Photosensitive polyimide photoresist and method for preparing the same

Abstract

The application provides a photosensitive polyimide photoresist and a preparation method thereof. The photosensitive polyimide photoresist comprises 20-50 parts by weight of polyimide, 2-10 parts by weight of a small-molecule monomer containing a double bond or a triple bond, 2-10 parts by weight of a thiol monomer, 1-10 parts by weight of a photoinitiator and 30-70 parts by weight of an organic solvent. The polyimide is polymerized from a magnolol-based bio-based diamine monomer and aromatic diamine monomers and aromatic dianhydride monomers. Compared with the prior art, the photosensitive polyimide photoresist prepared by the application has good low-temperature curing and photo pattern performance, and the cured film has good thermal and optical transmission performance, can be applied to the fields of photoelectric and optical devices, and conforms to the development trend of green and sustainable development.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high molecular compounds, in particular to a photosensitive polyimide photoresist and a preparation method thereof. BACKGROUND

[0002] Polyimide (PI) as a kind of special engineering material, has been widely used in aviation, aerospace, microelectronics, nanometer, liquid crystal, separation membrane, laser and other fields. Due to excellent thermal stability, mechanical properties, dielectric properties and solution processability, polyimide is also an important insulating material in the semiconductor industry. For example, polyimide is used as a buffer layer, passivation layer, planarization layer of multi-layer interconnection and interlayer dielectric layer in integrated circuits. In these applications, polyimide film needs to be patterned to realize the interconnection of specific areas of the semiconductor chip.

[0003] In the early semiconductor industry, the patterning of polyimide is realized by means of photoresist, that is, a layer of photoresist is coated on the surface of polyimide, and after the photoresist is patterned, the bottom layer of polyimide is treated by chemical etching and other methods, so as to transfer the pattern of the photoresist to the polyimide layer. In order to simplify the process of patterning polyimide, researchers endow polyimide with photosensitivity, that is, to synthesize photosensitive polyimide (PSPI), and to compose photosensitive polyimide photoresist with photosensitive polyimide and additives such as photoinitiator, and to directly make patterns on the photosensitive polyimide layer by using photolithography technology, so as to realize the self-patterning of the photosensitive polyimide.

[0004] However, the traditional PSPI material needs to be treated at high temperature, and shows low transparency, which limits its application in heat-sensitive optical devices. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a photosensitive polyimide photoresist and a preparation method thereof.

[0006] In a first aspect, the present application provides a photosensitive polyimide photoresist, which comprises 20-50 parts by weight of polyimide, 2-10 parts by weight of small molecule monomer containing double bond or triple bond, 2-10 parts by weight of thiol monomer, 1-10 parts by weight of photoinitiator, and 30-70 parts by weight of organic solvent.

[0007] The general structure of the polyimide is as follows:

[0008]

[0009] In the formula, n and m represent the degree of polymerization, n is an integer of 1-150, m is an integer of 1-150, Ar is an aromatic unit fragment in the bio-based diamine monomer based on magnolol, X is a four-valent aromatic hydrocarbon group, and Ar1 is the residue of diamine.

[0010] The structure general formula of the bio-based magnolol-based diamine monomer is:

[0011]

[0012] wherein R1 is selected from any one of an ester group or an ether bond; and Ar1 is selected from any one of the following structures:

[0013]

[0014] wherein R1, R2, R3, and R4 are the same as or different from each other, and each is independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, t-butyl, oxymethyl, or oxybutyl;

[0015] Ar2 is selected from any one of the following structures:

[0016]

[0017] wherein R5, R6, R7, and R8 are the same as or different from each other, and each is independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, t-butyl, oxymethyl, or oxybutyl.

[0018] In one embodiment, X is preferably selected from any one of:

[0019]

[0020] In one embodiment, Ar1 is preferably selected from any one of:

[0021]

[0022] In one embodiment, the small molecule monomer containing a double bond or a triple bond includes at least one of N,N'-methylenebisacrylamide, N,N'-1,6-hexanediylbis[2-methyl-2-propenamide], N,N'-(1,2-dihydroxy-1,2-ethanediyl)bis[2-methyl-2-propenamide], diallylamine, N-methyldiallylamine, tetraethylene glycol dimethacrylate, tripropylene glycol trimethacrylate, 1,3,5-triallyl cyanurate, 1,3,5-triallylisocyanurate, triallyl phosphate, ethylene glycol 1,2-bis(2-propynyl) ether, and 3,3-dimethyl-1-butyne.

[0023] In one embodiment, the thiol monomer includes at least one of trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate), tris[2-(3- mercaptopropoxy)ethyl] isocyanurate, and 2,2'-(1,2-ethanediylbis(oxy))bisethanethiol.

[0024] In one embodiment, the photoinitiator includes at least one of Michler's ketone, benzophenone, benzoin, 2,4,6-trimethylbenzoylphenyl ethylphosphonate, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, a,a'-diethoxyacetophenone, and thioxanthone.

