Photosensitive dry film, composition solution for producing it, and electroless plating method for a metal layer

Abstract

To provide a photosensitive dry film, to provide a composition solution which generates the same, and to provide an electroless plating method of a kind of metal layer.SOLUTION: A photosensitive dry film includes a composition for catalyst formation and a photocatalyst 102. The composition for catalyst formation includes a metal complex and a water-soluble polymer 106. The photocatalyst is dispersed in the composition for catalyst formation, and the photocatalyst is deposition of a photocatalyst precursor. In the photosensitive dry film, a composition solution is dried, exposed and developed and the photocatalyst is deposited first, and then, the photocatalyst is induced to generate an electron-hole, and on the surface of the photocatalyst, metal particles 104 are reduced and generated. With the metal particles being a catalyst, electroless plating is performed and a metal layer can be formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to electroless plating technology, and more particularly to a photosensitive dry film, a composition solution for producing the same, and a method for electroless plating a metal layer. [Background technology]

[0002] In electroless plating, metallic palladium is used as a seed to induce the reaction, but metallic palladium is expensive, and replacing it with other materials is a trend in technological development. In particular, in electroless copper plating using formaldehyde as a reducing agent, the catalytic activity order of each metal is estimated to be Cu > Au > Ag > Pt > Pd > Ni > Co based on a comparison of oxidation potentials.

[0003] Therefore, using copper as a catalyst for copper plating with formaldehyde is considered to have the advantage of obtaining relatively high activity. However, the reason why copper is not commonly used as a catalyst is that it is difficult to use and its advantages are not clear. For example, when using copper metal particles produced by a preliminary reaction as a catalyst, there are many disadvantages, such as high cost, surface oxidation and tendency of the particles to aggregate, requiring complicated operations such as redispersion for use, and making storage difficult. When generating copper metal particles in situ using the ionic method, they are easily oxidized and lose their activity, making it not as simple as with precious metals such as Pd and Ag, and it cannot be achieved with conventional wet susceptibility / substitution methods. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The present invention provides a photosensitive dry film having a composition that can use light energy to induce in-situ reduction and generate catalytic metal particles.

[0005] The present invention further provides a compositional solution for producing a photosensitive dry film that can be used to form the dry film described above.

[0006] The present invention further provides an electroless plating method for a metal layer that can form a catalytic pattern by light, has metal particles formed on the surface of a photocatalyst as a patterned catalyst, and continuously induces a reaction of an electroless plating metal to produce a conductive wire. [Means for solving the problem]

[0007] The photosensitive dry film of the present invention comprises a catalyst-forming composition and a photocatalyst. The catalyst-forming composition comprises a metal complex and a water-soluble polymer. The photocatalyst is dispersed in the catalyst-forming composition and is a precipitate obtained after drying a photocatalyst precursor.

[0008] The composition solution for producing the photosensitive dry film of the present invention comprises a metal salt compound, an amine compound as a complexing agent, a photocatalytic precursor, a water-soluble polymer, and a solvent.

[0009] The electroless plating method for a metal layer of the present invention includes preparing a composition solution for generating the above-mentioned photosensitive dry film, preparing a substrate, forming an adhesive layer on the substrate, applying the composition solution for generating the above-mentioned photosensitive dry film to the surface of the substrate, and forming a photosensitive dry film after drying. The above-mentioned photosensitive dry film comprises a catalyst-forming composition and a photocatalyst dispersed in the catalyst-forming composition, the catalyst-forming composition comprises a metal complex and the above-mentioned water-soluble polymer, and the photocatalyst is a precipitate obtained after drying a photocatalyst precursor. Subsequently, a localized or entire region of the photosensitive dry film is exposed to light to induce a photocatalyst and generate electron-holes, the metal complex is reduced on the surface of the photocatalyst to generate metal particles, and then electroless plating is performed using the above-mentioned metal particles as a catalyst to form a metal layer. [Effects of the Invention]

[0010] Based on the above, the present invention employs a photoelectric reduction method, using a photocatalyst as a carrier to provide electron-hole pairs, and can induce the generation of electrons necessary for the reduction reaction using light energy. Furthermore, the present invention uses a water-soluble polymer as a hole scavenger to achieve energy transfer and balance, while simultaneously providing anti-oxidative protection for newly generated metal particles and avoiding excessive oxidation. After light irradiation, the metal particles (catalyst) precipitate and become embedded in the surface of the photocatalyst, fixing it on the substrate, but the areas not irradiated with light still exhibit an ionic state and can be removed with detergent. Therefore, a catalyst seed pattern can be formed using light, and the reaction of electroless plated metal can be continuously induced to form a conductive wire.

