TW200810621A - Heat spreaders with vias - Google Patents

Abstract

Constructions for and methods of manufacturing graphite heat spreaders having thermal vias placed therethrough are provided. Thermal vias having one or two flanges are disclosed, as are flush thermal vias. Graphite heat spreaders having surface layers covering the graphite material are provided. Graphite heat spreaders having a layer of cladding for increased structural integrity are provided. Also disclosed are methods of co-forging a graphite heat spreader element with a metal thermal via in place therein.

Description

200810621 IX. INSTRUCTIONS: The present invention is a contiguous case of the "heat dissipation circuit assembly" of the US Patent Application No. 1 /267,93 3 filed by Reis et al. The trial is in the process; the details of the consecutive case are referred to in this case by reference. TECHNICAL FIELD OF THE INVENTION The present invention is generally directed to a heat spreader made of an anisotropic graphite planar material, and more particularly to such a heat dispersion comprising a heat tunnel to facilitate heat transfer through the thickness of the heat spreader. Device. [Prior Art] Graphite heat spreaders have previously been proposed to remove heat from a number of dispersed heat sources. The surface of the disperser is placed against a discrete heat source and heat is moved therefrom into the disperser. Heat is then conducted through the disperser and dissipated from the two surfaces of the disperser by conduction or radiation to the cooler adjacent surfaces or dissipated into the air by convection. Thick graphite dispersers with high in-plane thermal conductivity have large cross-sectional areas to allow heat to be transferred and remove more heat than a thin disperser made of the same material. However, graphite materials having a high in-plane thermal conductivity have a relatively low thickness throughout thermal conductivity. This low thickness throughout the thermal conductivity impedes the flow through the graphite thickness and does not maximize heat transfer through the disperser. This problem can be overcome by embedding the hot aisle in a graphite disperser located at the location of the heat source. The thermal pathway is made of an isotropic material, and the thermal conductivity of the isotropic material is higher than the thickness of graphite throughout 200810621. The candidate channel materials include: gold, silver, copper, aluminum, etc. and various alloys thereof. The hot aisle is typically circular and sized to have a diameter large enough to substantially cover the entire surface of the heat source. The end of the channel contacts the heat source' and heat flows into and through the channel. Heat is transferred into the graphite via the outer diameter of the channel. The channels effectively transfer heat through the thickness of the graphite and can utilize the full thickness of the graphite disperser to maximize heat transfer. A prior art example of the use of a channel in a graphite heat dissipator is disclosed in U.S. Patent No. 6,7,8,263, issued to the assignee of The details of the U.S. patents are incorporated herein by reference. A thick graphite heat disperser made of thermal conductivity graphite in a planar plane and breaking into a hot aisle is a more efficient heat disperser than a relative graphite, all copper or all aluminum heat disperser, and It is usually lighter than a full copper or all-aluminum heat spreader. In a particular application, a heat spreader is used in conjunction with a printed circuit board. Printed circuit boards have traditionally been fabricated from dielectric materials such as fiberglass laminates (known as FR4 panels), polytetrafluoroethylene, and the like. On one of the surfaces of such a board, or between layers of dielectric material, is a circuit typically composed of copper. These circuits are typically formed by photolithography, sputtering, screen printing, or the like (as far as the circuitry is placed between the layers, the circuitry must be laid before the laminate is formed) On the dielectric material). In addition, components such as LEDs, processors or the like can be disposed on the surface of the board and in contact with circuitry on the surface. These components may generate a lot of heat, which must be -6-

200810621 is dissipated to allow components to operate reliably, flat. Due to these heat generating components, the amount of printed electricity can be large. The so-called "hot plate" is opposed to the surface of the dielectric phase circuit and the heat generating component by a layer of a heat dispersing material such as an alloy for dispersing from the electronic components. It is important that the heat spreader must be positioned to direct the heat spreader to the circuit(s) to be electrically conductive, if they are in contact with each other. There are many commercially available "絜-metal core printed circuit boards (MCPCB), T-CladTM hot plates of Insulated Metal SubstrateTM hot plates, and dielectric layers from Denka's Anotherm TN thermal conductivity from TT Electronics. For example, the first three types of heat can be filled with a plurality of heat conductive particles, or the thin positive particles on the top of the aluminum heat disperser layer may be expensive, and the subsequent layers are protected from pinholes, which increases the design. The above factor is due to its lack of manufacturing a curved or non-dielectric material covering the entire layer of the thermal disperser layer as a dielectric layer to overcome the above-mentioned difficulties and achieve its expected performance. The water-path board must assist in the dissipation of heat. For example, where copper or aluminum and its materials are stacked, and in conjunction with . On the surface or in the plies, the heat of the heat generated by = is dispersed such that at least one of the dielectric materials is opened, because the heat dissipating devices touch the plates of the circuit, which is sometimes referred to as ί is from Bergquist, HITT Plate from Thermagon, and [board. These hot plates can be used by those who can pass through the dielectric layer 1 Anotherm board can be processed through the layer. However, the thermal plate must be enough Thick enough to confirm the thermal resistance. The extra limit of this method = the elasticity of the surface circuit structure, and the fact of the surface. Some problems are caused at the anode, but because copper can not be anodized, it can only be used. Aluminum acts as its heat disperser layer. Since aluminum has a thermal conductivity significantly less than that of copper, it may become a heat loss. However, all of the aforementioned methods may suffer from soldering difficulties because of printed circuit boards and The same heat dissipation properties during operation of the assembly inhibit assembly procedures that require a point source for soldering (eg, hot rod bonding). To overcome some of the above, not all Conventional printed circuit boards can be combined with a separate metal heat spreader layer in a separate process. In this configuration, the printed circuit board can be designed to have a number of hot runners (typically plated) Holes are drilled with copper so that heat can be better conducted through the unfilled dielectric layer of the printed circuit board, but these can only be used where there is no need for electrical insulation between the components and the components. In addition, conventional heat-dispersible materials (for example, copper or aluminum) will greatly increase the weight of the board, which is unpleasant, and the coefficient of thermal expansion (CTE) of these materials cannot be closely related to the thermal expansion coefficient of the glass fiber laminate. Ground matching, which under thermal action will cause physical stress on the printed circuit board, and potentially can cause delamination or cracking. Furthermore, because the thermal diffuser layer on these plates is an isotropic The thin (relative to its length and width) metal material is formed so that heat can flow immediately through the thickness of the heat spreader and the resulting hot spot can occur directly opposite the heat source. A circuit assembly class is called "flexible circuit" of face similar problems of thermal management in this industry. The flexible circuit is constructed by providing a circuit (e.g., 200810621 copper circuit as described above) on the surface of a polymer material (e.g., polyimide or polyester) as a dielectric layer. As the name implies, these circuit materials are soft and can even be provided in the form of a coil of circuit material that can later be combined with a layer of heat disperser such as copper or Ming. Although very thin, the dielectric layer in a flexible circuit still significantly increases the thermal resistance of a given design and faces some of the same problems observed in printed circuit boards. The use of the channel is still limited to electrical insulation as described above. Moreover, it is clear that the use of a hard metal layer (such as copper or aluminum) will make it impossible to utilize the softness of the flexible circuit, which is important in end applications. ^ Use of compressed, exfoliated graphite particles ( The heat spreader consisting of flakes will remedy many of the losses encountered with copper or aluminum heat spreaders because such graphite materials offer the advantage of being reduced by 80% by weight compared to copper, and at the same time Or even more than the thermal conductivity required for copper to disperse heat throughout the surface of the printed circuit board in the in-plane direction. In addition, graphite has a coefficient of thermal expansion (CTE) in the plane of substantially zero and a lower stiffness than that of copper, thereby reducing the thermal stress at the graphite-dielectric bond. Although the compressed sheet of exfoliated graphite particles may even have the flexibility to be used in conjunction with a flexible circuit, the addition of a graphite-containing thermal disperser layer does not overcome all of the defects that result from the self-heating disperser. The location will separate the heat spreader from the heat generating components by one or more layers of dielectric material, resulting in reduced heat transfer from the components to the heat spreader layer. One or more of the layers of the laminate are composed of soft graphite flakes as is well known in the art. These structures can be seen, for example, in the manufacture of gaskets, -9-200810621. See U.S. Patent No. 4,961,991 issued to Howard. The Howard case discloses various laminate structures comprising a plurality of metal or plastic sheets bonded between soft graphite sheets. The Howard case discloses that such a structure can be prepared by cold working a soft graphite flake on both sides of a metal mesh and then pressing the graphite to the metal mesh. How. The ard case also discloses that a coating of a polymer resin is placed between two soft graphite sheets while heating to a temperature sufficient to soften the polymer resin, thereby coating the polymer resin with a cloth. Bonded between the two soft graphite sheets to form a soft graphite laminate. No. 5,509,993 to Hirschvogel discloses a soft graphite/metal laminate which is prepared by a method in which the main step of the method is to apply a surfactant to the bond to be bonded. On the surface. U.S. Patent No. 5,1,92,605 to Mercuri also incorporates a laminate of flexible graphite sheets bonded to a core material of metal, fiberglass or carbon. The Mercuri case deposits and then cures the coating of the epoxy resin on the core material and the particles of the thermoplastic prior to feeding the core material and soft graphite through the roller press roll to form the laminate. In addition to its utility on gasket materials, graphite laminates also have utility as heat transfer or cooling devices. The use of various solid structures as heat transfer bodies is well known in the art. For example, U.S. Patent Nos. 5,3,6,080 and 5,224,030, the disclosure of each of each of each each each each each each each each each Such devices are used to passively conduct heat from a heat source (e.g., a semiconductor) to a heat sink. </ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; Through the thickness of the assembly. However, the disclosures of Krassowski and Chen do not describe materials that conduct heat from a source of heat through a plurality of layers that are relatively non-conductive (such as a dielectric layer of a circuit assembly). As indicated previously, the graphite material which is preferably used as the heat disperser material of the present invention is a sheet of compressed exfoliated graphite particles, which is commonly referred to as a soft graphite flake material. The following is a brief description of graphite and the manner of forming, wherein the forming method is usually carried out to constitute a soft graphite sheet material. In microscopic form, the graphite consists of a hexagonal array of carbon atoms or a laminate plane of the network. The planes of the layers of carbon atoms in a hexagonal configuration are generally flat and are oriented or arranged to be substantially parallel and equidistant from one another. These generally flat, parallel and equidistant carbon atom flakes or layers (often referred to as graphite flake layers or substrate planes are joined or bonded together, and their groups are arranged in microcrystals. Highly ordered graphite The material consists of crystallites of considerable size, and the crystallites are highly aligned or oriented relative to one another and have a number of relatively ordered carbon layers. In other words, highly ordered graphite has a height. Microcrystal orientation is preferred. It should be noted that, by definition, graphite has an anisotropic structure and thus exhibits or has many properties of high directivity, such as thermal and electrical conductivity and fluid diffusivity. Briefly, graphite It is characterized by a K-layer structure of carbon 'that is, a structure composed of a stack of layers or thin layers of -11-200810621 carbon atoms which are connected by a weak van der Waal s force. As far as the graphite