Embodiments described herein relate generally to interconnection of electronic components, and more particularly to electrical cables.
There is increasing demand to connect very high bandwidth interconnects to semiconductor packages in high-performance computing (HPC) and server applications. Traditionally, signals in HPC and server applications are routed from a die on a package, through the package, and through socket pins that serve as an electrical interface between the package and a HPC/server board. However, socket pins are unable to support increasingly high data rates with acceptable signal integrity. One alternative to relying on socket pins to support high-speed data rates, is to include a cable/connector type connection directly to a top side of a package.
Invention features and advantages will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, various embodiments; and, wherein:
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope or to specific invention embodiments is thereby intended.
Before invention embodiments are disclosed and described, it is to be understood that no limitation to the particular structures, process steps, or materials disclosed herein is intended, but also includes equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for describing particular examples only and is not intended to be limiting. The same reference numerals in different drawings represent the same element. Numbers provided in flow charts and processes are provided for clarity in illustrating steps and operations and do not necessarily indicate a particular order or sequence. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.
As used in this written description, the singular forms “a,” “an” and “the” include express support for plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a conductor” includes a plurality of such conductors.
In this specification, “comprises,” “comprising,” “containing” and “having” and the like can have the meaning ascribed to them in U.S. Patent law and can mean “includes,” “including,” and the like, and are generally interpreted to be open ended terms. The terms “consisting of” or “consists of” are closed terms, and include only the components, structures, steps, or the like specifically listed in conjunction with such terms, as well as that which is in accordance with U.S. Patent law. “Consisting essentially of” or “consists essentially of” have the meaning generally ascribed to them by U.S. Patent law. In particular, such terms are generally closed terms, with the exception of allowing inclusion of additional items, materials, components, steps, or elements, that do not materially affect the basic and novel characteristics or function of the item(s) used in connection therewith. For example, trace elements present in a composition, but not affecting the composition's nature or characteristics would be permissible if present under the “consisting essentially of” language, even though not expressly recited in a list of items following such terminology. When using an open ended term in the written description, like “comprising” or “including,” it is understood that direct support should be afforded also to “consisting essentially of” language as well as “consisting of” language as if stated explicitly and vice versa.
The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Similarly, if a method is described herein as comprising a series of steps, the order of such steps as presented herein is not necessarily the only order in which such steps may be performed, and certain of the stated steps may possibly be omitted and/or certain other steps not described herein may possibly be added to the method.
The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. The term “coupled,” as used herein, is defined as directly or indirectly connected in an electrical or nonelectrical manner. Objects described herein as being “adjacent to” each other may be in physical contact with each other, in close proximity to each other, or in the same general region or area as each other, as appropriate for the context in which the phrase is used. Occurrences of the phrase “in one embodiment,” or “in one aspect,” herein do not necessarily all refer to the same embodiment or aspect.
As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result. For example, an object that is “substantially” enclosed would mean that the object is either completely enclosed or nearly completely enclosed. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context. However, generally speaking the nearness of completion will be so as to have the same overall result as if absolute and total completion were obtained. The use of “substantially” is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, a composition that is “substantially free of” particles would either completely lack particles, or so nearly completely lack particles that the effect would be the same as if it completely lacked particles. In other words, a composition that is “substantially free of” an ingredient or element may still actually contain such item as long as there is no measurable effect thereof.
As used in this specification, the term “about” when used in connection with a numerical value is used to provide flexibility by providing that the given numerical value may be “a little above” or “a little below” the value. It is to be understood that in the written description any numerical value accompanied by the term “about” also provide express support for the numerical value per se.
As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.
Concentrations, amounts, sizes, and other numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. As an illustration, a numerical range of “about 1 to about 5” should be interpreted to include not only the explicitly recited values of about 1 to about 5, but also include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5, etc., as well as 1, 2, 3, 4, and 5, individually.
This same principle applies to ranges reciting only one numerical value as a minimum or a maximum. Furthermore, such an interpretation should apply regardless of the breadth of the range or the characteristics being described.
Reference throughout this specification to “an example” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment. Thus, appearances of the phrases “in an example” in various places throughout this specification are not necessarily all referring to the same embodiment.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In this description, numerous specific details are provided, such as examples of layouts, distances, network examples, etc. One skilled in the relevant art will recognize, however, that many variations are possible without one or more of the specific details, or with other methods, components, layouts, measurements, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail but are considered well within the scope of the disclosure.
