TWI694470B - Three-dimensional structure of conductive carbon glue - Google Patents

Abstract

Conductive carbon adhesive is a very active research technology around the world, and its application range is quite wide, such as liquid crystal display (TFTLCD), organic light-emitting diode (OLED), radio frequency identification system (RFID), antenna, solar cell, sensing Electronic components such as devices. Since the two-dimensional carbon material used for the conductive carbon paste is easily stacked and agglomerated in the polymer, the present invention adds a nano filler to the carbon material to prepare a three-dimensional conductive carbon paste to prevent the carbon material from agglomerating.

Description

Three-dimensional structure of conductive carbon glue

The invention relates to a conductive carbon adhesive, in particular to add different fillers and proportions to prepare a three-dimensional structure conductive carbon adhesive.

The conductive paste is formulated with synthetic resin as a binder and a good conductive material as a filler. The conductive filler can be gold, silver, copper, aluminum, zinc, iron, nickel powder and graphite and some conductive compounds, so that The connection material forms a conductive path, which is characterized by good conductivity and jointness, and the viscosity can be adjusted in accordance with construction. It has been widely used in liquid crystal display (LCD), light emitting diode (LED), integrated circuit (IC) wafers, Packaging and bonding of printed circuit board components (PCBA), dot matrix blocks, ceramic capacitors, membrane switches, smart cards, radio frequency identification and other electronic components and components.

In the electronics industry, conductive adhesives have become an indispensable material. Conductive adhesives are divided into carbon adhesives and silver adhesives. Because silver adhesives are expensive, the present invention is based on conductive carbon adhesives and is filled with nano-sized particles To prevent the reunion of two-dimensional carbon materials.

One category of the present invention is to provide a three-dimensional conductive carbon paste. According to a specific embodiment of the present invention, a three-dimensional conductive carbon paste of the present invention includes: a carbon material; a filler, which is added to the carbon material in a proportion and mixed into a conductive powder; and a high The molecules are physically mixed with the conductive powder to form a paste; wherein the paste is cured with a light or a The three-dimensional structure conductive adhesive is prepared by thermal curing.

Preferably, the filler may be selected from titanium dioxide, boron nitride, aluminum oxide, or a combination thereof.

Preferably, the carbon material may be graphite or graphene.

Preferably, the polymer may include a first monomer of one diisocyanate and a second monomer of two hydroxyl groups.

Preferably, the ratio of adding the carbon material to the filler may be 100:0~80:20 (wt.%).

Preferably, the reaction temperature of light curing or heat curing may be 100°C to 200°C.

Preferably, the curing time of light curing or heat curing may be 30 minutes to 12 hours.

Preferably, the time for physical mixing may be 1 day to 2 days.

Preferably, the solid content of the conductive powder added to the polymer may be 1 wt.% to 80 wt.%.

Preferably, the molecular weight of the glycol monomer ranges from 500 to 4000.

Preferably, the organic solvent used for the polymer may be isopropyl alcohol, ethanol, ethyl acetate, acetone, or a combination thereof.

In summary, the present invention uses a two-dimensional carbon material and a nano-level filler for three-dimensional structural design, using a small powder mixer to compound the two-dimensional carbon material and the filler in different proportions, and then adds this conductive powder to In the polymer, the slurry is coated with a physical mixing method for 24 hours, and then the slurry is coated and placed in an oven or cured by UV to prepare a three-dimensional conductive adhesive. In this invention, two-dimensional carbon materials of graphite and graphene are combined with nano-sized aluminum oxide, boron nitride, and titanium dioxide to prevent the two-dimensional carbon materials from stacking and agglomerating in the conductive adhesive, thereby increasing effective conductive paths and enhancing the two-dimensional carbon material. The dispersibility of carbon materials in conductive adhesive.

The above summary, the following detailed description and the accompanying drawings are intended to further illustrate the ways, means and effects of this creation to achieve its intended purpose. The other purposes and advantages of this creation will be explained in the subsequent description and drawings.

