Resin for preparing photosensitive film, initiator composition and coating

Abstract

The invention provides a resin for preparing a photosensitive dry film, an initiator composition and a photosensitive film coating containing the raw materials. Compared with the prior art, the photosensitive dry film prepared by adopting the photosensitive film coating provided by the invention has better flexibility while having more excellent chemical resistance, so that the electroplating resistance and hole sealing capability are improved.

Description

Technical Field

[0001] The present application relates to a resin, an initiator combination and a coating for preparing a photosensitive film. Background Art

[0002] In the manufacturing process of printed circuit boards (PCBs), lead frames (LFs), and semiconductor packaging (IC) substrates, photosensitive film coatings are widely used as resist materials for etching or electroplating, also known as photosensitive dry films, dry film resists, etc. The photosensitive dry film is composed of a PET support film layer, an intermediate photosensitive resist layer, and a PE protective layer. The pattern is transferred by photocuring and manufactured by the following method: first, the photosensitive film coating is pressed onto a copper plate; then a specific area of ​​the photosensitive film coating layer is exposed; then the support film PET is peeled off, and the unexposed area is removed with a liquid; then the substrate with the resist pattern is etched and the resist layer is peeled off to form a circuit pattern; or electroplating is performed, and then the resist layer is peeled off and removed, and the metal surface covered by the resist layer is etched to form a circuit pattern.

[0003] Ordinary photosensitive dry film is no longer suitable for the market's high-speed and high-efficiency production needs, so high-sensitivity and low-energy photosensitive dry film came into being, which can greatly improve the production efficiency of customers. However, due to the high-sensitivity dry film's too fast light initiation speed, the dry film surface is well cured but the deep layer is poorly cured, resulting in poor chemical resistance and anti-plating performance of this dry film, and the occurrence of undesirable phenomena such as line sawtooth. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a resin for preparing a photosensitive film, wherein the monomer of the resin includes styrene.

[0005] Optionally, the resin is synthesized according to the following steps:

[0006] Add the first component into the reaction kettle and raise the temperature in the kettle to 65℃±5℃;

[0007] The second component is added into the reaction kettle by dropwise addition for 4 hours;

[0008] Add the third component into the reactor and keep it warm for 3 hours;

[0009] The fourth component is added into the reaction kettle by dropwise addition for 1 hour;

[0010] Add the fifth component into the reactor and keep warm for 4 hours;

[0011] Cooling to 50°C ± 5°C to obtain the resin;

[0012] The first component, the third component and the fifth component include an organic solvent;

[0013] The second component comprises: methacrylic acid, acrylic acid, methyl methacrylate, butyl acrylate, styrene and an initiator;

[0014] The fourth component includes an initiator.

[0015] Optionally, in terms of mass fraction, the second component includes:

[0016] Methacrylic acid, 5-8%;

[0017] Acrylic acid, 1-2%;

[0018] Methyl methacrylate, 20-27%;

[0019] Butyl acrylate, 7-12%;

[0020] Styrene, 1-2%; and

[0021] Azobisisobutyl cyanide, 0.15-0.25%;

[0022] Tetrabutylammonium bromide, 0.001~0.0015%.

[0023] Optionally, the first component includes 33-37% methanol and 0.01-0.015% trimethylolpropane trimethacrylate in terms of mass fraction.

[0024] Optionally, the third component includes 3-5% methanol.

[0025] Optionally, the fifth component includes 6.5-8.5% methanol.

[0026] Optionally, in terms of mass fraction, the fourth component includes:

[0027] Acetone, 3-5%; and

[0028] Azobisisobutyl cyanide, 0.25~0.75%.

[0029] The present invention also provides a resin for preparing a photosensitive film, wherein the monomer of the resin comprises hydroxyethyl acrylate.

[0030] Optionally, the resin is synthesized according to the following steps:

[0031] Add the first component into the reaction kettle and raise the temperature in the kettle to 65℃±5℃;

[0032] The second component is added into the reaction kettle by dropwise addition for 4 hours;

[0033] Add the third component into the reactor and keep it warm for 3 hours;

[0034] The fourth component is added into the reaction kettle by dropwise addition for 1 hour;

[0035] Add the fifth component into the reactor and keep warm for 4 hours;

[0036] Cooling to 50°C ± 5°C to obtain the resin;

[0037] The first component, the third component and the fifth component include an organic solvent;

[0038] The second component comprises: methacrylic acid, acrylic acid, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and an initiator;

[0039] The fourth component includes an initiator.

