US20180320880A1

US20180320880A1 - Systems and methods for a heat sink with a folded fin

Info

Publication number: US20180320880A1
Application number: US15/678,855
Authority: US
Inventors: Dung Duong; Randall Johnson; Nicholas Klase
Original assignee: Fluence Bioengineering Inc
Current assignee: Fluence Bioengineering Inc
Priority date: 2017-05-03
Filing date: 2017-08-16
Publication date: 2018-11-08
Also published as: US10488028B2; PL3619468T3; US20180324980A1; US11333341B2; CN110730884A; US20180320878A1; ES2989837T3; US20220260240A1; USD907592S1; DK3619468T3; US11774082B2; US10935227B2; CA3061336A1; EP3619468B1; EP3619468A1; CA3061336C; US10627093B2; US10208940B2; US20190234605A1; EP3619468A4

Abstract

Embodiments may utilize a series of exposed fins, which increase the surface area of the heat sink creating additional air flow. As hotter air rises within the system, cooler is drawn into the heatsink. The fins may be exposed on both sides of the longitudinal axis, allowing cooler air to be drawn towards the longitudinal axis above the heatsink and flow upward. This process may cool the fins. Additionally, the spacing between the fins may have to be wide enough to allow for air to freely enter the heatsink.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims a benefit of priority under 35 U.S.C. § 119 to Provisional Application No. 62/500,945 filed on May 3, 2017, which is fully incorporated herein by reference in their entirety.

BACKGROUND INFORMATION

Field of the Disclosure

Examples of the present disclosure are related to systems and methods for a heat sink with a folded fin. More particularly, embodiments disclose a heat sink configured to dissipate heat caused by a light fixture, wherein the heat sink includes exposed fins created by folding and extruding a unitary sheet of metal that allow for additional air flow.

Background

Greenhouses are buildings or complexes in which plants are grown. For various reasons including price, it is typically ideal for greenhouses to operate with as much natural sunlight as possible. To supplement natural light from the sun, high powered lights are used within greenhouses when the sun or other natural light does not provide enough light for optimal plant growth.
However, the operation of the high powered lights is more costly than utilizing free sunlight. More so, conventional high powered lights are larger in size, which blocks the incoming free sunlight. Furthermore, the blocking of the incoming sunlight causes shading on the plants within the greenhouse, which negatively impacts the grower's productivity.
Although light emitting diodes (LEDs) are more efficient than traditional high powered lights, their manufacturing costs are higher. Additionally, the LEDs cause excessive shading based on requiring larger fixtures to dissipate heat. To circumvent the large fixtures required to dissipate the heat, some manufacturers have attempted to build smaller LED fixtures that use active cooling fans. However, in greenhouse environments, active cooling fans quickly clog with dirt, bugs, etc. This causes the LED fixtures with active cooling fans to quickly become inoperable.
Conventional LED fixtures that do not include active cooling fans use traditional linear heat sinks. However, traditional linear heat sinks include wings that extend in a direction parallel with a central axis of the conventional LED fixtures. Heat generated through conventional LED fixtures may dissipate based on convection, conduction or radiation. However, due to LED fixtures being suspended, there is minimal heat dissipation via conduction. Radiation is a function of the fixture temperature and may be significant, and convection is the primary method to dissipate heat. In applications, air particles remove heat from the fixture through air movement. For longer heat sinks, air movement within the middle of the fixtures is minimal. This severely limits the amount of power conventional LED fixtures can consume because additional power consumption leads to more heat.
Accordingly, needs exist for more effective and efficient systems and methods for heat sinks with exposed fins created by folding and cutting a unitary sheet of metal allowing for additional air flow.

