PATENT DOCUMENT

Publication Number: US-9065225-B2
Application Number: US-201313871765-A
Country: US
Kind Code: B2

Title: Edge connector having a high-density of contacts

Abstract:
High-speed connectors having a high density of contacts may be provided. One example may provide a connector having a housing with a slot forming an opening in a top side. The slot and opening may be arranged to receive a card. This connector may provide a high density of contacts by arranging the contacts in multiple rows in the slot. Various contacts may include barbs to be inserted into the housing. The barbs may be angled and may have one or more teeth to help anchor the contacts in place. A conductive or nonconductive shield or shell may be placed over the housing. When a conductive shield is used, metal pins may be inserted into the housing for mechanical stability and secured to the shield, and various contacts may have contacting portions in contact with the shield to improve signal integrity.

Claims:
What is claimed is: 
     
       1. A connector comprising:
 a housing having a slot, the slot forming an opening in a top surface; 
 a first row of contacts having contacting portions in a first side of the slot; 
 a second row of contacts having contacting portions in the first side of the slot between the first row of contacts and the opening; 
 a third row of contacts having contacting portions in a second side of the slot; and 
 a fourth row of contacts having contacting portions in the second side of the slot between the third row of contacts and the opening, 
 wherein each of the contacts further comprises a contacting portion emerging from a bottom of the housing, and 
 wherein the contacting portions for each contact in the second row of contacts and the fourth row of contacts are each surface-mount contacts and the contacting portions of each contact in the first row of contacts and the third row of contacts are through-hole contacts. 
 
     
     
       2. The connector of  claim 1  further comprising ground tabs in the housing and substantially beneath the slot. 
     
     
       3. The connector of  claim 2  wherein each of the ground tabs comprises a contacting portion emerging from a bottom of the housing. 
     
     
       4. The connector of  claim 1  wherein the slot is configured to receive a riser board having a plurality of surface contacts. 
     
     
       5. The connector of  claim 4  wherein a bottom of the connector is adapted to mate with a printed circuit board. 
     
     
       6. The connector of  claim 4  wherein a bottom of the connector is adapted to mate with a flexible circuit board. 
     
     
       7. The connector of  claim 1  wherein at least one of the contacts in the first row of contacts includes one or more barbs to extend into the housing, the barbs including one or more teeth along an edge of the barb. 
     
     
       8. The connector of  claim 1  further comprising side panels inserted into notches in the housing over the first outside side and the second outside side of the housing. 
     
     
       9. A connector comprising:
 a housing having a central passage to accept a card, the central passage having a first side and a second side, the housing further having a first outside side and a second outside side; 
 a first plurality of contacts inserted into slots in the first outside side and the second outside side of the housing to form a first row of contacts on the first side and the second side of the central passage, wherein at least one of the first plurality of contacts includes one or more barbs to extend into the housing, the barbs including one or more teeth along an edge of the barb; 
 a second plurality of contacts inserted into slots in the first side and the second side of the central passage to form a second row of contacts on the first side and the second side of the central passage; and 
 side panels inserted into notches in the housing over the first outside side and the second outside side of the housing. 
 
     
     
       10. The connector of  claim 9  wherein the second plurality of contacts include contacts of a first type and a second type, where a difference between the first type and the second type is a position of a through-hole contact portion. 
     
     
       11. The connector of  claim 9  wherein side panels are insulated. 
     
     
       12. The connector of  claim 11  wherein the side panels are secured in place using dovetailed notches in the housing. 
     
     
       13. The connector of  claim 9  further comprising:
 metal pins inserted through the housing; and 
 a shield over the housing and attached to tops of the metal pins. 
 
     
     
       14. The connector of  claim 9  wherein the one or more barbs includes an upper barb having one or more teeth along a top edge and a lower barb having one or more teeth along a bottom edge. 
     
     
       15. The connector of  claim 9  wherein the upper barb and the lower barb are angled upward. 
     
     
       16. The connector of  claim 9  wherein each of the first plurality of contacts further comprises a surface-mount contact portion emerging from a bottom of the housing near an edge of the housing and extending away from the housing, and each of the second plurality of contacts further comprises a through-hold contact portion emerging from a bottom of the housing near a center of the housing. 
     
     
       17. A method of manufacturing a robust connector, the method comprising:
 receiving a housing having a central passage to accept a card, the central passage having a first side and a second side, the housing further having a first outside side and a second outside side; 
 inserting a first plurality of contacts into slots in the first outside side and the second outside side of the housing to form a first row of contacts on the first side and the second side of the central passage, wherein at least one of the first plurality of contacts include one or more barbs to extend into the housing, the barbs including one or more teeth along an edge of the barb; 
 inserting a second plurality of contacts into slots in the first side and the second side of the central passage to form a second row of contacts on the first side and the second side of the central passage; and 
 inserting side panels over the first outside side and the second outside side of the housing. 
 
     
     
       18. The method of  claim 17  wherein the second plurality of contacts include contacts of a first type and a second type, where a difference between the first type and the second type is a position of a contact tail. 
     
     
       19. The method of  claim 17  wherein the side panels are insulated. 
     
     
       20. The method of  claim 19  further comprising securing the side panels in place using dovetailed notches in the housing. 
     
