KR20150082133A - Conductive hybrid Cu ink and light sintering method using the same - Google Patents

Abstract

The present invention relates to a conductive hybrid copper ink and a light sintering method using the same. The copper ink includes: a copper precursor; a nanoparticle having the diameter of 5-500 nm, a precursor of metal, except copper, with solubility of 1-70 g of the metal precursor per 100 g of a solvent, or a mixture of the same; and a polymer binder resin. Therefore, the conductive hybrid copper ink can be reduced and sintered at room temperature under an atmospheric environment within a very short time of 1-100 ms. Therefore, mass production of the conductive hybrid copper ink is possible.

Description

Conductive hybrid copper ink and a light sintering method using the same

The present invention relates to a conductive hybrid copper ink capable of photo-sintering using white light emitted from a xenon lamp, and a light sintering method using the same.

The inks currently used in printing electronics are gold / silver / copper nanoinks. The key technology in inkjet printing is sintering of conductive ink. Up to now, high temperature sintering processes have been used to sinter various particles. In the thermal sintering process, the metal nanoparticles are heated to a temperature of about 200 ° C. to 350 ° C. in an inert gas state in order to sinter the metal nanoparticles. In addition, a laser sintering method capable of sintering at room temperature / atmospheric pressure has been invented and used.

However, recently, attempts have been made to fabricate such electronic patterns on flexible low-temperature polymers or paper, and thus the high-temperature sintering method has become a great obstacle to the printing electronics industry and technology. It is also known that copper has an oxide layer formed on the surface thereof due to thermochemical equilibrium so that sintering is very difficult and the conductivity is low even after sintering.

Laser sintering is also known, but it is not practicable because only a small area can be sintered.

In addition, although the extreme ultraviolet white light irradiation technique has been used for annealing and heat treating ion-implanted semiconductor wafers in a very short time, a technique for replacing the high temperature sintering process using extreme ultraviolet white light has not been developed to date.

1. S. Tatasov, A. Kolubaev, S. Belyaev, M. Lerner, and F. Tepper, Wear 252, 63 (2002). 2. Y. Xuan and Q. Li, Int. J. Heat Fluid Flow 21, 58 (2000). 3. J.A. Eastman, S.U.S. Choi, S. Li, W. Yu, and L.J. Thompson, Appl. Phys. Lett. 78, 718 (2001). 4. A.G. Nasibulin, P.P. Ahonen, O. Richard, E.I. Kauppinen, and I.S. Altman, J. Nanoparticle Res. 3, 385 (2001). 5. Y.I. Lee, J.R. Choi, K.J. Lee, N.E. Stott, and D.H. Kim, Nanotechnology 19, 415 (2008). 6. M. Berggren, D. Nilsson, and D. Robinson, Nat. Mater. 6, 3 (2007). 7. S.H. Jeong, K.H. Woo, D.J. Kim, S.K. Lim, J.S. Kim, H.S. Shin, Y.N. Xia, and J.H. Moon, Adv. Funct. Mater. 18, 679 (2008). 8. B.K. Park, D.J. Kim, S.H. Jeong, J.H. Moon, and J.S. Kim, Thin Solid Films 151, 7706 (2007).

An object of the present invention is to provide a conductive hybrid copper ink which can be reduced and sintered in a very short time at room temperature / atmospheric conditions, thereby enabling mass production.

Another object of the present invention is to provide a light sintering method using the hybrid copper ink.

To achieve the above object, the present invention provides a conductive hybrid copper ink comprising: a copper precursor; Metal nanoparticles having a particle diameter of 5 to 500 nm, a metal precursor other than copper having a solubility of 1 to 70 g as a _{metal precursor} / 100 g _solvent or a mixture thereof; And a polymeric binder resin.

The polymeric binder resin may be contained in an amount of 1 to 50% by weight based on the total weight of the hybrid copper ink.

A copper precursor; Metal nanoparticles, metal precursors other than copper, or mixtures thereof may be mixed in a weight ratio of 1: 0.1 to 10.

The copper precursors are CuCl2, Cu (acac) ₂, Cu (hfac) ₂, Cu (tfac) ₂, Cu (dpm) Cu (nona-F) ₂, Cu (acen) ₂, Cu (NO 3) 2 · 3H 2 0, Cu (C 3 H 4 F 3 O 2) 2 and CuSO ₄ · selected from the group consisting of 5H ₂ 0 And the metal nanoparticles may be at least one selected from a group of nanoparticles composed of copper, gold, silver, nickel, platinum, cobalt, iron, cadmium, tungsten, molybdenum, manganese, chromium, .

