WO2004109797A1

WO2004109797A1 - Heatsink for integrated circuit such as cpu

Info

Publication number: WO2004109797A1
Application number: PCT/JP2004/007703
Authority: WO
Inventors: Noriyoshi Kaneko; Akira Ota
Original assignee: Ceramission Co., Ltd.
Priority date: 2003-06-04
Filing date: 2004-06-03
Publication date: 2004-12-16
Also published as: JP2004363310A

Abstract

A heatsink for integrated circuits such as CPUs is disclosed which comprises a coating film with high emissivity. The coating film is formed by applying a suspension which is obtained by dispersing a silicon oxide powder, an aluminum oxide powder and a kaolin powder into a binder containing an alkoxysilane, a binder containing an aqueous sodium silicate solution and an aqueous potassium silicate solution, or a binder containing a silicone emulsion. Such a coating film is preferably formed on the outer surface of a mounting cover (6) for fixing a fan motor (5) to a heatsink main body (7) composed of fins (10) and/or respective outer side of the outermost fins. The coating film preferably has a thickness of 10-100 μm.

Description

Specification

Heat sink for integrated circuits such as CPU

Technical field

The present invention relates to a radiator for an integrated circuit such as a CPU, and more particularly, to a radiator for an integrated circuit such as a CPU having excellent heat radiation.

Background art

[0002] In recent years, as electronic devices such as personal computers, mobile terminals PCs, printers, fax machines, and mobile phones have increased in density, it has become essential to reduce the size of each part used inside the devices. In fields other than OA equipment, such as precision machine tools other than OA equipment and FA equipment such as industrial small robots, the miniaturization of parts is accelerating due to the development of computerization technology and semiconductor integration technology.

[0003] When miniaturizing various electronic devices, a rise in the temperature of components and devices due to heat generated by internal elements such as semiconductors and electronic circuit portions has become a major problem. With the miniaturization of equipment, the temperature rise has become even higher, and this rise in temperature has been greatly affecting the reliability and life of the equipment. In particular, since the heat generated by the CPU is large, it is important to dissipate the heat generated by the CPU.

[0004] In order to solve the problem of CPU heat generation, various devices have been devised to suppress a rise in temperature inside the device. Conventionally, it has been widely practiced to dissipate heat to the outside by providing a radiation fin and a cooling fan. However, this is no longer enough.

[0005] Patent Document 1 discloses a CPU cooling device including a fan having a discharge port directed forward on a ridge-shaped protrusion provided on a rear side of a CPU mounting portion of a socket. Have been. A cooling device that cools the heat-generating component by providing a cooler that cools the heat-generating component by exchanging heat between the heat-generating component and the heat-generating component and the refrigerant, cools the heat-generating component by circulating the refrigerant between them, is a patent. It is disclosed in reference 2. Further, Patent Document 3 discloses that a hollow body having buoyancy is contained in a paint so that the density of the hollow body becomes coarse from the base surface to the surface of the coating film so that the thermal conductivity is reduced. Thermal conductivity to minimize It is disclosed that a film having a gradient imparted thereto is formed to effectively radiate the heat generated by the CPU.

[0006] While merely changing the structure and installation position of the fins of the fan motor and heat sink as described in Patent Document 1, the heat radiation effect of the CPU is slightly improved, but is basically insufficient. In the method of circulating a refrigerant as disclosed in Patent Document 2, the device is in the direction of a large compound, and goes against the tide of miniaturization. On the other hand, the coating film of Patent Document 3 has a problem that the amount of heat conduction is suppressed and the effect is adversely affected.

An object of the present invention is to provide a heat radiator for an integrated circuit such as a CPU and the like which has a large heat radiation effect at a low cost without requiring a great deal of equipment. The present inventors have found that forming a film with a specific coating material improves the heat radiation effect of a radiator for CPUs and the like, and have completed the present invention. Here, the term “heat dissipation” refers to the characteristics of suppressing the temperature rise of integrated circuits such as CPUs and electronic devices that use these circuits by releasing the heat accumulated in the CPU and the like to the outside.

