CN115975595B - Antistatic conductive adhesive for circuit board - Google Patents
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Abstract
The invention discloses an antistatic conductive adhesive for a circuit board, which comprises the following components in parts by weight: 50-85 parts of nano silver/functionalized graphene hybrid conductive filler, 10-40 parts of siloxane resin, 0.1-0.8 part of catalyst, 0.1-0.8 part of reinforcing agent, 0.1-0.5 part of inhibitor and 0.1-0.5 part of cross-linking agent. The nano silver/functionalized graphene hybridized conductive filler is prepared by using perylene diimide oxynitride prepared by preparation as a surfactant to perform non-covalent functionalization on graphene nano sheets, and then performing hybridization with silver acetate. The non-covalent bonding enhances the connection between the graphene and the metallic silver particles, so that the conductivity can be enhanced, the mechanical property of the conductive adhesive can be improved by adding the graphene, and the performance tends to be stable when the temperature is changed.
Description
Technical Field
The invention relates to the technical field of adhesives, in particular to an antistatic conductive adhesive for a circuit board.
Background
The rapid progress of electronic information technology makes electronic products applied to aerospace, medical agriculture, chemical industry and daily life of people develop to microminiaturization and integration, which puts forward higher requirements on the performance of packaging materials. Tin-lead solder has been used as a traditional packaging material for nearly a hundred years, but has the following disadvantages: the soldering temperature of the tin-lead solder is higher than 200 ℃, so that the electronic device is easy to be thermally deformed and damaged; the minimum soldering pitch of tin-lead solder is 650 microns. The packaging requirements of the miniature electronic products cannot be met, so that the development of tin-lead solder is limited; lead is a heavy metal which causes irreversible injury and pollution to human body and environment. With the increasing importance of people on health and environment, the world starts to restrict or even prohibit the use of lead-containing materials, and related measures are put out from various countries, and with the successive promulgation of the laws of WEEE/RoHS and the like, lead-free packaging materials are promoted to become a necessary development trend. Since Henry Wolfso issued the first piece of conductive adhesive in 1956, the conductive adhesive has the advantages of high line resolution, convenient operation process, green environmental protection and the like, and becomes an ideal substitute product for replacing tin-lead solder.
The conductive paste is a material having both conductivity and adhesion after curing or drying. Which bonds the conductive fillers together, primarily by bonding, to form a continuous conductive path. Conductive adhesives are mainly classified into four types according to structure, conductive direction, curing temperature, and resin type. (1) it is classified into: intrinsic and complex conductive adhesives. The intrinsic conductive adhesive is a conjugated polymer with conductive property, such as polythiophene, polyacetylene, polyaniline and the like. The intrinsic conductive adhesive has high resistivity, but poor stability and high cost. Currently in the stage of laboratory research , the method is not widely used. The composite conductive adhesive is conductive by taking resin as a matrix and providing conductive performance by metal particles such as tin, lead, gold, silver, copper and the like, namely the conductive adhesive in the traditional sense is widely used in industry. (2) The conductive direction is classified into ACA (anisotropic conductive paste) and ICA (isotropic conductive paste). The conductive filler content of ACA is small, and it is difficult to form a continuous conductive path. By adding insulating material or conductive filler with insulating material coated on the outermost layer, a certain pressure is applied to the Z-axis direction, so that the Z-axis direction has conductivity, and the X, Y axis does not have conductivity. ACA is pressurized in the industrial production process, so that the process danger coefficient is large, the operation is difficult, and the ACA is not suitable for large-scale production. Compared with ACA, ICA has the same conductivity in all directions. The conductive filler of ICA is mostly metal, surface-plated polymer, carbon material, or the like. The conductive filler of ICA has a large