KR20070096318A - Conductive ball for anisotropic conductive film and method of preparing same - Google Patents

Abstract

A conductive particle for an anisotropic conductive film and a manufacturing method thereof are provided to reduce a size of the conductive particle by mixing an amino chemical with an aldehyde chemical to form an amino resin precursor. A conductive particle for an anisotropic conductive film contains polymer complex particles and a metal plating layer. The polymer complex particles contain an amino resin. The metal plating layer is formed on the polymer complex particles. A hydrophobic functional group is coupled with a surface of the metal plating layer. The metal plating layer contains an Ni plating layer and an Au plating layer to form a two-layer structure. An amino resin precursor is formed by mixing a first chemical with a second chemical. The first chemical contains amino groups. The second chemical contains an aldehyde chemical.

Description

Conductive particles for anisotropic conductive films and a manufacturing method thereof {CONDUCTIVE BALL FOR ANISOTROPIC CONDUCTIVE FILM AND METHOD OF PREPARING SAME}

1 is a view schematically showing the structure of conductive particles for anisotropic conductive film of the present invention.

Figure 2 schematically shows a process for producing the conductive particles for anisotropic conductive film of the present invention.

Figure 3 is a schematic diagram schematically showing a reaction tank used in the plating process of the present invention.

Figure 4 is a SEM photograph of the amino resin composite particles before dispersion treatment prepared according to Example 11 of the present invention.

Figure 5 is a SEM photograph of the amino resin composite particles after the dispersion treatment prepared according to Example 11 of the present invention.

Figure 6 is a biological micrograph before the dispersion treatment of the amino resin composite particles prepared according to Example 11 of the present invention.

7 is a biological micrograph before dispersion treatment of the amino resin composite particles prepared according to Example 12 of the present invention.

8 is a biomicrograph before dispersion of the amino resin composite particle prepared according to Comparative Example 6.

9 is a biological micrograph before dispersion of the amino resin composite particle prepared according to Comparative Example 6.

10 is a biological micrograph after the dispersion treatment of the amino resin composite particles prepared according to Example 13 of the present invention.

FIG. 11 is a biomicrograph before dispersion of amino resin composite particles prepared according to Comparative Example 8. FIG.

12 is a biological micrograph before dispersion treatment of the amino resin composite particles prepared according to Example 14 of the present invention.

13 is a biomicrograph before dispersion of the amino resin composite particle prepared according to Comparative Example 9. FIG.

14 is a biological micrograph before dispersion treatment of the amino resin composite particle prepared according to Comparative Example 10.

15 is a biomicrograph before dispersion of the amino resin composite particle prepared according to Comparative Example 13. FIG.

Figure 16 is a biological micrograph before the dispersion treatment of the amino resin composite particles prepared according to Example 17 of the present invention.

17 is a biological micrograph before dispersion treatment of the amino resin composite particle prepared according to Comparative Example 14.

FIG. 18 is a micrograph of a product before dispersion of amino resin composite particles prepared according to Comparative Example 15; FIG.

19 is a biomicrograph before dispersion of the amino resin composite particle prepared according to Example 18 of the present invention.

20 is a biomicrograph before dispersion of the amino resin composite particle prepared according to Example 19 of the present invention.

Figure 21 is a biological micrograph after the dispersion treatment of the amino resin composite particles prepared according to Example 20 of the present invention.

Figure 22 is a biological micrograph after the dispersion treatment of the amino resin composite particles prepared according to Example 11 of the present invention.

23 is a biomicrograph after dispersion of the amino resin composite particle prepared according to Comparative Example 16.

24 is a biomicrograph after dispersion of the amino resin composite particle prepared according to Comparative Example 17.

FIG. 25 is a biological photomicrograph taken of a state before dispersing of an amino resin composite particle prepared according to Example 11 of the present invention from a portion different from FIG. 6; FIG.

FIG. 26 is a biomicrograph before dispersion of an amino resin composite particle prepared according to Comparative Example 18. FIG.

[Industrial use]

The present invention relates to conductive particles for anisotropic conductive films and methods for producing the same, and more particularly, to conductive particles for anisotropic conductive films with appropriate elasticity and corrosion resistance and not to aggregate, and a method for producing the same.

[Prior art]

Recently, in electronic packaging, especially in LCD, chip on glass (COG), and chip on film (COF), the necessity of connecting a large number of narrow gap electrodes at one time is gradually increasing as the microgap of the circuit and the connection density increase. have. For this purpose, studies on anisotropic conductive films have been actively conducted. The anisotropic conductive film contains electroconductive particle and an insulating adhesive agent, and nickel, copper, silver, etc. are mainly used as this electroconductive particle.

However, since the metal conductive particles have problems such as corrosion or oxidation at the surface, gold-coated conductive particles have been developed, and recently, conductive particles coated with nickel on a polymer ball and then coated with gold again thereon Research on particles is ongoing.

As the polymer ball, monodisperse polymer particles composed of polystyrene, polymethyl methacrylate, and amino resin polymers are mainly used.

Japanese Patent Application Laid-Open No. 49-057019 discloses a process of producing an initial condensate, which is an amino resin precursor, by reacting an amino compound with formaldehyde, dyeing, emulsifying and curing to prepare colored amino resin crosslinked particles. Described.

Japanese Patent Publication No. Hei 7-17723 discloses an amino resin precursor having an average particle diameter of 0.1 to 20 µm by producing and curing an amino resin precursor using alkylbenzenesulfonic acid as a surfactant when reacting an amino compound with formalin. A method is disclosed.

Japanese Patent Application Laid-open No. Hei 4-211450 discloses that amino resin particles are produced by adding an inorganic pigment to an initial condensation product to emulsify and harden, to produce amino resin particles, and to grind the dried product into ball mills, jet mills, and hammer mills to form 5 micron amino crosslinked particles. It is.

However, the polymer ball produced in this way is not preferable because it is difficult to control to have the desired elasticity.

In addition, electroless plating is mainly used as a method of plating Ni and Au on such polymer particles.

In order to perform such an electroless plating method, a process of pretreating the polymer particles to be plated in a state suitable for plating is important. This pretreatment process consists of etching, conditioning, sensitization, activation, and predeposition processes in that order.

Among them, the etching step is mostly difficult to Pd adsorption is not suitable from an economical aspect to the environment and process costs due to CrO ₃ waste solution as carried out in excess using a CrO ₃ also due to the unreacted remaining during particle synthesis Ni It is not preferable because significant aggregation and sticking phenomenon occurs between particles during plating.

An object of the present invention is to provide a conductive particle for an anisotropic conductive film that can adjust the elastic force and can economically form a metal plating layer, and small in size.

Another object of the present invention is to provide a method for producing conductive particles for the anisotropic conductive film.

In order to achieve the above object, the present invention provides conductive particles for anisotropic conductive films including a polymer composite particle comprising an amino resin and a metal plating layer formed on the polymer composite particle and having a hydrophobic functional group bonded to a surface thereof.

The present invention also prepares an amino resin precursor by mixing a compound containing an amino group and an aldehyde compound, adds an emulsion solution to the amino resin precursor, mixes and polymerizes, and adds a curing catalyst to the obtained polymerization product to include an amino resin. Preparing a polymer composite particle, washing the polymer composite particle, activating by adding a Pd-containing compound to the washed polymer composite particle, and preliminarily depositing the activated polymer composite particle by adding alcohol to the prepolymer, It provides a method for producing conductive particles for anisotropic conductive films comprising the step of forming an electroless metal plating layer on the particles, dispersing the polymer composite particles having the metal plating layer and introducing a hydrophobic functional group.

The metal plating layer forming process may include a process of forming Ni and Au plating layers by performing electroless Ni plating to form a Ni plating layer and performing Au plating on the polymer composite particles having the Ni plating layer formed thereon.

Hereinafter, the present invention will be described in more detail.

The present invention relates to conductive particles used in anisotropic conductive films that are widely used in LCD, COG (Chip on Glass), and COF (Chip on Film).

As shown in FIG. 1, the electroconductive particle of this invention includes the polymer composite particle 1 containing an amino resin, and the metal composite particle 1 formed in this polymer composite particle 1, and the metal plating layer 3 which the hydrophobic functional group couple | bonded with the surface. Shall .