[0025] In a second aspect, the present application provides a preparation method of the photosensitive polyimide photoresist as described above, comprising the following steps:

[0026] (1) Taking magnolol as a raw material, a bio-based diamine monomer based on magnolol is prepared;

[0027] (2) The bio-based diamine monomer based on magnolol is polymerized with an aromatic diamine monomer and an aromatic dianhydride monomer to obtain a polyimide, wherein the aromatic diamine monomer is p-phenylenediamine, m-phenylenediamine, or a flexible aromatic diamine;

[0028] (3) The polyimide is dissolved in an organic solvent under a protective atmosphere, then a small-molecule monomer containing a double bond or a triple bond is added, stirring is performed, a mercaptan monomer and a photoinitiator are continuously added to the system, and stirring is continuously performed to obtain a photosensitive polyimide photoresist.

[0029] In one embodiment, step (1) comprises: reacting magnolol with bromobenzoyl chloride containing R1, R2, R3, and R4 in aprotic solvent and alkaline environment at low temperature to obtain an allyl-containing bromo compound; and obtaining the diamine monomer by Suzuki reaction of the bromo compound with aminobenzenboronic acid or benzenboronic ester containing R5, R6, R7, and R8.

[0030] In one embodiment, step (1) comprises: reacting magnolol with bromonitrobenzene containing R1, R2, R3, and R4 in aprotic high-polarity solvent and alkaline environment to obtain an allyl-containing dinitro compound; and obtaining the diamine monomer by Suzuki-Miyaura coupling reaction of the dinitro compound with aminobenzenboronic acid or benzenboronic ester containing R5, R6, R7, and R8.

[0031] In one embodiment, step (2) comprises: mixing the bio-based diamine monomer based on magnolol, the aromatic diamine monomer, the aromatic dianhydride monomer, and a third organic solvent to perform copolymerization reaction to obtain polyamic acid; and mixing the polyamic acid, a dehydrating agent, and a third catalyst to perform chemical imidization reaction to obtain polyimide.

[0032] Compared with the prior art, the present application utilizes a bio-based diamine monomer prepared based on magnolol to prepare a polyimide, which has good solubility in conventional organic solvents at room temperature, and the side groups of the polyimide contain allyl groups, which can undergo a chemical cross-linking reaction with small-molecule monomers and cross-linking agents in a photo-patterning process based on a photo-initiated thiol-ene click reaction, so that the exposed area has good solvent resistance in the development process, and then a photoetching pattern is obtained through low-temperature treatment, and the cured film has excellent optical transmittance. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A hydrogen spectrum nuclear magnetic diagram of the diamine monomer prepared for the embodiment 1 of the present application;

[0034] Figure 2 An infrared spectrum of the polyimide prepared for the embodiment 1 of the present application;

[0035] Figure 3 An electron microscope diagram of the photo-sensitive polyimide patterning prepared for the embodiment 1 of the present application. DETAILED DESCRIPTION

[0036] In order to further understand the present application, the preferred embodiments of the present application are described below in combination with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present application, and are not a limitation on the claims of the present application.

[0037] In order to enable the photo-sensitive polyimide photoresist to be cured at low temperature, and for the cured film to have excellent optical transmittance, the present application utilizes a soluble polyimide as the base resin of the PSPI, which can avoid the escape of small molecules when the resin is further imidized in the curing stage. However, the conventional soluble polyimide cannot obtain a photoetching pattern in the photo-patterning process based on the photo-initiated thiol-ene click reaction. Further research found that this is mainly because the conventional soluble polyimide lacks a photo-curable group.

[0038] Based on this, the present application utilizes a bio-based diamine monomer prepared based on magnolol to prepare a polyimide, which has good solubility in conventional organic solvents at room temperature, and the side groups of the polyimide contain allyl groups, which can undergo a chemical cross-linking reaction with small-molecule monomers and cross-linking agents in a photo-patterning process based on a photo-initiated thiol-ene click reaction, so that the exposed area has good solvent resistance in the development process, and then a photoetching pattern is obtained through low-temperature treatment, and the cured film has excellent optical transmittance.

[0039] Specifically, the embodiment of the present application discloses a photo-sensitive polyimide photoresist, which comprises 20-50 parts by weight of a polyimide, 2-10 parts by weight of a small-molecule monomer containing a double bond or a triple bond, 2-10 parts by weight of a thiol monomer, 1-10 parts by weight of a photo-initiator, and 30-70 parts by weight of an organic solvent.

[0040] The general structural formula of the polyimide is:

[0041]

[0042] In the formula, n and m represent the degree of polymerization, n is an integer of 1 to 150, m is an integer of 1 to 150, Ar is an aromatic unit fragment in a bio-based diamine monomer based on magnolol, X is a tetravalent aromatic hydrocarbon group, and Ar1 is a diamine residue;

[0043] The general structural formula of the bio-based diamine monomer based on magnolol is:

[0044]

[0045] Wherein, R1 is selected from any one of an ester group or an ether bond; Ar1 ​​is selected from any one of the following structures:

[0046]

[0047] wherein R1, R2, R3, and R4 are the same or different from each other and are independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, tert-butyl, oxymethyl, or oxybutyl;

[0048] Ar2 is selected from any one of the following structures:

[0049]

[0050] wherein R5, R6, R7, and R8 are the same as or different from each other, and are independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, tert-butyl, oxymethyl, or oxybutyl.

