Photosensitive polyimide photoresist and preparation method thereof

Abstract

The invention provides a photosensitive polyimide photoresist and a preparation method thereof. The photosensitive polyimide photoresist comprises the following components in parts by weight: 20-50 parts of polyimide, 2-10 parts of a micromolecular monomer containing double bonds or triple bonds, 2-10 parts of a thiol monomer, 1-10 parts of a photoinitiator and 30-70 parts of an organic solvent. The polyimide is formed by polymerizing a magnolol-based bio-based diamine monomer, an aromatic diamine monomer and an aromatic dianhydride monomer. Compared with the prior art, the photosensitive polyimide photoresist prepared by the invention has good low-temperature curing and light pattern performance, and a cured film has good thermal and optical transmission performance and the like, can be applied to the fields of photoelectric devices, optical devices and the like, and also conforms to the development trend of green sustainable development.

Description

Technical Field

[0001] The invention relates to the technical field of polymer compounds, in particular to a photosensitive polyimide photoresist and a preparation method thereof. Background Art

[0002] As a special engineering material, polyimide (PI) has been widely used in aviation, aerospace, microelectronics, nano, liquid crystal, separation membrane, laser and other fields. Due to its 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 multilayer interconnection and interlayer dielectric layer in integrated circuits. In these applications, polyimide films need to be patterned to achieve interconnection of specific areas of semiconductor chips.

[0003] In the early semiconductor industry, the patterning of polyimide was achieved with the help of photoresist, that is, a layer of photoresist was coated on the surface of polyimide, and after it was photolithographically patterned, the underlying polyimide was treated by chemical etching and other methods to transfer the pattern of the photoresist to the polyimide layer. In order to simplify the patterning process of polyimide, researchers gave polyimide photosensitivity, that is, synthetic photosensitive polyimide (PSPI), and combined photosensitive polyimide with additives such as photoinitiators to form photosensitive polyimide photoresist. The pattern was directly made into the photosensitive polyimide layer using photolithography technology to achieve its self-patterning.

[0004] However, conventional PSPI materials need to be processed at high temperatures and exhibit low transparency, limiting their applications in heat-sensitive optical devices. Summary of the invention

[0005] Based on this, the object of the present invention is to provide a photosensitive polyimide photoresist and a preparation method thereof.

[0006] In a first aspect, the present invention provides a photosensitive polyimide photoresist, comprising 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;

[0007] The general structural formula of the polyimide is:

[0008]

[0009] 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 residue of a diamine;

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

[0011]

[0012] 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:

[0013]

[0014] 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;

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

[0016]

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

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

[0019]

[0020] In one embodiment, Ar1 is preferably any one of the following:

[0021]

[0022] In one embodiment, the small molecule monomer containing double bonds or triple bonds includes at least one of N,N'-methylenebisacrylamide, N,N'-1,6-hexanediylbis[2-methyl-2-acrylamide], N,N'-(1,2-dihydroxy-1,2-ethanediyl)bis[2-methyl-2-acrylamide], diallylamine, N-methyldiallylamine, tetraethylene glycol dimethacrylate, propane trimethanol triacrylate, 1,3,5-triacrylic acid triallyl ester, 1,3,5-triallyl isocyanurate, 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 tetrakis(3-mercaptopropionate), tris[2-(3-mercaptopropoxy)ethyl]isocyanurate and 2,2'-(1,2-ethylenedioxy)bis(ethylenethiol).

[0024] In one embodiment, the photoinitiator includes at least one of Michler's ketone, benzophenone, benzoin, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, a,a'-diethoxyacetophenone and thioxanthanone.

