Patent Description:
It is known in the art to arrange a vapor chamber accommodating a liquid on an electronic component such that heat, which is generated during operation of the electronic component, is dissipated from the electronic component to the vapor chamber. The thermal energy corresponding to the heat causes the liquid in the vapor chamber to become vaporized, wherein the energy is "stored" in the corresponding vapor is transferred from a hot side of the vapor chamber, which is connected to the electronic component, to the cold side of the vapor chamber. At the cold side the vapor condenses and transfers the stored energy as thermal energy to the cold side such that the cold side is heated, while the condensed liquid is transferred back to the hot side of the vapor chamber. The heat is dissipated to the surroundings at the outside of the cold side of the vapor chamber and in the result the electronic component is cooled very efficiently.

Conventional <NUM>-dimensional vapor chambers are composed of a solid top cover, a solid bottom cover, a porous top wick structure, a porous bottom wick structure, solid pillars, and annulus porous pillars. The top cover and the bottom cover form a vapor cavity, in which the porous top wick structure, the porous bottom wick structure, and the solid pillars are arranged. The porous top wick structure is arranged at the top cover and the porous bottom wick structure is arranged at the bottom cover. The solid pillars are embedded in and surrounded by the annulus porous pillars and these combined pillars are arranged in recesses of the wick structures such that the combined pillars extend from the bottom cover through the recesses to the top cover. The solid pillars are arranged for providing mechanical strength to the vapor chamber. The annulus porous pillars and the porous wick structures are provided for distributing the liquid in the vapor cavity.

Standard manufacturing methods for vapor chambers are e.g. powder sintering or diffusion bonding. These manufacturing methods allow the use of cylindrical and annulus pillars only, in order to be of economic value. This constraint has the shortcomings that the cylindrical solid pillars provide structural strength limited to the contact area with the solid covers only and that the annulus porous pillars provide a limited flow rate of the liquid from the cold side to the hot side due the high flow resistance of the corresponding porous structures. Therefore, the structural strength and the cooling efficiency of the vapor chamber are limited.

<CIT> describes a manufacturing method of a vapor chamber. The method includes preparing an upper metal case and a plurality of hollow metal members, and forming an inner wall on the upper metal case. Each of the hollow metal members is fastened on the inner wall. A capillary structure is filled in the hollow metal member thereby forming a plurality of support posts. The capillary structure may be a metal woven net, fiber bundles or metal powders which are respectively filled in the interior of each of the hollow metal members thereby forming the plurality of support posts, and each of the support posts may be composed of one of the hollow metal members and one of the capillary structures filled in the hollow metal member.

Therefore it is an object of the present invention to provide a vapor chamber for cooling an electronic component, having an improved structural strength and an improved cooling efficiency.

It is another object of the present invention to provide an electronic arrangement which may be operated very efficiently.

It is another object of the present invention to provide a method for manufacturing a vapor chamber for cooling an electronic component, which contributes to that that the vapor chamber has an improved structural strength and an improved cooling efficiency and that the vapor chamber may be manufactured at relative low costs.

These objects are achieved by the subject-matter of the independent claims. Further exemplary embodiments are evident from the dependent claims and the following description.

According to an aspect a vapor chamber for cooling an electronic component is provided. The vapor chamber comprises: a bottom cover for receiving waste heat from the electronic component; a top cover, which is arranged on the bottom cover, wherein the bottom cover and the top cover are formed such that a vapor cavity for accommodating a liquid is formed between the bottom cover and the top cover; a crate element for providing mechanical strength to the vapor chamber, wherein the crate element has at least one compartment, which is formed by at least three side panels being connected to each other and extending from the bottom cover to the top cover, and a top recess facing the top cover and a bottom recess facing the bottom cover; and at least one porous pillar for transferring the liquid from the top cover to the bottom cover, wherein the porous pillar is arranged in the compartment and extends from the bottom cover through the bottom recess and the top recess to the top cover.

The crate element and the porous pillar form a support structure of the vapor chamber. The crate element, in particular the side panels of the crate element enclosing the compartment, contribute to that that a support area, in which the covers are supported by the support structure, can be made relative large compared to the prior art such that structural strength of the vapor chamber is improved. In addition, less material is necessary for forming the crate element than for forming the solid pillars of the prior art such that the crate element allows for a more optimal material utilization.

During normal usage of the vapor chamber a liquid is arranged in the vapor cavity of the vapor chamber. The vapor cavity may be sealed such that a fixed amount of the liquid stays in the vapor cavity. Alternatively, the vapor chamber may comprise an intake and/or a drain communicating with the vapor cavity for exchanging the liquid.

