Patent Description:
Hinged or otherwise flexible electronic devices are known. Such devices comprise components such as processors which generate unwanted levels of heat. Therefore, components that enable distribution of this heat are useful.

D1 (<CIT>) discloses examples that relate to heat transfer devices comprising a vapor chamber and a flexible hinge. One disclosed example provides an electronic device comprising a first portion and a second portion connected by a hinge region, and a vapor chamber extending from the first portion to the second portion across the hinge region, the vapor chamber comprising a first layer comprising titanium, a second layer comprising titanium joined to the first layer to form the vapor chamber, a working fluid within the vapor chamber, and a third layer comprising titanium positioned between the first layer and the second layer, the third layer comprising one or more features configured to conduct the working fluid via capillary action.

D2 (<CIT>) discloses an electronic device that can be configured to include a torsional heat pipe. The torsional heat pipe can include a first housing static portion located in a first housing of an electronic device, where the first housing static portion is coupled to a heat source, a second housing static portion located in a second housing of the electronic device, where the second housing static portion is coupled to a heat spreader, and a torsion portion located in a hinge of the electronic device, where the hinge rotatably couples the first housing to the second housing and the torsion portion rotates as the second housing rotates relative to the first housing and the torsion portion couples the first housing static portion to the second housing static portion.

According to various, but not necessarily all, examples of the disclosure there can be provided an apparatus comprising: at least a first vapour chamber portion and a second vapour chamber portion wherein the vapour chamber portions each comprise walls housing an internal volume where the internal volume is configured to enable vapour flow; at least one hinge formed from walls of the first vapour chamber portion and walls of the second vapour chamber portion and configured to enable the first vapour chamber portion to be moved relative to the second vapour chamber portion; and wherein the hinge is thermally conductive and configured to enable heat to be transferred from the first vapour chamber portion to the second vapour chamber portion, wherein the first vapour chamber portion is configured so that working fluid condenses on the area of the walls that forms the hinge and the second vapour chamber portion is configured so that working fluid evaporates from the area of the walls that forms the hinge.

The at least one hinge may comprise a thermally conductive material.

The at least one hinge may comprise one or more of, teethed structure, interleaved projections, ball and socket arrangement.

The walls may define at least part of an external housing of the vapour chamber portions.

The walls may comprise a wick structure configured to enable flow of a working fluid via capillary action.

The first chamber portion may be configured to be positioned in proximity to a heat source.

The vapour chamber portions may comprise an internal support structure configured to support the walls of the vapour chamber portions.

The internal support structure may comprise one or more struts configured to control flow of working fluid within the vapour chamber portions.

The support structure may be formed using an additive manufacturing process.

The apparatus may comprise more than two vapour chamber portions connected by hinges.

According to various, but not necessarily all, examples of the disclosure there can be provided an electronic device comprising an apparatus as described above The electronic device may comprise one or more screens.

According to some examples of the disclosure, not encompassed by the wording of the claims but considered useful for understanding the invention, there can be provided a method comprising: designing a support structure for a vapour chamber wherein the support structure comprises a network of struts; modelling fluid flow through the network of struts to determine one or more parameters of the network of struts; and adjusting the network of struts to improve the one or more parameters.

The one or more parameters may comprise thermal resistance, pressure drop.

The network of struts may be designed to be manufactured using additive manufacturing.

Designing a support structure may comprise creating structures from a plurality of nodes within a base plane where the struts satisfy one or more set requirements.

The set requirements may comprise any one or more of; that struts do not overlap, that the struts are a minimum distance apart.

The struts may maintain spacing between external walls of the vapour chamber to provide an internal volume for fluid flow.

According to various, but not necessarily all, examples of the disclosure there can be provided a vapour chamber apparatus comprising an internal support structure designed using the methods described above.

Examples of the disclosure relate to vapour chambers. Embodiments of the invention relate to hinged vapour chambers. The hinged vapour chambers comprise at least two vapour chamber portions that are configured to be moved relative to each other. The hinges are also configured to enable heat to be transferred across the hinge between the different vapour chamber portions.

<FIG> schematically shows a cross section through an apparatus <NUM> according to examples of the disclosure. The apparatus <NUM> comprises a first vapour chamber portion <NUM>, a second vapour chamber portion <NUM> and a hinge <NUM>.