     
       21. The method of  claim 17  further comprising:
 inserting metal pins through the housing; 
 placing a shield over the housing; and 
 attaching the shield to tops of the metal pins.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a nonprovisional of U.S. provisional patent No. 61/639,061, filed Apr. 26, 2012, which is incorporated by reference. 
     BACKGROUND 
     The number and types of electronic devices available to consumers have increased tremendously the past few years, and this increase shows no signs of abating. Devices such as portable computers; tablet, desktop, and all-in-one computers; cell, smart, and media phones; storage devices; portable media players; navigation systems; monitors; and others have become ubiquitous. 
     The complexity of these devices has similarly been increasing. Additional functionality, such as graphics processing, networking, increases in memory size, and others, has led to an increase in the number and types of circuits included in these devices. These circuits may be located on boards, such as main-logic boards, in these devices. 
     However, due to increases in complexity, it is becoming more difficult to include all these needed circuits on one board. Also, there is a desire to be able to customize devices to target user preferences and varying price points. These factors have led to an increase in the use of daughter or riser cards. These cards may include various circuits. A card may connect to main-logic board via contacts along an edge of the card, where the edge of the card may plug into a corresponding connector on the main-logic board. Use of these cards allows functionality to be moved off the main-logic board, and also allows different cards to be used in different device configurations. 
     Unfortunately, these connectors may consume space on the main-logic board. This increased space means the main-logic board can either support less functionality or has to grow correspondingly larger. The latter may also mean that the entire electronic device may have to increase in size. 
     Also, these connectors may degrade signal quality and high-speed performance. Specifically, a signal traveling from a circuit on a card to a circuit on a main-logic board may need to travel along a trace on the card to a contact at an edge of the card, then through a connector joining the card to the main-logic board. From there, the signal needs to travel along a trace on the main-logic board itself. These multiple connections may increase signal path resistance and reactance, as well as signal coupling, thereby degrading signal quality. 
     Cards supported by these connectors may also be of considerable size, weight, and complexity. A large mass may place high rotational, lateral, and other forces on the connector. 
     Thus, what is needed are connectors having a high density of contacts that may also provide improved performance at high-speeds and be robust enough for use with large, heavy cards. 
     SUMMARY 
     Accordingly, embodiments of the present invention may provide high-speed connectors that may have a high density of contacts, may provide improved performance at high speeds, and may be robust for use with large, complex cards. 
     An illustrative embodiment of the present invention may provide a connector for mating a daughter, riser, or other board, card, or device to a printed circuit board, flexible circuit board, or other appropriate substrate. In various embodiments of the present invention, the daughter, riser, or other board, card, or device may be a memory card, audio card, central processing unit or other processor card, graphics card, wired or wireless networking card, memory device, or other type of board, card, or device. The printed circuit board, flexible circuit board, or other appropriate substrate may be a main-logic board, motherboard, or other board. 
     An illustrative embodiment of the present invention may provide a connector having a housing with a slot forming an opening in a top side. The slot and opening may be arranged to receive a daughter, riser, or other card, board, or device. This connector may provide a high density of contacts by arranging contacting portions of contacts in multiple rows in the slot. Tail portions of the contacts may emerge from a bottom of the housing. The tail portions may be through-hole, surface-mount, or other type of contacting portion, or combination thereof. The tail portions may be soldered or otherwise fixed to a printed circuit board, flexible circuit board, or other appropriate substrate. 
     Another illustrative embodiment of the present invention may provide a connector having a slot forming an opening in a top of a housing. The slot may accept or receive an edge of a daughter or riser card. Contacting portions of contact pins in the connector housing may be arranged to mate with surface contacts near the edge of the daughter card. To improve high-speed performance, these contacting portions and corresponding surface contacts may be arranged in various patterns to provide shielding for signals, such as differential pair signals. 
     In one example, contacting portions and surface contacts may be arranged in two or more rows, and these rows may be at least approximately aligned, or they may be offset. Where contacts in these rows may be aligned, a first contact in a first row may be aligned with a second contact in a second row. These contacts may have a ground contact on each side, where the ground contact runs the length of both contacts and the space between them. This configuration may be used to carry differential signals. Where contacts are offset, two adjacent contacts may be used to carry a differential signal. These adjacent contacts may have a ground contact on each side, and a third ground contact below (or above). By positioning ground contacts in these ways, differential pair signals may be shielded to reduce cross-talk and to improve signal quality. To further improve signal quality, the ground contacts may include one or more contacting points to form electrical connections to a shield around a housing of the connector. Air gaps may be placed between contacts to reduce pin-to-pin capacitive coupling. 