[0025] In a second aspect, the present invention provides a method for preparing the photosensitive polyimide photoresist as described above, comprising the following steps:

[0026] (1) Using magnolol as a raw material, preparing a bio-based diamine monomer based on magnolol;

[0027] (2) polymerizing the magnolol-based bio-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;

[0028] (3) Under a protective gas atmosphere, the polyimide is dissolved in an organic solvent, and then a small molecule monomer containing a double bond or a triple bond is added and stirred. A thiol monomer and a photoinitiator are continuously added to the system and stirred 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 a non-protonic solvent and alkaline environment at low temperature to obtain a brominated compound containing an allyl group; and reacting the brominated compound with aminophenylboronic acid or phenylboronic acid ester containing R5, R6, R7 and R8 through a Suzuki reaction to obtain the diamine monomer.

[0030] In one embodiment, step (1) comprises: reacting magnolol with bromonitrobenzene containing R1, R2, R3 and R4 in a non-protonic high-polar solvent and an alkaline environment to obtain an allyl-containing dinitro compound; and reacting the dinitro compound with aminophenylboronic acid or phenylboronic acid ester containing R5, R6, R7 and R8 through a Suzuki-Miyaura coupling reaction to obtain the diamine monomer.

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

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

[0033] Figure 1 This is the hydrogen NMR spectrum of the diamine monomer prepared in Example 1 of the present invention;

[0034] Figure 2 The infrared spectrum of the polyimide prepared in Example 1 of the present invention;

[0035] Figure 3 This is an electron microscope image of the patterned photosensitive polyimide prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0036] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0037] In order to enable the photosensitive polyimide photoresist to be cured at low temperatures and the cured film to have excellent optical transmittance, the present invention uses soluble polyimide as the base resin of PSPI, which can prevent the escape of small molecules when the resin is further imidized during the curing stage. However, conventional soluble polyimide cannot obtain a photolithographic pattern during the photopatterning process based on the photo-initiated thiol-ene click reaction. Further research found that this is mainly because conventional soluble polyimide lacks photocurable groups.

[0038] Based on this, the present invention utilizes bio-based diamine monomers prepared based on magnolol to prepare polyimide, which has good solubility in conventional organic solvents at room temperature, and the polyimide side group contains an allyl group. In the photopatterning process based on the photoinitiated thiol-ene click reaction, it can undergo chemical cross-linking reaction with small molecule monomers and cross-linking agents, so that the exposed area has good solvent resistance during the development process, and then a photolithography pattern is obtained after low-temperature treatment, and the cured film has excellent optical transmittance.

[0039] Specifically, the embodiment of the present invention discloses a photosensitive polyimide photoresist, comprising 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;

[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 residue of a diamine;

[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] In the formula, R5, R6, R7, and R8 are the same as each other or different, 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 bonds or triple bonds includes at least one of N,N'-methylenebisacrylamide, N,N'-1,6-hexanediylbis[2-methyl-2-acrylamide], N,N'-(1,2-dihydroxy-1,2-ethanediyl)bis[2-methyl-2-acrylamide], diallylamine, N-methyldiallylamine, tetraethylene glycol dimethacrylate, propane trimethanol triacrylate, 1,3,5-triallyl cyanurate, 1,3,5-triallyl isocyanurate, triallyl 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 tetrakis(3-mercaptopropionate), tris[2-(3-mercaptopropoxy)ethyl]isocyanurate and 2,2'-(1,2-ethylenedioxy)bis(ethylenethiol).

[0057] Preferably, the photoinitiator includes at least one of Michler's ketone, benzophenone, benzoin, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, a,a'-diethoxyacetophenone and thioxanthanone.

[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 γ-butyrolactone.

[0059] The present invention also provides a method for preparing a photosensitive polyimide photoresist, comprising the following steps:

[0060] (1) Using magnolia officinalis as raw material, a bio-based diamine monomer based on magnolia officinalis was 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 a non-protonic solvent and alkaline environment to obtain a brominated compound containing an allyl group; the brominated compound is reacted with aminophenylboronic acid or phenylboronic acid ester containing R5, R6, R7 and R8 through a 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 alkaline environment is triethylamine or pyridine environment.