The present invention suppresses a rise in temperature of an integrated circuit such as a CPU by forming a specific film on a radiator for an integrated circuit such as a CPU and radiating heat accumulated in the integrated circuit such as the CPU. At the same time, it suppresses the temperature rise of devices that use the integrated circuit such as the CPU. By minimizing the temperature rise of integrated circuits such as CPUs, equipment, components, etc., it is possible to easily reduce the size of equipment. Here, a radiator for an integrated circuit such as a CPU refers to a device or device for dissipating heat generated by the CPU to the outside to prevent a temperature rise of the integrated circuit such as the CPU. A radiator is also generally called a heat sink.

Patent Document 1: JP 2002-190562 A

Patent Document 2: Japanese Patent Application Laid-Open No. 2002-368471

Patent Document 3: Japanese Patent Application Laid-Open No. 2002-309180

Disclosure of the invention

Problems the invention is trying to solve

[0009] The gist of the present invention is to provide a film formed from a mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, silicon oxide powder, aluminum oxide powder, and kaolin powder. It is a radiator for integrated circuits such as CPUs. Further, the alkoxysilane can contain at least one of dialkoxysilane, trialkoxysilane and tetraalkoxysilane. Furthermore, a titanium alkoxide and / or an aluminum alkoxide can be further mixed.

[0010] Further, the present invention is a radiator for an integrated circuit such as a CPU having a film formed from a mixture of an aqueous solution of sodium silicate and potassium silicate, silicon oxide powder, aluminum oxide powder, and kaolin powder.

[0011] Further, the present invention relates to a heat sink for an integrated circuit such as a CPU having a film formed from a mixture of an emulsion containing a silicone resin, silicon oxide powder, aluminum oxide powder, and kaolin powder.

[0012] The radiator includes a fin-type heat sink, an outer surface of a mounting cover of the heat sink, and

A radiator for integrated circuits such as CPUs, characterized in that a film is formed on the outer surface of the fin located on the outermost side of the heat sink, and the radiator includes a fin-type heat sink and a fan motor. A coating on the outer surface of the mounting cover and / or the outer surface of the fin located on the outermost side of the heat sink.

This is a radiator for integrated circuits such as CPU. The thickness of the film is preferably 10-100 μ—η.

[0013] The film in the present invention is a film formed from a mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, silicon oxide powder, aluminum oxide powder and kaolin powder, an aqueous solution of sodium silicate, and an aqueous solution of potassium silicate. A film formed from a mixture of, silicon oxide powder, aluminum oxide powder, and kaolin powder or a mixture containing silicone resin, emulsion containing silicon resin, silicon oxide powder, aluminum oxide powder, and kaolin powder. It is. That is, silicon oxide powder, aluminum oxide powder and kaolin powder are dispersed in a binder containing an alkoxysilane, a binder containing an aqueous solution of sodium silicate and potassium silicate, or a binder containing a silicone emulsion to form a suspension. This film is formed by applying a turbid liquid to a radiator for integrated circuits such as CPU.

[0014] In addition to silicon oxide, aluminum oxide and kaolin, various constituents of the film include Metal oxides and nitrides can be used. That is, as metal oxides, zirconium oxide, titanium oxide, tin oxide, copper oxide, iron oxide, cobalt oxide, magnesium oxide, manganese oxide, zinc oxide, germanium oxide, antimony oxide, boron oxide, and barrier oxide And at least one metal oxide such as bismuth oxide, calcium oxide and strontium oxide. In addition to metal oxides, nitrides such as boron nitride, aluminum nitride, dinoleconium nitride, tin nitride, strontium nitride, titanium nitride, and barium nitride / silicon nitride can be contained.

[0015] The metal oxide, kaolin, nitride, and the like contained in the film should preferably have a particle size of 15 x m-10 Onm. More preferably, those having a particle size of 10 zm-80 nm are used. The use of particles with this particle size makes the surface of the film smooth and clean and increases the efficiency of heat dissipation.

[0016] Kaolin is preferably a mixture of alkoxysilane, sodium silicate and potassium silicate by weight, or 0.1-20 addition to silicone resin 1. The amount of the metal oxide added is preferably 0.5 to 70 parts by weight of alkoxysilane, a combination of sodium silicate and potassium silicate, or 1 part of the silicone resin. This is to maintain high heat dissipation performance while maintaining film forming properties.

