Evaporator assembly, vapor chamber, and method for manufacturing vapor chamber

Abstract

To provide a vaporizer assembly, a vapor chamber assembly, and a method for manufacturing a vapor chamber. In one embodiment, an evaporator assembly for a vapor chamber includes an evaporator face, an array of posts extending from the evaporator face, and an array of vapor vents in the evaporator face. Each vapor vent in the array of evaporative vents is configured as a recess in the evaporator face. The evaporator assembly further includes a porous layer disposed on the evaporative face, the array of posts, and the array of vapor vents.

Description

[Technical Field]

[0001] The present application relates generally to vapor chambers, and more particularly to vapor chambers with low thermal resistance and high heat dissipation. [Background technology]

[0002] Heat-generating equipment such as motors, power electronics, and microprocessors generate large amounts of heat that must be removed to allow the equipment to operate below its maximum operating temperature. As power demands increase and the size of heat-generating components decreases, removing heat flux from the equipment becomes a challenge.

[0003] Therefore, alternative cooling devices are needed to remove heat flux from heat generating equipment. Summary of the Invention

[0004] In one embodiment, an evaporator assembly for a vapor chamber includes an evaporator face, an array of posts extending from the evaporator face, and an array of vapor vents in the evaporator face. Each vapor vent in the array of vapor vents is configured as a recess in the evaporator face. The evaporator assembly further includes a porous layer disposed on the evaporator face, the array of posts, and the array of vapor vents.

[0005] In another embodiment, an assembly includes an evaporator assembly and a condenser plate. The evaporator assembly includes an evaporator face, an array of posts extending from the evaporator face, and an array of vapor vents in the evaporator face. Each vapor vent in the array of vapor vents is configured as a recess in the evaporator face. The evaporator assembly further includes a porous layer disposed on the evaporator face, the array of posts, and the array of vapor vents. The condenser plate includes a condensing surface, the condensing surface bonded to a top surface of the array of posts such that the evaporator assembly and the condenser plate define a vapor chamber.

[0006] In yet another embodiment, a method for manufacturing a vapor chamber includes forming an array of posts and an array of vents on an evaporator surface, applying a metal powder including metal particles to the evaporator surface, the array of posts, and the array of vents, sintering the metal powder to form a porous layer, and bonding a condensing surface of a condenser plate to the top surface of the array of posts.

[0007] These and additional features presented by the embodiments described herein can be better understood from the following detailed description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0008] The embodiments illustrated in the drawings are illustrative and exemplary in nature and are not intended to limit the subject matter defined in the claims. The following detailed description of exemplary embodiments will be best understood when read in conjunction with the accompanying drawings, in which like structure is designated with like reference numerals.

[0009] [Figure 1A] 1 is a schematic top perspective view of an example evaporator assembly having an evaporator face with an array of posts and an array of vents according to one or more embodiments described and illustrated herein. FIG. [Figure 1B] 1B is a schematic top perspective view of an example post of the evaporator assembly of FIG. 1A. FIG. [Figure 2] FIG. 2 is a schematic bottom perspective view of an example condenser plate having a condensing surface according to one or more embodiments described and illustrated herein. [Figure 3] 1 is a schematic cross-sectional view of a vapor chamber according to one or more embodiments described and illustrated herein. [Figure 4] FIG. 1 is a schematic diagram of an example evaporator surface having an array of posts and an array of steam vents, where the distance between adjacent posts and the distance between adjacent steam vents varies across the evaporator surface, according to one or more embodiments described and illustrated herein. [Figure 5]FIG. 1 is a schematic diagram of an example evaporator surface having an array of posts and an array of steam vents, where the size of the individual posts and the size of the individual steam vents vary across the evaporator surface, according to one or more embodiments described and illustrated herein. [Figure 6] FIG. 10 is a schematic diagram illustrating plots of total thermal resistance with power variation for four different vapor chamber designs, according to one or more embodiments described and illustrated herein. [Figure 7] 7A-7C are schematic diagrams illustrating plots of heater temperature with power variation for the four different vapor chamber designs of FIG. 6, according to one or more embodiments described and illustrated herein. [Figure 8] FIG. 7 is a schematic diagram illustrating plots of through-plane thermal resistance with power variation for the four different vapor chamber designs of FIG. 6, according to one or more embodiments described and illustrated herein. [Figure 9] FIG. 1 is a flowchart of an example method for manufacturing a vapor chamber according to one or more embodiments described and illustrated herein. DETAILED DESCRIPTION OF THE INVENTION

