Internal cover thermal conduction

An apparatus and associated methodology associated with a thermally conductive frame having a perimeter surface defining a passage. A printed circuit board assembly (PCBA) is operably disposed within the passage and connected to the frame. The PCBA includes a solid state memory component. An internal cover is disposed in the passage on one side of the PCBA. The internal cover conducts heat to the frame that is operably generated by the solid state memory component. An external cover is attachable to the frame on an opposing side of the PCBA. The external cover cooperates with the frame and the internal cover to enclose the PCBA.

FIELD

The present embodiments relate generally to data storage, and more particularly, a solid state data storage assembly.

SUMMARY

Some embodiments of the present invention contemplate an apparatus having a thermally conductive frame with a perimeter surface defining a passage. A printed circuit board assembly (PCBA) is operably disposed within the passage and connected to the frame. The PCBA includes a solid state memory component. An internal cover is disposed in the passage on one side of the PCBA. The internal cover conducts heat to the frame that is operably generated by the solid state memory component. An external cover is attachable to the frame on an opposing side of the PCBA. The external cover cooperates with the frame and the internal cover to enclose the PCBA.

Some embodiments of the present invention contemplate a method including steps of: obtaining a thermally conductive frame having a perimeter surface defining a passage; positioning a conductive internal cover in the passage; positioning a PCBA in the passage, the PCBA including a solid state memory component; and attaching an external cover to the frame, thereby urging the solid state memory component in contact against a compressible layer of the internal cover and urging a rigid layer of the internal cover in contact against the frame, establishing a conductive path via the internal cover for transferring heat to the frame that is operably generated by the solid state memory component.

Some embodiments of the present invention contemplate a data storage device having an enclosure constructed of opposing external sides that are spatially separated by a peripheral edge defining a cavity. A PCBA is mounted in the cavity substantially parallel to the external sides and defining a dead air space in the cavity between the PCBA and at least one of the external sides. Means are provided for conducting heat from the dead air space to the peripheral edge of the enclosure.

DETAILED DESCRIPTION

Initially, it is to be appreciated that this disclosure is by way of example only, not by limitation. The heat transfer concepts herein are not limited to use or application with any specific system or method for using storage element devices. Thus, although the instrumentalities described herein are for the convenience of explanation, shown and described with respect to exemplary embodiments, it will be appreciated that the principles herein may be applied equally in other types of storage element systems and methods involving the storage and retrieval of data.

Solid state data storage is an advancing technology for data storage applications. Solid state data storage devices differ from non-solid state devices in that they typically have no moving parts and include memory chips to store data. Examples of solid state memory components used for solid state data storage include flash memory and magnetic random access memory (MRAM).

FIG. 1is a perspective view of an example solid state data storage assembly10, which can be a non-volatile data storage assembly. Solid state data storage assembly10may also be referred to as a solid-state drive. Data storage assembly10is suitable for use in various applications, such as computing devices, portable electronic devices or other devices that store data. Solid state data storage assembly10differs from non-solid state devices, such as disc drives, in that solid state data storage assembly10typically does not have moving parts.

Data storage assembly10includes outer housing12, which is defined by frame14, first cover16, and a second cover18(shown inFIG. 2), where first and second covers16,18are mechanically coupled to opposite sides of frame12to define a space within which electrical components of data storage assembly10are enclosed. Covers16,18can be mechanically connected to housing12using any suitable technique, such as using one or more screws, connection fingers, locking/clipping structures, adhesives, rivets, other mechanical fasteners, welding (e.g., ultrasonic welding) or combinations thereof. Housing12may be formed from any suitable material, such as metal (e.g., aluminum), plastic, or other suitable material or combinations thereof. Housing12substantially encloses at least one printed circuit board assembly (“PCBA,” not shown inFIG. 1), which includes electrical components, such as memory components (e.g., flash memory, magnetic random access memory (MRAM), static random access memory (SRAM) or dynamic random access memory (DRAM) chips) that store data and one or more controllers.

FIG. 2is an exploded perspective view of data storage assembly10. The example data storage assembly10shown inFIGS. 1 and 2includes frame14, first cover16, second cover18, PCBA20, thermal interfaces22,24, and label26. Label26may indicate the parameters of data storage assembly10, e.g., the memory capacity. In other examples, data storage assembly10does not include label26or may include more than one label.

