KR102442606B1 - A conductive paste composition - Google Patents

Abstract

The present invention relates to a conductive paste composition. The conductive paste composition comprises: a first conductive filler including metal powder; a second conductive filler including carbon black having a specific surface area of 900 to 1300 m^2/g; a binder; and a dispersing agent. Therefore, the conductive paste composition increases conductive performance, work/process convenience and economic feasibility.

Description

Conductive paste composition {A CONDUCTIVE PASTE COMPOSITION}

The present invention relates to a conductive paste composition that can be used to form electrodes in various circuits or electronic products.

With the recent development of the electronic industry, miniaturization and high reliability of electronic products and devices are required, and various methods have been tried to form circuit patterns or electrodes of electronic products requiring high integration.

Among them, the use of a conductive paste composition is of interest because it produces less by-products or contaminants during the process.

A commonly used conductive paste composition includes a conductive metal, a glass frit, and a binder, and silver (Ag) having excellent conductivity is used as the conductive metal.

Currently, the conductive paste composition is mainly used for mounting of hybrid ICs and semiconductor ICs, as well as various capacitors and electrodes, etc. is being applied

In addition, it is applied to reduce the contact resistance of solid oxides in the fuel cell field, where R&D is being actively conducted as a future industry, and the demand for it is further increasing as the industry related to high-tech products expands.

Meanwhile, in recent years, conductive fillers such as metal powder and carbon materials have been applied to improve the conductive performance of the conductive paste composition. However, there is a difference in conductive performance depending on the shape and composition of the conductive filler.

At this time, when silver powder having excellent conductivity is applied as a metal powder, the production cost of the conductive paste composition is very high, and there is a problem in that economical efficiency is lowered, and in the case of carbon materials such as carbon black, graphite or carbon nanotube (CNT) , a special dispersion technique is required, and there is a limit to the increase in the composition due to the high specific surface area, so an appropriate composition is required.

In addition, in order to increase the binding force between the conductive fillers and to improve the printing stability of the conductive paste composition, it is necessary to select an appropriate binder and solvent.

Patent Publication No. 2009-0030995 (published on March 25, 2009) “Conductive paste composition”

In the present invention, by forming a paste composition using a conductive paste composition, specifically, a conductive filler and a binder including needle-shaped metal powder and carbon black, conductive performance, work/process convenience, and economic feasibility can be improved. An object of the present invention is to provide a conductive paste composition.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. will be able

In order to solve the above problems, the present invention provides a first conductive filler including a needle-shaped metal powder, a second conductive filler including carbon black having a specific surface area of 900 to 1300 m 2 /g, a binder and a dispersant. It provides a conductive paste composition comprising.

In addition, the metal powder is a silver (Ag)-coated copper (Cu) powder, and provides a conductive paste composition having an average particle size (D ₅₀ ) of 2 to 8 μm.

In addition, the first conductive filler provides a conductive paste composition in which 100 to 140 parts by weight are mixed based on 100 parts by weight of the binder.

In addition, the second conductive filler provides a conductive paste composition in which 1 to 8 parts by weight are mixed based on 100 parts by weight of the first conductive filler.

In addition, the binder provides a conductive paste composition formed by dissolving a phenoxy resin and an epoxy resin in a high-boiling solvent having a boiling point of 150° C. or higher at normal pressure.

In addition, the epoxy resin provides a conductive paste composition in which 25 to 150 parts by weight are dissolved based on 100 parts by weight of the phenoxy resin.

The conductive paste composition according to an embodiment of the present invention is prepared by mixing a needle-shaped metal powder and a type of carbon black having a large specific surface area, thereby forming a contact point between the needle-shaped powder or carbon black particles. At the same time, it is possible to induce a large contact area while increasing the conductivity, thereby greatly improving the conduction performance.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art from the following description. will be.