[0010] With reference to the accompanying drawings, embodiments of the present disclosure relate to a cooling device configured as a vapor chamber for removing heat flux from heat-generating equipment, such as electronic devices. Electronic devices, such as microprocessors and power electronic switching devices ("power electronic devices"), generate large amounts of heat that must be removed to maintain the electronic devices below their maximum operating temperature. Electronic devices operating above their maximum operating temperature are at risk of failure. The cooling device can be used to remove heat flux to maintain the electronic device (or other heat-generating equipment, such as a motor) below its maximum operating temperature.

[0011] In electrified vehicles, wide bandgap (WBG) devices such as silicon carbide can replace traditional silicon-based power semiconductors due to their low power loss and high efficiency. Furthermore, WBG devices can withstand higher heat fluxes (e.g., 1 kW / cm 2 The WBG devices operate at high temperatures above 473 K, dissipating heat (higher than 1000 W). The high temperature operation of the WBG devices provides a larger thermal budget for designing lower-cost and more compact cooling systems, such as air cooling. To achieve a compact and high-performance air cooling system, the transfer of heat from the heat source to the heat sink plays a major role.

[0012] A vapor chamber is a cooling device that removes heat flux by changing the phase of the cooling fluid from liquid to gas. Typically, a vapor chamber is a closed system in which a liquid cooling fluid resides on an evaporator surface that receives heat flux from a heat-generating device. When the temperature of this cooling fluid rises to its boiling point, it evaporates into a gas that migrates toward the condenser surface. The condenser surface is cooler than the evaporator surface, lowering the temperature of the gas and causing it to condense into a liquid that returns to the evaporator surface. In some cases, a wicking structure can be provided to allow the cooling fluid to migrate toward the evaporator surface by capillary action. Conventionally, vapor chamber heat spreaders are used to efficiently spread heat, but their performance is limited to approximately 500 W / cm in a 1 cm x 1 cm area. 2 The heat flux is limited to less than

[0013] A major problem with vapor chambers is the phenomenon of dryout. Dryout occurs when the power of the heat-generating equipment raises the temperature to such a point that the coolant cannot return to the evaporator surface quickly enough to cool the heat-generating equipment. In effect, the evaporator surface "dries out" due to the complete absence of coolant. This causes the temperature of the heat-generating equipment to rise above its maximum operating temperature.

[0014] Embodiments of the present disclosure provide a more efficient vapor chamber that significantly increases the vapor chamber's dryout temperature and therefore the maximum operating power of the heat-generating device. In embodiments of the present disclosure, an array of porous posts connects the evaporator surface with the condenser surface to provide a wicking path for condensed coolant to return from the condenser surface to the evaporator surface. Additionally, an array of vapor vents is positioned within the evaporator surface to allow additional nucleation sites and more efficient evaporation of the coolant. The combination of the array of posts and the array of vapor vents allows the heat-generating device to operate at higher temperatures with minimal risk of dryout, including, but not limited to, operating at powers greater than 600 W. Furthermore, the vapor chambers of the embodiments described herein provide low thermal resistance. In particular, the tested vapor chamber of the embodiments described herein achieved the highest heat flux of 589 W / cm among all vapor chamber designs evaluated. 2 to provide a minimum total thermal resistance of 0.28K / W.

[0015] Various embodiments of the vaporizer assembly, the power electronics assembly, and the method of manufacturing the vapor chamber are described in detail below.

[0016] 1A , a schematic diagram of an example evaporator assembly 110 that can be used with a condenser plate to form a vapor chamber is shown. The evaporator assembly 110 is configured as an evaporator plate having an evaporator surface 111 and a heat-receiving surface 117. The evaporator assembly 110 is fabricated from a thermally conductive material, such as, but not limited to, copper. The heat-receiving surface 117 receives a heat-receiving device (not shown), such as a power electronic device. The power electronic device can be a power switching device, such as a metal-oxide semiconductor field-effect power transistor (MOSFET), a power transistor, a power insulated gate bipolar transistor (IGBT), or the like. The power electronic device can be a WBG device, including, but not limited to, silicon carbide. It should be understood that embodiments are not limited to electronic devices or heat-generating devices.

