CN109705770B - Elastic conductive microsphere for anisotropic conductive adhesive film and preparation method - Google Patents
Elastic conductive microsphere for anisotropic conductive adhesive film and preparation method Download PDFInfo
- Publication number
- CN109705770B CN109705770B CN201910025600.6A CN201910025600A CN109705770B CN 109705770 B CN109705770 B CN 109705770B CN 201910025600 A CN201910025600 A CN 201910025600A CN 109705770 B CN109705770 B CN 109705770B
- Authority
- CN
- China
- Prior art keywords
- microspheres
- parts
- temperature
- vinyl imidazole
- elastic
- 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
Landscapes
- Adhesives Or Adhesive Processes (AREA)
- Conductive Materials (AREA)
Abstract
The invention relates to the technical field of conductive adhesive film fillers, and provides elastic conductive microspheres for an anisotropic conductive adhesive film and a preparation method thereof. The method comprises the steps of preparing 1-hydroxyethyl-3-vinyl imidazole bromide salt by using 1-vinyl imidazole and 2-bromoethanol, carrying out block copolymerization on the 1-vinyl imidazole and the 2-bromoethanol to obtain polyion liquid-butadiene elastic microspheres, and carrying out coarsening, sensitization, activation and chemical silver plating to obtain the elastic conductive microspheres for the anisotropic conductive adhesive film. Compared with the traditional method, the invention prepares the block copolymerization elastic microspheres by using the 1-hydroxyethyl-3-vinyl imidazole bromine salt and the butadiene, the introduction of the flexible chain segment obviously improves the elasticity of the microspheres, can reduce the breakage of the microspheres during compression joint interconnection, increases the operable compression joint pressure range and reduces the operation difficulty.
Description
Technical Field
The invention belongs to the technical field of conductive adhesive film fillers, and provides an elastic conductive microsphere for an anisotropic conductive adhesive film and a preparation method thereof.
Background
Electronic industry packaging materials dominate in electronic component assembly, however, the traditional soldering process has the defects of poor environmental protection, complex process and the like, so the traditional soldering technology is gradually replaced by the conductive adhesive which has both conductivity and gluing and fixing functions. Among them, the conductive adhesive film is very important, and the conductive adhesive film mainly comprises a resin binder, conductive particles and the like. With the continuous development of miniaturization, thinning and flexibility of electronic components, the application of the conductive adhesive film is wider and wider.
The conductive adhesive film is classified into an isotropic conductive adhesive film and an anisotropic conductive adhesive film. The anisotropic conductive adhesive film is a composite material prepared by blending micron-sized conductive particles and a controllable and fast-curing resin adhesive to form a film, wherein the conductive particles are used for realizing the electric conduction among the interconnected salient points, and the resin adhesive has the functions of bonding, heat resistance, insulation, fixing the relative positions of the interconnected salient points and maintaining the contact area between the salient points and the conductive particles. It is insulating in the X, Y direction and conducting in the Z direction, thus exhibiting anisotropy.
The composite microsphere using micron-sized monodisperse polymer as a core and conductive metal as a shell has the advantages of high roundness of the polymer microsphere, uniform particle size, good elasticity, light weight and good conductive performance of metal, so that the composite microsphere is used as conductive particles of an anisotropic conductive adhesive film. The polymer/metal composite microsphere has a large design space, and composite particles with different properties can be obtained by selecting different core layer materials and shell layer materials. Wherein, the shell layer is usually selected from gold, silver, copper, nickel and other metals, and the core layer is usually selected from monodisperse polystyrene microspheres, monodisperse polymethyl methacrylate microspheres and the like.
When the anisotropic conductive film is used for interconnection, pressure is required to be applied between two interconnected electrodes. If the applied pressure is too small, the degree of deformation of the conductive particles is small, the contact area with the electrode is small, and the conductive ability in the Z direction cannot be realized. If the applied pressure is too large, the conductive particles are crushed with too large a degree of deformation, the metal layer is broken, the conductivity in the Z direction is decreased, and the conductivity in the X, Y direction is increased, thereby losing anisotropy. Thus, the polymer core layer should possess some elasticity. The polystyrene microspheres and the polymethyl methacrylate microspheres have poor elasticity, and the compression joint pressure needs to be strictly limited during interconnection, so that the operation difficulty is high.
Disclosure of Invention
It can be seen that the polymer microspheres used as the conductive microsphere core layer in the prior art have poor elasticity, the crimping pressure needs to be strictly limited during interconnection, and the operation difficulty is high. Aiming at the situation, the invention provides an elastic conductive microsphere for an anisotropic conductive adhesive film and a preparation method thereof, wherein 1-hydroxyethyl-3-vinyl imidazole bromide and butadiene are used for preparing the block copolymerization elastic microsphere, the introduction of a flexible chain segment obviously improves the elasticity of the microsphere, can reduce the breakage of the microsphere during compression joint interconnection, increases the operable compression joint pressure range and reduces the operation difficulty.
