WO2015116087A1

WO2015116087A1 - Signal interface component for a printed circuit board

Info

Publication number: WO2015116087A1
Application number: PCT/US2014/013771
Authority: WO
Inventors: David W. Engler
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2014-01-30
Filing date: 2014-01-30
Publication date: 2015-08-06
Also published as: TW201539869A

Abstract

A signal interface component for a printed circuit board (PCB) is described herein. The signal interface component may include a connector capable of communicating high speed signals between a plurality of components on the printed circuit board (PCB), and a plurality of end couplers. An end coupler being coupled on each end of the connector, and each end coupler from the plurality of end couplers can be engagable with an industry standard connector connected to a component from the plurality of components.

Description

SIGNAL INTERFACE COMPONENT FOR A PRINTED CIRCUIT BOARD

BACKGROUND

[0001] Computing devices_., such as servers, laptops, and desktops, include one or more processing circuits usually provided on a printed circuit board (PCB), PCBs support and electrically connect various electronic components using metallic conductive tracks, pads, and other features etched on a non-conductive substrate. Computing devices may include one or more motherboards having one or more PCBs for mounting and connecting various electronic components of the computing device. For instance, motherboards can be used for mounting sound cards, video cards, network cards, hard drives or other forms of persistent storage, TV tuner cards, universal serial bus (USB) ports, FireWire slots, and a variety of other components. Generally, the conductive tracks connecting two or more components on a PCB can be used for different kinds of connectivity between the components, including data transmission and power transmission. BRIEF DESCRIPTION OF DRAWINGS

[0002] The detailed description is described with reference to the accompanying figures, in the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components:

[0003] FIG. 1 illustrates a schematic of a printed circuit board (PCB) assembly, in accordance with an implementation of the present subject matter.

[0004] FIG. 2 illustrates a schematic of a signal interface component for the printed circuit board (PCB) assembly, in accordance with an implementation of the present subject matter

[0005] FIG. 3A, FIG. 3B, and FIG. 3C illustrate various components of the PCB assembly and the signal interface component, in accordance with an implementation of the present subject matter.

[0006] FIG. 4 illustrates an industry standard connector of the PCB assembly, in accordance with an example of the present subject matter. [0007] FIG. 5 illustrates an end coupler of the signal interface component, in accordance with an implementation of the present subject matter.

[0008] FIG. 8 illustrates an end coupler casing of the signal interface component assembled with the industry standard connector, in accordance with an implementation of the present subject matter.

DETAILED DESCRIPTION

[0009] Printed circuit boards (PCBs) can be deployed for providing data connectivity, power connectivity, or other types of connectivity between components mounted thereon. In case of data transmission, conductive tracks etched on the PCBs usually allow for transmission rates of up to tens of Gigabits per second (Gbps). However, transmission of signals through the conductive tracks is also accompanied by some loss in energy and signal integrity.

[0010] Generally, energy losses and integrity of the signal during transmission are dependent on various factors, such as length of the conductive track and frequency of the signal. For example, PCBs can handle transmission of signals at frequencies of about 2.5 Gigahertz (GHz) up to 8 GHz with considerably low losses. However, the distance over which the signals can be is transmitted is usually less. Accordingly, when signals with relatively high frequencies, for example, in the range of tens of GHz, are transmitted over relatively long conductive tracks, such signal transmission may result in loss of energy and signal integrity. For instance, losses may occur during signal transmission when the signals are transmitted through the conductive tracks, over lengths greater than about 12 inches.

[0011] Therefore, when transmitting high frequency or high speed signals, various alternate mechanisms may be employed. For example, PCBs of relatively short lengths can be used, or a repeater with an integrated circuit can be used to extend the distance over which the signals can be transmitted. In some cases, dielectrics may be used for the conductive tracks of the PCBs to prevent signal attenuation during transmission of signals. For example, in case of a PCB used in a motherboard of a server, the PCB can be formed of multiple layers of dielectric. In such a case, each layer can serve as a conductive track to carry power or data signals at high speed. PCBs having such dielectric layers are capable of providing signal speeds in relatively high ranges, for example, speeds in the Gigabits per second (Gbps) range.

[0012] However, the dielectric material can be costly and the use of such low-loss dielectric layers in the PCBs can increase the cost of the PCBs. Therefore, using dielectrics in PCBs for signal transmission may not be cost effective. For example, if the PCB transmits 10,000 low range signals and 10 high speed signals, the use of the expensive dielectric material in the PCB and the conductive tracks may still be unavoidable, so that the transmission of the high speed signals can be achieved. Therefore, even though the high speed signals may be a minor proportion of the signals handled by the PCB, the PCB may still be designed, and the dielectric material selected, based on scenarios involving transmission of signals of highest frequency or speed range.