structure is concerned, two axes or directions are usually mentioned, namely the "C" axis or direction and the "a" axis or direction. For the sake of simplicity, the "C" axis or direction can be considered to be perpendicular to the carbons. The direction of the "a" axis or direction can be considered to be parallel to the direction of the carbon layers, or perpendicular to the direction of the "c" direction. Graphite suitable for the manufacture of soft graphite sheets has a very high degree of directivity. As mentioned, the bonding force that holds the parallel layers of carbon atoms together is only a weak van derma force. Natural graphite can be chemically treated so that the intervals between layers or thin layers of carbon atoms can be significantly opened. So that a significant expansion along the direction perpendicular to the layers (i.e., along the "c" direction) can be provided, and thus an expanded or swollen graphite structure is formed, wherein the thin layer properties of the carbon layers are substantially retained Graphite sheets that have been chemically or thermally expanded, and more specifically, have been expanded to have a final thickness or "c" direction dimension that is about 80 times or more larger than the original "c" direction dimension, The graphite sheet can be formed into a bonded or integral expanded graphite sheet without the use of a binder, such as a mesh, paper, strip, tape or the like (generally referred to as "soft graphite"). The mechanical bonding or bonding achieved between the expanded graphite particles allows the graphite particles to be formed into a unitary flexible sheet by compression without the use of any bonding material, wherein the graphite particles have been expanded to have a final thickness or "c" direction dimension that is approximately 80 times or more larger than the original "c" direction dimension. In addition to softness, the sheet material as set forth above is also found in thermal and electrical conductivity. And the high degree of anisotropy in fluid diffusibility, although less than -12-200810621, but comparable to natural graphite starting materials, because the direction of the expanded graphite particles is roughly parallel to the very high compression (for example The roll processing comprises the opposite faces of the formed sheets. The resulting sheet material thus has excellent softness, good strength and very high directivity. There is a need for processing that can more fully utilize these properties. Briefly, the use of a non-adhesive anisotropic graphite sheet material (such as a mesh, paper, strip, tape, foil, mat, or the like) for forming a non-adhesive agent is included under a predetermined load and without a binder. Lower compression or compaction of the graphite particles, which have a size of about 80 times or more the "c" direction of the "C" direction of the original particles so as to form a substantially flat, soft, And integrated into the graphite sheet. Expanded graphite particles, which are generally in the form of insects or worms in appearance, will remain compressively deformed once compressed and aligned with the opposite major surfaces of the sheet. The nature of the sheet can be altered by precoating and/or adding binders and additives prior to the compression step. See US Patent No. 3,404,0 61 to Shane et al. The density and thickness of the sheet material can be varied by controlling the degree of compression. • Lower density is advantageous where surface details must be embossed or molded, and lower density helps to achieve good detail. However, denser sheets typically have higher in-plane strength and thermal conductivity. Typically, the density of the sheet material will be from about 0. 04g/cm3 to about 1. Within the range of 9 g/cm3. The soft graphite sheet material produced as described above generally exhibits an appreciable degree of anisotropy due to the alignment of the graphite particles parallel to the main opposite parallel surfaces of the sheet, while making the anisotropy The degree is increased immediately after the sheet material is pressed to increase the density in rolls-13-200810621. In the rolled anisotropic sheet material, the 'thickness (ie, perpendicular to the opposite parallel sheet surfaces) includes the ''C' direction and the direction along the length, and the width (ie, 'edge' Or parallel to the opposing major surfaces, including the "a" direction, and generally in terms of size, the thermal properties of the sheets in the "c" and "a" directions are very different. [Invention] It is an object of the invention to provide an improved structure of a channel P in a graphite heat disperser. Another object of the present invention is to provide an improved method for fabricating a graphite heat disperser having a hot aisle. Another object of the present invention is to provide a convex a rim channel having a flange that engages one of the major surfaces of the graphite heat spreader to improve heat transfer between the channel and the graphite heat spreader. Another object of the present invention is to provide a A low cost method of manufacturing a heat spreader with channels using inexpensive push nuts. • Another object of the present invention is to provide a graphite heat spreader for constructing a flushed hot aisle Structure and Method Another object of the present invention is to provide a graphite heat spreader having a plurality of heat passages and a layer that provides a coating layer that facilitates structural integrity of the heat spreader. Still another object of the present invention is A method of forging a hot aisle with a graphite heat disperser is provided. For those skilled in the art, the present invention can be easily and clearly understood after reading the disclosure and referring to the accompanying drawings. The object, features and advantages of the invention are provided. The invention provides for the manufacture of graphite heat having a hot aisle: a preferred structure and method. In one embodiment, the flange channel is provided with at least one flange 'with graphite One of the planar surfaces of the graphite planar element of the heat spreader is engaged. The flange channel can be pushed through the nut or can be secured by using a second flange that is rigidly connected to the channel. On the graphite disperser. Thus, this comprises at least one flange and a second flange or a push nut that is above the surface of the graphite thermal element. In another embodiment A hot runner that is flush with the major planar surfaces of the graphite hot component in a final position. A variety of different techniques that can be used in the fabrication of the embodiments are provided. Two embodiments preferably relate to a method of manufacture, wherein The through is press fit into a hole of the same shape but slightly smaller and extending through the element so as to provide a close fit between the stem and the through hole of the graphite. One of the special uses of such a graphite heat spreader is Can be used in conjunction with a circuit board circuit assembly. When the heat generating component (the heat path between the heat sink layer and the heat spreader layer (ie, the heat path) is thermally dispersed by the heat dissipator layer on the lifter assembly) Substantially corrected, by virtue of the use of this thermal path, the graphite-based heat spreader can provide improved thermal dispersion 'even comparable to the use of aluminum or other and other dispersers. The flange channel on the column is fully extended to provide the element of the element. The two elements of the graphite column are printed on the surface of the graphite. The light is LED). Time: electricity: good. The use of the real layer Copper heat score -15- 200810621 The person who has the weight also has the advantage of reducing weight. By "circuit assembly" is meant an assembly comprising one or more electronic circuits positioned on a dielectric material, and may include a laminate in which one or more of the circuits are sandwiched Between the dielectric layers. Specific examples of circuit assemblies are printed circuit boards and flexible circuits, as is well known to those skilled in the art. Before explaining the method of the present invention for improving existing materials, the graphite and how it is formed into a flexible sheet will be briefly described in the first place, and the soft sheets will become the main heat dispersers for constituting the product of the present invention. A microcrystalline version of graphite-based carbon that includes atoms that are covalently bonded in the plane of the flat stack and that bond the planes to a weaker bond. By treating the graphite particles (such as natural graphite flakes) with an intercalant such as a solution of sulfuric acid and nitric acid, the crystalline structure of the graphite will act to form a compound of graphite and the intercalant. The treated graphite particles are hereinafter referred to as "intercalated graphite particles". After exposure to elevated temperatures, the intercalating agent in the graphite then decomposes and volatilizes, which causes the intercalated graphite particles to be sized along the "C" direction (ie, along the direction perpendicular to the crystalline surfaces of the graphite). A type like the accordion expands to 80 times or more of its original volume. The exfoliated graphite particles are worm-like in appearance and are therefore commonly referred to as worms. The worms can be compressed together into a flexible sheet which, unlike the original graphite sheet, can be formed and cut into various shapes. Graphite starting materials suitable for use in the present invention include highly graphitized carbonaceous materials which can be inserted into organic and inorganic acids and halogens and then swell when exposed to heat by the storm. These highly graphitized carbonaceous materials preferably have a degree of graphitization of about 1.0. As used herein, the term "graphitization" refers to the g値 obtained from the following formula: =3. 45 X d(Q02) g— ~ ~0. 095 wherein d(002) is the interval between the graphite layers of carbon in the crystal structure measured in Angstrom units. The spacing between the graphite layers is measured by standard X-ray diffraction techniques. The positions of the diffraction peaks corresponding to the (002), (004), and (006) Miller Indices are measured, and the standard least squares technique is used to derive the interval, which minimizes the total of all of these peaks. error. Examples of tubular graphitized carbonaceous materials include natural graphite from various sources, as well as other carbonaceous materials such as graphite prepared by chemical vapor deposition, high temperature pyrolysis of polymers, or crystallization and the like. . Natural graphite is the best. The graphite starting material used in the present invention may comprise a non-graphite component as long as the crystal structure of the starting materials maintains the desired degree of graphitization and is peelable. In general, any carbonaceous material is suitable for use in conjunction with the present invention, and the crystal structure of the carbonaceous materials has a desired degree of graphitization and is exfoliable. Such graphite preferably has a purity of at least about 80% by weight. More preferably, the graphite used in the present invention has a purity of at least about 94%. In the preferred embodiment, the graphite used will have a purity of at least about 98%. A general method for the manufacture of a graphite sheet is described in U.S. Patent No. 3,404,061, the entire disclosure of which is incorporated herein by reference. In a typical implementation of the method of Shane et al., Day-17-200810621 graphite flakes are intercalated by dispersing the flakes in a solution comprising, for example, a mixture of nitric acid and sulfuric acid, most advantageously by weight. Approximately 20 to about 300 parts of the intercalation solution per 100 parts of graphite flakes (pph). The intercalation solution includes an oxidizing agent and other intercalating agents known in the art. Examples include those comprising: an oxidizing agent and an oxidizing mixture such as a solution containing nitric acid, potassium chlorate, chromic acid, potassium permanganate, potassium chromate, potassium dichromate, perchloric acid, and the like; or a mixture such as concentrated nitric acid and chlorine a mixture of an acid salt, chromic acid and phosphoric acid, sulfuric acid and nitric acid; or a strong organic acid such as trifluoroacetic acid; and a strong oxidizing agent dissolved in the organic acid. Alternatively, the potential can be used to cause oxidation of the graphite. Chemical substances which can be introduced into the graphite crystal by electrolytic oxidation include sulfuric acid and other acids. In a preferred embodiment, the intercalating agent is a solution of sulfuric acid, or a mixture of sulfuric acid and phosphoric acid, and an oxidizing agent, wherein the oxidizing agent is nitric acid, perchloric acid, chromic acid, barium permanganate, hydrogen peroxide, iodic acid. , periodic acid, or the like. Although not preferred, the intercalation solution may comprise: a metal halide such as ferric chloride, and ferric chloride mixed with sulfuric acid; or a halide such as bromine as a solution of bromine and sulfuric acid, or in an organic Bromine in the solvent. The amount of intercalation solution can range from about 20 to about 35 Opph, and more typically from about 40 to about 160 pph. After the sheets are intercalated, any excess solution is discharged from the sheets and the sheets are washed with water. Alternatively, the amount of the intercalation solution can be limited to between about 10 and about 40 pph, which will allow the water wash step to be eliminated as taught and suggested in U.S. Patent No. 4,895,731, the disclosure of which is incorporated herein. The content is also incorporated herein by reference. -18- 200810621 The particles of the graphite flakes treated with the intercalation solution can be contacted, for example by mixing, with a reducing organic agent selected from the group consisting of alcohols, saccharides, aldehydes and esters at 25 ° C. It can react with the surface film of the oxidized intercalation solution in the temperature range of 125 °C. Suitable specific organic agents include: cetyl alcohol, octadecyl alcohol, 1-octanol, 2-octanol, decyl alcohol, U0 diol, awake, 1-propanol, 1,3 propylene glycol, ethylene Alcohol, polypropylene glycol, glucose, fructose, lactose, sucrose, potato starch, ethylene glycol monostearate, diethylene glycol dibenzoate, propylene glycol monostearate, glyceryl monostearate, carboxylic acid Dimethyl ester, diethyl carboxylate, methyl formate, ethyl formate, ascorbic acid, and compounds derived from lignin, such as sodium lignosulfonate. The amount of the organic reducing agent is suitably about 0. 