DE202022105382U1 - Heat sink with microchannels - Google Patents

Abstract

A microchannel heat sink device (100), the device (100) comprising:
a heat sink (102) having a distal end and a proximal end, a plurality of microchannels (104) extending from the heat sink;
a channel pool (106) formed at the proximal end of the heat sink (102) connecting the plurality of microchannels;
a plurality of ribs (108) extending from a proximal end of the channel basin (106) attached along a longitudinal direction of fluid flow;
a plurality of walls surrounding the plurality of microchannels (104), a top wall (110a) having an adiabatic surface connecting the plurality of microchannels (104) filled with the flowing liquid coolant, a bottom wall (110b) the absorbs heat dissipated from the heat sink (102) and at least one sidewall (110c) provides the adiabatic surface area; and
a channel layer (112) positioned at a top of the channel pool (106) in a direction of downstream flow connects the plurality of microchannels (104) to cooling liquids in the channel pool (106).

Description

FIELD OF THE INVENTION

The present invention relates to a field of heat exchange devices. More particularly, the present invention relates to a microchannel heat sink having a channel basin and rectangular fins.

BACKGROUND OF THE INVENTION

The miniaturization of electronic devices leads to a high heat flow in the devices and thus to a lack of space in such miniaturized components. The housing of mini-pumps used for the circulation of the coolant has become a big problem. Lower pressure drop, which results in lower pump performance in such micro devices, is an important solution. The heat transfer performance in terms of heat transfer coefficient, Nusselt number, Nusselt number ratio and total performance, i. H. the heat transfer improvement factor in macro or micro heat exchanger components, must be optimal.

US9513059B2 discloses a radial-flow lamellar heat exchanger with a multiplicity of heat exchanger units which are connected to one another and form an annular core. The core has a plurality of first fluid passageways that are circumferentially spaced from one another and extend generally axially from a first end of the core to a second end. The core also has a plurality of second fluid passageways spaced circumferentially from one another and extending generally radially from the central fluid passageway through an outer wall of the core.

JP5296990B2 discloses a fin collar with a shape that improves flux deposition and solder flow into the tube-fin joint to provide improved thermal and structural bonding.

The structure of the heat fins described above is complex and leads to a high heat flow and thus to a lack of space.

Therefore, there is a need to develop a micro-channel heatsink with a channel pool and rectangular fins for efficient cooling.

The technical advances disclosed by the present invention overcome the limitations and disadvantages of existing and conventional systems and methods.

SUMMARY OF THE INVENTION

The present invention generally relates to a microchannel heat sink device.

An object of the present invention is to provide a microchannel heat sink;

Another object of the present invention is to reduce heat flow; and

Another object of the present invention is to improve the heat flow mechanism.

• einen Kühlkörper mit einem distalen Ende und einem proximalen Ende, wobei sich eine Vielzahl von Mikrokanälen von dem Kühlkörper aus erstreckt;
• ein Kanalpool, der am proximalen Ende des Kühlkörpers ausgebildet ist, verbindet die Vielzahl von Mikrokanälen;
• eine Vielzahl von Rippen, die sich von einem proximalen Ende des Kanals erstrecken, der entlang einer Längsrichtung des Fluidstroms angebracht ist;
• eine Vielzahl von Wänden die Vielzahl von Mikrokanälen umgibt, wobei eine obere Wand mit einer adiabatischen Oberfläche die Vielzahl von Mikrokanälen, die mit dem fließenden flüssigen Kühlmittel gefüllt sind, verbindet, eine untere Wand die durch den Kühlkörper abgeleitete Wärme absorbiert und mindestens eine Seitenwand die adiabatische Oberfläche bereitstellt; und
• eine Kanalschicht, die an einer Oberseite des Kanalpools in Richtung eines stromabwärts gelegenen Flusses angeordnet ist, verbindet die Vielzahl von Mikrokanälen mit Kühlflüssigkeiten im Kanalpool.

In one embodiment, a microchannel heat sink device, the device comprising:

• a heat sink having a distal end and a proximal end, a plurality of microchannels extending from the heat sink;
• a channel pool formed at the proximal end of the heat sink connects the plurality of microchannels;
• a plurality of ribs extending from a proximal end of the channel attached along a longitudinal direction of fluid flow;
• a plurality of walls surrounding the plurality of microchannels, with a top wall having an adiabatic surface filling the plurality of microchannels with the flowing liquid coolant are connected, a bottom wall that absorbs heat dissipated by the heat sink and at least one side wall provides the adiabatic surface; and
• a channel layer arranged at a top of the channel pool in a direction of a downstream flow connects the plurality of microchannels with cooling liquids in the channel pool.

