CN111761049B - Metal paste for manufacturing capillary structure in uniform temperature plate - Google Patents
Metal paste for manufacturing capillary structure in uniform temperature plate Download PDFInfo
- Publication number
- CN111761049B CN111761049B CN201910255845.8A CN201910255845A CN111761049B CN 111761049 B CN111761049 B CN 111761049B CN 201910255845 A CN201910255845 A CN 201910255845A CN 111761049 B CN111761049 B CN 111761049B
- Authority
- CN
- China
- Prior art keywords
- metal
- metal powder
- capillary structure
- powder
- copper
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/06—Metallic powder characterised by the shape of the particles
- B22F1/065—Spherical particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/05—Metallic powder characterised by the size or surface area of the particles
- B22F1/052—Metallic powder characterised by the size or surface area of the particles characterised by a mixture of particles of different sizes or by the particle size distribution
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/06—Metallic powder characterised by the shape of the particles
- B22F1/068—Flake-like particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/107—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing organic material comprising solvents, e.g. for slip casting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/17—Metallic particles coated with metal
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/11—Making porous workpieces or articles
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/08—Alloys with open or closed pores
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C9/00—Alloys based on copper
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
- F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
- F28D15/04—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with tubes having a capillary structure
- F28D15/046—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with tubes having a capillary structure characterised by the material or the construction of the capillary structure
Abstract
The invention provides a metal slurry for manufacturing a capillary structure in a uniform temperature plate, which comprises two metal powders with the same material but different particle size distributions or different shapes, a polymer and an organic solvent. The colloid formed by mixing the polymer and the organic solvent can be used for uniformly dispersing and suspending and mixing two metal powders to form a metal slurry. The metal slurry can volatilize the organic solvent through the heating process, the polymer is burnt out through the baking process, and the two mixed metal powders form a porous capillary structure with water absorption through the sintering process. The metal slurry is easily laid on the metal substrate by steel plate printing, screen printing or dispensing to manufacture the capillary structure of the uniform temperature plate, so that the mass production efficiency of the capillary structure in the uniform temperature plate can be improved, and the mass production yield of the uniform temperature plate product can be improved.
Description
Technical Field
A metal paste for manufacturing capillary structures in uniform temperature plates, in particular to a metal paste for manufacturing porous capillary structures in uniform temperature plates (Vapor Chamcer).
Background
Conventionally, a Metal Paste (Metal Paste) is prepared by adding a Metal Powder (Metal Powder) as a filler (filler) into a colloid (colloid) mixed by a polymer and an organic solvent and sufficiently mixing, so that the Metal Powder is dispersed and suspended in the colloid to form a Metal Paste. Since the slurry itself has rheology (rhology), the metal slurry can be easily spread on the surface of the substrate. Generally, except for the electromagnetic shielding material, most of the copper Paste is used as an electronic Paste (electronic Paste) and is disposed on a ceramic substrate or a device by Thick film Printing (Thick film Printing), and a conductive circuit or electrode material is formed by sintering process (sintering process). In order to make the metal powder adhere and bond with the ceramic substrate or component tightly after sintering, the electronic paste using the metal powder as the filler usually needs to be added with glass or ceramic powder. The conventional electronic paste contains, as a filler, metal powder such as copper (Cu), silver (Ag), aluminum (Al), nickel (Ni), palladium (Pd), gold (Au), platinum (Pt), (W), molybdenum (Mo) … …, and copper alloy such as silver/palladium (Ag/Pd) and copper powder with silver on the surface.
In order to achieve the electrical performance of the metal paste after sintering, the metal powder added to the conventional metal paste is expected to achieve good compactness after sintering, so the requirements on the particle size and the particle size distribution of the metal powder are very strict.
The metal slurry of the invention, in particular to the metal slurry used for manufacturing the capillary structure in the Vapor Chamber (Vapor Chamber), is required to have compactness after being sintered, which is different from the metal powder of the common metal slurry. Instead, it is desirable that the metal powder of the metal slurry is loosely bonded to each other to form a porous structure after sintering, and that the metal slurry is also bonded to a metal substrate of the vapor chamber.
With the rapid development of technology, the appearance of all electronic devices is gradually designed to be light, thin and small, especially for thin pen phones (notewood PCs), smart phones (smartphones), smart glasses (Smartglasses) and the like for Mobile Computing (Mobile Computing) and Mobile communication. However, in order to achieve the thinness of the electronic communication device, the most common problem is the heat dissipation and heat management. Since in thinner devices the space in which the heat-dissipating component can be placed is more compressed. Generally, a Vapor Chamber (Vapor Chamber) or a Micro Heat Pipe (Micro Heat Pipe) used in a conventional desktop computer or notebook computer is difficult to meet the ultra-thin specification requirement of the new generation of mobile computing and mobile communication in terms of the thickness of the device.