5 to 4%. The use of expansion aids prior to intercalation, during intercalation, or just after intercalation may also provide improvements. Among these improvements may be a reduced peel temperature and an increased expansion volume (also referred to as "worm volume"). The swelling aid herein will preferably be an organic material which is sufficiently soluble in the intercalation solution to achieve expansion improvement. More strictly speaking, such organic materials containing carbon, hydrogen and oxygen (preferably exclusively) can be used. Carboxylic acids have been found to be particularly effective. A suitable carboxylic acid which may be used as an expansion aid may be selected from aromatic, aliphatic or alicyclic, linear or branched, saturated and unsaturated monocarboxylic acids, dicarboxylic acids and polycarboxylic acids having at least one One carbon atom (preferably up to 15 carbon atoms) can be dissolved in the intercalation solution in an amount effective to provide a predictable improvement for one or more exfoliation patterns. A suitable organic solvent can be used to improve the solubility of the organic expansion aid in the intercalation solution from -19 to 200810621. ^ Representative examples of saturated aliphatic carboxylic acids such as those having the formula H(CH2)nCOOH, wherein η is a number from 〇 to about 5, and the acids include: formic acid, acetic acid, propionic acid, Butyric acid, valeric acid, caproic acid, and the like. An aldehyde or a reactive carboxylic acid derivative such as an alkyl ester may also be used in place of the carboxylic acid. Representative of alkyl esters are methyl formate and ethyl formate. Sulfuric acid, nitric acid, and other conventional aqueous intercalants have the ability to ultimately decompose formic acid into water and carbon dioxide. Therefore, formic acid and other sensitive φ expansion aids are preferably contacted with the graphite flakes before the graphite flakes are immersed in the aqueous intercalation agent. The dicarboxylic acid is represented by an aliphatic dicarboxylic acid having 2 to 12 carbon atoms, especially oxalic acid, fumaric acid, malonic acid, maleic acid, succinic acid, glutaric acid, adipic acid. 1,5-pentanedicarboxylic acid, 1,6-hexanedicarboxylic acid, 1,10-decanedicarboxylic acid, ring. Hexane-1,4.dicarboxylic acid, and an aromatic dicarboxylic acid such as phthalic acid or terephthalic acid. Representative of alkyl esters are dimethyl carboxylic acid and diethyl carboxylic acid. Representative of cycloaliphatic acids are cyclohexanedicarboxylic acids, and representatives of aromatic carboxylic acids are benzoic acid, naphthoic acid, #o-aminobenzoic acid, hydrazine-p-aminobenzoic acid, salicylic acid, hydrazine-, m - and ρ-tolyl acid, methoxy and ethoxybenzoic acid, acetyl acetamide benzoin and acetamide benzoic acid, phenylacetic acid and naphthoic acid. Representative of hydroxyaromatic acids are p-hydroxybenzoic acid, 3-hydroxy-1-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4-hydroxy-2-naphthoic acid, 5-hydroxy-1-naphthoic acid, 5- Hydroxy-2-naphthoic acid, 6-hydroxy-2.naphthoic acid, and 7-carbamoyl-2-naphthoic acid. The important one of the polyphthalic acids is citric acid. The intercalation solution is aqueous and preferably contains from 1 to 10% of the swelling adjuvant. This amount will effectively increase the peeling. In embodiments in which the expansion aid -20-200810621 is thinner than graphite before or after immersion in the aqueous intercalation solution, the expansion aid may be mixed with the graphite by a suitable device (eg, a machine), which is typically It accounts for about 0. 2% to about 10%. After the graphite flakes are inserted, and after the ink flakes to be coated with the intercalant are mixed with the organic reducing agent, the mixture is exposed to a temperature range of 125 ° C to promote the reaction of the reducing agent with the intercalation. The heating period can be as long as about 20 hours, while at the upper temperature it is only necessary, for example, at least about 10 minutes. It can be used at higher temperatures for half an hour or less, followed by 10 to 25 minutes. The graphite particles thus treated are sometimes referred to as "intercalated particles". When exposed to high temperatures (eg, at least about 160 ° C, about 700 ° C to 1000 ° C, and higher temperatures), the intercalated stone is along the "c" direction (ie, perpendicular to the constituent graphite particles) The direction of the plane is expanded to an original 80 to 1,000 times or more in an original accordion type. The swells (i.e., the smear-off particles are worm-like in appearance, and thus are generally referred to as worms that can be compressed together into a soft sheet which, unlike the original sheet, can be shaped and cut A variety of different shapes. Soft graphite sheets and foils with good processing strength, and suitable for being compressed to a pressure of about 3. The thickness between 75 mm, and a typical density of grams per cubic centimeter (g/cm3). For example, in the United States, the 5th, 902,762 pieces are in contact with the V-type mixed weight of the intercalated stone: 25 ° C to the coating surface within the range of short heating time, for example, the graphite particles, especially the large ink particles, the microcrystalline starting volume The stone worm. The graphite thin system is mutually adhesive: 0. 075mm 0·1 to 1. In the patent No. 9-200810621 (which is incorporated herein by reference), the ceramic additive of the weight of 1.5 to 30% can be mixed with the intercalated graphite flakes so that Provides increased resin implantation in the final soft graphite product. The additives include ceramic fiber particles having a value of about 0. 丨5 to i. The length between 5mm. The width of the particles is suitably from 〇·〇4 to 〇. 〇〇 4mm. The ceramic fiber particles do not react to the graphite and are not adherent, and are stable at a temperature of about 1100 ° C, preferably about 1400 ° C or higher. Appropriate ceramic fiber particles are made of soaked soft glass fiber, carbon and graphite fiber, oxidized • chromium, boron nitride, tantalum carbide and magnesia fiber, naturally occurring mineral fiber, such as calcium metasilicate fiber, calcium aluminum silicate Made up of fibers, alumina fibers, and the like. The above method for intercalating and stripping graphite flakes can be pretreated by graphite flakes at a graphitization temperature (i.e., at a temperature in the range of about 3000 ° C and above), and by intercalating agents. It is advantageously enhanced by the inclusion of a lubricating additive, as described in the International Patent Application No. PCT/US02/39749, the disclosure of which is incorporated herein by reference. • Pre-treatment or annealing of the graphite flakes will result in a significantly increased expansion (i.e., an increase in expansion volume to 300% or greater) as the graphite flakes subsequently undergo intercalation and exfoliation. Indeed, the increase in expansion is satisfactorily at least about 50%, as compared to a similar treatment without the annealing step. The temperature used in the annealing step should not be significantly lower than 3000 ° C because even a lower temperature of 100 ° C results in a substantially reduced expansion. The annealing of the present invention is carried out for a period of time sufficient to cause the sheet, which sheet then has an increased bulk -22-200810621 after the intercalation and subsequent stripping. The time usually required is 1 hour or more, preferably 1 to 3 hours, and most advantageously carried out in an inert environment. For the best benefit results, the annealed graphite sheet will also be subjected to other methods of increasing the degree of expansion in the art, that is, the intercalation method, which comprises an organic reducing agent, such as organic The acid intercalation aid and the surfactant rinse after the intercalation is completed. In addition, the intercalation step can be repeated for maximum benefit results. The annealing step of the present invention can be carried out in an induction furnace or other such apparatus as is well known and understood in the art of graphitization; as for the temperature used for Φ here is in the range of 3000 ° C, and this temperature It should be at the upper end temperature in the temperature range encountered in the graphitization procedure. It has been observed that worms made from graphite that has been subjected to pre-intercalation annealing may sometimes "block" together, which may negatively affect the uniformity of the weight of the punched surface, thus assisting in the formation of "free flow" The worm additive is highly necessary. The addition of a lubricating additive to the intercalation solution helps the worm to more evenly distribute the machine across the compression equipment (eg a machine tool of a press station), which has traditionally been used to compress graphite worms (rolling) Into a soft graphite sheet. Therefore, the resulting sheet has a higher area uniformity and a larger tensile strength. The lubricating additive is preferably a long bond carbon oxide, more preferably a carbon oxide having at least about 10 carbons. Other organic compounds with long-chain carbon oxide groups can be used even in the presence of other functional groups. More preferably, the lubricating additive is an oil, and the best is mineral oil, especially considering that the mineral oil is less prone to spoilage and odor, which is an important consideration for those who need long-term storage. It will be noted that certain -23-200810621 swelling aids, which have been detailed above, also meet the definition of lubricating additives. When these materials are used as expansion aids, it is not necessary to include a separate lubricant additive in the intercalant. The lubricating additive is present in the intercalant in an amount of at least about 1 · 4 ρ ρ 1 , preferably at least about 1 · 8 pph. Although the upper limit of the amount of the lubricant additive is not as important as the following, the lubricating additive content does not appear to have any significant additional benefit at levels greater than about 4 pph. The soft graphite sheet of the present invention, if necessary, can be used to temper the granules of the soft graphite sheet instead of the newly expanded mites, as described in U.S. Patent No. 6,673,289, the disclosure of which is incorporated herein by reference. The way is to be included in this article. The sheets may be freshly finished sheet material, recycled sheet material, discarded sheet material, or any suitable source thereof. The method of the present invention may also use a mixture of unused materials and recycled materials. The source material of the recycled material may be the trimmed portion of the sheet or sheet which has been compression molded as described above, or may have been compressed by, for example, a pre-rolling roll but not impregnated with resin. Plate. In addition, the source material may be the trimmed portion of the sheet or sheet that has been implanted with the resin but not cured, or the trimmed portion of the cured sheet or sheet that has been implanted with the resin. The source material can also be a recycled soft graphite proton exchange membrane (PEM) fuel cell assembly, such as a flow plate or electrode. Each of the various graphite sources can be used as a natural graphite flake or can be mixed with natural graphite flakes. Once the source material of the soft graphite sheet is available, it can then be powdered by a conventional method or apparatus (such as a jet honing machine, air mill, mixer, etc.) so that it can be made into granules. Preferably, most of the particles have a diameter that allows them to pass through the U.S. National Standard 20 mesh; more preferably, most (greater than about 20%, the best system is greater than about 50%) will not pass the United States. Standard 80 mesh. Most preferably, the particles have a particle size greater than about 20 U.S. National Standards. It is preferable to cool the soft graphite sheet while it is being powdered and simultaneously implanted with the resin so that the resin system can be prevented from being thermally damaged during the powder formation. The size of the granulated particles can be selected so as to balance the processability and formability of the graphite article having the desired thermal characteristics. Thus, smaller particles will result in a graphite article that is easier to process and/or shape, while larger particles will result in a graphite article that has a higher anisotropy and therefore greater in-plane electrical and thermal conductivity. Once the source material is broken into powder, it is then re-expanded. The re-expansion can be achieved by the use of the above-described intercalation and exfoliation methods, as well as those described in U.S. Patent No. 3,404,061, issued to the entire entire entire entire disclosure of And it happened. In general, after intercalation, the particles are stripped by heating the intercalated particles in an oven. During this stripping step, the intercalated natural graphite flakes can be added to the recovered intercalated particles. Preferably, the particles are expanded to have a specific volume in the range of at least about 100 cC/g and up to about 35 cc/g or greater during the re-expansion step. Finally, after re-expansion, the re-expanded particles can be compressed into flexible sheets, as described below. According to the present invention, a graphite sheet prepared as described above (which usually has -25-200810621 has about 0. A thickness of from 075 mm to about 10 mm, but which may vary, for example, according to the degree of compression used) may be treated with a resin, and the absorbed resin may enhance the moisture resistance and handling strength (i.e., rigidity) of the sheet after curing. And "fixed" the shape of the plate. The amount of resin in the epoxy-implanted graphite sheet must be an amount sufficient to ensure that the final combined and cured layered structure is dense and adhesive, while the anisotropic thermal conductivity associated with the dense graphite structure is Not adversely affected. A suitable resin content is preferably at least about 5% by weight, more preferably from about 10% to about 5% by weight, and suitably up to about 60% by weight. Resins found to be particularly advantageous for practicing the invention include: acrylic based, epoxy based and phenolic based resin systems, fluorine based polymers, or mixtures thereof. Suitable epoxy resin systems include those based on bisphenol A (DGEBA) epoxy resins and other multifunctional resin systems; phenolic resins that can be used include Resol and Νονοί ac phenolic resins. Alternatively, in addition to the resin, the soft graphite may be implanted with fibers and/or salts; or the soft graphite may be implanted with fibers and/or salts to replace the resin. In addition, reactive or non-reactive additives can be used with resin systems to modify properties such as adhesion, material flow, water repellency, and the like. An apparatus for the continuous molding of a resin and a compressed soft graphite material is disclosed in U.S. Patent No. 6,706,400 issued to thessssssssssssssssssssssssssssssssssssssssssssssssssssssss Advantageously, when the sheet consisting of the compressed exfoliated graphite particles is impregnated with resin, after the compression step (for example by means of wheel pressing), it is impregnated -26-