[0040] Optionally, in terms of mass fraction, the second component includes:

[0041] Methacrylic acid, 5-8%;

[0042] Acrylic acid, 1-2%;

[0043] Methyl methacrylate, 20-27%;

[0044] Butyl acrylate, 7-12%;

[0045] Hydroxyethyl acrylate, 1-2%; and

[0046] Azobisisobutyl cyanide, 0.15-0.25%;

[0047] Tetrabutylammonium bromide, 0.001~0.0015%.

[0048] Optionally, the first component includes 33-37% methanol and 0.01-0.015% trimethylolpropane trimethacrylate in terms of mass fraction.

[0049] Optionally, the third component includes 3-5% methanol;

[0050] Optionally, the fifth component includes 6.5-8.5% methanol.

[0051] Optionally, in terms of mass fraction, the fourth component includes:

[0052] Acetone, 3-5%; and

[0053] Azobisisobutyl cyanide, 0.25~0.75%.

[0054] The present invention also provides an initiator combination for preparing a photosensitive film, which includes tetraphenylbiimidazole, fading crystal violet, tetraethyl Michler's ketone, 9-phenylacridine, N-phenylglycine, isooctyl p-N,N-dimethylaminobenzoate, tribromomethylphenyl sulfone and benzoin dimethyl ether.

[0055] The present invention also provides a coating for preparing a photosensitive film, the coating comprising:

[0056] A first resin, wherein the first resin is the resin according to claim 1 to claim 5;

[0057] A second resin, wherein the second resin is the resin according to claim 6 to claim 10; and

[0058] An initiator combination, wherein the initiator combination is the initiator combination according to claim 11.

[0059] Optionally, the coating, in parts by weight, includes:

[0060] First resin, 28-38 parts;

[0061] Second resin, 30-42 parts;

[0062] Nonylphenol acrylate, 2-4 parts;

[0063] Bisphenol A dimethacrylate, 8-12 parts;

[0064] Bisphenol A diacrylate, 4-8 parts;

[0065] Trimethylolpropane triacrylate, 2 to 4 parts;

[0066] Tetraphenylbiimidazole, 2-4 parts;

[0067] Faded crystal violet, 0.4-0.6 parts;

[0068] Tetraethyl Michler’s ketone, 0.4-0.6 parts;

[0069] 9-phenylacridine, 0.08-0.12 parts;

[0070] N-phenylglycine, 0.04-0.12 parts;

[0071] 2-ethylhexyl p-N,N-dimethylaminobenzoate, 0.1 to 1.2 parts;

[0072] Tribromomethylphenylsulfone, 0.1-0.4 parts;

[0073] Benzoin dimethyl ether, 0.8-2.2 parts;

[0074] Malachite green, 0.01-0.03 parts;

[0075] Methanol, 4-6 parts; and

[0076] Acetone, 1 to 3 parts.

[0077] Optionally, the coating is prepared according to the following method:

[0078] Adding the first resin and the second resin into a batching tank;

[0079] Keep stirring and add nonylphenol acrylate, bisphenol A dimethacrylate and bisphenol A diacrylate into the mixing tank;

[0080] Dissolving tetraphenylbiimidazole, faded crystal violet, tetraethyl Michler's ketone, 9-phenylacridine, N-phenylglycine, isooctyl p-N,N-dimethylaminobenzoate, tribromomethylphenyl sulfone, and benzoin dimethyl ether in a mixed solvent of methanol and acetone to form a first solution;

[0081] dissolving malachite green in methanol solvent to form a second solution;

[0082] Keep stirring, add the first solution into the batching tank, and then add the second solution into the batching tank;

[0083] Keep stirring for 3 hours, and then take samples to test viscosity and solid content. If the viscosity of the sample is between 900 and 1100 cps and the solid content is between 53% and 57%, continue stirring at high speed for 5 hours and start the filtration circulation system at the same time.

[0084] After the stirring is completed, the coating is formed by standing for 2 hours;

[0085] The temperature of the above ingredients is controlled at 25℃±3 throughout the whole process.

[0086] Compared with the prior art, the photosensitive film produced by the coating provided by the present invention has better chemical resistance and flexibility, thereby improving the anti-plating and sealing capabilities. In addition, the initiator combination used in the coating provided by the present invention has better photosensitivity efficiency than the prior art, so that both the inside and outside of the photosensitive film can be well cured. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0088] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0089] Figure 1 : Experimental group line effect diagram;

[0090] Figure 2 : Sealing effect diagram of the experimental group;

[0091] Figure 3 : Comparison group line effect diagram;

[0092] Figure 4 : Sealing effect diagram of comparison group; DETAILED DESCRIPTION

[0093] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0094] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." are not excluded from the package.

[0095] Embodiment 1:

[0096] This embodiment provides a resin for preparing a photosensitive film, wherein the monomer of the resin includes styrene; further, the monomer includes methacrylic acid, acrylic acid, methyl methacrylate, butyl acrylate and styrene. In an optional implementation of this embodiment, the initiator used to prepare the resin is azobisisobutyl cyanide. It is understandable that the initiator may also use other types of polymer polymerization initiators, which will not be described in detail in the present invention.

[0097] In an optional implementation of this embodiment, the resin is synthesized according to the following steps:

[0098] S1: Add the first component into the reaction kettle and raise the temperature in the kettle to 65℃±5℃;

[0099] S2: adding the second component into the reactor, wherein the second component is added into the reactor by dropwise addition for 4 hours;

[0100] S3: adding the third component into the reaction kettle and keeping the temperature for 3 hours;

[0101] S4: adding the fourth component into the reaction kettle, wherein the fourth component is added into the reaction kettle in a dropwise manner for 1 hour;

[0102] S5: Add the fifth component into the reactor and keep warm for 4 hours;

[0103] S6: Cooling to 50°C±5°C to obtain the resin.

[0104] In the above synthesis method, the first component, the third component and the fifth component include an organic solvent; the fourth component includes an initiator; the organic solvent can use an organic solvent commonly used in polymerization reactions, such as methanol, acetone, toluene, etc., which will not be elaborated in the present invention.

[0105] In an optional implementation of this embodiment, the second component includes: methacrylic acid, acrylic acid, methyl methacrylate, butyl acrylate, styrene and an initiator.

[0106] In an optional implementation of this embodiment, the second component includes, by mass fraction: methacrylic acid, 5-8%; acrylic acid, 1-2%; methyl methacrylate, 20-27%; butyl acrylate, 7-12%; styrene, 1-2%; azobisisobutyl cyanide, 0.15-0.25%; and tetrabutylammonium bromide, 0.001-0.0015%.

[0107] In an optional implementation of this embodiment, the first component includes 33-37% methanol and 0.01-0.015% trimethylolpropane trimethacrylate in terms of mass fraction;

[0108] In an optional implementation of this embodiment, the third component includes 3-5% methanol;

[0109] In an optional implementation of this embodiment, the fifth component includes 6.5-8.5% methanol.

[0110] In an optional implementation of this embodiment, the fourth component includes, by mass fraction: acetone, 3-5%; and azobisisobutylcyanide, 0.25-0.75%.

[0111] Embodiment 2:

[0112] This embodiment also provides a resin for preparing a photosensitive film, wherein the monomer of the resin includes hydroxyethyl acrylate; more specifically, the monomer of the resin includes methacrylic acid, acrylic acid, methyl methacrylate, butyl acrylate and hydroxyethyl acrylate. The initiator used to prepare the resin is azobisisobutylcyanide. It is understandable that the initiator may also use other types of polymer polymerization initiators, which will not be described in detail in the present invention.

[0113] In an optional implementation of this embodiment, the resin is synthesized according to the following steps:

[0114] S1: Add the first component into the reaction kettle and raise the temperature in the kettle to 65℃±5℃;

[0115] S2: adding the second component into the reactor, wherein the second component is added into the reactor by dropwise addition for 4 hours;

[0116] S3: adding the third component into the reaction kettle and keeping the temperature for 3 hours;

[0117] S4: adding the fourth component into the reaction kettle, wherein the fourth component is added into the reaction kettle in a dropwise manner for 1 hour;

[0118] S5: Add the fifth component into the reactor and keep warm for 4 hours;

[0119] S6: Cooling to 50°C±5°C to obtain the resin;

[0120] In the above synthesis method, the first component, the third component and the fifth component include an organic solvent; the fourth component includes an initiator; the organic solvent can use an organic solvent commonly used in polymerization reactions, such as methanol, acetone, toluene, etc., which will not be elaborated in the present invention.

[0121] In an optional implementation of this embodiment, the second component includes: methacrylic acid, acrylic acid, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and an initiator;

[0122] In an optional implementation of this embodiment, the second component includes, by mass fraction: methacrylic acid, 5-8%; acrylic acid, 1-2%; methyl methacrylate, 20-27%; butyl acrylate, 7-12%; hydroxyethyl acrylate, 1-2%; azobisisobutyl cyanide, 0.15-0.25%; and tetrabutylammonium bromide, 0.001-0.0015%.

[0123] In an optional implementation of this embodiment, the first component includes 33-37% methanol and 0.01-0.015% trimethylolpropane trimethacrylate in terms of mass fraction.

[0124] In an optional implementation of this embodiment, the third component includes 3-5% methanol.

[0125] In an optional implementation of this embodiment, the fifth component includes 6.5-8.5% methanol.

[0126] In an optional implementation of this embodiment, the fourth component includes, by mass fraction: acetone, 3-5%; and

[0127] Azobisisobutyl cyanide, 0.25~0.75%.

[0128] Embodiment 3:

[0129] The present embodiment provides an initiator combination for preparing a photosensitive film, which includes tetraphenylbiimidazole, fading crystal violet, tetraethyl Michler's ketone, 9-phenylacridine, N-phenylglycine, isooctyl p-N,N-dimethylaminobenzoate, tribromomethylphenyl sulfone and benzoin dimethyl ether.

[0130] Embodiment 4:

[0131] This embodiment provides a coating for preparing a photosensitive film, the coating comprising:

[0132] A first resin, wherein the first resin is the resin described in Example 1;

[0133] A second resin, wherein the second resin is the resin described in Example 2; and

[0134] The initiator combination is the initiator combination described in Example 3.

[0135] In an optional implementation of this embodiment, the coating, in parts by weight, includes:

[0136] The first resin, 28 to 38 parts; the second resin, 30 to 42 parts; nonylphenol acrylate, 2 to 4 parts; bisphenol A dimethacrylate, 8 to 12 parts; bisphenol A diacrylate, 4 to 8 parts; trimethylolpropane triacrylate, 2 to 4 parts; tetraphenylbiimidazole, 2 to 4 parts; decolorized crystal violet, 0.4 to 0.6 parts; tetraethyl Michler's ketone, 0.4 to 0.6 parts; 9-phenylacridine, 0.08 to 0.12 parts; N-phenylglycine, 0.04 to 0.12 parts; isooctyl p-N,N-dimethylaminobenzoate, 0.1 to 1.2 parts; tribromomethylphenyl sulfone, 0.1 to 0.4 parts; benzoin dimethyl ether, 0.8 to 2.2 parts; malachite green, 0.01 to 0.03 parts; methanol, 4 to 6 parts; and acetone, 1 to 3 parts.

[0137] In an optional implementation of this embodiment, the coating is prepared according to the following method:

[0138] S1: adding the first resin and the second resin into a batching tank;

[0139] S2: Add nonylphenol acrylate, bisphenol A dimethacrylate and bisphenol A diacrylate into the mixing tank while stirring;

[0140] S3: dissolving tetraphenylbiimidazole, faded crystal violet, tetraethyl Michler's ketone, 9-phenylacridine, N-phenylglycine, isooctyl p-N,N-dimethylaminobenzoate, tribromomethylphenyl sulfone, and benzoin dimethyl ether in a mixed solvent of methanol and acetone to form a first solution;

[0141] S4: dissolving malachite green in methanol solvent to form a second solution;

[0142] S5: Keep stirring, add the first solution into the batching tank, and then add the second solution into the batching tank;

[0143] S6: Keep stirring for 3 hours, and then take samples to test viscosity and solid content. If the viscosity of the sample is between 900 and 1100 cps and the solid content is between 53% and 57%, continue stirring at high speed for 5 hours, and start the filtration circulation system at the same time;

[0144] S7: After the stirring is completed, the coating is allowed to stand for 2 hours to form the coating;

[0145] The temperature of the above ingredients is controlled at 25℃±3 throughout the whole process.

