Photosensitive resin composition, microlens and preparation method thereof, and optical device

Abstract

The invention provides a photosensitive resin composition, a micro lens, a preparation method of the micro lens and optical equipment, and relates to the technical field of optical materials. The photosensitive resin composition provided by the invention comprises the thermal crosslinking copolymer, the photosensitizer, the epoxy additive and the photoacid, the reflux temperature of the photosensitive resin composition is further reduced by adding small epoxy molecules, so that the photosensitive resin composition is suitable for heat-labile semiconductor devices, and due to reflux under a low-temperature condition, the crosslinking degree among the components is insufficient, so that the heat-labile performance of the semiconductor devices is improved. According to the invention, the photoresist which can be refluxed at a low temperature (90-95 DEG C) and has excellent chemical resistance is obtained by adding low-wavelength absorption photoacid, not influencing 365nm photoetching, exposing with low wavelength after refluxing and then baking under a low-temperature condition.

Description

Technical Field

[0001] The present application relates to the technical field of optical materials, and in particular to a photosensitive resin composition, a microlens and a preparation method thereof, and an optical device. Background Art

[0002] Microlens is a micro-optical element. Through the design of microlens, the incident light can be diffused, beam shaped, light averaged, optically focused, etc., to achieve many special functions that are difficult to achieve with traditional optical components. The application of microlens array requires that the light emitted from the organic light-emitting layer must pass through each upper microlens. Under the condition that the total amount of light remains unchanged, the refraction and focusing effect of the microlens is greatly utilized to change the optical path design, and the light scattered to the side of the screen is focused to the front of the screen as much as possible, so as to brighten the screen and maintain higher brightness at the same power consumption, which is beneficial to the visibility of the screen. Therefore, microlens technology plays an important role in reducing the power consumption of silicon-based OLED devices and improving the brightness.

[0003] The preparation method of the microlens adopts a positive photosensitive resin and a photosensitizer combination, performs pre-baking to remove the solvent, performs pattern exposure, forms a corresponding pattern after development, and then performs full exposure, and finally performs heating treatment to cause reflux, thereby obtaining a microlens.

[0004] The materials currently used in microlenses, such as OLED, are not resistant to high temperatures during use and require low-temperature reflow. In addition to a lower reflow temperature, the microlens material also needs to have a higher refractive index to better improve the light output efficiency. However, it is difficult for existing microlens materials to have both a low reflow temperature and a high refractive index. Summary of the invention

[0005] The purpose of the present application is to provide a photosensitive resin composition, a microlens and a preparation method thereof and an optical device, aiming to solve the problem that the existing microlens materials are difficult to achieve both low reflow temperature and high refractive index.

[0006] To achieve the above purpose, the present application provides a photosensitive resin composition, which comprises, by weight: 60-120 parts of a thermally cross-linked copolymer, 10-60 parts of a photosensitizer, 1-10 parts of an epoxy additive, and 0.5-5 parts of a photoacid;

[0007] The general chemical formula of the thermally cross-linked copolymer is as follows:

[0008]

[0009] Wherein, R1 is methyl or H, R2 is an epoxy group, R3 is an alkyl group substituted with a benzene ring, and R4 is methyl or H; n=40-60 mol%, m=20-40 mol%, l=20-40 mol%; a and b are the numbers of the corresponding groups, and a+b≤3;

[0010] The photosensitizer is a reaction product of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 4,4'-{1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylene}bisphenol;

[0011] The epoxy additive is selected from any one of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bis(7-oxabicyclo[4.1.0]3-heptylmethyl)adipate, 1,2:5,6-diepoxyhexahydroindane, and 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane;

[0012] The absorption wavelength of the photoacid is 200-260nm.

[0013] In some embodiments, the chemical structure of the photosensitizer is as follows:

[0014]

[0015] Wherein, R is a group represented by the following structural formula:

[0016]

[0017] In some embodiments, the epoxy additive is selected from any one of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 1,2:5,6-diepoxyhexahydroindane, and 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane.

[0018] In some embodiments, the chemical structure of the photoacid is as follows:

[0019]

[0020] In some embodiments, the molecular weight of the thermally cross-linked polymer is 4,000-10,000, preferably 7,000-10,000.

[0021] In some embodiments, the composition comprises, by weight: 90-110 parts of a thermally cross-linked copolymer, 20-30 parts of a photosensitizer, 5-8 parts of an epoxy additive, and 1-3 parts of a photoacid.

[0022] The present application also provides a microlens, the raw material of which includes the above-mentioned photosensitive resin composition.

