A negative photosensitive composition and its application

Abstract

The present invention discloses a novel polyimide precursor, a negative-type photosensitive composition containing the polyimide precursor, and applications of the composition. The negative-type photosensitive composition of the present invention is composed of the following raw materials in certain weight percentages: (A) a polyimide precursor containing an unsaturated bond, (B) a polymerizable monomer containing an unsaturated bond, (C) a photopolymerization initiator, and (D) a solvent. After photolithography and curing, the composition produces a cured film having a convex-concave structure. This cured film can be used in electronic devices as a redistribution layer, interlayer insulating buffer film, cover coating, or surface protective film material.

Description

Technical Field

[0001] The present invention relates to a photosensitive dielectric material used in the field of electronic devices, and in particular to a negative photosensitive composition of a novel polyimide precursor and a polymerizable monomer containing an unsaturated bond, a cured product prepared therefrom, and applications thereof in semiconductor packaging and display manufacturing. Background Art

[0002] The advancement of science and technology has always been closely linked to the development of materials science. This is especially true for the semiconductor chip and display manufacturing industries that underpin many cutting-edge technologies, which rely heavily on the latest advances in materials science. Recently developed semiconductor chip and display manufacturing methods rely heavily on high-performance organic polymer thin film materials. Many of these new manufacturing processes require organic polymers to possess excellent insulation properties, high mechanical properties, excellent adhesion, high-temperature stability, low water absorption, and high chemical resistance. Traditional materials such as epoxies, phenolics, and polyacrylates no longer fully meet these requirements.

[0003] On the other hand, from the perspective of simplifying the process and reducing manufacturing costs, the manufacturing process of electronic devices such as chips / displays is increasingly inclined to select photosensitive organic polymer materials. The photosensitivity of this type of material can help to provide a thin film layer (also known as a relief pattern layer) with different convex and concave patterns at a lower cost. These relief pattern layers can provide an effective process solution for preparing deposited copper metal wires during chip packaging, thereby making it possible to transmit electrical signals between the chip and the external circuit. In addition, they can also be used as various insulating dielectric materials such as surface protection coatings, base layers, flat layers, pixel segmentation layers, and adhesive materials in display manufacturing processes. In these applications, organic polymer dielectric materials can simultaneously play the role of protection, insulation, packaging, buffering, bonding, and anti-metal migration.

[0004] Due to the above comprehensive requirements, photosensitive polyimide (PI), benzocyclobutene (BCB), and polybenzoxazole (PBO) have gradually become the mainstream photosensitive dielectric film materials. Each of these three materials has its own advantages, but all have some shortcomings in practical applications: the first photosensitive polyimide material is still the best choice for many processes, but it has the disadvantages of high water absorption and large film thickness loss during post-curing. The benzocyclobutene (BCB) material developed by Dow Electronic Chemicals in the United States has poor tensile properties and cannot solve the material stability problem caused by long-term thermal expansion and contraction in some applications. Photosensitive polybenzoxazole has been increasingly widely used in recent years due to its ability to use alkaline aqueous developers and its high tensile strength, but it also suffers from large film thickness loss during the process. It can be seen that the above-mentioned existing photosensitive compositions containing polyimide, benzocyclobutene, and polybenzobisoxazole, and the cured products prepared therefrom, still have various inconveniences and defects, and are in urgent need of further improvement.

[0005] Building upon the three previously described high-performance photosensitive materials, this invention introduces a novel negative-type photosensitive composition based on a polyimide precursor containing unsaturated bonds. Films prepared using this composition have demonstrated excellent mechanical properties, adhesion, long-term stability, and chemical resistance. Furthermore, while maintaining high mechanical properties, this new composition exhibits excellent developability and high resolution, resulting in significant market demand and application prospects. Summary of the Invention

[0006] The main purpose of the present invention is to overcome the defects of existing photosensitivity dielectric materials and provide a new negative photosensitive composition. The solid film prepared from the composition has excellent mechanical properties, insulation properties, adhesion, high temperature stability, low water absorption, high chemical corrosion resistance and other advantages.

[0007] Another main object of the present invention is to provide a patterned cured product prepared using the novel negative photosensitive composition.

[0008] Another object of the present invention is to provide application of the above-mentioned solidified material in a redistribution layer, an interlayer insulating buffer film, a cover coating or a surface protection film.

[0009] Another object of the present invention is to use the above-mentioned cured product in related electronic products.

[0010] The purpose of the present invention and the technical problem solved are achieved by adopting the following technical solutions: A negative photosensitive composition comprising:

[0011] (A) a polyimide precursor containing an unsaturated bond,

[0012] (B) a polymerizable monomer containing an unsaturated bond,

[0013] (C) a photopolymerization initiator, and

[0014] (D) Solvent.

[0015] The negative photosensitive composition according to claim 1, wherein the component (A) is a polyimide precursor structural unit containing an unsaturated bond represented by the following general formula (1):

[0016]

[0017] wherein p is an integer between 2 and 150. In the general formula (1), X is a trivalent organic group, wherein the -COOR1 group and one of the -CO- groups are ortho-positioned; Y is a divalent organic group; and R1 in the general formula (1) is a monovalent organic group represented by the following general formula (2).