[0146] Performance experiment:

[0147] In order to prove the superiority of the photosensitive film prepared by the present invention over the prior art, the following experiments were conducted:

[0148] Step 1: Preparation of resin containing styrene monomer

[0149] 33-37% methanol by mass and 0.01-0.015% trimethylolpropane trimethacrylate by mass are added into the reaction kettle and heated to 65°C; then 5-8% methacrylic acid by mass, 1-2% acrylic acid by mass, 20-27% methyl methacrylate by mass, 7-12% butyl acrylate by mass, 1-2% styrene by mass, 0.15-0.25% azobisisobutyl cyanide by mass and 0.001-0.001% by mass are added. 5% tetrabutylammonium bromide is mixed to form a mixed solution, and the mixed solution is dripped into the reactor for 4 hours; 3-5% by mass of methanol is flowed into the reactor and kept warm for 3 hours; 0.25-0.75% by mass of azobisisobutylcyanide is dissolved in 3-5% by mass of acetone solvent, and then dripped into the reactor for 1 hour; 6.5-8.5% by mass of methanol solvent is flowed into the reactor and kept warm for 4 hours; after the reaction is completed, the reaction is cooled to 50° C., discharged and stored to obtain the resin containing styrene monomer.

[0150] Step 2: Preparation of Resin Containing Hydroxyethyl Acrylate Monomer

[0151] 33-37% methanol by mass and 0.01-0.015% trimethylolpropane trimethacrylate by mass are added into the reaction kettle and heated to 65°C; then 5-8% methacrylic acid by mass, 1-2% acrylic acid by mass, 20-27% methyl methacrylate by mass, 7-12% butyl acrylate by mass, 1-2% hydroxyethyl acrylate by mass, 0.15-0.25% azobisisobutyl cyanide by mass and 0.001-0.001% by mass are added. 5% tetrabutylammonium bromide is mixed to form a mixed solution, and the mixed solution is dripped into the reactor for 4 hours; 3-5% by mass of methanol is flowed into the reactor and kept warm for 3 hours; 0.25-0.75% by mass of azobisisobutylcyanide is dissolved in 3-5% by mass of acetone solvent, and then dripped into the reactor for 1 hour; 6.5-8.5% by mass of methanol solvent is flowed into the reactor and kept warm for 4 hours; after the reaction is completed, the mixture is cooled to 50° C. and discharged for storage to obtain the resin containing hydroxyethyl acrylate monomer.

[0152] Step 3: Preparation of coating

[0153] Prepare the coating as follows:

[0154] Add the resin prepared in step 1 and the resin prepared in step 2 into a batching tank; keep stirring, add nonylphenol acrylate, bisphenol A dimethacrylate and bisphenol A diacrylate into the batching tank; dissolve tetraphenylbiimidazole, faded crystal violet, tetraethyl Michler's ketone, 9-phenylacridine, N-phenylglycine, isooctyl p-N,N-dimethylaminobenzoate, tribromomethylphenyl sulfone and benzoin dimethyl ether in a mixed solvent of methanol and acetone to form a first solution;

[0155] Dissolve malachite green in methanol solvent to form a second solution; keep stirring, add the first solution into the batching tank, and then add the second solution into the batching tank; keep stirring for 3 hours, take samples after 3 hours to test the viscosity and solid content, if the sampled viscosity range is between 900~1100cps, and the solid content range is between 53%~57%, continue to stir at high speed for 5 hours, and start the filtration circulation system at the same time; after the stirring is completed, let it stand for 2 hours to form the coating; the temperature of the above ingredients is controlled at 25℃±3 throughout the process.