     Embodiments of the present invention may improve high-speed performance by shielding signals as described above. Further shielding, for example, by providing a conductive shield around the housing, may further improve high-speed performance. Again, further shielding may be provided by embodiments of the present invention where ground contacts have one or more contacting portions forming electrical connections with a shield. In other embodiments of the present invention, shielding is omitted to prevent coupling through the shield between signal lines. In these embodiments, a nonconductive frame or shell may be placed around a housing of the connector. In a specific embodiment of the present invention, the nonconductive frame or shell is stretched before being placed over the housing for increased mechanical durability. The nonconductive frame or shell may be placed over the housing during manufacturing before reflow, or after reflow so that the nonconductive frame or shell may avoid the intense heat of this manufacturing step. 
     Another embodiment of the present invention may provide improved high-speed performance by simplifying an interconnect between a daughter or riser board and a main-logic board. In one specific embodiment of the present invention, a single contact may be used to convey a signal from a surface contact on a card or board to a surface contact on a main-logic board. This interconnect may reduce a number of contact points that may otherwise be needed, thus reducing the impendence and reactance of the interconnect path and improving high-speed performance. 
     Another embodiment of the present invention may provide a robust connector by including one or more barbs extending from the contacts, where the one or more barbs are inserted into a housing of the connector. These barbs may each include one or more teeth that may be used to secure the barb in place. These teeth may help to reduce or prevent movement of the contact in the housing that may otherwise occur due to forces placed on the contact by a card inserted into the connector. Durability of these connectors may be further enhanced by embodiments of the present invention, where one or more metal pins are used to provide mechanical support for a housing. These pins may be spot or laser welded or otherwise fixed to a shield. The pins may extend through the housing and emerge from a bottom of the connector, where they may be inserted into openings or make contact with contacts of a printed circuit board or other appropriate substrate. The pins may also be soldered to traces around the openings, or to contacts on a surface of the printed circuit board. Similarly, a key may be made of metal or other durable material in embodiments of the present invention to prevent damage to the connector or card by improper insertion of a card. 
     Another embodiment of the present invention may provide a method of manufacturing a robust connector. This method may include receiving a housing having central passage to accept a card, the central passage having a first side and a second side. The housing may further have a first outside side and a second outside side. A first plurality of contacts may be inserted into slots in the first outside side and the second outside side of the housing. Some or all of the first plurality of contacts may include one or more barbs that may extend into the housing. The barbs may include one or more teeth along a top or bottom edge, or along both edges, of the barb. A second plurality of contacts may be inserted into slots in the first side and the second side of the central passage. The second plurality of contacts may include contacts of a first type and a second type, where a difference between the types is a position of a contact tail. Where these contact tails are through-hole contact tails, varying the type of contact, and therefore the position of the contact tail, may space the through-hole contacts apart from each other. This may aid in construction of a printed circuit board on which the connector may reside. 
     This method may further include inserting side panels over the first outside side and the second outside side of the housing. These side panels may be insulative to isolate the first plurality of contacts from a shield and from each other. Dovetailed notches in the housing may be used to help secure the side panels in place. Metal pins may be inserted through the housing. A shell or shield may be placed over the housing and spot or laser welded, or otherwise fixed, to the metal pins. The shell or shield may be conductive or nonconductive. 
     Another embodiment of the present invention may route traces to provide shielding on a daughter or riser board or card. These techniques may also be applied to routing traces on main-logic boards. In a specific embodiment, traces on a card that are connected to contacts for a differential pair may be routed under a ground pad on the card. The ground pad may be further connected to ground on other layers of a printed circuit board of the daughter or riser card. Such grounding may provide shielding, improve signal quality, and decrease crosstalk. 
     Another embodiment of the present invention may provide a connector having a high-density of contacts. This embodiment may provide a high density of contacts by providing multiple rows of contacts on each side of an opening arranged to receive a card. Density may be further increased by close spacing of contacts that is achieved by placing air-gaps between contacts to reduce coupling. Density may also be improved by using side panels and a shell or shield to secure contacts in place. Barbs on some contacts may be used to further secure contacts. Mechanical stability may be improved by the use of pins and one or more keying features located in a housing of the connector. A use of a mix of through-hole and surface-mount contacts may be used to enable the routing of signals away from the connector and may help to improve the ability of the connector to be mounted on a printed circuit board or other substrate. 
     Various embodiments of the present invention may incorporate one or more of these and the other features described herein. A better understanding of the nature and advantages of the present invention may be gained by reference to the following detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  illustrate a portion of an electronic device according to an embodiment of the present invention; 
         FIG. 2  illustrates a simplified cut-away view of a connector according to an embodiment of the present invention; 
         FIG. 3  illustrates portions of two rows of contacts arranged according to an embodiment of the present invention; 
         FIG. 4  illustrates a cut-away view of a portion of a connector according to an embodiment of the present invention; 
         FIGS. 5A and 5B  illustrate side views of contact pins that may be used in connectors according to embodiments of the present invention; 
         FIG. 6  illustrates a side view of a cut-away portion of a connector according to an embodiment of the present invention; 
         FIG. 7  illustrates a cut-away view of a connector according to an embodiment of the present invention; 