number of sizes and shapes and a high content, and can form a continuous conductive path after the matrix resin is cured. The ICA preparation process is simple and convenient, and the use temperature can be reduced by adjusting the curing agent, so that the loss of the electronic device caused by the temperature is reduced. (3) according to the curing temperature: low temperature, medium temperature, high temperature; the low-temperature (25-100 ℃) curing has lower thermal damage to the electronic device, but has the defects of long curing time (18-20 hours), unstable volume resistivity and the like, so that the conductivity is poor. The curing time at the medium temperature (100-150 ℃) is shorter (0.5-1 h), the matching degree of the curing temperature and the temperature resistant range of the electronic device is high, and the application is wider. The high temperature (150-300 ℃) curing time is shortest, but the high temperature is too high, which is easy to oxidize metal particles and reduce conductivity. (4) according to the matrix, the following are classified into: thermoplastic and thermosetting conductive adhesives. The resin structure of the thermoplastic conductive adhesive is long, and has good fluidity and reciprocability after solidification, thereby being beneficial to the disassembly of electronic devices and improving the recycling rate of the electronic devices. However, the resin has poor heat resistance and rigidity, has fluidity when cured, easily causes electronic device displacement, reduces the accuracy of bonding sites, and is not suitable for the bonding requirement of microminiature integrated electronic devices. The resin of the thermosetting conductive adhesive and the curing agent are subjected to polymerization reaction to form a highly crosslinked network structure, and the thermosetting conductive adhesive has the characteristics of high temperature resistance, high hardness, high rigidity, difficult flow and the like, and meets the development requirements of modern electronic devices.
Currently, the conductive adhesive systems commonly used in the market include: epoxy systems, acrylic systems, silicone systems, and the like, all have their own advantages and disadvantages. The epoxy resin has the advantages of good adhesion performance and good adhesion to different base materials. Good thermal stability and shear strength. However, epoxy resins have the disadvantage that they have a relatively high modulus and water absorption, although this is generally possible, but when the epoxy system is slightly delaminated from the substrate, moisture is relatively easy to enter, the water absorption is relatively high, and the dielectric constant is relatively high. The main advantage of acrylic resins is the diversity of curing formats, since the reaction is radical curing, which can be carried out simultaneously by light, heat, or light and heat. The general viscosity of acrylic resins is relatively low and the range of viscosity control in formulation is relatively wide. In addition, the tear strength of the adhesive made of acrylic resin is relatively high. However, acrylic systems are poor in weatherability, not particularly good in flame retardancy, and tend to smell during use. The organic silicon system has the advantages of low stress, relatively good stress resistance, relatively flexibility and excellent high and low temperature resistance and weather resistance. Because of the relatively large bond energy, the modified polypropylene has good acid and alkali resistance and ultraviolet resistance. The disadvantage is that the adhesive force is not as high as that of the epoxy resin and the acrylic resin.
Chinese patent 202010373987.7 discloses a single-end-capped propionyloxy organic silicon resin, a preparation method thereof, a conductive adhesive containing the organic silicon resin and a preparation method thereof, wherein the structural formula of the single-end-capped propionyloxy organic silicon resin is shown as formula (I), and the conductive adhesive comprises 10-30 parts of the single-end-capped propionyloxy organic silicon resin and the following raw materials in parts by weight: 0.5 to 5 parts of thermal initiator, 1 to 5 parts of thermoplastic powder filler, 60 to 80 parts of modified silver powder, 1 to 10 parts of solvent and 0.1 to 1 part of stabilizer; wherein the weight portion of the single-end-capped propionyloxy organic silicon resin is 10-30 portions. The conductive adhesive has excellent elongation, bonding strength, conductivity, flexibility and anti-drop property of a cured product, and can be widely applied to the electronic industry.
