JP2018189349A - Vapor chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vapor chamber capable of preventing deterioration of performance even with change of an ambient temperature, without narrowing a portion where evaporated working liquid moves.SOLUTION: A vapor chamber comprises a housing 2, a column 3 arranged in an internal space of the housing so as to support the housing from the inside, working liquid sealed in the internal space of the housing, and a wick 4 arranged in the internal space of the housing. At least a portion of a main inner surface of the housing is exposed to the internal space of the housing, and has pores with average depth of 10 nm or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vapor chamber.

  In recent years, the amount of heat generated due to higher integration and higher performance of elements has increased. Moreover, since the heat generation density increases with the miniaturization of products, heat dissipation measures have become important. This situation is particularly remarkable in the field of mobile terminals such as smartphones and tablets. In recent years, a graphite sheet or the like is often used as a heat countermeasure member, but since the amount of heat transport is not sufficient, use of various heat countermeasure members has been studied. In particular, the use of a vapor chamber, which is a planar heat pipe, has been studied because it is possible to diffuse heat very effectively.

  The vapor chamber is one in which an appropriate amount of working fluid that easily volatilizes is sealed in a flat airtight container. The working fluid is vaporized by the heat from the heat source, moves inside the internal space, and then releases the heat to the outside to return to the liquid. The working fluid that has returned to the liquid is transported again to the vicinity of the heat source by a capillary structure called a wick, and vaporizes again. By repeating this, the vapor chamber operates independently without having external power, and heat can be diffused at a high speed two-dimensionally using the latent heat of vaporization and the latent heat of condensation of the working fluid.

  Patent Document 1 describes a heat pipe having a condensing part for condensing the working fluid and an evaporating part for evaporating the working fluid. In Patent Document 1, a working fluid is sealed inside a container of a heat pipe, and a wick structure having a concavo-convex structure of nanometer order is formed on both the inner wall of the lower container and the inner wall of the upper container. With such a configuration, two-dimensional heat diffusion is achieved.

JP 2012-057841 A

  Since the vapor chamber needs to be used in the vicinity of a high-temperature heat source, it is preferable that the performance does not deteriorate due to a change in ambient temperature. However, when the vapor chamber becomes hot, impurity gas may be generated inside. Such impurity gases can change the desired heat transport properties of the vapor chamber. Further, when the impurity gas is trapped in the wick, the hydrophilicity of the wick is lowered, and the heat transport property of the vapor chamber may be lowered. If a wick structure having a concavo-convex structure on the order of nanometers is formed on both the inner wall of the lower container and the inner wall of the upper container as in Patent Document 1, impurity gas can be trapped by the wick. There is a possibility that the hydrophilicity is lowered and the heat transport property of the vapor chamber is lowered. Moreover, there is a concern that by providing the wick on both the inner wall of the lower container and the inner wall of the upper container, the portion where the working fluid that has become vapor moves becomes narrow.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vapor chamber that is less likely to deteriorate in performance even when the ambient temperature changes.

  In order to solve the above-described problem, a vapor chamber according to an aspect of the present invention includes a housing, a column disposed in the internal space of the housing so as to support the housing from the inside, The hydraulic fluid enclosed in the internal space and a wick disposed in the internal space of the housing, and at least a part of the main inner surface of the housing is exposed in the internal space of the housing, and the average It has pores with a depth of 10 nm or more.

  In one embodiment, the average depth of the pores on the main inner surface of the casing is 40 nm or less.

  Moreover, in the vapor chamber of one embodiment, the average diameter of the pores on the main inner surface of the casing is 10 nm or more and 100 nm or less.

  In one embodiment, at least a portion of the pillar is provided with pores having an average depth of 10 nm or more.

  Moreover, the vapor chamber of one Embodiment WHEREIN: The average depth of the pore of the said column is 40 nm or less.

  Moreover, the vapor chamber of one Embodiment WHEREIN: The average diameter of the pore of the said column is 10 nm or more and 100 nm or less.

  Further, in the vapor chamber of one embodiment, a convex portion having a height of 1 μm or more and 100 μm or less is formed on the main inner surface of the casing facing the main inner surface of the casing.

  Moreover, the vapor chamber of one Embodiment WHEREIN: The said housing | casing consists of two opposing sheets by which the outer edge part was sealed.

  Further, in the vapor chamber of one embodiment, the wick is in contact with the main inner surface facing the main inner surface having at least a part of the pores.

  Furthermore, according to this invention, the thermal radiation device which has the vapor chamber of this invention is provided.

  Furthermore, according to the present invention, an electronic apparatus comprising the vapor chamber of the present invention or the heat dissipation device of the present invention is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the vapor chamber which does not produce a performance fall by the change of ambient temperature is provided, without narrowing the part to which the working fluid used as the vapor moves.

It is sectional drawing of the vapor chamber of one Embodiment of this invention. It is a schematic diagram of the cross section of the main inner surface which has the pore of the vapor chamber of one Embodiment of this invention. It is sectional drawing of the vapor chamber of one Embodiment of this invention. It is a schematic diagram of the convex part of the main inner surface of the vapor chamber of one Embodiment of this invention. It is a schematic diagram of the convex part of the main inner surface of the vapor chamber of one Embodiment of this invention. It is a SEM image of the cross section of the main inner surface which has the pore of the vapor chamber of one Embodiment of this invention. It is a SEM image of the cross section of the main inner surface which has the pore of the vapor chamber of one Embodiment of this invention. It is a SEM image of the cross section of the main inner surface which has the pore of the vapor chamber of one Embodiment of this invention. It is sectional drawing of the vapor chamber of one Embodiment of this invention. It is an upper perspective view of the upper housing | casing sheet | seat of the vapor chamber of one Embodiment of this invention, and the lower housing | casing sheet | seat which has a joining layer.