The average particle size of the polymer composite particles is preferably 1 to 10 μm, more preferably 2 to 5 μm. In addition, the standard deviation of the polymer composite particles is preferably ± 0.30㎛.

The metal plating layer preferably comprises a Ni plating layer and Au plating layer.

In the present invention, the amino resin constituting the polymer composite particles has a suitable elastic force.

Conventionally, polymers having high strength, such as polystyrene, polymethyl methacrylate, and amine resins, have been mainly used as polymer composite particles. Such high strength polymers have the advantages of being relatively hard or difficult to deform, but have high initial resistance values or problems such as destruction or cracking of particles. In addition, when the polymer composite particles are relatively soft and easily deformable polymer such as acrylic resin or polyurethane resin, the initial conductivity is good, but the deformation is easily made and excessively crushed, so that the conductive particles undergo plastic deformation during thermocompression, thereby increasing resistance. There is a problem.

In the present invention, in order to solve such a problem, an amino resin having an appropriate elastic force was obtained by optimizing the process in preparing the amino resin, which will be described in detail later with reference to FIG. 2.

In addition, according to the present invention, the process of stirring for 3 to 5 hours using an emulsifying solution and a curing catalyst is carried out for 3 to 5 hours to easily remove inert formaldehyde harmful to the human body which may remain after the reaction and at the same time. By fully reacting the unreacted substance in amino resin particle, it became possible to further accelerate the emulsion polymerization process (condensation (crosslinking)) in amino resin particle. Therefore, as disclosed in Korean Patent Laid-Open Publication No. 2003-27849, it is possible to solve the problem of discoloration and deformation of particle size caused by the acid catalyst and formalin remaining during the reaction of removing formaldehyde dry.

1. Manufacturing Process of Polymer Composite Particles

An amino resin precursor is prepared by mixing a first compound including an amino group (—NH ₂ ), a second compound including an amino group, and an aldehyde compound (S1A).

As the first and second compounds having an amino group, those selected from the group consisting of melamine, benzoguanamine (2,4-diamine-6-phenyl-sym-triazine) and cyclohexanecarboguanamine independently of each other can be used. It is possible to use melamine and benzoguanamine. Examples of the aldehyde compound include formaldehyde, acetaldehyde, glutaraldehyde, paraformaldehyde or metaformaldehyde. However, the compound and aldehyde compound having the amino group are not limited thereto. The compound which has such an amino group is excellent in heat resistance, water resistance, acid resistance, and alkali resistance.

As for the mixing ratio of the 1st compound, the 2nd compound, and the aldehyde compound which have the said amino group, 1: 1-2: 2.6-4 molar ratio is preferable. In addition, since it is preferable to use benzoguanamine and melamine as a compound which has an amino group, the mixing ratio of benzoguanamine, melamine, and an aldehyde compound is 1: 1-2: 2.6-4 mol ratio is preferable.

Since the degree of polymerization shows a large difference depending on the molar ratio when preparing the amino resin, that is, a large difference in strength may appear, it is not preferable because the amino resin having the desired strength cannot be prepared when out of the above range.

In the mixing process, the pH of the reaction solution is preferably adjusted to about 7 to 10 neutral or weakly basic. When the pH of the reaction solution exceeds 10, the viscosity of the amino resin precursor is increased, which is not preferable because a non-spherical lump of amino resin is formed when added to the emulsion. In addition, when the pH is less than 7, very small particles are generated, which is not preferable because particles of a desired size cannot be produced.

The pH control can be adjusted using a pH adjuster such as sodium carbonate, sodium hydroxide, ammonia, sodium citrate or potassium hydroxide. At this time, the addition amount of the pH adjuster is preferably 1.5 to 3 parts by weight based on 100 parts by weight of the aldehyde compound.

In addition, the mixing process is preferably carried out by stirring for 1 to 3 hours at a temperature of 50 to 90 ℃.

According to this process, an amino resin precursor is produced, an emulsion containing the amino resin precursor is added to the emulsion solution, mixed and polymerized (S1B).

The emulsion solution may be prepared by mixing an emulsifier and a solvent and reacting at a predetermined temperature. The emulsifier may be polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical), polyvinyl alcohol, sodium alginate, polyvinyl pyrrolidone or carboxy methyl cellulose, water may be used as the solvent. The emulsion solution is prepared by adding 2 to 5 g of solvent per 800 g of solvent, i.e., 0.25 to 0.63 parts by weight based on 100 parts by weight of solvent, by ultrasonic dissolving at room temperature.

At this time, the mixing ratio of the emulsion containing the amino resin precursor and the emulsion solution is preferably 1 to 1.5: 6 to 8 parts by weight. If the mixing ratio of the emulsion solution is less than 6, the adhesion between particles occurs during the production process, and the particles are aggregated to form two or three spherical non-spherical or trilobal crobars (eg, ♣, θ). )) And when the particle size distribution (standard deviation) is large and the amount of the emulsion solution used is greater than 8, very small particles are generated, which does not form a desired size. Moreover, it is suitable to perform the addition process of the said emulsion solution at 50-70 degreeC. If the temperature of the addition process is higher than 70 ℃, due to the rapid cross-linking reaction occurs in the particles and the reaction tank severe sticking, if it is less than 50 ℃ it is not preferable because a very late cross-linking reaction requires a lot of time when the particles are generated.

It is preferable to perform the said process of mixing and superposing | polymerizing at the stirring speed | rate of 50-100 rpm. If the stirring speed is less than 50 rpm, there is a problem in that the particle size distribution (standard deviation) of the resulting polymer composite particles is wide, and if it exceeds 100 rpm, they are fixed to each other and are not preferable.

Subsequently, the cured catalyst solution is added to the obtained mixture and mixed to prepare polymer composite particles (S1C). The curing catalyst liquid contains a curing catalyst and a solvent. The curing catalyst is preferably 20 to 40 parts by weight based on 100 parts by weight of the amino resin precursor. If the amount of the curing catalyst is less than 20 parts by weight, the particles produced after 3 to 5 hours of stirring (reaction) are not completely crosslinked (cured), and thus the resulting particles change back to an emulsion state of the amino resin precursor, which is not preferable. If the catalyst is used in an excess of 40 parts by weight, it is difficult to remove the acid catalyst and there is a risk of discoloration due to acid when stored for a long time after completion of the curing reaction.

As the curing catalyst, dodecylbenzenesulfonic acid, sulfonated paraffin, hydrochloric acid, sodium laurate, sodium dodecyl sulfate or sulfuric acid may be used. In addition, water may be used as the solvent.

The addition step may be carried out by dropwise addition in small amounts at intervals of 1 to 2 minutes. The mixing process is carried out by stirring for 3 to 5 hours.

Since the suspension containing a polymer composite particle is obtained in the said process, the obtained suspension is filtered, a polymer composite particle is isolate | separated, and a hardening | curing agent is added to this separated polymer composite particle.

The filtration process is carried out after cooling the suspension, and centrifugation is suitable.

As the curing agent, the emulsifier, the curing catalyst and the solvent can be mixed and used, and the same emulsifier, the curing catalyst and the solvent can be used. In this case, the amount of the curing catalyst is preferably 3 to 5 parts by weight based on 100 parts by weight of the solvent. If the amount of the curing catalyst used is out of the above range, it is discolored, which is not preferable. The amount of the emulsifier is suitably 0.3 to 0.6 parts by weight based on 100 parts by weight of the solvent.

Subsequently, the obtained mixture is subjected to ultrasonic crushing for 5 to 10 minutes, and then stirred at a temperature of 50 to 90 ° C. for 1 to 3 hours. Subsequently, the obtained product is filtered to prepare polymer composite particles. The filtration process is carried out by cooling, and centrifugation is suitable.

2. Plating process

[Washing process]

The polymer composite particles prepared by the above-described process are washed to remove unreacted substances (eg formalin) and foreign substances that may interfere with the binding of the amino group (-NH ₂ ⁺ ) and PdX ^- present on the surface of the polymer composite particles. Thereby strengthening the adhesion between the metal layer and the polymer. In this case, the washing process is performed by an ultrasonic washing process using a mixed solvent of water (for example, ultrapure water) and alcohol. Methanol, ethanol or propanol may be used as the alcohol.

