KR101220327B1 - Preparation of the Pd catalytic ink, method for forming metal pattern using the same and method for the surface modification of substrate - Google Patents

Abstract

The present invention relates to a palladium catalyst ink, a substrate surface treatment technology and a metal pattern forming method, and more particularly, palladium catalyst ink composition consisting of a palladium salt, ammonium salt and stabilizer and (a) inkjet printing the palladium catalyst ink composition on a substrate Making; (b) reducing the printed substrate; And (c) metal plating to form a metal pattern by performing electroless plating on the reduced substrate and surface treatment of the polyimide or polyester film used as the substrate material with an alkaline solution. It is about how to. The palladium catalyst ink according to the present invention is economical, has a very low viscosity and surface tension, and has excellent storage stability. The metal pattern forming method is simpler and more economical than conventional methods, and thus roll-to-roll inkjet printing is performed. There is an advantage that mass production of printed circuits is possible.

Description

Palladium catalytic ink composition, metal pattern forming method and substrate surface treatment method using the same {Preparation of the Pd catalytic ink, method for forming metal pattern using the same and method for the surface modification of substrate}

The present invention relates to a palladium catalyst ink, a substrate surface treatment technology and a metal pattern forming method, and more particularly, to a palladium catalyst ink composition consisting of a palladium salt, an ammonium salt and a stabilizer, a metal pattern forming method and a substrate surface treatment method using the same will be.

Solution process using printing is capable of manufacturing electronic devices at room temperature, large area and mass production at low cost, and also has a number of advantages, such as light, impact-resistant and sufficient flexibility can be secured. Recently, research on fabrication of electronic devices using a roll-to-roll printing process instead of vacuum deposition, photolithography, and screen printing has been studied.

Inkjet printing has an advantage in that a very small amount of fluid can be printed in various shapes in a desired time and a virtual space of a computer by a digital signal. In addition, since the fluid printing method is a non-contact method from the substrate, it is possible to print on a large area of several tens of mm to several square meters on various substrates such as paper, textile, metal, ceramic, and polymer. In particular, the so-called drop-on-demand process can be formed to shape the required material where desired, enabling the formation of fine patterns, minimizing the amount of ink used, and eliminating contaminants. Realization of eco-friendly process is possible. In addition, it does not need expensive vacuum equipment, so it is very effective in creating product price competitiveness by reducing costs, and it is easy to simplify the process because it does not have to go through the lithography process. Recently, research on printable electronic devices using inkjet printing technology has been actively conducted.

Recently, due to the development of the electronics industry, the miniaturization, light weight, and high functionality of electronic devices such as computers and peripherals, communication equipment, and medical equipment are rapidly progressing. The surface treatment technology of the substrate constituting the flexible printed circuit (FPC), which is one of the core technologies that enable such development, has emerged as very important and its utilization is increasing. The polyimide film used as the insulating layer of the FPC is a polymer material that is spotlighted as a material having excellent thermal stability, chemical resistance and mechanical strength, and its application to the FPC field is expanding. However, since there is no polar group on the surface, there is a disadvantage in that the adhesion to the metal or polymer material is lowered.

An electroless plating process using a catalyst nucleus is very suitable for forming a metal film of a thick film on a substrate at a high speed by a printing process. For this purpose, a research that can maximize the binding energy with the catalyst nucleus by controlling the surface characteristics of the substrate is performed. need. In addition, the catalyst ink acting as a catalyst nucleus should have a low viscosity and low surface tension value for easy jetting, and should have excellent storage stability. However, the catalyst ink that satisfies the above properties has not been developed yet.

Therefore, the present inventors have studied to overcome the problems of the prior art as a result, developed a low-cost palladium catalytic ink synthesis method instead of the conventional expensive metal ink, can be used in printed electronic circuits instead of the substrate used in electronic circuits A method of surface treatment of a flexible film substrate was developed, and a method of forming a metal pattern using the catalyst ink and the flexible film substrate was developed to complete the present invention.