  Hereinafter, the present invention will be described in more detail with reference to the drawings.

  1 and 3 are cross-sectional views of vapor chambers 1a and 1b, respectively, according to an embodiment of the present invention. As shown in FIGS. 1 and 3, the vapor chamber of the present invention includes a housing 2, a column 3 disposed in the internal space of the housing 2 so as to support the housing 2 from the inside, and a housing 2 and a wick 4 disposed in the internal space. Although not shown, the vapor chamber of the present invention further has a working fluid sealed in the internal space of the housing 2. As shown in FIGS. 1 and 3, at least a part of the main inner surface of the housing 2 is exposed in the internal space of the housing 2.

  FIG. 2 is a partially enlarged view schematically showing a portion having the pores 10 on the main inner surface exposed to the internal space of the casing 2 of the vapor chamber of the present invention. The average depth of the pores 10 is 10 nm or more. Since at least a part of the main inner surface of the casing 2 of the vapor chamber of the present invention is exposed in the internal space of the casing 2 and has the pores 10 having an average depth of 10 nm or more, the vapor chamber is Impurity gas that can be generated inside when the temperature becomes high can be trapped in the pores 10. Thereby, the quantity of the impurity gas adhering to the wick 4 can be reduced effectively, and the fall of the heat transport capability of a vapor chamber can be suppressed. Further, for trapping the impurity gas, by using the pores 10 on the main inner surface exposed in the internal space of the housing 2, the impurity gas can be trapped without narrowing the portion where the working fluid that has become a vapor moves. Can do.

  Below, each structure of the vapor chamber of this invention is demonstrated in detail.

  The housing 2 of the vapor chamber of the present invention only needs to have two opposing main inner surfaces. The shape of the main inner surface of the housing 2 may be polygonal or circular. In the present specification, the main inner surface refers to a surface having the largest area among surfaces defining the internal space of the housing 2 and a surface facing the surface.

  The height A of the housing 2 indicated by A in FIG. 1 (that is, the thickness of the vapor chamber) may be, for example, not less than 100 μm and not more than 600 μm, and preferably in the range of not less than 200 μm and not more than 500 μm. The width B of the housing 2 indicated by B in FIG. 1 (that is, the width of the vapor chamber) may be, for example, 5 mm or more and 500 mm or less, preferably 20 mm or more and 300 mm or less. Although not shown, the depth D (that is, the depth of the vapor chamber) of the housing 2 that is perpendicular to the arrow indicating the width B of the housing 2 in FIG. Or less, preferably in the range of 20 mm to 300 mm. The height A, the width B, and the depth D described above may be uniform or different at any location of the housing 2.

  The housing 2 may be integrally formed from a single member. For example, as shown in FIGS. 1 and 3, the housing 2 is composed of two opposing sheets whose outer edges are sealed. May be. Moreover, you may form from two or more plate-shaped members. 1 and 3, the upper housing sheet 6 forms an upper main inner surface of the housing 2, and the lower housing sheet 7 forms a lower main inner surface of the housing 2. In the housing 2, the upper housing sheet 6 and the lower housing sheet 7 are sealed with each other at their outer edge portions. The outer edge portions of the upper housing sheet 6 and the lower housing sheet 7 refer to a region of a predetermined distance inward from the end portion of the sheet. 1 and 3, the outer edge portion of the upper housing sheet 6 and the outer edge portion of the lower housing sheet 7 are sealed by laser welding, but this is the method of sealing the outer edge portion. For example, resistance welding, diffusion bonding, brazing, TIG welding, resin sealing, or the like can be used.

  The material which forms the housing | casing 2 is not specifically limited, For example, copper, nickel, aluminum, magnesium, titanium, iron, an alloy which has them as a main component, etc. can be used, Preferably copper is used.

  When the housing 2 is formed by sealing the upper housing sheet 6 and the lower housing sheet 7 with the outer edge portion, the upper housing sheet 6 and the lower housing sheet 7 are both made of the same material. It may be formed, and each may be formed from two different materials.

  The thickness C (in the example shown, the thickness of the housing sheet) of the wall surface constituting the housing 2 indicated by C in FIG. 1 may be, for example, 10 μm or more and 200 μm or less, and preferably 30 μm or more and 150 μm or less. More preferably, it is in the range of 30 μm or more and 100 μm or less, and more preferably in the range of 40 μm or more and 60 μm or less. The thickness C described above may be uniform or different at any location of the housing 2. The thickness C of the upper housing sheet 6 and the thickness of the lower housing sheet 7 may be different.

  Here, in the vapor chamber according to an embodiment of the present invention, the casing is composed of two opposing sheets whose outer edges are sealed, and the thermal conductivity of at least one of the two sheets is 1 W / (m -K) or more and 100W / (m * k) or less may be sufficient.