When the vapor chamber is used to cool the electronic component, the vapor chamber is preferably arranged on the electronic component, with the bottom cover being in thermal contact with the electronic component. In this context, the vapor chamber may be referred to as heat-transfer device. When heat is generated by the electronic component and is dissipated to the bottom cover of the vapor chamber, the temperature of the bottom cover is increased such that the bottom cover forms the hot side of the vapor chamber. Then, the liquid in the vapor cavity gets vaporized by the thermal energy of the heat, wherein the thermal energy is "stored" in the vapor because of its aggregation state. The vapor transfers the energy from the hot side of the vapor chamber to the cold side of the vapor chamber, i.e. the top cover. In particular, the vapor transfers the energy to the top cover of the vapor chamber while its aggregation state changes again, wherein the vapor condenses at least in part, and the corresponding the liquid is lead back to the hot side, i.e. the bottom cover, at least in part by the porous pillars. In particular, the purpose of the porous pillars is to ensure an homogeneous flow of the liquid throughout the vapor chamber and to provide the capillary pumping necessary to keep the internal fluid circulation independently of gravity.

A cross section of the crate element may be circular or polygonal, e.g. triangle-shaped, rectangle-shaped, square-shaped, etc. In this description, the term "cross section" always refers to a cross section, which is parallel to the bottom or top cover and/or perpendicular to the extension of the porous pillars.

A cross section of the compartment may be polygonal, e.g. triangle-shaped, rectangle-shaped, square-shaped, etc..

A cross section of the porous pillar may be circular or polygonal, e.g. triangle-shaped, rectangle-shaped, square-shaped, etc..

A cross section area of the porous pillar is smaller than a cross section area of the compartment such that an open channel for guiding the liquid from the top cover to the bottom cover is formed between the porous pillar and at least one of the side panels of the compartment. The open channel contributes to a very efficient transfer of the liquid from the hot side to the cold side of the vapor chamber. In other words, the purpose of this empty open channel is to allow a free circulation of the liquid from the cold to the hot side of the vapor chamber. This allows an increased flow rate of the liquid, i.e. a high permeability, compared to the prior art, because the pressure drop through the empty open channel is negligible compared to that through the porous pillars.

According to one or more embodiments, at least one of the side panels has a side recess. For example, each side panel may have a side recess. The side recesses may be referred to as through cut-outs and/or may be formed polygonal, e.g. prism-shaped, or circular. These recesses decrease the material needed for the crate element and as such for the support structure and the vapor chamber, improve an overall mechanical resistance and decrease the weight of the support structure and as such of the vapor chamber.

According to an aspect a vapor chamber for cooling an electronic component is provided. The vapor chamber comprises: a bottom cover for receiving waste heat from the electronic component; a top cover, which is arranged on the bottom cover, wherein the bottom cover and the top cover are formed such that a vapor cavity for accommodating a liquid is formed between the bottom cover and the top cover; a crate element for providing mechanical strength to the vapor chamber, wherein the crate element has at least one compartment, which is formed by at least three side panels being connected to each other and extending from the bottom cover to the top cover, and a top recess facing the top cover and a bottom recess facing the bottom cover; and at least one porous pillar for transferring the liquid from the top cover to the bottom cover, wherein the porous pillar is arranged in the compartment and extends from the bottom cover through the bottom recess and the top recess to the top cover, wherein at least one of the side panels has a side recess.

According to one or more embodiments, a cross section area of the porous pillar is smaller than a cross section area of the compartment such that an open channel for guiding the liquid from the top cover to the bottom cover is formed between the porous pillar and at least one of the side panels of the compartment.

According to one or more embodiments, the porous pillar is arranged at at least one of the side panels. In particular, the porous pillar may be in direct contact with the corresponding side panel. For example, one edge or side surface of the porous pillar is fixedly connected to an inner wall of the compartment of the crate element, i.e. the surface of the corresponding side panel facing the porous pillar. Optionally, more than one side of the porous pillar may be in direct contact with the crate element, e.g. two or three sides. The arrangement of the porous pillar directly at the crate element provides mechanical strength to the porous pillar and the crate element and therefore contributes to the improved mechanical strength of the vapor chamber.

According to one or more embodiments, the compartment is formed by at least four side panels. Therefore, the compartment may has a rectangular, e.g. square, cross section. Optionally, the compartment is formed by five or more side panels such that e.g. a honeycombed structure is formed. This may contribute to a very efficient use of space inside the vapor chamber.

According to one or more embodiments, the porous pillar has a polygonal cross section parallel to the bottom or top cover. For example, the porous pillar may have a square or rectangular cross section such that each side surface of the porous pillar facing a corresponding one of the side panels of the crate element may be plane. This contributes to a proper coupling of the porous pillar to the crate element, if the porous pillar, in particular at least one of its side surfaces, is directly attached to one or more of the side panels.

According to one or more embodiments, the crate element comprises an array of corresponding compartments, wherein adjacent compartments share at least one of their side panels, and wherein at least one corresponding porous pillar is arranged in each of the compartments. The array of compartments contributes to that that the mechanical strength of the support structure and as such of the vapor chamber is further increased. The corresponding array of porous pillars contributes to that that the flow of the liquid in the vapor cavity is further enhanced leading to a more efficient heat dissipation and cooling efficiency of the vapor chamber.