[0051] The X is preferably selected from any one of the following:

[0052]

[0053] The Ar1 is preferably any one of the following:

[0054]

[0055] Preferably, the small molecule monomer containing double bond or triple bond includes at least one of N,N'-methylenebisacrylamide, N,N'-1,6-hexanediylbis[2-methyl-2-propenamide], N,N'-(1,2-dihydroxy-1,2-ethanediyl)bis[2-methyl-2-propenamide], diallylamine, N-methyldiallylamine, tetraethylene glycol dimethacrylate, tripropylenglycol triacrylate, 1,3,5-triallylisocyanurate, 1,3,5-triallylisocyanurate, triallylphosphonium phosphate, ethylene glycol 1,2-bis(2-propynyl) ether, and 3,3-dimethyl-1-butyne.

[0056] Preferably, the thiol monomer includes at least one of trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate), tris[2-(3-mercaptopropoxy)ethyl] isocyanurate, and 2,2'-(1,2-ethanediylbis(oxy))bisethanethiol.

[0057] Preferably, the photoinitiator includes at least one of Michler's ketone, benzophenone, benzoin, 2,4,6-trimethylbenzoylphenyl phosphinate, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, a,a'-diethoxyacetophenone, and thioxanthone.

[0058] Preferably, the organic solvent includes at least one of propylene glycol methyl ether acetate, tetrahydrofuran, ethyl acetate, methyl ethyl ketone, N,N'-dimethylacetamide, N,N'-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, and gamma-butyrolactone.

[0059] The present application also provides a preparation method of the photosensitive polyimide photoresist, including the following steps:

[0060] (1) Taking magnolol as raw material, a bio-based diamine monomer based on magnolol is prepared.

[0061] Specifically, the bio-based diamine monomer based on magnolol is prepared by the following steps: magnolol is reacted with bromobenzoyl chloride containing R1, R2, R3 and R4 at low temperature in an aprotic solvent and an alkaline environment to obtain an allyl-containing bromo compound; the bromo compound is reacted with aminobenzeneboronic acid or benzeneborate containing R5, R6, R7 and R8 by Suzuki reaction to obtain the diamine monomer.

[0062] Preferably, the aprotic solvent is N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 1,4-dioxane, acetone, acetonitrile, toluene, chloroform, dichloromethane or tetrahydrofuran. More preferably, the aprotic solvent is dichloromethane or tetrahydrofuran.

[0063] Preferably, the basic environment is a triethylamine or pyridine environment.

[0064] Preferably, the low-temperature reaction temperature is -15-10℃, and more preferably -5-5℃.

[0065] Alternatively, the magnolol-based biobased diamine monomer is prepared by the following steps: reacting magnolol with bromonitrobenzene containing R1, R2, R3 and R4 in an aprotic high-polarity solvent and a basic environment to obtain an allyl-containing dinitro compound; and reacting the dinitro compound with aminobenzene boronic acid or benzene boronic ester containing R5, R6, R7 and R8 by Suzuki-Miyaura coupling reaction to obtain the diamine monomer.

[0066] Preferably, the aprotic high-polarity solvent is N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or sulfolane.

[0067] Preferably, the basic environment is a potassium carbonate or sodium carbonate environment.

[0068] (2) polymerizing the magnolol-based biobased diamine monomer with an aromatic diamine monomer and an aromatic dianhydride monomer to obtain a polyimide; the aromatic diamine monomer is p-phenylenediamine, m-phenylenediamine, or a flexible aromatic diamine.

[0069] Specifically, the polyimide is prepared by the following steps: mixing the magnolol-based biobased diamine monomer, the aromatic diamine monomer, the aromatic dianhydride monomer, and a third organic solvent to perform a copolymerization reaction to obtain a polyamic acid; and mixing the polyamic acid with a dehydrating agent and a third catalyst to perform a chemical imidization reaction to obtain the polyimide.

[0070] wherein the flexible aromatic diamine is an aromatic diamine containing a flexible group. Preferably, the flexible aromatic diamine is selected from the group consisting of 4,4'-oxydianiline, 4,4'-diaminodiphenylmethane, 1,3-bis(4'-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-oxydianiline, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diaminodiphenyl sulfone, 4,4'-bis(3-aminophenoxy)benzophenone, 3,3'-diaminodiphenyl sulfone, 2 2'-diaminodiphenyl sulfide, 4,4-diaminodiphenyl sulfide, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4-diamino-3,3-difluorobiphenyl, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylmethane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 1,2-bis(4-aminophenoxy)ethane, 4,4'-bis(3-aminophenoxy)diphenyl sulfone.

[0071] Preferably, the aromatic dianhydride monomer is selected from the group consisting of 3,3',4,4'-diphenyltetracarboxylic dianhydride, 2,3,3',4'-diphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, 3,3,4,4-diphenyl sulfone tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-biphenyldiol dianhydride, ethylene glycol bis-trimellitic anhydride.

[0072] Preferably, the third organic solvent is selected from the group consisting of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, sulfolane, 1,4-dioxane, acetone, acetonitrile, toluene, chloroform, hexamethylphosphoramide, and tetrahydrofuran, one or more than two mixed solvents.

