ELECTRONICS COLD PLATE

A cold plate assembly includes a cold plate block having a first surface and a second surface opposite the first surface. The cold plate block is configured to mount a heat source thereto. A channel is formed in the first surface of the cold plate block. A cover plate covers the channel. A thermal interface material layer is disposed on the cover plate.

FIELD OF INVENTION

This disclosure relates generally to a cold plate assembly for thermal management of a heat source and, more particularly, to a cold plate assembly for thermal management of electronic devices, wherein the cold plate assembly includes a cold block defining a cooling channel therein and a cover plate covering the cooling channel.

FIELD OF INVENTION

As known, solid-state electronic devices, such as electronic components in vehicles, generate heat during operation thereof. The heat generated, if significant enough, can damage the electronic devices resulting in a loss of performance of the electronic devices or actual physical damage to the electronic devices. It is commonly desired to minimize a size of the electronic devices depending on package requirements. However, as the size of the electronic devices are minimized, the heat generated by the device during operation at higher electrical power usage becomes more of a concern. Therefore, it is desired to efficiently cool the electronic devices to avoid damage.

Solid-state electronic devices often employ a thermal interface such as a heat sink or a cold plate that draws heat away from, and thus cools, the electronic devices during operation of the electronic devices. Often, the heat sink relies on a flow of air around the heat sink and the electronic device to help minimize the temperature of the electronic devices. Known machined cold plates often employ a thermal interface material (TIM) on a top surface of the cold plate. However, the cold plates typically have an uneven top surface. The TIM on the uneven top surface of the cold plate causes small gaps to form between the TIM and the cold plate. As a result of the gaps, the efficiency of the heat transfer between the electronic device and the cold plate is minimized. Thus, known cold plates with TIM typically do not allow for optimal or direct contact between the electronic device and the cold plate which results in inefficient and undesirable cooling of the electronic devices.

Therefore, it is desired to have a cold plate configured for direct mounting to a heat source such as an electronic device, wherein the cold plate maximizes an efficiency of cooling the heat source and a complexity of manufacturing the cold plate is minimized.

SUMMARY

In accordance and attuned with the present invention, a cold plate configured for direct mounting to a heat source such as an electronic device, wherein the cold plate maximizes an efficiency of cooling the heat source and a complexity of manufacturing the cold plate is minimized has surprisingly been discovered.

Additional features of the disclosure will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1shows a heat source cooling assembly10including a heat source28under thermal management and a cold plate assembly11. The heat source28is configured as an electronic device such as a solid-state electronic device for an autonomous vehicle. Although it is understood the heat source28can be any electronic device for any vehicle or for any other application. Additionally, the heat source28can be any device or component requiring cooling or thermal management. The cold plate assembly11is directly mounted to the heat source28and configured to transfer heat from the heat source28to the cold plate assembly11.

The cold plate assembly11includes a cold plate block12. For example, the cold plate block12is an aluminum block. Although it is understood the cold plate block12can be formed from any material with a high thermal conductivity such as a copper material, an aluminum alloy material, a gold material, an iron material, or any other material, as desired. The cold plate block12has a first surface14and a second surface16opposite the first surface14. The first surface14faces the heat source28and is substantially planar except for portions described herein below such as a cooling channel18and a groove20. As used herein, “substantially” means “to a considerable degree,” “largely,” or “proximately” as a person skilled in the art in view of the instant disclosure would understand the term. In the embodiment illustrated, the cold plate block12has a substantially rectangular cross-sectional shape. However, the cold plate block12can have any cross-sectional shape, as desired such as circular, polygonal, ovular, a combination thereof, or any other shape.

The cold plate block12defines the cooling channel18. The cooling channel18may be formed in the first surface14by a machining process or other process. The cooling channel18conveys a cooling fluid there through. The cooling fluid can be a glycol, for example. Although, other cooling fluids can be employed such as a coolant, water, or a refrigerant, for example. The cooling fluid is conveyed to the cooling channel18of the cold plate block12from a cooling fluid source (not shown). The cooling channel18can extend linearly from one end of the cold plate block12to an opposing end of the cold plate block12. However, in other embodiments, the cooling channel18can extend in an arcuate, serpentine, angled, or other manner from the one end of the cold plate block12to the opposing end of the cold plate block12. Additionally, the cooling channel18can extend from any end or side and return to the same end or side or to an adjacent end or side. The groove20is formed into the first surface14along a perimeter or an edge of the cooling channel18. As shown, the groove20has a depth less than a depth of the cooling channel18.