[0018]

[0019] In the general formula (2), q is any integer between 1 and 30, wherein R2, R3 and R4 are the same or different monovalent organic groups selected from hydrogen or aliphatic hydrocarbon groups having 1 to 3 carbon atoms.

[0020] The purpose of the present invention and the technical problems solved therein are also achieved by adopting the following technical solutions. According to the negative photosensitive composition proposed in the present invention, it further comprises:

[0021] The negative photosensitive composition according to any one of claims 1 to 2, wherein the component (B) contains a polymerizable monomer having a group containing an unsaturated double bond.

[0022] The component (B) according to claim 3 has two or more groups containing unsaturated double bonds.

[0023] According to the negative photosensitive composition of claims 1 to 4, the component (C) is at least one photoinitiator, and the photoinitiator is selected from but not limited to benzophenone derivatives, acetophenone derivatives, thioxanthone derivatives, benzyl derivatives, benzoin derivatives, and oxime ester compounds.

[0024] The negative photosensitive composition according to claims 1 to 5, wherein the component (D) is an organic solvent comprising at least one compound selected from the group consisting of esters, ethers, ether-esters, ketones, ketone-ester hydrocarbons, aromatic compounds, and / or halogenated hydrocarbons.

[0025] The negative photosensitive composition of the present invention may contain various functional optional components as needed in addition to the above components. Examples of the optional components include a thickener, a sensitizer, a polymerization inhibitor, an anti-discoloration agent, and a leveling agent.

[0026] The purpose of the present invention and the technical problems solved therein are also achieved by the following technical solutions. The cured product having a relief pattern prepared from the negative photosensitive composition proposed in the present invention is prepared by a method comprising the following steps:

[0027] (a) coating the composition on a substrate and heating to remove the solvent to form a photosensitive resin film;

[0028] (b) exposing the photosensitive resin film to a pattern using a mask;

[0029] (c) removing the unexposed areas of the coating to obtain a cured resin film having a relief pattern, and

[0030] (d) a step of heating and curing the relief pattern resin film.

[0031] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0032] The aforementioned cured product having a relief pattern, wherein the temperature of the heating treatment is 300-400°C.

[0033] The aforementioned cured product having a relief pattern is a cured product film having a micron-structured relief pattern.

[0034] The purpose of the present invention and the technical problems solved therein are also achieved by the following technical solutions: The solidified material with the relief pattern proposed in the present invention is applied to a redistribution layer, an interlayer insulating buffer film, a cover coating or a surface protection film.

[0035] The purpose of the present invention and the technical problems solved therein are also achieved by adopting the following technical solutions: An electronic device proposed in the present invention comprises the aforementioned redistribution layer, interlayer insulating buffer film, covering coating or surface protection film.

[0036] As can be seen from the foregoing, the present invention discloses a novel polyimide precursor, a negative-type photosensitive composition containing this polyimide precursor, and applications of the composition. The negative-type photosensitive composition comprises the following raw materials in certain weight percentages: (A) a polyimide precursor containing an unsaturated bond, (B) a polymerizable monomer containing an unsaturated bond, (C) a photopolymerization initiator, and (D) a solvent. After photolithography and curing, the composition produces a cured film having a convex-concave structure. This cured film can be used in electronic devices as a redistribution layer, interlayer insulating buffer film, cover coating, or surface protective film material.

[0037] Compared with the prior art, the present invention has obvious advantages and beneficial effects. As can be seen from the above technical solutions, in order to achieve the above-mentioned invention objectives, the main technical contents of the present invention are as follows:

[0038] A negative photosensitive composition containing (A) a polyimide precursor containing an unsaturated bond, (B) a polymerizable monomer containing an unsaturated bond, (C) a photopolymerization initiator, and (D) a solvent, a cured product prepared therefrom, and its use in semiconductor packaging.

[0039] By virtue of the above technical solution, the negative photosensitive composition, the cured product prepared therefrom, and its application in semiconductor packaging proposed in the present invention have at least the following advantages:

[0040] In light of the various drawbacks of conventional photosensitive dielectric materials, the present invention utilizes a novel negative-type photosensitive composition containing a polyimide precursor with unsaturated bonds. It has been found that this composition can produce films with excellent relief microstructures. Furthermore, after curing, this resin composition exhibits excellent adhesion to various substrates. Finally, by using a fluorine-containing polyimide precursor in the composition, these new materials exhibit improved light transmittance at I-line wavelengths and reduced water absorption, making the cured films produced from this composition more suitable for current advanced packaging process requirements.

[0041] In summary, the technical solution of the present invention has the above-mentioned many advantages and practical value, and is truly innovative because no similar design has been publicly published or used in similar products. It has made significant improvements in both formulation and function, and has produced easy-to-use and practical effects. It also has multiple enhanced functions compared to existing products, making it more suitable for practical use and has wide industrial utilization value. It is truly a novel, progressive and practical new design.

[0042] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is an embodiment of the present invention, which involves the fabrication of a redistribution layer. DETAILED DESCRIPTION

[0044] To further illustrate the technical means and effectiveness of the present invention in achieving its intended purpose, the following describes in detail the negative photosensitive composition, the cured product prepared therefrom, and its application in semiconductor packaging according to the present invention.

[0045] The term "(meth)acrylate" used in this specification is a general term for "acrylate" and "methacrylate".

[0046] The photosensitive resin composition of the present invention contains: (A) a polyimide precursor containing an unsaturated bond (hereinafter also referred to as "(A) component"), (B) a polymerizable monomer containing an unsaturated bond (hereinafter also referred to as "(B) component"), (C) a photopolymerization initiator (hereinafter also referred to as "(C) component"), and (D) a solvent (hereinafter also referred to as "(D) component").

[0047] The photosensitive resin composition of the present invention is a negative-working photosensitive resin composition. The present invention is further described below by exemplifying the various components of the composition. It should be noted that the present invention is not limited to these examples, and those skilled in the art will be able to make various modifications within the technical concept of the present invention.

[0048] 1. (A) Ingredients:

[0049] The component (A) in the negative photosensitive composition of the present invention is a novel polyimide precursor structural unit containing an unsaturated bond as shown in the following general formula (1):

[0050]

[0051] wherein p is an integer between 2 and 150. In the general formula (1), X is a trivalent organic group, wherein the -COOR1 group and one of the -CO- groups are ortho-positioned; Y is a divalent organic group; and R1 in the general formula (1) is a monovalent organic group represented by the following general formula (2).

[0052]

[0053] In the general formula (2), q is any integer between 1 and 30, wherein R2, R3 and R4 are the same or different monovalent organic groups selected from hydrogen or aliphatic hydrocarbon groups having 1 to 3 carbon atoms.

[0054] Furthermore, X in the general formula (1) is a trivalent aromatic linking group, which may be different or the same groups represented by the following general formula (3), (4), or (5);

[0055]

[0056] Wherein Q in Formula-4 is a direct bond or a divalent organic group, wherein the organic group is selected from O, S, CO, SO2, Si(CH3)2, CH(OH), (CH2) p (1≤p≤10), (CF2) m(1≤m≤10), C(CH3)2, C(CF3)2, substituted or unsubstituted o-, m-, p-phenylene, and phenyl ether (C6H4-O-C6H4) n (1 ≤n≤10); H and I in Formula-5 are the same or different organic groups selected from CH2, O, S, C=O, O=S=O, O=P-(Ph), CHOH, C(CH3)2, C(CF3)2, and Si(CH3)2.

[0057] Wherein Y in the general formula (1) is a divalent aromatic linking group, which can be different or the same groups represented by the following general formula (6) or (7);

[0058]

[0059] wherein R5, R6, R7, and R8 represent a hydrogen atom or a monovalent organic group;

[0060]

[0061] Wherein said U is a direct bond or a divalent organic group, said organic group is selected from O, S, CO, SO2, Si(CH3)2, CH(OH), (CH2) p (1≤p≤10), (CF2) m (1≤m≤10), C(CH3)2, C(CF3)2, substituted or unsubstituted o-, m-, p-phenylene, wherein R9~R 16 are the same or different monovalent organic groups selected from H, CH3, or CF3.

[0062] In addition, the transmittance of the i-line directly affects the resolution of the photosensitive composition during the process. In order to obtain the optimal microstructure relief pattern under the same film thickness conditions, the (A) component of the negative photosensitive composition preferably has a polyimide monomer structure with good transmittance, which can be achieved by selecting Y in the (A) component as a diamine precursor containing fluorine. These fluorine-containing monomers are also beneficial in reducing the effect of the solution on the immersion swelling of the film during development, thereby inhibiting exudation from the surface, and can also reduce the water absorption of the composition after curing. Therefore, from the perspective of transmittance and water absorption, Y in the negative photosensitive composition (A) component preferably contains a trifluoromethyl group and has a structural unit represented by the following general formula (8).

[0063]

[0064] Films prepared from the negative photosensitive composition are typically developed using organic solvents. Therefore, polyimide precursors with high solubility in organic solvents are preferred. This requires that the weight-average molecular weight of the polyimide precursor (component (A)) in the present invention be generally between 5,000 and 200,000, preferably between 10,000 and 150,000. The molecular weight is determined by gel permeation chromatography (GPC) and calculated using a standard polystyrene calibration curve.

[0065] The above-mentioned method for synthesizing the polyimide precursor is not particularly limited. A method for synthesizing a polyimide precursor is described below in detail with reference to several synthesis examples. Here, a compound having a carboxylic acid anhydride group and a monocarboxylic acid group, as shown in Formula 9, is used as another monomer structure in addition to the diamine in the synthesis.

[0066]

[0067] Synthesis example 1:

[0068] First, a compound represented by formula (9-1) (100 mmol), 2-hydroxyethyl methacrylate (HEMA, 100 mmol) and hydroquinone (0.110 g) dried in a dryer were added to a three-necked flask and dissolved in N-methyl-2-pyrrolidone (NMP, 198 g). After adding a catalytic amount of 1,8-diazabicycloundecene (DBU), the mixture was stirred at room temperature (25°C) for 36 hours for esterification to obtain a HEMA esterification solution of the corresponding acid.

[0069] Then, thionyl chloride (212 mmol) was added dropwise over half an hour to the HEMA esterification solution obtained in the above step in a stirrer and a thermometer while cooling in an ice bath (maintaining the reaction solution temperature at 10°C or less). After the addition of thionyl chloride was completed, the reaction was continued for 1.5 hours while cooling in an ice bath to obtain an acyl chloride solution.

[0070] Finally, using a dropping funnel, a mixed solution containing 2,2'-bis(trifluoromethyl)benzidine (100.0 mmol), pyridine (430 mmol), hydroquinone (0.08 g), and N-methyl-2-pyrrolidone (NMP, 90 g) was added dropwise to the reaction flask containing the acid chloride solution, maintaining the solution temperature at no more than 10°C. After the reaction, the reaction solution was added dropwise to a flask filled with a large amount of distilled water. The precipitate was collected by filtration with stirring and then dried under reduced pressure to obtain a polyimide precursor (referred to as Polymer-1). The structure is shown below. Its molecular weight is 42,020, and its polydispersity (PD) is 1.52.

[0071]

[0072] The same synthesis method was adopted, except that the diamine precursor was replaced with the same molar amounts of 4,4'-diaminodiphenyl ether, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, and 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, respectively, to obtain the following polyimide precursors: polymer-2 (molecular weight of 39,030, dispersity of 1.59), and polymer-3 (molecular weight of 49,250, dispersity of 1.64), respectively.

[0073]

[0074] The synthesis method of polymer-4 is exactly the same as that of polymer-1, except that the compound represented by formula-(9-1) is replaced by the compound monomer represented by formula-(9-2), and the following polymer-4 (molecular weight is 38,270, and dispersity is 1.55) is obtained.

[0075]

[0076] The polyimide precursor containing an unsaturated bond as the component (A) may be used alone or in combination of two or more in the negative photosensitive composition.

[0077] Component (B): Polymerizable monomer containing an unsaturated bond

[0078] Component (B) in the negative photosensitive composition of the present invention is a polymerizable monomer containing an unsaturated bond. The polymerizable monomer is preferably a (meth)acrylate compound. To increase crosslinking density and sensitivity and suppress post-development pattern swelling, the (meth)acrylate compound preferably contains two or more polymerizable unsaturated double bonds, as shown in Formula 10 below.

[0079]

[0080] The component (B) may be used alone or in combination of two or more. The amount of the component (B) is preferably 3 to 80 parts by mass, more preferably 5 to 50 parts by mass, per 100 parts by mass of the component A.

[0081] Component (C): Photopolymerization initiator

[0082] The photoinitiator (C) in the present invention is a compound that generates free radicals upon exposure to light. In the negative photosensitive composition according to claims 1 to 4, component (C) is at least one photoinitiator selected from, but not limited to, benzophenone derivatives, acetophenone derivatives, thioxanthone derivatives, benzyl derivatives, benzoin derivatives, and oxime ester compounds. From the perspectives of sensitivity and imaging properties, oxime ester compounds such as those represented by the following formula 11 are preferred.

[0083]

[0084] After film formation, the negative-type photosensitive composition containing an oxime ester compound photoinitiator generates free radicals through mask exposure, which causes crosslinking of the film components, significantly reducing the solubility of the exposed portions. In the unexposed portions, these photoinitiators do not chemically react, maintaining good solubility in the developer. This results in a significant contrast in dissolution rates between the exposed and unexposed (dark) areas, resulting in a film with a microstructured relief pattern after the development step.

[0085] Component (C) can be used alone, in combination of two or more, or in combination with a sensitizer in the negative photosensitive composition. The amount of component (B) is preferably 0.5 to 20 parts by mass, more preferably 1 to 20 parts by mass, relative to 100 parts by mass of component (A). Within this range, the exposed polymer will undergo a significant degree of crosslinking, resulting in a practical relief pattern with uniform film thickness.

[0086] 4. Component (D): Solvent

[0087] In the negative photosensitive composition according to claims 1 to 5, component (D) is an organic solvent comprising at least one compound selected from the group consisting of esters, ethers, ether-esters, ketones, ketone-ester hydrocarbons, aromatic compounds, and / or halogenated hydrocarbons. Component (D) dissolves components (A), (B), and (C) to form a varnish. Generally, there are no particular limitations as long as the solvent can fully dissolve the other components in the negative photosensitive composition. Commonly used solvents include N-methyl-2-pyrrolidone, γ-butyrolactone, ε-caprolactone, cyclopentanone, dimethyl sulfoxide, 2-methoxyethanol, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butanediol acetate, 1,3-butanediol acetate, cyclohexanone, and tetrahydrofuran. Among these solvents, N-methyl-2-pyrrolidone, γ-butyrolactone, and cyclopentanone are preferably used from the viewpoint of excellent solubility and coating properties of the resin film.

[0088] Component (D) can be used alone or in combination in the negative photosensitive composition. The content of component (D) is not particularly limited; however, from the perspective of controlling film thickness and coating process coatability, the content of component (D) is preferably 60 to 600 parts by mass, and more preferably 100 to 400 parts by mass, relative to 100 parts by mass of component (A).

[0089] 5. Other ingredients of the composition

[0090] In addition to the aforementioned components (A), (B), (C), and (D), the negative photosensitive composition of the present invention may also contain other auxiliary ingredients as needed, such as crosslinkers, corrosion inhibitors, tackifiers, sensitizers, polymerization inhibitors, nanoparticles, and surfactants. The addition of these auxiliary ingredients is essential so as not to substantially impair the basic physical properties of the final cured film of the present invention. Furthermore, their addition often improves the processing properties of the material or enhances certain characteristics of the final cured film, making it more suitable for specific processes. The following describes each of these ingredients and their functions in detail.

[0091] Crosslinker: The negative photosensitive composition of the present invention may contain a crosslinker component. The crosslinker typically undergoes a crosslinking reaction with other components of the negative photosensitive composition during the curing step. Therefore, a compound that does not react with other components of the negative photosensitive composition is preferred. The crosslinker component includes at least one alkoxy compound, peroxide, epoxy compound, oxetane compound, or vinyl ether compound. From the perspective of mechanical properties of the cured film and high reactivity during low-temperature curing, a compound represented by the following formula (12) is preferred.

[0092]

[0093] To achieve optimal resolution and chemical resistance of the cured film, the crosslinker content is preferably 3 to 50 parts by mass, more preferably 5 to 40 parts by mass, relative to 100 parts by mass of component (A). If the crosslinker content is less than 3 parts by mass, the resolution will not be significantly improved; if the crosslinker content is greater than 50 parts by mass, the mechanical properties of the material may be degraded. The crosslinker component may be used alone or in combination of two or more.

[0094] Corrosion inhibitor - When the negative photosensitive composition of the present invention is applied to a copper or copper alloy substrate, in order to suppress discoloration and stability reduction caused by copper corrosion, at least one compound containing a triazole ring, an imidazole ring, and a thiazole ring as shown in the general formula (13) containing carbon atoms and nitrogen atoms can be added to the composition. Examples of the azole compound include 1H-triazole, 1H-benzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 1,5-dimethyltriazole, 4,5-diethyl-1H-triazole, 4-tert-butyl-5-phenyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 5-phenyl-1H-triazole, 5-hydroxyphenyl-1H-triazole, p-ethoxyphenyltriazole, 5-phenyl-1-(2-dimethylaminoethyl)triazole, 5-benzyl-1H-triazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, 2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-tert-butyl-5-methyl-2-hydroxyphenyl)-benzotriazole, 2-(3,5-di-tert-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, hydroxyphenylbenzotriazole, tolyltriazole, 4-methyl-1H-benzotriazole, 4-carboxy-1H-benzotriazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, tetrazole, 5-amino-tetrazole, 1-methyl-1H-tetrazole, and the like.

[0095]

[0096] In order to obtain the best anti-metal corrosion effect, the content of the anti-corrosion agent is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the component (A1).

[0097] Adhesion Promoter - To improve the adhesion between the cured film formed from the negative photosensitive composition of the present invention and the substrate, an adhesion promoter (adhesion promoter) component may be optionally added to the negative photosensitive composition. The adhesion promoter may be an organosilane compound or an aluminum-based adhesion promoter such as tris(ethylacetoacetoxy)aluminum, tris(acetylacetonato)aluminum, or ethylaluminum diisopropyl acetoacetate. Organosilane compounds are preferred for improving adhesion to substrates such as copper. The organic silane compounds include: 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-[bis(2-hydroxyethyl)amino]propane-triethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, triethoxysilylpropylethyl carbamate, 3-(triethoxysilyl)propylsuccinic anhydride, phenyltriethoxysilane, phenyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. These organosilane compounds may be used alone or in combination of two or more.

[0098] The content of the tackifier component in the composition is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 6 parts by mass, relative to 100 parts by mass of the component (A), from the viewpoint of improving adhesion to the substrate.

[0099] Sensitizer - The negative photosensitive composition of the present invention may further contain a sensitizer. Examples of the sensitizer include benzylideneacetophenone, 4'-N,N-dimethylaminobenzylideneacetophenone, 4'-acetylaminobenzylidene-4-methoxyacetophenone, dimethylaminobenzophenone, diethylaminobenzophenone, 4,4'-bis(N-ethyl,N-methyl)benzophenone, and 4,4'-bis-(diethylamino)benzophenone. These sensitizers may be used alone or in combination of two or more. The content of the sensitizer in the composition is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of component (A).

[0100] Polymerization Inhibitor - To enhance the long-term storage stability of the negative photosensitive composition of the present invention, the negative photosensitive composition of the present invention may further contain a polymerization inhibitor. Examples of such inhibitors include 2,6-di-tert-butyl-p-cresol, m-dinitrobenzene, N-phenyl-2-naphthalene, and nitrosamines. These polymerization inhibitors may be used alone or in combination of two or more. The content of the polymerization inhibitor in the composition is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of component (A).

[0101] Nanoparticles - The resin composition of the present invention may further contain nanosized particles. These nanoparticles are added to the composition, particularly to improve the optical properties, hardness, thermal expansion coefficient, and other aspects of the resulting cured film. Examples of nanoparticles include silicon oxide, titanium oxide, aluminum oxide, and zirconium oxide. These nanosized particles preferably have a particle size of 70 nm or less and are surface-modified. The content of the nanoparticles is preferably 0.5 to 50 parts by mass, more preferably 2 to 30 parts by mass, per 100 parts by mass of component (A).

[0102] Surfactant - To improve coating properties and surface smoothness during spin coating, a surfactant can be added to the composition as a leveling agent. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene octylphenol ether. Commercially available examples include Megafac F171 and F173 (manufactured by Dainippon Ink & Chemicals Co., Ltd.); organosiloxanes KP341, KBM303, and KBM803 (manufactured by Shin-Etsu Chemical Co., Ltd.); and fluorinated surfactants such as PolyFox PF-6320 (manufactured by Omnova Solutions) and Fluorad FC430 and FC171 (manufactured by Sumitomo 3M Co., Ltd.). The surfactant content is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, per 100 parts by mass of component (A).

[0103] The following Table 1 is a preferred embodiment of the negative photosensitive composition of the present invention.

[0104] In these embodiments and tables, component A is set to 100 parts by mass, and the numbers in brackets () after each component represent the specific proportion of this component in these 100 parts by mass; the numbers in brackets () after other components (including component (B), component (C), component (D), and optional other components) represent the specific mass parts of this component relative to 100 parts by mass of component A.

[0105] In addition, in these embodiments, the specific information of other components used in addition to the aforementioned unsaturated bond-containing polyimide (A) is as follows:

[0106]

[0107] (C-1):OXE-1 (BASF, Germany)

[0108] (C-2):TR-PBG-3057 (Changzhou Qiangli New Materials, China)

[0109] (C-3):TR-PBG-346 (Changzhou Qiangli New Materials, China)

[0110] (D-1): N-methyl-2-pyrrolidone (NMP)

[0111] (D-2): 80% γ-butyrolactone + 10% cyclopentanone + 10% ethyl lactate

[0112] (E-1): Tetrazolium

[0113] (E-2):5-amino-tetrazole

[0114] (E-3):1H-Benzotriazole

[0115] (F-1): 3-(2,3-Epoxypropyloxy)propyltrimethoxysilane

[0116] (F-2): 3-[Bis(2-hydroxyethyl)amino]propane-triethoxysilane

[0117] (F-3):γ-ureidopropyltriethoxysilane

[0118] Example 1: The polymer-1 (100 parts by mass) obtained in Synthesis Example 1, the B-3 component (15 parts by mass), and the photoinitiator C-1 (2 parts by mass) are dissolved in N-methyl-2-pyrrolidone (NMP) (D-1, 160 parts by mass), and E-2 (1.5 parts by mass) as an anti-corrosion agent and F-3 (3 parts by mass) as a thickener are added to obtain the negative photosensitive resin composition described in the present invention.

[0119] The preparation methods of Examples 2 to 10 and Comparative Examples 1 to 2 are exactly the same as those of Example 1, except that the components or contents used therein are different. Detailed information is shown in Table 1 below.

[0120] Table-1

[0121]

[0122] NA: indicates that the composition does not contain such component.

[0123] The negative photosensitive composition (also known as varnish) obtained from the above Examples / Comparative Examples was filtered through a polytetrafluoroethylene filter membrane to obtain the final negative photosensitive composition. Depending on the polymer concentration in the composition and the viscosity of the varnish, a polytetrafluoroethylene filter membrane with a pore size of 0.45-3 microns can be selected. The varnish obtained from the above Examples / Comparative Examples was then coated onto a copper wafer to form a negative photosensitive cured film according to the method described in claim 7.

[0124] 6. Manufacturing method and application of solidified materials

[0125] Hereinafter, embodiments of the present invention are described in detail for a method for producing a patterned cured product, a cured product, a redistribution layer, an interlayer insulating buffer film, a cover coat or a surface protection film, and an electronic device. It should be noted that the present invention is not limited to the following embodiments.

[0126] A method for preparing a patterned cured product using the negative photosensitive composition of the present invention comprises the following steps:

[0127] (a) Resin Film Formation Step: A step of applying the negative photosensitive composition described in claims 1 to 6 onto a substrate and heating and drying to remove the solvent, thereby forming a photosensitive resin film. Examples of substrates include semiconductor substrates such as Si substrates (silicon wafers), ceramic substrates, metal substrates (including copper substrates, aluminum substrates, copper alloy substrates, etc.), and silicon nitride substrates. Coating methods include spin coating, spray coating, and dipping. For controlling film thickness, spin coating using a spin coater is preferred. Heating and drying can be performed using a hot plate, oven, or the like. The heating and drying temperature is preferably 90 to 150°C, more preferably 90 to 130°C, and the heating time is preferably 60 to 500 seconds.

[0128] (b) Exposure step: The step of subjecting the photosensitive resin film to pattern exposure using a mask. Pattern exposure involves, for example, exposing the film to a predetermined pattern through a photomask. Examples of active light used for irradiation include ultraviolet rays such as i-rays, visible light, and radiation, with i-rays being preferred. Examples of exposure equipment include a scanner, projection exposure system, and stepper.

[0129] (c) Development Step: By performing the development step, a resin film having a microstructure relief pattern can be obtained. Development is generally performed by methods such as immersion and rotary spraying. When a negative-type photosensitive composition is used in the present invention, a developer can remove the unexposed portions of the film, thereby obtaining a relief pattern. The development time is generally 10 seconds to 15 minutes, and preferably 20 seconds to 5 minutes for improved productivity and process control. Developers can be selected from N-methyl-2-pyrrolidone, cyclopentanone, N-acetyl-2-pyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, α-acetyl-γ-butyrolactone, and cyclohexanone. To these developers, an appropriate amount of surfactant can be added as needed to enhance the development effect. Cyclopentanone is preferred among these developers. After development, the developer can be removed using a rinse solution to obtain a patterned film. As a rinse solution, ethanol, isopropyl alcohol, toluene, xylene, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, etc. can be used alone or in combination. After the negative photosensitive composition is prepared as a solution, it is spin-coated onto a substrate such as a silicon wafer and heated and dried to remove the solvent, forming a resin film approximately 10 microns thick. This film is then immersed in a cyclopentanone solvent at 20-25°C. The time required for the film to completely dissolve determines the ease with which component (A) dissolves in the organic developer solution.

[0130] (d) Heating and curing step: The heating treatment step is a process of heating and curing the relief pattern resin film to obtain the optimal physical properties of the material. In this step, the relief pattern obtained by the above-mentioned development is heated to convert it into a cured relief pattern. A method using a hot plate or an oven can be selected, and the heating temperature is preferably 300-400°C. The heating treatment time is usually 30 minutes to 4 hours, more preferably 30 minutes to 2 hours, considering the time required for the cross-linking reaction. The atmosphere for the heating treatment is usually carried out in an atmosphere of inert gases such as nitrogen and argon. In order to prevent the oxidation of the pattern resin film and the process cost, it is preferably heated and cured in an atmosphere of high-purity nitrogen (≥99.999%).

[0131] The cured product of the present invention is a cured film of the polymer resin obtained by the above-mentioned treatment process. This film can be either a cured film having a relief pattern as described above or a cured film without a pattern.

[0132] As a cured film, it can be laminated directly onto a semiconductor device or sandwiched between other layers. It can also be used to encapsulate other materials, such as metal conductors, acting as an insulating medium. Examples of applications include redistribution layers, interlayer insulating buffer films, cover coatings, or surface protection film materials.

[0133] The cured product of the present invention is a cured film of the polymer resin obtained by the above-mentioned treatment process. This film can be either a cured film having a relief pattern as described above or a cured film without a pattern.

[0134] As a cured film, it can be laminated directly onto a semiconductor device or sandwiched between other layers. It can also be used to encapsulate other materials, such as metal conductors, acting as an insulating medium. Examples of applications include redistribution layers, interlayer insulating buffer films, cover coatings, or surface protection film materials.

[0135] The following is combined with Figure 1 An example of a method for manufacturing a redistribution layer according to the present invention will be described.

[0136] Figure 1 (Schematic diagram of a structural cross section) is a construction of a redistribution layer structure using the composition of the present invention and its embodiment. It should be noted that the film thickness and device size ratio in the figure do not represent the actual ratio. In this embodiment, through the design of a two-layer wiring structure, the signal can realize the signal input / output function between the chip (Al Pad: aluminum contact plate electrode) and the outside world (SolderBump: solder ball). The two-layer wiring structure is realized by copper redistribution layer leads (Cu RDL) wrapped on insulating material polymer layers (polymer layer 1 and polymer layer 2). As Figure 1 As shown, copper wires connect the aluminum contact plate electrodes (Al Pad) and solder bumps on the chip. In the next process after packaging, the solder bumps will be connected to other packages or the motherboard to achieve package-to-package or package-to-motherboard connections. The connection between the solder bumps and the copper wires is achieved through the under-ball metallization layer (UBM stud). The two layers of insulating material (polymer layer 1 and polymer layer 2) use the polyimide cured film described in the present invention. This design and construction allows for rewiring and optimization of the contact electrode position / size. In addition, the polyimide cured film here is not only an insulating dielectric material that wraps the copper wires, but also plays a structural role in alleviating internal stress. These materials need to have good long-term stability to maintain excellent stability and material recovery capabilities during the thermal expansion and contraction cycles caused by temperature changes and the accompanying stress changes.

[0137] By using one or more of the above-mentioned redistribution layers, interlayer insulating buffer films, covering coatings or surface protection film materials, it is possible to manufacture electronic components such as semiconductor packages, multilayer circuit boards, and display circuits with high reliability and good stability.

[0138] 7. Evaluation of Negative Photosensitive Resin Composition

[0139] Adhesion Evaluation - The cured film in this invention is primarily used as an insulating material for wrapping copper conductors, so good adhesion between the two materials is a critical material parameter. The present invention utilizes the following American Society for Testing and Materials (ASTM) standard method to evaluate the material's adhesion: D3359, Standard Test Methods for Measuring Adhesion by Tape Test. The specific procedure is as follows: The resulting cured film (on a copper substrate) without a relief pattern is cut vertically into 10×10 grids (each grid measuring 1 mm x 1 mm) using a zigzag razor blade. Adhesive tape (manufactured by 3M) is applied to these small pieces of cured film according to the ASTM D3359 method, and the tape is then peeled off. The material's adhesion is determined by the number of small pieces of cured film that peel off from the substrate when the tape is peeled off. In this invention, the following criteria, A or B, are used to determine the adhesion of the material film to the copper substrate. Detailed results are listed in Table 2.

[0140] A: No peeling grid

[0141] B: The number of peeling grids is at least 1

[0142] As can be seen from Table 2 below, the cured film obtained by the present invention generally has excellent adhesion to the copper substrate.

[0143] Evaluation of Discoloration Inhibition - The appearance of the resulting cured film covering the copper metal was evaluated using an optical microscope and the naked eye. If the cured film well retained the original color of the underlying copper metal film after curing, it was evaluated as A: Discoloration Inhibited. If the color of the copper beneath the cured film shifted significantly to a dark red / brown color, it was evaluated as B: Discoloration Not Inhibited. Detailed results are listed in Table 2.

[0144] A: Suppressed discoloration

[0145] B: Discoloration not suppressed

[0146] In summary, the polyimide cured film proposed in the present invention effectively solves the shortcoming of this type of material having poor adhesion to the copper substrate material, and plays an excellent protective role for the copper metal of the substrate.

[0147] Table-2

[0148] Examples / Comparative Examples Adhesion Discoloration inhibition Example #1 A A Example #2 A A Example #3 A A Example #4 A A Example #5 A A Example #6 A A Example #7 A A Example #8 A A Example #9 A A Example #10 A A Comparative Example #1 Unable to form film Unable to form film Comparative Example #2 Unable to form film Unable to form film Comparative Example #3 A B Comparative Example #4 B A

[0149] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the present profession can make slight changes or modifications to equivalent embodiments of the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A negative photosensitive composition comprising at least: (A) A polyimide precursor containing an unsaturated bond, wherein the polyimide precursor structure is: (B) a polymerizable monomer containing an unsaturated bond, (C) a photopolymerization initiator, (D) solvent, (E) corrosion inhibitors, and (F) Thickener. 2 . The negative photosensitive composition according to claim 1 , wherein the polymerizable monomer containing an unsaturated bond contains a polymerizable monomer having a group containing an unsaturated double bond. 3 . The negative photosensitive composition according to claim 2 , wherein the polymerizable monomer containing an unsaturated bond has two or more unsaturated double bond groups.

4. The negative photosensitive composition according to claim 1, wherein the photopolymerization initiator is at least one photoinitiator selected from benzophenone derivatives, acetophenone derivatives, thioxanthone derivatives, benzyl derivatives, benzoin derivatives, and / or oxime ester compounds.

5. The negative photosensitive composition according to claim 1, wherein the solvent is an organic solvent comprising at least one compound selected from the group consisting of esters, ethers, ether-esters, ketones, keto-ester hydrocarbons, aromatic compounds, and / or halogenated hydrocarbons.

6. A cured article having a relief pattern, the cured article being prepared by a method comprising the following steps: (a) coating the negative photosensitive composition according to claim 1 on a substrate and heating to remove the solvent to form a photosensitive resin film; (b) exposing the photosensitive resin film to a pattern using a mask; (c) removing the unexposed areas of the coating to obtain a cured resin film having a relief pattern, and (d) a step of heating and curing the cured resin film having the relief pattern. 7 . The cured product having a relief pattern according to claim 6 , wherein the temperature of the heating and curing treatment is 300-400° C. The cured product having a relief pattern according to claim 6 , which is a cured product film having a microstructured relief pattern.

9. Use of the cured product having a relief pattern according to any one of claims 6 to 8 in a redistribution layer, an interlayer insulating buffer film, a cover coating, or a surface protection film. 10 . An electronic device comprising the redistribution layer, interlayer insulating buffer film, cover coating, or surface protection film according to claim 9 .

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