FIG. 1 is a graph showing the resistance value of the conductive carbon film added with different proportions of titanium dioxide (TiO ₂ ) in the present invention.

FIG. 2 is a graph showing the resistance value of the conductive carbon film with different proportions of boron nitride (BN) added in the present invention.

FIG. 3 is a graph showing the resistance value of the conductive carbon film with different proportions of alumina (Al ₂ O ₃ ) added in the present invention.

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings and examples. It is worth noting that these embodiments are only representative embodiments of the present invention, and the specific methods, devices, conditions, materials, etc. exemplified therein are not intended to limit the present invention or the corresponding embodiments.

In the description of this specification, the description referring to the terms “a specific embodiment”, “another specific embodiment” or “partial specific embodiment” means that the specific features, structures, materials or characteristics described in conjunction with the embodiment include In at least one embodiment of the invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment. Moreover, the specific features described Features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments.

In the description of the present invention, it should be understood that the terms "portrait, landscape, top, bottom, front, back, left, right, top, bottom, inner, outer" and other indications are based on the drawings The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limit.

One category of the present invention is to provide a three-dimensional conductive carbon paste. According to a specific embodiment of the present invention, a three-dimensional conductive carbon paste of the present invention includes: a carbon material, a filler, and a polymer. The carbon material may be graphite (artificial graphite, natural graphite) or graphene as the main body of the conductive carbon glue. The filler may be selected from titanium dioxide, boron nitride, aluminum oxide, or a combination thereof. The filler is added in proportion to the carbon material and mixed into conductive powder. The polymer system and the conductive powder are physically mixed to form a slurry, wherein the slurry is prepared by a photo-curing or a thermal curing to prepare a three-dimensional conductive adhesive.

In this embodiment, the polymer may include a polymer formed by a first monomer of diisocyanate and a second monomer of two hydroxyl groups (glycol monomer); wherein the second monomer is a polyalcohol ( (Example: PEG, PPG are also called polyethylene oxide or polyoxyethylene).

In this embodiment, the ratio of adding the carbon material to the filler may be 100:0~80:20 (wt.%).

In this embodiment, the reaction temperature of light curing or heat curing may be 100°C to 200°C.

In this embodiment, the curing time of light curing or heat curing may be 30 minutes to 12 hours.

In this embodiment, the time for physical mixing may be 1 day to 2 days.

In this embodiment, the solid content of the conductive powder added to the polymer may be 1 wt.% to 80 wt.%.

In this embodiment, the molecular weight of the glycol monomer ranges from 500 to 4000.

In this embodiment, the organic solvent used for the polymer may be isopropyl alcohol, ethanol, ethyl acetate, acetone, or a combination thereof.

Please refer to FIG. 1, which is a graph showing the resistance value of the conductive carbon film with different proportions of titanium dioxide (TiO ₂ ) according to the present invention. In the first part, examples 1 to 4 are different ratios of titanium dioxide added to KS44 graphite, of which the optimal ratio is 95:5. 0.082 grams of titanium dioxide is added to 1.56 grams of KS44 graphite, put in a small powder mixer for mixing to achieve uniform dispersion Conductive powder, then add 50% solids powder to the polymer glue (for example: the polymer may contain a first monomer of diisocyanate and a second monomer of two hydroxyl groups (glycol monomer) Polymer; where the second monomer is a polyalcohol), stir for 24 hours, after confirming that the slurry is evenly mixed, pour it on a glass slide for coating, the thickness control is about 0.1mm, and finally put it in an oven or UV After curing, a three-dimensional conductive carbon adhesive is obtained. Add different proportions of titanium dioxide (TiO ₂ ) to KS44 graphite conductive carbon film resistance value, as shown in Table 1.