[0156] The above coatings were prepared using the following recipes:

[0157] Table 1: Recipe 1

[0158]

[0159] Table 2: Recipe 2

[0160]

[0161] Table 3: Recipe 3:

[0162]

[0163] Table 4: Recipe 4

[0164]

[0165] Table 5: Recipe 5

[0166]

[0167] Step 4: Preparation of the coating

[0168] The coating was prepared using the following formulation:

[0169] Table 6: Formulation 6 (Prior Art)

[0170]

[0171] The coating was prepared as follows:

[0172] Add acrylic resin (commercially available) to the batching tank; keep stirring at medium speed, add nonylphenol acrylate, bisphenol A dimethacrylate and bisphenol A diacrylate to the batching tank; keep stirring quickly, dissolve tetraphenylbiimidazole, faded crystal violet, tetraethyl Michler's ketone and 9-phenylacridine in a mixed solvent of methanol and acetone, dissolve malachite green in methanol solvent, and then add the above-configured solution to the batching tank; after the feeding is completed, start high-speed stirring for 3 hours, and take samples to test the viscosity, solid content and performance after 3 hours (the viscosity range is required to be 900~1100cps, if the viscosity is too high, methanol can be added to adjust the viscosity; the solid content range is required to be 53%~57%), continue to stir at high speed for 5 hours after the test is qualified, and start the filtration circulation system; after the stirring is completed, let it stand for 2 hours to form the coating. The temperature is controlled at 25℃±3 throughout the process.

[0173] Step 5: Preparation of photosensitive film

[0174] Preparation of photosensitive dry film

[0175] The photosensitive dry film is prepared from the coating (also called photosensitive film coating) prepared in step 3 and step 4. The photosensitive dry film is laminated on the FPC soft board by a laminator, and the FPC finished circuit board is obtained through processes such as exposure, development, and etching.

[0176] Test experimental parameters and test data

[0177] Experimental group: The photosensitive dry film prepared by the recipe in step 3 was tested. The experimental conditions and results are shown in Table 7:

[0178] Table 7: Experimental parameters and result data

[0179]

[0180] The experimental group circuit effect diagram is as follows Figure 1 As shown in Figure 2, the sealing conditions of the experimental group are as follows: Figure 2 shown.

[0181] Comparative group: The photosensitive dry film prepared by the formula in step 4 was tested. The experimental conditions and results are shown in Table 8:

[0182] Table 8: Experimental parameters and result data

[0183]

[0184] The comparison group line effect diagram is as follows Figure 3 As shown in Figure 2, the sealing conditions of the experimental group are as follows: Figure 4 shown.

[0185] The experimental results show that

[0186] Compared with the control group, the photosensitive film prepared by the experimental group has straight lines, no jagged edges, and higher resolution. Moreover, in the sealing experiment, compared with the control group, the experimental group was able to seal 8mm and 6mm round holes without damage, and had stronger flexibility.

[0187] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A resin for preparing a photosensitive film, characterized in that: The monomer of the resin includes styrene.

2. The resin according to claim 1, characterized in that The resin is synthesized according to the following steps: Add the first component into the reaction kettle and raise the temperature in the kettle to 65℃±5℃; The second component is added into the reaction kettle by dropwise addition for 4 hours; Add the third component into the reactor and keep it warm for 3 hours; The fourth component is added into the reaction kettle by dropwise addition for 1 hour; Add the fifth component into the reactor and keep warm for 4 hours; Cooling to 50°C ± 5°C to obtain the resin; The first component, the third component and the fifth component include an organic solvent; The second component comprises: methacrylic acid, acrylic acid, methyl methacrylate, butyl acrylate, styrene and an initiator; The fourth component includes an initiator.

3. The resin according to claim 2, characterized in that In terms of mass fraction, the second component includes: Methacrylic acid, 5-8%; Acrylic acid, 1-2%; Methyl methacrylate, 20-27%; Butyl acrylate, 7-12%; Styrene, 1-2%; and Azobisisobutyl cyanide, 0.15-0.25%; Tetrabutylammonium bromide, 0.001~0.0015%.

4. The resin according to claim 2, characterized in that In terms of mass fraction, the first component comprises 33-37% methanol and 0.01-0.015% trimethylolpropane trimethacrylate; and / or, The third component includes 3-5% methanol; and / or, The fifth component includes 6.5-8.5% methanol.

5. The resin according to claim 2, characterized in that In terms of mass fraction, the fourth component includes: Acetone, 3-5%; and Azobisisobutyl cyanide, 0.25~0.75%.

6. A resin for preparing a photosensitive film, characterized in that: The monomers of the resin include hydroxyethyl acrylate.

7. The resin according to claim 6, characterized in that The resin is synthesized according to the following steps: Add the first component into the reaction kettle and raise the temperature in the kettle to 65℃±5℃; The second component is added into the reaction kettle by dropwise addition for 4 hours; Add the third component into the reactor and keep it warm for 3 hours; The fourth component is added into the reaction kettle by dropwise addition for 1 hour; Add the fifth component into the reactor and keep warm for 4 hours; Cooling to 50°C ± 5°C to obtain the resin; The first component, the third component and the fifth component include an organic solvent; The second component comprises: methacrylic acid, acrylic acid, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and an initiator; The fourth component includes an initiator.

8. The resin according to claim 2, characterized in that In terms of mass fraction, the second component includes: Methacrylic acid, 5-8%; Acrylic acid, 1-2%; Methyl methacrylate, 20-27%; Butyl acrylate, 7-12%; Hydroxyethyl acrylate, 1-2%; and Azobisisobutyl cyanide, 0.15-0.25%; Tetrabutylammonium bromide, 0.001~0.0015%.

9. The resin according to claim 2, characterized in that In terms of mass fraction, the first component comprises 33-37% methanol and 0.01-0.015% trimethylolpropane trimethacrylate; and / or, The third component includes 3-5% methanol; and / or, The fifth component includes 6.5-8.5% methanol.

10. The resin according to claim 2, characterized in that In terms of mass fraction, the fourth component includes: Acetone, 3-5%; and Azobisisobutyl cyanide, 0.25~0.75%.

11. An initiator combination for preparing a photosensitive film, characterized in that: These include tetraphenylbiimidazole, decolorized crystal violet, tetraethyl Michler's ketone, 9-phenylacridine, N-phenylglycine, isooctyl p-N,N-dimethylaminobenzoate, tribromomethylphenyl sulfone, and dimethyl benzoate.

12. A coating for preparing a photosensitive film, characterized in that: The coating comprises: A first resin, wherein the first resin is the resin according to claim 1 to claim 5; A second resin, wherein the second resin is the resin according to claim 6 to claim 10; and An initiator combination, wherein the initiator combination is the initiator combination according to claim 11.

13. The coating according to claim 12, characterized in that In parts by weight, the coating comprises: First resin, 28-38 parts; Second resin, 30-42 parts; Nonylphenol acrylate, 2-4 parts; Bisphenol A dimethacrylate, 8-12 parts; Bisphenol A diacrylate, 4-8 parts; Trimethylolpropane triacrylate, 2 to 4 parts; Tetraphenylbiimidazole, 2-4 parts; Faded crystal violet, 0.4-0.6 parts; Tetraethyl Michler’s ketone, 0.4-0.6 parts; 9-phenylacridine, 0.08-0.12 parts; N-phenylglycine, 0.04-0.12 parts; 2-ethylhexyl p-N,N-dimethylaminobenzoate, 0.1 to 1.2 parts; Tribromomethylphenylsulfone, 0.1-0.4 parts; Benzoin dimethyl ether, 0.8-2.2 parts; Malachite green, 0.01-0.03 parts; Methanol, 4-6 parts; and Acetone, 1 to 3 parts.

14. The coating according to claim 13, characterized in that The coating is prepared according to the following method: Adding the first resin and the second resin into a batching tank; Keep stirring and add nonylphenol acrylate, bisphenol A dimethacrylate and bisphenol A diacrylate into the mixing tank; Dissolving tetraphenylbiimidazole, faded crystal violet, tetraethyl Michler's ketone, 9-phenylacridine, N-phenylglycine, isooctyl p-N,N-dimethylaminobenzoate, tribromomethylphenyl sulfone, and benzoin dimethyl ether in a mixed solvent of methanol and acetone to form a first solution; dissolving malachite green in methanol solvent to form a second solution; Keep stirring, add the first solution into the batching tank, and then add the second solution into the batching tank; Keep stirring for 3 hours, and then take samples to test viscosity and solid content. If the viscosity of the sample is between 900 and 1100 cps and the solid content is between 53% and 57%, continue stirring at high speed for 5 hours and start the filtration circulation system at the same time. After the stirring is completed, the coating is allowed to stand for 2 hours to form; The temperature of the above ingredients is controlled at 25℃±3 throughout the whole process.

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