first embodiment). [Figure 12] 10 is a partial plan view of a second conductor layer of the mounting board (first embodiment). [Figure 13] 10 is a partial plan view of a third conductor layer of the mounting board (first embodiment). [Figure 14] 10 is a partial plan view of a fourth conductor layer of the mounting board (first embodiment). [Figure 15] 10 is a partial plan view of a fifth conductor layer of the mounting board (first embodiment). [Figure 16] 10 is a partial plan view of a sixth conductor layer of the mounting board (first embodiment). [Figure 17] 1 is a projection view of a plurality of conductor layers of a mounting substrate (first embodiment). [Figure 18] 10 is a partial bottom view of the third and fourth conductor layers of the contact substrate (first modified example). [Figure 19] 10 is a partial plan view of a third conductor layer and a fourth conductor layer of the mounting board (first modified example). [Figure 20] 10 is a projection view of a plurality of conductor layers of a contact substrate (first comparative example). [Figure 21] 10 is a projection view of a plurality of conductor layers of a mounting board (first comparative example). [Figure 22] 10 is a projection view of a plurality of conductor layers of a contact substrate (second comparative example). [Figure 23] 10 is a projection view of a plurality of conductor layers of a mounting board (second comparative example). [Figure 24] 10 is a projection view of a plurality of conductor layers of a contact substrate (third comparative example). [Figure 25] 10 is a projection view of a plurality of conductor layers of a mounting board (third comparative example). [Figure 26]10 is a projection view of a plurality of conductor layers of a contact substrate (fourth comparative example). [Figure 27] 10 is a projection view of a plurality of conductor layers of a mounting board (fourth comparative example). [Figure 28] 10 is a partial bottom view of the second to fourth conductor layers of the contact substrate (Fifth Comparative Example). [Figure 29] 10 is a partial plan view of the second to fourth conductor layers of the mounting board (fifth comparative example). [Figure 30] 10 is a graph showing the analysis results of insertion loss. [Figure 31] 10 is a graph showing the analysis results of return loss. [Figure 32] 10 is a graph showing the analysis results of differential impedance by a TDR method. [Figure 33] 10 is a graph showing the analysis results of insertion loss. [Figure 34] 10 is a graph showing the analysis results of return loss. [Figure 35] 10 is a graph showing the analysis results of differential impedance by a TDR method. [Figure 36] This is a simplified diagram of FIG. 16 of Patent Document 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) The first embodiment will be described below with reference to FIGS.

[0012] 1 and 2 show exploded perspective views of an information processing device 1. As shown in FIGS. 1 and 2, the information processing device 1 includes a differential transmission assembly 2 (assembly) and a support board 3.

[0013] The differential transmission assembly 2 includes a differential transmission board set 4 and a compression connector 5 .

[0014] The differential transmission board set 4 includes a contact board 6 and a mounting board 7. The contact board 6 and the mounting board 7 are electrically connected to each other via a compression connector 5. The contact board 6 and the mounting board 7 are both differential transmission boards. The contact board 6 and the mounting board 7 are parallel to each other while being electrically connected to each other via the compression connector 5.

[0015] Two bolt fastening holes 6A are formed in the contact substrate 6. Similarly, two bolt fastening holes 7A are formed in the mounting substrate 7.

[0016] The support board 3 is typically part of a housing that houses the contact substrate 6, compression connector 5, and mounting substrate 7, and is made of, for example, aluminum or an aluminum alloy. The support board 3 includes a flat board body 8 and two nuts 9 protruding from the board body 8.

[0017] The information processing device 1 is assembled as follows: First, the compression connector 5 is mounted on the mounting board 7. Next, the mounting board 7 with the compression connector 5 mounted thereon is attached to the support board 3. At this time, the two nuts 9 on the support board 3 pass through the two bolt fastening holes 7A of the mounting board 7.

[0018] The contact board 6 is then attached to the support board 3 so as to be superimposed on the compression connector 5. Specifically, two bolts 10 are fastened to two nuts 9 on the support board 3 through two bolt fastening holes 6A in the contact board 6. As a result, the contact board 6 is pressed against the compression connector 5 and comes into contact with the compression connector 5, and as a result, the contact board 6 and the mounting board 7 are electrically connected to each other via the compression connector 5. In other words, the compression connector 5 is not mounted on the contact board 6, and the compression connector 5 and the contact board 6 come into contact with each other only when the contact board 6 is pressed against the compression connector 5.

[0019] 1 and 2, the compression connector 5 includes a plurality of compression contacts 11 and a housing 12 that holds the plurality of compression contacts 11. The plurality of compression contacts 11 form a plurality of contact rows 13. The plurality of contact rows 13 extend parallel to one another.

[0020] Here, the pitch direction, width direction, and up-down direction are defined. The pitch direction, width direction, and up-down direction are perpendicular to each other. The pitch direction is the row direction of each contact row 13. The width direction is the direction in which multiple contact rows 13 extending parallel to each other are arranged. The up-down direction is the direction in which the contact board 6 and the compression connector 5, and the compression connector 5 and the mounting board 7, face each other. Therefore, the thickness direction of the contact board 6 and the thickness direction of the mounting board 7 coincide with the up-down direction. The direction in which the contact board 6 is viewed from the compression connector 5 is referred to as the upward direction, and the direction in which the mounting board 7 is viewed from the compression connector 5 is referred to as the downward direction. The up-down direction is merely defined for convenience of explanation and does not indicate the orientation of the information processing device 1 during actual use.

[0021] Fig. 3 shows a cross-sectional view of the differential transmission assembly 2. As shown in Fig. 3, each compression contact 11 is accommodated in a contact accommodating chamber 12A of a housing 12 by press-fitting. Each compression contact 11 includes a soldered portion 20, a spring portion 21, and a press-fit portion 22. The spring portion 21 has a contact portion 21A that is elastically displaceable in the vertical direction. The spring portion 21 is supported in a cantilevered manner by the press-fit portion 22, allowing the contact portion 21A to be elastically displaceable in the vertical direction.

[0022] The contact substrate 6 is a multilayer substrate in which a plurality of conductor layers 6CL and a plurality of insulator layers 6SL are alternately stacked. The plurality of conductor layers 6CL include, in order from the compression connector 5 side toward the top, a first conductor layer 6CL1, a second conductor layer 6CL2, a third conductor layer 6CL3, a fourth conductor layer 6CL4, a fifth conductor layer 6CL5, and a sixth conductor layer 6CL6. The plurality of insulator layers 6SL include, in order from the compression connector 5 side toward the top, a first insulator layer 6SL1, a second insulator layer 6SL2, a third insulator layer 6SL3, a fourth insulator layer 6SL4, and a fifth insulator layer 6SL5. Therefore, the first conductor layer 6CL1, the first insulator layer 6SL1, the second conductor layer 6CL2, the second insulator layer 6SL2, the third conductor layer 6CL3, the third insulator layer 6SL3, the fourth conductor layer 6CL4, the fourth insulator layer 6SL4, the fifth conductor layer 6CL5, the fifth insulator layer 6SL5, and the sixth conductor layer 6CL6 are stacked in this order from the compression connector 5 side upward. The stacking direction of the contact substrate 6 coincides with the vertical direction. The second conductor layer 6CL2 is the conductor layer closest to the first conductor layer 6CL1.

[0023] Each conductor layer 6CL is typically made of copper foil, which has excellent conductivity, and each insulator layer 6SL is typically made of glass epoxy.

[0024] Similarly, the mounting board 7 is a multilayer board in which multiple conductor layers 7CL and multiple insulator layers 7SL are alternately stacked. The multiple conductor layers 7CL include, in order from the compression connector 5 side downward, a first conductor layer 7CL1, a second conductor layer 7CL2, a third conductor layer 7CL3, a fourth conductor layer 7CL4, a fifth conductor layer 7CL5, and a sixth conductor layer 7CL6. The multiple insulator layers 7SL include, in order from the compression connector 5 side downward, a first insulator layer 7SL1, a second insulator layer 7SL2, a third insulator layer 7SL3, a fourth insulator layer 7SL4, and a fifth insulator layer 7SL5. Therefore, the first conductor layer 7CL1, the first insulator layer 7SL1, the second conductor layer 7CL2, the second insulator layer 7SL2, the third conductor layer 7CL3, the third insulator layer 7SL3, the fourth conductor layer 7CL4, the fourth insulator layer 7SL4, the fifth conductor layer 7CL5, the fifth insulator layer 7SL5, and the sixth conductor layer 7CL6 are stacked in this order from the compression connector 5 side downward. The stacking direction of the mounting board 7 coincides with the up-down direction. The second conductor layer 7CL2 is the conductor layer closest to the first conductor layer 7CL1.

[0025] Each conductor layer 7CL is typically made of copper foil, which has excellent conductivity, and each insulator layer 7SL is typically made of glass epoxy.

[0026] <Contact board 6> 4 to 9 show partial bottom views of the first conductor layer 6CL1, the second conductor layer 6CL2, the third conductor layer 6CL3, the fourth conductor layer 6CL4, the fifth conductor layer 6CL5, and the sixth conductor layer 6CL6 of the contact substrate 6. In Figures 4 to 9, the conductor portions are hatched simply for ease of viewing.

[0027] First, the first conductor layer 6CL1 will be described with reference to Figures 2 and 4. As shown in Figures 2 and 4, the first conductor layer 6CL1 has a plurality of electrode pads 30 corresponding to the plurality of compression contacts 11 of the compression connector 5. That is, each electrode pad 30 is configured so that the spring portion 21 of the corresponding compression contact 11 can come into contact with it. The plurality of electrode pads 30, like the plurality of compression contacts 11, form a plurality of pad rows.

[0028] As shown in FIG. 4 , the multiple electrode pads 30 belonging to each pad row are configured by arranging two ground pads 31 and two signal pads 32 alternately in the pitch direction. That is, the ground pad 31, ground pad 31, signal pad 32, signal pad 32, ground pad 31, ground pad 31, signal pad 32, signal pad 32, ... are arranged in this order along the pitch direction. In other words, two signal pads 32 for differential transmission are arranged between two ground pads 31. Only four electrode pads 30 are shown in FIG. 4 . The four electrode pads 30 shown in FIG. 4 include two ground pads 31 and two signal pads 32 arranged between the two ground pads 31. The two ground pads 31 include a first ground pad 33 and a second ground pad 34. The two signal pads 32 include a first signal pad 35 and a second signal pad 36. The first ground pad 33, the first signal pad 35, the second signal pad 36, and the second ground pad 34 are arranged in this order along the pitch direction.

[0029] The first signal pad 35 includes a spring contact portion 35A and a via connection portion 35B. The spring contact portion 35A and the via connection portion 35B are connected to each other in the width direction and are integrally formed. For ease of explanation, a boundary 35C between the spring contact portion 35A and the via connection portion 35B is indicated by a dashed line. The spring contact portion 35A includes a substantially square base portion 35D and a tapered portion 35E that extends from the base portion 35D in the width direction so as to taper.