As described above, silicon oxide powder, aluminum oxide powder, kaolin powder and the like are dispersed and suspended in a binder containing alkoxysilane, a binder containing an aqueous solution of sodium silicate and potassium silicate, or a binder containing silicone emulsion. This suspension is applied to a radiator for integrated circuits such as CPU to form a film. At this time, if the viscosity of the suspension increases, adjust the viscosity by adding a solvent or water as necessary. By applying the suspension thus obtained to an object, a film can be obtained. The suspension is applied to the object with a brush, spray, roller, printing, etc., dried at room temperature or warming, and then, if necessary, heat-treated at 80 ° C or 300 ° C to obtain a metal surface. A film having a high degree of adhesion to the film can be obtained.

The film is formed on an integrated circuit radiator such as a CPU with an appropriate thickness. Unless the thickness of the present film is a certain thickness, the heat radiation effect is not sufficiently exhibited. On the contrary, if the thickness is too large, a heat storage effect occurs in the film, and the heat radiation effect becomes insufficient. Inventors' fruit According to experiments, the film thickness is preferably 100 / im or less, more preferably 10 μΐη-100 m, and particularly preferably 30 μm-80 μm.

[0019] The coating film of the present invention has excellent heat resistance such as heat shock resistance, heat dissipation, heat shielding and the like. It also has a high emissivity of 0.95, which has a high ability to radiate the stored energy as far-infrared rays into the air. The heat stored inside can be converted into far-infrared electromagnetic waves, which can be radiated efficiently, thereby suppressing the temperature rise of objects. Efficiently radiating far-infrared rays means converting the heat accumulated inside into far-infrared rays and radiating heat efficiently, resulting in the effect of suppressing temperature rise. This leads to the result that heat is dissipated efficiently without using a means of air flow. Looking at the radiation characteristics of substances that have conventionally been considered to have a high far-infrared radiation capability (eg, zeolite, cordierite, apatite, dolomite, etc.) The emissivity differs depending on the wavelength that does not have characteristics. In most cases, the emissivity tends to decrease in the area around 9 microns wavelength. On the other hand, far infrared rays emitted from the composition provided by the present invention maintain an emissivity of 0.9 or more over the entire range of wavelengths from 4 to 14 microns, and have extremely high radiation efficiency.

A film formed from a mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, silicon oxide, aluminum oxide, kaolin and the like is basically formed by hydrolysis and condensation of alkoxysilane. It is. That is, the alkoxysilane hydrolyzes and binds to the silane groups present on the surface of the colloidal silica, forming a film. The formation of a film by hydrolysis of alkoxysilane is described, for example, in JP-A-11-223191, JP-A-63-207868, JP-A-3-47883 and the like.

[0021] The above-mentioned JP-A-1-223191, JP-A-63-207868, JP-A-3-47883 and the like describe coating compositions excellent in far-infrared radiation. However, the purpose of the coating composition is to enhance the heating effect in a heater, a heater, or the like, and the present invention releases heat from an object having a high temperature to suppress the temperature rise. In terms of the purpose and effect, the invention is different from the invention described in the patent document. It becomes.

[0022] Since alkoxysilane undergoes hydrolysis / condensation in the presence of water, it is preferable that the alkoxysilane be kept free of water until immediately before use. That is, it is stored as a solution in a water-soluble solvent. At the time of use, a water-soluble solvent solution of alkoxysilane, water dispersion of colloidal silica, silicon oxide, aluminum oxide, kaolin, etc. are mixed and applied to a heat sink for integrated circuits such as CPU to form a film. Under the action of water present in the aqueous dispersion of colloidal silica, alkoxysilane is hydrolyzed and condensed to form a film.

[0023] Immediately before use, the alkoxysilane solution is mixed with an aqueous dispersion of colloidal silica, a metal oxide powder, and the like. The mixing ratio of the alkoxysilane solution and the aqueous dispersion of colloidal silica is preferably such that the weight ratio of colloidal silica (solid content) to alkoxysilane is 0.011. The water in the aqueous colloidal silica dispersion contributes to the hydrolysis of the alkoxysilane. At the same time, the alkoxysilane reacts with the silanol groups of the colloidal silica during the hydrolysis process to form a film in a form that embraces the colloidal silica. Colloidal silica contributes to film formability, film retention, heat dissipation, and heat shielding.