200810621 The material of the stain is cut into the appropriate size of the slice, and the resin is used here at a raised temperature by the @ graphite sheet can be applied in the form of a laminate, and the other graphite sheets together The temperature that is stacked in the press and prepared for use in the press must be sufficient to ensure that the stone pressure is densified while the thermal properties of the structure are not loud. In general, this would require a minimum of about 90 and typically up to about 200 °C. Most preferably, the curing system is at a temperature range of S to 20 °C. The pressure used for curing will be a function of temperature, but will be sufficient to ensure that the graphite structure is densified without adversely affecting the properties. In general, the benefits will be exploited to intensify the structure to the required pressure. This pressure will typically be at least about 7 MPa (1000 lbs) and no more than about 35 MPa (comparably and more generally from about 7 to about 21 MPa (1000 liters depending on the resin system and the temperature used) The pressure is usually in the range of from about 0.5 hours to about 2 hours. The E material is found to have a density of from about 1.8 g/cm3 to about 2.0 g/cm3 of at least about 1.8 g/cm3. Advantageously, when the graphite sheet is soft. It appears in itself that the resin in the implanted sheet will serve as a laminate, and according to another embodiment of the invention, the soft graphite sheet will be pre-formed prior to the soft sheet. Suitable adhesives include epoxy, acrylic based on a press. In addition, soft can be adversely affected by curing the ink structure, and ί from about 150 ° C How much is used to heat the structure for the minimum degree of manufacturing must be equivalent to 500 psi per square, 3000 psi). The solid 3 changes, but after the completion of the pass, I, and usually in the laminated plate, the adhesive of 5 is stored. They are then stacked and cured: the coating is adhered to a phenolic based resin. -27- 200810621 The phenolic resin found to be particularly advantageous for the practice of the present invention comprises: R e s c Novolak type phenolic resin. Although the formation of the sheet by means of wheel pressing or molding is the most commonly used method for carrying out the graphite material of the present invention, a forming method can also be used. The temperature- and pressure-cured graphite/resin of the present invention is a composite of a graphite-based composite material which has a planar heat-conducting body which is comparable to or exceeds the thermal conductivity of copper in only a small part of the weight of copper. The article has an in-plane rate of at least about 300 W/m ° K while having a through-plane heat transfer of less than about 15 W/m ° K of less than about 10 W/m ° K. Referring now to the drawings, and in particular to Figure 1, a circuit assembly in accordance with the present invention in which a graphite heat spreader is coupled to a plurality of hot channels is designated by the component symbol 10. The circuit assembly 10 includes at least one dielectric layer 20 disperser 30, wherein the heat spreader 30 abuts the dielectric layer 20. The heat dissipator 30 includes at least one sheet of compressed exfoliated graphite which is prepared as previously described. The circuit assembly is a printed circuit board or a flexible circuit, but may also include, for example, a conductive ink print or screen pattern on an electrolyte layer 20. The circuit assembly 10 also typically includes a conventionally formed 40 of copper which is applied to the dielectric layer 20 by photomask engraving, sputtering, screen printing, and the like. The circuit 40 as before may also be formed of conductive ink which is applied to the dielectric layer 20 by, for example, a screen printing method. &gt;le type and other parts of the forming offer g. More thermal conductivity, but more than a standard and a heat of $ good, the structure of the grain is usually located in the circuit brush or mentioned, brush or wire -28- 200810621 dielectric layer 20 can be printed As is well known in the circuit board industry, such as: glass fiber with resin (FR-4), preferably formed into a laminated 'plate; polytetrafluoroethylene (PTFE), commercially available Teflon brand materials; and expanded PTFE, sometimes labeled as ePTFE; and the impregnated or inhaled resin type of the above items. Additionally, dielectric layer 20 can be a polymer such as polyamidamine or polyester, as is used in the formation of flexible circuits. The dielectric layer 20 may also comprise a ceramic material, such as aluminum nitride, aluminum oxide, alumina, which is presented in the form of a separate layer or is laid through, for example, anode φ processing, vapor deposition, or flame spraying. On a substrate layer (e.g., heat spreader layer 30); the use of anodization is particularly relevant to the case where the heat spreader layer 30 is aluminum. Moreover, in some cases, it is preferred to at least partially enclose the heat spreader layer 30 or provide a coating on the surface of the heat spreader layer 30 so as to prevent particulate matter from the heat spreader layer 30. Peel off. For example, some people's opinion is that graphite materials are prone to flakes. Whether or not it is true, providing a cladding layer of a polymeric material such as My y 1 a r (typically at a level less than 2 〇 micron Φ) to prevent sheet flaking will be associated with the above-described teachings. In this case, the polymeric material can serve as the dielectric layer 20 of the circuit assembly 1 because the material used can be non-conductive and thin enough to not substantially interfere with thermal conduction to the heat spreader layer 3〇. Alternatively, an anodized layer may be used to inhibit spalling, while the anodized layer may also serve as dielectric layer 20. Preferably, the heat spreader layer 30 is from about 〇25 mm to about 25 mm' in thickness, more preferably from about 〇5 mm to about 14 mm in thickness, and includes one sheet to be from -29 to 200810621. Advantageously, the heat spreader layer 30 can be a laminate of up to 1 inch or more of graphite sheets to provide the desired heat dissipating ability. The graphite composite can be used to at least partially replace copper or other metals used as circuit assembly heat spreaders, and in the preferred embodiment can be completely replaced. Surprisingly, when the heat spreader layer 30 becomes black, for example by paint, especially when it is composed of one or more sheets of compressed, exfoliated graphite particles, improved heat is obtained. Resistance. In other words, where the surfaces of the graphite heat disperser layer 30 not adjacent to the dielectric layer 20 are black, the effective thermal resistance of the thermal path from the heat generating component is reduced. Although the exact cause of this situation is not known, it is generally believed that making the graphite heat disperser layer 30 black will improve the emissivity of the disperser layer 30, thereby improving the ability of the heat spreader layer 30 to dissipate heat. The heat spreader layer 30 need not necessarily be planar, but may also include one or more "bends" so as to form a three-dimensional shape. This is particularly advantageous where the circuit assembly 10 must be positioned on a different plane than the heat spreader layer 30. This configuration is used, for example, for an edge-lit liquid crystal display (LCD display) in which a plurality of LEDs are mounted on a circuit assembly 1 且 and in a plane having a confined space (ie, the thickness of the LCD display), and the heat is The diffuser layer 30 extends perpendicular to the LED mounting plane.

Indeed, in one embodiment of the invention, the heat spreader layer 30 has a surface area that is larger than the dielectric layer 20 and any circuitry 40 located thereon. In this case, the dielectric layer 20 and the heat generating component(s) 50 and the circuit(s) 40 can be located in a plane (eg, for the LED plane of the side-lit LCD-30-200810621 display), while thermally dispersing The layer 30 then stretches into another plane as previously described (e.g., a face having a curvature of about 90°, such as in a plane behind the LCD display), and thus dispersed into other planes for additional dissipation. The graphite/dielectric material laminate can be refined by laminating a plurality of dielectric heat disperser layers 30, for example, in a laminated circuit board of a forming circuit assembly and using conventional adhesives. The graphite/dielectric material laminate may be formed to be pre-compressed and simultaneously pressurize and cure the graphite materials. The implanted graphite sheet epoxy polymer is sufficient to bond the non-graphite and graphite layers of the structure to the proper location when cured. In any event, preferably, the graphite composite is used as a thermal disperser for the circuit assembly 10 to replace a copper or aluminum heat spreader in a so-called "metal backed" printed circuit board or circuit. As mentioned previously, the material 20 forming the central portion of the circuit assembly 10 has two major surfaces 20a and 20b. The heat spreader is one of the surfaces 20a of the dielectric material 20; the other meter has been provided with at least one heat generating component 50 thereon, and often has replica generating components 50a, 50b, 50c, etc., such as LEDs, Chipsets, other components familiar to those skilled in the art. The heat generating assembly 50 is in contact with a portion of the circuit 40, and the circuit 40 is mounted on the surface 20b of the circuit assembly 10 of the assembly 50. Some manufacturers' LEDs contain hot fillets to help dissipate the heat itself; these hot fillets are generally considered to be charged. In general, the heat can be made horizontally and the conventional one can be formed. Or stacked, in the slice implanted embodiment layer 30, in a soft dielectric i 30 o: face 20b several heat or familiar are placed in their LEDs therefore, -31- 200810621 when these LEDs When more than one is provided on the circuit assembly 10, care must be taken to avoid shorting between the slugs on the two or more LEDs of the assembly; therefore, the individual LEDs often must be electrically insulated. To facilitate the transfer of heat from the heat generating assembly 50 to the heat spreader layer 30&apos;, a heat path 60 (also referred to as a hot channel or simply channel 60) extends through the heat spreader layer 30 and abuts the heat generating assembly 50. Advantageously, the passage 60 also extends through the circuit assembly 10 between the respective heat generating assemblies 50 and the heat spreader layer 30. While other highly thermally conductive materials such as aluminum or compressed exfoliated graphite particles φ can be used, the channel 60 still includes a fillet or "rivet" made of a highly thermally conductive material such as copper or its alloy. . By "high thermal conductivity" is meant that the thermal conductivity of the channel 60 in the direction between the heat generating component 50 and the heat spreader layer 30 is greater than the thickness of the dielectric layer 30 throughout the thermal conductivity; preferably, the thermal conductivity of the channel 60 It is at least about 100 W/m °K, more preferably at least about 200 W/m °K, and even more preferably at least about 350 W/m °K. Although channel 60 is most generally cylindrical in shape, each channel 60 can take any particular cross-sectional shape. #通道 60 may be a single integral component, but may also include more than one portion, such as a pair of separate components that are press fit or otherwise joined together, as will be described below in conjunction with Figures 7-27. By. Moreover, based on location considerations, the channel 60 can advantageously have a shoulder or step 61 on a side adjacent dielectric layer. If electrical insulation is required, a dielectric layer (such as anodized aluminum, aluminum nitride, alumina or alumina, etc.) can be placed thereon or on all surfaces of the channel 60, such as by flame spraying or The vapor deposited alumina is placed on the copper or, for example, the aluminum treated with -32-200810621 anodized as the channel 60. In addition, the surface of the channel 60 can remain