KR101977125B1 - method for fabricating PCB using carbon-based materal for LED lighting - Google Patents

Abstract

The present invention relates to a method for manufacturing a carbon-based printed circuit board for an LED lighting device, which directly radiates heat to the outside using a carbon material having excellent thermal conductivity and heat radiation, and applies the same to a lighting device to reduce the weight thereof and to be slim. The method of the present invention comprises the steps of: homogenizing carbon fillers including a graphite material, carbon nanotubes, and graphene by crushing and surface-treating the same, separately; drying, mixing, and stirring the homogenized carbon fillers; dispersing and freeze-drying the mixed and stirred carbon fillers; crushing the dried carbon fillers to form a carbon nano-composite powder; mixing an organic solvent of a surfactant, a dispersant, and a reducing agent with the carbon nano-composite powder, and dispersing the same with ultrasonic waves; stirring and drying the ultrasonic-dispersed carbon nano-composite powder; dissolving a polymer material in a solvent to mix the same; mixing the stirred and dried carbon nano-composite powder with the mixed polymer material to disperse the same; drying and crushing the dispersed carbon nano-composite powder and the polymer material to form a raw material of a compound or pellet type; and extruding, molding, and processing the raw material manufactured in the compound or pallet type to form a heat radiation plate which is a base of a printed circuit board.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon-based printed circuit board (PCB)

The present invention relates to an LED lighting apparatus, and more particularly, to a method of manufacturing a carbon-based printed circuit board for an LED lighting apparatus having excellent heat radiation effect.

2. Description of the Related Art Various electronic components such as an integrated circuit (IC), a transistor (TR), and a light emitting diode (LED) are mounted on a printed circuit board.

Recently, in the field of electric and electronic technology, electronic components are designed in consideration of high efficiency, high integration, high performance, light weight and short life, and the requirements of the printed circuit board are also closely related to high speed and high density in the electronic industry .

In order to meet such requirements in the printed circuit board, it is necessary to solve various problems such as fine circuitization, improvement of electrical characteristics, high reliability, and high functionality.

In accordance with design trends in the electronics industry, electronic components mounted on a printed circuit board generate a lot of heat, and a method of effectively emitting generated heat is further required.

Particularly, if the heat generated from the printed circuit board on which the heat generating element is mounted is not effectively discharged, the temperature of the printed circuit board is increased to cause malfunction and inoperability of the mounted heat emitting element, .

For example, optical devices such as LEDs emit a lot of heat in particular, and the generated heat may have a large influence on the image quality of the screen. As the resolution increases and the screen size increases, the effect of heat becomes larger, and studies are continuing to effectively solve heat-related problems such as heat dissipation, thermal diffusion, heat dissipation, and heat transfer.

In addition, the major advantage of the LED device is that it is a low power device due to high efficiency. Therefore, characteristics such as reduction of electric energy and prolongation of service life can be said to be a technical part different from conventional general lighting.

In recent years, there is an increasing interest in utilizing LEDs in the field of lighting, and this is a structure in which a plurality of LEDs are properly connected in series or in parallel.

For example, a plurality of LED elements are arranged on a top surface of a printed circuit board (PCB) on which electrode patterns are formed, and the arranged LED elements are connected in series or in parallel with the electrode patterns, do.

However, a disadvantage of such an LED lighting device is the deterioration of characteristics and the failure due to thermal stress. That is, the higher the power input to operate the LED, the more heat is generated, so that the failure and the characteristic deterioration occur.

Accordingly, the conventional printed circuit board for LED lighting is intended to solve thermal stress caused by LED light emission by mounting a heat sink such as a heat sink or slug using a metal material having excellent thermal conductivity. However, The thickness of the heat sink is increased to satisfy the required heat dissipation efficiency due to the limitation of the size of the LED lighting device.

