Ground shield contact member

Abstract

An electrical connector has a housing having at least one slot for receiving an electrical wafer therein. A signal contact is positioned on a first side of the at least one slot. A signal contact resilient contact arm exerts a first normal force on the electronics wafer inserted in the at least one slot. At least one ground shield contact member is positioned on a second side of the at least one slot. Ground shield resilient contact arms exert a second normal force on the wafer inserted in the at least one slot. The second normal force applied by the ground shield resilient contact arm is greater than the first normal force applied by the signal contact resilient contact arm. The wafer is biased toward a signal contact resilient contact arm of the signal contact regardless of the thickness of the wafer.

Description

TECHNICAL FIELD

[0001] The present invention relates to a ground shield contact member that integrates the functions of a ground contact and a shield in a single component. In particular, the ground shield member serves multiple purposes for signal integrity (SI), connector mechanical requirements, and manufacturability. BACKGROUND

[0002] As the complexity of electronic components increases, it is desirable to fit more components in less space on a circuit board or other substrate. As a result, the spacing between electrical terminals within a connector has been reduced while the number of electrical terminals housed in the connector has increased, thereby increasing the demand in the electrical arts for electrical connectors that can handle ever higher speeds and do so with ever greater pin density. It is desirable that such connectors not only have a reasonably constant impedance level, but also acceptable impedance and crosstalk levels, as well as other acceptable electrical and mechanical characteristics. Thus, there remains a need to provide adequate shielding to maintain signal integrity and minimize crosstalk as signal speeds increase and the footprint of the connector remains the same or decreases. SUMMARY

[0003] Accordingly, it would be beneficial to provide a ground shield contact member that integrates the functions of a ground contact and a shield in a single component. It would also be beneficial to provide a connector assembly in which signal paths in the signal contacts are minimized to improve signal integrity.

[0004] The solution is provided by a connector system that includes a ground shield contact member that integrates the functions of a ground contact and a shield in a single component. The ground shield member serves multiple purposes for signal integrity, connector mechanical requirements, and manufacturability. The ground shield contact forms a connection from the backplane to the connector system's backside ground plane on the wafer. This provides a ground connection and required shielding in the area of the backplane signal contacts. Mechanically, the ground shield contact pushes the connector wafer against the plastic housing wall adjacent to the signal contacts. This reduces the tolerance stack-up that causes variations in the normal force between the signal contacts and the wafer mating pads. The ground shield contact is designed to meet signal integrity parameters so that conventional ground contacts do not have to be stitched near the signal contacts in the backplane connector. BRIEF DESCRIPTION OF DRAWINGS

[0005] The present invention will now be described by way of example with reference to the accompanying drawings in which:

[0006] Figure 1 is a bottom perspective view of an illustrative mating connector assembly in which an illustrative daughter card connector assembly is mated to an illustrative backplane connector assembly.

[0007] Figure 2 isFigure 1 perspective view of the illustrative connector assembly of

[0008] Figure 3 is a cross-sectional view taken along line 3-3 of Figure 1

[0009] Figure 4 is a rear perspective view of one of the illustrative ground shield contact members of the backplane connector assembly of Figure 2

[0010] Figure 5 is a front perspective view of the ground shield contact member of Figure 4

[0011] Figure 6 is a side view of the ground shield contact member of Figure 4

[0012] Figure 7 is a cross-sectional view of an illustrative single mating cavity of the backplane connector assembly with a respective wafer of the connector assembly partially inserted into the mating cavity.

[0013] Figure 8 is a cross-sectional view of the single mating cavity of Figure 7 with the respective wafer fully inserted into the mating cavity, the ground shield contact spring fingers of the ground shield contact member biasing the wafer toward the signal contact beams in the backplane connector assembly.

[0014] Figure 9 is a perspective view of the ground shield contact member of the backplane connector assembly engaged with a respective wafer of the connector assembly, the housing of the backplane connector and the connector assembly not shown.