solderable or can be coated to be solderable, thereby facilitating the attachment of the &quot;heat generating assembly 50 to the channel 60. Each channel 60 extends into and is in thermal contact with the heat spreader layer 30. For example, the channel 60 can be assembled into a slit or hole in the heat spreader layer 30, which utilizes a thermal adhesive or pressure fit, such as a so-called "fast nut" or push nut, so that Ensure good thermal contact between the channel 60 and the heat spreader layer 30 and ensure that heat transfer from the channel 60 can pass through the thickness of the φ diffuser layer 30. A suitable way for the channel 60 to be assembled into the diffuser layer 30 so as to establish sufficient thermal contact is to force the passage 60 through a hole in the diffuser layer 30 having a diameter smaller than the diameter of the passage 60, such as For example, as illustrated in Figures 14, 20, 30 and 36; in this manner, the action of forcing passage 60 through the aperture will provide a pressure fit between the two. Alternatively, the apertures in the diffuser layer 30 can be formed by utilizing the channel 60 itself as a punch. The nature of the compressed exfoliated graphite particles allows the mating to be accomplished without undue damage to the hot aisle 60 or the heat disperser layer 3〇. Likewise, the passage 60 must be in good thermal contact with the heat generating assembly 50. Therefore, the channel 60 must be thermally bonded or bonded to the heat generating assembly 50 by using solder, a thermal paste, a thermal adhesive such as an epoxy resin, a sheet of compressed exfoliated graphite particles, or the like. . Accordingly, the passage 60 preferably extends through the circuit assembly 1 〇 and is exposed at the surface of the circuit assembly 10, on which the heat generating assembly 50 is disposed. Thus, in this embodiment, the channel 60 has a length that is substantially equal to -33.60 200810621 The combined thickness of the dielectric layer 20 and the heat spreader layer 30, plus the channel self-dielectric layer 20 or heat spreader Any distance from the layer 30, as shown in Fig. 2A. Alternatively, the hot aisle or thermally conductive dielectric material can be transferred from the heat generating assembly to the passage 60 and the passage 6 〇 extends only through the heat disperser layer 30 to disperse heat through the thickness of the heat disperser layer 30; Thus, in this case, the passage 60 will have a length that is equal to the thickness of the heat spreader layer 30, plus any distance that the passage 60 extends from the heat spreader 30. φ To provide good thermal contact between the channel 60 and the heat generating component 50. The channel 60 can extend above the face 20b of the dielectric layer 20 as shown in Fig. 2A. Alternatively, the channel 60 may be placed flush with the surface 20b of the dielectric layer 20 as shown in FIG. 2B, or may be opposite the surface of the dielectric layer 20 as shown in FIG. 2C. It is recessed and this will determine the nature of the heat generating component 50 and a preferred method for providing a thermal connection between the channel 60 and the heat generating group 50. One is to provide good thermal contact between the channel 60 and the heat spreader layer 30. The advantageous method is by using a "rivet" type channel 60, as described below in conjunction with Figures 7-27. In this manner, a rivet-type passage 60 can be compression-compressed to seal against the outer surface of the heat spreader layer 30 (i.e., not adjacent to the dielectric), in the same manner as the rivet is compressed to seal against the substrate. Surface), which will form a good thermal connection between the two. As mentioned previously, the heat spreader layer 30 is advantageously laminated or bonded to the dielectric layer 20. However, it is contemplated that the use of the channel 60 will result in a gap between the heat divider layer 30 and the dielectric layer 20 so that the large layer of the stretched layer can be optimized to be placed in the piece of the pin or layer to dissipate heat - 34- 200810621 Dissipation. In other words, since the heat transfer between the heat generating component 5 and the heat spreader layer 30 is primarily via the channel 60 rather than via the dielectric layer 20, the diffuser layer 30 does not need to be in contact with the dielectric layer 20. Therefore, a gap of up to about or even larger can be provided between the heat spreader layer 30 and the dielectric layer 20, for example, by using a separator or the like (not shown in the east). In this formula, if it is a heat spreader Layer 30 remains in thermal contact with channel 60, more surface area of diffuser layer 30 is exposed, and more heat is dissipated therefrom. Briefly, in this embodiment, heat dispersion g 30 can At the same time, as a heat disperser and a heat dissipating piece. In an alternative embodiment shown in Fig. 4, the channel 60 can be integrated with the green component 50. For example, if an LED is used as the thermal component 50, then The LED can have a high thermal conductivity or rivet extending therefrom that can then extend through the circuit assembly 1 〇 and in thermal contact with the thermal dispersion 30 (eg, via a press fit or riveted connection as previously described) In order to facilitate heat dispersion from the LED to the thermal stratification 30. φ In another embodiment illustrated in Figures 6A and 6B, the 60(s) may be present in a collection extending through the heat spreader layer 30. Strip 62, the collecting strip 62 includes an elongated member having a thousand extensions extending from there The individual channel elements 64a, 64b, 64c of the dielectric layer 20 are as shown in Figure 6B. Alternatively, the collector strips may extend through the dielectric layer while the individual channel units extend through the heat spreader layer 30 (not shown) In another embodiment, shown in Figure 5, the channel 60 can extend and extend beyond the heat spreader layer 30' so that it can be used as another heat dissipation layer between the heat points of 1 mm, Figure 1 and the heat can be thermally produced from the layer. The inserter layer pin-shaped diffuser channel is generated and the direction is equal, 20, Fig.). Support through 30a, -35-200810621 30b, 30c, etc. (eg, a heat spreader layer or a heat dissipating fin). In other words, if space permits, the channel 60 can extend through the heat spreader layer 30, and other heat spreader layers or heat dissipation fins 30a, 30b, 30c, etc. (preferably also from compressed exfoliated graphite particles) The slabs can then be placed in thermal contact with the channel 60, and additional heat dissipation can be provided by an air gap between the additional layers or fins 30a, 30b, 30c, and the like. A plurality of spacers (not shown) may be used to maintain separation of the layers 30a, 30b, 30c, and the like. § As shown in Figure 3, the present invention is particularly useful when the circuit assembly is a flexible circuit 100. Because of the nature of the flexible circuit 100, conventional heat dissipating materials that are relatively rigid compared to the compressed exfoliated graphite sheets are not practical. However, the use of one or more compressed exfoliated graphite sheets as the heat spreader layer 30 will effectively dissipate heat from the heat generating assembly 50 via passage 60 without severely compromising softness. In addition, since each of the channels 60 is generally a discontinuous article, even if a plurality of channels 60a, 60b, 60c are included, the flexibility will not be compromised. φ Thus, by utilizing the present invention, effective dispersion in a circuit assembly can be achieved to an unprecedented level, even in the case of flexible circuits, and even in the case of heat source LEDs. Flange passages. Figures 7 through 27 illustrate the construction of the flange passage and illustrate a method of assembling a flange passage having a graphite planar member. 1. Low cost hot rivets In some applications, the hot aisle is allowed or necessary to protrude above the surface of the diffuser -36- 200810621. Similarly, in some applications it is necessary to reduce the cost of the disperser while still attempting to maximize the heat flow through the disperser. &quot; The goal of these conflicts can be achieved by using a flanged rivet-type channel in the diffuser, as shown in Figure 7. In Fig. 7, a thermal management system is indicated by the symbol 100. System 100 includes an anisotropic graphite planar element 102 having first and second opposing planar surfaces 104 and 106 and having a thickness 108 formed between the planar surfaces. The planar element 102 has a relatively high φ parallel to the planar surfaces 104 and 106 and a relatively low thermal conductivity through the thickness 108. The planar element 1 〇 2 has a circular recess or hole 1 1 贯穿 therethrough and located between the planar surfaces 10 4 and 106, the recess 100 being defined by a cylindrical inner cavity wall 112. The rivet-type thermal passage 114 has a cylindrical stem 116 that extends through the pocket 110 and tightly engages the inner pocket wall 112. The passage 114 further includes a flange that extends laterally from the stem 6 and closely engages the first planar surface 104 of the graphite planar member 1 〇 2 . • As mentioned previously, the channel 141 is preferably constructed of an isotropic material such that heat from a heat source (e.g., 1 20) can be conducted through the channel 1 14 and into the thickness of the graphite planar element 102. 108. Channel 114 is preferably comprised of a material selected from the group consisting of gold, silver, copper, aluminum, and alloys thereof. The anisotropic graphite planar element 1 〇 2 is preferably made of compressed exfoliated graphite particles. As is apparent from Fig. 7, the flange end 1 1 8 of the rivet-type channel 丨丨 4 protrudes from one side of the graphite planar member 102, and the stem U6 is self-contained from the graphite flat-37-200810621 surface element 102 One side stands out. The rivet-type channel 1 14 is sized such that the diameter of the stem 1 16 is large enough to substantially cover the entire surface of the heat source 120. The flange passage 114 is held in position relative to the graphite planar member 102 by pressing a commercially available push nut 122 on the stem 116 of the passage 114. The push nut 122 does not need to be made of the same material as the channel 114 because it does not contribute to heat transfer; its sole purpose is to maintain the rivet type channel 1 1 4 relative to the graphite planar element 102. φ is the position. The inner diameter of the push nut 1 22 is slightly smaller than the outer diameter of the stem 1 16 so that the push nut can be in intimate contact with the stem 116 of the passage 114. The upper end or free end 124 of the passage 114 contacts the heat source 120, and heat flows from the heat source 120 into the stem 1 16 and the flange 1 18 of the passage 11 4 . Heat is transferred into the graphite planar element 102 via both the outer diameter of the stem 1 16 and the inner side surface 126 of the flange 1.18. Because the flange 118 contacts the first side 104 of the graphite planar element 102 opposite the heat source 120, the heat transferred to the graphite planar element 102 is maximized. # It will be appreciated that there is a contact area between the heat source 120 and the free end 124 of the stem 116, which may be referred to as a thermally conductive contact area defined on the heat source 120. Although the heat source may be moderately larger than the area of the free end 1 24 of the stem 1 16 and the advantages of the present invention are substantially achieved, the contact area is preferably less than the free end 1 24 of the stem 1 16 area. The push nut 122 is received over and in frictional engagement with the stem 116. The push nut 122 abuts the second planar surface 106 of the graphite planar element i〇2 such that the graphite planar element 1〇2 is sandwiched between the flange 118•38-200810621 and the push nut 122. In the embodiment illustrated in FIG. 7, the free end 124 of the stem 116 extends entirely through the push nut 122. The diameter and thickness of the flange 11 8 should be selected to ensure that heat is well transferred into the graphite planar member 102. The diameter of the flange 118 should also be large enough that the flange 118 does not create excessive pressure or cut into the graphite planar member 102 when the push nut 122 is depressed. If the outer diameter of the push nut 122 is not sufficiently increased to prevent the graphite planar element 102 from being damaged by excessive pressure, a larger diameter washer 1 28 can be used to push the lower radius φ of the nut 1 22, As shown in Figure 7A. Because the gasket 128 is used primarily for mechanical purposes (i.e., not for conducting heat), it can be loosely assembled to the stem 116 and does not need to be made of the same material as the hot aisle 114. Figures 8 and 9 show the detailed plane and front view of the hot aisle 1 1 4, respectively. The 10th and 1st drawings respectively show the detailed plane and front view of the push nut 1 22 . Preferably, as shown in Fig. 12, in order to use the rivet type hot aisle 114, the aperture 110 is preferably die cut into the graphite planar element 102. Die cutting produces an aperture that has a large tolerance associated with it. In order to ensure good heat transfer between the hot aisle 114 and the graphite planar element 102, the diameter of the die-cut hole 1 1 1 1 3 0 is preferably selected such that the largest hole obtained by die-cutting is still slightly smaller than the hot aisle 1 1 4 of the heart column 1 1 6 outer diameter. Preferably, as shown in Fig. 14, after the hole, 110 is die cut into the graphite planar member 102, the stem 1 16 of the channel 14 is pushed up and passed through as shown in Fig. 14. Hole 1 1 0. Since the stem 1 1 6 of the channel 1 14 has a diameter slightly larger than the diameter of the hole 110, the graphite will be in the shape of 覃 -39-200810621 around the stem 116, thereby forming an annular beak-like projection 132. To ensure good heat transfer, the beak-like projections 132 are pressed down into the dome-like projections as shown in Fig. 14 and forced downwardly to the top surface or surface of the graphite planar member 102. 