1 to 3 are diagrams showing surface images of conductive paste compositions on which adhesion evaluation was performed according to Example 2, Comparative Example 1, and Comparative Example 2 of the present invention, respectively, in order to confirm adhesion.
4 to 6 show images of the surface after printing of the conductive paste compositions according to Example 1, Comparative Example 12, and Comparative Example 13 of the present invention, respectively, in order to confirm printability.
7 and 8 show images taken by SEM of the conductive paste composition according to Example 1 and Comparative Example 13 of the present invention, respectively, after printing to confirm flatness.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

DETAILED DESCRIPTION The detailed description set forth below in conjunction with the appended drawings is intended to describe exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced.

In order to clearly explain the present invention in the drawings, parts irrelevant to the description may be omitted, and the same reference numerals may be used for the same or similar components throughout the specification.

In an embodiment of the present invention, expressions such as “or” and “at least one” may indicate one of the words listed together, or a combination of two or more.

The conductive paste composition of the present invention is applied to form circuit patterns or electrodes in various electrical and electronic fields, and by forming a paste composition using a conductive filler and binder containing needle-shaped metal powder and carbon black, Conductive performance, work/process convenience and economy can be improved.

The conductive paste composition according to an embodiment of the present invention may include a first conductive filler, a second conductive filler, a binder, and a dispersant.

The conductive paste composition of this embodiment is prepared by adding the first and second conductive fillers and the dispersing agent to the binder and mixing them, then performing a milling process (eg, 3-roll mill) for dispersion, post mixing, and It may be manufactured through a paste mixing process for defoaming.

The first conductive filler may apply a metal powder coated with silver (Ag) on the surface in order to improve the conductive performance.

At this time, as the metal powder, silver (ag), copper (Cu), nickel (Ni), chromium (Cr), cobalt (Co), aluminum (Al), tin (Sn), lead (Pb), zinc (Zn) Alternatively, various metal materials such as iron (Fe) may be used, and copper may be preferably used depending on the economic feasibility of the metal powder, conductivity, and whether it can be manufactured in a needle shape.

In this embodiment, by using the copper powder coated with silver (Ag) as the first conductive filler, it is possible to reduce the amount of expensive silver used without reducing the conductive performance, thereby securing economic efficiency.

As an example, the weight of silver coated on the copper powder may be 5 to 10 parts by weight, preferably 6 parts by weight, based on 100 parts by weight of the silver-coated copper powder.

Also, the average particle size (D ₅₀ ) of the silver (Ag)-coated copper powder may be 2 to 8 μm, and may be formed in a needle shape.

Here, the needle-shaped powder can increase the contact point between the powders and induce a wider mutual contact area, compared to the spherical or plate-shaped powder, so that the conductive performance can be greatly improved.

Carbon black may be applied as the second conductive filler, and this carbon black may be provided to fill the voids between the first conductive fillers having a needle shape.

As an example, carbon black having a specific surface area of 900 to 1300 m 2 /g may be used as the carbon black applied as the second conductive filler in this embodiment.

That is, the carbon black of this embodiment has a specific surface area of 900 to 1300 m2/g, compared to the case of commonly used conductive carbon black having a specific surface area of approximately 200 to 300 m 2 /g, so that it can be produced through a large specific surface area. The contact point between the carbon black particles and the contact point between the carbon black and the first conductive filler can be increased in the voids between the first conductive fillers, and through this, the conductive performance can be improved.

In addition, the content of the second conductive filler compared to the first conductive filler may include 1 to 8 parts by weight based on 100 parts by weight of the first conductive filler.

When the amount of the second conductive filler is insufficient compared to the first conductive filler, the contact in the voids between the first conductive fillers is insufficient, the conductive performance is lowered, and when the amount of the second conductive filler is excessive, the conductivity is caused by the second conductive filler The viscosity of the paste composition increases, resulting in poor printing properties.

Meanwhile, the binder may be prepared by dissolving a polymer resin in a solvent.

In this case, the polymer resin may be used by mixing a thermoplastic resin and a thermosetting resin, and due to the mixed use of the thermoplastic resin and the thermosetting resin, the final composition may have excellent impact resistance and heat resistance.

Here, the thermoplastic resin is butadiene rubber resin, polyester resin, rosin, phenoxy resin, polyvinyl butyral (PVB, Polyvinyl Butyral) resin, polymethyl methacrylate (PMMA, Poly Methyl Meta Acrylate) resin or polyethylene One or more types of (PE, Poly Ethylene) resins may be used.