The cold plate assembly11further includes a stamped cover plate24with an outer surface22and an inner surface23opposite the outer surface22, although other processes can be used to form the cover plate24as desired. The cover plate24can be an aluminum plate. However, other materials can be employed to form the cover plate24, as desired, such as materials with a high thermal conductivity. The cover plate24is configured to fit within the groove20and cover the cooling channel18. The cover plate24has a thickness substantially equal to the depth of the groove20, wherein the outer surface22of the cover plate24is substantially flush or substantially constant with the first surface14of the cold plate block12. The cover plate24is brazed to the cold plate block12in a suitable oven by using a clad brazing material (not shown) that melts under heat to join the cover plate24and the cold plate block12. The brazing results in a thermal joint providing the desired thermal contact between the cover plate24and the cold plate block12. The brazing occurs between the cover plate24and the cold plate block12at the groove20and an outer perimeter of the inner surface23of the cover plate24aligning with the groove20. A surface area of the outer surface22of the cover plate24is advantageously equal to a surface area of a surface of the heat source28contacting the cover plate24. Although, it is understood the surface area of the outer surface22of the cover plate24can be greater than the surface area of the surface of the heat source28contacting the cover plate24.

A thermal interface material (TIM) layer26is disposed between the heat source28and the cover plate24. The TIM layer26can be any thermal interface material now known or later developed providing efficient thermal communication between the heat source28and the cover plate24. For example, the TIM layer26can be a suitable plastic, a grease, an epoxy, a phase change material, a polymide tape, a graphite tape, an aluminum tape, a silicon coated material, a thermal paste, a gap filler, a combination thereof, or any other suitable TIM as desired. The TIM layer26is in complete contact with the outer surface22of the cover plate24and does not extend beyond edges of the cover plate24. The heats source28is in complete contact with the TIM layer26. The cooling fluid flows through the cooling channel18and transfers heat generated by the heat source28through the TIM layer26and the cover plate24.

To assemble the heat source cooling assembly10, after separately machining the cold plate block12and the cover plate24, the cover plate24is received in the groove20and is brazed to the cold plate block12to cover the cooling channel18. The TIM layer26is disposed on the cover plate24. The cooling channel18is positioned in fluid communication with the fluid source via an inlet and an outlet (not shown). The heat source28is mounted directly to the TIM layer26and cover plate24by mounting means.

FIGS. 2-3show a heat source cooling assembly40according to another embodiment of the disclosure. The heat source cooling assembly40is substantially similar to the heat source cooling assembly10ofFIG. 1but with a substantially U-shaped cooling channel26and a substantially U-stamped shaped cover plate52.

The heat source cooling assembly40includes a heat source80under thermal management and a cold plate assembly41. The heat source80is configured as an electronic device such as a solid-state electronic device for an autonomous vehicle. Although, it is understood, the heat source80can be any electronic device for any vehicle or for any other application. Additionally, the heat source80can be any device or component requiring cooling or thermal management. The cold plate assembly41is directly mounted to the heat source80and configured to transfer heat from the heat source80to the cold plate assembly41.

The cold plate assembly41includes a cold plate block42. For example, the cold plate block42is an aluminum block. Although, it is understood the cold plate block42can be formed from any material with a high thermal conductivity such as a copper material, an aluminum alloy material, a gold material, an iron material, or any other material, as desired. The cold plate block42has a first surface44and a second surface45opposite the first surface44. The first surface44faces the heat source80and is substantially planar. As used herein, “substantially” means “to a considerable degree,” “largely,” or “proximately” as a person skilled in the art in view of the instant disclosure would understand the term. In the embodiment illustrated, the cold plate block42has a substantially rectangular cross-sectional shape. However, the cold plate block42can have any cross-sectional shape, as desired such as circular, polygonal, ovular, a combination of shapes, or any other shape.

The cold plate block42defines the cooling channel46. The cooling channel46is formed in the first surface44by a machining process. The cooling channel46conveys a cooling fluid there through. The cooling fluid can be a glycol, for example. Although, other cooling fluids can be employed such as a coolant, water, or refrigerant, for example. The cooling fluid is conveyed to and from the cooling channel46of the cold plate block42from a cooling fluid source (not shown) through a pair of cooling fluid connectors72,74. The cooling channel46is substantially U-shaped having leg portions66,67, and a base portion68. A groove48is formed into the first surface44along an edge perimeter of the cooling channel46. The groove48has a depth less than a depth of the cooling channel46. The groove48has a widened area50, wherein a width of the groove48at the widened area50is greater than a width of the groove48at a remaining area of the groove48.

