阅读说明：本技术 一种具有高解析度和优异附着力的光致抗蚀剂 (Photoresist with high resolution and excellent adhesion ) 是由 刘罡 于 2021-09-22 设计创作，主要内容包括：本发明公开了一种光致抗试剂,该光致抗蚀剂作为感光干膜的核心层,包含：50-70重量份的碱溶性树脂、15-40重量份光聚合化合物、0.2-8.0重量份的光引发剂、0.1-2.0重量份其他助剂。上述光致抗蚀剂制成感光干膜后,显影后具有高解析度、优异的附着力及柔韧性、退膜快等优点,有利于提升下游电子产品的良品率。(The invention discloses a photoresist agent, which is used as a core layer of a photosensitive dry film and comprises the following components: 50-70 parts of alkali-soluble resin, 15-40 parts of photopolymerization compound, 0.2-8.0 parts of photoinitiator and 0.1-2.0 parts of other auxiliary agents. After the photoresist is made into a photosensitive dry film, the developed photoresist has the advantages of high resolution, excellent adhesive force and flexibility, fast film stripping and the like, and is favorable for improving the yield of downstream electronic products.)

1. A photoresist having high resolution and excellent adhesion, characterized in that: consists of alkali soluble resin 50-70 weight portions, light polymerized compound 15-40 weight portions, light initiator 1.0-8.0 weight portions and other assistant 0.1-2.0 weight portions.

2. The photoresist with high resolution and excellent adhesion according to claim 1, characterized in that the alkali soluble resin is at least one of (meth) acrylic resin, styrene resin, phenol resin, cellulose acetate phthalate, ethyl hydroxyethyl cellulose phthalate.

3. The photoresist with high resolution and excellent adhesion according to claim 1, wherein the photopolymerizable compound comprises: one or more of lauryl acrylate, isodecyl acrylate, bisphenol A dimethacrylate, polyethylene glycol diacrylate, propoxylated nonylphenol acrylate, N-vinyl caprolactam, and hydroxybutyl vinyl ether.

4. The photoresist with high resolution and excellent adhesion according to claim 1, characterized in that the photoinitiator is at least 1 of 4,4 ', 5, 5' -tetraphenyldiimidazole, 2- (o-chlorophenyl) -4, 5-diphenyldiimidazole, 2, 4-trichloromethyl-6-triazine, benzophenone, benzoin bismethyl ether, 2-isopropylthioxanthone, 1, 4-dimethylmercaptobenzene, N-dimethylethanolamine, pentaerythritol tetrathioglycolate, p-tert-butyltrichloroacetophenone, 2, 4-dimethylthioxanthone, benzyl ketone dimethyl acetal and 2-chlorothioxanthone.

5. The photoresist of high resolution and excellent adhesion according to claim 1, wherein the other auxiliary agent comprises one or more of a diluent, a plasticizer, a coloring agent, a color former, an antioxidant, a thermal polymerization inhibitor, a defoaming agent, a flame retardant and a leveling agent.

6. The photoresist with high resolution and excellent adhesion according to claim 5, wherein the coloring agent is composed of at least one of leuco crystal violet, magenta, phthalocyanine green, phthalocyanine blue, fluorane, malachite green, rhodamine, etc. in any ratio; the adhesion promoter is a thiol compound; the plasticizer comprises: at least one of dibutyl phthalate, diallyl phthalate, tetraethylene glycol diacetate, benzene sulfonamide, triphenyl phosphate, and the like.

7. A method for preparing a photoresist with high resolution and excellent adhesion is characterized by comprising the following steps:

synthesis of alkali soluble resins

Preparation of photoresist slurry: adding alkali soluble resin, a photopolymerization compound, a photoinitiator and other additives into a solvent according to a formula, mixing uniformly, stirring, and removing undissolved impurities for later use;

preparing a photosensitive dry film: coating the photoresist slurry on a base material (PET) by adopting a coating machine, and baking at the temperature of 60-80 ℃ to form a photoresist film layer; and coating a PE film on the photoresist film layer, cutting, thermally sealing and rolling to obtain a photosensitive dry film sample.