[0015] Figure 10 is a perspective view of the signal contact beams of the backplane connector assembly engaged with a respective wafer of the connector assembly, the housing of the backplane connector and the connector assembly not shown.

[0016] Figure 11 is a front perspective view of an alternative illustrative ground shield contact member of the backplane connector assembly.

[0017] Figure 12 is a perspective cross-sectional view of a plurality of ground shield contact members of Figure 11 positioned in an illustrative backplane connector. DETAILED DESCRIPTION

[0018] The connector system includes a ground shield contact member that integrates the functions of a ground contact and a shield in a single member. The ground shield member serves multiple purposes for signal integrity, connector mechanical requirements, and manufacturability.​​​​

[0019] The ground shield contacts make the connection from the backplane to the connector system ground plane on the wafer backside. This provides the ground connection and required shielding in the area of the backplane signal contacts. Mechanically, the ground shield contacts push the connector wafer against the plastic housing wall adjacent to the signal contacts. This reduces the tolerance stack-up that causes variation in the normal force between the signal contacts and the wafer mating pads. The ground shield contacts are designed to meet the signal integrity parameters so that conventional ground contacts do not have to be stitched near the signal contacts in the backplane connector.

[0020] An additional benefit is that the ground shield contacts can also provide significant current carrying capability for wafer based connector systems used in power wafer variants. The ground shield contacts provide a current path to the power wafer backside and provide a large surface area for heat dissipation.

[0021] The ground shield contacts provide a positive low resistance connection between the BP PCB and the wafer in the wafer based connector. It also biases the wafer to reduce the tolerance stack-up so that the normal force from the wafer to the signal contacts is more consistent. It also provides a positive low resistance connection in power wafer applications to enhance current capacity.

[0022] One embodiment relates to an electrical connector having a housing with at least one slot for receiving an electrical wafer therein. A signal contact is positioned on a first side of the at least one slot. The signal contact has a signal contact spring contact arm that extends into the at least one slot. The signal contact spring contact arm exerts a first normal force on an electronic wafer inserted into the at least one slot. At least one ground shield contact member is positioned on a second side of the at least one slot. The second side is opposite the first side. The at least one ground shield contact member has a ground shield spring contact arm that extends into the at least one slot. The ground shield spring contact arm exerts a second normal force on the wafer inserted into the at least one slot. The second normal force exerted by the ground shield spring contact arm is greater than the first normal force exerted by the signal contact spring contact arm. The wafer is biased toward the signal contact spring contact arm of the signal contact regardless of the thickness of the wafer, allowing the first normal force exerted on the wafer to be independent of the wafer thickness tolerance.

[0023] One embodiment relates to an electrical connector having a ground shield contact member. The ground shield contact member includes a planar ground shield portion from which a ground shield spring contact arm extends from a first end of the planar ground shield portion. The ground shield spring contact arm is configured to exert a normal force on a wafer inserted into a slot of the electrical connector. The normal force exerted by the ground shield spring contact arm biases the wafer toward a signal contact of the connector regardless of the thickness of the wafer. The ground shield contact member is configured to provide ground and shielding.

[0024] Figure 1 andFigure 2 An illustrative electrical connector system 10 is shown, comprising a backplane connector 12 and a daughter card connector 14 for electrically connecting a backplane circuit board (not shown) and a daughter card circuit board (not shown). While the electrical connector system 10 is described herein with reference to the backplane connector 12 and daughter card connector 14, it should be understood that the subject matter can be used with different types of electrical connectors other than the backplane connector or daughter card connector. The backplane connector 12 and daughter card connector 14 are merely illustrative of the electrical connector system 10.

[0025] In the illustrative embodiment shown, the daughter card connector 14 is configured as a right-angle connector, wherein the mating interface 16 and the mounting interface 18 of the daughter card connector 14 are oriented perpendicularly to each other. The daughter card connector 14 is mounted to the daughter card circuit board at the mounting interface 18. In alternative embodiments, other orientations of the interfaces 16, 18 are possible.

