KR20180095410A - Conductive Adhesive Composition - Google Patents

Abstract

The present invention relates to a conductive adhesive composition, which comprises at least one selected from (A) a conductive material, (B) a cyclohexane-based polyfunctional epoxy compound as a binder, (C) a curing agent, and (D) a curing accelerator. The conductive adhesive composition according to the present invention exhibits high heat resistance by having a high glass transition temperature and exhibits high adhesive strength while suppressing yellowing in a high temperature environment, and thus is effective to be applied to electronic devices.

Description

[0001] Conductive Adhesive Composition [

More particularly, the present invention relates to a conductive adhesive composition which exhibits high heat resistance and exhibits excellent adhesion while suppressing yellowing in a high-temperature environment.

When the conductive adhesive is connected between the conductive circuits or between the conductive circuit and the other printed circuit board on the printed circuit board so that electricity can be conducted between the integrated circuit (IC) chip and the printed circuit board or between the electrodes, It is widely used in the process of manufacturing various electronic devices such as a case where a chip and a printed circuit board are electrically connected to each other or a case where electrodes are connected to each other in a solar cell.

The conductive adhesive varies depending on the kind of chip or substrate, the required environmental resistance, and the kind of the product to be applied depending on the reliability. Conventional conductive adhesives are prepared by mixing a conductive powder such as gold (Au), silver (Ag), and solder powder with a binder, an organic solvent, an additive, and the like in a paste form. Particularly, silver powder, gold powder and alloy powder thereof are mainly used in the field where high heat dissipation characteristics and conductivity are required. In the case of solder particles, alloy particles (Pb) are not added due to environmental problems (Korean Patent Laid-Open No. 10-2011-0049466), the use of silver is more advantageous than that of silver powder because of its high adhesion properties and reliability.

Conductive adhesives using such solder particles are mainly used in surface mounting technology (SMT) processes. In the past, only the function of the solder was emphasized, and the conductive adhesive was used for stamping, stencil printing, dispensing ), And it has not been satisfactory in environmental resistance and reliability when applied as a conductive adhesive between a chip and an electrode. In addition, solder particles have limited heat resistance (~ 68 W / mK) in a chip requiring high heat dissipation. Conventional wax and rosin-based paste compositions have a problem in that solder particles There is a problem that the conductivity and reliability between the chip and the electrode deteriorate.

In addition, due to the miniaturization and high performance of semiconductor devices and LED chip components, the amount of heat generated by the chip itself is increased, and the interface temperature between the chip and the lead frame or substrate increases to 140 ° C. 300 < [deg.] ≫ C. Therefore, in the case of an adhesive that adheres a chip component to a lead frame or a substrate, it is required to maintain thermal conductivity, heat resistance, and adhesive strength to some extent.

Korean Patent Application No. 10-2006-0020908 discloses a conductive resin paste containing an acrylic copolymer and an epoxy resin in order to solve the problem that the adhesive force falls after a reflow process at a high temperature of 260 캜. However, as in the case of the wire bonding process, which is carried out while maintaining a temperature of 150 ° C or more, maintaining the adhesive force in the process of maintaining the high temperature during the manufacturing process of the electronic device is directly related to the yield of electronic device manufacturing. The maintenance of the adhesive strength after the high-temperature process is different from the maintenance of the adhesive strength during the high-temperature process. As the acrylic copolymer having a low Tg (glass transition temperature), it is difficult to solve the problem of maintaining the adhesive strength during the high temperature process, The yellowing easily occurs due to the low glass transition temperature, which is weak in reliability in the process and in the external environment.

In addition, U.S. Patent Application No. 11 / 992,790 discloses compositions with excellent reliability at 85 ° C and high humidity of 85% using an epoxy resin and a high Tg phenoxy resin. However, such a composition can maintain the adhesive strength and conductivity at a relatively low temperature of 85 캜, but has a problem that the adhesive strength is significantly lowered at a temperature higher than Tg (glass transition temperature).

[Patent Document 1] Korean Patent Publication No. 10-2011-0049466 [Patent Document 2] Korean Patent Application No. 10-2006-0020908 [Patent Document 3] U.S. Patent Application No. 11 / 992,790

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to provide a curable resin composition containing at least one selected from the group consisting of a conductive material, a cyclohexane-based polyfunctional epoxy compound as a binder, and a curing agent and a curing accelerator To provide a conductive adhesive composition which exhibits high heat resistance according to a high glass transition temperature after curing and can exhibit a high adhesive force while suppressing yellowing in a high temperature environment.

Another object of the present invention is to provide a curable composition which comprises a conductive material, a cyclohexane-based polyfunctional epoxy compound and a phenoxy resin, a norbornene-based acid anhydride curing agent, a curing accelerator and a yellowing inhibitor as a binder, And exhibits high heat resistance and can exhibit a high adhesive force while suppressing yellowing in a high temperature environment.

It is still another object of the present invention to provide an electronic device to which the conductive adhesive composition according to the present invention is applied.

In order to achieve the above object,

(A) a conductive material; (B) a cyclohexane-based polyfunctional epoxy compound as a binder; And at least one selected from the group consisting of (C) a curing agent and (D) a curing accelerator; And a conductive adhesive composition.

In the conductive adhesive composition of the present invention, the (C) curing agent may be a norbornene-based acid anhydride curing agent.

