CN102573415B - For the radiator of display device - Google Patents

Abstract

For a kind of radiator (10) for display device such as plasma display panel, light emitting diode or liquid crystal display of radiator of display device, it includes the compressed particles piece of at least one leafing graphite, surface area of its surface area more than the part that localized high temperature regions are produced in the rear surface of display device.

Description

For the radiator of display device

The application be application number be the 200410087798.4, applying date be October 29, denomination of invention in 2004 be " to be used for The divisional application of the Chinese invention patent application of the radiator of display device ".

Explanation

Known we are, live in Ohio North Omsted, 5250Columbia street Apt.407 (44070) United States citizen Timothy Clovesko；Live in Ohio Chagrin Falls, 17635Plum Creek Trail (44023) United States citizen Julian Norley；Live in Ohio Parma, 5608Ely Vista Drive (44129) United States citizen Martin David Smalc and live in Ohio Strongsville, 10094Juniper Court (44136) United States citizen Joseph Payl Capp inventions it is a kind of novel and useful " for the radiating of display device Device ".

Related application

The application be on October 14th, 2003 by Norley, CO-PENDING that Smalc, Capp and Clovesko are submitted and altogether With entitled " for the radiator of plasma display panel " (the Heat Spreader for Plasma Display for assigning Panel U.S. Patent Application Serial Number No.10/685), 103, and on May 12nd, 2004 is by Clovesko, Norley, CO-PENDING and commonly assigned entitled " for the radiator of emission display " (Heat that Smalc and Capp are submitted Spreader for Emissive Display Device) U.S. Patent Application Serial Number No.10/844,537 part Continuous to apply, the content of these applications is hereby incorporated by reference.

Technical field

The present invention relates to a kind of be used for display device such as plasma display panel (PDP), liquid crystal display (LCD), light The radiator of diode (LED) etc., and the thermal problem of the uniqueness caused by these devices.

Background technology

Plasma display panel is a kind of display device comprising multiple discharge cells, and by electrode discharge list In unit, applied voltage causes desired discharge cell launching light and constitutes display image.As the main portion of plasma display panel The face equipment for dividing, by two glass substrates are bonded together so as to sandwiched multiple discharge cells are fabricated by therebetween.

In plasma display panel, cause launching light so as to the discharge cell for being used for image formation and produce heat, so as to every One discharge cell constitutes thermal source, and the temperature of plasma display panel can be made to rise overally.The heat produced in discharge cell The glass for constituting substrate is passed to, but due to the property of glass substrate material, it is difficult in the direction heat parallel to panel surface Conduction.

Additionally, the temperature of the discharge cell for being activated and lighting significantly is raised, without the discharge cell being activated Temperature will not raise it is so many.Thus, the plate surface temperature of the panel of plasma display panel is in the region for producing image Local raises.Additionally, the discharge cell encouraged in white or brighter color spectrum is swashed with black or dark color spectrum The discharge cell encouraged is compared, and produces more heats.Thus, depending on the color produced when generating image, the temperature of panel surface It is different on local.These local temperature differences accelerate the heat drop matter of impacted discharge cell, unless taken some cooling measures Improve this species diversity.Additionally, when the property of display epigraph changes, the delivery in hot weather life position of local becomes with image.

Further, since the temperature difference between excited target and non-excited target discharge cell is higher, in fact, producing white light and producing Temperature difference between the discharge cell of raw dead color light is also higher, and panel component is stressed, and causes usual plasma display panel It is easy to rupture and destroys.

When the voltage for being applied to discharge cell electrode increases, the brightness increase of discharge cell, but produce in these units Raw heat also increases.Therefore, there is the unit of big driving voltage to be easier to heat drop matter for those, and exacerbate plasma The splintering problem of the face equipment of body display panel.For being thermally generated, LED be present and PDP identicals.Show in transmitting In display device beyond device, such as LCD, there is identical, the wherein efficiency of bright spot meeting limits device or life-span.

Morita, Ichiyanagi, Ikeda, Nishiki, Inoue, Komyoji and Kawashima are in United States Patent (USP) Propose in No.5,831,374 a kind of using so-called " highly oriented graphite film " (high orientation graphite Film) as the thermo-contact material of plasma display panel, to fill the space between the back side of display panel and heat abstractor, and And reduce local temperature differences, but, do not refer to use or the particular advantages of flexible graphite platelet.Additionally, U.S. of Tzeng State's patent No.6,482,520 disclose the compressed particles piece using leafing graphite as thermal source such as electronic unit radiator ( It is referred to as heat dissipation interface in the patent).In fact, can be from the Advanced Energy Technology of Ohio Lakewood Company buysSpreaderShield classes material is used as this material.

Graphite is made up of the hexagonal array or network layered planes of carbon atom.These are arranged with the hexagonal layers of carbon atom Shape plane is generally planar, and is orientated or is ranked into and is substantially parallel to each other and equidistant.Commonly referred to as graphene layers Or the generally flat of basic plane, parallel equidistant are from carbon atom sheet or layer, it are bonded or bond together, its group is arranged in crystalline substance Grain.The graphite of high-sequential is made up of quite large-sized crystal grain, and height is arranged or is orientated crystal grain each other, and is had good Orderly carbon-coating.In other words, the graphite of high-sequential has the preferred crystal grain orientation of height.It should be noted that graphite have it is each to Anisotropic approach, so as to show or the property with many great directivity, such as heat conductivity and electric conductivity.

In brief, the feature of graphite is carbon layer structure, i.e., the carbon original being combined together by weak Van der Waals for The structure that sub- lamination or thin layer are constituted.When graphite-structure is considered, two axis or direction, i.e. " c " axis or direction are often noted " a " axis or direction.For the sake of simple, " c " axis or direction can be assumed to perpendicular to the direction of carbon-coating." a " axis or Direction is assumed to direction or the direction perpendicular to " c " direction parallel to carbon-coating.It is suitable to manufacture the graphite tool of flexible graphite platelet There is very high orientation.

As described above, the adhesion that carbon atom parallel layers keep together is only weak Van der Waals for.Can be to natural Graphite is processed, and significantly increases the spacing between the carbon-coating or lamination of lamination, so as to perpendicular to the direction of layer i.e. " c " side To significant expansion is produced, so as to form the graphite-structure by expanding, wherein keeping substantially the laminar property of carbon-coating.