As shown inFIG. 3, which is a schematic illustration of an example PCBA20, PCBA20can include printed circuit board30and electrical components32. Electrical components32include components such as one or more controller chips (e.g., controller integrated circuits) that control the storage and retrieval of data by data storage assembly10, one or more memory chips (e.g., flash memory, MRAM, SRAM or DRAM chips), one or more passive electrical components (e.g., capacitors or resistors), and the like. Electrical components32are electrically and mechanically coupled to printed circuit board30using any suitable technique, such as using solder joints or connector pins that are positioned between electrical contacts of electrical components32and electrical contacts on printed circuit board30. In the example shown inFIG. 3, electrical components32are soldered onto printed circuit board20using a surface mount technology process. As a result, solder joints34are formed between each electrical component32and printed circuit board30.

PCBA20may include electrical contacts that electrically connect to a plurality of input/output connectors21, which are each configured to provide as an interface with one or more host device (e.g., a computer, a consumer electronic device, etc.). For example, input/output connectors21can be configured to transmit data, power and control signals to and from a host device. Example input/output connectors21can, but need not include a service expansion shelf (SES) connector, a serial advanced technology attachment (SATA) connector, and/or a four pin test connector. Frame14of housing12defines opening15through which input/output connectors21may be accessed. PCBA20can also be electrically connected to additional connectors such as, but not limited to, a pin connector (e.g., a J1 connector, which is a 110-pin connector). The additional connectors may be positioned on any suitable side of PCBA20, such as side20A substantially opposite side20B on which connector21is positioned.

Printed circuit board30may include electrical components on more than one side. Thus, although electrical components32are shown on a single side of printed circuit board30in the example shown inFIG. 3, in other examples, electrical components32may be positioned on more than one side of printed circuit board30(e.g., on opposite sides of printed circuit board30). In addition, although one PCBA20is shown inFIG. 2, in other examples, data storage assembly10may include any suitable number of PCBAs, such as two, three or more. If data storage assembly10includes a plurality of PCBAs, the PCBAs may be stacked in a z-axis direction (orthogonal x-y-z axes are shown inFIGS. 1 and 2), stacked in the x-y plane or any combination thereof.

During operation of data storage assembly10, heat may be generated by electrical components32of PCBA20. The generation of heat from the operation of data storage assembly10may be especially compounded when a plurality of data storage assemblies10are positioned next to each other, e.g., in a device or in a server room or other data center. As heat builds up within housing12(FIG. 1), the performance of data storage assembly10may degrade and the useful life of electrical components32may decrease due to the added stress on components32from the relatively high temperature operating environment.

The issue of heat build-up becomes particularly pronounced when housing12substantially encloses PCBA20, e.g., as shown inFIGS. 1 and 2, due to limited air circulation within housing12as well as the relative small size of housing12. While one or both covers16,18may be removed from data storage assembly10in order to help improve the heat conduction of data storage assembly10, covers16,18serve various purposes in assembly10. As a result, other issues may arise as a result of removing one or both covers16,18from assembly10. For example, covers16,18provide shock protection to assembly10by increasing the stiffness of assembly10. In addition, covers16,18helps protect PCBA20and its electrical components32from environmental contaminants, such as dust particles, liquids, and the like. Thus, it may be undesirable to remove covers16,18from housing12in some instances. The present embodiments leverage the use the covers16,18as large “single fin” heat sinks by constructing highly thermal conductive paths for heat transfer to some or all of the components mounted to the printed circuit board, which are otherwise thermally insulated from the covers16,18by being mounted to the printed circuit board.

In order to help improve the heat conduction data storage assembly10, data storage assembly10includes thermal interface22positioned between PCBA20and cover16, and thermal interface24positioned between PCBA20and cover18. Thermal interfaces22,24contact different sides of printed circuit board assembly20. In contrast to thermally insulating material, thermal interfaces22,24each comprise a thermally conductive material, which aids in the conduction of heat away from electrical components32of PCBA20and improves the thermal transfer efficiency of data storage assembly10. In some examples, thermal interfaces22,24exhibit a thermally conductivity of about 0.1 watts per meter-Kelvin (W/mK) to about 3.0 W/mK, although other thermal conductivities are contemplated. The conduction of heat away from components32can help maintain the operational integrity of electrical components32and increase the useful life of data storage assembly10by decreasing the stress on components32that is generated from relatively high operating temperatures. In some examples, thermal interfaces22,24may each comprise a ceramic filled silicone elastomer. However, other thermally conductive materials may also be used to form thermal interfaces22,24.

In some examples, thermal interfaces22,24are formed of a substantially mechanically conformable material, such that thermal interfaces22,24are capable of substantially conforming to the topography of PCBA20. In such examples, when thermal interfaces22,24are positioned over PCBA20and compressed, thermal interfaces22,24may contact one or more surfaces of PCBA20(e.g., the surface of electrical components32). Increasing the contact between thermal interfaces22,24and PCBA20with a conformable material may be desirable in order to increase the conduction of heat away from electrical components32. Furthermore, some of the heat generated by the electrical components32is directed toward and into the printed circuit board30, potentially creating a hot spot in the area of the printed circuit board30where the electrical component32is mounted. The conformable material compressingly engaged against the PCBA20likewise conducts heat away from any such hot spot.