Therefore, the present invention is to provide a palladium catalyst ink composition that is economical, low in viscosity and surface tension, and excellent in storage stability.

It is a second object of the present invention to provide a method for producing the palladium catalyst ink.

Another object of the present invention is to provide a metal pattern forming method using the palladium catalyst ink and the surface-treated flexible film substrate.

In order to achieve the above object, the present invention provides a palladium catalyst ink composition comprising a palladium salt, an ammonium salt and a stabilizer.

In addition, the present invention comprises the steps of (a) preparing the ink by stirring the palladium salt and ammonium salt in a solvent; And (b) adding a stabilizing agent to the ink and then filtering the palladium catalyst ink.

Finally, the present invention comprises the steps of (a) inkjet printing the palladium catalyst ink composition on a substrate; (b) reducing the printed substrate; And (c) metal plating to form a metal pattern by performing electroless plating on the reduced substrate.

In the case of the palladium catalyst ink according to the present invention can be produced in an economical way than the existing metal ink, the viscosity and surface tension is very low, the smooth discharge from the printing head occurs, there is an advantage that the storage stability. In addition, by using a flexible film having excellent characteristics as a substrate when forming a metal pattern, it may have excellent physical properties and has an advantage of convenience of use. In addition, in the case of the surface treatment process of the flexible film using an alkaline solvent is simpler and much more economical than the conventional process.

Compared to the conventional method, the present invention is simple and inexpensive, and very economical, so that mass production of printed circuits is possible through roll-to-roll inkjet printing.

1 is a flowchart illustrating a method of forming a metal pattern on a flexible substrate according to the present invention.
FIG. 2 is a side cross-sectional view of a circuit board made according to the method of FIG. 1 (1: surface treated substrate, 2: particle layer due to printing and reduction of catalytic ink, 3: metal pattern by electroless plating).
3 is a UV / vis spectra of Pd (II) catalyst inks measured after storage at room temperature.
4 is a graph showing the contact angle and surface energy of the polyimide film at various concentrations of KOH solution (top) and surface treatment time (bottom).
5 is an AFM three-dimensional image photograph of a polyimide film surface treated in (a) the original sample, (b) 1 M KOH, (c) 3 M KOH, (d) 5 M KOH and (e) 7 M KOH. to be.
FIG. 6 is a comparison table (top) of surface roughness measurements of polyimide films surface treated before and at various concentrations of KOH solution, and (a) 0 minutes, (b) 1 minute, (c) in 1 M KOH solution. It is a graph which shows the FTIR-ATR spectra (bottom) of the polyimide film surface-treated for 10 minutes, (d) 30 minutes, and (e) 60 minutes.
7 shows FTIR-ATR spectra of polyimide films surface treated in (a) original samples, (b) 1 M KOH, (c) 3 M KOH, (d) 5 M KOH and (e) 7 M KOH. It is a graph.
FIG. 8 is a photograph showing FE SEM images of Pd particles on a polyimide film surface-treated in (a) 1 M KOH and (b) 3 M KOH.
9 is a graph showing Pd 3d core-level spectra of polyimide films surface-treated in (a) 1 M KOH, (b) 3 M KOH, (c) 5 M KOH and (d) 7 M KOH.
10 is a photograph showing an AFM image of Pd catalyst particles bound on a polyimide film surface-treated in (a) 1 M KOH and (b) 3 M KOH.
Figure 11 is a photograph showing the copper pattern image of the polyimide film surface-treated in (a) 1 M KOH, (b) 3 M KOH, (c) 5 M KOH and (d) 7 M KOH.

The present invention relates to a method of synthesizing a palladium catalyst ink and a method of surface treatment of a substrate with an alkali solution and a metal pattern forming method so that the palladium catalyst ink adheres well to the substrate, specifically, the viscosity and the smooth discharge that can occur in the printing head and Technology to manufacture palladium catalyst ink with very low surface tension and storage stability, technology to control contact angle by etching substrate with alkaline solution so that palladium catalyst ink can be printed on polymer substrate and printed palladium (Pd (II)) catalyst The present invention relates to a technique for forming a metal circuit through electroless plating by liquid-reducing the ink and depositing it into Pd (0) metal.