Without using binding agent in the bonding or integration slice of expanded graphite, it is possible to form final thickness or " c " direction The graphite flake of significant expansion or particularly significant expansion of the size for about 80 times of original " c " direction size, such as paper web, paper , bar, band, paper tinsel, mat etc. (so-called " soft graphite ").Believe due to the machinery realized between a large amount of expanded graphite particles Interlocking condenses, without using any adhesivess, it is possible to will be expanded into final thickness by compression or " c " direction size is The graphite particle of about 80 times of original " c " direction size forms integrated flexible sheets.

In addition to flexibility, as mentioned above, it was found that due to the orientation and graphite of expanded graphite particles caused by high pressure Layer is arranged essentially parallel to sheet material apparent surface, and pyrogenicity conduction makes sheet material be particularly well-suited to cooling application with high anisotropy In.Manufactured sheet material has excellent flexible, good intensity and height-oriented property.

In short, soft, soap-free emulsion polymeization anisotropic graphite sheet material, the such as manufacture of net, paper, bar, band, paper tinsel, mat etc. Journey, under conditions of being included in predetermined load and no binding agent, compression or extruding " c " direction size are that predecessor size is big About 80 times of expanded graphite particles, so as to form general planar, soft integrated graphite flake.Generally profile is vermiform or earthworm shape Expanded graphite particles, once being compressed, will just keep compressive deformation and be aligned with the corresponding main surfaces of thin slice.By control Compression degree changes the density and thickness of sheet material.The density of sheet material can be from about 0.04g/cc to the scope of about 2.0g/c It is interior.

As graphite particle is parallel to the opposing parallel master meter planar orientation of thin slice, flexible graphite sheet shows significantly each Anisotropy, with sheet material compression increase orientation, anisotropic degree increase.It is in the anisotropic sheet material by compressing, thick Degree includes " c " direction perpendicular to the direction of opposing parallel sheet surface, and length and width direction is i.e. along or parallel to relative The direction of first type surface includes " a " direction, and for " c " and " a " direction, the calorifics or electrical properties of thin slice is extremely different, width The several magnitudes of value difference.

But, concern in electronics industry, the material based on graphite is usually used can cause graphite particle to peel off, as a result thin Sector-meeting causes mechanical (i.e. with dust particle identical mode) interference to equipment operation and function, due to the conduction property of graphite, Graphite flake can be disturbed to emission display noise electricity.Although it is believed that have shown that these concern be it is unsuitable, but Which is still present.

Additionally, it is sometimes unfavorable that heat radiator is fixed on emission display using binding agent.Specifically, (remove and more heat exchange radiator) when needing to reprocess, binding agent should be more higher than the structural intergrity of graphite flake；In this respect In, can not use scraper or other instruments and graphite flake is neatly peeled off, can so expend time and possibility Graphite flake, display panel can be damaged or both can be damaged.

Accordingly, it would be desirable to a kind of lightweight and cost-effective radiator for emission display, particularly a kind of single Can prevent graphite particle from peeling off when solely using, and the radiator that can effectively remove from device when needed.Required radiator The temperature difference in the device area contacted by radiator should be made to become balance, be subject to so as to reduce display panel in other cases Thermal stress, and can be used for reducing hot spot, even if the position of hot spot is also such when not fixing.

The content of the invention

Therefore, it is an object of the present invention to provide it is a kind of for display device such as plasma display panel, light two The radiator of pole pipe or liquid crystal display.

Another object of the present invention is to provide it is a kind of can be used for display device to improve use during the temperature that produces The radiator material of degree difference.

A further object of the present invention is that one or more units for being provided as thermal source such as plasma display panel provide scattered Hot equipment material, so as to the temperature difference compared with the display panel for not having radiator of the present invention, on display panel between any two position Reduce.

A further object of the present invention be provide one kind can be applicable to thermal source or thermal source group such as plasma display panel or The heat sink material of light emitting diode, and thermo-contact good between radiator and plasma display panel is bonding.

A further object of the present invention is to provide a kind of radiator material, and which is isolated can prevent or reduce graphite particle The raw probability peeled off.

A further object of the present invention be provide can by way of causing minimal damage to radiator or thermal source bonding The radiator removed extremely and from thermal source.

A further object of the present invention is to provide a kind of radiator that can be produced in a large number and by cost-effective mode.

By reading explained below, these and other purposes that those skilled in the art obviously can draw can pass through There is provided it is a kind of realizes for the radiator of display device, the radiator include at least one from graphite compressed particles piece, its Surface area of the surface area more than the part such as discharge cell in the face of the rear surface of the device.The display device can be Emission display such as plasma display panel or light-emitting diode display panel, or another kind of display device such as liquid crystal display Device.It is further preferred that the surface area of the compressed particles piece of at least one leafing graphite is more than in the face of the rear surface of the device Multiple discharge cells part surface area.Advantageously, radiator is the compressed particles for including multiple leafing graphite The lamination of piece, and there is protective coating above to prevent graphite particle from peeling off from this.In a preferred embodiment, radiator Surface has sheet facings, such as aluminum or copper sheet, further sealed heat-dissipating device and to be easy to reprocess.

In a preferred embodiment, there is binding agent and separation material on radiator, is arranged to binding agent and is interposed in radiator Between separation material.When separation material and binding agent are chosen to make separation material separate at a predetermined velocity, will not be to the material that radiates Material causes undesirable infringement.In fact, binding agent and separation material should be produced not when separating rate is about 1 meter per second Average tearaway load more than about 40 grams per cm, is preferably no greater than per cm about 10 under about one meter per second of separating rate Gram.

Additionally, binding agent preferably obtains at least about 125 grams (g/cm every square centimeter²) minimum overlay shear bond it is strong Degree, preferably average lap-shear adhesive strength is at least about 700 grams every square centimeter.Binding agent should make binding agent/radiating The thermal resistance of the thickness direction of combination of materials, with heat sink material in itself compared with, increase less than about 35%.Adhesive thickness should No more than about 0.015 millimeter (mm), preferred thickness is not greater than about 0.005mm.

It should be appreciated that above general description and detailed description below provide embodiments of the present invention, and anticipate It is used for offer to originally in the summary or framework of offer understanding, and the property and feature accompanying drawing of the such as present invention that claim is proposed Invention further understand, and comprising and constitute description a part.The numerous embodiments of the present invention have been illustrated, It is used for together with the description illustrating principle and the operation of the present invention.