[0011] To make the above features of the present invention clearer and easier to understand, embodiments are given below and described in detail with reference to the accompanying drawings. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of the reaction that occurs in the light irradiation process of a photosensitive dry film according to an embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view showing the electroless plating flow of a metal layer according to another embodiment of the present invention. [Figure 3] This is a schematic cross-sectional view showing the electroless plating flow of a metal layer according to yet another embodiment of the present invention. [Figure 4] This is a schematic cross-sectional view showing the electroless plating flow of a metal layer according to yet another embodiment of the present invention. [Figure 5] This diagram shows the relationship between wavelength and transmittance under different conditions in Experimental Example 3 of the present invention. [Figure 6] This diagram shows the relationship between wavelength and transmittance under different conditions in Experimental Example 4 of the present invention. [Figure 7]It is a diagram showing the relationship between wavelength and transmittance under different conditions in Experimental Example 5 of the present invention. [Figure 8] It is a diagram showing the relationship between wavelength and transmittance under different conditions in Experimental Example 6 of the present invention.

Mode for Carrying Out the Invention

[0013] The photosensitive dry film according to an embodiment of the present invention contains a catalyst-forming composition and a photocatalyst.

[0014] The above photocatalyst is a composition solution for generating a photosensitive dry film, is the first solid matter deposited in the drying process, and is dispersed in the catalyst-forming composition.

[0015] In the present embodiment, the catalyst-forming composition contains a metal complex and a water-soluble polymer. Here, the metal complex is the remaining product after drying the composition solution for generating the photosensitive dry film.

[0016] The above photosensitive dry film is obtained by coating and drying a composition solution for generating the photosensitive dry film. The composition solution contains a mixture of a metal salt compound, an amine compound as a complexing agent, a water-soluble polymer, a photocatalyst precursor, and a solvent. After applying and drying the above composition solution on a substrate, photocatalyst particles are deposited on the substrate, leaving the catalyst-forming composition. The formed photocatalyst particles are dispersed in the catalyst-forming composition. The metal complex in the above catalyst-forming composition is a reactant formed by a complex reaction between the amine compound and the metal salt compound in the above composition solution.

[0017] The above metal salt compound may be one or more mixtures selected from the group consisting of sulfates, nitrates, acetates, formates, and chloride salts of nickel (Ni), copper (Cu), palladium (Pd), and silver (Ag). For example, the metal salt compound may be copper acetate, copper formate, palladium acetate, etc. The above amine compound may be at least one selected from the group consisting of ethanolamine (MEA), triethanolamine (TEA), diethanolamine (DEA), ethylenediamine (EDA), propylenediamine (1,2-diaminopropane), dimethylamine, 2-aminoisobutanol (AMP), isopropanolamine (1-amino-2-propanol), and 1-octylamine. The amine compound as a complexing agent can form a metal complex with the metal salt compound.

[0018] In one embodiment, the molar concentration ratio of the total amine groups of the amine compound to the metal ions of the metal salt compound is 1.5 to 10, for example, 1.5 to 4, or 2 to 4. However, the present invention is not limited thereto, and the molar ratio may be lower or higher depending on the metal salt compound or amine compound, and is determined by whether the formed complex can be reduced by photoelectric action and at the same time maintain stability during storage at room temperature. The formed complex is supplied to the subsequent reduction and precipitation of metal particles (catalyst) in a dry film state. Examples of the water-soluble polymer include, but are not limited to, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polyethyleneimine (PEI), methylcellulose, gelatin, starch, chitosan, or combinations thereof.

[0019] In this embodiment, the photocatalyst is a precipitate formed from the photocatalytic precursor during the drying process. Examples of the aforementioned photocatalyst include, but are not limited to, titanium dioxide (TiO2), zinc oxide (ZnO), or a combination thereof. In one embodiment, the content of the photocatalyst is, for example, 1% to 70% based on the total weight (weight percentage) of the photosensitive dry film.

[0020] In this embodiment, the photocatalytic precursor may be, but is not limited to, titanium isopropoxide, titanium butoxide, zinc methoxide, zinc n-propoxide, or a combination thereof. In one embodiment, the content of the photocatalytic precursor is 0.1% to 3.0% based on the total weight (weight percentage) of the composition solution. Known solvents such as methanol, ethanol, and water can be used as the solvent for the composition solution, but the present invention is not limited to these.

[0021] The above-mentioned photosensitive dry film exists in the form of photocatalytic particles dispersed in the composition before irradiation with light (such as UV light), but after irradiation, it is as shown in Figure 1. The left side of Figure 1 shows structure 100 after illumination, and the right side of Figure 1 is a partially enlarged schematic diagram of the left side.