[0026] The daughter card connector 14 includes a housing 20 made of one or more components, in which a plurality of wafers 22 are held, for example, but not limited to, a circuit board. The wafers 22 may have different configurations, for example, but not limited to, microstrip (two layers) or stripline (four or more layers). In an illustrative embodiment, the wafers 22 have paired individual signal paths or traces (not shown) extending between a mating interface 16 and a mounting interface 18. The signal traces have signal conductive pads 24 disposed near the mating interface 16. Figure 10 The wafer 22 has a ground plane member 28 on the side of the wafer 22 opposite to the signal conductive pad 24. Figure 9 Ground plane member 28 extends between mating interface 16 and mounting interface 18. In an alternative embodiment, wafer 22 may be a contact module, signal traces may be mating signal contacts, and ground traces may be ground contacts.

[0027] In the illustrated embodiment, the backplane connector 12 constitutes a plug connector for mounting to a backplane circuit board. However, other types of connectors may be used. When the backplane connector 12 mates with the daughter card connector 14, the daughter card circuit board is oriented substantially perpendicularly to the backplane circuit board.

[0028] like Figure 2 As shown, the backplane connector 12 includes a mating end 30 and a mounting end 32 that are generally oriented parallel to each other. The backplane connector 12 is mounted to a backplane circuit board at the mounting end 32. In alternative embodiments, other orientations of the mating end 30 and the mounting end 32 are possible.

[0029] In an illustrative embodiment, the backplane connector 12 includes a single-piece housing 34. Alternatively, the housing may comprise multiple separate housings or modules. The housing 34 has one or more wafer receiving slots 36 extending from the mating end 30 toward the mounting end 32. The housing 34 holds at least one row of signal contacts 42 and at least one ground shield contact member 44. The at least one row of signal contacts 42 is positioned on one side of one or more wafer receiving slots 36. The at least one ground shield contact member 44 is positioned on the opposite side of one or more wafer receiving slots 36.

[0030] Signal contact 42 extends between mating end 30 and mounting end 32. In an exemplary embodiment, signal contact 42 is arranged to carry a pair of differential signals. However, in other configurations, signal contact 42 may not be arranged to carry a pair of differential signals, for example, to carry a single-ended signal. Grounding shield contact member 44 extends between mating end 30 and mounting end 32.

[0031] Each signal contact 42 has a resilient contact arm 46, a retaining portion 48, and a circuit board mounting portion 50. In the illustrated embodiment, each of the resilient contact arms 46 has an introduction portion 52 and an engagement portion 54. The resilient contact arm 46 is configured to press against the signal conductive pad 24 of the signal trace of the chip 22 of the daughter card connector 14 when the daughter card connector 14 is inserted into the chip receiving slot 36 of the backplane connector 12.

[0032] The retaining portion 48 has a retaining member 56, which may be, but is not limited to, a barb or protrusion extending from the surface of the retaining portion 48. The retaining member 56 mates with the housing 34 to retain the signal contact 42 in the backplane connector 12.

[0033] The circuit board mounting portion 50 has compliant portions 58, such as pinholes, but other configurations can be used. The configuration of the signal contact 42 is intended to be illustrative, as other embodiments of the signal contact can be used. For example, the signal contact 42 can have an asymmetrical configuration or other configuration that allows for optimal performance under different conditions. The circuit board mounting portion 50 cooperates with the backplane circuit board to hold the signal contact 42 on the backplane circuit board.

[0034] like Figures 3 to 9 As shown, the grounding shield contact member 44 has a planar grounding shield portion 60. A grounding shield resilient contact beam or grounding shield contact spring finger 62 extends from a first end of the grounding shield portion 60. In the illustrated embodiment, the grounding shield contact beams 62 are evenly spaced along the length of the grounding shield portion 60; however, other configurations may be used. The grounding shield contact member 44 forms a ground connection between the backplane circuit board and the wafer 22 and is configured to provide both mechanical integrity and signal integrity.