Description of the drawings

Fig. 1 is the top perspective of the cross-section of radiator one embodiment of the present invention；

Fig. 2 is the top perspective of the cross-section of another embodiment of radiator of the present invention；

Fig. 3 is the side view of another embodiment of radiator of the present invention；

Fig. 4 represents the system for continuously generating the flexible graphite platelet for being injected with resin；And

Fig. 5 is the top perspective of the cross-section of the of the present invention radiator similar with Fig. 1.

Specific embodiment

Graphite is the crystal form of carbon, and which is included between plane with weaker key covalent bond into flat layered plane Atom.When the raw material of above-mentioned flexible graphite platelet is obtained, the solution generally with intercalator such as sulphuric acid with nitric acid processes granular graphite Son, such as natural graphite flake, wherein the crystal structure of graphite react, to form the compound of graphite and intercalator.Below Treated graphite particle is referred to as into " embedded graphite particle ".Once being exposed to high temperature, the intercalator in graphite just decomposes, waves Send out, make the particle of embedded graphite in " c " direction, i.e., perpendicular to the direction of graphite crystal face, size is expanded in Z-shaped mode original About 80 times or more of volume.(or referred to as leafing) graphite particle outward appearance of expansion is vermiform, so as to be commonly referred to as lira Body.Lira body can be compressed together to form flexible sheets, and which is different from original graphite flake, may be constructed and cut into and be various Shape, and little transverse opening is formed by deforming mechanical impact.

The graphite raw material of the flexible sheets suitable for the present invention is included and can be embedded in organic and mineral acid high graphite carbonaceous Material and halogen, are expanded when exposed to heat.The preferred degree of graphitization of these high graphite carbonaceous materials is about 1.0.Such as this Used in explanation, term " degree of graphitization " represents value g according to following formula：

Wherein d (002) is the spacing between the graphite linings of carbon in the crystal structure for measuring, by angstrom in units of.By standard X-ray diffraction technique measurement graphite linings between spacing d.Measurement and (002), (004) and (006) Miller index (Miller Indices) the position of corresponding diffraction maximum, and the least square technology using standard derives all these peak values of sening as an envoy to The minimum spacing of total error.Native graphite of the high graphitic carbon material for example including various sources, and other carbon materials, such as The graphite of the preparations such as the crystallization by chemical vapor deposition, the pyrolytic of polymer or molten metal solutions.More preferably day Right graphite.

In the present invention, the graphite raw material of flexible sheets used can contain non-graphite composition, as long as the crystal structure of raw material Required degree of graphitization is kept, and can be with leafing.Generally, crystal structure has required degree of graphitization, And the present invention can be suitable for any carbonaceous material of leafing.This graphite preferably has less than 20 percent weight The dust burdening of percentage ratio.It is preferred that the purity of the graphite of present invention employing is at least of about 94%.In most preferred embodiment, institute Using the purity of graphite be at least of about 98%.

Shane et al. describes a kind of conventional method for manufacturing graphite flake in United States Patent (USP) No.3, in 404,061, The patent content is hereby incorporated by reference.In the representative embodiments of Shane et al. methods, by by thin slice be scattered in containing For example in the solution of the mixture of nitric acid and sulphuric acid, about 20 to about 300 parts of weight preferably in per 100 parts of weight graphite flakes Under the degree of embedded solution (pph), natural graphite flake is embedded in.Embedded solution is embedding with other comprising oxidation as known in the art Enter agent.For example include the material containing oxidant and oxidation mixture, such as contain nitric acid, potassium chlorate, chromic acid, potassium permanganate, chromium Sour potassium, potassium dichromate, perchloric acid etc.；Or mixture, such as cone nitric acid and chlorate, chromic acid and phosphoric acid, sulphuric acid and nitric acid；Or The mixture of person's strong organic acid, such as borontrifluoride acetic acid, and the strong oxidizer for being dissolved in organic acid.Or, stone can be made using potential Ink oxidation.The chemical substance that can be introduced into using electrolytic oxidation in graphite crystal includes sulphuric acid and other acid.

In a preferred embodiment, intercalator is sulphuric acid, or sulphuric acid and phosphoric acid, the mixture solution with oxidant, oxidation Agent such as nitric acid, perchloric acid, chromic acid, potassium permanganate, hydrogen peroxide, iodic acid or periodic acid etc..Although not being more preferably Bu Guoqian Enter solution and comprising metal halide such as iron chloride, and the iron chloride of sulphuric acid, or halogenide such as bromine, bromine and sulphuric acid can be mixed with Bromine in solution or organic solvent.

The amount of embedded solution about 20 to about 350pph, preferably about 40 to about 160pph.After embedded thin slice, Excess solution is discharged from thin slice, and thin slice is rinsed with water.

Or, the amount of embedded solution may be limited to about 10 to about between 40pph, such as United States Patent (USP) No.4, and 895, Taught in 713 with description can be also incorporated by reference without the need for rinsing step, the content here of the patent.

With the particle of the graphite flake of embedded solution process, selectively for example contacted with organic reducing agent by mixing, can Organic going back is selected from the alcohol under 25 DEG C to 125 DEG C range temperatures with the surface film reaction of the embedded solution of oxidation, sugar, aldehyde and ester Former agent.Suitable special organic agent includes hexadecanol, octadecanol, 1- capryl alcohol, sec-n-octyl alcohol, decanol, 1,10 decanediols, capraldehyde, 1- Propanol, 1,3 Propylene Glycol, 1,2 ethylidene glycols, polypropylene glycol, glucose, Fructose, Lactose, sucrose, potato starch, ethylene glycol Monostearate, dibenzoic diglycol laurate, propylene glycol monostearate, glycerol monostearate, dimethyl oxalate., oxalic acid Diethylester, methyl formate, Ethyl formate, ascorbic acid and lignin-derived compounds, such as sodium lignin sulfonate.Organic reducing agent Amount when accounting for about 0.5 to 4% graphite flake particle weight part than convenient.