In addition, as the thermosetting resin, one or more of a urethane resin, an epoxy resin, a phenol resin, an unsaturated polyester resin, a melamine resin, or a polyester resin may be used.

Preferably, a phenoxy resin and an epoxy resin having excellent adhesive properties may be used together so that adhesion to the substrate is good, compatibility between resins is good, and adhesion between the first and second conductive fillers can be improved.

Here, the epoxy resin means a resin containing an epoxy curing agent to match the equivalent ratio of the epoxy resin.

In addition, the polymer resin may be mixed with 25 to 150 parts by weight of the epoxy resin based on 100 parts by weight of the phenoxy resin and the phenoxy resin.

This is because, when the content of the epoxy resin, which is a curable resin, is less than 25 compared to 100 parts by weight of the phenoxy resin, adhesion deterioration due to the insufficient content of the epoxy resin causes a problem of poor adhesion in which the conductive filler is removed from the binder, and the epoxy resin When the content exceeds 150 parts by weight based on 100 parts by weight of the phenoxy resin, the sheet resistance may be greatly increased due to the crystallinity of the epoxy resin.

Meanwhile, in this embodiment, a method of injecting a solvent into a solvent for mixing a phenoxy resin and an epoxy resin has been described as an example, but the present invention is not limited thereto. It is self-evident that it can also be injected.

In addition, as the solvent included in the binder, a high boiling point solvent may be used to facilitate storage safety and printing continuity of the conductive paste composition.

Here, as the high boiling point solvent, a solvent having a boiling point of 150° C. or higher at normal pressure may be used, and for example, cyclohexanone, butyl cellosolve, butyl carbitol acetate, texanol, dimethylformamide, dimethyl sulfoxide, di One or more types of basic ester or terpineol may be used.

The dispersant may be used for smooth dispersion of the first and second conductive fillers mixed in the binder.

As an example, as the dispersant, one or more of urethane-based, acrylic-based, phosphorus-based, organic acid-based, and inorganic acid-based dispersants may be used, and these dispersants may range from 0.1 to 5 parts by weight based on 100 parts by weight of the composition of the first and second conductive fillers and the binder. It may be included in parts by weight.

Meanwhile, in preparing the conductive paste composition of this embodiment using the first conductive filler, the second conductive filler, the binder and the dispersant configured as described above, the binder may be prepared by first dissolving the polymer resin in a solvent.

As an example, the binder contains 40 to 70 parts by weight of a polymer resin based on 100 parts by weight of a high boiling point solvent. It can be prepared by dissolving parts by weight.

Next, the first conductive filler, the second conductive filler, and the dispersing agent may be added to the binder and mixed. For example, based on 100 parts by weight of the conductive paste composition, which is the final composition, the binder is 30 to 60 parts by weight, the first conductive 40 to 70 parts by weight of the filler, 0.1 to 5 parts by weight of the second conductive filler, and 0.1 to 5 parts by weight of the dispersant may be added and mixed.

Then, a milling process for dispersion may be performed, and a paste mixing process for post mixing and defoaming may be performed to prepare a conductive paste composition.

Hereinafter, a conductive paste composition prepared according to a preferred embodiment and a comparative example of the present invention will be described.

However, these are presented as preferred examples of the present invention and cannot be construed as limiting the present invention in any sense.

1) Evaluation of binder properties

[Examples 1 to 3]

In Example 1, a binder was prepared by dissolving 60 parts by weight of a polymer resin in which a phenoxy resin and an epoxy resin were mixed in a ratio of 60:40 in butyl carbitol acetate, based on 100 parts by weight of butyl carbitol acetate.

After mixing and stirring 4 parts by weight of a dispersant to the prepared binder, based on 100 parts by weight of the binder, as a first conductive filler, silver-coated copper powder (silver-coated copper) having an average particle size (D ₅₀ ) of 4.5 μm in needle shape The silver content is 6 parts by weight based on 100 parts by weight of the powder), and 120 parts by weight and 4 parts by weight of carbon black having a specific surface area of 1270 m 2 /g as a second conductive filler, based on 100 parts by weight of the binder, respectively, are mixed, followed by dispersion and A conductive paste composition was prepared through a mixing process.