         FIG. 8  illustrates the arrangement of contacts for two differential pairs according to an embodiment of the present invention; 
         FIG. 9  illustrates a cut-away side view of a portion of a connector according to an embodiment of the present invention; 
         FIG. 10  illustrates a method of routing signals to provide shielding for signals on a daughter or riser card according to an embodiment of the present invention; 
         FIG. 11  illustrates cutaway views of a connector according to an embodiment of the present invention; 
         FIG. 12  illustrates contacts that may be used in connectors according to an embodiment of the present invention; 
         FIG. 13  illustrates other contacts that may be used in connectors according to an embodiment of the present invention; 
         FIG. 14  illustrates a contact having angled barbs according to an embodiment of the present invention; 
         FIG. 15  illustrates a card edge connector according to an embodiment of the present invention; 
         FIG. 16  illustrates an underside view of a card connector according to an embodiment of the present invention; 
         FIG. 17  is an exploded view of a connector according to an embodiment of the present invention; 
         FIG. 18  illustrates contacts that may be used in a connector according to an embodiment of the present invention; 
         FIG. 19  illustrates a housing for a connector according to an embodiment of the present invention; 
         FIG. 20  illustrates side panels on a housing of a connector according to an embodiment of the present invention; 
         FIG. 21  illustrates a connector according to an embodiment of the present invention; 
         FIG. 22  illustrates a side view of a connector having a nonconductive shield; 
         FIG. 23  illustrates a metal pin for a connector according to an embodiment of the present invention; and 
         FIG. 24  illustrates a keying feature for a connector according to an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
       FIGS. 1A and 1B  illustrate a portion of an electronic device according to an embodiment of the present invention. This figure, as with the other included figures, is shown for illustrative purposes and does not limit either the possible embodiments of the present invention or the claims. 
       FIG. 1A  illustrates a side view of connector  110 , daughter or riser card  120 , and main-logic board  130 . Connector  110  may include a housing having a slot forming an opening in the top of the housing. This slot and opening may receive card  120 . Connector  110  may be soldered or otherwise fixed to main-logic board  130 . 
     In various embodiments of the present invention, daughter or riser card  120  may be a memory card, audio card, central processing unit or other processor card, graphics card, wired or wireless networking card, memory device, or other type of board, card, or device. Main-logic board  130  may be a printed circuit board, flexible circuit board, or other appropriate substrate. While in this example, connector  110  is shown as providing an orthogonal connection between card  120  and main-logic board  130 , in other embodiments of the present invention, card  120  and main-logic board  130  may be parallel or have other orientations. 
       FIG. 1B  illustrates a side view of connector  110 , card  120 , and main-logic board  130 . In various embodiments of the present invention, connector  110  may save space on main-logic board  130 . Specifically, connector  110  may have a reduced footprint. Embodiments of the present invention may reduce this footprint by providing multiple rows of contacts on one or more sides of a slot in connector  110 . By providing multiple rows of contacts, the contact density in connector  110  may be increased. This increase in density may also allow for the use of narrower cards  120 . 
     Embodiments of the present invention may also provide an improved high-speed performance. This may be done by simplifying interconnect between card  120  and main-logic board  130 . High-speed performance may also be improved through improved arrangements of contacts in connector  110 . Examples are shown in the following figures. 
       FIG. 2  illustrates a simplified cut-away view of a connector according to an embodiment of the present invention. In this example, connector  110  is shown accepting card  120 . A bottom side of connector  110  may be mated to a main-logic board or other appropriate substrate. In this example, card  120  may include two rows of contacts  222  and  224 . In other embodiments of the present invention, card  120  may include three or more rows of contacts. These contacts may be surface contacts. That is, they may be formed by plating conductive material on a surface of card  120 . Connector  110  may have corresponding contact pins having contacting portions arranged to mate with surface contacts on card  120 . A back side of card  120  may have a similar pattern of contacts, which may mate with corresponding contacts in connector  110 . Contacts in rows  222  and  224  may be arranged in various ways. Specifically, they may be arranged to provide improved high-speed performance. For example, they may be arranged to provide shielding for differential pairs of signals. An example is shown in the following figure. 
       FIG. 3  illustrates portions of two rows of contacts arranged according to an embodiment of the present invention. In this example, the portions of two rows of contacts  322  and  324  are offset from each other. A differential pair of contacts, DP 1  and DN 1 , may have ground contacts on either side. This differential pair further may have a ground contact below it. This arrangement may provide ground isolation from differential pairs DP 1  and DN 1  to differential pairs DP 2  and DN 2 , DP 3  and DN 3 , and DP 4  and DN 4 . This ground isolation may improve signal quality on the differential pair lines, and it may reduce cross talk. This may, in turn, provide improved high-speed performance. 
     While the various ground contacts shown herein may be connected to ground, in various embodiments of the present invention they may be connected to other low-impedance paths, or AC grounds. For example, they may be connected to a power supply, bias line, control signal, or other appropriate line. 
       FIG. 4  illustrates a cut-away view of a portion of a connector according to an embodiment of the present invention. In this example, connector  110  may include a first row of contact pins  410  and a second row of contact pins  420 . Contact pins  410  and  420  may improve high-speed performance by providing simplified interconnections between card  120  and a main-logic board or other substrate (not shown). For example, contacts  410  may provide a simple and direct path from a surface contact  222  on card  120  to a contact (not shown) on a main-logic board (not shown). 