In the present invention, graphene is prepared by a low-temperature crushing process. First, 25 grams of KS44 graphite is weighed into 500 grams of solvent (DI water) to obtain a uniform suspension with a solid content of 5%. The solution is poured into a low-temperature crushing cycle machine. Different pressures (800bar, 1200bar, 1500bar) were operated three times, and finally filtered by suction, and the product was put into a 40 degree oven to obtain moKS44 graphene.

Examples 5 to 8 are different ratios of titanium dioxide added to moKS44 graphene, of which the optimal ratio is 95:5. 0.029 grams of titanium dioxide is added to 0.543 grams of moKS44, placed in a small powder mixer for mixing to obtain uniformly dispersed conductive powder Polymer, and then add 50% solids powder to the polymer glue (for example: the polymer may include a first monomer with diisocyanate and a second monomer with two hydroxyl groups (glycol monomer); Where the second monomer is a polyalcohol), stir for 24 hours, after confirming that the slurry is evenly mixed, pour it on a glass slide for coating, the thickness control is about 0.1mm, and finally put it in an oven or UV to cure, Get a three-dimensional conductive carbon glue. Add different proportions of titanium dioxide (TiO ₂ ) to the conductive carbon film resistance value of moKS44 graphene, as shown in Table 2.

Please refer to FIG. 2, which is a graph showing the resistance value of the conductive carbon film with different proportions of boron nitride (BN) added in the present invention. In the second part, the filler is replaced with nano-scale boron nitride and added to the two-dimensional carbon material in different proportions.

Examples 9 to 12 are different ratios of boron nitride added to KS44 graphite, of which 95:5 is taken as an example, 0.08 grams of boron nitride is added to 1.526 grams of KS44 graphite, put into a small powder mixer for mixing to obtain dispersion Uniform conductive powder, then add 50% solids powder to the polymer glue (for example: the polymer may contain a first monomer with diisocyanate and a second monomer with two hydroxyl groups (glycol monomer) Polymer; where the second monomer is a polyalcohol), stir for 24 hours, after confirming that the slurry is evenly mixed, pour it on a glass slide, and finally put it in an oven or UV to cure, to obtain a three-dimensional structure of conductive carbon glue . Add different proportions of boron nitride to the conductive carbon film resistance value of KS44 graphite, as shown in Table 3.

Examples 13 to 14 are different ratios of boron nitride added to moKS44 graphene, where the optimal ratio is 95:5, 0.099 grams of boron nitride is added to 1.893 grams of moKS44 graphene, put into a small powder mixer to mix To obtain uniformly dispersed conductive powder, then add 50% solids powder To polymer glue (for example: the polymer may include a polymer formed by a first monomer of diisocyanate and a second monomer of two hydroxyl groups (glycol monomer); wherein the second monomer is a polyalcohol) Stir for 24 hours in the middle, after confirming that the slurry is evenly mixed, pour it on a glass slide for coating, the thickness of which is controlled to about 0.1mm, and finally put it in an oven or UV to cure, to obtain a three-dimensional structure of conductive carbon glue. Add different proportions of boron nitride to the conductive carbon film resistance value of moKS44 graphene, as shown in Table 4.

Please refer to FIG. 3, which is a graph showing the resistance value of the conductive carbon film with different proportions of aluminum oxide (Al ₂ O ₃ ) according to the present invention. In the third part, the filler is replaced with nano-grade alumina and added to the two-dimensional carbon material in different proportions.

Examples 17-20 are different ratios of alumina added to KS44 graphite, of which 95:5 is taken as an example, 0.08 g of boron nitride is added to 1.526 g of KS44 graphite, put into a small powder mixer for mixing to achieve uniform dispersion Conductive powder, then add 50% solids powder to the polymer gel (for example: the polymer may contain a first monomer with isocyanate and a second monomer with two hydroxyl groups (glycol monomer) to form a polymerization Material; wherein the second monomer is a polyalcohol) stirred for 24 hours, after confirming that the slurry is evenly mixed, pour it on a glass slide for coating, the thickness of which is controlled to about 0.1mm, and finally put it in an oven or Cured by UV to obtain a three-dimensional conductive carbon glue. Add different proportions of alumina to the conductive carbon film resistance value of KS44 graphite, as shown in Table 5.