According to one or more embodiments, the vapor chamber comprises an array of corresponding crate elements, with corresponding porous pillars being arranged in the corresponding compartments. The array of crate elements contributes to that that the mechanical strength of the vapor chamber is further increased. The corresponding arrays of porous pillars contribute to that that the flow of the liquid in the vapor cavity is further enhanced leading to a more efficient heat dissipation and cooling efficiency of the vapor chamber.

According to one or more embodiments, the vapor chamber comprises at least one perforated plate, which is parallel to the bottom cover or parallel to the top cover and which has at one plate recess for each crate element, with the crate element being arranged in and extending through the corresponding plate recess. Optionally, the vapor chamber comprises one perforated top plate being arranged at or next to the top cover and/or one perforated bottom plate being arranged at or next to the bottom cover. The perforated plate may be referred to as wick structure.

According to one or more embodiments, the top cover comprises at least one top chamber extending in direction away from the bottom cover, the top chamber communicating with the vapor chamber. The top chamber may accommodate the vapor during cooling the electronic component and provides an increased surface for dissipating the heat to the surroundings. So, the top chamber contributes to a very high cooling efficiency of the vapor chamber.

According to one or more embodiments, the top cover comprises at least two corresponding top chambers, wherein outer walls of the top chambers are connected to each other by at least one cooling rib. The cooling rib further increases the surface for dissipating the heat and therefore contributes to a very high cooling efficiency of the vapor chamber.

According to another aspect, an electronic arrangement is provided. The electronic arrangement comprises: the electronic component, which generates heat while being operated; and the above vapor chamber, with the bottom cover of the vapor chamber being in thermal contact with the electronic component for cooling the electronic component. It has to be understood that features, advantages and/or embodiments of the vapor chamber as described above and in the following may be features, advantages and/or embodiments of the electronic arrangement.

It has to be understood that features, advantages and/or embodiments of the vapor chamber and/or electronic arrangement as described above and in the following may be features, advantages and/or embodiments of the method as described in the following.

According to another aspect, a method for manufacturing a vapor chamber for cooling an electronic component is provided. The method comprises the steps of: providing the bottom cover for receiving waste heat from the electronic component; forming the crate element for providing mechanical strength to the vapor chamber on the bottom cover by additive manufacturing using a first energy input, wherein the crate element has the at least one compartment, which is formed by the at least three side panels connected to each other and which has the top recess and the bottom recess, which faces the bottom cover; forming the at least one porous pillar on the bottom cover in the compartment by additive manufacturing using a second energy input, wherein the first energy input is greater than the second energy input; and providing the top cover on the bottom cover, the crate element, and the porous pillar such that the vapor cavity for accommodating the liquid is formed between the bottom cover and the top cover, that the crate element and the porous pillar are arranged in the vapor cavity, and that the compartment and the porous pillar extend from the bottom cover to the top cover, with the top recess of the compartment facing the top cover, wherein a cross section area of the porous pillar is smaller than a cross section area of the compartment such that an open channel for guiding the liquid from the top cover to the bottom cover is formed between the porous pillar and at least one of the side panels of the compartment, and/or at least one of the side panels has a side recess.

Manufacturing the vapor chamber by additive manufacturing contributes to that that the vapor chamber may be formed in a simple and cost efficient way. Forming the crate element by using a first energy input and forming the porous pillars by using a second energy input, wherein the first energy input is greater than the second energy input, enables to provide the solid structure of the crate element and the porous structure of the porous pillars in a simple way, simultaneously and/or in the same process.

According to one or more embodiments, the bottom cover is provided by forming the bottom cover by additive manufacturing. Manufacturing the bottom cover by additive manufacturing contributes to that that the bottom cover and as such the vapor chamber may be formed in a simple and cost efficient way. Further, the bottom cover and the support structure may be formed during the same additive manufacturing process such that the support structure may be integrally formed with the bottom cover. This contributes to that that the support structure may be fixedly secured at the bottom cover and does not have to be fixed to the bottom cover in a separate process. This contributes to a very high mechanical strength of the vapor chamber and to a fast and simple manufacturing of the vapor chamber.

According to one or more embodiments, the top cover is provided by forming the top cover by additive manufacturing. Manufacturing the top cover by additive manufacturing contributes to that that the top cover and as such the vapor chamber may be formed in a simple and cost efficient way. Further, the support structure and the top cover may be formed during the same additive manufacturing process such that the support structure may be integrally formed with the top cover. This contributes to that that the support structure may be fixedly secured at the top cover and does not have to be fixed to the top cover in a separate process. This contributes to a very high mechanical strength of the vapor chamber and to a fast and simple manufacturing of the vapor chamber.

Optionally, the bottom cover, the top cover and the support structure are formed by additive manufacturing, for example during the same additive manufacturing process. This contributes to a very high mechanical strength of the vapor chamber and to a fast and simple manufacturing of the vapor chamber.