[0030] Similarly, the second signal pad 36 includes a spring contact portion 36A and a via connection portion 36B. The spring contact portion 36A and the via connection portion 36B are connected to each other in the width direction and are integrally formed. For ease of explanation, a boundary 36C between the spring contact portion 36A and the via connection portion 36B is indicated by a dashed line. The spring contact portion 36A includes a substantially square base portion 36D and a tapered portion 36E that extends from the base portion 36D in the width direction so as to taper.

[0031] The first ground pad 33 includes a spring contact portion 33A, a first via connection portion 33B, and a second via connection portion 33C. The first via connection portion 33B, the spring contact portion 33A, and the second via connection portion 33C are arranged in this order in the width direction. The spring contact portion 33A, the first via connection portion 33B, and the second via connection portion 33C are integrally formed. For ease of explanation, a boundary 33D between the spring contact portion 33A and the first via connection portion 33B is indicated by a dashed line. Similarly, a boundary 33E between the spring contact portion 33A and the second via connection portion 33C is indicated by a dashed line. The spring contact portion 33A includes a substantially square base portion 33F and a tapered portion 33G extending from the base portion 33F in the width direction so as to taper.

[0032] Similarly, the second ground pad 34 includes a spring contact portion 34A, a first via connection portion 34B, and a second via connection portion 34C. The first via connection portion 34B, the spring contact portion 34A, and the second via connection portion 34C are arranged in this order in the width direction. The spring contact portion 34A, the first via connection portion 34B, and the second via connection portion 34C are integrally formed. For ease of explanation, a boundary 34D between the spring contact portion 34A and the first via connection portion 34B is indicated by a dashed line. Similarly, a boundary 34E between the spring contact portion 34A and the second via connection portion 34C is indicated by a dashed line. The spring contact portion 34A includes a substantially square base portion 34F and a tapered portion 34G extending from the base portion 34F in the width direction.

[0033] 4, the first signal pad 35 and the second signal pad 36 have the same shape, and the first ground pad 33 and the second ground pad 34 have the same shape. The spring contact portion 35A of the first signal pad 35, the spring contact portion 36A of the second signal pad 36, the spring contact portion 33A of the first ground pad 33, and the spring contact portion 34A of the second ground pad 34 all have the same shape and are aligned in the pitch direction. The via connection portion 35B of the first signal pad 35, the via connection portion 36B of the second signal pad 36, the first via connection portion 33B of the first ground pad 33, and the first via connection portion 34B of the second ground pad 34 all have the same shape and are aligned in the pitch direction.

[0034] 4, the first ground pad 33 has an inner region 33P and an outer region 33Q. The inner region 33P is closer to the first signal pad 35 than a bisector 33R that bisects the pad area of ​​the first ground pad 33 in the pitch direction. The outer region 33Q is farther from the first signal pad 35 than the bisector 33R. The first ground pad 33 has a symmetrical shape in the pitch direction with respect to the bisector 33R.

[0035] Similarly, the second ground pad 34 has an inner region 34P and an outer region 34Q. The inner region 34P is closer to the second signal pad 36 than a bisector 34R that bisects the pad area of ​​the second ground pad 34 in the pitch direction. The outer region 34Q is farther from the second signal pad 36 than the bisector 34R. The second ground pad 34 has a symmetrical shape in the pitch direction with respect to the bisector 34R.

[0036] Next, the sixth conductor layer 6CL6 will be described with reference to Fig. 9. As shown in Fig. 9, the sixth conductor layer 6CL6 has a first ground pad 43, a second ground pad 44, a first signal pad 45, and a second signal pad 46, which correspond to the first ground pad 33, the second ground pad 34, the first signal pad 35, and the second signal pad 36 shown in Fig. 4, respectively.

[0037] The first ground pad 43 is composed of a first via connection portion 43A and a second via connection portion 43B. The first via connection portion 43A and the second via connection portion 43B are formed apart from each other in the width direction, but may be formed integrally with each other.

[0038] The second ground pad 44 is composed of a first via connection portion 44A and a second via connection portion 44B. The first via connection portion 44A and the second via connection portion 44B are formed apart from each other in the width direction, but may be formed integrally with each other.

[0039] The first via connection portion 43A of the first ground pad 43 is electrically connected to the first via connection portion 33B of the first ground pad 33 shown in Fig. 4 via a via hole 50A shown in Fig. 5 etc. Similarly, the second via connection portion 43B of the first ground pad 43 is electrically connected to the second via connection portion 33C of the first ground pad 33 shown in Fig. 4 via a via hole 50B shown in Fig. 5 etc.

[0040] The first via connection portion 44A of the second ground pad 44 is electrically connected to the first via connection portion 34B of the second ground pad 34 shown in Fig. 4 via a via hole 51A shown in Fig. 5 etc. Similarly, the second via connection portion 44B of the second ground pad 44 is electrically connected to the second via connection portion 34C of the second ground pad 34 shown in Fig. 4 via a via hole 51B shown in Fig. 5 etc.

[0041] The first signal pad 45 is electrically connected to the via connection portion 35B of the first signal pad 35 shown in FIG. 4 through a via hole 52 shown in FIG. 5 and the like.

[0042] The second signal pad 46 is electrically connected to the via connection portion 36B of the second signal pad 36 shown in FIG. 4 through a via hole 53 shown in FIG. 5 and the like.

[0043] Next, the second conductor layer 6CL2 to the fifth conductor layer 6CL5 will be described with reference to Figures 5 to 8. The second conductor layer 6CL2 to the fifth conductor layer 6CL5 are electrically connected to each other via via holes 50A, 50B, 51A, and 51B, and all function as ground layers.

[0044] As shown in FIG. 5, a through hole 55 is formed in the second conductor layer 6CL2. The through hole 55 has an inner peripheral edge 55A. In FIG. 5, the via holes 52 and 53 are arranged inside the inner peripheral edge 55A of the through hole 55. The via holes 50A, 50B, 51A, and 51B are arranged outside the inner peripheral edge 55A of the through hole 55. The through hole 55 includes a substantially rectangular portion 55B and two extension portions 55C extending from the rectangular portion 55B in the pitch direction. One of the two extension portions 55C extends to pass between the via holes 50A and 50B, and the other extends to pass between the via holes 51A and 51B.

[0045] As shown in FIG. 6, a through hole 56 is formed in the third conductor layer 6CL3. The through hole 56 has an inner periphery 56A. In FIG. 6, the via holes 52 and 53 are arranged inside the inner periphery 56A of the through hole 56. The via holes 50A, 50B, 51A, and 51B are arranged outside the inner periphery 56A of the through hole 56. The through hole 56 is substantially rectangular.

[0046] As shown in FIG. 7, a through hole 57 is formed in the fourth conductor layer 6CL4. The through hole 57 has an inner periphery 57A. In FIG. 7, the via holes 52 and 53 are arranged inside the inner periphery 57A of the through hole 57. The via holes 50A and 50B, 51A and 51B are arranged outside the inner periphery 57A of the through hole 57. The through hole 57 is substantially rectangular.

[0047] As shown in FIG. 8, two through holes 58 are formed in the fifth conductor layer 6CL5. Each through hole 58 has an inner periphery 58A. In FIG. 8, the via holes 52 and 53 are respectively arranged inside the inner peripheries 58A of the two through holes 58. The via holes 50A and 50B, as well as the via holes 51A and 51B, are arranged outside the inner peripheries 58A of the two through holes 58. Each through hole 58 is approximately circular.

[0048] 10 shows a projection view of an inner periphery 55A of the through hole 55, an inner periphery 56A of the through hole 56, and an inner periphery 57A of the through hole 57 projected onto the first conductor layer 6CL1 to explain the positional relationship of the through hole 55, the through hole 56, and the through hole 57 with respect to the first conductor layer 6CL1. The inner periphery 55A of the through hole 55, the inner periphery 56A of the through hole 56, and the inner periphery 57A of the through hole 57 are indicated by thick lines, and the first ground pad 33, the second ground pad 34, the first signal pad 35, and the second signal pad 36 are indicated by two-dot chain lines. For ease of explanation, an outer region 33Q of the first ground pad 33 and an outer region 34Q of the second ground pad 34 are hatched.

[0049] 10, in the contact substrate 6, the through-hole 55 is formed such that, when viewed from the top and bottom, the first signal pad 35 and the second signal pad 36 are both located inside the inner periphery 55A of the through-hole 55. That is, the inner periphery 55A of the through-hole 55 surrounds the first signal pad 35 and the second signal pad 36. In other words, the first signal pad 35 and the second signal pad 36 overlap one through-hole 55 in an unbroken manner.

[0050] Furthermore, when viewed in the up-down direction, the through hole 55 is formed to overlap with the outer region 33Q of the first ground pad 33 and the outer region 34Q of the second ground pad 34. That is, one extension portion 55C of the through hole 55 extends in the pitch direction from the rectangular portion 55B beyond the bisector 33R so as to overlap with the outer region 33Q of the first ground pad 33, and the other extension portion 55C extends in the pitch direction from the rectangular portion 55B beyond the bisector 34R so as to overlap with the outer region 34Q of the second ground pad 34.

[0051] In detail, the rectangular portion 55B of the through hole 55 does not overlap the first via connection portion 33B and the second via connection portion 33C of the first ground pad 33, or the first via connection portion 34B and the second via connection portion 34C of the second ground pad 34, but is in contact with the first via connection portion 33B and the second via connection portion 33C of the first ground pad 33, or the first via connection portion 34B and the second via connection portion 34C of the second ground pad 34 in the pitch direction.

[0052] The two extension portions 55C of the through hole 55 do not overlap the first via connection portion 33B and the second via connection portion 33C of the first ground pad 33, or the first via connection portion 34B and the second via connection portion 34C of the second ground pad 34, but are in contact in the width direction with the first via connection portion 33B and the second via connection portion 33C of the first ground pad 33, or the first via connection portion 34B and the second via connection portion 34C of the second ground pad 34.

[0053] Therefore, two dividing lines 55D that divide the two extension portions 55C of the inner periphery 55A of the through hole 55 in the pitch direction are far away from the first signal pad 35 and the second signal pad 36 in the pitch direction. This means that the second conductor layer 6CL2 is far away from the first signal pad 35 and the second signal pad 36 in the pitch direction. This makes it possible to suppress a decrease in differential impedance at the first signal pad 35 and the second signal pad 36.