Before embedded, during or after the expansion acid that adopts immediately can also bring improvement effect.These improvement include drop Low exfoliation temperature and increase swelling volume (also referred to as " lira body volume ").Expansion acid herein can preferably be substantially soluble in embedding Enter the organic material in solution, to improve expansion.Further limit, preferably but non-exclusively using containing carbon, hydrogen and This kind of organic material of oxygen.It has been found that carboxylic acid is especially effective.Can be from at least one carbon original suitable for the carboxylic acid of expansion acid Son, preferably has up to aromatic series, aliphatic or alicyclic, side chain or side chain, saturation or the unsaturation of about 15 carbon atoms Select in monocarboxylic acid, dicarboxylic acids and polybasic carboxylic acid, its amount being dissolved in embedded solution be enough to effectively to produce it is measurable go out Improvement to the one or more aspects of leafing.Appropriate organic solvent can be adopted to improve organic expander sour in embedded solution Dissolubility.

The representative example of representative examples of saturated aliphatic carboxylic is H (CH for such as chemical formula₂)_nThe acid of COOH, wherein n are from 0 to big About 5 numeral, including formic acid, acetic acid, propanoic acid, butanoic acid, valeric acid, caproic acid etc..Replace carboxylic acid, it is also possible to use acid anhydride or active carboxylic acid spreads out Biological such as Arrcostab.The typical example of Arrcostab is methyl formate and Ethyl formate.Sulphuric acid, nitric acid and water-soluble intercalator known to other Formic acid can be decomposed, water and carbon dioxide is ultimately breaks down into.For this reason, be conducive to before thin slice immerses water-soluble intercalator Make formic acid and other sensitive expansion acid contacts.Representational dicarboxylic acids are the aliphatic dicarboxylic acid with 2-12 carbon atom, special Be not oxalic acid, fumaric acid, malonic acid, maleic acid, succinic acid, 1,3-propanedicarboxylic acid, adipic acid, 1,5- pentane dicarboxylic acids, 1,6- adipic acids, 1, 10- decane dicarboxylic acids, hexamethylene -1-4- dicarboxylic acids and aromatic dicarboxylic acid such as phthalic acid or p-phthalic acid.It is representational Arrcostab is dimethyl oxalate. and ethyl oxalate.Representational alicyclic acid is cyclohexane-carboxylic acid, and aromatic carboxylic acids are benzene first Acid, naphthoic acid, ortho-aminobenzoic acid, p- amino benzoic Acid, salicylic acid, o-, m- and p- ar-Toluic acids, methoxyl group and ethyoxyl Benzoic acid, acetyl acetamide benzoic acid, acetaminobenzoic acid, phenylacetic acid and naphthoic acid.Representational hydroxy aromatic acid is Hydroxy benzoic acid, 3- hydroxyl -1- naphthoic acids, 3- hydroxy-2-naphthoic acids, 4- hydroxy-2-naphthoic acids, 5- hydroxyl -1- naphthoic acids, 5- Hydroxy-2-naphthoic acid, 6-Hydroxy-2-naphthoic acid and 7- hydroxy-2-naphthoic acids.Citric acid is mainly in polybasic carboxylic acid.

Embedded solution contains water, and to preferably comprise the amount of expansion acid be of about 1% to 10%, and this quantity is conducive to strengthening Leafing.In this embodiment, contact wherein expanding acid before or after the embedded solution of graphite flake immersion aqueouss with graphite flake.Expansion Acid can be mixed with graphite by appropriate device such as V- blending machines, and general quantity accounts for about the 0.2% of graphite weight portion to about 10%.

After embedded graphite flake, embedded graphite flake is mixed with organic reducing agent, mixture is placed on into 25 DEG C then To in 125 DEG C of temperature ranges, promote the reaction of reducing agent and embedded graphite flake.Reach heating cycle about 20 hours, for upper Higher temperature in the range of stating, heating cycle are shorter, for example, at least about 10 minutes.In higher temperature, half an hour can be adopted Or the shorter time, such as 10 to 25 minutes magnitudes.

By in the range of graphitization temperature i.e. about 3000 DEG C and the temperatures above to graphite flake pretreatment, and intercalator In by the method that comprising lubricating additive, is conducive to strengthening above-mentioned embedded and leafing graphite flake.

The pretreatment or annealing of graphite flake causes when thin slice is then subjected to embedded and leafing, and swell increment is significantly increased (i.e. Swelling volume increases to 300% or bigger).It is indeed desired to compared with the similar process without annealing steps, expansion increases Big at least 50%.The temperature adopted by annealing steps should not be significantly lower than 3000 DEG C, even if because temperature reduces by 100 DEG C, also can Expansion is caused to be substantially reduced.

Perform the annealing of the present invention for a period of time, the time be enough to cause thin slice swelling degree in embedded and subsequent leafing to increase Greatly.The commonly required time is for 1 hour or longer, preferably 1 to 3 hour, more preferably processes in an inert atmosphere.In order to Realize maximum beneficial effect, through graphite flake annealing also by undergo it is as known in the art for increase swelling degree other Process-i.e. embedded when there is organic reducing agent, embedded acid such as organic acid, and surfactant flushing is carried out after insertion.This Outward, in order to obtain the beneficial effect of maximum, Embedded step can be repeated.

The annealing steps of the present invention are performed in faradism electric furnace or graphitization field in known other this kind equipments； The temperature in the range of 3000 DEG C for adopting herein, in graphitizing process, met temperature range is high-end.

Because it has been observed that using through pre- embedded annealing graphite manufacture lira body, sometimes " coagulation " exist Together, region weight uniformity can be had a negative impact, the highly desirable additive for contributing to forming " without flowing " lira body. Lubricating additive is added in embedded solution, is easy to lira body (to be such as conventionally used to graphite in the workbench of compression device Lira body compresses (or " calendering ") into the workbench of the calendering operation station of flexible graphite platelet) on distribution evenly.So as to institute The thin slice of generation has higher region weight uniformity and bigger tensile strength, even if raw graphite particle is less than institute in tradition It is also such during graphite particle.Lubricating additive is preferably long chain hydrocarbon.May also be employed with long chain hydrocarbon groups, very To the organic compound that there are other functional groups.

It is further preferred that lubricating additive is oil, most preferably mineral oil, particularly in view of mineral oil is not easy to rancid and sends Abnormal smells from the patient, is a kind of important Consideration for long-term preservation.Notice that some above-mentioned expansion acid also meets to add lubrication Plus the definition of agent.When using these materials as expansion acid, lubricating additive in intercalator, is not necessarily individually included.

The quantity that lubricating additive is present in the intercalant is at least of about 1.4pph, preferably at least about 1.8pph.To the greatest extent The upper limit of pipe lubricant content is strict not as lower limit, but seems to bring more than about 4pph comprising lubricating additive Obvious attendant advantages.