The subject matter of the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the attached drawings.

<FIG> shows a top view of a bottom cover <NUM> of a vapor chamber <NUM> in accordance with one embodiment and <FIG> shows a sectional side view of the short side of the vapor chamber <NUM> shown in <FIG>. The vapor chamber <NUM> of <FIG> may be referred to as <NUM>-dimensional vapor chamber <NUM> and/or as heat-transfer device.

The vapor chamber <NUM> comprises the bottom cover <NUM>, the top cover <NUM> and several support structures <NUM>. The top cover <NUM> is arranged on the bottom cover <NUM> such that a vapor cavity <NUM> is formed between the top cover <NUM> and the bottom cover <NUM>. During normal operation of the vapor chamber <NUM> a liquid is arranged in the vapor cavity <NUM>. The vapor cavity <NUM> may be sealed such that a fixed amount of the liquid stays in the vapor cavity <NUM>. Alternatively, the vapor chamber <NUM> may comprise an intake and/or a drain (not shown in the figures) communicating with the vapor cavity <NUM> for exchanging the liquid during operation.

The support structures <NUM> are arranged in the vapor cavity <NUM> and extend from the bottom cover <NUM> to the top cover <NUM>. In the embodiment shown in <FIG>, the support structures <NUM> are arranged in lines and columns, wherein adjacent lines are arranged such that the given distance is present between the lines corresponding lines.

The vapor chamber <NUM> may be used for cooling an electronic component <NUM>, which generates heat during operation. For this purpose, the vapor chamber <NUM> is in thermal contact with the electronic component <NUM>. In particular, the bottom cover <NUM> is in thermal contact with the electronic component <NUM>. For example, the bottom cover <NUM> is directly attached to the electronic component <NUM>. If the electronic component <NUM> generates heat, the heat is transferred to the vapor chamber <NUM> via the bottom cover <NUM>. So, the bottom cover <NUM> may be referred to as warm side of the vapor chamber <NUM> and the top cover <NUM> may be referred to as cold side of the vapor chamber <NUM>.

The thermal energy of the transferred heat causes a change of the aggregation state of the liquid in the vapor cavity <NUM> such that it is at least partly vaporised, wherein the corresponding energy is "stored" in the corresponding vapor as heat of vaporization. The vapor is distributed in the vapor cavity <NUM> and at least partly condenses at the inside of the top cover <NUM>, releasing the stored energy, by changing its aggregation state again, to the top cover <NUM> facing away from the electronic component <NUM>. The top cover <NUM> is correspondingly heated and may dissipate the heat to the surroundings of the vapor chamber <NUM>. The condensed liquid flows back to the bottom cover <NUM> at least partly assisted by the support structures <NUM>. In addition, the heat is transferred from the bottom cover <NUM> to the top cover <NUM> by the support structures <NUM>, which are directly connected to the bottom cover <NUM> and to the top cover <NUM>. So, the vapor chamber <NUM> dissipates the heat away from the electronic component <NUM> and as such cools the electronic component <NUM> very efficiently.

The embodiment shown in <FIG> comprises a given number of support structures <NUM>, i.e. <NUM> support structures <NUM>. However, there may be arranged more or less support structures <NUM> as shown in <FIG>. Further, the support structures <NUM> of <FIG> are arranged in lines and columns, i.e. in <NUM> lines and <NUM> columns. However, there may be more or less lines and/or columns of corresponding support structures, and/or the support structures <NUM> may be arranged in a different pattern, for example comprising circular or arbitrary structures. Further, as can be seen from <FIG>, each support structure <NUM> has a rectangular, in particular a square cross-section. Alternatively, the support structures <NUM> each may have another polygonal cross-section or a circular cross-section.

<FIG> shows a crate element <NUM> of one of the support structures <NUM> shown in <FIG> in accordance with one or more embodiments. The crate element <NUM> has several compartments <NUM>, wherein each compartment <NUM> is formed by four side panels <NUM> and wherein adjacent compartments <NUM> share at least two of the side panels <NUM>. In other words, some of the side panels <NUM> extend along two or more of the compartments <NUM> and/or contribute to form two or more of the compartments <NUM>. Each compartment <NUM> has a bottom recess <NUM> and a top recess <NUM>, facing away from the bottom recess <NUM>. If the support structure <NUM> is arranged in the vapor cavity <NUM>, the bottom recess <NUM> faces the bottom cover <NUM> and the top recess <NUM> faces the top cover <NUM>. In addition, the side panels <NUM> are in direct contact with the bottom cover <NUM> at the side of the bottom recess <NUM>, and the side panels <NUM> are in direct contact with the top cover <NUM> at the side of the top recess <NUM>. Each of the side panels <NUM> has a corresponding side recess <NUM>. A thickness of the side panels may be around <NUM> to <NUM>.

