KR20220075765A - The Vapor Chamber - Google Patents

Abstract

This application relates to a vapor chamber. The vapor chamber of the present application may have various performances within a given size, for example, improved heat load capacity and effective thermal conductivity. In addition, excellent performance may be obtained regardless of the installation direction of the vapor chamber.

Description

The Vapor Chamber

This application relates to a vapor chamber.

As the performance of electronic products improved, the calorific value of the products also increased. As the amount of heat generated by an electronic product increases, a means for effectively dissipating heat from the product, for example, a means such as a heat-radiating element, has been required.

A vapor chamber is known as a representative example of a heat dissipation element. As mentioned in Non-Patent Document 1, the vapor chamber is usually composed of a sealed case having a rectangular parallelepiped shape, a porous wick formed along the rim of the internal space of the case, and a working fluid filling the internal space of the case. When the vapor chamber is placed on an external heat source, the working fluid is evaporated by the heat of the external heat source. Since evaporation is an endothermic reaction, the temperature decreases as the working fluid evaporates. The evaporated working fluid moves along the interior space of the vapor chamber and is condensed in the process. Since condensation is an exothermic reaction, heat is released from the opposite side of the heat source during the condensation process. As a result, if the vapor chamber is used, the heat generated from the heat source can be discharged to the outside. In addition, the working liquid generated during the condensation of the working fluid moves along the wick to an area where evaporation occurs (see FIG. 1 ). At this time, the working fluid moves by the capillary force of the working fluid acting on the wick. In addition, since the heat transfer direction of the vapor chamber is in the planar direction, the vapor chamber has an advantage that can be applied to a heat source of a large area.

The performance of a vapor chamber is usually determined by the properties of the wick formed therein. As mentioned in Patent Document 1 and Non-Patent Document 2, the wick exists in the form of a pattern having a certain shape and shape in the vapor chamber. However, since the vapor chamber usually has a certain size, there is a limit in improving the heat dissipation characteristics within the predetermined size as described above. In addition, the conventional heat dissipation element has a problem in that the performance is deteriorated depending on the installation direction.

Japanese Patent Publication No. 6587164

Entropy, 2020, 22(1), 35 Applied Thermal Engineering Vol. 167 (2020), 114726

It is an object of the present application to provide a vapor chamber. An object of the present application is to provide a vapor chamber capable of having various performances, for example, improved heat load capacity and effective thermal conductivity, etc. within a given vapor chamber size. Another object of the present invention is to provide a vapor chamber having excellent performance regardless of the installation direction of the vapor chamber.

The purpose of the present application is not limited to the above purpose.

Among the physical properties mentioned in this specification, when the measured temperature affects the result, unless otherwise specified, the corresponding physical property is a physical property measured at room temperature. The term ambient temperature is the natural temperature, whether heated or not reduced, usually a temperature in the range of about 10°C to 30°C, or a temperature on the order of about 23°C or about 25°C. In addition, unless otherwise specified in this specification, the unit of temperature is °C.

Among the physical properties mentioned in this specification, when the measured pressure affects the result, unless otherwise specified, the corresponding physical property is a physical property measured at normal pressure. The term atmospheric pressure refers to a natural temperature that has not been pressurized or depressurized, and usually about 1 atmosphere is referred to as atmospheric pressure.

An exemplary vapor chamber of the present invention is described in detail below with reference to the drawings.

In the following description, the drawings may be exaggerated for easy understanding, but this may be understood by focusing on the interrelationship between the components.

The present application relates to a heat dissipation device capable of effectively controlling heat generated during the operation of a battery or various electronic devices. More specifically, the present application relates to a vapor chamber as a heat dissipation element. While conventionally known heat-pipes transfer heat in one direction (1-direction), the vapor chamber has the advantage of transferring heat in two directions (2-direction).

2 is an exemplary schematic diagram of a vapor chamber according to the present application. Referring to FIG. 2 , the vapor chamber according to the present application includes a first substrate 100 ; a second substrate 200 facing the first substrate; It is positioned between the first substrate and the second substrate and includes a closed space 300 in which the working fluid is sealed.

The above first and second expressions do not prescribe a front-to-back or up-and-down relationship of the substrate.

As an example, the first substrate or the second substrate may be a metal substrate. More preferably, each of the first substrate and the second substrate may be a metal substrate.

A thermally conductive substrate may be used as the metal substrate. In one example, the thermal conductivity of the first substrate and the second substrate is about 8 W/mK or more, about 10 W/mK or more, about 15 W/mK or more, about 20 W/mK or more, about 25 W/mK or more, respectively. or more, about 30 W/mK or more, about 35 W/mK or more, about 40 W/mK or more, about 45 W/mK or more, about 50 W/mK or more, about 55 W/mK or more, about 60 W/mK or more , about 65 W/mK or more, about 70 W/mK or more, about 75 W/mK or more, about 80 W/mK or more, about 85 W/mK or more, or about 90 W/mK or more. The metal substrate may obtain a vapor chamber having excellent heat dissipation efficiency as the thermal conductivity is higher, and thus the upper limit thereof is not particularly limited, and may be, for example, about 1,000 W/mK or less.