The average particle diameter of the metal nanoparticles may be 10 to 200 nm.

The metal precursor may be at least one selected from the group consisting of precursors of silver, nickel, gold and iron, and the polymeric binder resin may be at least one selected from the group consisting of polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polymethyl methacrylate, ≪ / RTI > and dextran.

According to another aspect of the present invention, there is provided a method of sintering a conductive hybrid copper ink comprising: a copper precursor; Metal nanoparticles having a particle diameter of 5 to 500 nm, a metal precursor other than copper having a solubility of 1 to 70 g as a _{metal precursor} / 100 g _solvent or a mixture thereof; Preparing a conductive hybrid copper ink comprising a polymeric binder resin and a polymeric binder resin; Coating the prepared hybrid copper ink on a substrate; And photo-sintering the copper ink coated on the substrate using white light emitted from a xenon flash lamp.

The hybrid copper ink can be soaked in water at 70 to 100 DEG C for 3 to 5 hours before being coated on the substrate.

The substrate may be selected from the group consisting of a polyimide film (PI), a BT epoxy / glass fiber, a polyethylene film (PT) and a photopaper. The coating method of the hybrid copper ink is screen printing, (inkjet printing) and gravuring (gravuring).

The light sintering step may be performed in one step or several steps. Specifically, the sintering step may be divided into a preliminary light irradiation step for preheating (texture densification) or solvent drying and a light sintering step for particle sintering have.

The pulse width of the xenon flash lamp is 0.01 to 100 ms, the pulse gap is 0.01 to 100 ms, the pulse number is 1 to 1000 times, the intensity is 0.01 to 100 J / Cm < 2 >.

The conductive hybrid copper ink of the present invention can reduce the specific resistivity of the pattern since the pores (obstructing the electrical conductivity of the pattern) are formed on the surface during sintering as compared with the copper ink prepared by using only copper nano particles. Therefore, it can be applied to a large number of printing electronic manufacturing processes.

In addition, since the conductive hybrid copper ink of the present invention contains metal nanoparticles and / or a metal precursor other than copper, conductivity is improved and light resonance phenomenon is caused by the material. Therefore, various light absorption is induced during the sintering process, Sintering energy can also have high conductivity and low surface roughness.

In addition, according to the sintering method and conditions of the conductive hybrid copper ink according to the present invention, a high temperature sintering process which was performed at a temperature of 300 ° C or more is replaced with a high temperature sintering system using a xenon lamp, Reduction and sintering can be performed in a very short sintering time of ~ 100 ms. In addition, it has the advantage of being able to obtain a resistivity value that can be used industrially, as well as being able to mass-produce high-temperature sintering process and laser sintering process which can not be performed.

The sintering method of the conductive hybrid copper ink according to the present invention can be applied to printing electronic technology copper (RFID) such as inkjet printing, flexo / gravure ring printing or screen printing, a radio frequency identification device (RFID), a flexible electronic device High-value-added products such as wearable electronics, large-area displays, thin-plate solar cells, and thin-plate batteries can be manufactured at low cost.

1 is a process flow diagram illustrating a process of sintering hybrid copper ink using extreme ultraviolet light according to an embodiment of the present invention.
2 is a view showing a light sintering apparatus according to the present invention.
FIG. 3 is a schematic view showing a process of sintering nano / micro size hybrid copper ink patterned on a substrate using an extreme ultraviolet light sintering system.
4 is a graph of a single pulse white light of a xenon lamp according to the present invention.
5 is a graph of specific resistivity after sintering of copper inks using different copper precursors prepared according to the examples.
FIG. 6 is an SEM photograph of the copper ink before and after photo-sintering produced according to the comparative example.
FIG. 7 is a SEM photograph of a hybrid copper ink prepared before and after photo-sintering according to an embodiment of the present invention.
FIG. 8 is an X-ray diffraction chart of the hybrid copper ink prepared according to an embodiment of the present invention before and after photo-sintering.
FIG. 9 is a graph showing resistance changes due to sintering of white light for a hybrid copper ink prepared according to an embodiment of the present invention and a copper ink prepared according to a comparative example.
10 is an SEM photograph of the hybrid copper ink prepared according to the content of the copper precursor after sintering by white light.
11 is a graph showing the change in resistivity of the hybrid copper ink produced according to the content of the copper precursor according to sintering of white light.