In the conductive adhesive composition of the present invention, the binder (B) may further comprise a phenoxy resin.

The conductive adhesive composition of the present invention may further comprise (E) a yellowing inhibitor, and the yellowing inhibitor may be at least one selected from triazole, phosphorus, and phenolic yellowing inhibitors.

In the conductive adhesive composition of the present invention, the (C) curing agent may be a phthalic acid anhydride curing agent.

As one embodiment of the present invention, the present invention provides a semiconductor device comprising: (A) a conductive material; (B) a cyclohexane-based polyfunctional epoxy compound and a phenoxy resin as binders; (C) a norbornene-based acid anhydride curing agent or a phthalic acid anhydride curing agent, and (D) a curing accelerator; And (E) a yellowing inhibitor, wherein the yellowing inhibitor is at least one selected from the group consisting of triazole, phosphorus, and phenol yellowing inhibitors.

The conductive material (A) may be at least one conductive metal particle selected from the group consisting of Group I, IIA, IIIA, IVA and VIII B metals.

The metal particles may be at least one selected from the group consisting of gold, silver, copper, aluminum, nickel, tin, palladium, platinum, zinc, iron, indium and magnesium.

The average particle diameter of the metal particles may be 0.5 to 30 占 퐉 and the specific surface area may be 0.1 to 1.2 m2 / g.

The conductive material (A) used in the present invention may be contained in an amount of 50 to 93% by weight based on the total weight of the conductive adhesive composition.

In the conductive adhesive composition of the present invention, the cyclohexane-based polyfunctional epoxy compound may be represented by the following formula (1).

Wherein R ₁ is selected from C ₁ -C ₂₀ alkyl, alkenyl and alkoxy groups substituted with at least one substituent selected from an ester group and an ether group,

R ₂ and R ₃ are independently selected from C ₁ -C ₄ alkyl, alkenyl, and alkoxy groups, respectively substituted or unsubstituted with at least one substituent selected from hydrogen, ester group, ether group and hydroxyl group.

The cyclohexane-based multifunctional epoxy compound may be 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, - epoxycyclohexylmethyl-4-epoxy. ≪ / RTI >

In the conductive adhesive composition of the present invention, the phenoxy resin used as the binder (B) may be a phenoxy resin having a weight average molecular weight of 10,000 or more and substituted with at least one substituent selected from a hydroxyl group and an epoxy group.

The phenoxy resin may be at least one selected from the group consisting of a bisphenol A phenoxy resin, a bisphenol F phenoxy resin, a brominated phenoxy resin, a phosphorus phenoxy resin, and a bisphenol S phenoxy resin.

The binder (B) may be contained in an amount of 6 to 18% by weight based on the total weight of the conductive adhesive composition.

As the binder (B), the weight mixing ratio of the cyclohexane-based polyfunctional epoxy compound and the phenoxy resin may be 2: 8 to 8: 2.

In the conductive adhesive composition of the present invention, the norbornene-based acid anhydride curing agent which can be used as the curing agent (C) may be at least one selected from the group consisting of methyl norbornene dicarboxylic acid anhydride and norbornene dicarboxylic acid anhydride have.

In the conductive adhesive composition of the present invention, the curing accelerator (D) may be one or more selected from the group consisting of an imidazole compound, an amine compound, a polyamine compound, an antimony cation initiator, a boron-based cationic initiator, It can be more than a species.

Specifically, the (D) curing accelerator is selected from the group consisting of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-dodecylimidazole, -phenyl-4-methylimidazole, 4-methylimidazole, a polyamine, SbF ₆ a sulfonic acid salt that contains the anion, SbF ₆ anions tertiary or quaternary amine salt containing the, BF ₃ the acid salts containing the anion , may be at least one kind of BF ₃ anion is a containing a tertiary or quaternary amine salts, PF ₆ anions include sulfonate, and PF ₆ anion is included selected from the group consisting of tertiary or quaternary amine salt is.

In the conductive adhesive composition of the present invention, the (E) yellowing inhibitor may be at least one selected from benzotriazole, tolyltriazole, aminobenzotriazole, hydroxybenzotriazole, dihydroxypropylbenzotriazole, dicarboxyethylbenzotriazole, Triphenylphosphine, triphenylphosphine, triphenylphosphate, butylatedhydroxytoluene, and butylatedhydroxy anisole. In the present invention, it is also possible to use at least one selected from the group consisting of triphenyl phosphite, triphenyl phosphine, triphenyl phosphate, butylated hydroxytoluene and butylated hydroxy anisole.

In the present invention, the conductive adhesive composition may include 10 to 150 parts by weight of the curing agent (C) relative to 100 parts by weight of the cyclohexane-based polyfunctional epoxy compound.

In the present invention, the conductive adhesive composition may include 0.1 to 20 parts by weight of the curing accelerator (D) relative to 100 parts by weight of the cyclohexane-based polyfunctional epoxy compound.

Also, in the present invention, the conductive adhesive composition may include 0.01 to 0.5 parts by weight of the yellowing inhibitor (E), based on 100 parts by weight of the cyclohexane-based polyfunctional epoxy compound.

In the present invention, the conductive adhesive composition may have a glass transition temperature (Tg) after curing of 150 ° C or higher.