  In the present invention, the upper housing sheet 6 and the lower housing sheet 7 can each be formed of a material having an arbitrary thermal conductivity. For example, 1 W / (m · k) or more, more preferably 10 W / ( m · k) and 100 W / (m · k) or less, more preferably 50 W / (m · k) or less. When the thermal conductivity of at least one of the upper housing sheet 6 and the lower housing sheet 7 is 1 W / (m · k) or more, effective heat diffusion can be performed. In addition, since the thermal conductivity of at least one of the upper housing sheet 6 and the lower housing sheet 7 is 100 W / (m · k) or less, the heat given to the outer edge portion when welding the two sheets, Since the outer edge portion can be effectively retained without being diffused, the efficiency of the welding process can be improved. In addition, the thermal conductivity in the direction perpendicular to the main surface of the vapor chamber can be lowered, and it can be effectively used in applications where heat is not transmitted in this direction. For example, in a mobile phone or the like, heat transfer to a battery, liquid crystal, or the like can be suppressed by installing a vapor chamber between a heat source and a battery, liquid crystal, or the like so as to block both.

  As a material having a thermal conductivity of 1 W / (m · k) or more and 100 W / (m · k) or less, for example, SUS444 (26.0 W / 2) which is an alloy containing TiCu (54 W / (m · k)) and titanium. (M · k)), SUS304 (16.7 W / (m · k)) which is an alloy containing nickel, SUS316 (16.7 W / (m · k)) which is an alloy containing nickel, etc. Can do.

  In the above embodiment, the upper housing sheet 6 and the lower housing sheet 7 do not have to be provided with the pores 10 described in detail later. That is, the housing, the pillar disposed in the internal space of the housing so as to support the housing from the inside, the working fluid sealed in the internal space of the housing, and the internal space of the housing And the housing is composed of two opposing sheets whose outer edges are sealed, and the thermal conductivity of at least one of the two sheets is 1 W / (m · k) or more A vapor chamber can be provided that is 100 W / (m · k) or less.

  In the vapor chamber according to an embodiment of the present invention, the housing includes two opposing sheets whose outer edge portions are sealed, and the two sheets have different rigidity.

  In the present invention, the upper housing sheet 6 and the lower housing sheet 7 can have arbitrary rigidity, but the upper housing sheet 6 and the lower housing sheet 7 preferably have different rigidity. In this specification, the rigidity of a housing sheet refers to the difficulty of deformation of the housing sheet with respect to a force such as bending. Since the rigidity of the upper casing sheet 6 and the rigidity of the lower casing sheet 7 are different from each other, one casing sheet having a lower rigidity is easily deformed when the outer edge portion is sealed. Since the adhesion at the outer edge of the housing sheet is improved, a vapor chamber having a larger bonding strength at the outer edge can be obtained. When the rigidity of the upper casing sheet 6 is larger than the rigidity of the lower casing sheet 7, the vapor chamber is not easily crushed by the pressure from the upper casing side. When the rigidity of the lower casing sheet 7 is larger than the rigidity of the upper casing sheet 6, the vapor chamber is not easily crushed by the pressure from the lower casing side.

  In the above embodiment, the upper housing sheet 6 and the lower housing sheet 7 may have different rigidity by being formed from materials having different Young's moduli. Thereby, when a pressure is applied to a housing | casing from the housing sheet side with a large Young's modulus, a deformation | transformation of a housing sheet with a small Young's modulus can be reduced effectively. The upper housing sheet 6 and the lower housing sheet 7 can each be formed from any material having a different Young's modulus. For example, the upper housing sheet 6 may be formed from Cu, and the lower housing sheet 7 may be formed from TiCu having a Young's modulus larger than Cu.

  FIG. 9 is a cross-sectional view of a vapor chamber 1c according to an embodiment of the present invention. In the above embodiment, the upper housing sheet 6 and the lower housing sheet 7 may have different thicknesses as shown in FIG. Thus, when the upper housing sheet 6 and the lower housing sheet 7 are formed to have different thicknesses, the upper housing sheet 6 and the lower housing sheet 7 are formed from the same material. Even so, they may have different stiffnesses. Specifically, when the upper housing sheet 6 and the lower housing sheet 7 are formed of the same material, the housing sheet having a larger thickness has a large rigidity. Thereby, a vapor chamber becomes difficult to be crushed by the pressure from the housing sheet side which has a large thickness. In addition, by appropriately setting the ratio of the thickness of the upper housing sheet and the thickness of the lower housing sheet, a small thickness when pressure is applied to the housing from the housing sheet side having a large thickness is reduced. The deformation | transformation of the housing | casing sheet | seat which has can be reduced effectively.

  In the above embodiment, the upper housing sheet 6 and the lower housing sheet 7 do not have to be provided with the pores described in detail later. That is, the housing, the pillar disposed in the internal space of the housing so as to support the housing from the inside, the working fluid sealed in the internal space of the housing, and the internal space of the housing A vapor chamber may be provided in which the housing is composed of two opposing sheets sealed at the outer edge, and the two sheets have different rigidity.