The present invention relates to a conductive hybrid copper ink capable of reducing and sintering at room temperature / atmospheric conditions and in a very short time of 1 to 100 ms or less and mass production, and a light sintering method using the conductive hybrid copper ink.

Hereinafter, the present invention will be described in detail.

The conductive hybrid copper ink of the present invention comprises a copper precursor; Metal nanoparticles, metal precursors other than copper, or mixtures thereof; And a polymeric binder resin.

The copper precursor used for producing the conductive hybrid copper ink of the present invention is not particularly limited as a substance which can be easily dissolved in a solvent, but Cu (Cu), CuCl, Cu (acac) ₂, Cu (hfac) Cu (acan) ₂, Cu (acen) ₂, Cu (NO ₃ ) ₂ , Cu (tfac) ₂, Cu _{· 3H 2 0, Cu (C} 3 H 4 F 3 O 2) 2 and CuSO ₄ · 1 can be all selected from the group consisting of 5H ₂ 0.

The metal nanoparticles and the metal precursor not only can lower the resistivity of the copper ink, improve the surface state after printing, but also use a metal having excellent conductivity, so that the conductivity of the copper ink can be improved.

The metal nanoparticles used in the present invention have a particle diameter of 5 to 500 nm and specifically include copper nanoparticles, gold nanoparticles, silver nanoparticles, nickel nanoparticles, platinum nanoparticles, cobalt nanoparticles, iron nanoparticles, One or more selected from the group consisting of nanoparticles, tungsten nanoparticles, molybdenum nanoparticles, manganese nanoparticles, chromium nanoparticles, zinc nanoparticles and aluminum nanoparticles. When the resistivity of the metal nanoparticles is high, the conductivity is low and the use of the conductive ink is inappropriate.

The average particle diameter of the metal nanoparticles is 10 to 200 nm, preferably 20 to 100 nm. When the average particle diameter of the metal nanoparticles is less than the lower limit value, the conductivity may not be excellent. If the average particle diameter is higher than the upper limit value, the energy required for sintering is increased. In order to increase the sintering efficiency, it is also possible to use various particle sizes together.

The metal precursor used in the present invention is a metal precursor other than copper having a solubility in the range of 1 to 70 g of _{metal precursor} / 100 g of _solvent and specifically includes one or two selected from the group consisting of silver precursors, nickel precursors, gold precursors and iron precursors More than species. When the solubility of the metal precursor is less than the lower limit, uniform dispersion is not achieved and electrical conductivity may decrease. If the solubility of the metal precursor is less than the lower limit, the energy required for sintering becomes large.

The solvent may further include a dispersing agent. Examples of the dispersing agent include a copolymer including ion groups such as Disperbyk 180, Disperbyk 111, styrene maleic anhydride copolymer (SMA 1440 flake); 2-butoxyethylacetate; Propylene glycol monomethyl ether acetate; Diethylene glycol monoethyl ether acetate; Ethylene glycol butyl ether; Cyclohexanone; Cyclohexanol; 2-ethoxyethyl acetate; Ethylene glycol diacetate; Terpineol; Isopropyl alcohol and isobutyl alcohol.

A copper precursor; The metal nanoparticles, the metal precursor other than copper, or a mixture thereof are mixed in a weight ratio of 1: 0.1 to 10, preferably 1: 0.1 to 8. If the weight ratio of the metal nanoparticles, the metal precursor other than copper, or the mixture thereof to the copper precursor is less than the lower limit value, the resistivity of the copper ink can not be lowered, the surface state after printing may be uneven and the conductivity may be lowered, The sintering efficiency may be lowered.

The polymeric binder resin used in the present invention is used as a dispersant (surfactant) to stably maintain a pattern during drying after printing and to prevent evaporation of the hybrid copper ink upon irradiation with white light. Specifically, polyvinylpyrrolidone , Polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polymethyl methacrylate, and dextran.