In contrast, a manufacturer of a heat dissipation module utilizes the principle of manufacturing a conventional uniform temperature plate (vapor chamber) to change the manufacturing method of a micro heat pipe into that after an upper copper substrate and a lower copper substrate are etched, the copper substrates with grooves are welded together in a groove-in manner to form a cavity. Then, a copper mesh or a woven mesh is laid on the substrate and sintered at a high temperature to form a capillary structure, and then the capillary structure is further sealed, injected with water, vacuumized and the like to manufacture an ultrathin hot tube Plate (Heat Pipe Plate) with the capillary structure or a Vapor Chamber (Vapor Chamber). The thickness of the element of the temperature-equalizing plate manufactured by the method can be controlled to be 0.4mm or less than 0.4mm theoretically. The cavity of the temperature-equalizing plate contains a capillary structure, an air passage and working fluid, and the working fluid in the vacuum cavity continuously performs liquid-gas two-phase change circulation in the capillary structure and the air passage so as to achieve rapid heat conduction. The liquid phase working fluid is evaporated into a gas phase at the Heat absorption end of the vacuum cavity and releases Latent Heat (Latent Heat). At this time, local pressure variation is generated in the vacuum cavity, and the working fluid in the gas phase is driven to flow to the condensation end at a high speed. Then, the gaseous phase working fluid is condensed into liquid phase working fluid at the condensation end. The liquid phase working fluid flows back to the heat absorption end by the capillary structure in the vacuum cavity through capillary action, and circulates and acts according to the capillary structure. Accordingly, the heat conduction effect of the ultrathin heat tube plate or the uniform temperature plate is determined by the physical structure, the hydrophilicity, the capillary force of the capillary structure, the air channel space in the uniform temperature plate element, the vacuum degree and other parameters of the capillary structure. However, when the thickness of the device is ultra-thin, the composition and thickness of the capillary structure and the arrangement of the air channel space are more difficult to control in mass production, which results in low yield and low production cost.
In the prior art, a method for manufacturing an ultrathin uniform temperature plate capillary structure with a thickness of 0.4mm or less is to use a manual tool to place a copper mesh or a weaving line conforming to the design shape of a uniform temperature plate element in a groove on an etched copper substrate, and then press-fit the copper mesh or the weaving line with a graphite tool and sinter the copper mesh or the weaving line at a high temperature to form the ultrathin uniform temperature plate capillary structure. The method for producing the capillary structure of the ultrathin heat tube plate or the uniform temperature plate in a mass mode consumes manpower, time and energy in sintering, and meanwhile, the thickness of the capillary structure and the air channel space in the element are difficult to control accurately, so that the production yield of products is low. Especially when the thickness of the element is 0.3mm or less, it is more difficult to manufacture and mass-produce the ultra-thin heat pipe plate or the vapor chamber plate by the conventional method. Therefore, how to manufacture a high-quality capillary structure and effectively control the thickness of the capillary structure and the air passage space when the thickness of the ultra-thin heat tube plate or the temperature-equalizing plate element is 0.4mm, 0.3mm or less is a problem which is greatly solved in the industry at present.
Disclosure of Invention
In view of the above, the present invention provides a Metal Paste (Metal Paste) for manufacturing a porous capillary structure in a Heat Pipe Plate (Heat Pipe Plate) or a Vapor Chamber Plate (Vapor Chamber), and particularly for manufacturing a capillary structure in an ultra-thin Heat Pipe Plate or Vapor Chamber Plate (Vapor Chamber) with an element thickness of only 0.4mm, even 0.3mm or less. By using the rheological property of the metal paste, the metal paste can be easily spread in the trench of the etched metal substrate of the isothermal plate device by using the automated manufacturing process. Then, by using different sintering characteristics of the two metal powder systems, the metal paste and the carrier substrate can be subjected to heating (baking) and sintering (sintering) processes to form a porous metal capillary structure with a certain thickness in the groove of the substrate.
In order to achieve the above object, the present invention discloses a metal paste for manufacturing a capillary structure in a vapor chamber, which is applied to manufacture the capillary structure in the vapor chamber, and forms the capillary structure after heating, baking and sintering processes, and is characterized by comprising:
a first metal powder having a spheroidal structure;
a second metal powder having a spheroidal structure, wherein the ratio of the average particle size of the first metal powder to the average particle size of the second metal powder is greater than 3;
an organic solvent, which is volatilized after being heated; and
a polymer which is burnt off after baking;
the organic solvent and the polymer are mixed to form a colloid which is used for dispersing, suspending and uniformly mixing the first metal powder and the second metal powder to form the metal slurry.
The metal slurry has rheological property, and is laid in a groove of a metal substrate for manufacturing the uniform temperature plate in a mode of being applied to steel plate printing, screen printing or dispensing.
Wherein, the grain diameter of the first metal powder is less than 53um, and the grain diameter of the second metal powder is less than 13 um.
Wherein, the first metal powder and the second metal powder are made of copper or copper alloy.
Wherein, the surface of the second metal powder is provided with a silver coating.
Also discloses a metal slurry for manufacturing a capillary structure in a uniform temperature plate, which is applied to the manufacture of a porous capillary structure in the uniform temperature plate, and forms the capillary structure after the heating, baking and sintering processes, and is characterized by comprising the following components:
a third metal powder having a spheroidal structure;
a fourth metal powder having a sheet-like structure;
an organic solvent, which is volatilized after being heated; and
a polymer, burned off after baking;
wherein, the organic solvent and the polymer are mixed to form a colloid for dispersing, suspending and uniformly mixing the third metal powder and the fourth metal powder to form the metal slurry.
The metal slurry has rheological property, and is laid in a groove of a metal substrate for manufacturing the uniform temperature plate in a mode of being applied to steel plate printing, screen printing or dispensing.