In addition to or instead of being formed from a substantially conformable material, thermal interfaces22,24may each define a plurality of openings (e.g., cutaway portions) that are configured to receive surface protrusions of PCBA20. The surface protrusions may be formed by the placement of electrical components32on printed circuit board30and extending from printed circuit board30. In this way, thermal interfaces22,24may better envelop electrical components32and increase the surface area for contacting electrical components32and conducting heat away from electrical components32.

Thermal interfaces22,24are each formed from one or more layers of thermally conductive material, which may be substantially continuous in order to define a path of low thermal resistance. In some examples, thermal interfaces22,24each comprise multiple layers of material that may be stacked in a z-axis direction or multiple layers of material that are positioned adjacent each other in the x-y plane.

In the example of data storage assembly10shown inFIG. 2, thermal interfaces22,24each define a structure having a stiffness that enables thermal interfaces22,24to be removed from housing12while maintaining their structural integrity. For example, thermal interfaces22,24may each be configured such that they may be removed from housing12without breaking apart or decomposing upon handling. As a result, thermal interfaces22,24may easily be introduced into and removed from housing12without generating particles or other contaminants that may affect the operation of data storage assembly10.

Configuring thermal interfaces22,24such that they may each be removed from housing12without leaving portions of thermally conductive material within housing12may be useful, e.g., for purposes of accessing electrical components32(FIG. 3) of PCBA20. After assembly of data storage assembly10, it may be useful to periodically access electrical components32in order to repair data storage assembly10or otherwise rework electrical components32. Thermal interfaces22,24that are removable from data storage assembly10without substantially adversely affecting the properties of PCBA20provides a cost-effective technique for aiding the conduction of heat away from PCBA20. In some examples, thermal interfaces22,24may be reused after being removed from housing12(e.g., may be replaced in housing12).

Thermal interfaces22,24may have any suitable thickness. In some examples, thermal interface layers22,24each have a thickness of about 0.1 millimeters (mm) to about 2.0 mm. However, other thicknesses are contemplated and may depend on the dimensions of the particular data storage assembly10. As described below, in some examples, a thickness of each of thermal interface layers22,24may be selected to fill a space between covers16,18and PCBA20within housing12.

When data storage assembly10is assembled, there may be an air gap between covers16,18and PCBA20. This air gap may act as a thermal insulator that precludes conduction of heat away electrical components32(FIG. 3). As a result, heat generated by components32may be retained within housing12. In examples in which thermal interfaces22,24are sized to fill a space between covers16,18, respectively, and PCBA20, thermal interfaces22,24eliminate the air gaps between covers16,18and PCBA20. Thus, by contacting both covers16,18and PCBA20, thermal interfaces22,24each provide a relatively low resistance thermal conduction path from PCBA20, a source of heat, and the exterior of housing12(through covers16,18), to which the heat may be dissipated. In this way, data storage assembly10is configured such that heat can be dissipated through a relatively low resistance thermal pathway including thermal interface material22,24, thereby reducing the operating temperatures within housing12.

The inclusion of thermal interfaces22,24in housing12may increase the number of potential uses of data storage assembly10and/or decrease the restrictions on the operating environment requirements for data storage assembly10. For example, the increased ability of data storage assembly10to conduct heat away from electrical components32may help decrease the cooling requirements for the applications in which data storage assembly10is used. Depending on the application in which data storage assembly10is used (e.g., within a device or a server room), an external cooling source (e.g., a fan or an air conditioning unit) may be used to help maintain a desirable operating temperature for data storage assembly10. The increased ability of data storage assembly10to conduct heat away from electrical components32may help increase the tolerable operating temperature for data storage assembly10, which may decrease the cooling requirements for data storage assembly10.

In addition to conducting heat away from electrical components32of printed circuit board assembly20, thermal interfaces22,24may help increase the mechanical robustness of data storage assembly10. Due to the configuration and placement of thermal interfaces22,24within housing12, thermal interfaces22,24help protect PCBA20from damage due to the application of a transient or cumulative mechanical load on housing12. In this way, thermal interfaces22,24may also be referred to as a shock protector of PCBA20. As described in further detail below, thermal interfaces22,24help increase the stiffness of data storage assembly10, as well as limit the movement of electrical components32(FIG. 3) relative to printed circuit board30(FIG. 3) of PCBA20.