(Patent Document 1) Patent Registration No. 10-1294943

(Patent Document 2) Patent Registration No. 10-1210419

DISCLOSURE OF THE INVENTION It is an object of the present invention to solve the above-described problems and to provide a lighting device capable of emitting light directly to the outside using a carbon material having excellent thermal conductivity and heat dissipation, And a method for manufacturing a carbon-based printed circuit board for a lighting device.

According to another aspect of the present invention, there is provided a method of manufacturing a carbon-based printed circuit board, comprising: homogenizing a graphite sheet, carbon nanotube, and graphene by crushing and surface treatment; Drying and homogenizing the homogenized graphite, carbon nanotubes and graphene to form a carbon filler; Dispersing the mixed and stirred carbon filler and lyophilizing by freezing with liquid nitrogen; Pulverizing the dried carbon filler to form carbon nanocomposite powder; Mixing the carbon nanocomposite powder with an organic solvent such as a surfactant, a dispersant, and a reducing agent, and ultrasonic dispersion; Stirring and drying the ultrasound-dispersed carbon nanocomposite powder; Dissolving and mixing the polymer material in a solvent; Mixing and dispersing the polymer material mixed with the agitated and dried carbon nanocomposite powder; Drying and pulverizing the dispersed carbon nanocomposite powder and the polymer material to form a raw material in the form of a compound or a pellet; And forming a heat dissipation plate, which is a base of a printed circuit board, by extrusion-molding a raw material prepared in the compound or pellet form. The carbon nanocomposite powder is formed by addition of glass fiber containing silicate as a main component, Characterized in that carbon black is contained in the polymer material, ethylene diamine is substituted for the carbon black terminal, and acrylamide is bonded to the terminal amine group and the surface is modified through ozone treatment.

The method for manufacturing a carbon-based printed circuit board for an LED lighting apparatus according to an embodiment of the present invention has the following effects.

First, a printed circuit board is manufactured using a carbon-based mixed material having an excellent heat radiation performance, so that heat can be directly discharged to the outside through the carbon-based printed circuit board to improve heat radiation and thermal conductivity.

Second, productivity can be improved by forming and forming a carbon-based printed circuit board by using a carbon-based mixed material adjusted to have a uniform particle size distribution.

Third, since it is not necessary to apply a separate heat sink to the carbon-based printed circuit board when manufacturing the LED lighting device, it is possible to improve the heat dissipation performance and the heat conduction performance while achieving weight reduction and slimness.

Fourth, since the carbon-based printed circuit board is manufactured for the heat dissipation of the LED lighting device, the corrosion resistance is excellent, so there is no deterioration of the heat radiation performance according to long-term use, and the maintenance management cost can be reduced.

1 is a flowchart showing a manufacturing method of a carbon-based heat-radiating printed circuit board according to the present invention.
2 and 3 are schematic front and rear perspective views of an LED lighting apparatus using a carbon-based heat-dissipating printed circuit board according to the present invention.
Fig. 4 is an exploded perspective view of the LED lighting device of Fig. 2,

Hereinafter, a method of manufacturing a carbon-based printed circuit board according to an embodiment of the present invention, a carbon-based printed circuit board manufactured thereby, and an LED lighting apparatus using the same will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

In addition, the same or corresponding components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. For convenience of explanation, the size and shape of each constituent member shown may be exaggerated or reduced have.

1 is a flowchart showing a method of manufacturing a carbon-based printed circuit board according to the present invention.

In the method of manufacturing a carbon-based printed circuit board according to the present invention, graphite, carbon nanotubes, graphene and carbon fibers are homogenized by crushing and surface treatment, respectively, as shown in FIG. 1 (S110).

Here, the graphite, carbon nanotube, graphene, and carbon fiber are surface-treated and homogenized separately by ball milling, induction milling, or crushing process using liquefied nitrogen.

Meanwhile, the graphite material may be formed of any one or a combination of two or more of crystalline graphite, synthetic graphite, amorphous graphite, and expandable graphite.

The particle size of the graphite is 2 to 20 μm. When the particle size is less than 2 μm, the crushing process is difficult, and the change in the heat radiation performance is small as the size decreases. When the particle size is more than 20 μm, The heat radiation performance is degraded.