8. The high resolution and excellent adhesion photoresist according to claim 1, for laser scanning exposure.

Technical Field

The invention relates to the technical field of printed circuit boards, in particular to a photoresist which is high in resolution, excellent in adhesive force and flexibility and fast in film stripping.

Background

Photoresist, also known as photoresist, is a photosensitive composite material. The material is widely used as a core material for pattern transfer in a Printed Circuit Board (PCB), a Liquid Crystal Display (LCD), a solar cell, a conductor package, and a semiconductor package, and the quality and performance of the material play an important role in the performance and yield of downstream electronic components. In the production process of the PCB, the photoresist transfers a desired circuit pattern from the mask to a base material to be processed, such as copper foil, through a photochemical reaction by exposure, development, etching, and the like.

In recent years, with the further popularity of portable electronic devices, electronic components have developed to be lighter in weight, thinner in thickness and smaller in volume, which also promotes the smaller width of printed circuit lines inside the electronic components and the further smaller contact area between the substrate and the photoresist. This leads to higher and higher requirements for the properties of the photoresist, such as higher resolution, good adhesion and flexibility.

Disclosure of Invention

The present invention has been made to solve the above problems occurring in the above products, and an object of the present invention is to provide a photoresist which has excellent resolution, excellent adhesion and flexibility after development, and a photosensitive dry film which is rapidly stripped.

In order to achieve the above object, the present invention provides the following technical solutions

The invention aims to realize a photosensitive dry film which comprises 50-70 parts by weight of alkali-soluble resin, 20-40 parts by weight of photopolymerization compound, 0.2-8.0 parts by weight of photoinitiator and 0.1-2.0 parts by weight of other auxiliary agents.

As a further aspect of the invention: the alkali soluble resin is at least one of (methyl) acrylic resin, styrene resin, phenolic resin, cellulose acetate-phthalate ester and ethyl hydroxyethyl cellulose phthalate.

As a further aspect of the invention: in the present invention, a (meth) acrylic resin is preferable, and the (meth) acrylic resin may be a methacrylic resin or an acrylic resin, or a mixture of the two resins at an arbitrary ratio.

As a further aspect of the invention: the (meth) acrylic resin is synthesized from at least two of methyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate, ethyl acrylate, butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, meth) acrylic acid, lauryl acrylate, meth) acrylic acid, isooctyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, (meth) acrylamide, styrene, and α -methylstyrene.

As a further aspect of the invention: the photopolymerizable compound comprises at least one of lauryl acrylate, isodecyl acrylate, bisphenol A dimethacrylate, polyethylene glycol diacrylate, propoxylated nonylphenol acrylate, N-vinylcaprolactam, and hydroxybutyl vinyl ether.

As a further aspect of the invention: the photoinitiator is one or more of 4,4 ', 5, 5' -tetraphenyl diimidazole, 2- (o-chlorophenyl) -4, 5-diphenyl diimidazole, 2, 4-trichloromethyl-6-triazine, benzophenone, benzoin dimethyl ether, 2-isopropyl thioxanthone, 1, 4-dimethyl mercaptobenzene, N-dimethyl ethanolamine, pentaerythritol tetrathioglycolate, p-tert-butyl trichloroacetophenone, 2, 4-dimethyl thioxanthone, benzyl ketone dimethyl acetal and 2-chlorothioxanthone.

As a further aspect of the invention: the other auxiliary agents comprise one or more of a diluent, a plasticizer, a coloring agent, a color former, an antioxidant, a thermal polymerization inhibitor, a defoaming agent, a flame retardant and a leveling agent.

As a further aspect of the invention: the coloring agent is one or more of leuco crystal violet, fuchsin, phthalocyanine green, phthalocyanine blue, fluorane, malachite green and rhodamine; preferably leuco crystal violet and phthalocyanine blue.

As a further aspect of the invention: the adhesion promoter is a thiol compound.

As a further aspect of the invention: the plasticizer contains at least one of dibutyl phthalate, diallyl phthalate, tetraethylene glycol diacetate, benzene sulfonamide, triphenyl phosphate and the like. Diallyl phthalate and benzenesulfonamides are preferred.

