Patent ID: 12213285

DETAILED DESCRIPTION

The electronic assemblies disclosed herein are usable for mounting electronic components within a chassis, such as a conventional or standard conduction cooled chassis. While the disclosed electronic assemblies are described herein with respect to mounting within a conventional or standard conduction cooled chassis, it will be understood that the invention is not so limited. To the contrary, aspects of the present invention are usable in any application in which stacking or aligning electronic assemblies within an electronic unit or frame is desired.

As used herein, the term “electronic assembly” comprises any multi-slot card assembly with multiple heat frames that need to interface directly with the chassis slots. As an exemplary embodiment, an electronic assembly may comprise a system having multiple interconnected circuit boards having high power field-programmable gate array (FPGA) sets, processors or high power electrical components. As another exemplary embodiment, an electronic assembly may comprise a system having conduction cooled products with multiple interconnected circuit boards having high power field-programmable gate array (FPGA) sets or high power electrical components. In another exemplary embodiment, an electronic assembly comprises a system using multiple circuit cards that have shared heat frames. This embodiment may include adding a heat frame with a circuit card mounted on the opposite side.

Still further, the electronic assembly comprises a system requiring thermal management of associated electronic components or any other electronics unit that requires cooling, such as via standard conduction cooling methods. Likewise, the term “heat frame” may include any electronic housing, unit, housing, frame, rack, compartment adapted to house, contain, or enclose (partially or entirely) associated electronic components, including associated electronic components that generate heat (of varying degrees) or require heat dissipation or cooling.

With reference to the drawings,FIGS.1A-1Dillustrates an exemplary electronic assembly100comprising one or more multi-slot card assemblies200mountable into an exemplary chassis102. AlthoughFIGS.1A-1C,5, and7show electronic assembly100as including a multi-slot card assembly200mounted into chassis102, a person of ordinary skill in the art would understand that multiple multi-slot card assemblies200may be mounted in any configuration within chassis102. Chassis102has sufficient rigidity and strength to securely fix one or more of multi-slot card assemblies200. Chassis102having two or more mounting slots104may comprise a single unitary part, or it may be an assembly of structural elements comprising multiple individual unitary parts. As best shown inFIG.1C, chassis mounting grooves or slots104each include at least three internal walls or surfaces106, which together define a mounting surface configured for receiving, seating, or securing a portion of one or more multi-slot card assemblies200. Additionally, it should be understood that althoughFIG.1Creferences internal walls106for one of a plurality of slots104, internal walls106are similarly present for each of the plurality of slots104of chassis102. As shown inFIGS.1A and1C, each slot104has a size and shape that corresponds to and is configured to receive a portion of one or more multi-slot card assemblies200. In an exemplary embodiment, as shown inFIG.1C, slot104includes three internal walls106.

Referring now toFIGS.1B and2, one or more multi-slot card assemblies200may comprise a single unitary part, or it may be an assembly of structural elements comprising multiple individual unitary parts. For example, as shown inFIG.2, one or more multi-slot card assemblies200may be an assembly of parts including at least one heat frame, such as a primary heat frame202and a secondary heat frame204, a guide rail206, and a diagonal fastener208. At least one heat frame202/204each includes a pair of corresponding surfaces or side walls230.

In an exemplary embodiment, adjacent to each surface or side wall230is at least a corresponding protrusion or floating rail assembly228(FIG.2) of multi-slot card assembly200comprising guide rail206and diagonal fastener208. As shown inFIG.1B, protrusion or floating rail assembly228is configured to be received by one or more slots104of chassis102. Further, it should be understood that althoughFIG.2references one protrusion or floating rail assembly228of multi-slot card assembly200, protrusion or floating rail assembly228may be similarly present and adjacent to each of side walls230of each heat frame202/204. In another exemplary embodiment, protrusion or floating rail assembly228(FIG.2) of multi-slot card assembly200may comprise guide rail206and a fastener, such as standard or unidirectional wedgelock210is used. In this configuration, the application of force by wedgelock210is unidirectional, e.g. standard fastener or wedgelock210forces at least one guide rail206against at least one of internal walls106of chassis mounting slot104.