The content of the polymeric binder resin is 1 to 50% by weight, preferably 3 to 40% by weight based on the total weight of the hybrid copper ink. When the content of the polymeric binder resin is less than the lower limit, the pattern can not be maintained during drying after the printing, and the printing power and conductivity of the copper ink may be lowered if the content exceeds the upper limit.

The present invention also relates to a sintering method for sintering a hybrid copper ink to improve conductivity.

As shown in FIG. 1, the light sintering method of the conductive hybrid copper ink of the present invention comprises (A) a copper precursor; Metal nanoparticles having a particle diameter of 5 to 500 nm, metal _precursors other than copper having a water solubility of 1 to 70 g as a _{metal precursor} / 100 g _solvent or a mixture thereof; Preparing a conductive hybrid copper ink comprising a polymeric binder resin and a polymeric binder resin; (B) coating (printing) the prepared hybrid copper ink on a substrate; And (C) photo-sintering the copper ink coated on the substrate using white light emitted from a xenon flash lamp.

First, in the step (A), a copper precursor; Metal nanoparticles, metal precursors other than copper, or mixtures thereof; And a polymeric binder resin to prepare a conductive hybrid copper ink.

The prepared hybrid copper ink was linearly dispersed using a sonicator, a mechanical stirrer, a ball mill, and a 3-roll mill in order to facilitate dispersion, and then was pre-soaked in water at 70 to 100 ° C for 3 to 5 hours . If the hybrid copper ink is coated on the substrate without being soaked, the metal nanoparticles contained in the copper ink, a metal precursor other than copper, or a mixture thereof may be accumulated in various places.

Next, in step (B), the hybrid copper ink is coated (printed) on the substrate.

The substrate may be selected from the group consisting of polyimide film (PI), BT epoxy / glass fiber, polyethylene film (PT) and photopaper, and the hybrid copper ink may be selected from the group consisting of screen printing, inkjet printing, And can be applied on a substrate by gravuring or the like. Since the polymer binder resin applied on the surface of the copper particles serves to reduce the copper oxide film upon irradiation with white light depending on the kind and amount thereof, it is preferable to use a single material or various materials to facilitate the reduction reaction will be.

Next, in step (C), the hybrid copper ink coated on the substrate is photo-sintered using the white light emitted from the xenon flash lamp.

The sintering step of the present invention may include a step of performing only light sintering; Or a preliminary light irradiation step for preheating (texture densification) or solvent drying, and light sintering for particle sintering.

Also, before the sintering step, the copper ink coated in the step (B) may be dried at a temperature of 100 to 120 ° C. for 3 to 5 hours to dry the solvent. If the drying is not properly performed, the ink may be phase-changed from a liquid phase to a solid phase upon irradiation with white light, and energy consumption may be considerable. On the other hand, drying of the applied ink may be achieved by adjusting the white light irradiation condition according to the present invention. In this case, the white light irradiation condition may be a sequential order of drying, sintering or three-step drying, preheating, and sintering in two steps. According to the present invention, complete drying and sintering are possible for a very short time of about 0.01 to 100 ms. The general structure of the extreme ultraviolet light sintering apparatus using the xenon lamp used in the present invention is shown in Fig.

The hybrid copper ink coated on the substrate is photo-sintered by being subjected to light energy by extreme ultraviolet white light emitted from the xenon lamp, and becomes conductive. 3 is a view showing a process in which a hybrid copper ink is sintered by receiving light energy. (3) is a state in which the hybrid copper ink is irradiated with light energy, (4) is a state in which the hybrid copper ink is applied on the substrate, (4) ) Is a state and arrangement of the sintered conductive hybrid copper ink.

In the light sintering step, the pulse width of the xenon flash lamp is 0.01 to 100 ms, the pulse gap is 0.01 to 100 ms, the pulse number is 1 to 1000, the intensity of the xenon flash lamp Intensity) is preferably 0.01 J / cm 2 to 100 J / cm 2. If the pulse width is greater than 100 ms, the energy input per unit time is reduced and the efficiency of sintering may be lowered, which is uneconomical. If the pulse gap is greater than 100 ms or the number of pulses is greater than 1000, the hybrid copper ink can not be sintered due to too low energy even when the intensity is less than 0.01 J / cm 2, and the pulse gap is less than 0.01 ms If it is larger than 100 J / cm 2, the lifetime of the equipment and the lamp is rapidly reduced because the equipment and the lamp are burdened.