[0013] In some cases, an external cable can be used for electronically coupling the components on the PCB. In such cases, connectors are used on the PCB for coupling the components through the external cable. Generally, the connectors are customized connectors, and may have a slot for engaging with the cable through a customized edge card, and coupled to the components. The external cable, in such cases, is often formed of the dielectric material and is able to transmit high speed signals with substantially less signal integrity issues.

[0014] However, such customized connectors are generally not industry standard connectors and are specially designed for connecting components on the PCB. Further, in order to accommodate the connectors on the PCB, a footprint of the PCB is selected to match the connector. Accordingly, a producer of PCBs may have to invest in manufacturing infrastructure for forming the PCB with the footprint matching the connectors. In such a situation, in case the producer is unable to match the supply of PCBs, then sourcing issues may arise, for example, for motherboard manufacturers. In addition, since the customized connectors are not industry standard, the external cable is also specially designed for use with the customized connectors. As a result, the use of an external cable with customized connectors for high speed signal transmission can be costly and may introduce sourcing issues. [0015] The present subject matter discloses a printed circuit board (PCB) assembly and a corresponding signal interface component for a printed circuit board (PCB) of the PCB assembly. In an example, the PCB assembly can be the PCB assembly of a server system. In one case, the signal component interface can provide for the connection between the components over a considerable distance on the PCB, for example, in the server system. In said example, the PCB can be the PCB of a motherboard of the server system. According to an aspect of the present subject matter, industry standard parts are used for connecting the plurality of components.

[0016] For connecting the components, a plurality of industry standard connectors can be mounted on the PCB, each industry standard connector coupled to the respective component to be connected. According to an implementation, in order to accommodate the industry standard connector, the PCB can be pinned-out based on the component to be coupled using the signal interface component. Further, the signal interface component can be coupled to the industry standard connectors to connect the components.

[0017] According to an implementation, the signal interface component can include a connector and an end coupler provided at each end of the connector. The end couplers can be provided for coupling to the industry standard connectors to connect the components through the connector. In an example, the connector can be a cable or a bus, such as a serial communication data bus. In another example, the connector can be a printed circuit board segment.

[0018] Further, the connector can be formed as having dielectric material and is capable of communicating high speed signals between the components with signal integrity and minimal losses. The high speed signals can be signals which are transmitted at high speeds, for example, having data rates of more than about 8 Gbps. In another case, the high speed signals can include signals transmitted at high frequencies of the order of more than about 4 GHz.

[0019] Accordingly, the PCB on which the components are mounted, in the present case, is not used for transmitting the high speed signals, and therefore, can use low cost dielectric or metal tracks. The more costly dielectric may be used in the connector for transporting high speed signals, and the cost of the dielectric may therefore be shifted to the connector. In addition, the length of the connector may be considerably shorter than the PCB and, therefore, the connector fabricated as having the dielectric may be more cost effective than providing the dielectric on the PCB, Further, when components on the PCB which communicate through high speed signals are replaced by other components which use low speed signals, the connector can be removed from the PCB assembly and deployed elsewhere,

[0020] In an example, the industry standard connector can be any connector which has standard design parameters, for example a standard pin configuration and slot size, and matches a standard footprint of the PCB. For instance, the industry standard connector can be a peripheral component interconnect express (PCIe) connector or any other standard slot connector.

[0021] Further, in said implementation of the present subject matter, the end coupler can be a printed circuit board member having a plurality of edge fingers formed at an edge of the printed circuit board member, and the plurality of edge fingers can be engagable to the industry standard connector on the PCB, In an example, in case the connector is a printed circuit board segment, the end coupler can be integrally formed with the connector. Further, in the above example in which the industry standard connector is a PCIe connector, the end coupler can be a PCIe edge connector. Further, the PCB, the signal interface component, and the industry standard connector, can collectively form the PCB assembly,

[0022] According to an aspect, the industry standard connector, such as the PC!e connector, is used as an interface for intra-board components exchanging high speed signals and which are generally connected by a dielectric material on the PCB. Therefore, the signal interface component of the present subject matter allows for the use a low cost, multi-source, standard connector along with a high quality connector, such as a high quality bus or a high quality PCB segment. In addition, the industry standard connector is conveniently procurable, thereby reducing supplying or sourcing issues for the connector or for the PCB. Accordingly, the signal interface component used with the connectors can also have a standard configuration. As a result, a supplier or manufacturer of the PCB assembly having the PCB, the industry standard connectors, and the signal interface component may mitigate against certain supply chain issues.