After the ultrasonic cleaning step is performed, it can be filtered and the ultrasonic cleaning step and the filtration step can be performed several times.

[Activation]

Subsequently, the Pd-containing compound is activated by adding the polymer composite particles to which the washing process is completed. The Pd-containing compound is preferably added in the form of a Pd-containing compound solution containing a Pd-containing compound having a concentration of 1 to 3 g / L.

The activation step is carried out by ultrasonic dispersion after addition of the Pd-containing compound, and PdX ^2- is chemically bonded by the amino group (NH ₂ ⁺ ) on the surface of the polymer composite particle according to this step. That is, when PdCl ₂ is described as an example, since Pd is a tetragonal metal, Pd (H ₂ O) ²⁺ and Pd (Cl ₄ ) ²⁻ exist in the solution, and this Pd (Cl ₄ ) ²⁻ polymer composite particle is present. The amino group (NH ²⁺ ) present on the surface is chemically bonded to the ionic pair, that is, chemically bonded, as shown in the following scheme. In Scheme 1 below, R represents a polymer composite particle.

Scheme 1

R-NH ₂ ⁺ + Pd (Cl ₄ ) ^2- -----> RH ₂ N ⁺ Pd (Cl ₄ ) ^2-

The Pd-containing compound may be PdCl ₂ , PdBr ₂ , Pd (NO ₃ ) ₂ , Pd (CN) _2, or a mixture thereof. Ethanol, methanol, or isopropyl alcohol may be used as a solvent in the Pd-containing compound solution. It is preferable to use an alcohol such as. In this case, when water is used as the solvent, the binding of PdX ⁻ is deteriorated by the unreacted material remaining in the preparation of the polymer, and due to the surface tension of water, many aggregation occurs during the bonding process, which is not preferable.

[Acceleration]

PdX ² --bonded polymer composite particles are added to alcohol and preliminarily deposited (S2C). The preliminary deposition step is carried out by adding to the alcohol, followed by ultrasonic dispersion treatment and adding a first reducing agent. Hydrazine, sodium hypophosphite or tin chloride can be used as this first reducing agent. According to this process, the metal is reduced to Pd metal so that Pd metal adheres to the surface of the polymer.

[Metal Electroless Plating]

The surface-treated surface-treated polymer composite particles are added to a dispersant solution containing a cationic surfactant, a second reducing agent and a first complexing agent, and a metal electroless including a metal salt, a third reducing agent and a second complexing agent. Metal electroless plating is performed by dropwise addition of a plating solution to form a metal plating layer on the surface of the polymer composite particles (S2D).

As the cationic surfactant, polyoxyethylene alkylamine, polyoxyethylene alkyl ether or dodecyltrimethylammonium bromide may be used.

As the second reducing agent and the third reducing agent, sodium hypophosphite (NaH ₂ PO ₂ ), sodium borohydride (NaBH ₄ ), hydrazine ((CH ₃ ) ₂ NH ₁₂ H ₃ ), EDTA (ethylenediaminetetraacetic acid) -2Na, Ammonium citrate, citric acid, dimethyl amine boron or potassium borohydride can be used.

The first and second complexing agents serve as buffers to prevent sudden pH changes of the solution by hydrogen ions generated during plating and to improve the stability of the solution by increasing the solubility of the orthophosphite produced as the plating proceeds. As the substance to be used, an organic acid or an organic salt may be used, and examples thereof may include ammonium acetate, sodium tartrate, sodium acetate, glycine, citric acid, gluconic acid, or hydroxy acetic acid.

In the dispersant solution, a mixed solvent of water and alcohol may be used as the solvent. Methanol, ethanol or propanol may be used as the alcohol, and the mixing ratio should be up to 50% by weight of alcohol, and when used in excess of 50% by weight, the reaction does not occur, that is, the plating reaction does not occur completely. It is not preferable, and if only alcohol is used, the plating reaction does not occur, which is not preferable.

The metal salt may be a Ni metal salt, Au metal salt or a mixture thereof, and NiSO ₄ · 6H ₂ O, NiCl ₂ or nickel acetate may be used as the Ni metal salt, and KAu (CN) ₂ , KAuO may be used as the Au metal salt. ₂ or KAu (CN) ₂ may be used.

In addition, in the dispersant solution, the mixing ratio of the cationic surfactant, the second reducing agent, the first complexing agent and the solvent is preferably 0.5 to 1.0 parts by weight, and the second reducing agent is 0.05 to 0.1 with respect to 100 parts by weight of the solvent. Suitable parts by weight and complexing agent are 0.05 to 0.1 parts by weight. If the amount of the cationic surfactant exceeds 1.0 parts by weight, the reaction rate is very fast to form a uniform plating. If the amount of the cationic surfactant is less than 0.5 parts by weight, aggregation between the particles occurs due to the surface tension of the water during plating, which is not preferable.

Moreover, as for the mixing ratio of the said metal salt, a reducing agent, and a complexing agent, 1: 1.0-1.5: 1.0-1.5 M are suitable.

In the present invention, the method of adding the metal electroless plating solution is preferably carried out by the dropwise addition process because it prevents the aggregation of particles generated before the process and also confirms the plating reaction start time. At this time, the dropping rate is preferably 3 to 7ml / min. If the dropping rate is less than 3ml / min, the reaction rate is slow, precipitation and debris is generated, and if the dropping rate is exceeded 7ml / min, the reduction substitution reaction is sharply formed, which is not preferable because severe aggregation and uniform plating layer is not formed.

The dispersant solution is more preferably used to remove oxygen through a process such as nitrogen bubbling in order to prevent oxidation of the metal generated during the plating process before use.

In addition, depending on the type of metal to be plated in the plating process, that is, the type of metal salt contained in the plating solution, a stabilizer may be additionally used to prevent unnecessary plating reactions. As the stabilizer, L-ascorbic acid and potassium cyanide may be used. Can be. Such stabilizers may be more preferably used when the metal salt is Au.

It is preferable to perform the said plating process at 60-80 degreeC. If the temperature of the plating process is less than 60 ℃, the plating rate is too slow to plate on the wall of the reactor or Ni metal is changed back to the ionic state, if it exceeds 80 ℃ to form a uniform plating by a rapid substitution reaction There is no problem.

In addition, the plating process is preferably carried out at a pH of 4 to 8, the pH is preferably adjusted by adding ammonia, NaOH or potassium hydroxide.

As for the said metal electroless plating process, it is more preferable to perform Ni electroless plating using Ni metal salt, and then to perform Au electroless plating process using Au metal salt. Hereinafter, after performing the Ni electroless plating process, the process of performing the Au electroless plating process will be described in more detail. In the following description, the description of the same parts as the above-described metal electroless plating process will be omitted.

The surface-treated polymer composite particles are added to a dispersant solution containing a cationic surfactant, a fourth reducing agent, and a third complexing agent, and a Ni electroless plating solution containing a Ni metal salt, a fifth reducing agent, and a fourth complexing agent is added thereto. Ni electroless plating is performed by the dropwise addition to form a Ni plating layer on the surface of the polymer composite particles.

The Ni metal salt is a material that serves to supply nickel ions required for plating, and examples thereof include NiSO ₄ · 6H ₂ O, NiCl ₂ , NiCl ₂ · 6H ₂ O, or nickel acetate.

As the fourth and fifth reducing agents, sodium hypophosphite (NaH ₂ PO ₂ ), sodium borohydride (NaBH ₄ ), hydrazine ((CH ₃ ) ₂ NH ₁₂ H ₃ ) or potassium borohydride may be used.

The third and fourth complexing agents play a role as a buffer to prevent a sudden pH change of the solution by hydrogen ions generated during plating and to improve the stability of the solution by increasing the solubility of the ortho phosphite produced as the plating proceeds. As the substance to be used, an organic acid or an organic salt may be used, and examples thereof may include ammonium acetate, sodium tartrate, glycine, citric acid, acetic acid, gluconic acid, or hydroxy acetic acid.

Moreover, as for the mixing ratio of the said Ni metal salt, a reducing agent, and a complexing agent, 1: 1.0-1.5: 1.0-1.5 M are suitable.

