connector

Abstract

To provide a connector capable of reducing fluctuation of characteristic impedance of a contact pair caused by variation of insertion depth along a fitting direction of a mating side contact.SOLUTION: The connector includes a contact pair CP1 including a pair of differential-signal contacts adjacent to each other and extending along a fitting direction, a conductive ground layer 15 extending so as to face the contact pair CP1, and an insulator holding the contact pair CP1 and the ground layer 15, wherein the ground layer 15 has an opening 18 disposed at a position facing the contact pair CP1, and the opening 18 has a first widthwise W1 on a front side in the fitting direction larger than a second widthwise W2 on a rear side in the fitting direction. The second widthwise size W2 is smaller than the widthwise size WP of the contact pair CP1.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a connector, and more particularly to a connector including contacts for transmitting signals at high speed. [Background technology]

[0002] As an example of a connector including contacts for high-speed signal transmission, Patent Document 1 discloses a connector 1 as shown in Figure 24. The connector 1 has a plurality of contacts 2A and a plurality of contacts 2B extending in the mating direction with the mating connector, and a flat metal ground plate 3. The plurality of contacts 2A and the plurality of contacts 2B face each other in a direction perpendicular to the mating direction, and the ground plate 3 is located between the plurality of contacts 2A and the plurality of contacts 2B. The plurality of contacts 2A, the plurality of contacts 2B, and the ground plate 3 are held by an insulator 4.

[0003] 25, an opening 5 is formed in the ground plate 3. The opening 5 is formed at a position facing the contact pair 7 for the purpose of adjusting the characteristic impedance of the contact pair 7, which is composed of two signal contacts 6 that transmit signals at high speed among the plurality of contacts 2A and 2B. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-072078 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a mating connector is mated with the connector 1 disclosed in Patent Document 1, looseness in the mating due to manufacturing tolerances of the connector 1 or the mating connector may occur, resulting in variations in the insertion depth of the mating contacts relative to the multiple contacts 2A and 2B of the connector 1. The inventors discovered that a difference occurs in the characteristic impedance of the contact pair 7, which transmits signals at high speed, depending on whether the insertion depth of the mating contacts in the mating direction is shallow or deep.

[0006] This invention has been made to solve these conventional problems, and its object is to provide a connector that can reduce the fluctuation in characteristic impedance of a contact pair caused by variations in the insertion depth of the mating contact along the mating direction. [Means for solving the problem]

[0007] The connector according to the present invention comprises: A connector that mates with a mating connector along a mating direction, a contact pair consisting of a pair of differential signal contacts adjacent to each other and extending along the mating direction; a conductive ground layer extending opposite the contact pair; an insulator for holding the contact pair and the ground layer; The ground layer has an opening positioned opposite the contact pair, and the opening has a first width dimension at the front side in the mating direction that is larger than a second width dimension at the rear side in the mating direction, and the second width dimension is smaller than the width dimension of the contact pair.

[0008] A pair of differential signal contacts constituting the contact pair extend along the mating direction, and each have a connection portion that is located at the front end in the mating direction and exposed from the insulator, and when the mating connector is mated with the connector, the connection portions of the pair of differential signal contacts can come into contact with a pair of mating contacts of the mating connector. In this case, the opening in the ground layer can be disposed at a position opposite the connection portion of the pair of differential signal contacts and embedded in the insulator.

[0009] The connector may include a ground plate made of a metal plate as a ground layer. In this case, each of the pair of differential signal contacts can have a mounting portion that is located at the rear end in the mating direction and exposed from the insulator, and a retaining portion that is located between the connection portion and the mounting portion and is embedded in and retained in the insulator.

[0010] Alternatively, the connector may have a plurality of contact pairs, each consisting of a pair of differential signal contacts, and the ground plate has a plurality of openings corresponding to the plurality of contact pairs and positioned opposite the plurality of contact pairs, and each of the plurality of openings preferably has a first width dimension at the front side in the mating direction that is larger than a second width dimension at the rear side in the mating direction, and the second width dimension is smaller than the width dimension of the corresponding contact pair.

[0011] Alternatively, contact pairs may be arranged on either side of the ground plate with the ground plate sandwiched therebetween.

[0012] In addition, the insulator forms the substrate body of the printed circuit board, the connection portions of the pair of differential signal contacts each consist of a conductive pad formed on the substrate body, and the ground layer consists of a conductive layer arranged inside the substrate body, so that a card edge connector can also be formed.

[0013] In this case, the connector may have a plurality of contact pairs, each consisting of a pair of differential signal contacts, and the ground layer has a plurality of openings corresponding to the plurality of contact pairs and positioned opposite the plurality of contact pairs, and it is preferable that each of the plurality of openings has a first width dimension at the front side in the mating direction that is larger than a second width dimension at the rear side in the mating direction, and the second width dimension is smaller than the width dimension of the corresponding contact pair.