The specific type of the metal substrate is not particularly limited as long as it has the above-mentioned thermal conductivity, and for example, SUS (Stainless Steel), copper, gold, silver, aluminum, silver, nickel, iron, cobalt, magnesium, molybdenum. , may be any one selected from the group consisting of tungsten, platinum, magnesium and zinc, or a substrate of an alloy of two or more of the above, but is not limited thereto.

As an example, the type of the working fluid enclosed in the sealed space may be determined according to an operating temperature range in which the vapor chamber should operate. Various types of working fluids are known, from compounds having a very low boiling point (eg, a temperature in the range of 2K to 4K) to a very high temperature (eg, a temperature in the range of 2,000K to 3,000K) Various kinds of components can be applied up to compounds having a boiling point of An exemplary working fluid is water, and it is known that vapor chambers applying water as the working fluid are operable at temperatures usually within the range of 20°C to 150°C.

Each of the first substrate and the second substrate is located in the closed space on one surface facing the closed space, and a plurality of vapor flow passages through which the vapor of the working fluid evaporated by an external heat source passes, and the liquid working fluid passes through A plurality of liquid flow passages are provided along the width direction of the first substrate and the second substrate, respectively.

In the above, the external heat source means heat transferred from the outside to the vapor chamber, and for example, may mean heat generated during the operation of a battery or various electronic devices.

Meanwhile, evaporation of the working fluid by an external heat source may be performed in an evaporation region of the vapor chamber. The term “evaporation region” may mean a region where a working fluid is evaporated to generate steam, which may mean a region of a vapor chamber adjacent to an external heat source. The external heat source may be located on the vapor chamber in consideration of the structure of the vapor chamber and heat dissipation efficiency of the vapor chamber, for example, the external heat source may be located on the central portion of the vapor chamber. The central portion of the vapor chamber refers to a direction perpendicular to the long axis direction at 1/2 of the long axis direction (eg, the x direction in FIG. 2 ) and the short axis direction of the vapor chamber (eg, FIG. 2 ). in the y-direction) may mean a portion located at a point where the direction perpendicular to the short-axis direction intersects at 1/2 of the position. Hereinafter, it is assumed that the evaporation region is positioned on the central portion of the vapor chamber, but the evaporation region is not limited to the central portion of the vapor chamber.

The vapor of the working fluid evaporated in the evaporation region by the external heat source moves in a direction away from the evaporation region (or in the direction of the condensation region), is cooled and condensed to become a liquid working fluid. The condensed liquid working fluid enters the liquid flow passage and moves to the evaporation region by capillary force.

3 is a schematic diagram showing a first substrate 100 and a second substrate 200 of a conventional vapor chamber. A conventional vapor chamber is located in the closed space on one surface facing the sealed space 300 of the first substrate 100 and a plurality of vapor flow passages 120 through which the vapor of the working fluid evaporated by an external heat source passes, and a liquid phase. A plurality of liquid flow passages 110 through which the working fluid passes are provided along the width direction of the first substrate. In addition, a plurality of vapor flow passages 220 located in the closed space on one surface of the second substrate 200 facing the sealed space 300 and through which the vapor of the working fluid evaporated by an external heat source passes, and the liquid phase operation A plurality of liquid flow passages 210 through which the fluid passes are provided along the width direction of the second substrate. Meanwhile, the sealed space 300 includes a plurality of liquid channel units 110 and vapor channel units 120 of the first substrate 100 , and a plurality of liquid channel units 210 and vapor channel units of the second substrate 200 . When the vapor chamber is manufactured by bonding the rim of the first substrate and the rim of the second substrate in a state where 220 is disposed to face each other, it may be formed between the first substrate and the second substrate.

Meanwhile, in the above, the width directions of the first substrate and the second substrate refer to the short axis direction of the vapor chamber, for example, the y direction in FIG. 3 .

The conventional vapor chamber is configured to correspond to the plurality of liquid flow passages and vapor flow passages provided on the second substrate when projecting the plurality of liquid passage portions and vapor passage portions provided on the first substrate onto one surface of the second substrate. That is, the plurality of liquid and vapor flow passages provided on the first substrate and the plurality of liquid and vapor flow passages provided on the second substrate are configured to correspond in directions facing each other. In addition, the plurality of liquid flow passages and vapor flow passages have a stripe pattern shape having a certain shape and shape, which is disadvantageous in improving heat dissipation characteristics within a predetermined size. For example, when the temperature of the external heat source is high, a dry-out phenomenon easily occurs in the evaporation region of the vapor chamber in which the external heat source is located, so that the heat dissipation efficiency by the vapor chamber is reduced. In addition, a vapor chamber having a configuration corresponding to a direction in which the plurality of liquid and vapor passages provided on the first substrate and the plurality of liquid and vapor passages on the second substrate face each other may be installed in the vapor chamber. Performance may decrease depending on the direction.