Although solid state data storage assembly10can exhibit an increased mechanical robustness compared to disc drives or other data storage devices with moving parts, solid state data storage assembly10may still be sensitive to applied mechanical loads. Mechanical loads may be exerted on housing12of data storage assembly10, e.g., when data storage assembly10is dropped or when an external force is applied to housing12. Printed circuit board30may flex or bend (e.g., from a planar configuration to a nonplanar configuration) when a shock or another type of mechanical load is applied to housing12. The bending or flexing of printed circuit board30may generate shear stresses that disrupt the mechanical joints between electrical components32and printed circuit board30. For example, if solder joints34(FIG. 3) are positioned between electrical components32and printed circuit board30(FIG. 3), the bending or flexing of printed circuit board30may result in the deformation and shearing of solder joints34. Some shear forces may have a magnitude sufficient to deform at least some of the solder joints34(or other mechanical connections between electrical components32and printed circuit board30) to the point of failure. When the mechanical connections between electrical components32and printed circuit board30fail, electrical components32may break loose from printed circuit board30, which disrupts the electrical connection between electrical components32and printed circuit board30, and compromises the ability of data storage assembly10to properly operate.

Note that although the illustrative embodiments ofFIG. 3depict the electrical components32electrically connected to the printed circuit board30by way of external leads the contemplated embodiments are not so limited, in that other types of electrical connections likewise benefit such as but not limited to using ball grid arrays (“BGAs”) and the like. Further, although the electrical components32are said to be solid state memory components for purposes of an illustrative description the contemplated embodiments are not so limited, in that other types of electrical components likewise benefit such as but not limited to the controller application-specific-integrated-circuit (“ASIC”) that performs top level control of the solid state memory components. All the advantageous heat transfer and vibration damping described herein is applicable to the controller ASIC and other electrical components as well, be they connected with external leads or BGAs or the like.

In some examples, thermal interfaces22,24may be configured (e.g., sized and shaped) to help maintain the mechanical and electrical connection between electrical components32and printed circuit board30of PCBA20when a mechanical load is applied to housing12. In particular, in some examples, thermal interfaces22,24are sized and shaped to contact both PCBA20and covers16,18, respectively, such that the stiffness of PCBA20is effectively increased. Increasing the stiffness of the PCBA can help maintain the integrity of the electrical and mechanical connections (e.g., connector pins or solder joints) between electrical components32(FIG. 3) and printed circuit board30(FIG. 3) of PCBA20by minimizing the stresses that are generated at the electrical and mechanical connections when a mechanical load is applied to housing12.

In particular, positioning thermal interfaces22,24such as thermal interfaces22,24contacting both PCBA20and covers16,18, respectively, decreases the possibility that printed circuit board30will bend or flex when a mechanical load is applied to data storage assembly10. The contact between covers16,18, thermal interfaces22,24, respectively, and printed circuit board30creates a composite or layered structure that effectively increases the rigidity of data storage assembly10and decreases the amount of available space for circuit board30to flex, thereby discouraging the bending or flexing of printed circuit board30. In this way, the positioning of thermal interfaces22,24in housing12increases the stiffness of PCBA20, thereby minimizing the magnitude of shear stresses that can result in the failure of the mechanical joints between the electrical components and the printed circuit board.

In some examples, thermal interfaces22,24fill the space between PCBA20and covers16,18, respectively. As a result, when a transient mechanical load is applied to housing12, thermal interfaces22,24may help hold electrical components32in place on printed circuit board30by limiting the movement of electrical components32relative to printed circuit board30. This may further help maintain the integrity of the electrical and mechanical connections (e.g., connector pins or solder joints) between electrical components32(FIG. 3) and printed circuit board30(FIG. 3) of PCBA20when a mechanical load is applied to housing12.

In addition, in some examples, thermal interfaces22,24help distribute a force that is applied to housing12across PCBA20, thereby reducing the concentration of mechanical stress generated within PCBA20. In this way, distributing the force across at least a part of PCBA20may reduce the possibility that the mechanical and electrical joints between electrical components32and printed circuit board30may break due to the application of external mechanical loads. In some cases, thermal interfaces22,24also dampen the mechanical loads (e.g., shocks) or vibrations that are applied to housing12and transmitted to PCBA20. For example, thermal interfaces22,24may each be formed of a material that has an elastomeric property that enables thermal interfaces22,24to absorb some mechanical loads that are applied to housing12.