In addition, the carbon nanotubes may be formed of single-wall carbon nanotubes (SWCNTs) in which a graphite layer of a single layer is deformed in a deformed shape of a graphite material and multi-walled carbon nanotubes Multi-wall carbon nanotubes, and MWCNTs.

The graphene is a material having a honeycomb structure having an atomic size made of carbon atoms. The thickness of the graphene is 0.2 nm. The physical and chemical stability is very high. The graphene is 100 times more electricity than copper, This is fast.

In addition, strength is more than 200 times stronger than steel, more than twice as high as that of diamond, which has the highest thermal conductivity, and is transparent and stretchable because it passes most of the light.

The particle size of the carbon nanotube or graphene is preferably 200 nm to 1 μm, and when the particle size is less than 200 nm, agglomeration tends to occur. When the particle size is larger than 1 μm, Homogeneous dispersion is difficult.

When the carbon fiber has a strength of 10 to 20 g / d and a specific gravity of 1.5 to 2.1, it has excellent heat resistance and impact resistance, is resistant to chemicals, and is highly resistant to pests. In the heating process, molecules such as oxygen, hydrogen, and nitrogen escape and lose weight, so they are lighter than metal (aluminum) while they are more elastic and stronger than metal (iron). These characteristics have made it possible to produce sports goods (fishing rods, golf clubs, tennis racquets), aerospace industries (heat-resistant materials, aircraft fuselages), automobiles, civil engineering constructions (lightweight materials, interior materials) , Water purifier) and so on.

Subsequently, the graphite, carbon nanotube, graphene and carbon fiber homogenized by the milling and surface treatment are dried (S120). At this time, the drying process may be further performed at a temperature of 60 to 80 ° C. for 12 to 36 hours.

Subsequently, the dried fillers are mixed and stirred to form a carbon filler (S130).

Here, in the mixing and stirring, the dried graphite, carbon nanotube, graphene and carbon fiber are put into a vacuum stirrer and mixed and stirred. This is because the graphite, carbon nanotubes, graphene and carbon fibers are mixed and stirred through a vacuum stirrer to uniformly mix the carbon filler.

On the other hand, among the carbon fillers mixed in the vacuum stirrer, the graphite was mixed with 97 wt% of carbon black, 2 wt% of carbon nanotubes and 1 wt% of graphene to improve bonding, dispersibility, stability, surface modification and compatibility Can have a high heat emissivity.

Here, the vacuum stirrer may be performed under a nitrogen atmosphere at a vacuum degree of about 10 ^-1 torr, a temperature of 80 to 120 ° C, and a stirring rate of 100 to 120 rpm for 40 to 100 minutes.

Subsequently, the mixed and stirred carbon filler is dispersed (S140). That is, a solvent is added to the carbon filler mixed with each other by the vacuum stirrer, and the mixture is homogeneously mixed and dispersed.

At this time, the solvent used in the dispersion process of the carbon filler is a mixture of distilled water, alcohol, dimethylformamide (DMF), methyl ethyl ketone (MEK), polyol and styrene. Meanwhile, the solvent can be suitably selected in consideration of various process conditions such as sedimentation property, long-term property, unit cost, manufacturing environment, and the like.

Subsequently, the uniformly dispersed carbon filler is freeze-dried (S150). Here, lyophilization of the carbon filler is performed by freeze-drying by rapid cooling with liquid nitrogen. At this time, it is rapidly freeze-dried with ultra-low temperature liquefied nitrogen below 170 ° C.

Subsequently, the dried carbon filler is pulverized to form a carbon nanocomposite powder (S160). At this time, the carbon nanocomposite powder is pulverized to an average of 150 nm by nanotechnology.

That is, the pulverizing step may be suitably selected from a variety of dry pulverizing or freezing pulverizing methods, such as ball milling, attrition milling, or pulverizing method using liquefied nitrogen, in order to obtain a desired particle size and a homogeneous distribution .