Further, a titanium alkoxide and / or an aluminum alkoxide can be mixed. The titanium alkoxide and / or the aluminum alkoxide may be used as a simple substance, or may be used as a solution. When used as a solution, titanium alkoxide and / or aluminum alkoxide may be used as a solution in an organic solvent, or an alkoxysilane solution may be further mixed with titanium alkoxide and / or aluminum alkoxide. ,. The titanium alkoxide and / or aluminum alkoxide is preferably added in a ratio of 0.01 to 0.5 with respect to the silicon atom of the alkoxysilane. The titanium alkoxide and the Z or aluminum alkoxide co-hydrolyze with the alkoxysilane with water to form a film containing titanium and / or aluminum in the main chain.

As the alkoxysilane, tetraalkoxysilane, trialkoxysilane (mono-organic group-substituted alkoxysilane), dialkoxysilane (di-organic group-substituted alkoxysilane) and the like can be used. These alkoxysilanes can also be used as an appropriate mixture. A Norecoxy silane is kept in a water-free state, ie, a water-free solution, until immediately before use. As the solvent used for the solution, use a water-soluble solvent that dissolves water. Specifically, alcohols such as methyl alcohol and ethyl alcohol, ketones such as acetone and methyl ethyl ketone, cyclic ethers such as dioxane and tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide and the like Solvent. Of these, solvents such as cyclic ethers such as dioxane and tetrahydrofuran, and solvents such as N-methylolepyrrolidone, methylformamide, methylacetamide, dimethylformamide, and dimethylacetamide can be suitably used.

Specific examples of the alkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and methyltripropoxy. Silane, ethyl tripropoxy silane, tinolegetoxy silane, tetramethoxy silane, tetra ethoxy silane, tetrapropoxy silane, tetrabutoxy silane, and may further have an organic group having an epoxy group. Specific examples of titanium alkoxides include tetramethoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, and specific examples of aluminum alkoxides include aluminum triisopropoxide and aluminum triethoxide. That can be S. However, it is not limited to these.

[0027] Colloidal silica can be easily obtained by hydrolyzing tetraalkoxysilane (tetraalkyl silicate) based on a known technique. It is also commercially available. For example, tetraethyl silicate is dropped into a mixture of ethyl alcohol and water containing a catalyst such as hydrochloric acid, nitric acid, and ammonia, and hydrolyzed.After the hydrolysis, ethyl alcohol and the catalyst are removed, for example, under vacuum. Thereby, an aqueous dispersion of colloidal silica is obtained. The particle size of the colloidal silica is as small as on the order of microns or less. Colloidal silica has silanol groups on the surface. The amount of colloidal silica in the aqueous dispersion of colloidal silica is about 10 to 60% by weight. This amount can be appropriately adjusted based on the amount of water used at the time of hydrolysis. After hydrolysis of the silicate, it is prepared by adding water. [0028] A mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, and a metal oxide is applied to a radiator for an integrated circuit such as a CPU to form a film. Immediately before forming a film, a solution of alkoxysilane and an aqueous dispersion of colloidal silica are first mixed, and a metal oxide powder or the like is added to the mixed solution to obtain a suspension. At the same time, an alkoxysilane solution, a colloidal silica aqueous dispersion, a metal oxide, and the like may be mixed. These mixtures form a suspension. This suspension is applied to a radiator for integrated circuits such as a CPU to form a film.

[0029] For forming a film, an alkali metal salt of silicic acid can be used. As the alkali metal salt of silicic acid, specifically, sodium silicate, potassium silicate and lithium silicate can be used. Since silicates such as sodium silicate, potassium silicate and lithium silicate are supplied as an aqueous solution, a metal oxide and kaolin nitride are added to and mixed with an aqueous solution of an alkali metal salt of silicate, and if necessary, mixed. By applying water to form a suspension and applying the suspension to an object, the film of the present invention can be obtained.

As the alkali metal salt of silicic acid, specifically, sodium silicate, potassium silicate and lithium silicate can be used, and it is preferable to use a mixture of both sodium silicate and potassium silicate. When used in a mixture, the ratio of sodium silicate to potassium silicate is preferably 0.5 to 7 (solid content basis) with respect to 1 potassium silicate. This is because if the amount of sodium silicate is large, it is difficult to remove water from the film, that is, it is difficult to dry and form the film, and if the amount of potassium silicate is large, the film form performance is deteriorated. It is preferable to use potassium in combination.