[0023] The present application also provides a method for preparing a microlens, comprising:

[0024] coating the photosensitive resin composition on a substrate to form a thin film;

[0025] Expose the film for the first time to obtain a film having a target pattern;

[0026] Developing and exposing the adhesive film having the target pattern for a second time;

[0027] The film after the second exposure is heated and refluxed at 90-95° C. to form a microlens.

[0028] In some embodiments, the adhesive film after the second exposure is heated and refluxed at 90-95° C. to form a microlens, and then further comprising:

[0029] The film after heating and reflow is exposed for the third time using a light source with a wavelength less than 300nm;

[0030] The film after the third exposure is heated at 90-95°C for cross-linking.

[0031] The present application also provides an optical device, comprising the above-mentioned microlens.

[0032] Compared with the prior art, the beneficial effects of this application include:

[0033] The photosensitive resin composition provided by the present application includes a thermally cross-linked copolymer, a photosensitizer, an epoxy additive and a photoacid. The epoxy additive is added to further reduce the reflow temperature of the photosensitive resin composition, making it suitable for heat-sensitive semiconductor devices. Due to the reflow under low temperature conditions, the crosslinking degree between the components is insufficient. The present application adds a photoacid that absorbs at a low wavelength (248nm) without affecting the photolithography at 365nm. After reflow, it is exposed with a low wavelength of 248nm and then baked under low temperature conditions, thereby obtaining a photoresist that can be reflowed at a low temperature (90-95°C) and has excellent chemical resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0035] Figure 1 This is a reflow morphology diagram of the photosensitive resin composition of Example 1. DETAILED DESCRIPTION

[0036] As used herein:

[0037] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0038] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0039] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0040] In these examples, parts and percentages are by mass unless otherwise indicated.

[0041] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0042] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0044] The present application provides a photosensitive resin composition, which comprises, by weight: 60-120 parts of a thermally crosslinked copolymer, 10-60 parts of a photosensitizer, 1-10 parts of an epoxy additive, and 0.5-5 parts of a photoacid;

[0045] The general chemical formula of the thermally cross-linked copolymer is as follows:

[0046]

[0047] Wherein, R1 is methyl or H, R2 is an epoxy group, R3 is an alkyl group substituted with a benzene ring, and R4 is methyl or H; n=40-60 mol%, m=20-40 mol%, l=20-40 mol%; a and b are the numbers of the corresponding groups, and a+b≤3;

[0048] The photosensitizer is a reaction product of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 4,4'-{1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylene}bisphenol;

[0049] The epoxy additive is selected from any one of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bis(7-oxabicyclo[4.1.0]3-heptylmethyl)adipate, 1,2:5,6-diepoxyhexahydroindane, and 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane;

[0050] The absorption wavelength of the photoacid is 200-260nm, for example, it can be 200nm, 210nm, 220nm, 230nm, 240nm, 241nm, 242nm, 243nm, 244nm, 245nm, 246nm, 247nm, 248nm, 249nm, 250nm, 255nm, 260nm or any value between 200-260nm.

[0051] The mass fraction of the thermally cross-linked copolymer can be, for example, 60 parts, 70 parts, 80 parts, 90 parts, 100 parts, 110 parts, 120 parts or any value between 60-120 parts, preferably 90-110 parts; the mass fraction of the photosensitizer can be, for example, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts or any value between 10-60 parts, preferably 90-110 parts. The mass fraction of the epoxy additive can be, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts or any value between 1-10 parts, preferably 5-8 parts; the mass fraction of the photoacid can be, for example, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts or any value between 0.5-5 parts, preferably 1-3 parts.

[0052] The chemical structure of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate is as follows:

[0053] In the embodiment of the present application, it is marked as C1.

[0054] The chemical structure of bis(7-oxabicyclo[4.1.0]3-heptylmethyl)adipate is shown below:

[0055] In the embodiment of the present application, it is marked as C2.

[0056] Among them, the chemical structure of 1,2:5,6-diepoxyhexahydroindane is as follows:

[0057] In the examples of this application, it is marked as C3.

[0058] Among them, the chemical structure formula of 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane is as follows:

[0059] In the examples of this application, it is marked as C4.

[0060] The epoxy additives in the examples of the present application were all purchased from Jiangsu Taitel New Materials Technology Co., Ltd.