In one embodiment, the length and width of the heatsink are essentially the same and are between 5 and 15 mm.

In one embodiment, the frame consists of a semiconductor substrate, preferably a silicon material, that encloses at least one surface of the heat sink for receiving the plurality of microchannels.

In one embodiment, the liquid coolant flow channel has a geometric cross-section and is thermally connected to a heat source and extends parallel to the extending direction of the liquid coolant flow path.

In one embodiment, the heat sink has a plurality of microchannels with liquid passages extending parallel to each other to the channel pool, and the liquid coolant flows through the channel pool connecting the plurality of parallel microchannels, thereby eliminating the solid substrate walls in the channel pool.

In one embodiment, the length of the channel pool is less than half the length of the heatsink and the width of the channel pool is substantially equal to the width of the heatsink.

In one embodiment, the depth or height (H _p ) of the channel pool is substantially equal to half the height of the liquid channel (H _c ) of the heatsink.

In one embodiment, the cross section of the liquid coolant flow path through the plurality of microchannels follows the geometry of the cross section of the channel basin.

In one embodiment, the heat sink is made up of single, double, or multiple layers.

In one embodiment, the heatsink is thermally connected to a heat source.

In one embodiment, the heat sink extends parallel to the direction of extension of the liquid coolant flow path.

In order to further clarify the advantages and features of the present invention, a more detailed description of the invention will be made by reference to specific embodiments thereof illustrated in the accompanying figures. It is understood that these figures show only typical embodiments of the invention and therefore should not be considered as limiting its scope. The invention will be described and illustrated with additional specificity and detail with the accompanying figures.

character list

• 1 ein Blockdiagramm eines Mikrokanal-Kühlkörpers zeigt,
• 2 eine schematische Darstellung der vorliegenden Erfindung zeigt,
• 3 ein schematisches Layout des Mikrokanal-Kühlkörpers mit den geometrischen Parametern des Kanalbeckens und der rechteckigen Rippe zeigt,
• 4 eine grafische Darstellung der Druckverluste für Fall 0, Fall 1, Fall 2 und Fall 3 in Bezug auf verschiedene Re zeigt,
• 5 eine grafische Darstellung des Wärmeübergangskoeffizienten (h) aller Kühlkörperdesigns zeigt,
• 6a-6b eine grafische Darstellung des Vergleichs der Leistungsparameter für Fall 1, Fall 2 und Fall 3: (a) Veränderung des Fanningschen Reibungsfaktors f/fo mit Re, (b) Veränderung von Nu/Nuo mit Re zeigen, und
• 7 eine grafische Darstellung des thermischen Leistungsfaktors η in Bezug auf verschiedene Re für Fall 1, Fall 2 und Fall 3 zeigt.

These and other features, aspects and advantages of the present invention will be better understood when the following detailed description is read with reference to the accompanying figures, in which like characters represent like parts throughout the figures, wherein:

• 1 shows a block diagram of a microchannel heatsink,
• 2 shows a schematic representation of the present invention,
• 3 shows a schematic layout of the microchannel heatsink with the geometric parameters of the channel basin and the rectangular fin,
• 4 shows a graphical representation of the pressure losses for case 0, case 1, case 2 and case 3 in relation to different Re,
• 5 shows a graphical representation of the heat transfer coefficient (h) of all heatsink designs,
• 6a-6b shows a graphical representation of the comparison of performance parameters for Case 1, Case 2 and Case 3: (a) Fanning's friction factor f/fo changing with Re, (b) Nu/Nuo changing with Re, and
• 7 Figure 12 shows a plot of thermal power factor η in relation to different Re for case 1, case 2 and case 3.

Those skilled in the art will understand that the elements in the figures are presented for simplicity and are not necessarily drawn to scale. For example, the flow charts illustrate the method of key steps to enhance understanding of aspects of the present disclosure. In addition, one or more components of the device may be represented in the figures by conventional symbols, and the figures only show the specific details relevant to understanding the embodiments of the present disclosure, not to encircle the figures with details to overload, which are easily recognizable to those skilled in the art familiar with the present description.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the invention, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe the same. It should be understood, however, that no limitation on the scope of the invention is intended, and such alterations and further modifications to the illustrated system and such further applications of the principles of the invention set forth therein are contemplated as would occur to those skilled in the art invention would normally come to mind.

Those skilled in the art will understand that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be limiting.