     In various embodiments of the present invention, contact pins in connector  110  may have various shapes. Examples are shown in the following figures. 
       FIGS. 5A and 5B  illustrate side views of contact pins that may be used in connectors according to embodiments of the present invention. Contact  510  may include contacting portion  512  and tail portion  514 . Contacting portion  512  may form electrical connections with surface contact  222  on card  120 . Tail portion  514  may contact surface contacts (not shown) on a main-logic board or other substrate (not shown). 
     Contact  520  may include contacting portion  522  and tail portion  524 . Contacting portion  522  may form electrical connections with surface contact  224  on card  120 . Tail portion  524  may contact a surface contact (not shown) on a main-logic board or other substrate (not shown). In other embodiments of the present invention, one or more of these contacts may have through-hole tail portions. For example, contact  510 , which may be located at an edge of the housing, may have surface-mount tail portion  514 , while interior contact  520  may have through-hole tail portion  524 . This arrangement may facilitate inspection of a finished device by having surface-mount contacts visible at an edge of the housing and through-hole contacts under the housing where they would otherwise not be visible. In still other embodiments of the present invention, the interior contact  520  may have a tail portion  524  extending into a central opening in the housing where it may be inspected. Contacts  550  and  560  may be similarly arranged to have contacting portions  552  and  562 , as well as surface-mount tail or contacting portions  554  and  564 . 
     In various embodiments of the present invention, one or more contacts in connector  110  may have different width. For example, a power or ground contact in connector  110  may have a wide width to handle large currents, or to provide increased isolation between adjacent pins on each of its sides. These wider connector contacts may have correspondingly wide surface contacts on a card  120  and main-logic board  130 . 
     While in these examples, tail portions are shown as surface-mount portions, other types of tail portions, such as through-hole portions, may be used consistent with embodiments of the present invention. 
     Again, these contacts may be arranged in ways to improve signal performance. Signal performance and shielding may be further improved by employing ground tabs in connector  110  below card  120 . An example is shown in the following figure. 
       FIG. 6  illustrates a side view of a cut-away portion of a connector according to an embodiment of the present invention. In this example, contacts  610 ,  620 ,  630 , and  640  may provide electrical connections between card  120  and main-logic board  130 . Ground tab  650  may be placed under daughter card  120  between the contacts. This ground tab may have surface-mount or through-hole contacting portions connected to corresponding contacts in main-logic board  130 . 
     Again, surface contacts on a card and corresponding contacts in a connector may be arranged in various ways consistent with embodiments of the present invention. Another example is shown in the following figure. 
       FIG. 7  illustrates a cut-away view of a connector according to an embodiment of the present invention. Connector  110  may accept an edge of card  120 . Card  120  may include two rows of contacts  710  and  720 . These contacts may include differential pairs of contacts, where one contact in the differential pair is located above the other. These pairs of contacts may be isolated by ground contacts that run the length of both contacts in the differential pair as well as the space between the two contacts. An example is shown in the following figure. 
       FIG. 8  illustrates the arrangement of contacts for two differential pairs, DP 1  and DN 1  and DP 2  and DN 2 , according to an embodiment of the present invention. These differential pairs are isolated by ground contacts that may substantially run the length of the differential pair contacts and the space between them. Since only one contact pin in connector  110  is needed for these ground contacts, it may have a different shape or profile as compared to the signal contacts shown earlier. An example is shown in the following figure. 
       FIG. 9  illustrates a cut-away side view of a portion of a connector according to an embodiment of the present invention. In this example, contacts  910 ,  920 , and  930  electrically connect contacts on card  120  to contacts on main-logic board  130 . In this example, contact  910  may be a ground contact, while contacts  920  and  930  may be signal contacts for differential pair. Ground contact  910  may be made wider, as shown, to provide reduced impedance in the ground line. Ground tabs  950  may be included as before. Ground tabs  950  may optionally be merged into a single structure with contact  910 . 
     Again, embodiments of the present invention may provide a high degree of ground shielding and crosstalk isolation. For example, as shown in  FIGS. 3 and 8 , shielding and isolation may be enhanced through arrangement of signal and ground contacts on a daughter or riser board. This shielding may further be improved by routing signals on the card in a manner consistent with an embodiment of the present invention. These techniques may also be applied to routing signals on a main logic board. An example is shown in the following figure. 
       FIG. 10  illustrates a method of routing signals to provide shielding for signals on a daughter or riser card according to an embodiment of the present invention. In this example, signals traces  1020  couple to pads for differential pair DP 4  and DN 4 . These traces may reach first vias  1010  and change layers on daughter or riser card  120 . Vias  1010 , and the other vias shown here, may be micro-vias that drop one or more layers into the printed circuit board of the daughter or rise card  120 . Traces  1020  may then proceed underneath ground pad  1050 . Once they have passed underneath ground pad  1050 , traces  1020  may emerge through a second set of vias  1010 . 