Wherein, the grain diameter of the third metal powder is less than 53um, and the average thickness of the sheet shape of the fourth metal powder is less than 1 um.
Wherein, the third metal powder and the fourth metal powder are made of copper or copper alloy.
Wherein, the surface of the fourth metal powder is provided with a silver coating.
For the metal paste of the present invention, the first metal powder and the second metal powder after mixing are texture materials constituting the capillary structure, and the polymer and the organic solvent are removed during the formation of the capillary structure by the metal paste. The colloid formed by mixing the polymer and the organic solvent is only used for dispersing, suspending and uniformly mixing the first metal powder and the second metal powder to form the metal slurry. The colloid may also be a multi-component system, and other minor additives, such as a dispersant, a surfactant, etc., may be added to adjust the characteristics of the metal paste, particularly the rheology of the metal paste.
In another embodiment of the present invention, the metal paste includes a third metal powder, a fourth metal powder, an organic solvent and a polymer, wherein the metal paste is the same as the foregoing embodiment except that the third metal powder and the fourth metal powder are different from the foregoing embodiment, and further description thereof will not be repeated.
The metal slurry is used for manufacturing a porous capillary structure in an ultrathin heat pipe plate or a temperature-equalizing plate, and the two kinds of metal powder used as fillers have different functions in the sintering process. The first metal powder and the third metal powder mainly play a role of a main body for constructing a porous capillary structure, and the second metal powder and the fourth metal powder mainly play a role of bonding and bridging between the first metal powder and the third metal powder. The first metal powder and the second metal powder are metal powders of the same material and similar shapes, but have a great difference in particle size of the powders. Besides different particle sizes, metal powders of the same material but different shapes can be used to achieve the same purpose, such as the third metal powder and the fourth metal powder of the present invention.
The metal slurry of the invention utilizes the difference of the surface energy of the powder particles between two powders which are made of the same material and have different particle shapes or the same material and different particle sizes to cause the two powders to have different sintering characteristics under the same sintering condition so as to form a porous capillary structure.
The metal slurry of the present invention utilizes the difference of the powder particle sizes of the two metal powder systems, especially the metal powder systems, or the difference of the powder particle shapes to cause the two metal powder systems to have different sintering effects during the sintering process. The Surface energy (Surface energy) of the small particle size powder is larger than that of the large particle size powder, and the Surface energy (Surface energy) of the flake-like powder is larger than that of the spheroidal powder. Under the same proper temperature, different sintering effects can cause the phenomenon that small-particle-size powder is not subjected to Liquid-phase sintering (Liquid-phase sintering) or partial Liquid-phase sintering, and large-particle-size powder is subjected to partial solid-phase sintering; or the flake powder is not partially liquid phase sintered, and the spheroidal powder is partially solid phase sintered. In the sintering effect, the powder with small particle size or the flake-shaped powder can randomly diffuse and flow in the mixed powder system, so that the mutual bonding of the powder particles in the powder system is facilitated, a porous capillary structure is generated after the temperature is cooled, and the bonding of the capillary structure and the surface of the groove of the metal base plate is facilitated.
In one embodiment, the first metal powder and the second metal powder comprise copper (Cu) or a Cu Alloy (Cu Alloy). The first metal powder is a powder having a spheroidal structure, and the second metal powder is also a powder having a spheroidal structure. Average particle diameter (D) of first metal powder 50 ) With the average particle diameter (D) of the second metal powder 50 ) Is greater than 3. When the metal slurry is in a sintering process at a certain temperature, part of the first metal powder is subjected to solid-phase sintering, and simultaneously the second metal powder or part of the second metal powder generates liquid-phase sintering to diffuse and flow in a viscous mode so as to be adhered between the first metal powder, and a porous capillary structure is formed after cooling and is also adhered to the surface of the groove of the metal substrate.
In another embodiment, the third metal powder and the fourth metal powder comprise copper (Cu) or a Cu Alloy (Cu Alloy). The third metal powder is spheroidal powder, the fourth metal powder is ultrathin flaky powder, and the flaky average thickness of the powder of the fourth metal powder is less than 1um and the average diameter-thickness ratio is more than 30. When the metal slurry is in a sintering process at a certain temperature, the third metal powder is partially sintered in a solid phase, and simultaneously the fourth metal powder or part of the fourth metal powder is diffused and flows in a viscous manner due to the liquid phase sintering, so that the fourth metal powder or part of the fourth metal powder is adhered among the first metal powder in a net breaking manner, a porous capillary structure is formed after the fourth metal powder or part of the fourth metal powder is cooled, and the capillary structure is also adhered to the surface of the groove of the metal substrate.
In one embodiment, the polymer may be a Natural Resin (Natural Resin) or a Synthetic Resin (Synthetic Resin), and the organic solvent may be an alcohol solvent. The polymers are dissolved in an organic solvent to form a colloid that can be removed from the metal paste during heating and baking.
In one embodiment, the first metal powder has a particle size of less than 53um (270mesh) because the capillary structure is formed by subtracting the thickness of the upper and lower metal substrates from the thickness of the space in the thin Heat Pipe Plate (Heat Pipe Plate) or the temperature equalization Plate with a thickness of 0.4mm by at most about 0.25mm (250um), and then subtracting the thickness of the reserved air channel by about 0.15mm (150 um). In other words, at least 3 metal powders are bonded and stacked to form a capillary structure with holes. In this embodiment, the particle size of the second metal powder is smaller than 13um (1000mesh), and the average particle size (D) of the first metal powder and the second metal powder 50 ) Is greater than 3 to create a sufficient difference in powder surface energy.