[0022] Referring to Figure 1, after light irradiation, the photocatalyst 102 generates electron-hole pairs. Here, electron e - The metal ions are supplied to the complex ions, reducing them to zero-valent metal particles 104 on the surface of the photocatalyst 102, or doping them into the photocatalyst 102 (not shown). The holes h generated in this process + The electrons e generated by the photocatalyst 102 are absorbed by the surrounding water-soluble polymer 106. In this absorption process, the water-soluble polymer, acting as a sacrificial acceptor, is oxidized by the holes and decomposed into CO, CO2, H2O, etc., while simultaneously protecting the newly generated metal particles 104 within the nucleus. In other words, this embodiment uses the photocatalyst 102 as a carrier, and the water-soluble polymer 106 provides anti-oxidative protection for the newly generated metal particles 104, while simultaneously acting as a hole scavenger to facilitate complete energy transfer. In this way, the photocatalyst 102 absorbs the generated electrons e - and hole h +By ensuring that all of these are absorbed by the receptors and reducing the possibility of ineffective self-recombination, favorable conditions are created for the deposition of metal particles 104 upon light detection, thereby achieving the objectives of in-situ reduction and generation.

[0023] Therefore, in the catalyst (metal particles 104) formation process of this embodiment, the reduction of metal ions can be induced by light irradiation alone, and there is no need to use a chemical reducing agent.

[0024] Figure 2 is a schematic cross-sectional view showing the electroless plating flow of a metal layer according to another embodiment of the present invention.

[0025] Referring to Figure 2, in the electroless plating method for metal layers of this embodiment, first, a composition solution for producing a photosensitive dry film is prepared. The composition solution for producing the photosensitive dry film includes, as described above, a metal salt compound, an amine compound, a photocatalyst precursor, a water-soluble polymer, and a solvent. The metal salt compound may be a mixture of one or more compounds selected from the group consisting of sulfates, nitrates, acetates, formates, and chlorides of nickel, copper, palladium, and silver. The amine compound may be at least one compound selected from the group consisting of ethanolamine, triethanolamine, ethylenediamine, propylenediamine, dimethylamine, 2-aminoisobutanol, isopropanolamine, and 1-octylamine. Examples of photocatalyst precursors include, but are not limited to, titanium isopropoxide, titanium butoxide, zinc methoxide, zinc propoxide, or combinations thereof. Examples of water-soluble polymers include, but are not limited to, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyethyleneimine, methylcellulose, gelatin, starch, chitosan, or combinations thereof. In one embodiment, the molar concentration of the metal salt compound is 0.01 M to 0.2 M. In one embodiment, the molar concentration ratio of the total amine groups of the amine compound to the metal ions of the metal salt compound is 1.5 to 10. In one embodiment, the concentration of the water-soluble polymer is 0.5 × 10 -3 M~1.0×10-1 M is the content of the photocatalytic precursor. In one embodiment, the content of the photocatalytic precursor is 0.1% to 3.0% based on the total weight of the composition solution that produces the above photosensitive dry film.

[0026] Subsequently, an adhesive layer 202 is formed on the substrate 200. Here, the adhesive layer 202 and the photocatalyst formed thereafter may be made of the same material or different materials. If they are made of the same material, it is advantageous for the photocatalyst to adhere to the surface of the adhesive layer. For example, the adhesive layer 202 may be titanium dioxide, zinc oxide, silane, self-assembly monolayer (SAM), polydopamine, etc. Then, a composition solution for producing a photosensitive dry film is applied to the surface of the adhesive layer 202, and after drying, a photosensitive dry film 204 is formed and photocatalyst particles are deposited in the photosensitive dry film 204.

[0027] Next, a localized or entire region of the photosensitive dry film 204 is exposed, for example, by a photomask 206 or digital exposure, to expose a localized region 204' of the photosensitive dry film 204 208, thereby inducing the photocatalyst in the photosensitive dry film 204 and generating electron-holes. This reduces the metal particles in the metal complex on the surface of the photocatalyst, achieving the effect of selectively reducing and precipitating the metal particles. Furthermore, during exposure, not only are the metal particles reduced on the surface of the photocatalyst, but the metal ions in the metal complex within the photocatalyst are also reduced, doping the metal particles within the photocatalyst and forming a mixed structure.

[0028] Since the photocatalyst in the unexposed photosensitive dry film 204 does not generate electron-hole pairs, the catalyst-forming composition in this case still contains metal complexes and water-soluble polymers that can be removed with detergent. Therefore, the unexposed photosensitive dry film 204 outside the local region 204' can be removed by methods such as detergent. At the same time, the unreacted metal complexes and water-soluble polymers in the local region 204' are also removed, leaving behind metal particles and photocatalyst. For example, rinsing with deionized water (DI) or using an aqueous solution of an amine compound having a Pd chelating effect (such as triethanolamine (TEA) or diethanolamine (DEA)) is more preferable. Subsequently, electroless plating is performed using the metal particles deposited in the local region 204' as a catalyst to form a metal layer 210. Here, the metal layer 210 may be a copper layer or a nickel layer. The patterned line layer after electroless plating includes the metal layer 210 and the patterning catalyst layer (i.e., the catalyst in the local region 204').

[0029] According to the method of this embodiment, a photosensitive dry film 204 is formed on the substrate 200, and then, if electroless plating is required, a catalyst (metal particles) can be deposited by exposure 208. This significantly reduces the oxidation of the catalyst, and as a result, less expensive metallic copper particles can be used as a catalyst for electroless copper plating. In another embodiment, palladium metallic particles may be used as a catalyst for electroless nickel plating.