[0054] 10 , in the contact substrate 6, the through holes 56 and 57 are formed to completely overlap each other when viewed from the top-bottom direction. That is, the inner peripheral edge 56A of the through hole 56 and the inner peripheral edge 57A of the through hole 57 overlap when viewed from the top-bottom direction. The through hole 56 is formed so that both the first signal pad 35 and the second signal pad 36 are located inside the inner peripheral edge 56A of the through hole 56. That is, the inner peripheral edge 56A of the through hole 56 surrounds the first signal pad 35 and the second signal pad 36. In other words, the first signal pad 35 and the second signal pad 36 overlap with one continuous through hole 56. The same is true for the through hole 57.

[0055] <Mounting board 7> 11 to 17 show partial plan views of the first conductor layer 7CL1, the second conductor layer 7CL2, the third conductor layer 7CL3, the fourth conductor layer 7CL4, the fifth conductor layer 7CL5, and the sixth conductor layer 7CL6 of the mounting board 7. In Fig. 11 to Fig. 17, the conductor portions are hatched simply for ease of viewing.

[0056] First, the first conductor layer 7CL1 will be described with reference to Figures 1 and 11. As shown in Figures 1 and 11, the first conductor layer 7CL1 has a plurality of electrode pads 60 corresponding to the plurality of compression contacts 11 of the compression connector 5. That is, each electrode pad 60 is configured so that the soldering portion 20 of the corresponding compression contact 11 can be soldered to it. The plurality of electrode pads 60, like the plurality of compression contacts 11, form a plurality of pad rows.

[0057] As shown in FIG. 11 , the electrode pads 60 in each pad row are configured by arranging two ground pads 61 and two signal pads 62 alternately in the pitch direction. That is, the ground pad 61, ground pad 61, signal pad 62, signal pad 62, ground pad 61, ground pad 61, signal pad 62, signal pad 62, ... are arranged in this order along the pitch direction. In other words, two signal pads 62 for differential transmission are arranged between two ground pads 61. Only four electrode pads 60 are shown in FIG. 11 . The four electrode pads 60 shown in FIG. 11 include two ground pads 61 and two signal pads 62 arranged between the two ground pads 61. The two ground pads 61 include a first ground pad 63 and a second ground pad 64. The two signal pads 62 include a first signal pad 65 and a second signal pad 66. The first ground pad 63, the first signal pad 65, the second signal pad 66, and the second ground pad 64 are arranged in this order along the pitch direction.

[0058] The first signal pad 65 is substantially square. The dimension in the pitch direction of the first signal pad 65 is smaller than that of the first signal pad 35 shown in Figure 4. Similarly, the dimension in the width direction of the first signal pad 65 is smaller than that of the first signal pad 35 shown in Figure 4.

[0059] The second signal pad 66 is substantially square. The dimension in the pitch direction of the second signal pad 66 is smaller than that of the second signal pad 36 shown in Figure 4. Similarly, the dimension in the width direction of the second signal pad 66 is smaller than that of the second signal pad 36 shown in Figure 4.

[0060] In this way, the first signal pad 35 and the second signal pad 36 of the contact substrate 6 are larger than the first signal pad 65 and the second signal pad 66 of the mounting substrate 7 in order to absorb positional misalignment of the contact substrate 6 relative to the compression connector 5 in the pitch direction and width direction.

[0061] Referring again to FIG. 11, the first ground pad 63 and the second ground pad 64 extend in the width direction.

[0062] As shown in FIG. 11, the first signal pad 35 and the second signal pad 36 have the same shape, and the first ground pad 33 and the second ground pad 34 have the same shape.

[0063] 11, the first ground pad 63 has an inner region 63P and an outer region 63Q. The inner region 63P is closer to the first signal pad 65 than a bisector 63R that bisects the pad area of ​​the first ground pad 63 in the pitch direction. The outer region 63Q is farther from the first signal pad 65 than the bisector 63R. The first ground pad 63 has a symmetrical shape in the pitch direction with respect to the bisector 63R.

[0064] Similarly, the second ground pad 64 has an inner region 64P and an outer region 64Q. The inner region 64P is closer to the second signal pad 66 than a bisector 64R that bisects the pad area of ​​the second ground pad 64 in the pitch direction. The outer region 64Q is farther from the second signal pad 66 than the bisector 64R. The second ground pad 64 has a symmetrical shape in the pitch direction with respect to the bisector 64R.

[0065] Next, the sixth conductor layer 7CL6 will be described with reference to Fig. 16. As shown in Fig. 16, the sixth conductor layer 7CL6 has a first ground pad 73, a second ground pad 74, a first signal pad 75, and a second signal pad 76, which correspond to the first ground pad 63, the second ground pad 64, the first signal pad 65, and the second signal pad 66 shown in Fig. 11, respectively.

[0066] The first ground pad 73 is composed of a first via connection portion 73A and a second via connection portion 73B. The first via connection portion 73A and the second via connection portion 73B are formed apart from each other in the width direction, but may be formed integrally with each other.

[0067] The second ground pad 74 is composed of a first via connection portion 74 A and a second via connection portion 74 B. The first via connection portion 74 A and the second via connection portion 74 B are formed apart from each other in the width direction, but may be formed integrally with each other.

[0068] The first via connection portion 73A of the first ground pad 73 is electrically connected to the end portion 63A in the width direction of the first ground pad 63 shown in Fig. 11 via a via hole 80A shown in Fig. 12 etc. Similarly, the second via connection portion 73B of the first ground pad 73 is electrically connected to the end portion 63A in the width direction of the first ground pad 63 shown in Fig. 11 via a via hole 80B shown in Fig. 12 etc.

[0069] The first via connection portion 74A of the second ground pad 74 is electrically connected to the end portion 64A in the width direction of the second ground pad 64 shown in Fig. 11 via a via hole 81A shown in Fig. 12 etc. Similarly, the second via connection portion 74B of the second ground pad 74 is electrically connected to the end portion 64A in the width direction of the second ground pad 64 shown in Fig. 11 via a via hole 81B shown in Fig. 12 etc.

[0070] The first signal pad 75 is electrically connected to the first signal pad 65 shown in FIG. 11 through a via hole 82 shown in FIG. 12 and other figures.

[0071] The second signal pad 76 is electrically connected to the second signal pad 66 shown in FIG. 11 through a via hole 83 shown in FIG. 12 and other figures.

[0072] Next, the second conductor layer 7CL2 to the fifth conductor layer 7CL5 will be described with reference to Figures 12 to 15. The second conductor layer 7CL2 to the fifth conductor layer 7CL5 are electrically connected to each other via via holes 80A, 80B, 81A, and 81B, and all function as ground layers.

[0073] As shown in FIG. 12, a through hole 85 is formed in the second conductor layer 7CL2. The through hole 85 has an inner periphery 85A. In FIG. 12, the via holes 82 and 83 are arranged inside the inner periphery 85A of the through hole 85. The via holes 80A, 80B, 81A, and 81B are arranged outside the inner periphery 85A of the through hole 85. The through hole 85 is substantially rectangular.

[0074] As shown in FIG. 13, a through hole 86 is formed in the third conductor layer 7CL3. The through hole 86 has an inner periphery 86A. In FIG. 13, the via holes 82 and 83 are arranged inside the inner periphery 86A of the through hole 86. The via holes 80A and 80B, the via holes 81A and 81B are arranged outside the inner periphery 86A of the through hole 86. The through hole 86 is substantially rectangular.

[0075] As shown in FIG. 14, a through hole 87 is formed in the fourth conductor layer 7CL4. The through hole 87 has an inner periphery 87A. In FIG. 14, the via holes 82 and 83 are arranged inside the inner periphery 87A of the through hole 87. The via holes 80A and 80B, the via holes 81A and 81B are arranged outside the inner periphery 87A of the through hole 87. The through hole 87 is substantially rectangular.

[0076] As shown in FIG. 15, two through holes 88 are formed in the fifth conductor layer 7CL5. Each through hole 88 has an inner periphery 88A. In FIG. 15, via holes 82 and 83 are respectively arranged inside the inner periphery 88A of the two through holes 88. Via holes 80A and 80B, as well as via holes 81A and 81B, are arranged outside the inner periphery 88A of the two through holes 88. Each through hole 88 is approximately circular.

[0077] 17 shows a projection view of an inner peripheral edge 85A of through hole 85, an inner peripheral edge 86A of through hole 86, and an inner peripheral edge 87A of through hole 87 projected onto the first conductor layer 7CL1 to explain the positional relationship of through hole 85, through hole 86, and through hole 87 with respect to the first conductor layer 7CL1. The inner peripheral edge 85A of through hole 85, the inner peripheral edge 86A of through hole 86, and the inner peripheral edge 87A of through hole 87 are indicated by thick lines, and the first ground pad 63, the second ground pad 64, the first signal pad 65, and the second signal pad 66 are indicated by dashed two-dot lines.

[0078] 17 , in the mounting substrate 7, the through hole 85 is formed such that, when viewed from the top and bottom, the first signal pad 65 and the second signal pad 66 are both located inside an inner periphery 85A of the through hole 85. That is, the inner periphery 85A of the through hole 85 surrounds the first signal pad 65 and the second signal pad 66. In other words, the first signal pad 65 and the second signal pad 66 overlap one continuous through hole 85.

[0079] Furthermore, when viewed in the up-down direction, the through hole 85 is formed spaced apart in the pitch direction from the first ground pad 63 and the second ground pad 64. Specifically, of two dividing lines 85D on the inner periphery 85A of the through hole 85 that divide the through hole 85 in the pitch direction, one is located between the first ground pad 63 and the first signal pad 65 in the pitch direction and equidistant from the first ground pad 63 and the first signal pad 65, and the other is located between the second ground pad 64 and the second signal pad 66 in the pitch direction and equidistant from the second ground pad 64 and the second signal pad 66.

[0080] 10, the dimensions in the pitch direction of the first signal pad 65 and the second signal pad 66 can be made smaller than those of the first signal pad 35 and the second signal pad 36, so that the differential impedance does not decrease so much due to parasitic capacitance. Therefore, the opening area of ​​the through-hole 85 in the second conductor layer 7CL2 is reduced, and the design prioritizes the electromagnetic shielding effect of the second conductor layer 7CL2.

[0081] 17 , in the mounting substrate 7, the through holes 85, 86, and 87 are formed to completely overlap one another when viewed from the top-bottom direction. That is, the inner peripheral edge 85A of the through hole 85, the inner peripheral edge 86A of the through hole 86, and the inner peripheral edge 87A of the through hole 87 overlap one another when viewed from the top-bottom direction. Therefore, the through hole 86 is formed so that both the first signal pad 65 and the second signal pad 66 are located inside the inner peripheral edge 86A of the through hole 86. That is, the inner peripheral edge 86A of the through hole 86 surrounds the first signal pad 65 and the second signal pad 66. In other words, the first signal pad 65 and the second signal pad 66 overlap one continuous through hole 86. The same is true for the through hole 87.

[0082] (First Modification) Next, a first modified example of the first embodiment will be described with reference to Figures 18 and 19. In Figures 18 and 19, conductor portions are hatched simply for ease of viewing.