In one embodiment of the metal paste of the present invention, the third metal powder has a spheroidal structure, and the particle size of the third metal powder is less than 53um (270 mesh). The fourth metal powder was a super-lamellar structure with an average aspect ratio of 30 greater. In detail, if the fourth metal powder is a flake powder with a diameter less than 30um, the thickness is less than 1um, or only several hundred nanometers (nm). The structure of the fourth metal powder is broken by partial liquid phase sintering to form a broken net shape, and further bonded between the spherical third metal powders.
In one embodiment, the surfaces of the second metal powder and the fourth metal powder have a silver (Ag) coating, and the thickness of the Ag coating is less than 100 nm. Plating silver on the surface of the metal powder can reduce the temperature for generating liquid phase sintering, thereby reducing the sintering temperature of the whole metal slurry. Since silver (Ag) itself has a lower melting point than copper (Cu), it is easily alloyed with copper. Therefore, when the silver coating layer is subjected to liquid phase sintering, diffusion and viscous flow are accelerated, and the porous capillary structure is formed by bonding other metal powder and the groove surface of the metal substrate.
In one embodiment, the added weight of the first metal powder is greater than the added weight of the second metal powder.
In one embodiment, the metal paste formed by mixing the first metal powder and the second metal powder or the third metal powder and the fourth metal powder has rheological property (rheology) and is applied to the inner side grooves of the metal substrate with upper and lower seals for manufacturing the temperature-uniforming plate by steel Printing (Stencil Printing) or Screen Printing (Screen Printing) or dispensing (Dispense).
In summary, the metal paste of the present invention is used for fabricating a capillary structure in a vapor chamber. The metal slurry is formed by mixing a polymer and an organic solvent into a colloid, and mixing two metal powders with different shapes or different particle sizes to uniformly disperse the two metal powders and suspend the two metal powders in the colloid. The metal slurry can be heated and baked to remove the organic solvent and the polymer from the metal slurry, and then sintered to bond and support the two metal powders to each other to form a porous capillary structure. The metal paste can be used for quickly manufacturing a thin capillary structure with high porosity and high uniformity, and the mass production capacity and the excellent rate of manufacturing the capillary structure by using an ultrathin heat tube plate or a temperature-equalizing plate are improved.
Drawings
FIG. 1: a schematic illustration of mixing a metal paste according to an embodiment of the invention is shown.
FIG. 2: a schematic composition diagram of the metal paste according to fig. 1 is shown.
FIG. 3: a flow chart of forming a capillary structure of a metal paste according to an embodiment of the invention is shown.
FIG. 4 a: a schematic diagram of a capillary structure with a low content of the second metal powder is shown according to an embodiment of the invention.
FIG. 4 b: a schematic diagram of a capillary structure with a higher content of the second metal powder according to an embodiment of the invention is shown.
FIG. 5: a roundness definition of the first metal powder or the second metal powder according to an embodiment of the invention is shown.
FIG. 6: a schematic structural diagram of the second metal powder according to an embodiment of the invention is shown.
FIG. 7 is a schematic view of: a flow chart of the steps of applying the metal paste according to fig. 1 to form a capillary structure is shown.
FIG. 8: the composition of the metal paste according to another embodiment of the invention is shown schematically.
FIG. 9: a schematic structural diagram of a fourth metal powder according to another embodiment of the invention is shown.
FIG. 10 a: there is shown a side view of a third metal powder and a fourth metal powder of a metal paste sintered to form a capillary structure according to another embodiment of the present invention.
FIG. 10 b: there is shown a top view of a third metal powder and a fourth metal powder of a metal paste sintered to form a capillary structure according to another embodiment of the present invention.
Detailed Description
In order that the advantages, spirit and features of the invention will be readily understood and appreciated, embodiments thereof will be described in detail hereinafter with reference to the accompanying drawings. It is to be understood that these embodiments are merely representative of the present invention, and that the specific methods, devices, conditions, materials, etc., described herein are not intended to limit the present invention or the corresponding embodiments. Also, the devices shown in the drawings are merely for relative positional representation and are not drawn to scale as they are actually drawn.
Referring to fig. 1 and 2, fig. 1 is a schematic view illustrating mixing of a metal paste P according to an embodiment of the present invention, and fig. 2 is a schematic view illustrating a composition of the metal paste P according to fig. 1. As shown in fig. 1 and fig. 2, in one embodiment, the metal paste P of the present invention is applied to manufacture the capillary structure 6 in a thin Heat Pipe Plate (Heat Pipe Plate) or a Vapor Chamber (Vapor Chamber). The mixture of the organic solvent 3 and the polymer 4 forms a colloid 5, which can be used to disperse and suspend the first metal powder 1 (indicated by oblique lines) and the second metal powder 2 (indicated by blank lines) and uniformly mix them to form the metal paste P. The metal paste P may be subjected to a heating process, a baking process, and a sintering process to form the capillary structure 6. As shown in fig. 2, the first metal powder 1 has a spheroidal structure, and the particle diameter of the powder is less than 53um (270 mesh). The second metal powder 2 is also of a spheroidal structure, the particle size of the powder particles of which is less than 13um (1000 mesh). Sieving with different mesh sieves to obtain the first metal powderThe particle size of the powder is different from the particle size of the second metal powder. In one embodiment, the average particle size (D) of the first metal powder 50 ) And the average particle diameter (D) of the second metal powder 50 ) Is greater than 3. In a preferred embodiment, the average particle size (D) of the first metal powder 50 ) And the average particle diameter (D) of the second metal powder 50 ) Is greater than 5. In a more preferred embodiment, the average particle diameter (D) of the first metal powder 50 ) And the average particle diameter (D) of the second metal powder 50 ) Is greater than 10.