106 is flush. The punch 134 has a cylindrical shape therein and has a size slightly larger than the outer diameter of the stem 1 16 . After the beak-like projection 1 3 2 has been flattened, the push-on nut is placed on the free end 1 24 of the stem 11 6 and forced to press against the stem of the facing element 1 16 to FIG. 7 Another punch in the final assembly that is similar to the punch 134 shown in Figure 14 and has a raised portion of the larger push nut 1 22 (not shown for achieving the push nut) 122 is placed in the stem 116. It should be used to firmly clamp the graphite planar member 0.02 between the push screw rivet flanges 1 18 to ensure that the heat can be transmitted well to the flange 1 18 . Although in the example shown in Figures 7 to 14, the hole 1 and the stem are also circular or cylindrical, it should be understood that the shape of the face can also be used. More generally, the hole 110 can be described as having A 1 has an inch parallel to the plane of the graphite planar element 102, and in this case the largest cross-sectional dimension is the diameter 130 of Figure 12. Similarly, the stem 116 of the channel 114 can be depicted in a cross-sectional shape. , which is complementary to the cross-sectional shape of the hole 110 and has the smallest cross-sectional dimension of the outer diameter of the stem 1 1 6 in the example. Inch 130. Alternatively, if the hole 110 is held by the second planar recess 1 3 6, 122 on the portion 132, the position of the graphite flat; the recess can be sufficiently strong to cap 122 and pass through The rivet 10 is rounded and the other cross-sectional shape, as seen in the large-section ruler, has a larger than the heart -40 - 200810621, and the inter-system between them should be smashed. It is filled with a thermal paste or the like to maximize heat transfer between the graphite planar member 102 and the passage 114. 2. Flange surge with double flanges As mentioned earlier, in some applications it is necessary for the channel to protrude above the surface of the graphite heat spreader element so that it can contact the heat source. In addition, in very high performance applications, it is important to minimize the thermal resistance between the channel and the surrounding graphite material. This can be achieved by a circular flange channel and washer assembly that can also be referred to as a dual flange channel (such as shown in Figure 15). In Fig. 15, an alternative embodiment of the present invention includes a thermal management system, which is collectively labeled with the component symbol 200. Thermal management system 200 includes a graphite planar element 202 that is similar to graphite planar element 102 shown in FIG. The graphite planar element 202 has opposing first and second major planar surfaces 204 and 206. Thickness 208 is defined between surfaces 204 and 206. A hole 210 defined by the inner wall 212 is formed through the graphite planar member 202. System 200 includes a hot aisle 214, which in this example is comprised of first and second portions 215 and 217. The first portion 215 includes a stem 2 16 and a first flange 2 18 . In this case, the hot aisle 214 can be secured to the graphite planar member 202 by a second portion 217 (which can also be referred to as a gasket or second flange 2 17). The second flange 217 is made of the same material as the stem 216 of the first portion 215 of the passage 214 and the first flange 218. Figures 18 and 19 show a detailed plan view of the second flange 217 and a cross-sectional front view of -41-200810621, respectively. The second flange 217 has an inner diameter 219 which is selected to be slightly smaller than the outer diameter of the stem 2 16 so that the inner diameter of the second flange 2 17 can be in close contact with the stem 2 16 , wherein The two flanges 2 1 7 are pressed into the dosing column 2 16 . Preferably, the outer diameter of the second flange 2 17 is slightly opposite the outer diameter of the first flange 218. The length 221 of the stem 216 is sized such that the graphite planar member 202 will be compressed between the first and second flanges 217 such that the first and second flanges 218 and 217 are both ink planar members 202. Close heat transfer. φ although the first and second portions 2 1 5 and 2 17 of the hot aisle 2 1 4 have been described as being preferably assembled by press fitting the second portion 217 into the first portion, but will be detectable It is also possible to use other groups of techniques. For example, the second portion 2 17 can be tightened onto the stem 2 1 6 and the two portions can be welded together. In the embodiment illustrated in Figures 15 through 19, the stem 2 16 has a stem shoulder 223 formed thereon and facing away from the first flange 2 1 8 . The inner bore 219 of the second flange 217 has a flange shoulder 22 formed thereon and complementary to and abutting the shoulder 22 3 . An alternative embodiment of the dual flange thermal management system is shown in Fig. 15A, which is collectively labeled with the component symbol 200A. The thermal management system is the same as the thermal management system 200 shown in Fig. 15, except that the design of the second 217A is modified such that it can be capped and has a blind hole with a perforated washer shape. In other respects, the above description of the thermal management system 200 shown in the Figure can be applied equally to the thermal management system 200A shown in Figure 15A.疋 219 is the same as the setting: 218 and the stone is depicted as '215 loading technique, or the same heart column is the same as the 200A flange to take I 15 on the -42- 200810621 by the 15th to 19th The edge channel 214 is a first flange 218 or a second flange to which a heat source such as 220 can be attached. Preferably, the stem 216 will have a diameter that is at least as large as the outer or maximum dimension of the heat source 220 to effectively assist heat transfer throughout the entire contact area between the heat source 220 and the channel 2 14 . By virtue of the double flange passages 214 of Figures 15 to 19, heat is transferred into the graphite planar member 202 via the outer diameter of the stems 2 16 and the inner diameters of the flanges 2 18 and 2 17 . In contrast to the single flange channel, which transfers heat only through the stem and a flange, as shown in Figure 7, a large number of contact surfaces naturally formed between the channel 214 and the graphite planar member 202 are formed by the dual flange channel design. The heat transferred to the graphite planar element 202 will be maximized. When the second flange 217 is assembled with the first portion 215 of the passage 214, the shoulders 225 and 223 will be butted together. The length 227 of the larger diameter portion of the stem 216 is selected to be smaller than the thickness 208 of the graphite planar member 202 to ensure that when the second flange 217 is pressed onto the first portion 215 and the shoulders 225 and 223 are docked at Together, the annular graphite area between the flanges 218 and 217 will be in a compressed state. This ensures that heat is well transferred from the flanges 218 and 217 into the graphite planar element 202. Figure 20 shows that the first portion 215 of the channel 214 is mounted at a suitable location within the graphite planar element 202. The graphite planar element 20 2 has a hole 2 1 0 that is die cut into it in a manner similar to that previously described with the graphite planar element 102 described in Fig. 12. Moreover, the diameter of the die cut hole 2 10 is selected such that the largest hole thus available is still slightly smaller than the third possible diameter of the larger portion of the stem 2 16 . The first portion 215 of the hot aisle 214 is pushed up to the graphite planar element 202 as shown in Fig. 20 of 2008-200810621. Inside, an annular beak-like projection 232 is formed again. To ensure good transmission, the beak-like projection 232 is forced downwardly to be flush with the top surface 206 of the graphite planar member 202 by a punch as shown in Fig. 20, the punch 234 having a cylindrical recess 236 Wherein, the size is set to be slightly larger than the maximum outer diameter of the stem 2 1 6 . After the beak-like projection 232 has been flattened, the second flange 217 is placed on the end of the stem 216 and sufficient force is applied to push the second 217 down onto the stem 216 until the shoulders 223 and 225 arrived. The diameters and thicknesses of the flanges 218 and 217 should be selected to provide good heat transfer into the graphite planar member 202. These diameters are large enough that the flanges 218 and 217 do not create excessive pressure or cut into the graphite flat when the second flange 217 is placed on the stem 216. Figures 21 through 24 show a second arrangement of the dual flange channel 21 4A which again includes a first portion 215A and a second portion 217A. Compared with Fig. 17, the only difference is that no shoulder is formed into the stem 2 1 6 A in this embodiment. Instead, the stem 2 1 6 A is a straight cylindrical stem with a small chamfer on it. Similarly, the second 217A has a straight cylindrical bore 219A therethrough. The stem 216A is slightly larger than the inner diameter 21 9A of the second flange 217A, thus providing an interference fit between the stem and the second washer 2 17 A. At the assembly, a solid (not shown) is used to force the second flange 21 7A down to the stem

L 210 heat 234 234 [The flat recess is flanged, it should also be pressed down, 16 and the mechanism end flange diameter 216A punch 216A -44- 200810621. The action is stopped when the upper surface 229 of the second flange 217A is flush with the upper end portion 231 of the stem 21 6A. To control the amount of compression of the graphite planar elements between the first and second flanges 218A and 217A, the length 233 of the stem 216A and the thickness 235 of the second flange 217A will be regulated. 3. Flush hot aisles The aforementioned hot aisles all have one or two flanges that protrude above the surface of the graphite planar element. However, in some applications, it is necessary for the heat spreader to have a perfectly flush surface, i.e., there is no portion of the hot runner that protrudes above the surface of the graphite planar component. These goals can be achieved using a hot aisle that has been embedded in the graphite disperser as shown in Figure 25. Figure 25 shows a thermal management system 300 comprising a graphite planar element 302 having first and second major planar surfaces 304 and 306. The graphite planar element 302 has a thickness 308 defined between the surfaces 304 and 306. A hole 310 defined by the inner wall 312 is formed through the thickness of the graphite planar member 302. The hot aisle 3 1 4 is housed in the hole 310. In this embodiment, the pass Φ 314 is a disc having chamfers 316 and 318 on its upper and lower ends 3 20 and 3 22, as best shown in Figures 26 and 27. As will be further described below, in the configuration of the disk-shaped hot aisle 314 having the embedded in the graphite planar member 302 shown in Fig. 25, the graphite material closely fits the disk-shaped hot aisle 314 and is superposed. On the corners 316 and 318 of the hot aisle 314. Channel 314 has upper and lower ends 320 and 322 that are flush with second major planar surface 306 and first major planar surface 304 of graphite planar member 302, respectively. This configuration adds heat transfer between the channel 314 and the graphite planar elements 302-45-200810621 and provides a mechanical bond. The disk shaped hot aisle 314 has a thickness that is substantially equal to the thickness 308 of the graphite planar element 302. Figures 28, 29, and 30 are illustrative diagrams of a series of methods in which the disk shaped hot aisle 314 is shown embedded within the graphite planar element 302. Again, the graphite planar element 302 has a hole 310 in which the die cut is formed. The die cut hole 310 is sized such that, given the relevant tolerances, the largest hole that can be formed by die cutting will still be slightly smaller than the outer diameter of the disk shaped hot aisle 3 1 4 . During the embedding operation, the channel 3 1 4 will stretch and enlarge the hole 3 10 . Figure 28 shows an exploded view of a buried device 324 including upper and lower steel mold halves 326 and 328 and a punch 330. The upper steel mold half 326 has a consistent perforation 3 3 2 and the lower steel mold half 3 28 has a portion of the bore 3 34 therein. The diameters of the holes 3 3 2 and 334 are the same and slightly larger than the outer diameter of the hot aisle 314. Alignment guides (not shown) are used to align the holes 3 32 and 3 34 in the upper and lower steel mold halves 3 26 and 3 28 with the die cut holes 310 in the graphite planar member 302. A stopper 3 36 is provided in the lower steel mold half 328. The upper end portion 3 3 8 of the stopper 3 36 is aligned with the die-cut hole 310. The stop member 336 is disposed flush with the top surface 340 and the diameter of the stop member is smaller than the diameter of the disk shaped heat passage 314 such that an annular recess 342 can surround the stop member 336. The punch 303 has the same outer diameter as the disk-shaped hot aisle 314 and is used to press the channel 314 in place. The operation of device 324 is best as shown in Figure 29. The graphite planar member 322 is aligned and clamped between the upper and lower steel mold halves 326 and 328. • 46- 200810621 Once clamped in position, the thin edge of the graphite material (not shown) extends into holes 332 and 334 in the upper and lower steel mold halves 326 and 328. The hot aisle 314 is positioned within the aperture 332 in the upper steel mold half 3 26, followed by the punch 330. Pressure is applied to the punch, which faces up the channel 314 and passes through the protruding graphite material. Some of the prominent graphite material is cut away and some are compressed around the channel 314. Channel 314 stops against end 338 of stop 336 and is flush with lower surface 304 of graphite planar element 302. The cut scrap of graphite material is collected in an annular space 342 around the stop 336. When the upper and lower steel mold halves 3 26 and 328 are removed and the graphite planar member 322 assembled with the disc shaped hot aisle 314 is removed from the apparatus, the graphite material compressed by the passage 314 forms a peripheral convex. Blocks 346 and 348 abut the chamfered edges 316 and 318 of the disk shaped hot aisle 314. To flatten the bumps 346 and 348, the assemblies 302 and 314 are then placed between the press and the lower platen as shown in Fig. 30, and pressure is applied to the assemblies 302 and 314. This pressure should be greater than 1 500 psi and less than 1000 psi, which is the minimum compressive strength of the graphite material. This pressure compresses the bumps 346 and 348 into flush with the end faces 320 and 322 of the disk shaped hot aisle 314 and presses the graphite material against the chamfered edges 316 and 318 of the channel 314, thereby securely channeling the channel 314. The lock is placed at a suitable location within the graphite planar element 302. This result in the heat spreader elements 302 and 314 as shown in Fig. 25. The chamfered edges 3 1 6 and 3 1 8 of the disk-shaped hot aisle 3 1 4 can be described as recesses formed in the channel 3 1 4 . As shown in Figure 25, '石-47·