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

[0065] Alternatively, the bio-based diamine monomer based on magnolol is prepared by the following steps: magnolol is reacted with bromonitrobenzene containing R1, R2, R3 and R4 in a non-protonic high-polar solvent and an alkaline environment to obtain an allyl-containing dinitro compound; the dinitro compound is reacted with aminophenylboronic acid or phenylboronic acid ester containing R5, R6, R7 and R8 through a Suzuki-Miyaura coupling reaction to obtain the diamine monomer.

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

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

[0068] (2) polymerizing the magnolol-based bio-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.

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

[0070] Among them, the flexible aromatic diamine refers to an aromatic diamine containing a flexible group. Preferably, the flexible aromatic diamine is selected from 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 1,3-bis(4'-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether, 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 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic 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'-(hexafluoroisopropylene) diphthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene diphthalic anhydride, 4,4'-terephthalic anhydride, bisphenol A diether dianhydride, and ethylene glycol ditrimellitate anhydride.

[0072] Preferably, the third organic solvent is selected from one or more mixed solvents of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 1,4-dioxane, acetone, acetonitrile, toluene, chloroform, hexamethylphosphoric triamide and tetrahydrofuran.

[0073] Preferably, the dehydrating agent is acetic anhydride, trifluoroacetic anhydride, or a mixture of the two.

[0074] Preferably, the third catalyst is one or a mixture of two or more of pyridine, triethylamine, quinoline, isoquinoline and imidazole.

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

[0076] (3) Under a protective gas atmosphere, the polyimide is dissolved in an organic solvent, and then a small molecule monomer containing a double bond or a triple bond is added and stirred. A thiol monomer and a photoinitiator are continuously added to the system and stirred to obtain a photosensitive polyimide photoresist.

[0077] In order to further understand the present invention, the preparation method of the photosensitive polyimide photoresist provided by the present invention is described in detail below in conjunction with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0078] Example 1

[0079] 4-bromobenzoyl chloride (24.14g, 105mmol) was dissolved in 120mL tetrahydrofuran, and then a tetrahydrofuran solution (60mL) of magnolol (13.32g, 50mmol) and triethylamine (20.9mL, 150mmol) was added dropwise thereto. After stirring at room temperature for 12h, 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 result was: 1 H NMR(400MHz,Chloroform-d)δ:7.78(dt,J=8.8,2.3Hz,2H),7.54(dt,J=8.9,2.3Hz,2H),7.18(d,J=1.9 Hz,3H),5.82(ddt,J=17.6,9.5,6.7Hz,1H),4.99(dq,J=13.1,1.8Hz,2H),3.33(dt,J=6.6,1.7Hz,2H). 13 C NMR (151MHz, 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] Under argon conditions, the above-mentioned allyl-containing brominated compound (9.48 g, 15 mmol) and tetrakistriphenylphosphine palladium were dissolved in 250 mL of tetrahydrofuran. After stirring for 10 minutes, 3M potassium phosphate aqueous solution (60 mL) and (4-aminophenyl) hydrochloride borate (7.80 g, 45 mmol) were added and further stirred at 75 ° C for 24 h. After cooling to room temperature, it was concentrated and purified to obtain a diamine monomer, named DDBA. DDBA was characterized by nuclear magnetic resonance, and the results were: 1 H NMR(400MHz, DMSO-d6)δ:7.89(d,J=8.3Hz,2H),7.69(d,J=8.4Hz,2H),7.48(d,J=8.4Hz,2H),7.32– 7.13(m,3H),6.66(d,J=8.5Hz,2H),5.89–5.73(m,1H),5.45(s,2H),5.09–4.85(m,2H),3.34(s,4H). 13 C NMR (151MHz, 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). Figure 1 shown.

[0081]

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

[0083]

[0084] 30 parts by weight of PI-1 were dissolved in 57 parts by weight of propylene glycol methyl ether acetate (PGEMA), and then 5 parts by weight of pentaerythritol tetrakis(3-mercaptopropionate) (TMTM), 5 parts by weight of triallyl 1,3,5-cyanurate (TAC) and 3 parts by weight of ethyl 2,4,6-trimethylbenzoylphenylphosphonate (TPO-L) were added to obtain a photosensitive polyimide photoresist.