An initial overview of technology embodiments is provided below and specific technology embodiments are then described in further detail. This initial summary is intended to aid readers in understanding the technology more quickly but is not intended to identify key or essential features of the technology nor is it intended to limit the scope of the claimed subject matter.
As currently implemented, the cables typically utilized in HPC/server designs to support high-speed data rates are twin-axial cables (“twinax”). Twinax cables, however, present problems for scaling cable input/output (IO) density, which is to be maximized for connecting to the limited space available on packages. Due to cost, density scaling, and flexibility, a traditional flex cable would be a desired solution. In order to achieve suitable IO density, however, typical flex cables incur unacceptable conductive losses and cross-talk at the desired dimensions. The competing objectives of maximizing IO density on one hand, and decreasing conductive loss and cross-talk on the other hand, cannot be resolved by typical flex cables, which are uniform cables having the same cross-section at any given location along the cable length.
Accordingly, electrical cables are disclosed that can provide a desired IO routing density while maintaining appropriate signal integrity for applications such as HPC and servers. In one example, an electrical cable can include a transmission line conductor, a ground conductor, and a dielectric material. The dielectric material can have at least a portion with a thickness separating the transmission line conductor and the ground conductor that is variable along a length of the electrical cable. Such a non-uniform cable (e.g., a cable having components or features that vary in size and/or geometry along the length of the cable) can provide high IO density with acceptable conductive losses and cross-talk while maintaining a desired impedance.
Referring to
A primary design consideration for cables interconnecting electronic components, such as for high speed data links between components, is maintaining controlled impedance lines (typically 50Ω single ended or 100 or 85Ω differential, although any suitable impedance value is contemplated). This impedance may be defined based on the type of transmission line (e.g., microstrip, stripline, etc.), the transmission line width, the distance between the transmission line (e.g., signal) and ground (e.g., a ground plane), which may be established by a substrate or dielectric thickness in the cable between the transmission line and ground, and the dielectric constant of the dielectric material. Another design concern is configuring a cable to couple to an electronic component, which may have a very limited area available for coupling with cables or other interconnects. In this case, it may be desirable to maximize IO density in a cable in order to couple with a relatively small area of an electronic component. To achieve high IO density, however, transmission lines within a cable are typically reduced in size and placed closer together, which increases conductive losses and cross-talk among the transmission lines, thus ultimately limiting the length and data rate of the cable. Technology embodiments disclosed herein can provide for tight spacing of transmission line conductors to achieve a desired IO density in an electrical cable with a desired impedance while minimizing cross-talk and losses.
For example, as shown in the side view of
For example, at least a portion of the dielectric material 130 can have a thickness 131 separating the transmission line conductor 110 and the ground conductor 120 that is variable along a length 150 of the electrical cable 101. A non-uniform dielectric thickness can enable good impedance matching to be maintained. In one aspect, the dielectric thickness 131 and a dielectric constant can vary along the length 150 to maintain an impedance match. In another aspect, the dielectric thickness 131 and transmission line conductor width (discussed in more detail below) can vary along the length 150 to maintain an impedance match. The connector 140 is disposed at an end 151 of the electrical cable 101 where the thickness 131 of the dielectric material 130 is at a minimum in order to increase IO density.
In some embodiments, the distance between the transmission line and ground as well as a width of the transmission line can influence the impedance in a cable. Thus, in addition to increasing the dielectric thickness 131, a width of the transmission line conductor 110 can also be increased along the length 150 (e.g., away from the connector 140) in order to maintain a desired impedance. For example, as shown in the top view of
In one aspect, shown in
In one example, utilizing a stripline and a starting dielectric thickness of 50 μm, 4 IO/mm could be achieved with 20 dB isolation. However, the loss would be on the order of 0.33 dB/cm at 10 GHz. By increasing the dielectric thickness to 100 μm, the loss could be reduced to 0.24 dB/cm in the region where the dielectric thickness is 100 μm. For an example line 18 inches in length, the loss could be reduced from about 15 dB to less than 12 dB. A 3 dB savings results in double the power at the receiver. Although this represents a single example, higher IO densities can be achieved by varying the dielectric constant, launching line width, cross talk requirements, and transmission line type. Greater power reductions can be realized by further increasing the thickness of the dielectric.