[0017] The example evaporator assembly 110 includes a peripheral surface 116 that surrounds the evaporator face 116. As described in more detail below, the peripheral surface 116 can be bonded to the peripheral surface of a condenser plate to form a vapor chamber. The evaporator assembly 110 further includes an input port 118 for providing a cooling fluid to the vapor chamber. The input port 118 can include a valve to close the vapor chamber during operation, thereby providing a closed system.

[0018] The evaporator surface 111 is offset from the peripheral surface 116 in the negative coordinate normal (i.e., the negative z-axis direction) so as to form a vapor chamber when the evaporator assembly 110 is coupled to a condenser plate. In this example, the evaporator assembly 110 further includes a porous peripheral ledge 115 configured to receive the porous condenser surface of the condenser plate. It should be appreciated that in other embodiments, the peripheral ledge is not provided. Instead, the entire peripheral wall is porous without a ledge.

[0019] The example evaporator assembly 110 includes an array of posts 112 extending from an evaporator surface 111. As described in more detail below, the array of posts 112 provides a wicking path for condensed coolant to return to the evaporator surface 111. The array of posts 112 is defined by a plurality of columns and a plurality of rows. Individual posts 112 in adjacent columns are offset from one another along the x-axis by an offset distance d1. Individual posts 112 in adjacent rows are offset from one another along the y-axis by an offset distance d2. Distances d1 and d2 are determined according to the overall dimensions of the cooling device, without being limited by this disclosure.

[0020] The posts 112 are shown as cylindrical, although embodiments are not so limited. For example, the posts 112 can be configured as prisms or other cross-sectional shapes. Embodiments are further not limited by the size of the posts. By way of non-limiting example, in cylindrical embodiments, the diameter of the posts 112 can be 0.5 mm to 3 mm, 1 mm to 1.5 mm, or 1 mm. It should be understood that the diameter can be other values ​​depending on the overall size of the cooling device. Furthermore, the height of the array of posts 112 is not limited by this disclosure. Non-limiting heights include 0.5 mm to 5 mm, 1 mm to 4 mm, 1.5 mm to 3 mm, or 2.5 mm. It should be understood that other heights can be utilized.

[0021] The evaporator surface 111 further includes an array of vapor vents 114, which are recessed in the negative z-axis direction within the evaporator surface 111. As described in more detail below, the array of vapor vents 114 increases the efficiency of the vapor chamber, allowing for high heat flux dissipation without dryout. The size and shape of the vapor vents 114 are not limited by this disclosure. In the illustrated embodiment, the individual vapor vents 114 are circular. However, embodiments are not limited to vapor vents 114 having a circular shape; other shapes are possible, such as rectangular, oval, triangular, or any shape. By way of non-limiting example, the diameter of the individual vapor vents 114 can be 0.25 mm to 2 mm, 0.5 mm to 1.5 mm, or 1 mm. Other diameters can be utilized depending on the overall size of the cooling device. Non-limiting depths of the individual vapor vents 114 include 0.1 mm to 1 mm, 0.25 mm to 0.75 mm, or 0.5 mm. It should be appreciated that other depths can be used.

[0022] Individual steam vents 114 in adjacent columns are offset from one another along the x-axis by an offset distance d3. Individual steam vents 114 in adjacent rows are offset from one another along the y-axis by an offset distance d4. The values ​​of distances d3 and d4 are not limited by this disclosure and are dependent on the overall dimensions of the cooling device. The array of posts 112 and the array of steam vents 114 are interwoven. Thus, the array of posts 112 and the array of steam vents 114 define a structural array, with each column of the structural array comprising alternating individual posts and individual steam vents and each row of the structural array comprising alternating individual posts and individual steam vents. Each individual steam vent 114 is surrounded by four individual posts 112.

[0023] The distiller assembly 110 further includes a porous layer 119 disposed over the evaporator surface 111, the array of posts 112, and the array of vapor vents 114. The porous layer 119 has a plurality of pores that act as a wicking structure to return liquid cooling fluid to the evaporator layer 111. The thickness of the porous layer 119 defines the dimensions of the array of posts 112 and the array of vapor vents 114 described above.