[0014] Alternatively, contact pairs are arranged on both sides of the substrate body, A pair of ground layers may be arranged inside the substrate body corresponding to the contact pairs arranged on both sides of the substrate body.

[0015] The first width dimension is preferably greater than the width dimension of the contact pair. The opening may have a trapezoidal planar shape. [Effects of the Invention]

[0016] According to this invention, the connector is a connector that mates with a mating connector along a mating direction, and includes a contact pair consisting of a pair of differential signal contacts that are adjacent to each other and each extend along the mating direction, a conductive ground layer that extends opposite the contact pair, and an insulator that holds the contact pair and the ground layer, wherein the ground layer has an opening that is positioned opposite the contact pair, and the opening has a first width dimension at the front side in the mating direction that is larger than a second width dimension at the rear side in the mating direction, and the second width dimension is smaller than the width dimension of the contact pair, thereby reducing fluctuations in the characteristic impedance of the contact pair that are caused by variations in the insertion depth of the mating contacts along the mating direction. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view of a connector according to a first embodiment, seen obliquely from above. [Figure 2] FIG. 2 is an exploded perspective view of the connector according to the first embodiment. [Figure 3] 3 is a perspective view of a plurality of upper contacts according to the first embodiment, viewed obliquely from above. FIG. [Figure 4] 2 is a perspective view of one contact according to the first embodiment, seen obliquely from above. FIG. [Figure 5] 1 is a cross-sectional view of the connector according to the first embodiment cut along the direction in which the connector is fitted to the mating connector. [Figure 6]3 is a plan view of a plurality of contacts and a ground plate according to the first embodiment, seen from above, stacked one on top of the other. FIG. [Figure 7] 1 is a cross-sectional view of the connector according to the first embodiment and the mating connector when they are deeply fitted together. [Figure 8] 1 is a cross-sectional view of the connector according to the first embodiment and the mating connector shallowly fitted together. FIG. [Figure 9] 10 is a graph showing an example of simulation calculation of characteristic impedance of a contact pair when a mating contact is deeply fitted into the connector of the first embodiment and when the mating contact is shallowly fitted into the connector. [Figure 10] FIG. 10 is a plan view showing a ground plate in a first comparative example compared to the first embodiment. [Figure 11] 10 is a graph showing an example of a simulation calculation of the characteristic impedance of the contact pair in Comparative Example 1. [Figure 12] FIG. 10 is a plan view showing a ground plate in a second comparative example compared to the first embodiment. [Figure 13] 10 is a graph showing an example of a simulation calculation of the characteristic impedance of the contact pair in Comparative Example 2. [Figure 14] FIG. 10 is a plan view showing a part of a ground plate in a modified example of the first embodiment. [Figure 15] 10 is a further enlarged plan view showing a part of the ground plate in a modification of the first embodiment. FIG. [Figure 16] FIG. 10 is a plan view showing a part of a ground plate according to another modification of the first embodiment. [Figure 17] FIG. 11 is a perspective view of a connector according to a second embodiment, seen obliquely from above. [Figure 18] FIG. 10 is a front view of a signal contact according to a second embodiment, as viewed from above. [Figure 19] 10 is a cross-sectional view of a connector according to a second embodiment taken along the direction in which the connector is fitted to a mating connector. FIG. [Figure 20] FIG. 10 is a plan view of the connector according to the second embodiment, as viewed from above. [Figure 21]10 is an enlarged plan view showing a part of the connector according to the second embodiment. FIG. [Figure 22] 10 is a cross-sectional view of a connector according to a second embodiment and a mating connector that are deeply fitted together. FIG. [Figure 23] 10 is a cross-sectional view of a connector according to a second embodiment and a mating connector shallowly fitted together. FIG. [Figure 24] FIG. 10 is a cross-sectional view showing a conventional connector. [Figure 25] FIG. 10 is a plan view showing a ground plate in a conventional connector. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. [Embodiment 1] 1 shows a connector 11 according to a first embodiment. This connector 11 is a connector that is fixed inside an electronic device such as a mobile device or an information device, and has a cylindrical metal shell 12 that opens toward the mating direction with a mating connector (not shown). An insulator 13 is disposed inside the metal shell 12, and a plurality of contacts 14 that are arranged along the width direction of the connector 11, which is perpendicular to the mating direction, are held by the insulator 13.

[0019] For convenience, the mating direction of connector 11 and the mating connector is referred to as the Y direction, and in particular, the direction in which metal shell 12 opens is referred to as the -Y direction. The width direction of connector 11 in which multiple contacts 14 are arranged is referred to as the X direction. The height direction of connector 11, which is perpendicular to the X and Y directions, is referred to as the Z direction.