[0061] In some embodiments, the chemical structure of the photosensitizer is as follows:

[0062]

[0063] Wherein, R is a group represented by the following structural formula:

[0064]

[0065] Among them, the photosensitizer of the present application is a trisubstituted product, marked as TPPA-PAC-3.0, and prepared at a feed ratio of 1:3. In addition, when the photosensitizer is a disubstituted product, it is marked as TPPA-PAC-2.0, and prepared at a feed ratio of 1:2; when the photosensitizer is a mixture of the above two, it is marked as TPPA-PAC-2.5.

[0066] In some embodiments, the epoxy additive is selected from any one of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 1,2:5,6-diepoxyhexahydroindane, and 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane.

[0067] In some embodiments, the chemical structure of the photoacid is as follows:

[0068]

[0069] , the product name is TR-PAG-30408, purchased from Jiangsu Changzhou Qiangli Electronic New Materials Co., Ltd.

[0070] In some embodiments, the molecular weight of the thermally cross-linked polymer is 4000-10000, for example, 4000, 5000, 6000, 7000, 8000, 9000, 10000, preferably 7000-10000.

[0071] In some embodiments, the photosensitive resin composition further includes a surfactant and a solvent.

[0072] The present application also provides a microlens, the raw material of which includes the above-mentioned photosensitive resin composition.

[0073] The shape of the microlens can be changed according to the design of the device, and can be various shapes such as prism, cylinder, truncated pyramid, truncated cone, spherical segment, etc. In the case of making a spherical segment-shaped microlens, a method of reflowing after forming a prism or truncated pyramid pattern is preferred.

[0074] The present application also provides a method for preparing a microlens, comprising:

[0075] coating the photosensitive resin composition on a substrate to form a thin film;

[0076] Expose the film for the first time to obtain a film having a target pattern;

[0077] Developing and exposing the adhesive film having the target pattern for a second time;

[0078] The film after the second exposure is heated and refluxed at 90-95° C. to form a microlens.

[0079] The coating method may be, for example, spin coating, spray coating, roller coating, rod coating, slit coating, preferably spin coating, rod coating. The substrate may be a silicon substrate, a glass substrate, an organic film substrate, a treated surface film substrate, a metal substrate, etc. After the photosensitive resin composition is coated, pre-baking is performed to obtain a thin film.

[0080] The first exposure of the film is pattern exposure, and this step uses a mask (half-color mask; gray tone mask, etc.) to form different exposure areas. The radiation used for exposure includes, but is not limited to, ultraviolet rays, X-rays, charged particle beams, etc.; ultraviolet rays are preferred, such as g-line (436nm), I-line (365nm), GHI mixed bands, etc.

[0081] The film after the first exposure is subjected to a developing process, and the developer is preferably tetramethylammonium hydroxide (TMAH). The developing time varies according to the thickness of the coated film, for example, 60S is preferred for a thickness of 1-3 um.

[0082] After the development process, the film is exposed for the second time to decompose the photosensitizer in the unexposed area for the subsequent heat reflow process. The energy of the second exposure (Flood Exposure) must be sufficient. The exposure energy varies with the thickness of the film, preferably 300-1000mJ / cm 2 .

[0083] The film after the second exposure is heated and refluxed at 90-95°C for curing. The purpose of this is to allow the photoresist to melt and flow, thereby forming a microlens due to surface tension.

[0084] In some embodiments, the adhesive film after the second exposure is heated and refluxed at 90-95° C. to form a microlens, and then further comprising:

[0085] The film after heating and reflow is exposed for the third time using a light source with a wavelength less than 300nm;

[0086] The film after the third exposure is heated at 90-95°C for cross-linking.

[0087] The film after heating and reflowing is exposed again to a light source of 248nm band to decompose the photoacid. In the presence of photoacid, the crosslinking degree in the film can be increased, so that the film has higher chemical resistance.

[0088] The present application also provides an optical device, comprising the above-mentioned microlens.

[0089] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0090] Example 1

[0091] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0092] A copolymer (A1) was synthesized from hydroquinone monomethacrylate, glycidyl methacrylate, and phenoxyethyl acrylate at a molar ratio of 48:26:26 to obtain a copolymer solution with Mw=7200. The chemical structure of the copolymer (A1) is as follows:

[0093]

[0094] Taking the solid mass of the polymer in the solution as the standard, 100 parts by mass of the copolymer solution, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 6.2 parts by mass of C1 (21P) and 1.3 parts by mass of the photoacid D TR-PAG-30408 ​​were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45um to obtain a photosensitive resin composition.