[0031] In addition, an emulsion containing a silicone resin can be used for forming a film. In other words, silicon oxide, aluminum oxide, force oil, etc. are mixed with an emulsion containing a silicone resin, and water is added as needed to form a suspension. This suspension is used for integrated circuits such as CPUs. Apply to radiator to form film. In a suspension obtained by mixing silicon oxide, aluminum oxide, kaolin and the like with an emulsion containing a silicone resin, the proportion of the silicone resin emulsion in the suspension is preferably 3070% by weight. The reason is that if the amount of the silicone resin emulsion is small, the stability of the film decreases, and at the same time, the adhesion of the film to a heat sink for integrated circuits such as a CPU decreases. is there. If the amount of the silicone resin emulsion is too large, the amount of the metal oxide and the like becomes relatively small, and the heat radiation effect is reduced.

[0032] The silicone resin emulsion is an emulsion in which a water-insoluble silicone resin is mainly dispersed in water. Silicone resin emulsions can be obtained roughly by the following five methods. 1) A method of emulsifying an alkylsilicone conjugate or its partially hydrolyzed / condensed product using various surfactants to obtain an aqueous emulsion (Japanese Patent Application Laid-Open Nos. 58-213046 and 62-197369) And JP-A-3-115485 and JP-A-3-200793. An emulsion obtained by emulsion-polymerizing a polymerizable butyl monomer can be further mixed with this emulsion (Japanese Patent Application Laid-Open No. 6-344665). 2) An alkylsilane compound is added to water without using a surfactant. Emulsion polymerization of a radically polymerizable vinyl monomer in the presence of a water-soluble polymer obtained by decomposition (JP-A-8-60098). 3) Hydrolysis of an alkyl silicate mixture containing a bullet polymerizable alkyl silicate A method of obtaining a graft copolymer fine particle (solid) emulsion by condensing to obtain an aqueous emulsion containing a solid silicone resin, further adding a radical polymerizable bur monomer, and performing emulsion polymerization (JP-A-5-209149, JP-A No. 7-196750), 4) Alkyl siliques are added to emulsions obtained by emulsion polymerization of radical polymerizable functional groups. A silicone compound is added to the emulsion particles, followed by hydrolysis and condensation, and a silicone resin is introduced into the emulsion particles (JP-A-3-45628, JP-A-8-3409); 5) alkyl containing a polymerizable functional group It can be obtained by a method such as a method of emulsion-polymerizing silicate together with a radical polymerizable biel monomer to prepare an emulsion (Japanese Patent Application Laid-Open Nos. 61-9463 and 8-27347). It can also be obtained as a commercial product.

With respect to paints and films using a silicone resin as a binder, JP-B-63-54314 describes a far-infrared radiation paint in which alumina alone or a mixture of alumina and an inorganic oxide is dispersed in a silicone resin binder. Japanese Patent Application Laid-Open No. Sho 60-213743, in which a coating made of a cured product of silicon oxide or aluminum oxide and a polysiloxane resin is provided on an infrared radiation surface, a cured product of a polysiloxane resin and a myric powder oxide JP-A-59-218444, in which coating is applied to an infrared radiation surface, far infrared radiation comprising a far infrared radiation material, a silicone resin, a flux and a solvent Japanese Patent Application Laid-Open No. 57-128753, in which a radiation paint is described, is known.All of these are used for heating and heating for cooking, and are for improving the heating efficiency of a heating body. The present invention radiates heat from an object having a high temperature to suppress a rise in temperature. Therefore, the present invention is different from the invention described in the above-mentioned patent document in terms of the object and effect.

[0034] The silicone resin used as the emulsion has excellent heat resistance, adhesiveness, and electrical properties. The silicone resin in the emulsion state serves as a binder for metal oxides and nitrides, and also serves to adhere these metal oxides and nitrides to the coating surface to form a stable and strong coating. .

[0035] The emulsion containing the silicone resin obtained by any of the above methods is made to contain a metal oxide. A powder such as a metal oxide is added to and mixed with the emulsion containing the silicone resin to obtain an emulsion suspension. Since water originally exists in an emulsion containing a silicone resin, a metal oxide or the like is mixed in a suspended state with the water to obtain an emulsion suspension containing the silicone resin and the metal oxide. it can.

