Photosensitive resin composition and preparation method and application thereof

Abstract

The invention discloses a photosensitive resin composition, which is prepared from the following raw materials in percentage by weight: 80 to 95 weight percent of polymer capable of being dissolved in alkaline aqueous solution, 2 to 10 weight percent of photoacid generator, 3 to 10 weight percent of organic acid and 1 to 6 weight percent of cross-linking agent. When the mass ratio of the polyamide acid macromolecular substance to the PAG to the sebacic acid to the 2, 6-bis (hydroxymethyl) p-cresol is 100: (5-5.75): (3-3.6): (5.75-6), the formed polymer film is firm in structure, high in resolution ratio in the etching process, small in developing thickness loss before and after baking, and good in overall polymer. The photosensitive resin composition of the present invention has excellent analysis and adhesion patterns, excellent dissolution rate ratio between a final exposure portion and an exposure portion, good sensitivity, resolution, adhesion, and storage stability, and can improve adhesion to a substrate.

Description

Technical Field

[0001] The invention discloses a photosensitive resin composition and a preparation method and application thereof, relates to G03F, and specifically relates to the field of photoengraving technology of pattern surfaces. Background Art

[0002] In recent years, the semiconductor electronic packaging industry has gradually developed in the direction of high density, high power, and lightness. In order to ensure that electronic components have sufficient mechanical strength in the use environment, electronic packaging must have high reliability, excellent heat dissipation and low cost. There are two types of existing polyimide resin packaging materials. Traditional polyimide needs to be combined with photoresist to obtain the target circuit pattern, while photosensitive resin can omit the three steps of photoresist coating, polyimide etching, and photoresist removal. Graphics can be made through direct exposure and development, reducing the complexity of processing, improving the yield rate, and reducing costs. However, the existing negative-type photosensitive resin is limited by structure, the operating space for analytical attachment is limited, and there is a problem of poor resolution of exposure and development.

[0003] Chinese invention patent CN202211402181.1 discloses a chemically amplified negative photosensitive polyimide coating adhesive and its application. By using a polyimide resin containing phenolic hydroxyl groups to work together with a photoacid generator and a cross-linking agent, the prepared photolithographic pattern has high resolution, a high and adjustable angle between the bevel and the bottom edge, low curing shrinkage, good adhesion to different substrate interfaces, and good chemical corrosion resistance, but the analytical process is complicated, and the yield rate is low and the cost is high. Chinese invention patent CN202210049783.7 discloses a cross-linked polyamic acid ester, a preparation method thereof, a polyimide composition containing it, and a preparation method of a polyimide resin film. The cross-linking is performed using polyphenol cross-linking agent residues and the carboxyl residues of the originally complete polyamic acid unit to form a cross-linked polyamic acid ester, which can effectively resist the development of alkaline developer, has good heat resistance, high resolution, high sensitivity, and high contrast. However, the adhesion with the electronic substrate is poor. Summary of the invention

[0004] In order to develop a photoresist with excellent dissolution rate ratio, good sensitivity, resolution, adhesion and storage stability, the first aspect of the present invention provides a photosensitive resin composition, the preparation raw materials include, by weight percentage: 80-95wt% of a polymer soluble in an alkaline aqueous solution, 2-10wt% of a photoacid generator, 3-10wt% of an organic acid, and 1-6wt% of a cross-linking agent.

[0005] As a preferred embodiment, the structural formula of the cross-linking agent is Where R1 is R2, R3 are selected from one of alkyl and alkoxy groups, A is an alkyl group, and R4 is selected from one of alkyl and alkoxy groups.

[0006] As a preferred embodiment, the structural formula of the organic acid is or In the formula, R5 is selected from one of an alkyl group or an alkoxy group, and R6 is selected from one of an alkyl group or an aromatic hydroxyl group.

[0007] As a preferred embodiment, the structural formula of the photoacid generator is

[0008]

[0009] As a preferred embodiment, the weight average molecular weight Mw of the polymer soluble in alkaline aqueous solution is 20000-50000 Da.