In the present invention, the optical sintering is performed according to the change of the pulse width (0.01 to 100 ms), the pulse gap (0.1 to 100 ms), the number of pulses (1 to 1000 times) and the intensity (0.01 J / cm ² to 100 J / cm ² ) The conditions are different and thus the total light energy is emitted up to 100J. At this time, sintering is possible only when sufficient light energy is irradiated. The energy range for sintering can be various, such as PI (10 ~ 50J), photo paper (5 ~ 15J) and BT (15 ~ 25J) depending on the substrate.

For the sake of clarity, a graph of the short-pulse white light of a xenon lamp is shown in Fig.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Example  1-4.

1.5 g of copper precursors CuCl ₂ , Cu (NO ₃ ) ₂ 3H ₂ O, CuSO ₄ 5H ₂ O and Cu (C ₃ H ₄ F ₃ O ₂ ) ₂ were added to 9 g of diethylene glycol (DEG) After dissolving in a sonicator for 1 hour, 0.9 g of polyvinylpyrrolidone (PVP) was added and dissolved in a sonicator for one hour. Then, copper nanoparticles having a particle diameter of 20 to 35 nm (Quantum Spehere Inc Co. Ltd ) Were added and dispersed for 12 hours using a sonicator, a mixed deaerator, a mechanical stirrer, a ball mill and a 3-roll mill to prepare four types of hybrid copper ink.

Using the copper inks prepared above, a polyimide (PI) substrate was coated by a doctor blade method to form a pattern having a coating thickness of 10 탆. The substrate coated with copper ink was dried on a hot plate at 100 ° C. for 4 hours, and then dried on a dried substrate using a xenon flash lamp under conditions of 10 J / cm ^{2 in} intensity, 10 ms in pulse width, White light was irradiated and sintered.

Test Example  One. Example  1-4 hybrid  Resistivity measurement of copper ink

FIG. 5 is a graph showing the results of the measurement of four copper precursors (CuCl ₂ , Cu (NO ₃ ) ₂ H ₂ O, CuSO ₄ H ₂ O, Cu (C ₃ H ₄ F ₃ O ₂ ) ₂ ) FIG. 5 is a graph showing resistivity after photo-sintering a hybrid copper ink prepared by using the same.

As shown in FIG. 5, it was confirmed that the lowest specific resistance value (40.8 μΩm, hieght: 1 μm) was observed when copper nitrate was added among the precursors. As a result, it can be seen that copper nitrate is a good precursor to metal nanoparticles.

Example  5.

6.3 g of copper nitrate (Cu (NO ₃ ) ₂ .3H ₂ O), which is a copper precursor, was dissolved in 38.4 g of diethylene glycol (DEG) for one hour using a sonicator, and polyvinylpyrrolidone (PVP) 7.5 (Quantum Spehere Inc Co., Ltd.) having a particle diameter of 20 to 35 nm was placed in a sonicator and dispersed for one hour in a sonicator. Then, 47.8 g of a copper nanoparticle having a particle diameter of 20 to 35 nm A ball mill, and a 3-roll mill to prepare a hybrid copper ink.

The prepared copper ink was coated on a polyimide (PI) substrate prepared by hot water bathing at 80 캜 for 4 hours by a doctor blade method to form a pattern having a coating thickness of 10 탆. The substrate coated with copper ink was dried on a hot plate at 110 ° C for 2 hours, and then dried on a substrate using a xenon flash lamp under conditions of a pulse strength of 20 J / cm ² , a pulse width of 20 ms and a pulse number of 1 pulse. White light was irradiated and sintered.

Example  6.

2.9 g of copper precursor CuCl (copper (I) chloride, 99.995 +%) is dissolved in 55 g of DMF solvent to prepare a copper precursor solution. On the other hand, 3.4 g of PVP and 17.1 g of diethylene glycol (DEG) were dispersed for 1 hour using a sonicator, and 21.6 g of copper nanoparticles having a particle diameter of 20 to 35 nm (Quantum Spehere Inc Co. Ltd) For a period of time using a sonicator, a mixed deaerator, a mechanical stirrer, a ball mill, and a 3-roll mill to prepare a hybrid copper ink.

The hybrid copper ink was coated on a polyimide substrate with an inkjet printer to coat a pattern having a coating thickness of 10 탆 and dried on a hot plate at 100 캜 for 2 hours, The lamp was irradiated with extreme ultraviolet light in a pulse irradiation condition of intensity 15 J / cm ² , pulse width 10 ms, pulse number 1, and sintered.