Referring to fig. 3, fig. 3 is a flow chart illustrating a process of forming the capillary structure 6 of the metal paste P according to an embodiment of the invention. The organic solvent 3 in the metal paste P of the present invention is volatilized after the heating process, and the polymer 4 is burned off by the baking process. In other words, as shown in fig. 3, when the metal paste P of the present invention is used to fabricate the capillary structure 6, the organic solvent 3 and the polymer 4 may be removed from the metal paste P by a heating (heating) process and a baking (baking) process. Then, the sintering process is further heated to sinter the first metal powder 1 (shown by oblique lines) and the second metal powder 2 (shown by blank lines) into a porous capillary structure 6.
Referring to fig. 4a and 4b, fig. 4a is a schematic diagram illustrating a capillary structure with a low content of the second metal powder according to an embodiment of the invention, and fig. 4b is a schematic diagram illustrating a capillary structure with a high content of the second metal powder according to an embodiment of the invention. In one embodiment, the added weight of the first metal powder 1 in the metal paste P is greater than the added weight of the second metal powder 2. This is because the main pores in the capillary structure 6 are gaps formed between the first metal powders 1 when the first metal powders 1 are stacked. As shown in fig. 3 and 4a, when the weight of the first metal powder 1 with larger particle size is larger, the capillary structure 6 formed after sintering the metal paste P has more pores. On the contrary, as shown in fig. 3 and 4b, if the weight of the second metal powder 2 with smaller particle size is larger, the gap between the first metal powder 1 is filled, and the pores are reduced, so that the metal paste P cannot form the capillary structure 6 with more pores.
Referring to fig. 5, fig. 5 illustrates the roundness definition of the first metal powder 1 or the second metal powder 2 according to an embodiment of the invention. As illustrated in fig. 5, the spheroidal shape of the first metal powder 1 (oblique line) of the present invention may be such that the ratio of the radius of the maximum inscribed circle (dotted line) to the radius of the minimum circumscribed circle (solid line) is 0.6 or more. It should be noted that the roundness of the second metal powder 2 can also be defined in the above manner.
Referring to fig. 6, fig. 6 is a schematic structural diagram of the second metal powder 2 according to an embodiment of the invention. As shown in FIG. 6, the second metal powder 2 of the present invention has a silver coating 7 on the surface thereof, and the thickness of the silver coating 7 is less than 100 nm. Since the melting point of silver is lower than that of copper, the purpose of the surface silver plating is to lower the liquid phase sintering temperature of the powder or to increase the diffusion and viscous flow of the powder, facilitating the bonding between the first metal powder 1 particles and the formation of the porous capillary structure 6. In another embodiment, the first metal powder 1 and the second metal powder 2 are made of one of copper, copper alloy, nickel, titanium and silver.
In practical applications, the vapor chamber is fabricated by welding, sealing and processing an upper copper (Cu) sheet and a lower copper (Cu) sheet or a Cu Alloy (Cu Alloy) sheet.
Referring to fig. 1, 3 and 7, fig. 7 is a flow chart illustrating a step of forming the capillary structure 6 by using the metal paste P of fig. 1. The metal paste P of the present invention is applied to steel plate Printing (steel Printing), Screen Printing (Screen Printing) or dispensing (dispensing) and is laid in the inner side groove 801 of the metal substrate 80 sealed up and down for manufacturing the uniform temperature plate, and the metal paste P is heated, baked and sintered, thereby forming the capillary structure 6 on the substrate 80. As shown in fig. 1, 3 and 7, the example of the steel plate printing is taken. First, as shown in fig. 1, a first metal powder 1, a second metal powder 2, an organic solvent 3, and a polymer 4 are uniformly mixed into a metal paste P. Next, referring to fig. 7, a metal paste P is deposited in the grooves 801 of the substrate 80 of the flat micro thermal conduit or the vapor chamber by means of stencil printing. In this embodiment, first, a plurality of holes corresponding to the grooves 801 of the capillary structure 6 in the substrate 80 of the heat pipe or the vapor chamber are formed in the steel plate 81, and the steel plate 81 is placed on the metal substrate 80. Next, the metal paste P is laid in the grooves 801 of the metal substrate 80 of the heat pipe or the vapor chamber by printing using the doctor blade 82. At this time, the metal paste P is spread in the groove 801 of the metal substrate 80 through the hole of the steel plate 81. After the placement, the metal substrate 80 containing the metal paste P is baked by heating. Referring to fig. 3, firstly, during the heating, baking and sintering processes, the organic solvent 3 is volatilized during the heating process due to its low boiling point, and the polymer 4 is also burned off during the baking process at a higher temperature, and finally, only the first metal powder 1 and the second metal powder 2 stacked on each other are left. Then, when the temperature is raised to the sintering process, part of the first metal powder 1 is solid phase sintered and part of the second metal powder 2 is liquid phase sintered to randomly diffuse and viscously flow in the mixed powder system, causing them to bond to each other between the first metal powder and creating a porous capillary structure 6 after the temperature is cooled. Here, it can be understood that, when the organic solvent 3 and the polymer 4 in the metal paste P are removed, the volume of the original metal paste P is reduced, and the volume reduction ratio can be adjusted by the solid content of the metal paste P.