[0024] FIG. 1B shows an enlarged view of a post. Each individual post 112 in the array of posts 112 can be configured as a pin 113 (e.g., pin fin) coated with a porous layer 119. Thus, the post 112 is formed with a core that is a solid pin 113 and an outer porous layer. The pin can be formed by any known or later-developed process, including, but not limited to, machining or chemical etching. For example, the array of posts 112 can include an array of smaller diameter pin fins, with the porous layer 119 surrounding the array of pins 113 setting the overall diameter of the array of posts 112. As a non-limiting example, each pin 113 can have a diameter of 0.5 mm, and the porous layer 119 can have a thickness of 0.5 mm, setting a diameter of 1 mm for each post 112. The thickness of the porous layer 119 is not limited by this disclosure. By way of non-limiting example, the thickness of the porous layer 119 can be between 0.2 mm and 1 mm, between 0.25 mm and 1 mm, or 0.5 mm. It should be understood that other thicknesses can be used.

[0025] In some embodiments, the porous layer 119 can be fabricated by applying a powder containing metal particles, such as copper particles. The size of the metal particles determines the size of the pores within the porous layer 119. By way of non-limiting example, the metal particles can have a diameter of 60-120 μm. After application of the powder of metal particles, the metal particles are sintered to form the porous layer 119 by raising the temperature of the evaporator assembly 110 above the sintering temperature of the metal particles (e.g., 750° C.-1000° C. for copper particles).

[0026] 2 shows a condenser plate 120 having a condenser surface 122 and a cooling surface 125. The condenser surface 122 can be surrounded by a condenser peripheral surface 124 that is configured to be coupled to or in contact with the peripheral surface 116 of the evaporator assembly 110. The condenser surface 122 can be formed by a porous layer extending from the condenser peripheral surface 124. The condenser surface 122 can also be formed by sintering metal particles (e.g., copper particles) as described above. The condenser surface 122 has a width, height, and depth that fits within the peripheral surface 116 of the evaporator assembly 110.

[0027] In forming the vapor chamber, the condenser face 122 is positioned over the array of posts 112 and the porous peripheral ledge 115 (if installed). After placing the condenser plate 120 on the evaporator assembly 110, the two components are bonded together, such as by diffusion bonding. The bond between these two components defines a vapor chamber that can then be filled with a cooling fluid.

[0028] 3 is a cross-sectional view of an example assembly 100 including a cooling device 101 with a vapor chamber 128, a heat-generating device 130, and a heat sink 140. FIG. 3 is a simplified view for illustrative purposes. Notably, the illustrated array includes only two posts 112 and three vapor vents 114. It should be understood that arrays of cooling devices 101 disclosed herein may include many additional posts 112 and vapor vents 114.

[0029] 3, the posts 112 include pin fins 113 surrounded by a porous layer 119. As mentioned above, the pin fins 113 can be formed by machining or chemically etching the evaporator surface 111. Having posts 112 with solid pin fin 113 cores reduces the thermal resistance between the condenser plate 120 and the evaporator assembly 110 compared to posts fabricated solely from a porous layer, further improving vapor chamber performance.

[0030] After the vapor chamber 128 is sealed by bonding the condenser plate 120 to the evaporator assembly 110, cooling fluid is introduced into the vapor chamber 128 through the input port (FIG. 1A) 118. During operation, a heat-generating device 130, such as a power electronic device, emits a heat flux. The cooling liquid on the evaporator surface 111 and in the porous layer 119 receives the heat flux and increases in temperature above its boiling point. The cooling liquid begins to boil and changes phase from liquid to vapor. The pores in the porous layer 119 provide nucleation sites for efficient boiling. The cooling vapor rises toward the condenser surface 122, as indicated by arrow A.

[0031] A heat sink 140 is attached to the cooling surface 125 of the condenser plate 120. The heat sink 140 can be any cooling device, such as a finned heat sink, a heat spreader, a liquid cooling device, and the like. The heat sink 140 condenses the heat flux from the condenser plate 120 to cool the cooling vapor so that the cooling fluid condenses back into a liquid. The porous condenser surface 122 and porous posts 112 suck the condensed liquid coolant back toward the evaporator surface 111, as shown by arrow B, where it is reheated and turned into a vapor.