In order to achieve the purpose, the invention relates to the following specific technical scheme:
a preparation method of elastic conductive microspheres for anisotropic conductive adhesive films comprises the following specific steps:
(1) adding 1-vinyl imidazole and 2-bromoethanol into a reaction container, magnetically stirring at the speed of 120-150 r/min, heating for reacting for a certain time, then adding anhydrous ether, refluxing for 20-30 min, stopping heating, cooling to room temperature, filtering, washing, and drying in vacuum to obtain 1-hydroxyethyl-3-vinyl imidazole bromide;
(2) adding the 1-hydroxyethyl-3-vinyl imidazole bromide salt prepared in the step (1), butadiene, ethylene glycol tert-butyl ether and sodium dodecyl sulfate into cyclohexane, continuously introducing nitrogen, stirring for 20-30 min, adding an alkyl lithium initiator, heating for polymerization reaction, centrifuging after the reaction is finished, washing, and drying in vacuum to obtain polyion liquid-butadiene elastic microspheres;
(3) and (3) sequentially carrying out coarsening, sensitization, activation and chemical silvering on the elastic microspheres prepared in the step (2) to prepare the elastic conductive microspheres for the anisotropic conductive adhesive film.
The reaction in the step (1) is used for introducing hydroxyl groups into a molecular structure of 1-vinylimidazole, and preferably, the weight parts of the raw materials are 40-45 parts of 1-vinylimidazole, 55-60 parts of 2-bromoethanol and 10-20 parts of anhydrous ether; the reaction temperature is 88-92 ℃, and the reaction time is 40-44 h; the temperature of the vacuum drying is 50-60 ℃, and the time is 8-10 h.
And (2) generating the block copolymerization microsphere with the butadiene elastic chain segment through the copolymerization reaction of the 1-hydroxyethyl-3-vinyl imidazole bromide and butadiene so as to improve the elasticity of the microsphere. In order to obtain microspheres with uniform particle size, sodium dodecyl sulfate is used as a dispersing agent, and ethylene glycol tert-butyl ether is added, so that the particle size of the prepared block copolymer microspheres is 3-5 mu m, and the particle size dispersion coefficient is 0.1-0.12. Preferably, the alkyl lithium initiator is one of tert-butyl lithium, isopropyl lithium, cyclohexyl lithium, phenyl lithium and naphthyl lithium; the raw materials comprise, by weight, 10-12 parts of 1-hydroxyethyl-3-vinylimidazole bromide, 3-5 parts of butadiene, 1-2 parts of ethylene glycol tert-butyl ether, 0.5-2 parts of sodium dodecyl sulfate, 0.5-1 part of an alkyl lithium initiator and 78-85 parts of cyclohexane; the reaction temperature is 70-75 ℃, and the reaction time is 2-4 h; the temperature of the vacuum drying is 40-50 ℃, and the time is 18-24 h.
The invention adopts the conventional process for coarsening, sensitizing and activating the block copolymerization microspheres. Preferably, the roughening in the step (3) adopts a mixed solution of 20-30 g/L potassium dichromate and 70-80 mL/L sulfuric acid, the temperature is 50-60 ℃, and the ultrasonic time is 60-80 min; the sensitization adopts a mixed solution of 15-18 g/L stannous chloride and 20-25 mL/L hydrochloric acid, the temperature is room temperature, and the ultrasonic time is 20-30 min; the activation adopts sol of 1-1.2 g/L chloroplatinic acid, 1.5-2 g/L sodium citrate and 0.4-0.6 g/L sodium borohydride, the temperature is 40-50 ℃, and the time is 15-20 min; the chemical silver plating solution comprises, by weight, 12-15 g/L of silver nitrate, 1.2-1.5 g/L of disodium hydrogen phosphate, 0.2-0.4 g/L of sodium hydroxide, 25-30 g/L of glucose, 3-4 g/L of tartaric acid, 30-40 mL/L of hexanediol and 0.3-0.5 g/L of polyvinylpyrrolidone, wherein the loading amount of the activated microspheres in the chemical plating solution is 3-5 g/L, the chemical silver plating temperature is 18-20 ℃, and the chemical silver plating time is 90-120 min. The polyvinylpyrrolidone is added into the chemical plating solution, so that the chemical plating solution has strong complexation effect on silver particles, and can improve the microstructure of a plating layer, so that the plating layer is more compact and uniform, and the thickness is reduced. The loading of the activated microspheres is controlled to prevent the microspheres from settling in the resin matrix and to ensure the formation of a continuous coating.
The invention also provides the elastic conductive microspheres for the anisotropic conductive adhesive film prepared by the preparation method. The elastic conductive microspheres are prepared by preparing 1-hydroxyethyl-3-vinyl imidazole bromide salt from 1-vinyl imidazole and 2-bromoethanol, then carrying out block copolymerization on the prepared 1-hydroxyethyl-3-vinyl imidazole bromide salt and butadiene to prepare polyion liquid-butadiene elastic microspheres, and then carrying out coarsening, sensitization, activation and chemical silver plating.
