Photosensitive dry film, composition solution for producing same, and method for electroless plating of metal layer

Abstract

The invention provides a photosensitive dry film, a composition solution for generating the photosensitive dry film and a method for electroless plating of a metal layer. The photosensitive dry film comprises a composition for forming a catalyst and a photocatalyst, and the composition for forming the catalyst comprises a metal complex and a water-soluble polymer. The photocatalyst is dispersed in the composition for forming the photocatalyst, and the photocatalyst is a precipitate of a photocatalyst precursor. According to the photosensitive dry film, the composition solution is dried, exposed and developed, the photocatalyst is separated out firstly, then the photocatalyst is triggered to generate electrons-holes, and metal particles are generated on the surface of the photocatalyst through reduction. And carrying out chemical plating by taking the metal particles as a catalyst to form a metal layer.

Description

Technical Field

[0001] The present invention relates to an electroless plating technique, 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 Art

[0002] In electroless plating, metallic palladium is usually used as a seed to trigger the reaction. However, the price of metallic palladium is high, and replacing it with other materials has always been a trend in technological development. Especially for electroless copper plating using formaldehyde as a reducing agent, based on the comparison of oxidation potentials, the catalytic activity order of various metals is deduced as: Cu>Au>Ag>Pt>Pd>Ni>Co.

[0003] Therefore, electroless copper plating with copper as a catalyst should have relatively high activity advantages. However, the reason why copper is not commonly used as a catalyst is that it is difficult and the benefits are not obvious. For example, using pre-reacted copper metal particles as a catalyst has many disadvantages. One is the high cost; the other is the difficulty in storage: such as surface oxidation or easy agglomeration of particles, so complex procedures such as redispersion are required in use. If copper metal particles are generated in-situ in ionic form, since they are easily oxidized and lose activity, they are not as simple as noble metals such as Pd or Ag, and the traditional wet sensitization / displacement method cannot be used. Summary of the Invention

[0004] The present invention is directed to a photosensitive dry film having a composition capable of triggering in-situ reduction by light energy to generate catalyst metal particles.

[0005] The present invention also relates to a composition solution for producing a photosensitive dry film, which can be used to form the above dry film.

[0006] The present invention further relates to a method for electroless plating a metal layer, which can define a catalyst pattern by light, having metal particles formed on the surface of a photocatalyst as a patterned catalyst, and sequentially triggering an electroless plating metal reaction to fabricate a conductor line.

[0007] According to an embodiment of the present invention, a photosensitive dry film includes a composition for forming a catalyst and a photocatalyst. The composition for forming a catalyst includes a metal complex and a water-soluble polymer. The photocatalyst is dispersed in the composition for forming a catalyst, and the photocatalyst is a precipitate after drying of a photocatalyst precursor.

[0008] According to another embodiment of the present invention, a composition solution for producing a photosensitive dry film includes a metal salt compound, an amino compound as a complexing agent, a photocatalyst precursor, a water-soluble polymer, and a solvent.

[0009] According to another embodiment of the present invention, a method for electroless plating a metal layer includes preparing the above-mentioned composition solution for generating a photosensitive dry film, providing a substrate and forming an adhesive layer on the substrate, coating the composition solution for generating a photosensitive dry film on the surface of the adhesive layer, and drying to form a photosensitive dry film. The photosensitive dry film includes a composition for forming a catalyst and a photocatalyst dispersed in the composition for forming a catalyst. The composition for forming a catalyst includes a metal complex and a water-soluble polymer, and the photocatalyst is a precipitate formed after drying of a photocatalyst precursor. Then, a local area or all areas of the photosensitive dry film are exposed to light to trigger the photocatalyst to produce electron-hole pairs and reduce the metal complex on the surface of the photocatalyst to generate metal particles, and then the metal particles are used as a catalyst for electroless plating to form a metal layer.

[0010] Based on the above, the present invention adopts a photo-electrical reduction method, and uses a photocatalyst as a carrier to provide electron-hole pairs, so that the electrons required for the reduction reaction can be generated by light energy. Moreover, the present invention also uses a water-soluble polymer as a hole scavenger to achieve energy transfer and balance, and at the same time as an anti-oxidative protection for the newly generated metal particles to avoid excessive oxidation. After irradiation, the precipitated metal particles (catalysts) are embedded on the surface of the photocatalyst and fixed on the substrate. The unirradiated parts are still in an ionic state and can be removed by a cleaning agent. Therefore, a pattern of catalyst seeds is defined by light, and the reaction of electroless plating metal can be continuously triggered to fabricate a conductor line. Description of the Drawings

[0011] Figure 1 It is a schematic diagram of the reaction occurring during the irradiation of a photosensitive dry film according to an embodiment of the present invention.

[0012] Figure 2 It is a schematic cross-sectional view of the process of electroless plating a metal layer according to another embodiment of the present invention.