Example  7.

0.5 g of copper nitrate (Cu (NO ₃ ) ₂ .3H ₂ O) was dissolved in 3.0 g of diethylene glycol (DEG) for one hour using a sonicator and silver nanoparticles having a particle diameter of 20 to 35 nm (PVP) was added to the dispersion, and the mixture was dispersed for 12 hours using a sonicator, a mixed deaerator, a mechanical stirrer, a ball mill, 3 roll mill to prepare a hybrid copper ink.

The prepared copper ink is coated on a polyimide (PI) substrate by a doctor blade method to form a pattern having a coating thickness of 10 탆. The substrate coated with copper ink was dried on a hot plate at 110 ° C for 3 hours, and then the substrate was sintered by irradiating extreme ultraviolet ray using a xenon flash lamp. The pulse irradiation conditions were the same as in Example 5.

Comparative Example  One.

12 g of Cu (NO ₃ ) ₂ .3H ₂ O was dissolved in 73 g of diethylene glycol (DEG) for one hour using a sonicator. 15 g of polyvinylpyrrolidone (PVP) was added to the solution and dispersed for 12 hours using a sonicator, a mixed deaerator, a mechanical stirrer, a ball mill, and a 3-roll mill to prepare a hybrid copper ink.

A polyimide (PI) substrate coated with the dispersed copper ink was coated with a pattern having a thickness of 10 탆 by a doctor blade method. The substrate coated with copper ink was dried on a hot plate at 110 ° C for 3 hours, and then the substrate was sintered by irradiating extreme ultraviolet ray using a xenon flash lamp. The pulse irradiation conditions were the same as in Example 5.

Comparative Example  2.

1.4 g of PVP (Mw 40,000, Sigma Aldrich Co, Ltd.) and 9.5 g of ethylene glycol (99%, Sigma Aldrich Co. Ltd) were mixed and dispersed for 4 hours using a sonicator to obtain copper nanoparticles 35 nm, manufactured by Quantum Spehere Inc Co., Ltd.) was added, followed by stirring with a stirrer, followed by dispersion using a mixed deaerator. Among them, the agglomerated copper agglomerates were removed by using a filter (pore size: 0.45 μm) and dispersed for 12 hours using a sonicator, a mixed deaerator, a mechanical stirrer, a ball mill and a 3 roll mill to prepare a hybrid copper ink .

To 1 g of the copper slurry thus obtained was added 360 mg of gamma -butyrolactone (Wako Pure Chemical Ind., Ltd) to adjust viscosity to 72 mg of a silane coupling agent (KBE-603, Shin-Etsu silicones), 2-ethoxy Ethanol (Wako Pure Chemical Ind., Ltd) was added and dispersed using a mixed deaerator to prepare a copper ink.

When the copper ink is printed 10 times on a polyimide substrate using an inkjet printer (T30, EPSON), a pattern having a thickness of about 1 mu m can be formed. When the surface tension and the viscosity are adjusted, it may be applied by gravuring, flexography or the like used in the high-speed roll-to-roll (R2R) process. When this pattern is dried using hot air at a temperature of 70 캜, a copper ink pattern to be photo-sintered is completed.

When this pattern is irradiated with extreme ultraviolet white light using a xenon flash lamp, a conductive copper (Cu) pattern is completed. The irradiation conditions of the extreme white light were 9 ms pulse width, 5 ms pulse width, 3 pulse number, 15 J / cm ² intensity or 20 ms pulse width, 0 ms pulse width, J / cm < ^{2 &} gt ;. In the previous condition, a stepped optical sintering technique was used, which divided into two stages of preheating (first pulse) and densification (second pulse). In some cases, a single pulse A light sintering technique can be used.

Comparative Example  3.

0.6 g of PVP and 6 g of diethylene glycol (DEG) were dispersed in a sonicator for 1 hour, and then 7.6 g of copper nanoparticles having a particle diameter of 20 to 35 nm (Quantum Spehere Inc Co., Ltd.) The mixture was dispersed using a kettle, a mixed deaerator, a mechanical stirrer, a ball mill, and a 3-roll mill.