Each of the vapour chamber portions <NUM>, <NUM> comprise walls <NUM>. The walls <NUM> house an internal volume <NUM>. A first internal volume <NUM> is provided inside the first vapour chamber portion <NUM> and a second internal volume <NUM> is provided inside the second vapour chamber portion <NUM>. The internal volumes <NUM> are configured to enable vapour flow within the vapour chamber portions <NUM>, <NUM>. The internal volumes <NUM> are configured to enable flow of a working fluid in a vapour phase. The walls <NUM> separate the internal volumes <NUM> of the vapour chamber portions <NUM>, <NUM> so that the working fluid does not flow between the respective vapour chamber portions <NUM>, <NUM>.

The walls <NUM> define the external housing of the apparatus <NUM>. The walls <NUM> comprise a thermally conductive material. The thermally conductive material can enable heat to be conducted into the internal volume <NUM> or out of the internal volume <NUM>. In some examples the walls <NUM> can comprise a metal such as copper. In other examples the walls <NUM> can comprise a plastic layer which is thin enough to enable heat to be conducted through it. In examples where the walls <NUM> comprise plastic one or more electronic components can be printed or otherwise provided on the plastic outer surface of the walls <NUM>.

The walls <NUM> can comprise a wick structure. The wick structure can be provided on the internal surfaces of the walls <NUM>. The wick structure can be configured to enable flow of a working fluid in a liquid phase. The wick structure can comprise a plurality of capillary channels configured to enable flow of the working fluid via capillary action. The wick structure can be formed by sintering or any other suitable process.

A hinge <NUM> is provided between the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM>. The hinge <NUM> enables the first vapour chamber portion <NUM> to be moved relative to the second vapour chamber portion <NUM>. The hinge <NUM> can provide a pivot point that enables the first vapour chamber portion <NUM> to be rotated relative to the second vapour chamber portion <NUM>.

The hinge <NUM> is formed from the walls <NUM> of the vapour chamber portions <NUM>, <NUM>. The hinge <NUM> is thermally conductive so that heat can be conducted from the first chamber portion <NUM> to the second vapour chamber portion <NUM> through the section of the walls <NUM> that form the hinge <NUM>.

In the example shown in <FIG> the hinge <NUM> couples the first vapour chamber portion <NUM> directly to the second vapour chamber portion <NUM> so that there are no intervening components between the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM>. The walls <NUM> of the first vapour chamber portion <NUM> are in direct thermal contact with the walls <NUM> of the second vapour chamber portion <NUM> so as to ensure that heat can be conducted between the vapour chamber portions <NUM>, <NUM> through the hinge <NUM>.

When the apparatus <NUM> is in use a working fluid is provided within the vapour chamber portions <NUM>, <NUM>. The working fluid could be water or any other suitable fluid. When the apparatus <NUM> is in use the working fluid circulates through the vapour chamber portions <NUM>, <NUM> so as to enable heat distribution. When the working fluid is in the internal volume <NUM> the working fluid is in a gas phase and when the working fluid is in the wick structure the working fluid is in a liquid phase.

When the apparatus <NUM> is in use a first end of the first vapour chamber portion <NUM> is provided in proximity to a heat source <NUM>. The first end of the first vapour chamber portion <NUM> is provided in proximity to a heat source <NUM> so that heat from the heat sources <NUM> can be transferred to the first end of the first vapour chamber portion <NUM>. When the first end of the first vapour chamber portion <NUM> is provided in proximity to a heat source <NUM> it is provided within any range of distance from the heat source <NUM> that enables this transfer to occur. The heat source <NUM> could be an electronic component such as a processor or a screen that generates unwanted heat during use or any other suitable source of heat. The heat source <NUM> creates an evaporator region <NUM> within the first vapour chamber portion <NUM>.

A second end of the first vapour chamber portion <NUM> provides a condenser region <NUM>.

In the examples of the disclosure the condenser region <NUM> is provided in the hinge <NUM> where the walls <NUM> of the first vapour chamber portion <NUM> are in thermal contact with the walls <NUM> of the second vapour chamber portion <NUM>. The hinge <NUM> has a cooler temperature than the region around the heat source <NUM>.