[0013] Figure 3 It is a schematic cross-sectional view of the process of electroless plating a metal layer according to still another embodiment of the present invention.

[0014] Figure 4 It is a schematic cross-sectional view of the process of electroless plating a metal layer according to yet another embodiment of the present invention.

[0015] Figure 5 It is a graph showing the relationship between wavelength and transmittance under different conditions in Experimental Example 3 of the present invention.

[0016] Figure 6It is a graph showing the relationship between wavelength and transmittance under different conditions in Experimental Example 4 of the present invention.

[0017] Figure 7 It is a graph showing the relationship between wavelength and transmittance under different conditions in Experimental Example 5 of the present invention.

[0018] Figure 8 It is a graph showing the relationship between wavelength and transmittance under different conditions in Experimental Example 6 of the present invention.

[0019] Explanation of Reference Numerals

[0020] 100: Structure after light irradiation

[0021] 102: Photocatalyst

[0022] 104: Metal fine particles

[0023] 106: Water-soluble polymer

[0024] 200: Substrate

[0025] 202: Adhesive layer

[0026] 204: Photosensitive dry film

[0027] 204’: Local area

[0028] 206: Photomask

[0029] 208: Exposure

[0030] 210: Metal layer

[0031] 300: Patterned photosensitive dry film

[0032] 300’: Photosensitive dry film after exposure

[0033] 400: Dam structure

[0034] e - : Electron

[0035] h + : Hole Detailed Description of the Invention

[0036] A photosensitive dry film according to an embodiment of the present invention includes a composition for forming a catalyst and a photocatalyst.

[0037] The aforementioned photocatalyst is a solid matter that first precipitates during the drying process of a composition solution for forming a photosensitive dry film, and is dispersed in the composition for forming a catalyst.

[0038] In this embodiment, the composition for forming a catalyst includes a metal complex and a water-soluble polymer, and the metal complex remains after the composition solution for forming a photosensitive dry film is dried.

[0039] The aforementioned photosensitive dry film is obtained by coating and drying the composition solution for forming a photosensitive dry film. The composition solution is mixed with a metal salt compound, an amine compound as a complexing agent, a water-soluble polymer, a photocatalyst precursor, and a solvent. The composition solution is coated on a substrate, and after drying, photocatalyst particles are precipitated on the substrate, and the composition for forming a catalyst remains. The formed photocatalyst particles are dispersed in the composition for forming a catalyst. The metal complex in the above composition for forming a catalyst is formed by the complexation reaction of the amine compound and the metal salt compound in the composition solution.

[0040] The above metal salt compound may be one or a mixture of more than one of sulfates, nitrates, acetates, formates, and chlorides of nickel (Ni), copper (Cu), palladium (Pd), and silver (Ag). For example, the metal salt compound is 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), 1,2-diaminopropane, dimethylamine, 2-amino-2-methyl-1-propanol (AMP), 1-amino-2-propanol, and 1-octylamine. The amine compound as a complexing agent can form a metal complex with the metal salt compound.

[0041] In one embodiment, the molar concentration ratio of the total amino groups of the above-mentioned amino compound to the metal ions of the above-mentioned metal salt compound is between 1.5 and 10, such as 1.5 to 4 or 2 to 4. However, the present invention is not limited thereto. Depending on different metal salt compounds or amino compounds, the above molar ratio may be lower or higher, mainly depending on whether the formed complex can be reduced by photoelectric action and has the stability for storage at room temperature. The formed complex is supplied for the subsequent reduction and precipitation of metal particles (catalysts) in the dry film state. The above-mentioned water-soluble polymers include but are not limited to polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), polyethyleneimine (PEI), methylcellulose, gelatin, starch, chitosan, or combinations thereof.

[0042] In this embodiment, the above-mentioned photocatalyst is the precipitate produced by the photocatalyst precursor during the drying process. The aforementioned photocatalysts include but are not limited to titanium dioxide (TiO2), zinc oxide (ZnO), or combinations thereof. In one embodiment, based on the total weight (weight percentage) of the photosensitive dry film, the content of the photocatalyst is, for example, between 1% and 70%.

[0043] In this embodiment, the above-mentioned photocatalyst precursors include but are not limited to titanium isopropoxide, titanium butoxide, zinc methoxide, zinc n-propoxide, or combinations thereof. In one embodiment, based on the total weight (weight percentage) of the composition solution, the content of the photocatalyst precursor is between 0.1% and 3.0%. As for the solvent of the composition solution, known solvents such as methanol, ethanol, water, etc. can be used, but the present invention is not limited thereto.

[0044] The above-mentioned photosensitive dry film exists in a state of being dispersed in the composition in the form of photocatalyst particles before being irradiated with light (such as UV light), and after being irradiated with light as Figure 1 shown, Figure 1 the left is the structure 100 after being irradiated with light, Figure 1 and the right is a partial enlarged schematic diagram of the left figure.

[0045] Please refer to Figure 1 , after being irradiated with light, the photocatalyst 102 will generate electron-hole pairs, where the electron e- Complex ions will be provided to force metal ions to be reduced to metallic particles 104 with a valence of 0 on the surface of the photocatalyst 102 or doped in the photocatalyst 102 (not shown); holes h generated during the process + are absorbed by the water-soluble polymer 106 coated on the periphery. On the one hand, during the absorption process, as a sacrificial acceptor, it undergoes oxidation by holes and decomposes into CO, CO2, H2O, etc.; on the other hand, it can protect the nascent metallic particles 104 in the core. In other words, in this embodiment, the photocatalyst 102 is used as a carrier

[0046] (carrier), and the water-soluble polymer 106 is used to protect the newly formed metallic particles 104 (anti-oxidative protection), and at the same time as a hole-scavenger for holes, forming a complete energy transfer. In this way, the electrons e - and holes h + are both absorbed by receptors, reducing the probability of ineffective self-recombination, constituting favorable conditions for the light-induced precipitation of metallic particles 104, and achieving the purpose of in-situ reduction and generation.

[0047] Therefore, during the formation process of the catalyst (metallic particles 104) in this embodiment, only by irradiating light can the reduction of metal ions be triggered, and no chemical reducing agent is required.

[0048] Figure 2 It is a schematic cross-sectional view of the process of electroless plating a metal layer according to another embodiment of the present invention.

[0049] Please refer to Figure 2, the method for electroless metal plating layer in this embodiment is to first prepare a composition solution for generating a photosensitive dry film. The composition solution for generating the photosensitive dry film is as described above, including a metal salt compound, an amino compound, a photocatalyst precursor, a water-soluble polymer, and a solvent. The metal salt compound can be one or a mixture of several in the group consisting of sulfates, nitrates, acetates, formates, and chlorides of nickel, copper, palladium, and silver. The amino compound can be at least one selected from the group consisting of ethanolamine, triethanolamine, ethylenediamine, propylenediamine, dimethylamine, 2-amino isobutanol, isopropanolamine, and 1-octylamine. The photocatalyst precursor can be exemplified but not limited to titanium isopropoxide, titanium butoxide, zinc methanol, zinc propanol, or a combination thereof. The water-soluble polymer can be exemplified but not limited to polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyethyleneimine, methylcellulose, gelatin, starch, chitin, or a combination thereof. In one embodiment, the molar concentration of the above metal salt compound is between 0.01M and 0.2M. In one embodiment, the molar concentration ratio of the total amino groups of the above amino compound to the metal ions of the above metal salt compound is between 1.5 and 10. In one embodiment, the concentration of the above water-soluble polymer is between 0.5×10 -3 M and 1.0×10 -1 M. In one embodiment, based on the total weight of the composition solution for generating the photosensitive dry film, the content of the photocatalyst precursor is between 0.1% and 3.0%.

[0050] Then, an adhesion layer 202 is formed on the substrate 200, where the adhesion layer 202 and the photocatalyst formed subsequently can be made of the same or different materials; if they are made of the same material, it is beneficial for the photocatalyst to adhere to the surface of the adhesion layer. For example, the adhesion layer 202 can be titanium dioxide, zinc oxide, silane self-assembly monolayer (SAM), polydopamine, etc. Then, the composition solution for generating the photosensitive dry film is coated on the surface of the adhesion layer 202, and after drying, a photosensitive dry film 204 is formed, and photocatalyst particles are precipitated in the photosensitive dry film 204.

[0051] Next, the local area or the entire area of the photosensitive dry film 204 can be exposed. For example, in the way of using a photomask 206 or digital exposure, the local area 204' of the photosensitive dry film 204 is exposed 208 to trigger the photocatalyst in the photosensitive dry film 204 to produce electrons and holes, and thus reduce the metal particles in the metal complex on the surface of the photocatalyst, achieving the effect of selectively reducing and precipitating metal particles. In addition, when exposure is carried out, in addition to reducing metal particles on the surface of the photocatalyst, metal ions in the metal complex are also reduced in the photocatalyst, and the metal particles are doped to form a mixed doping structure in the photocatalyst.

[0052] Since the photocatalyst in the unexposed photosensitive dry film 204 does not generate electron-hole pairs, metal complexes and water-soluble polymers that can be removed by a cleaning agent still exist in the composition for forming the catalyst here. Therefore, the unexposed photosensitive dry film 204 outside the local area 204' can be removed by means such as a cleaning agent. At the same time, the unreacted metal complexes and water-soluble polymers in the local area 204' will also be removed, leaving metal particles and the photocatalyst. For example, deionized water (DI) can be used for rinsing; or an aqueous solution containing an amino compound (such as triethanolamine (TEA), diethanolamine (DEA), etc.) with the ability to chelate Pd can be used, which has a better effect. Then, using the metal particles precipitated in the local area 204' as a catalyst, electroless plating is carried out to form a metal layer 210, and the metal layer 210 can be a copper layer or a nickel layer. The patterned circuit layer after electroless plating includes the metal layer 210 and the patterned catalyst layer (i.e., the catalyst in the local area 204').

[0053] According to the method of this embodiment, a photosensitive dry film 204 can be formed on the substrate 200, and then the catalyst (metal particles) is precipitated by exposure 208 when electroless plating is required. Therefore, the situation of catalyst oxidation can be significantly reduced, and copper metal particles with lower cost can be used as the catalyst for electroless copper plating. In another embodiment, palladium metal particles can be used as the catalyst for electroless nickel plating.

[0054] Figure 3 It is a schematic cross-sectional view of a process for electroless plating a metal layer according to another embodiment of the present invention, where the same or similar parts and components are denoted by the same reference numerals as in the previous embodiment, and the relevant content of the same or similar parts and components can also be referred to the content of the previous embodiment and will not be repeated.

[0055] Please refer to Figure 3 , the difference between the method of this embodiment and the previous embodiment is that after forming the adhesive layer 202 on the substrate 200, the composition solution for generating the photosensitive dry film can be made into an ink, and by means of screen printing, inkjet printing, gravure printing, etc., a patterned photosensitive dry film 300 is directly formed on the surface of the adhesive layer 202. Therefore, subsequently, as long as overall exposure 302 is carried out without equipment such as a photomask, the photocatalyst in the patterned photosensitive dry film 300 can be induced to produce electron-hole pairs, and thus metal particles are reduced on the surface of the photocatalyst to obtain the exposed photosensitive dry film 300'. Then, using the metal particles precipitated in the exposed photosensitive dry film 300' as a catalyst, electroless plating can be carried out to form the metal layer 210.

[0056] Figure 4 It is a schematic cross-sectional view of a process for electroless plating a metal layer according to another embodiment of the present invention, where the same as Figure 2The same component symbols as those in the embodiments are used to represent the same or similar parts and components, and the relevant content of the same or similar parts and components can also be referred to Figure 2 the content of the embodiments, which will not be elaborated here.

[0057] Please refer to Figure 4 , the difference between the method of this embodiment and Figure 2 the embodiments is that after forming an adhesive layer 202 on the substrate 200 and coating and drying a composition solution for generating a photosensitive dry film on the surface of the adhesive layer 202, a dam structure 400 is additionally formed on the surface of the photosensitive dry film 204, and a part of the photosensitive dry film 204 is exposed. The dam structure 400 is made of a photosensitive polymer such as photoresist or patternable photosensitive polyimide (PSPI), and the formation method of the dam structure 400 is, for example, but not limited to, screen printing, inkjet printing or yellow light lithography.

[0058] After that, the entire area of the photosensitive dry film 204 is exposed 302 to trigger the photocatalyst in the photosensitive dry film 204 to produce electrons - holes, and metal particles are reduced and precipitated on the surface of the photocatalyst in the local area 204'.

[0059] Then, using the metal particles precipitated in the local area 204' as a catalyst, electroless plating is carried out to form a metal layer 210. The dam structure 400 can be retained after electroless plating. Since this embodiment has the dam structure 400, the metal layer 210 can be kept in a set area through the dam structure 400. Therefore, the method of this embodiment is applicable to metal layer patterns with higher resolution requirements.

[0060] The following lists several experiments to verify the efficacy of the present invention, but the present invention is not limited to the following content.

[0061] Experimental Example 1

[0062] First, a composition solution for generating a photosensitive dry film is prepared. The raw materials used are as follows:

[0063] Metal salt compound: Copper acetate, concentration: 0.1M.

[0064] Amino compound: Triethanolamine (TEA), concentration: 0.1M.

[0065] The amine / Cu molar ratio of TEA to copper acetate is between 3.

[0066] Photocatalyst precursor: Titanium butoxide (Ti(OBu)4) 0.5wt%.

[0067] Water-soluble polymer: PVA, 0.5 wt%.

[0068] Solvent: methanol.

[0069] (All of the above raw materials use chemical reagents provided by Alfa Aesar, Merck, and Aldrich pharmaceutical factories)

[0070] Pretreatment of the glass substrate: Add 0.5 wt% of titanium butoxide to butanol to form a slurry, and spin-coat it on the glass substrate at a speed of 2000 rpm. After drying at 120°C and calcining at 400°C in air for one hour, a TiO2 adhesion layer with a thickness of about 2 to 20 nanometers is obtained.

[0071] Next, spin-coat the composition solution for generating the photosensitive dry film on the TiO2 adhesion layer of the glass substrate at a speed of 2000 rpm, and dry it at 120°C to obtain a photosensitive dry film with a thickness of about 0.5 to 10 micrometers.

[0072] Prepare the copper plating bath: Mix copper sulfate (2.5 g / mL) and formaldehyde (6 mL / L) to form a solution, and adjust its pH value to about 12.5 to form the copper plating bath for electroless copper plating.

[0073] Next, irradiate the photosensitive dry film on the substrate with UV light (185 & 254 nm, 80 W) for 15 minutes. It can be observed visually that not only does the color of the photosensitive dry film change, but also black solid particles adhere to it. Then, immerse the entire substrate in the above copper plating bath for 10 minutes, and control the temperature at 55°C to 60°C. After observation, the substrate is almost immediately further darkened, accompanied by the generation of bubbles, and a comprehensive electroless copper plating reaction is successfully initiated. After immersion for 10 minutes, the copper plating has made the glass substrate no longer transparent.

[0074] Experimental Example 2

[0075] Adopt the same preparation method as in Experimental Example 1, but change copper acetate in the composition solution for generating the photosensitive dry film to copper formate, and change triethanolamine in the composition solution for generating the photosensitive dry film to monoethanolamine (MEA) (using chemical reagents provided by Alfa Aesar, Merck, and Aldrich pharmaceutical factories).

[0076] After irradiation with UV light, it is also observed that the color of the photosensitive dry film changes, and black solid particles adhere to it. After electroless plating, it is observed that the copper plating has made the glass substrate no longer transparent.

[0077] Comparative Example 1

[0078] The same preparation method as in Experimental Example 1 was adopted, but no water-soluble polymer was added to the composition solution for generating the photosensitive dry film, and the solvent was changed to ethanol (using chemical reagents provided by Alfa Aesar, Merck, and Aldrich pharmaceutical factories).

[0079] After UV light irradiation, the complex turned yellow. However, most of the coated dry film was observed to have disappeared after electroless plating. In other words, in Comparative Example 1, the photoelectrochemical reduction reaction was not completed, causing the unreacted complex to detach from the substrate and dissolve into the copper plating bath. Therefore, it can be obtained that simply adding a photocatalyst is not sufficient to generate copper metal particles with sufficient activity to effectively trigger copper plating.

[0080] Comparative Example 2

[0081] The same preparation method as in Experimental Example 1 was adopted, but no photocatalyst precursor was added to the composition solution for generating the photosensitive dry film, the proportion of PVA was 1.0 wt%, and the solvent was changed to ethanol.

[0082] After UV light irradiation and electroless plating, no sign of copper plating was observed. In other words, in Comparative Example 2, since no photocatalyst particles were generated and there was a lack of photoelectrochemical reduction, the precipitation of catalyst particles was basically not formed.

[0083] Experimental Example 3

[0084] First, prepare the following four groups of composition solutions for generating photosensitive dry films. (The following raw materials are all using chemical reagents provided by Alfa Aesar, Merck, and Aldrich pharmaceutical factories)

[0085] The first group (only adding a photosensitizer): copper formate (concentration: 0.1 M), 2-amino-2-methyl-1-propanol, benzophenone as a photosensitizer, and ethanol, where the amine / Cu molar ratio of 2-amino-2-methyl-1-propanol to copper formate is 2.

[0086] The second group (water-soluble polymer): copper formate (concentration: 0.1 M), 2-amino-2-methyl-1-propanol, PVA (concentration: 1.0×10 - 2 M), and ethanol, where the amine / Cu molar ratio of 2-amino-2-methyl-1-propanol to copper formate is 2.

[0087] The third group (photocatalyst): copper formate (concentration: 0.1 M), 2-amino-2-methyl-1-propanol, 0.5 wt% titanium butoxide, and ethanol, where the amine / Cu molar ratio of 2-amino-2-methyl-1-propanol to copper formate is 2.

[0088] The fourth group (water-soluble polymer and photocatalyst): copper formate (concentration: 0.1 M), 2-amino-2-methyl-1-propanol, 0.5 wt% titanium butoxide, PVA (concentration: 1.0×10 -2M) and ethanol, where the amine / Cu molar ratio of 2-aminoisobutanol to copper formate is 2.

[0089] In the same manner as in Experimental Example 1, a TiO2 underlayer was first formed on a glass substrate, and then photosensitive dry films were respectively formed using the above four groups of different compositions of the photosensitive dry film-forming solution, and irradiated with UV light (185&254 nm, 80 W) for 20 minutes, but without electroless plating.

[0090] The four groups of samples after irradiation were taken for ultraviolet-visible (UV-vis) transmittance testing, and the results showed that Figure 5 .

[0091] From Figure 5 it can be obtained that the simple use of a photosensitizer makes no contribution to the precipitation of copper metal particles; only adding a water-soluble polymer or only forming a photocatalyst (TiO2) starts to have a more obvious reaction to the UV light irradiation time; and when the water-soluble polymer and the photocatalyst coexist, the reaction to the UV light irradiation time is the most obvious. Therefore, after using 2-aminoisobutanol as a complexing agent and irradiating with UV light for 20 minutes, a significant reduction in light transmittance can be achieved in the near-ultraviolet to visible light wavelength range (330 nm - 600 nm). Such results show that the composition for forming a catalyst of the present invention is sufficient to induce the precipitation of a large amount of zero-valent copper metal particles, thus producing an effect of blocking light penetration.