[0036] When the amount of the metal oxide or the like added to the emulsion suspension becomes relatively large, the viscosity of the emulsion suspension may increase. In such a case, the viscosity of the emulsion suspension is preferably adjusted by appropriately adding water. Conversely, the emulsion containing the silicone resin may have a large water content, and the viscosity of the emulsion suspension containing a metal oxide or the like may be low. When the viscosity is small as described above, the viscosity can be adjusted by appropriately adding a thickener.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail based on examples. FIG. 11 and FIG. 3 show an embodiment of a radiator for an integrated circuit such as a CPU according to the present invention. In FIG. 1, a member denoted by reference numeral 1 is a CPU to be radiated, and a radiator 3 is arranged on an upper side of the CPU 1.

[0038] As shown in Figs. 2 and 3, the CPU radiator 3 includes a heat sink body 7, a fan motor 5, and a fan motor 5 in which a number of flat fins 10 are arranged in parallel. And a mounting cover 6 for mounting. As shown in FIG. 1, the CPU radiator 3 is connected to the CPU 1 via a thermally conductive grease (jewel) 2. In order to measure the temperature of the CPU 1, a thermocouple holding plate 4 holding a thermocouple 11 is provided between the CPU and the jewel 2.

The mounting cover 6 has a role of covering the heat sink body 7 and connecting the fan motor 5 to the heat sink body 7. The mounting cover 6 is provided with a pair of opposing side surfaces 8.

The side surface 8 is arranged parallel to the fins 10 of the heat sink body 7. Since the surface perpendicular to the fins 10 serves as a passage for the air for cooling the fins, no side surface is arranged on the surface perpendicular to the fins 10.

[0042] Further, a pair of end faces 9 are arranged on the mounting cover 6 so as to be opposed to each other in order to promote fixing of the fan motor 5. The pair of end surfaces 9 are erected on the side surface on which the side surface 8 is not provided. It should be noted that the side surface 8 may not always be provided if necessary.

Further, in the example shown in FIGS. 1 and 3, a plurality of through-holes are formed in the side surface 8, but these through-holes need not necessarily be formed. You don't have to open it. In the illustrated example, the radiator 3 is not necessarily provided with the force fan motor 5 which has been described to include the fins 10 and the fan motor 5. A film may be formed on the outer surface of the mounting cover 6 by providing only the fins 10. At this time, if the mounting cover 6 does not have the side surface 8, a film can be formed on the outer surface of the fin 10 located on the outermost layer of the fin 10 of the heat sink body 7.

A feature of the present invention is that a film is formed on the outer surface of the mounting cover 6 in the heatsink 3 for CPU. In the heatsink 3 for CPU shown in FIGS. 2 and 3, the outer surfaces are the side surface 8 and the end surface 9. A film is formed on these side surfaces 8 and end surfaces 9. It is needless to say that the side surface 8 and the end surface 9 each have two surfaces, so that each of the two surfaces forms a film.

When the side surface 8 is not provided, a film is formed on the outer surfaces of the two fins 10 located on both sides of the outermost layer of the fins 10 of the heat sink body 7. Even when the side surface 8 is present, a coating may be provided on the outermost fin 10, but in this case, the effect of the coating provided on the fin 10 is not significant. The location where the film is formed is not limited to the side face 8 and the end face 9. This is because the side surface 8 and the end surface 9 differ depending on the shape of the mounting cover 6. Features of the present invention The reason is that a film is formed on the outer surface of the mounting cover 6, that is, the surface where the mounting cover 6 comes into contact with the atmosphere.

As shown in FIGS. 1 and 3, a copper fin 10 constitutes a heat sink body 7, and an aluminum or steel mounting cover 6 is arranged so as to surround the periphery thereof. The fan motor 5 is provided above the mounting cover 6. The heat generated by the CUP 1 is conducted to the heat sink body 7 and is radiated from the fins 10. The high temperature air staying in the vicinity of the fins 10 is discharged to the outside by the fan motor 5 to prevent the temperature of the CPU 1 from rising.

By forming a film on the outer surface (8, 9) of the mounting cover 6, heat is radiated from the outer surface in the same manner, and the temperature rise of the CPU 1 is further prevented. That is, in addition to the cooling effect of the fins 10 and the fan motor 5, the cooling effect of the coating is added, and a large heat radiation effect is exhibited. As described above, the film is a mixture of an alkoxysilane solution, an aqueous dispersion of colloidanoresili force, a mixture of silicon oxide powder, aluminum oxide powder and kaolin powder. The film is formed by an aqueous solution of sodium silicate and potassium silicate, It is a film formed from a mixture of silicon oxide powder, aluminum oxide powder, and kaolin powder, and a film formed from a mixture of emulsion containing silicone resin, silicon oxide powder, aluminum oxide powder, and kaolin powder.