SUMMARY

Embodiments disclosed herein describe systems and methods for heat sinks within light fixtures. In embodiments, a heat sink may be a passive system that continually and passively creates a cross-flow thermal management system dissipating large amounts of heat in a slim light fixture.
Embodiments may utilize a series of exposed fins that increase the surface area of the heat sink creating additional air flow. As hotter air rises within the system, cooler is drawn into the heatsink. The fins may have exposed sides, lower surface, and upper surface, allowing cooler air to be drawn towards the longitudinal axis above the light source and flow upward. This process may cool the fins. Additionally, the spacing between the fins may be wide enough to allow for air to freely enter the heatsink.
Embodiments may include systems having folded sheet metal to create the plurality of fins from an aluminum block. By creating the plurality of fins via aluminum sheet metal and directly coupling the base or MCPCB to the fins, no secondary operations may be required to create the heat sink.
Embodiments may include folded sheet metal to create the plurality of fins.
Embodiments may include a folded fin. The folded fin may be comprised of sheet metal that is folded over itself multiple times at even intervals from a first end of the longitudinal axis to a second end of the longitudinal axis. By folding the fin over itself, the heatsink may be formed having alternating closed and opened adjacent upper and lower surfaces. Portions of the upper surface and/or lower surface of the fins may then be cut to have more exposed surface area.
Embodiments may include a MCPCB base that is directly attached to the sheet metal plurality of fins. This may allow for lower thermal resistance from heat sources to the fins, while also having less interfaces and/or coupling points. This may lead to a lower probability of air bubbles. The MCPCB may include vents that are configured to allow increased air flow through the system. In embodiments, the MCPCB may be folded or bent along the longitudinal axis to add mechanical strength and rigity to embodiments along the longitudinal axis of the heat sink. The height of the bends in the MCPCB may provide rigity to the MCPCB and system along the vertical axis of the system.
These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. The following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions or rearrangements may be made within the scope of the invention, and the invention includes all such substitutions, modifications, additions or rearrangements.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

FIG. 1 depicts a cross flow heat sink, according to an embodiment.

FIG. 2 depicts a cross flow heat sink system, according to an embodiment.

FIGS. 3 and 4 depict a cross flow heat sink system, according to an embodiment.

FIG. 5 depicts a method for manufacturing a heat sink, according to an embodiment.

FIG. 6 depicts a method for utilizing a heat sink, according to an embodiment.

FIG. 7 depicts a cross flow heat sink system, according to an embodiment.

Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present disclosure. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present embodiments. It will be apparent, however, to one having ordinary skill in the art that the specific detail need not be employed to practice the present embodiments. In other instances, well-known materials or methods have not been described in detail in order to avoid obscuring the present embodiments.
Embodiments may utilize a series of exposed fins that increase the surface area of the heat sink creating additional air flow. The fins may be exposed on both sides of the longitudinal axis, allowing cooler air to be drawn internally towards the longitudinal axis of the heatsink, above the heat source, and flow upward. This process may cool the fins. Additionally, the spacing between the fins may be wide enough to allow for air to freely enter the heatsink via the sides of the fins and/or through exposed lower surfaces of the fins.
FIG. 1 depicts a cross flow heat sink 100, according to an embodiment.
Heat sink 100 may be comprised of a unitary, folded sheet of metal, such as aluminum. The sheet of metal may be folded over itself from a first end of heat sink 100 to a second end of heat sink 100 to create fins 110. By folding the sheet over itself, alternating fins 110 may have a closed upper surface 120 followed by an open upper surface 130. In embodiments, chambers may be formed between the alternating fins 110, wherein air may enter into chambers via open lower ends and/or open sidewalls of the chambers. Air may flow out of the chambers via openings in the upper surfaces of the chambers and/or the open sidewalls of the chambers.
A first chamber 140 may be formed of first alternating fin pairs, including a first fin and a second fin. Initially, first chamber 140 may include a closed, rounded, upper surface 142, which extends across the entire width of heat sink 100. First chamber 140 may also include an open lower surface 144, which extends across the entire width of heat sink 100.
A second chamber 150 may be formed of alternating fin pairs, including the second fin and a third fin. Second chamber 150 may include an open upper surface, which extends across the entire width of heat sink 100. Second chamber 150 may also include a closed, rounded, lower surface, which extends across the entire width of heat sink 100. In embodiments, first chambers 140 and second chamber 150 pairs may be created from a proximal end to a distal end of heat sink 100 by folding the unitary sheet of metal.
The closed upper and lower surfaces of fins 110 may restrict the flow of air into and out of heat sink 100. To increase the flow of air into and out of heat sink 100, portions of the upper ends of first chambers 140 may be cut to form flat planar upper surfaces 146 of first chambers 140. The cut planar surface 146 may expose more of the upper surfaces of fins 110, which may allow for more effective heat flow. However, portions of the closed upper surfaces may not be cut to maintain physical contact between first chambers 140 and second chambers 150.
By maintaining contact between adjacent fins 110 via the non-cut portions of the upper surfaces and the closed lower surfaces, heat sink 100 may have sufficient strength along the central axis of heat sink 100.
Base 160 may be positioned at a lower surface of fins 110. Base 160 may extend from the proximal end to the distal end of heat sink 100. This may be utilized to couple the folded fins 110 together. Base 160 may be formed by extruding the entirety of the block of metal, wherein base 160 is the remaining portions of the block of metal after extrusion. Base 160 may be directly coupled to the closed rounded edges of second chambers 150 via adhesives or other coupling mechanisms.
Protrusions 170 may be positioned at the outer edges of base 340. Protrusions 170 may be projections extending away from base 340. In embodiments, protrusions 170 may project at a downward angle, and may be configured to guide heated air into the heat sink 100 via the lower, open surfaces of first chambers 140 and/or the open sidewalls of first chambers 140 and second chambers 150.
FIG. 2 depicts a cross flow heat sink system 100, according to an embodiment. Elements depicted in FIG. 2 may be described above. For the sake of brevity, an additional description of these elements is omitted.
As depicted in FIG. 2, base 160 may cover the internal, lower surfaces of chambers 140, 150, while not covering the outer, lower surfaces of chambers 140. However, the lower surfaces of chambers 140 may be closed due to the folding of the unitary sheet of metal. Thus, heated air may enter chambers 140 via the open sidewalls. The lower surfaces of chambers 150 may be open, which may allow heated air to enter chambers 150 via the open lower surfaces.
FIGS. 3 and 4 depict a cross flow heat sink system 300, according to an embodiment. Elements depicted in FIGS. 3 and 4 may be described above. For the sake of brevity, an additional description of these elements is omitted.
Heat sink 300 may be comprised of a folded sheet of metal, such as aluminum. The sheet of metal may be folded over itself from a first end to a second end of heat sink. This may create fins with alternating open and closed upper and lower surfaces.
After forming the heat sink 300 with alternating open and closed surfaces, top portions of heat sink 300 may be cut. Then the cut sheet of metal may be folded over itself. This may create portions of heat sink 300 being open 305, 310, 315 from the first end to the second end of heat sink 300, while portions of heat sink 300 may be closed 307. In embodiments, the closed upper surfaces 307 of the fins may not extend from the first end to the second end of heat sink 300 due to the sheet of metal being folded over itself, which may be utilized to add rigidly to heat sink 300 along the central axis of heat sink 300. Therefore, the closed upper surfaces 307 of the fins may still alternate between closed upper surfaces and opened surfaces adjacent fins.
By having multiple, continuous open ends 305, 310, 315 that extend in parallel to each other with multiple, continuous closed 307 portions of fins, heat sink 300 may have the rigidity and openness to operate efficiently. In embodiments, the surface area of the upper surfaces of the fins covered by opened portions may be greater than the surface area of the upper surfaces of fins covered by closed portions.
FIG. 5 illustrates a method 500 for manufacturing a heat sink, according to an embodiment. The operations of method 500 presented below are intended to be illustrative. In some embodiments, method 500 may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of method 500 are illustrated in FIG. 5 and described below is not intended to be limiting.
At operation 510, portions of a sheet of metal may be closed, wherein the cut portions of the sheet of metal correspond with open upper surfaces of the heat sink.
At operation 520, the sheet of metal may be folded over itself to form a plurality of fins. By folding the sheet of metal over itself, upper surfaces between alternating, adjacent fins may be open and closed. Similarly, lower surfaces between alternating, adjacent fins may be closed and opened. Furthermore, the cut upper surfaces of the sheet of metal may be utilized as demarcations points of where to fold the sheet of metal, such that alternating upper surfaces have cut portions.
At operation 530,
a base may be coupled to closed lower surfaces of alternating fins. The base may be coupled in a plurality of manners.
FIG. 6 illustrates a method 600 for utilizing a heat sink, according to an embodiment. The operations of method 600 presented below are intended to be illustrative. In some embodiments, method 600 may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of method 600 are illustrated in FIG. 6 and described below is not intended to be limiting.
At operation 610, air below a heat sink may be heated by a light source positioned directly below the heat sink.
At operation 620, the heated air may travel upward and around protrusions of the heat sink.
At operation 630, the heated air may travel into the body of the heat sink via the open lower surfaces between fins and through the open sidewalls between fins.
At operation 640, the heated air may conduct upward towards the open upper surfaces and towards the open upper portions of the sidewalls.
At operation 650, the heated air may exit the heat sink via the open upper surfaces, and the open sidewalls.
FIG. 7 depicts a cross flow heat sink system 700, according to an embodiment. Elements depicted in FIG. 7 may be described above. For the sake of brevity, an additional description of these elements is omitted.
As depicted in FIG. 7, heat sink system 700 the heat sink may include cuts on the bottom surface 710 as well as on the top surface. The cuts on the bottom surface 710 may be configured to correspond and accommodate for the bend in the MCPCB base, which may be directly coupled to bottom surface 710. Additionally, the folds in the heat sink may asymmetrical 720 from the front end to the rear end of system 700. This may allow for various heat flow patterns to be constructed, as well as allowing for electronic components to be embedded within heat sink system 700.
Although the present technology has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred implementations, it is to be understood that such detail is solely for that purpose and that the technology is not limited to the disclosed implementations, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present technology contemplates that, to the extent possible, one or more features of any implementation can be combined with one or more features of any other implementation.
Reference throughout this specification to “one embodiment”, “an embodiment”, “one example” or “an example” means that a particular feature, structure or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, “one example” or “an example” in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures or characteristics may be combined in any suitable combinations and/or sub-combinations in one or more embodiments or examples. In addition, it is appreciated that the figures provided herewith are for explanation purposes to persons ordinarily skilled in the art and that the drawings are not necessarily drawn to scale.
The flowcharts and block diagrams in the flow diagrams illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, may be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Claims