[0020] Figure 2 shows an exploded view of connector 11. As shown in this figure, connector 11 includes metal shell 12, insulator 13, and multiple contacts 14, as well as ground plate 15, which is a conductive ground layer made of a metal plate and connected to ground potential when mounted on a circuit board. As will be described later, ground plate 15 is embedded in insulator 13.

[0021] The metal shell 12 covers the outer periphery of the insulator 13 except for the front portion of the insulator 13 in the mating direction, i.e., the -Y direction end, and the back portion, i.e., the +Y direction end, and a mating connector accommodating portion 12A is formed inside the cylindrical shape to accommodate the mating connector when the mating connector is mated with the connector 11 along the Y direction.

[0022] The plurality of contacts 14 includes a plurality of upper contacts 14A located on the +Z direction side and held by the insulator 13, and a plurality of lower contacts 14B located on the -Z direction side and held by the insulator 13. As shown in FIG. 3, the plurality of upper contacts 14A includes a plurality of signal contacts 16 for transmitting signals between the mating connector and a plurality of non-signal contacts 17 used for purposes other than signal transmission. The plurality of signal contacts 16 includes a contact pair CP1 for high-speed transmission, each consisting of a pair of adjacent differential signal contacts located on both sides in the X direction, and a contact pair CP2 for low-speed transmission, each consisting of a pair of adjacent signal contacts 16 located in the center in the X direction. The plurality of non-signal contacts 17 includes, for example, a power supply contact, a ground contact, and a contact for detecting connector mating.

[0023] As shown in FIG. 4, the signal contacts 16 constituting the high-speed transmission contact pair CP1 have a connecting portion 16A exposed from the insulator 13 at their front end (i.e., the -Y end), a retaining portion 16B embedded and fixed in the insulator 13 at their middle portion, and a board-mounting portion 16C mounted on a board at their rear end (i.e., the +Y end). The connecting portion 16A is the portion that comes into contact with the contact of the mating connector, and the connecting portion 16A and the retaining portion 16B extend linearly along the Y direction on the XY plane. The board-mounting portion 16C connected to the retaining portion 16B protrudes from the rear end (i.e., the +Y end) of the insulator 13, bends relative to the retaining portion 16B, and extends in the +Z direction from the bent position. The signal contacts 16 and non-signal contacts 17 constituting the low-speed transmission contact pair CP2 have shapes similar to those of the signal contacts 16 constituting the high-speed transmission contact pair CP1.

[0024] Like the plurality of upper contacts 14A, the plurality of lower contacts 14B are composed of a plurality of signal contacts and a plurality of non-signal contacts. Like the signal contacts 16 and non-signal contacts 17 of the upper contacts 14A, the signal contacts and non-signal contacts of the lower contacts 14B also have a connection portion, a holding portion, and a board mounting portion, but the board mounting portion of the lower contacts 14B differs from the board mounting portion 16C of the upper contacts 14A in that it extends in the -Z direction from a position where it bends relative to the holding portion.

[0025] Similarly to the plurality of upper contacts 14A, the plurality of lower contacts 14B also form two pairs of high-speed transmission contacts, each consisting of two adjacent signal contacts that form a pair of differential signal contacts. The two pairs of high-speed transmission contacts CP1 in the plurality of upper contacts 14A and the two pairs of high-speed transmission contacts in the plurality of lower contacts 14B are positioned opposite each other in the Z direction.

[0026] 5 shows a cross-sectional view of connector 11 taken along the YZ plane that passes through one signal contact 16 of one high-speed transmission contact pair CP1 in upper contact 14A and the corresponding lower signal contact. As can be seen in this figure, ground plate 15 is embedded and fixed in insulator 13, sandwiched between multiple upper contacts 14A and multiple lower contacts 14B. Therefore, high-speed transmission contact pair CP1 is disposed on both sides of ground plate 15 in the Z direction, with ground plate 15 sandwiched between them.

[0027] The ground plate 15 also has an opening 18 formed in a position facing both the connection portion 16A of the upper contact pair CP1 for high-speed transmission and the connection portion of the lower contact pair. The opening 18 is embedded in the insulator 13 and is formed to adjust the characteristic impedance of the high-speed transmission contact pair CP1. More specifically, by forming the opening 18 in the ground plate 15 and increasing the distance between the portion of the contact pair CP1 that overlaps with the opening 18 and the ground plate 15 compared to the other portions of the contact pair CP1, the capacitance of the capacitor formed between the contact pair CP1 and the ground plate 15 can be reduced, and the characteristic impedance of the contact pair CP1 can be increased.