Referring to fig. 8, fig. 8 is a schematic view illustrating a composition of a metal paste P according to another embodiment of the present invention. The metal paste P includes a third metal powder 90 (shown by oblique lines), a fourth metal powder 91 (shown by blank lines), and a colloid 5, wherein the colloid 5 is formed by mixing an organic solvent 3 and a polymer 4. The colloid 5 may be used to disperse and suspend the third metal powder 90 and the fourth metal powder 91 and to uniformly mix to form the metal paste P.
Referring to fig. 9, fig. 9 is a schematic structural diagram of a fourth metal powder according to another embodiment of the invention. The metal paste P is the same as the above except that the third metal powder 90 and the fourth metal powder 91 are different from those in the above embodiments, and will not be described again. As shown in fig. 9, the surface of the fourth metal powder 91 may also have a silver plating layer 7 as the second metal powder 2, and the purpose and function of the silver plating layer 7 are also the same as those of the second metal powder 2 and will not be described herein. The third metal powder 90 and the fourth metal powder 91 are made of one of copper, copper alloy, nickel, titanium, and silver.
In another embodiment, the material of the metal substrate 80 with etched grooves of the thin Heat Pipe plate (Heat Pipe plate) or the Vapor Chamber plate (Vapor Chamber) comprises copper or a copper alloy containing trace amounts of phosphorus (P) and tin (Sn). In the metal paste P, the third metal powder 1 is a spheroidal copper (Cu) powder, and the particle size distribution thereof may be selected from 1.3um to 53 um. As shown in fig. 9, the fourth metal powder 91 is a spherical copper (Cu) powder having a silver (Ag) plated layer on the surface, the irregular flake copper powder has a thickness 911 of a nanometer scale of several hundred nanometers (nm), an average diameter 910 of a micrometer scale of several tens of micrometers (um), and a ratio of diameter to thickness of more than 30.
Referring to fig. 9, 10a and 10b, fig. 10a is a side view illustrating a capillary structure 6 formed by sintering a third metal powder 90 and a fourth metal powder 91 of a metal paste P according to another embodiment of the present invention, and fig. 10b is a top view illustrating a capillary structure 6 formed by sintering a third metal powder 90 and a fourth metal powder 91 of a metal paste P according to another embodiment of the present invention. The third metal powder 90 is a spheroidal structure having a particle size of less than 53um (270 mesh). The fourth metal powder 91 is a super-thin sheet-like structure having an average aspect ratio of 30 or more. In detail, if the fourth metal powder 91 is a flake powder with a diameter 910 less than 30um, the thickness 911 is less than 1um, or only several hundred nanometers (nm). As shown in fig. 10a and 10b, the structure of the fourth metal powder 91 is broken by partial liquid phase sintering to form a broken network, and is further bonded between the spherical third metal powders 90.
The particle size, as described herein, can be controlled generally by a screen. For example, powder particles having a particle size distribution of 25um to 48um can be obtained by sieving with a 500mesh sieve and a 300mesh sieve together. Average particle diameter (D) of the sieved powder particles 50 ) It can be calculated by the conventional methods such as sedimentation, laser, screening, imaging and resistance methods.
In summary, the metal paste P of the present invention is used for manufacturing the capillary structure 6 in the vapor chamber. The organic solvent 3 and the polymer 4 are mixed to form a colloid 5, and the colloid 5 is used to mix two kinds of metal powder with different particle sizes or spheroidal metal powder and flake metal powder with different shapes, so that the first metal powder 1 and the second metal powder 2 or the third metal powder 90 and the fourth metal powder 91 are uniformly dispersed in the colloid 5 to form the metal slurry P. The first metal powder 1, the third metal powder 90, and the fourth metal powder 91 are made of copper (Cu) or a copper Alloy (Cu Alloy). The organic solvent 3 is volatilized after heating and the polymer 4 is burned off after baking, and a sintering process is performed to bond the first metal powder 1 and the second metal powder 2 or the third metal powder 90 and the fourth metal powder 91 to each other. The metal slurry P of the invention is heated to form the capillary structure 6 with stable structure, high porosity and uniform distribution by the spheroidal metal powder and the flaky metal powder with different grain diameters or two shapes of the two metal powders. Therefore, the present invention can be used to fabricate the capillary structure 6 with high porosity and high uniformity, and the mass production capability and yield of fabricating the capillary structure 6 can be improved.
The above detailed description of the preferred embodiments is intended to more clearly illustrate the features and spirit of the present invention, and is not intended to limit the scope of the present invention by the preferred embodiments disclosed above. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the scope of the claims. The scope of the claims is thus to be accorded the broadest interpretation so as to encompass all such modifications and equivalent arrangements as is within the scope of the appended claims.