[0083] As shown in Fig. 18, in the first modified example, the third conductor layer 6CL3 and the fourth conductor layer 6CL4 have the same configuration as the fifth conductor layer 6CL5 shown in Fig. 8. That is, as shown in Fig. 18, two through holes 90 are formed in the third conductor layer 6CL3 and the fourth conductor layer 6CL4. Each through hole 90 has an inner peripheral edge 90A. The via holes 52 and 53 are respectively arranged inside the inner peripheral edges 90A of the two through holes 90. The via holes 50A and 50B, and the via holes 51A and 51B are respectively arranged outside the inner peripheral edges 90A of the two through holes 90. Each through hole 90 is approximately circular.

[0084] In this way, the two through holes 90 formed in the third conductor layer 6CL3 and the fourth conductor layer 6CL4 are of the minimum size necessary to prevent the third conductor layer 6CL3 and the fourth conductor layer 6CL4 from being electrically connected to the via holes 52 and 53. Therefore, when viewed in the vertical direction, the third conductor layer 6CL3 and the fourth conductor layer 6CL4 overlap with the first signal pad 35 and the second signal pad 36 indicated by the two-dot chain line in Fig. 18. This results in a design that prioritizes the electromagnetic shielding effect of the third conductor layer 6CL3 and the fourth conductor layer 6CL4.

[0085] Similarly, as shown in Fig. 19, in the first modified example, the third conductor layer 7CL3 and the fourth conductor layer 7CL4 have the same configuration as the fifth conductor layer 7CL5 shown in Fig. 15. That is, as shown in Fig. 19, two through holes 91 are formed in the third conductor layer 7CL3 and the fourth conductor layer 7CL4. Each through hole 91 has an inner periphery 91A. Via holes 82 and 83 are respectively arranged inside the inner periphery 91A of the two through holes 91. Via holes 80A and 80B, and via holes 81A and 81B are arranged outside the inner periphery 91A of the two through holes 91. Each through hole 91 is approximately circular.

[0086] In this way, the two through holes 91 formed in the third conductor layer 7CL3 and the fourth conductor layer 7CL4 are of the minimum size necessary to prevent the third conductor layer 7CL3 and the fourth conductor layer 7CL4 from being electrically connected to the via holes 82 and 83. Therefore, when viewed in the vertical direction, the third conductor layer 7CL3 and the fourth conductor layer 7CL4 overlap with the first signal pad 65 and the second signal pad 66 indicated by the two-dot chain line in Fig. 19. This results in a design that prioritizes the electromagnetic shielding effect provided by the third conductor layer 7CL3 and the fourth conductor layer 7CL4.

[0087] The first modified example described above can be directly applied to the first to fourth comparative examples described later.

[0088] (First Comparative Example) A first comparative example of the present disclosure will be described below with reference to Figures 20 and 21. The following description will focus on the differences between this comparative example and the first embodiment, and redundant description will be omitted.

[0089] <Contact board 6> 20 shows a projection view of an inner periphery 55A of the through hole 55, an inner periphery 56A of the through hole 56, and an inner periphery 57A of the through hole 57 projected onto the first conductor layer 6CL1 to explain the positional relationship of the through hole 55, the through hole 56, and the through hole 57 with respect to the first conductor layer 6CL1. The inner periphery 55A of the through hole 55, the inner periphery 56A of the through hole 56, and the inner periphery 57A of the through hole 57 are indicated by thick lines, and the first ground pad 33, the second ground pad 34, the first signal pad 35, and the second signal pad 36 are indicated by two-dot chain lines. For ease of explanation, an outer region 33Q of the first ground pad 33 and an outer region 34Q of the second ground pad 34 are hatched.

[0090] As shown in FIG. 20, the contact substrate 6 in this comparative example has the same configuration as the contact substrate 6 in the first embodiment shown in FIG.

[0091] 20 , in the contact substrate 6, the through-hole 55 is formed such that, when viewed from the top-bottom direction, both the first signal pad 35 and the second signal pad 36 are located inside an inner periphery 55A of the through-hole 55. That is, the inner periphery 55A of the through-hole 55 surrounds the first signal pad 35 and the second signal pad 36. In other words, the first signal pad 35 and the second signal pad 36 overlap one continuous through-hole 55.

[0092] Furthermore, when viewed in the up-down direction, the through hole 55 is formed to overlap with the outer region 33Q of the first ground pad 33 and the outer region 34Q of the second ground pad 34. That is, one extension portion 55C of the through hole 55 extends in the pitch direction from the rectangular portion 55B beyond the bisector 33R so as to overlap with the outer region 33Q of the first ground pad 33, and the other extension portion 55C extends in the pitch direction from the rectangular portion 55B beyond the bisector 34R so as to overlap with the outer region 34Q of the second ground pad 34.

[0093] Therefore, two dividing lines 55D that divide the two extension portions 55C of the inner periphery 55A of the through hole 55 in the pitch direction are far away from the first signal pad 35 and the second signal pad 36 in the pitch direction. This means that the second conductor layer 6CL2 is far away from the first signal pad 35 and the second signal pad 36 in the pitch direction. This makes it possible to suppress a decrease in differential impedance at the first signal pad 35 and the second signal pad 36.

[0094] <Mounting board 7> 21 shows a projection view of an inner peripheral edge 85A of the through hole 85, an inner peripheral edge 86A of the through hole 86, and an inner peripheral edge 87A of the through hole 87 projected onto the first conductor layer 7CL1 to explain the positional relationship of the through hole 85, the through hole 86, and the through hole 87 with respect to the first conductor layer 7CL1. The inner peripheral edges 85A of the through hole 85, the inner peripheral edge 86A of the through hole 86, and the inner peripheral edge 87A of the through hole 87 are indicated by thick lines, and the first ground pad 63, the second ground pad 64, the first signal pad 65, and the second signal pad 66 are indicated by two-dot chain lines. For ease of explanation, an outer region 63Q of the first ground pad 63 and an outer region 64Q of the second ground pad 64 are hatched.

[0095] 21, this comparative example is different from the first embodiment in the shape of the through holes 85 of the second conductor layer 7CL2, but the other configurations are the same as those of the first embodiment. That is, the through holes 85 of this comparative example are formed wider in the pitch direction than the through holes 85 of the first embodiment shown in FIG.

[0096] 21, through hole 85 includes a substantially rectangular portion 85B and two extension portions 85C extending in the pitch direction from rectangular portion 85B. One of the two extension portions 85C extends to pass between via hole 80A and via hole 80B, and the other extends to pass between via hole 81A and via hole 81B.

[0097] When viewed in the up-down direction, the through-hole 85 is formed to overlap with the outer region 63Q of the first ground pad 63 and the outer region 64Q of the second ground pad 64. That is, one extension portion 85C of the through-hole 85 extends in the pitch direction from the rectangular portion 85B beyond the bisector 63R so as to overlap with the outer region 63Q of the first ground pad 63, and the other extension portion 85C extends in the pitch direction from the rectangular portion 85B beyond the bisector 64R so as to overlap with the outer region 64Q of the second ground pad 64.

[0098] Therefore, two dividing lines 85D that divide the two extension portions 85C of the inner periphery 85A of the through hole 85 in the pitch direction are far away from the first signal pad 65 and the second signal pad 66 in the pitch direction. This means that the second conductor layer 6CL2 is far away from the first signal pad 65 and the second signal pad 66 in the pitch direction. This makes it possible to suppress a decrease in the differential impedance at the first signal pad 65 and the second signal pad 66.

[0099] (Second Comparative Example) A second comparative example of the present disclosure will be described below with reference to Figures 22 and 23. The following description will focus on the differences between this comparative example and the first embodiment, and redundant description will be omitted.

[0100] <Contact board 6> 22 shows a projection view of an inner periphery 55A of the through hole 55, an inner periphery 56A of the through hole 56, and an inner periphery 57A of the through hole 57 projected onto the first conductor layer 6CL1 to explain the positional relationship of the through hole 55, the through hole 56, and the through hole 57 with respect to the first conductor layer 6CL1. The inner periphery 55A of the through hole 55, the inner periphery 56A of the through hole 56, and the inner periphery 57A of the through hole 57 are indicated by thick lines, and the first ground pad 33, the second ground pad 34, the first signal pad 35, and the second signal pad 36 are indicated by two-dot chain lines. For ease of explanation, an outer region 33Q of the first ground pad 33 and an outer region 34Q of the second ground pad 34 are hatched.

[0101] As shown in FIG. 22, the contact substrate 6 in this comparative example has the same configuration as the contact substrate 6 in the first embodiment shown in FIG.

[0102] 22 , in the contact substrate 6, the through-hole 55 is formed such that, when viewed from the top-bottom direction, both the first signal pad 35 and the second signal pad 36 are located inside an inner periphery 55A of the through-hole 55. That is, the inner periphery 55A of the through-hole 55 surrounds the first signal pad 35 and the second signal pad 36. In other words, the first signal pad 35 and the second signal pad 36 overlap one continuous through-hole 55.

[0103] Furthermore, when viewed in the up-down direction, the through hole 55 is formed to overlap with the outer region 33Q of the first ground pad 33 and the outer region 34Q of the second ground pad 34. That is, one extension portion 55C of the through hole 55 extends in the pitch direction from the rectangular portion 55B beyond the bisector 33R so as to overlap with the outer region 33Q of the first ground pad 33, and the other extension portion 55C extends in the pitch direction from the rectangular portion 55B beyond the bisector 34R so as to overlap with the outer region 34Q of the second ground pad 34.

[0104] Therefore, two dividing lines 55D that divide the two extension portions 55C of the inner periphery 55A of the through hole 55 in the pitch direction are far away from the first signal pad 35 and the second signal pad 36 in the pitch direction. This means that the second conductor layer 6CL2 is far away from the first signal pad 35 and the second signal pad 36 in the pitch direction. This makes it possible to suppress a decrease in differential impedance at the first signal pad 35 and the second signal pad 36.

[0105] <Mounting board 7> 23 shows a projection view of an inner peripheral edge 85A of the through hole 85, an inner peripheral edge 86A of the through hole 86, and an inner peripheral edge 87A of the through hole 87 projected onto the first conductor layer 7CL1 to explain the positional relationship of the through hole 85, the through hole 86, and the through hole 87 with respect to the first conductor layer 7CL1. The inner peripheral edges 85A of the through hole 85, the inner peripheral edge 86A of the through hole 86, and the inner peripheral edge 87A of the through hole 87 are indicated by thick lines, and the first ground pad 63, the second ground pad 64, the first signal pad 65, and the second signal pad 66 are indicated by two-dot chain lines. For ease of explanation, an inner region 63P and an outer region 63Q of the first ground pad 63 and an inner region 64P and an outer region 64Q of the second ground pad 64 are hatched.