It is preferable to perform the said plating process at 60-80 degreeC. If the temperature of the plating process is less than 60 ° C, the reaction is performed by Pd catalyst, but the substitution reduction process gradually occurs, causing the Ni metal to precipitate on the wall of the reactor or the Ni metal to change back to the ionic state. There exists a possibility that uniform plating may not be formed by reaction.

In addition, the plating process is preferably carried out at a pH of 5 to 6 and the pH is preferably adjusted by adding ammonia, NaOH or KOH.

Au electroless plating was performed on the polymer composite particles in which the Ni plating layer was formed by using an Au plating solution containing an Au metal salt and a sixth reducing agent. As a result, polymer composite particles in which the Au plating layer was formed on the Ni plating layer were prepared.

As the Au metal salt, KAu (CN) ₂ , KAuO ₂ or KAu (CN) ₄ may be used, and as the reducing agent, EDTA (ethylenediaminetetraacetic acid) -2Na, ammonium citrate, citric acid, citric acid 1-hydrate Or these can be mixed and used.

In addition, a stabilizer may be additionally used to prevent unnecessary plating reaction in the plating process, and as the stabilizer, L-ascorbic acid and potassium cyanide may be used.

Preferably, the plating process is performed at a temperature of 60 to 80 ° C., and when the plating process temperature is less than 60 ° C., the reaction rate is slow, and Ni metal may be melted due to the acidity of the Au plating solution. It is not preferable because uniform plating may not be formed by a sudden reaction.

In addition, the plating process is preferably carried out under the conditions of pH 3 to 3.5, the pH can be adjusted using NaOH, ammonia or hydrochloric acid.

3. Distributed Processing

The polymer composite particle 1 having the metal plating layer 3 formed therein is dispersed and bonded to a hydrophobic functional group, preferably a thiol group, on the surface of the polymer composite particle (S3). This dispersion treatment step is carried out by adding C _n H _{2n + 1} SH and a solvent to the polymer composite particles and stirring under ultrasonic conditions. As this solvent, alcohol such as methanol, ethanol or propanol can be used.

At this time, as shown in the following equation 1, a polymer composite particle 1 having a hydrophobic functional group, preferably a thiol group, is prepared on the metal plating layer 3 surface. At this time, in the case of using C _n H _{2n + 2} , adhesion to Au is not preferable, which is not preferable.

[Equation 1]

The polymer composite particles produced according to this process can be uniformly distributed without aggregation, and this process is called dispersion treatment. In C _n H _{2n + 1} SH, n is preferably an integer of 4 to 7. In this case, when the n value is 6 to 7, the dispersion is good and the volatility is easy to handle, but the solubility is somewhat lower, and when the n value is 4 to 5, it is easy to dissolve but the volatility is strong. Therefore, what is necessary is just to adjust and use suitably according to the purpose of use.

The mixing ratio of the polymer composite particles and the C _n H _{2n + 1} SH is preferably 15 to 45 parts by weight based on 100 parts by weight of the polymer composite particles. When the amount of C _n H _{2n + 1} SH is less than 15 parts by weight, the amount of C _n H _{2n +1} SH is too small to be dispersed, and when it exceeds 45 parts by weight, it is difficult to dissolve, isohexane, 3-methyl As a solvent such as pentane, neohexane, or dimethylbutane should be used, the metal plating layer is peeled off by the solvent during the dispersing process, and there is a problem that agglomeration and severe cracking of the plating layer occurs. In this case, an appropriate amount of solvent may be used.

Hereinafter, preferred examples and comparative examples of the present invention are described. The following examples are only one preferred embodiment of the present invention and the present invention is not limited by the following examples.

Table 1 summarizes the amount of the components used in the examples, the reaction conditions, the average particle diameter and the standard deviation of the prepared amino resin composite particles. In Table 1, the molar ratio is formaldehyde (FO): melamine (ME): benzoguanamine (BE). In the following Examples and Comparative Examples, melamine, benzoguanamine (2,4-diamino-6-phenyl-1,3,5-triazine) and formaldehyde were used without purification. In addition, Examples 1a, 1b, 1c, 1d and 1e are repeated the same experiment as Example 1, the difference in the measured physical properties such as pH, particle size and standard deviation is due to errors that can occur in the course of the experiment, In addition, the amount of melamine, benzoguanamine, formaldehyde and sodium carbonate used in the preparation of the amino resin precursor is the same Comparative Example 1, Examples 1 to 3, Examples 6 to 7, Comparative Example 2, Examples 8 to 9, Comparative Examples In the case of 3 and Examples 12 to 13, a difference in pH of about 0.05 to 0.1 was caused by errors that may occur in the course of the experiment.

Emulsifier addition amount (g) Sodium carbonate addition amount (g) Resin precursor pH Stirring Speed (rpm) Polymerization temperature (℃) Molar Ratios (FO: ME: BE) Average particle size (㎛) Standard Deviation (S.D) Comparative Example 1 0.5 0.5 7.86 100 60 3: 1: 1 4.32 0.62 Example 1 2.5 0.5 7.94 100 60 3: 1: 1 3.69 0.24 Example 2 5.0 0.5 7.89 100 60 3: 1: 1 2.17 0.27 Example 1a 2.5 0.5 7.92 100 60 3: 1: 1 3.77 0.29 Example 3 2.5 1.0 8.37 100 60 3: 1: 1 4.13 0.29 Example 4 2.5 1.5 8.55 100 60 3: 1: 1 4.27 0.28 Example 5 2.5 0.5 7.88 50 60 3: 1: 1 3.69 0.30 Example 1b 2.5 0.5 7.91 100 60 3: 1: 1 3.76 0.24 Comparative Example 2 2.5 0.5 7.83 200 60 3: 1: 1 Interruption of reaction due to sticking Example 1c 2.5 0.5 7.81 100 60 3: 1: 1 3.84 0.25 Example 6 2.5 0.5 7.81 100 70 3: 1: 1 3.13 0.30 Comparative Example 3 2.5 0.5 7.93 100 80 3: 1: 1 2.65 0.58 Comparative Example 4 2.5 0.5 6.57 100 60 2.5: 1: 1 7.68 0.32 Example 7 2.5 0.5 6.83 100 60 2.7: 1: 1 4.91 0.30 Example 8 2.5 0.5 7.21 100 60 2.9: 1: 4.47 0.27 Example 1d 2.5 0.5 7.96 100 60 3: 1: 1 3.89 0.28 Example 1e 2.5 0.5 7.84 100 60 3: 1: 1 3.37 0.24 Example 9 2.5 0.5 7.86 100 60 3: 1.5: 1 3.84 0.27 Example 10 2.5 0.5 7.93 100 60 3: 2: 1 2.78 0.25 Comparative Example 5 2.5 0.5 7.79 100 60 3: 1: 2 4.96 0.21

(Comparative Example 1)

Melamine, benzoguanamine and 37% formaldehyde were mixed in a 1: 1: 3 molar ratio in the reactor, and 0.5 g of a sodium carbonate pH adjuster was added, followed by heating and stirring for 1 hour at a temperature of 85 ° C. At this time, while an amino resin precursor was manufactured, the emulsion containing an amino resin precursor was obtained, and pH of the amino resin precursor was 7.86.

Subsequently, an emulsion containing the amino resin precursor was added to the emulsion solution at a temperature of 60 ° C. in a ratio of 1 to 8, and mixed at a stirring speed of 100 rpm. The emulsion solution was prepared by adding a polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical) emulsifier and water in an amount of 0.5g and 800g to the reaction tank at a predetermined temperature.

30g of dodecylbenzenesulfonic acid curing catalyst solution was added to the obtained mixture, followed by stirring for 3 hours to prepare a suspension. At this time, the dodecyl benzene sulfonic acid curing catalyst solution was mixed with 95 g of water and 5 g of dodecyl benzene sulfonic acid, and 30 g was used therein.

After the completion of the predetermined reaction, the suspension was cooled, a curing agent was added to the amino resin crosslinked particles obtained by centrifugation, and ultrasonically crushed. The curing agent was prepared by mixing a polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical) emulsifier, 5% dodecylbenzene sulfonic acid curing catalyst and water, the amount of the emulsifier is based on 100 parts by weight of water 0.42 parts by weight and the amount of the curing catalyst used were 5 parts by weight based on 100 parts by weight of water. Thereafter, centrifugation and washing were performed to prepare amino resin composite particles.