[0023] In an implementation, the connector of the signal interface component, having a standard configuration for being used with the industry standard connector, can be customized based on the components to be connected. For example, the connector can be used for coupling a universal serial bus (USB) 3.0 port to a chip or for transmitting video between input/output (I/O) panel and secondary memory, and can be selected accordingly.

[0024] In addition, in an implementation, the signal interface component may include an end coupler casing for housing each end coupler. According to said implementation, the end coupler casing may include a latching mechanism for coupling the end coupler casing to the industry standard connector. In an example, the latching mechanism can be a spring-loaded clip, pivotabie for coupling and decoupling the end coupler casing from the industry standard connector. The latching mechanism can couple to a latch on the industry standard connector. In one case, the latch can be wedge-shaped for the pivotabie latching mechanism to disengagabiy fasten to the industry standard connector. The provision of the latching mechanism facilitates convenient coupling and decoupling of the signal interface component with the industry standard connector and prevents inadvertent loss of connection between the end couplers to the respective industry standard connector.

[0025] Accordingly, the present subject matter provides for exchange of high speed signals between two components on relatively large PCBs, such as motherboards in a server system. In the present subject matter, the industry standard connector and the signal interface component are used for signal transport, instead of being a destination for the signals. Accordingly, the industry standard connector and the signal interface component provide for low-cost routing of high speed signals.

[0026] The above described PCB assembly and signal interface component therefor are further described in the figures and associated description below. It should be noted that the description and figures merely illustrate the principles of the present subject matter. Therefore, various arrangements can be devised that, although not explicitly described or shown herein, embody the principles of the present subject matter. Moreover, ail statements herein reciting principles, aspects, and implementations of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.

[0027] FIG. 1 illustrates a schematic of a printed circuit board (PCB) assembly 100, for example, for a server system, in accordance with an implementation of the present subject matter. In said implementation, the PCB assembly 100 includes a printed circuit board (PCB) 102 which provides for mounting a plurality of components (not shown) and a signal interface component 104 for connecting the plurality of components to transmit high speed signals between the components.

[0028] Further, the PCB assembly 100 can include a plurality of industry standard connectors 106 mounted on the PCB 102 to facilitate the connection between the signal interface component 104 and the components. In said implementation, each of the components can be connected on the PCB 102 to an industry standard connector 108. Further, the ends of the signal interface component 104 can engage with the industry standard connectors 106 to connect the plurality of components.

[0029] In an example, in order to accommodate the industry standard connector 106, the PCB 102 can be pinned-out based on the components to be coupled using the signal interface component 104. Accordingly, in one case, ground pins, power pins, high speed signal pins, and low speed signal pins of the PCB 102 can be customized based on the components to be coupled.

[0030] FIG. 2 illustrates a schematic of the signal interface component 104 for connecting the components in the PCB assembly 100, according to an implementation of the present subject matter. In said implementation, the signal interface component 104 includes a connector 200 capable of communicating high speed signals between the components on the PCB. Further, the signal interface component 104 includes a plurality of end couplers 202, one end coupler 202 being coupled at each end of the connector 200. The end couplers 202 can each be coupled to a component from among the components. Accordingly, in said implementation, the end couplers 202 can engage with the industry standard connector 106 to provide connection between the components.

[0031] In an implementation, the industry standard connector 108 can be a slot-type connector, i.e., having a slot with pins serving as connections, in said implementation, the end coupler 202 can be a printed circuit board member 204 having a plurality of edge fingers 206 formed at an edge of the printed circuit board member 204. The edge fingers 208 formed as gold fingers can engage with the pins in the slot of the industry standard connector 108 to operabiy couple the components. In one instance, the end coupler 202, for example, the edge fingers 206 of the end coupler 202, can be designed as per specification of the industry standard connector 106. In addition, in said example, form factor and actual pinout of the end coupler 202 can be designed as per the components to be connected and the implementation.

[0032] In an example, the PCB 102 can be a PCB of a motherboard of the server system. Accordingly, the signal interface component 104 can facilitate exchange of high speed signals between the connected components over a considerable distance on the PCB 102 in the server system. According to an aspect of the present subject matter, the signal interface component 104 is designed to allow industry standard parts to be used along with the industry standard connector 106 in the PCB assembly 100 for connecting the plurality of components, thereby preventing supply or sourcing issues for procuring the parts.

