JP7074715B2 - Heat dissipation device - Google Patents

Description

The present invention relates to a radiator, and more particularly to a radiator made of pure titanium metal.

Current electronic devices tend to generate high heat in the electronic elements inside them as the calculation speed becomes faster, and those skilled in the art have dealt with the problem of heat dissipation of these electronic elements, such as heat pipes, heat plates, vapor chambers, and radiators. At least one heat radiating means such as, etc. has been brought into direct contact with the electronic element to thermally couple the two, and a fan has been added to combine the heat radiating means with the heat radiating means to improve the effect of forced heat dissipation.

The heat radiating means generally selects a material such as aluminum, copper or stainless steel, and utilizes the characteristics that copper and materials such as aluminum and stainless steel have high heat radiating effect and thermal conductivity, and particularly heat of copper. Due to its high conductivity advantage, copper is most often used as a material for thermal conductivity devices. However, copper also has a drawback. After copper (Cu) has undergone a high temperature reduction step, the crystals are coarsened due to the growth of crystal grains, so that the yield strength is significantly reduced and the mass of copper is heavy. Since its hardness is low, it is relatively easy to deform, and after it is deformed, it cannot return to its original state.

In addition, current smart portable devices (for example, smartphones, tablets, tablet computers or laptop computers) and wearable devices or electronic devices that require thinning need to dissipate heat with a thinner passive heat dissipation device. Therefore, those skilled in the art must meet the demand for thinning by replacing the copper plate with a copper foil. However, although copper foil meets the demand for thinning, its structure becomes softer and lacks sufficient structural support strength, so it is not very suitable for many special applications and does not have support capacity, so external force. When it receives it, it is easily deformed and the internal heat conduction structure is also destroyed.

In addition to this, the above-mentioned heat dissipation means using materials such as aluminum or copper or stainless steel can be used in various special environments or harsh climatic conditions (for example, corrosion, high humidity, high salt content, extremely cold, high temperature, etc.). There is a problem that it cannot be used in vacuum or outer space. Those skilled in the art also use titanium alloys as an alternative to copper. Titanium alloys have useful properties such as high hardness, corrosion resistance, high temperature resistance, extreme cold resistance and light mass, but their processing is extremely difficult, and cutting or some unconventional processing methods are used. Except for cases, it is very difficult to plastically deform titanium alloys, so it is often still impossible to use titanium alloys as an alternative to copper.

Therefore, in order to solve the above-mentioned drawbacks of the prior art, a main object of the present invention is to replace commercial pure titanium with copper as a material for a heat dissipation device and to provide a heat dissipation device having an excellent heat dissipation effect. Is.

In order to achieve the above object, the present invention
A first pure titanium metal plate having a first plane and a second plane and having a plurality of protrusions on the first plane, a third plane and a fourth plane, and the third plane is composed of a metal mesh. The sealed housing formed between the second pure titanium metal body, the first plane of the first pure titanium metal plate, and the third plane of the second titanium metal body, and the sealed housing are filled. The first pure titanium metal plate and the second pure titanium metal plate are heat-treated in an atmosphere furnace at 400 ° C. to 700 ° C. for 30 to 90 minutes, including the working fluid. It is a feature.

When the heat dissipation device disclosed in the present invention is used, it is possible to improve the conventional defect that plastic working cannot be performed on pure titanium, and it is ultra-thin and flexible, and is lightweight and strong, which is a characteristic of titanium. It is possible to provide a structure of a heat dissipation device and a method for manufacturing the same. That is, by heat-treating the first and second pure titanium metal plates, plastic working such as press working becomes possible. The plurality of protrusions formed on the first pure titanium metal plate by pressing increase the heat conduction area with the working fluid, enhance the effect of condensing the working fluid and the reinforcing effect, and generate capillary force. The metal mesh provided on the second pure titanium metal plate also increases the heat conduction area between the working fluid and the working fluid, so that the heat absorption effect of the second pure titanium metal plate is increased. Can be improved. Other effects of the present invention will be described individually below.