[0073] Preferably, the dehydrating agent is acetic anhydride, trifluoroacetic anhydride, one or more than two mixed solvents.

[0074] Preferably, the third catalyst is pyridine, triethylamine, quinoline, isoquinoline, and imidazole, one or more than two mixed solvents.

[0075] Preferably, the specific step of the chemical imidization is: adding dehydrating agent and catalyst in the polyamic acid viscous solution, using acetic anhydride as the dehydrating agent and pyridine as the catalyst, stirring at room temperature for 24-40 h, then pouring into a large amount of ethanol to obtain fibrous polyimide, washing with ethanol for three times, and drying for standby use.

[0076] (3) Dissolving the polyimide in an organic solvent under a protective atmosphere, then adding small molecule monomer containing double bond or triple bond, stirring, continuously adding thiol monomer and photoinitiator to the system, and continuously stirring to obtain photosensitive polyimide photoresist.

[0077] In order to further understand the present application, the preparation method of the photosensitive polyimide photoresist provided by the present application is described in detail below in combination with examples, and the protection scope of the present application is not limited by the following examples.

[0078] Example 1

[0079] The 4-bromobenzoyl chloride (24.14 g, 105 mmol) was dissolved in 120 mL of tetrahydrofuran, and then a tetrahydrofuran solution (60 mL) of magnolol (13.32 g, 50 mmol) and triethylamine (20.9 mL, 150 mmol) was added dropwise. After stirring at room temperature for 12 h, the solution was extracted with dilute hydrochloric acid and deionized water to neutralization to obtain an allyl-containing bromo compound. The allyl-containing bromo compound was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform-d) δ: 7.78 (dt, J = 8.8, 2.3 Hz, 2H), 7.54 (dt, J = 8.9, 2.3 Hz, 2H), 7.18 (d, J = 1.9 Hz, 3H), 5.82 (ddt, J = 17.6, 9.5, 6.7 Hz, 1H), 4.99 (dq, J = 13.1, 1.8 Hz, 2H), 3.33 (dt, J = 6.6, 1.7 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 164.44, 146.52, 137.92, 136.93, 131.91, 131.65, 131.33, 130.27, 129.33, 128.76, 128.47, 122.54, 116.31, 39.61.

[0080] The above allyl-containing bromide compound (9.48 g, 15 mmol) and tetrakis triphenylphosphine palladium were dissolved in 250 mL of tetrahydrofuran under argon. After stirring for 10 minutes, 3M aqueous potassium phosphate solution (60 mL) and (4-aminophenyl)boronic acid hydrochloride (7.80 g, 45 mmol) were added and further stirred at 75 °C for 24 h. After cooling to room temperature, purification by concentration gave the diamine monomer, named DDBA. DDBA was characterized by nuclear magnetic resonance, the results of which are as follows: 1 H NMR (400 MHz, DMSO-d6) δ: 7.89 (d, J = 8.3 Hz, 2H), 7.69 (d, J = 8.4 Hz, 2H), 7.48 (d, J = 8.4 Hz, 2H), 7.32 - 7.13 (m, 3H), 6.66 (d, J = 8.5 Hz, 2H), 5.89 - 5.73 (m, 1H), 5.45 (s, 2H), 5.09 - 4.85 (m, 2H), 3.34 (s, 4H). 13 C NMR (151 MHz, DMSO-d6) δ: 164.32, 149.63, 146.21, 145.79, 137.29, 137.19, 130.76, 130.23, 129.83, 129.07, 127.71, 125.42, 125.25, 125.02, 123.00, 116.05, 114.14, 38.65. HR-MS (ESI, m / z). The nuclear magnetic hydrogen spectrum is as shown in Figure 1 .

[0081]

[0082] The diamine monomer DDBA (7.61 mmol) and 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether (6FODA, 7.61 mmol) were dissolved in anhydrous N-methyl pyrrolidone (NMP) solution (57 mL), and then 4,4-hexafluoroisopropyl phthalic anhydride (6FDA, 14.27 mmol) was added to obtain a polyamic acid solution under nitrogen protection and at room temperature. Subsequently, acetic anhydride (4.02 mL) and pyridine (1.73 mL) were added to perform chemical imidization. After the solution was continuously stirred for 24 hours, it was precipitated in a large amount of ethanol and washed with ethanol three times, and dried to obtain a polyimide powder with the structure shown in Formula 1, denoted as PI-1. The number average molecular weight was 28000 g / mol. The infrared spectrum is as shown in Figure 2 .

[0083]

[0084] A photosensitive polyimide photoresist was prepared by dissolving 30 parts by weight of PI-1 in 57 parts by weight of propylene glycol methyl ether acetate (PGEMA), and then adding 5 parts by weight of tetra(3-mercaptopropionic acid) pentaerythritol ester (TMTM), 5 parts by weight of 1,3,5-triallyl cyanurate (TAC), and 3 parts by weight of 2,4,6-trimethylbenzoylphenyl phosphinate ethyl ester (TPO-L).