The present invention can effectively suppress the dry-out phenomenon in the evaporation region even when the temperature of the external heat source is high, so that an improved heat dissipation effect, for example, improved heat load capacity and effective thermal conductivity conductivity). In addition, it has excellent performance regardless of the installation direction of the vapor chamber.

Hereinafter, exemplary embodiments of the present application will be described in detail.

4 is a schematic diagram illustrating a first substrate 100 and a second substrate 200 of a vapor chamber according to an example of the present application. According to an example of the present application, when the plurality of vapor passage units 120 provided on the first substrate 100 projects the vapor passage portion 120 onto one surface of the second substrate 200 , the second substrate 200 ) is provided so as not to overlap with the plurality of vapor flow passages 220 provided in at least some regions.

In FIG. 4 , the plurality of vapor passage units 120 provided on the first substrate and the plurality of vapor passage units 220 provided on the second substrate overlap in some regions when the first substrate and the second substrate are disposed to face each other. doesn't happen As described above, when the plurality of vapor passage portions of the first substrate and the plurality of vapor passage portions of the second substrate do not overlap in some regions, the vapor of the working fluid moving through the plurality of vapor passage portions of the first substrate and the second substrate 2 Vapors of the working fluid moving through the plurality of vapor passages of the substrate may have different directions. Accordingly, heat supplied from an external heat source may be transferred in various directions within the vapor chamber, thereby improving the problem of deterioration in performance depending on the installation direction of the vapor chamber.

As an example, the plurality of liquid channel units provided on the first substrate are provided so as not to overlap with the plurality of liquid channel units provided on the second substrate in at least some regions when the liquid channel units are projected onto one surface of the second substrate. can be

In FIG. 4 , the plurality of liquid channel units 110 of the first substrate and the plurality of liquid channel units 210 of the second substrate do not overlap in a partial region where the first substrate and the second substrate are disposed to face each other. As described above, when the plurality of liquid passage portions of the first substrate and the plurality of liquid passage portions of the second substrate do not overlap in some regions, the liquid working fluid moves toward the center through the plurality of liquid passage portions of the first substrate. and the liquid working fluid moving through the plurality of liquid passages of the second substrate may have different directions. Therefore, the liquid working fluid can be supplied to the evaporation area of the vapor chamber in which the external heat source is located through various routes, so that the dry-out phenomenon in the evaporation area can be effectively suppressed.

As an example, when the at least one vapor passage portion provided on the first substrate is projected onto one surface of the second substrate, it intersects the vapor passage portion of the second substrate, and the projected vapor passage portion and the vapor of the second substrate The angle of the flow passage may be in the range of greater than 0 degrees to less than 180 degrees. As another example, when the at least one vapor channel part provided on the first substrate is projected onto one surface of the second substrate, the projected angle of the vapor channel part of the second substrate and the vapor channel part of the second substrate is about 5 degrees or more , 10 degrees or more, 15 degrees or more, 20 degrees or more, 25 degrees or more, or about 30 degrees or more, or about 175 degrees or less, 170 degrees or less, 165 degrees or less, 160 degrees or less, 155 degrees or less, or about 150 degrees or less; , it can be adjusted to an appropriate angle range in consideration of the installation direction of the vapor chamber.

As an example, when projecting the plurality of vapor channel units provided on the first substrate onto one surface of the second substrate, if the plurality of vapor channel units provided on the second substrate do not overlap in at least some regions, the The shape of the vapor flow path part and the vapor flow path part of the second substrate is not particularly limited, and may have various well-known shapes. In the case of FIG. 4 , both the vapor passage portion of the first substrate and the vapor passage portion of the second substrate have a stripe pattern shape. However, when the stripe pattern of the plurality of vapor flow passages provided on the first substrate is projected onto one surface of the second substrate, regions that do not overlap with the stripe patterns of the plurality of vapor passages provided on the second substrate are included.

As an example, the width of the liquid passage portion of the first substrate may be different from the width of the liquid passage portion of the second substrate. The width of the liquid passage portion of the first substrate and the width of the liquid passage portion of the second substrate may be adjusted in consideration of the location of the external heat source. For example, when the external heat source is close to the side of the first substrate of the vapor chamber, the width of the liquid passage portion of the first substrate may be greater than the width of the liquid passage portion of the second substrate. Conversely, when the external heat source is close to the side of the second substrate of the vapor chamber, the width of the liquid passage portion of the second substrate may be greater than the width of the liquid passage portion of the first substrate.