[0030] Figure 3 is a schematic cross-sectional view showing the electroless plating flow of a metal layer according to yet another embodiment of the present invention. Here, the same reference numerals as in the previously described embodiments are used to indicate the same or similar parts and components. Furthermore, since the details of the same or similar parts and components can be found by referring to the previously described embodiments, their explanation is omitted.

[0031] Referring to Figure 3, the difference between the method of this embodiment and the above embodiment is that, after forming an adhesive layer 202 on the substrate 200, an ink is prepared using a composition solution that generates a photosensitive dry film, and a patterned photosensitive dry film 300 can be directly formed on the surface of the adhesive layer 202 by methods such as screen printing, inkjet printing, or gravure printing. Therefore, as long as the subsequent exposure 302 is performed completely without using a device such as a photomask, the photocatalyst inside the patterned photosensitive dry film 300 can be induced to generate electron-holes. This reduces the metal particles on the surface of the photocatalyst, obtaining the photosensitive dry film 300' after exposure. Subsequently, the metal particles deposited in the photosensitive dry film 300' after exposure can be used as a catalyst to perform electroless plating and form a metal layer 210.

[0032] Figure 4 is a schematic cross-sectional view showing the electroless plating flow of a metal layer according to yet another embodiment of the present invention. Here, the same reference numerals as in the embodiment of Figure 2 are used to indicate the same or similar parts and components. Details relating to the same or similar parts and components can be found by referring to the details of the embodiment of Figure 2, so a detailed explanation is omitted.

[0033] Referring to Figure 4, the difference between the method of this embodiment and the embodiment in Figure 2 is that an adhesive layer 202 is formed on the substrate 200, and a composition solution for generating a photosensitive dry film is applied to the surface of the adhesive layer 202 and dried. Separately, a barrier structure 400 is formed on the surface of the photosensitive dry film 204 to expose a portion of the photosensitive dry film 204. Here, the barrier structure 400 is made of a photosensitive polymer such as photoresist or patternable photosensitive polyimide (PSPI), and the method for forming the barrier structure 400 is, for example, screen printing, inkjet printing, or photolithography, but is not limited to these.

[0034] Subsequently, the entire area of ​​the photosensitive dry film 204 is exposed 302 to induce the photocatalyst within the photosensitive dry film 204, generating electron-holes, and reducing and depositing metal particles on the surface of the photocatalyst in the local area 204'.

[0035] Subsequently, electroless plating is performed using the metal particles deposited within the local region 204' as a catalyst to form a metal layer 210. After electroless plating, the barrier structure 400 can be maintained. Because this embodiment has a barrier structure 400, the metal layer 210 can be maintained within the set region via the barrier structure 400. Therefore, the method of this embodiment can be applied to metal layer patterns requiring higher resolution.

[0036] The following lists several experiments to verify the effectiveness of the present invention, but the present invention is not limited to the following.

[0037] Experimental Example 1

[0038] First, a composition solution for producing a photosensitive dry film was prepared. The raw materials used were as follows: Metal salt compound: copper acetate. Concentration: 0.1M. Amine compound: Triethanolamine (TEA), concentration: 0.1M. The molar ratio of amine groups to copper acetate in TEA is 3. Photocatalytic precursor: Titanium butoxide (Ti(OBu)4) 0.5 wt%. Water-soluble polymer: PVA 0.5 wt%. Solvent: Methanol. (All of the above raw materials use chemical reagents provided by Alpha-Acer, Merck & Co., and Aldrich.)

[0039] Pretreatment of glass substrate: A slurry was formed by adding 0.5 wt% titanium butoxide to butanol, which was then spin-coated onto a glass substrate at a speed of 2000 rpm, dried at 120°C, and fired in air at 400°C for 1 hour to obtain a TiO2 adhesive layer with a thickness of approximately 2 to 20 nanometers.

[0040] Next, the composition solution for producing the photosensitive dry film was spin-coated onto the TiO2 adhesive layer of a glass substrate at a speed of 2000 rpm, dried at 120°C, and a photosensitive dry film with a thickness of approximately 0.5 to 10 micrometers was obtained.

[0041] Preparation of the copper plating bath: After mixing copper sulfate (2.5 g / mL) and formaldehyde (6 mL / L) to form a solution, the pH value was adjusted to approximately 12.5 to prepare the copper plating bath to be used for electroless copper plating.

[0042] Next, when the photosensitive dry film on the substrate was irradiated with UV light (185 & 254 nm, 80 W) for 15 minutes, not only did the color of the photosensitive dry film change, but it was also visually observed that black solid fine particles were being generated and adhering to it. Subsequently, the entire substrate was immersed in the copper plating bath for 10 minutes, and the temperature was controlled to 55°C to 60°C. Almost immediately, the substrate became even darker, and it was observed that a complete electroless copper plating reaction had started, along with the generation of bubbles. After 10 minutes of immersion plating, the glass substrate was no longer transparent due to the copper plating.