[0085] After the above photosensitive polyimide photoresist was filtered, spin-coated on a silicon wafer, and then baked, exposed, developed, rinsed, and dried, a negative photoresist pattern with a resolution of 5 μm was formed. The electron microscope image is shown in Figure 3

[0086] Example 2

[0087] A solution of 2-trifluoromethyl-4-bromobenzoyl chloride (30.18 g, 105 mmol) in 150 mL of tetrahydrofuran was prepared, and then a solution of magnolol (13.32 g, 50 mmol) and triethylamine (20.9 mL, 150 mmol) in 60 mL of tetrahydrofuran was added dropwise. After stirring at room temperature for 12 h, the solution was extracted with dilute hydrochloric acid and deionized water until neutralization, to obtain an allyl-containing bromo compound. The allyl-containing bromo compound was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform-d) δ: 8.02 (d, J = 8.3 Hz, 1H), 7.93 (d, J = 2.0 Hz, 1H), 7.64 (dd, J = 8.3, 2.0 Hz, 1H), 7.31-7.24 (m, 2H), 7.21 (ddt, J = 8.8, 2.0, 1.0 Hz, 1H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 166.76, 148.53, 137.67, 134.25, 133.08, 132.71, 132.25, 130.96, 130.59, 130.29, 129.03, 126.28, 125.44, 123.14, 119.01, 115.61, 39.44.

[0088] ​The above allyl-containing bromide compound (11.53 g, 15 mmol) and tetrakis triphenylphosphine palladium were dissolved in 250 mL of tetrahydrofuran under argon. After stirring for 10 minutes, 3M aqueous potassium phosphate solution (60 mL) and (4-aminophenyl)boronic acid hydrochloride (7.80 g, 45 mmol) were added and further stirred at 75 °C for 24 h. After cooling to room temperature, purification by concentration gave the diamine monomer, named F-DDBA. F-DDBA was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform-d) δ: 8.07 (d, J = 7.5 Hz, 1H), 7.93 (d, J = 2.0 Hz, 1H), 7.64-7.57 (m, 2H), 7.57 (dd, J = 7.6, 2.1 Hz, 1H), 7.31-7.24 (m, 2H), 7.21 (ddt, J = 8.8, 2.0, 1.0 Hz, 1H), 6.72-6.66 (m, 2H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 4.21 (d, J = 5.7 Hz, 1H), 4.13 (d, J = 5.7 Hz, 1H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 167.71, 148.86, 148.53, 143.97, 137.67, 134.83, 134.25, 131.80, 131.36, 130.59, 130.29, 129.03, 127.73, 126.72, 125.88, 125.82, 123.13, 119.01, 115.61, 115.35, 39.44.

[0089]

[0090] The preparation method of the polyimide of this example was basically the same as that of Example 1, except that DDBA was replaced by F-DDBA, to obtain a polyimide having the structure shown in Formula 2, denoted as PI-2. The number average molecular weight was 32000 g / mol.

[0091]

[0092] The preparation method of the photosensitive polyimide photoresist of this example was basically the same as that of Example 1, except that PI-1 was replaced by PI-2. After the photosensitive polyimide photoresist was filtered, it was spin-coated on a silicon wafer, and then the silicon wafer was baked, exposed to light, developed and rinsed, and after drying, a negative photoetching pattern with a resolution of 8 μm was formed.

[0093] Example 3

[0094] Dissolve 2-trifluoromethyl-4-bromobenzoyl chloride (30.18 g, 105 mmol) in 150 mL of tetrahydrofuran, then add dropwise a tetrahydrofuran solution (60 mL) of magnolol (13.32 g, 50 mmol) and triethylamine (20.9 mL, 150 mmol) thereto. After stirring at room temperature for 12 h, extract the solution with dilute hydrochloric acid and deionized water to neutralization to obtain an allyl group-containing bromo compound. Characterize the allyl group-containing bromo compound using nuclear magnetic resonance, and the results are as follows: 1 H NMR (400 MHz, Chloroform-d) δ: 8.02 (d, J = 8.3 Hz, 1H), 7.93 (d, J = 2.0 Hz, 1H), 7.64 (dd, J = 8.3, 2.0 Hz, 1H), 7.31-7.24 (m, 2H), 7.21 (ddt, J = 8.8, 2.0, 1.0 Hz, 1H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 166.76, 148.53, 137.67, 134.25, 133.08, 132.71, 132.25, 130.96, 130.59, 130.29, 129.03, 126.28, 125.44, 123.14, 119.01, 115.61, 39.44.

[0095] Dissolve the above allyl group-containing bromo compound (11.53 g, 15 mmol) and tetrakis triphenylphosphine palladium in 250 mL of tetrahydrofuran under argon. After stirring for 10 min, add 3M aqueous potassium phosphate solution (60 mL) and (3-amino-5-methylphenyl)boronic acid (6.80 g, 45 mmol), and further stir at 75°C for 24 h. After cooling to room temperature, concentrate and purify to obtain a diamine monomer, designated as F-DDBA-CH3. Characterize F-DDBA-CH3 using nuclear magnetic resonance, and the results are as follows: 1H NMR (400 MHz, Chloroform-d) δ: 7.99 (d, J = 7.5 Hz, 1H), 7.92 (d, J = 2.1 Hz, 1H), 7.46 (dd, J = 7.5, 2.1 Hz, 1H), 7.31 - 7.24 (m, 3H), 7.21 (ddt, J = 8.8, 2.0, 1.0 Hz, 1H), 6.96 (t, J = 2.1 Hz, 1H), 6.58 - 6.53 (m, 1H), 6.01 - 5.87 (m, 1H), 5.10 (dd, J = 13.3, 3.6 Hz, 2H), 4.38 (s, 2H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 167.71, 148.53, 147.44, 144.09, 141.21, 140.45, 137.67, 134.25, 131.83, 131.33, 130.59, 130.29, 129.03, 125.82, 124.78, 124.43, 123.13, 120.90, 119.01, 115.69, 115.61, 110.85, 39.44, 21.13.

[0096]

[0097] The preparation method of the polyimide of this example is basically the same as that of Example 1, except that DDBA is replaced by F-DDBA-CH3, to obtain a polyimide with the structure shown in Formula 3, denoted as PI-3. The number average molecular weight is 30000 g / mol.

[0098]

[0099] The preparation method of the photosensitive polyimide photoresist of this example is basically the same as that of Example 1, except that PI-1 is replaced by PI-3. After filtering the photosensitive polyimide photoresist, it is spin-coated on a silicon wafer, and then the silicon wafer is baked, exposed, developed and rinsed, and a negative photoetching pattern with a resolution of 6 μm is formed after drying.

[0100] Example 4

[0101] Magnolol (6.00 g, 22.5 mmol), p-bromonitrobenzene (13.64 g, 67.5 mmol) and potassium carbonate (12.44 g, 90.0 mmol) were dissolved in 100 mL of anhydrous N,N-dimethylacetamide, and the reaction was carried out under nitrogen protection. After the reaction was completed, the solid was collected by filtration and recrystallized to obtain a dinitro compound. The dinitro compound was characterized by nuclear magnetic resonance, and the results were as follows: 1H NMR (400 MHz, Chloroform-d) δ: 8.28-8.22 (m, 2H), 7.29 (dt, J = 2.0, 1.1 Hz, 1H), 7.25-7.19 (m, 1H), 7.19-7.13 (m, 2H), 7.01 (d, J = 8.6 Hz, 1H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.7 Hz, 2H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 162.43, 154.71, 142.77, 137.67, 134.27, 130.13, 129.67, 128.70, 125.57, 118.42, 117.02, 115.61, 39.44.

[0102] The above dinitro compound (2.00 g, 3.9 mmol), (4-aminophenyl)boronic acid hydrochloride (2.03 g, 11.7 mmol), palladium acetate (catalytic amount), BrettPhos ligand (catalytic amount) and potassium phosphate (6.62 g, 31.2 mmol) were dissolved in 50 mL of 1,4-dioxane under a nitrogen atmosphere and further stirred at 130 °C for 24 h. After cooling to room temperature, concentration and purification gave the diamine monomer, named DBA. DBA was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform-d) δ: 7.63-7.57 (m, 2H), 7.51-7.45 (m, 2H), 7.29 (dt, J = 2.0, 1.0 Hz, 1H), 7.25-7.17 (m, 1H), 7.20 (s, 1H), 7.18 (d, J = 1.6 Hz, 1H), 7.00 (d, J = 8.5 Hz, 1H), 6.72-6.66 (m, 2H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 4.21 (d, J = 5.7 Hz, 1H), 4.13 (d, J = 5.7 Hz, 1H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 158.26, 154.53, 148.86, 137.67, 134.27, 132.93, 130.13, 130.05, 129.67, 129.28, 128.87, 128.70, 119.76, 117.02, 116.49, 115.61, 39.44.

[0103]

[0104] The preparation method of the polyimide of this example is basically the same as that of Example 1, except that DDBA is replaced by DBA to obtain a polyimide having the structure shown in Formula 4, denoted as PI-4. The number average molecular weight is 27500 g / mol.

[0105]

[0106] The preparation method of the photosensitive polyimide photoresist of this example is basically the same as that of Example 1, except that PI-1 is replaced by PI-4. After filtering the photosensitive polyimide photoresist, it is spin-coated on a silicon wafer, and then the silicon wafer is baked, exposed, developed, rinsed, and dried to form a negative photoetching pattern with a resolution of 5 μm.

[0107] Example 5

[0108] Magnolol (6.00 g, 22.5 mmol), p-bromonitrobenzene (13.64 g, 67.5 mmol) and potassium carbonate (12.44 g, 90.0 mmol) were dissolved in 100 mL of anhydrous N,N-dimethylacetamide and reacted under nitrogen protection. After the reaction was completed, the solid was collected by filtration and recrystallized to obtain a dinitro compound. The dinitro compound was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform-d) δ: 8.28-8.22 (m, 2H), 7.29 (dt, J = 2.0, 1.1 Hz, 1H), 7.25-7.19 (m, 1H), 7.19-7.13 (m, 2H), 7.01 (d, J = 8.6 Hz, 1H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.7 Hz, 2H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 162.43, 154.71, 142.77, 137.67, 134.27, 130.13, 129.67, 128.70, 125.57, 118.42, 117.02, 115.61, 39.44.