[0085] After filtering the above-mentioned photosensitive polyimide photoresist, spin-coat it on the silicon wafer, then bake, expose, develop and rinse the silicon wafer, and after drying, a negative photolithography pattern with a resolution of 5μm can be formed. Figure 3 shown.

[0086] Example 2

[0087] 2-trifluoromethyl-4-bromobenzoyl chloride (30.18g, 105mmol) was dissolved in 150mL tetrahydrofuran, and then a tetrahydrofuran solution (60mL) of magnolol (13.32g, 50mmol) and triethylamine (20.9mL, 150mmol) was added dropwise thereto. After stirring at room temperature for 12h, 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 result was: 1 H NMR(400MHz,Chloroform-d)δ:8.02(d,J=8.3Hz,1H),7.93(d,J=2.0Hz,1H),7.64(dd,J=8.3,2.0Hz,1H),7.31-7.24(m, 2H), 7.21 (ddt, J=8.8, 2.0, 1.0Hz, 1H), 5.94 (tt, J=9.8, 7.5Hz, 1H), 5.10 (d, J=9.6Hz, 2H), 3.33 (dt, J=7.5, 1.0Hz, 2H). 13 C NMR(151MHz,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] Under argon conditions, the above-mentioned allyl-containing brominated compound (11.53 g, 15 mmol) and tetrakistriphenylphosphine palladium were dissolved in 250 mL of tetrahydrofuran. After stirring for 10 minutes, 3M potassium phosphate aqueous solution (60 mL) and (4-aminophenyl) hydrochloride borate (7.80 g, 45 mmol) were added and further stirred at 75 ° C for 24 h. After cooling to room temperature, it was concentrated and purified to obtain a diamine monomer named F-DDBA. F-DDBA was characterized by nuclear magnetic resonance, and the results were: 1 H NMR(400MHz,Chloroform-d)δ:8.07(d,J=7.5Hz,1H),7.93(d,J=2.0Hz,1H),7.6 4-7.57(m,2H),7.57(dd,J=7.6,2.1Hz,1H),7.31-7.24(m,2H),7.21(ddt,J=8.8, 2.0,1.0Hz,1H),6.72-6.66(m,2H),5.94(tt,J=9.8,7.5Hz,1H),5.10(d,J=9.6H z, 2H), 4.21 (d, J = 5.7Hz, 1H), 4.13 (d, J = 5.7Hz, 1H), 3.33 (dt, J = 7.5, 1.0Hz, 2H). 13 C NMR(151MHz,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 in this embodiment is basically the same as that in embodiment 1, except that DDBA is replaced by F-DDBA to obtain a polyimide having a structure shown in Formula 2, which is denoted as PI-2. The number average molecular weight is 32000 g / mol.

[0091]

[0092] The preparation method of the photosensitive polyimide photoresist in this embodiment is basically the same as that in embodiment 1, except that PI-1 is replaced by PI-2. After filtering, the photosensitive polyimide photoresist is spin-coated on a silicon wafer, and then the silicon wafer is baked, exposed, developed, rinsed, and dried to form a negative photolithography pattern with a resolution of 8 μm.