(Example 1)

The emulsification solution was carried out in the same manner as in Comparative Example 1 except that 2.5 g of polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical) emulsifier and 800 g of water were used.

(Example 2)

The emulsification solution was carried out in the same manner as in Comparative Example 1 except that 5.0 g of polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical) emulsifier and 800 g of water were used.

Average particle diameter and standard deviation were determined using PSA (Particel Size Analysis, Sympatec GmbH System-Partikel-Technik, Windox, Version 4.1).

The average particle diameter and standard deviation of the amino resin composite particles prepared by the method of Comparative Example 1 and Examples 1 to 2 were measured, and the results are shown in Table 2 below.

Particle diameter and standard deviation according to the amount of emulsifier added Comparative Example 1 Example 1 Example 2 Emulsifier addition amount (g) 0.5 2.5 5.0 Average particle size (㎛) 4.32 3.69 2.17 Standard Deviation (S.D) 0.62 0.24 0.27

As shown in Table 2, in Comparative Example 1 in which the amount of the emulsifier added was 0.5 g, the average particle was good at 4.32 µm, but the standard deviation was large at 0.62 µm. On the other hand, in the case of Example 1 to which 2.5 g was added, uniform polymer particles having a value of average particle size of 3.69 µm and a small standard deviation of about 0.24 µm were obtained. In contrast, in Example 2 in which the amount of the emulsifier was increased to 5.0 g, the standard deviation was almost unchanged, but the average particle diameter was decreased. As a result, as the concentration of emulsifier decreased, the standard deviation increased considerably. When the concentration was too high, the standard deviation remained unchanged but the average particle diameter decreased.

(Example 1a)

The process of Example 1 was repeated. The pH of the amino resin precursor prepared in this experiment was 7.92.

(Example 3)

It carried out similarly to Example 4 except having changed the sodium carbonate addition amount into 1 g.

(Example 4)

It carried out similarly to Example 4 except having changed the sodium carbonate addition amount into 1.5 g.

The average particle diameter and standard deviation of the amino resin composite particles prepared according to Examples 1a to 4 were measured, and the results are shown in Table 3 together.

Particle Size and Standard Deviation According to pH of Amino Resin Precursor Example 1a Example 3 Example 4 Sodium carbonate addition amount (g) 0.5g 1.0 g 1.5 g Amino resin precursor pH 7.92 8.37 8.55 Particle Average Particle Size (㎛) 3.77 4.13 4.27 Standard Deviation (S.D) 0.29 0.29 0.28

As shown in Table 3 above, in Example 1a where the amount of sodium carbonate added was 0.5 g, the average particle was 3.77 µm, and the standard deviation was 0.29 µm. It can be seen that the particle size gradually increases in the case of Example 4 having a 4.13 mu m, a standard deviation of 0.29 mu m, and a sodium carbonate addition amount of 1.5 g. That is, the higher the pH of the amino resin precursor before the emulsifier was added, the larger the particle formation size was.

(Example 5)

Melamine, benzoguanamine and formaldehyde were mixed in a 1: 1: 3 molar ratio in the reactor, and 0.5 g of a sodium carbonate pH adjuster was added, followed by 1 at a temperature of 85 ° C. It was heated and stirred for a time. At this time, while the amino resin precursor was produced, an emulsion containing the amino resin precursor was obtained, and the pH of the amino resin precursor was 7.88.

Subsequently, the emulsion containing the amino resin precursor was added to the emulsion solution at a temperature of 60 ° C. in a 1: 8 weight ratio. Add and mix at 50 rpm stirring rate. The emulsion solution was prepared by adding a polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical) emulsifier and water in an amount of 2.5g and 800g into the reaction tank to react at a predetermined temperature.

30g of dodecylbenzenesulfonic acid curing catalyst solution was added to the obtained mixture, followed by stirring for 3 hours to prepare a suspension. At this time, the dodecyl benzene sulfonic acid curing catalyst solution was mixed with 95 g of water and 5 g of dodecyl benzene sulfonic acid, and 30 g was used therein.

After the completion of the predetermined reaction, the suspension was cooled, a curing agent was added to the amino resin crosslinked particles obtained by centrifugation, and ultrasonically crushed. The curing agent was prepared by mixing a polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical) emulsifier, 5% dodecylbenzene sulfonic acid curing catalyst and water, the amount of the emulsifier is based on 100 parts by weight of water 0.42 parts by weight and the amount of the curing catalyst used were 5 parts by weight based on 100 parts by weight of water. Thereafter, centrifugation and washing were performed to prepare amino resin composite particles.

(Example 1b)

The experimental process of Example 1 was repeated.

(Comparative Example 2)

After adding the emulsion solution to the amino resin precursor, it was carried out in the same manner as in Example 5 except that the stirring rate during the reaction was changed to 200rpm.

The average particle diameter and standard deviation of the amino resin composite particles prepared according to Examples 5 to 1b and Comparative Example 2 were measured, and the results are shown in Table 4 together.

Particle Size and Standard Deviation According to Stirring Speed in Polymerization Example 5 Example 1b Comparative Example 2 Impeller Velocity during Polymerization (rpm) 50 100 200 Particle Average Particle Size (㎛) 3.69 3.76 Interruption of reaction due to sticking Standard Deviation (S.D) 0.30 0.24

As shown in Table 4, in Example 5 having a stirring rate of 50 rpm during polymerization, the average particle showed a relatively large standard deviation of 3.69 µm and a standard deviation of 0.30 µm, and Example 1b stirred at 100 rpm The average particle was 3.76 mu m, and the standard deviation was 0.24 mu m. However, in the case of Comparative Example 2 at 200 rpm, severe sticking phenomenon was observed in the reactor and the impeller. In other words, the more the dispersion rate is active during the polymerization reaction, the smaller the standard deviation is, but when the stirring is performed at excessive speed, it can be shown that agglomeration may occur due to the impeller force when forming the particles.

(Example 1c)

The experiment of Example 1 was repeated. The pH of the prepared amino resin precursor was 7.81.

(Example 6)

When the amino resin precursor emulsion solution was added, the polymerization was carried out in the same manner as in Example 1c, except that the polymerization temperature was changed to 70 ° C.

(Comparative Example 3)

When the amino resin precursor emulsion solution was added, the polymerization was carried out in the same manner as in Example 1c, except that the polymerization temperature was changed to 80 ° C.

The average particle diameter and standard deviation of the amino composite resin particles prepared according to Example 1c, Example 6, and Comparative Example 3 were measured, and the results are shown in Table 5 together.

Particle diameter and standard deviation according to polymerization temperature during polymerization Example 1c Example 6 Comparative Example 3 Temperature during polymerization (℃) 60 70 80 Particle Average Particle Size (㎛) 3.84 3.13 2.65 Standard Deviation (S.D) 0.25 0.30 0.58

As shown in Table 5 above, in Example 1c having a polymerization temperature of 60 ° C., the average particle was 3.84 μm and the standard deviation was 0.31 μm. On the other hand, as the temperature is increased to 70 ℃ (Example 6), 80 ℃ (Comparative Example 3) and the like showed severe sticking phenomenon, the particle size is reduced to 3.13, 2.65㎛, etc. Showed results.

(Comparative Example 4)

Melamine, benzoguanamine and formaldehyde were mixed in a 1: 1: 2.5 molar ratio in the reactor, and 0.5 g of a sodium carbonate pH adjuster was added, followed by heating and stirring for 1 hour at a temperature of 85 ° C. At this time, while the amino resin precursor was manufactured, the emulsion containing the aminu resin precursor was obtained, and pH of the amino resin precursor was 6.57.

Subsequently, an emulsion containing the amino resin precursor was added to the emulsion solution at a temperature of 60 ° C. in a 1: 8 weight ratio, and mixed at a stirring speed of 100 rpm. The emulsion solution was prepared by adding a polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical) emulsifier and water in an amount of 2.5g and 800g into the reaction tank at a predetermined temperature.