[0048] By forming a film on the outer surfaces 8, 9 of the mounting cover 6 in the CPU radiator 3, it is possible to prevent the temperature of the CPU 1 from rising. This uses the far-infrared radiation performance of the film to convert thermal energy into far-infrared radiation and radiates it into the air, reducing heat energy and consequently improving heat radiation performance. It brings. In this method, more efficient heat dissipation measures are taken by adding a method of radiating heat energy that can be achieved only by the methods of heat conduction and convection used in conventional heat dissipation measures.

[0049] Specific example 1

A solution prepared by dissolving 300 parts by weight of methyltrimethoxysilane, 170 parts by weight of dimethyldimethoxysilane, 30 parts by weight of glycidoxypropyltrimethoxysilane, and 15 parts by weight of tetrabutoxytitanium in 485 parts by weight of N-methylpyrrolidone. % Of an acidic colloidal silica aqueous dispersion. Take 700 parts by weight of this mixture 110 parts by weight of phosphorus, 435 parts by weight of silicon oxide powder, 190 parts by weight of aluminum oxide powder and 120 parts by weight of dinoreconium oxide powder were added and mixed by stirring to obtain a suspension. This suspension was applied to the entire side surface 8 and the end surface 9 of the mounting cover 6 and air-dried in the air. Film thickness is 52 xm

there were. Subsequently, it was dried at 95 ° C for 30 minutes, and further heat-treated at 100 ° C for 60 minutes.

The degree of temperature rise of the CPU 1 was measured using the CPU radiator 3 to which the mounting cover 6 on which the above-mentioned film was formed was attached. The film was formed on the side surface 8 and the end surface 9 of the mounting cover 6 in FIGS. In each case, a film was formed on both front and rear surfaces. The fan motor 5 was mounted on the mounting cover 6, and the radiator 3 for the CPU was assembled.

The CPU radiator 3 was connected to the CPU 1 via the thermocouple holding plate 4 and the jewel 2, as shown in FIG. CPU1 equipped with a heatsink for CPU3 was mounted on a commercially available motherboard for temperature measurement and placed in a normal PC housing. A load of 75W was applied to CPU1 to track the temperature rise of CPU1.

FIG. 4 shows a time curve of the temperature rise. In FIG. 4, symbol A indicates the temperature rise curve of CPU 1 when no film is formed on the outer surface of mounting cover 6, and symbol B indicates that a film is formed on side surface 8 and end surface 9 which are the outer surface of mounting cover 6. The figure shows the temperature rise curve of CPU1 in the case of this. Eight minutes after the start of the measurement, a temperature difference of about 15 ° C was generated between the presence and absence of the film, and the effect of preventing the rise of the temperature of the film was confirmed because the temperature of CPU1 was low when the film was formed.

[0053] After 30 minutes, the temperature almost reaches an equilibrium state. In this state, the temperature of CPU1 when a film is formed is about 62 ° C, and the temperature of CPU1 when no film is formed is 78 ° C. The temperature difference was about 16 ° C. This shows the effect of the film on preventing CPU temperature rise. When the temperature was measured in the same manner when the fan motor 5 was not provided, the temperature difference between when the film was formed and when the film was not formed in the equilibrium state was about 12 ° C.

[0054] Specific Example 2

16 parts by weight of 54.5% by weight aqueous solution of sodium silicate, 30.0% by weight aqueous solution of potassium silicate The solution was mixed with 12 parts by weight of water and further diluted with 20 parts by weight of water, and 18.0 parts by weight of fine powder of silicon dioxide, 12.0 parts by weight of fine powder of aluminum oxide and 8 parts by weight of kaolin were added to the diluted aqueous solution. , Mixed to obtain a suspension.

In the same manner as in Example 1, this suspension was applied to the entire side surface 8 and the end surface 9 of the mounting cover 6 to form a film. The film thickness after air drying in the atmosphere was 49 zm. After drying, it was heat-treated at 100 ° C for 1 hour.