An electrical cable as disclosed herein can therefore be configured with geometry that is varied along its length to provide high IO density while maintaining an appropriate impedance, as well as having reduced cross-talk and conductive losses along the length of the cable that enable longer reaches and higher data rates. The variable sizes and geometries discussed herein can be of any suitable dimension or configuration and may only be limited by practical considerations such as space constraints, manufacturing capabilities, etc. Such non-uniform and variable geometries of the cable can be achieved by any suitable technique or process. For example, geometries of the dielectric material (e.g., polyimide, polyether ether ketone, etc.), transmission line and/or ground conductors (e.g., copper) can be formed by an additive manufacturing technique, such as 3D printing. In one aspect, a transmission line and/or ground conductor variable cross-section can be formed by rolling a copper sheet with a variable force. In another aspect, a transmission line and/or ground conductor variable cross-section can be formed by electroplating with the only electrode at a relatively thick end of the conductor. The dielectric constant can be varied and controlled (e.g., along the length of the cable) by a number of manufacturing processes, such as by utilizing 3D printing and/or layering dielectric materials to achieve a non-uniform or non-homogeneous dielectric material. Aside from the non-uniform characteristics and attributes of the electrical cables disclosed herein, some embodiments may be similar in general construction to typical flex cables.
In one aspect of the present technology, electrical cables can be configured with multiple layers of transmission line conductors and or ground conductors, several examples of which are shown in
With the examples provided in
It should be noted that features of an electrical cable as disclosed herein, such as the dielectric material thickness and transmission line conductor geometry (e.g., width and thickness) and spacing, can be constant or variable as desired and, when variable, can vary in any suitable manner. For example, as shown in
The following examples pertain to further embodiments.
In one example there is provided an electrical cable comprising a transmission line conductor, a ground conductor, and a dielectric material having at least a portion with a thickness separating the transmission line conductor and the ground conductor that is variable along a length of the electrical cable.
In one example of an electrical cable, the transmission line conductor is variable in width along the length of the electrical cable.
In one example of an electrical cable, the transmission line conductor is variable in thickness along the length of the electrical cable.
In one example of an electrical cable, the transmission line conductor is variable in cross-sectional area along the length of the electrical cable.
In one example of an electrical cable, the transmission line conductor comprises a plurality of transmission line conductors.
In one example of an electrical cable, a gap between adjacent transmission line conductors is variable along the length of the electrical cable.
In one example of an electrical cable, the transmission line conductor, the dielectric material, and the ground conductor are arranged in a coaxial configuration.
In one example of an electrical cable, the thickness varies linearly along the length of the electrical cable.
In one example of an electrical cable, the thickness varies non-linearly along the length of the electrical cable.
In one example of an electrical cable, the thickness varies exponentially along the length of the electrical cable.
In one example, an electrical cable further comprises a connector for coupling the transmission line conductor to an electronic component.
In one example of an electrical cable, the connector is disposed at an end of the electrical cable where the thickness of the dielectric material is at a minimum.
In one example, an electrical cable further comprises a second connector disposed at an end of the electrical cable opposite the first connector.
In one example of an electrical cable, a second portion of the dielectric material has a second thickness separating the transmission line conductor and the ground conductor that is constant along the length of the electrical cable.
In one example of an electrical cable, the second portion of the dielectric material with a constant second thickness is between the first portion of the dielectric material with a variable first thickness and a connector.
In one example, an electrical cable further comprises a second transmission line conductor disposed such that the first and second transmission line conductors are about opposite sides of the ground conductor, wherein the dielectric material has a portion with a second thickness that separates the second transmission line conductor and the ground conductor and is variable along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in width along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in thickness along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in cross-sectional area along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor comprises a plurality of second transmission line conductors.
In one example of an electrical cable, a gap between adjacent second transmission line conductors is variable along the length of the electrical cable.
In one example, an electrical cable further comprises a second ground conductor disposed such that the first and second ground conductors are between the first and second transmission line conductors, wherein the dielectric material has a portion with a third thickness that separates the second transmission line conductor and the second ground conductor and is variable along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in width along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in thickness along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in cross-sectional area along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor comprises a plurality of second transmission line conductors.
In one example of an electrical cable, a gap between adjacent second transmission line conductors is variable along the length of the electrical cable.
In one example, an electrical cable further comprises a second ground conductor disposed such that the first and second ground conductors are about opposite sides of the first transmission line conductor, wherein the dielectric material has portion with a third thickness that separates the first transmission line conductor and the second ground conductor and is variable along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in width along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in thickness along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in cross-sectional area along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor comprises a plurality of second transmission line conductors.