[0033] FIG. 3A, FIG. 3B, and FIG. 3C illustrate various components of the PCB assembly 100 and the signal interface component 104, respectively, in accordance with an implementation of the present subject matter. FIG. 3A illustrates a schematic showing a cross-sectional view of the PCB assembly 100, as an example; FIG. 3B illustrates an exploded view of the components of the PCB assembly 100; and FIG. 3C illustrates the signal interface component 104. For the sake of brevity, FIG. 3A, FIG. 3B, and FIG. 3C are described in conjunction.

[0034] In continuation to the above description, the present subject matter provides for using industry standard parts in the PCB assembly 100, for example, the PCB 102, the signal interface component 104, and the industry standard connector 106, so that procurement of the parts is convenient and perpetual, in an example, the industry standard connector 106 can be a peripheral component interconnect express (PCIe) or any other standard slot connector. Accordingly, the PCB 102 can be designed as having a footprint corresponding to standard design of the industry standard connector 106. As a result, a manufacturer of motherboards or server systems can procure the parts of the PCB assembly 100 from different sources. Therefore, the availability of the parts is less likely to affect the production or manufacturing of the PCB assembly 100 or the parts thereof. As an example, the industry standard connector 106 is shown in FIG. 4 and is explained in further detail with reference to FIG. 6.

[0035] Further, according to said implementation, the signal interface component 104 can provide an interface for connecting the plurality of components 300 on the PCB 102. The connector 200 can be selected based on the components 300 between which the signal interface component 104 is used. For example, the connector 200 can be customized based on signal speed to be achieved, acceptable energy losses, and density of signals to be transmitted.

[0036] Further, in one example, the signal interface component 104 can be used for coupling a universal serial bus (USB) 3.0 port to a chip, both being provided on the same PCB 102. In another example, the signal interface component 104 can be used for transmitting video between input/output (I/O) panel and secondary memory, again with both components on the same PCB 102. Based on the implementation, the connector 200 can be customized or selected. In an example, the connector 200 can be a cable or a bus, such as a serial communication bus. In said example, the connector 200 can be a standard configuration bus customized according to the implementation. In another example, the connector 200 can be a printed circuit board segment.

[0037] Further, according to an aspect, the connector 200 can be formed of a dielectric material and can carry signals at high speeds or may transmit signals at high frequencies between the components 300. In one example, the dielectric used in the connector 200 can be Teflon®. For instance, the connector 200 can transmit signals at a speed of more than about 8 Gigabits per second (Gbps) or signals of a frequency of more than about 4 Gigahertz (GHz). Such signals, referred to as high speed signals as mentioned previously, can be transmitted by the connector 200 with substantially low signal attenuation and high signal integrity. As a result, when the connector 200 is used for transmitting signals between the components 300 on the PCB 102, the losses in signal transmission are relatively low. Further, the connector 200 can be customized to carry any appropriate type of signal, such as data signals or power signals.

[0038] In addition, the end couplers 202 can be coupled to the respective ends of the connector 200 through cloth tape 301 , as shown in FIG. 3A. In addition, the orientation of the end couplers 202 while connecting to the connector 200 can be selected based on the orientation of the industry standard connectors 106 to be coupled to. For example, consider a case in which the industry standard connectors 108 are oriented on the PCB 102 so that the slots (not shown) of the industry standard connectors 106 are facing each other or are facing in the same direction. In such a case, ends of the connector 200 can be coupled to the edges of the respective end coupler 202 opposite to the edges having the edge fingers 206.

[0039] In another case in which the industry standard connectors 106 can be mounted on the PCB 102 with the slots at an angle, for example, perpendicular, to each other. In such a case, for one of the end couplers 202, the connector 200 can be coupled to the edge which is adjoining to the edge having the edge fingers 206. Such orientation prevents damage to the signal interface component 104, for example, to the connector 200 of the signal interface component 104, when engaged with the industry standard connectors 106.

[0040] The end coupler 202 is shown in detail in FIG. 5, in accordance with an implementation of the present subject matter, In said implementation, the end coupler 202 can be provided with a plurality of grooves 500 for alignment with respect to edges or walls of the industry standard connector shown in FIG. 4.

[0041] Further, as shown in FIG. 3B, in said implementation, the signal interface component 104 can include a plurality of end coupler casings 302, each for housing one end coupler 202. Accordingly, each end coupler casing 302 can be formed as a hollow part to accommodate the end coupler 202. Further, the end coupler casing 302 can have an opening on each of the two parallel lateral walls. One opening allows the edge bearing the edge fingers 206 to protrude outside the end coupler casing 302, and the other opening provides for the end coupler 202 to be coupled to the connector 200. !n one example, the end coupler casings 302 can be formed of a plastic material by molding process in two parts. For instance, the end coupler casing 302 can be split along a plane perpendicular to the two openings. In said example, generally used fasteners may be employed for attaching the two parts to form the end coupler casing 302.