The crate element <NUM> has a square cross-section. Alternatively, the crate element <NUM> may have another rectangular or polygonal cross-section, or the crate element <NUM> may have a circular cross-section. The crate element <NUM> has four rows and four columns of four compartments <NUM> in each column and, respectively, row. Alternatively, the crate element <NUM> may have more or less rows and/or columns each having more or less compartments <NUM>. Each compartment <NUM> is formed by four side panels <NUM> and has a square cross section. Alternatively, the compartments <NUM> may be formed by only three or more than four side panels <NUM> and as such may have a triangle, another rectangular, or polygonal cross-section. The bottom recesses <NUM> and the top recesses <NUM> are square-shaped for partly accommodating the porous pillars <NUM> (see <FIG>). Alternatively, the bottom recess <NUM> and/or the top recess <NUM> may have another rectangular or polygonal cross-section, or the bottom recess <NUM> and/or the top recess <NUM> may have a circular cross-section. The side recesses <NUM> are prism-shaped. Alternatively, the side recesses <NUM> may have a rectangular, e.g. square, or polygonal shape, or the side recesses <NUM> may have a circular shape.

<FIG> shows a perspective view of an array of porous pillars <NUM> of the support structure <NUM>. Each of the porous pillars <NUM> comprises a bottom surface <NUM> and a top surface <NUM>, facing away from the bottom surface <NUM>. If the porous pillars <NUM> are arranged in the vapor cavity <NUM>, the porous pillars <NUM> extend from the bottom cover <NUM> to the top cover <NUM> and the bottom surfaces <NUM> are in direct contact with the bottom cover <NUM> and the top surfaces <NUM> are in direct contact with the top cover <NUM>. The porous pillars <NUM> of the support structure <NUM> are formed such that at least a part of the liquid in the vapor cavity <NUM> may be transferred through the pores of the porous pillars <NUM>.

The porous pillars <NUM> of the embodiment shown in <FIG> are cuboid-shaped, each having a square cross-section. Alternatively, the porous pillars <NUM> may be formed differently and may, for example, have rectangular, polygonal, or circular cross-sections. In the embodiment shown in <FIG>, the array of porous pillars <NUM> has four rows and four columns of four porous pillars <NUM> in each column and, respectively, row. Alternatively, the array of porous pillars <NUM> may have more or less rows and/or columns each having more or less porous pillars <NUM>.

<FIG> shows the support structure <NUM> comprising the crate element and the porous pillars <NUM>. The porous pillars <NUM> are arranged in the compartments <NUM> of the crate element <NUM>. In particular, each compartment <NUM> contains one of the porous pillars <NUM>. The height of the porous pillars <NUM> is the same as the height of the crate element <NUM>, in particular of the side panels <NUM>. If the support structure <NUM> is arranged in the vapor cavity <NUM>, the crate element <NUM>, in particular the side panels <NUM>, and the porous pillars <NUM> extend from the bottom cover <NUM> to the top cover <NUM> and are in direct contact with the bottom cover <NUM> and the top cover <NUM>.

The porous pillars <NUM> are arranged in the compartments <NUM> such that two sides of each porous pillar <NUM> are in direct contact with at least one of the side panels <NUM>. The cross-sections of the porous pillars <NUM> are smaller than the cross-sections of the corresponding compartments <NUM>. Therefore, open channels for guiding the liquid from the cold side to the hot side of the vapor chamber <NUM> are formed between each of the porous pillars <NUM> and the corresponding side walls <NUM> of the corresponding compartment <NUM>. The open channels may have an area of <NUM> to <NUM> times <NUM>, which may be around <NUM>% to <NUM>% times <NUM>% of the cross-section of the porous pillars <NUM>, wherein the cross-section is parallel to the bottom or top cover <NUM>, <NUM>.

The alternative embodiments of the crate element <NUM> and the porous pillars <NUM> as described above in connection with <FIG> and, respectively, <NUM> may be transferred to alternative embodiments of the support structure <NUM> comprising the crate element <NUM> and the porous pillars <NUM> as shown in <FIG>. Therefore, a repetitive description of these alternatives is omitted in order to not to obscure the idea of the invention. In addition, alternatively, the porous pillars <NUM> may be arranged in the corresponding compartments <NUM> such that only one side or three sides of the porous pillars <NUM> are in direct contact with the corresponding side panels <NUM> of the corresponding compartments <NUM>, wherein the open channels between the porous pillars <NUM> and the other side panel(s) <NUM> of the corresponding compartment <NUM> are modified accordingly. Further, in the embodiment shown in <FIG>, each compartment <NUM> comprises at least one porous pillar <NUM>. Alternatively, some of the compartments <NUM> may not comprise any porous pillar <NUM> and/or some of the compartments <NUM> may comprise more than one porous pillar <NUM>.