200810621 The graphite material of the ink planar element 302 is superposed on the recesses or 3 1 6 and 3 1 8 . Referring now to Figures 31 and 3, the same method can be used with a heat spreader having a plurality of thin surface layers 354. These surface types are composed of Mylar, aluminum, aluminum or the like. Here the surface layer 354 will be laid over the graphite planar element 302 in the die plane element 302. Hole 310 is then die cut into both the face member 302 and the surface layer 354. The outer diameter of the straight hole 310 of the hole 310 must be selected such that the hole through the surface layer can complete a heat source such as 320 that is placed in contact with the channel 314 as shown in Fig. 32 having a surface layer 3 54 The aesthetic steps of assembling the product are as previously described with reference to Figures 28-30. The heat dissipator of the heat-inducing channel is formed, and both sides of the channel are exposed by holes located in the surface layer 354 as in the 32nd g. ! The channel 3 1 4 is in direct contact with the heat source 3 2 0 while the surface layer 354 is provided over all exposed areas of the facet element 302. In general, the surface layer 3 54 can be described as a surface layer of a thickness 308 of a thinner gray component 302 that covers the opposing major planar surfaces 304 and 306 of the graphite member 302. Coated Disperser and Flush Hot Drain Figure 33 is similar to Figure 25. Arrow 35 6 represents pressing the tray 3 14 against one of the heat sources 3 20 to mount the load such that no &lt; is applied to the graphite planar element 302 itself. The graphite planar element 302 is shaped and has an angular edge between the graphite planar element 302 and the hot aisle 3 1 4 to create a 354 pattern which is previously surrounded by the graphite flat and channel. The result is that the residual assembly has a buried heat so that the hot graphite flat graphite flat planar heat transfer is flattened, and the heat transfer between the hot channel 314 and the graphite planar element 302 is Great. As shown in Fig. 34, however, mounting holes such as 358 and 366 are often placed through the graphite planar member 302 and screws are placed, and mounting screws are applied to the adjacent holes 358 and 360 on the graphite planar member 302, such as Represented by arrows 362 and 364. This mounting load is now applied directly to the graphite planar element 302. Because of the relatively low modulus of elasticity of the graphite planar element 302, typical mounting loads as represented by arrows 362 and 364 can cause the graphite planar element 302 to bend as shown in Figure 34, while portions of the graphite planar element 302 are labeled The zone 366 is pulled away from the hot aisle 314, thus creating a number of gaps between the graphite planar element 302 and the hot aisle 3 14 . This results in a reduced heat transfer between the hot aisle 3 1 4 and the graphite planar element 3 0 2 and a significant decrease in the thermal performance of the heat spreader. Even a less large mounting load as shown in Figure 34 is sufficient to permanently bend the graphite planar member 302. To overcome this problem, a continuous and relatively rigid thin layer of material 386 can be coated on the underside 304 of the graphite planar element 302, as shown in Figure 35. The cladding material may include copper, indium, etc., and alloys thereof. For example, aluminum sheets having a minimum thickness of 0.003 in. are typically used as a coating. The cladding 368 can be adhered to the surface 304 of the graphite planar element 302 and to the lower end 322 of the channel 314 using an adhesive such as Ashland Aroset 3250. Once adhered, the mounting screw holes 358 and 360 are stamped or drilled through the cladding layer 368 and the graphite planar member 302. It should be noted that the cladding layer 368 is continuous over the lower end face 32 of the hot aisle 314, and the perforation through the cladding layer is through the mounting screw _ wire hole 35 8 of the graphite planar member 322. And 3 60. When the coated disperser is pressed against the heat source 320 as shown in Fig. 3, the disperser will remain flat and due to the gap formed between the hot channel 314 and the material of the graphite planar member 302, There is no longer a performance degradation. Co-forged flush-type hot runners 36 through 39 include a series of illustrative illustrations showing another modification of a heat spreader with a flush-type hot aisle, wherein the flush-type hot φ channel is similar to the previous fit Described in Figures 25 to 35. In some very high performance applications, it is important to minimize the thermal resistance between the disk channel and the surrounding graphite material. This can be achieved by forging the channel and surrounding graphite material together after the channel has been embedded in the graphite planar element. Co-forging will result in plastic deformation of both the channel and the graphite planar material and will bond the channel material as tightly as possible to the surrounding stone material and minimize the thermal resistance between these materials. First, the graphite planar member 302 and the disk shaped hot aisle 314 are assembled as previously described in conjunction with Figures 28 through 30. This results in a structure as shown in Fig. 36 having annular projections 346 and 348 extending over the wrap material above and below the disk-shaped hot aisle 3 14 . In order to forge graphite and channel materials together, the assemblies 302 and 314 shown in the figures are placed in a closed pocket forging die formed by upper and lower steel mold halves 370 and 372 as shown in FIG. Within 368. The pockets 374 and 376 are machined into steel mold halves 370 and 372, respectively, and the mating stop surfaces 378 and 380 form the edges of the pockets 374 and 376, respectively. The two recesses -50- 200810621 The total depth of the pockets formed by the eight sections 3 7 4 and 3 7 6 is smaller than the thickness of the original graphite material or the original disk shaped heat tunnel 314. The size of the closed pocket is selected such that when the channel 314 and the graphite planar element 302 are plastically deformed, the pocket will be large enough to allow the material to flow and fill the pocket, as shown in FIG. The stop surfaces 3 7 8 and 3 8 〇 control the amount of plastic deformation allowed. The stop surfaces 377 and 380 are sized such that once they are in contact with one another, the forge load is transferred to the stop surfaces and no further plastic deformation of the channels 314 and graphite planar elements 302 occurs. The common forging of # channel 314 and graphite planar element 3 02 is shown in Figure 38. The minimum force applied to the forging die 386 must be sufficient to ensure transient plastic deformation of the graphite material of the graphite planar member 302 and the material of the hot aisle 314. This allows the channels 3 14 and graphite to be vertically compressed and flow horizontally. A disperser that has completed co-forging is shown in Figure 39. Plastic flow during common forging results in intimate contact between channel 314 and graphite planar element 302 and minimizes thermal resistance between the two materials. After co-forging, a number of surface layers may be applied to the finished disperser as previously described in conjunction with Figures 31 and 32, and/or a cladding layer may be as previously described in connection with Figure 35. The ground is laid. All cited patents, patent applications, and publications are herein incorporated by reference. The above description is intended to enable those skilled in the art to practice the invention. The purpose of this document is not to clarify the details of all possible variations and modifications, and such changes and modifications are apparent to those skilled in the art of the present invention -51-200810621. However, it is contemplated that modifications and variations are intended to be included within the scope of the invention as defined by the appended claims. These claims are intended to be in any configuration or order of elements and steps, which are intended for the purpose of the present invention, unless specifically described herein. A total body image is shown in which the circuit assembly has a heat on one surface thereof and a thermal path component between the heat spreader layer and the heat generating component is tied to the second surface of the circuit assembly. 2A-2C is a partial cross-sectional view of a different alternative configuration of the heat of the circuit assembly shown in FIG. 1, taken along the first figure, and showing the second surface path extending to the circuit assembly, respectively. The second surface is flush and recessed into the thermal path within the circuit assembly. Figure 3 is a partial view of a flexible circuit in accordance with the present invention, wherein the flexible circuit has a plurality of thermally dispersed strips on one surface thereof between the heat spreader layer and the plurality of heat generating components. Second surface i of the flexible circuit: Figure 4 is a partial sound 1 circuit assembly of a circuit assembly according to the present invention having a heat spreader layer on one surface thereof to provide a thermal path between the diffuser layer and the heat generating component And the heat is placed on the second surface of the circuit assembly, wherein the heat path is integrated with the heat. All such variable scope rights are intended to cover effectively: representation. The partial rupture disperser layer has a diameter, and the thermal production path is above the 2-2 line, the second surface of the electric sweat ruptures the stereoscopic layer, and the complex f heat path, and A thermal component is a component assembly-52-200810621. FIG. 5 is a partial cross-sectional view of a circuit assembly according to the present invention, wherein the circuit assembly has a heat spreader layer on one surface thereof and a heat collector The heat path between the diffuser layer and the heat generating component, and the heat generating component is positioned on the second surface of the circuit assembly, wherein the heat path extends beyond the heat spreader layer and supports an additional heat dissipation layer. Figure 6A is a bottom plan view of a circuit assembly in accordance with the present invention, wherein the circuit assembly has an elongated base-type thermal path combination. Figure 6B is a top plan view of the circuit assembly shown in Figure 6A. φ Figure 7 is a front elevational cross-sectional view of a graphite heat spreader with a hot rivet type channel with a push nut mounted on the channel. Figure 7A is a view similar to Figure 7 showing the optional use of the gasket under the push nut. Figure 8 is a plan view of the flange hot aisle shown in Figure 7. Figure 9 is a front elevational view of the flanged hot aisle shown in Figure 8. Figure 10 is a plan view of the push nut shown in Figure 7. Fig. 1 is a front cross-sectional view showing the push nut shown in Fig. 10. • Fig. 12 is a plan view of a portion of the graphite planar member shown in Fig. 7, showing a die cut hole for receiving a flange passage therethrough. Figure 13 is a front cross-sectional view of the graphite planar member shown in Figures 7 and 12. Figure 14 is a front cross-sectional view of the flanged channel having been forcedly assembled through the die cut holes in the graphite planar member to form a serpentine graphite flange. Located directly above the graphite planar element and the channel is a punch that is used to compress the graphite rim. -53- 200810621 Figure 15 is a front elevational, cross-sectional view of another embodiment of the present invention utilizing a hot aisle having two flanges on each end. Although the heat source in this example is shown to be in contact with the lower flange, it can also be placed against any of the flanges of this channel. As can be seen from the section of the section in Fig. 15, the channel is composed of two parts, the first part comprising the stem and the lower flange, and the second part comprising the upper flange. Section 15A is a view similar to Figure 15, which shows an alternative form of a double flange channel. φ Fig. 16 is a plan view of the stem and the lower flange shown in Fig. 15. Fig. 17 is a front elevational view of the stem having an integral with the lower flange as shown in Fig. 16. Figure 18 is a plan view of the upper flange before it is assembled with the heat path of Figure 15. Figure 19 is a front cross-sectional view of the upper flange shown in Figure 18. Figure 20 is a view similar to Figure 14 and showing the stem of the flange channel shown in Figure 17, wherein the stem of the flange channel has been pressed through the graphite planar element to form a serpentine graphite Convex edge. A punch is shown above the channel and is ready to move down