[0093] Example 3

[0094] 2-trifluoromethyl-4-bromobenzoyl chloride (30.18g, 105mmol) was dissolved in 150mL tetrahydrofuran, and then a tetrahydrofuran solution (60mL) of magnolol (13.32g, 50mmol) and triethylamine (20.9mL, 150mmol) was added dropwise thereto. After stirring at room temperature for 12h, 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 result was: 1 H NMR(400MHz,Chloroform-d)δ:8.02(d,J=8.3Hz,1H),7.93(d,J=2.0Hz,1H),7.64(dd,J=8.3,2.0Hz,1H),7.31-7.24(m, 2H), 7.21 (ddt, J=8.8, 2.0, 1.0Hz, 1H), 5.94 (tt, J=9.8, 7.5Hz, 1H), 5.10 (d, J=9.6Hz, 2H), 3.33 (dt, J=7.5, 1.0Hz, 2H). 13 C NMR(151MHz,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] Under argon conditions, the above-mentioned allyl-containing brominated compound (11.53 g, 15 mmol) and tetrakistriphenylphosphine palladium were dissolved in 250 mL of tetrahydrofuran. After stirring for 10 minutes, 3M potassium phosphate aqueous solution (60 mL) and (3-amino-5-methylphenyl) boronic acid (6.80 g, 45 mmol) were added and further stirred at 75 ° C for 24 h. After cooling to room temperature, it was concentrated and purified to obtain a diamine monomer named F-DDBA-CH3. F-DDBA-CH3 was characterized by nuclear magnetic resonance, and the results were: 1H NMR(400MHz,Chloroform-d)δ:7.99(d,J=7.5Hz,1H),7.92(d,J=2.1Hz,1H),7.46(dd,J=7.5,2.1Hz,1H),7.31-7.24(m,3H),7.21(ddt,J=8.8,2.0 ,1.0Hz,1H),6.96(t,J=2.1Hz,1H),6.58-6.53(m,1H),6.01-5.87(m,1H) ,5.10(dd,J=13.3,3.6Hz,2H),4.38(s,2H),3.33(dt,J=7.5,1.0Hz,2H). 13 C NMR(151MHz,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 in this embodiment is basically the same as that in embodiment 1, except that DDBA is replaced by F-DDBA-CH3 to obtain a polyimide having a structure shown in formula 3, which is denoted as PI-3. The number average molecular weight is 30,000 g / mol.

[0098]

[0099] The preparation method of the photosensitive polyimide photoresist in this embodiment is basically the same as that in embodiment 1, except that PI-1 is replaced by PI-3. After filtering, the photosensitive polyimide photoresist is spin-coated on a silicon wafer, and then the silicon wafer is baked, exposed, developed, rinsed, and dried to form a negative photolithography pattern with a resolution of 6 μm.

[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 reacted under nitrogen protection. After the reaction, the solid was collected by filtration and recrystallized to obtain a dinitro compound. The dinitro compound was characterized by nuclear magnetic resonance, and the result was: 1H NMR(400MHz,Chloroform-d)δ:8.28-8.22(m,2H),7.29(dt,J=2.0,1.1Hz,1H),7.25-7.19(m,1H),7.19-7.13( m,2H),7.01(d,J=8.6Hz,1H),5.94(tt,J=9.8,7.5Hz,1H),5.10(d,J=9.7Hz,2H),3.33(dt,J=7.5,1.0Hz,2H). 13 C NMR (151MHz, 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] Under nitrogen atmosphere, the above dinitro compound (2.00 g, 3.9 mmol), (4-aminophenyl) hydrochloride borate (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 and further stirred at 130 ° C for 24 h. After cooling to room temperature, it was concentrated and purified to obtain a diamine monomer named DBA. DBA was characterized by nuclear magnetic resonance, and the results were: 1 H NMR(400MHz,Chloroform-d)δ:7.63-7.57(m,2H),7.51-7.45(m,2H),7.29(dt,J =2.0,1.0Hz,1H),7.25-7.17(m,1H),7.20(s,1H),7.18(d,J=1.6Hz,1H),7.00(d ,J=8.5Hz,1H),6.72-6.66(m,2H),5.94(tt,J=9.8,7.5Hz,1H),5.10(d,J=9.6Hz ,2H),4.21(d,J=5.7Hz,1H),4.13(d,J=5.7Hz,1H),3.33(dt,J=7.5,1.0Hz,2H). 13 C NMR(151MHz,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 in this embodiment is basically the same as that in embodiment 1, except that DDBA is replaced by DBA to obtain a polyimide having a structure shown in formula 4, which is denoted as PI-4. The number average molecular weight is 27500 g / mol.