[0032] The vapor vent 114 reduces the resistance to vapor escape from the evaporator surface 111. The vapor vent 114 provides an easier location for nucleated bubbles to escape from the porous layer 119 of the evaporator surface 111. Thus, the vapor vent 114 allows vapor to vent toward the condenser surface 122.

[0033] The size, shape, and / or density of posts 112 and / or steam vents 114 may vary across the evaporator surface 111 to address localized hot spots. For example, the size, shape, and / or density of posts 112 and / or steam vents 114 immediately above the heat-generating equipment 130 may be different from the size, shape, and / or density of posts 112 and / or steam vents 114 away from the heat-generating equipment 130. The size, shape, and / or density of posts 112 and / or steam vents 114 may vary arbitrarily across the evaporator surface 111.

[0034] 4 is a partial view of an example evaporator face 211, where adjacent centrally located posts 212 have a spacing dp1 and adjacent centrally located steam vents 214 have a spacing dv1. However, adjacent posts 212 closer to the periphery of the evaporator face 211 have a spacing dp2, and adjacent steam vents 214 closer to the periphery of the evaporator face 211 have a spacing dv2. In the example shown, dp1 is greater than dp2, and dv1 is greater than dv2. By way of example, the density of posts 212 and steam vents 214 may be greater immediately above the heat-generating equipment than in an area outside the heat-generating equipment.

[0035] 5 is a partial view of an example evaporator face 311 with varying sizes of posts 312 and vapor vents 314. Centrally adjacent posts 312 have a diameter dia. p1 and the centrally adjacent steam vents 314 have a diameter dia. v1 However, adjacent posts 312 near the periphery of the evaporator surface 311 have a diameter dia. p2 and adjacent steam vents 314 near the periphery of the evaporator face have a diameter dia. v2 In the illustrated example, dia p1 Dia p2 Larger, dia v1 Dia v2 In other embodiments, dia p1 Dia p2 Smaller diameter v1 Dia v2 Smaller than.

[0036] To assess the performance of the vapor chamber, two sets of experiments were conducted. One experiment measured the total thermal resistance of the vapor chamber during an air-cooling test, while the second extracted the in-plane thermal resistance of the vapor chamber itself. As shown in Figure 1A, a vapor chamber was fabricated with machined posts approximately 1.5 mm in diameter and 2.4 mm in height with a porous layer and a 1 mm diameter, 0.5 mm deep vapor vent. Three comparative vapor chamber examples were also fabricated. The first comparative vapor chamber contains a single-layer evaporator surface without posts or vapor vents. The second comparative vapor chamber contains 1.5 mm diameter, 2.4 mm high posts (non-solid pin fins) made only from the porous layer material and does not contain a vapor vent. The third comparative vapor chamber contains posts made of 0.5 mm diameter, 2.4 mm high pin fins surrounded by a porous layer to form posts measuring 1 mm in diameter and 2.4 mm in height. The third comparative vapor chamber does not contain a vapor vent.

[0037] The changes in thermal resistance and heater temperature with input power are shown in Figures 6 and 7, respectively. Trace 401 is the first comparative example, trace 402 is the second comparative example, trace 403 is the third comparative example, and trace 404 is the vapor chamber with posts and vapor vents. As shown in Figure 6, the thermal resistance trends for each vapor chamber are very similar. That is, the thermal resistance is high at low power (<100 W), decreases as the onset of nucleate boiling (ONB) is reached, and remains almost constant in the nucleate boiling region. When the input power is below 100 W, the first comparative example (i.e., the single-layer vapor chamber) has a lower thermal resistance than the second comparative example (i.e., the vapor chamber with sintered posts) and the third comparative example (i.e., the vapor chamber with machined posts). However, in the boiling region at input powers greater than 300 W, the thermal resistance of the first comparative example is higher than that of the post-equipped design.

[0038] The thermal resistance of the vapor chamber with machined posts (trace 403) is slightly lower than the sintered post design (trace 402) throughout the power range. For example, at an input power of 110 W, the thermal resistance of the vapor chamber with machined posts (trace 403) is approximately 6% lower than the vapor chamber with sintered posts (trace 402), and 11% lower at a high input power of 450 W.

[0039] Among all vapor chamber designs, the vapor chamber with machined posts and vents according to the present disclosure (trace 404) has the lowest thermal resistance across the entire range of input power. Unlike the trends of the other vapor chambers, the thermal resistance of the machined posts and vents vapor chamber (trace 404) does not plateau in the boiling region, but continues to decrease until it reaches the maximum capacity of the power supply.