[0109] The above dinitro compound (2.00 g, 3.9 mmol), (3-amino-5-methylphenyl)boronic acid (1.77 g, 11.7 mmol), palladium acetate (catalytic amount), BrettPhos ligand (catalytic amount) and potassium phosphate (6.62 g, 31.2 mmol) were dissolved in 50 mL of 1,4-dioxane under a nitrogen atmosphere and further stirred at 130 °C for 24 h. After cooling to room temperature, concentration, purification, a diamine monomer was obtained, named DBA-CH3. DBA-CH3 was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform-d) δ: 7.63-7.57 (m, 2H), 7.51-7.45 (m, 2H), 7.29 (dt, J = 2.0, 1.0 Hz, 1H), 7.25-7.17 (m, 1H), 7.20 (s, 1H), 7.18 (d, J = 1.6 Hz, 1H), 7.00 (d, J = 8.5 Hz, 1H), 6.72-6.66 (m, 2H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 4.21 (d, J = 5.7 Hz, 1H), 4.13 (d, J = 5.7 Hz, 1H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ: 158.26, 154.53, 148.86, 137.67, 134.27, 132.93, 130.13, 130.05, 129.67, 129.28, 128.87, 128.70, 119.76, 117.02, 116.49, 115.61, 39.44.

[0110]

[0111] The preparation method of the polyimide of this example is basically the same as that of Example 1, except that DDBA is replaced by DBA-CH3, to obtain a polyimide having the structure shown in Formula 5, denoted as PI-5. The number average molecular weight is 33000 g / mol.

[0112]

[0113] The preparation method of the photosensitive polyimide photoresist of this example is basically the same as that of Example 1, except that PI-1 is replaced by PI-5. After filtering the photosensitive polyimide photoresist, it is spin-coated on a silicon wafer, and then the silicon wafer is baked, exposed, developed and rinsed, and after drying, a negative photoetching pattern with a resolution of 6 μm is formed.

[0114] Comparative Example 1

[0115] Dissolve 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether (6FODA, 5 mmol) in anhydrous N-methylpyrrolidone (NMP) solution (15 mL), then add 4,4-hexafluoroisopropyl phthalic anhydride (6FDA, 4.69 mmol) to obtain a polyamic acid solution under nitrogen protection and at room temperature. Subsequently, add acetic anhydride (1.32 mL) and pyridine (0.57 mL) to perform chemical imidization reaction. After the solution is continuously stirred for 24 hours, it is precipitated in a large amount of ethanol and washed with ethanol three times, and dried to obtain a polyimide powder having a structure shown in formula 6, denoted as PI-6. The number average molecular weight is 28000 g / mol.

[0116]

[0117] The photosensitive polyimide photoresist of the present comparative example is substantially the same as the preparation method of Example 1, except that PI-1 is replaced by PI-6.

[0118] Comparative Example 2

[0119] The preparation method of the present comparative example is substantially the same as that of Comparative Example 1, except that 6FODA is replaced by TFMB to prepare a polyimide having a structure of formula 7, denoted as PI-7. The number average molecular weight is 32000 g / mol.

[0120]

[0121] The photosensitive polyimide photoresist of the present comparative example is substantially the same as the preparation method of Example 1, except that PI-1 is replaced by PI-7.

[0122] Comparative Example 3

[0123] The preparation method of the present comparative example is substantially the same as that of Example 1, except that 5 parts by weight of TMTM is replaced by 5 parts by weight of TAC.

[0124] The photosensitive polyimide films prepared in Examples 1-5 and Comparative Examples 1-3 are subjected to thermal, optical and patterning tests, and the results are shown in Table 1.

[0125] Table 1 Performance data of photosensitive polyimide films

[0126]

[0127] As can be seen from Table 1, the cured film prepared from the photosensitive polyimide photoresist of the application has excellent thermal and optical transmission properties. Compared with Comparative Example 1-2, the photosensitive polyimide photoresist prepared in the application is based on a photo-induced thiol-ene click reaction, and after UV exposure, a complete photoetching pattern can be obtained.

[0128] This is mainly because the allyl group contained in the side group of the polyimide prepared in the application can undergo chemical crosslinking reaction with small molecule monomers and crosslinking agents, so that the exposed area has good solvent resistance during development, and after low temperature treatment, a photoetching pattern is obtained. The side group of the polyimide of Comparative Example 1 and 2 does not contain an allyl group, and the polyimide and small molecule monomers and crosslinking agents do not undergo chemical crosslinking during the exposure stage, so that the exposed area is completely cleaned during development, and no photoetching pattern is obtained.

[0129] Compared with Example 1, Comparative Example 3 lacks a thiol crosslinking agent, so that the crosslinking degree of the exposed area is not enough, and then it is partially cleaned in development, and a complete photoetching pattern is not obtained.

[0130] In addition, the application uses a bio-based diamine monomer prepared based on magnolol to prepare a polyimide, which has a lower carbon footprint compared with diamine monomers derived from fossil fuels, which helps to build a more sustainable chemical industry and meets the development trend of green and sustainable development.