Chinese patent 201310148749.6 provides a preparation method of graphene-containing high-thermal-conductivity conductive adhesive, which comprises the following steps: (1): surface functionalization of graphene: adding graphene into an acetone solution containing an organic matter of a conjugated ring, and performing intense ultrasonic vibration at 40-100 ℃ for 6-48 hours to form non-covalent modified graphene; (2): mixing epoxy resin and epoxy diluent for 3-30 minutes at room temperature to obtain a mixture of the epoxy resin and the epoxy diluent, and sequentially adding metal powder and a coupling agent into the mixture; (3): adding the non-covalent modified graphene prepared in the step (1) into the mixture in the step (2); (4): and (3) adding a curing agent into the mixture in the step (3) to prepare the uniform conductive adhesive. The invention has the advantages that: the graphene is subjected to surface functionalization through a non-covalent bond, so that the graphene is favorable for dispersing and enhancing interface combination in an epoxy system, and then is mixed with metal powder for use, so that the high-heat-conductivity conductive adhesive is obtained, and the high-heat-conductivity conductive adhesive has application prospect in high-power devices.
The liquid silicone rubber is non-conductive, and a certain amount of conductive filler is required to be added in order to obtain the organic silicon conductive rubber, and the liquid silicone rubber only shows electrical performance when the addition amount of the conductive filler reaches a seepage threshold value. At present, the conductive fillers of the organosilicon conductive adhesive are various in variety, including metal conductive fillers, carbon conductive fillers, metal composite conductive fillers and the like. The carbon-based filler has inferior conductivity to the metal-based conductive filler, and may be difficult to disperse during the preparation process. The price of the metal conductive filler is higher, but the conductive performance is outstanding, while the carbon conductive filler has poorer conductive performance, but can give a certain strength to the material to improve the overall performance. Therefore, a hybrid material formed between a nanostructure such as a metal nanoparticle and a carbon-based material has attracted attention from researchers. The connection between the metal nanoparticles and the graphene carrier and the effective control of the distribution and structure of the metal nanoparticles are the difficulty and key for preparing the metal nanoparticle/graphene hybrid structure. Graphene is generally required to be functionalized, and the generation of metal nanoparticles on the surface of the graphene is controlled by a functionalizing agent. Although the defect sites of graphene oxide or reduced graphene are active sites, they can be utilized to promote the growth of metal nanoparticles on their surfaces. But these defect sites tend to cause the growth of metal nanoparticles on the graphene surface to exhibit an uneven distribution. When pure graphene is used as a carrier, as the surface of the graphene has no organic group, the stability in a solvent is poor, and how to realize good preparation stability and effectively control the distribution and structure of the nano particles on the surface of the graphene is still a great difficulty.
Disclosure of Invention
In view of the above-mentioned drawbacks in the prior art, the present invention aims to provide a functionalized graphene with good dispersibility in a solvent, which is hybridized with metal particles to obtain a novel conductive filler and applied to the preparation of conductive adhesive.
Because the surface of the graphene has no organic group and has poor stability in a solvent, the surface of the graphene needs to be functionalized to be hybridized with metal nano particles, but in the invention, the inventor performs functionalization modification on the graphene by taking perylene diimide oxynitride, which is a non-covalent copolymer, as a surfactant, and the surfactant can perform strong interaction with the graphene due to the fact that the skeleton structure has electron-deficient carbon atoms and large pi-pi interaction area, and the zwitterionic side chain groups in the molecular structure enhance good support for enhancing the dispersibility of the graphene in the solvent, and the perylene diimide oxynitride can also realize high-efficiency functionalization and excellent dispersibility of the graphene through water and repulsive effect. The functional modification of the graphene can enable the surface of the graphene to be well combined with the metal nano particles, so that the combination property of the hybrid is further improved. The non-covalent bonding enhances the connection between the graphene and the metallic silver particles, and the contact resistance is reduced through the conduction structure bridged by the surface nano silver particles and the graphene, so that the conductivity can be enhanced. The mechanical property of the conductive adhesive can be improved by adding the graphene, the shearing strength of the conductive adhesive is improved, and the performance tends to be stable when the temperature is changed.
The technical scheme of the invention is as follows:
the antistatic conductive adhesive for the circuit board mainly comprises the following components in parts by weight: 50-85 parts of nano silver/functionalized graphene hybrid conductive filler, 10-40 parts of siloxane resin, 0.1-0.8 part of catalyst, 0.1-0.8 part of reinforcing agent, 0.1-0.5 part of inhibitor and 0.1-0.5 part of cross-linking agent.