The invention provides an elastic conductive microsphere for an anisotropic conductive adhesive film and a preparation method thereof, and compared with the prior art, the elastic conductive microsphere has the outstanding characteristics and excellent effects that:
1. according to the elastic conductive microspheres prepared by the invention, the conductive path is formed on the surfaces of the microspheres through the continuous and compact silver plating layer, and the conductive network is formed in the microspheres through the conductivity of the polyion liquid, so that the microspheres have good conductivity.
2. According to the preparation method, hydroxyl is introduced into the molecular structure of the 1-vinyl imidazole, and the hydroxyl on the molecular structure of the prepared 1-hydroxyethyl-3-vinyl imidazole bromide salt contains lone pair electrons, has an adsorption effect on Ag, and can prevent the cracking and falling of a silver coating.
3. According to the preparation method, the 1-hydroxyethyl-3-vinyl imidazole bromide and butadiene are used for preparing the block copolymerization elastic microspheres, the elasticity of the microspheres is obviously improved due to the introduction of the flexible chain segment, the breakage of the microspheres during compression joint interconnection can be reduced, the operable compression joint pressure range is enlarged, and the operation difficulty is reduced.
Drawings
FIG. 1 is a schematic view of a test piece for testing the performance of a conductive adhesive film.
Detailed Description
The present invention will be described in further detail with reference to specific embodiments, but it should not be construed that the scope of the present invention is limited to the following examples. Various substitutions and alterations can be made by those skilled in the art and by conventional means without departing from the spirit of the method of the invention described above.
Example 1
(1) Adding 1-vinyl imidazole and 2-bromoethanol into a reaction vessel, magnetically stirring at the speed of 130r/min, heating for reacting for a certain time, then adding anhydrous ether, refluxing for 26min, stopping heating, cooling to room temperature, filtering, washing, and vacuum drying to obtain 1-hydroxyethyl-3-vinyl imidazole bromide; the weight parts of the raw materials are 43 parts of 1-vinyl imidazole, 57 parts of 2-bromoethanol and 15 parts of anhydrous ether; the reaction temperature is 89 ℃, and the reaction time is 43 hours; the temperature of vacuum drying is 56 ℃, and the time is 9 h;
(2) adding the 1-hydroxyethyl-3-vinyl imidazole bromide salt prepared in the step (1), butadiene, ethylene glycol tert-butyl ether and sodium dodecyl sulfate into cyclohexane, continuously introducing nitrogen, stirring for 26min, adding an alkyl lithium initiator, heating for polymerization reaction, centrifuging after the reaction is finished, washing, and drying in vacuum to obtain polyion liquid-butadiene elastic microspheres; the alkyl lithium initiator is tert-butyl lithium; the weight portions of the raw materials are 11 portions of 1-ethoxyl-3-vinyl imidazole bromide, 4 portions of butadiene, 1.5 portions of ethylene glycol tert-butyl ether, 1 portion of sodium dodecyl sulfate, 0.5 portion of alkyl lithium initiator and 82 portions of cyclohexane; the reaction temperature is 73 ℃ and the reaction time is 3.5 h; the temperature of vacuum drying is 46 ℃, and the time is 20 h;
(3) sequentially carrying out coarsening, sensitization, activation and chemical silvering on the elastic microspheres prepared in the step (2) to prepare elastic conductive microspheres for the anisotropic conductive adhesive film; the coarsening adopts a mixed solution of 26g/L potassium dichromate and 76mL/L sulfuric acid, the temperature is 56 ℃, and the ultrasonic time is 72 min; sensitizing by using a mixed solution of 17g/L stannous chloride and 23mL/L hydrochloric acid, wherein the temperature is room temperature, and the ultrasonic time is 26 min; activating with sol of 1.1g/L chloroplatinic acid, 1.7g/L sodium citrate and 0.5g/L sodium borohydride at 46 deg.C for 17 min; the concentration of each component of the chemical silver plating solution is 13g/L of silver nitrate, 1.3g/L of disodium hydrogen phosphate, 0.3g/L of sodium hydroxide, 27g/L of glucose, 3.4g/L of tartaric acid, 36mL/L of hexanediol and 0.4g/L of polyvinylpyrrolidone, the loading amount of the activated microspheres in the chemical silver plating solution is 4.5g/L, the temperature of chemical silver plating is 19 ℃, and the time is 100 min.