When this specification refers to "an aspect," "another aspect," or the like, it means that a particular feature, structure, or characteristic described in connection with the embodiment is present in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in another embodiment," and similar phrases throughout this specification may or may not all refer to the same embodiment.

The terms "comprises," "including," or other variations thereof are intended to cover non-exclusive inclusion such that a method or method that includes a list of steps includes not only those steps, but may also include other steps that are not expressly stated or pertaining to any such process or method. Likewise, any device or subsystem or element or structure or component preceded by "comprises...a" does not, without further limitation, exclude the existence of other devices or other subsystem or other element or other structure or other component or additional device or additional subsystems or additional elements or additional structures or additional components.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The system, methods, and examples provided herein are for purposes of illustration only and are not intended to be limiting.

Embodiments of the present invention are described in detail below with reference to the attached figures.

1 Figure 12 shows a block diagram of a microchannel heatsink device (100), the device (100) comprising: a heatsink (102), a plurality of microchannels (104), a channel pool (106), a plurality of fins (108), a top wall (110a), a bottom wall (110b), a side wall (110c), and a channel layer (112).

The heat sink (102) has a distal end and a proximal end, with a plurality of microchannels (104) extending from the heat sink. The frame consists of a semiconductor substrate, preferably a silicon material enclosing at least one surface of the heat sink (102) to support the plurality of microchannels (104). The liquid coolant flow channel has a geometric cross section and is thermally connected to a heat source and extends parallel to the extending direction of the liquid coolant flow path.

The channel pool (106) is formed at the proximal end of the heat sink (102) and connects the plurality of microchannels. The length of the channel pool (106) is less than half the length of the heat sink (102) and the width of the channel pool (106) is substantially equal to the width of the heat sink (102).

The plurality of ribs (108) extend from a proximal end of the channel basin (106) attached along a longitudinal direction of fluid flow.

The plurality of walls surround the plurality of microchannels (104), with a top wall (110a) having an adiabatic surface connecting the plurality of microchannels (104) filled with the flowing liquid coolant, a bottom wall (110b) connecting the absorbs heat dissipated by the heat sink (102) and at least one sidewall (110c) provides the adiabatic surface area; and

The channel layer (112) is at the top of the channel pool (106) in a downstream direction and connects the plurality of microchannels (104) to the cooling liquids in the channel pool (106).

The heat sink (102) has a plurality of microchannels (104) with liquid passages extending parallel to each other to the channel sump (106), and the liquid coolant flows through the channel sump (106) connecting the plurality of parallel microchannels (104). and eliminating solid substrate walls in the channel sump (106). The cross section of the liquid coolant flow path through the plurality of microchannels (104) follows the geometry of the cross section of the channel basin (106).

The heat sink (102) has one, two or more layers. The heat sink (102) is thermally connected to a heat source. The heat sink (102) extends parallel to the extending direction of the liquid coolant flow path.

The device with the novel pool structure is suitable for the channel substrate made of silicon or other thermally conductive materials, and is compatible with a variety of cooling liquids such as air, water, nanofluids, etc. The pooled channel according to the invention can have a pooled channel at any point of the microchannel, regardless of the axial, transverse and vertical direction. The hydraulic and thermal performances of the heat sink can vary depending on the location of the canal pool. However, the present investigation is based on a microchannel heatsink, where the liquid pool and fins are placed downstream of the flow, replacing the walls of the substrate channel. The heat generated on the surface of the heat-generating component is dissipated via the micro-channels of the heat sink. Thus, the bottom wall of the heatsink is exposed to heat flow since the bottom of the heatsink is attached to the surface of the heat source of the circuitry.

2 shows a schematic representation of the present invention.

The parallel micro-channels filled with the flowing liquid are sealed by the adiabatic surface, called the top wall. The semiconductor substrate, mainly silicon, is treated as the frame of the heatsink that holds the parallel microchannels. The bottom wall absorbs the heat while the side wall serves as an adiabatic surface. The channel pool, which lies at the bottom of the channel layer in the direction of downstream flow, connects all cooling liquids of all microchannels in this pool area. At the bottom of the channel there are ribs attached along the longitudinal direction of the liquid flow.

3 shows a schematic layout of the microchannel heatsink with the geometric parameters of the channel basin and the rectangular fin.

The basin is defined by its length L _p and height H _p , where L _p = 2000 µm and H _p = 100 µm. The ribs have parameters of height (H _r ), width (W _r ), and length (L _r ). The design parameter height-to-length ratio (δ), defined by H _{r /} L _r , is varied for the three novel models, ie Case 1, Case 2 and Case 3. The values of the geometric parameters of the pelvis and ribs are given in Table 1 and Table 2 guided. In Table 1 and Table 2, H _c , W _c , and W _w represent the original liquid channel height and width and the silicon substrate wall thickness, respectively. Table 1: Dimensions of single-layer microchannel heat sinks and channel pools case H _c (µm) W _c (µm) W''p-in) Dimensions of the pool L _p (µm) H _p (µm) Case 0 (without pool and ribs) 200 100 200 - - Case 1, Case 2, Case 3 200 100 200 2000 100 Table 2: Dimensions of the rectangular ribs case H _r (µm) W _r (µm) L _r (µm) Dimensionless number δ case 1 50 100 50 1 case 2 100 100 50 2 case 3 200 100 50 4

The performance results of the present invention in the form of average values of the Nusselt number (Nu) and the heat transfer coefficient (h), the ratio of the Nusselt number (Nu), the ratio of the Fanning friction factor (f), the heat transfer improvement factor (η), etc determined by suitable and thorough numerical investigations.

4 shows a graphical representation of the pressure losses for case 0, case 1, case 2 and case 3 in relation to different Re. The pelvic channel allows for low pressure drop and low friction loss, but the presence of ribs in the pelvis introduces a little more friction. The fins increase the Nusselt number (Nu) and heat transfer coefficient (h) in exchange for high pressure drops. Therefore, case 2 and case 3 offer the heat sink a larger pressure drop compared to case 0. However, the heat sink, ie case 1, results in a lower pressure drop compared to the base heat sink due to the basin and short fin size. It is obvious that the presence of a channel pool results in a significantly lower pressure drop. The liquid coolant basin helps to avoid solid substrates or ribs inside the basin, which in turn reduces friction surfaces on the walls.

According to the results of the study, the pressure drop reduction for Case 1 is 9.55% at Re=172 versus the base heatsink with no pool or fins.

5 shows a graphical representation of the heat transfer coefficient (h) of all heatsink designs. It expresses the improvement of h for case 1, case 2 and case 3. Using basins and fins together in the heat sink results in a remarkable increase in h, indicating excellent heat transfer. All three cases of the design are capable of reaching an impressive amount of h at all Reynolds numbers. Case 3, with the largest δ of 4, shows the best h-parameter, showing the highest h-value of 39.97 kW/m ² K, which is an 80% increase over case 0.

6a-6b show a graphical representation of the comparison of performance parameters for case 1, case 2 and case 3: (a) changing Fanning's friction factor f/fo with Re, (b) changing Nu/Nuo with Re.

The parameter f/f ₀ changes differently for the two cases, with case 1 having a small f/f ₀ value of less than 1 at all Re, which means that the friction loss in the present invention of the heat sink of case 1 is lower is. This presentation of the data suggests that the channel pool has the obvious benefits in terms of low friction. The different f/f ₀ curves for Case 2 and Case 3 indicate that the dimensions of the rectangular ribs in the pool channel play a greater role in the effectiveness.

The basin along with the fins help improve heat transfer according to the Nu ratio. The height of the ribs has a significant impact on the Nu/Nuo parameter. the Nu/Nuo of case 3 reaches the maximum of 1.81 at Re=171, while the largest Nu/Nuo is 1.60 for case 2 at Re=170. It is apparent that the present invention exhibits higher Nu/Nuo in all Re ranges, regardless of rib size.

$$Nu={\text{hD}}_{\text{h}}/\text{k}$$

$$\text{h}={\text{Q}}_{\text{b}\text{,gesamt}}/\left[{\text{A}}_{\text{con}}\left({\text{T}}_{\text{b}\text{,av}}-{\text{T}}_{\text{av}}\right)\right]$$

The Fanning friction factor (f) and the Nusselt number (Nu) and the heat transfer coefficient (h) are calculated as follows, $$f=\frac{\mathrm{<figure-callout\; id="2"\; label="\Delta \; pD\; H"\; filenames="DE202022105382U1\_0008.png,DE202022105382U1\_0009.png"\; state="\{\{state\}\}">\Delta </figure-callout>}{\text{pD}}_{\text{H}}{}_{}}{2\mathrm{\rho }{\text{and}}^2\text{L}}$$

$$N\mathrm{and}={\text{hD}}_{\text{H}}/\text{k}$$

$$\text{H}={\text{Q}}_{\text{b}\text{,total}}/\left[{\text{A}}_{\text{con}}\left({\text{T}}_{\text{b}\text{,v}}-{\text{T}}_{\text{like}}\right)\right]$$

Δp, L, k stand for the pressure drop, the channel length and the thermal conductivity of the fluid. Q _b,total , A _con , T _b,av , T _av represent the total heat input at the bottom wall, the convective heat rejection area, the average bottom wall temperature, and the average channel fluid temperature, respectively.

7 shows a plot of the thermal performance factor η in relation to different Re for case 1, case 2 and case 3. The thermal performance factor or heat transfer improvement factor (η) is defined as: $$n=\left(N\mathrm{and}/N{\mathrm{and}}_0\right)/{\left(f/f_0\right)}^{\left(1/3\right)}$$

Where and are the Nusselt number and friction factor of the smooth-bottomed microchannel without pool and rib (case 0), respectively. The figure shows an interesting relationship between the heat transfer factor and Re. The apparent trend of η is that it varies with increasing Re and reaches its lowest value at the largest Re. From this it follows that a low flow rate or a lower Re is suitable to obtain the optimal performance parameter. The graph of this parameter underlines the impressive overall performance of the present novel heatsink design. The results show that the use of pool channels and fins always leads to an improvement in the Nusselt number (Nu) and the heat transfer improvement factor (η). The largest values of η are 1.61, 1.64, and 1.81 for case 1, case 2, and case 3, respectively, as achieved in the present invention, which directly show that the present invention is very appreciable.

The figures and the preceding description give examples of embodiments. Those skilled in the art will understand that one or more of the elements described may well be combined into a single functional element. Alternatively, certain elements can be broken down into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, the order of the processes described herein may be changed and is not limited to the manner described herein. Additionally, the actions of a flowchart need not be performed in the order shown; Also, not all actions have to be carried out. Also, those actions that are not dependent on other actions can be performed in parallel with the other actions. The scope of the embodiments is in no way limited by these specific examples. Numerous variations are possible, regardless of whether they are explicitly mentioned in the description or not, e.g. B. Differences in structure, dimensions and use of materials. The scope of the embodiments is at least as broad as indicated in the following claims.

Advantages, other benefits, and solutions to problems have been described above with respect to particular embodiments. However, the benefits, advantages, problem solutions, and components that can cause an advantage, benefit, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all claims.

Reference List

100

A microchannel heatsink device.

102

heat sink

104

A multitude of micro-channels

106

canal pool

108

A multitude of ribs

110a

top wall

110b

lower wall

110c

Side wall

112

gutter layer

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US 9513059 B2 [0003]
• JP 5296990 B2 [0004]

Claims (10)

A microchannel heat sink device (100), the device (100) comprising: a heat sink (102) having a distal end and a proximal end, a plurality of microchannels (104) extending from the heat sink; a channel pool (106) formed at the proximal end of the heat sink (102) connecting the plurality of microchannels; a plurality of ribs (108) extending from a proximal end of the channel basin (106) attached along a longitudinal direction of fluid flow; a plurality of walls surrounding the plurality of microchannels (104), a top wall (110a) having an adiabatic surface connecting the plurality of microchannels (104) filled with the flowing liquid coolant, a bottom wall (110b) the absorbs heat dissipated from the heat sink (102) and at least one sidewall (110c) provides the adiabatic surface area; and a channel layer (112) positioned at a top of the channel pool (106) in a direction of downstream flow connects the plurality of microchannels (104) to cooling liquids in the channel pool (106). device after claim 1 , where the length and width of the heatsink are essentially the same and are in the range of 5-15 mm. device after claim 1 , wherein the frame consists of a semiconductor substrate, preferably a silicon material, which encloses at least one surface of the heat sink (102) for receiving the plurality of microchannels (104). device after claim 1 wherein the liquid coolant flow channel has a geometric cross-section and is thermally connected to a heat source and extends parallel to the extending direction of the liquid coolant flow path. device after claim 1 , wherein the heat sink (102) has a plurality of microchannels (104) with liquid passages which extend parallel to one another to the channel sump (106), and the liquid coolant flows through the channel sump (106) which contains the plurality of parallel microchannels (104 ) connects and eliminates the solid substrate walls in the channel sump (106). device after claim 1 wherein the length of the channel pool (106) is less than half the length of the heat sink (102) and the width of the channel pool (106) is substantially equal to the width of the heat sink (102). device after claim 1 wherein the cross section of the liquid coolant flow path through the plurality of microchannels (104) follows the geometry of the cross section of the channel basin (106). device after claim 1 wherein the heat sink (102) is formed of single, double or multiple layers. device after claim 1 , wherein the heat sink (102) is thermally connected to a heat source. device after claim 1 wherein the heat sink (102) extends parallel to the extending direction of the liquid coolant flow path.

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