As an example, the size of the width of the vapor passage portion of the first substrate and the size of the vapor passage portion of the second substrate may be different from each other. The width of the vapor passage portion of the first substrate and the width of the vapor passage portion of the second substrate may also be adjusted in consideration of the location of the external heat source. For example, when the external heat source is close to the side of the first substrate of the vapor chamber, the width of the vapor passage portion of the first substrate may be greater than the width of the vapor passage portion of the second substrate. Conversely, when the external heat source is close to the side of the second substrate of the vapor chamber, the width of the vapor passage portion of the second substrate may be greater than the width of the vapor passage portion of the first substrate.

In one embodiment, when the external heat source is located close to the side of the second substrate of the vapor chamber, the evaporation rate of the working fluid in the evaporation region of the second substrate is faster than the evaporation rate of the working fluid in the evaporation region of the first substrate. can In such a case, the widths of the liquid and vapor passages of the second substrate may be greater than the widths of the liquid and vapor passages of the first substrate. That is, in consideration of the evaporation rate in the evaporation region, the widths of the liquid flow passage portion and the vapor passage portion of the first substrate and the width of the liquid passage portion and the vapor passage portion of the second substrate may be adjusted. Through this, it is possible to more effectively suppress the occurrence of dry-out in the evaporation region.

As an example, in each of the first substrate and the second substrate, the vapor passage portion and the liquid passage portion may be alternately disposed. The alternate arrangement means, for example, a structure in which the vapor flow path part and the liquid flow path part are alternately arranged in the y direction of the vapor chamber in FIG. 4 .

As an example, the liquid flow passage may occupy a range of 5% to 90% by volume relative to 100% of the volume of the closed space. In another example, the liquid passage portion occupies about 10% or more, 15% or more, 20% or more, or about 25% or more of the volume of 100% of the volume of the sealed space, or about 85% or less, 80% or less, 75% or less, or about 70% or less can occupy a volume range of When the volume occupied by the liquid passage portion in the enclosed space is less than 5% or exceeds 90%, the liquid working fluid and the vapor phase working fluid may be disadvantageous in forming a smooth flow in the enclosed space. Specifically, when the volume occupied by the liquid flow passage part is less than 5%, it is not sufficient to move the liquid working fluid to the evaporation region through the liquid flow passage part. When the volume occupied by the liquid flow passage part exceeds 90%, the vapor phase working fluid It may not be enough to move in a direction away from the evaporation region (condensation region direction) through the vapor flow passage.

As an example, the liquid passage part may be a porous metal layer including thermally conductive metal particles. When the liquid passage part is a porous metal layer including thermally conductive metal particles, heat dissipation efficiency may be improved.

Meanwhile, the term porous metal layer refers to a porous structure including a metal as a main component. In the above, having a metal as a main component means that the proportion of metal is 55 wt% or more, 60 wt% or more, 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% based on the total weight of the metal layer. It means a case of weight % or more, 90 weight % or more, or 95 weight % or more. The upper limit of the ratio of the metal included as the main component is not particularly limited, and may be, for example, 100% by weight.

In addition, the term porosity may mean a case in which the porosity is at least 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 75% or more, or 80% or more. The upper limit of the porosity is not particularly limited, and for example, may be less than about 100%, less than about 99%, less than about 98%, less than about 95%, or less than about 90%. In the above, the porosity may be calculated in a known manner by calculating the density of the metal layer.

The thermally conductive metal particles have, in one example, a thermal conductivity of about 8 W/mK or more, about 10 W/mK or more, about 15 W/mK or more, about 20 W/mK or more, about 25 W/mK or more, about 30 W/mK or more, about 35 W/mK or more, about 40 W/mK or more, about 45 W/mK or more, about 50 W/mK or more, about 55 W/mK or more, about 60 W/mK or more, about 65 W/mK or greater, about 70 W/mK or greater, about 75 W/mK or greater, about 80 W/mK or greater, about 85 W/mK or greater, or about 90 W/mK or greater. The metal particles may obtain a liquid channel portion having excellent heat dissipation efficiency as the thermal conductivity is higher, and thus the upper limit thereof is not particularly limited, and may be, for example, about 1,000 W/mK or less.

Specific types of the metal particles are not particularly limited as long as they have the above-mentioned thermal conductivity, and for example, copper, gold, silver, aluminum, silver, nickel, iron, cobalt, magnesium, molybdenum, tungsten, platinum, magnesium. And it may be any one selected from the group consisting of zinc or an alloy of two or more of the above, but is not limited thereto.

The shape of the metal particles may be appropriately selected in consideration of the desired pore size, porosity, or pore shape of the liquid passage part. For example, the metal particles may have various shapes such as a substantially spherical shape, a needle shape, a plate shape, a dendrite shape, or a star shape.