It is a three-dimensional exploded view of the heat dissipation device which concerns on Example 1 of this invention. It is an assembly sectional view of the heat dissipation device which concerns on Example 1 of this invention. It is an assembly sectional view of the heat dissipation device which concerns on Example 2 of this invention. It is an assembly sectional view of the heat dissipation device which concerns on Example 3 of this invention. It is an assembly sectional view of the heat dissipation device which concerns on Example 4 of this invention. It is an electron micrograph of the metal mesh of the heat dissipation device which concerns on this invention. It is an electron micrograph of the first, second, and third coating layers of the heat dissipation device which concerns on this invention. It is an electron micrograph of the first, second, and third coating layers of the heat dissipation device which concerns on this invention. It is an electron micrograph of the first, second, and third coating layers of the heat dissipation device which concerns on this invention. It is a step flowchart of the manufacturing method of the heat radiating apparatus which concerns on Example 1 of this invention. It is a step flowchart of the manufacturing method of the heat dissipation device which concerns on Example 2 of this invention.

The above object of the present invention and its structural and functional features will be described with reference to preferred embodiments of the accompanying drawings.

Referring to FIGS. 1 and 2, these are a three-dimensional exploded view and an assembly sectional view of the heat dissipation device according to the first embodiment of the present invention. As shown in the figure, the heat dissipation device 1 of the present invention includes a first pure titanium metal plate 11 and a second pure titanium metal plate 12.
The first pure titanium metal plate 11 includes a first plane 111 and a second plane 112, the first plane 111 has a plurality of convex portions 113 (FIG. 2), and the convex portions 113 are stamped. The second plane 112 is the condensation side (heat dissipation side).

The second pure titanium metal plate 12 includes a third plane 121 and a fourth plane 122, and a metal mesh 123 (FIG. 2) is provided on the third plane 121, and these first and second pure titanium metals are provided. The sealed housing 13 is defined by covering the plates 11 and 12 so as to face each other, the closed housing 13 is filled with a working fluid (not shown), and the fourth plane 122 is on the heat absorbing side.

Referring to FIG. 3, the figure is an assembled cross-sectional view of the heat dissipation device according to the second embodiment of the present invention. As shown in the figure, since this embodiment has the same technical features as the partial structure of the first embodiment, the description thereof will be omitted here. The difference between the present embodiment and the first embodiment is that, in the present embodiment, the first coating layer 114 is provided on the surface of the convex portion 113, and the metal mesh 123 (see FIG. 5) and the third plane surface are provided. A second coating layer 124 is provided between 121 and a third coating layer 125 is provided on the surface of the metal mesh 123, and these first, second and third coating layers 114, 124 and 125 are hydrophilic coating layers or hydrophobic. It has the property of any of the sex coating layers, and the hydrophilic coating layer is either titanium dioxide or silicon dioxide (see FIGS. 6, 7, 8 and 9).

The first, second and third coating layers 114, 124 and 125 are selected to selectively have hydrophilic or hydrophobic properties and are mainly divided into areas and uses, for example, the first of the first plane 111. For the coating layer 114, either a hydrophilic coating layer or a hydrophobic coating layer can be selected. A hydrophilic coating layer is selected for the second coating layer 124 on the third plane 121, the main purpose of which is to increase the water absorption capacity and the binding force between the third plane 121 and the metal mesh 123. For the third coating layer 125 on the metal mesh 123, a hydrophilic coating layer is selected, which is primarily to increase the water content and increase the effect of liquid (working fluid) reflux.

The metal mesh 123 is made of either pure titanium material, stainless steel, copper, aluminum, or other metal material, and the present embodiment describes the pure titanium material, but the present invention is not limited to this, and of course, pure titanium and stainless steel. Can be a composite knitting.

As the first and second pure titanium metal plates 11 and 12, commercial pure titanium can be selected and plastic working can be performed by subjecting it to preheat treatment before plastic working.

Referring to FIG. 4, the figure is an assembled cross-sectional view of the heat dissipation device according to the third embodiment of the present invention. As shown in the figure, since this embodiment has the same technical features as the partial structure of the first embodiment, the description thereof will be omitted here. The difference between the present embodiment and the first embodiment is that, in the present embodiment, the portion corresponding to the convex portion 113 on the first plane 111 is located on the second plane 112 of the first pure titanium metal plate 11. The point is that the recesses 115 are provided, and these are formed by an embossing method. By providing the plurality of recesses 115 on the second flat surface 112 of the first pure titanium metal plate 11 in this way, the condensation (heat dissipation) effect of the second flat surface 112 can be enhanced.