[0043] Experimental Example 2

[0044] The same preparation method as in Experimental Example 1 was used, but copper acetate in the composition solution for producing the photosensitive dry film was replaced with copper formate, and triethanolamine in the composition solution for producing the photosensitive dry film was replaced with ethanolamine (MEA) (chemical reagents provided by Alpha Acer, Merck, and Aldrich were used).

[0045] After UV light irradiation, the color of the photosensitive dry film changed, and it was observed that black solid particles were formed and adhering to it. After electroless plating, it was observed that the glass substrate was no longer transparent due to the copper plating.

[0046] Comparative Example 1

[0047] The same preparation method as in Experimental Example 1 was used, but the water-soluble polymer was not added to the composition solution for producing the photosensitive dry film, and the solvent was changed to ethanol (using chemical reagents provided by Alpha Acer, Merck, and Aldrich).

[0048] After UV light irradiation, the complex turned yellow. However, it was observed that most of the applied dry film disappeared after electroless plating. In other words, in Comparative Example 1, the photoelectric reduction reaction was not completed, and the unreacted complex detached from the substrate and dissolved in the copper plating bath. This indicates that simply adding the photocatalyst was insufficient to generate sufficiently active copper metal particles and was unable to effectively induce copper plating.

[0049] Comparative Example 2

[0050] The same preparation method as in Experimental Example 1 was used, but the photocatalytic precursor was not added to the composition solution for producing the photosensitive dry film, the proportion of PVA was set to 1.0 wt%, and the solvent was changed to ethanol.

[0051] After UV light irradiation and electroless plating, the copper plating phenomenon was not observed. In other words, in Comparative Example 2, since no photocatalytic particles were generated, the photoelectric reduction effect was insufficient, and basically, the deposition of catalyst fine particles did not form.

[0052] Experimental Example 3

[0053] First, we prepared compositional solutions for producing the following four groups of photosensitive dry films. (All of the raw materials below were chemical reagents provided by Alpha-Acer, Merck, and Aldrich.)

[0054] Group 1 (with photosensitizer added only): Copper formate (concentration: 0.1M), 2-aminoisobutanol, benzophenone and ethanol as photosensitizers, with an amine / Cu molar ratio of 2-aminoisobutanol to copper formate of 2.

[0055] Group 2 (Water-soluble polymers): Copper formate (concentration: 0.1M), 2-aminoisobutanol, PVA (concentration: 1.0 × 10⁻⁶) -2 M) and ethanol, and the amine / Cu molar ratio of 2-aminoisobutanol to copper formate is 2.

[0056] The third group (photocatalyst) consists of copper formate (concentration: 0.1M), 2-aminoisobutanol, 0.5 wt% titanium butoxide, and ethanol, with an amine / Cu molar ratio of 2-aminoisobutanol to copper formate of 2.

[0057] Group 4 (Water-soluble polymers and photocatalysts): Copper formate (concentration: 0.1M), 2-aminoisobutanol, titanium butoxide 0.5wt%, PVA (concentration: 1.0×10) -2 M) and ethanol, and the amine / Cu molar ratio of 2-aminoisobutanol to copper formate is 2.

[0058] Using the method of Experimental Example 1, a TiO2 adhesive layer was first formed on a glass substrate, and then a photosensitive dry film was formed using a composition solution from the four groups described above, each with a different photosensitive dry film. These films were then irradiated with UV light (185 & 254 nm, 80 W) for 20 minutes, but electroless plating was not performed.

[0059] UV-visible (UV-vis) transmittance tests were performed on the four groups of samples after light irradiation, and the results are shown in Figure 5.

[0060] Figure 5 shows the following: When only the photosensitizer was used, it did not contribute to the deposition of copper metal particles. When only the water-soluble polymer was added or only the photocatalyst (TiO2) was formed, a significant reaction began to appear with respect to UV light irradiation time. The reaction with UV light irradiation time was most significant when both the water-soluble polymer and the photocatalyst were present. Therefore, when 2-aminoisobutanol was used as a complexing agent and irradiated with UV light for 20 minutes, the light transmittance in the near-ultraviolet to visible light wavelength range (330 nm to 600 nm) was significantly reduced. These results indicate that the catalyst-forming composition of the present invention is sufficient to induce the deposition of a large amount of zero-valent copper metal particles and exhibits an effect of blocking light transmission.

[0061] Experimental Example 4

[0062] The same manufacturing method as in Experimental Example 3 was used, but the complexing agent was changed to ethylenediamine. The remaining raw materials, adhesive layer, and the method of forming the photosensitive dry film and irradiating it with light (for 10 minutes) were all the same as in Experimental Example 3.

[0063] Subsequently, transmittance tests were performed on the four sample groups after light irradiation, and the results are shown in Figure 6.