[0028] 6 is a plan view of multiple upper contacts 14A and ground plate 15 stacked together, viewed from the +Z direction. Openings 18 are positioned facing two high-speed transmission contact pairs CP1. Opening 18 has a lower base with a first width dimension W1 along the X direction on the front side in the mating direction, i.e., the -Y direction, and an upper base with a second width dimension W2 along the X direction on the rear side in the mating direction, i.e., the +Y direction, and has a trapezoidal planar shape with a length L along the Y direction. The -Y direction end of opening 18 is spaced a distance D1 in the -Y direction from the -Y direction end of contact pair CP1.

[0029] Because opening 18 has a trapezoidal planar shape, its first width dimension W1 is larger than its second width dimension W2. Furthermore, opening 18's first width dimension W1 is larger than the width dimension WP of contact pair CP1, and its second width dimension W2 is smaller than the width dimension WP of contact pair CP1. The width dimension WP of contact pair CP1 refers to the maximum width dimension between both ends of contact pair CP1 in the X direction at the portion that overlaps opening 18. Furthermore, opening 18 is arranged symmetrically with respect to the center line of contact pair CP1 in the Y direction.

[0030] When the mating connector moves in the +Y direction while facing the -Y-direction end of connector 11 and the mating connector and connector 11 mate with each other along the Y direction, mating connector M is accommodated in mating connector accommodating portion 12A of metal shell 12 of connector 11, as shown in Fig. 7. If mating connector M has a pair of mating contacts CM facing each other in the Z direction, the pair of mating contacts CM contact a signal contact 16 constituting high-speed transmission contact pair CP1 included in the plurality of upper contacts 14A and a signal contact constituting a high-speed transmission contact pair included in the plurality of lower contacts 14B, respectively. At this time, contact position P1 between the mating contact CM and the signal contact 16 constituting high-speed transmission contact pair CP1 overlaps with opening 18 of ground plate 15 in the Z direction.

[0031] However, due to manufacturing tolerances of the connector 11 and the mating connector M, rattles may occur in the fit between the connector 11 and the mating connector M, and the insertion depth of the mating contacts CM in the Y direction may vary, for example, when the mating connector M is deeply fitted into the connector 11 and the mating contacts CM are deeply inserted into the connector 11 along the Y direction, as shown in Figure 7, or when the mating connector M is shallowly fitted into the connector 11 and the mating contacts CM are shallowly inserted into the connector 11 along the Y direction, as shown in Figure 8.

[0032] When the mating connector M is mated with the connector 11, the mating contact CM comes into contact with the signal contact 16 that constitutes the contact pair CP1 for high-speed transmission. In this case, the portion of the signal contact 16 on the -Y side of the contact position P1 with the mating contact CM functions as a stub for the signal transmission path. The shallower the insertion depth of the mating contact CM in the Y direction, the shorter the stub, and the deeper the insertion depth of the mating contact CM in the Y direction, the longer the stub. The longer the stub, the lower the characteristic impedance of the signal transmission path tends to be, and as a result, the characteristic impedance of the contact pair CP1 tends to vary depending on the insertion depth of the mating contact CM in the Y direction.

[0033] The present inventors have found that by making the first width dimension W1 of the opening 18 formed in the ground plate 15 larger than the second width dimension W2, as in the trapezoidal planar shape shown in Fig. 6, it is possible to reduce fluctuations in the characteristic impedance of the high-speed transmission contact pair CP1 caused by fluctuations in the insertion depth in the Y direction of the mating contacts CM into the connector 11. Furthermore, as a result of repeated experiments using simulation calculations regarding the planar shape of the opening 18, the present inventors have found that by making the second width dimension W2 of the opening 18 smaller than the width dimension WP of the high-speed transmission contact pair CP1, as in the opening 18 of the first embodiment, it is possible to further reduce fluctuations in the characteristic impedance of the high-speed transmission contact pair CP1 caused by fluctuations in the insertion depth in the Y direction of the mating contacts CM into the connector 11.

[0034] Example 1 Here, a simulation calculation of the characteristic impedance of the contact pair CP1 for high-speed transmission in the first embodiment was performed as Example 1 using CST STUDIO SUITE 2021 (manufactured by Dassault Systèmes). In the simulation calculation of Example 1, the frequency and voltage value of the signal transmitted through the contact pair CP1 were set to 80 GHz. In addition, the first width dimension W1 of the opening 18 was set to 1.50 mm, the second width dimension W2 was set to 0.30 mm, and the length L was set to 2.35 mm. The width dimension WP of the contact pair CP1 overlapping the opening 18 was set to 0.76 mm, and the distance D1 along the Y direction between the contact pair CP1 and the -Y direction end of the opening 18 was set to 0.20 mm. In addition, the characteristic impedance was calculated when the contact position P1 between the mating contact CM and the contact pair CP1 was 0.88 mm along the Y direction from the -Y direction end of the opening 18, assuming that the insertion depth of the mating contact CM was shallow, and the characteristic impedance was calculated when the contact position P1 between the mating contact CM and the contact pair CP1 was 1.38 mm along the Y direction from the -Y direction end of the opening 18, assuming that the insertion depth of the mating contact CM was deep.