Sometimes this treated graphite particle is referred to as into " embedded graphite particle ".When exposing at high temperature, for example At least about 160 DEG C, especially from about 700 DEG C to 1000 DEG C and higher temperature, are embedded in graphite particle along c- directions, i.e., along vertical In the direction of the crystal face for constituting graphite particle, by a kind of Z- shapes mode be expanded into about 80 to 1000 times of its initial volume or It is bigger.Through expansion be leafing graphite particle outward appearance be worm shape, so as to be commonly referred to as lira body.Lira body can be embossed in one Rise, become the flexible sheets with little transverse opening different from original graphite flakes, separation material can be formed and be cut into various Shape, as described below.

Or, the flexible graphite platelet of the present invention can utilize the lira of reground flexible graphite platelet rather than new expansion Body.Thin slice can be the new sheet material for being formed, again green sheet, scrap sheet material or any other appropriate sources.

And the process of the present invention can use fresh material with the mixture of regrown material or whole regrown materiaves.

Raw material for regrown material can be that the thin slice or thin slice for passing through above-mentioned molding passes through the part repaired, or Person Jing rolls the thin slice of roll compaction in advance.Additionally, raw material can be the thin slice or thin slice for having been injected into resin but without solidification Through the part repaired, or have been injected into resin and the part of cured thin slice or thin slice process finishing.Raw material may be used also Think regeneration flexible graphite PEM fuel battery component such as flow-field plate or electrode.Can use graphite raw material in each, or Person is used in mixed way with natural graphite flakes.

Once obtain the raw material of flexible graphite platelet, then can pass through known procedure or device for example jet grinding, Air mill, Blender etc. is crushed, and generates particle.Preferably, the diameter of most of particle is more than 20U.S. meshes；More preferably major part (is more than About 20%, more preferably greater than about 50%) less than 80U.S. meshes.Most preferably, the particle size of particle is little In about 20 meshes.

Can so select to grind the size of particle, the balanced balance machinability and formability for considering graphite particle with Required thermal property.Thus, smaller particless produce the graphite product for being more readily processed and/or shaping, and larger particle will be produced It is raw that there is more high anisotropy, so as to the higher graphite product of electric conductivity and heat conductivity in face.

Once grinding raw material, then any resin is removed if desired, is then re-inflated.Can using above-mentioned and Embedded and stripping described in the United States Patent (USP) 4,895,713 of the United States Patent (USP) 3,404,061 of Shane et al. and Greinke et al. It is re-inflated from process.

Usually, delamination occurs to make particle by heating imbedded particle in a furnace after insertion.In this leafing step During, embedded natural graphite flakes can be added in regeneration imbedded particle.It is preferred that, in step process is re-inflated, particle It is expanded into a certain designated volume with least about 100cc/g to about 350cc/g or in larger scope.Finally, again After expansion step, the particle being re-inflated is compressed into into flexible sheets, it is as described above.

Soft graphite and paper tinsel are condensed into good processing intensity, and are for example compressed into about by compression molded The thickness of 0.025mm to 3.75mm, usual density are about 0.1 to 1.5 grams (g/cc) per cubic centimeter.Although and not always excellent Choosing, but with when can also advantageously process flexible graphite platelet with resin, and after hardening, the resin tooth for being adsorbed The moisture resistance of flexible graphite platelet and processing intensity are hardness, and the form of " fixation " thin slice.When in use, appropriate resin contains Amount is preferably at least about 5% percentage by weight, and more preferably about 10% to 35% percentage by weight is appropriate for up to 60% percentage by weight.Find that useful especially resin includes acrylic acid, epoxy and phenolic aldehyde Ji Shu in implementation process of the present invention Fat system, or its mixture.Suitable epoxy resin include the resin based on diglycidyl ether or bisphenol-A (DGEBA) and its His polyfunctional group resin system；Adoptable phenolic resin includes resol and novolac phenol.

Referring to Fig. 4, a kind of system of the flexible graphite platelet that resin is embedded with for continuous manufacture is disclosed, wherein by graphite Thin slice and liquid intercalator are filled in reactor 104.More specifically, container 101 is used for comprising liquid intercalator.Container 101 are suitable to be made of stainless steel, and continuously compensate for liquid intercalator by conduit 106.Container 102 includes graphite flake, Import to together with the intercalator from container 101 in reactor 104.Intercalator and stone are controlled by valve 108,107 such as The corresponding speed of black thin slice input reactor 4.Graphite flake in container 102 can be continuously supplemented by conduit 109.Can pass through Allotter 110 adds additive, for example micro acid of such as embedded reinforcing agent, and organic chemicalss, wherein in allotter 110 Outfan is measured by valve 111.

Produced embedded graphite particle is moistening and scribbles acid, and is directed (such as by conduit 112) to punching Tank-washer 114, rinses particle in this place, preferably by the water that flushing cisterns 114 is passed in and out at reference 116,118.Then, pass through The embedded graphite flake for rinsing is as passed through conduit 120 by hothouse 122.The such as dirty chemicals of buffer agent, antioxidant, drop In the liquid stream that the additive of matter can add embedded graphite flake from container 119, to change coming to the surface for leafing in expansion process Property is learned, and utilization and change cause the gas of expansion to discharge.

Embedded graphite flake is dried in exsiccator 122, is preferably dried at a temperature of about 75 DEG C to about 150 DEG C, is led to Embedded graphite flake is often avoided to occur any to swell or expand.After drying, graphite flake is embedded in for example, by continuous using conduit 126 Injection collecting vessel 124, is input in flame 200, then as shown in reference 2 as fluid stream, expands as fluid stream input In flame 200 in container 128.Additive such as quartz glass fibre, carbon and graphite fibre, zirconium oxide, boron nitride, the gold macerated The ceramic fibre particle that emery and magnesia fibers are constituted, the mineral fibres for naturally occurring such as calcium metasilicate fibers, calcium silicates aluminum Under conditions of fiber, alumina fibre etc. can be added by not having active gasess introducing at reference 127 from container 129 In the stream stock of the embedded graphite particle carried secretly and advance.