What is claimed is:

1. A heat sink comprising:

a unitary sheet of metal that is configured to be folded over itself to form a series of plurality of alternating first chambers and second chambers;

a first chamber being one of the plurality of first chambers, the first chamber being formed of a first fin and a second fin, and the first chamber having a first open lower surface;

a second chamber being one of the plurality of second chambers, the second chamber being formed of the second fin and a third fin, the second chamber having a second open upper surface and a second closed lower surface, wherein the first chamber is positioned adjacent to the second chamber.

2. The heat sink of claim 1, wherein the first chamber and the second chamber include open sidewalls.

3. The heat sink of claim 1, wherein the first chamber includes a first closed upper surface.

4. The heat sink of claim 1, wherein the first chamber includes a first partially closed upper surface.

5. The heat sink of claim 4, wherein the first partially closed upper surface is formed by cutting a first closed upper surface of the first chamber.

6. The heat sink of claim 5, wherein the first closed upper surface is cut along a longitudinal axis of the heat sink.

7. The heat sink of claim 6, wherein the first closed upper surface is cut such that a first portion of the first closed upper surface is a different size than a second portion of the first closed upper surface.

8. The heat sink of claim 1, further comprising:

a base being configured to be coupled with the second closed lower surface, wherein the base is comprised of metal core PCB.

9. The heat sink of claim 8, wherein side edges of the base includes downwardly angled protrusions.

10. The heat sink of claim 8, wherein the base partially covers the first open lower surface.

11. A method of forming a heat sink comprising:

folding a unitary sheet of metal over itself to form a series of plurality of alternating first chambers and second chambers, wherein a first chamber of the plurality of first chambers being formed of a first fin and a second fin, and the first chamber having a first open lower surface, and a second chamber of the plurality of second chambers being formed of the second fin and a third fin, the second chamber having a second open upper surface and a second closed lower surface, wherein the first chamber is positioned adjacent to the second chamber.

12. The method of claim 11, wherein the first chamber and the second chamber include open sidewalls.

13. The method of claim 11, wherein the first chamber includes a first closed upper surface.

14. The method of claim 11, wherein the first chamber includes a first partially closed upper surface.

15. The method of claim 14, further comprising:

cutting portions of a first closed upper surface of the first chamber to form the first partially closed upper surface, wherein the first partially closed upper surface includes open segments.

16. The method of claim 15, wherein the first closed upper surface is cut along a longitudinal axis of the heat sink.

17. The method of claim 16, wherein the first closed upper surface is cut such that a first portion of the first closed upper surface is a different size than a second portion of the first closed upper surface.

18. The method of claim 11, further comprising:

coupling a base with the second closed lower surface, wherein the base is comprised of metal core PCB.

19. The method of claim 18, wherein side edges of the base includes downwardly angled protrusions.

20. The method of claim 18, further comprising:

partially covering the first open lower surface with the base.