The mounting cover 6 was attached to the CPU 1 in the same manner as in the specific example 1, and the degree of temperature rise of the CPU 1 was measured. The temperature measurement results were almost the same as those shown in FIG. After 30 minutes, when the temperature reaches an equilibrium state, the temperature of CPU1 when a film is formed is 63 ° C, and the temperature of CPU1 without a film is approximately 77 ° C and approximately 14 ° C. Temperature difference. That is, the temperature of the CPU 1 when the film is formed is low, and the effect of preventing the temperature of the film from rising is recognized.

[0057] Specific example 3

The product "P @ LON_MF_56" manufactured by Shin-Etsu Chemical Co., Ltd. was used as the emulsion containing silicone resin. To 50.8 parts by weight of the emulsion containing the silicone resin, 12 parts by weight of a force absorber, 8.2 parts by weight of silicon oxide, 12.3 parts by weight of aluminum oxide, 6.2 parts by weight of titanium oxide, and 10.5 parts by weight of zirconium oxide. The mixture was added and mixed to obtain an emulsion suspension. This emulsion suspension was applied to the entire side surface 8 and the end surface 9 of the mounting cover 6 to form a film. The film thickness after air drying in the atmosphere was 51 μΐη. After drying, heat treatment was performed at 100 ° C. for 1 hour. Similarly, the degree of temperature rise of CPU1 was measured. After 30 minutes, when the temperature reaches an equilibrium state, the temperature of CPU1 when a film is formed is 64 ° C, and the temperature of CPU1 when a film is not formed is about 78 ° C and about 14 ° C. A temperature difference occurred. In other words, the temperature of the CPU 1 when the film was formed was low, and the effect of preventing the temperature of the film from rising was recognized.

As described above in detail in the examples and the specific examples, it was confirmed that the film of the present invention has an effect of suppressing a temperature rise of the CPU. Suppressing the temperature rise of the CPU facilitates miniaturization of electronic devices and improves the reliability of the CPU.

In the above-described embodiment and specific example, the CPU 1 is illustrated as a heat radiation target. The embodiments of the present invention can be applied to, but not limited to, large-scale integrated circuits such as digital signal processors.

Industrial applicability

The radiator for an integrated circuit such as a CPU according to the present invention can suppress a rise in temperature, and can contribute to miniaturization of an integrated circuit such as a CPU.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory side view showing an embodiment of an integrated circuit radiator such as a CPU according to the present invention.

FIG. 2 is an exploded view of the radiator shown in FIG. 1.

FIG. 3 is an assembly view of the radiator shown in FIG. 2.

FIG. 4 is a graph of a measurement result obtained by measuring a temperature rise of a radiator according to the present invention over time.

Claims

The scope of the claims

[1] A radiator for an integrated circuit such as a CPU, which has a film formed from a mixture of an alkoxysilane solution, an aqueous dispersion of colloidal silica, silicon oxide powder, aluminum oxide powder, and kaolin powder.

2. The radiator for an integrated circuit such as a CPU according to claim 1, wherein said alkoxysilane power contains at least one of dialkoxysilane, trialkoxysilane and tetraalkoxysilane.

3. The radiator for an integrated circuit such as a CPU according to claim 1, wherein the titanium alkoxide and / or the aluminum alkoxide is further mixed.

[4] CP having a film formed from a mixture of an aqueous solution of sodium silicate and potassium silicate, silicon oxide powder, aluminum oxide powder, and kaolin powder

Heat sink for integrated circuits such as U.

[5] A radiator for an integrated circuit such as a CPU, which has a film formed from a mixture of an emulsion containing a silicone resin, a silicon oxide powder, an aluminum oxide powder, and a phosphor powder.

[6] The radiator includes a fin-type heat sink, and a film is formed on an outer surface of a mounting cover of the heat sink and / or an outer surface of a fin located on an outermost side of the heat sink. A radiator for an integrated circuit such as a CPU according to any of 5 above.

[7] The radiator includes a fin-type heat sink and a fan motor, and a film is formed on an outer surface of a mounting cover for attaching the fan motor to the heat sink and an outer surface of z or a fin located on the outermost side of the heat sink. 6. A radiator for an integrated circuit such as a CPU according to claim 1, wherein the radiator is for a CPU or the like.

[8] The radiator for an integrated circuit such as a CPU according to any one of claims 1 to 7, wherein the thickness of the film is 10100 x m.