To this end, the present invention is characterized by providing a palladium catalyst ink composition consisting of a palladium salt, an ammonium salt and a stabilizer and a method for synthesizing thereof.

In another aspect, the present invention comprises the steps of (a) inkjet printing the palladium catalyst ink composition on a substrate; (b) reducing the printed substrate; And (c) forming a metal pattern by performing electroless plating on the reduced substrate to form a metal pattern. It also provides a surface treatment method using an alkali solution of a polyimide film or polyester-based film used as the material of the substrate.

Hereinafter, the present invention will be described in detail.

The present invention provides a palladium catalyst ink composition consisting of a palladium salt, an ammonium salt and a stabilizer, the preparation of the palladium catalyst ink composition comprises the steps of (a) preparing the ink by stirring the palladium salt and ammonium salt in a solvent; And (b) filtration after adding the stabilizer to the ink. At this time, the stirring in the step (a) is preferably carried out in a range of 30 minutes to 2 hours.

The palladium catalyst ink may be prepared by, for example, the following method. PdCl ₂ in pure water (H ₂ O) And after stirring for 1 hour to add NH ₄ Cl and PdCl ₂ in the solution Pd ^{2 +} ion and Cl ^- ion does not dissociate to a PdCl ₂ as shown in scheme 1 It will form a PdCl ₂ (H ₂ O) ₂ complex containing 2 moles of water molecules per mole.

[Reaction Scheme 1]

PdCl ₂ + 2NH ₄ Cl + 2H ₂ O → PdCl ₂ (H ₂ O) ₂ + 2NH ₃ + 2HCl

Since stabilizer 35% H ₂ O ₂ And by adding 2-propanol and filtering, a palladium catalyst ink can be prepared. The prepared palladium catalyst ink is preferably stored refrigerated.

In the present invention, the palladium salt serves as a precursor of the palladium complex, PdCl ₂ , PdSO ₄ , Pd (NO ₃ ) ₂ , K ₂ [PdCl ₄ ], [Pd (NH ₃ ) ₄ Cl ₂ ], [Pd ( NH ₃ ) ₂ (NO ₂ ) ₂ ] and the like may be used alone or in combination.

In the present invention, the ammonium salt serves to dissolve the palladium salt in water to form a PdCl ₂ (H ₂ O) ₂ complex, NH ₄ Cl, (NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₂ CO ₃ , NH ₄ NO ₃ and the like can be used alone or in a mixed form, the amount of the ammonium salt is preferably used 50 to 200 parts by weight based on 100 parts by weight of the palladium salt. When using less than 50 parts by weight, it is difficult to dissolve the palladium salt in water, making it impossible to form the PdCl ₂ (H ₂ O) ₂ complex, and when used in excess of 200 parts by weight, the storage stability of the PdCl ₂ (H ₂ O) ₂ complex This problem is lowered, so it is better to maintain the above range.

In the present invention, the stabilizer prevents the precipitation of the metal (prevents the precipitation of Pd (II) into the metal) to increase the stability of the solution, and has a low surface tension value and low viscosity of less than 72.00 mN / m surface tension value of water H ₂ O ₂ , propanol, isopropanol, butanol, methanol and the like can be used alone or in combination. The amount of the stabilizer is preferably used 2,000 to 6,000 parts by weight based on 100 parts by weight of palladium salt. When using less than 2,000 parts by weight, PdCl ₂ (H ₂ O) ₂ complex precipitates as Pd (0) metal particles during storage, and there is a problem that inkjet printing is difficult due to an increase in surface tension and viscosity, and exceeds 6,000 parts by weight. In the case of use, since the concentration of the PdCl ₂ (H ₂ O) ₂ complex is too low to act as a catalyst nucleus after reduction, there is a problem in that a metal circuit can be formed through electroless plating, so it is preferable to maintain the above range.