Referring to FIG. 5, it is an assembly sectional view of the heat dissipation device according to the fourth embodiment of the present invention. As shown in the figure, since this embodiment has the same partial structural technical features as those of the first embodiment, the description thereof will be omitted here. The difference between the fourth embodiment and the first embodiment is that the metal mesh 123 includes a first metal mesh 123a and a second metal mesh 123b, the first metal mesh 123a is a pure titanium material, and the second metal. The mesh 123b is made of stainless steel, and the first and second metal meshes 123a and 123b are provided by laminating each other, and the first and second metal meshes 123a and 123b are the first and second pure titanium metals, respectively. It is bonded to the plates 11 and 12.

Referring to FIG. 10, FIG. 10 is a step flowchart of a method for manufacturing a heat radiating device according to the present invention. Hereinafter, FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG. 7, FIG. 8, and FIG. 9 will be referred to and described together. As shown in the figure, the method for manufacturing a heat radiating device according to the present invention includes the following steps S1 to S5.

Step S1: Prepare the first pure titanium metal plate and the second pure titanium metal plate, and perform the following pre-cleaning work.
Pre-cleaning work is performed on the first and second pure titanium metal plates 11 and 12 to be manufactured and processed. In the cleaning operation, first wipe with acetone, then rinse with deionized water using an ultrasonic cleaner, and finally, the surfaces of the first and second pure titanium metal plates 11 and 12 are dried with nitrogen gas. For the first and second pure titanium metal plates 11 and 12, commercial pure titanium is selected and used instead of a general titanium alloy. The advantage of choosing pure titanium is that it has a relatively high strength (tensile strength / density), the tensile strength of pure titanium is superior to that of copper, and the density of pure titanium (Ti) (4.54 g / cm ³ ). ) Is about half the density of copper (Cu) (8.96 g / cm ³ ), so pure titanium (Ti) with high specific strength in the same volume provides further strength and weight reduction. Can be combined.

Pure titanium forms a layer of oxide film (TIO ₂ , Ti ₂ O ₃ , TIO) on its surface at room temperature, which is highly stable with a thickness of several hundred Å (1 Å = 10 ^-10 m) and has strong adhesion. However, it has the property of being able to be regenerated immediately after damage, which indicates that pure titanium is a metal having a strong stabilizing tendency. Therefore, the corrosion resistance of pure titanium is far superior to that of copper (Cu), which is advantageous for the operation of the vapor chamber in various environments. Furthermore, pure titanium has excellent corrosion resistance even in moist environments, seawater, chlorine-containing solutions, hypochlorite, nitric acid, chromic acid and general oxidizing acids.

Step S2: The following heat treatment is performed on the first and second pure titanium metal plates.
The first and second pure titanium metal plates 11 and 12 are placed in an atmosphere furnace (not shown), argon gas is blown into the atmosphere furnace, and the mixture is heated to 400 ° C. to 700 ° C., and the heating time is 30 to 90. Minutes. Its main purpose is to enable plastic working on the first and second pure titanium metal plates 11 and 12.

Step S3: The first pure titanium metal plate is pressed to form a plurality of convex portions.
By press working as machining, a plurality of convex portions 113 are formed on one side of the first pure titanium metal plate 11, and the convex portions 113 have an effect of condensing the working fluid and a structure having high support strength. To have the effect of

Step S4: A metal mesh is bonded to one side of the second pure titanium metal plate body.
It is a step of connecting the metal mesh 123 to the third plane 121 of the second pure titanium metal plate 12 by the diffusion bonding method, and in that case, the second pure titanium metal plate 12 [pure titanium titanium heat dissipation plate ( Ti-VC)] and the metal mesh have a diffusion bonding temperature of 650 ° C to 850 ° C, and the process atmosphere must be positive pressure high pure argon gas (Ar) or high vacuum environment (10 ^-4 to 10 ^-6 torr). The process pressure is 1 kg to 5 kg, and the process time is 30 min to 90 min. Pure titanium is a chemically very active metal and exhibits a phase transformation temperature at 883 ° C, that is, becomes a β phase at 883 ° C or higher and becomes a BCC (body-centered cubic;). It has a body-centered cubic lattice) crystal structure, and at 883 ° C or lower, it becomes an α phase and has an HCP (hexagonal closest packed structure) crystal structure.