In an embodiment, the crate element <NUM> and the porous pillars <NUM> are made by additive manufacturing, wherein the crate element <NUM> is formed by a first energy input and the porous pillars <NUM> are formed by a second energy input smaller than the first energy input. The first energy input being greater than the second energy input contributes to that that a density of the material of the crate element <NUM> is larger than a density of the porous pillars <NUM>. In other words, the different energy inputs by forming the crate element <NUM> and the porous pillars <NUM> leads to the fact that the material of the crate element <NUM> is more solid than that of the porous pillars <NUM>, and that the material of the porous pillars <NUM> has pores, in contrast to the material of the crate element <NUM>. The solid structure of the crate elements <NUM> contributes to the improved mechanical strength of the vapor chamber <NUM>. The porous structure of the porous pillars <NUM> contributes to a very efficient distribution of the liquid in the vapor chamber <NUM> and as such to a very high cooling efficiency of the vapor chamber <NUM>.

The crate element <NUM> and the porous pillars <NUM> may be produced at the same time, wherein, in this description, if one element is referred to as being formed "at the same time" as another element, the one element is formed "during the same process" and/or "by the same device without removing the one element" as the other element. For example, the crate element <NUM> and the porous pillars <NUM> may selectively be sintered from loose metal powder grains by additive manufacturing. Metal powder grains have a good heat conductivity. The grains may be made out of a metal material. The grains may be sintered together. The metal material may be a copper material or an aluminum material for example. The metal material may be an alloy. The crate element <NUM> and the porous pillars <NUM> may be sintered according to a CAD model. The porous pillars <NUM> are shaped three-dimensionally to optimize a pumping capability of the micro-porous and to optimize flow resistance in the macro-pores of the porous pillars.

According to the above embodiment, the crate elements <NUM> and the porous pillars <NUM> are connected to the bottom cover <NUM> and the top cover <NUM>. In this context, the bottom cover <NUM> and the top cover <NUM> may be formed, e.g. sintered, integrally with the crate elements <NUM> and the porous pillars <NUM>. The bottom cover <NUM> and the top cover <NUM> may be produced at the same time as the crate elements <NUM> and the porous pillars <NUM>. By integrally connecting the bottom cover <NUM>, the crate elements <NUM>, the porous pillars <NUM>, and the top cover <NUM> an optimum thermal connection may be achieved between the bottom cover <NUM>, the crate elements <NUM>, the porous pillars <NUM> and the top cover <NUM>. Further, by integrally connecting the bottom cover <NUM>, the crate elements <NUM>, the porous pillars <NUM>, and the top cover <NUM> an optimum mechanical strength of the vapor chamber <NUM> may be achieved.

<FIG> shows an alternative embodiment of the crate element <NUM>. The circumference of the cross-section of the crate element <NUM> parallel to the bottom cover <NUM> or top cover <NUM> is circular. For example, the crate element <NUM> has been formed out of one piece of several connected crate elements <NUM> and has been separated from the other crate elements <NUM> afterwards, e.g. by cutting or sawing along a circular line. This may contribute to a simple and cost effective manufacturing of the crate element <NUM>.

<FIG> shows a sectional side view of an alternative embodiment of the vapor chamber <NUM>. The vapor chamber <NUM> may be referred to as a <NUM>-dimensional vapor chamber <NUM>. The vapor chamber <NUM> comprises top chambers <NUM>, each of which comprising one top cavity <NUM>. The top cavities <NUM> communicate with the vapor cavity <NUM> for exchanging liquid and/or vapor. The top chambers <NUM> increase the outer surface of the vapor chamber <NUM> and as such the cooling capacity of the vapor chamber <NUM> compared to the vapor chamber <NUM> without the top chambers <NUM>. Optionally, cooling ribs <NUM> connect adjacent top chambers <NUM> for further increasing the outer surface of the vapor chamber <NUM> and as such the cooling capacity of the vapor chamber <NUM>.

The embodiment of the vapor chamber <NUM> shown in <FIG> has ten top chambers <NUM> and three cooling ribs <NUM>. Alternatively, the vapor chamber <NUM> may comprise more or less of the top chambers <NUM>. Further, more or less of the top chambers <NUM> may be connected by corresponding cooling ribs <NUM>. For example, at least one cooling rib <NUM> may be arranged between two adjacent ones of the top chambers <NUM>. Further, there may be arranged two or more cooling ribs <NUM> next to each other between each pair of the top chambers <NUM>.

<FIG> shows an embodiment of a perforated plate <NUM>. The perforated plate <NUM> may be referred to as a wick structure. The perforated plate <NUM> comprises several plate recesses <NUM>. The plate recesses <NUM> are formed and arranged such that the perforated plate <NUM> may be arranged on the bottom cover <NUM> of the vapor chamber <NUM> of <FIG> and that the support structures <NUM> are arranged in the plate recesses <NUM> and extend through the plate recesses <NUM>.