[0092] Experimental Example 4

[0093] The same preparation method as in Experimental Example 3 was adopted, but the complexing agent was changed to ethylenediamine, and the other raw materials, the method of forming the underlayer, the photosensitive dry film, and the irradiation (for 10 minutes) were the same as in Experimental Example 3.

[0094] Then, the four groups of samples after irradiation were taken for transmittance testing, and the results showed that Figure 6 .

[0095] From Figure 6 it can also be observed that the simple addition of a photosensitizer makes no contribution to the precipitation of copper metal particles, and under the condition that the water-soluble polymer and the photocatalyst coexist, the light transmittance is the lowest. Therefore, even if the complexing agent is changed, metal particles will be precipitated after irradiation. Moreover, the irradiation time in Experimental Example 4 using ethylenediamine is shorter than 20 minutes in Experimental Example 3, and the transmittance is even lower, indicating that different complexing agents exhibit different efficiencies of photoreduction reactions due to different chelating effects. As shown in this example, the effect of photoreductive precipitation using ethylenediamine as a complexing agent may be preferred compared to 2-aminoisobutanol.

[0096] Experimental Example 5

[0097] The same preparation method as in Experimental Example 4 was adopted, but only the light irradiation time was changed. Then, the samples with different light irradiation times were taken for transmittance testing, and the results are shown in Figure 7 .

[0098] From Figure 7 it can be obtained that the transmittance will change with different light irradiation times, and the transmittance of the 10-minute light irradiation is the lowest. After the light irradiation time exceeds 10 minutes, the transmittance may increase slightly due to the aggregation of copper metal particles, but the difference in morphology does not affect the effect of the metal particles triggering electroless copper plating. In other words, as long as an appropriate light irradiation time is selected, the result of catalyst formation can be achieved.

[0099] Experimental Example 6

[0100] First, a composition solution for generating a photosensitive dry film was prepared. The raw materials used are as follows:

[0101] Metal salt compound: Palladium acetate, concentration: 0.03 M.

[0102] Amino compound: Propylenediamine, concentration: 0.03 M.

[0103] The amine / Pd molar ratio of propylenediamine to palladium acetate is 2.

[0104] Photocatalyst precursor: Titanium butoxide (Ti(OBu)4) 0.5 wt%.

[0105] Water-soluble polymer: PEG, concentration: 1.0×10 -2 M.

[0106] Solvent: Isopropyl alcohol.

[0107] (All of the above raw materials use chemical reagents provided by Alfa Aesar; Merck; Aldrich pharmaceutical factories)

[0108] Then, 0.5 wt% of titanium butoxide was added to butanol to form a slurry, and it was spin-coated on a glass substrate at a speed of 2000 rpm, dried at 120 °C, and calcined at 400 °C in air for one hour to obtain a TiO2 adhesion layer with a thickness of about 2 to 20 nanometers.

[0109] Next, the composition solution for generating the photosensitive dry film was spin-coated on the TiO2 adhesion layer of the glass substrate at a speed of 2000 rpm and dried at 120 °C to obtain a photosensitive dry film with a thickness of about 0.5 to 10 micrometers. The above process was repeated to fabricate another substrate with a photosensitive dry film.

[0110] Next, the photosensitive dry film on different substrates was irradiated with UV light (365 nm, 200 W) for 5 minutes and 10 minutes respectively. It was observed that there were obvious changes in the Pd complex after 5 minutes of light irradiation, confirming that it had the catalytic activity for chemical copper deposition. The samples with different light irradiation times were taken for transmittance testing, and the results showed that in Figure 8 .

[0111] From Figure 8 it can be obtained that by replacing different metal salt compounds, metal particles will precipitate after light irradiation. Moreover, because the photosensitivity of palladium is greater than that of copper and the photoreactivity is stronger, the light irradiation time can be shortened.

[0112] Experimental Example 7

[0113] First, a composition solution for generating a photosensitive dry film was prepared. The raw materials used were as follows:

[0114] Metal salt compound: Copper acetate, concentration: 0.1 M.

[0115] Amino compound: Triethanolamine (TEA), concentration: 0.1 M.

[0116] The amine / Cu molar ratio of TEA to copper acetate was 2.

[0117] Photocatalyst precursor: Titanium butoxide (Ti(OBu)4) 0.5 wt%.

[0118] Water-soluble polymer: PVA, concentration: 0.5×10 -3 M.

[0119] Solvent: Isopropyl alcohol.

[0120] (All of the above raw materials used chemical reagents provided by Alfa Aesar; Merck; Aldrich Pharmaceutical Factory)

[0121] Pretreatment of the glass substrate: 0.5 wt% of titanium butoxide was added to butanol to form a slurry, which was spin-coated on the glass substrate at a speed of 2000 rpm, dried at 120 °C and calcined at 400 °C in air for one hour to obtain a TiO2 adhesion layer with a thickness of about 2 to 20 nanometers.