30g of dodecylbenzenesulfonic acid curing catalyst solution was added to the obtained mixture, followed by stirring for 3 hours to prepare a suspension. At this time, the dodecyl benzene sulfonic acid curing catalyst solution was mixed with 95 g of water and 5 g of dodecyl benzene sulfonic acid, and 30 g was used therein.

After the completion of the predetermined reaction, the suspension was cooled, a curing agent was added to the amino resin crosslinked particles obtained by centrifugation, and ultrasonically crushed. The curing agent was prepared by mixing a polyoxyethylene oleyl ether (trade name: Emulgen, Kao Chemical) emulsifier, 5% dodecylbenzene sulfonic acid curing catalyst and water, the amount of the emulsifier is based on 100 parts by weight of water 0.42 parts by weight and the amount of the curing catalyst used were 5 parts by weight based on 100 parts by weight of water. Thereafter, centrifugation and washing were performed to prepare amino resin composite particles.

(Example 7)

It carried out similarly to the said Comparative Example 4 except having changed the molar ratio of benzoguamine: melamine: formaldehyde into 1: 1: 2.7.

(Example 8)

It carried out similarly to the said Comparative Example 4 except having changed the molar ratio of benzoguamine: melamine: formaldehyde into 1: 1: 2.9.

(Example 1d)

The experimental process of Example 1 was repeated.

The average particle diameters and standard deviation results of the amino resin composite particles prepared according to Examples 7 to 8, Example 1d, and Comparative Example 4 were measured, and the results are shown in Table 6 below.

Benzoguamine + Melamine in Preparation of Amino Resin Precursor: Particle Size and Standard Deviation According to Molar Concentration of Formalin Comparative Example 4 Example 7 Example 8 Example 1d Benzoguamine (mole) One One One One Melamine One One One One Formaldehyde (mole) 2.5 2.7 2.9 3.0 Average particle size (μm) 7.68 4.91 4.47 3.89 Standard Deviation (S.D) 0.32 0.30 0.27 0.28

As shown in Table 6, when the molar concentration ratio of formaldehyde is increased, the standard deviation does not significantly affect, but the average particle size shows a result.

(Example 1e)

The experimental process of Example 1 was repeated.

(Example 9)

It carried out similarly to Example 1e except having changed the molar ratio of benzoguamine: melamine: formaldehyde into 1: 1.5: 3.

(Example 10)

It carried out similarly to Example 1e except having changed the molar ratio of benzoguamine: melamine: formaldehyde into 1: 2.0: 3.

(Comparative Example 5)

The procedure was carried out in the same manner as in Example 1e, except that the molar ratio of benzoguamine: melamine: formaldehyde was changed to 2: 1: 3.

The average particle diameter and fracture strength of the amino resin composite particles prepared according to Examples 1e, 9, 10, and Comparative Example 5 were measured, and the results are shown in Table 7 below.

The breaking strength was measured using MCT-W201, a microparticle strength analyzer manufactured by Shimadzu Corporation, to measure particle strength.

Benzoguanamine: Fracture strength according to the molar ratio of melamine Example 1e Example 9 Example 10 Comparative Example 5 Benzoguanamine (mole) One One One 2 Melamine One 1.5 2.0 One Formaldehyde (mole) 3 3 3 3 Particle Average Particle Size (㎛) 3.37 3.84 2.78 4.96 Standard Deviation (S.D) 0.24 0.27 0.25 0.21 Fracture Strength (kg / mm ² ) 21.5 18.4 16.1 50.2

As shown in Table 7, when the melamine content is increased as compared to the content of benzoguanamine, the elasticity is low, and thus the fracture rate is low, and in the case of Comparative Example 5 in which the melamine content is lower than the content of benzoguanamine, Even if the dispersed particles are obtained, the elasticity is high, that is, it is found to be inadequate for anisotropic conductive films because it deviates from 16.0 to 22.0 kg / mm ² , which is the breaking strength of the amino resin suitable for conductive ball production.

2) Electroless Plating

Ni, Au electroless plating was performed using the amino resin composite particles prepared according to Example 9 as follows.

(Example 11)

[Washing process]

2.5 g of the amino resin composite particle prepared according to Example 9 was put into 200 g of ethanol for 10 minutes by ultrasonic washing and filtration to obtain amino resin composite particles having an amino group (NH ₂ ) present on the surface thereof. Prepared.

[Activation]

An amino resin composite particle having an amino group (NH ₂ ) present on the prepared surface was added to 200 ml of a 2g / L PdCl ₂ ethanol solution, ultrasonically dispersed, and stirred for about 5 minutes. PdCl ₂ was bound.

[Preliminary deposition]

Subsequently, the amino resin composite particles bonded with PdCl ₂ were ultrasonically dispersed in 300 ml of ethanol, and then, 3 drops of hydrazine was added thereto, stirred and reduced to Pd metal to prepare surface-treated amino resin composite particles.

[Metal Electroless Plating]

The dispersant solution was put into the reactor shown in FIG. This dispersant solution was mixed with a mixed solvent of water and ethanol (4: 1 volume ratio of water: ethanol), dodecyltrimethylammonium bromide cationic surfactant, sodium hypophosphite reducing agent, and sodium acetate complexing agent, and subjected to nitrogen bubbling. To remove oxygen. At this time, it was used in the amount of 0.7 parts by weight of cationic surfactant, 0.1 parts by weight of reducing agent and 0.1 parts by weight of complexing agent based on 100 parts by weight of the solvent.

Subsequently, the temperature of the reactor was maintained at 60 ° C. using a thermostat. Subsequently, 2.5 g of the amino composite resin particles surface-treated in the above step into the reaction tank was added to the dispersion, and then a nickel electroless plating solution containing nickel sulfate, a reducing agent, and a complexing agent was charged at a speed of 5 ml / min. Was added dropwise.

The nickel electroless plating solution was prepared by mixing 1M nickel sulfate, 1.0M sodium hypophosphite reducing agent and 1.0M sodium acetate complexing agent.

Subsequently, a 10% NH 4 OH aqueous solution was added to maintain the pH in the reactor at 6.0 while an electroless plating process was performed to form a Ni plating layer on the surface of the amino resin composite particle. After the plating process was completed, the water was washed with ultrapure water and filtered.

After the Ni electroless plating process was completed, the obtained product was added to the reactor again, and Au plating solution was added. Au plating solution was prepared by mixing KAu (CN) ₂ , EDTA-2Na 20g / L, ammonium citrate 10g / L and 10g / L citric acid 1-hydrate. In addition, L-ascorbic acid and potassium cyanide stabilizer were added to the reactor in an amount of 0.08 g and 0.24 g to suppress unnecessary plating reaction.

Subsequently, while maintaining the temperature of the reactor at 60 ° C., NaOH was added to maintain the pH at 3.5 to carry out the Au plating step. After the Au plating process was completed, the Au plating layer was formed by filtration and drying with a vacuum dryer.

A SEM photograph of the amino resin composite particles in which the Ni plating layer and the Au plating layer prepared according to this process are sequentially formed is shown in FIG. 4.

Subsequently, 3 g of the amino resin composite particles in which the Ni plating layer and the Au plating layer were sequentially formed were added to a 0.02 mol octadecane thiol ethanol dispersion in which 1.15 g of octadecane thiol was dissolved in 200 ml of ethanol, followed by ultrasonic stirring for about 3 hours at high speed After dispersing, the resultant was washed with ethanol and filtered to prepare conductive particles.

The SEM photograph of the electroconductive particle manufactured according to this process is shown in FIG.

As shown in FIG. 4 and FIG. 5, the particles are agglomerated with each other before being treated with the thiol dispersion, but it can be seen that the particles are uniformly distributed without agglomeration after the treatment.

(Example 12)

The same procedure as in Example 11 was carried out except that the solvent was used as a methanol solution instead of ethanol in the activation and pre-deposition process.

(Comparative Example 6)

Example 11 was carried out in the same manner as in Example 11 except that the solvent was used instead of ethanol in the activation and pre-deposition process.

(Comparative Example 7)

In the activation and pre-deposition process was carried out in the same manner as in Example 11, except that a solvent was used as a solvent (50:50 volume ratio) of water instead of ethanol.