Pure titanium can react with many elements and compounds and cause phase changes in materials in high temperature environments, for example titanium in the air begins to occlude hydrogen at 250 ° C and store oxygen at 500 ° C. Is started, and nitrogen storage is started at 600 ° C. As the temperature rises, the ability to occlude pure titanium gas becomes stronger, and hydrogen (H), oxygen (O), carbon (C), and nitrogen (N) react with pure titanium to cause an intrusive solid solution. Is formed on the material, the mechanical properties change, further defects occur, and related compounds such as TiO ₂ , TiC, TiN and TiH ₂ are formed, which has a bad influence (hard brittleness) on the material properties. .. Therefore, the process temperature and process atmosphere (environmental control) are extremely important for the thermal process related to the manufacture of pure titanium heat sinks.

In the conventional copper heat sink (Cu-VC), the diffusion bonding temperature of the metal mesh is 750 ° C to 950 ° C, the process atmosphere is 15% H ₂ + 85% N ₂ , the process pressure is 1 kg to 5 kg, and the process time is 40 min. It was done in ~ 60 minutes. In that case, the phase transformation behavior unlike that of pure titanium does not occur in the high temperature process, but the crystal grains are grown and coarsened by heating, and the mechanical properties are significantly deteriorated (softened).

Step S5: One side of the first pure titanium metal plate 11 having the convex portion 113 and one side of the second pure titanium metal plate 12 having the metal mesh 123 are opposed to each other and covered with the first and second sides. The edge portion of the pure titanium metal plate is sealed to form the sealed housing 13, and water injection (filling of working fluid), exhaust, and mouth sealing work for the mouths 116 and 126 are performed on the sealed housing 13. conduct.

That is, steps such as edge sealing are performed on the first and second pure titanium metal plates 11 and 12 that have undergone the process steps (S1 to S4) described above. That is, after the first and third planes 111 and 121 (having the convex portion 113 and the metal mesh 123) of the first and second pure titanium metal plates 11 and 12 are opposed to each other and covered with each other, the first and second planes are covered. The edges of the pure titanium metal plates 11 and 12 are sealed by a laser welding method, and then water is injected (filled with working fluid) and exhausted in sequence, and finally the mouths 116 and 126 are treated. Perform steps such as partial sealing.

Laser welding technology is used in the edge sealing step. The laser excitation source is a disk type (Disk) solid Yb: YAG (yttrium aluminum garnet), the laser wavelength is 1030 nm, the laser output is 100 to 500 W (determined according to the thickness of the material), and the operating environment is Since it is necessary to use a protective gas, helium gas or argon gas is blown in, and the leakage rate thereof is made smaller than 1.0 × 10 ^-8 mbar · L / sec, or in a vacuum environment ^10-2 torr. Select whether to do it or not.

The advantages of laser welding are that energy can be concentrated (welding can be performed in a small area and does not affect nearby materials), working time is short (it is difficult to change the mechanical properties of the entire element), and ultra-cleaning is performed. Welding (no welding material required) is possible, and rapid automated production can be achieved relatively easily.

Referring to FIG. 11, the figure is a step flowchart of a method for manufacturing a heat radiating device according to a second embodiment of the present invention. Hereinafter, a description will be given with reference to FIGS. 1, 2, 3, 4, 4, 5, 6, 6, 7, 8, and 9. As shown in the figure, the method for manufacturing a heat dissipation device according to a second embodiment of the present invention first includes the following steps S1 to S5. That is,
Step S1 in which the first pure titanium metal plate and the second pure titanium metal plate are prepared and their pre-cleaning work is performed, and
Step S2 for heat-treating the first and second pure titanium metal plates,
Step S3, in which the first pure titanium metal plate is pressed to form a plurality of convex portions,
Step S4, in which a metal mesh is bonded to one side of the second pure titanium metal plate,
One side of the first pure titanium metal plate having a convex portion and one side of the second pure titanium metal plate having a metal mesh are opposed to each other and covered with each other, and these first and second pure titanium metal plates are covered. This includes step S5 in which the closed portion is sealed to form a closed housing, and the closed housing is filled with working fluid, exhausted, and the mouth portion is sealed.