Subsequently, an organic solvent such as a surfactant, a dispersant, and a reducing agent is mixed with the carbon nanocomposite powder and subjected to ultrasonic dispersion (S170). Here, the organic solvent is used for solution-phase dispersion of the carbon nanocomposite powder to be subsequently conducted.

Here, the surfactant is added to coat the surface of the particles, and the dispersant is added to adjust the particle distribution and size, and the reducing agent is added to improve the dispersibility.

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Subsequently, the ultrasound-dispersed carbon nanocomposite powder is stirred and dried (S180). At this time, the stirring and drying are continued at a temperature of 25 to 300 ° C in an agitator. Here, the drying temperature may be set in consideration of the boiling point of the solvent and other additives, and may range from 25 to 300 ° C, specifically from the vaporization temperature of the solvent to 300 ° C. Productivity can be improved.

Meanwhile, the carbon nanocomposite powder ultrasonically dispersed by the solution is stirred in a stirrer, and slowly dried at room temperature, thereby maximizing the dispersion effect of the carbon nanocomposite powder.

Subsequently, the polymer material is dissolved in a solvent and mixed (S190). The polymeric material may be selected from the group consisting of polycarbonate (PC), polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), homopolyamide based on hexamethylenediamine and adipic acid PA66, polypropylene (PP) (PMMA), ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), and polyether ketone (PEK) Depending on the properties (thermoplasticity, thermosetting property), a curing agent and a dispersion stabilizer may be further mixed and used.

At this time, the polymer material has processability and economy for extrusion or injection molding of a heat dissipation plate as a base in the production of a carbon-based printed circuit board. The polymer material is mixed with the carbon nanocomposite powder having excellent thermal conductivity to provide a heat dissipation plate Can be formed.

Such a polymer material has an easy processability and economic efficiency for injection molding in the production of a heat dissipation plate, and can be mixed with a carbon-based mixed material having excellent thermal conductivity to form a molding structure having heat radiation characteristics.

The carbon black may be prepared by gradually mixing 50 g of carbon black DC 2500G with 500 ml of 60% nitric acid and 200 ml of 95% sulfuric acid by mixing the carbon black with the polymer material, thereby improving the physical properties and workability of the polymer material. After the addition, the temperature of the reaction solution was elevated to 110 DEG C, and the mixture was heated and stirred for 24 hours. The reaction solution was cooled to room temperature, and the reaction solution was gradually added to 300 mL of 10% NaOH solution and stirred for 1 hour. As a result, the precipitated solid is filtered, washed with water and dried to obtain a carbon black having a yield of 82%. Then, in order to improve the oxidation potential through chemical amine surface modification of the carbon black, ethylenediamine is substituted at the terminal of the carbon black to bond the acrylamide to the amine group of the terminal group.

The carbon black can improve the oxidation potential through the physical modification of the carboxyl surface through ozone treatment. This increases the surface oxygen content of the carbon black and improves the conductivity and thermal emissivity as a function of the pH change, and forms a carbon black having a pH of 3 or less through surface modification.

 Next, the polymer material mixed with the carbon nanocomposite powder is stirred and dispersed (S200). 20 to 60% by weight of the carbon nanocomposite powder and 40 to 80% by weight of the polymer material are respectively supplied and mixed in an appropriate amount discharge device.

When the content of the carbon nanocomposite powder is more than 60% by weight, it is difficult to produce the carbon nanocomposite powder in the form of pellets and the mechanical properties of the molded structure may be deteriorated, which is unsuitable as a molding structure. The effect as a heat radiation structure can not be obtained.

Also, the carbon nanocomposite powder and the polymer material are mixed using a pre-confinement mixer.

At this time, in the process of dispersing the carbon nanocomposite powder and the polymer material, the polymer material that is intermixed with the carbon nanocomposite powder is dissolved by the solvent, and the curing agent or the dispersion stabilizer is added in consideration of the thermal characteristics of the dissolved polymer material, The polymer material and the carbon nanocomposite powder are mixed in a pre-confinement mixer.