The copper ink was coated on a polyimide substrate with a spin coater to form a pattern having a thickness of 10 μm, dried at 100 ° C. using a hot plate, and then dried on a dried copper ink pattern using DMF as a solvent The copper precursor solution (DMF: 84 g, Cu (NO 3) 2 .3H 2 O: 1.8 g) was dropped and dried at 100 ° C. using a hot plate to prepare a copper ink pattern coated with a copper precursor. And then sintered by irradiation with extreme ultraviolet light. The pulse irradiation conditions were the same as in Example 5.

Test Example  2. Example  5-7 and Comparative Example  1-3 hybrid  Of copper ink Light sintering  Results analysis

For confirmation of sintering according to the present invention, sheet resistance was measured for electron conductivity (SEM) analysis and electrical conductivity analysis before and after photo-sintering of hybrid copper ink by extreme ultraviolet light of a xenon lamp.

FIG. 6 is an SEM photograph of the copper ink before and after photo-sintering prepared according to Comparative Example 1, and FIG. 7 is a SEM photograph showing the hybrid copper ink prepared before and after photo-sintering according to Example 5 of the present invention.

As shown in FIGS. 6 and 7, the copper inks before and after sintering show distinctly different shapes in the case of both before and after sintering. In the case of before sintering, many particles are separated, but in the case of sintering after the sintering, It can be confirmed that a complete grain structure is formed.

However, compared with the copper ink of Comparative Example 1 (Fig. 6), the hybrid copper ink of Example 5 (Fig. 7) was sintered with good pattern retention. In addition, it was confirmed that sintering of the hybrid copper ink having higher conductivity was possible according to the light irradiation condition of the xenon flash lamp.

8 is an X-ray diffraction chart of the hybrid copper ink prepared according to Example 5 of the present invention before and after photo-sintering.

As shown in FIG. 8, it was confirmed that after the light sintering, the X-ray detection was stronger at the copper peaks (43.2 °, 50.4 °, and 74.1 °).

FIG. 9 is a graph showing a change in resistance of a hybrid copper ink prepared according to Example 5 of the present invention upon sintering white light.

As shown in Fig. 9, the lowest resistance in the resistance measurement after sintering of the hybrid copper ink is 0.7? At 15 J / cm. At an energy of less than 15 J / cm 2, the hybrid copper ink is not sufficient to sinter, and at an energy of more than 15 J / cm 2, the copper particles contained in the hybrid copper ink cause a combustion reaction, . Also, irradiating energy in excess of 15 J / cm may lead to substrate damage.

Example 6 and Example 7 also formed good quality patterns similar to those of Example 5, confirming that X-ray detection is stronger at the copper peak. In particular, Example 6 maintained a superior pattern as compared to Comparative Example 1, but formed patterns with slightly lower quality than Examples 5 and 7. In Example 6, the resistivity was lower than that in Comparative Example 2 and Comparative Example 3. However, the resistivity was slightly higher than that in Example 5 and Example 7.

In addition, it was confirmed that Comparative Examples 2 and 3 formed a pattern in which the quality deteriorated as compared with Comparative Example 1.

The following Examples 8-11 and Comparative Example 4 relate to a hybrid copper ink prepared according to the content of a copper precursor.

Example  8-11.

(10% of copper nanoparticles), 2.16 g (20%) and 3.24 g (30%) of copper nitrate (Cu (NO ₃ ) ₂ .3H ₂ O) as a copper precursor, ), 4.32 g (40%); PVP 0.8 g; 10.8 g of copper nanoparticles were used to prepare four hybrid copper inks and sintered.

Comparative Example  4.

The procedure of Example 8 was followed except that hybrid copper ink was prepared using only copper nitrate without using copper nanoparticles and sintered.

Test Example  3. Example  8-11 and Comparative Example  4 hybrid  Of copper ink Light sintering  Results analysis

10 is a scanning electron micrograph (SEM) photograph showing the state of copper surface according to sintering of white light of the hybrid copper ink prepared according to Examples 8-11 and Comparative Example 4. Fig.

As shown in FIG. 10, when a copper ink was prepared using only copper nanoparticles (Comparative Example 4, FIG. 10A) and sintering was performed, a large number of holes were present on the surface. However, as the content of copper nitrate, which is a copper precursor, It can be seen that the holes gradually decrease. It seems that copper sulphate of copper nitrate bonds with copper nanoparticles during photo-sintering to induce holes between copper nanoparticles.