As a further aspect of the present invention: the preparation of the photoresist slurry comprises the following steps

1) Adding alkali soluble resin, a photopolymerization compound, a photoinitiator and other auxiliary agents into a solvent according to a formula;

2) mechanically stirring the mixture until the mixture is uniform;

3) filtering out undissolved impurities for later use.

As a further aspect of the invention: the solvent is one or more of acetone, methanol, monoethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol methyl ether, propylene glycol monobutyl ether, dichloromethane, carbon tetrachloride, etc. Acetone or propylene glycol methyl ether is preferred.

As a further aspect of the present invention: the preparation of the photosensitive dry film comprises the following steps

1) Coating the photoresist slurry on a substrate (PET) by using a coating machine;

2) baking the materials in an oven at a certain temperature of 60-80 ℃ to form a photoresist film layer;

3) and coating a PE film on the photoresist film layer, cutting, thermally sealing and rolling to obtain a photosensitive dry film sample.

As a further aspect of the invention: the dry film-related property test of the photoresist is as follows

In the invention, before the film is pasted on the copper-clad plate, the copper-clad plate needs to be pre-cleaned by a plate grinding machine so as to ensure that the copper-clad plate is clean and flat.

After the copper-clad plate is treated, an automatic film sticking machine is adopted for sticking films, the temperature is 100-115 ℃, and the film sticking speed is 1.0-2.0 m/s.

The UV light curing machine is adopted for processing, the lamp source is a 5 kW high-pressure mercury lamp, and the wavelength is 365 nm.

1.5% sodium carbonate solution is used as developing solution, the developing temperature is 30-40 ℃, and the pressure is 2.0-2.5 kg/cm². The developing time is 35-50S. Wherein unexposed acrylic esters and acrylic resin react with the weak alkaline sodium carbonate solution to generate substances which are easy to dissolve in water.

The solidified film layer is treated by using 4 to 6 percent potassium hydroxide solution to saponify and dissolve the film layer, and then the film is removed.

The demoulding temperature is 40-55 ℃, and the demoulding pressure is 1.5-2.5 kg/cm². The stripping process involves an acid-base reaction and a saponification reaction.

Adhesion test

The adhesion test used an RP-4 test pattern (L/S = n/400).

Hardness test

The hardness test is carried out according to GB/T1730-1993, and a coating swing rod is measured by a swing rod hardness tester.

Flexibility test

After film pasting, exposure and development, folding the flexible base material for 20 times from different angles, observing whether the dry film cracks, counting the cracking times, and expressing the result by using a number, wherein the smaller the numerical value, the better the flexibility of the dry film is.

Well: the dry film is cracked for 0-1 time after being folded; in general: the dry film is cracked for 2-5 times after being folded; difference: the dry film is cracked for more than 5 times after being folded in half.

Evaluation of resolution

At an exposure intensity of 10mJ/cm²The photosensitive dry film laminated by the above method was subjected to laser exposure for patterning, followed by developing the dry film, and the minimum size of the remaining adhesion/resolution (line and space) pattern was evaluated. Resolution evaluation (line and space) was performed using test patterns provided by aobao technologies.

The resolution levels are classified into three levels of "1", "2", and "3", wherein the "1" level standard is capable of reproducing thin line evaluation of less than 50 μm, the "2" level standard is capable of reproducing thin lines between 50 μm and 100 μm, and the "3" level standard represents that thin lines of 100 μm or more cannot be reproduced.

Detailed description of the preferred embodiments

Detailed description of the preferred embodiment 1

1) Synthesis of alkali soluble resins

The alkali soluble resin is prepared by carrying out suspension polymerization on butyl methacrylate, methacrylic acid and alpha-methyl styrene, wherein the weight ratio of the butyl methacrylate to the methacrylic acid to the alpha-methyl styrene is 40:30: 30.

2) Preparation of photoresist slurry

Sequentially adding the alkali-soluble resin obtained in the step 1), isodecyl acrylate, 2, 4-trichloromethyl-6-triazine, leuco crystal violet and dibutyl phthalate into acetone according to the weight ratio of 60:35:4.0:0.4:0.6, completely dissolving, mechanically stirring for 3 hours at the experimental temperature of 40 ℃ at the rotating speed of 3000 rpm/min to obtain uniformly dispersed photoresist slurry, removing impurities by using a 5-micron filter element, and standing for later use.