And Examples 2 and 3 were prepared in the same manner as in Example 1, except that the phenoxy resin and the epoxy resin were prepared in a ratio of 80:20 in Example 2 and 40:60 in Example 3

The prepared conductive paste composition was screen-printed on a substrate, dried at 120° C. for 5 minutes to form a coating film, and cured at 180° C. for 10 minutes, and then printability, adhesion and sheet resistance were measured.

Here, the printability evaluated the thickness deviation and shape of the conductive paste composition printed on the substrate, and the thickness deviation was compared with the maximum thickness and the minimum thickness of the printed conductive paste composition, and the printed shape matched the shape of the screen mask. Adhesion was evaluated by immersing the substrate printed with the conductive paste composition in an ultrasonic water bath (70° C.) and then applying ultrasonic waves for 60 minutes to evaluate the degree of peeling of the coating film from the substrate. It was measured three times using CMT-100S, and the average value was derived and evaluated.

[Comparative Examples 1 to 4]

It was prepared in the same manner as in Example 1, but in Comparative Example 1, the mixing ratio of the phenoxy resin and the epoxy resin was 100:0, in Comparative Example 2, the mixing ratio of the phenoxy resin and the epoxy resin was 90:10, and Comparative Example 3 was The mixing ratio of the phenoxy resin and the epoxy resin is 30:70, and in Comparative Example 4, the ratio of the phenoxy resin and the epoxy resin is 10:90 A conductive paste composition was prepared using a phosphorus binder.

In addition, the conductive paste compositions prepared in Comparative Examples 1 to 4 were screen-printed on a substrate, dried at 120° C. for 5 minutes to form a coating film, and cured at 180° C. for 10 minutes to obtain printability, adhesion and sheet resistance. measured.

Table 1 below shows the results of measuring printability, adhesion, and sheet resistance of the conductive paste compositions prepared by using different binders according to Examples 1 to 3 and Comparative Examples 1 to 4, respectively.

In addition, FIGS. 1 to 3 show surface images of the conductive paste compositions in which adhesion evaluation according to Examples 2 and Comparative Examples 1 and 2 of the present invention was performed to confirm adhesion, respectively.

Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Mixing ratio of polymer resin (wt%) phenoxy resin 60 80 40 100 90 30 10 epoxy resin 40 20 60 0 10 70 90 second conductive filler type carbon black carbon black carbon black carbon black carbon black carbon black carbon black specific surface area
(m2/g) 1270 1270 1270 1270 1270 1270 1270 first conductive filler
(silver coated copper powder) shape couch couch couch couch couch couch couch average particle size
(D ₅₀ ) 4.5㎛ 4.5㎛ 4.5㎛ 4.5㎛ 4.5㎛ 4.5㎛ 4.5㎛ printability Good Good Good Good Good Good Good adherence Good Good Good error error Good Good Sheet resistance (Ω/□) 1.0 1.0 1.1 0.50 0.80 1.7 5.8

As shown in Table 1, compared to Example 2 in which the mixing ratio of the polymer resin, that is, the mixing ratio of the phenoxy resin and the epoxy resin, was 80:20, the mixing ratio of the phenoxy resin and the epoxy resin was 100:0. In the case of Example 1 and Comparative Example 2, in which the mixing ratio was 90:10, the sheet resistance was slightly improved, but it was confirmed that the adhesion was poor as shown in FIGS. 2 and 3 .

It is expected that the content of the epoxy resin, which is a curable resin, is insufficient, and the coating film stability is lowered, and thus the conductive fillers in the conductive paste composition are removed.

In addition, Comparative Example 3, in which the mixing ratio of the phenoxy resin and the epoxy resin is 30:70, and Comparative Example 4, in which the mixing ratio is 10:90, has a high content of the epoxy resin, which is a curable resin. It can be seen that the sheet resistance is significantly increased compared to Examples 1 to 3 by causing a decrease in conductivity due to the crystallinity of the resin.