11 is a graph showing changes in resistivity of the hybrid copper ink prepared according to Examples 8-11 and Comparative Example 4 according to sintering of white light.

As shown in Fig. 11, the resistivity values (673 nΩm, 279 nΩm, 17.2 nΩm, 133 nΩm, and hieght: 10 μm, respectively) after sintering the hybrid copper ink produced in Examples 8-11, (882 n [Omega] m, hieght: 10 [mu] m) after the copper ink is sintered. This is consistent with the result of the photograph taken in the SEM of FIG.

As the amount of copper precursor increases by 4.32 g (40%) or more, the amount of holes on the surface increases, which is expected to result from the failure of reduction of copper nitrate during light sintering.

In addition, when the ink is produced and sintered with only copper nitrate, due to the absence of the copper nanoparticles, a large number of holes are formed in the sintering, and as shown in the graph of FIG. 11, the copper nanoparticles exhibit a higher resistivity value.

Claims (18)

Copper precursor; Metal nanoparticles having a particle diameter of 5 to 500 nm, a metal precursor other than copper having a solubility of 1 to 70 g as a _{metal precursor} / 100 g _solvent or a mixture thereof; And a polymeric binder resin. The conductive hybrid copper ink according to claim 1, wherein the polymeric binder resin is contained in an amount of 1 to 50 wt% based on the total weight of the hybrid copper ink. 2. The method of claim 1, further comprising: providing the copper precursor; Metal nanoparticles, metal precursors other than copper, or mixtures thereof are mixed in a weight ratio of 1: 0.1 to 10. The method of claim 1, wherein the copper precursor is selected from the group consisting of CuCl2, Cu (acac) ₂, Cu (hfac) ₂, Cu (tfac) Cu (NO ₃ ) ₂ .3H ₂ O, Cu (C ₃ H ₄ F ₃ O ₂ ) _2, and CuSO ₄ .5H ₂ O Wherein the conductive hybrid copper ink is one kind selected from the group consisting of copper, The method according to claim 1, wherein the metal nanoparticles are at least one selected from the group consisting of copper, gold, silver, nickel, platinum, cobalt, iron, cadmium, tungsten, molybdenum, manganese, chromium, ≪ / RTI > The conductive hybrid copper ink according to claim 1, wherein the average particle diameter of the metal nanoparticles is 10 to 200 nm. The conductive hybrid copper ink according to claim 1, wherein the metal precursor is at least one selected from the group consisting of precursors of silver, nickel, gold and iron. The conductive polymer resin composition according to claim 1, wherein the polymeric binder resin is at least one selected from the group consisting of polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polymethyl methacrylate, and dextran. Hybrid copper ink. Copper precursor; Metal nanoparticles having a particle diameter of 5 to 500 nm, a metal precursor other than copper having a solubility of 1 to 70 g as a _{metal precursor} / 100 g _solvent or a mixture thereof; Preparing a conductive hybrid copper ink comprising a polymeric binder resin and a polymeric binder resin,
Coating the prepared hybrid copper ink on a substrate, and
And photo-sintering the copper ink coated on the substrate using white light emitted from a xenon flash lamp. 10. The method of claim 9, wherein the hybrid copper ink is soaked in water at 70 to 100 DEG C for 3 to 5 hours before being coated on the substrate. The method of claim 9, wherein the substrate is selected from the group consisting of a polyimide film (PI), a BT epoxy / glass fiber, a polyethylene film (PT), and a photopaper. The method according to claim 9, wherein the coating method of the hybrid copper ink is selected from the group consisting of screen printing, inkjet printing, and gravuring. Sintering method. 10. The method of claim 9, wherein the light sintering step is performed in one step or several steps. [14] The method of claim 13, wherein the light sintering step is performed in a preliminary light irradiation step for preheating (texture densification) or solvent drying, and a light sintering step for particle sintering . The method of claim 9, wherein the pulse width of the xenon flash lamp is 0.01 to 100 ms. The method according to claim 9, wherein the pulse gap of the xenon flash lamp is 0.01 to 100 ms. [10] The method of claim 9, wherein the pulse number of the xenon flash lamp is 1 to 1000 times. 10. The method of claim 9, wherein the intensities of the xenon flash lamps are in the range of 0.01 to 100 J / cm2.

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