Example 2
(1) Adding 1-vinyl imidazole and 2-bromoethanol into a reaction vessel, magnetically stirring at the speed of 130r/min, heating for reacting for a certain time, then adding anhydrous ether, refluxing for 22min, stopping heating, cooling to room temperature, filtering, washing, and vacuum drying to obtain 1-hydroxyethyl-3-vinyl imidazole bromide; the weight parts of the raw materials are 41 parts of 1-vinyl imidazole, 59 parts of 2-bromoethanol and 12 parts of anhydrous ether; the reaction temperature is 89 ℃, and the reaction time is 43 hours; the temperature of vacuum drying is 53 ℃, and the time is 9.5 h;
(2) adding the 1-hydroxyethyl-3-vinyl imidazole bromide salt prepared in the step (1), butadiene, ethylene glycol tert-butyl ether and sodium dodecyl sulfate into cyclohexane, continuously introducing nitrogen, stirring for 23min, adding an alkyl lithium initiator, heating for polymerization reaction, centrifuging after the reaction is finished, washing, and drying in vacuum to obtain polyion liquid-butadiene elastic microspheres; the alkyl lithium initiator is isopropyl lithium; the weight portion of each raw material is 1-ethoxyl-3-vinyl imidazole bromine salt 10. 5 parts by weight, 3.5 parts by weight of butadiene, 1 part by weight of ethylene glycol tert-butyl ether, 1 part by weight of sodium dodecyl sulfate, 0.5 part by weight of alkyl lithium initiator and 83.5 parts by weight of cyclohexane; the reaction temperature is 72 ℃ and the reaction time is 3.5 h; the temperature of vacuum drying is 42 ℃, and the time is 22 h;
(3) sequentially carrying out coarsening, sensitization, activation and chemical silvering on the elastic microspheres prepared in the step (2) to prepare elastic conductive microspheres for the anisotropic conductive adhesive film; the coarsening adopts a mixed solution of 22g/L potassium dichromate and 73mL/L sulfuric acid, the temperature is 52 ℃, and the ultrasonic time is 75 min; sensitizing by using a mixed solution of 16g/L stannous chloride and 21mL/L hydrochloric acid, wherein the temperature is room temperature, and the ultrasonic time is 27 min; activating by sol of 1g/L chloroplatinic acid, 1.6g/L sodium citrate and 0.4g/L sodium borohydride at 42 ℃ for 18 min; the concentration of each component of the chemical silver plating solution is 13g/L of silver nitrate, 1.3g/L of disodium hydrogen phosphate, 0.2g/L of sodium hydroxide, 26g/L of glucose, 3g/L of tartaric acid, 32mL/L of hexanediol and 0.3g/L of polyvinylpyrrolidone, the loading amount of the activated microspheres in the chemical silver plating solution is 3.5g/L, the temperature of chemical silver plating is 19 ℃, and the time is 95 min.
Example 3
(1) Adding 1-vinyl imidazole and 2-bromoethanol into a reaction vessel, magnetically stirring at the speed of 140r/min, heating for reacting for a certain time, then adding anhydrous ether, refluxing for 28min, stopping heating, cooling to room temperature, filtering, washing, and vacuum drying to obtain 1-hydroxyethyl-3-vinyl imidazole bromide; the weight parts of the raw materials are 44 parts of 1-vinyl imidazole, 56 parts of 2-bromoethanol and 18 parts of anhydrous ether; the reaction temperature is 91 ℃, and the reaction time is 41 h; the temperature of vacuum drying is 58 ℃ and the time is 8.5 h;
(2) adding the 1-hydroxyethyl-3-vinyl imidazole bromide salt prepared in the step (1), butadiene, ethylene glycol tert-butyl ether and sodium dodecyl sulfate into cyclohexane, continuously introducing nitrogen, stirring for 28min, adding an alkyl lithium initiator, heating for polymerization reaction, centrifuging after the reaction is finished, washing, and drying in vacuum to obtain polyion liquid-butadiene elastic microspheres; the alkyl lithium initiator is cyclohexyl lithium; the weight portions of the raw materials are 11.5 portions of 1-ethoxyl-3-vinyl imidazole bromide, 4.5 portions of butadiene, 2 portions of ethylene glycol tert-butyl ether, 1.5 portions of sodium dodecyl sulfate, 1 portion of alkyl lithium initiator and 79.5 portions of cyclohexane; the reaction temperature is 74 ℃ and the reaction time is 2.5 h; the temperature of vacuum drying is 48 ℃, and the time is 19 hours;
(3) sequentially carrying out coarsening, sensitization, activation and chemical silvering on the elastic microspheres prepared in the step (2) to prepare elastic conductive microspheres for the anisotropic conductive adhesive film; the coarsening adopts a mixed solution of 28g/L potassium dichromate and 78mL/L sulfuric acid, the temperature is 58 ℃, and the ultrasonic time is 65 min; sensitizing by using a mixed solution of 17g/L stannous chloride and 24mL/L hydrochloric acid, wherein the temperature is room temperature, and the ultrasonic time is 28 min; activating by adopting sol of 1.2g/L chloroplatinic acid, 1.9g/L sodium citrate and 0.6g/L sodium borohydride, wherein the temperature is 47 ℃ and the time is 16 min; the concentration of each component of the chemical silver plating solution is 14g/L of silver nitrate, 1.4g/L of disodium hydrogen phosphate, 0.4g/L of sodium hydroxide, 28g/L of glucose, 3.8g/L of tartaric acid, 38mL/L of hexanediol and 0.5g/L of polyvinylpyrrolidone, the loading amount of the activated microspheres in the chemical silver plating solution is 4.5g/L, the temperature of chemical silver plating is 20 ℃, and the time is 95 min.