In one example, the average particle diameter of the metal particles may be in the range of about 100 nm to 200 μm. Within the above range, the average particle diameter may be appropriately selected in consideration of the porosity, pore size, or pore shape of the desired porous metal layer.

The thermally conductive metal particles included in the liquid passage part may have an average particle diameter in the range of 100 nm to 200 μm. Within the above range, the average particle diameter may be appropriately selected in consideration of the pore size or porosity of the liquid channel portion.

As an example, the liquid passage part may include at least a metal having an appropriate relative permeability and conductivity. The application of such a metal may allow sintering according to the method to be smoothly performed when the induction heating method is applied when forming the liquid flow passage in a method of manufacturing a vapor chamber to be described later.

For example, as the metal, a metal having a relative magnetic permeability of 90 or more may be used. In the above, the relative permeability (μr) is the ratio (μ/μ0) of the magnetic permeability (μ) of the material to the magnetic permeability (μ0) in a vacuum. The metal used in the present application has a relative permeability of 95 or more, 100 or more, 110 or more, 120 or more, 130 or more, 140 or more, 150 or more, 160 or more, 170 or more, 180 or more, 190 or more, 200 or more, 210 or more, 220 or more, 230 or more, 240 or more, 250 or more, 260 or more, 270 or more, 280 or more, 290 or more, 300 or more, 310 or more, 320 or more, 330 or more, 340 or more, 350 or more, 360 or more, 370 or more, 380 or more , 390 or more, 400 or more, 410 or more, 420 or more, 430 or more, 440 or more, 450 or more, 460 or more, 470 or more, 480 or more, 490 or more, 500 or more, 510 or more, 520 or more, 530 or more, 540 or more, 550 or more or more, 560 or more, 570 or more, 580 or more, or 590 or more. The upper limit of the relative permeability is not particularly limited because the higher the value, the higher the heat is generated when an electromagnetic field for induction heating is applied in a method of manufacturing a vapor chamber to be described later. In one example, the upper limit of the relative permeability may be, for example, about 300,000 or less.

The metal has a conductivity at 20°C of about 8 MS/m or more, 9 MS/m or more, 10 MS/m or more, 11 MS/m or more, 12 MS/m or more, 13 MS/m or more, or 14.5 MS/m or more. It may be a metal or an alloy thereof. The upper limit of the conductivity is not particularly limited, and may be, for example, about 30 MS/m or less, 25 MS/m or less, or 20 MS/m or less.

In the present application, the metal having the above relative permeability and conductivity may be simply referred to as a conductive magnetic metal.

By applying the conductive magnetic metal, sintering can be performed more effectively when an induction heating process is performed in a method of manufacturing a vapor chamber to be described later. Such a metal may be exemplified by nickel, iron or cobalt, but is not limited thereto.

As an example, the liquid channel portion may have an average pore size of 100 μm or less. The pore size may be confirmed by, for example, scanning electron microscope (SEM) image analysis. The lower limit of the pore size is not particularly limited, and may be, for example, about 1 nm to 1 μm.

As an example, the liquid channel portion may have a porosity of 30% or more. In the above, the porosity may be calculated in a known manner by calculating the density of the liquid channel portion. In another example, the porosity is about 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, or about 65% or more, or about 99% or less, 95% or less, 90% or less , 85% or less, 80% or less, or about 75% or less.

As an example, the filling rate (R) of the working fluid enclosed in the sealed space may satisfy the following general formula (1).

[General formula 1]

30 ≤ R (%) = (Lv / Wv) * 100 ≤ 200

In Formula 1, R is the filling rate of the working fluid enclosed in the sealed space, Lv is the volume of the working fluid enclosed in the sealed space, and Wv is the volume of pores in the liquid passage part existing in the sealed space.

In Formula 1, the filling rate (R) of the working fluid may be, for example, about 35% or more, 40% or more, 45% or more, 50% or more, or about 40% or more, and about 190% or less, 180% or less, 170% or less or about 160% or less.

If the filling rate (R ) of the working fluid enclosed in the enclosed space does not reach 30%, the dry-out phenomenon in the evaporation area may intensify, and if it exceeds 200%, the working fluid may leak from the vapor chamber. have.

When the liquid flow passage part has the above characteristics, the liquid working fluid can be more easily moved to the evaporation area, and thus the dry-out phenomenon in the evaporation area can be more effectively suppressed. In addition, the liquid channel portion has excellent thermal conductivity, so that heat dissipation efficiency can be improved.

The excellent heat dissipation characteristics of the vapor chamber of the present application are more significant when an external heat source is disposed together. For example, when an external heat source is positioned in the vaporization region of the vapor chamber with respect to the vapor chamber of the present application and the conventional vapor chamber, the vapor chamber of the present application has relatively excellent heat dissipation characteristics (this point is more detailed).

The present application also relates to a method for manufacturing a vapor chamber. The components used in the method of manufacturing the vapor chamber may be the same as those described above.