As the solvent, it is preferable to use pure water, distilled water, ion-exchanged water, and the like, and the amount of the solvent used is preferably 10,000 to 150,000 parts by weight based on 100 parts by weight of the palladium salt. When the amount is less than 10,000 parts by weight, the concentration of PdCl ₂ (H ₂ O) ₂ complex is increased, so that the bonding strength between the substrate and the metal circuit layer is reduced during electroless plating, and the consumption of catalyst ink is excessively increased. 150,000 In case of using it in excess of the weight part, the concentration of PdCl ₂ (H ₂ O) ₂ complex is so low that it is difficult to form the Pd (0) catalyst layer on the substrate, and thus it is not possible to form a metal circuit through electroless plating. It is good to keep it.

The palladium catalyst ink prepared according to the present invention has a storage stability of 120 days or more for the application of the printed electronic device, has a low surface tension of about 40 to 50 Nm / m and a low viscosity of 1.4 to 2.0 cP Jetting is easy.

The present invention also comprises the steps of (a) inkjet printing the palladium catalyst ink composition on a substrate; (b) reducing the printed substrate; And (c) metal plating to form a metal pattern by performing electroless plating on the reduced substrate.

The substrate used in the step (a) is not limited to those used in the art, but preferably a polyimide film or a polyester-based film may be used as the flexible film. For example, a KAPTON film, an Upilex-s film, or a polyester film, a PET film, or a PEN film, which is a polyimide film, may be used, but is not limited thereto.

In this case, in the case of the polyimide film, it is preferable to use the surface treated for 1 to 30 minutes in an alkaline solution of 1 to 12 M, because Pd particles are uniformly dispersed and bonded to the polyimide film, and more preferably in the range of 1 to 3 M. Or in the range of 7 to 12 M. In addition, in the case of the polyester film, it is preferable to use a surface treated 30 to 120 minutes in an alkaline solution of 7 to 14 M because Pd particles are uniformly dispersed and bonded on the polyester film. As the alkaline solution, KOH, NaOH or NH ₄ OH solution may be used, and these alkaline solutions may be used alone or in combination. More specifically, the KAPTON film is preferably treated for 1 to 30 minutes in a 1 to 3 M KOH solution, and the Upilex-s film is preferably treated for 1 to 30 minutes in a 7 to 12 M KOH solution. And when using a PET film and a PEN film, it is preferable to treat for 30 to 120 minutes with a 7 ~ 14 M KOH solution at 40 ~ 80 ℃.

As the concentration of the alkaline solution increases above the maximum molar concentration (M) or as the treatment time is longer than the maximum value, irregular surfaces are formed and surface roughness increases, thereby lowering the bonding force, thereby providing a uniform metal line width in the metal plating step. It is preferable to maintain the above range because a problem arises that formation is impossible.

In the step (b) of reducing the printed substrate, reduction may be performed by a chemical method using NaBH ₄ , HCOOH, C ₄ H ₅ O ₆ , N ₂ H _4, etc. as a reducing agent, but is not limited thereto. . Preferably from 0.01 to 1 M NaBH ₄ Reduction by precipitation in the solution for 5 to 60 minutes is preferred. In the step (a), when printing the Pd (II) ink on the surface-treated flexible film, Pd ^{2 +} ions are bonded to the carboxyl group formed on the film, and in the step (b), the printed Pd (II) ink NaBH ₄ By liquid phase reduction into solution, Pd (0) particles acting as catalyst nuclei are formed. This can be represented as in Scheme 2 below.