[0095] Example 2

[0096] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0097] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C1 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0098] Example 3

[0099] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0100] A copolymer (A2) was synthesized from hydroquinone monomethacrylate, glycidyl methacrylate, and phenoxyethyl acrylate at a molar ratio of 50:25:25 to obtain a copolymer solution with Mw=7500. The chemical structure of the copolymer (A2) is as follows:

[0101]

[0102] Taking the polymer solid mass in the solution as the standard, 100 parts by mass of the copolymer solution, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 6.2 parts by mass of C1 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45um to obtain a photosensitive resin composition.

[0103] Example 4

[0104] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0105] 100 parts by mass of the copolymer (A2) of Example 3, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C1 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0106] Example 5

[0107] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0108] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of a surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 6.2 parts by mass of C2 and 1.3 parts by mass of a photoacid D were dissolved in PGMEA to prepare a polymer solution having a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 μm to obtain a photosensitive resin composition.

[0109] Example 6

[0110] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0111] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of a surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C2 and 1.3 parts by mass of a photoacid D were dissolved in PGMEA to prepare a polymer solution having a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0112] Example 7

[0113] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0114] 100 parts by mass of the copolymer (A2) of Example 3, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 6.2 parts by mass of C2 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0115] Example 8

[0116] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0117] 100 parts by mass of the copolymer (A2) of Example 3, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C2 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0118] Example 9

[0119] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0120] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of a surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 6.2 parts by mass of C3 and 1.3 parts by mass of a photoacid D were dissolved in PGMEA to prepare a polymer solution having a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 μm to obtain a photosensitive resin composition.

[0121] Example 10

[0122] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0123] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C3 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0124] Embodiment 11

[0125] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0126] 100 parts by mass of the copolymer (A2) of Example 3, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 6.2 parts by mass of C3 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0127] Example 12

[0128] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0129] 100 parts by mass of the copolymer (A2) of Example 3, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C3 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0130] Example 13

[0131] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0132] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of a surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 6.2 parts by mass of C4 and 1.3 parts by mass of a photoacid D were dissolved in PGMEA to prepare a polymer solution having a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0133] Embodiment 14

[0134] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0135] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of a surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C4 and 1.3 parts by mass of a photoacid D were dissolved in PGMEA to prepare a polymer solution having a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 μm to obtain a photosensitive resin composition.

[0136] Embodiment 15

[0137] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0138] 100 parts by mass of the copolymer (A2) of Example 3, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 6.2 parts by mass of C4 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0139] Example 16

[0140] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0141] 100 parts by mass of the copolymer (A2) of Example 3, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C4 and 1.3 parts by mass of the photoacid D were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0142] Embodiment 17

[0143] This embodiment provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0144] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-2.0, 6.2 parts by mass of C1 (21P) and 1.3 parts by mass of the photoacid TR-PAG-30408 ​​were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 μm to obtain a photosensitive resin composition.

[0145] Comparative Example 1

[0146] This comparative example provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0147] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of the surfactant BYK-310, and 25 parts by mass of TPPA-PAC-3.0 were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 μm to obtain a photosensitive resin composition.

[0148] Comparative Example 2

[0149] This comparative example provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0150] 100 parts by mass of the copolymer (A2) of Example 3, 0.02 parts by mass of the surfactant BYK-310, and 25 parts by mass of TPPA-PAC-3.0 were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0151] Comparative Example 3

[0152] This comparative example provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0153] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, and 6.2 parts by mass of C1 were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0154] Comparative Example 4

[0155] This comparative example provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0156] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-3.0, 3.1 parts by mass of C1 and 1.3 parts by mass of the photoacid ILP-110 were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0157] Among them, the chemical structure formula of ILP-110 is as follows:

[0158] Purchased from Heraeus.

[0159] Comparative Example 5

[0160] This comparative example provides a photosensitive resin composition, and the preparation method thereof comprises the following steps:

[0161] 100 parts by mass of the copolymer (A1) of Example 1, 0.02 parts by mass of the surfactant BYK-310, 25 parts by mass of TPPA-PAC-2.0, and 6.2 parts by mass of C1 (21P) were dissolved in PGMEA to prepare a polymer solution with a solid content of 25%. After the prepared polymer solution was fully dissolved, it was filtered using a filter membrane with a pore size of 0.45 um to obtain a photosensitive resin composition.

[0162] The components of the photosensitive resin composition of each embodiment and comparative example are shown in Table 1.