to compress the graphite rim. Figure 21 is a plan view of an alternative construction of the flange channel. Figure 22 is a front elevational view of the flange channel shown in Figure 21. Figure 23 is a plan view of a second flange having a straight bore which will be used in conjunction with the flange passages shown in Figures 21 and 22. Figure 24 is a front cross-sectional view of the second flange shown in Figure 23. Figure 25 is a partial cross-sectional view of another embodiment of the present invention having a flush channel, -54-200810621, wherein the channel is flush with the major planar surface of the graphite planar element. Figure 26 is a plan view of the hot aisle shown in Figure 25, and the thermal path is in the shape of a disk having a plurality of chamfered edges at each end. Figure 27 is a front elevational view of the hot aisle shown in Figure 26. Figure 28 is a cross-sectional exploded view of a front view of a device which is used to embed the thermal channels shown in Figures 26 and 27 in a graphite planar member to form a heat spreader structure as shown in Figure 25. The punch, the hot aisle, the upper steel mold half, the graphite disperser, and the lower steel mold half are sequentially displayed from the top of Fig. 28 to the bottom of the §. Figure 29 is a front elevational view of the apparatus shown in Figure 28 after the punch has forced the hot aisle through the upper steel mold half and into position within the graphite disperser. Figure 30 is an exploded front elevational cross-sectional view of two press plates of a press for compressing the annular bumps of the graphite disperser having flush channels. • Figure 31 is a front cross-sectional view of a graphite heat spreader having a surface layer thereon. Figure 32 is a view similar to Figure 25 showing a graphite heat spreader that has been assembled and has a surface layer and includes a flush heat channel and has a heat source that is shown at a suitable location thereon. Fig. 3 is a view similar to Fig. 5, which illustrates the installation modes appearing in one mode of use of the heat spreader. Figure 34 is a view similar to Figure 3, which shows another type of mounting die -55-200810621 in which two screws extend through the graphite planar element, which in turn causes bending of the graphite heat spreader. Figure 35 is a view similar to Figure 34 of a modified embodiment of the present invention in which a cladding layer has been applied to the graphite heat spreader and the mounting holes extend through the cladding layer to provide graphite heat dispersion. The structural integrity of the device thus minimizes its bending. Figure 36 is a front elevational cross-sectional view of a graphite planar element having flush channels in which the channels can be embedded in the graphite planar elements by the procedures illustrated in Figures 28 and 29. Figure 37 is an exploded view of a steel mold for forging a hot aisle along with a graphite planar element. The two steel mold halves are separated and the graphite heat spreader is shown in place between the two steel mold halves. Figure 38 is another view of the steel mold assembly shown in Figure 37, showing that the two steel mold halves have been combined so that the hot aisle can be forged together with the graphite planar element, resulting in a hot aisle The lateral faces of the graphite planar elements are stretched. ® Figure 39 is a graphite planar element obtained by co-forging from the procedures shown in Figures 37 and 38. As shown in Fig. 36, both the hot aisle and the graphite planar element have been laterally stretched for forging. [Main component symbol description] 10 Circuit assembly 20 Dielectric layer 20a/20b Main surface 30 Heat disperser -56- 200810621

30a/30b/30c Heat dissipation layer 40 Circuit 50 Heat generation assembly 50a/50b/50c Heat generation assembly 60 Hot aisle 6 0 a / 6 0 b / 6 0 c Channel 61 Shoulder 62 Collection strip 64a/64b/64c Channel unit 100 Flexible Circuit/Thermal Management System 102 Graphite Plane Element 104/106 Planar Surface 108 Thickness 110 Die Cut Hole 112 Inner Hole 114 Heat Pass 116 Heart Post 118 Flange 120 Heat Source 122 Push Nut 124 Free End 126 Inner Surface 128 Washer 130 Diameter 132 Tabular projection -57- 200810621 134 Punch 136 Recession 200 Thermal management system 200A Double flange thermal management system 202 Graphite planar element 204/206 Main planar surface 208 Thickness 210 Hole 212 Inner wall 214 Hot aisle 215 Part 1 21 5 A First part 216 Pillar 21 6A Pillar 217 Second part / Second flange 217A Second part / Second flange 218 First flange 21 8A First flange 219 Inner diameter 219A Hole 223 Pillar shoulder Section 225 flange shoulder 227 length 232 蕈 突出 -58- 200810621

233 Length 234 Punch 234A Double Flange Channel 235 Thickness 236 Recess 300 Thermal Management System 302 Graphite Plane Element 304/306 Main Plane Surface 308 Thickness 310 Hole 312 Inner Wall 3 14 Hot Passage 316/318 Degauss 320/322 Upper and Lower Ends Section 324 Embedding Equipment 326/328 Upper and Lower Steel Moulds 330 Punch 33 2 Perforations 334 Partial Holes 33 6 Stops 340 Top Surface 342 Pockets 346/348 Bumps 354 Surface Layers -59- 200810621 358/360 Mounting hole 368 Closed pocket forging die 370/372 Upper and lower steel mold half 374/376 Pocket 378/380 Stop surface -60-

Claims (1)

200810621 X. Patent Application Range: 1. An assembly method for a thermal management system, comprising the steps of: (a) forming a hole through a thickness of an anisotropic graphite planar element, the planar element having a first and a Two opposite major planar surfaces' the aperture has a cross-sectional shape having a maximum cross-sectional dimension parallel to the plane of the planar element; (b) providing a thermal pathway formed of an isotropic material having The cross-sectional shape of the hole is a complementary cross-sectional shape and has a minimum cross-sectional dimension larger than the largest cross-sectional dimension of the hole; and (c) press-fitting the hot channel into the hole of the graphite planar member, whereby the hot channel is A tight fit is formed with the graphite planar element such that heat from the heat source can be conducted into the thickness of the planar element via the passage. 2. The method of claim 1, wherein the graphite planar element is formed by compressing a plurality of stripped graphite particles. 3. The method of claim 1, wherein the channel is formed from a material selected from the group consisting of gold, silver, copper, aluminum, and alloys thereof. 4. The method of claim 1, wherein: the hole and the cross-sectional shape of the channel are circular. 5. The method of claim 1, wherein: in step (a), the forming of the hole comprises die cutting the hole. 6. The method of claim 1, wherein: in step (b), the channel comprises a stem and a first flange, and -61-200810621 the stem comprises the minimum cross-sectional dimension; and in the step ( In c), the stem is press fit into the bore until the flange engages one of the major planar surfaces of the graphite planar member. 7. The method of claim 6, wherein the method further comprises: during the step (c), the graphite is expanded upwardly around the stem to form a dome-shaped protrusion; and forced downward The beak-like projection is flush with the other of the major planar surfaces of the graphite planar member, which is opposite the flange of the passage. 8. The method of claim 6, wherein the method further comprises: fitting a second flange tightly on a free end of the stem opposite the first flange, and compressing the graphite planar member Waiting between the first and second flanges. 9. The method of claim 6, wherein the method further comprises: pressing a push nut to a free end of the core column opposite the first flange so that the push nut can be Engaging with the graphite planar element to securely secure the channel within the bore of the graphite planar element. 10. The method of claim 1, wherein: in step (b), the channel has a thickness that is substantially equal to the thickness of the graphite planar element. 11. The method of claim 10, further comprising: in step (b), the channel is in the shape of a cylindrical disk having a plurality of chamfered edges; 62-200810621; during step (C), The graphite planar element is raised at a plurality of circumferential edges adjacent the channel* to form a plurality of circumferential bumps; and after step (C), compressing the circumferential bumps to align the channel to the graphite plane The two main planar surfaces of the component. 12. The method of claim 11, wherein the method further comprises: co-forging the channel with the graphite planar element during the compressing step to simultaneously produce plastic deformation of both the channel and the graphite planar element. 13. The method of claim 11, wherein the method further comprises, after the compressing step, coating one of the major planar surfaces and covering the passage with the covering. 14. A thermal management system comprising: an anisotropic graphite planar element having first and second opposing major planar surfaces; and a thermal pathway comprised of an isotropic material that is buried Φ is disposed in the graphite planar member and has first and second exposed ends that are respectively flush with the first and second opposing major planar surfaces of the graphite planar member, the channel having a defined thereon a recess, and the graphite planar element overlaps the recess. The system of claim 14, wherein the anisotropic graphite planar element comprises a plurality of compressed, exfoliated graphite particles. 16. The system of claim 14, wherein the channel is comprised of a material selected from the group consisting of gold, silver, copper, aluminum, and alloys thereof, 63-200810621. 17. The system of claim 14, wherein: the recess comprises a circumferential bevel on each of the first and second ends of the channel. 18. The system of claim 14, wherein the overlap between the graphite planar element and the recess of the channel enhances heat transfer between the graphite planar element and the channel. The system of claim 14 wherein the overlap of the graphite planar element φ with the recess of the channel provides a mechanical bond between the channel and the graphite. 20. The system of claim 14, wherein the channel is cylindrical. 21. The system of claim 14, further comprising: a surface layer that is thinner than the thickness of the graphite planar element and covers the opposing major planar surfaces of the graphite planar element, and the first of the channels And the second exposed end is flush with the surface layer. 22. The system of claim 14, further comprising: a cladding adhered to the first major planar surface and covering the first end of the thermal pathway. 23. The system of claim 22, further comprising a mounting screw aperture extending through the cladding layer and the graphite planar member. 24. A thermal management system comprising: an anisotropic graphite planar element having first and second opposing major planar surfaces and having a thickness between -64 and 200810621 degrees formed between the planar surfaces; The planar element has a relatively high thermal conductivity parallel to the planar surfaces and a relatively low thermal conductivity in a direction through the thickness; the planar element having a through formation between the planar surfaces a hole portion defined by an inner cavity wall; and a hot channel having: a core post extending through the hole portion and closely engaging the inner cavity wall; a flange, the self The stem extends laterally and closely engages one of the planar surfaces of the planar member; and the passage is formed of an isotropic material such that heat from the heat source can pass through the passage It is conducted into the thickness of the planar element. 25. The system of claim 24, wherein the anisotropic graphite planar element comprises a plurality of compressed exfoliated graphite particles. 26. The system of claim 24, wherein the channel is comprised of a material selected from the group consisting of gold, silver, copper, tin, and alloys thereof. 27. The system of claim 24, further comprising: a push-on nut that is received on the stem and frictionally engaged therewith, the nut being snugly engaged with the projection The edge engages the other planar surface of the planar surfaces such that the planar surface can be clamped between the flange and the nut. 28. The system of claim 27, wherein the nut is comprised of a material different from the channel. 2 9. The system of claim 27, further comprising: -65-200810621 a heat source having a heat transfer contact area defined thereon for contacting the core opposite the flange The end of the column, and the contact area is smaller than the end area of the stem. 30. The system of claim 27, wherein the stem has a free end opposite the flange, the free end extending throughout and beyond the push nut. 3. The system of claim 27, further comprising: a pad that is loosely received around the stem and clamped to the push nut and the graphite planar element between. 3. The system of claim 24, further comprising: a second flange attached to the stem and abutting the end of the stem opposite the first flange, The second flange has an inner bore that is tightly received around the stem; and the graphite planar member has an annular portion that surrounds the first and second flanges that are compressed between the first and second flanges The pockets are such that both the first and second flanges can be intimately thermally coupled to the graphite planar member. The system of claim 32, wherein the second flange is press fit onto the stem. 34. The system of claim 32, wherein: the stem has a body defined thereon and facing away from the first flange portion; and the inner bore of the second flange has a body defined thereon a flanged shoulder that is complementary to and abuts the shoulder of the stem of the stem. 3 5 · For the system of patent application No. 32, where: -66- 200810621 The stem includes a straight cylindrical outer surface having a constant diameter, and the inner hole of the second flange is a straight cylindrical inner hole; and the second flange is flush with the first flange The end of the stem. -67-