[0064] Similarly, as shown in Figure 6, adding only the photosensitizer did not contribute to the deposition of copper metal particles, and the light transmittance was lowest when the water-soluble polymer and photocatalyst were present simultaneously. Therefore, even when the complexing agent was changed, metal particles were deposited similarly after light irradiation. Furthermore, the light irradiation time in Experimental Example 4, which used ethylenediamine, was shorter than the 20 minutes in Experimental Example 3, resulting in an even lower transmittance. This indicates that each complexing agent exhibits a different efficiency in photoelectric reduction reactions based on the differences in chelating effects. As shown in this experiment, when ethylenediamine is used as a complexing agent, its photochemical reduction deposition effect may be superior to that of 2-aminoisobutanol.

[0065] Experimental Example 5

[0066] The same production method as in Experimental Example 4 was adopted, and only the light irradiation time was simply changed. Thereafter, transmittance tests were conducted on samples with different light irradiation times, and the results are shown in Fig. 7.

[0067] As can be seen from Fig. 7, the following can be understood. The transmittance changed due to the difference in the light irradiation time. Here, the transmittance when irradiated with light for 10 minutes was the lowest. When the light irradiation time exceeded 10 minutes, presumably due to the aggregation of copper metal particles, the transmittance increased slightly, but the difference in morphology did not affect the effect of the metal particles inducing electroless copper plating. That is, as long as an appropriate light irradiation time was selected, the result of catalyst formation could be achieved.

[0068] Experimental Example 6

[0069] First, a composition solution for generating a photosensitive dry film was prepared. The raw materials used were as follows. Metal salt compound: Palladium acetate Concentration: 0.03 M. Amine compound: Propylenediamine Concentration: 0.03 M. Propylenediamine to palladium acetate amine / Pd molar ratio 2. Photocatalyst precursor: Titanium butoxide (Ti(OBu)4) 0.5 wt%. Water-soluble polymer: PEG Concentration: 1.0×10 -2 M. Solvent: Isopropyl alcohol. (All of the above raw materials used chemical reagents provided by Alfa Aesar, Merck, and Aldrich)

[0070] Thereafter, 0.5 wt% of titanium butoxide was added to butanol to form a slurry, which was spin-coated onto a glass substrate at a speed of 2000 rpm, dried at 120°C, and calcined at 400°C in air for 1 hour to obtain a TiO2 adhesion layer with a thickness of about 2 to 20 nanometers.

[0071] Next, the composition solution for producing the photosensitive dry film was spin-coated onto the TiO2 adhesive layer of a glass substrate at a speed of 2000 rpm and dried at 120°C to obtain a photosensitive dry film with a thickness of approximately 0.5 to 10 micrometers. Another substrate equipped with the photosensitive dry film was fabricated by repeating the above process.

[0072] Next, photosensitive dry films on different substrates were irradiated with UV light (365 nm, 200 W) for 5 minutes and 10 minutes, respectively. The Pd complex showed a significant change after 5 minutes of light irradiation, confirming its catalytic activity for copper chemical deposition. Transmittance tests were performed on samples with different irradiation times, and the results are shown in Figure 8.

[0073] Figure 8 shows the following: When different metal salt compounds were used, metal particles precipitated in all cases after light irradiation. Furthermore, palladium is more photosensitive and photoreactive than copper, allowing for a reduction in the light irradiation time.

[0074] Experimental Example 7

[0075] First, a composition solution for producing a photosensitive dry film was prepared. The raw materials used were as follows: Metal salt compound: copper acetate. Concentration: 0.1M. Amine compound: Triethanolamine (TEA), concentration: 0.1M. The amine / Cu molar ratio of TEA to copper acetate is 2. Photocatalytic precursor: Titanium butoxide (Ti(OBu)4) 0.5 wt%. Water-soluble polymer: PVA Concentration: 0.5 × 10 -3 M. Solvent: Isopropyl alcohol. (All of the above raw materials use chemical reagents provided by Alpha-Acer, Merck & Co., and Aldrich.)

[0076] Pretreatment of glass substrate: A slurry was formed by adding 0.5 wt% titanium butoxide to butanol, which was then spin-coated onto a glass substrate at a speed of 2000 rpm, dried at 120°C, and fired in air at 400°C for 1 hour to obtain a TiO2 adhesive layer with a thickness of approximately 2 to 20 nanometers.

[0077] Preparation of the copper plating bath: After mixing copper sulfate (2.5 g / mL) and formaldehyde (6 mL / L) to form a solution, the pH value was adjusted to approximately 12.5 to form the copper plating bath to be used for electroless copper plating.

[0078] Next, the composition solution for producing the photosensitive dry film was spin-coated onto the TiO2 adhesive layer of a glass substrate at a speed of 2000 rpm, dried at 120°C, and a photosensitive dry film with a thickness of approximately 0.5 to 10 micrometers was obtained.