[0042] Further, according to an implementation, the end coupler casing 302 can provide for coupling the end coupler casing 302 to the industry standard connector 106, in order to detachably fix the end coupler 202 to the industry standard connector 106. FIG. 6 illustrates the end coupler casing 302 coupled to the industry end connector 106 of FIG. 4, in accordance with an implementation of the present subject matter.

[0043] In an implementation, as shown in FIG. 6, the end coupler casing

302 can be provided with a latching mechanism 600 to couple to the industry standard connector 106. Accordingly, the industry standard connector 106 can be provided with a latch 602 engagable with the latching mechanism 600. In an example, the latching mechanism 600 can be a spring-loaded clip, pivotable about a point for coupling and decoupling the end coupler casing 302 from the industry standard connector 106. In said example, as can be seen from FIG. 4 and FIG. 6, the latch 602 of the industry standard connector 106 can be a wedge- shaped latch with which a wedge-shaped extension of the spring-loaded clip of the latching mechanism can engage for fixing.

[0044] The provision of the end coupler casings 302 prevents entry of dust onto the end couplers 202 and protects the end couplers 202 from damage. In addition, the provision of the latching mechanism 600 and the corresponding latch 602 on the end coupler casing 302 and the industry standard connector 106, respectively, provides for effective engagement of the end coupler 202 in the industry standard connector 106.

[0045] Although implementations of the PCB assembly 100 and the corresponding signal interface component 104 have been described in terms of the structural features above, the present subject matter is not limited to the described features. Rather, the features are disclosed and explained in the context of a few implementations of the PCB assembly 100 and the corresponding signal interface component 104,

Claims

I/We claim:

1 , A signal interface component for a printed circuit board (PCB), the signal interface component comprising:

a connector capable of communicating high speed signals between a plurality of components on the printed circuit board (PCB); and

a plurality of end couplers, an end coupler being coupled on each end of the connector, wherein each end coupler from the plurality of end couplers is engagabie with an industry standard connector connected to a component from the plurality of components.

2. The signal interface component as claimed in claim 1 , wherein the end coupler is a peripheral component interconnect express (PCIe) edge card, the end coupler being a printed circuit board member having a plurality of edge fingers formed at an edge of the printed circuit board member.

3. The signal interface component as claimed in claim 1 , wherein the connector is a bus.

4. The signal interface component as claimed in claim 1 , wherein the connector is a printed circuit board segment.

5. The signal interface component as claimed in claim 1 , wherein the connector is capable of communicating signals at a speed of more than about 8 Gigabits per second (Gbps).

6. The signal interface component as claimed in claim 1 , wherein the connector is capable of communicating signals of a frequency of more than about 4 Gigahertz (GHz).

7. The signal interface component as claimed in claim 1 , further comprising a plurality of end coupler casings, an end coupler casing housing one end coupler, wherein the end coupler casing comprises a latching mechanism for coupling the end coupler casing to the industry standard connector.

8. The signal interface component as claimed in claim 7, wherein the industry standard connector comprises a latch engagable with the latching mechanism.

9. The signal interface component as claimed in claim 7, wherein the latching mechanism is a spring-loaded clip, pivotable for coupling and decoupling the end coupler casing from the industry standard connector.

10. A printed circuit board (PCB) assembly, the PCB assembly comprising:

a printed circuit board (PCB) having mounted thereon a plurality of components to be connected;

a plurality of industry standard connectors mounted on the PCB, wherein a industry standard connector is coupled to one component from the plurality of components; and

a signal interface component for connecting the plurality of components, the signal interface component comprising,

a connector capable of communicating high speed signals between the plurality of components; and

a plurality of end couplers, an end coupler being coupled on each end of the connector, wherein the end coupler is engagable with the industry standard connector.

1 1 . The PCB assembly as claimed in claim 10, wherein the signal interface component further comprises a plurality of end coupler casings, an end coupler casing housing one end coupler, wherein the end coupler casing comprises a latching mechanism for coupling the end coupler casing to the industry standard connector.

12. The PCB assembly as claimed in claim 10, wherein the industry standard connector is a peripheral component interconnect express (PC!e) connector.

13. The PCB assembly as claimed 10, wherein the end coupler is a peripheral component interconnect express (PCIe) edge card, the end coupler being a printed circuit board member having a plurality of edge fingers formed at an edge of the printed circuit board member.

14. The PCB assembly as claimed in claim 10, wherein the PCB is the PCB of a motherboard of a server system.

15. The PCB assembly as claimed in claim 10, wherein the connector is selected based on the plurality of components to be connected by the signal interface.