In some examples, thermal interfaces22,24are relatively tacky, such that when thermal interfaces22,24are positioned between PCBA20and covers16,18, respectively, and, sized to fill the space between covers16,18, respectively, and PCBA20, thermal interfaces22,24adhere to the respective cover16,18and PCBA20. In some examples, at least one of the thermal interfaces22,24has a peel strength in a range of about 0.44 Newton (about 0.1 pound-force) to about 2.22 Newton (0.5 pound-force) for a 5.08 centimeter (2 inch) by 8.89 centimeter (3.5 inch) sample size relative to PCBA20. The adhesion between thermal interfaces22,24and the respective cover16,18and PCBA20may also help increase the stiffness of data storage assembly10, which may further improve the shock protection capability of thermal interfaces22,24.

In addition, the adhesion between thermal interfaces22,24and the respective cover16,18and PCBA20may provide a visible indication that data storage assembly10has been tampered with. For example, when thermal interfaces22,24are formed from a relatively tacky material, thermal interfaces22,24may adhere to PCBA20and the respective cover16,18when data storage assembly10is first assembled. However, the material from which thermal interfaces22,24are formed may not allow thermal interfaces22,24to re-adhere as well (if at all) to the respective cover16,18and PCBA20after data storage assembly10is disassembled. Thus, if cover16and thermal interface22are separated from the other components of data storage assembly10, e.g., to gain access to electrical components32of PCBA20, such tampering with data storage assembly10may be evidenced by the lack of adhesion or a decrease in adhesion between thermal interface22and PCBA20. The same visual indication of tampering may also be provided by thermal interface24if cover18and thermal interface24are separated from the other components of data storage assembly10.

It may be desirable to determine whether the internal components of data storage assembly10were exposed, thereby indicating tampering with electrical components32, for various purposes. For example, the manufacturer of data storage assembly10may provide a buyer with a limited warranty (e.g., covering manufacturing defects), which may be nullified if the data storage assembly10is tampered with. Prior to performing any warranty repairs on a data storage assembly10, the manufacturer may determine whether data storage assembly10has been tampered with by examining the adhesion between thermal interfaces22,24and covers16,18, respectively, and PCBA20. A diminished adhesion (e.g., compared to an expected adhesion) between one or both of the thermal interfaces and PCBA20may indicate that the thermal interface has been removed from housing12and subsequently replaced in housing12.

If thermal interfaces22,24are formed from a substantially conformable material, the manufacturer may also visually inspect thermal interfaces22,24to determine whether the pattern defined by the surface of thermal interfaces22,24facing PCBA20substantially matches the expected pattern of a thermal interface22that has been first removed from housing12. If pattern defined by the surface of one or both thermal interfaces22,24differs from the expected pattern, it may indicate that the thermal interface has been removed from housing12and subsequently replaced in housing12, thereby indicating data storage assembly10has been tampered with.

Example

An experiment was performed to compare the shock resistance of a solid state drive assembly including a thermally conductive interface material compared to a solid state drive assembly that is otherwise similar, but does not include a thermally conductive interface material. A ½ sine pulse shock was applied to a solid state drive assembly including a housing similar to housing12shown inFIGS. 1 and 2and a PCBA including a plurality of electrical components soldered to a printed circuit board. In particular, a solid state drive assembly was dropped using a Lansmont Drop Tester (made available by Lansmont Corporation of Monterey, Calif.), which helped maintain the desired orientation of the solid state drive assembly as it was dropped. The acceleration at which the drive assemblies were dropped was determined using Model 352A25 and Model 352C22 accelerometers (made available by PCB Piezotronics, Inc. of Depew, N.Y.).

A plurality of solid state drive assemblies each having a different printed circuit board thickness and excluding a thermal interface material were dropped in various orientations. Table 1 illustrates the accelerations with which the solid state drive assemblies were dropped, the thickness of the printed circuit board of the solid state drive assembly, and a duration of each of the drops.

In each of the iterations, the solid state drive assembly was dropped with the solid state drive assembly oriented such that the electrical components were facing in either a positive z-axis direction (“memory array up”) or a negative-z-axis direction (“memory array down”), such that the input-output (I/O) connector of the solid state drive assembly was face down (e.g., electrical components facing in positive y-axis direction) or face up (e.g., electrical components facing in negative y-axis direction), or such that a four pin connector of the solid state drive assembly was face up (e.g., electrical components facing in positive x-axis direction) or face down (e.g., electrical components facing in negative x-axis direction). In each of the solid state drive assemblies that were dropped, the four pin connector and the I/O connector are positioned on opposite sides of a housing of the solid state drive assembly.