The preparation method of the nano silver/functionalized graphene hybrid conductive filler comprises the following steps:
s1, weighing 30-50 parts by weight of 3,4,9, 10-tetracarboxylic anhydride and 7-10 parts by weight of N, N-dimethylethylenediamine, adding into 35-75 parts by weight of N-butanol, heating to 80-100 ℃, stirring for 4-6 hours, and evaporating the solvent to dryness after the reaction is finished to obtain N, N' -bis [3- (dimethylamino) propyl ] perylene-3, 4,9, 10-tetracarboxylic diimide;
s2, weighing 10-20 parts by weight of N, N' -bis [3- (dimethylamino) propyl ] perylene-3, 4,9, 10-tetracarboxylic acid diimide in the step S1, adding into 80-120 parts by weight of absolute ethyl alcohol, dripping 4.5-6.5 parts by weight of 30wt% hydrogen peroxide solution under the protection of argon, stirring for 1-4 hours at room temperature, heating to 60-90 ℃ and refluxing for 3-9 hours, cooling to room temperature and removing the solvent under reduced pressure, and washing residues with acetone and N-hexane for three times in sequence to obtain perylene diimide nitrogen oxides;
s3, weighing 10-20 parts by weight of graphite and 2-8 parts by weight of potassium, mixing, heating to 100-120 ℃ under nitrogen atmosphere, and reacting for 1-3 hours to obtain potassium intercalation graphite;
s4, weighing 2-6 parts by weight of potassium intercalated graphite in the step S3, adding the potassium intercalated graphite into 8-10 parts by weight of pyridine, carrying out cracking reaction for 20-28 h at the temperature of minus 35-minus 30 ℃, adding 0.1-0.125 part by weight of perylene diimide nitrogen oxide in the step S2, stirring for 20-24 h, then carrying out ultrasonic dispersion for 1-2 h, and filtering to obtain noncovalently functionalized graphene;
and S5, adding the non-covalent functionalized graphene obtained in the step S4 into 70-100 parts by weight of methanol, adding 60-100 parts by weight of silver acetate, stirring until the silver acetate is dissolved, and concentrating at low temperature under reduced pressure to remove the solvent to obtain the nano silver/functionalized graphene hybridized conductive filler.
Preferably, the silicone resin is formed by mixing vinyl silicone oil and vinyl MQ silicone resin in a mass ratio of 2-3:1.
Preferably, the catalyst is a platinum-based catalyst.
Preferably, the reinforcing agent is fumed silica.
Preferably, the inhibitor is one of an alkyne compound, a dibasic acid ester containing double bonds or a nitrogen-containing compound.
Preferably, the cross-linking agent is hydrogen-containing silicone oil.
The preparation method of the antistatic conductive adhesive for the circuit board comprises the following steps:
and weighing siloxane resin and nano silver/functionalized graphene hybridized conductive filler according to the formula amount, stirring and dispersing uniformly, stirring for 0.5-1 h, grinding for 1-3 times, continuously adding a catalyst, a reinforcing agent, an inhibitor and a crosslinking agent, stirring uniformly, and vacuumizing and degassing to obtain the antistatic conductive adhesive.
Compared with the prior art, the invention has the beneficial effects that:
(1) In the invention, the inventor performs functional modification on graphene by preparing a non-covalent copolymer, namely perylene diimide oxynitride, as a surfactant, wherein the surfactant has electron-deficient carbon atoms and large pi-pi interaction area in a skeleton structure, so that the surfactant can perform strong interaction with the graphene, and zwitterionic side chain groups in a molecular structure of the surfactant improve good support for enhancing the dispersibility of the graphene in a solvent;
(2) The non-covalent bonding enhances the connection between the graphene and the metallic silver particles, and the contact resistance is reduced through the conduction structure bridged by the surface nano silver particles and the graphene, so that the conductivity can be enhanced;
(3) The mechanical property of the conductive adhesive can be improved by adding the graphene, the shearing strength of the conductive adhesive is improved, and the performance tends to be stable when the temperature is changed.