[0106] 23, this comparative example is different from the first embodiment in the shape of the through holes 85 of the second conductor layer 7CL2, but the other configurations are the same as those of the first embodiment. That is, the through holes 85 of this comparative example are formed wider in the pitch direction than the through holes 85 of the first embodiment shown in FIG.

[0107] 23 , the through-hole 85 is formed so as not to overlap with the outer region 63Q of the first ground pad 63 and the outer region 64Q of the second ground pad 64 when viewed in the up-down direction. Furthermore, the through-hole 85 is formed so as not to overlap with the inner region 63P of the first ground pad 63 and the inner region 64P of the second ground pad 64 when viewed in the up-down direction. However, the through-hole 85 extends in the pitch direction so as to be in contact with the inner region 63P of the first ground pad 63 and the inner region 64P of the second ground pad 64 when viewed in the up-down direction.

[0108] That is, one of two dividing lines 85D of the inner periphery 85A of the through hole 85 that divides the through hole 85 in the pitch direction overlaps with a contour 63S on the first signal pad 65 side of the first ground pad 63, and the other overlaps with a contour 64S on the second signal pad 66 side of the second ground pad 64. By moving the second conductor layer 6CL2 away from the first signal pad 65 and the second signal pad 66 in the pitch direction in this way, a decrease in the differential impedance at the first signal pad 65 and the second signal pad 66 is suppressed, and the opening area of ​​the through hole 85 in the second conductor layer 7CL2 is reduced, ensuring the electromagnetic shielding effect of the second conductor layer 7CL2.

[0109] However, in this comparative example, the through hole 85 may be formed to overlap the inner region 63P of the first ground pad 63 and the inner region 64P of the second ground pad 64 as long as it does not overlap the outer region 63Q of the first ground pad 63 and the outer region 64Q of the second ground pad 64 when viewed in the up-down direction. That is, the through hole 85 may extend beyond the contour 63S of the first ground pad 63 in the pitch direction to overlap with the inner region 63P, or may extend beyond the contour 64S of the second ground pad 64 in the pitch direction to overlap with the inner region 64P. Even in this case, it is possible to achieve both the effect of suppressing a decrease in differential impedance in the first signal pad 65 and the second signal pad 66 and the electromagnetic shielding effect provided by the second conductor layer 7CL2.

[0110] (Third Comparative Example) A third comparative example of the present disclosure will be described below with reference to Figures 24 and 25. The following description will focus on the differences between this comparative example and the first embodiment, and redundant description will be omitted.

[0111] <Contact board 6> 24 shows a projection view of an inner periphery 55A of the through hole 55, an inner periphery 56A of the through hole 56, and an inner periphery 57A of the through hole 57 projected onto the first conductor layer 6CL1 to explain the positional relationship of the through hole 55, the through hole 56, and the through hole 57 with respect to the first conductor layer 6CL1. The inner periphery 55A of the through hole 55, the inner periphery 56A of the through hole 56, and the inner periphery 57A of the through hole 57 are indicated by thick lines, and the first ground pad 33, the second ground pad 34, the first signal pad 35, and the second signal pad 36 are indicated by two-dot chain lines. For ease of explanation, an inner region 33P and an outer region 33Q of the first ground pad 33 and an inner region 34P and an outer region 34Q of the second ground pad 34 are hatched.

[0112] 24, this comparative example is different from the first embodiment in the shape of the through holes 55 of the first conductor layer 6CL1, but the other configurations are the same as those of the first embodiment. That is, the through holes 55 of this comparative example are formed narrower in the pitch direction than the through holes 55 of the first embodiment shown in FIG. 10. Furthermore, the through holes 55 of this comparative example are substantially rectangular.

[0113] 24 , the through hole 55 is formed so as not to overlap the outer region 33Q of the first ground pad 33 and the outer region 34Q of the second ground pad 34 when viewed in the up-down direction. However, the through hole 55 extends in the pitch direction so as to overlap the inner region 33P of the first ground pad 33 and the inner region 34P of the second ground pad 34 when viewed in the up-down direction. That is, the through hole 55 extends beyond the contour 33S of the first ground pad 33 on the first signal pad 35 side in the pitch direction to overlap with the inner region 33P, and also extends beyond the contour 34S of the second ground pad 34 on the second signal pad 36 side in the pitch direction to overlap with the inner region 34P. In this way, by moving the second conductor layer 6CL2 away from the first signal pad 35 and the second signal pad 36 in the pitch direction, the reduction in differential impedance at the first signal pad 35 and the second signal pad 36 is suppressed, and the opening area of ​​the through hole 55 in the second conductor layer 6CL2 is reduced, ensuring the electromagnetic shielding effect of the second conductor layer 6CL2.

[0114] However, in this comparative example, one of two dividing lines 55D of the inner periphery 55A of the through hole 55 that divide the through hole 55 in the pitch direction may overlap with the contour 33S of the first ground pad 33, and the other may overlap with the contour 34S of the second ground pad 34. In other words, the through hole 55 may be formed so as to contact the inner region 33P of the first ground pad 33 and the inner region 34P of the second ground pad 34 when viewed in the up-down direction. Even in this case, it is possible to achieve both the effect of suppressing a decrease in differential impedance in the first signal pad 35 and the second signal pad 36 and the electromagnetic shielding effect provided by the second conductor layer 6CL2.

[0115] <Mounting board 7> 25 shows a projection view of an inner peripheral edge 85A of the through hole 85, an inner peripheral edge 86A of the through hole 86, and an inner peripheral edge 87A of the through hole 87 projected onto the first conductor layer 7CL1 to explain the positional relationship of the through hole 85, the through hole 86, and the through hole 87 with respect to the first conductor layer 7CL1. The inner peripheral edges 85A of the through hole 85, the inner peripheral edge 86A of the through hole 86, and the inner peripheral edge 87A of the through hole 87 are indicated by thick lines, and the first ground pad 63, the second ground pad 64, the first signal pad 65, and the second signal pad 66 are indicated by two-dot chain lines. For ease of explanation, an outer region 63Q of the first ground pad 63 and an outer region 64Q of the second ground pad 64 are hatched.

[0116] 25, this comparative example is different from the first embodiment in the shape of the through holes 85 of the second conductor layer 7CL2, but the other configurations are the same as those of the first embodiment. That is, the through holes 85 of this comparative example are formed wider in the pitch direction than the through holes 85 of the first embodiment shown in FIG.

[0117] 25, through hole 85 includes a substantially rectangular portion 85B and two extension portions 85C extending in the pitch direction from rectangular portion 85B. One of the two extension portions 85C extends to pass between via hole 80A and via hole 80B, and the other extends to pass between via hole 81A and via hole 81B.

[0118] When viewed in the up-down direction, the through-hole 85 is formed to overlap with the outer region 63Q of the first ground pad 63 and the outer region 64Q of the second ground pad 64. That is, one extension portion 85C of the through-hole 85 extends in the pitch direction from the rectangular portion 85B beyond the bisector 63R so as to overlap with the outer region 63Q of the first ground pad 63, and the other extension portion 85C extends in the pitch direction from the rectangular portion 85B beyond the bisector 64R so as to overlap with the outer region 64Q of the second ground pad 64.

[0119] Therefore, two dividing lines 85D that divide the two extension portions 85C of the inner periphery 85A of the through hole 85 in the pitch direction are far away from the first signal pad 65 and the second signal pad 66 in the pitch direction. This means that the second conductor layer 6CL2 is far away from the first signal pad 65 and the second signal pad 66 in the pitch direction. This makes it possible to suppress a decrease in the differential impedance at the first signal pad 65 and the second signal pad 66.

[0120] (Fourth Comparative Example) A fourth comparative example of the present disclosure will be described below with reference to Figures 26 and 27. The following description will focus on the differences between this comparative example and the first embodiment, and redundant description will be omitted.

[0121] <Contact board 6> 26 shows a projection view of an inner peripheral edge 55A of through hole 55, an inner peripheral edge 56A of through hole 56, and an inner peripheral edge 57A of through hole 57 projected onto the first conductor layer 6CL1 to explain the positional relationship of through hole 55, through hole 56, and through hole 57 with respect to the first conductor layer 6CL1. The inner peripheral edge 55A of through hole 55, the inner peripheral edge 56A of through hole 56, and the inner peripheral edge 57A of through hole 57 are indicated by thick lines, and the first ground pad 33, the second ground pad 34, the first signal pad 35, and the second signal pad 36 are indicated by dashed two-dot lines.

[0122] 26, this comparative example is different from the first embodiment in the shape of the through holes 55 of the first conductor layer 6CL1, but the other configurations are the same as those of the first embodiment. That is, the through holes 55 of this comparative example are formed narrower in the pitch direction than the through holes 55 of the first embodiment shown in FIG. 10. Furthermore, the through holes 55 of this comparative example are substantially rectangular.

[0123] 26 , when viewed in the up-down direction, the through hole 55 is formed spaced apart from the first ground pad 33 and the second ground pad 34 in the pitch direction. Specifically, one of two dividing lines 55D dividing the through hole 55 in the pitch direction is between the first ground pad 33 and the first signal pad 35 in the pitch direction and is positioned at an equal distance from the first ground pad 33 and the first signal pad 35, and the other is between the second ground pad 34 and the second signal pad 36 in the pitch direction and is positioned at an equal distance from the second ground pad 34 and the second signal pad 36. In this way, the opening area of ​​the through hole 55 in the second conductor layer 6CL2 is reduced, giving priority to the electromagnetic shielding effect of the second conductor layer 6CL2.

[0124] <Mounting board 7> 27 shows a projection view of an inner peripheral edge 85A of the through hole 85, an inner peripheral edge 86A of the through hole 86, and an inner peripheral edge 87A of the through hole 87 projected onto the first conductor layer 7CL1 to explain the positional relationship of the through hole 85, the through hole 86, and the through hole 87 with respect to the first conductor layer 7CL1. The inner peripheral edges 85A of the through hole 85, the inner peripheral edge 86A of the through hole 86, and the inner peripheral edge 87A of the through hole 87 are indicated by thick lines, and the first ground pad 63, the second ground pad 64, the first signal pad 65, and the second signal pad 66 are indicated by two-dot chain lines. For ease of explanation, an outer region 63Q of the first ground pad 63 and an outer region 64Q of the second ground pad 64 are hatched.

[0125] 27, this comparative example is different from the first embodiment in the shape of the through holes 85 of the second conductor layer 7CL2, but the other configurations are the same as those of the first embodiment. That is, the through holes 85 of this comparative example are formed wider in the pitch direction than the through holes 85 of the first embodiment shown in FIG.

[0126] 27, through hole 85 includes a substantially rectangular portion 85B and two extension portions 85C extending in the pitch direction from rectangular portion 85B. One of the two extension portions 85C extends to pass between via hole 80A and via hole 80B, and the other extends to pass between via hole 81A and via hole 81B.