Since this embodiment is the same as a partial step of the first embodiment, the description thereof will be omitted here. Explaining the difference between the present embodiment and the first embodiment, in the present embodiment, after the step S4 in which the metal mesh is bonded to one side of the second pure titanium metal plate, the first and second pure titanium are further described. The step S6 is to perform a surface modification treatment on the metal plate to form at least one coating layer on the surface of the first and second pure titanium metal plates and the surface of the metal mesh.

The surface modification treatment for the first and second pure titanium metal plates can be performed by selecting one of the following four methods.
First method: The first and second pure titanium metal plates 11 and 12 are placed in an atmosphere furnace (not shown), and the inside of the atmosphere furnace is sucked by vacuum means and heated to 400 ° C. to 700 ° C., and the heating thereof is performed. The time was set to 30 to 90 minutes, the process atmosphere was set to positive pressure pure argon gas (Ar), and superheat reduction was generated on the surfaces of the first and second pure titanium metal plates 11 and 12, both of which were processes. By controlling the trace oxygen in the atmosphere, fine titanium dioxide nano _- rods of titanium sharp cone (Anatase) are generated on the surface of pure titanium material, and its structure has good hydrophilicity and has good hydrophilicity. It has a long aging effect (1 to 2 weeks). However, with the passage of time and the influence of the environment (humidity), the hydrophilic effect decreases. In that case, when the product is irradiated with UV light and the irradiation time is set to about 20 min to 60 min (determined according to the intensity of the UV light), the hydrophilicity is restored by the photocatalytic action.
Second method: The first and second pure titanium metal plates 11 and 12 are placed in an atmosphere furnace, and the inside of the atmosphere furnace is sucked by vacuum means and heated to 400 ° C. to 700 ° C., and the heating time is 30 to 90. Overheat reduction is generated on the surfaces of the first and second pure titanium metal plates 11 and 12 for a minute, and in each of these processes, trace oxygen in the process atmosphere is controlled and fine titanium anatase is formed on the surface of the pure titanium material. It produces anatase titanium dioxide nano _- rods, the structure of which has good hydrophilicity and long aging (1-2 weeks). However, with the passage of time and the influence of the environment (humidity), the hydrophilic effect decreases. In that case, when the product is irradiated with UV light and the irradiation time is set to about 20 min to 60 min (determined according to the intensity of the UV light), the hydrophilicity is restored by the photocatalytic action.
Third method: Sol-gel coating treatment is performed. The metal mesh 123 on the surface of the second pure titanium metal plate 12 is mainly processed. First, a layer of crystalline silicon dioxide (SiO ₂ ) is coated to form a base layer, which is dried in an oven at 80 ° C., and then a layer of titanium anatase titanium dioxide (TIO ₂ ) is placed on the base layer. A SiO ₂ / TiO ₂ composite film is formed by coating and performing a fully dense sintering treatment of the heat-treated coating layer. The temperature of the densification / sintering treatment is 400 ° C. to 700 ° C., the sintering time is 30 to 90 min, and the process atmosphere is a positive pressure pure argon gas (Ar). The hydrophilicity of the SiO ₂ / TiO ₂ composite film is good, and the aging is long (1 to 2 weeks). However, with the passage of time and the influence of the environment (humidity), the hydrophilic effect decreases. In that case, when the product is irradiated with UV light and the irradiation time is set to about 20 min to 60 min (determined according to the intensity of UV light), the hydrophilicity is restored by the photocatalytic action of the surface layer of the SiO ₂ / TiO ₂ composite film. do.
Fourth method: Sol-gel coating treatment is performed. The metal mesh 123 on the surface of the second pure titanium metal plate 12 is mainly processed. First, a layer of crystalline silicon dioxide (SiO ₂ ) is coated to form a base layer, which is dried in an oven at 80 ° C., and then a layer of titanium anatase titanium dioxide (TIO ₂ ) is placed on the base layer. A SiO ₂ / TiO ₂ composite film is formed by coating and performing a fully dense sintering treatment of the heat-treated coating layer. The temperature of the densification / sintering treatment is 400 ° C. to 700 ° C., the sintering time is 30 to 90 min, and the process environment is vacuum suction. The hydrophilicity of the SiO ₂ / TiO ₂ composite film is good, and the aging is long (1 to 2 weeks). However, with the passage of time and the influence of the environment (humidity), the hydrophilic effect decreases. In that case, when the product is irradiated with UV light and the irradiation time is set to about 20 min to 60 min (determined according to the intensity of UV light), the hydrophilicity is restored by the photocatalytic action of the surface layer of the SiO ₂ / TiO ₂ composite film. do.