In the method for manufacturing a vapor chamber according to the present application, a slurry containing thermally conductive metal particles is pattern-coated on a first substrate and a second substrate, respectively, and the pattern-coated slurry is sintered on the first and second substrates. It may include the step of forming a liquid passage part.

The pattern coating on the substrate may be, for example, pattern-coated on the first substrate and the second substrate by using the slurry so as to have the same pattern as shown in FIGS. 4 and 5 .

If necessary, drying the pattern-coated slurry under appropriate conditions may be performed between the pattern coating on the substrate and the sintering process. When the drying process proceeds, the conditions are not particularly limited, and, for example, may be performed at a temperature within the range of about 20° C. to about 150° C. for about 20 minutes to 5 hours, but is not limited thereto.

A method of performing sintering of the pattern-coated slurry on the substrate is not particularly limited, and a known sintering method that applies appropriate heat in consideration of the material composition or shape of the pattern-coated slurry may be applied. The sintering temperature and sintering time applied at this time are not particularly limited, and may be set in consideration of the material composition or shape of the slurry.

As an example, the sintering may be performed by an induction heating method. That is, as described above, when the slurry includes a conductive magnetic metal, an induction heating method may be applied. While including pores uniformly formed by this method, the mechanical properties are excellent, and the porosity of the metal layer is adjusted to a desired level can be more smoothly manufactured.

The induction heating is a phenomenon in which heat is generated in a specific metal when an electromagnetic field is applied. For example, when an electromagnetic field is applied to a conductive magnetic metal having appropriate conductivity and permeability, eddy currents are generated in the metal, and Joule heating is generated due to the resistance of the metal. Through this phenomenon, the sintering process of the pattern-coated slurry on the support may be performed. When this method is applied, sintering of the liquid channel portion coated with the pattern on the support can be carried out in a short time to ensure fairness, and at the same time, it is a thin film form with high porosity, has a small pore size, and has excellent adhesion to the support. A metal layer can be prepared.

Accordingly, the sintering process may include applying heat or an electromagnetic field to the pattern-coated slurry. In the above, the application of heat may be performed by treating the pattern-coated slurry at a temperature within the range of about 300° C. to 2,000° C. for a time within the range of 30 minutes to 10 hours using an appropriate means such as an oven.

In addition, Joule heating may be generated in the conductive magnetic metal due to an induction heating phenomenon even by application of an electromagnetic field, and thereby the structure may be sintered. In this case, the conditions for applying the electromagnetic field are not particularly limited as they are determined according to the type and ratio of the conductive magnetic metal in the slurry. For example, the induction heating may be performed using an induction heater formed in the form of a coil or the like. In addition, induction heating, for example, may be performed by applying a current of about 100A to 1,000A. In another example, the magnitude of the applied current may be 900 A or less, 800 A or less, 700 A or less, 600 A or less, 500 A or less, or 400 A or less. The magnitude of the current may be about 150 A or more, about 200 A or more, or about 250 A or more in another example.

Induction heating, for example, may be performed at a frequency of about 100 kHz to 1,000 kHz. In another example, the frequency may be 900 kHz or less, 800 kHz or less, 700 kHz or less, 600 kHz or less, 500 kHz or less, or 450 kHz or less. The frequency may be about 150 kHz or more, about 200 kHz or more, or about 250 kHz or more in another example.

The application of the electromagnetic field for the induction heating may be performed within a range of, for example, about 1 minute to 10 hours. In another example, the application time may be about 10 minutes or more, about 20 minutes or more, or about 30 minutes or more. The application time is, in another example, about 9 hours or less, about 8 hours or less, about 7 hours or less, about 6 hours or less, about 5 hours or less, about 4 hours or less, about 3 hours or less, about 2 hours or less, about 2 hours or less, about It may be 1 hour or less or about 30 minutes or less.

The above-mentioned induction heating conditions, for example, an applied current, a frequency, and an application time may be changed in consideration of the type and ratio of the conductive magnetic metal as described above.

The sintering of the liquid channel portion pattern-coated on the substrate may be performed by either means of the application of the heat or the electromagnetic field, or by applying both of them simultaneously, that is, by applying appropriate heat together with the application of the electromagnetic field. can also be done

As an example, each of the first and second substrates may be a metal substrate.

As an example, in the method of manufacturing a vapor chamber according to the present application, the first metal substrate on which the liquid passage portion is formed and the second metal substrate on which the liquid passage portion is formed face each other, and the liquid passage portion of the first substrate and the liquid passage portion of the second substrate face each other. The method may further include bonding edges of the first metal substrate and the second metal substrate in a state in which they are placed to be viewed. In the above, a method of bonding the first metal substrate and the second metal substrate is not particularly limited, and a known metal attachment method may be applied. An enclosed space is formed between the first metal substrate and the second metal substrate by bonding the first metal substrate and the second metal substrate.