[0035] Each grounding shield contact beam 62 has a grounding shield resilient contact arm 64, which has an introduction portion 66 and an engagement portion 68. The resilient contact arm 64 is configured to press against the grounding plane member 28 of the daughter card connector 14 when it is mated to the backplane connector 12.

[0036] The elastic member 70 extends from the second end of the grounding shield portion 60. The second end of the grounding shield portion 60 is opposite to the first end of the grounding shield portion 60. In the illustrated embodiment, the elastic members 70 are evenly spaced along the length of the grounding shield portion 60; however, other configurations may be used. The longitudinal axis of each of the elastic members 70 is offset from the longitudinal axis of each of the grounding shield contact beams 62.

[0037] Each of the elastic members 70 has a U-shaped member 72 (when in Figure 7 and Figure 8 (As observed in the image), a U-shaped member 72 extends from the grounding shield portion 60. The U-shaped member 72 is received in a cavity 38, which receives each extension of the slot 36 from one or more wafers. The engagement of the U-shaped member 72 with the wall of the cavity 38 helps to hold each grounding shield contact member 44 in place within the housing 34.

[0038] A circuit board engagement surface 74 is provided at the free end of each U-shaped member 72. The circuit board engagement surface 74 is configured to engage with and form an electrical connection with a contact pad on the surface of the backplane circuit board.

[0039] In the illustrated embodiment, a grounding contact 76 is located at the end of the grounding shield portion 60. The grounding contact 76 provides an additional grounding connection between the grounding shield of the daughter card connector 14 and the backplane. The grounding contact member 76 extends substantially perpendicular to the plane of the grounding shield portion 60 and has a retaining portion 78. In the illustrated embodiment, the retaining portion 78 is a pinhole compliant member, but other types of retaining portions 78 can be used. A retaining tab 80 may also be provided on the grounding contact 76. The retaining tab 80 mates with the housing 34 of the backplane connector 12 to secure the grounding shield contact member 44 in place.

[0040] Reference Figure 7 and Figure 8 The diagram shows the wafer 22 inserted into the wafer receiving slot 36. When the daughter card connector 14 mates with the backplane connector 12, the mating interface 16 of the daughter card connector 14 engages and inserts into the mating end 30 of the backplane connector 12. When this occurs, the front end 40 of the wafer 22 is positioned in the corresponding slot 36 of the backplane connector 12.

[0041] As insertion continues, the front end 40 moves past the introduction portion 52 and engagement portion 54 of the resilient contact arm 46 of the signal contact 42, causing the resilient contact arm 46 to move along... Figure 8 The movement is directed in the direction of arrow A. This movement causes the engaging portion 54 of the resilient contact arm 46 to apply a normal force F1 to the wafer 22.

[0042] The wafer 22 is further inserted into the slot 36, causing the front end 40 to move past the introduction portion 66 and engagement portion 68 of the elastic contact arm 64 of the grounding shield contact member 44, thereby causing the elastic contact arm 64 to move along... Figure 8 The direction of arrow B in the diagram is moved. This movement causes the engaging portion 68 of the resilient contact arm 64 to apply a normal force F2 to the wafer 22.

[0043] Due to the construction of the ground shield contact member 44, including the cooperation between the elastic member 70 and the housing 14, the force F2 applied to the wafer 22 by the elastic contact arm 64 is greater than the force F1 applied to the wafer 22 by the elastic contact arm 46. This causes the elastic contact arm 64 of the ground shield contact member 44 to bias the wafer 22 toward the elastic contact arm 46 of the signal contact 42.

[0044] Because the sum of the normal forces F2 is always greater than the sum of the normal forces F1, the wafer 22 will always be biased toward the elastic contact arm 46 of the signal contact 42, regardless of the thickness T of the wafer 22. Since the wafer 22 is always biased toward the signal contact 42, the normal force applied by the elastic contact arm 46 of the signal contact 42 can be determined and controlled, regardless of the thickness T of the wafer 22. The normal force F1 applied to the wafer 22 is independent of the wafer thickness tolerance.