  FIG. 10 is an upper perspective view showing the upper housing sheet 6 and the lower housing sheet 7 and the bonding layer 8 forming the vapor chamber housing 2 according to the embodiment of the present invention. In FIG. 10, the upper housing sheet 6 and the lower housing sheet 7 are described separately. However, in the vapor chamber of the present invention, both of them are sealed at the outer edge portion, and one housing 2 is formed. Form. That is, in the vapor chamber of this embodiment, the casing includes two opposing casing sheets 6 and 7 whose outer edge portions are sealed, and a bonding layer 8 positioned between the outer edge portions of the two casing sheets. And have.

  In the vapor chamber of one embodiment of the present invention, the bonding layer 8 is made of a material having a lower thermal conductivity than the material forming the housing sheet. Between the outer edge portions of the upper housing sheet 6 and the lower housing sheet 7, the bonding layer 8 made of a material having a lower thermal conductivity than the material forming the housing sheet is positioned, thereby welding the two sheets. In this case, part of the heat applied to the outer edge portion can be effectively retained in the bonding layer 8 at the outer edge portion without being diffused, so that the efficiency of the welding process can be improved. For the bonding layer 8, any material having a lower thermal conductivity than the material forming the housing sheet can be used. For example, when the upper housing sheet 6 and the lower housing sheet 7 are made of Cu, Ni or the like having a lower thermal conductivity than Cu can be used as a material for forming the bonding layer 8.

  In the above embodiment, the upper casing sheet 6 and the lower casing sheet 7 are provided with the bonding layer 8 made of a material having a lower thermal conductivity than the material forming the casing sheet between the entire circumference of the casing. By being sealed by, it becomes possible to more effectively suppress the conduction of heat to the inner portion of the outer edge portion, and the efficiency of the welding process can be further improved. The outer edge portion may have a portion where the bonding layer 8 and the bonding layer 8 are provided apart from each other. For example, the bonding layer 8 may be formed without being provided only in the portion where the vacuum pump is inserted in order to reduce the pressure inside the vapor chamber body.

  In the said embodiment, the upper housing sheet 6 and the lower housing sheet 7 can be joined with sufficient strength by appropriately setting the thickness of the joining layer 8. Further, by appropriately setting the thickness of the bonding layer 8, the gap formed in the portion where the bonding layer 8 is not provided does not become too large, and the upper housing sheet 6 and the lower housing sheet 7 have sufficient strength. And can be joined so as to have a sealing property. The thickness of the bonding layer 8 may be uniform throughout the bonding layer 8 or may vary depending on the location. For example, the bonding layer 8 may be formed so that the thickness is reduced only at the portion where the vacuum pump is inserted in order to reduce the pressure inside the vapor chamber body.

  In the above embodiment, the upper housing sheet 6 and the lower housing sheet 7 do not have to be provided with the pores 10 described in detail later. That is, the housing, the pillar disposed in the internal space of the housing so as to support the housing from the inside, the working fluid sealed in the internal space of the housing, and the internal space of the housing The casing is composed of two opposing sheets whose outer edge portions are sealed, and the bonding layer 8 is located between the outer edge portions of the two casing sheets. A vapor chamber may be provided.

  In the vapor chamber of one embodiment of the present invention, the bonding layer 8 is made of a material having a lower melting point than the material forming the housing sheet. Since the bonding layer 8 made of a material having a lower melting point than the material forming the housing sheet is positioned between the outer edge portions of the upper housing sheet 6 and the lower housing sheet 7, the outer edge portion is welded at a lower temperature. Therefore, the efficiency of the welding process can be improved. For the bonding layer 8, any material having a lower melting point than the material forming the housing sheet can be used. For example, when the upper housing sheet 6 and the lower housing sheet 7 are made of Cu, a bulk Sn alloy or the like having a melting point lower than that of Cu can be used as a material for forming the bonding layer 8.

  In the above embodiment, the upper casing sheet 6 and the lower casing sheet 7 are sealed by providing the bonding layer 8 made of a material having a lower melting point than the material forming the casing sheet between the entire circumference of the casing. By being stopped, the upper housing sheet 6 and the lower housing sheet 7 can be joined with sufficient strength. The outer edge portion may have a portion where the bonding layer 8 and the bonding layer 8 are provided apart from each other. For example, the bonding layer 8 may be formed without being provided only in the portion where the vacuum pump is inserted in order to reduce the pressure inside the vapor chamber body.

  In the said embodiment, the upper housing sheet 6 and the lower housing sheet 7 can be joined with sufficient strength by appropriately setting the thickness of the joining layer 8. Further, by appropriately setting the thickness of the bonding layer 8, the gap formed in the portion where the bonding layer 8 is not provided does not become too large, and the upper housing sheet 6 and the lower housing sheet 7 have sufficient strength. And can be joined so as to have a sealing property. The thickness of the bonding layer 8 may be uniform throughout the bonding layer 8 or may vary depending on the location. For example, the bonding layer 8 may be formed so that the thickness is reduced only at the portion where the vacuum pump is inserted in order to reduce the pressure inside the vapor chamber body.

  In the above embodiment, the upper housing sheet 6 and the lower housing sheet 7 do not have to be provided with the pores 10 described in detail later. That is, the housing, the pillar disposed in the internal space of the housing so as to support the housing from the inside, the working fluid sealed in the internal space of the housing, and the internal space of the housing The casing is composed of two opposing sheets whose outer edge portions are sealed, and the bonding layer 8 is located between the outer edge portions of the two casing sheets. A vapor chamber may be provided.