[0040] Furthermore, the single-layer vapor chamber (trace 401) reached dryout (DO) at an input power of 467 W. Dryout was observed as a linear increase in transient heater temperature without reaching steady state. The remaining vapor chamber designs did not exhibit this dryout phenomenon. The maximum power dissipated by the sintered post (trace 402) and machined post designs (trace 403) was 450 W and 447 W, respectively. The test was stopped because the heater temperature exceeded the maximum allowable temperature of 478°C. In the case of the machined post + vent vapor chamber (404), the test was stopped because the input power supply reached its maximum capacity.

[0041] The change in heater temperature with input power is shown in Figure 7. The vapor chambers with sintered posts (trace 502) and machined posts (trace 503) show a linear increase in temperature with power until reaching an ONB power of approximately 100 W. Unlike the vapor chambers with sintered posts and machined posts, the ONB point for the vapor chambers with single layer (trace 501) and machined posts and vents (trace 504) is not clearly observable in Figure 7. Furthermore, the rate of increase in heater temperature for the machined post and vented vapor chamber begins to decrease between 300 W and 400 W (as seen in trace 504), after which the heater temperature increases linearly. The machined post and vented vapor chamber can dissipate significantly more power than other designs for the same heater temperature. For example, at a heater temperature of 473 °C, the machined post and vented vapor chamber dissipates 30% more power than the single layer vapor chamber (trace 501).

[0042] The change in the thermal resistance of the vapor chambers as a function of input power is shown in Figure 8. The single-layer vapor chamber (trace 601) has a generally higher thermal resistance compared to the post-type design. The vapor chambers with sintered posts (trace 602) and machined posts (trace 603) have slightly higher thermal resistance than the single-layer design at low power levels below 50 W. At input powers of approximately 98 W and 93 W, ONB is observed in the vapor chambers with sintered posts (trace 602) and machined posts (trace 603), respectively. At ONB power, the thermal resistance of both vapor chambers drops dramatically, almost by half.

[0043] The machined-post + vent vapor chamber (trace 604) has the lowest surface thermal resistance across the entire power range. For example, at input powers of 110 W and 559 W, the surface thermal resistances of the machined-post + vent vapor chamber are 0.18 K / W and 0.27 K / W, respectively. At powers higher than ONB power, the thermal resistance of all vapor chambers increases linearly with input power. Of all vapor chambers tested, only the single-layer vapor chamber (trace 601) reached dryout (DO) at an input power of 457 W. The maximum power dissipated by the remaining vapor chamber designs was limited by the maximum current capacity of the power supply (~10 A), so testing was terminated. The maximum power dissipated by the machined-post + vent vapor chamber (trace 604) was 589 W.

[0044] 9 is a flowchart 700 illustrating an example method for fabricating a vapor chamber. In block 702, an array of posts and an array of vents are formed on the evaporator surface of the evaporator plate. The array of posts and the array of vents can be fabricated, for example, by machining. As another example, the array of posts and the array of vents can be fabricated by chemical etching. For example, if the evaporator surface is made of copper, a mask can be placed over the evaporator surface and a chemical etchant, such as ferric chloride, can be applied to form the desired array of posts and array of vents.

[0045] At block 704, a metal powder containing metal particles is applied to the evaporation surface, the array of posts, and the array of vents. The metal particles may include, for example, copper particles. At block 706, the metal powder is sintered to form a porous layer around the evaporator surface, the array of posts, and the array of vents. The porous layer provides both enhanced nucleation sites and a wicking structure for returning coolant to the evaporator surface and the array of vents.

[0046] At block 708, the porous condenser surface of the condenser plate is positioned on top of the array of posts, thereby defining a vapor chamber between the condenser surface and the evaporator surface. Finally, at block 710, the condenser surface is bonded to the top surface of the array of posts. As a non-limiting example, the condenser surface is bonded to the top surface of the array of posts by a diffusion bonding process.