     In some embodiments of the present invention, the impedance (Zo) requirements are such that the ground plane under contacts for differential pair DP 4  and DN 4  should be removed. Since the ground plane does not shield the surface from inner route layers, the signal traces  1020  may be routed beneath ground pad  1050 . In this way, traces  1020  are at least partially shielded by ground pad  1050 . This shielding may be further enhanced by connecting ground pad  1050  to grounds on one or more other layers through vias  1030 . By burying traces  1020  beneath ground pad  1050 , cross talk and isolation to differential pairs DP 1  and DN 1 , and DP 2  and DN 2 , which are routed on traces  1040 , may be improved. 
     To further improve signal quality, stub portions of vias  1010  may be avoided. Specifically, printed circuit boards may be manufactured where vias, such as vias  1010 , traverse through all layers of the board. These multilayer vias are then connected to traces on intermediate layers, thereby leaving stubs above or below the traces on these intermediate levels. These stubs may emit radio-frequency interference, degrading the signal and increasing crosstalk. Accordingly, embodiments of the present invention may route signals such that they change layers through vias which begin and terminate on the individual layers where traces  1020  are routed. 
     Again, contacts in various embodiments of the present invention may have various shapes. Further examples are shown in the figures below. 
       FIG. 11  illustrates cutaway views of a connector according to an embodiment of the present invention. This connector may include central passage  1190  to accept a card. Connector  110  may include contacts  1110  and  1150 , which may be supported by housing  1120 . Housing  1120  may be at least partially surrounded by shield  1130 . Housing  1120  may include one or more posts  1122 , which may be inserted into openings in a printed circuit board for mechanical stability. One or more metal pins  1140  may also be included for mechanical stability. Metal pins  1140  may also be inserted into openings in a printed circuit board. Metal pins  1140  may further be soldered to ground or other connections on a printed circuit board. 
     Contact  1110  may include contacting portion  1118  to mate (form an electrical connection) with a contact on a card (not shown.) Contact  1110  may also include contacting portion  1112 , which may contact shield  1130 , and surface-mount contact portion  1115 . 
     One or more barbs  1114  may be included as part of contact  1110 . These one or more barbs  1114  may be inserted into housing  1120  for mechanical stability. To provide further stability, one or more teeth  1116  may be provided along edges of barbs  1114 . In a specific embodiment of the present invention, teeth  1116  may be located along a top edge of an upper barb  1114  and a lower edge of a lower barb  1114 . When a card is inserted into central passage  1190 , rotational stresses due to the force from the card on contact  1110  may have a tendency of driving teeth  1116  into housing  1120 . This may further secure the position of contacts  1110  in housing  1120 . 
     Contacts  1150  may include contacting portions  1152  to mate with corresponding contacts on a card (not shown.) Contacts  1150  may further include through-hole contacting portions  1152 . Contacts  1150  may further include contacting portion  1154  to mate with a contact on a board inserted in central opening or passage  1190 . 
     Again, power and ground contacts in connectors according to embodiments the present invention may be formed to have an additional width. This additional width may increase current carrying capabilities of the contacts. Also, the additional width may increase isolation between contacts on each side of the wider contact. An example is shown in the following figure. 
       FIG. 12  illustrates contacts that may be used in connectors according to an embodiment of the present invention. This example includes contacts  1210  and  1250 . Contacts  1210  may include a contacting portion  1218  to make contact to pad or contact area on card  1260  and surface-mount contact portion  1215 . Contacts  1210  may further include wider portions  1219  and  1217  to improve current carrying capabilities and isolation. In particular, contacts such as contacts  1210  may be placed between signal pins where isolation between the signal pins is important. This may be the case where contacts  1210  are on each side of a pair of contacts carrying differential signals. Contacts  1210  may include barbs  1214  having teeth  1216 . Contacts  1250  may include contacting portions  1254  and through-hole contact portion  1252 . 
       FIG. 13  illustrates other contacts that may be used in connectors according to an embodiment of the present invention. These contacts include contacts  1310  and  1350 . Contact  1310  may include contacting portions  1312  and  1319  to form electrical connections with shell  1330 , and contacting portion  1318  to contact a contact on card  1360 . Contact  1310  may include a serpentine portion between contacting portion  1318  and contacting portion  1319 . This serpentine portion may help to ensure that contacting portion  1319  engages shield  1330  when a card  1360  is inserted. As before, contact  1310  may include a barbs  1314  having teeth  1316 . Contacts  1350  may include contacting portion  1354  and through-hole portions  1352 . 
     In the above examples, the barbs on the various contacts may extend horizontally into a housing of the connector. In this way, if various ones of the contacts are inserted into the housing at different depths, the surface-mount portions of the contacts may remain aligned. For example, in  FIG. 11  above, if various contacts  1110  are inserted into housing  1120  to various depths, surface-mount contacting portions  1115  may remain aligned in a single plane. For this reason, in the above example, barbs  1114  are parallel to the surface-mount portions  1115 . However, in other embodiments of the present invention, it may be desirable to angle one or more of these barbs to provide increased mechanical support. An example is shown in the following figure. 
       FIG. 14  illustrates a contact having angled barbs according to an embodiment of the present invention. In this example, contact  1410  includes contacting portion  1418  and barbs  1414 . Barbs  1414  may include teeth  1416  as before. In this example, barbs  1414  may be angled into housing  1420 . Again, as force is exerted on contact  1410  at contacting portion  1418 , the teeth  1416  on barbs  1414  will engage housing  1420 , thereby tending to reduce or prevent movement of contact  1410  relative to housing  1420 . Contact  1410  may further include surface-mount contact portion  1415 . 