Example 4
(1) Adding 1-vinyl imidazole and 2-bromoethanol into a reaction vessel, magnetically stirring at the speed of 120r/min, heating for reacting for a certain time, then adding anhydrous ether, refluxing for 20min, stopping heating, cooling to room temperature, filtering, washing, and vacuum drying to obtain 1-hydroxyethyl-3-vinyl imidazole bromide; the weight parts of the raw materials are 40 parts of 1-vinyl imidazole, 60 parts of 2-bromoethanol and 10 parts of anhydrous ether; the reaction temperature is 88 ℃ and the reaction time is 44 h; the temperature of vacuum drying is 50 ℃, and the time is 10 hours;
(2) adding the 1-hydroxyethyl-3-vinyl imidazole bromide salt prepared in the step (1), butadiene, ethylene glycol tert-butyl ether and sodium dodecyl sulfate into cyclohexane, continuously introducing nitrogen, stirring for 20min, adding an alkyl lithium initiator, heating for polymerization reaction, centrifuging after the reaction is finished, washing, and drying in vacuum to obtain polyion liquid-butadiene elastic microspheres; the alkyl lithium initiator is phenyl lithium; the weight portions of the raw materials are 10 portions of 1-ethoxyl-3-vinyl imidazole bromide, 3 portions of butadiene, 1 portion of ethylene glycol tert-butyl ether, 0.5 portion of sodium dodecyl sulfate, 0.5 portion of alkyl lithium initiator and 85 portions of cyclohexane; the reaction temperature is 70 ℃, and the reaction time is 4 hours; the temperature of vacuum drying is 40 ℃, and the time is 24 hours;
(3) sequentially carrying out coarsening, sensitization, activation and chemical silvering on the elastic microspheres prepared in the step (2) to prepare elastic conductive microspheres for the anisotropic conductive adhesive film; the coarsening adopts a mixed solution of 20g/L potassium dichromate and 70mL/L sulfuric acid, the temperature is 50 ℃, and the ultrasonic time is 80 min; sensitizing by using a mixed solution of 15g/L stannous chloride and 20mL/L hydrochloric acid, wherein the temperature is room temperature, and the ultrasonic time is 30 min; activating by sol of 1g/L chloroplatinic acid, 1.5g/L sodium citrate and 0.4g/L sodium borohydride at 40 ℃ for 20 min; the concentration of each component of the chemical silver plating solution is 12g/L of silver nitrate, 1.2g/L of disodium hydrogen phosphate, 0.2g/L of sodium hydroxide, 25g/L of glucose, 3g/L of tartaric acid, 30mL/L of hexanediol and 0.3g/L of polyvinylpyrrolidone, the loading amount of the activated microspheres in the chemical silver plating solution is 3g/L, the temperature of chemical silver plating is 18 ℃, and the time is 120 min.
Example 5
(1) Adding 1-vinyl imidazole and 2-bromoethanol into a reaction vessel, magnetically stirring at the speed of 150r/min, heating for reacting for a certain time, then adding anhydrous ether, refluxing for 30min, stopping heating, cooling to room temperature, filtering, washing, and vacuum drying to obtain 1-hydroxyethyl-3-vinyl imidazole bromide; the weight parts of the raw materials are 45 parts of 1-vinyl imidazole, 55 parts of 2-bromoethanol and 20 parts of anhydrous ether; the reaction temperature is 92 ℃, and the reaction time is 40 h; the temperature of vacuum drying is 60 ℃, and the time is 8 hours;
(2) adding the 1-hydroxyethyl-3-vinyl imidazole bromide salt prepared in the step (1), butadiene, ethylene glycol tert-butyl ether and sodium dodecyl sulfate into cyclohexane, continuously introducing nitrogen, stirring for 30min, adding an alkyl lithium initiator, heating for polymerization reaction, centrifuging after the reaction is finished, washing, and drying in vacuum to obtain polyion liquid-butadiene elastic microspheres; the alkyl lithium initiator is lithium naphthyl; the weight parts of the raw materials are 12 parts of 1-hydroxyethyl-3-vinyl imidazole bromide, 5 parts of butadiene, 2 parts of ethylene glycol tert-butyl ether, 2 parts of sodium dodecyl sulfate, 1 part of alkyl lithium initiator and 78 parts of cyclohexane; the reaction temperature is 75 ℃, and the reaction time is 2 hours; the temperature of vacuum drying is 50 ℃, and the time is 18 h;
(3) sequentially carrying out coarsening, sensitization, activation and chemical silvering on the elastic microspheres prepared in the step (2) to prepare elastic conductive microspheres for the anisotropic conductive adhesive film; the coarsening adopts a mixed solution of 30g/L potassium dichromate and 80mL/L sulfuric acid, the temperature is 60 ℃, and the ultrasonic time is 60 min; sensitizing by using a mixed solution of 18g/L stannous chloride and 25mL/L hydrochloric acid, wherein the temperature is room temperature, and the ultrasonic time is 20 min; activating by adopting sol of 1.2g/L chloroplatinic acid, 2g/L sodium citrate and 0.6g/L sodium borohydride at the temperature of 50 ℃ for 15 min; the concentration of each component of the chemical silver plating solution is 15g/L of silver nitrate, 1.5g/L of disodium hydrogen phosphate, 0.4g/L of sodium hydroxide, 30g/L of glucose, 4g/L of tartaric acid, 40mL/L of hexanediol and 0.5g/L of polyvinylpyrrolidone, the loading amount of the activated microspheres in the chemical silver plating solution is 5g/L, the temperature of chemical silver plating is 20 ℃, and the time is 90 min.