In the present invention, the conductive adhesive composition may have an adhesive force of 5 kgf / mm < 2 > or higher at 200 to 300 DEG C after curing.

In the present invention, the conductive adhesive composition may have a yellowing ratio of 10% or less as compared to a sample not subjected to high temperature evaluation at a high temperature environment of 80 ° C or 500 hours or more after curing.

According to the present invention, an electronic device to which the conductive adhesive composition according to the present invention is applied is also provided.

The conductive adhesive composition of the present invention exhibits a high glass transition temperature after curing and thus has a high heat resistance and has an effect of exhibiting a high adhesive force while suppressing yellowing in a high temperature environment.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described in detail below. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. It is intended that the scope of the invention be defined by the claims and the equivalents thereof.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

Hereinafter, the conductive adhesive composition according to the present invention will be described in detail.

The conductive adhesive composition according to the present invention comprises

(A) a conductive material; (B) a cyclohexane-based polyfunctional epoxy compound as a binder; And (C) a curing agent and (D) a curing accelerator.

In the conductive adhesive composition of the present invention, the (C) curing agent may be a norbornene-based acid anhydride curing agent.

In the conductive adhesive composition of the present invention, the binder (B) may further comprise a phenoxy resin.

The conductive adhesive composition of the present invention may further comprise (E) a yellowing inhibitor, and the yellowing inhibitor may be at least one selected from triazole, phosphorus, and phenolic yellowing inhibitors.

According to one embodiment of the present invention, (A) a conductive material; (B) a cyclohexane-based polyfunctional epoxy compound and a phenoxy resin as binders; (C) a norbornene-based acid anhydride curing agent and (D) a curing accelerator; And (E) a yellowing inhibitor,

The yellowing inhibitor is at least one selected from the group consisting of triazole series, phosphorus series, and phenolic yellowing inhibitors.

The conductive material (A) used in the present invention may be at least one conductive metal particle selected from the group consisting of Group I, IIA, IIIA, IVA and VIII B metals, But may be at least one selected from the group consisting of copper, aluminum, nickel, tin, palladium, platinum, zinc, iron, indium and magnesium.

The metal particles may be spherical, flaky, or spherical and flake mixed particles. When the flake is used, the contact area between the substrate and the object to be bonded may be widened to exhibit excellent conductivity and excellent thermal characteristics. When a mixture of spherical and flake types is used, low viscosity can be realized.

The metal particles may have an average particle diameter of 0.5 to 30 탆, a specific surface area of 0.1 to 1.2 m 2 / g and a transverse length of 2 times or more of the longitudinal length of the particles. Within this range, Which is suitable for exhibiting the performance of

When the content of the conductive material is less than 50% by weight, the desired conductivity can not be obtained, and the content of the conductive material (A) is not suitable for the purpose. When the content of the conductive material is less than 93% The viscosity increases and the application process of the conductive adhesive is difficult, so that the problem of lowering of the processability and the adhesion may be deteriorated.

The binder (B) to be used in the present invention is a resin capable of imparting high heat resistance after curing, and is preferably a cyclohexane-based polyfunctional epoxy compound alone or a cyclohexane-based polyfunctional epoxy compound and a phenoxy resin .

The cyclohexane-based polyfunctional epoxy compound can be obtained through an epoxidation reaction of an organic compound containing cycloalkene. Since the halogen compound is synthesized through a reaction that does not include a halogen compound, It can be useful to control. Particularly, since halogen substances in electronic parts can cause defects due to corrosion of the metal substrate and ion exchange between metals, the cyclohexane-based multifunctional epoxy compound should be controlled to a minimum, It has advantages over ether epoxy compounds. In addition, when cured through a cationic catalyst, the glass transition temperature can be increased to 200 ° C, which is advantageous in terms of heat resistance, environmental resistance, and impact resistance at relatively high temperatures, and can maintain adhesiveness even in a high temperature and harsh environment It has an advantageous aspect.

The cyclohexane-based multi-functional epoxy compound may be represented by the following formula (1).

Wherein R ₁ is selected from C ₁ -C ₂₀ alkyl, alkenyl and alkoxy groups substituted with at least one substituent selected from an ester group and an ether group,

R ₂ and R ₃ are independently selected from C ₁ -C ₄ alkyl, alkenyl, and alkoxy groups, respectively substituted or unsubstituted with at least one substituent selected from hydrogen, ester group, ether group and hydroxyl group.

The cyclohexane-based multifunctional epoxy compound may be 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, - epoxycyclohexylmethyl-4-epoxy, but is not limited thereto.

The weight average molecular weight of the phenoxy resin which can be used as a binder together with the cyclohexane-based polyfunctional epoxy compound is not particularly limited, but it is preferable that the weight average molecular weight is 10,000 or more in view of the improvement of the adhesion.

The phenoxy resin may be at least one selected from the group consisting of a bisphenol A phenoxy resin, a bisphenol F phenoxy resin, a brominated phenoxy resin, a phosphorus phenoxy resin, and a bisphenol S phenoxy resin, And the phenoxy resin preferably has a basic form in which at least one substituent selected from a hydroxyl group and an epoxy group is substituted for the bisphenol-type resin. The hydroxyl group can improve the adhesive force with the base material, Can be improved.