[0035] As a result of the simulation, the characteristic impedance shown in Figure 9 was obtained. The solid line graph shows the characteristic impedance of the contact pair CP1 for high-speed transmission when the insertion depth of the mating contact CM in the Y direction is shallow, and the dotted line graph shows the characteristic impedance of the contact pair CP1 for high-speed transmission when the insertion depth of the mating contact CM in the Y direction is deep. The vertical axis shows the impedance, and the horizontal axis shows the time elapsed since voltage was applied to the contact pair CP1. The difference DZ between the maximum and minimum values ​​of the characteristic impedance in these two graphs was 25.26 Ω.

[0036] <Comparative Example 1> In the first embodiment of the present invention, the opening 18 formed in the ground plate 15 has a trapezoidal planar shape. However, for comparison with this embodiment, as Comparative Example 1, the characteristic impedance of the high-speed transmission contact pair CP3 when an opening Q1 having a rectangular planar shape is formed in the ground plate G1 as shown in FIG. 10 was calculated by simulation using CST STUDIO SUITE 2021. This opening Q1 has a rectangular planar shape with two sides extending linearly along the X direction and two sides extending linearly along the Y direction. The first width dimension W1 and the second width dimension W2 of the opening Q1 are equal to each other. Furthermore, the opening Q1 is arranged symmetrically with respect to the center line of the contact pair CP3 along the Y direction.

[0037] In the simulation of Comparative Example 1, the first width dimension W1 and second width dimension W2 of the opening Q1 were set to 1.20 mm, and the length L was set to 2.35 mm, and the other conditions were the same as those of Example 1.

[0038] As a result of the simulation, the characteristic impedance shown in Figure 11 was obtained. The solid line graph shows the characteristic impedance of the contact pair CP3 for high-speed transmission when the insertion depth of the mating contact CM in the Y direction is shallow, and the dotted line graph shows the characteristic impedance of the contact pair CP3 for high-speed transmission when the insertion depth of the mating contact CM in the Y direction is deep. The difference DZ between the maximum and minimum values ​​of the characteristic impedance in these two graphs was 30.66 Ω.

[0039] <Comparative Example 2> In embodiment 1 of the present invention, the second width dimension W2 of the opening 18 formed in the ground plate 15 is smaller than the width dimension WP of the contact pair CP1. To compare with this embodiment, as comparative example 2, as shown in FIG. 12, an opening Q2 having a trapezoidal planar shape but with a second width dimension W2 at the +Y direction end larger than the width dimension WP of the contact pair CP3 for high-speed transmission is formed in the ground plate G2. The characteristic impedance of the contact pair CP3 was calculated by simulation using CST STUDIO SUITE 2021.

[0040] In the simulation of Comparative Example 2, the first width dimension W1 of the opening 18 was 1.50 mm, the second width dimension W2 was 1.00 mm, which was larger than the width dimension WP (0.76 mm) of the contact pair CP3, and the length L was 2.35 mm; all other conditions were the same as in Example 1.

[0041] As a result of the simulation, the characteristic impedance shown in Figure 13 was obtained. The solid line graph shows the characteristic impedance of the contact pair CP3 for high-speed transmission when the insertion depth of the mating contact CM in the Y direction is shallow, and the dotted line graph shows the characteristic impedance of the contact pair CP3 for high-speed transmission when the insertion depth of the mating contact CM in the Y direction is deep. The difference DZ between the maximum and minimum values ​​of the characteristic impedance in these two graphs was 29.16 Ω. Hereinafter, this example of simulation calculation will be referred to as Comparative Example 2.

[0042] <Comparative Example 3> Although not shown, in Comparative Example 3, a simulation calculation was performed with both the second width dimension W2 of the opening Q2 and the contact pair CP3 in Comparative Example 2 set to 0.76 mm, with the other parameters being the same as in Comparative Example 2. The difference DZ between the maximum and minimum values ​​in the characteristic impedance of the contact pair CP3 for high-speed transmission when the insertion depth of the mating contact CM in the Y direction is shallow and the characteristic impedance of the contact pair CP3 for high-speed transmission when the insertion depth of the mating contact CM in the Y direction is deep was 27.30 Ω. Hereinafter, this example of the simulation calculation will be referred to as Comparative Example 3.

[0043] The calculation results for Example 1 and Comparative Examples 1 to 3 are shown in Table 1 below. [Table 1]

[0044] From these results, it can be seen that the difference DZ in characteristic impedance can be reduced by making the first width dimension W1 of the opening 18 formed in the ground plate 15 larger than the second width dimension W2. It can also be seen that the difference DZ in characteristic impedance can be further reduced by making the second width dimension W2 smaller than the width dimension WP of the contact pair CP1. Thus, it can be seen that by making the first width dimension W1 of the opening 18 formed in the ground plate 15 larger than the second width dimension W2 and making the second width dimension W2 smaller than the width dimension WP of the contact pair CP1, it is possible to reduce the variation in the characteristic impedance of the contact pair CP1 caused by variations in the insertion depth of the mating contact CM in the Y direction.