[0045] Since the positioning of the wafer 22 is controlled by the normal force F2 of the resilient contact arm 64 of the grounding shield contact member 44, the normal force F1 applied by the resilient contact arm 46 of the signal contact 42 must be only sufficient to ensure that proper contact is formed and maintained between the signal pad 24 and the engagement portion 54 of the resilient contact arm 46 of the signal contact 42, ensuring proper positioning of the wafer 22. Because this normal force is less than the force required by known signal contacts, the length of the signal contact 42 can be minimized due to the smaller force required. This allows the length of the resilient contact arm 46 of the signal contact 42 and the length of the signal contact to be minimized for signal integrity purposes, while still meeting the normal force requirements of a reliable contact system.

[0046] Because the total tolerance from the base of the resilient contact arm 46 of the signal contact 42 to the front side of the wafer 22 is reduced, the resilient contact arm 46 and the signal contact 42 can generally be shorter in length (requiring a smaller working range for mechanical purposes to achieve the required normal force), which improves the signal integrity of the backplane connector 12 because there is less chance of crosstalk between the signal contacts 42.

[0047] Another advantage of this invention is that it eliminates the need for ground contacts from known chip-based connector systems. The ground shield contact member 44 combines the functions of a ground contact and shielding into a single component. Furthermore, the ground shield contact member 44 can be tuned for signal integrity to eliminate the need for ground contact members between differential contact member pairs.

[0048] The grounding shield contact member 44 can increase the current / power capacity of the wafer-based power contact system. For high-power / current wafer 22, in addition to the current path on the front side of the wafer provided by the signal contact 42, the grounding shield contact member 44 also provides a current path to the rear side of the wafer 22, such as... Figure 8 As shown.

[0049] like Figure 11 and Figure 12 As shown, the alternative illustrative grounding shield contact member 144 has a planar grounding shield portion 160. Grounding shield resilient contact beams or grounding shield contact spring fingers 162 extend from a first end of the grounding shield portion 160. In the illustrated illustrative embodiment, the grounding shield contact beams 162 are spaced substantially evenly along the length of the grounding shield portion 160, with a larger space 161 provided in one region; however, other configurations may be used. Similar to grounding shield contact member 44, grounding shield contact member 144 forms a ground connection between the backplane circuit board and the wafer 22 and is configured to provide both mechanical integrity and signal integrity.

[0050] Each grounding shield contact beam 162 has a grounding shield resilient contact arm 164, which has an introduction portion 166 and an engagement portion 168. The resilient contact arm 164 is configured to press against the grounding plane member 28 of the daughter card connector 14 when it is mated to the backplane connector 112.

[0051] A retaining portion 170 extends from a second end of a grounding shield portion 160. The second end of the grounding shield portion 160 is opposite to a first end of the grounding shield portion 160. In the illustrated embodiment, the retaining portion 170 bends out of the plane of the grounding shield portion 160. A portion 172 of the retaining portion 170 extends substantially perpendicular to the grounding shield portion 160, but other configurations may be used.

[0052] like Figure 12 As shown, the retaining portion 170 cooperates with the retaining protrusion 174 of the backplane connector 112 to retain the grounding shield contact member 144 in the backplane connector 112.

[0053] Mounting member 176 extends from fixing portion 170. Mounting member 176 is positioned substantially parallel to the plane of ground shield portion 160, but offset from the plane of ground shield portion 160. In the illustrated embodiment, mounting member 176 is an eyelet compliant member, but other types of mounting member 176 can be used. Mounting member 176 is configured to engage with and electrically connect to through-holes in the backplane circuit board.

[0054] The function and operation of grounding shield contact member 144 and grounding shield contact beam 162 are the same as those of grounding shield contact member 44 and grounding shield contact beam 62. The benefits and advantages of using grounding shield contact member 144 are also the same as those of grounding shield contact member 44.