At the evaporator region <NUM>, heat from the heat source <NUM> causes the working fluid to evaporate and change phase from a liquid to a gas. The working fluid in the gas phase travels from the evaporator region <NUM>, through the internal volume <NUM> to the condenser region <NUM> at the hinge <NUM>. At the condenser region <NUM>, the comparatively cooler temperature causes the working fluid to condense and change phase from a gas to a liquid. As a result, heat is moved from the evaporator region <NUM> to the condenser region <NUM> in the hinge <NUM>.

At the condenser region <NUM>, the working fluid condenses back into a liquid phase and travels back to the evaporator region <NUM> through capillary action in the wick structure in the walls <NUM>. Once the liquid phase working fluid has reached the evaporator region <NUM> again the heat at the evaporator region <NUM> will change the working fluid back into the gas phase. The cycle of the working fluid changing phase repeats so as to drive the working fluid in the gas phase and the heat from the evaporator region <NUM> to the condenser region <NUM> in the hinge <NUM>.

A similar process is performed in the second vapour chamber portion <NUM>. In the second vapour chamber portion <NUM> an evaporator region <NUM> is provided in the hinge <NUM> so that heat transferred from the first vapour chamber portion <NUM> through the hinge <NUM> causes the evaporation of the working fluid in the second vapour chamber portion <NUM>.

In the second vapour chamber portion <NUM> shown in <FIG> the condenser region <NUM> is provided at the opposite end of the second vapour chamber portion <NUM> to the hinge <NUM> which has a cooler temperature than the region around the hinge <NUM>.

At the evaporator region <NUM>, heat from first vapour chamber portion <NUM> that is conducted through the walls <NUM> of the hinge <NUM> causes the working fluid to evaporate and change phase from a liquid to a gas. In examples of the disclosure the heat is transferred from the first vapour chamber portion <NUM>, <NUM> to the second vapour chamber portion <NUM> via conduction through the walls <NUM>. There is no transfer of the working fluid between the vapour chamber portions <NUM>, <NUM>.

The working fluid in the gas phase travels from the evaporator region <NUM>, through the internal volume <NUM> to the condenser region <NUM> at the opposite end of the second vapour chamber portion <NUM>. At the condenser region <NUM>, the comparatively cooler temperature causes the working fluid to condense and change phase from a gas to a liquid. As a result, heat is moved away from the evaporator region <NUM> in the hinge <NUM>.

At the condenser region <NUM>, the working fluid condenses back into a liquid phase and travels back to the evaporator region <NUM> through capillary action of the wick structure in the walls <NUM>. Once the liquid phase working fluid has reached the evaporator region <NUM> again the heat at the evaporator region <NUM> will change the working fluid back into the gas phase. The cycle of the working fluid changing phase repeats so as to drive the working fluid in the gas phase and the heat from the evaporator region <NUM> in the hinge to the condenser region <NUM> at the other end of the second vapour chamber portion <NUM>.

The hinged vapour chamber portions <NUM>, <NUM> therefore enable heat to be transferred away from heat sources <NUM> to other locations. The vapour chamber portions <NUM>, <NUM> can therefore be used for heat distribution in hinged or otherwise deformable electronic devices.

It is to be appreciated that the apparatus <NUM> could comprise additional components that are not shown in <FIG>. For instance, the apparatus <NUM> can comprise internal support structures within the internal volumes <NUM>. The internal support structures can be configured to support the walls <NUM> of the vapour chamber portions <NUM>, <NUM>.

The internal support structures can be formed using additive manufacturing or any other suitable process. The internal support structures can comprise a plurality of struts or supports that are positioned so as to control the flow of the working fluid in the vapour phase through the internal volume <NUM>.

<FIG> shows a cross section of an example hinge <NUM> of an apparatus <NUM>. The apparatus <NUM> comprises a first vapour chamber portion <NUM> and a second vapour chamber portion <NUM> which are as described above and shown in <FIG>. Corresponding reference numerals are used for corresponding features.

In the example apparatus <NUM> shown in <FIG> the hinge <NUM> is formed from the walls <NUM> of vapour chamber portions <NUM>, <NUM> so that the walls <NUM> of the first vapour chamber portion <NUM> are in direct thermal contact with the walls <NUM> of the second vapour chamber portion <NUM>. In this example the hinge <NUM> is teethed so as to increase the surface area of the walls <NUM> that are in thermal contact. This provides for efficient heat transfer between the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM>.