Electronic components, such as at least one circuit card module212, may be mounted to one or more primary heat frame(s)202and secondary heat frame(s)204. In an exemplary embodiment, multi-slot card assembly200comprises two or more circuit modules212, each having an exemplary FPGA chipset222, which need to communicate quickly with each other. At least one circuit card module212and other electronic components may generate heat or otherwise require heat dissipation or cooling. In particular, more than one electronic component, e.g. two or more circuit card modules212, can generate sufficient heat within an electronics assembly or system, thereby including heat dissipation capabilities tied to or involving chassis102. Accordingly, at least one heat frame202/204may be constructed with any suitable materials or metals, including metals such as aluminum, adapted to provide or facilitate efficient heat transfer/dissipation.

Using separate heat frames, such as primary heat frame202and secondary heat frame204, with a rigid header220therebetween, advantageously allows two circuit card modules212to maintain signal integrity, i.e. allows an FPGA chipset222of an exemplary circuit card module212(as shown in inFIG.7) to communicate quickly with another FPGA chipset222of another circuit card module212. However, some amount of misalignment between at least one heat frames202/204and respective chassis mounting slots104, may result due to manufacturing tolerances, such as machining tolerances on at least one heat frames202/204as well as thickness tolerances of circuit card modules212. Such misalignment can be detrimental (e.g. including stress and/or insufficient heat dissipation/conduction cooling) for circuit card modules212that rely on sufficient intimate contact between at least one heat frame202/204and chassis102.

Thus, mitigating or eliminating this misalignment and its resulting effects requires maintaining sufficient intimate contact between at least one heat frame202/204and chassis102, without inducing stresses in or less efficient (or insufficient) heat transfer through circuit card modules212and at least one heat frame202/204.

Further, only using multiple sets of conventional or standard fasteners, such as wedgelocks or uni-directional wedgelocks, on each of at least one heat frame202/204risks less than optimal results with respect to (i) maintaining proper alignment and mechanical retention of at least one heat frame202/204relative to slots104of chassis102and (ii) thermal performance. If a first set of standard fasteners is engaged to seat secondary heat frame204against respective slot104of chassis102, and if a second set of standard fasteners is engaged to seat primary heat frame202against respective slot104of chassis102, merely using multiple sets of conventional fasteners in this way does not reliably close a gap formed between secondary heat frame204and chassis102. This would lead to higher thermal resistance and lesser thermal performance, as well as misalignment issues. Thus, the use of conventional fasteners alone, results in at least one heat frame202/204and chassis102not being able to maintain sufficient intimate contact for proper alignment or mechanical retention and thermal management purposes.

To mitigate these misalignment and thermal management concerns between at least one heat frame202/204and chassis102, multi-slot card assembly200of the present invention comprises both a moveable guide rail206and a fastener, such as a bi-directional or diagonal wedgelock208, both of which are discussed further below.

Turning now toFIG.3, multi-slot card assembly200may comprise at least one guide rail206, such as a floating rail, that is loosely attached, meaning that at least one guide rail206is moveable relative to at least one heat frame202/204. As an exemplary embodiment, at least one guide rail206is loosely attached and movable relative to secondary heat frame204. To facilitate this loose attachment between at least one guide rail206and at least one heat frame202/204, at least one guide rail206defines a plurality of openings, such as mounting holes214(FIG.4), and any suitable fasteners or combinations of fastening means, such as screws, nuts and bolts, rivets, spacers, washers, and so on may be used. In an exemplary embodiment, one or more fastening means, such as shoulder screws216, are configured to extend through mounting holes214, such that at least one guide rail206is sufficiently retained by at least one heat frame202/204and is also movable relative to at least one heat frame202/204. In an exemplary embodiment, shoulder screws216extending through mounting holes214facilitates both the retention of at least one guide rail206to secondary heat frame204and movement of at least one guide rail206relative to secondary heat frame204. The translational or rotational movement of shoulder screws216within a space defined by mounting holes214facilitates the movement of at least one guide rail206relative to secondary heat frame204.

As an exemplary embodiment and as illustrated inFIGS.4-5, at least one guide rail206may be displaced along a direction, y, in a generally longitudinal or vertical (up and down) direction. Particularly, at least one guide rail206may be displaced along a generally orthogonal direction, y, relative to one of internal walls106of slot104. Displacement along direction, y, accounts for tolerance stackup due to manufacturing tolerances of chassis102and heat frame202/204. In yet another exemplary embodiment, at least one guide rail206may also be displaced along a direction, x, in a generally lateral or horizontal (left to right, or right to left) direction. Still further, at least one guide rail206may also be displaced along a combination of a direction, y, and a direction, x.