[0045] Although the above description has been given of the opening 18 having a trapezoidal planar shape in the ground plate 15, the planar shape of the opening 18 is not limited to a trapezoid. For example, as shown in FIGS. 14 and 15 , the opening 18A may have a shape in which a first rectangular portion 19A extending along the X direction and having two sides with a first width dimension W1, a trapezoidal portion 19B having a lower base with the first width dimension W1 and an upper base with a second width dimension W2, and a second rectangular portion 19C extending along the X direction and having two sides with the second width dimension W2 are connected to each other. The +Y-direction end of the first rectangular portion 19A is connected to the -Y-direction end of the trapezoidal portion 19B, and the +Y-direction end of the trapezoidal portion 19B is connected to the -Y-direction end of the second rectangular portion 19C. Because a step is formed on the side in the X direction in this shape, this shape will be referred to as a stepped trapezoid for convenience hereinafter. Furthermore, the opening 18A is arranged symmetrically with respect to the center line of the contact pair CP1 along the Y direction. Note that the contour lines of first rectangular portion 19A, trapezoidal portion 19B, and second rectangular portion 19C actually overlap the contour line of the planar shape of opening 18A, but the contour lines of first rectangular portion 19A, trapezoidal portion 19B, and second rectangular portion 19C shown by dotted lines in Figure 15 are drawn smaller than they actually are for the purpose of explanation.

[0046] <Example 2> In this way, the characteristic impedance of the contact pair CP1 for high-speed transmission when the opening 18A has a stepped trapezoidal planar shape was calculated as Example 2 by simulation using CST STUDIO SUITE2021.

[0047] In Example 2, opening 18A having a stepped trapezoidal planar shape had a first width dimension W1 of 1.50 mm, a second width dimension W2 of 0.30 mm, and a length L of 2.35 mm, with the other conditions being the same as in Example 1. As a result of this simulation calculation, the difference DZ in characteristic impedance was 24.92 Ω.

[0048] <Comparative Example 4> As Comparative Example 4, the characteristic impedance was calculated by setting the second width dimension W2 to 1.00 mm, which is larger than the width dimension WP (0.76 mm) of the contact pair CP1 in Example 2. As a result, the difference DZ in the characteristic impedance was 29.29 Ω.

[0049] <Comparative Example 5> As Comparative Example 5, the characteristic impedance was calculated by setting the second width dimension W2 to 0.76 mm, the same as the width dimension WP of the contact pair CP1 in Example 2. As a result, the difference DZ in the characteristic impedance was 27.80Ω.

[0050] The calculation results for Example 2 and Comparative Examples 1, 4 and 5 are shown in Table 2 below. [Table 2]

[0051] From these results, it can be seen that even when the opening 18A formed in the ground plate 15A has a stepped trapezoidal planar shape, by making the first width dimension W1 of the opening 18A larger than the second width dimension W2 and making the second width dimension W2 smaller than the width dimension WP of the contact pair CP1, it is possible to reduce the fluctuation in the characteristic impedance of the contact pair CP1 caused by the variation in the insertion depth of the mating contact CM in the Y direction.

[0052] 16, for example, opening 18B may have a triangular planar shape whose -Y direction end is the base of first width dimension W1. In this case, the second width dimension W2 of opening 18B at the +Y direction end is smaller than first width dimension W1 and width dimension WP of contact pair CP1, thereby reducing fluctuations in the characteristic impedance of contact pair CP1 for high-speed transmission caused by variations in the insertion depth of mating contacts CM.

[0053] As explained above, the planar shape of the opening 18 formed in the ground plate 15 is not particularly limited as long as the first width dimension W1 is greater than the second width dimension W2 and the second width dimension W2 is smaller than the width dimension WP of the high-speed transmission contact pair CP1. However, it is preferable that the planar shape of the opening 18 be a shape in which the width dimension along the X direction monotonically decreases from the front to the rear in the mating direction, i.e., from the -Y end to the +Y end. When the opening 18 has such a planar shape, the maximum and minimum values ​​of the characteristic impedance of the contact pair CP1 tend to change monotonically over time as the insertion depth of the mating contact CM along the Y direction gradually increases or decreases, thereby preventing large fluctuations in the characteristic impedance of the contact pair CP1 at a specific insertion depth of the mating contact CM. This makes it possible, for example, to easily adjust the characteristic impedance of the contact pair CP1 to meet the specifications required by the device in which the connector 11 is installed.