In the example of <FIG> the teethed hinge <NUM> comprises a plurality of projections <NUM> and recesses <NUM> on the surfaces of the walls <NUM> of each vapour chamber portion <NUM>, <NUM>. The projections <NUM> on each vapour chamber portion <NUM>, <NUM> fit into corresponding recesses <NUM> in the wall of the other vapour chamber portion <NUM>, <NUM>. The projections <NUM> and recesses <NUM> are configured to allow the vapour chamber portions <NUM>, <NUM> to be rotated relative to each other about the hinge <NUM>.

The projections <NUM> and recesses <NUM> are provided over the surface of the hinge <NUM> so that as the hinge <NUM> is moved between open and closed configurations the projections <NUM> and recesses <NUM> mesh together. This ensures that there is a large surface area available for heat transfer when the apparatus <NUM> is in an open configuration, or a closed configuration or an intermediate configuration.

<FIG> show perspective views of a section of an apparatus <NUM> comprising a teethed hinge <NUM> such as the apparatus <NUM> shown in <FIG>.

<FIG> shows the apparatus <NUM> in an open configuration and <FIG> shows the apparatus <NUM> in a closed configuration. It is to be appreciated that the apparatus <NUM> could also be used in an intermediate configuration in which the apparatus <NUM> is partially open.

In the example shown in <FIG> the hinge comprises a teethed structure comprising projections <NUM> and recesses <NUM> as shown in <FIG>. In the example shown in <FIG> the projections <NUM> and recesses <NUM> are provided on a helical structure <NUM> that extends along an edge of the apparatus <NUM>. In the example shown in <FIG> the helical structure <NUM> extends along the whole of the adjacent edges of the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM>. The helical structure <NUM> provides a large surface area for thermal contact between the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM> so as to enable efficient heat transfer between the vapour chamber portions <NUM>, <NUM>.

The helical structure <NUM> allows the rotation of the first vapour chamber portion <NUM> relative to the second vapour chamber portion <NUM>. The helical structure is configured so that as the apparatus <NUM> is moved between an open an closed configuration the projections <NUM> and recesses <NUM> provided on the surface of the helical structure can be meshed together.

In <FIG> the apparatus <NUM> is shown in a fully open configuration. In the fully open configuration the first vapour chamber portion <NUM> is positioned so that an edge of the first vapour chamber portion <NUM> is positioned adjacent to a corresponding edge of the second vapour chamber portion <NUM>. A first face <NUM> of the first vapour chamber portion <NUM> is provided level, or substantially level, with a first face <NUM> of the second vapour chamber portion <NUM> so as to create a large surface area for the apparatus <NUM>.

In <FIG> the apparatus <NUM> is shown in a fully closed configuration. In the fully closed configuration the first vapour chamber portion <NUM> is positioned so that a first face <NUM> of the first vapour chamber portion <NUM> is positioned adjacent to a corresponding first face <NUM> of the second vapour chamber portion <NUM>.

It is to be appreciated that the apparatus <NUM> could also be configured in partially open configurations which would comprise positions in between those shown in <FIG>.

<FIG> shows a perspective view of an apparatus <NUM> comprising a first vapour chamber portion <NUM> and a second vapour chamber portion <NUM>. In this example both the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM> have rectangular shapes. Other shapes of vapour chamber portions <NUM>, <NUM> could be used in other examples of the disclosure.

The hinge <NUM> is provided along the walls <NUM> of the respective vapour chamber portions <NUM>, <NUM>. The hinge <NUM> extends along the length of the walls <NUM> so that it is provided along the whole of the adjacent sides of the respective vapour chamber portions <NUM>, <NUM>. This provides a large surface area for heat exchange between the vapour chamber portions <NUM>, <NUM>.

In the example shown in <FIG> the hinge <NUM> comprises a teethed helical structure <NUM> which can be as shown in <FIG> and <FIG>. The teeth of the helical structure <NUM> comprise projections <NUM> and recesses <NUM> that are configured so that projections <NUM> on the first vapour chamber portion <NUM> fit into recesses <NUM> in the second vapour chamber portion <NUM> and correspondingly projections <NUM> on the second vapour chamber portion <NUM> fit into recesses <NUM> in the first vapour chamber portion <NUM>.

In the example shown in <FIG> a connector <NUM> is provided between the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM>. The connector <NUM> secures the two vapour chamber portions <NUM>, <NUM> together while allowing the relative movement of the two vapour chamber portions <NUM>, <NUM>. The connector <NUM> is configured to hold the vapour chamber portions <NUM>, <NUM> securely against each other so as to ensure good thermal contact between the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM>. The connector <NUM> can ensure that the two vapour chamber portions <NUM>, <NUM> are held in good thermal contact as the two vapour chamber portions <NUM>, <NUM> are moved relative to each other.

<FIG> shows an example connector <NUM> in more detail. The connector <NUM> comprises a first pin <NUM> that is coupled to the first vapour chamber portion <NUM> and a second pin <NUM> that is coupled to the second vapour chamber portion <NUM>. A connecting member <NUM> is provided between the first pin <NUM> and the second pin <NUM>. The connecting member <NUM> prevents the two pins <NUM>, <NUM> from moving away from each other and so ensures that the two vapour chamber portions <NUM>, <NUM> are held securely together while allowing the rotation of the two vapour chamber portions <NUM>, <NUM> relative to each other.

The connector <NUM> also comprises a pivot <NUM> which provides a point for the hinge <NUM> to pivot against. The pivot <NUM> is provided between the first pin <NUM> and the second pin <NUM>.

In the example shown in <FIG> the pins <NUM>, <NUM> comprise projections that fit into recesses within the walls <NUM> of the respective vapour chamber portions. This enables the connectors <NUM> to be fitted to the outer surface of the apparatus <NUM>.

<FIG> shows an example recess <NUM> that can be provided in the outer surface of the apparatus <NUM>. <FIG> shows a section of the walls <NUM> of a vapour chamber portion. The vapour chamber portion could be a first vapour chamber portion <NUM> or a second vapour chamber portion <NUM>.

The recess <NUM> comprises a circular indent that is provided within the external walls <NUM> in an area close to the hinge <NUM>. The recess <NUM> is shaped to correspond to the shapes of the pins <NUM>, <NUM> of the connector <NUM>. The recess <NUM> is sized and shaped so that a pin <NUM> ,<NUM> from the connector fits tightly in the recess <NUM> and can be held in place as the apparatus <NUM> is moved between an open and closed configuration. The recess <NUM> does not extend through the walls <NUM>. The internal volume <NUM> formed by the walls <NUM> remains sealed.

In the example shown in <FIG> the recess <NUM> is shallow so that it does not project very far into the walls <NUM> of the vapour chamber portion <NUM>, <NUM>. This ensures that the recess <NUM> and pins <NUM>, <NUM> do not project into the area of the hinge <NUM> where heat transfer is occurring and helps to ensure that a large surface area is provided for the heat transfer between the first vapour chamber portion <NUM> and the second vapour chamber portion <NUM>.

In the example shown in <FIG> the indent provided is circular to enable a circular pin <NUM>, <NUM> to be fitted into the recess <NUM>. In other examples a different shaped pins <NUM>, <NUM> and recesses <NUM> could be provided.

shows another example apparatus <NUM> with a different type of hinge <NUM>. The apparatus <NUM> comprises a first vapour chamber portion <NUM> and a second vapour chamber portion <NUM> which can be as shown in <FIG> and described above. Corresponding reference numerals are used for corresponding features. <FIG> shows the apparatus <NUM> in a closed configuration, <FIG> shows the apparatus <NUM> in an open configuration, and <FIG> show a close up of the hinge.

In the example shown in <FIG> the hinge <NUM> comprises an interleaved structure rather than a teethed helical structure <NUM>. Each of the vapour chamber portions <NUM>, <NUM> comprise a plurality of projections <NUM> that extend out of the outer surface of the vapour chamber portion <NUM>, <NUM>. The plurality of projections <NUM> extend along the length of the edges of the vapour chamber portion <NUM>, <NUM> that forms the hinge <NUM>. The plurality of projections <NUM> are positioned spaced from each other so that a gap is provided between adjacent projections <NUM>. The gaps are sized so that a corresponding projection <NUM> from the other vapour chamber portion <NUM>, <NUM> fits tightly within the gap. This ensures that the surfaces of a projection <NUM> on the first vapour chamber portion <NUM> are in good thermal contact with the surfaces of a projection <NUM> on the second vapour chamber portion <NUM>. This provides a large surface area between the interleaved projections <NUM> to enable good heat transfer between the respective vapour chamber portions <NUM>, <NUM>.

In the example shown in <FIG> the projections <NUM> have a substantially triangular cross section that extends out of the outer surface of the respective vapour chamber portions <NUM>, <NUM>. It is to be appreciated that other shapes could be used for the projections <NUM> in other examples of the disclosure.

shows another example apparatus <NUM> with another different type of hinge <NUM>. The apparatus <NUM> shown in <FIG> also comprises a first vapour chamber portion <NUM> and a second vapour chamber portion <NUM> which can be as shown in <FIG> and described above. Corresponding reference numerals are used for corresponding features. <FIG> shows the apparatus <NUM> in a closed configuration, <FIG> shows the apparatus <NUM> in an open configuration and <FIG> shows an exploded view of the hinge <NUM>.

In the example shown in <FIG> the hinge <NUM> comprises a ball and socket arrangement. The first vapour chamber portion <NUM> comprises a plurality of sockets <NUM> that extend along the edge of the first vapour chamber portion <NUM> that forms the hinge <NUM>. The sockets <NUM> comprise partly spherical recesses that are configured to received ball shaped projections <NUM>.

The second vapour chamber portion <NUM> comprises a plurality of ball projections <NUM> that extend along the edge of the second vapour chamber portion <NUM> that forms the hinge <NUM>. The ball projections <NUM> are sized and shaped so as to fit into the corresponding sockets <NUM> in the first vapour chamber portion <NUM>. As shown in the examples in <FIG> the projections are partly spherical. This allows the rotation of the first vapour chamber portion <NUM> relative to the second vapour chamber portion <NUM> while maintaining good thermal contact between the two vapour chamber portions <NUM>, <NUM>.

Examples of the disclosure therefore provide for a vapour chamber apparatus <NUM> that can be used in an articulated or otherwise flexible device. The flexible device can comprise components that generate unwanted heat during use. For example the flexible device could be an electronic device comprising one or more screens that generate heat during use and/or the flexible device could be an electronic device comprising one or more processors that generate unwanted heat during use.

It is to be appreciated that variations from the above described examples can be made. For instance, in the above described examples the apparatus <NUM> comprises two vapour chamber portions <NUM>, <NUM>. In other examples the apparatus <NUM> could comprises more than two vapour chamber portions <NUM>, <NUM>. In such examples the vapour chamber portions <NUM>, <NUM> could be arranged in a chain or other configuration. The chain could be provided within a watch strap or other wearable device and could enable heat distribution along the length of the chain. The heat distribution could be for the purposes of cooling an electronic device, for providing an alert to a user or for any other suitable purpose.

The embodiments of <FIG> are not encompassed by the wording of the claims but are considered as useful for understanding the invention.

<FIG> shows an example method that can be used to design an internal support structure for an apparatus <NUM>. The internal support structure could be provided within the internal volume <NUM> of the vapour chamber portions <NUM>, <NUM>.

The method comprises, at block <NUM>, designing a support structure for a vapour chamber wherein the support structure comprises a network of struts.

The vapour chamber that the support structure is provided in can be a vapour chamber portion <NUM>, <NUM> comprising walls <NUM> comprising a wick structure as shown above. The support structure can be configured to support the walls <NUM> so as to define the internal volume <NUM> of the vapour chamber portions <NUM>, <NUM>. The support structure can be designed to maintain the spacing of the walls <NUM>.

The network of struts can be designed to be formed using an additive manufacturing process.

At block <NUM> the method comprises modelling fluid flow through the network of struts that form the support structure. This modelling enables one or more parameters of the network of struts to be determined.

When the vapour chamber is in use the working fluid in a vapour phase will flow through the internal volume in which the support structure is provided. The parameters of the fluid flow through the network of struts can therefore be determined to identify if the fluid flow is sufficient.

The parameters that are determined at block <NUM> can comprise thermal resistance of the struts, pressure drop of the fluid as it flows through the vapour chamber or any other suitable parameter or combination of parameters.

At block <NUM> the method comprises adjusting the support structure by adjusting the network of struts to improve the one or more parameters. The network of struts could be adjusted by removing one or more struts, reshaping one or more struts, repositioning one or more struts or by any making any other suitable modification.