[0127] When viewed in the up-down direction, the through-hole 85 is formed to overlap with the outer region 63Q of the first ground pad 63 and the outer region 64Q of the second ground pad 64. That is, one extension portion 85C of the through-hole 85 extends in the pitch direction from the rectangular portion 85B beyond the bisector 63R so as to overlap with the outer region 63Q of the first ground pad 63, and the other extension portion 85C extends in the pitch direction from the rectangular portion 85B beyond the bisector 64R so as to overlap with the outer region 64Q of the second ground pad 64.

[0128] Therefore, two dividing lines 85D that divide the two extension portions 85C of the inner periphery 85A of the through hole 85 in the pitch direction are far away from the first signal pad 65 and the second signal pad 66 in the pitch direction. This means that the second conductor layer 6CL2 is far away from the first signal pad 65 and the second signal pad 66 in the pitch direction. This makes it possible to suppress a decrease in the differential impedance at the first signal pad 65 and the second signal pad 66.

[0129] (Fifth Comparative Example) Next, a fifth comparative example of the present disclosure will be described with reference to Figures 28 and 29. Below, the differences between this comparative example and the first embodiment will be mainly described, and overlapping descriptions will be omitted.

[0130] Fig. 28 shows a partial bottom view of the second conductor layer 6CL2, the third conductor layer 6CL3, and the fourth conductor layer 6CL4 of the contact substrate 6 in this comparative example. Fig. 29 shows a partial plan view of the second conductor layer 7CL2, the third conductor layer 7CL3, and the fourth conductor layer 7CL4 of the mounting substrate 7 in this comparative example. In Figs. 28 and 29, the conductor portions are hatched simply for ease of viewing.

[0131] In comparison with the first embodiment described above, this comparative example differs from the first embodiment in the shapes of the second conductor layer 6CL2, the third conductor layer 6CL3, and the fourth conductor layer 6CL4 of the contact substrate 6 and the second conductor layer 7CL2, the third conductor layer 7CL3, and the fourth conductor layer 7CL4 of the mounting substrate 7, but the other configurations are the same as those of the first embodiment described above.

[0132] <Contact board 6> As shown in FIG. 28, two through holes 100 are formed in the second conductor layer 6CL2 instead of the through hole 55 shown in FIG. 5. Each through hole 100 has an inner periphery 100A. In FIG. 28, the via hole 52 and the via hole 53 are respectively arranged inside the inner periphery 100A of the two through holes 100. The via holes 50A and 50B, the via holes 51A and 51B are arranged outside the inner periphery 100A of the two through holes 100. Each through hole 58 is substantially circular. The third conductor layer 6CL3 and the fourth conductor layer 6CL4 have the same shape as the second conductor layer 6CL2.

[0133] <Mounting board 7> As shown in FIG. 29, two through holes 101 are formed in the second conductor layer 7CL2 instead of the through hole 85 shown in FIG. 12. Each through hole 101 has an inner periphery 101A. In FIG. 29, the via hole 82 and the via hole 83 are respectively arranged inside the inner periphery 101A of the two through holes 101. The via holes 80A and 80B, the via holes 81A and 81B are arranged outside the inner periphery 101A of the two through holes 101. Each through hole 101 is substantially circular. The third conductor layer 7CL3 and the fourth conductor layer 7CL4 have the same shape as the second conductor layer 7CL2.

[0134] (First transmission signal quality analysis) Next, the transmission signal quality (Signal Integrity) in the differential transmission substrate sets 4 of the first embodiment and the first to fourth comparative examples was analyzed, and the analysis results will be reported with reference to FIGS. 30 to 32.

[0135] The analysis software used was Ansys HFSS (registered trademark) manufactured by ANSYS, Inc. The thicknesses of the multiple conductor layers 6CL and 7CL were each 18 micrometers, the first insulator layer 6SL1, the fifth insulator layer 6SL5, the first insulator layer 7SL1, and the fifth insulator layer 7SL5 were each 100 micrometers, and the second insulator layer 6SL2, the third insulator layer 6SL3, the fourth insulator layer 6SL4, the second insulator layer 7SL2, the third insulator layer 7SL3, and the fourth insulator layer 7SL4 were each 200 micrometers. The pitch of the multiple compression contacts 11 was 0.7 millimeters. In FIG. 3, the first conductor layer 6CL1 and the first conductor layer 7CL1 were vertically spaced apart by 0.7 millimeters. The via holes 50A, 50B, 51A, and 51B of the contact substrate 6 shown in Figures 5 to 8 all had a diameter of 0.12 mm. The via holes 80A, 80B, 81A, and 81B of the mounting substrate 7 shown in Figures 12 to 15 all had a diameter of 0.15 mm. The dielectric constants of the insulator layers 6SL and 7SL were set to 3.5.

[0136] Fig. 30 is a graph showing the analysis results of insertion loss in differential transmission using the differential transmission substrate set 4. In the graph of Fig. 30, the horizontal axis represents frequency and the vertical axis represents insertion loss. In Fig. 30, approximate curves A to E correspond to the first embodiment and first to fourth comparative examples, respectively.

[0137] Fig. 31 is a graph showing the analysis results of return loss in differential transmission using the differential transmission substrate set 4. In the graph of Fig. 31, the horizontal axis represents frequency and the vertical axis represents return loss. In Fig. 31, approximate curves A to E correspond to the first embodiment and first to fourth comparative examples, respectively.

[0138] FIG. 32 is a graph showing the results of a TDR (time domain reflectometry) analysis of differential transmission using the differential transmission substrate set 4. In the graph of FIG. 32, the horizontal axis represents time, and the vertical axis represents differential impedance. In FIG. 32, approximate curves A to E correspond to the first embodiment and first to fourth comparative examples, respectively. As shown in FIG. 32, in the TDR analysis, the differential transmission substrate set 4 is designed, as an example, to have a differential impedance of 85Ω. In FIG. 32, the differential impedance at 0.065 nsec on the horizontal axis represents the differential impedance at the first signal pad 35 and the second signal pad 36 of the contact substrate 6, and the differential impedance at 0.095 nsec on the horizontal axis represents the differential impedance at the first signal pad 65 and the second signal pad 66 of the mounting substrate 7.

[0139] 30, it can be seen that the differential transmission substrate sets 4 of the first embodiment and the first to fourth comparative examples all have excellent transmission characteristics. In particular, it can be seen that the first embodiment and the first to third comparative examples have particularly low insertion loss compared to the fourth comparative example.

[0140] 31, it can be seen that the differential transmission substrate sets 4 of the first embodiment and the first to fourth comparative examples all have excellent transmission characteristics. In particular, it can be seen that the first embodiment and the first to third comparative examples have lower return loss than the fourth comparative example. It can also be seen that the first embodiment has particularly lower return loss than the first to fourth comparative examples.

[0141] It can be seen from FIG. 32 that the differential impedance in the differential transmission substrate sets 4 of the first embodiment and the first to fourth comparative examples falls within a narrow range of ±13Ω from the design value of 85Ω.

[0142] 32, focusing on the differential impedance at 0.065 nsec on the horizontal axis, i.e., the differential impedance at the first signal pad 35 and the second signal pad 36 of the contact substrate 6, it can be seen that the first embodiment and the first to third comparative examples are able to suppress the decrease in differential impedance compared to the fourth comparative example. This is thought to be because, as shown in FIG. 10, for example, in the first embodiment and the first to third comparative examples, the second conductor layer 6CL2, i.e., the inner periphery 55A of the through hole 55, is sufficiently far away from the first signal pad 35 and the second signal pad 36 of the contact substrate 6 in the pitch direction. In FIG. 30, the insertion loss in the first embodiment and the first to third comparative examples is smaller than that in the fourth comparative example. This is thought to be because the decrease in differential impedance at the first signal pad 35 and the second signal pad 36 of the contact substrate 6 was effectively suppressed. Similarly, in Figure 31, the return loss in the first embodiment and the first to third comparative examples is less than the return loss in the fourth comparative example, which is thought to be because the decrease in differential impedance at the first signal pad 35 and the second signal pad 36 of the contact substrate 6 was effectively suppressed.

[0143] 32, focusing on the differential impedance at 0.095 nsec on the horizontal axis, i.e., the differential impedance at the first signal pad 65 and the second signal pad 66 of the mounting board 7, it can be seen that the differential impedance in the first embodiment is further reduced compared to the first to fourth comparative examples. This is thought to be because, as shown in FIG. 17, in the first embodiment, the second conductor layer 7CL2, i.e., the through hole 85, is narrow in the pitch direction. However, the reduction in differential impedance at the first signal pad 65 and the second signal pad 66 of the mounting board 7 is not a significant problem. This is because the reduction in differential impedance at the first signal pad 65 and the second signal pad 66 of the mounting board 7 is about one-fifth of that at the first signal pad 35 and the second signal pad 36 of the contact board 6.

[0144] 32, focusing on the differential impedance at the compression contact 11, i.e., the 0.08 nsec horizontal axis, it can be seen that the increase in differential impedance is suppressed in the first embodiment compared to the first to fourth comparative examples. As described above, this is believed to be due to the fact that the differential impedance at the first signal pad 65 and the second signal pad 66 of the mounting board 7 is even lower in the first embodiment compared to the first to fourth comparative examples, i.e., the 0.095 nsec horizontal axis. The reason why the return loss in the first embodiment is particularly lower than that in the first to fourth comparative examples, as shown in FIG. 31, is believed to be because the increase in differential impedance at the compression contact 11 is suppressed in the first embodiment, as shown in FIG. 32. In other words, in the first embodiment, the effect of suppressing the decrease in differential impedance at the first signal pad 65 and the second signal pad 66 of the mounting board 7 is deliberately moderated, thereby reducing the return loss.

[0145] (Second transmission signal quality analysis) Next, the transmission signal quality of the differential transmission board set 4 in which the first modification example was applied to the above-described first embodiment and first to fourth comparative examples, and the differential transmission board set 4 in the fifth comparative example, was analyzed, and the analysis results will be reported with reference to Fig. 33 to Fig. 35. Note that the application of the first modification example to the first embodiment means the first modification example itself.

[0146] The analysis software used was Ansys HFSS (registered trademark) manufactured by ANSYS, Inc. The thicknesses of the multiple conductor layers 6CL and 7CL were each 18 micrometers, the first insulator layer 6SL1, the fifth insulator layer 6SL5, the first insulator layer 7SL1, and the fifth insulator layer 7SL5 were each 100 micrometers, and the second insulator layer 6SL2, the third insulator layer 6SL3, the fourth insulator layer 6SL4, the second insulator layer 7SL2, the third insulator layer 7SL3, and the fourth insulator layer 7SL4 were each 200 micrometers. The pitch of the multiple compression contacts 11 was 0.7 millimeters. In FIG. 3, the first conductor layer 6CL1 and the first conductor layer 7CL1 were vertically spaced apart by 0.7 millimeters. The via holes 50A, 50B, 51A, and 51B of the contact substrate 6 shown in Figures 5 to 8 all had a diameter of 0.12 mm. The via holes 80A, 80B, 81A, and 81B of the mounting substrate 7 shown in Figures 12 to 15 all had a diameter of 0.15 mm. The dielectric constants of the insulator layers 6SL and 7SL were set to 3.5.