Referring now toFIGS.6A-6B, multi-slot card assembly200comprises at least one fastener, such as a bi-directional or diagonal wedgelock208. At least one fastener208is coupled to at least one guide rail206, such that at least one guide rail206is moveable relative to at least one heat frame202/204. In an exemplary embodiment, at least one fastener208may be attached to at least one guide rail206with attachment means, such as flathead screws226(FIG.3), so that that at least one fastener208is loosely attached to at least one guide rail206. In other words, at least one fastener208and at least one guide rail206are loosely attached, such that they are moveable relative to one another, but at least one fastener208and at least guide rail206are not disconnected upon engagement of one or more components of electronic assembly100. A person of ordinary skill in the art would understand from the description herein that at least one fastener208may be attached to at least one guide rail206based on known attachment means, such that they are loosely attached to each other. Additionally or optionally, at least one fastener may include a conventional wedgelock210. At least one fastener208may have a size and shape that corresponds to the size and shape of respective slot104of chassis102so that a respective protrusion or floating rail assembly228of multi-slot card assembly200may be inserted into a respective slot104. When multi-slot card assembly200is mounted into chassis102, at least one fastener208provides a robust mechanical joint that properly aligns and secures multi-slot card assembly200within chassis102. In this way, at least one fastener208allows for chassis102to hold or retain multi-slot card assembly200during normal operation and movement, if any, of electronic assembly100.

At least one fastener208is moveable or expandable to apply force to at least one guide rail206and respective chassis mounting slot104when multi-slot card assembly200is mounted into chassis102. In an exemplary embodiment, when at least one fastener208is moved or expanded, at least one fastener208forces at least one guide rail206against both side wall230of secondary heat frame204and one of internal walls106of chassis mounting slot104. When standard fastener or wedgelock210is used, the application of force is unidirectional, e.g. standard fastener or wedgelock210forces at least one guide rail206against one of internal walls106of chassis mounting slot104.

In operation, as shown inFIG.6B, at least one fastener208is engaged to move or expand along an oblique displacement direction, z, relative to one of internal walls106of chassis mounting slot104. Specifically, the diagonal expansion of at least one fastener208, creates orthogonal reaction loads between at least one guide rail206, chassis102, and secondary heat frame204. As at least one fastener208moves or expands, it applies force in a lateral or horizontal direction relative to one of internal walls106of chassis mounting slot104. In an exemplary embodiment, the application of force in a lateral direction, x, causes at least one guide rail206to make contact with side wall230of secondary heat frame204. Additionally, the application of force in a lateral direction, x′, causes at least one guide rail206to make contact with one of internal walls106of chassis mounting slot104. Further, as at least one fastener208moves or expands, it applies force in an orthogonal direction relative to one of internal walls106of chassis mounting slot104. In an exemplary embodiment, the application of force in an orthogonal direction, y, causes at least one guide rail206to make contact with two or more of internal walls106of chassis mounting slot104. In effect, when multi-slot card assembly200is mounted within chassis102and at least one fastener208is moved or expanded, at least one fastener208forces at least one guide rail206against both side wall230of secondary heat frame204and one of internal walls106of chassis mounting slot104. AlthoughFIGS.6A-6Bdepict the operation or expansion of at least one fastener208, it should be understood from the description herein that the same operation or expansion may be applied to any other fastener208of multi-slot card assembly200. Thus, fastener208coupled to a side of at least one heat frame202/204and another fastener208coupled to an opposite side of at least one heat frame202/204, as depicted inFIG.1B, may have a similar operation or expansion as described inFIGS.6A-6B.

Therefore, at least one fastener208and least one guide rail206together provide robust mechanical retention of multi-slot card assembly200into chassis102. Specifically, at least one fastener208creates orthogonal forces which securedly fix (i) at least one guide rail206to at least one heat frame202/204and (ii) at least one guide rail206to chassis102simultaneously. This configuration advantageously does not rely on deformation of secondary heat frame204to conform to chassis slot104, which may be less mechanically reliable.