Example 6
(1) Adding 1-vinyl imidazole and 2-bromoethanol into a reaction vessel, magnetically stirring at the speed of 135r/min, heating for reacting for a certain time, then adding anhydrous ether, refluxing for 25min, stopping heating, cooling to room temperature, filtering, washing, and vacuum drying to obtain 1-hydroxyethyl-3-vinyl imidazole bromide; the weight parts of the raw materials are 42 parts of 1-vinyl imidazole, 58 parts of 2-bromoethanol and 15 parts of anhydrous ether; the reaction temperature is 90 ℃ and the reaction time is 42 h; the temperature of vacuum drying is 55 ℃, and the time is 9 h;
(2) adding the 1-hydroxyethyl-3-vinyl imidazole bromide salt prepared in the step (1), butadiene, ethylene glycol tert-butyl ether and sodium dodecyl sulfate into cyclohexane, continuously introducing nitrogen, stirring for 25min, adding an alkyl lithium initiator, heating for polymerization reaction, centrifuging after the reaction is finished, washing, and drying in vacuum to obtain polyion liquid-butadiene elastic microspheres; the alkyl lithium initiator is tert-butyl lithium; the weight parts of the raw materials are 11 parts of 1-hydroxyethyl-3-vinyl imidazole bromide, 4 parts of butadiene, 1.5 parts of ethylene glycol tert-butyl ether, 1 part of sodium dodecyl sulfate, 1 part of alkyl lithium initiator and 81.5 parts of cyclohexane; the reaction temperature is 72 ℃, and the reaction time is 3 hours; the temperature of vacuum drying is 45 ℃ and the time is 20 h;
(3) sequentially carrying out coarsening, sensitization, activation and chemical silvering on the elastic microspheres prepared in the step (2) to prepare elastic conductive microspheres for the anisotropic conductive adhesive film; the coarsening adopts a mixed solution of 25g/L potassium dichromate and 75mL/L sulfuric acid, the temperature is 55 ℃, and the ultrasonic time is 70 min; sensitizing by using a mixed solution of 16g/L stannous chloride and 22mL/L hydrochloric acid, wherein the temperature is room temperature, and the ultrasonic time is 25 min; activating by adopting sol of 1.1g/L chloroplatinic acid, 1.8g/L sodium citrate and 0.5g/L sodium borohydride at the temperature of 45 ℃ for 18 min; the concentration of each component of the chemical silver plating solution is 14g/L of silver nitrate, 1.4g/L of disodium hydrogen phosphate, 0.3g/L of sodium hydroxide, 28g/L of glucose, 3.5g/L of tartaric acid, 35mL/L of hexanediol and 0.4g/L of polyvinylpyrrolidone, the loading amount of the activated microspheres in the chemical silver plating solution is 4g/L, the temperature of chemical silver plating is 19 ℃, and the time is 105 min.
Comparative example 1
The conductive microsphere is prepared by taking polystyrene microsphere as a core layer through coarsening, sensitizing, activating and chemical silvering.
And (3) performance testing:
preparing a conductive adhesive film: mixing 53 parts by weight of bisphenol A epoxy resin, 20 parts by weight of elastic conductive microspheres prepared by the method of the invention or conductive microspheres prepared in comparative example 1 and 20 parts by weight of acetone, stirring at a speed of 20-30 r/min for 4 hours, adding 2 parts by weight of 1-cyanoethyl-2-methylimidazole, 2 parts by weight of fumed silica, 1 part by weight of gamma-aminopropyltriethoxysilane, 1 part by weight of polyoxypropylene glycerol ether and 1 part by weight of poly (dipropylene glycol) phenyl phosphite, continuously stirring for 1.5 hours, defoaming, coating the prepared jelly on an isolating membrane through a coating machine, drying by hot air at 70 ℃, cutting and winding into a coil to prepare an anisotropic conductive adhesive film;
an assembly test piece is prepared in a form of FOG (flex-on-glass), a flexible circuit board takes a polyimide film as a base material, and then copper lines are printed on the surface of the polyimide film, wherein the distance between the copper lines is 500 mu m. Attaching the prepared anisotropic conductive adhesive film to a flexible circuit board, then placing conductive glass on the conductive adhesive film, carrying out compression joint in a constant-temperature hot press at the temperature of 160 ℃, wherein the compression joint pressure is respectively 0.3MPa, 0.5MPa, 1MPa and 1.5MPa, and the time is 15s, so that the flexible circuit board is connected with the conductive glass through the anisotropic conductive adhesive film to obtain test pieces under different pressures, and measuring the contact resistance between a and b in the z direction and the insulation resistance between a and c in the x direction by using a universal meter. When the line pitch is 500 μm, we set the insulation resistance between a and c to < 108Omega is regarded as conduction between a and c, namely the material loses anisotropy.