Meanwhile, a method of encapsulating the working fluid in the sealed space is not particularly limited, and a known encapsulation method may be used. For example, at least one of the first and second substrates is provided with an injection hole through which a working fluid is injected, so that after bonding the edges of the first and second metal substrates, at least one of the first and second substrates After injecting the working fluid through the inlet provided in the , the working fluid can be sealed in the sealed space by vacuum sealing the inlet using a well-known sealing agent such as an epoxy resin.

The vapor chamber of the present application may have various performances within a given size, for example, improved heat load capacity and effective thermal conductivity. In addition, excellent performance may be obtained regardless of the installation direction of the vapor chamber.

1 is a simplified view of a driving principle of a vapor chamber.
2 is an exemplary schematic diagram of a vapor chamber according to the present application.
3 is a plan view of a closed space in a conventional vapor chamber.
4 to 5 are plan views of an exemplary closed space in the vapor chamber according to the present application.
6 is a simplified view of the manufacturing process of the vapor chamber of the present application.

Hereinafter, the present application will be described in detail through examples. However, the protection scope of the present application is not limited by the examples described below.

Qmax measurement

Qmax means maximum heat transport power (unit: W), and is measured in the following manner. That is, the higher this value, the better the heat dissipation performance.

(1) In the vapor chambers manufactured in Examples and Comparative Examples, a heat source (direct current power supply) is connected to the evaporation region, and a cooling bath (Cooling bath) is connected to the condensation region.

(2) Connect the thermocouple to 7 points which are arranged at intervals of 12mm along the long axis direction (x direction) of the steam chamber.

(3) The short axis direction of the vapor chamber is perpendicular to gravity, the long axis direction is horizontal to gravity (first vertical state), and the long axis direction of the vapor chamber is perpendicular to gravity and the minor axis direction is horizontal to gravity In the arranged state (the second vertical state), the following (4) and (5) were performed, respectively.

(4) Apply heat at 0.5 W from the heat source, and when thermal equilibrium occurs and the temperature change at each point is less than 0.1°C, measure the temperature of each of the seven points.

(5) At this time, when the temperature difference between the point closest to the heat source and the point farthest from the heat source at the seven points becomes 6°C, the power applied from the heat source is subtracted by 0.4W, which is an error depending on the measurement environment, to obtain Qmax.

On the other hand, Qmax evaluation was described as a ratio of the Qmax values of the remaining preparation examples based on the Qmax value when the position of the external heat source in Comparative Example 1 was in the evaporation region.

Example 1. Fabrication of the vapor chamber

A vapor chamber was manufactured through the following process. The process is simplified and illustrated in FIG. 6 .

(1) A slurry is prepared using copper (Cu) powder having an average particle diameter (D50 particle diameter) of about 10 μm to 20 μm as a metal component. As a dispersant, ethylene glycol (EG) and ethyl cellulose (EC) as a binder are mixed in a 4:5 weight ratio (EG:EC) of the copper powder, and the binder and copper powder are mixed in a weight ratio of about 10:1 (Cu:EC) is mixed to prepare a slurry.

(2) A frame (printing area) having a thickness of about 100 μm and a frame (printing area) provided to print the shape as shown by the numerals 110 and 120 of FIG. is 18mm wide and 72mm long), the slurry prepared in (1) is applied and the slurry is printed on copper foil to have a specific pattern.

(3) Dry the printed slurry at 120°C for 30 minutes using a dryer.

(4) The dried slurry is sintered at 1,000° C. for 1 hour using a sintering furnace to prepare a first substrate ( 100 in FIG. 4 ) on which a liquid flow passage is formed.

(5) Repeat the process of (1) to (4) above, but using a frame provided to print the shape as shown by reference numerals 210 and 220 in FIG. 4 to form a second substrate (200 in FIG. 4) manufacture

(6) In a state in which the liquid channel part of the first substrate and the liquid channel part of the second substrate are arranged to face each other, the remaining edges except for the injection hole are combined.

(6) Create a vacuum atmosphere in the inner space by supplying 50 μL of water (working fluid) through the inlet, injecting an inert gas through the inlet, and sealing the inlet using an epoxy resin.

In the vapor chamber manufactured according to Example 1, when the plurality of vapor passage units provided on the first substrate are projected onto one surface of the second substrate, the projected angle of the vapor passage portion and the vapor passage portion of the second substrate is about 90 degrees is to the extent

Example 2. Fabrication of the vapor chamber

In the process of (2) of Example 1, a frame prepared to print a shape as shown by numerals 110 and 120 of FIG. 5, and a shape as shown by numerals 210 and 220 of FIG. 5 in the process (5) A vapor chamber was manufactured in the same manner as in Example 1, except that a frame prepared for printing was applied.