The cold plate assembly41further includes the cover plate52with an outer surface51and an inner surface53opposite the outer surface51. The cover plate52can be an aluminum plate. However, other materials can be employed to form the cover plate52, as desired, such as materials with high thermal conductivity. The cover plate52is configured to fit within the groove48and cover the cooling channel46. The cover plate52has a thickness substantially equal to the depth of the groove48, wherein the outer surface51of the cover plate52is substantially flush or substantially constant with the first surface44of the cold plate block41. The cover plate52is brazed to the cold plate block41in a suitable oven by using a clad brazing material (not shown) that melts under heat to join the cover plate52and the cold plate block42. The brazing results in a thermal joint providing the desired thermal contact between the cover plate52and the cold plate block42. The brazing occurs between the cover plate52and the cold plate block42at the groove48and an outer perimeter of the inner surface53of the cover plate52aligning with the groove48.

The cover plate52is substantially U-shaped including leg portions54,56corresponding in shape to the leg portions66,67of the cooling channel46and a base portion58corresponding in shape to the base portion68of the cooling channel46. The base portion68of the cover plate52has a widened area60corresponding to the widened area50of the groove48, wherein a width of the base portion68of the cover plate52at the widened area60is greater than a width of a remaining portion of the base portion68of the cover plate52. A surface area of the outer surface51of the cover plate52at the widened area60is advantageously greater than a surface area of a surface of the heat source80contacting the cover plate52. Although, it is understood the surface area of the outer surface51of the cover plate52at the widened area60can be substantially equal to the surface area of the surface of the heat source80contacting the cover plate52.

A thermal interface material (TIM) layer64is disposed between the heat source80and the cover plate52. In the embodiment illustrated, the TIM layer64is disposed between the widened area60of the base portion58of the cover plate52and the heat source80. The TIM layer64can be any thermal interface material now known or later developed providing efficient thermal communication between the heat source80and the cover plate52. For example, the TIM layer64can be a suitable plastic, a grease, an epoxy, a phase change material, a polymide tape, a graphite tape, an aluminum tape, a silicon coated material, a thermal paste, a gap filler, a combination thereof, or any other suitable TIM as desired. The TIM layer64is in complete contact with the cover plate52and does not extend beyond the edges of the cover plate52. The heat source80is in complete contact with the TIM layer64. The cooling fluid flows through the cooling channel46and draws away heat generated by the heat source80through the TIM layer64and the cover plate52.

An array of four threaded mounting holes70is formed through the cold plate block42around and outside the widened area60of base portion58of the cover plate52. The holes70are configured to provide a means for mounting the heat source80to the TIM layer64with a bracket or other structure (not shown). The holes70are close to the cover plate52but not abutting the cover plate52. Since the cover plate52is recessed into the groove48, clad material from brazing the cover plate52to the cold plate block42does not run into the holes70which could otherwise affect thermal performance of the cold plate assembly41. It is understood more than or fewer than four holes can be formed in the cold plate block42as desired.

To assemble the heat source cooling assembly40, after separately machining the cold plate block42and the cover plate52, the cover plate52is received in the groove48and is brazed to the cold plate block42to cover the cooling channel46. The holes70are formed through the cold plate block42. The TIM layer64is disposed on the cover plate52in the widened area60of the base portion58of the cover plate52. The cooling channel46is positioned in fluid communication with the fluid source via the cooling fluid connectors72,74. The heat source80is mounted directly to the TIM layer64and cover plate52by mounting means engaging and received by the holes70.

Advantageously, the heat source cooling assembly10,40of the present disclosure maximizes a cooling efficiency of the heat source28,80. Additionally, the cold plate assembly11,41only includes two plate components, the cold plate block12,42and the cover plate24,52compared to prior art assemblies includes three or more plate components. The cold plate block12,42is configured to allow mounting of the heat source28,80directly to the cold plate assembly11,41. The smooth outer surface22,51of cover plate24,52being flush with the first surface14,44of the cold plate block12,42also allows the heat source28,80to be directly mounted to the cold plate assembly11,41. As a result, the surface of the heat source28,80contacting the cold plate assembly11,41can directly engage evenly with cold plate assembly11,41, and directly to the TIM layer26,64, to maximize heat transfer between the heat source28,80and the cold plate assembly11,41. The heat source cooling assembly10,40of the present disclosure also minimizes leaks because and minimizes complexity of assembly and manufacturing.