The content of the binder (B) used in the present invention may be in the range of 6 to 18% by weight based on the total weight of the conductive adhesive composition. If the content is less than 6% by weight, the curing density may be poor enough to withstand high temperatures. If the weight% is exceeded, the filler may not be dispersed properly and hardening may be difficult.

When the cyclohexane-based polyfunctional epoxy compound and the phenoxy resin are used together as the binder (B), the weight mixing ratio of the cyclohexane-based polyfunctional epoxy compound and the phenoxy resin is 2: 8 to 8: 2 Outside the above range, a high glass transition temperature can not be exhibited after curing, so that it can not exhibit a high adhesive force in a high temperature environment, or there is a fear that the conductivity and the adhesive force are lowered.

Since the binder (B) has a polyfunctional epoxy group or hydroxyl group in the basic structure, it can undergo a crosslinking reaction with various curing agents and / or curing accelerators, and the glass transition temperature is determined depending on the kind of the curing agent causing the crosslinking reaction. It is preferable to use a curing agent capable of ensuring a high glass transition temperature of at least < RTI ID = 0.0 >

As the curing agent (C), for example, a norbornene-based acid anhydride curing agent and a phthalic acid anhydride curing agent can be used, but are not limited thereto.

When the norbornene-based acid anhydride curing agent (C) is used as the curing agent (C), a glass transition temperature of 150 ° C or higher after curing can be ensured and high physical properties such as high temperature bonding strength, glass transition temperature and heat resistance characteristics are obtained.

The norbornene-based acid anhydride curing agent which can be used as the (C) curing agent may be at least one selected from the group consisting of methyl norbornene dicarboxylic acid anhydride and norbornene dicarboxylic acid anhydride, It is not. The phthalic acid anhydride curing agent that can be used as the curing agent (C) may be, for example, hexylhydroxyphthalic acid anhydride, but is not limited thereto.

The content of the (C) curing agent may be 10 parts by weight to 150 parts by weight based on 100 parts by weight of the cyclohexane-based polyfunctional epoxy compound. When the amount is less than 10 parts by weight, the crosslinking reaction does not progress sufficiently, And adhesion at high temperature can not be expected, and when it exceeds 150 parts by weight, the glass transition temperature can be lowered.

The (D) curing accelerator may be used to promote the curing reaction and increase the degree of crosslinking.

The curing accelerator (D) may be at least one selected from the group consisting of an imidazole-based compound, an amine-based compound, a polyamine-based compound, an antimony-based cationic initiator, a boron-based cationic initiator, and a phosphorus-based cationic initiator.

As specific examples, the (D) curing accelerator may be selected from the group consisting of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-dodecylimidazole, 2-phenyl-4-methylimidazole, 4-methylimidazole, a polyamine, SbF ₆ a sulfonic acid salt that contains the anion, SbF ₆ anions tertiary or quaternary amine salt containing the, BF ₃ acid containing the anion salt, BF ₃ anion tertiary or quaternary amine salt containing the, PF ₆ the acid salts include the anionic, and PF ₆ can be one kinds or more selected from the group consisting of anionic tertiary or quaternary amine salt containing the but Specific examples of the sulfonic acid salt containing the SbF ₆ anion include triarylsulfonium hexafluoro-antimonate and the like, and the sulfonic acid salt containing the PF ₆ anion Specific examples include triarylsulfonium hexafluoro-phosphate and t-butylamine hexafluoro-phosphate And the like. The tertiary or quaternary amine salt containing BF ₃ anion includes methyl (diphenyl) sulfonium trifluoro-borate and the like.

The amount of the curing accelerator (D) may be 0.1 part by weight to 20 parts by weight based on 100 parts by weight of the cyclohexane-based polyfunctional epoxy compound. When the amount is less than 0.1 parts by weight, the curing time becomes longer, The crosslinking reaction can not be completed within 120 minutes. If it exceeds 20 parts by weight, the glass transition temperature may be lowered due to the curing accelerator not participating in crosslinking, so that the heat resistance and the adhesion at high temperature may be lowered.

In the present invention, when the above-mentioned (C) curing agent and (D) curing accelerator are used together, they can be used in one-component form. In the case of one-component type, in order to secure stability at room temperature for 48 hours or more, a latent curing accelerator curing agent may be used. Optionally, it may be coated with a polyurethane or polyester resin to form particles of 1 to several tens of 탆, and the coating may be melted at a certain temperature or higher to induce curing to start.

The yellowing inhibitor (E) used in the present invention has the function of increasing the environmental resistance after curing of the conductive adhesive by preventing the oxidation of metal particles, which are conductive materials, in a current-applied state and in a high-temperature environment in which moisture is present. In other words, in the corrosion process in which the metal component changes into metal oxide or metal hydrate, side effects such as a decrease in electric conductivity, a short circuit due to intermetallic migration, and a decrease in adhesion due to reaction of metal oxide or metal hydrate with the surrounding organic matter Yellowing agents function to prevent the corrosion of these metal particles and the side effects thereof. Such a yellowing inhibitor can be usefully added in order to improve the environmental resistance by suppressing the reduction in performance due to yellowing when the conductive adhesive is applied to the bonding of the optical element and the bonding process of the semiconductor element.