[0054] Furthermore, as an example of the planar shape of the opening 18, the shape of the side portion in the X direction has been described as being straight or a bent line shape made up of a plurality of straight lines, but it may also be a curved shape.

[0055] Although the above description shows an example in which the upper contacts 14A and the lower contacts 14B each include two contact pairs CP1, the upper contacts 14A and the lower contacts 14B may each include only one contact pair, or may each include three or more contact pairs. In this case, the ground plate 15 may be formed with only one opening 18, or three or more openings 18, or as many openings 18 as there are contact pairs CP1.

[0056] Also, although the connector 11 has been described as having a plurality of upper contacts 14A and a plurality of lower contacts 14B, the connector 11 may have only one of the plurality of upper contacts 14A and the plurality of lower contacts 14B.

[0057] [Embodiment 2] Although the first embodiment describes the connector 11 having the metal shell 12, the present invention can also be applied to a so-called card edge connector mounted on a circuit board.

[0058] 17 shows a connector 21 according to a second embodiment. This connector 21 is a card edge connector consisting of a connection portion with a mating connector M formed at the -Y direction end of a printed circuit board 20 that extends like a flat plate on the XY plane and has a thickness in the Z direction. The connector 21 has an insulator 23 that forms the board body of the printed circuit board 20, and a plurality of contacts 24 formed on the insulator 23. The printed circuit board 20 has a resist layer 22 that covers and protects an electronic circuit (not shown) that is connected to the plurality of contacts 24.

[0059] The plurality of contacts 24 includes twelve signal contacts 26 used for high-speed signal transmission and a plurality of other non-signal contacts 27. The twelve signal contacts 26 form six contact pairs CP4, each consisting of two signal contacts 26 adjacent to each other to form a pair of differential signal contacts.

[0060] 18, the signal contact 26 has, at its front end in the mating direction, i.e., its end in the -Y direction, a connection portion 26A consisting of a conductive pad formed on the insulator 23 and exposed from the resist layer 22. A holding portion 29 formed on the insulator 23, connected to the electronic circuit of the printed circuit board 20, and covered with the resist layer 22 extends from the end in the +Y direction of this connection portion 26A.

[0061] 19, the multiple contacts 24 are composed of multiple upper contacts 24A located on the +Z direction side of the insulator 23 and multiple lower contacts 24B located on the -Z direction side of the insulator 23, and each is covered with a resist layer 22 except for its -Y direction end. The multiple upper contacts 24A are formed on a first surface 23A located on the +Z direction side of the insulator 23, and the multiple lower contacts 24B are formed on a second surface 23B located on the -Z direction side of the insulator 23.

[0062] Connector 21 also has, as a ground layer, conductive layer 25 consisting of upper conductive layer 25A and lower conductive layer 25B arranged inside the board body formed by insulator 23. Upper conductive layer 25A and lower conductive layer 25B have openings 28 formed therein, which are arranged at positions facing connecting portion 26A of upper contact pair CP4 and connecting portion 26A of lower contact pair CP4.

[0063] FIG. 20 is a plan view of connector 21 as viewed from the +Z direction, with six openings 28 in upper conductive layer 25A indicated by dashed lines. Openings 28 are located at positions facing six contact pairs CP4, respectively. As shown enlarged in FIG. 21, openings 28 have a lower base with a first width dimension W1 along the X direction on the front side in the mating direction, i.e., the -Y direction, and an upper base with a second width dimension W2 along the X direction on the rear side in the mating direction, i.e., the +Y direction. Openings 28 have a trapezoidal planar shape with a length L along the Y direction. The first width dimension W1 of openings 28 is greater than the second width dimension W2, and the second width dimension W2 of openings 28 is smaller than the width dimension WP of contact pairs CP4.

[0064] Opening 28 in lower conductive layer 25B has a shape similar to opening 28 in upper conductive layer 25A. In openings 28 in upper conductive layer 25A and lower conductive layer 25B, first width dimension W1 is larger than second width dimension W2, and second width dimension W2 is smaller than width dimension WP of contact pair CP4. Therefore, similar to connector 11 of embodiment 1, connector 21 of embodiment 2 can reduce the variation in the characteristic impedance of contact pair CP4 for high-speed transmission that occurs between a case where the mating contact CM is inserted shallowly, as shown in FIG. 22, and a case where the mating contact CM is inserted deep, as shown in FIG. 23, for example.

[0065] Although the example has been described in which the plurality of upper contacts 24A and the plurality of lower contacts 24B each have six contact pairs CP4, the plurality of upper contacts 24A and the plurality of lower contacts 24B may each have, for example, only one contact pair CP4, two to five contact pairs CP4, or seven or more contact pairs CP4. In this case, the upper conductive layer 25A and the lower conductive layer 25B may each have one opening 28, two to five openings 28, or seven or more openings 28, the number of which corresponds to the number of contact pairs CP4 that the plurality of upper contacts 24A and the plurality of lower contacts 24B have.