[0147] Fig. 33 is a graph showing the analysis results of insertion loss in differential transmission using the differential transmission substrate set 4. In the graph of Fig. 33, the horizontal axis represents frequency and the vertical axis represents insertion loss. In Fig. 33, approximate curve A corresponds to the first embodiment, approximate curve A-dashed to approximate curve E-dashed correspond to the first embodiment and the first to fourth comparative examples to which the first modified example has been applied, respectively, and approximate curve F corresponds to the fifth comparative example.

[0148] Fig. 34 is a graph showing the analysis results of return loss in differential transmission using the differential transmission substrate set 4. In the graph of Fig. 34, the horizontal axis represents frequency and the vertical axis represents return loss. In Fig. 34, approximate curve A corresponds to the first embodiment, approximate curve A-dashed to approximate curve E-dashed correspond to the first embodiment and the first to fourth comparative examples to which the first modified example has been applied, respectively, and approximate curve F corresponds to the fifth comparative example.

[0149] FIG. 35 is a graph showing the results of a TDR (time domain reflectometry) analysis of differential transmission using the differential transmission substrate set 4. In the graph of FIG. 35, the horizontal axis represents time and the vertical axis represents differential impedance. In FIG. 35, approximate curve A corresponds to the first embodiment, approximate curves A-dashed to E-dashed correspond to the first embodiment and the first to fourth comparative examples to which the first modification has been applied, respectively, and approximate curve F corresponds to the fifth comparative example. As shown in FIG. 35, in the TDR analysis, the differential transmission substrate set 4 is designed, as an example, to have a differential impedance of 85 Ω. In FIG. 35, the differential impedance at 0.065 nsec on the horizontal axis represents the differential impedance at the first signal pad 35 and the second signal pad 36 on the contact substrate 6, and the differential impedance at 0.095 nsec on the horizontal axis represents the differential impedance at the first signal pad 65 and the second signal pad 66 on the mounting substrate 7.

[0150] According to FIG. 33, when the first modified example is applied to the first embodiment and the first to fourth comparative examples, the insertion loss increases slightly, but it can be seen that it is significantly less than the insertion loss in the fifth comparative example.

[0151] According to FIG. 34, when the first modification example is applied to the first embodiment and the first to fourth comparative examples, the return loss increases slightly, but it can be seen that it is significantly less than the return loss in the fifth comparative example.

[0152] According to FIG. 35, when the first modified example is applied to the first embodiment and the first to fourth comparative examples, the decrease in differential impedance at the first signal pad 35 and the second signal pad 36 of the contact substrate 6 becomes slightly larger, but it can be seen that this decrease is significantly smaller than the decrease in the fifth comparative example.

[0153] The first embodiment of the present disclosure has been described above.

[0154] The first embodiment has the following features. 1 to 3, the differential transmission board set 4 is composed of a mounting board 7 on which a compression connector 5 is mounted and a contact board 6 that is brought into contact with the compression connector 5. The contact board 6 and the mounting board 7 are electrically connected to each other via the compression connector 5. The compression connector 5 includes four compression contacts 11 arranged in a row, each of which includes a soldering portion 20 and a spring portion 21, and a housing 12 that holds the four compression contacts 11. As shown in FIG. 3, the mounting board 7 is a multilayer board in which multiple conductor layers 7CL and multiple insulator layers 7SL are alternately stacked. The contact board 6 is a multilayer board in which multiple conductor layers 6CL and multiple insulator layers 6SL are alternately stacked. In the mounting board 7, the multiple conductor layers 7CL include, in this order from the compression connector 5 side, a first conductor layer 7CL1 and a second conductor layer 7CL2. In the contact board 6, the multiple conductor layers 6CL include, in this order from the compression connector 5 side, a first conductor layer 6CL1 and a second conductor layer 6CL2. 11, in the mounting board 7, the first conductor layer 7CL1 has four electrode pads 60 corresponding to the four compression contacts 11. The four electrode pads 60 include a first signal pad 65, a second signal pad 66, a first ground pad 63, and a second ground pad 64. The first ground pad 63, the first signal pad 65, the second signal pad 66, and the second ground pad 64 are arranged in this order along the pitch direction (first direction). The soldering portions 20 of the four compression contacts 11 can be soldered to the first ground pad 63, the first signal pad 65, the second signal pad 66, and the second ground pad 64, respectively. 4, in the contact substrate 6, the first conductor layer 6CL1 has four electrode pads 30 corresponding to the four compression contacts 11. The four electrode pads 30 include a first signal pad 35, a second signal pad 36, a first ground pad 33, and a second ground pad 34. The first ground pad 33, the first signal pad 35, the second signal pad 36, and the second ground pad 34 are arranged in this order along the pitch direction (first direction). The spring portions 21 of the four compression contacts 11 can come into contact with the first ground pad 33, the first signal pad 35, the second signal pad 36, and the second ground pad 34, respectively. 12, in the mounting board 7, the second conductor layer 7CL2 is a ground layer and has a through hole 85 formed therein. As shown in Fig. 17, in the mounting board 7, the through hole 85 is formed such that both the first signal pad 65 and the second signal pad 66 are located inside an inner periphery 85A of the through hole 85 when viewed in the up-down direction (stacking direction). As shown in Fig. 11, in the mounting board 7, the first ground pad 63 includes an inner region 63P that is closer to the first signal pad 65 than a bisector 63R that bisects the pad area of ​​the first ground pad 63 in the pitch direction, and an outer region 63Q that is farther from the first signal pad 65 than the bisector 63R. In the mounting board 7, the second ground pad 64 includes an inner region 64P that is closer to the second signal pad 66 than the bisector 64R that bisects the pad area of ​​the second ground pad 64 in the pitch direction, and an outer region 64Q that is farther from the second signal pad 66 than the bisector 64R. As shown in Fig. 5, in the contact substrate 6, the second conductor layer 6CL2 is a ground layer and has a through hole 55 formed therein. As shown in Fig. 10, in the contact substrate 6, the through hole 55 is formed so that both the first signal pad 35 and the second signal pad 36 are located inside an inner peripheral edge 55A of the through hole 55 when viewed in the up-down direction (stacking direction). As shown in Fig. 4, in the contact substrate 6, the first ground pad 33 includes an inner region 33P that is closer to the first signal pad 35 than a bisector 33R that bisects the pad area of ​​the first ground pad 33 in the pitch direction, and an outer region 33Q that is farther from the first signal pad 35 than the bisector 33R. In the contact substrate 6, the second ground pad 34 includes an inner region 34P that is closer to the second signal pad 36 than a bisector 34R that bisects the pad area of ​​the second ground pad 34 in the pitch direction, and an outer region 34Q that is farther from the second signal pad 36 than the bisector 34R. 10 of the first embodiment, in the contact substrate 6, the through-hole 55 is formed to overlap with the outer region 33Q of the first ground pad 33 and the outer region 34Q of the second ground pad 34 when viewed in the vertical direction. On the other hand, as shown in FIG. 17 of the first embodiment, in the mounting substrate 7, the through-hole 85 is formed away from the first ground pad 63 and the second ground pad 64 when viewed in the vertical direction. According to the above configuration, a differential transmission substrate set 4 having excellent transmission characteristics is realized, as shown in Fig. 30 and Fig. 31. In particular, it is possible to realize excellent transmission characteristics compared to the first to fourth comparative examples shown by approximate curves B, C, D, and E.

[0155] The first modified example has the following features. 19, in the mounting board 7, the third conductor layer 7CL3 is a ground layer and overlaps in the vertical direction with the first signal pad 65 and the second signal pad 66. Also, as shown in Fig. 18, in the contact board 6, the third conductor layer 6CL3 is a ground layer and overlaps in the vertical direction with the first signal pad 35 and the second signal pad 36. The above configuration also makes it possible to realize a differential transmission substrate set 4 having excellent transmission characteristics, as shown in Figures 33 and 34. Furthermore, an electromagnetic shielding effect can be expected in the third conductor layer 7CL3 and the third conductor layer 6CL3.

[0156] The first embodiment has the following features. That is, as shown in FIGS. 13 and 14 , in the mounting board 7, the third conductor layer 7CL3 and the fourth conductor layer 7CL4 are ground layers in which a through hole 86 and a through hole 87 are respectively formed. As shown in FIG. 17 , in the mounting board 7, the through hole 86 of the third conductor layer 7CL3 is formed such that the first signal pad 65 and the second signal pad 66 are both located inside an inner periphery 86A of the through hole 86 when viewed from the top-bottom direction. Similarly, the through hole 87 of the fourth conductor layer 7CL4 is formed such that the first signal pad 65 and the second signal pad 66 are both located inside an inner periphery 87A of the through hole 87 when viewed from the top-bottom direction. As shown in FIG. 15 , in the mounting board 7, the fifth conductor layer 7CL5 is a ground layer and overlaps the first signal pad 65 and the second signal pad 66 in the top-bottom direction (please refer to FIG. 19 for a clearer understanding). 6 and 7, in the contact substrate 6, the third conductor layer 6CL3 and the fourth conductor layer 6CL4 are ground layers, and have through holes 56 and 57 formed therein, respectively. As shown in FIG. 10, in the contact substrate 6, the through hole 56 of the third conductor layer 6CL3 is formed such that the first signal pad 35 and the second signal pad 36 are both located inside an inner periphery 56A of the through hole 56 when viewed from the top-bottom direction. Similarly, the through hole 57 of the fourth conductor layer 6CL4 is formed such that the first signal pad 35 and the second signal pad 36 are both located inside an inner periphery 57A of the through hole 57 when viewed from the top-bottom direction. As shown in FIG. 8, in the contact substrate 6, the fifth conductor layer 6CL5 is a ground layer, and overlaps the first signal pad 35 and the second signal pad 36 in the top-bottom direction (please refer to FIG. 18 for a clearer understanding). According to the above configuration, as shown in FIGS. 30 and 31, a differential transmission board set 4 having excellent transmission characteristics is realized.

[0157] As shown in FIG. 2, the compression connector 5 is configured by arranging a plurality of compression contact groups 11G, each of which is made up of four compression contacts 11 arranged in a row.