       FIG. 15  illustrates a card edge connector according to an embodiment of the present invention. Card edge connector  110  may include an opening  1190  to accept a card (not shown.) A key  1570  may be used to ensure the card is inserted in a proper orientation. Shield  1130  may at least partially surround housing  1120 . Tabs  1132  may be inserted into corresponding slots on a printed circuit board and soldered, for example, to ground traces. Surface-mount contacts  1115  may emerge from outer sides of connector  110 . 
     Again, shield  1130  may be connected to a ground of a board to which it is mounted via tabs  1132 . That is, tabs  1132  may be inserted into openings on the board which may be plated with metal that is connected to ground. Tabs  1132  may be soldered to the plating of the openings to make an electrical connection between shield  1130  and ground. Also, as shown above, internal contacts  1110  and  1310  may include contacting portions, such as contacting portions  1112 ,  1132 , and  1319 , that make electrical connections to shield  1130 . Contacts  1110  and  1310  may further connect to ground, thereby providing a ground path from the shield  1130 , through contacts  1110  or  1310 , to ground. This arrangement provides several parallel ground paths from shield  1130  to ground. In still other embodiments of the present invention, a conductor, such as a flexible or elastic conductor, may be used to connect shield  1130  to ground. Such a conductor may similarly be used to connect a ground on a card inserted into connector  110  to shield  1130 . 
       FIG. 16  illustrates an underside view of a card connector according to an embodiment of the present invention. Connector  110  may include shield  1130  at least partially around housing  1120 . Metal pins  1140  may be inserted into housing  1120  for increased mechanical strength. Housing  1120  may include posts  1122  for additional increased mechanical stability. Shield  1130  may include opening  1133  to accept tab  1122  on housing  1120 . 
     Outer surface-mount contacting portions  1115  and inner through-hole contacting portions  1152  may emerge from the underside of connector  110 . Surface-mount contacting portions  1115  may emerge from the underside of the connector near an edge of the connector  110  and extend away from the connector  110 , and may be soldered to corresponding contacts on a surface of a printed circuit board. Through-hole contacting portions  1152  may emerge from the underside of the connector near a center of the connector and may be inserted into corresponding holes in a printed circuit board. 
     This arrangement may facilitate inspection of the finished product. Specifically, surface-mount contacts  1115  are readily visible along edges of connector  110 . Through-hole contact portions  1152  may be inspected by viewing an underside of a printed circuit board supporting connector  110 . If through-hole contact portions  1152  were instead surface-mount contacting portions, they would not be visible for inspection. Further, having that many rows of surface-mount contact portions would greatly increase the co-planarity requirement that would result from a pure surface mount design. Not exceeding two rows of surface-mount contact portions helps to avoid the difficulty of aligning a high number of surface-mount contact portions to a single plane. 
     It should be noted that inspection could also be accomplished by making all contacting portions through-hole contact portions. For example, surface-mount contacting portions  1115  could be replaced with through-hole contact portions and all contacts could be inspected. However, the use of through-holes near the edges of the connector  110  would block route paths from through-hole contact portions  1152  through a printed circuit board on which connector  110  is mounted. Also, the use of this many through-hole contacts would result in a high true position requirement. Using a mix of surface-mount and through-hole contact portions relaxes the requirement for co-planarity or positioning that would result from a design that uses only surface-mount or through-hole contact portions. 
       FIG. 17  is an exploded view of a connector according to an embodiment of the present invention. This connector may include housing  1120 . Contacts  1110  may be inserted into slots in the outside sides of housing  1120 . Contacts  1150  may be inserted into sides of central passage  1190 . Metal pins  1140  may be inserted into housing  1120  for stability. Side panels  1170  may be fitted along sides of housing  1120  to provide mechanical support for contacts  1110 . A shell or shield  1130  may be placed over housing  1120 . The tops of pins  1140  may be spot or laser welded to shell or shield  1130 . 
     Again, contacts  1150  may include through-hole contacting portions  1152 . However, there are physical limitations as to how close through holes can be located on a printed circuit board. Accordingly, embodiments of the present invention alternate the positions of these through-hole portions  1152  in order to spread out their locations. This may aid in the manufacture of a printed circuit board designed to have this connector reside on it. An example is shown in the following figure. 
       FIG. 18  illustrates contacts that may be used in a connector according to an embodiment of the present invention. In this example, contacts  1150  are implemented as two types of contacts  1150 A and  1150 B. Contacts  1150 A have through-hole portions  1152 A towards a center of a housing, while contacts  1150 B have through-hole portions emerging near an outside of the housing. Contacts  1150 A and  1150 B may be alternated such that through portions  1152 A and  1152 B may alternate. This increases spacing between through-hole portions and simplifies the manufacturing of a printed circuit board designed to receive the connector. 
     Again, embodiments of the present invention may provide connectors having conductive or nonconductive shells or shields. A conductive shield may contact contacting portions of contacts inside the connector, thus providing good ground shielding. However, when contacting portions of contacts are not used to contact a shield, a connecting shield may instead provide a pathway for increased signal coupling among contacts. In these situations, a nonconductive shell or shield may be used. Since either a shield or shell may be used, embodiments the present invention may provide a housing that may be used with either one. An example of such a housing is shown in the following figure. 