6 to 9 show biomicrographs before the dispersion treatment of the conductive particles of Examples 11 to 12 and Comparative Examples 6 to 7, respectively. As shown in FIG. 8, in Comparative Example 6 using only water as a solvent of the activation and pre-deposition process, a large number of unplated portions were observed, and in Comparative Example 7 using water and alcohol together, plating state was compared to Comparative Example 6 using only water. Was somewhat good, but some unplated particles were observed (FIG. 9). In contrast, as shown in Figures 6 and 7, it can be seen that in the case of Examples 11 and 12 using only alcohol as a solvent of the activation and preliminary deposition process, the plating was quite good.

(Example 13)

The solvent of the dispersion liquid used in the metal electroless plating process was carried out in the same manner as in Example 11, except that a mixed solvent of water and ethanol (3: 1 volume ratio) was used instead of ethanol.

(Comparative Example 8)

The solvent of the dispersion used in the metal electroless plating process was carried out in the same manner as in Example 11 except that ethanol was used instead of water.

Biological micrographs after dispersion treatment of the conductive particles of Example 13 and Comparative Example 8 are shown in FIGS. 10 and 11, respectively. As shown in FIGS. 10 and 11, in Comparative Example 8 in which the solvent of the dispersion was used in water, the plating state was good, but severe aggregation was observed, whereas in the case of using water and ethanol together as the solvent, the plating state of Example 11 There is no difference, but it can be seen that the aggregation phenomenon is much improved.

(Example 14)

A nickel electroless plating solution was used in the same manner as in Example 11 except that 1M nickel sulfate, 1.5M sodium hypophosphite reducing agent, and 1.5M sodium acetate complexing agent were mixed and used.

(Comparative Example 9)

It carried out similarly to Example 11 except having used the thing manufactured by mixing nickel sulfate 1M, sodium hypophosphite reducing agent, and 2M complexing agent with the nickel electroless plating solution.

(Comparative Example 10)

It carried out similarly to Example 11 except having used the thing manufactured by mixing nickel sulfate 1M, sodium hypophosphite reducing agent, and 3M complexing agent with the nickel electroless plating solution.

The biomicrographs before the dispersion treatment of the conductive particles of Example 14 and Comparative Examples 9 and 10 are shown in FIGS. 12 to 14, respectively. In addition, FIG. 6 of Example 11 using a reducing agent and a complexing agent, respectively, was also compared. As a result, only slight aggregation was observed for Examples 11 and 1.5M, each having a molar concentration of reducing agent and complexing agent of 1 M) (FIGS. 6 and 12). On the other hand, in Comparative Example 9 in which the molar concentrations of the reducing agent and the complexing agent were 2 mol, it can be seen that some particles were not plated (FIG. 13). In addition, as shown in FIG. 14, in Comparative Example 10 in which the molar concentrations of the reducing agent and the complexing agent were 3 mol, a large number of particles which were not plated by the rapid reduction reaction were observed.

In order to determine the metal content of the metal plating layer of the conductive particles of Examples 11 and 14 and Comparative Examples 9 and 10, ICP analysis was performed, and the results are shown in Table 8 below.

Comparative Example 10 Comparative Example 9 Example 11 Example 14 Ni (% by weight) 32 33 35 28 Au (% by weight) 14.2 14.9 15.2 13.2

As shown in Table 6, the nickel content (plating thickness) increases as the mixed molar concentration of the reducing agent and the complexing agent increases, but the nickel content decreases from 2 moles or more of the mixed molar concentration of the reducing agent and the complexing agent. have. This is considered to be because the plating is formed nonuniformly due to the rapid reaction rate when using an excess of reducing agent and complexing agent.

(Comparative Example 11)

The same procedure as in Example 13 was carried out except that the dropping rate of the nickel plating solution was changed to 1.5 ml / min.

(Example 15)

The same procedure as in Example 13 was carried out except that the dropping rate of the nickel plating solution was changed to 3 ml / min.

(Example 16)

The same procedure as in Example 13 was carried out except that the dropping rate of the nickel plating solution was changed to 7 ml / min.

(Comparative Example 12)

The same procedure as in Example 13 was carried out except that the dropping rate of the nickel plating solution was changed to 9 ml / min.

In order to determine the metal content of the metal plating layer of the conductive particles of Example 13 and Examples 15 to 16, and Comparative Examples 11 to 12, ICP analysis was performed, and the results are shown in Table 9 below.

Comparative Example 11 Example 15 Example 13 Example 16 Comparative Example 12 Ni (% by weight) 31.4 37 41 41 34 Au (% by weight) 14.6 14.8 14.8 14.5 13.6

As shown in Table 9, as the dropping rate of the nickel plating solution increases, the nickel content (plating thickness) increases, and the comparative example 12 and Likewise, if the dropping rate increases too much to 9 ml / min, it can be seen that the nickel content is rather reduced. This is thought to be because the dropping rate is so fast that the plating is formed unevenly due to the rapid reaction rate.

(Comparative Example 13)

The nickel plating solution was changed in the same manner as in Example 13 except that the dropping rate of the nickel plating solution was changed to 6 ml / min and the pH of the Ni electroless plating process was changed to 4.0.

(Example 17)

The same process as in Comparative Example 13 was carried out except that the pH of the Ni electroless plating process was changed to 5.0.

(Comparative Example 14)

The same process as in Comparative Example 13 was carried out except that the pH of the Ni electroless plating process was changed to 7.0.

(Comparative Example 15)

The same process as in Comparative Example 13 was carried out except that the pH of the Ni electroless plating step was changed to 8.0.

Biomicrographs of the conductive particles of Comparative Example 13, Example 17, Comparative Example 14, and Comparative Example 15 are shown in Figs. 15 to 18, respectively. As shown in Figs. 15 to 18, in Comparative Example 13 (FIG. 15) in which the Ni electroless plating process was performed at pH 4, the plating state was poor but the dispersion state was very good. In addition, when the pH is 5, the plating state is the best (Fig. 16), and when the pH is 7, a lot of metal residues are precipitated (Fig. 17), and when the pH is 8, the precipitation and plating state of the crystal are very poor ( 18).

(Example 18)

The same procedure as in Example 11 was carried out except that propanethiol ethanol dispersion in which 0.5 g of propanethiol was dispersed in 200 ml of ethanol instead of the octadecane thiol ethanol dispersion was used.

(Example 19)

The same procedure as in Example 11 was carried out except that a pentanthiol ethanol dispersion in which 0.5 g of pentanethiol was dispersed in 200 ml of ethanol instead of an octadecane thiol ethanol dispersion was used.

(Example 20)

The same procedure as in Example 11 was carried out except that hexanethiol ethanol dispersion in which 0.5 g of hexanethiol was dispersed in 200 ml of ethanol instead of octadecane thiol ethanol dispersion was used.

Biological micrographs after dispersion treatment of the conductive particles prepared according to Examples 18 to 20 are shown in FIGS. 19 to 21, respectively. As shown in Figure 19 to Figure 21, it can be seen that as the carbohydrate of the alkyl group of the thiol increases, the dispersibility is improved.

(Example 21)

In the same manner as in Example 11, except that an octadecanethiol ethanol dispersion in which 1.0 g of octadecanethiol was dispersed in 200 ml of ethanol was used instead of the octadecanethiol ethanol dispersion in which 1.15 g of octadecanethiol was dispersed in 200 ml of ethanol. Was carried out.

(Comparative Example 16)

In the same manner as in Comparative Example 13, except that an octadecanethiol ethanol dispersion in which 1.5 g of octadecanethiol was dispersed in 200 ml of ethanol was used instead of the octadecanethiol ethanol dispersion in which 01.15 g of octadecanethiol was dispersed in 200 ml of ethanol. Was carried out.

(Comparative Example 17)

Except for the use of octadecanethiol ethanol-hexane dispersion in which 2.0 g of octadecanethiol was dispersed in 200 ml of ethanol and a small amount of 20 g of hexane instead of the octadecanethiol ethanol dispersion of 1.15 g of octadecanethiol in 200 ml of ethanol. It carried out similarly to the said comparative example 13.

Biological micrographs after dispersion treatment of the conductive particles prepared according to Example 11 and Comparative Examples 16 to 17 are shown in FIGS. 22 to 24, respectively. As shown in FIGS. 22 to 24, dispersibility is improved as the concentration of octadecanethiol is increased, but it can be seen that cracking in a plating state occurs when 1.5 g or more of thiol is added (Comparative Example 16).