3) Preparation of photosensitive dry film

Coating the photoresist slurry obtained in the step 2) on a PET (polyethylene terephthalate) base material by adopting a coating machine, and baking the material in an oven at a certain temperature of 70 ℃ to form a photoresist film layer; and coating a PE film on the photoresist film layer, cutting, thermally sealing and rolling to obtain a photosensitive dry film sample. The photosensitive dry film sample was named # 1.

Experiments show that the No. 1 photosensitive dry film has the resolution grade of 1, the adhesive force of 20 mu m, good flexibility, the hardness of 0.129, the demolding time of 45S and good dimensional stability of circuits.

Detailed description of the preferred embodiment 2

1) Synthesis of alkali soluble resins

The alkali soluble resin is prepared by suspension polymerization of methyl methacrylate, methacrylic acid, tert-butyl methacrylate and styrene, wherein the weight ratio of the methyl methacrylate to the methacrylic acid to the tert-butyl methacrylate to the styrene is 20:20:40: 20.

2) Preparation of photoresist slurry

Sequentially adding the alkali-soluble resin obtained in the step 1), polyethylene glycol diacrylate, 1, 4-dimethyl mercapto benzene, phthalocyanine blue and thiol compounds into propylene glycol monomethyl ether according to the weight ratio of 62:32:4.8:0.6:0.6, completely dissolving, mechanically stirring for 3.5 hours at the experimental temperature of 35 ℃ at the rotating speed of 3000 rpm/min to obtain uniformly dispersed photoresist slurry, removing impurities by using a 5-micron filter element, and standing for later use.

3) Preparation of photosensitive dry film

Coating the photoresist slurry obtained in the step 2) on a PET (polyethylene terephthalate) base material by adopting a coating machine, and baking the material in an oven at a certain temperature of 75 ℃ to form a photoresist film layer; and coating a PE film on the photoresist film layer, cutting, thermally sealing and rolling to obtain a photosensitive dry film sample. The photosensitive dry film sample was named # 2.

Experiments show that the 2# photosensitive dry film has the resolution grade of 1, the adhesive force of 25 mu m, good flexibility, the hardness of 0.143, the stripping time of 40S and good line dimensional stability.

Detailed description of the preferred embodiment 3

1) Synthesis of alkali soluble resins

The alkali soluble resin is prepared by suspension polymerization of 2-hydroxyethyl methacrylate, methacrylic acid, butyl methacrylate and ethyl acrylate, wherein the weight ratio of the 2-hydroxyethyl methacrylate to the methacrylic acid to the butyl methacrylate to the ethyl acrylate is 20:20:40: 20.

2) Preparation of photoresist slurry

Sequentially adding the alkali-soluble resin obtained in the step 1), N-vinyl caprolactam, pentaerythritol tetrathioglycolate, leuco crystal violet and a thiol compound into a mixed solvent of acetone and dichloromethane according to a weight ratio of 65:29:5.0:0.4:0.6 (the weight ratio of the acetone to the dichloromethane is 9: 1), completely dissolving, mechanically stirring for 4 hours at an experimental temperature of 30 ℃ at a rotating speed of 3000 rpm/min to obtain uniformly dispersed photoresist slurry, removing impurities by using a 5-micron filter element, and standing for later use.

3) Preparation of photosensitive dry film

Coating the photoresist slurry obtained in the step 2) on a PET (polyethylene terephthalate) base material by adopting a coating machine, and baking the material in an oven at a certain temperature of 75 ℃ to form a photoresist film layer; and coating a PE film on the photoresist film layer, cutting, thermally sealing and rolling to obtain a photosensitive dry film sample. The photosensitive dry film sample was named # 3.

Experiments show that the 3# photosensitive dry film has the resolution grade of 1, the adhesive force of 30 mu m, good flexibility, the hardness of 0.138, the demolding time of 50S and good line dimensional stability.