       FIG. 19  illustrates a housing for a connector according to an embodiment of the present invention. Housing  1120  may include a central passage  1190  to accept a card. Housing  1120  may further include outside side slots  1122  and slots  1124  to accept contacts. Housing  1120  may further include openings  1126  for metal or other types of pins, which may be used for increased mechanical support. Dovetailed portions  1128  may be used to secure side panels to housing  1120 . In this configuration, housing  1120 , contacts, pins, and side panels may be at least partially covered by a conductive shield or shell. In other embodiments, this configuration may be covered with a nonconductive shield or shell. A nonconductive shield or shell may be placed over housing  1120  either before or after a reflow step in the manufacturing process. By putting a nonconductive shell over housing  1120  after the reflow process, the nonconductive shell avoids the heat that it would otherwise be exposed to during reflow. Again, the nonconductive shield may be stretched before it is placed over housing  1120 . This may help secure contacts in place in housing  1120 . 
     Again, dovetailed portions  1128  of housing  1120  may be used to secure side panels  1170  in place. An example is shown in the following figure. 
       FIG. 20  illustrates side panels on a housing of a connector according to an embodiment of the present invention. Again, dovetailed portions  1128  may secure side panels  1170  in place. Side panel  1170  may be nonconductive to electrically insulate contacts from a conductive shell or shield and from each other. 
     Again, embodiments of the present invention may provide a connector having a nonconductive shell. An example is shown in the following figure. 
       FIG. 21  illustrates a connector according to an embodiment of the present invention. In this example, the connector has a nonconductive shell  2110 . A card  2120  is shown as being inserted into the connector. 
       FIG. 22  illustrates a side view of a connector having a nonconductive shield. In this example, nonconductive shell  2110  at least partially surrounds housing  1120 . 
     Again, embodiments of the present invention may optionally include one or more metal pins in a housing to provide additional mechanical stability. An example is shown in the following figure. 
       FIG. 23  illustrates a metal pin for a connector according to an embodiment of the present invention. As shown before, pin  1140  may be inserted into housing  1120 . When connector shielding  1130  is placed over housing  1120 , a top of pin  1140  may be spot or laser welded at point  1133  to conductive shield  1130 . 
     Again, embodiments of the present invention may include one or more keying features to assure that a card is inserted properly into the connector. In various embodiments of the present invention, this keying feature may be formed of metal to provide additional stability and mechanical support. An example is shown in the following figure. 
       FIG. 24  illustrates a keying feature for a connector according to an embodiment of the present invention. Keying feature  1570  may be formed of metal or other durable material. Keying feature  1570  may include tabs  1572 , which may insert into corresponding slots in a housing, such as housing  1120 . Keying feature  1570  may further include posts  1574 . Posts  1574  may be inserted and soldered to openings on a printed circuit board. 
     In various embodiments of the present invention, connectors may be formed of various materials. For example, a housing for a connector may be formed of one or more types of plastics, nylons, or other materials or combination of materials. The contact pins and ground tabs for the connector may be formed of stainless steel, copper, brass, aluminum, or other materials or combination of materials. These contact pins and ground tabs may be at least partially plated with nickel, gold, palladium-nickel, or other plating materials or combination of materials. 
     In various embodiments of the present invention, signal isolation may be improved and crosstalk reduced through selective use of these materials. For example, some plastics and other materials may have dielectric constants that are three to four times that of air. Accordingly, the use of such materials in a housing for connector  110  may increase pin-to-pin capacitance or coupling capacitance. Such an increase may be useful between differential signal pairs, such as DP 4  and DN 4  in the example in  FIG. 10 . Specifically, coupling these lines together may increase their common-mode rejection of unassociated signals and may help to provide a desired impedance. 
     While an increase in coupling capacitance may be useful between contact pins for signals of a differential pair, it may not be useful between contact pins for signals of different differential pairs or between contact pins for signals of a differential pair and ground or other unassociated signal. Specifically, such an increase in coupling capacitance may increase crosstalk or slow edge rates. In such a situation, embodiments of the present invention may use an air gap, or a lower-dielectric material, between these contact pins. These air gaps or areas of lower-dielectric material may also be placed between rows of contact pins. By using higher-dielectric material between contact pins for differential signal pairs and lower-dielectric material or air gaps between contact pins for differential pairs and grounds, and between rows of contact pins, coupling may be concentrated between contact pins for signals in differential pairs and reduced elsewhere. It should be noted that in various embodiments of the present invention, the use of air gaps or lower-dielectric materials may be limited by the need for a certain level of mechanical stability and durability. 
     The above description of embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Thus, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.

Metadata:
Filing Date: 20130426
Publication Date: 20150623
Grant Date: 20150623
Priority Date: 20120426
Inventors: DEGNER BRETT W.
AMINI MAHMOUD
CORNELIUS WILLIAM P.
GAO ZHENG
MILETICH AARON P.
SIMMEL GEORGE MARC
Assignee: APPLE INC
CPC Classifications: [{"code": "H01R43/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49204", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R12/737", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R12/721", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R43/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49204", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R12/721", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R12/737", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 49477696