After flame 200 of the embedded graphite particle 2 in by expanding chamber 201,80 times are expanded more than in " c " direction, and And present a kind of " vermiform " expanded form 5；What stream stock introduce from reference 129 and with embedded graphite particle mixed Additive, is essentially unaffected when by flame 200.Expanded graphite particles 5 can pass through gravity separator 130, wherein from Heavier ash shape natural minerals particle is isolated in expanded graphite particles, subsequently in wider butt funnel 132.When being not required to Separator 130 can be bypassed when wanting.

Expansion is the free-falling in funnel 132 together with any additive of leafing graphite particle 5, and is for example passed through Groove 134 arbitrarily disperses and enters compressor station 136.Compressor station 136 include it is detached it is contrary, assemble mobile porous belts 157,158, To receive the expanded graphite particles 5 of leafing.As the space between contrary mobile belt 157,158 reduces, the expansion of leafing Graphite particle is compressed in the soft graphite pad shown in reference 148, its thickness from such as about 25.4 to 0.075mm, Particularly from about 25.4 to 2.5mm, density is from about 0.08 to about 2.0g/cm³.Can be removed using gas washer 149 The gas sent from expanding chamber 201 and funnel 132 with cleaning.

Pad 148 is by container 150, and injects liquid resin from spray nozzle 138, and the resin is preferably by vacuum chamber 139 " being extracted out by padding ", and resin is dried preferably in exsiccator 160 afterwards, reduces the viscosity of resin, and afterwards in calendering By 143 thickening of resin by injection pad into rolling flexible graphite platelet 147 in machine 170.It is preferred that in scrubber 165 collect and clean from The gas and smog of container 150 and exsiccator 160.

After thickening, the resin in flexible graphite platelet 147 solidifies in curing oven 180 at least in part.Or, can be Partially cured, but it is preferred that thickening solidify afterwards are carried out before thickening.

But, in an embodiment of the invention, flexible graphite platelet does not have embedded resin, can omit appearance in this case Device 150, exsiccator 160 and curing oven 180.

Manufacture size is the plasma display panel of more than 1 meter (angle is to angular measurement) now.So as to for cooling down and improving The heat-radiator plate of the hot spot effect on this display panel also requires that quite big, is of about 270 millimeters and takes advantage of about 500 micron dimensions, Or be of about 800 microns and take advantage of 500 micron dimensions or bigger.In plasma display panel, as described above, there is thousands of Unit containing plasma gass respectively.Fluorophor when voltage is applied to each unit, in plasma gass and each unit Reaction, produces colored light.Due to needing sizable energy by gas ionization to produce plasma, plasma scope can Can be very hot.Additionally, depending on the color in the specific region of display panel, hot spot is produced on screen, fluorophor can be caused Too early damage, shortens display life, and produces thermal stress with display panel sheet.Accordingly it is desirable to radiator is reducing The impact of these hot spots.

Leafing graphite compressed particles piece, the particularly lamination of leafing graphite compressed particles piece are had found, is particularly well-suited to show Show the radiator of device such as plasma scope.More specifically, by one or more pieces leafing graphite compressed particles, here referred to as Flexible graphite platelet, is arranged to thermally contact with the dorsal part of plasma display panel, covers flexible graphite platelet multiple in display panel Thermal source (i.e. discharge cell).In other words, electric discharge list of the surface area of flexible graphite platelet more than the dorsal part of plasma display panel The surface area of unit；In fact, dorsal part multiple discharge cell of the surface area of flexible graphite platelet more than plasma display panel Surface area.Therefore, because the property of the excellent type graphite material of radiator of the present invention is formed, when the image shown by display panel When changing, the heat of the hot spot produced in the diverse location of plasma display panel can be dissipated by which.

Due to the property of flexible graphite platelet material, i.e., with other materials, the graphite-phase ratio even with other forms, more Comply with, contact resistance between radiator and plasma display panel reduces, and with using prior art radiator and impose Compare during equal pressure, preferably thermo-contact can be obtained.

Poor (the i.e. Δ of heat that the soft graphite sheet heat radiator of the present invention is used between the multiple positions for reducing on display T).In other words, with Δ T-phase ratio when there is no flexible graphite platelet, by using the soft graphite radiator of the present invention, can reduce As between the position for producing white image and the adjacent position for producing dark image between hot spot on plasma display panel Temperature difference.So as to reducing the thermal stress that plasma display panel in the case of other is subject to, extending display panel life-span and effectiveness. Further, due to reducing hot spot (i.e. thermal spike), whole part is may operate under higher temperature so that image enhancement.

In fact, radiator is bonded to into plasma display panel with a layer of adhesive thereon, particularly in plasma In body display panel assembling process, it is favourable for heat radiator to be manufactured.So as to be covered using release liner Lid binding agent, by adhesive clip between release liner and graphite flake, can preserve before plasma display panel is bonded to and Transport heat radiator.

Using the graphite flake (or lamination of piece) for scribbling binding agent with release liner, for extensive plasma Need to meet some requirements when in body display board manufacturing process.Specifically, release liner must be able to from piece remove at a high speed, will not Make graphite laminated.In the case that release liner actually makes binding agent and some graphite flake release sheets when removing occur to divide Layer, causes graphite to waste, and graphite flake itself is damaged, and graphite flake is bonded to the binding agent needed for plasma display panel and subtracts It is few, and outward appearance is ugly and not good.

Even so, as binding agent and release liner must be selected so that binding agent/graphite flake can be made and lining is separated Pad is separated and graphite will not be layered, and the intensity of binding agent must be enough to for graphite flake to be maintained at appropriate on plasma display panel At position, while display panel presents any one of various orientations, to ensure heat good between radiator and display panel Contact.

Additionally, binding agent must will not cause significantly reducing for radiator thermal property.In other words, be applied as one layer it is larger The binding agent of thickness may affect the thermal property of radiator because binding agent heat can be affected from plasma display panel or Other display devices are transmitted to radiator.

Therefore, binding agent and release liner combination must reach certain balance so that under the separating rate of about 1m/s, When measuring on such as ChemInstruments HSR-1000 high-speed separations detector, they produce and are not more than about 40g/ The disengaging load of cm, preferably approximately 20g/cm, most preferably from about 10g/cm.For example, if requiring to go with the speed of about 1m/s Except release liner is to be consistent with the extensive manufacture requirements of display device such as plasma display panel, then release liner is average Depart from load and should be not more than about 40g/cm, preferably approximately 20g/cm, more preferably from about 10g/cm, so as in the separating rate Graphite laminated is not result in during lower removal release liner.In order to realize this purpose, the thickness of binding agent is preferably no more than about 0.015mm, more preferably no more than about 0.005mm.