Detailed Description
The technical scheme of the present invention will be described in detail by means of specific examples, which should be explicitly set forth for illustration, but should not be construed as limiting the scope of the present invention.
The parameters of partial raw materials in the embodiment of the invention are as follows:
vinyl silicone oil, 200 mPa.s, vinyl mass fraction 0.7%, ningbo He high new material technology Co., ltd.
Vinyl MQ silicone resin, 6300 mPa.s, vinyl mass fraction 0.96%, ningbo Ruo He high new material.
Nanometer silver powder, goods number: PT-Ag-300nm, shanghai Pantian powder material.
A cassiterite catalyst, model: ACS-PT-50, 6000ppm, jinan Baozheng commercial trade.
Fumed silica, model: a-200, wherein the content is more than or equal to 99.8%, and the new material technology of Bohai chlor-alkali in Hebei province.
Polymethylhydrosiloxane, 15-40 mPa.s, ala-dine.
Graphene, cat No.: 100393 the diameter of the tablet is 0.5-5 mu m, the thickness is 0.8-1.2 nm, and Nanjing Xianfeng nanometer.
Comparative example 1
The preparation method of the antistatic conductive adhesive for the circuit board comprises the following steps:
2.5kg of vinyl silicone oil, 1kg of vinyl MQ silicone resin and 5.1kg of nano silver powder are weighed, uniformly stirred and dispersed, stirred for 1h and ground for 2 times, 10g of Karster catalyst, 50g of fumed silica, 10g of ethynyl cyclohexanol and 10g of polymethyl hydrogen siloxane are continuously added, and the antistatic conductive adhesive is obtained after uniform stirring, vacuumizing and degassing.
Example 1
The preparation method of the antistatic conductive adhesive for the circuit board comprises the following steps:
2.5kg of vinyl silicone oil, 1kg of vinyl MQ silicone resin and 5.1kg of nano silver/functionalized graphene hybridized conductive filler are weighed, stirred and dispersed uniformly, stirred for 1h and ground for 2 times, 10g of Kasite catalyst, 50g of fumed silica, 10g of ethynyl cyclohexanol and 10g of polymethyl hydrogen siloxane are continuously added, stirred uniformly and vacuumized and degassed to obtain the antistatic conductive adhesive.
The preparation method of the nano silver/functionalized graphene hybrid conductive filler comprises the following steps:
s1, 3.7kg of 3,4,9, 10-tetracarboxylic anhydride and 0.8kg of N, N-dimethylethylenediamine are weighed and added into 4L of N-butanol, the mixture is stirred for 5 hours at the temperature of 90 ℃, and after the reaction is finished, the solvent is evaporated to dryness to obtain N, N' -bis [3- (dimethylamino) propyl ] perylene-3, 4,9, 10-tetracarboxylic diimide;
s2, weighing 2kg of N, N' -bis [3- (dimethylamino) propyl ] perylene-3, 4,9, 10-tetracarboxylic acid diimide in the step S1, adding into 10L of absolute ethyl alcohol, dropwise adding 0.5kg of 30wt% hydrogen peroxide water solution under the protection of argon, stirring at room temperature for 3 hours, heating to 80 ℃ for reflux for 6 hours, cooling to room temperature, decompressing, removing a solvent, and washing residues with acetone and N-hexane for three times in sequence to obtain perylene diimide nitrogen oxide;
s3, weighing 1kg of graphite and 0.4kg of potassium, mixing, and heating to 110 ℃ under nitrogen atmosphere to react for 3 hours to obtain potassium intercalated graphite;
s4, weighing 0.6kg of potassium intercalated graphite in the step S3, adding the potassium intercalated graphite into 1L of pyridine, carrying out cracking reaction for 24 hours at the temperature of minus 30 ℃, adding 0.1kg of perylene diimide nitrogen oxide in the step S2, stirring for 24 hours, performing ultrasonic dispersion for 2 hours, and filtering to obtain noncovalently functionalized graphene;
and S5, adding the non-covalent functionalized graphene obtained in the step S4 into 10L of methanol, adding 4.5kg of silver acetate, stirring until the silver acetate is dissolved, and concentrating and removing the solvent at 40 ℃ and minus 0.9MPa to obtain the nano silver/functionalized graphene hybrid conductive filler.
Example 2
The preparation method of the antistatic conductive adhesive for the circuit board comprises the following steps:
2.5kg of vinyl silicone oil, 1kg of vinyl MQ silicone resin and 5.1kg of graphene are weighed, stirred and dispersed uniformly, stirred for 1h and ground for 2 times, 10g of Karster catalyst, 50g of fumed silica, 10g of ethynyl cyclohexanol and 10g of polymethyl hydrosiloxane are continuously added, stirred uniformly and then vacuumized and degassed to obtain the antistatic conductive adhesive.
Example 3
The preparation method of the antistatic conductive adhesive for the circuit board comprises the following steps:
2.5kg of vinyl silicone oil, 1kg of vinyl MQ silicone resin and 5.1kg of nano silver/graphene compound are weighed, stirred and dispersed uniformly, stirred for 1h and ground for 2 times, 10g of Karster catalyst, 50g of fumed silica, 10g of ethynyl cyclohexanol and 10g of polymethyl hydrogen siloxane are continuously added, stirred uniformly, and vacuumized and degassed to obtain the antistatic conductive adhesive.
The preparation method of the nano silver/graphene composite comprises the following steps:
dispersing 4.5kg of silver acetate into 10L of acetonitrile, then adding 0.6kg of graphene, stirring at room temperature until the silver acetate is dissolved, centrifuging the mixed solution, taking the lower layer of precipitate, and drying to obtain the nano silver/graphene compound.
Test example 1
The conductive adhesives prepared in the comparative examples and the examples were subjected to volume resistivity test, and the prepared conductive adhesives were cured at 110 ℃ for 2 hours, and the test results are shown in table 1. Each sample was tested 3 times using a dc resistance meter and averaged. Volume resistivity calculation formula ρ=r× (w×t)/L, where ρ—volume resistivity (Ω·cm); r-test resistance value (. OMEGA.); w-sample width (cm); t-sample thickness (cm); l-distance (cm) between two copper wires.
Table 1 results of volume resistivity test of conductive paste
| Experimental protocol | Volume resistivity/Ω·cm |
| Comparative example 1 | 1.2×10 ﹣3 |
| Example 1 | 0.8×10 ﹣3 |
| Example 2 | 2.5×10 ﹣3 |
| Example 3 | 2.1×10 ﹣3 |
The volume resistivity can well reflect the conductivity of the material, and it can be seen from the test results that the graphene used in example 2 has a higher volume resistivity due to poor conductivity, while the nano silver used in comparative example 1 has a lower volume resistivity due to good conductivity, while the nano silver is composited with graphene in example 3, but the graphene has poor dispersibility in a solvent, so that the graphene and the graphene cannot be well combined when composited, which causes the conductive adhesive to form agglomeration inside when cured, thereby affecting the transmission of electrons, and thus has a higher volume resistivity. The covalent functionalization of the graphene in the embodiment 1 is realized through van der Waals attractive force between the aromatic trunk and the graphene, and a certain interaction exists between the prepared perylene diimide nitrogen oxide and the graphene, so that the graphene is stably dispersed, and the structure of the graphene is not influenced. Covalent bonding enhances the connection between graphene and metallic silver particles, and reduces contact resistance through a conducting structure bridged by the surface nano silver particles and graphene, so that conductivity can be enhanced.
Test example 2
The conductive adhesive prepared in the comparative example and the example was subjected to shear strength test, and the prepared conductive adhesive was cured at 110 ℃ for 2 hours, and the specific test results are shown in table 2. Tensile shear Strength test of conductive adhesive the test (Al/Al lap joint) was performed with reference to GB/T7124-2008 "determination of adhesive tensile shear Strength (rigid Material vs. rigid Material)", specifically as follows. The overlap length of the test pieces was 12.5.+ -. 0.5mm. And (3) placing the prepared sample into an oven, curing according to the set temperature and time, after curing, cooling the sample to room temperature, testing the shear strength by using a testing machine, setting the testing speed to be 5mm/min, and finally taking the average value as a test result of the shear strength. Tensile shear strength is given by the formula: τ=p/b×l formula: τ—tensile shear strength (MPa); p-maximum tensile force (N); b-overlap width (mm); l-overlap length (mm).
Table 2 table of results of shear strength test of conductive adhesive
| Experimental protocol | Shear Strength/MPa |
| Comparative example 1 | 3.1 |
| Example 1 | 6.2 |
| Example 2 | 4.0 |
| Example 3 | 4.7 |
From the shear strength test, it can be seen that the addition of graphene can actually improve the mechanical properties of the conductive adhesive to a certain extent, which is caused by the rigid structure of graphene itself, however, when it is compounded with nano silver, a certain effect occurs on the mechanical properties, which may be because the compatibility of graphene at the time of bonding cannot be well ensured due to the poor dispersibility of graphene in a solvent when the graphene is compounded with metal particles, which also causes agglomeration to occur in the adhesive when it is added to the conductive adhesive, which affects not only the conductive properties but also the toughness of the material, thereby causing the shear strength to be affected to a certain extent, so that the improvement of the mechanical properties in example 3 is limited. In the embodiment 1, the dispersibility of the graphene in the solution is improved by performing functional transformation, so that aggregation is reduced, and the active groups on the surface of the graphene can also help the combination of the graphene and silver particles, so that the combination is not only favorable for improving conductivity, but also can help the conductive adhesive to improve mechanical properties.
Test example 3
The conductive adhesive prepared in the comparative example and the example was subjected to cold and hot impact test, the prepared conductive adhesive was cured at 110 ℃ for 2 hours, and was subjected to a test by referring to test example 2, in which the conductive adhesive was held at-40 ℃ for 30min, heated to 100 ℃ for 30min, cooled to-40 ℃ for 2min, and held for 30min, and 1 cycle was performed for 100 cycles per week, and the sample performance was tested for shear strength performance, and the shear strength test method was referred to test example 2, and specific test results are shown in table 3.
TABLE 3 shear Strength Performance of conductive pastes after Cold and Hot impact testing
| Experimental protocol | Shear Strength/MPa |
| Comparative example 1 | 2.4 |
| Example 1 | 5.7 |
| Example 2 | 3.4 |
| Example 3 | 4.1 |
Since the use environment of the conductive adhesive is sensitive to temperature change, the stability of the performance of the conductive adhesive under cold and hot impact is very important. As can be seen from the cold and hot impact test, the conductive adhesive prepared in the embodiment 1 still can maintain good mechanical properties after undergoing 100 cold and hot cycles, which is probably due to the fact that the non-covalent bonding of the graphene and the perylene diimide nitroxide enhances the connection between the graphene and the metal silver particles, so that the performance of the conductive adhesive is not greatly affected when the temperature is changed.
Claims (6)
1. The antistatic conductive adhesive for the circuit board is characterized by comprising the following components in parts by weight: 50-85 parts of nano silver/functionalized graphene hybrid conductive filler, 10-40 parts of siloxane resin, 0.1-0.8 part of catalyst, 0.1-0.8 part of reinforcing agent, 0.1-0.5 part of inhibitor and 0.1-0.5 part of cross-linking agent;
the nano silver/functionalized graphene hybridized conductive filler is prepared by preparing perylene diimide oxynitride as a surfactant to perform non-covalent functionalization on graphene nano sheets, and then carrying out hybridization with silver acetate;
the preparation method of the nano silver/functionalized graphene hybrid conductive filler comprises the following steps:
s1, adding 3,4,9, 10-tetracarboxylic anhydride and N, N-dimethylethylenediamine into N-butanol, heating and stirring, and evaporating a solvent to dryness after the reaction is finished to obtain N, N' -bis [3- (dimethylamino) propyl ] perylene-3, 4,9, 10-tetracarboxylic diimide;
s2, weighing N, N' -bis [3- (dimethylamino) propyl ] perylene-3, 4,9, 10-tetracarboxylic acid diimide in the step S1, adding into absolute ethyl alcohol, dropwise adding 30wt% hydrogen peroxide solution under the protection of argon, stirring at room temperature, heating for reflux, cooling to room temperature, decompressing, removing the solvent, and washing residues with acetone and N-hexane for three times in sequence to obtain perylene diimide nitrogen oxide;
s3, mixing graphite and potassium, and then heating to react under the nitrogen atmosphere to obtain potassium intercalated graphite;
s4, weighing potassium intercalated graphite in the step S3, adding the potassium intercalated graphite into pyridine, performing a cracking reaction at the temperature of minus 35 ℃ to minus 30 ℃, adding perylene diimide nitrogen oxide in the step S2, stirring, performing ultrasonic dispersion, and filtering to obtain noncovalently functionalized graphene;
s5, dissolving the non-covalent functionalized graphene obtained in the step S4 in methanol, adding silver acetate, stirring until the non-covalent functionalized graphene is dissolved, and concentrating at low temperature under reduced pressure to remove a solvent to obtain a nano silver/functionalized graphene hybridized conductive filler;
the silicone resin is formed by mixing vinyl silicone oil and vinyl MQ silicone resin in a mass ratio of 2-3:1.
2. The antistatic conductive adhesive of claim 1, wherein: the catalyst is a platinum-based catalyst.
3. The antistatic conductive adhesive of claim 1, wherein: the reinforcing agent is fumed silica.
4. The antistatic conductive adhesive of claim 1, wherein: the inhibitor is one of alkyne compound, dibasic acid ester containing double bond or nitrogen-containing compound.
5. The antistatic conductive adhesive of claim 1, wherein: the cross-linking agent is hydrogen-containing silicone oil.
6. A method for preparing the antistatic conductive adhesive according to any one of claims 1 to 5, comprising the steps of:
and weighing the siloxane resin and the nano silver/functionalized graphene hybrid conductive filler according to the formula amount, stirring and dispersing uniformly, stirring for 0.5-1 h, grinding for 1-3 times, continuously adding the catalyst, the reinforcing agent, the inhibitor and the cross-linking agent, stirring uniformly, and vacuumizing and degassing to obtain the antistatic conductive adhesive.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102153976A (en) * | 2011-03-01 | 2011-08-17 | 华南理工大学 | Preparation method of graphene/nano silver epoxy conductive adhesive |
| CN103194165A (en) * | 2013-04-26 | 2013-07-10 | 中国电子科技集团公司第三十八研究所 | Method for preparing high-heat-conductivity conductive adhesive containing graphene |
| WO2020012236A1 (en) * | 2018-07-13 | 2020-01-16 | Bosch Car Multimedia Portugal S.a. | Carbon/metal hybrid fillers, electrically conductive adhesive, methods and uses thereof |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102153976A (en) * | 2011-03-01 | 2011-08-17 | 华南理工大学 | Preparation method of graphene/nano silver epoxy conductive adhesive |
| CN103194165A (en) * | 2013-04-26 | 2013-07-10 | 中国电子科技集团公司第三十八研究所 | Method for preparing high-heat-conductivity conductive adhesive containing graphene |
| WO2020012236A1 (en) * | 2018-07-13 | 2020-01-16 | Bosch Car Multimedia Portugal S.a. | Carbon/metal hybrid fillers, electrically conductive adhesive, methods and uses thereof |
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