Claims (6)
1. A metal paste for manufacturing a capillary structure in a vapor chamber is applied to manufacturing the capillary structure in the vapor chamber, and forms the capillary structure after heating, baking and sintering processes, and is characterized by comprising the following components:
a first metal powder with a globular structure and made of copper or copper alloy, wherein the particle size of the first metal powder is less than 53 um;
the second metal powder is of a sphere-like structure and is made of copper or copper alloy, the particle size of the second metal powder is smaller than 13um, and the ratio of the average particle size of the first metal powder to the average particle size of the second metal powder is larger than 3;
an organic solvent, which is volatilized after being heated; and
a polymer which is burnt off after baking;
the organic solvent and the polymer are mixed to form a colloid which is used for dispersing, suspending and uniformly mixing the first metal powder and the second metal powder to form the metal slurry.
2. The metal paste according to claim 1, wherein the metal paste has rheological properties and is applied to the grooves of a metal substrate for fabricating the isothermal plate by using a stencil printing method, a screen printing method or a dispensing method.
3. The metal paste according to claim 1 wherein the surface of the second metal powder has a silver coating.
4. A metal slurry for manufacturing a capillary structure in a uniform temperature plate is applied to manufacturing a porous capillary structure in the uniform temperature plate, and forms the capillary structure after heating, baking and sintering processes, and is characterized by comprising the following components in percentage by weight:
a third metal powder with a sphere-like structure, wherein the material of the third metal powder is copper or copper alloy, and the particle size of the third metal powder is less than 53 um;
the fourth metal powder is of a sheet-shaped structure and is made of copper or copper alloy, the average sheet thickness of the fourth metal powder is less than 1um, and the average diameter-thickness ratio is more than 30;
an organic solvent, which is volatilized after being heated; and
a polymer which is burnt off after baking;
wherein, the organic solvent and the polymer are mixed to form a colloid for dispersing, suspending and uniformly mixing the third metal powder and the fourth metal powder to form the metal slurry.
5. The metal paste according to claim 4, wherein the metal paste has rheological properties and is applied to the grooves of a metal substrate for fabricating the isothermal plate by using a stencil printing method, a screen printing method or a dispensing method.
6. The metal paste according to claim 4, wherein the surface of the fourth metal powder has a silver plating layer.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910255845.8A CN111761049B (en) | 2019-04-01 | 2019-04-01 | Metal paste for manufacturing capillary structure in uniform temperature plate |
| TW109108955A TWI784248B (en) | 2019-04-01 | 2020-03-18 | A metal paste for making wick structure of vapor chamber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910255845.8A CN111761049B (en) | 2019-04-01 | 2019-04-01 | Metal paste for manufacturing capillary structure in uniform temperature plate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111761049A CN111761049A (en) | 2020-10-13 |
| CN111761049B true CN111761049B (en) | 2022-08-05 |
Family
ID=72718861
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910255845.8A Active CN111761049B (en) | 2019-04-01 | 2019-04-01 | Metal paste for manufacturing capillary structure in uniform temperature plate |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN111761049B (en) |
| TW (1) | TWI784248B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI798604B (en) * | 2020-12-01 | 2023-04-11 | 奇鋐科技股份有限公司 | Thin-type two-phase fluid device |
| CN114659396B (en) * | 2020-12-23 | 2023-12-19 | 广州力及热管理科技有限公司 | Patterned capillary structure element and manufacturing method thereof |
| US11732974B2 (en) | 2021-01-06 | 2023-08-22 | Asia Vital Components Co., Ltd. | Thin-type two-phase fluid device |
| JPWO2022196653A1 (en) * | 2021-03-17 | 2022-09-22 | ||
| CN113388753B (en) * | 2021-06-22 | 2022-01-04 | 沈伟 | Alloy with capillary structure and preparation method thereof |
| CN114131016A (en) * | 2021-12-01 | 2022-03-04 | 联德电子科技(常熟)有限公司 | Method for processing coreless rod sintered heat pipe |
| CN115533105A (en) * | 2022-08-30 | 2022-12-30 | 中国石油化工股份有限公司 | Low-temperature sintered surface porous heat exchange tube and preparation method thereof |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3840069A (en) * | 1971-04-27 | 1974-10-08 | Bbc Brown Boveri & Cie | Heat pipe with a sintered capillary structure |
| CN1435669A (en) * | 2002-01-30 | 2003-08-13 | 三星电机株式会社 | Heat pipe and mfg. method thereof |
| CN1920467A (en) * | 2005-08-26 | 2007-02-28 | 富准精密工业(深圳)有限公司 | Method for manufacturing sintered heat pipe |
| CN1932426A (en) * | 2005-09-16 | 2007-03-21 | 富准精密工业(深圳)有限公司 | Heat tube and powder and method for sintering forming the same heat tube capillary structure |
| CN101787178A (en) * | 2010-03-09 | 2010-07-28 | 王全胜 | Heat-conduction electric insulation composite material component and manufacturing method thereof |