In one example of an electrical cable, a gap between adjacent second transmission line conductors is variable along the length of the electrical cable.
In one example, an electrical cable further comprises a third ground conductor disposed such that the first and third ground conductors are about opposite sides of the second transmission line conductor, wherein the dielectric material has portion with a fourth thickness that separates the second transmission line conductor and the third ground conductor and is variable along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in width along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in thickness along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor is variable in cross-sectional area along the length of the electrical cable.
In one example of an electrical cable, the second transmission line conductor comprises a plurality of second transmission line conductors.
In one example of an electrical cable, a gap between adjacent second transmission line conductors is variable along the length of the electrical cable.
In one example there is provided an electronic system comprising an electronic component, and an electrical cable operably coupled to the electronic component.
In one example, an electronic system further comprises a substrate, wherein the electronic component is coupled to the substrate.
In one example of an electronic system, the substrate comprises a motherboard.
In one example of an electronic system, the electronic system further comprises a processor, a memory device, a radio, a slot, a port, or a combination thereof operably coupled to the motherboard.
In one example, an electronic system further comprises a second electronic component operably coupled to the first electronic component.
In one example of an electronic system, the second electronic component is coupled to the substrate.
In one example of an electronic system, the electronic system comprises a computing system.
In one example of an electronic system, the computing system comprises a desktop computer, a laptop, a tablet, a smartphone, a HPC, a server, a wearable device, or a combination thereof.
In one example there is provided a method for making an electrical cable comprising obtaining a dielectric material, forming the dielectric material having at least a portion with a thickness that is variable along a length, and disposing a transmission line conductor and a ground conductor about the dielectric material such that the thickness of the dielectric material separates the transmission line conductor and the ground conductor.
In one example, a method for making an electrical cable further comprises forming the transmission line conductor with a width that varies along the length.
In one example, a method for making an electrical cable further comprises forming the transmission line conductor with a thickness that varies along the length.
In one example, a method for making an electrical cable further comprises forming the transmission line conductor with a cross-sectional area that varies along the length.
In one example of a method for making an electrical cable, the transmission line conductor comprises a plurality of transmission line conductors.
In one example, a method for making an electrical cable further comprises forming a gap between adjacent transmission line conductors that is variable along the length.
In one example of a method for making an electrical cable, the transmission line conductor, the dielectric material, and the ground conductor are arranged in a coaxial configuration.
In one example of a method for making an electrical cable, the thickness of the dielectric material varies linearly along the length.
In one example of a method for making an electrical cable, the thickness of the dielectric material varies non-linearly along the length.
In one example of a method for making an electrical cable, the thickness of the dielectric material varies exponentially along the length of the electrical cable.
In one example, a method for making an electrical cable further comprises electrically coupling a connector to the transmission line conductor to facilitate coupling the transmission line conductor to an electronic component.
In one example of a method for making an electrical cable, the connector is disposed at an end of the electrical cable where the thickness of the dielectric material is at a minimum.
In one example, a method for making an electrical cable further comprises electrically coupling a second connector to the transmission line conductor at an end of the electrical cable opposite the first connector.
In one example, a method for making an electrical cable further comprises forming a second portion of the dielectric material with a second thickness separating the transmission line conductor and the ground conductor that is constant along the length.
In one example of a method for making an electrical cable, the second portion of the dielectric material with a constant second thickness is between the first portion of the dielectric material with a variable first thickness and a connector.
Circuitry used in electronic components or devices (e.g. a die) of an electronic device package can include hardware, firmware, program code, executable code, computer instructions, and/or software. Electronic components and devices can include a non-transitory computer readable storage medium which can be a computer readable storage medium that does not include signal. In the case of program code execution on programmable computers, the computing devices recited herein may include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. Volatile and non-volatile memory and/or storage elements may be a RAM, EPROM, flash drive, optical drive, magnetic hard drive, solid state drive, or other medium for storing electronic data. Node and wireless devices may also include a transceiver module, a counter module, a processing module, and/or a clock module or timer module. One or more programs that may implement or utilize any techniques described herein may use an application programming interface (API), reusable controls, and the like. Such programs may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) may be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.
While the forgoing examples are illustrative of the specific embodiments in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without departing from the principles and concepts articulated herein.