[0163] Table 1 Components of the photosensitive resin composition of each embodiment and comparative example (parts by mass)

[0164]

[0165]

[0166] Performance Testing

[0167] The photosensitive resin compositions of each embodiment and comparative example were tested for performance, and the testing methods were as follows:

[0168] 1. Development

[0169] The photosensitive resin composition obtained in Examples 1-16 and Comparative Examples 1-4 was coated on a 5cm*5cm substrate (including but not limited to glass, silicon and other substrates), and a coating film with a film thickness of 1-3um was formed after pre-baking at 90℃ / 90s. After I-line exposure treatment, different exposure times were changed, and after passing through a mask, a pattern with a spacing of 3-4um was obtained, and then it was developed with a 2.38% TMAH solution at 25℃ for 60s, and then it was rinsed with distilled water for 20s to obtain a pattern. Observe whether the obtained pattern shape is good, and the pattern shape is good as ◎, the pattern is better as ○, and the pattern is present but the shape is not good as ×.

[0170] 2. Reflux temperature

[0171] The photosensitive resin composition obtained in Examples 1-16 and Comparative Examples 1-4 is coated on a 5cm*5cm substrate (including but not limited to glass, silicon and other substrates), and a coating with a film thickness of 1-3um is formed after pre-baking at 90°C / 90S. Use I-line exposure treatment, and after passing through a mask, a spaced dot pattern of varying sizes is obtained. Then, it is developed with a 2.38% TMAH solution at 25°C for 60s, and then rinsed with distilled water for 20s to obtain a pattern. Then, a flood exposure is performed, using a cumulative 500mJ / cm 2 Energy treatment, followed by treatment on a hot plate at 90℃, 95℃ or 100℃ for 5 minutes to melt and flow the glue, thereby forming microlenses due to surface tension, and then using a 248nm wavelength light source for exposure, and finally using a hot plate at the corresponding temperature for another 5 minutes to crosslink and cure the glue. 90℃ can be reflowed as ◎, 95℃ can be reflowed as ○, and 100℃ cannot be reflowed as ×.

[0172] 3. Microlens morphology

[0173] The photosensitive resin composition obtained in Examples 1-16 and Comparative Examples 1-4 is coated on a 5cm*5cm substrate (including but not limited to glass, silicon and other substrates), and a coating with a film thickness of 1-3um is formed after pre-baking at 90°C / 90s. Use I-line exposure treatment, and after passing through a mask, a pattern of spaced dots of varying sizes is obtained. Then, it is developed with a 2.38% TMAH solution at 25°C for 60s, and then rinsed with distilled water for 20s to obtain a pattern. Perform flood exposure again, using a cumulative 500mJ / cm 2 Energy treatment, followed by treatment on a 95°C hot plate for 5 minutes to form a microlens, and then exposure using a 248nm wavelength light source, and finally treatment on a 95°C hot plate for 5 minutes to crosslink and cure the glue. SEM observation shows that the reflow morphology of the microlens in Example 1 is as follows Figure 1As shown, if reflow is possible and the shape is good, it is ◎; if reflow can occur and the shape is good, it is ○; if reflow cannot occur, it is ×.

[0174] 4. Permeability test

[0175] The photosensitive resin composition obtained in Examples 1-16 and Comparative Examples 1-4 is coated on a 5cm*5cm substrate (including but not limited to glass, silicon and other substrates), and a coating with a film thickness of 1-3um is formed after pre-baking at 90℃ / 90s. After I-line flood exposure, a post-baking treatment at 95℃ / 5min is performed on a hot plate, and then a light source with a wavelength of 248nm is used for exposure. Finally, a hot plate treatment at 95℃ is used for 5min to cross-link and cure the glue. The transmittance of the sample is measured at 450nm. The test equipment uses UV-1900i (produced by Shimadzu Corporation), and the test results are ◎ for 90% and above, ○ for 80%-90%, and × for less than 80%.

[0176] 5. Chemical resistance test

[0177] The photosensitive resin composition obtained in Examples 1-16 and Comparative Examples 1-4 is coated on a 5cm*5cm substrate (including but not limited to glass, silicon and other substrates), and a coating with a film thickness of 1-3um is formed after pre-baking at 90℃ / 90s. First, an I-line is used for exposure, and then it is treated at 95℃ for five minutes, followed by exposure using a light source with a wavelength of 248nm, and finally treated on a hot plate at 95℃ for 5min to cross-link and cure the glue, thereby obtaining a sample. The film thickness (T1) of the sample is measured. Then, after the sample is immersed in propylene glycol monomethyl ether acetate (PGMEA) for 3 minutes, the film thickness (T2) of the sample after immersion is measured, and the film thickness change rate is calculated according to the following formula, and it is used as an indicator of chemical resistance.