| CN101839663A (en) * | 2010-05-12 | 2010-09-22 | 锘威科技(深圳)有限公司 | Sintered flat plate heat pipe and manufacturing method thereof |
| CN107201216A (en) * | 2017-05-11 | 2017-09-26 | 天津莱尔德电子材料有限公司 | Controllable heat-conducting interface material of a kind of viscosity and preparation method and application |
| CN107462097A (en) * | 2017-09-22 | 2017-12-12 | 安徽工业大学 | A kind of variable aperture capillary wick and its processing method applied to loop circuit heat pipe system |
| KR20180047524A (en) * | 2016-10-31 | 2018-05-10 | 한국생산기술연구원 | Heat pipe and it's wick containing Metal-Carbon composite material |
| CN108871024A (en) * | 2017-05-12 | 2018-11-23 | 双鸿科技股份有限公司 | Heat exchange combined structure |
| CN109312989A (en) * | 2016-05-30 | 2019-02-05 | 株式会社村田制作所 | The manufacturing method of heat conducting pipe |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6994152B2 (en) * | 2003-06-26 | 2006-02-07 | Thermal Corp. | Brazed wick for a heat transfer device |
-
2019
- 2019-04-01 CN CN201910255845.8A patent/CN111761049B/en active Active
-
2020
- 2020-03-18 TW TW109108955A patent/TWI784248B/en active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3840069A (en) * | 1971-04-27 | 1974-10-08 | Bbc Brown Boveri & Cie | Heat pipe with a sintered capillary structure |
| CN1435669A (en) * | 2002-01-30 | 2003-08-13 | 三星电机株式会社 | Heat pipe and mfg. method thereof |
| CN1920467A (en) * | 2005-08-26 | 2007-02-28 | 富准精密工业(深圳)有限公司 | Method for manufacturing sintered heat pipe |
| CN1932426A (en) * | 2005-09-16 | 2007-03-21 | 富准精密工业(深圳)有限公司 | Heat tube and powder and method for sintering forming the same heat tube capillary structure |
| CN101787178A (en) * | 2010-03-09 | 2010-07-28 | 王全胜 | Heat-conduction electric insulation composite material component and manufacturing method thereof |
| CN101839663A (en) * | 2010-05-12 | 2010-09-22 | 锘威科技(深圳)有限公司 | Sintered flat plate heat pipe and manufacturing method thereof |
| CN109312989A (en) * | 2016-05-30 | 2019-02-05 | 株式会社村田制作所 | The manufacturing method of heat conducting pipe |
| KR20180047524A (en) * | 2016-10-31 | 2018-05-10 | 한국생산기술연구원 | Heat pipe and it's wick containing Metal-Carbon composite material |
| CN107201216A (en) * | 2017-05-11 | 2017-09-26 | 天津莱尔德电子材料有限公司 | Controllable heat-conducting interface material of a kind of viscosity and preparation method and application |
| CN108871024A (en) * | 2017-05-12 | 2018-11-23 | 双鸿科技股份有限公司 | Heat exchange combined structure |
| CN107462097A (en) * | 2017-09-22 | 2017-12-12 | 安徽工业大学 | A kind of variable aperture capillary wick and its processing method applied to loop circuit heat pipe system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111761049A (en) | 2020-10-13 |
| TW202037682A (en) | 2020-10-16 |
| TWI784248B (en) | 2022-11-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111761049B (en) | Metal paste for manufacturing capillary structure in uniform temperature plate | |
| CN111761050B (en) | Method for manufacturing capillary structure by using metal slurry | |
| Schneider et al. | Highly conductive, printable pastes from capillary suspensions | |
| CN109979904B (en) | Multi-size nano-particle mixed metal film and preparation method thereof | |
| TWI750769B (en) | A chain-like copper metal wick structure and manufacturing method thereof | |
| CN111822712B (en) | Method for manufacturing thin type temperature-equalizing plate | |
| DE112015006583T5 (en) | Conductive adhesive structure of the solid-state crystal of the LED flip-chip and its mounting method | |
| CN111128435A (en) | Electronic paste for mixing two kinds of metal powder with different melting points | |
| CN112444151B (en) | Metal oxide slurry for manufacturing capillary structure of uniform temperature plate element | |
| CN112304135B (en) | Capillary structure element of temperature equalizing plate and manufacturing method thereof | |
| CN109979905B (en) | Nano metal film prefabricated module and preparation method thereof | |
| CN111112600B (en) | Composite powder and preparation method thereof | |
| CN113976886A (en) | Porous structure, temperature-uniforming plate, manufacturing method and application thereof | |
| CN114071938A (en) | Capillary structure, temperature-uniforming plate, manufacturing method and application thereof | |
| KR20080055013A (en) | Anisotropic conductive film and manufacturing method of anisotropic conductive film | |
| TW202006308A (en) | A method of fabricating capillary wick structure | |
| CN112708400A (en) | Thermal interface material and manufacturing method thereof | |
| TW202101686A (en) | A ceramic circuit board with thick copper structure and manufacturing method thereof | |
| TW202018015A (en) | Electronic paste with two metal powder mixing together with different melting points | |
| CN114659396B (en) | Patterned capillary structure element and manufacturing method thereof | |
| Li et al. | Experimental study on drop penetration and wetting characteristics of sintered copper powders with nanostructures | |
| KR20210033807A (en) | Radiation sheet and radiation system including the same | |
| CN215373655U (en) | Flat light capillary structure for vapor chamber | |
| CN115468445A (en) | Ultra-thin temperature equalization plate element structure and manufacturing method thereof | |
| KR102507930B1 (en) | Heat Dissipation sheet having electromagnetic wave shield function using optical sintering metal coating and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |