Photosensitive resin composition, photosensitive dry film and application thereof

Abstract

The invention discloses a photosensitive resin composition, a photosensitive dry film and application thereof. The photosensitive resin composition comprises the following raw material components in parts by mass: 40-60 parts of alkali-soluble resin, 5-15 parts of a photopolymerization monomer and 0.5-3 parts of a photoinitiator, the alkali-soluble resin is a multi-block polymer with a branched chain containing a siloxy group, siloxane groups are introduced into the alkali-soluble resin, a plurality of acrylic resin monomers are combined for copolymerization to obtain the alkali-soluble resin, and the siloxy group can form a bonding and interface fusion promoting mechanism on inorganic and organic interfaces, so that the adherence of the photoresist can be effectively improved; according to the present invention, the development window is increased so as to prepare the thick dry film photoresist with characteristics of high adherence and high resolution, such that the key problem that the pattern easily falls off during the photoetching process is effectively solved, and the thick dry film photoresist can be adopted as the pattern transfer material during the printed circuit board manufacturing process so as to obtain the high resolution photoetching pattern with the high depth-to-width ratio.

Description

Technical Field

[0001] The present invention belongs to the technical field of photosensitive materials, and particularly relates to a photosensitive resin composition, a photosensitive dry film and their applications. Background Art

[0002] A printed circuit board (PCB) is an indispensable core component in electronic devices, providing electrical connection and support for electronic components through metal wires and conductive paths, and is widely used in fields such as consumer electronics, communication devices, automotive electronics, and industrial control. The design and manufacturing quality of a PCB are directly related to the performance and reliability of electronic products. In the process of PCB manufacturing, the formation of precise circuits and patterns is a key step, and the formation of these patterns depends on materials such as photosensitive resin compositions and dry film photoresists.

[0003] A photoresist is an important material used to define fine patterns in semiconductor processes. Its basic principle is that through the exposure and development processes, the solubility or adhesion of the unexposed or exposed parts of the photoresist is changed, so as to transfer a predetermined pattern onto the substrate. Traditional photoresists are usually liquid-coated photoresists, while dry film photoresists are in the form of thin-film solids and are attached to the surface of the substrate through hot pressing or hot-pressing film technology. Dry film photoresists have the characteristics of good mechanical strength, high resolution, and thick film ability compared with traditional photoresists. In the application of thick film photoresists, dry film photoresists are particularly suitable for various fields such as metallization, circuit definition, and packaging structures, and can provide higher resolution and stability. The high-resolution thick film dry film photoresist technology mainly solves the need to maintain a relatively thick photoresist layer while requiring high resolution. However, the use of thick film photoresists usually faces the following challenges: (1) Resolution problem: The thickness of the thick film photoresist is relatively large, which may lead to insufficient light penetration during exposure, thus affecting the resolution. To overcome this problem, developers usually adopt multiple exposure techniques or optimize the chemical composition of the photoresist to improve its resolution; (2) Adhesion problem: For the photosensitive dry film with a relatively thick film layer produced by current technology, due to the influence of its film thickness, it is difficult to control the development process, resulting in further peeling phenomena and low pattern yield.

[0004] High-resolution thick film dry film photoresists usually have stronger chemical stability, thermal stability, and mechanical strength, enabling them to maintain a high pattern resolution in a relatively thick film layer, and are particularly suitable for manufacturing high-precision devices such as large-area integrated circuits and microstructural sensors. Currently, the main raw materials for the dry film photoresist manufacturing process in the market are alkali-soluble resins, photopolymerizable monomers, photoinitiators, and various additives. Among them, alkali-soluble resins are often selected from the perspective of improving resolution and adhesion, and acrylic acid, alkyl acrylates, etc. are often used. However, the adhesion of the thick film dry film photoresist prepared from the above resin materials still needs to be improved. Summary of the Invention

[0005] In order to overcome the problems existing in the above-mentioned prior art, one of the objectives of the present invention is to provide a photosensitive resin composition. Another objective of the present invention is to provide a dry film resist. A third objective of the present invention is to provide a photosensitive dry film. A fourth objective of the present invention is to provide the application of the above-mentioned photosensitive resin composition or photosensitive dry film.

[0006] In order to achieve the above objectives, the technical solutions adopted by the present invention are as follows:

[0007] The present invention provides a photosensitive resin composition in the first aspect, which comprises the following raw material components in parts by mass: 40-60 parts of an alkali-soluble resin, 5-15 parts of a photopolymerizable monomer, and 0.5-3 parts of a photoinitiator; the alkali-soluble resin is a multi-block polymer, and the alkali-soluble resin comprises a repeating unit shown in formula a1:

[0008]

[0009] wherein p is the number of repeating units.

[0010] Preferably, it comprises the following raw material components in parts by mass: 45-55 parts of an alkali-soluble resin, 7-12 parts of a photopolymerizable monomer, and 0.5-2 parts of a photoinitiator.

[0011] Preferably, the structural formula of the alkali-soluble resin is as shown in formula A:

[0012]

[0013] wherein x, y, z, p, and q are the numbers of respective repeating units.

[0014] More preferably, calculated according to the mass ratio of the raw materials, the preparation raw materials of the alkali-soluble resin comprise the following monomers: 10-20 parts of styrene, 25-35 parts of methyl methacrylate, 20-30 parts of butyl methacrylate, 15-25 parts of 2-ethylhexyl methacrylate, and a methacrylate derivative with a silane oxy group.

[0015] Further preferably, the structural formula of the methacrylate derivative with a silane oxy group is as shown in formula a2:

[0016]

[0017] Still further preferably, the preparation method of the methacrylate derivative with a silane oxy group comprises the following steps: reacting dehydrated propylene glycol methyl ether acetate, mercaptopropyltrimethoxysilane, and glycidyl methacrylate to obtain the methacrylate derivative with a silane oxy group.

[0018] More preferably, the mass ratio of dehydrated propylene glycol methyl ether acetate, mercaptopropyltrimethoxysilane and glycidyl methacrylate is (5 - 7):(0.8 - 1.2):(0.8 - 1.2).

[0019] More preferably, the temperature of the reaction is 80 - 90 °C.

[0020] Further preferably, the preparation method of the alkali-soluble resin comprises the following steps: mixing styrene, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and a methacrylate derivative with a silane oxy group, and an initiator, and carrying out a polymerization reaction to obtain the alkali-soluble resin.

[0021] Even more preferably, the preparation method of the alkali-soluble resin comprises the following steps: reacting dehydrated propylene glycol methyl ether acetate, mercaptopropyltrimethoxysilane and glycidyl methacrylate to obtain the methacrylate derivative with a silane oxy group; then adding styrene, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and an initiator into the mixed system, and carrying out a polymerization reaction to obtain the alkali-soluble resin.

[0022] Even more preferably, the temperature of the polymerization reaction is 80 - 90 °C.

[0023] Even more preferably, the time of the polymerization reaction is 3 - 6 h.

[0024] Even more preferably, the organic solvent is a diol ether ester. Exemplarily, the diol ether ester is selected from at least one of propylene glycol methyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether propionate, and propylene glycol monopropyl ether propionate.

[0025] Even more preferably, the initiator is selected from at least one of benzoyl peroxide, dibenzoyl peroxide, and tert-butyl peroxybenzoate.

[0026] Preferably, the photopolymerizable monomer comprises at least one of a monofunctional (meth)acrylate-based ethylenically unsaturated double bond monomer, a difunctional (meth)acrylate-based ethylenically unsaturated double bond monomer, and a polyfunctional (meth)acrylate-based ethylenically unsaturated double bond monomer.

[0027] More preferably, the photo-polymerizable monomer includes at least one of lauryl (meth)acrylate, octadecyl (meth)acrylate, nonylphenol acrylate, isobornyl acrylate, tetrahydrofurfuryl acrylate, bisphenol A di(meth)acrylate, polyethylene glycol (propylene glycol) di(meth)acrylate, ethoxylated (propoxylated) neopentyl glycol diacrylate, trimethylolpropane tri(meth)acrylate, ethoxylated (propoxylated) trimethylolpropane tri(meth)acrylate, ethoxylated (propoxylated) pentaerythritol triacrylate, ethoxylated (propoxylated) pentaerythritol tetraacrylate, ethoxylated bisphenol A dimethacrylate, ethoxylated (propoxylated) dipentaerythritol pentaacrylate, and ethoxylated (propoxylated) dipentaerythritol hexaacrylate.

[0028] Preferably, the photoinitiator includes at least one of benzoin ether compounds, benzophenone and its derivatives, thioxanthone series compounds, anthraquinone and its derivatives, thioxanthone series compounds, and hexaarylbiimidazole series compounds.

[0029] More preferably, the photoinitiator includes benzophenone and benzoin dimethyl ether.

[0030] Preferably, the raw material components further include additives; the additives include at least one of resin curing accelerators, thixotropic thickeners, diluents, polymerization inhibitors, thickeners, defoamers, leveling agents, coupling agents, antioxidants, dyes, color developers, and plasticizers.

[0031] Preferably, the raw material components further include 0.1 - 1 part of plasticizer.

[0032] Preferably, by mass, the raw material components further include 30 - 50 parts of organic solvent.

[0033] More preferably, the organic solvent is selected from at least one of acetone, toluene, and methyl ethyl ketone.

[0034] The second aspect of the present invention provides a dry film resist, which is obtained by curing the photosensitive resin composition described in the first aspect.

[0035] Preferably, the preparation method of the dry film resist includes the following steps: mixing each preparation raw material.

[0036] The third aspect of the present invention provides a photosensitive dry film, which includes a PET layer, a photosensitive resist layer, and a polyethylene film protective layer arranged in sequence; the photosensitive resist layer is formed by coating and curing the photosensitive resin composition described in the first aspect on the surface of the PET layer.

[0037] The fourth aspect of the present invention provides the application of the photosensitive resin composition described in the first aspect or the photosensitive dry film described in the third aspect in semiconductor preparation, display panel manufacturing, or printed circuit boards.

[0038] The beneficial effects of the present invention are as follows:

[0039] The present invention provides a photosensitive resin composition and its application. The alkali-soluble resin in the photosensitive resin composition is introduced with siloxane groups and copolymerized with a variety of acrylic resin monomers. Among them, the silane oxy groups can form bonds at the inorganic and organic interfaces, promoting the mechanism of interface fusion, effectively improving the adhesion of the photoresist, increasing the development window, and then preparing a thick film dry film photoresist with high adhesion and high resolution, effectively solving key problems such as easy pattern peeling during the lithography process. It can also be used as a pattern transfer material in the manufacturing process of printed circuit boards, and a high-resolution lithography pattern with a relatively high aspect ratio can be obtained. Specific Embodiments

[0040] The content of the present invention will be further described in detail through specific embodiments below. The raw materials used in the following embodiments, unless otherwise specified, can be obtained from conventional commercial channels or prepared and separated through simple synthesis; the processes used, unless otherwise specified, are all conventional processes in the art.

[0041] Example 1

[0042] This example provides an alkali-soluble resin, a photosensitive dry film photoresist and its preparation method. The following raw materials are in parts by mass, and the specific preparation method is as follows:

[0043] 1. Preparation of alkali-soluble resin

[0044] 1) Add 30 parts of dehydrated propylene glycol methyl ether acetate to a four-necked flask equipped with a reflux condenser, mechanical stirrer, constant pressure dropping funnel and nitrogen protection system, heat up to 80 °C and maintain a nitrogen atmosphere. Weigh 5 parts of mercaptopropyltrimethoxysilane and 5 parts of glycidyl methacrylate, stir and mix well, control the temperature at 80 to 85 °C, and keep warm for 2 hours.

[0045] 2) Then add 30 parts of methyl methacrylate, 25 parts of butyl methacrylate, 18 parts of 2-ethylhexyl methacrylate and 15 parts of styrene, stir and mix well to form a monomer mixture. Slowly drop the monomer mixture and 2 parts of benzoyl peroxide (BPO) initiator solution into the reaction system in step 1), control the temperature at 80 to 85 °C. After dropping, keep warm for 4 hours. Heat up to 90 °C and keep for 1 hour to decompose the residual initiator, cool to room temperature, take out the reaction solution, and obtain it.

[0046] The structural formula of the alkali-soluble resin is as shown in Formula A:

[0047]

[0048] 2. Preparation of photosensitive dry film

[0049] (1) Prepare a photosensitive resin composition solution. The raw material components are shown in Table 1 as follows:

[0050] Table 1

[0051]

[0052] Mix the components in proportion according to the formula in Table 1 above, add acetone as a solvent, and then stir well at room temperature until completely dissolved to prepare a resin composition solution with a solid content of 60%. Let it stand for more than 30 minutes to allow sufficient degassing to obtain the photosensitive resin composition solution.

[0053] (2) Prepare a photosensitive dry film

[0054] Coat the above-mentioned photosensitive resin composition solution on a PET substrate, for example, spin-coat to obtain a coating with a film thickness of 40 μm. Next, perform baking. The baking conditions depend on the type and mixing ratio of each component, but usually bake in an oven at 60 - 150 °C for 10 seconds to 60 minutes, or preferably bake at a temperature of 100 °C for 30 minutes to remove the solvent contained in the photosensitive resin composition. Then, attach a polyethylene film protective layer with a thickness of 20 μm on its surface to obtain a three-layer structured photosensitive dry film.

[0055] Comparative Example 1

[0056] Compared with the photosensitive resin composition solution of Example 1, the alkali-soluble resin with the structural formula shown in Formula A in Comparative Example 1 was replaced with an alcohol-soluble resin (Guangdong Kedding MR1715), and then a photosensitive dry film was prepared using the same preparation method as in Example 1.

[0057] Experimental tests

[0058] Polish the copper surface of the copper clad laminate with a grinding machine, then wash and dry it with water to obtain a bright and unoxidized copper surface. Then, remove the PE protective layers of the photosensitive dry films of Example 1 and Comparative Example 1 respectively, and then laminate the photosensitive resin composition on the copper clad laminate using a laminating machine. During the lamination process, set the temperature of the pressure roller to 110 °C, adjust the conveying speed to 1.5 m / min, and perform hot pressing lamination under standard pressure conditions. Let the samples stand for more than 30 minutes after lamination, and use a SUSSMicroTec exposure machine, model: MA / BA 8Gen 4 for exposure. Let the samples stand for more than 15 minutes after exposure, and the developing temperature is 30 °C, and the pressure is 1.2 Kg / cm 2, the developer is an aqueous solution of sodium carbonate with a concentration of 1 wt%, the development time is 2.0 times the minimum development time, and after development, it is washed with water and dried. The minimum time required to completely dissolve the unexposed part of the resist layer is taken as the minimum development time. A metal layer is deposited on the developed film surface by electroplating technology. The stripping solution is NaOH, with a concentration of 2.5 wt%, a temperature of 50 °C, and a pressure of 1.2 Kg / cm 2 , the stripping time is 1.5 - 2.0 times the minimum stripping time, and after stripping, it is washed with water and dried.

[0059] Sensitivity evaluation: The photosensitive dry film is attached to the sample and left standing for at least 30 min before exposure. At the same time, a stouffer 41-step exposure scale is used for sensitivity testing. After that, it is developed with an aqueous solution of Na2CO3 with a concentration of 1 wt% at 30 °C, and the development time is 2 times the minimum development time to obtain a developed pattern, and the change of the grid on the exposure scale is observed. When the number of remaining segments reaches 15 grids, record the required exposure amount (in mJ / cm 2 as the unit). The smaller this value is, the more excellent the sensitivity is.

[0060] Resolution evaluation: Exposure is carried out using a mask with a wiring pattern having a width ratio of exposed part to unexposed part of 1:1 (Line:Space = 1:1). After development with 2 times the minimum development time, record the minimum opening where the pattern is normally formed. The smaller this resin is, the more excellent the resolution is.

[0061] Adhesion evaluation: Exposure is carried out using a mask with a wiring pattern having a width ratio of exposed part to unexposed part of n:400 (Line:Space = n:400). After development with 2 times the minimum development time, record the minimum opening where the pattern is normally formed. The smaller this resin is, the more excellent the adhesion is.

[0062] The performance evaluation results are shown in Table 2:

[0063] Table 2

[0064] Example 1 Comparative Example 1 <![CDATA[ISO (mj / cm 2 )]]> 60 60 Resolution (μm) 15 35 Adhesion (μm) 10 30

[0065] It can be found through the comparison between the examples and the comparative examples that: the examples obtained a dry film resist with relatively excellent resolution and adhesion. In the comparative examples, the alkali-soluble resin system is a common alcohol-soluble resin, resulting in poor adhesion between the dry film resist layer and the substrate, leading to low adhesion.

[0066] The above is the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches are also regarded as the protection scope of the present invention.

Claims

1. A photosensitive resin composition, characterized in that: The invention comprises the following raw material components in parts by weight: 40 to 60 parts of alkali-soluble resin, 5 to 15 parts of photopolymerizable monomers, and 0.5 to 3 parts of photoinitiator; the alkali-soluble resin is a multi-block polymer, and the alkali-soluble resin comprises repeating units of the structure shown in formula a1: Where p is the number of repeating units.

2. The photosensitive resin composition according to claim 1, characterized in that: The structural formula of the alkali-soluble resin is shown in Formula A: Wherein x, y, z, p, q are the numbers of each repeating unit.

3. The photosensitive resin composition according to claim 2, characterized in that: According to the raw material mass ratio, the raw materials for preparing the alkali-soluble resin include the following monomers: 10 to 20 parts of styrene, 25 to 35 parts of methyl methacrylate, 20 to 30 parts of butyl methacrylate, 15 to 25 parts of 2-ethylhexyl methacrylate, and a methacrylate derivative with a silaneoxy group.

4. The photosensitive resin composition according to claim 3, characterized in that: The preparation method of the alkali-soluble resin comprises the following steps: mixing styrene, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, a methacrylate derivative with a silaneoxy group and an initiator, and performing a polymerization reaction to obtain the alkali-soluble resin.

5. The photosensitive resin composition according to claim 1, characterized in that: The photopolymerizable monomer includes at least one of a monofunctional (meth)acrylate ethylenically unsaturated double-bond monomer, a difunctional (meth)acrylate ethylenically unsaturated double-bond monomer, and a multifunctional (meth)acrylate ethylenically unsaturated double-bond monomer.

6. The photosensitive resin composition according to claim 1, characterized in that: The photoinitiator comprises at least one of benzoin ether compounds, benzophenone and its derivatives, thioxanthone series compounds, anthraquinone and its derivatives, thioxanthone series compounds, and hexaarylbiimidazole series compounds; And / or, the raw material components also include additives; the additives include at least one of a resin curing accelerator, a thixotropic tackifier, a diluent, an inhibitor, a tackifier, a defoamer, a leveling agent, a coupling agent, an antioxidant, a dye, a developer, and a plasticizer.

7. The photosensitive resin composition according to claim 1, characterized in that: The raw material components also include 30 to 50 parts of organic solvents by mass.

8. A dry film resist, characterized in that The photosensitive resin composition is obtained by curing the photosensitive resin composition according to any one of claims 1 to 7.

9. A photosensitive dry film, characterized in that: The photosensitive dry film comprises a PET layer, a photosensitive resist layer, and a polyethylene film protective layer arranged in sequence; the photosensitive resist layer is formed by coating and curing the photosensitive resin composition described in any one of claims 1 to 7 on the surface of the PET layer.

10. Use of the photosensitive resin composition according to any one of claims 1 to 7, or the photosensitive dry film according to claim 9 in semiconductor preparation, display panel manufacturing or printed circuit board manufacturing.

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