[0158] The plurality of conductor layers 6CL of the contact substrate 6 include, in order from the compression connector 5 side, a first conductor layer 6CL1, a second conductor layer 6CL2,..., an (N-1)th conductor layer, and an Nth conductor layer, where N is a natural number equal to or greater than four. In the first embodiment, the (N-1)th conductor layer and the Nth conductor layer correspond to the fifth conductor layer 6CL5 and the sixth conductor layer 6CL6, respectively. The sixth conductor layer 6CL6 (Nth conductor layer) includes a first signal pad 45 and a second signal pad 46 electrically connected to the first signal pad 35 and the second signal pad 36 of the first conductor layer 6CL1, respectively. As shown in FIGS. 8 and 9, the fifth conductor layer 6CL5 (the (N-1)th conductor layer) is a ground layer and overlaps the first signal pad 45 and the second signal pad 46 of the sixth conductor layer 6CL6 in the stacking direction. According to the above configuration, it is possible to sufficiently ensure the electromagnetic shielding effect of the first signal pad 45 and the second signal pad 46 of the sixth conductive layer 6CL6 (Nth conductive layer). Similarly, the multiple conductor layers 7CL of the mounting board 7 include, in order from the compression connector 5 side, a first conductor layer 7CL1, a second conductor layer 7CL2,..., an (N-1)th conductor layer, and an Nth conductor layer, where N is a natural number equal to or greater than 4. In the first embodiment, the (N-1)th conductor layer and the Nth conductor layer correspond to the fifth conductor layer 7CL5 and the sixth conductor layer 7CL6, respectively. The sixth conductor layer 7CL6 (Nth conductor layer) includes a first signal pad 75 and a second signal pad 76 electrically connected to the first signal pad 65 and the second signal pad 66, respectively, of the first conductor layer 7CL1. As shown in FIGS. 15 and 16 , the fifth conductor layer 7CL5 (the (N-1)th conductor layer) is a ground layer and overlaps the first signal pad 75 and the second signal pad 76 of the sixth conductor layer 7CL6 in the stacking direction. According to the above configuration, it is possible to sufficiently ensure the electromagnetic shielding effect of the first signal pad 75 and the second signal pad 76 on the sixth conductive layer 7CL6 (Nth conductive layer). However, both the contact substrate 6 and the mounting substrate 7 may have the characteristics of the above-mentioned (N-1)th conductor layer, or only one of the contact substrate 6 and the mounting substrate 7 may have the characteristics of the above-mentioned (N-1)th conductor layer.

[0159] The above first embodiment can be modified, for example, as follows.

[0160] That is, in Fig. 5, either one of via hole 50A or via hole 50B can be omitted. In Fig. 5, either one of via hole 51A or via hole 51B can be omitted. In Fig. 12, either one of via hole 80A or via hole 80B can be omitted. In Fig. 12, either one of via hole 81A or via hole 81B can be omitted.

[0161] 3, in the first embodiment, the contact substrate 6 includes first to sixth conductor layers as the plurality of conductor layers 6CL. However, instead of this, the contact substrate 6 may further include a seventh and eighth conductor layer as the plurality of conductor layers 6CL. The sixth conductor layer 6CL6, the seventh conductor layer, and the eighth conductor layer are arranged in this order from the compression connector 5 side. In this case, the seventh and eighth conductor layers are typically used as ground layers. The thickness and shape of the seventh and eighth conductor layers can be arbitrary. The same applies to the mounting substrate 7. [Explanation of symbols]

[0162] 1. Information processing equipment 2 Differential transmission assembly (assembly) 3 Support Board 4 Differential transmission board set 5 compression connector 6 contact board 6A Bolt fastening hole 6CL conductor layer 6CL1 First conductor layer 6CL2 Second conductor layer 6CL3 Third conductor layer 6CL4 4th conductor layer 6CL5 5th conductor layer 6CL6 6th conductor layer 6SL Insulator Layer 6SL1 First insulating layer 6SL2 Second insulating layer 6SL3 Third insulating layer 6SL4 4th insulating layer 6SL5 5th insulating layer 7 Mounting board 7A Bolt fastening hole 7CL Conductor layer 7CL1 First conductor layer 7CL2 Second conductor layer 7CL3 Third conductor layer 7CL4 4th conductor layer 7CL5 5th conductor layer 7CL6 6th conductor layer 7SL insulation layer 7SL1 First insulating layer 7SL2 Second insulating layer 7SL3 Third insulating layer 7SL4 4th insulating layer 7SL5 5th insulating layer 8. Board body 9 Nuts 10 volts 11 Compression Contact 11G Compression Contact Group 12 Housing 12A Contact Containment Room 13 Contact Row 20 Soldering section 21 Spring part 21A contact part 22 Press-fit section 30 electrode pads 31 Ground Pad 32 Signal Pad 33 First Ground Pad 33A Spring contact part 33B First via connection 33C Second via connection 33D boundary 33E Boundary 33F Base 33G tapered part 33P inner area 33Q outer area 33R Bisector 33S Contour 34 Second Ground Pad 34A spring contact part 34B First via connection 34C Second via connection 34D boundary 34E Boundary 34F Base 34G tapered part 34P inner area 34Q outer area 34R Bisector 34S Contour 35 First Signal Pad 35A spring contact 35B via connection 35C boundary 35D base part 35E tapered section 36 Second signal pad 36A spring contact part 36B via connection 36C Boundary 36D base part 36E tapered section 43 First Ground Pad 43A 1st via connection 43B Second via connection 44 Second Ground Pad 44A 1st via connection 44B Second via connection 45 First Signal Pad 46 Second Signal Pad 50A via hole 50B Beer Hole 51A Via Hole 51B Beer Hall 52 Beer Hall 53 Beer Hall 55 Through hole 55A inner rim 55B Rectangular part 55C Extension 55D Lane 56 Through hole 56A Inner edge 57 Through hole 57A Inner edge 58 Through Hole 58A Inner edge 60 electrode pads 61 Ground Pad 62 Signal Pad 63 First Ground Pad 63A End 63P inner area 63Q outer area 63R Bisector 63S Contour 64 Second Ground Pad 64A End 64P inner area 64Q outer area 64R Bisector 64S Contour 65 First Signal Pad 66 Second Signal Pad 73 First Ground Pad 73A 1st via connection 73B Second via connection 74 Second Ground Pad 74A 1st via connection 74B Second via connection 75 First Signal Pad 76 Second Signal Pad 80B Via Hole 80A via hole 81A Via Hole 81B Beer Hall 82 Beer Hall 83 Beer Hall 85 through hole 85A inner rim 85B Rectangular part 85C extension 85D Lane 86 Through Hole 86A Inner edge 87 Through Hole 87A inner periphery 88 Through Hole 88A Inner edge 90 through holes 90A inner rim 91 Through hole 91A inner rim 100 through holes 100A inner rim 101 Through hole 101A Inner edge

Claims

1. A differential transmission board set comprising two differential transmission boards electrically connected to each other via a compression connector having four compression contacts arranged in a row, each of the compression contacts including a soldering portion and a spring portion, and a housing for holding the four compression contacts, the two differential transmission substrates include a mounting substrate on which the compression connector is mounted and a contact substrate that is brought into contact with the compression connector, Both the mounting substrate and the contact substrate are multilayer substrates in which a plurality of conductor layers and a plurality of insulator layers are alternately stacked, In both the mounting board and the contact board, the plurality of conductor layers include, in order from the compression connector side, a first conductor layer and a second conductor layer, In both the mounting substrate and the contact substrate, the first conductor layer has four electrode pads corresponding to the four compression contacts; the four electrode pads include a first signal pad, a second signal pad, a first ground pad, and a second ground pad; the first ground pad, the first signal pad, the second signal pad, and the second ground pad are arranged in this order along a first direction; the soldering portions of the four compression contacts can be soldered to the first ground pad, the first signal pad, the second signal pad, and the second ground pad on the mounting board, respectively; In the contact substrate, the spring portions of the four compression contacts are capable of coming into contact with the first ground pad, the first signal pad, the second signal pad, and the second ground pad, respectively; In both the mounting board and the contact board, the second conductor layer is a ground layer having a through hole formed therein; In both the mounting substrate and the contact substrate, the through hole is formed such that, when viewed from the stacking direction, both the first signal pad and the second signal pad are located inside an inner periphery of the through hole, In both the mounting substrate and the contact substrate, the first ground pad includes an inner region closer to the first signal pad than a bisector that bisects a pad area of ​​the first ground pad in the first direction, and an outer region farther from the first signal pad than the bisector; In both the mounting substrate and the contact substrate, the second ground pad includes an inner region closer to the second signal pad than a bisector that bisects a pad area of ​​the second ground pad in the first direction, and an outer region farther from the second signal pad than the bisector, the through hole is formed in the contact substrate so as to overlap the outer region of the first ground pad and the outer region of the second ground pad when viewed along the stacking direction; In the mounting board, the through hole is formed away from the first ground pad and the second ground pad when viewed along the stacking direction. Differential transmission board set.

2. 2. The differential transmission board set according to claim 1, In both the mounting board and the contact board, the plurality of conductor layers further includes a third conductor layer, and the first conductor layer, the second conductor layer, and the third conductor layer are stacked in this order from the compression connector side; In both the mounting board and the contact board, the third conductor layer is a ground layer and overlaps with the first signal pad and the second signal pad in the stacking direction. Differential transmission board set.

3. 2. The differential transmission board set according to claim 1, In both the mounting board and the contact board, the plurality of conductor layers further include a third conductor layer, a fourth conductor layer, and a fifth conductor layer, and the first conductor layer, the second conductor layer, the third conductor layer, the fourth conductor layer, and the fifth conductor layer are stacked in this order from the compression connector side, In both the mounting substrate and the contact substrate, the third conductor layer and the fourth conductor layer are ground layers having through holes formed therein; In both the mounting substrate and the contact substrate, the through holes of the third conductor layer and the fourth conductor layer are formed such that, when viewed from the stacking direction, both the first signal pad and the second signal pad are located inside an inner periphery of the through hole, In both the mounting board and the contact board, the fifth conductor layer is a ground layer and overlaps with the first signal pad and the second signal pad in the stacking direction. Differential transmission board set.

4. 4. A differential transmission board set according to claim 1, a combination of two differential transmission boards electrically connected to each other via a compression connector in which a plurality of compression contact groups each consisting of four compression contacts arranged in a row are arranged; Differential transmission board set.

5. 4. A differential transmission board set according to claim 1, In at least one of the mounting board and the contact board, the plurality of conductor layers include, in order from the compression connector side, the first conductor layer, the second conductor layer, ..., the (N-1)th conductor layer, and the Nth conductor layer (where N is a natural number of 4 or more), the Nth conductor layer includes a first signal pad and a second signal pad electrically connected to the first signal pad and the second signal pad of the first conductor layer, respectively; the (N-1) conductor layer is a ground layer and overlaps the first signal pad and the second signal pad of the N conductor layer in the stacking direction; Differential transmission board set.

6. A differential transmission substrate set according to any one of claims 1 to 3; the compression connector; Including, Assembly.

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