[0122] Prepare a copper plating bath: Copper sulfate (2.5 g / mL) and formaldehyde (6 mL / L) were mixed to form a solution, and its pH value was adjusted to about 12.5 to form a copper plating bath for electroless copper plating.

[0123] Next, the composition solution for generating a photosensitive dry film was spin-coated on the TiO2 adhesion layer of the glass substrate at a speed of 2000 rpm and dried at 120 °C to obtain a photosensitive dry film with a thickness of about 0.5 to 10 micrometers.

[0124] The substrate coated with the copper complex is dried in an oven at 100 °C for 5 minutes, covered with a stainless-steel photomask. The pattern of the photomask is parallel lines with a line width / line pitch L / S = 100 / 100 and 80 μm / 80 μm. After being irradiated with UV light (185 & 254 nm, 80 W) for 15 minutes, it is rinsed with deionized water (DI) to remove the excess catalyst, and then the whole substrate is immersed in the above copper plating bath for 10 minutes, with the temperature controlled at 55 °C to 60 °C.

[0125] Upon observation, in the non-irradiated areas, since there are no precipitates adhering, they can be removed by deionized water, obtaining the resolved pattern. Limited by the size of the photomask, through experiments at L / S = 100 / 100 and L / S = 80 / 80, the pattern can be clearly resolved.

[0126] Experimental Example 8

[0127] First, a composition solution for generating a photosensitive dry film is prepared. The raw materials used are as follows:

[0128] Metal salt compound: Copper acetate, concentration: 0.05 M.

[0129] Amino compounds: (First group) 2-Aminoisobutanol; (Second group) Isopropanolamine; (Third group) 1-Octylamine; (Fourth group) Ethylenediamine; (Fifth group) Propylenediamine, with concentrations all being 0.15 M.

[0130] The amine / Cu molar ratio of the amino compound to copper acetate is 3.

[0131] Photocatalyst precursor: Titanium butoxide 0.5 wt%.

[0132] Water-soluble polymer: PVP, concentration: 0.5×10 -3 M.

[0133] Solvent: Ethanol.

[0134] (All of the above raw materials use chemical reagents provided by Alfa Aesar; Merck; Aldrich pharmaceutical factories)

[0135] Pretreatment of the glass substrate: Titanium butoxide 0.5 wt% is added to butanol to form a slurry, and it is spin-coated on the glass substrate at a speed of 2000 rpm. After drying at 120 °C and calcining in air at 400 °C for one hour, a TiO2 adhesion layer with a thickness of about 2 to 20 nanometers is obtained.

[0136] Next, five groups of composition solutions for generating photosensitive dry films containing different amino compounds are spin-coated on the TiO2 adhesion layer of the glass substrate at a speed of 2000 rpm, and after drying at 120 °C, a photosensitive dry film with a thickness of about 0.5 to 10 microns is obtained.

[0137] Prepare a copper plating bath: After mixing copper sulfate (2.5 g / mL) and formaldehyde (6 mL / L) to form a solution, adjust its pH value to about 12.5 to form the copper plating bath for electroless copper plating.

[0138] Next, irradiate the photosensitive dry film on the substrate with UV light (185 & 254 nm, 80 W) for 15 minutes. It can be observed that there is a change in the color of the photosensitive dry film, and black solid particles are also generated and attached to it. Then, immerse the entire substrate in the above copper plating bath for 10 minutes, and control the temperature at 55°C to 60°C. After observation, copper metal layers can be formed in the five groups of composition solutions for generating photosensitive dry films containing different amino compounds after photo-induced electroless plating. Therefore, it can be verified that the types of complexing agents (amino compounds) used in this experiment have little effect on the formation of copper metal particles, and the reduction and precipitation of copper metal particles can be triggered by the mechanism of photoreduction. The copper metal particles generated by different amino compounds all have the activity to trigger chemical copper deposition.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photosensitive dry film, characterized in that: include: A composition for forming a catalyst, comprising a metal complex and a water-soluble polymer; and a photocatalyst dispersed in the catalyst-forming composition, wherein the photocatalyst is a precipitate obtained by drying the photocatalyst precursor.

2. The photosensitive dry film according to claim 1, characterized in that: The photosensitive dry film is formed by coating and drying a composition solution for forming a photosensitive dry film.

3. The photosensitive dry film according to claim 1, characterized in that: The metal complex is formed by complexation reaction between an amino compound and a metal salt compound in a composition solution for generating a photosensitive dry film, and the molar concentration ratio of the total amino groups of the amino compound to the metal ions of the metal salt compound is between 1.5 and 10.

4. The photosensitive dry film according to claim 1, characterized in that: The photocatalyst includes titanium dioxide, zinc oxide or a combination thereof.

5. The photosensitive dry film according to claim 1, characterized in that: Based on the total weight of the photosensitive dry film, the content of the photocatalyst is between 1% and 70%.

6. A composition solution for forming a photosensitive dry film, characterized in that: include: Metal salt compounds; Amine compounds as complexing agents; Photocatalyst precursor; Water-soluble polymers; as well as Solvent.

7. The composition solution for forming a photosensitive dry film according to claim 6, characterized in that: The metal salt compound is one or a mixture of multiple ones of the group consisting of sulfates, nitrates, acetates, formates and chlorides of nickel, copper, palladium and silver.

8. The composition solution for forming a photosensitive dry film according to claim 6, characterized in that: The amino compound is at least one selected from the group consisting of ethanolamine, triethanolamine, ethylenediamine, propylenediamine, dimethylamine, 2-aminoisobutyl alcohol, isopropanolamine and 1-octylamine.

9. The composition solution for forming a photosensitive dry film according to claim 6, characterized in that: The molar concentration ratio of the total amino groups of the amino compound to the metal ions of the metal salt compound is between 1.5 and 10.

10. The composition solution for forming a photosensitive dry film according to claim 6, characterized in that: The water-soluble polymer includes polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyethylene imine, methyl cellulose, gelatin, starch, chitin or a combination thereof.

11. The composition solution for forming a photosensitive dry film according to claim 6, characterized in that: The photocatalyst precursor includes titanium isopropoxide, titanium butoxide, zinc methoxide, zinc propoxide or a combination thereof.

12. The composition solution for forming a photosensitive dry film according to claim 6, characterized in that: Based on the total weight of the composition solution, the content of the photocatalyst precursor is between 0.1% and 3.0%.

13. A method for chemically plating a metal layer, characterized in that: include: Preparing a composition solution for generating a photosensitive dry film according to any one of claims 6 to 12, wherein the composition solution comprises a metal salt compound, an amino compound as a complexing agent, a photocatalyst precursor, a water-soluble polymer and a solvent; Providing a substrate, and forming an adhesive layer on the substrate; Applying the composition solution on the surface of the adhesive layer; Drying the 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, wherein the catalyst-forming composition comprises a metal complex and the water-soluble polymer, and wherein the photocatalyst is a precipitate obtained after drying the photocatalyst precursor; Exposing a local area or the entire area of ​​the photosensitive dry film to light to induce the photocatalyst to generate electrons-holes and reduce the metal complex on the surface of the photocatalyst to generate metal particles; and The metal fine particles are used as a catalyst to form a metal layer by chemical plating.

14. The method for chemically plating a metal layer according to claim 13, characterized in that: The metal complex is formed by the complexation reaction between the amino compound and the metal salt compound in the composition solution, and in the photosensitive dry film, the molar concentration ratio of the total amino groups of the amino compound to the metal ions of the metal salt compound is between 1.5 and 10.

15. The method for chemically plating a metal layer according to claim 13, characterized in that: The metal layer includes a copper layer or a nickel layer.

16. The method for chemically plating a metal layer according to claim 13, characterized in that: The step of performing the exposure includes reducing metal ions in the metal complex in the photocatalyst to form the metal particles, and the metal particles are doped in the photocatalyst.

17. The method for chemically plating a metal layer according to claim 13, characterized in that: The method of coating the composition solution includes screen printing, inkjet printing or gravure printing to form a pattern on the surface of the adhesive layer.

18. The method for chemically plating a metal layer according to claim 13, characterized in that: The method of exposing the local area of ​​the photosensitive dry film includes selectively reducing and precipitating the metal particles by means of a photomask or digital exposure.

19. The method for chemically plating a metal layer according to claim 13, characterized in that: After exposing the local area of ​​the photosensitive dry film, the method further includes removing the photosensitive dry film that is not exposed outside the local area.

20. The method for chemically plating a metal layer according to claim 13, characterized in that: After forming the photosensitive dry film, the method further includes: forming a retaining wall structure on the surface of the photosensitive dry film and exposing a local area of ​​the photosensitive dry film.

21. The method for chemically plating a metal layer according to claim 13, characterized in that: The adhesive layer and the photocatalyst are made of homogeneous or heterogeneous materials.

22. The method for chemically plating a metal layer according to claim 13, characterized in that: The molar concentration of the metal salt compound is between 0.01M and 0.2M.

23. The method for chemically plating a metal layer according to claim 13, characterized in that: The molar concentration ratio of the total amino groups of the amino compound to the metal ions of the metal salt compound is between 1.5 and 10.

24. The method for chemically plating a metal layer according to claim 13, characterized in that: The concentration of the water-soluble polymer is between 0.5×10 -3 M~1.0×10 -1 M.

25. The method for chemically plating a metal layer according to claim 13, characterized in that: Based on the total weight of the composition solution, the content of the photocatalyst precursor is between 0.1% and 3.0%.

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