On the other hand, in Examples 1 to 3, it was confirmed that the sheet resistance was lowered as the conductivity was improved due to the high density between the first and second conductive fillers, and the adhesion was also shown to be good as shown in FIG. 1 (Example 2). can confirm.

2) Evaluation of physical properties for the shape of the first conductive filler and metal powder

[Comparative Examples 5 and 6]

It was prepared in the same manner as in Example 1, but as the first conductive filler, in Comparative Example 5, silver-coated copper powder in the form of a plate having an average particle size (D ₅₀ ) of 4.5 μm was used, and in Comparative Example 6, an average particle size (D ₅₀ ) Each conductive paste composition was prepared using silver-coated copper powder having a spherical shape of 4.5 μm.

In addition, the conductive paste compositions prepared in Comparative Examples 5 and 6 were screen-printed on a substrate, dried at 120° C. for 5 minutes to form a coating film, and after curing at 180° C. for 10 minutes, printability, adhesion and sheet resistance were improved. measured.

Table 2 below shows the results of measuring printability, adhesion, and sheet resistance of the conductive paste composition prepared by changing the shape of the first conductive filler according to Example 1 and Comparative Examples 5 and 6, respectively.

Item Example 1 Comparative Example 5 Comparative Example 6 first conductive filler
(silver coated copper powder) shape couch plate conception printability Good Good Good adherence Good Good Good Sheet resistance (Ω/□) One 4 50

As shown in Table 2, in the case of Example 1 in which a needle-shaped silver-coated copper powder having an average particle size (D ₅₀ ) of 4.5 μm was applied as the first conductive filler, an average particle size (D ₅₀ ) of a plate-like shape having an average particle size (D 50 ) of 4.5 μm It can be seen that the sheet resistance is improved compared to Comparative Example 5 to which the silver-coated copper powder is applied, and the sheet resistance is significantly improved compared to Comparative Example 6 to which the spherical silver-coated copper powder having an average particle size (D ₅₀ ) of 4.5 μm is applied. that can be checked

3) Evaluation of physical properties for the average particle size (D ₅₀ ) of the first conductive filler

[Examples 4 and 5]

Prepared in the same manner as in Example 1, but as the first conductive filler, Example 4 uses a needle-shaped silver-coated copper powder having an average particle size (D ₅₀ ) of 2 μm, and Example 5 has an average particle size (D ₅₀ ) Each conductive paste composition was prepared using silver-coated copper powder having a needle shape of 8 μm.

[Comparative Examples 7 and 8]

Prepared in the same manner as in Example 1, but as the first conductive filler, Comparative Example 7 used a needle-shaped silver-coated copper powder having an average particle size (D ₅₀ ) of 1 μm, and Comparative Example 8 had an average particle size (D ₅₀ ) Each conductive paste composition was prepared using silver-coated copper powder having a needle shape of 10 μm.

In addition, after screen printing the conductive paste compositions prepared in Examples 1, 4 and 5 and Comparative Examples 7 and 8 on a substrate, drying at 120° C. for 5 minutes to form a coating film, and curing at 180° C. for 10 minutes. Printability, adhesion and sheet resistance were measured.

The results of measuring printability, adhesion and sheet resistance of the conductive paste composition prepared by varying the average particle size (D ₅₀ ) of the first conductive filler according to Examples 1, 4 and 5 and Comparative Examples 7 and 8, respectively, are shown below. shown in Table 3.

Item Example 1 Example 4 Example 5 Comparative Example 7 Comparative Example 8 first conductive filler
(silver coated copper powder) average particle size
(D ₅₀ ) 4.5㎛ 2㎛ 8㎛ 1㎛ 10㎛ printability Good Good Good Good Good adherence Good Good Good Good Good Sheet resistance (Ω/□) One 1.3 1.1 5 2.1

As shown in Table 3, Examples 1, 4 and 5 to which the needle-shaped silver-coated copper powder having an average particle size (D ₅₀ ) of 4.5 μm, 2 μm, and 8 μm, respectively, was applied, showed good sheet resistance, Comparative Example 7 to which a needle-shaped silver-coated copper powder having an average particle size (D ₅₀ ) of 1 μm was applied and Comparative Example 8 to which a needle-shaped silver-coated copper powder having an average particle size (D ₅₀ ) of 10 μm was applied is Example 1, As compared to 4 and 5, it can be seen that the sheet resistance is significantly increased.