Iterations 1-3 shown in Table 1 represent the dropping of three solid state drive assemblies each having a printed circuit board thickness of about 0.76 millimeters (mm). Iterations 4-9 shown in Table 1 represent the dropping of a single solid state drive assembly having a printed circuit board thickness of about 0.94 mm. In each subsequent drop for iterations 4-9, the solid state drive assembly was rotated, such that the consequences of dropping the solid state drive assembly in each of a plurality of orientations was determined. Iterations 10-15 shown in Table 1 represent the dropping of a single solid state drive assembly having a printed circuit board thickness of about 1.20 mm. In each subsequent drop for iterations 10-15, the solid state drive assembly was rotated, such that the consequences of dropping the solid state drive assembly in each of a plurality of orientations was determined.

A solid state drive assembly was considered to fail the shock test if, upon visual inspection, any of the electrical components were loose or had fallen off the printed circuit board of the solid state drive assembly. As Table 1 demonstrates at least some of the solid state drive assemblies that did not include a thermal interface material were unable to withstand the applied shock. In particular, the solid state drive assemblies showed a sensitivity to accelerations in a negative z-axis direction.

A solid state drive assembly similar in configuration to those tested to generate the data shown in Table 1 was modified to include a thermal interface material between the covers of the housing and the PCBA. The thermal interface material was Bergquist Gap Pad 2202, which is available from Bergquist Company of Chanhassen, Minn., and was selected to have a thickness of about 0.051 mm (about 0.020 inches) to fill the space between the covers of the housing and the PCBA. The solid state drive assembly including a thermal interface material was dropped five times using the Lansmont Drop Tester to determine whether the thermal interface material helped improve the ability of the solid state drive assembly to withstand a shock applied to the outer housing.

Table 2 illustrates the various accelerations with which the solid state drive assembly was dropped, as well as the thickness the printed circuit board and a duration of the drop. As with the testing performed to generate the data shown in Table 1, the solid state drive assembly was considered to fail the shock test if, upon visual inspection, any of the electrical components (e.g., memory chips) were loose or had fallen off the printed circuit board of the solid state drive assembly.

As Table 2 demonstrates, the solid state drive assembly including a thermal interface material positioned between the covers of the housing and the printed circuit board assembly was able to withstand accelerations up to 1957 G when the solid state drive assembly was dropped with the electrical components (e.g., the memory array) facing in a positive z-axis direction. This suggests that the thermal interface material improves the shock protection of a solid state drive assembly, and, in particular, the electrical components of a PCBA.

FIG. 4is a flow diagram of an example technique for forming solid state data storage assembly10. In accordance with the technique shown inFIG. 4, one or more PCBAs20are placed within frame14(40). The one or more PCBAs20can be attached to frame14using any suitable technique. In some examples, frame14includes side rails, brackets or other mechanical structures that align with and support the one or more PCBAs20. The one or more PCBAs20can be mechanically connected to these side rails, brackets or other mechanical structures of frame14. For example, the one or more PCBAs can be connected to frame14using one or more screws, connection fingers, locking/clipping structures, adhesives, rivets, other mechanical fasteners, welding (e.g., ultrasonic welding) or combinations thereof.

After placing one or more PCBAs20within frame14, thermally conductive material defining thermal interface22is placed over PCBA20(42). In some examples, the thermally conductive material is placed over PCBA20such that the major surface of PCBA20that is exposed by frame14is substantially covered by the thermally conductive material. In this way, thermal interface22may be sized and shaped to substantially cover PCBA20. After the thermally conductive material is placed over PCBA20to define thermal interface22(42), cover16is positioned over thermal interface22(44) and attached to frame14(46). Cover16can be attached to frame14using any suitable technique, such as screws, connection fingers, locking/clipping structures, adhesives, rivets, other mechanical fasteners, welding (e.g., ultrasonic welding) or combinations thereof.

Thermally conductive material can be pre-attached to cover16or can separate from cover16prior to inclusion in housing12. In some examples, thermal interface22has a thickness that is greater than or equal to a distance between cover16and PCBA20. As a result, when cover16is positioned over thermal interface22(44) and attached to frame14(46), thermal interface22substantially fills the space between cover16and PCBA20. In addition, in examples in which thermal interface22has a thickness that is greater than a distance between cover16and PCBA20, the attachment of cover16to frame14compresses thermally interface22, which may further increase the stiffness of data storage assembly10. As discussed above, this may help reduce the possibility that printed circuit board30(FIG. 3) bends or flexes in the z-axis direction, which can help maintain the integrity of the mechanical and electrical connection between electrical components32(FIG. 3) and printed circuit board30.

In some examples of data storage assembly10, housing12may include a single cover. In other examples, however, housing12of data storage assembly10includes two covers (e.g., as shown inFIG. 1) or more than two covers. Thus, in some examples of the technique shown inFIG. 4, a thermal conductive material may also be placed over the opposite surface of PCBA20to define second thermal interface24, and second cover18may subsequently be positioned over second thermal interface24and attached to frame14.