With respect to the alternative embodiments of the vapor chamber <NUM> and the support structures <NUM> as explained above in context with <FIG>, the perforated plate <NUM> and in particular the plate recesses <NUM> may be modified accordingly. For example, if there are more or less of the support structures <NUM>, the perforated plate <NUM> may correspondingly comprise more or less plate recesses <NUM>. Alternatively or additionally, if the support structures <NUM> have another cross-section area, e.g. a circular cross-section area, the plate recesses <NUM> may be adapted accordingly, e.g. such that they are circular.

The perforated plate <NUM> may support the vapor chamber <NUM> and/or the support structures <NUM>. Therefore, the perforated plate <NUM> may contribute to the mechanical strength of the vapor chamber <NUM>. Alternatively or additionally, if the perforated plate <NUM> is made of a porous material, the perforated plate <NUM> may contribute to the distribution of the liquid in the vapor cavity <NUM>. The perforated plate <NUM> arranged on the bottom cover <NUM> may be referred to as perforated bottom plate. Alternatively or additionally, another perforated plate <NUM> may be arranged at the top cover <NUM> of the vapor chamber <NUM>, which may be referred to as perforated top plate. The perforated bottom and/or top plate may be formed of the same material as the bottom cover <NUM>, the crate elements <NUM>, the porous pillars <NUM>, and/or the top cover <NUM>. The perforated bottom and/or top plate may be formed by additive manufacturing, for example at the same time as the bottom cover <NUM>, the support structures <NUM>, and/or the top cover <NUM>.

<FIG> shows a flow chart of an embodiment of a method for manufacturing a vapor chamber for cooling an electronic component, e.g. the vapor chamber <NUM> for cooling the electronic component <NUM> as explained in accordance with one of the above embodiments.

In step S2 a manufacturing of a vapor chamber, e.g. the vapor chamber <NUM>, is prepared and started. For example, in step S2 the materials for manufacturing the vapor chamber <NUM> are prepared and/or a software, a structural design, e.g. a CAD-file, and/or corresponding parameters are loaded into a device for manufacturing the vapor chamber. The device may be a 3D-printer.

In step S4 a bottom cover, e.g. the above bottom cover <NUM>, is provided. Optionally, the bottom cover <NUM> may be provided by forming the bottom cover <NUM> by additive manufacturing. If the bottom cover <NUM> is formed by additive manufacturing, the bottom cover <NUM> may be formed at the same time and/or integrally with the crate elements <NUM> and/or the porous pillars <NUM>. Optionally, a perforated plate, e.g. the perforated plate <NUM>, e.g. the perforated bottom plate, may be formed on the bottom cover <NUM>.

In step S6 crate elements, e.g. the above crate elements <NUM>, are formed on the bottom cover <NUM>. The crate elements <NUM> are formed by additive manufacturing using a first energy input. The first energy input causes the material of the crate elements <NUM> as being solid without any pores.

In step S8 porous pillars, e.g. the above porous pillars <NUM>, are formed in compartments of the crate elements, e.g. in the compartments <NUM> of the crate elements <NUM>. The porous pillars <NUM> are formed by additive manufacturing using a second energy input, wherein the first energy input is greater than the second energy input. The second energy input causes the material of the porous pillars <NUM> as being porous while having micro- and/or macro-pores. The porous pillars <NUM> may be formed at the same time and/or integrally with the corresponding crate element <NUM>.

Step S8 may be carried out before step S6, or steps S6 and S8 are carried out at the same time. For example, the crate element <NUM> and the porous pillars <NUM> may be produced at the same time. For example, the crate element <NUM> and the porous pillars <NUM> may selectively be sintered from loose metal powder grains by additive manufacturing. Metal powder grains have a good heat conductivity. The grains may be made out of a metal material. The grains may be sintered together. The metal material may be a copper material or an aluminum material for example. The metal material may be an alloy. The crate element <NUM> and the porous pillars <NUM> may be sintered according to a CAD model represented by the CAD-file. The porous pillars <NUM> are shaped three-dimensionally to optimize a pumping capability of the micro-porous and to optimize flow resistance in the macro-pores of the porous pillars.

<FIG> shows one possible embodiment of a manufacturing method. However, when the vapor chamber <NUM> or at least parts of it are manufactured with an additive manufacturing processes, there may be other printing steps or solely one printing step at all. These one or more printing steps may depend on the printing orientation of the piece in the printer and/or the chosen laser path. Layers may be printed in succession on top each another, and within each layer the laser path may be programmed to follow a certain pattern. A best laser path may not be determined in advance, it may depend on the part functionalities and the engineer know-how.

When the porous pillars <NUM> are formed by additive manufacturing, an energy beam having a given energy, e.g. the above second energy, may be targeted at a surface of a feedstock of loose metal powder grains over an expanse of the porous pillars <NUM> to heat near-surface grains forming the porous pillars <NUM> to a sintering temperature of the metal and fuse the heated grains to the bodies of the porous pillars <NUM>, wherein an energy exposure of the grains forming the body of the porous pillars <NUM> is limited to a sintering energy density and grains in macro-pores of the porous pillars <NUM> are circumnavigated by the energy beam. Optionally, a perforated plate, e.g. the perforated plate <NUM>, e.g. the perforated top plate, may be formed surrounding the porous pillars <NUM>.