Scheme 2

PdCl ₂ (H ₂ O) ₂ + ₂ NaBH ₄ + H ₂ O Pd (0) + 2NaCl + 2BH ₃ + 3H ₂ O

Step (c) is a metal plating step of forming a metal pattern by performing electroless plating on the reduced substrate. The metal used in the metal plating step may be used one or two or more selected from the group consisting of copper (Cu), silver (Ag), gold (Au) and platinum (Pt), but is not limited thereto. In this step, in order to finally obtain a circuit pattern, an electroless plating solution is prepared, and preferably, a copper electroless plating solution is prepared and used. The copper electroless plating solution may be, for example, copper ions (CuSO ₄ · 5H ₂ O), copper chloride, copper oxide, etc. as copper ions, chelating agents such as EDTA, tartarate, etc. as complexing agents, and formalin as reducing agents. (HCHO), prepared using hydrazine and caustic soda (NaOH) to adjust pH. The pH of the electroless plating solution is preferably adjusted to 11 to 13. Using the electroless plating solution, the electroless plating may be performed in the same manner as in Example 3, followed by repeated washing with distilled water several times, followed by drying to form a metal pattern.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are intended to illustrate the invention, and the content of the invention is not limited by the following examples.

Example  1: Preparation of palladium catalyst ink

4 g of PdCl _{2 and} 4 g of NH ₄ Cl were added to 2400 ml of a pure solvent, and stirred for 1 hour to prepare a Pd (II) ink. Since stabilizer 35% H ₂ O ₂ 15 ml and 125 g of 2-propanol were added and filtered to prepare a palladium catalyst ink. The prepared palladium catalyst ink was stored in a refrigerator at about 4 ° C.

The viscosity of the prepared palladium catalyst ink (Pd (II)) was measured using a LVDV-E Viscometer with UL Adapter, and the surface tension was measured using a DST30 surface tension meter using the Du Nouy ring (Platinum-Iridium) method. It was measured by. As a result of the measurement, the palladium catalyst ink according to the present invention showed a low surface tension of 46.04 mN / m and a low viscosity of 1.5 cP.

Example  2: Preparation of Surface-treated Polyimide Film Substrate

The 50 × 80 mm polyimide film (Tape World, TW-PI025) was washed in distilled water for 30 minutes, immersed in 1 M KOH solution for 5 minutes, washed with distilled water, and dried to complete the surface treatment.

Example  3: Formation of Metal Pattern Using Palladium Catalytic Ink

Palladium catalyst ink prepared from Example 1 was injected into HP Deskjet Printer (D1560) and printed on the polyimide substrate of Example 2 at 300 mm line width, followed by 0.2 M NaBH ₄ After the liquid phase reduction to the solution, washed with distilled water and dried at room temperature. Thereafter, 35 g of 0.8 M NaOH, 51 g of 0.2 M EDTA, 25 g of 0.1 M CuSO ₄ · 5H ₂ O, and 4 ml of 35% formaldehyde were mixed to prepare an electroless solution, followed by Cu electroless plating, and distilled water. After repeated washing several times with and dried.

Experimental Example  1: alkali solution concentration and Immersion time  Measurement of physical properties of polyimide film according to the difference

In order to investigate the change in physical properties according to the characteristics of the polyimide film, the experiment was performed while changing the concentration and time of the alkaline solution used in the surface treatment of the polyimide film. After washing the 50 × 80 mm polyimide film (Tape World, TW-PI025) in distilled water for 30 minutes, the concentration of the KOH solution and the time immersed in the KOH solution was changed as shown in Table 1 and Table 2 Physical property changes were measured. After the immersion, washed with distilled water and dried to complete the surface treatment. The contact angle of the polyimide film was measured by sessile drop method using SEO 300 Phoenix, and the surface energy was calculated by Girifalco-Good-Fowkes-Young method using 72.00 mN / m distilled water.

Property Changes with Changes in KOH Concentration division KOH solution concentration (M) Immersion time (minutes) Contact angle ( ^o ) Surface energy (mN / m) One Untreated 0 48.67 62.01 2 One 5 36.66 73.65 3 3 5 36.30 73.72 4 5 5 36.11 73.87 5 7 5 35.90 74.01

Changes in Physical Properties with Time Submerged in KOH Solution division KOH solution concentration (M) Immersion time (minutes) Contact angle ( ^o ) Surface energy (mN / m) One Untreated 0 48.67 62.01 2 One One 39.15 71.20 3 One 5 36.66 73.65 4 One 10 36.21 73.84 5 One 15 35.97 74.03

As can be seen in Table 1, 2 and Figure 4, the contact angle was measured for the surface characteristics analysis of the polyimide film surface-treated with KOH solution, the contact angle after the surface treatment at 1 M KOH concentration at 48.67 ° contact angle before surface treatment The change was made to 36.66 ° and decreased by about 13 °. Thereafter, even when the concentration of KOH increased to 7 M, the contact angle did not show a large change of about 35 to 36 °. In case of surface treatment for 1 minute, 5 minutes, 10 minutes, and 15 minutes to measure the change of contact angle with time under KOH 1 M condition, the contact angle was slightly decreased to 39.15 °, 38.66 °, 36.21 °, and 35.97 °, respectively. It showed a tendency to decrease. In addition, the surface energy was increased to 11.64 mN / m from 62.01 mN / m before surface treatment to 73.65 mN / m after surface treatment at 1 M KOH concentration. Thereafter, even when the concentration of KOH increased to 7 M, the surface energy did not change as large as 74.01 mN / m. In order to measure the change of surface energy over time under KOH 1 M condition, surface treatment for 1, 5, 10 and 15 minutes was performed at 71.20 mN / m, 73.65 mN / m, 73.84 mN / m, The trend was slightly increased to 74.03 mN / m. Based on the above results, the contact angle decreased and the surface energy increased slightly as the concentration of KOH solution and surface treatment time increased, but no significant change occurred. It was found that surface treatment for minutes is desirable.

Experimental Example  2: measurement of surface state of polyimide film substrate

An experiment was conducted to measure the surface state of the polyimide film substrate according to Experimental Example 2. 5 is a photograph showing the 3-D shape of the polyimide film surface-treated with a KOH solution. As can be seen from the photo, low concentration alkali solution in the range of 1 M to 3 M shows uniformly etched overall, and high concentration alkali solution of 5 M or more shows a large number of traces due to excessive etching, forming a non-uniform surface. It can be seen. In addition, the surface roughness of the polyimide film before the surface treatment was measured in FIG. 6 and the average roughness (Ra) was found to be 1.530 nm, and the surface treated with 1 M of KOH solution had 2.454 nm of curvature and 3 M of KOH. The solution treated surface was found to have a uniform bend of 3.261 nm. However, the surface roughness increased significantly in KOH solution of 5 M or more, showing 6.039 nm at 5 M and 14.864 nm at 7 M.

Experimental Example  3: Infrared spectroscopic analysis of the polyimide film substrate

6 (bottom) and 7 are the results of infrared spectroscopy according to the surface treatment conditions change. In FIG. 6, it can be seen that the NH characteristic peak increases gradually around 3400 cm ⁻¹ from the sample treated for 10 minutes in a 1 M KOH solution as compared to before the surface treatment, and the intensity of the spectrum further increases after 30 minutes. I can see that. After 30 minutes, the intensity of the C = O characteristic peak around 1700 cm ⁻¹ decreases, and after 60 minutes, the peaks are separated into two peaks. 7 shows that the (c), (d) and (e) spectra increase more and more the NH characteristic peaks around 3400 cm ⁻¹ compared to (b) spectra. On the other hand, the C = O characteristic peak near 1700 cm ⁻¹ appears to gradually decrease from (b) to (c), (d), and (e), and is separated into two peaks in (d). This means that as the imide ring is opened, a carboxyl group and an amide group are formed to modify the surface from hydrophobic to hydrophilic. If through this surface modification printing a Pd (II) the ink on the polyimide film can be seen that the Pd ^{2 +} ion to the carboxyl groups formed on the film to be bonded.

Experimental Example  4: on polyimide film Combined Pd (0) particle shape analysis and binding energy measurement

The shape of the Pd (0) particles bonded to the polyimide film of Experimental Example 2 was analyzed by FE SEM (Philips, XL-30S FEG) and shown in FIG. 8. It can be observed that Pd particles are uniformly dispersed and bonded to the polyimide film surface-treated with 1 M and 3 M KOH solution for 10 minutes. However, in 5 M and 7 M KOH solutions, it was not possible to observe uniformly dispersed Pd particles due to irregular surfaces due to excessive etching.

In addition, as a result of performing Kras Axis-Nova photoelectron spectroscopy (XPS) analysis to measure the binding energy between the polyimide film and Pd (0) according to the surface treatment conditions, the concentration of the KOH solution was 1 as shown in FIG. 9. When M was the greatest intensity, the intensity tended to decrease as the concentration of KOH solution increased. As a result, as the KOH concentration increased, the surface treatment proceeded more severely, and the surface roughness increased, indicating that the adhesion decreased.

10 is a photograph showing an AFM image of a film in which Pd (0) catalyst cores are bonded to a film surface-treated in 1 M and 3 M KOH solutions. In the photograph, it was observed that the Pd (0) catalyst nuclei were uniformly adsorbed on the polyimide film, and the surface roughness showed 14 to 20 nm similar to the size of the Pd (0) particles in the SEM photograph of FIG. 8.

Experimental Example  5: KOH  Depending on the concentration of the solution Patterning  Result analysis

As a result of the formation of the metal pattern using the palladium catalyst ink according to Example 3, when forming the Cu circuit through the electroless plating process to the polyimide film bonded to the catalyst ink reduced to Pd (0), the printed line width of the catalyst ink The line width of Cu tended to increase slightly, and the pattern of the patterned Cu line differed according to the concentration of KOH solution. 11 shows Cu patterning results according to the concentration of the KOH solution. As the concentration of the KOH solution increases, the Cu line width gradually increases, and a rough pattern is formed due to the irregular surface shape. As shown in FIG. 11, when the surface treatment was performed within 1 to 3 M of KOH solution within 10 minutes, the patterning property of Cu wire was the best.

Claims (14)

delete delete delete delete delete delete delete delete (a) PdCl ₂ , PdSO ₄ , Pd (NO ₃ ) ₂ , K ₂ [PdCl ₄ ], [Pd (NH ₃ ) ₄ Cl ₂ ], [Pd (NH ₃ ) ₂ (NO ₂ ) ₂ ] One or two or more selected from the group consisting of palladium salts, NH ₄ Cl, (NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₂ CO ₃ and NH ₄ NO ₃ selected from the group consisting of one or two or more ammonium salts and H ₂ Palladium catalyst ink with viscosity ranging from 1.4 to 2.0 cP and surface tension ranging from 40 to 50 mN / m, including one or two or more stabilizers selected from the group consisting of O ₂ , propanol, isopropanol, butanol and methanol Inkjet printing the composition onto a substrate;
(b) reducing the printed substrate; And
(c) metal plating to form a metal pattern by performing electroless plating on the reduced substrate;
Metal pattern forming method comprising a.
10. The method of claim 9, wherein the substrate is a polyimide film or a polyester film.
The method of claim 10, wherein the polyimide film is surface treated in a 1 to 12 M alkaline solution for 1 to 30 minutes.
The method of claim 10, wherein the polyester film is a metal pattern forming method, characterized in that the surface treatment for 30 to 120 minutes in 7 to 14 M alkali solution.
The method of claim 9, wherein the reducing agent used for the reduction is NaBH ₄ , HCOOH, C ₄ H ₅ O ₆ Or N ₂ H ₄ .
The method of claim 9, wherein the metal used in the metal plating step is one or two or more selected from the group consisting of copper (Cu), silver (Ag), gold (Au) and platinum (Pt). Metal pattern formation method.

Images