Also, as in Comparative Example 17, 2.0 g of octadecanethiol was not completely dissolved in ethanol, and a small amount of 20 g of hexane was added thereto to completely dissolve. Then, as a dispersion treatment was performed, severe cracks in the aggregated and plated state were generated.

(Comparative Example 18)

After the nickel plating solution was added to the dispersant aqueous solution, the same process as in Example 11 was conducted except that the surface-treated amino resin composite particles were added.

Biological micrographs before dispersion treatment of the conductive particles prepared according to Example 11 and Comparative Example 18 are shown in FIGS. 25 and 26, respectively. FIG. 25 shows another part of the conductive particles different from the biological micrograph shown in FIG. 6. As shown in FIGS. 25 and 26, only a slight aggregation occurred in Example 11 in which the nickel plating solution was added dropwise. In the case of Comparative Example 18, in which all of the nickel plating solutions were added to the dispersant aqueous solution, and the composite particles were added, it can be seen that very severe aggregation phenomenon occurred.

(Comparative Example 19)

The amino resin composite particles prepared according to Example 9 were dispersed in a mixed solution of CrO ₃ -H ₂ SO ₄ (20 g of chromic acid: 400 g of sulfuric acid), treated for about 30 minutes, and washed with water.

The washed amino resin composite particles were added to the NaOH alkaline solution to neutralize them, and then added to the aqueous surfactant solution to prepare the conditioning amino resin composite particles.

The prepared conditioning amino resin composite particles were immersed in a SnCl ₂ .2H ₂ O aqueous solution, and then washed with ultrapure water to prepare amino resin composite particles in which tin ions were adsorbed.

The amino resin composite particles in which tin ions were adsorbed were immersed in an aqueous PdCl ₂ solution, washed with ultrapure water, and filtered to prepare amino resin composite particles in which Pd metal was adsorbed as shown in Scheme 1 below.

Scheme 1

Amino resin composite particles adsorbed with Pd metal were precipitated in an aqueous hydrazine solution to reduce PdCl ₂ to Pd metal.

The dispersant aqueous solution was put into the reaction tank (double jacket) shown in FIG. This aqueous dispersant solution was mixed with water, polyoxyethylene alkyl amine cationic surfactant, and sodium hypophosphite reducing solution, and subjected to nitrogen bubbling to remove oxygen.

Subsequently, the temperature of the reactor was maintained at 60 ° C. using a thermostat. Subsequently, 3 g of the amino composite resin particles and the nickel plating solution obtained in the above step were added dropwise to the reactor using a syringe pump.

The nickel plating solution was prepared by mixing 1 mol of nickel sulfate, 1 mol of sodium hypophosphite reducing agent, and 1 complexing agent.

Subsequently, an electrolytic plating process was performed while adding a 10% NH ₄ OH aqueous solution to maintain the pH in the reactor at 6 to form a Ni plating layer on the surface of the amino resin composite particles. After the plating process was completed, the water was washed with ultrapure water and filtered.

After the Ni electroless plating process was completed, the obtained product was added to the reactor again, and Au plating solution was added. Au plating solution was prepared by mixing KAu (CN) ₂ , EDTA-2Na 20g / L, ammonium citrate 10g / L and 10g / L citric acid 1-hydrate. In addition, L-ascorbic acid and potassium cyanide stabilizer were added to the reactor in an amount of 0.8 g and 1.0 g to suppress unnecessary plating reaction.

Subsequently, while maintaining the temperature of the reactor at 60 ° C., NaOH was added to maintain pH at 4 to carry out the Au plating step. After the Au plating process was completed, the Au plating layer was formed by filtration and drying with a vacuum dryer.

Since the electroconductive particle of this invention has a suitable elastic force and corrosion resistance, and has a plating layer formed in the uniform thickness efficiently without aggregation, it can be usefully used for an anisotropic conductive film.

Claims (18)

Polymer composite particles comprising an amino resin; And Metal plating layer formed on the polymer composite particles, the hydrophobic functional group is bonded to the surface Electroconductive particle for anisotropic conductive films containing a. The method of claim 1, The metal plating layer is conductive particles for anisotropic conductive film which is a double layer of Ni plating layer and Au plating layer. An amino resin precursor is prepared by mixing a first compound including an amino group, a second compound containing an amino group, and an aldehyde compound; Adding an emulsion solution to the amino resin precursor and mixing and polymerizing; Adding a curing catalyst to the obtained mixture to prepare a polymer composite particle containing an amino resin; Washing the polymer composite particles; In the washed polymer composite particles Activation by addition of a Pd containing compound; Pre-depositing the activated polymer composite particles by adding them to alcohol; Adding the pre-deposited polymer composite particles to a dispersant solution, and then dropping a metal plating solution to form a metal plating layer; Dispersing the polymer composite particles in which the metal plating layer is formed to bond hydrophobic functional groups to the surface of the polymer composite particles The manufacturing method of the electroconductive particle for anisotropic conductive films containing these. The method of claim 3, The first and second compounds containing the amino group are independently selected from each other selected from the group consisting of benzoguanamine, cyclohexane carboguanamine, melamine and mixtures thereof. The method of claim 3, The aldehyde compound is a method of producing conductive particles for anisotropic conductive film is selected from the group consisting of formaldehyde, acetaldehyde, glutaraldehyde, paraformaldehyde, metaformaldehyde and mixtures thereof. The method of claim 3, The mixing ratio of the 1st compound, the 2nd compound, and the aldehyde compound containing the said amino group is the manufacturing method of the electroconductive particle for anisotropic conductive films whose ratio is 1: 1-2: 2.6-4 mol. The method of claim 3, The mixing process of the 1st compound, the 2nd compound, and the aldehyde compound containing the said amino group is performed at pH 7-10, The manufacturing method of the electroconductive particle for anisotropic conductive films. The method of claim 3, The manufacturing method of the electroconductive particle for anisotropic conductive films which further adds a pH adjuster in the mixing process of the compound containing the said amino group, and an aldehyde compound. The method of claim 8, The addition amount of the said pH adjuster is a manufacturing method of the electroconductive particle for anisotropic conductive films which is 1.5-3 weight part with respect to 100 weight part of said aldehyde compounds. The method of claim 4, wherein The addition process of the said emulsion solution is a manufacturing method of the electroconductive particle for anisotropic conductive films which is performed at 50-70 degreeC. The method of claim 3, The mixing process in the process of superposing | polymerizing is a manufacturing method of the electroconductive particle for anisotropic conductive films which mixes and implements at the stirring speed of 50-100 rpm. The method of claim 3, The Pd-containing compound is a method for producing conductive particles for an anisotropic conductive film is added in the form of a solution. The method of claim 1, The Pd-containing compound is selected from the group consisting of PdCl ₂ , PdBr ₂ , Pd (NO ₃ ) ₂ , Pd (CN) ₂ and mixtures thereof. The method of claim 12, The solution form is a method for producing conductive particles for anisotropic conductive film that comprises a solvent selected from the group consisting of ethanol, methanol, isopropyl alcohol and mixtures thereof. The method of claim 3, The dropping speed of the dropping step is a manufacturing method of the conductive particles for anisotropic conductive film that is carried out at 3 to 7ml / min. The method of claim 3, The metal electroless plating process After adding the pre-deposited polymer composite particles to the dispersant solution, Ni electroless plating solution is added dropwise to perform electroless Ni plating to form a Ni plating layer; Forming Ni and Au plating layers by performing Au plating on the polymer composite particles having the Ni plating layer formed thereon The manufacturing method of the electroconductive particle for anisotropic conductive films which comprises a process. The method of claim 3, The dispersing process is anisotropic that is performed by adding C _n H _{2n + 1} SH (where n is 4 to 7) and a solvent to the polymer composite particles having Ni and Au plating layers and stirring under ultrasonic conditions. The manufacturing method of the electroconductive particle for electroconductive films. The method of claim 17, The C _n H _{2n + 1} SH (where n is 4 to 7) of the addition amount is 15 to 45 parts by weight based on 100 parts by weight of the polymer composite particles, the method for producing conductive particles for anisotropic conductive film.

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