Coplanar Card Edge Connector

Abstract

The connection system includes a printed circuit board. The printed circuit board has a top surface and a bottom surface. The printed circuit board also has a first edge perpendicular to the top and bottom surfaces. The printed circuit board also has a second edge perpendicular to the top and bottom surfaces. The first edge surface and the second edge surface intersect at a non-rectangular angle. The connection system also includes a coplanar card edge socket on the printed circuit board. The socket has an upper section interfacing with the top surface of the printed circuit board along the first and second edge surfaces of the printed circuit board. The socket also has a lower section interfacing with the bottom surface of the printed circuit board along the first and second edge surfaces of the printed circuit board.

Description

[Background technology]

[0001] The present invention relates to a card edge connector, and more particularly to a card edge connector for use in environments where installation space is limited.

[0002] A card edge connector is a type of connection between a circuit board and a discrete component. The discrete component may take the form of a socket attached to a second circuit board, in which case the card edge connector can be used as the connection between the circuit board and the second circuit board. In a typical card edge connector, contact traces (sometimes referred to herein as "card edge contacts") are located on one or both sides of the circuit board, near or directly at the edge of the circuit board. A corresponding socket may include openings (sometimes referred to herein as "slots") in the circuit board shape and contacts therein that may interface with the contact traces when the edge of the circuit board is inserted into the slot. Summary of the Invention

[0003] Some embodiments of the present disclosure can be described as a connection system for a card edge connector. The connection system includes a printed circuit board. The printed circuit board has an upper surface and a lower surface. The printed circuit board also has a first edge surface perpendicular to the upper surface and the lower surface, and a second edge surface perpendicular to the upper surface and the lower surface. The first edge and the second edge intersect at a non-rectangular angle. The connection system also includes a coplanar card edge socket on the printed circuit board. The socket has an upper section that interfaces with the upper surface of the printed circuit board along the first and second edge surfaces of the printed circuit board. The socket also has a lower section that interfaces with the lower surface of the printed circuit board along the first and second edge surfaces of the printed circuit board.

[0004] Some embodiments of the present disclosure can also be described as a printed circuit board. The printed circuit board has a top surface and a bottom surface. The printed circuit board also has a first edge surface perpendicular to the top surface and the bottom surface, and a second edge surface perpendicular to the top surface and the bottom surface. The first edge surface and the second edge surface intersect at a non-rectangular angle. The printed circuit board also has a first set of card edge contacts on the top surface along the first edge surface, and a second set of card edge contacts on the top surface along the second edge surface. The printed circuit board also has a circuit chip module attached to the top surface of the printed circuit board. The circuit chip module is partially surrounded by the first set of card edge contacts and the second set of card edge contacts.

[0005] Some embodiments of the present disclosure can also be described as a connection system for a card edge connector. The connection system includes a first printed circuit board. The first printed circuit board has a first upper surface and a first lower surface. The first printed circuit board also has a first edge perpendicular to the first upper surface and the first lower surface. The first printed circuit board also has a second edge perpendicular to the first upper surface and the first lower surface. The first edge and the second edge intersect at a first angle that is not a straight angle. The connection system also includes a second printed circuit board. The second printed circuit board has a second upper surface and a second lower surface. The second printed circuit board also has a third edge perpendicular to the second upper surface and the second lower surface. The second printed circuit board also has a fourth edge perpendicular to the second upper surface and the second lower surface. The third edge and the fourth edge intersect at an angle complementary to the first angle. The second printed circuit board also has a first set of card edge contacts on its second top surface along the third edge. The connection system also includes a coplanar card edge socket on the first printed circuit board. The socket has an upper section interfacing with the first top surface of the first printed circuit board along the first and second edges of the first printed circuit board. The socket also has a lower section interfacing with the first bottom surface of the first printed circuit board along the first and second edges of the first printed circuit board. Inserting the third and fourth edges of the second printed circuit board into the coplanar card edge socket places the first printed circuit board in the same plane as the second printed circuit board. [Brief explanation of the drawings]

[0006] [Figure 1A] A card edge connector connection system is disclosed before a printed circuit board is inserted into a coplanar card edge socket.