The data obtained are shown in Table 1. Therefore, the epoxy resin conductive adhesive film prepared by the elastic conductive microspheres can keep good anisotropy under the pressure of 0.3-1.5 MPa. When the crimping pressure is lower, the electric conductivity of the epoxy resin conductive adhesive film made of the polystyrene conductive microspheres is similar to that of an elastic conductive microsphere adhesive film along with the change of the crimping pressure, along with the increase of the crimping pressure, due to the gradual breakage of the conductive microspheres, the indirect electric resistance of the a and the b tends to increase, the insulation resistance between the a and the c gradually becomes smaller, and when the crimping pressure reaches 1-1.5 MPa, the conductive adhesive film loses anisotropy.
Table 1:
Claims (6)
1. a preparation method of elastic conductive microspheres for anisotropic conductive adhesive films is characterized in that the preparation method of the elastic conductive microspheres comprises the following specific steps:
(1) adding 1-vinyl imidazole and 2-bromoethanol into a reaction container, magnetically stirring at the speed of 120-150 r/min, heating for reacting for a certain time, then adding anhydrous ether, refluxing for 20-30 min, stopping heating, cooling to room temperature, filtering, washing, and drying in vacuum to obtain 1-hydroxyethyl-3-vinyl imidazole bromide; the weight parts of the raw materials are 40-45 parts of 1-vinyl imidazole, 55-60 parts of 2-bromoethanol and 10-20 parts of anhydrous ether;
(2) adding the 1-hydroxyethyl-3-vinyl imidazole bromide salt prepared in the step (1), butadiene, ethylene glycol tert-butyl ether and sodium dodecyl sulfate into cyclohexane, continuously introducing nitrogen, stirring for 20-30 min, adding an alkyl lithium initiator, heating for polymerization reaction, centrifuging after the reaction is finished, washing, and drying in vacuum to obtain polyion liquid-butadiene elastic microspheres; the lithium alkyl initiator is one of tert-butyl lithium, isopropyl lithium, cyclohexyl lithium, phenyl lithium and naphthyl lithium; the raw materials comprise, by weight, 10-12 parts of 1-hydroxyethyl-3-vinylimidazole bromide, 3-5 parts of butadiene, 1-2 parts of ethylene glycol tert-butyl ether, 0.5-2 parts of sodium dodecyl sulfate, 0.5-1 part of an alkyl lithium initiator and 78-85 parts of cyclohexane;
(3) sequentially carrying out coarsening, sensitization, activation and chemical silvering on the elastic microspheres prepared in the step (2) to prepare elastic conductive microspheres for the anisotropic conductive adhesive film; the coarsening adopts a mixed solution of 20-30 g/L potassium dichromate and 70-80 mL/L sulfuric acid, the temperature is 50-60 ℃, and the ultrasonic time is 60-80 min; the sensitization adopts a mixed solution of 15-18 g/L stannous chloride and 20-25 mL/L hydrochloric acid, the temperature is room temperature, and the ultrasonic time is 20-30 min; the activation adopts sol of 1-1.2 g/L chloroplatinic acid, 1.5-2 g/L sodium citrate and 0.4-0.6 g/L sodium borohydride, the temperature is 40-50 ℃, and the time is 15-20 min; the chemical silver plating solution comprises, by weight, 12-15 g/L of silver nitrate, 1.2-1.5 g/L of disodium hydrogen phosphate, 0.2-0.4 g/L of sodium hydroxide, 25-30 g/L of glucose, 3-4 g/L of tartaric acid, 30-40 mL/L of hexanediol and 0.3-0.5 g/L of polyvinylpyrrolidone, wherein the loading amount of the activated microspheres in the chemical plating solution is 3-5 g/L, the chemical silver plating temperature is 18-20 ℃, and the chemical silver plating time is 90-120 min.
2. The method of claim 1, wherein the method comprises the following steps: the reaction temperature in the step (1) is 88-92 ℃, and the reaction time is 40-44 h.
3. The method of claim 1, wherein the method comprises the following steps: and (2) drying in vacuum at the temperature of 50-60 ℃ for 8-10 h.
4. The method of claim 1, wherein the method comprises the following steps: the reaction temperature in the step (2) is 70-75 ℃, and the reaction time is 2-4 h.
5. The method of claim 1, wherein the method comprises the following steps: and (3) drying in vacuum in the step (2) at the temperature of 40-50 ℃ for 18-24 h.