In the vapor chamber manufactured according to the second embodiment, when the plurality of vapor passage units provided on the first substrate are projected onto one surface of the second substrate, the projected angle of the vapor passage portion and the vapor passage portion of the second substrate is about 30 degrees it is about

Comparative Example 1. Preparation of steam chamber

In the process of (2) of Example 1, a frame provided to print a shape as shown by symbols 110 and 120 of FIG. 3, and a shape as shown by symbols 210 and 220 of FIG. 3 in the process (5) A vapor chamber was manufactured in the same manner as in Example 1, except that a frame prepared for printing was applied.

In the vapor chamber manufactured according to Comparative Example 1, when the plurality of vapor passage units provided on the first substrate are projected onto one surface of the second substrate, the projected angle of the vapor passage portion and the vapor passage portion of the second substrate is about 0 degrees it is about

Relative Qmax was evaluated for the heat dissipation characteristics of the vapor chambers of Examples and Comparative Examples, and the results are summarized in Table 1 below.

Relative Qmax (unit: W) flat state first vertical state 2nd vertical state Comparative Example 1 1.00 0.97 0.89 Example 1 1.39 1.34 1.34 Example 2 1.16 1.12 1.09

Referring to Table 1, when the plurality of vapor passage units provided on the first substrate are projected onto one surface of the second substrate, the vapor chamber has a structure provided so as not to overlap with the plurality of vapor passage units provided on the second substrate in some regions. In the embodiment of It can be seen that the excellent heat dissipation performance is exhibited. In addition, in the vapor chamber of the embodiment, the difference in performance according to the installation direction is not as large as 0.1 W or less compared to the planar state, whereas the vapor chamber of the comparative example has a performance change of 0.1 W or more in the second vertical direction compared to the planar state. It can be seen that there is

10: vapor chamber
100: first substrate
110: liquid passage portion of the first substrate
120: vapor flow path portion of the first substrate
200: second substrate
210: liquid passage portion of the second substrate
220: vapor flow path portion of the second substrate
300: enclosed space

Claims (13)

a first substrate; a second substrate facing the first substrate; and a closed space positioned between the first substrate and the second substrate and sealed with a working fluid,
The first substrate and the second substrate are located in the closed space on one surface facing the closed space, respectively, a plurality of vapor flow passages through which the vapor of the working fluid evaporated by an external heat source passes, and a plurality of liquid working fluids passing through. A liquid flow passage portion of the first substrate and the second substrate are respectively provided along the width direction,
The plurality of vapor flow passages provided on the first substrate is provided so as not to overlap with the plurality of vapor passages provided on the second substrate in at least a partial region when the vapor flow passages are projected onto one surface of the second substrate. The vapor chamber of claim 1 , wherein the first substrate and the second substrate facing the first substrate are metal substrates, respectively. The method of claim 1,
When the at least one vapor passage portion provided on the first substrate is projected onto one surface of the second substrate, it intersects the vapor passage portion of the second substrate, and the angle of the projected vapor passage portion and the vapor passage portion of the second substrate is 0 A vapor chamber within a range of greater than 180 degrees and less than 180 degrees. The vapor chamber of claim 1 , wherein a width of the liquid passage portion of the first substrate is different from a width of the liquid passage portion of the second substrate. The vapor chamber of claim 1 , wherein a width of the vapor passage portion of the first substrate is different from a size of the vapor passage portion of the second substrate. The vapor chamber according to claim 1, wherein in each of the first substrate and the second substrate, the vapor flow passage portions and the liquid passage portions are alternately disposed. The vapor chamber of claim 1 , wherein the liquid passage portion occupies a range of 5% to 90% of the volume of 100% of the sealed space. The vapor chamber of claim 1 , wherein the liquid passage part is a porous metal layer including thermally conductive metal particles. The method according to claim 8, wherein the thermally conductive metal particles are any one or two selected from the group consisting of iron particles, cobalt particles, copper particles, gold particles, aluminum particles, silver particles, nickel particles, molybdenum particles, platinum particles, and magnesium particles. A vapor chamber that is a mixture of more than one. The vapor chamber of claim 8, wherein the thermally conductive metal particles have an average particle diameter in a range of 100 nm to 200 μm. The vapor chamber of claim 1 , wherein the liquid passage portion has an average pore size of 100 μm or less. The vapor chamber of claim 1 , wherein the liquid passage part is a porous metal layer having a porosity of 30% or more. The vapor chamber according to claim 11, wherein the filling rate (R) of the working fluid enclosed in the enclosed space satisfies the following general formula (1):
[General formula 1]
30 ≤ R (%) = (Lv / Wv) * 100 ≤ 200
In Formula 1, R is the filling rate of the working fluid enclosed in the sealed space, Lv is the volume of the working fluid enclosed in the sealed space, and Wv is the volume of pores in the liquid passage part existing in the sealed space.

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