  At least a part of the main inner surface of the housing 2 is exposed in the internal space of the housing 2, and the portion exposed in the internal space has pores 10 having an average depth of 10 nm or more as shown in FIG. doing. In this specification, the “exposed” portion of the main inner surface of the housing 2 is the portion of the housing 2 that can come into contact with the gas in the internal space. For example, the wick 4, the pillar 3, and other members It is the part that is not touching. By providing the pores 10 having an average depth of 10 nm or more on the main inner surface of the housing 2, the impurity gas can be trapped by the pores 10. Thereby, the quantity of the impurity gas adhering to the wick 4 can be reduced, and the fall of the heat transport capability of a vapor chamber can be suppressed.

  In this specification, the “impurity gas” refers to a gas other than the components contained in the hydraulic fluid present in the internal space of the housing 2. For example, the component of the rust preventive agent adhering to the metal foil constituting the housing 2 can be generated by gasification when the housing 2 becomes high temperature. Examples of the component of the impurity gas include alcohols, hydrocarbons, aromatics, and carbon dioxide.

  In the present specification, the average depth of the pores 10 means that the cross section is observed at a length of 1 μm at three arbitrary positions on the main inner surface, and the pores having a depth of 5 nm or more and a diameter of 300 nm or less are the pores. The value measured by measuring the average value of the depth. The average depth of the pores 10 of the vapor chamber of the present invention is 10 nm or more, preferably 20 nm or more, more preferably 30 nm or more. When the average depth of the pores 10 is 10 nm or more, a sufficient amount of impurity gas can be trapped in the pores 10 on the main inner surface, and it becomes difficult to release the trapped impurity gas.

  The average depth of the pores 10 on the main inner surface is preferably 40 nm or less. When the average depth of the pores 10 is 40 nm or less, embrittlement of the main inner surface can be effectively prevented.

  The average diameter of the pores 10 on the main inner surface is in the range of 10 nm to 100 nm, more preferably in the range of 10 nm to 80 nm, and still more preferably in the range of 10 nm to 50 nm. When the average diameter of the pores 10 on the main inner surface is 10 nm or more, the impurity gas can be effectively trapped. When the average diameter of the pores 10 on the main inner surface is 100 nm or less, the possibility that the working fluid is trapped in the pores 10 on the main inner surface can be significantly reduced. Furthermore, when the average diameter of the pores 10 on the main inner surface is 50 nm or less, it is possible to prevent the working fluid from entering the pores 10 and substantially trap only gas.

  In this specification, the average diameter of the pores 10 refers to pores having a depth of 5 nm or more and a diameter of 300 nm or less that are observed when cross-sectional observation is performed at a length of 1 μm at three arbitrary positions on the main inner surface. The average value of the diameters.

The average number of pores 10 provided per 1 μm ^{2 of} the surface defining the internal space of the housing 2 is
It may be 10 or more and 1000 or less, preferably 30 or more and 400 or less, and more preferably 50 or more and 200 or less. When the case 2 becomes high temperature, there is a possibility that impurity gas derived from the component of the anticorrosive agent is generated from the portion exposed to the internal space of the case 2 to the internal space. The amount of the impurity gas generated at this time is proportional to the area of the surface that defines the internal space of the housing 2, so that the average number of pores 10 is 10 or more per 1 μm ^{2 of} the surface that defines the internal space of the housing 2. By being provided, it becomes possible to effectively trap the generated impurity gas. Further, since the average number of pores 10 provided per 1 μm ^{2 of} the surface defining the internal space of the housing 2 is 1000 or less on average, embrittlement of the main inner surface having the pores 10 is effectively prevented. be able to.

Although the formation method of the pore 10 is not specifically limited, For example, the method of forming by surface treatments, such as an etching and a blast, is mentioned, As plating, spraying etc. are mentioned as another method. When the pores 10 are formed by etching, the average depth, average diameter and casing 2 of the pores 10 to be formed are adjusted by adjusting the conditions such as the type of etchant used, the etching temperature and the etching time. It is possible to control the average of the number of the pores 10 provided per 1 μm ^{2 of} the surface that defines the internal space.

  The pillar 3 is disposed in the internal space of the housing 2 so as to support the housing 2 from the inside. The pillar 3 may be formed integrally with the housing 2 in the internal space of the housing 2 or may be joined to the housing 2. By disposing the pillar 3 in the internal space of the housing 2, it is possible to reduce deformation of the housing 2 when a load is applied to the housing 2.

  In the vapor chamber of the present invention, the pores 10 having an average depth of 10 nm or more provided on the main inner surface of the housing 2 are similarly provided on at least a part of the portion of the pillar 3 exposed to the internal space of the housing 2. It may be done. The average depth of the pores 10 of the pillar 3 is 10 nm or more, preferably 20 nm or more, more preferably 30 nm or more. By providing the pillars 3 with the pores 10 having an average depth of 10 nm or more, the impurity gas can be trapped more effectively by the pores 10. Thereby, the quantity of the impurity gas adhering to the wick 4 can be reduced effectively, and the fall of the heat transport capability of a vapor chamber can be prevented.

  The average depth of the pores 10 of the pillar 3 is preferably 40 nm or less. This effectively prevents embrittlement of the main inner surface.