Claims

1. An electrical connector, comprising: A housing having at least one slot for receiving an electronic wafer therein; A signal contact located on a first side of at least one slot, the signal contact having a signal contact resilient contact arm extending into at least one slot, the signal contact resilient contact arm applying a first normal force on an electronic chip inserted into at least one slot; At least one grounding shield contact member is positioned on a second side of at least one slot, the second side being opposite to a first side, and the at least one grounding shield contact member has a grounding shield resilient contact arm extending into the at least one slot, the grounding shield resilient contact arm applying a second normal force on a wafer inserted into the at least one slot; The second normal force applied by the grounding shield elastic contact arm is greater than the first normal force applied by the signal contact elastic contact arm; Regardless of the wafer thickness, the wafer is biased toward the elastic contact arm of the signal contact, thereby allowing the first normal force applied to the wafer to be independent of the wafer thickness tolerance.

2. The electrical connector of claim 1, wherein at least one grounding shield contact member has a planar grounding shield portion, and the grounding shield resilient contact arm extends from a first end of the planar grounding shield portion.

3. The electrical connector according to claim 2, wherein the grounding shield resilient contact arms are evenly spaced along the length of the planar grounding shield portion.

4. The electrical connector of claim 3, wherein the ground shielded resilient contact arm has an introduction portion and an engagement portion, wherein when the wafer is inserted into at least one slot, the engagement portion presses against the ground plane member of the wafer.

5. The electrical connector of claim 3, wherein the elastic member extends from a second end of the planar ground shield portion, the second end of the planar ground shield portion being opposite to a first end of the planar ground shield portion.

6. The electrical connector of claim 5, wherein the resilient members are spaced evenly along the length of the planar grounding shield portion.

7. The electrical connector of claim 6, wherein the longitudinal axis of each of the resilient members is offset from the longitudinal axis of each of the grounded shield resilient contact arms.

8. The electrical connector according to claim 6, wherein the elastic member has a U-shaped member.

9. The electrical connector of claim 8, wherein a circuit board mating surface is disposed at the free end of the U-shaped member, the circuit board mating surface being configured to engage a contact pad on the surface of the backplane circuit board and to electrically connect with the contact pad.

10. The electrical connector of claim 2, wherein the fixing portion extends from the second end of the planar ground shield portion, the second end of the planar ground shield portion being opposite to the first end of the planar ground shield portion.

11. The electrical connector of claim 10, wherein the fixing portion is bent out from the plane of the grounding shield portion, the fixing portion cooperating with a fixing protrusion of the connector to retain the grounding shield contact member in the connector.

12. The electrical connector of claim 11, wherein a portion of the fixed portion extends substantially perpendicular to the grounding shield portion.

13. The electrical connector of claim 11, wherein a mounting member extends from the fixed portion, the mounting member being configured to engage with and electrically connect to a through-hole of a backplane circuit board.

14. The electrical connector of claim 2, wherein the grounding contact is disposed at the end of the planar grounding shield portion of at least one grounding shield contact member.

15. The electrical connector of claim 1, wherein at least one ground shield contact member provides a ground connection from the backplane circuit board on which the electrical connector is mounted to the ground plane of the wafer, and the at least one ground shield contact member provides mechanical stability and signal integrity.

16. The electrical connector of claim 1, wherein at least one grounding shield contact member provides grounding and shielding for the electrical connector.

17. The electrical connector of claim 1, wherein the signal contact has a signal contact resilient contact arm, a fixing portion, and a mounting portion.

18. The electrical connector of claim 17, wherein the signal contact resilient contact arm has an introduction portion and an engagement portion, wherein the engagement portion presses against the signal conductive pad of the wafer when the wafer is inserted into at least one slot.

19. The grounding shield contact component according to claim 1, wherein for the purpose of signal integrity, the signal contact length across the signal contact is minimized while still satisfying the normal force requirements of a reliable contact system.

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