[0079] The substrate coated with the copper complex was dried in a 100°C oven for 5 minutes and covered with a stainless steel photomask. The photomask pattern consisted of parallel lines with line width / spacing L / S = 100 / 100 and 80 μm / 80 μm. After irradiation with UV light (185 & 254 nm, 80 W) for 15 minutes, the substrate was rinsed with deionized water (DI) to remove excess catalyst, and then the entire substrate was immersed in the copper plating bath for 10 minutes, with the temperature controlled at 55°C to 60°C.

[0080] Upon observation, it was found that precipitates were not fixed in the areas not irradiated with light, and by removing them with deionized water, a resolved pattern could be obtained. When limited to photomask sizes, after testing with L / S=100 / 100 and L / S=80 / 80, the pattern could be clearly resolved.

[0081] Experimental Example 8

[0082] First, a composition solution for producing a photosensitive dry film was prepared. The raw materials used were as follows: Metal salt compound: copper acetate. Concentration: 0.05 M. Amine compounds: (Group 1) 2-aminoisobutanol; (Group 2) isopropanolamine; (Group 3) 1-octylamine; (Group 4) ethylenediamine; (Group 5) propylenediamine. All concentrations are 0.15 M. The amine / Cu molar ratio of the amine compound to copper acetate is 3. Photocatalytic precursor: Titanium butoxide 0.5 wt%. Water-soluble polymer: PVP Concentration: 0.5 × 10 -3 M. Solvent: Ethanol. (All of the above raw materials use chemical reagents provided by Alpha-Acer, Merck & Co., and Aldrich.)

[0083] Pretreatment of glass substrate: A slurry was formed by adding 0.5 wt% titanium butoxide to butanol, which was then spin-coated onto a glass substrate at a speed of 2000 rpm, dried at 120°C, and fired in air at 400°C for 1 hour to obtain a TiO2 adhesive layer with a thickness of approximately 2 to 20 nanometers.

[0084] Next, five groups of photosensitive dry film compositions, each containing a different amine compound, were spin-coated onto a TiO2 adhesive layer on a glass substrate at a speed of 2000 rpm. The films were then dried at 120°C to obtain photosensitive dry films with a thickness of approximately 0.5 to 10 micrometers.

[0085] Preparation of the copper plating bath: After mixing copper sulfate (2.5 g / mL) and formaldehyde (6 mL / L) to form a solution, the pH value was adjusted to approximately 12.5 to form the copper plating bath to be used for electroless copper plating.

[0086] Next, when the photosensitive dry film on the substrate was irradiated with UV light (185 & 254 nm, 80 W) for 15 minutes, it was observed that the color of the photosensitive dry film changed, and black solid fine particles were formed and adhered to it. Subsequently, the entire substrate was immersed in the copper plating bath for 10 minutes, with the temperature controlled to 55°C to 60°C. It was observed that all five groups of composition solutions that produced photosensitive dry films, each containing a different amine compound, were able to form a copper metal layer by electroless plating after light irradiation. Therefore, it was verified that the type of complexing agent (amine compound) used in this test did not have a significant effect on the formation of copper metal particles, and that all of them could induce the reduction deposition of copper metal particles using the photoelectric reduction mechanism, and that the copper metal particles produced by each amine compound all had the activity to induce the deposition of electroless copper.

[0087] Although the present invention has been disclosed through embodiments described above, these are not intended to limit the invention, and any person with ordinary skill in the relevant art may make several changes and modifications without departing from the spirit and scope of the invention. Accordingly, the scope of protection of the present invention shall be determined by the scope of the appended patent application. [Industrial applicability]

[0088] The photosensitive dry film, the composition solution for producing it, and the electroless plating method for the metal layer of the present invention can all be applied to apparatus having an electroless metal plating layer. [Explanation of symbols]

[0089] 100: Structure after light irradiation 102: Photocatalyst 104: Metal particles 106: Water-soluble polymer 200: Circuit board 202: Adhesive layer 204: Photosensitive dry film 204': Local area 206: Photomask 208: Exposure 210: Metal layer 300: Patterned photosensitive dry film 300': Photosensitive dry film after exposure 302: Exposure 400: Barrier structure e - : electronic h + : Hole

Claims

1. A catalyst-forming composition comprising a metal complex and a water-soluble polymer, A photocatalyst, which is a precipitate obtained after drying the photocatalyst precursor, is dispersed in the catalyst-forming composition, Includes, The metal complex is a reactant formed by a complex reaction between an amine compound and a metal salt compound in a composition solution for producing a photosensitive dry film, wherein the ratio (number of moles of amino groups contained in the amine compound) / (number of moles of metal ions in the metal salt compound) is 1.5 to 10, and the metal ions are copper ions, palladium ions, or silver ions in the photosensitive dry film.

2. The aforementioned photosensitive dry film is formed by applying and drying a composition solution that produces the photosensitive dry film. The photosensitive dry film according to claim 1.

3. The aforementioned photocatalyst includes titanium dioxide, zinc oxide, or a combination thereof. The photosensitive dry film according to claim 1.