In step S10 a top cover, for example the above top cover <NUM>, is provided. Optionally, the top cover <NUM> may be provided by forming the top cover <NUM> by additive manufacturing. If the top cover <NUM> is formed by additive manufacturing, the top cover <NUM> may be formed at the same time and/or integrally with the crate elements <NUM> and/or the porous pillars <NUM>.

When one element out of a group consisting of the bottom cover <NUM>, the crate elements <NUM>, and/or the top cover <NUM> is formed by additive manufacturing, the corresponding element may be formed by steering the corresponding energy beam having a given energy, e.g. the above second energy, over an expanse of the corresponding element to heat the near-surface grains forming the element to a melting temperature of the metal and melt the grains to the element, wherein the energy exposure of the grains forming the element equates at least a melting energy density.

A feedstock may be a bed of metal powder grains. The bed may have a flat surface. The feedstock may contain excess material. Unused material of the feedstock may be reusable.

An energy beam may be an electron beam or a laser beam for example. The energy beam may be pointed at the surface. The energy beam may narrow towards the surface. The energy beam may hit the surface in a spot. In particular, the energy beam may be oriented approximately perpendicular to the surface. The energy beam may be steered across the surface in two dimensions. There may also be multiple energy beams targeted at the surface.

A temperature of the grains may be raised by absorbing energy from the energy beam and by heat conduction from heated grains to adjoining colder grains. Grains at the surface may be heated directly by the beam. Grains under the surface may be heated by the beam and/or the heat conduction.

A sintering temperature may be below a melting temperature. The sintering temperature may be dependent on the feedstock material. For a copper material the sintering temperature may be between <NUM> and <NUM>, for an aluminum material the sintering temperature may be between <NUM> and <NUM>. At the sintering temperature the grains may be still solid. At the sintering temperature contacting surfaces of the grains may interact on an atomic level and fuse together. Fused particles may be still discernible as individual grains. The fused or sintered grains may have grown together at their contact points.

A sintering energy density may be between <NUM> J/mm3 and <NUM> J/mm3. In that range the grains may only reach the sintering temperature. The energy density may be raised slowly to facilitate spreading the energy evenly.

A melting energy density may be between <NUM> J/mm3 and <NUM> J/mm3. The melting temperature of a copper material may be between <NUM> and <NUM>. The melting temperature of an aluminum material may be between <NUM> and <NUM>.

The above vapor chamber <NUM> may be defined by the CAD model. The vapor chamber <NUM> may be two- or three-dimensional. The CAD model may be sliced into two-dimensional layers. In each layer the vapor chamber <NUM> may have a cross-section area defined by the CAD model. An expanse of the vapor chamber <NUM> may be equivalent to the cross-section area. The expanse may be defined by borders of the cross-section area. The layers of micro-porous bodies, i.e. the porous pillars <NUM>, may be embedded in loose feedstock material during the production process. The loose feedstock grains in the macro-pores are removed after the grains forming the body have fused after the sinter process.

In step S12 the vapor chamber <NUM> is finished and may be removed from the device for manufacturing the vapor chamber <NUM>, e.g. the 3D-printer.

Claim 1:
A vapor chamber (<NUM>) for cooling an electronic component (<NUM>), comprising:
a bottom cover (<NUM>) for receiving waste heat from the electronic component (<NUM>);
a top cover (<NUM>), which is arranged on the bottom cover (<NUM>), wherein the bottom cover (<NUM>) and the top cover (<NUM>) are formed such that a vapor cavity (<NUM>) for accommodating a liquid is formed between the bottom cover (<NUM>) and the top cover (<NUM>);
a crate element (<NUM>) for providing mechanical strength to the vapor chamber (<NUM>), wherein the crate element (<NUM>) has at least one compartment (<NUM>), which is formed by at least three side panels (<NUM>) being connected to each other and extending from the bottom cover (<NUM>) to the top cover (<NUM>), and a top recess (<NUM>) facing the top cover (<NUM>) and a bottom recess (<NUM>) facing the bottom cover (<NUM>); and
at least one porous pillar (<NUM>) for transferring the liquid from the top cover (<NUM>) to the bottom cover (<NUM>), wherein the porous pillar (<NUM>) is arranged in the compartment (<NUM>) and extends from the bottom cover (<NUM>) through the bottom recess (<NUM>) and the top recess (<NUM>) to the top cover (<NUM>),
wherein a cross section area of the porous pillar (<NUM>) is smaller than a cross section area of the compartment (<NUM>) such that an open channel for guiding the liquid from the top cover (<NUM>) to the bottom cover (<NUM>) is formed between the porous pillar (<NUM>) and at least one of the side panels (<NUM>) of the compartment (<NUM>).