The (E) yellowing inhibitor may be at least one selected from the group consisting of benzotriazole, tolyltriazole, aminobenzotriazole, hydroxybenzotriazole, dihydroxypropylbenzotriazole, dicarboxyethylbenzotriazole, triphenylphosphite, triphenylphosphine , Triphenylphosphate, butylated hydroxytoluene, and butylated hydroxy anisole, but not limited thereto, and when two or more of them are used in combination, a more excellent yellowing prevention So that the reduction in performance due to yellowing can be further suppressed.

The content of the (E) yellowing inhibitor may be 0.01 to 0.5 parts by weight based on 100 parts by weight of the cyclohexane-based polyfunctional epoxy compound. When the amount is less than 0.01 parts by weight, the yellowing prevention effect may not be sufficiently exhibited. The residual yellowing inhibitor may react to lower the adhesive force.

The conductive adhesive composition according to the present invention can exhibit sufficient performance through a curing reaction, but it is advantageous to have suitable viscosity and thixotropic for printing and application of the conductive adhesive during the chip bonding process.

In order to achieve such viscosity and thixotropic performance, a viscosity control process of the conductive adhesive is required. To this end, the conductive adhesive composition of the present invention may include an organic solvent and a diluent, either singly or in combination.

Examples of the organic solvent that can be used in the present invention include isopropyl acetate, butanol, 2-butanol, octanol, 2-ethylhexanol, pentanol, benzyl alcohol, hexanol, , Nonanol, diethylene glycol, triethylene glycol, tetraethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene Glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol mono Methyl ether acetate, diethylene glycol moiety Triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, triethylene glycol monobutyl ether acetate, dimethyl carbonate, diethyl carbonate, propylene glycol methyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, 2-methoxyethyl acetate, and propylene glycol monomethyl ether. However, the solvent is not limited to these solvents.

As the diluent that can be used in the present invention, a monofunctional epoxy or polyfunctional epoxy compound is suitable, and hexahydrophthalic acid diglycidyl ester, trimethylolpropane triglycidyl ether, butyl glycidyl ether, phenyl glycidyl ether , And cresyl glycidyl ether may be used alone or in combination with a solvent, but the present invention is not limited thereto.

The content of the solvent and / or the diluent may be 1 to 10% by weight based on the total weight of the conductive adhesive composition. If the content is less than 1% by weight, the viscosity of the conductive adhesive composition may be difficult to control, , The crosslinking degree may decrease in the crosslinking reaction and the glass transition temperature and adhesion may be lowered.

The conductive adhesive composition according to the present invention has a high glass transition temperature of 150 ° C or higher after curing and can exhibit a high adhesive strength of 5 kgf / mm 2 or more at 200 to 300 ° C, thereby exhibiting high reliability in a high temperature process or a high temperature environment .

In addition, the conductive adhesive composition according to the present invention may have a yellowing rate of 10% or less as compared to a sample not subjected to a high temperature evaluation in a high temperature environment of 80 占 폚 for 500 hours or more after curing.

According to the present invention, an electronic device to which the conductive adhesive composition according to the present invention is applied is also provided. Examples of the electronic device include a semiconductor, a liquid crystal display, an electronic component, a semiconductor package, a printed circuit board, a tape carrier package, And various kinds of fine circuits such as a printed circuit board and a connection between a TCP and a PCB. Specific examples of the device include an LED chip packaging product, a semiconductor chip packaging product, and a camera module component. It is not.

Hereinafter, the present invention will be described in detail by way of examples to demonstrate the superiority of the conductive adhesive composition of the present invention. However, the following examples are for illustrative purposes only, and the present invention is not limited to the following examples.

Materials and materials

The conductive metal particles, the epoxy compound, the phenoxy resin, the curing agent, the curing accelerator, the solvent, the diluting agent and the yellowing inhibitor used in the following examples and comparative examples are shown in detail in the following Table 1.

Conductive metal particles a The flakes consisted of particles (average particle diameter 1.8 占 퐉, specific surface area 1.2 m2 / g) b Spherical silver particles (mean particle diameter 2.0 mu m, specific surface area 0.6 m2 / g) c The flakes consisted of particles (average particle diameter 7.5 mu m, specific surface area 1.1 m2 / g) Epoxy compound a 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate b Bis (3,4-epoxycyclohexylmethyl) adipate c Bisphenol A diglycidyl ether Phenoxy resin a Bisphenol A type phenoxy resin (weight average molecular weight: 20,000) b Bisphenol A type / F type phenoxy (weight average molecular weight: 40,000) diluent Hexahydroxyphthalic acid diglycidyl ester menstruum Diethylene glycol monobutyl ether acetate Hardener a Methyl norbornenedicarboxylic acid anhydride b Norbornene dicarboxylic anhydride c Hexylhydroxyphthalic anhydride Hardening
accelerant a Sulfonates containing BF ₃ anions b Latent polyamine hardener Yellow
Inhibitor a Triphenylphosphite b Dihydroxypropylbenzotriazole

Example  1 to 17 and Comparative Example  1-2

Preparation of conductive adhesive

The conductive metal particles and the epoxy compound, the phenoxy resin, the diluent or the solvent, the curing agent, the curing accelerator and the yellowing inhibitor were mixed using a rotary stirring mixer according to the composition shown in the following Table 1, The dispersion was further dispersed using a 3-roll mill, and then a solvent or a diluent was further added thereto, followed by stirring at the latter half of the stirring, followed by defoaming to prepare a conductive adhesive.