The process of blocks <NUM> and <NUM> can be repeated until the parameters measured at block <NUM> provide a satisfactory level. The satisfactory level can be a threshold level, a maximum level or any other suitable level.

<FIG> show details of an example method of designing a support structure.

In this example the design method mimics an additive manufacturing process to ensure that the support structure could be formed using such processes. The example method begins by defining the outer limits of the support structure. The outer limits may be defined by the boundaries of the walls <NUM> of the vapour chamber portions <NUM>, <NUM> that will comprise the support structure. In some examples the outer limits can comprise a rectangular shape corresponding to the shape of the vapour chamber portions <NUM>, <NUM>. In other examples the outer limits can comprise a different shape.

In addition to defining the outer limits of the support structure a base plane <NUM> is also defined. The base plane <NUM> is a plane from which the design of the support structure grows. The base plane <NUM> can be equivalent to a build-plate that could be used in additive manufacturing.

In the example method a plurality of seed nodes <NUM> are defined on the base plane <NUM>. <FIG> shows an example plurality of seed nodes <NUM>. The seed nodes <NUM> represent points within space from which struts of the support structure can extend.

The seed nodes <NUM> are positioned within the defined outer limits of the support structure.

The plurality of seed nodes <NUM> can be defined in any suitable arrangement. In some examples the seed nodes <NUM> can be provided in a random, pseudo-random or predefined configuration. In some examples the seed nodes <NUM> can be distributed evenly over the surface of the base plane <NUM>. In the example shown in <FIG> the seed nodes <NUM> have been defined on a base plane <NUM> using the Halton sequence. Other pseudo-random distributions of dots can be used in other examples of the disclosure.

Struts are created from the seed nodes <NUM> by defining end points. In some examples one or more struts can be created from each of the seed nodes <NUM>. In other examples the struts can be created from a subset of the seed nodes <NUM>.

The end point of the struts can be defined in a spherical coordinate system by defining a length (r), polar angle (θ) and azimuthal angle (φ) as shown in <FIG>. The end points of the struts are limited by the requirement that the support structure needs to be formed using an additive manufacturing process.

<FIG> shows an example layer of struts <NUM> that are formed by defining end points <NUM> from the seed nodes <NUM>. In examples of the disclosure it is ensured that the struts <NUM> satisfy one or more set requirements. The set requirements comprise that struts <NUM> do not overlap or that the struts <NUM> are a minimum distance apart or any other suitable set requirements. The minimum distance between the struts <NUM> can depend on the required properties of the support structure so that different minimum distances can be used in different implementations of the disclosure.

In the example shown in <FIG> a plurality of struts <NUM> can originate from a single seed node <NUM>. In some examples the struts <NUM> can contact other struts <NUM> at the end points <NUM> so that two or more struts <NUM> can be joined together.

The end points <NUM> of the first layer of struts <NUM> provide a second set of seed nodes <NUM>. The second set of seed nodes <NUM> provide points from which a second layer of struts <NUM> can extend. The process of defining an end point for the struts <NUM> in the second layer can be the same as shown in <FIG> and <FIG> and described above. It is to be appreciated that any number of layers of struts <NUM> can be provided within the design. The process of adding a layer of struts <NUM> to the most recent layer can be completed until the internal volume defined by the walls <NUM> of the vapour chamber portions <NUM>, <NUM> is sufficiently occupied.

<FIG> shows the process of the providing additional layers of struts <NUM> upon a first layer of struts <NUM>. The results in a network of seed nodes <NUM> that are connected by the struts <NUM>. The locations and connectivity between the seed nodes <NUM> is known.

Once the network of seed nodes <NUM> has been defined a skin <NUM> is then provided over the defined network as shown in <FIG>. Any suitable process can be used to define the skin <NUM> over the network of seed nodes <NUM>. In the example shown in <FIG> a convex hull method has been used to create the structure. When defining the skin <NUM> over the network of seed nodes <NUM> the parameters of the skin <NUM> can be controlled based on requirements of the support structure. For example, the diameter of a skin <NUM> around the network can be dependent upon performance requirements such as structural strength, fluid resistance, pressure drop, thermal resistance and any other suitable parameters.