[0178] Film thickness change rate = [(T2-T1) / T1] x 100%.

[0179] When the absolute value of the film thickness change rate was less than 2%, it was evaluated as ◎, when it was 2% or more and less than 5%, it was evaluated as ○, and when it was 5% or more, it was evaluated as ×, and because there was no reflow, it was not measured and recorded as / .

[0180] The test results of the photosensitive resin compositions of various embodiments and comparative examples are shown in Table 2.

[0181] Table 2 Test results of the photosensitive resin compositions of various embodiments and comparative examples

[0182]

[0183]

[0184] According to Table 2, Examples 1 to 17 of the present application provide a photosensitive resin composition with a polymer molecular weight of 4000-10000. After adding epoxy molecules, the overall reflux temperature of the formula can be reduced and the reflux morphology can be significantly improved. In addition, due to the reduction in reflux temperature, the crosslinking reaction activity in the glue sample is reduced, the crosslinking degree is reduced, and the chemical resistance of the coating film is reduced. By adding a PAG structure to the formula, the addition of this compound increases the crosslinking degree of the glue sample, and the chemical resistance is significantly improved; in addition, the introduction of a high-refractive-low-Tg monomer in the present application enables the refractive index of the glue sample after coating to reach 1.57, which is improved compared to the prior art (1.56). Among them, the photosensitizer in the photosensitive resin composition of Example 17 uses TPPA-PAC-2.0. Although the reflux temperature and chemical resistance are both good, the difference between its ADR after exposure and ADR before exposure is small, which affects the final contrast of the glue.

[0185] In summary, the present application provides a photosensitive resin composition that can achieve low-temperature reflow, has good chemical resistance, and can provide a high refractive index.

[0186] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0187] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A photosensitive resin composition, characterized in that: The composition comprises, by weight: 60-120 parts of a heat-crosslinking copolymer, 10-60 parts of a photosensitizer, 1-10 parts of an epoxy additive and 0.5-5 parts of a photoacid; The general chemical formula of the thermally cross-linked copolymer is as follows: Wherein, R1 is methyl or H, R2 is an epoxy group, R3 is an alkyl group substituted with a benzene ring, and R4 is methyl or H; n=40-60 mol%, m=20-40 mol%, l=20-40 mol%; a and b are the numbers of the corresponding groups, and a+b≤3; The photosensitizer is a reaction product of 1,2-naphthoquinonediazide-5-sulfonyl chloride and 4,4'-{1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylene}bisphenol; The epoxy additive is selected from any one of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bis(7-oxabicyclo[4.1.0]3-heptylmethyl)adipate, 1,2:5,6-diepoxyhexahydroindane, and 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane; The absorption wavelength of the photoacid is 200-260nm.

2. The photosensitive resin composition according to claim 1, characterized in that The chemical structural formula of the photosensitizer is shown below: Wherein, R is a group represented by the following structural formula:

3. The photosensitive resin composition according to claim 1, characterized in that: The epoxy additive is selected from any one of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 1,2:5,6-diepoxyhexahydroindane, and 1-methyl-4-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane.

4. The photosensitive resin composition according to claim 1, characterized in that: The chemical structural formula of the photoacid is shown below:

5. The photosensitive resin composition according to claim 1, characterized in that: The molecular weight of the heat-crosslinking polymer is 4000-10000, preferably 7000-10000.

6. The photosensitive resin composition according to claim 1, characterized in that: The invention comprises, by weight, 90-110 parts of a heat-crosslinking copolymer, 20-30 parts of a photosensitizer, 5-8 parts of an epoxy additive and 1-3 parts of a photoacid.

7. A microlens, characterized in that: The raw materials include the photosensitive resin composition according to any one of claims 1 to 6.

8. A method for preparing a microlens as claimed in claim 7, characterized in that: include: coating the photosensitive resin composition on a substrate to form a thin film; Expose the film for the first time to obtain a film having a target pattern; Developing and exposing the adhesive film having the target pattern for a second time; The film after the second exposure is heated and refluxed at 90-95° C. to form a microlens.

9. The method for preparing a microlens according to claim 8, characterized in that: The film after the second exposure is heated and refluxed at 90-95°C to form a microlens, and then the following steps are included: The film after heating and reflow is exposed for the third time using a light source with a wavelength less than 300nm; The film after the third exposure is heated at 90-95°C for cross-linking.

10. An optical device, characterized in that: Comprising the microlens as claimed in claim 7.

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