The adhesive strength that another factor that balance considers is above-mentioned binding agent is needed, in plasma display panel manufacture process In must be enough to the appropriate position that radiator is maintained on plasma display panel, to ensure radiator and plasma display Show thermo-contact good between plate.For the bonding needed for realizing, such as in ChemInstruments TT-1000 pull force calculations When measuring on instrument, binding agent must have at least about 125g/cm²Minimum overlay shear bond strength, more preferably average weight Folded shear bond strength is at least about 700g/cm²。

By above-described full content, binding agent should have no substantial effect on the thermal property of radiator.This meaning , the presence of binding agent is not result in that the thermal resistance ratio in heat sink thickness direction does not have the heat sink material increase of binding agent itself More than 100%.In fact, in a more preferred embodiment, binding agent will not make heat compared with the heat sink material for not having binding agent Resistance increase about more than 35%.Therefore, binding agent must is fulfilled for departing from the overlap shear bond strength requirement of loading demands peace, together When it is fully thin avoiding thermal resistance from undesirably extremely increasing.In order to meet these requirements, the thickness of binding agent should be less than About 0.015mm, preferred thickness are less than 0.005mm.

In high volume manufacturing process, heat sink applications are when display device such as plasma display panel, required in order to realize Above-mentioned equilibrium, radiator be thickness be not more than about 2.0mm, density between per cubic centimeter about 1.6 to about 1.9 grams it Between leafing graphite compressed particles piece or the lamination of piece, the pressure sensitive acrylic adhesive of commercially available desired thickness, with reference to painting There are release liner made by the Kraft paper of siloxanes, the L2 that such as can be buied from SilTech portions of TechicoteInc. branches or L4 Release liner, is capable of achieving results needed.Therefore it provides such a radiator composite, which includes heat sink material, such as leafing The compressed particles piece or the lamination of piece of graphite, in the above with certain thickness binding agent, makes the thermal property of heat sink material Essentially without suffering damage, stratum disjunctum makes binding agent be arranged between heat sink material and separation material.Then, when in use, Can remove separation material from the combination of radiator/binding agent, and and then by heat sink material/binding agent combination application in display device Such as plasma display panel, so as to heat sink material is bonded to plasma display panel by binding agent.Additionally, manufacture multiple grades from During daughter display panel, by least one radiator/binding agent combination application in multiple plasma display panels each.

When using flexible graphite laminate as radiator of the present invention, can also other laminations be included to improve the machine of lamination Tool or thermal property.For example, can plant between soft graphite layer the lamination of heat-conducting metal shape aluminum or copper, to increase lamination Thermal diffusivity, without sacrificing the low contact resistance that shows of graphite；Other materials, such as polymer can also be adopted, to strengthen Or improve the intensity of lamination.Additionally, no matter monolithic or lamination, graphite material can be provided with plastic board, or can in one kind In the mode of selection, the backing layer that thin dry resin coating is formed can be provided with, to improve the process of material and/or reduce transport Or damage when being applied to display device to thin slice, without compromising on the heat-sinking capability of radiator of the present invention.Can also be using insulation Material layer.

Additionally, the surface that radiator makes a reservation for abut display device can have material facing, to improve radiator of the present invention Thermal property and/or reprocess property.Preferably metal shape aluminum or copper, most preferably aluminum.Although just bigger contact Some heat loss (because the graphite surface complied with when using facing is no contacting with apparatus surface) are there may be for resistance, Can be compensated by ML calorifics isotropism.But, moreover, due to being that facing bonds to apparatus surface, just In in the radiator for reprocessing or removing during other purposes the present invention, because the structure of metal finish is more higher than bonding, it is allowed to quick And radiator is removed from display device surface with no damage.

As shown in fig. 1, the reference for radiator of the present invention is 10 flexible graphite platelet or lamination, once shape Into, it is possible to the shape needed for cutting into, is in most of the cases rectangle.Radiator 10 has two first type surfaces 12 and 14, And at least one edge（Or side）Face, and generally there are if radiator 10 is rectangle four edge surface 16a（It is aobvious So, when radiator 10 is cut into not square shape, such as circular or more complicated shape will be with varying number Edge surface）.

Referring now to Fig. 1-3, it is advantageous to which radiator 10 includes protective coating 20, to prevent graphite particle from composition The flexible graphite platelet of radiator 10 or lamination are peeled off, conversely, graphite particle can occur to separate.Protective coating 20 is also helped effectively Ground isolated radiator 10, to avoid conductive material is included in electronic installation（Graphite）The electrical interference of Shi Yinqi.Protective coating 20 can Be enough to prevent graphite material from peeling off and/or electrically insulating the suitable material of graphite including any, such as thermoplastic such as polyethylene, Polyester or polyimides, paraffin and/or lacquer materials.In fact, when ground connection is needed, protective coating 20 different from electric isolution May include metal such as aluminum.

Advantageously, for the piece resistance needed for obtaining and/or electric isolution, protective coating 20 should preferably be at least about 0.001mm is thick.Although protective coating 20 does not have real maximum gauge, but protective coating 20 should be no more than about 0.025mm is thick, in order to the preferred thickness that effectively works is no more than about 0.005mm.

When radiator 10 is applied to display device such as plasma display panel, the first type surface 12 of radiator 10 is and display The surface of plate effective contact.Equally, in numerous applications, the contact between first type surface 12 and display panel is used for " sealing " first type surface 12, prevent graphite from peeling off, so as to first type surface 12 need not be coated with protective coating 20.Equally, if first type surface 14 be provided with radiating The remainder electric isolution of the electronic installation of device 10, then need not electrically insulate first type surface 12.But, in order to process or other are examined Consider, in some embodiments, protective coating 20 can be coated on two first type surfaces 12 and 14 of radiator 10, radiator 10 Between any binding agent used on graphite flake and first type surface 12, binding agent is for bonding to plasma by radiator 10 Body display panel（It is not shown）.

Can be that radiator 10 arranges protective coating 20 by various distinct methods.For example, once by flexible graphite platelet or Lamination cuts into the size and dimension of regulation to form radiator 10, then can coat on single radiator 10 and protect for being formed The material of shield coating 20, to be flow to around first type surface 14 and edge surface etc. completely, and extends to beyond side etc., with Protectiveness lamellar border is formed around radiator 10, as shown in fig. 1.For this purpose, can pass through well known to those skilled in the art Various painting methods coat protective coating 20, such as spraying, roller coat and heat lamination.