[0066] Although the contacts 24 have been described as including upper contacts 24A and lower contacts 24B, they may include only one of the upper contacts 24A and the lower contacts 24B. In this case, the connector 21 may include only one of the upper conductive layer 25A and the lower conductive layer 25B.

[0067] Furthermore, in embodiment 2, it is described that opening 28 has a trapezoidal planar shape, but similar to opening 18 in embodiment 1, the planar shape of opening 28 is not limited to a trapezoid, as long as the first width dimension W1 is greater than the second width dimension W2 and the second width dimension W2 is smaller than the width dimension WP of contact pair CP4. [Explanation of symbols]

[0068] 1 Connector, 2A, 2B contacts, 3 Ground plate, 4 Insulator, 5 Opening, 6 Signal contact, 7 Contact pair, 11, 21 connector, 12 metal shell, 12A mating connector accommodating portion, 13, 23 insulator, 14, 24 contact, 14A, 24A upper contact, 14B, 24B lower contact, 15, 15A, 15B, G1, G2 ground plate, 16, 26 signal contact, 16A, 26A connection portion, 16B, 29 holding portion, 16C board mounting portion, 17, 27 non-signal contact, 18, 18A, 18B, 28, Q1, Q2 opening, 19A first rectangular portion, 19B trapezoidal portion, 19C second rectangular portion, 22 resist layer, 25 conductive layer, 25A upper conductive layer, 25B lower conductive layer, CM mating contact, CP1, CP2, CP3, CP4 contact pair, D1 distance, DZ difference, L length, M Mating connector, P1 contact position, W1 first width dimension, W2 second width dimension, WP width dimension.

Claims

1. A connector that mates with a mating connector along a mating direction, a contact pair consisting of a pair of differential signal contacts adjacent to each other and each extending along the mating direction; a conductive ground layer extending opposite the contact pair; an insulator that holds the contact pair and the ground layer; Equipped with The ground layer has an opening positioned opposite the contact pair, and the opening has a first width dimension at the front side in the mating direction that is larger than a second width dimension at the rear side in the mating direction, and the second width dimension is smaller than the width dimension of the contact pair.

2. the pair of differential signal contacts constituting the contact pair extend along the mating direction, each having a connection portion that is located at a front end in the mating direction and exposed from the insulator, 2. The connector according to claim 1, wherein when the mating connector is mated with the connector, the connecting portions of the pair of differential signal contacts come into contact with a pair of mating contacts of the mating connector.

3. 3. The connector according to claim 2, wherein the opening of the ground layer is disposed at a position facing the connecting portion of the pair of differential signal contacts and is embedded in the insulator.

4. 4. The connector according to claim 3, wherein the ground layer is a ground plate made of a metal plate.

5. The pair of differential signal contacts each include: a mounting portion disposed at a rear end in the fitting direction and exposed from the insulator; a holding portion that is disposed between the connection portion and the mounting portion and is embedded in and held by the insulator; 5. The connector of claim 4, comprising:

6. a plurality of contact pairs each consisting of a pair of differential signal contacts; the ground plate has a plurality of openings arranged at positions corresponding to the plurality of contact pairs and facing the plurality of contact pairs; 5. The connector of claim 4, wherein the first width dimension of each of the plurality of openings at the front side in the mating direction is larger than the second width dimension at the rear side in the mating direction, and the second width dimension is smaller than the width dimension of the corresponding contact pair.

7. 5. The connector according to claim 4, wherein the contact pairs are arranged on either side of the ground plate with the ground plate sandwiched therebetween.

8. the insulator forms a substrate body of a printed circuit board; the connection portions of the pair of differential signal contacts are each made of a conductive pad formed on the substrate body; the ground layer is made of a conductive layer disposed inside the substrate body, 4. The connector of claim 3, which is configured as a card edge connector.

9. a plurality of contact pairs each consisting of a pair of differential signal contacts; the ground layer has a plurality of openings arranged at positions corresponding to the plurality of contact pairs and facing the plurality of contact pairs; 9. The connector of claim 8, wherein the first width dimension of each of the plurality of openings at the front side in the mating direction is larger than the second width dimension at the rear side in the mating direction, and the second width dimension is smaller than the width dimension of the corresponding contact pair.

10. The contact pairs are arranged on both sides of the substrate body, 9. The connector according to claim 8, wherein a pair of the ground layers are arranged inside the board body in correspondence with the contact pairs arranged on both sides of the board body.

11. 2. The connector of claim 1, wherein the first width dimension is greater than the width dimension of the contact pair.

12. The connector according to claim 11 , wherein the opening has a trapezoidal planar shape.

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