There being “more than two covers” generally contemplates embodiments in which there can be one or more internal cover(s) in addition to the two external covers16,18discussed above. Also as previously discussed, some embodiments contemplate the data storage assembly having a plurality of PCBAs in the same enclosure.FIG. 5is an exploded perspective depiction of illustrative embodiments in which the frame14ahas a perimeter surface50defining a passage52into which two PCBAs20a,20bcan fit. As discussed previously, each of the PCBAs20a,20bhas a plurality of solid state memory components (“components”)32, as well as other electronic components, operably generating heat that is necessarily controlled in accordance with embodiments of this invention. As described above, the thermal interface22contactingly engages and thereby conducts heat away from the components32during their operation. That is, the thermal interface22conducts the heat to the cover16which sheds the heat load by convection, such as can be enhanced by a directed airflow over the data storage assembly enclosure.

However, heat can build up in the space inside the enclosure on the other side of the PCBA20a, especially where components32are mounted on that opposing side of the PCBA20a. The data storage assembly10ais incapable of conductively shedding heat from the components32on the opposing side of the PCBA20a; it is a dead air space. Clarifying, for purposes of this description and meaning of the appended claims the term “dead air space” is an area inside the enclosure where there is no conductive heat transfer path from the components32to the enclosure. The components32are attached to the printed circuit board30which might, in turn, be in contact with the enclosure. However, the printed circuit board30is not a thermally conductive structure and as such does not provide a conductive heat transfer path as that term is meant in accordance with these embodiments. The heat load in the dead air space is exacerbated when both of the sides of the PCBAs20a,20bforming the dead air space have mounted components32that operably generate heat.

To transfer heat out of the dead air space an internal cover54is disposed within the passage52on the opposing side of the PCBA20afrom the external cover16. It will be noted that here the internal cover54and the external cover16are substantially parallel to each other, and that they cooperate with the frame14ato enclose the PCBA20a. The internal cover54is constructed of a rigid layer56that is thermally conductive, such as made of steel or aluminum and the like. In these illustrative embodiments the rigid layer56is connected in direct contact with the frame14a, and for that reason the frame14ais likewise constructed of a thermally conductive material such as aluminum or steel and the like.

FIG. 6is a partial cross-sectional depiction of the data transfer assembly10adepicting the frame14adefining a protuberant rail58extending from the peripheral surface50. The protuberant rail58includes an upper (as depicted here) surface60upon which the rigid layer56is supported. A compressible conductive layer62, such as used in constructing the thermal interfaces22,24, is compressingly sandwiched between the rigid layer56and the PCBA20a. For example, without limitation, the compressible conductive layer62can be adhered or otherwise joined to the rigid layer56, or the compressible conductive layer62can be stacked onto the rigid layer56. An attachment feature64in the rail58, such as the depicted threaded bore, can be sized to receivingly engage a fastener66that attaches both the external cover16and the internal cover54, as well as the sandwiched compressible members62,22, respectively, to the frame14a. The contacting engagement of the compressible conductive layer62creates a thermally conductive path for conducting heat from the component32to the rigid layer56. The contacting engagement of the rigid layer56against the protuberant rail58extends that thermally conductive path for conducting heat to the external surface of the rail14awhere the heat can be shed by convection to the surrounding environment. The entire path for conducting heat from the component32is depicted by the enlarged arrow67.

In the same way in these embodiments another internal cover70(FIG. 5) is parallel to the external cover18on opposing sides of the PCBA20b, such that the covers70,18and the frame14aenclose the PCBA20b. The internal cover70has a rigid layer72constructed like the rigid layer56. A surface73of the protuberant rail58provides a lower (as depicted here) surface against which the rigid layer72is supported. The gap between the rigid layers56,72, as defined by the height (as depicted here) of the protuberant rail58, can be sized as appropriate for clearance purposes of the overall assembly such as to provide space for one or more electrical connectors joining the PCBAs20a,20btogether.

A compressible conductive layer74, like the compressible conductive layer62, is compressingly sandwiched between the rigid layer72and the PCBA20b. As before, the compressible conductive layer74can be adhered or otherwise joined to the rigid layer72, or the compressible conductive layer74can be stacked onto the rigid layer72. Another attachment feature64, such as the depicted threaded bore, can be sized to receivingly engage a fastener66that attaches both the external cover18and the internal cover70, as well as the sandwiched compressible members74,24, respectively, to the frame14a. The contacting engagement of the compressible conductive layer74creates a thermally conductive path for conducting heat from the component32to the rigid layer72. The contacting engagement of the rigid layer72against the protuberant rail58extends that thermally conductive path for conducting heat to the external surface of the rail14awhere the heat can be shed by convection to the surrounding environment. The entire path for conducting heat from the component32is depicted by the enlarged arrow67.