In another embodiment, as shown in Figure 2, protective coating 20 can be coated on radiator 10, to cover one Individual or multiple edge surface 16a（Which for example, expose outside, so as to potentially peeling off and/or producing depending on edge surface Electrical interference）.Protective coating 20 can be coated by machinery mapping and to this enforcement lamination.

In still another embodiment of the process, and as shown in Figure 3, protective coating 20 is applied on radiator 10, so as to First type surface 14 is coated only.A kind of particularly preferred method of manufacture the present embodiment radiator 10, is such as by roller coat, uses bonding Oxidant layer is folded or heat lamination, with 20 coating flexible graphite flake of protective coating or lamination, is then cut flexible graphite platelet or lamination 10 shape of radiator needed for being cut into.By this method, in manufacture process, manufacture efficiency is maximum, and the waste of protective coating 20 is most It is little.

Generally, for great majority application, 20 sufficient intensity of protective coating is bonded to radiator 10 by coating procedure.No Cross, if desired, or for comparatively non-sticky protective coating 20, such as Mylar polyester materials and Kapton is poly- Acid imide material（Both of which can be from the E.I. du Pont de Nemours and of Wilmington Delaware Company is buied）, adhesive phase 30 can be coated between radiator 10 and protective coating 20, as shown in Figure 3.Appropriate Binding agent is easy for the binding agent that protective coating 20 is bonded to radiator 10, such as acrylic acid or emulsion binder.Adhesive phase 30 can be coated in any one of radiator 10 and protective coating 20 or be coated on both.Advantageously, bond Oxidant layer 30 is thin as far as possible, while still keeping between protective coating 20 and radiator 10 bonding.Preferably, the thickness of adhesive phase 30 Degree is not more than about 0.015mm.

Additionally, in another embodiment, radiator 10 may include the first type surface 12 and display device of plant radiator 10 Finish coat 40 between surface.As described above, finish coat 40 is preferably metal, such as aluminum, and can be using being coated in radiator 10 Surface 12 and finish coat 40 between adhesive phase 50 be bonded to surface 12, as shown in Figure 5.Appropriate binding agent is propylene Acid or emulsion binder, and can be coated in spreader surface 12 and 40 any of which of finish coat one or both.When So, adhesive phase 50 coats thin as far as possible, while still keeping bonding between finish coat 40 and surface 12, preferred thickness is not More than about 0.015mm.

Additionally, as shown in Figure 5, heat radiator 10 can be sealed in together with protective coating 20 by finish coat 40 Between finish coat 40 and protective coating 20.Specifically, if finish coat 40 extends to the edge surface of radiator 10, can be Radiator 10 and 40 surrounding of finish coat coating protective coating.Or, the material of such as aluminium strip, sealing finish coat 40 and guarantor can be adopted Edge surface between shield coating 20 etc..

Although the radiator for being just applied to plasma display panel is illustrated to the application, but understand the present invention's Method and radiator are similarly applied to other emission display thermals source, or thermal source collector (correlation function is equivalent to structure Into the set of each discharge cell of plasma display panel), such as light emitting diode, and other produce areas of localized hyperthermia or heat The display device of speckle, such as liquid crystal display.

The operation of the examples below explanation one embodiment of the invention and effect, but be merely to illustrate, do not limit wanted The scope of the present invention asked and width.

Example 1

Under the conditions of following different screens, analysis is using the acrylic acid radiator of the dorsal part of attachment plasma display panel Panasonic's plasma television (model：TH42PA20 thermal property).White and black pattern are produced over the display, and are used Thermal camera measures screen surface temperature.Background is all black in all cases.Pattern includes：1) level on screen Evenly spaced three white lines (23.9% screen illumination) and 2) uniform intervals white point 4 × 3 arrays (4% screen illumination). After device of the detection with Conventional acrylic radiator, acrylic acid radiator is removed, and thickness is replaced by for 1.4mm and plane Thermal conductivity is of about the soft graphite radiator of 260W/m ° of K.Then under conditions of same as described above again detection etc. from Daughter display, lists result in table 1.

Table 1

Example 2：

Aluminum/silicones radiating of the analysis using the dorsal part for being attached to plasma display panel under the conditions of following different screens NEC plasma scope (the models of device：Plasmasync 42 " 42XM2HD) thermal property.Produce over the display white Normal complexion black pattern, and screen surface temperature is measured using thermal camera.Background is all black in all cases.Pattern Including：1) on screen horizontal homogeneous interval three white lines (23.9% screen illumination) and 2) 4 × 3 gusts of uniform intervals white point Row (4% screen illumination).After device of the detection with conventional aluminum/silicones radiator, aluminum/silicones radiator is removed, And thickness is replaced by for 1.4mm and plane thermal conductivity and is of about the soft graphite radiator of 260W/m ° of K.Then with Detect plasma scope under the conditions of stating identical again, in table 2, list result.

Table 2

These examples are illustrated in terms of the maximum temperature (Tmax) and temperature range (T range) observed, using flexible stone Black radiator is more beneficial than conventional diffusers technology.

The all references patent mentioned in the application and publication are hereby incorporated by reference.

The described present invention obviously can change in several ways.This change is not regarded as a departure from the essence of the present invention God and scope, all these modifications that those skilled in the art obviously can draw are all contained in scope.

Claims (3)

1. a kind of display device, the display device have：

A. the liquid crystal display with 1 meter or more of size, and

B. there is the radiator of two first type surfaces, the radiator includes：

I. the compressed particles piece of at least one leafing graphite,

Ii. the protective coating of the first first type surface of radiator is connected to, and

Iii. the binding agent on the surface of second first type surface and liquid crystal display of radiator is connected to,

Wherein, the second first type surface of the radiator is substantially all is directly thermally contacted with liquid crystal display,

Wherein, the temperature difference produced when radiator improves using liquid crystal display.

2. display device as claimed in claim 1, it is characterised in that the radiator also includes at least one edge surface, protection Coating is connected to the edge surface.

3. display device as claimed in claim 1, it is characterised in that the binding agent is chosen to, is 1 meter per second in separating rate When, the disengaging load of the combination of binding agent and release liner is not more than 40g/cm.