When the support structure is in use, the working fluid in the vapour phase will flow through it. Once the support structure has been designed the flow of the working fluid though the support structure can be modelled. The modelling of the fluid flow can be similar to the designing of the network structure and is shown in <FIG>. The modelling of the fluid network starts with a plurality of fluid seed nodes <NUM>. The fluid seed nodes <NUM> are located in the locations where the fluid enters the solid support structure. The locations of the fluid seed nodes <NUM> can correspond to the evaporator section of the vapour chamber. Different vapour chambers can have the evaporator sections located in different places. For instance, in the examples described above the evaporator section is located close to an external heat source in the first vapour chamber portion <NUM> but is located close to the hinge in the second vapour chamber portion <NUM>. Therefore, the locations of the fluid seed nodes <NUM> will be dependent upon how the vapour chamber portion <NUM>, <NUM> is intended to be used.

Once the fluid seed nodes <NUM> have been positioned the fluid struts are added. The fluid struts are designed to mimic fluid flow through the solid structure and are free from some of the constraints that are used for the solid struts <NUM> such as the capability of being able to manufacture it using additive manufacturing. At each seed node <NUM> within the fluid network the locations of the fluid particles and the struts <NUM> of the solid support structure are checked to ensure that there is no overlap. A tolerance factor can be added during the check for overlaps to take into account the skin <NUM> that is to be added over the solid network of struts <NUM>.

Once the fluid network has been added to the solid network then the parameters of the designed support structure can be determined. The model can be used to estimate parameters that determine the functioning of the support structure and the vapour chamber portion <NUM>, <NUM>. In some examples the structural strength of the support structure can be estimated by calculating parameters such as volume, surface area and porosity.

<FIG> shows the thermal resistance to conduction through the solid network being calculated. The thermal resistance to conduction through the solid network can be calculated by using an electrical network analogy. Each strut <NUM> has an effective thermal resistance defined by, <MAT> l: strut length, k: thermal conductivity, A: strut cross - sectional area.

The effective resistance can be calculated by calculating this resistance for each strut <NUM> within the network.

<FIG> shows the pressure drop across the fluid network being calculated. The pressure drop across the fluid network can be calculated using an electrical network analogy. From Poiseuille flow, the pressure drop for each fluid strut can be defined as, <MAT> l: strut length, Q: volumetric flow rate, A: cross - sectional area.

The strut length within the fluid network is known while the cross-sectional area can be calculated based on the area occupied by the skin <NUM> of the support structure. The volumetric flow rate at the inlet can be used to calculate the volumetric flow rate for individual fluid struts. Once these parameters are known, the net pressure drop across the network in the direction of flow as shown in <FIG> can be calculated.

Other methods, such as graph theory, can be used to calculate other parameters for solid structure or for the fluid flow. For example, the mean shortest path between any two nodes can be calculated to gauge connectivity within the network, which can be related to a performance parameter.

Once the performance parameters have been determined the support structure can be adjusted to improve the performance parameters. For example, one or more struts <NUM> can be moved or otherwise adjusted to improve performance parameters. The networks can be adjusted until one or more of the performance parameters exceed a threshold level.

In the above examples the internal support structure is used in a hinged vapour chamber apparatus <NUM>. It is to be appreciated that in other examples the internal support structure could be provided in different types of vapour chamber apparatus <NUM> that do not comprise hinges or other flexible portions.

The term 'a' or 'the' is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising a/the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use 'a' or 'the' with an exclusive meaning then it will be made clear in the context. In some circumstances the use of 'at least one' or 'one or more' may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning.

Claim 1:
An apparatus (<NUM>) comprising:
at least a first vapour chamber portion (<NUM>) and a second vapour chamber portion (<NUM>) wherein the vapour chamber portions each comprise walls (<NUM>) housing an internal volume (<NUM>) where the respective internal volumes are configured to enable vapour flow;
at least one hinge (<NUM>) formed from walls of the first vapour chamber portion and walls of the second vapour chamber portion and configured to enable the first vapour chamber portion to be moved relative to the second vapour chamber portion; and
wherein the hinge is thermally conductive and configured to enable heat to be transferred from the first vapour chamber portion to the second vapour chamber portion,
wherein the first vapour chamber portion (<NUM>) is configured so that working fluid condenses on the area of the walls that forms the hinge (<NUM>) and the second vapour chamber portion (<NUM>) is configured so that working fluid evaporates from the area of the walls that forms the hinge.