[0131] The results show that the polyimide photoresist prepared in the application has good low-temperature curing and photo-pattern properties, and the cured film has good thermal and optical transmission properties, and can be applied in the fields of optoelectronics and optical devices, and also meets the development trend of green and sustainable development.

[0132] The above-described embodiments only express several embodiments of the application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are within the scope of protection of the application.

Claims

1. A photosensitive polyimide photoresist, characterized by, The composition comprises 20-50 parts by weight of polyimide, 2-10 parts by weight of small molecule monomer containing double bond or triple bond, 2-10 parts by weight of thiol monomer, 1-10 parts by weight of photoinitiator, and 30-70 parts by weight of organic solvent. The general structure of the polyimide is: wherein n and m represent the degree of polymerization, n is an integer of 1-150, m is an integer of 1-150, Ar is an aromatic unit segment in the bio-based magnolol-based diamine monomer, X is a tetravalent aromatic hydrocarbon group, and Ar1 is a residue of aromatic diamine; The general structure of the bio-based magnolol-based diamine monomer is: wherein R1 is selected from any one of an ester group or an ether bond; and Ar1 is selected from any one of the following structures: wherein R1, R2, R3, and R4 are the same or different from each other and are each independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, t-butyl, oxymethyl, or oxybutyl; Ar2 is selected from any one of the following structures: wherein R5, R6, R7, and R8 are the same or different from each other and are each independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, t-butyl, oxymethyl, or oxybutyl.

2. The photosensitive polyimide photoresist according to claim 1, wherein X is preferably selected from any one of the following:

3. The photosensitive polyimide photoresist of claim 1, wherein Ar1 is preferably any one of the following:

4. The photosensitive polyimide photoresist according to any one of claims 1 to 3, wherein, The small molecule monomer containing double bond or triple bond includes at least one of N,N'-methylenebisacrylamide, N,N'-1,6-hexanediylbis[2-methyl-2-propenamide], N,N'-(1,2-dihydroxy-1,2-ethanediyl)bis[2-methyl-2-propenamide], diallylamine, N-methyldiallylamine, tetraethylene glycol dimethacrylate, tripropylene glycol trimethacrylate, 1,3,5-triallylisocyanurate, 1,3,5-triallylisocyanurate, triallyl phosphate, ethylene glycol 1,2-bis(2-propynyl) ether, and 3,3-dimethyl-1-butyne.

5. The photosensitive polyimide photoresist according to any one of claims 1 to 3, wherein The thiol monomer includes at least one of trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate), tris[2-(3-mercaptopropoxy)ethyl] isocyanurate, and 2,2'-(1,2-ethanediylbis(oxy))bisethanethiol.

6. The photosensitive polyimide photoresist according to any one of claims 1 to 3, wherein The photoinitiator includes at least one of Michler's ketone, benzophenone, benzoin, 2,4,6-trimethylbenzoylphenyl phosphinic acid ethyl ester, 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide, a,a'-diethoxyacetophenone, and thioxanthone.

7. A method for preparing the photosensitive polyimide photoresist according to any one of claims 1-6, comprising the following steps: (1) preparing a bio-based magnolol-based diamine monomer using magnolol as a raw material; (2) polymerizing the bio-based magnolol-based diamine monomer with an aromatic diamine monomer and an aromatic dianhydride monomer to obtain a polyimide; the aromatic diamine monomer is p-phenylenediamine, m-phenylenediamine, or a flexible aromatic diamine. (3) under the protection of atmosphere, the polyimide is dissolved in organic solvent, then a small molecule monomer containing double bond or triple bond is added, stirring, continue to add mercaptan monomer and photo initiator to the system, continue to stir, to obtain photosensitive polyimide photoresist.

8. The method for preparing the photosensitive polyimide photoresist according to claim 7, wherein: Step (1) comprises: reacting magnolol with bromobenzoyl chloride containing R1, R2, R3 and R4 in aprotic solvent and alkaline environment at low temperature to obtain an allyl-containing bromide compound; and reacting the bromide compound with aminobenzene boronic acid or benzene borate containing R5, R6, R7 and R8 through Suzuki reaction to obtain the diamine monomer.

9. The method for preparing the photosensitive polyimide photoresist according to claim 7, wherein: Step (1) comprises: reacting magnolol with bromonitrobenzene containing R1, R2, R3 and R4 in aprotic high-polarity solvent and alkaline environment to obtain an allyl-containing dinitro compound; and reacting the dinitro compound with aminobenzene boronic acid or benzene borate containing R5, R6, R7 and R8 through Suzuki-Miyaura coupling reaction to obtain the diamine monomer.

10. The method for preparing a photosensitive polyimide photoresist according to any one of claims 7 to 9, characterized in that: Step (2) comprises: mixing the magnolol-based bio-based diamine monomer, aromatic diamine monomer, aromatic dianhydride monomer and third organic solvent to perform copolymerization reaction to obtain polyamic acid; and mixing the polyamic acid and dehydrating agent and third catalyst to perform chemical imidization reaction to obtain polyimide.

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