[0105]

[0106] The preparation method of the photosensitive polyimide photoresist in this embodiment is basically the same as that in embodiment 1, except that PI-1 is replaced by PI-4. After filtering, the photosensitive polyimide photoresist is spin-coated on a silicon wafer, and then the silicon wafer is baked, exposed, developed, rinsed, and dried to form a negative photolithography 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, the solid was collected by filtration and recrystallized to obtain a dinitro compound. The dinitro compound was characterized by nuclear magnetic resonance, and the result was: 1 H NMR(400MHz,Chloroform-d)δ:8.28-8.22(m,2H),7.29(dt,J=2.0,1.1Hz,1H),7.25-7.19(m,1H),7.19-7.13( m,2H),7.01(d,J=8.6Hz,1H),5.94(tt,J=9.8,7.5Hz,1H),5.10(d,J=9.7Hz,2H),3.33(dt,J=7.5,1.0Hz,2H). 13 C NMR (151MHz, 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] Under nitrogen atmosphere, 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 and further stirred at 130 ° C for 24 h. After cooling to room temperature, it was concentrated and purified to obtain a diamine monomer named DBA-CH3. DBA-CH3 was characterized by nuclear magnetic resonance, and the results were: 1 H NMR(400MHz,Chloroform-d)δ:7.63-7.57(m,2H),7.51-7.45(m,2H),7.29(dt,J =2.0,1.0Hz,1H),7.25-7.17(m,1H),7.20(s,1H),7.18(d,J=1.6Hz,1H),7.00(d ,J=8.5Hz,1H),6.72-6.66(m,2H),5.94(tt,J=9.8,7.5Hz,1H),5.10(d,J=9.6Hz ,2H),4.21(d,J=5.7Hz,1H),4.13(d,J=5.7Hz,1H),3.33(dt,J=7.5,1.0Hz,2H). 13 C NMR(151MHz,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 in this embodiment is basically the same as that in embodiment 1, except that DDBA is replaced by DBA-CH3 to obtain a polyimide having a structure shown in Formula 5, which is denoted as PI-5. The number average molecular weight is 33000 g / mol.

[0112]

[0113] The preparation method of the photosensitive polyimide photoresist in this embodiment is basically the same as that in embodiment 1, except that PI-1 is replaced by PI-5. After filtering, the photosensitive polyimide photoresist is spin-coated on a silicon wafer, and then the silicon wafer is baked, exposed, developed, rinsed, and dried to form a negative photolithography pattern with a resolution of 6 μm.

[0114] Comparative Example 1

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

[0116]

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

[0118] Comparative Example 2

[0119] The preparation method of this comparative example is basically 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, which is denoted as PI-7 and has a number average molecular weight of 32000 g / mol.

[0120]

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

[0122] Comparative Example 3

[0123] The preparation method of this comparative example is basically 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 were subjected to thermal, optical and patterning tests. The results are shown in Table 1.

[0125] Table 1 Performance data of photosensitive polyimide film

[0126]

[0127] As shown in Table 1, the cured film prepared by the photosensitive polyimide photoresist of the present invention has excellent thermal and optical transmittance. Compared with Comparative Examples 1-2, the photosensitive polyimide photoresist prepared by the present invention is based on a photo-triggered thiol-ene click reaction, and a complete photolithographic pattern can be obtained after ultraviolet exposure.

[0128] This is mainly because the polyimide side groups prepared by the present invention contain allyl groups, which can react with small molecule monomers and cross-linking agents to undergo chemical cross-linking reactions, so that the exposed area has good solvent resistance during the development process, and then a photolithographic pattern is obtained after low-temperature treatment. However, the polyimide side groups of Comparative Examples 1 and 2 do not contain allyl groups, and the polyimide and small molecule monomers and cross-linking agents do not undergo chemical cross-linking structures during the exposure stage, so that the exposed area is completely cleaned during the development process and no photolithographic pattern is obtained.