The protuberant rail58and open passage52arrangement advantageously simplifies the manufacturing methodology employed to assemble the data storage assembly10a.FIG. 7is a flow diagram of an illustrative technique for forming the solid state data storage assembly10a. In these embodiments the frame14ais suitably supported, such as in an assembly fixture and the like, such that the internal cover54is positioned within the passage52and supported upon the rail58(100). The frame14acan advantageously be positioned horizontally in order that gravity can assist in positioning the internal cover54on the rail58. From the above description it is noted that the internal cover54can include both the rigid layer56and the compressible conductive layer62, so either the layers56,62are positioned as a unitary assembly or they are positioned individually and in order (100). The PCBA20ais then positioned within the passage52upon the internal cover54(102). The external cover16is then positioned against the frame14a(104). In embodiments where the compressible thermal interface22is included then the layers16,22are either positioned as a unitary assembly or the layers16,22are positioned individually and in order. A plurality of fasteners66are then coupled at distal ends thereof to the respective attachment features64in the rail58to attach both covers54,16and the PCBA20ato the rail58, and to also compressingly sandwich the thermal interface materials62,22therebetween (106).

With the top (as depicted) half assembled a determination is then made as to whether the other side needs to be assembled (108). If the determination is “no,” then the technique ends. Otherwise, if the determination is “yes,” then optionally the frame14acan be repositioned to facilitate the further assembly operations (110). For example, if the frame14ais positioned horizontally during the assembly above for the advantage of using gravity to assist in positioning the components of assembly, then the frame14acan be rotated 180 degrees so that it is presented in the same advantageous position for assembling the rest of the components of assembly.

In any event, control returns to the beginning of the technique such that the internal cover70is positioned within the passage52and supported upon the rail58(100). Again, from the above description it is noted that the internal cover70can include both the rigid layer72and the compressible conductive layer74, so either the layers72,74are positioned as a unitary assembly or they are positioned individually and in order (100). The PCBA20bis then positioned within the passage52upon the internal cover70(102). The external cover18is then positioned against the frame14a(104). In embodiments where the compressible thermal interface24is included then the layers18,24are either positioned as a unitary assembly or the layers18,24are positioned individually and in order. A plurality of fasteners66are then coupled at distal ends thereof to the respective attachment features64in the rail58to attach both covers70,18and the PCBA20bto the rail58, and to also compressingly sandwich the thermal interface materials74,24therebetween (106).

All of the foregoing embodiments employing internal covers54,70are used in an enclosure that is constructed of two external covers16,18, although the contemplated embodiments are not so limited.FIG. 8, for example, depicts illustrative alternative embodiments of a data storage assembly10bthat employs the two internal covers54,70as above, but only employs one external cover16. Instead of the other external cover18as described above, these depicted embodiments employ a unitary closed-bottom frame14bwith the components of assembly described above assembled in the same arrangement but from bottom-up. Here, instead of the protuberant rail58extending from the peripheral surface50, a spacer112is positioned within the passage52upon the rigid layer72of the internal cover70. The rigid layer56of the internal cover54is then positioned upon the spacer112, and on as in the same manner as upon the rail58described above.

Generally, the embodiments of the present invention contemplate a data storage device having an enclosure constructed of opposing external sides (such as the external covers16,18) that are spatially separated by a peripheral edge (such as frame14) defining a cavity. A PCBA (such as20) is mounted in the cavity substantially parallel to the external sides and defining the dead air space in the cavity between the PCBA and at least one of the external sides. A means is provided for conducting heat from the dead air space to the peripheral edge of the enclosure. For purposes of this description and meaning of the claims, the term “means for conducting heat” encompasses the disclosed structure and structural equivalents thereof that are capable of conducting heat from the dead air space to the peripheral edge of the enclosure. For example, the disclosed structure includes the components and arrangement constructing the conductive path67from the component32to the outer edge of the frame14aas depicted inFIG. 6; the compressible conductive layer62compressingly engaged against the component32, the rigid layer56contactingly engaging the compressible conductive layer62and, in turn, compressingly engaging the protuberant rail58portion of the frame14a.

It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with the details of the structure and function of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. For example, any single or multiple pluralities of the PCBAs and various arrangements for mounting the PCBAs are contemplated while still maintaining substantially the same functionality without departing from the scope and spirit of the claimed invention. Further, although the preferred embodiments described herein are directed to data storage drives, and related technology, it will be appreciated by those skilled in the art that the claimed invention can be applied to other devices employing heat generating components, without departing from the spirit and scope of the present invention.