  The average diameter of the pores 10 of the column 3 is in the range of 10 nm to 100 nm, more preferably in the range of 10 nm to 80 nm, and still more preferably in the range of 10 nm to 50 nm. When the average diameter of the pores 10 of the pillar 3 is 10 nm or more, the impurity gas can be effectively trapped. When the average diameter of the pores 10 of the column 3 is 100 nm or less, the possibility that the hydraulic fluid is trapped in the pores 10 of the column 3 can be significantly reduced. Furthermore, when the average diameter of the pores 10 of the pillar 3 is 50 nm or less, the working fluid can be prevented from entering the pores 10 and substantially only gas can be trapped.

The average number of pores 10 per 1 μm ² of the surface of the pillar 3 may be 10 or more and 1000 or less, preferably 30 or more and 400 or less, more preferably 50 or more and 200 or less. . When the number of the pores 10 per 1 μm ² of the surface of the column 3 is 10 or more, the impurity gas can be effectively trapped. In addition, since the number of pores 10 per 1 μm ² of the surface of the pillar 3 is 1000 or less, embrittlement of the surface of the pillar 3 having the pores 10 can be effectively prevented.

  As shown in FIG. 3, a convex portion 5 having a height of 1 μm or more and 100 μm or less may be formed on the main inner surface of the housing 2 that faces the main inner surface of the housing 2 provided with the pores 10. . The convex part 5 may be directly formed on the main inner surface of the housing 2 as shown in FIG. The space between the convex parts 5 can play the role of refluxing the working fluid. For this reason, in the vapor chamber of the present invention having the convex portion 5, since the reflux of the hydraulic fluid is promoted by both the wick 4 and the space between the convex portions 5, the efficiency is higher than that of the vapor chamber having no convex portion 5. Thermal diffusion can occur. As shown in FIG. 3, when the convex portion 5 is directly formed on the main inner surface of the housing 2, the area of the main inner surface of the housing 2 exposed to the internal space of the housing 2 increases. Thereby, since the housing | casing 2 comes to have many more pores 10, it becomes possible to trap an impurity gas more effectively by the pores 10. FIG. Thereby, the quantity of the impurity gas adhering to the wick 4 can be reduced effectively, and the fall of the heat transport capability of a vapor chamber can be prevented.

  Instead of forming the convex portion 5, a metal foil having the convex portion 5 may be separately prepared and placed on the main inner surface. By installing the metal foil having the convex portions 5 in the casing as described above, the same effect as that obtained when the convex portions 5 are formed on the main inner surface can be obtained.

  In this specification, a convex part means the part which has a height larger than the adjacent part among the main inner surfaces of the housing | casing 2. As shown in FIG. The convex portion may be formed by providing a protrusion on the main inner surface or metal foil of the housing 2, and, for example, by providing a plurality of grooves on the main inner surface or metal foil of the housing 2, the provided grooves and grooves Between the two.

  The convex part 5 of the housing | casing 2 can be formed in arbitrary shapes so that the space which can circulate a hydraulic fluid between adjacent convex parts 5 is formed. The height E of the convex portion 5 may be in the range of 1 μm to 100 μm, for example, and is preferably in the range of 5 μm to 50 μm. The distance F between the convex portion 5 and the adjacent convex portion 5 may be, for example, in the range of 1 μm to 500 μm, preferably in the range of 5 μm to 300 μm, and more preferably in the range of 15 μm to 150 μm. Is in range. When the distance F is within such a range, the working fluid can be effectively refluxed.

  The convex part 5 of the housing | casing 2 is preferably formed in the column shape which has the mutually opposing bottom face parallel to each other. The convex part 5 of the housing | casing 2 may be a substantially square pillar shape, a substantially cylindrical shape, and a frustum shape, for example. When the convex portion 5 of the housing 2 is formed in a substantially quadrangular prism shape, the bottom surface of the convex portion 5 has a ratio of the length of the short side to the length of the long side close to 1, as shown in FIG. It may be a rectangle. Further, as shown in FIG. 5, the ratio of the length of the short side to the length of the long side may be significantly lower than 1. Although not shown, the ratio of the length of the short side to the length of the long side may be 1. That is, the bottom surface of the convex portion 5 may be square.

  The wick 4 is disposed in the internal space of the housing 2 and plays a role of refluxing the working fluid. The arrangement | positioning aspect of the wick 4 is not specifically limited, For example, as FIG. 1 shows, you may arrange | position so that it may be clamped between the main inner surface of the housing | casing 2, and the pillar 3. As shown in FIG. In addition, as shown in FIG. 2, when the convex portion 5 is formed on the main inner surface of the casing 2 that faces the main inner surface of the casing 2 provided with the pores 10, the convex portion 5 and the column are formed. 3 may be arranged so as to be held between the two.

  The thickness of the wick 4 may be, for example, in the range of 5 μm to 200 μm, preferably 10 μm to 80 μm, and more preferably 30 μm to 50 μm. The thickness of the wick 4 may be uniform everywhere in the wick 4 or may be different. Moreover, the wick 4 does not necessarily need to be formed over the entire main inner surface of the vapor chamber casing 2, and may be partially formed.

  The material of the wick 4 is not particularly limited, and for example, a porous body, a mesh, a sintered body, a nonwoven fabric, a wire, or the like can be used, and a mesh or a nonwoven fabric is preferably used.

  The wick 4 is preferably arranged on the main inner surface facing the main inner surface having the pores 10 at least in part. When the wick 4 is disposed on one main inner surface, the liquid is easily distributed on the main inner surface side where the wick 4 is disposed, and the gas is easily distributed on the main inner surface side facing the main inner surface where the wick 4 is disposed. Therefore, the wick 4 is arranged on the main inner surface opposite to the main inner surface having the pores 10 at least in part, so that gas is easily distributed on the main inner surface side having the pores 10, and the pores 10 are impurities. Since it becomes easy to come into contact with the gas, the impurity gas can be effectively trapped in the pores 10.

  In this specification, “the wick 4 is disposed on the main inner surface” means that the distance between the main inner surface and the wick 4 is shorter than the distance between the main inner surface facing the main inner surface and the wick 4. That means. The state in which the wick 4 is disposed on the main inner surface includes, for example, the state in which the main inner surface on the lower casing sheet 7 side and the wick 4 are in contact with each other as shown in FIG. And the wick 4 is in contact with the convex portion 5 on the main inner surface where the convex portion 5 is formed. Further, although not shown, the state in which the metal foil convex portion 5 having the convex portion 5 placed on the main inner surface is in contact with the wick 4 also indicates that “the wick 4 is disposed on the main inner surface. It is included in the state.

  Although not shown in FIGS. 1 and 3, the working fluid is further sealed in the housing 2 of the vapor chamber of the present invention. The hydraulic fluid is vaporized by the heat from the heating element and becomes vapor. Thereafter, the working fluid that has become vapor moves in the housing 2, releases heat, and returns to the liquid. The working fluid that has returned to the liquid is transported to the heat source again by capillary action by the wick 4. And it is vaporized by the heat from the heat source again to become steam. By repeating this, the vapor chamber of the present invention operates independently without requiring external power, and can rapidly diffuse heat in two dimensions using the latent heat of evaporation / condensation of the working fluid. .

  The type of hydraulic fluid is not particularly limited, and for example, water, alcohols, alternative chlorofluorocarbons, etc. can be used, and water is preferably used.

  The vapor chamber of the present invention can be mounted on a heat dissipation device so as to be close to a heat source. Accordingly, the present invention also provides a heat dissipation device comprising the vapor chamber of the present invention. By providing the heat dissipation device of the present invention with the vapor chamber of the present invention, it is possible to effectively suppress an increase in temperature around the electronic component that generates heat and the component.

  The vapor chamber or the heat dissipation device of the present invention can be mounted on an electronic apparatus for the purpose of heat dissipation. Accordingly, the present invention provides an electronic apparatus comprising the vapor chamber or heat dissipation device of the present invention. Examples of the electronic device of the present invention include a smartphone, a tablet, and a notebook PC. As described above, the vapor chamber of the present invention operates independently without requiring external power, and can diffuse heat at a high speed two-dimensionally using latent heat of evaporation / condensation of the working fluid. Therefore, by providing the electronic apparatus with the vapor chamber or the heat dissipation device of the present invention, it is possible to effectively realize heat dissipation in a limited space inside the electronic apparatus.

Example 1
First, two Cu foils for forming the upper housing sheet 6 and the lower housing sheet 7 were prepared. The dimensions of the Cu foil forming the upper housing sheet 6 were 110 mm in length and 60 mm in width, and the thickness was 0.2 mm. The dimensions of the Cu foil forming the lower housing sheet 7 were 110 mm long and 60 mm wide, and the thickness was 0.08 mm. The pillar 3 was formed on the Cu foil forming the upper housing sheet 6 by etching. The etching solution used for forming the pillar 3 was sodium persulfate, and the etching time was adjusted so that the height of the pillar 3 was 150 μm. After the pillar 3 was formed, the Cu foil forming the upper housing sheet 6 was heat-treated at 180 ° C. for 30 minutes at atmospheric pressure to form an oxide film on the surface of the Cu foil forming the upper housing sheet 6. The pores 10 were formed by etching in a Cu foil having an oxide film on the surface and forming the upper housing sheet 6. The etching solution used for forming the pores 10 was iron chloride, the etching temperature was 25 ° C., and the etching time was 30 seconds. The wick 4 is disposed so as to be sandwiched between the upper housing sheet 6 and the lower housing sheet 7 in which the pores 10 are formed, and the outer edge portion of the upper housing sheet 6 and the outer edge portion of the lower housing sheet 7 Was sealed by laser welding to obtain a vapor chamber body of the present invention. Next, one of the four corners of the obtained vapor chamber main body was cut out, a Cu pipe was inserted therein, and the vapor chamber main body and the Cu pipe were fixed with solder. This Cu pipe was connected to a syringe containing water as a working fluid through a switching valve. First, the switching valve was connected to the inside of the vapor chamber and the vacuum pump, and the inside of the vapor chamber body was depressurized. Thereafter, the valve was switched, the inside of the vapor chamber and the syringe containing the working fluid were connected, and after a predetermined amount of working fluid was injected into the vapor chamber, the Cu pipe was caulked and sealed to form a vapor chamber. The thickness of the wick 4 used was 50 μm, and the resulting vapor chamber had a height A of 0.3 mm, a width B of 110 mm, and a depth D of 60 mm.

(Example 2)
The vapor chamber of the present invention was the same as in Example 1 except that the etching solution used for forming the pores 10 was iron chloride, the etching temperature was 25 ° C., and the etching time was 1 minute. Got.