This is because, when the particle size is reduced, the conductivity is reduced due to continuity of conductivity, and when the particle size is increased, the size of the voids between the first conductive fillers is increased, and the second conductive filler is not properly filled in the voids of the increased size. Rather, the sheet resistance increased.

4) Evaluation of physical properties of the second conductive filler

[Examples 6 to 7]

Prepared in the same manner as in Example 1, but as the second conductive filler, Example 6 contained 1 part by weight of carbon black having a specific surface area of 1270 m 2 /g based on 100 parts by weight of the binder, and Example 7 had a specific surface area of 1270 Each conductive paste composition was prepared by containing 8 parts by weight of carbon black of m 2 /g based on 100 parts by weight of the binder.

[Comparative Examples 9 to 13]

It was prepared in the same manner as in Example 1, but as the second conductive filler, Comparative Example 9 contained carbon black having a specific surface area of 150 m 2 /g, and Comparative Example 10 contained carbon black having a specific surface area of 254 m 2 /g. , Comparative Example 11 contained carbon black having a specific surface area of 68 m 2 /g to prepare a conductive paste composition, respectively.

In addition, prepared in the same manner as in Example 1, but as the second conductive filler, Comparative Example 12 contained 0.5 parts by weight of carbon black having a specific surface area of 1270 m 2 /g based on 100 parts by weight of the binder, and Comparative Example 13 had a specific surface area A conductive paste composition was prepared by containing 10 parts by weight of this 1270 m 2 /g carbon black based on 100 parts by weight of the binder.

In addition, after screen printing the conductive paste compositions prepared in Examples 1, 6 and 7 and Comparative Examples 9 to 13 on a substrate, drying at 120° C. for 5 minutes to form a coating film, and curing at 180° C. for 10 minutes Printability, adhesion and sheet resistance were measured.

The results of measuring the viscosity, printability, adhesion and sheet resistance of the conductive paste compositions prepared by different second conductive fillers according to Examples 1, 6 and 7 and Comparative Examples 9 to 13 are shown in Table 4 below. indicated.

In addition, FIGS. 5 and 6 show images of the surface after printing of the conductive paste compositions according to Comparative Examples 12 and 13 of the present invention, respectively, in order to confirm printability, and FIGS. 7 and 8 show flatness confirmation. For this purpose, the images of the conductive paste compositions according to Example 1 and Comparative Example 13 of the present invention after printing were taken by SEM.

Item Example 1 Example 6 Example 7 Comparative Example 9 Comparative Example 10 Comparative Example 11 Comparative Example 12 Comparative Example 13 second conductive filler type carbon black carbon black carbon black carbon black carbon black carbon black carbon black carbon black specific surface area
(m2/g) 1270 1270 1270 150 254 68 1270 1270 Viscosity (cps) 35,000 20,000 60,000 17,000 28,000 7,000 9,000 220,000 printability Good Good Good Good Good error error error adherence Good Good Good Good Good Good Good Good Sheet resistance (Ω/□) One 1.3 One 7 4 11 3 2

As shown in Table 4, in the case of Example 1 containing carbon black having a specific surface area of 1270 m 2 /g as the second conductive filler, Comparative Example 9 containing carbon black having a specific surface area of 150 m 2 /g, and the ratio It can be seen that the sheet resistance is improved as compared with Comparative Example 10 containing carbon black having a surface area of 254 m 2 /g, respectively.

In addition, in Comparative Example 11 to which carbon black having a specific surface area of 68 m 2 /g was applied, printability was poor, and it was confirmed that the sheet resistance was increased due to a small number of binding points between the carbon black particles.