INDUSTRIAL APPLICABILITY The present invention can provide a heat dissipation device such as a vapor chamber manufactured mainly by using pure titanium for commercial use as a base material instead of copper. Further, according to the present invention, it is possible to realize that pure titanium can be used as a substitute material for copper, and the advantages of pure titanium can improve the drawbacks of the copper material. The present invention also makes use of the characteristics that pure titanium itself can be used as an alternative material for copper, aluminum, stainless steel, etc., and that pure titanium itself has a light mass, high strength, and high corrosion resistance. A portable device or a mounting pedestal or a mounting frame for a mobile device can be manufactured, and at the same time, the mounting structure and the heat dissipation structure are directly integrated and manufactured, and the thinness of the current mobile device or portable device is manufactured. It can be adapted to the structure of titanium and not only has a mounting function but also has a heat dissipation effect.

For the metal mesh of each example described above, either pure titanium material or stainless steel or copper or aluminum or other metal material can be selected, or at the same time, two metal meshes are pure titanium material and stainless steel material, respectively. One of each of the above can be selected, and two metal meshes can be overlapped with each other and provided between the first and second pure titanium metal plates.

By giving the thin pure titanium material a function as a shape memory alloy, it bends and deforms under external force, and after removing the external force, it can return to its original state again. It can be used in combination with a smart watch, or it can be manufactured directly as a wristwatch belt from pure titanium material, which can be used not only for heat dissipation and support, but also for wearing at the same time.

1 Heat dissipation device 11 1st pure titanium metal plate 12 2nd pure titanium metal plate 111 1st plane 112 2nd plane 113 Convex part 114 1st coating layer 115 Concave part 116 Mouth 121 3rd plane 122 4th plane 123 Metal Mesh 124 2nd coating layer 125 3rd coating layer 126 Mouth 13 Sealed housing

Claims (7)

A first pure titanium metal plate body having a first plane and a second plane and having a plurality of protrusions on the first plane,
A second pure titanium metal plate body having a third plane and a fourth plane and having the third plane made of a metal mesh,
A sealed housing formed between the first plane of the first pure titanium metal plate and the third plane of the second pure titanium metal plate.
Containing the working fluid filled in the sealed housing
The first pure titanium metal plate body and the second pure titanium metal plate body are heat-treated in an atmosphere furnace at 400 ° C. to 700 ° C. for 30 minutes to 90 minutes. The heat dissipation device according to claim 1 , wherein the convex portion of the first pure titanium metal plate is formed by press working . A first coating layer is provided on the surface of the convex portion of the first pure titanium metal plate, and a second coating layer is provided between the metal mesh and the third plane, and the metal mesh surface is provided with a second coating layer. Is characterized in that a third coating layer is provided, and each of the first, second, and third coating layers individually has the property of any one of a hydrophilic coating layer and a hydrophobic coating layer. Item 1. The heat dissipation device according to Item 1. The heat dissipation device according to claim 3 , wherein the hydrophilic coating layer is any one of titanium dioxide and silicon dioxide. The heat dissipation device according to claim 1, wherein the second plane is on the condensation side and the fourth plane is on the endothermic side. The heat dissipation device according to claim 1, wherein the metal mesh is made of any one of pure titanium material, stainless steel, copper, aluminum, and other metal materials. The metal mesh includes a first metal mesh and a second metal mesh, the first metal mesh is a pure titanium material, the second metal mesh is a stainless steel material, and the first and second metal meshes described above are used. The heat radiating device according to claim 1, wherein the heat radiating devices are provided so as to be laminated on each other.

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