[0010] As a preferred embodiment, the weight average molecular weight Mw of the polymer soluble in alkaline aqueous solution is 25000-45000 Da.

[0011] As a preferred embodiment, the preparation raw material further includes an organic solvent, and the amount of the organic solvent used is 1-2 times the mass of the polymer soluble in the alkaline aqueous solution.

[0012] As a preferred embodiment, the amount of the organic solvent used is 1.5-2 times the mass of the polymer soluble in the alkaline aqueous solution.

[0013] As a preferred embodiment, the raw materials for preparing the polymer soluble in alkaline aqueous solution include 50-80 parts by weight of organic solvent, 5-20 parts of fluorine-containing alkane, 0.3-1.5 parts of aminophenol, and 5-30 parts of fluorine-containing dianhydride.

[0014] As a preferred embodiment, the raw materials for preparing the polymer soluble in alkaline aqueous solution include 50-70 parts by weight of organic solvent, 10-15 parts of fluorine-containing alkane, 0.5-1 part of aminophenol, and 15-20 parts of fluorine-containing dianhydride.

[0015] As a preferred embodiment, the fluorine-containing alkane is hexafluoropropane containing an amino group and a hydroxyl group, and the fluorine-containing dianhydride is hexafluorodianhydride.

[0016] As a preferred embodiment, the hexafluoropropane containing amino and hydroxyl groups is bis(3-amino-4-hydroxyphenyl)hexafluoropropane. Preferably, the aminophenol is m-aminophenol. The organic solvent is N-methylpyrrolidone.

[0017] As a preferred embodiment, the method for preparing the polymer soluble in alkaline aqueous solution comprises the following steps:

[0018] S1 Add organic solvent, fluoroalkyl and m-aminophenol into a flask and stir to dissolve;

[0019] S2 At room temperature, add fluorinated dianhydride dropwise into the flask within 20-40 minutes, and continue stirring for 10-15 hours to obtain a reaction solution;

[0020] S3: adding m-xylene to the reaction solution, heating to reflux, the reflux temperature is 140-160°C, the reflux time is 1-3h, then cooling to room temperature, adding dropwise to distilled water, filtering and collecting the precipitate, and drying under reduced pressure at room temperature to obtain a polymer soluble in alkaline aqueous solution, namely PAA.

[0021] The purpose of reflux is to remove the imide ring from the system by azeotropy.

[0022] The applicant introduced a polymer soluble in alkaline aqueous solution and then used it in combination with sebacic acid and a crosslinking agent to improve the adhesion to the substrate, and the dissolution rate ratio of the unexposed part to the exposed part is excellent, and the resolution and sensitivity performance are good. The possible reason is speculated that the polyamic acid polymer prepared by 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and hexafluorodianhydride has excellent analytical adhesion to the substrate due to its special molecular structure. When the polyamic acid polymer is used in combination with sebacic acid and 2,6-bis(hydroxymethyl)-p-cresol, photodevelopment can be achieved in alkaline substances and has good resolution in alkaline substances. In particular, when the mass ratio of the polyamic acid polymer to PAG, sebacic acid and 2,6-bis(hydroxymethyl)-p-cresol is 100:(5-5.75):(3-3.6):(5.75-6), the structure of the formed polymer film is solid, the resolution is high during the development process, the thickness loss before and after baking is small, and the overall polymer is better.

[0023] A second aspect of the present invention provides a method for preparing a photosensitive resin composition, comprising the following steps:

[0024] The polymer is prepared by adding an organic solvent, a photoacid generator, an organic acid and a cross-linking agent to a polymer soluble in an alkaline aqueous solution and stirring the mixture until the polymer is completely dissolved.