Meanwhile, in order to confirm whether or not the carbon nanocomposite powder and the polymer material are uniformly dispersed, a process of checking viscosity and characteristics may be further performed.

Then, the carbon nanocomposite powder and the polymer material are dried and pulverized, and the carbon nanocomposite powder and the polymer material are formed into a pellet form by compound or dry-milling extrusion molding to produce a raw material used as a base for a printed circuit board (S210).

Meanwhile, the carbon nanocomposite powder and the polymer material may be prepared by adding a curing agent or a dispersion stabilizer to the raw material of the heat dissipation plate in the form of a compound or a pellet. In this case, the glass fiber containing silicate as a main component may be added together with the polymer material. The content of the silicate may be 5 to 20% by weight. If the content of the silicate exceeds 20 wt%, the pellet is difficult to form due to the high viscosity and the pellet is difficult to form if it is lower than 5 wt%, which is not effective in improving the fire resistance.

Here, the silicate is one or more selected from the group consisting of potassium silicate, sodium silicate, silicon oxide, silicon nitride, and silicon carbide.

Then, a raw material manufactured in the compound or pellet form is extruded and formed to form a heat radiation plate, which is the base of the printed circuit board (S220). At this time, in the extrusion molding process, the material fed by the rotation of the screw is transported, melted, extruded, and homogenously metered and pressurized while maintaining the cylinder temperature of the extruder at 260 to 320 ° C.

The carbon-based heat dissipation plate formed through the extrusion molding is inserted into a vacuum cooler and cooled, and the heat dissipation plate is formed into a desired size through a compression drawing or cutting according to a desired standard.

Here, the cooling step is performed in a vacuum cooler so as to prevent the deformation from occurring due to the shape and shape of the squeezing mold by a predetermined tension and vacuum in order to obtain accurate specifications such as the thickness of the heat dissipating plate.

In order to obtain a desired thickness of the heat dissipating plate cooled through the vacuum cooler, rolling is carried out, and the cut is performed at a constant speed to perform the inspection process further.

Accordingly, the carbon-based heat dissipation plate manufactured according to the present invention is manufactured by mixing carbon black fillers and silicate compounds of graphite, carbon nanotubes, and graphene impregnated with polyamide with a uniform particle size distribution, The present invention can be applied to a printed circuit board having a printed circuit board. In addition, since the heat dissipation plate used in the carbon-based printed circuit board manufactured by the present invention has a significantly lighter weight than a general metal printed circuit board, it can be made slim and lightweight while improving conduction and heat radiation performance, And can be applied to devices more widely.

FIGS. 2 and 3 are a front view and a rear perspective view schematically showing an LED lighting apparatus using a carbon-based printed circuit board according to the present invention, and FIG. 4 is an exploded perspective view of the LED lighting apparatus of FIG.

As shown in FIGS. 2 to 4, the LED lighting apparatus 100 using the carbon-based printed circuit board according to the present invention includes a main body case 110 having an upper opening and an inner space 111, A carbon-based PCB 200 having a plurality of LED elements 121 mounted on a bottom surface of the body 110 at predetermined intervals, a body case 110 A diffusion plate 130 coupled to the body case 110, a fixing frame 140 for fixing the diffusion plate 130 to the body case 110, And a converter 150 configured to convert a current supplied to the LED element 121.

However, the present invention is not limited thereto. The LED lighting apparatus 100 may be formed into a square, triangular or more polygonal shape, a circular or elliptical shape, and a size It can be formed larger or smaller in consideration of various conditions of the mounting portion, and the scope of right of the present invention is not limited thereto.

The LED element 121 is provided on a PCB substrate 122 in a pattern in which a plurality of LED elements 121 are arranged in a predetermined pattern and the red, green, At least one or a plurality of light emitting diodes may be mixed and used.

The main body case 110 is fixed to the ceiling of the room, and may be installed on the side wall or the floor in some cases. It is preferable that the body case is formed in a substantially 'C' shape or a 'C' shape on one end face, and the back face or the side face is made of a metal material in order to maximize the heat radiating effect.