[0129] Compared with Example 1, Comparative Example 3 lacks a mercapto crosslinking agent, so that the degree of crosslinking in the exposed area is insufficient, and then it is partially washed away during development, and a complete photolithographic pattern cannot be obtained.

[0130] In addition, the present invention utilizes bio-based diamine monomers prepared based on magnolol to prepare polyimide. Compared with diamine monomers derived from fossil fuels, the present invention has a lower carbon footprint, helps to build a more sustainable chemical industry, and is in line with the development trend of green and sustainable development.

[0131] The results show that the polyimide photoresist prepared by the present invention has good low-temperature curing and light patterning properties, and the cured film has good thermal and optical transmittance and other properties. It can be used in optoelectronics, optical devices and other fields, and is also in line with the development trend of green and sustainable development.

[0132] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A photosensitive polyimide photoresist, characterized in that: The invention 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 general structural formula of the polyimide is: 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 residue of a diamine; The general structural formula of the bio-based diamine monomer based on magnolol is: 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: 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; Ar2 is selected from any one of the following structures: In the formula, R5, R6, R7, and R8 are the same as each other or different, and are independently selected from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, tert-butyl, oxymethyl, or oxybutyl.

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

3. The photosensitive polyimide photoresist according to claim 1, characterized in that: The Ar1 is preferably any one of the following:

4. The photosensitive polyimide photoresist according to any one of claims 1 to 3, characterized in that: The small molecule monomer containing double bonds or triple bonds includes at least one of N,N'-methylenebisacrylamide, N,N'-1,6-hexanediylbis[2-methyl-2-acrylamide], N,N'-(1,2-dihydroxy-1,2-ethanediyl)bis[2-methyl-2-acrylamide], diallylamine, N-methyldiallylamine, tetraethylene glycol dimethacrylate, propane trimethanol triacrylate, 1,3,5-triallyl cyanurate, 1,3,5-triallyl isocyanurate, 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, characterized in that: The thiol monomer includes at least one of trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), tris[2-(3-mercaptopropoxy)ethyl]isocyanurate and 2,2'-(1,2-ethylenedioxy)bis(ethylenethiol).

6. The photosensitive polyimide photoresist according to any one of claims 1 to 3, characterized in that: The photoinitiator includes at least one of Michler's ketone, benzophenone, benzoin, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, a,a'-diethoxyacetophenone and thioxanthanone.

7. A method for preparing the photosensitive polyimide photoresist according to any one of claims 1 to 6, comprising the following steps: (1) Using magnolol as a raw material, preparing a bio-based diamine monomer based on magnolol; (2) polymerizing the magnolol-based bio-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 a protective gas atmosphere, the polyimide is dissolved in an organic solvent, and then a small molecule monomer containing a double bond or a triple bond is added and stirred. A thiol monomer and a photoinitiator are continuously added to the system and stirred to obtain a photosensitive polyimide photoresist.

8. The method for preparing the photosensitive polyimide photoresist according to claim 7, characterized in that: Step (1) comprises: reacting magnolol with bromobenzoyl chloride containing R1, R2, R3 and R4 at low temperature in a non-protonic solvent and alkaline environment to obtain a brominated compound containing an allyl group; and reacting the brominated compound with aminophenylboronic acid or phenylboronic acid ester 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, characterized in that: Step (1) comprises: reacting magnolol with bromonitrobenzene containing R1, R2, R3 and R4 in a non-protonic high-polar solvent and an alkaline environment to obtain an allyl-containing dinitro compound; and reacting the dinitro compound with aminophenylboronic acid or phenylboronic acid ester containing R5, R6, R7 and R8 through a 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 bio-based diamine monomer based on magnolol, aromatic diamine monomer, aromatic dianhydride monomer and a third organic solvent, and performing a copolymerization reaction to obtain polyamic acid; mixing the polyamic acid, a dehydrating agent and a third catalyst, and performing a chemical imidization reaction to obtain polyimide.

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