[0025] The third aspect of the present invention provides an application of a photosensitive resin composition, which is applied to a photoresist solution of electronic equipment.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The photosensitive resin composition of the present invention can improve the adhesion to the substrate by introducing a polymer soluble in an alkaline aqueous solution and then using it in combination with sebacic acid and a crosslinking agent, and has an excellent dissolution rate ratio between the unexposed part and the exposed part, and has good resolution and sensitivity performance.

[0028] (2) In the photosensitive resin composition of the present invention, when the mass ratio of the polyamic acid polymer to PAG, sebacic acid and 2,6-bis(hydroxymethyl)-p-cresol is 100:(5-5.75):(3-3.6):(5.75-6), the formed polymer film has a solid structure, a high resolution during etching, a small thickness loss before and after baking, and a better overall polymer.

[0029] (3) The photosensitive resin composition of the present invention has good analytical adhesion pattern, excellent dissolution rate ratio between the unexposed part and the exposed part, good sensitivity, resolution, adhesion and storage stability, and can improve adhesion to the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The process flow chart of the photoetching of the present invention comprises: (1) coating polyimide; (2) coating photoresist; (3) ultraviolet irradiation; (4) baking; (5) polyimide etching; and (6) photoresist removal.

[0031] In the figure: 1. substrate; 2. polyimide layer; 3. photoresist layer; 4. ultraviolet curing.

[0032] Figure 2 is a photograph of the photosensitive resin composition of the present invention after coating; Figure 3 is a photograph of the photosensitive resin composition of the present invention after exposure; Figure 4 This is a photograph of the photosensitive resin composition of the present invention after development. Figure 5 A picture of the width of the attached line measured under a microscope for Example 12; Figure 6 This is a picture of Example 12 sliced ​​under a microscope to measure the thickness after baking. DETAILED DESCRIPTION

[0033] Example

[0034] A photosensitive resin composition, the raw materials for preparation include: a polymer soluble in alkaline aqueous solution (PAA), a photoacid generator (PAG), an organic acid (p-toluenesulfonic acid / sebacic acid), a crosslinking agent (2,6-bis(hydroxymethyl)-p-cresol), and an organic solvent of N-methylpyrrolidone. The usage amount is in parts by weight, see Table 1 and Table 2.

[0035] The raw materials for preparing the polymer (PAA) soluble in alkaline aqueous solution include 60 parts of N-methylpyrrolidone, 12.23 parts of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 0.74 parts of m-aminophenol, and 16.34 parts of hexafluorodianhydride in parts by weight.

[0036] The method for preparing the polymer soluble in alkaline aqueous solution comprises the following steps:

[0037] S1 Add organic solvent, fluoroalkyl and m-aminophenol into a flask and stir to dissolve;

[0038] S2 At room temperature, add fluorinated dianhydride dropwise into the flask within 30 minutes and continue stirring for 12 hours to obtain a reaction solution;

[0039] S3: Add 20 g of m-xylene to the reaction solution, heat to reflux, the reflux temperature is 150°C, the reflux time is 2 h, then cool to 25°C, add dropwise into distilled water, collect the precipitate by filtration, and dry under reduced pressure at room temperature to obtain a polymer soluble in alkaline aqueous solution, namely PAA.

[0040] The structural formula of the photoacid generator PAG is

[0041] A method for preparing a photosensitive resin composition comprises the following steps:

[0042] The polymer is prepared by adding an organic solvent, a photoacid generator, an organic acid and a cross-linking agent to a polymer soluble in an alkaline aqueous solution and stirring the mixture until the polymer is completely dissolved.

[0043] Table 1

[0044]

[0045] Table 2

[0046]

[0047]

[0048] Performance Testing

[0049] The photosensitive resin composition prepared in the embodiment was rotated onto a silicon wafer and pre-baked at 120°C for 3 minutes to form a photoresist film layer with a thickness of 10 μm. Then, the photoresist film was exposed under a photomask with a UV ultra-high pressure mercury lamp (Zhisheng M552 5KW mercury-xenon short arc lamp) at an energy of 400 mj / cm2, and then developed with 2.38wt% tetramethylammonium hydroxide for 200 seconds to form a patterned film, and then baked at a high temperature in a nitrogen oven at 225°C for 1 hour.