Accordingly, an appropriate amount of carbon black having a large specific surface area (eg, 900 to 1300 m2/g) (eg, 1 to 8 parts by weight relative to 100 parts by weight of binder) is used to form an appropriate viscosity (eg, 20,000 to 70,000 cps). In this case, it can be confirmed that the sheet resistance performance is excellent compared to the same content of carbon black, and the printability is excellent.

In addition, compared with Example 1, Comparative Example 12 containing 0.5 parts by weight of carbon black having a specific surface area of 1270 m 2 /g based on 100 parts by weight of the binder had a lower viscosity than Example 1, and thus the printability as shown in FIG. 5 was lower. In the case of Comparative Example 13, which contained 10 parts by weight of carbon black having a specific surface area of 1270 m 2 /g based on 100 parts by weight of the binder, the viscosity was very high and the printability was poor as shown in FIG. can be checked

In addition, referring to FIGS. 7 and 8 , Example 1 containing 4 parts by weight of carbon black having a specific surface area of 1270 m 2 /g based on 100 parts by weight of a binder showed good flatness after printing, but the specific surface area In the case of Comparative Example 13, which contained 10 parts by weight of 1270 m 2 /g of carbon black relative to 100 parts by weight of the binder, the thixotropy of the conductive paste composition increased due to the increase in the carbon black content, and the shape of the mask remained on the coating film during the printing process. It can be seen that the flatness decreased after printing.

This is because in carbon black having the same specific surface area, when the content of carbon black is increased, the amount of oil absorption of the binder is increased, so that the overall fluidity of the conductive paste composition is lowered, thixotropy is increased, and the viscosity of the conductive paste composition is increased. It can be confirmed that the printability is poor, and the flatness after printing is also lowered.

As described above, the conductive paste composition according to an embodiment of the present invention includes a dry binder in which a phenoxy resin is dissolved, a needle-shaped silver-coated copper powder, and a type of carbon having a large specific surface area. By mixing black, the contact area between the needle-shaped powder or carbon black particles can be increased, and the contact area can be widened, thereby greatly improving the conduction performance.

Embodiments of the present invention disclosed in the present specification and drawings are merely provided for specific examples in order to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention.

Therefore, the scope of the present invention should be construed as including all changes or modifications derived based on the technical spirit of the present invention in addition to the embodiments disclosed herein are included in the scope of the present invention.

Claims (6)

A first conductive filler comprising a needle-shaped metal powder;
a specific surface area of 900 to 1300 m 2 /g a second conductive filler comprising carbon black;
bookbinder; and
a dispersant;
The first conductive filler increases the contact between each other through the needle shape and induces a wider contact area,
The second conductive filler has a specific surface area of 900 to 1300 m 2 /g, and thus, in the void formed between the needle-shaped first conductive fillers, a contact point between the second conductive fillers and the second conductive filler and the first By increasing the contact point between the conductive fillers, the conductive performance is increased,
A conductive paste composition having improved sheet resistance by the first conductive filler and the second conductive filler.
The method of claim 1,
The metal powder is
A conductive paste composition comprising silver (Ag)-coated copper (Cu) powder and having an average particle size (D ₅₀ ) of 2 to 8 μm.
The method of claim 1,
The first conductive filler,
A conductive paste composition in which 100 to 140 parts by weight are mixed based on 100 parts by weight of the binder.
The method of claim 1,
The second conductive filler,
A conductive paste composition in which 1 to 8 parts by weight are mixed based on 100 parts by weight of the first conductive filler.
The method of claim 1,
The second conductive filler,
A conductive paste composition comprising 1 to 8 parts by weight based on 100 parts by weight of the binder to improve printability and sheet resistance.
A first conductive filler comprising a needle-shaped metal powder;
a specific surface area of 900 to 1300 m 2 /g a second conductive filler comprising carbon black;
bookbinder; and
a dispersant;
The binder is
A polymer in which a phenoxy resin and an epoxy resin are mixed in a weight ratio of 4:6 to 6:4 in a high boiling point solvent having a boiling point of 150° C. or higher at normal pressure to increase the density between the first conductive filler and the second conductive filler It is formed by dissolving the resin,
A conductive paste composition having improved adhesion and sheet resistance by the binder.

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