Example 3
The vapor chamber of the present invention was prepared in the same manner as in Example 1 except that the etching solution used for forming the pores 10 was iron chloride, the etching temperature was 25 ° C., and the etching time was 2 minutes. Got.

(Comparative Example 1)
A vapor chamber of the present invention was obtained in the same manner as in Example 1 except that the etching step for forming the pores 10 was not performed.

  When SEM images of the cross section of the main inner surface of the upper casing sheet 6 of Examples 1 to 3 were measured, the results were as shown in FIGS. Here, the upper side from the white part in the central part of FIGS. 6 to 8 is a protective film provided later for observation, and the lower part from the white part in the central part of the figure is a cross section of the casing. The main inner surface of the upper housing sheet 6 of Example 1 shown in FIG. 6 had pores 10 having an average depth of 10 nm. The main inner surface of the upper housing sheet 6 of Example 2 shown in FIG. 7 had pores 10 having an average depth of 20 nm. The main inner surface of the upper housing sheet 6 of Example 3 shown in FIG. 8 had pores 10 having an average depth of 40 nm. 6-8, in order to show the position of the pore 10, the one part pore 10 is enclosed with the circle of the broken line.

  Five vapor chambers of Example 1 were manufactured and subjected to 300 cycles of the thermal shock test at 85 ° C. on the high temperature side and −40 ° C. on the low temperature side. As a result, the maximum heat transport amount was 60 compared with before the thermal shock test. There were no 0% or less. When five vapor chambers of Examples 2 and 3 were manufactured and the thermal shock test was performed in the same manner, the maximum heat transport amount was 60% or less compared with that before the thermal shock test. There were zero.

  On the other hand, when five vapor chambers of Comparative Example 1 were manufactured and the thermal shock test was performed in the same manner, the maximum heat transport amount of four of the five vapor chambers was before the thermal shock test. Compared to 60% or less. This is thought to be because the vapor chamber of Comparative Example 1 does not have the pores 10 because the etching process for forming the pores 10 is not performed in the manufacturing process of the vapor chamber of Comparative Example 1. . Since the main inner surface of the casing 2 of the vapor chamber of Comparative Example 1 does not have the pores 10, the amount of impurity gas trapped by the wick cannot be reduced, and the hydrophilicity of the wick is deteriorated. It is considered that the heat conduction characteristics of the chamber have deteriorated.

  In this specification, the maximum heat transport amount means that when a ceramic heater of 1.5 cm × 1.5 cm is installed at the center of one short side of the vapor chamber and the input heat amount by this heater is increased, The amount of heat input from the heater when the temperature of the surface of the casing opposite to the surface on which the ceramic heater is installed is 5 ° C. or more higher than the temperature at the center of the vapor chamber.

  From this, the vapor chamber of the present invention has the pores 10 on the main inner surface of the housing 2 so that the amount of impurity gas trapped by the wick 4 can be reduced, and the hydrophilicity of the wick 4 is deteriorated. And it became clear that it can prevent that the heat conduction characteristic of a vapor chamber falls.

  The vapor chamber, heat dissipation device and electronic apparatus of the present invention can be used for a wide range of applications in the field of portable information terminals and the like. For example, it can be used to lower the temperature of a heat source such as a CPU and extend the usage time of an electronic device, and can be used for a smartphone, a tablet, a notebook PC, and the like.

DESCRIPTION OF SYMBOLS 1a Vapor chamber 1b Vapor chamber 1c Vapor chamber 2 Case 3 Pillar 4 Wick 5 Convex part 6 Upper case sheet 7 Lower case sheet 8 Bonding layer 10 Pore

Claims (11)

A housing,
Pillars arranged in the internal space of the housing so as to support the housing from the inside;
Hydraulic fluid sealed in the internal space of the housing;
Having a wick disposed in the internal space of the housing;
A vapor chamber in which at least a part of the main inner surface of the casing is exposed to the internal space of the casing and has pores having an average depth of 10 nm or more.   The vapor chamber according to claim 1, wherein an average depth of pores on a main inner surface of the casing is 40 nm or less.   The vapor chamber according to claim 1 or 2, wherein an average diameter of pores on a main inner surface of the casing is 10 nm or more and 100 nm or less.   The vapor chamber according to any one of claims 1 to 3, wherein pores having an average depth of 10 nm or more are provided in at least a part of the pillar.   The vapor chamber according to claim 4, wherein the average depth of the pores of the pillar is 40 nm or less.   The vapor chamber according to claim 4 or 5, wherein an average diameter of pores of the pillar is 10 nm or more and 100 nm or less.   The vapor chamber according to any one of claims 1 to 6, wherein a convex portion having a height of 1 µm or more and 100 µm or less is formed on the main inner surface facing the main inner surface having the pores.   The vapor chamber according to any one of claims 1 to 7, wherein the casing is composed of two opposing sheets whose outer edges are sealed.   The vapor chamber according to any one of claims 1 to 8, wherein the wick is disposed on a main inner surface facing the main inner surface having the pores at least in part.   A heat dissipation device comprising the vapor chamber according to any one of claims 1 to 9.   An electronic apparatus comprising the vapor chamber according to any one of claims 1 to 9 or the heat dissipation device according to claim 10.

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