4. The content of the photocatalyst is 1% to 70% based on the total weight of the photosensitive dry film. The photosensitive dry film according to claim 1.

5. Metal salt compounds, An amine compound as a complexing agent, wherein the ratio (number of moles of amino groups contained in the amine compound) / (number of moles of metal ions in the metal salt compound) is 1.5 to 10, and the metal ions are copper ions, palladium ions, or silver ions. Photocatalytic precursor and Water-soluble polymers, Solvents and, A compositional solution containing the following to produce a photosensitive dry film.

6. The aforementioned metal salt compound is a mixture of one or more selected from the group consisting of sulfates, nitrates, acetates, formates, and chlorides of copper, palladium, or silver. A compositional solution for producing the photosensitive dry film described in claim 5.

7. The amine compound is at least one selected from the group consisting of ethanolamine, triethanolamine, ethylenediamine, propylenediamine (1,2-diaminopropane), dimethylamine, 2-aminoisobutanol (2-amino-2-methyl-1-propanol), isopropanolamine (1-amino-2-propanol), and 1-octylamine. A compositional solution for producing the photosensitive dry film described in claim 5.

8. The water-soluble polymer includes polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polyethyleneimine (PEI), methylcellulose, gelatin, starch, chitosan, or a combination thereof. A compositional solution for producing the photosensitive dry film described in claim 5.

9. The aforementioned photocatalytic precursor includes titanium isopropoxide, titanium butoxide, zinc methoxide, zinc propoxide, or a combination thereof. A compositional solution for producing the photosensitive dry film described in claim 5.

10. The content of the photocatalytic precursor is 0.1% to 3.0% based on the total weight of the aforementioned composition solution. A compositional solution for producing the photosensitive dry film described in claim 5.

11. To prepare a composition solution for producing a photosensitive dry film according to any one of claims 5 to 10, comprising a metal salt compound, an amine compound as a complexing agent, a photocatalytic precursor, a water-soluble polymer, and a solvent, To provide a substrate and to form an adhesive layer on the substrate, Applying the composition solution to the surface of the adhesive layer, The process involves drying the aforementioned composition solution to form a photosensitive dry film, wherein the photosensitive dry film comprises a catalyst-forming composition and a photocatalyst dispersed in the catalyst-forming composition, the catalyst-forming composition comprises a metal complex and the water-soluble polymer, and the photocatalyst is a precipitate obtained after drying the photocatalyst precursor. The photosensitive dry film is exposed to light to induce the photocatalyst, generate electron-holes, and provide electrons from the electron-holes to the metal salt compound, thereby reducing the metal complex on the surface of the photocatalyst and generating metal particles. Using the aforementioned metal particles as a catalyst, electroless plating is performed to form a metal layer, A method for electroless plating of a metal layer, including the following:

12. The metal complex is formed by a complex reaction between the amine compound and the metal salt compound in the composition solution, and in the photosensitive dry film, the ratio (number of moles of amino groups contained in the amine compound) / (number of moles of metal ions in the metal salt compound) is 1.5 to 10. The electroless plating method for a metal layer according to claim 11.

13. The aforementioned metal layer includes a copper layer. The electroless plating method for a metal layer according to claim 11.

14. The exposure step includes reducing the metal ions in the metal complex within the photocatalyst to form the metal particles, and doping the metal particles into the photocatalyst. The electroless plating method for a metal layer according to claim 11.

15. The method for applying the composition solution includes screen printing, inkjet printing, or gravure printing for forming a pattern on the surface of the adhesive layer. The electroless plating method for a metal layer according to claim 11.

16. The method for exposing the localized area of ​​the photosensitive dry film includes selectively reducing and depositing the metal particles using a photomask or digital exposure method. The electroless plating method for a metal layer according to claim 11.

17. The process further includes exposing the localized area of ​​the photosensitive dry film and then removing the unexposed portion of the photosensitive dry film other than the localized area. The electroless plating method for a metal layer according to claim 11.

18. The process further includes forming a barrier structure on the surface of the photosensitive dry film after it has formed, thereby exposing a localized area of ​​the photosensitive dry film. The electroless plating method for a metal layer according to claim 11.

19. The adhesive layer and the photocatalyst are made of the same or different materials. The electroless plating method for a metal layer according to claim 11.

20. The molar concentration of the metal salt compound is 0.01 M to 0.2 M. The electroless plating method for a metal layer according to claim 11.

21. The ratio of (the number of moles of amino groups contained in the amine compound) to (the number of moles of metal ions in the metal salt compound) is 1.5 to 10. The electroless plating method for a metal layer according to claim 11.

22. The concentration of the water-soluble polymer is 0.5 × 10 －３ M ~ 1.0 x 10 －１ It is M. The electroless plating method for a metal layer according to claim 11.

23. The content of the photocatalytic precursor is 0.1% to 3.0% based on the total weight of the aforementioned composition solution. The electroless plating method for a metal layer according to claim 11.

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