Additionally or optionally, at least one fastener208and at least one guide rail206together provide an efficient heat transfer path for heat dissipation or cooling from at least one circuit card module212. The efficient heat transfer path is achieved by maintaining sufficient intimate contact between multi-slot card assembly200and chassis102based on the expansion and diagonal displacement of at least one fastener208that causes at least one guide rail206to be sufficiently intimately connected with both side wall230of at least one heat frame202/204and at least one of internal walls106of slot104. This increases the surface area available to dissipate or transfer the heat generated by the electronic components, such as at least one circuit card module212having an exemplary FPGA chipset222. In particular, when multi-slot card assembly200contains multiple circuit card modules212that together generate heat, it is beneficial to provide for a greater surface area through which heat may be dissipated.

In an exemplary embodiment, a heatflow path or heat transfer path224through least one guide rail206and at least one fastener208is illustrated inFIG.7. Heat is generated by an exemplary FPGA chipset222and heat flows out, as indicated by arrow (1) inFIG.7. Heat flows or dissipates through secondary heat frame204from FPGA chipset222, as indicated by arrow (2) inFIG.7. Further, heat passes through at least one guide rail206and one of internal walls106, as indicated by arrow (3) inFIG.7. Heat also flows through at least one fastener208and into another of internal walls106, as indicated by arrow (4) inFIG.7. Heat further flows through at least one fastener208and into another of internal walls106, as indicated by arrow (5) inFIG.7. AlthoughFIG.7shows an exemplary heat flow path or heat transfer path224through at least one guide rail206and at least one fastener208, it should be understood from the description herein that a similar heat flow path or heat transfer path may be applied throughout similar components of multi-slot card assembly200. Thus, guide rail206and fastener208coupled to a side wall230of at least one heat frame202/204and another guide rail206and fastener208coupled to an opposite side wall230of at least one heat frame202/204, as depicted inFIG.1B, may have similar heat flow path or heat transfer path224as described inFIG.7. Still further, it should be understood that althoughFIG.7shows am FPGA chipset222as a heat-generating component, the circuit card module212may include one or more other heat-generating components.

Still further, multi-slot card assembly200can be advantageously mounted within a standard conduction cooled chassis, without additional components or special tools for in-field maintenance of module replacement.

Moreover, the use of a pair of at least one moveable guide rail206and a corresponding pair of at least one diagonal fastener208, at least one standard or unidirectional wedgelock210), or a combination thereof, for each circuit card module212of multi-slot card assembly200is preferable over an alternative design of separating circuit card modules212into distinct and separate card assemblies with a cable therebetween because routing a large amount of cables between two or more circuit modules212would be logistically impractical. Additionally, the use of a pair of at least one moveable guide rail206and a corresponding pair of at least one diagonal fastener208, at least one standard or unidirectional wedgelock210), or a combination thereof, is preferable over an alternative design of connecting the two circuit modules212through the backplane because this would be electrically undesirable based on the necessity of highly dense, complex routing and additional length in the signal path. Still further, the use of a pair of at least one moveable guide rail206and a corresponding pair of at least one diagonal fastener208, at least one standard or unidirectional wedgelock210), or a combination thereof, is preferable over an alternative design of mounting the circuit card modules212such that the high power dissipating components, or heat-generating components, face inwards toward each other and using one intermediary heat frame202/204for heat sinking because two circuit card modules212would generate too much power to be effectively cooled by single heat frame202/204, such that additional thermal management components (i.e. heat pipes, vapor chambers, etc.) would be required, thereby adding undesired complexity, weight, and cost.

A second embodiment of electronic assembly100including mufti-slot card assembly200mounted into chassis102, such as electronic assembly1000, is illustrated inFIGS.8-9. Electronic assembly1000corresponds or is similar to the exemplary embodiment discussed above, except that plurality of slots104of chassis102is configured to receive a portion of at least one heat frame202/204. For example, at least one side wall230of at least one heat frame202/204at least partially extends within respective slot104of chassis102, such that a portion of at least one heat frame202/204extends above diagonal fastener208(FIG.8). Thus, adjacent to each internal wall or surface106of respective slot104of chassis102is at least corresponding protrusion228(FIG.2) of multi-slot card assembly200comprising side wall230of at least one heat frame202/204and diagonal fastener208. As shown inFIG.8, protrusion228is configured to be received by one or more slots104of chassis102. Further, it should be understood that althoughFIG.8references one protrusion228of multi-slot card assembly200, protrusion228may be similarly present and adjacent to each internal wall or surface106of respective slot104of chassis102.