Examples 21 to 28 are different ratios of alumina added to moKS44 graphene, of which the optimal ratio is 98:2. 0.022 g of alumina is added to 2.159 g of moKS44 graphene, put in a small powder mixer for mixing to obtain dispersion Uniform conductive powder, then add 50% solids powder to the polymer gel (for example: the polymer may contain a first monomer with isocyanate and a second monomer with two hydroxyl groups (glycol monomer) Polymer; where the second monomer is a polyalcohol), stir for 24 hours, after confirming that the slurry is evenly mixed, pour it on a glass slide for coating, the thickness control is about 0.1mm, and finally put it in an oven or UV After curing, a three-dimensional conductive carbon adhesive is obtained. Add different ratios of alumina to the conductive carbon film resistance value of moKS44 graphene, as shown in Table 6.

It is found from the above examples that the addition of alumina to moKS44 graphene has the lowest sheet resistance value. Therefore, the present invention takes the weight percentage of graphene and alumina of 95:5 as an example. When the solid content of the conductive powder is increased from 50% to 60 %, and the change in sheet resistance was also significantly decreased, as shown in Table 7 Examples 29~31.

In summary, the present invention uses a two-dimensional carbon material and a nano-level filler for three-dimensional structural design, using a small powder mixer to compound the two-dimensional carbon material and the filler in different proportions, and then add this conductive powder Into the polymer, the slurry is coated with the physical mixing method for 24 hours, and then the slurry is coated and placed in an oven or cured by UV to prepare a three-dimensional conductive adhesive. In this invention, two-dimensional carbon materials of graphite and graphene are combined with nano-sized aluminum oxide, boron nitride, and titanium dioxide to prevent the two-dimensional carbon materials from stacking and agglomerating in the conductive adhesive, thereby increasing the effective conductive flux Road, improve the dispersion of two-dimensional carbon materials in conductive adhesive.

The above-mentioned embodiments are only illustrative of the characteristics and effects of the present invention, rather than limiting the scope of the essential technical content of the present invention. Anyone who is familiar with this skill can modify and change the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention should be as listed in the scope of patent application mentioned later.

Claims (5)

A three-dimensional structured conductive carbon paste, which includes: a carbon material; a filler, which is added to the carbon material in a proportion to mix into a conductive powder; and a polymer, which forms a physical relationship with the conductive powder Mixed into a slurry; wherein the slurry is prepared by a photo-curing or a thermal curing to prepare the three-dimensional structure conductive adhesive, wherein the filler is selected from boron nitride, wherein the conductive powder is added to the polymer with a solid content of 60wt .%, wherein the physical mixing time is 1 day, wherein the polymer comprises a polymer formed by a first monomer of diisocyanate and a second monomer of two hydroxyl groups, wherein the second monomer is a polycyclic Ethylene oxide or polyoxyethylene, wherein the ratio of the carbon material and the filler added is 95:5 (wt.%). The three-dimensional conductive carbon paste as described in item 1 of the patent application scope, wherein the carbon material is graphite or graphene. The three-dimensional conductive carbon glue as described in item 1 of the patent application scope, wherein the reaction temperature of the photocuring or the thermal curing is 100°C to 200°C. The conductive carbon adhesive with three-dimensional structure as described in item 1 of the patent application scope, wherein the curing time of the photo-curing or the thermal-curing is 30 minutes to 12 hours. The three-dimensional conductive carbon glue as described in item 1 of the patent application scope, wherein the organic solvent used for the polymer is isopropyl alcohol, ethanol, ethyl acetate, acetone or a combination thereof.

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