Conductive metal particles
(a + b + c ¹⁾ )
(Wt% ^{2 )} ) Epoxy
compound
(Wt% ^{2 )} ) Phenoxy
Suzy
(Wt% ^{2 )} ) Hardener
(Parts by weight ^{3 )} )
Hardening
accelerant
(Parts by weight ^{3 )} ) Yellow
Inhibitor
(a + b4 ⁾ )
(Parts by weight ^{3 )} ) diluent Example 1 65 2 (a) 6 (a) 10 (a) 0.16 (a) 0.1 balance Example 2 65 3 (a) 5 (a) 10 (a) 0.16 (a) 0.1 balance Example 3 65 4 (a) 4 (a) 10 (a) 0.16 (a) 0.1 balance Example 4 65 5 (a) 3 (a) 10 (a) 0.16 (a) 0.1 balance Example 5 65 6 (a) 2 (a) 10 (a) 0.16 (a) 0.1 balance Example 6 65 6 (b) 2 (a) 10 (a) 0.16 (a) 0.1 balance Example 7 65 6 (a) 2 (b) 10 (a) 0.16 (a) 0.1 balance Example 8 65 6 (a) 2 (a) 10 (b) 0.16 (a) 0.1 balance Example 9 65 6 (a) 2 (a) 10 (a) 0.16 (a) 0.1 balance Example 10 65 6 (a) 2 (a) 10 (a) 0.16 (a) 0.1 balance Example 11 65 6 (a) 2 (a) 10 (a) 0.16 (a) 0.1 balance Example 12 65 8 (a) - 10 (a) 0.16 (b) 0.1 balance Example 13 65 8 (b) - 10 (a) 1.2 (b) 0.1 balance Example 14 65 12 (a) 6 (a) - 1.2 (b) 0.1 balance Example 15 65 12 (a) 6 (a) - 0.16 (a) 0.1 balance Example 16 65 8 (a) - 10 (a) 1.2 (b) - balance Example 17 65 6 (a) 2 (a) 10 (c) 0.16 (a) 0.2 ⁵⁾ balance Comparative Example 1 65 - 8 (a) 10 (a) 0.16 (b) - balance Comparative Example 2 65 6 (c) 2 (b) 10 (c) 1.2 (b) - balance

Note 1) 50% by weight of conductive metal particles (a) 25% by weight of conductive metal particles (b) + 25% by weight of conductive metal particles (c)

2)% by weight means the content of each component based on the total weight of the conductive adhesive composition.

3) parts by weight means the content of each component with respect to 100 parts by weight of the epoxy compound.

4) 0.03 parts by weight of yellowing inhibitor (a) + 0.07 parts by weight of yellowing inhibitor (b)

5) 0.1% by weight of yellowing inhibitor (a) + 0.1% by weight of yellowing inhibitor (b)

Adhesion evaluation

The conductive adhesive obtained in Examples 1 to 17 and Comparative Examples 1 and 2 was printed on a substrate or lead frame through a die bonder by stamping printing at 5,000 mu m. A silicone chip having a width of 2 mm and a length of 2 mm was placed on the printed conductive adhesive, and the conductive adhesive was cured under the conditions of primary curing at 50 ° C for one hour and secondary curing at 170 ° C for one hour Respectively. After bonding, the adhesive force was measured at room temperature (25 ° C) while applying a shear stress at a rate of 0.3 mm / sec through an adhesive force evaluation device (Nordson Company, Dage 4000 series). Subsequently, the temperature of the substrate support was heated to 100 ° C. and 250 ° C. through a heating block, and the adhesive strength was measured under the same conditions. The results are shown in Table 3 below.

Yellow  evaluation

The conductive adhesive obtained in the above Examples 1 to 17 and Comparative Examples 1 and 2 was applied to a glass substrate with a bar coater in a thickness of 30 mu m and then primary cured at 50 DEG C for 1 hour and then cured at 170 DEG C for 1 hour , And after curing, it was allowed to stand in a high temperature environment of 80 占 폚 for 500 hours to observe the yellowing phenomenon. Yellowing is mainly caused by oxidation of metals or decomposition of epoxy compounds, which may affect adhesion and reliability.

The yellowing index b * value before leaving was measured for each specimen, and the yellowing index b * value was measured after standing. The degree of increase in yellowing index was converted into a percentage, and the yellowing inhibition effect was measured. .

Glass transition temperature measurement

The conductive adhesives obtained in Examples 1 to 17 and Comparative Examples 1 and 2 were applied to a glass substrate in a thickness of 30 mu m using a bar coater and cured at 50 DEG C for 1 hour and then cured at 170 DEG C for 1 hour , And then scraped with a knife to collect a sample. The glass transition temperature of each sample was measured by dynamic mechanical analysis (DMA). The results are shown in Table 3 below.

Shear modulus measurement

The prepared conductive adhesive was cured in the form of a thickness of 0.5 mm, a length of 20 mm and a width of 10 mm, and the shear coefficient at each temperature was measured using dynamic mechanical analysis (DMA) Respectively. By measuring the shear rate, it is possible to deduce the shrinkage characteristics at low temperature and high temperature.