[0007] [Figure 1B] A card edge connector connection system is disclosed after a printed circuit board is inserted into a coplanar card edge socket.

[0008] [Figure 2] A coplanar card edge socket for a printed circuit board is disclosed.

[0009] [Figure 3] A printed circuit board having card edge contacts on four edges of the printed circuit board and a module between the card edge contacts is disclosed.

[0010] [Figure 4A] A connection system for a set of card edge connectors having three printed circuit boards is disclosed.

[0011] [Figure 4B] A connection system is disclosed after a first printed circuit board is inserted into a coplanar card edge socket of a second printed circuit board.

[0012] [Figure 4C] The connection system is disclosed after a third printed circuit board is inserted into the coplanar card edge socket of the first printed circuit board. DETAILED DESCRIPTION OF THE INVENTION

[0013] Aspects of the present disclosure relate to electrical connector sockets, and more particular aspects relate to card edge connector sockets. While the present disclosure is not necessarily limited to such applications, various aspects of the present disclosure may be understood through a discussion of various examples using this context.

[0014] A typical card edge connector takes the form of trace contacts (sometimes referred to herein as "card edge contacts") located on the surface of a printed circuit board (sometimes referred to herein as a "PCB"), which are designed to be inserted into PCB-shaped slots in a socket. The socket typically contains contacts (sometimes in the form of contact pins) that interface with the trace contacts when the PCB is inserted into the slot.

[0015] Because card edge connectors allow the PCB itself to be inserted directly into the connector, they can provide an efficient means for connecting components on a PCB to other components in a larger system. For example, in some embodiments, the connection system of a card edge connector may allow a first PCB to be inserted directly into a socket that extends directly from a second PCB. This allows for connections between components on both PCBs without relying on any connectors (e.g., cables) that are external to either PCB.

[0016] However, some connection systems for card edge connectors impose limitations on the design of the circuit boards on and within which those connectors are incorporated. Because typical card edge contacts on a PCB are designed as a series of spaced-apart metal traces at the edge of the PCB's surface, card edge connectors requiring a large number of connectors also require that a potentially long span (i.e., length) of the PCB be dedicated to the series of traces. For example, the relatively large width of a typical consumer read-only memory ("ROM") module is dictated not by the amount of memory carried by its ROM circuit chips, but rather by (1) the width required to lay out the metal traces to connect those chips to the overall system, and (2) the wiring required through the ROM module PCB to connect the chips to those metal traces.

[0017] In some use cases, even if the area of ​​card edge contacts on the card edge does not impose undesirable constraints on the design of the PCB itself, the wiring from those connections to components on the PCB can result in undesirable design constraints. For example, some circuit chip modules, such as memory modules and microchip processors, require that the lengths of each wire between the chip and each card edge contact be similar, if not identical. This is because the chip requires that each signal transmitted on one of those wires arrive at each card edge contact simultaneously. This can be difficult when the chip is connected to multiple card edge contacts spread across the edge of the PCB, because the wiring between the nearest card edge contact and the chip can be significantly shorter than the wiring between the farthest card edge contact and the chip. In some such situations, extra PCB space is designed in to allow the wiring between the nearest card edge contact and the chip to take a much more circuitous route than the wiring between the farthest card edge contact and the chip. This circuitous route may artificially lengthen the wiring to be equal to the wiring of other card edge contacts, but it may also require a significant amount of PCB space.

[0018] In some use cases, card edge connectors can also impose design constraints not only on the PCB that holds the connector (i.e., the card edge contacts and corresponding card edge socket), but also on the entire system. For example, some connection systems for card edge connectors involve a first PCB with card edge contacts being plugged into a socket extending from a surface of a second PCB, resulting in the first PCB (sometimes called a "daughter board") extending perpendicularly from the second PCB. In other words, the bottom and top surfaces of the first PCB are perpendicular to the bottom and top surfaces of the second PCB. As a result, the system into which the connection system is implemented must be large enough to accommodate the width and depth of the first PCB in a first plane and the width and depth of the second PCB in a second plane.

[0019] Some connection systems for card edge connectors attempt to reduce the overall system space required for the connector by stacking the connected PCBs. In other words, a first PCB may be inserted into a socket on a second PCB so that the resulting first PCB is parallel to but above the second PCB. For example, some thin RAM modules in laptop computers utilize these or similar connection system designs. However, while such designs certainly reduce the amount of space on the second PCB required to support the first PCB, they also typically impose constraints on the design of the second PCB. This is because the first PCB typically overlaps closely above the second PCB, so the area of ​​the second PCB below the first PCB cannot be used for components tall enough to contact the first PCB. In other words, the width and depth of the first PCB must be virtually guaranteed above the surface of the second PCB, as if the first PCB were designed to be nearly embedded in the second PCB.

[0020] All of the above problems with card edge connectors are mitigated in use cases requiring a large number of card edge contacts or large daughterboard PCBs. For example, connections requiring very high bandwidth or connectors for a large number of microprocessor pins may require a significant length of the card edge to be reserved for the card edge contacts and may also require a significant amount of PCB space dedicated to routing those contacts. Furthermore, large daughterboards, such as pluggable VRM boards, may not only require a large number of contacts, but may themselves have large PCBs to hold the necessary power stages.

[0021] The above issues can sometimes limit the environments in which card edge connectors can be used. Furthermore, even if card edge connectors can be used in a particular environment, the benefits derived from them can be reduced or mitigated by the space required to support them. For example, environments in which multiple servers are deployed in a small space often have very limited space, but also require high, reliable power and high bandwidth. A more space-efficient card edge connector system could increase the benefits derived from card edge connectors in those systems.

[0022] Some embodiments of the present disclosure address the above problem by incorporating card edge contacts on multiple adjacent edges of a PCB. For example, rather than lining up all of the card edge contacts on a single edge of the PCB, which would require at least one edge of sufficient length for all of those contacts to be incorporated into the overall PCB design, some embodiments of the present disclosure distribute the contacts for a single connector across two edges of the PCB at a corner of the PCB.

[0023] Additionally, some embodiments of the present disclosure utilize a coplanar card edge connector system that allows a daughterboard to be plugged into a motherboard socket so that both PCBs are not only parallel but also planar with one another. In other words, the first PCB and the second PCB are parallel, but neither PCB overlaps the other. This eliminates the need to consider the surface area of ​​the daughterboard PCB when selecting components to be placed on the surface of the motherboard PCB near the connector. Similarly, the daughterboard PCB can incorporate large components on both its top and bottom surfaces without affecting the surface area of ​​the motherboard PCB.

[0024] Finally, some embodiments of the present disclosure position chips or other modules that are connected to card edge traces in a way that reduces the difference in wire lengths connecting the traces to the chip. For example, some embodiments of the present disclosure may position chips near card edge connectors that form a 90-degree angle, so that lines drawn between a set of contacts and a module on one edge of the PCB may intersect at a right angle with lines drawn between a set of contacts and a module on another edge of the PCB.

[0025] 1A and 1B show an exemplary coplanar connection system 100 of card edge connectors spaced across two edges of respective corresponding printed circuit boards. FIG. 1A discloses a first printed circuit board 102 prior to insertion into a coplanar card edge socket 104 on a second printed circuit board 106.

[0026] A first printed circuit board 102 (sometimes referred to herein as “PCB 102”) includes ten card edge contacts 108A, 108B, 108C, 108D, 108E, 108F, 108G, 108H, 108I, and 108J (collectively “108”) distributed along two edges 110 and 112 of the top surface of PCB 102. Specifically, card edge contacts 108A-108E form a first set of card edge contacts distributed along edge 110, and card edge contacts 108F-108J form a first set of card edge contacts distributed along edge 112. Note that in practice, card edge contacts may often be distributed on both the top and bottom surfaces of the PCB. Thus, while only the contacts on the top surface of PCB 102 are visible in the view shown in FIG. 1A , PCB 102 may also include contacts on its bottom surface.

[0027] Because the contacts 108 are distributed along the two edges 110 and 112, the total surface area of ​​the first PCB 102 may be designed to be smaller. For example, it may not be possible to fit all of the contacts 108 along any single edge 110 or 112 without lengthening that edge. However, lengthening either edge would also increase the total surface area of ​​the first PCB 102, which may make it too large for the overall system or at least increase production costs.

[0028] It should be noted that while edges 110 and 112 are shown at right angles to one another, other angles are possible in other embodiments. For example, edges 110 and 112 may be offset at an obtuse angle (i.e., an angle greater than 90 degrees but less than 180 degrees), an acute angle (i.e., an angle less than 90 degrees), or a reflex angle (i.e., an angle greater than 180 degrees). Edges 110 and 112 could, in theory, be offset at any angle other than a straight angle (i.e., 180 degrees) or no angle (i.e., 0 degrees). It should be noted that in some embodiments, PCB 102 may also include a matching number of card edge contacts on the same two edges of the underside of PCB 102, although these are not shown in FIG. 1A .

[0029] The card edge contacts 108 are oriented at an angle that corresponds to the direction in which the first PCB 102 is intended to be inserted into the card edge socket 104 on the second PCB 106. Specifically, rather than being oriented perpendicular to their respective edges, they are oriented at a 45-degree angle from their respective edges. For example, card edge contact 108J is oriented at a 45-degree angle from edge 112, rather than at a 90-degree angle from edge 112.

[0030] The first PCB 102 also includes alignment notches 114. The alignment notches 114 may match alignment tabs in the socket 104 on the PCB 106. The interaction between the alignment notches 114 and the corresponding alignment tabs may not only help ensure that the first PCB 102 is securely inserted into the socket 104, thereby ensuring that the card edge contacts 108 establish proper connections with corresponding contacts in the socket 104, but may also prevent the first PCB 102 from moving within the socket 104.

[0031] For purposes of understanding, FIG. 1B discloses connection system 100 after first PCB 102 has been inserted into socket 104 on second PCB 106. Because the card edge contacts 108 are distributed across two edges of PCB 102 (i.e., edges 110 and 112) rather than a single edge, first PCB 102 could be shaped to a smaller footprint to accommodate the cutouts in second PCB 106. This may significantly reduce the total space required to support connection systems 100 for both first PCB 102 and second PCB 106. Furthermore, because connection system 110 is a coplanar design, first PCB 102 and second PCB 106 are parallel to each other and in the same plane. This may also significantly reduce the overall space within the system required to support the combination of first PCB 102 and second PCB 106.

[0032] It is noted that, even if the PCBs are considered "coplanar" for purposes of this disclosure, in reality, some portions of PCB 102 may not be exactly in the same plane as PCB 106. For example, in some use cases, the top surface of the first PCB 102 may be parallel to and exactly in the same plane as the top surface of the second PCB 106. This may occur, for example, when the opening of the socket 104 is the same size as the width (i.e., the thickness of PCB 106). However, in some use cases, the top surface of the first PCB 102 may be in a slightly different plane than the second PCB 106. This may occur, for example, when PCB 102 and PCB 106 are of different thicknesses and when the opening of the socket 104 is smaller or larger than the thickness of PCB 102. However, in these use cases, most of the thicknesses of PCBs 102 and 106 may still overlap and be exactly in the same plane. Therefore, the PCBs themselves are still in the same plane and are therefore considered "coplanar" for the purposes of this disclosure.

[0033] For complete illustration, Figure 2 discloses an exemplary coplanar card edge socket 202 on a printed circuit board 204. Socket 202 may, in some embodiments, be similar to socket 104 of Figures 1A and 1B.

[0034] The socket 202 includes an upper section 206 that interfaces with a top surface 208 of the printed circuit board 204 (sometimes referred to herein as “PCB 204”) along a first edge 210 and a second edge 212 of the PCB 204. The upper section 206 may be structurally joined to the top surface 208 of either or any combination of edge surfaces along the first edge 210 and the second edge 212. The socket 202 also includes a lower section 214 that interfaces with a bottom surface (not shown in FIG. 2 ) of the PCB 204 along the first edge 210 and the second edge 212. Like the upper section 206, the lower section 214 may be structurally joined to the bottom surface of either or any combination of edge surfaces along the first edge 210 and the second edge 212. While the upper and lower sections are shown as physically separate components that together form socket 202, in some embodiments the upper and lower sections may be physically connected to one another before or after being attached to PCB 204.

[0035] The socket 202 includes an alignment tab 216 that can interact with an alignment notch on a PCB inserted into the socket 202. The alignment notch may be similar to the alignment notch 114 of FIG. 1 . The interaction between the alignment tab 216 and the alignment notch may prevent the PCB from moving within the socket 202. Although not shown in FIG. 2 , in some embodiments, the socket 202 may include other structure designed to align, guide, and secure the PCB within the socket 202. For example, the two ends of the socket 202 farthest from the alignment tab 216 may include guides designed to facilitate inserting the PCB into the socket 202 in the correct position and orientation. These guides may also include a locking mechanism that locks the PCB into the socket 202 when fully inserted.

[0036] 2, the socket 202 may also include contacts in one or both of the upper section 206 and the lower section 214. These contacts may take various forms (e.g., pins, springs, traces) and may correspond to card edge contacts on a PCB that is inserted into the socket 202.

[0037] The opening of socket 202 is slightly narrower than the width of PCB 204, so the PCB inserted into socket 202 is slightly thinner than PCB 204. For this reason, the top surfaces of the two PCBs are not exactly in the same plane, although the two PCBs themselves are still considered to be parallel and in the same plane. However, the PCBs are still considered to be "coplanar" for purposes of this disclosure.

[0038] On the other hand, in some embodiments, the opening in socket 202 may be the same size as the thickness of PCB 204. In these embodiments, the PCB inserted into socket 202 may actually be exactly the same thickness as PCB 204. Thus, in these embodiments, the top (and bottom) surfaces of the two PCBs may lie exactly in the same plane.

[0039] As noted above, some embodiments of the present disclosure include modules that are surrounded or partially surrounded by one or more card edge connectors, which may reduce the difference in wire length between the card edge contacts and the module, which in turn may reduce the need to reserve PCB space for circuitous wire routing of wires that would otherwise be too short.

[0040] 3 discloses a printed circuit board 300 having card edge contacts on four edges of the printed circuit board and modules between the card edge contacts. The printed circuit board 300 (sometimes referred to herein as "PCB 300") includes four sets of card edge contacts 302A, 302B, 304A, and 304B. The set of card edge contacts 302A and 302B (collectively "302") is part of a first card edge connector, and the set of card edge contacts 304A and 304B (collectively "304") is part of a second card edge connector.

[0041] Specifically, set of card edge contacts 302A resides on the top surface of PCB 300 along edge 306, and set of card edge contacts 302B resides on the top surface of PCB 300 along edge 308. By inserting edges 306 and 308 of PCB 300 into a corresponding socket (e.g., a socket of a coplanar card edge connector), the contacts in set of contacts 302 may be connected to the corresponding contacts in the socket. Similarly, by inserting edges 310 and 312 into another corresponding socket, the contacts in set of contacts 304 may be connected to the corresponding contacts in the socket.

[0042] PCB 300 includes module 314. Module 314 may be, for example, a microprocessor chip, a memory chip, a chipset, or another type of computer chip module. Set of contacts 302A is located on a first edge (edge ​​306) of PCB 300 closest to the first edge of module 314, while set of contacts 302B is located on a second edge (edge ​​308) of PCB 300 closest to the second edge of module 314, so that set of contacts 302 partially surrounds module 314. Similarly, set of contacts 304A and set of contacts 304B are similarly located on edges 310 and 312, so that set of contacts 304 also partially surrounds module 314.

[0043] Each set of contacts 302A, 302B, 304A, and 304B has a corresponding set of wiring traces that pass from the respective contacts to module 314. Specifically, set of contacts 302A has set of wiring traces 316A, set of contacts 302B has set of wiring traces 316B, set of contacts 304A has set of wiring traces 318A, and set of contacts 304B has set of wiring traces 318B. Note that because the contacts in the sets of contacts 302 and 304 surround module 314, all traces within the sets of wiring traces 316A, 316B, 318A, and 318B have equal lengths as shown.

[0044] This equal length allows the module 314 to communicate with, for example, components on another PCB, through contacts in a set of card edge contacts 302 without the negative design constraints of (1) extending the length of a single edge of the PCB 300 to provide sufficient length for all of the contacts in the set of card edge contacts 302, and (2) increasing the overall surface area of ​​the PCB 300 to allow for circuitous routing between the sets of card edge contacts 302 to avoid uneven timing. This may enable higher performance, for example, through corresponding card edge connections in a smaller connection system.

[0045] Note that PCB 300 is shown as having a tapered shape. Specifically, edges 306 and 308 intersect at a 90-degree angle, as do edges 310 and 312, while the other two corners of PCB 300 are absent. This tapered shape may allow PCB 300 to interact with guided components in corresponding sockets, for example, as shown in FIGS. 4A and 4B . Additionally, this tapered shape may reduce component costs for PCB 300 and allow PCB 300 to be installed in a physically smaller environment.

[0046] It is further noted that for ease of understanding, PCB 300 is depicted as including two overlapping card edge connectors. However, in some embodiments, a similar PCB design may include a single card edge connector (e.g., set of contacts 302) that partially surrounds module 314. Furthermore, while the card edge connectors associated with the sets of contacts 302 and 304 are overlapping as shown, in some embodiments, a similar PCB may incorporate two or more different card edge connectors. For example, a similar PCB may include a module and set of contacts similar to module 314 and a set of contacts similar to the set of contacts 302, but the PCB may include a card edge connector with fewer traces or traces conforming to a different standard (e.g., Peripheral Component Interconnect Express) along edges 310 and 312. In some embodiments, one or both sets of trace contacts 302 and 304 may be replaced with a card edge socket that may be designed to accept a PCB card edge connector.

[0047] 4A-4C show connection system 400, a set of card edge connectors that can be used to connect together three printed circuit boards 402, 404, and 406. PCBs 402-406 may represent various types of system components, but in the illustrated example, PCB 402 may represent a backplane board with connections to a larger server system, PCB 404 may represent a daughterboard with a processor that can be added to the system (e.g., an add-in central processing unit, graphics processing unit, data processing unit, or application processing unit), and PCB 406 may represent a second daughterboard with resources needed to run the processor on PCB 404 (e.g., a voltage regulation module, a volatile memory module such as RAM; a non-volatile storage module; a module for security or IoT sensors; a module for a smart key for a security system).

[0048] PCB 402 includes a coplanar card edge socket 408. Socket 408 is in a 90-degree form factor, meaning that it has two sections offset from one another at a 90-degree angle: section 410, which interfaces with the top surface of PCB 402 along a first edge of the PCB, and section 412, which interfaces with the top surface of PCB 402 along a second edge of the PCB. For this reason, socket 408 is configured to interface with a card edge connector that also has two edges offset from one another at a 90-degree angle. Note that in some embodiments, sections 410 and 412 may actually be physically separate components that may or may not be physically fixed to one another. In some embodiments, socket 408 may also have a separate lower section that interfaces with the bottom surface of PCB 402, in which case sections 410 and 412 may be considered “upper sections.” In some embodiments, sections 410 and 412 may be one contiguous component, but may still be referred to as separate sections herein for ease of understanding.

[0049] Socket 408 also includes alignment guides 414A and 414B. Alignment guides 414A and 414B (collectively "414") may be configured to interface with an edge connector of a tapered PCB (e.g., PCB 404) to facilitate correct insertion of the edge connector into socket 408. In some embodiments, the alignment guides may also help lock the PCB in place when the edge connector is fully inserted into socket 408.

[0050] The PCB 404 includes an edge connector distributed along two edges of the PCB 404. Specifically, the edge connector includes a set of card edge contacts 416A and a set of card edge contacts 416B (collectively "416"). The set of contacts 416A is configured to interface with a corresponding set of contacts in section 410 of the socket 408, while the set of contacts 416B is configured to interface with a corresponding set of contacts in section 412 of the socket 408.

[0051] PCB 404 also includes a circuit module 418. Circuit module 418 may be, for example, a processor that can be added to a system to which PCB 402 is connected. Circuit module 418 may be configured to pass signals through wiring traces to contacts in set of contacts 416 and then to a card edge connector socket into which PCB 404 is inserted.

[0052] PCB 404 also includes coplanar card edge socket 420. Like socket 408, socket 420 is in a 90-degree form factor. However, the form factors of sockets 408 and 420 differ in the manner in which a connector is inserted into them. Socket 408 forms a concave opening, while socket 420 forms a convex opening. In other words, from the perspective of a connector inserted into socket 408, socket 408 forms an angle less than 180 degrees (i.e., 90 degrees). However, from the perspective of a connector inserted into socket 420, socket 420 forms an angle greater than 180 degrees (i.e., 270 degrees).

[0053] PCB 406 includes a set of card edge contacts 422A and 422B (collectively "422") that form a card edge connector capable of connecting PCB 406 to a card edge socket (e.g., card edge socket 420).

[0054] 4B shows connection system 400 after a card edge connector on PCB 404, comprised of a set of contacts 416, has been inserted into socket 408 on PCB 402. As shown, socket 408 is a coplanar socket, such that PCBs 402 and 404 are now coplanar. In other words, the top surface of PCB 402 is coplanar with the top surface of PCB 404. In some embodiments, PCBs 402 and 404 may be exactly coplanar (e.g., if the opening in socket 408 is the same width as PCB 402), while in other embodiments, the top surfaces of PCBs 402 and 404 may be in slightly different planes (e.g., if the opening in socket 408 is slightly larger or slightly smaller than the width of PCB 402). In these embodiments, a majority of the widths (i.e., thicknesses) of PCBs 402 and 404 will likely overlap, and for purposes of this disclosure, PCBs 402 and 404 will still be considered "coplanar." In a typical embodiment, even when the top surfaces of PCBs 402 and 404 are on slightly different planes, the center layers of PCBs 402 and 404 may still be exactly on the same plane.

[0055] 4C shows connection system 400 after PCB 406's card edge connector, comprised of a set of contacts 422, has been inserted into socket 420 on PCB 402. Like socket 408, socket 420 is a coplanar socket as shown. As such, PCBs 402, 404, and 406 are now all coplanar with one another. As discussed with respect to FIG. 4B, the top surfaces of 402, 404, and 406 may still be in slightly different planes, and most of the widths of PCBs 402, 404, and 406 will likely overlap, so PCBs 402, 404, and 406 are still considered to be coplanar (i.e., coplanar) for purposes of this disclosure.

[0056] The description of various embodiments of the present invention is presented for illustrative purposes, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the described embodiments. The terminology used herein has been selected to best explain the principles of the embodiments, practical applications or technical improvements over commercially available technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. 1. A connection system for a card edge connector, the connection system comprising: upper and lower surfaces; and a first edge surface perpendicular to the upper and lower surfaces, and a second edge surface perpendicular to the upper and lower surfaces; wherein the first edge surface and the second edge surface intersect at an angle that is not a straight angle. a printed circuit board having a coplanar card edge socket on said printed circuit board, said socket comprising: an upper section interfaced with the top surface of the printed circuit board along the first and second edge surfaces of the printed circuit board; and a lower section interfaced with the lower surface of the printed circuit board along the first and second edge surfaces of the printed circuit board; having A connection system comprising:

2. The connection system of claim 1 , wherein the first edge surface and the second edge surface intersect at a 90 degree angle.

3. The connection system of claim 1 , wherein the coplanar card edge socket has alignment tabs.

4. 1. A printed circuit board comprising: upper and lower surfaces; a first edge surface perpendicular to the upper and lower surfaces, and a second edge surface perpendicular to the upper and lower surfaces, wherein the first and second edge surfaces intersect at an angle that is not a straight angle; a first set of card edge contacts on the top surface along the first edge surface; a second set of card edge contacts on the top surface along the second edge surface; and a circuit chip module attached to the top surface of the printed circuit board; Equipped with The circuit chip module is partially surrounded by the first set of card edge contacts and the second set of card edge contacts.

5. 5. The printed circuit board of claim 4, wherein a first line from a first contact in the first set of card edge contacts to a center of the circuit chip module intersects a second line from a second contact in the second set of card edge contacts to the center of the circuit chip module at a 90 degree angle.

6. The printed circuit board of claim 4 , wherein the first edge surface and the second edge surface intersect at a 90 degree angle.

7. 5. The printed circuit board of claim 4, wherein the circuit chip module is a microprocessor chip.

8. The printed circuit board of claim 4 further comprising an alignment notch.

9. The printed circuit board of claim 4 , wherein the printed circuit board comprises a tapered shape.

10. a third edge surface perpendicular to the upper and lower surfaces; a fourth edge surface perpendicular to the upper and lower surfaces, wherein the third and fourth edge surfaces intersect at an angle that is not a straight angle; a third set of card edge contacts on the top surface along the third edge surface; and a fourth set of card edge contacts on the top surface along the fourth edge surface; The printed circuit board of claim 4 further comprising:

11. a third edge surface perpendicular to the upper and lower surfaces; a fourth edge surface perpendicular to the upper and lower surfaces, where the third and fourth edge surfaces intersect at an angle that is not a straight angle; and a coplanar card edge socket on said printed circuit board, said socket comprising: an upper section interfaced with the top surface of the printed circuit board along the third and fourth edge sides of the printed circuit board; and a lower section interfaced with the lower surface of the printed circuit board along the third and fourth edge surfaces of the printed circuit board; having The printed circuit board of claim 4 further comprising:

12. 1. A connection system for a card edge connector, the connection system comprising: a first upper surface and a first lower surface; and a first edge perpendicular to the first upper surface and the first lower surface, and a second edge perpendicular to the first upper surface and the first lower surface; wherein the first edge and the second edge intersect at a first angle that is not a straight angle. a first printed circuit board having: a second upper surface and a second lower surface; a third edge perpendicular to the second upper surface and the second lower surface, and a fourth edge perpendicular to the second upper surface and the second lower surface, wherein the third edge and the fourth edge intersect at a second angle complementary to the first angle; and a first set of card edge contacts on the second top surface along the third edge; a second printed circuit board having a coplanar card edge socket on the first printed circuit board, the socket comprising: an upper section interfaced with the first top surface of the first printed circuit board along the first and second edges of the first printed circuit board; and a lower section interfaced with the first lower surface of the first printed circuit board along the first and second edges of the first printed circuit board; Equipped with wherein the third and fourth edges of the second printed circuit board are inserted into the coplanar card edge socket, thereby causing the first printed circuit board to be coplanar with the second printed circuit board.

13. The connection system of claim 12 , wherein the first and second edges intersect at an obtuse angle.

14. The connection system of claim 12 , wherein the first and second edges intersect at an acute angle.

15. The connection system of claim 12 , wherein the second printed circuit board includes a non-volatile storage module.

16. The connection system of claim 12 , wherein the second printed circuit board has alignment cutouts.

17. The connection system of claim 12 , wherein the second printed circuit board has a tapered shape.

18. The second printed circuit board includes: a fifth edge perpendicular to the second upper surface and the second lower surface: a sixth edge perpendicular to the second upper surface and the second lower surface; and a second set of the card edge contacts on the second top surface along the fifth edge; 13. The connection system of claim 12, comprising:

19. The second printed circuit board includes: a fifth edge perpendicular to the second upper surface and the second lower surface: a sixth edge perpendicular to the second upper surface and the second lower surface; and a coplanar card edge socket on the second printed circuit board, the socket comprising: an upper section interfaced with the second top surface of the second printed circuit board along the fifth and sixth edges of the second printed circuit board; and a lower section interfaced with the second lower surface of the second printed circuit board along the fifth and sixth edges of the second printed circuit board; 13. The connection system of claim 12, comprising:

20. 13. The connection system of claim 12, further comprising a third printed circuit board, said third printed circuit board having a card edge connector that interfaces with a corresponding card edge connector on said second printed circuit board.

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