[0050] Test the analytical and adhesion thickness, thickness after development, and thickness after baking. Figure 1 See the photo after coating. Figure 2 , see the photos after exposure Figure 3 , the developed photos are shown in Figure 4 .

[0051] Example 12: The image of measuring the width of the attached line under a microscope is shown in Figure 5 Example 12: The thickness of the slices after baking was measured under a microscope. Figure 6 .

[0052] The test results are shown in Table 3.

[0053] Table 3

[0054]

[0055]

[0056] By comparing Examples 1-4, it can be found that the use of p-toluenesulfonic acid can obtain a good polymerization reaction effect and the obtained analytical adhesion is better, but the use ratio exceeds the preferred range and the pattern cannot be obtained.

[0057] By comparing Examples 5-8, it can be found that the use of sebacic acid can obtain a good polymerization reaction effect and the obtained analytical adhesion is better, but the use ratio exceeds the preferred range and the pattern cannot be obtained.

[0058] By comparing Examples 9-15, it can be found that the thickness before and after high-temperature baking is different due to the volatilization of residual solvents and the difference in the degree of polymerization of the photosensitive resin composition, which makes it different in the dissolution in the developer, and the thickness loss after high-temperature baking also affects the resolution. Under the preferred usage ratio of the cross-linking agent, PAG and sebacic acid, a photosensitive resin composition with less loss of development thickness, relatively thick thickness after baking and better overall degree of polymerization can be obtained.

Claims

1. A photosensitive resin composition, characterized in that The raw materials for preparation include, by weight percentage: 80-95 wt % of a polymer soluble in alkaline aqueous solution, 2-10 wt % of a photoacid generator, 3-10 wt % of an organic acid, and 1-6 wt % of a crosslinking agent.

2. The photosensitive resin composition according to claim 1, characterized in that: The structural formula of the cross-linking agent is Where R1 is R2, R3 are selected from one of alkyl and alkoxy groups, A is an alkyl group, and R4 is selected from one of alkyl and alkoxy groups.

3. The photosensitive resin composition according to claim 1, characterized in that: The structural formula of the organic acid is In the formula, R5 is selected from one of an alkyl group or an alkoxy group, and R6 is selected from one of an alkyl group or an aromatic hydroxyl group.

4. The photosensitive resin composition according to claim 1, characterized in that: The structural formula of the photoacid generator is 5. The photosensitive resin composition according to claim 1, characterized in that: The weight average molecular weight Mw of the polymer soluble in alkaline aqueous solution is 20000-50000 Da.

6. The photosensitive resin composition according to claim 1, characterized in that: The preparation raw materials also include an organic solvent, and the usage amount of the organic solvent is 1-2 times the mass of the polymer soluble in the alkaline aqueous solution.

7. The photosensitive resin composition according to claim 1, characterized in that: The raw materials for preparing the polymer soluble in alkaline aqueous solution include, by weight, 50-80 parts of organic solvent, 5-20 parts of fluorine-containing alkane, 0.3-1.5 parts of aminophenol, and 5-30 parts of fluorine-containing dianhydride.

8. The photosensitive resin composition according to claim 7, characterized in that: The fluorine-containing alkane is hexafluoropropane containing an amino group and a hydroxyl group, and the fluorine-containing dianhydride is hexafluorodianhydride.

9. A method for preparing the photosensitive resin composition according to any one of claims 6 to 8, characterized in that: The following steps are involved: The polymer is prepared by adding an organic solvent, a photoacid generator, an organic acid and a cross-linking agent to a polymer soluble in an alkaline aqueous solution and stirring the mixture until the polymer is completely dissolved.

10. An application of the photosensitive resin composition according to any one of claims 6 to 8, characterized in that: Used in photoresist liquid for electronic equipment.

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