Adhesion (kgf) Yellow
b value variation
(%) Glass transition
Temperature (℃) Shear rate (Gpa) 25 ℃ 100 ℃ 250 ℃ 25 ℃ 100 ℃ 250 ℃ Example 1 35.5 30.2 6.0 4.8 151 3.04 2.62 0.47 Example 2 34.9 29.8 6.5 4.5 155 3.25 2.78 0.56 Example 3 34.3 30.2 6.2 4.7 162 3.31 2.89 0.63 Example 4 32.6 29.3 6.5 4.2 174 3.26 2.98 0.85 Example 5 31.1 28.3 6.7 4.6 184 3.38 3.02 0.98 Example 6 32.5 28.9 6.8 4.6 186 3.42 3.15 1.02 Example 7 31.4 28.5 6.7 4.6 182 3.35 3.01 0.96 Example 8 30.8 28.5 6.6 4.6 184 3.32 3.05 0.97 Example 9 30.8 28.0 6.6 4.7 183 3.22 3.00 0.93 Example 10 30.3 27.7 6.5 4.7 185 3.33 3.03 0.99 Example 11 30.5 25.3 5.9 4.5 155 3.55 2.85 0.67 Example 12 28.5 24.6 7.5 3.2 195 3.25 2.95 1.11 Example 13 27.5 25.6 8.2 3.8 185 3.85 2.85 1.21 Example 14 25.5 21.2 10.5 3.5 195 3.75 3.01 1.50 Example 15 26.5 20.5 11.5 3.9 201 4.20 3.12 1.60 Example 16 16.4 15.1 4.1 7.2 206 4.10 3.18 1.27 Example 17 30.2 20.3 3.2 6.9 135 3.34 2.11 0.35 Comparative Example 1 29.7 24.4 3.3 16.5 131 2.94 2.14 0.32 Comparative Example 2 15.5 7.2 1.2 20.5 121 2.50 1.75 0.15

As shown in Table 3, the glass transition temperature and the high-temperature shear rate of the conductive adhesive composition within the range of the amount of the cyclohexane-based polyfunctional epoxy compound according to the present invention exhibited a high overall value. In addition, Examples 1 to 11 using a cyclohexane-based polyfunctional epoxy compound and a phenoxy resin as binders showed better results than the adhesive force of Comparative Example 1 using only phenoxy resin as a binder, The high crosslinking degree of the polyfunctional epoxy compound and the shrinking property of the phenoxy resin are combined to show an optimum adhesive force.

Further, Examples 1 to 15 and 17 using the yellowing inhibitor showed further inhibition of yellowing than Comparative Examples 1 and 2 which did not use the yellowing inhibitor.

Examples 1 to 13 and Example 16 in which a norbornene-based acid anhydride curing agent was used as a curing agent exhibited excellent properties particularly in terms of high temperature adhesive force, yellowing, glass transition temperature and high temperature shear rate.

In Examples 12 and 13 using cyclohexane-based polyfunctional epoxy compounds alone as curing agents and curing accelerators, the adhesive strength was lowered at room temperature than in the case of using phenoxy resins as in Examples 1 to 11, And 10 ~ 15% at high temperature. This is because the adhesive strength is low at room temperature due to the fragility property due to the high shear modulus at room temperature, but the adhesive strength is relatively high due to a sufficiently high Tg and a high shear rate at high temperature.

Further, as in the cases of Examples 14 and 15, when only the curing accelerator was added to the cyclohexane-based polyfunctional epoxy compound without the curing agent, there was a clear tendency to lower the adhesive force at room temperature and to improve the adhesive force at high temperature.

In Example 16 in which the yellowing inhibitor was not added, the yellowing rate was higher than that in the case where the yellowing inhibitor was present, but it was not more than 10%.

As a result, it can be seen that the cyclohexane-based polyfunctional epoxy composition has excellent adhesion at high temperature, and when a phenoxy resin is used together as a binder and a norbornene-based acid anhydride curing agent is used as a curing agent, And that the yellowing inhibitory effect can be further enhanced by the yellowing inhibitor.

In addition, when the general bisphenol A type epoxy compound was applied as in Comparative Example 2, adhesion was remarkably decreased not only at a low temperature but also at a high temperature. It can be seen that the cyclohexane-based polyfunctional epoxy compounds have a significant influence on the yellowing and high-temperature adhesive strength.

Claims (27)