The inner surface of the body case 110 may be coated with a white material such as silver (Ag), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), aluminum .

In the present invention, a plurality of ventilation holes having a louver-type structure are formed to penetrate through the side surface and the back surface of the main body case 110, so that the heat generated in the hermetically sealed interior is rapidly discharged to the outside through the ventilation holes, Can be maximized.

At this time, the main body case 110 may be directly fixed to the fixing surface by a fastener or may be detachably attached using a separate fixing means (not shown).

The fixed frame 140 is coupled to the lower side of the main body case 110. The fixed frame 140 is formed to correspond to the shape of the corner portion of the main body case 110, and is detachably coupled along the corner portion.

The diffusion plate 130 is interposed between the fixed frame 140 and the main body case 110 so that the fixed frame 140 and the main body case 110 are coupled to each other, Respectively.

The diffusion plate 130 may be fixed at the same time while the fixing frame 140 is fixed on the main body case 110 and may be coupled to the main body case 110 or the fixing frame 140 And the diffusion plate 130 may be slidingly coupled by forming a sliding groove.

The diffusion plate 130 is made of a transparent or translucent material and can be mounted with the degree of transparency or translucency corrected according to the amount of light transmitted from each LED element 121.

In the LED lighting apparatus according to the embodiment of the present invention, only the surface illumination and the down-down illumination are performed. However, the present invention is not limited thereto, and the carbon-based heat dissipation plate can be applied to all the LED illumination apparatuses requiring heat dissipation. For example, it can be applied to a floodlight of 5W, 10W, 20W, 25W, 30W, 50W, 70W, 100W, 125W, 180W and 200W fluorescent lamps,

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications and changes may be made thereto without departing from the spirit and scope of the invention as set forth in the appended claims. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

100: LED lighting device 200: carbon-based printed circuit board

Claims (13)

Homogenizing the graphite, carbon nanotube and graphene by crushing and surface treatment, respectively;
Drying and homogenizing the homogenized graphite, carbon nanotubes and graphene to form a carbon filler;
Dispersing the mixed and stirred carbon filler and lyophilizing by freezing with liquid nitrogen;
Pulverizing the dried carbon filler to form carbon nanocomposite powder;
Mixing the carbon nanocomposite powder with an organic solvent such as a surfactant, a dispersant, and a reducing agent, and ultrasonic dispersion;
Stirring and drying the ultrasound-dispersed carbon nanocomposite powder;
Dissolving and mixing the polymer material in a solvent;
Mixing and dispersing the polymer material mixed with the agitated and dried carbon nanocomposite powder;
Drying and pulverizing the dispersed carbon nanocomposite powder and the polymer material to form a raw material in the form of a compound or a pellet;
Forming a heat dissipation plate which is a base of the printed circuit board by extrusion-molding the raw material manufactured in the compound or pellet form,
The carbon nanocomposite powder is further subjected to a forming process by adding a glass fiber containing a silicate as a main component,
The carbon-based printed circuit board for LED lighting device according to claim 1, wherein the polymer material comprises carbon black, the carbon black terminal is substituted with ethylenediamine, acrylamides are bonded to the terminal amine groups and the surface is modified through ozone treatment Gt; delete The method according to claim 1, wherein mixing and stirring the graphite material, carbon nanotube, and graphene are performed in a vacuum stirrer. delete The carbon-based printed circuit board for LED lighting device according to claim 1, wherein the silicate is one or more selected from the group consisting of potassium silicate, sodium silicate, silicon oxide, silicon nitride, and silicon carbide. Gt; The method of manufacturing a carbon-based printed circuit board for LED lighting device according to claim 1, wherein the graphite material is one or more of graphite, graphite, artificial graphite, graphite and expanded graphite. delete delete The method according to claim 1, wherein the carbon nanocomposite powder and the polymer material are mixed using a pre-emitter mixer. delete delete delete delete

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