[0047] It should be appreciated that embodiments of the present disclosure relate to a vapor chamber having an evaporator surface with an array of posts and an array of vapor vents. Each post includes a solid core surrounded by a porous layer. The solid core, which may be provided by pin fins, lowers the thermal resistance between the condenser surface and the evaporator surface. The array of vents provides paths for easy vapor escape as well as additional nucleation sites for vapor. The vapor chambers described herein have low thermal resistance and high dryout temperatures. Vapor chambers can be utilized to cool power electronic devices, such as wide bandgap power electronic devices that generate large heat fluxes, such as those used in inverter circuits for electric or hybrid-electric vehicles.

[0048] While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications can be made without departing from the spirit and scope of the claims. Moreover, although various forms of the claims have been described herein, these forms do not necessarily come into use in combination. Accordingly, the claims are intended to cover all changes and modifications that fall within the scope of the claims.

Claims

1. 1. A vaporizer assembly for a vapor chamber, comprising: an evaporator surface; an array of posts extending from the evaporator surface; an array of steam vents in the evaporator face, each steam vent in the array of steam vents configured as a recess in the evaporator face; a porous layer disposed on the evaporator surface, the array of posts, and the array of vapor vents; An evaporator assembly comprising:

2. The evaporator assembly of claim 1 , wherein the array of posts is interwoven with the array of vapor vents.

3. the spacing between adjacent posts of the array of posts varies across the evaporator surface; the spacing between adjacent vapor vents in the array of vapor vents varies across the evaporator surface; The evaporator assembly of claim 1 .

4. 10. The evaporator assembly of claim 1, wherein at least one of a size and a shape of individual vapor vents in the array of vapor vents varies across the evaporator face.

5. 2. The evaporator assembly of claim 1, wherein the porous layer has a thickness of 0.20 mm to 1 mm including the end points.

6. 10. The evaporator assembly of claim 1, wherein the depth of the individual vapor vents varies across the evaporator face.

7. 2. The evaporator assembly of claim 1, wherein the array of posts and the array of vapor vents define a structural array, each row of the structural array comprising alternating individual posts and individual vents.

8. 1. An assembly comprising an evaporator assembly and a condenser plate, The evaporator assembly includes: an evaporator surface; an array of posts extending from the evaporator surface; an array of steam vents in the evaporator face, each steam vent in the array of steam vents configured as a recess in the evaporator face; a porous layer disposed on the evaporator surface, the array of posts, and the array of vapor vents; Equipped with The condenser plate includes a condenser surface, the condenser surface being bonded to an upper surface of the array of posts such that the evaporator assembly and the condenser plate define a vapor chamber.

9. the evaporator surface is provided on an evaporator plate further comprising a heat receiving surface; The assembly further comprises an electronic device coupled to the heat receiving surface.

9. The assembly of claim 8.

10. the condenser surface is provided on a condenser plate further comprising a cooling surface; The assembly further comprises a heat sink coupled to the cooling surface.

10. The assembly of claim 9.

11. The assembly of claim 8 , wherein the array of posts interweaves within the array of vapor vents.

12. the spacing between adjacent posts of the array of posts varies across the evaporator surface; the spacing between adjacent vapor vents in the array of vapor vents varies across the evaporator surface; 9. The assembly of claim 8.

13. The assembly of claim 8 , wherein at least one of a size and a shape of individual vapor vents in the array of vapor vents varies across the evaporator face.

14. The assembly of claim 8, wherein the porous layer has a thickness of 0.20 mm to 1 mm including the endpoints.

15. The assembly of claim 8 , wherein the depth of the individual vapor vents varies across the evaporator face.

16. 9. The assembly of claim 8, wherein the array of posts and the array of vapor vents define a structural array, each row of the structural array comprising alternating individual posts and individual vents.

17. 1. A method for manufacturing a vapor chamber, comprising: forming an array of posts and an array of vents on the evaporator surface; applying a metal powder comprising metal particles to the evaporator surface, the array of posts, and the array of vents; sintering the metal powder to form a porous layer; bonding a condenser surface of a condenser plate to a top surface of the array of posts; A method comprising:

18. 20. The method of claim 17, wherein forming the array of posts and the array of vents is performed by machining.

19. The method of claim 17 , wherein bonding the condenser surface of the condenser plate to the top surface of the array of posts is performed by diffusion bonding.

20. 18. The method of claim 17, wherein the metal powder comprises copper particles having diameters ranging from 60 μm to 120 μm in diameter, including the endpoints.

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