Additionally or optionally, electronic assembly1000may include a thermal pad, such as thermal pad1100having an equilibrium height and positionable between at least two circuit modules212. Thermal pad1100may be configured to provide a thermal interface between primary heat frame202and secondary heat frame204and/or between two or more circuit modules212, each having an exemplary FPGA chipset222. Additionally or optionally, thermal pad1100may be adapted to accommodate misalignment or slip, such as a misalignment or slip that may occur when multi-slot card assembly200is mounted into chassis102, To achieve this, thermal pad1100may comprise conformable or less rigid material (relative to chassis102or heat frame202/204, for example). In a non-limiting example, thermal pad1100may comprise material, such as the T-FLEX™ 700, a ceramic filled silicon sheet, as described and designed by Laird Technologies, Inc. of Chesterfield, Missouri, and/or the silicone-based thermal interface materials (TIM) as described and designed by Shin-Etsu Chemical Co., Ltd, of Tokyo, Japan. In this way, thermal pad1100may be sufficiently conformable or adjustable during mounting of multi-slot card assembly200into chassis102, such that thermal pad1100is able to move between a more compressed state and a more relaxed state. This movement may be along the vertical direction (as indicated by arrow D inFIG.9). Displacement along this direction, D, accounts for tolerance stackup due to manufacturing tolerances of chassis102and heat frame202/204. Still further, at least a portion of the thermal pad decreases in height relative to the equilibrium height when the thermal pad is in the more compressed state, and at least another portion of the thermal pad increases in height to return to the equilibrium height when the thermal pad is in the more relaxed state.

Finally, as with electronic assembly100and components thereof discussed above, components of electronic assembly1000may be secured to at least one other component of electronic assembly1000(e.g. heat frame202/204and diagonal fastener208) using any suitable fasteners or combinations of fastening means, such as screws, nuts and bolts, rivets, spacers, washers, and so on.

A third embodiment of electronic assembly100including multi-slot card assembly200mounted into chassis102, such as electronic assembly2000, is illustrated inFIG.10. Electronic assembly2000corresponds or is similar to the exemplary embodiments discussed above, such electronic assemblies100,1000, except that there is no additional heat frame aside from primary heat frame202and it includes a heat transfer apparatus comprising at least one heat pipe2100. Heat pipe2100is positioned relative to circuit module212having FPGA chipset222and primary heat frame202, such that heat pipe2100is in thermal contact with one or more of chipset222and primary heat frame202. Still further, heat pipe2100may be positioned relative to the two or more mounting slots104of the chassis102, such that a first end of heat pipe2100is adjacent or in thermal contact with a fastener, such as diagonal fastener208or standard fastener210, and a second end of heat pipe2100opposite the first end is adjacent or in thermal contact with another fastener, such as diagonal fastener208or standard fastener210. In this configuration, heat pipe2100provides a heat transfer path224for the heat generated by FPGA chipset222. Heat transfer from FPGA chipset222of another circuit card module212(i.e. above primary heat frame202) may be dissipated via heat transfer path224provided by heat pipe2100. In a non-limiting example, a channel formed between FPGA chipset222of another circuit card module212and heat pipe2100may be used to achieve heat dissipation. Additionally or optionally, heat pipe2100may comprise flexible or conformable material and because they undergo a sintering process during manufacture, tolerance stackup issues may be mitigated or prevented. In an exemplary embodiment, as shown inFIG.11, heat pipe2100comprises at least one first section2110extending along a plane substantially parallel to one of walls106of mounting slots104of chassis102. Additionally or optionally, heat pipe2100comprises at least one second section2120extending along a plane angled relative to at least one first section2110. In one non-limiting example, heat pipe2100comprises at least one second section2120extending along a plane angled at approximately 90°, such that at least one second section2120is substantially perpendicular to at least one first section2110. Additionally or optionally, heat pipe2100comprises at least one third section2130, which extends along a plane substantially parallel to at least one first section2110and/or angled relative to at least one second section2120.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.