(A) a conductive material;
(B) a cyclohexane-based polyfunctional epoxy compound as a binder; And
(C) a curing agent and (D) a curing accelerator;
≪ / RTI >
The method according to claim 1,
Wherein the curing agent (C) is a norbornene-based acid anhydride curing agent.
The method according to claim 1,
Wherein the binder (B) further comprises a phenoxy resin.
The method according to claim 1,
(E) a yellowing inhibitor,
Wherein the yellowing inhibitor is at least one selected from the group consisting of triazole series, phosphorus series, and phenolic yellowing inhibitors. 5. The method of claim 4,
Wherein the (C) curing agent is a phthalic acid anhydride curing agent.
(A) a conductive material;
(B) a cyclohexane-based polyfunctional epoxy compound and a phenoxy resin as binders;
(C) a norbornene-based acid anhydride curing agent or a phthalic acid anhydride curing agent, and (D) a curing accelerator; And
(E) a yellowing inhibitor,
Wherein the yellowing inhibitor is at least one selected from the group consisting of triazole series, phosphorus series, and phenolic yellowing inhibitors.
7. The method according to any one of claims 1 to 6,
Wherein the conductive material (A) is at least one conductive metal particle selected from the group consisting of Group I, IIA, IIIA, IVA and VIII B metals.
8. The method of claim 7,
Wherein the metal particles are at least one selected from the group consisting of gold, silver, copper, aluminum, nickel, tin, palladium, platinum, zinc, iron, indium and magnesium.
8. The method of claim 7,
Wherein the metal particles have an average particle diameter of 0.5 to 30 占 퐉 and a specific surface area of 0.1 to 1.2 m2 / g.
7. The method according to any one of claims 1 to 6,
Wherein the conductive material (A) comprises 50 to 93% by weight based on the total weight of the conductive adhesive composition.
7. The method according to any one of claims 1 to 6,
Wherein the cyclohexane-based polyfunctional epoxy compound is represented by the following formula (1).

Wherein R ₁ is selected from C ₁ -C ₂₀ alkyl, alkenyl and alkoxy groups substituted with at least one substituent selected from an ester group and an ether group,
R ₂ and R ₃ are independently selected from C ₁ -C ₄ alkyl, alkenyl, and alkoxy groups, respectively substituted or unsubstituted with at least one substituent selected from hydrogen, ester group, ether group and hydroxyl group.
7. The method according to any one of claims 1 to 6,
The cyclohexane-based multifunctional epoxy compound may be 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, -Epoxycyclohexylmethyl-4-epoxy. ≪ / RTI >
The method according to claim 3 or 6,
Wherein the phenoxy resin is a phenoxy resin having a weight average molecular weight of 10,000 or more and at least one substituent selected from a hydroxyl group and an epoxy group may be substituted.
The method according to claim 3 or 6,
Wherein the phenoxy resin is at least one selected from the group consisting of a bisphenol A phenoxy resin, a bisphenol F phenoxy resin, a brominated phenoxy resin, a phosphorus phenoxy resin, and a bisphenol S phenoxy resin.
7. The method according to any one of claims 1 to 6,
Wherein the binder (B) comprises 6 to 18% by weight based on the total weight of the conductive adhesive composition.
The method according to claim 3 or 6,
Wherein the weight mixing ratio of the cyclohexane-based polyfunctional epoxy compound to the phenoxy resin is from 2: 8 to 8: 2 as the (B) binder. 7. The method according to claim 2 or 6,
Wherein the (C) norbornene acid anhydride curing agent is at least one selected from the group consisting of methyl norbornene dicarboxylic anhydride and norbornene dicarboxylic acid anhydride.
7. The method according to any one of claims 1 to 6,
Wherein the curing accelerator (D) is at least one selected from the group consisting of an imidazole-based compound, an amine-based compound, a polyamine-based compound, an antimony-based cationic initiator, a boron-based cationic initiator, and a phosphorous-based cationic initiator.
19. The method of claim 18,
The curing accelerator (D) is selected from the group consisting of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-dodecylimidazole, 4-methylimidazole, 4-methylimidazole, a polyamine, SbF _6-sulfonic acid salt that contains the anion, SbF ₆ a containing a tertiary or quaternary amine salts, BF ₃ anion include a sulfonate anion, BF ₃ tertiary or quaternary amine salt containing the anion, PF ₆ sulfonic acid salt containing the anion, PF ₆ anion and includes a tertiary or quaternary least one member conductive adhesive composition is selected from the group consisting of amine salts.
The method according to claim 4 or 6,
The (E) yellowing inhibitor may be at least one selected from the group consisting of benzotriazole, tolyltriazole, aminobenzotriazole, hydroxybenzotriazole, dihydroxypropylbenzotriazole, dicarboxyethylbenzotriazole, triphenylphosphite, triphenylphosphine , Triphenyl phosphate, butylated hydroxytoluene, and butylated hydroxy anisole.
7. The method according to any one of claims 1 to 6,
And 10 to 150 parts by weight of the curing agent (C) relative to 100 parts by weight of the cyclohexane-based multi-functional epoxy compound.
7. The method according to any one of claims 1 to 6,
And 0.1 to 20 parts by weight of the curing accelerator (D), based on 100 parts by weight of the cyclohexane-based polyfunctional epoxy compound.
The method according to claim 4 or 6,
0.01 to 0.5 parts by weight of the yellowing inhibitor (E), based on 100 parts by weight of the cyclohexane-based polyfunctional epoxy compound.
7. The method according to any one of claims 1 to 6,
Wherein the conductive adhesive composition has a glass transition temperature (Tg) of 150 DEG C or higher after curing.
7. The method according to any one of claims 1 to 6,
Wherein the conductive adhesive composition has an adhesive strength of 5 kgf / mm < 2 > or more at 200 to 300 DEG C after curing.
7. The method according to any one of claims 1 to 6,
Wherein the conductive adhesive composition has a yellowing ratio of 10% or less as compared to a sample not subjected to a high temperature evaluation in a high temperature environment of 80 占 폚 for 500 hours or more after curing.
An electronic device to which the conductive adhesive composition according to any one of claims 1 to 6 is applied.