6. An elastic conductive microsphere for anisotropic conductive adhesive film prepared by the preparation method of any one of claims 1 to 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910025600.6A CN109705770B (en) | 2019-01-11 | 2019-01-11 | Elastic conductive microsphere for anisotropic conductive adhesive film and preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910025600.6A CN109705770B (en) | 2019-01-11 | 2019-01-11 | Elastic conductive microsphere for anisotropic conductive adhesive film and preparation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109705770A CN109705770A (en) | 2019-05-03 |
| CN109705770B true CN109705770B (en) | 2021-01-05 |
Family
ID=66261032
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910025600.6A Active CN109705770B (en) | 2019-01-11 | 2019-01-11 | Elastic conductive microsphere for anisotropic conductive adhesive film and preparation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109705770B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101269650B1 (en) * | 2011-06-17 | 2013-05-30 | 성균관대학교산학협력단 | Metal-carbon hybrid adhesive having flexibility, adhesiveness and conductivity, and conductive pattern using the same |
| CN103555313A (en) * | 2013-11-06 | 2014-02-05 | 山东大学 | Imidazolium salt ionic liquid acidizing corrosion inhibitor as well as preparation method and application thereof |
| CN105070351A (en) * | 2015-06-30 | 2015-11-18 | 苏州纳微科技有限公司 | Flexible conductive microballoon and applications thereof |
-
2019
- 2019-01-11 CN CN201910025600.6A patent/CN109705770B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101269650B1 (en) * | 2011-06-17 | 2013-05-30 | 성균관대학교산학협력단 | Metal-carbon hybrid adhesive having flexibility, adhesiveness and conductivity, and conductive pattern using the same |
| CN103555313A (en) * | 2013-11-06 | 2014-02-05 | 山东大学 | Imidazolium salt ionic liquid acidizing corrosion inhibitor as well as preparation method and application thereof |
| CN105070351A (en) * | 2015-06-30 | 2015-11-18 | 苏州纳微科技有限公司 | Flexible conductive microballoon and applications thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109705770A (en) | 2019-05-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102260378B (en) | Composite material, high-frequency circuit board manufactured therefrom and manufacturing method of high-frequency circuit board | |
| US7851063B2 (en) | Polymer particles and conductive particles having enhanced conducting properties, and anisotropic conductive packaging materials containing the same | |
| KR100568491B1 (en) | Adhesive for semiconductor components | |
| KR20050028779A (en) | Resin composition, prepreg, laminate sheet and printed wiring board using the same | |
| CN104130565B (en) | Resin composition, film, and substrate comprising same | |
| CN104830247A (en) | Sheet/branch silver-coated copper powder and green halogen-free low-silver-content economical electrically conductive adhesive capable of replacing traditional electrically conductive adhesives with high silver contents | |
| WO2024027191A1 (en) | Modification method for polyphenyl ether resin, laminated film composite material, laminated film, and substrate | |
| CN109705770B (en) | Elastic conductive microsphere for anisotropic conductive adhesive film and preparation method | |
| CN114274618A (en) | Halogen-containing high-Tg high-speed copper-clad plate for communication server and preparation method thereof | |
| CN114591580B (en) | Fluorine-containing resin mixture, prepreg and high-heat-conductivity high-frequency copper-clad plate | |
| US20040222523A1 (en) | Insulated conductive ball for anisotropic conductive connection, method of preparing the same, and product using the same | |
| CN104673128A (en) | High-performance modified bismaleimide conductive adhesive as well as preparation method and curing method thereof | |
| JP3620751B2 (en) | Anisotropic conductive film | |
| CN107626917B (en) | Preparation method of silver-plated copper powder | |
| CN116515439B (en) | Heat-resistant low-dielectric-loss copper-clad plate adhesive and preparation method thereof | |
| CN109735257B (en) | Heat-resistant conductive microsphere for anisotropic conductive adhesive film and preparation method | |
| CN110885536A (en) | Conductive buoyancy material and preparation method thereof | |
| CN114605831B (en) | Anti-corrosion magnetic shielding rubber and preparation method thereof | |
| CN114559712B (en) | High-temperature-resistant low-loss copper-clad plate and preparation process thereof | |
| CN109735276B (en) | Micron copper sheet-polyphenyl ether-epoxy resin conductive adhesive and preparation method thereof | |
| WO2022002278A1 (en) | Conductive microsphere for anisotropic conductive adhesive film and preparation method therefor | |
| CN117586714B (en) | Conductive adhesive film with anisotropy and preparation method thereof | |
| CN114536923B (en) | Fluorine-containing resin-based high-heat-conductivity high-frequency copper-clad plate with high dielectric constant | |
| CN115011279B (en) | Conductive adhesive film material with dual curing mode and preparation method thereof | |
| JP2964790B2 (en) | Metal-coated novolak-epoxide spherical resin |
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 | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20201216 Address after: 215411 No. 162 Renmin South Road, Chengxiang Town, Taicang City, Suzhou City, Jiangsu Province Applicant after: SUZHOU NUMATER NEW MATERIAL TECHNOLOGY Co.,Ltd. Address before: 610000 1, 3, 1, 366 north section of lakeside road, Tianfu New District, Chengdu, Sichuan Applicant before: CHENGDU QIQI XIAOSHU TECHNOLOGY Co.,Ltd. |
|
| TA01 | Transfer of patent application right | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |