Photosensitive ink resin as well as preparation method and application thereof

Abstract

The invention relates to the technical field of ink resin, in particular to photosensitive ink resin as well as a preparation method and application thereof. The photosensitive ink resin is characterized by being prepared from the following raw materials in parts by weight: 60 to 80 parts of acrylamide analogue, 10 to 20 parts of acrylic acid or methacrylic acid, 100 to 120 parts of acrylate, 1 to 5 parts of initiator, 100 to 200 parts of solvent and 5 to 20 parts of epoxy diluent. When the photosensitive dry film is applied, the problems of unstable performance, low developing speed and the like of an existing photosensitive dry film can be solved while the resolution and the adhesive force are not reduced, and the requirements of 3D packaging and advanced semiconductor manufacturing are met.

Description

Technical Field

[0001] This invention relates to the field of ink resin technology, specifically to a photosensitive ink resin, its preparation method, and its application. Background Technology

[0002] Photosensitive dry film, a core material for pattern transfer in printed circuit boards (PCBs) and semiconductor packaging, consists of polyester film (PET), a photoresist layer (photosensitive layer), and a polyethylene protective film (PE). Its performance directly determines the precision and production efficiency of circuit lines. With the explosive growth in AI computing power, high-density packaging technology places higher demands on the resolution, adhesion, and development speed (target >7m / min) of photosensitive dry films, but existing technologies have significant bottlenecks. Traditional photosensitive dry films are mostly constructed with amino- or acrylic monomers as the main chain. Although this ensures a certain degree of adhesion, their acid value is low, requiring a slow dissolution of unexposed areas using an alkaline solution during development, which is insufficient to meet the rapid development requirements of high-precision circuits.

[0003] Chinese invention patent CN109062005B optimizes resolution by introducing vinyl unsaturated groups, but fails to solve the problem of limited development speed, making it difficult to improve production efficiency; Chinese invention patent CN111965939B uses nitrogen-containing sugar-based polyether acrylate to improve adhesion, but still fails to break through the technical barrier of development efficiency and cannot meet the mass production requirements of high-density packaging. Summary of the Invention

[0004] The first aspect of the present invention provides a photosensitive ink resin, wherein the raw materials for preparation, by weight, include: 60-80 parts of acrylamide analog, 10-20 parts of acrylic acid or methacrylic acid, 100-120 parts of acrylate, 1-5 parts of initiator, 100-200 parts of solvent, and 10-20 parts of epoxy diluent.

[0005] Optionally, by weight, the raw materials include: 60-70 parts of acrylamide analog, 10-18 parts of acrylic acid or methacrylic acid, 100-120 parts of acrylate, 1-3.5 parts of initiator, 120-180 parts of solvent, and 5-15 parts of epoxy diluent.

[0006] Optionally, the weight ratio of the acrylamide analog, acrylic acid or methacrylic acid, and acrylate is 65:(10-20):(100-120).

[0007] Optionally, the weight ratio of the acrylamide analog, acrylic acid or methacrylic acid, and acrylate is 65:(12-16):(105-115).

[0008] The acrylamide analog has the structure shown in Formula 1: Both R and R1 are selected from one of the following: hydrogen atom, C. 1-10 straight-chain alkyl, C 1-10 Branched alkyl, C 1-10 Alkyl groups containing heteroatoms, C 1-10 Aryl groups containing heteroatoms.

[0009] Optionally, the acrylamide analogues include acrylamide, methacrylamide, and ethylacrylamide.

[0010] Optionally, the acrylamide analogues include methacrylamide.

[0011] The acrylate has the structure shown in Formula 2: R2 and R3 are both selected from one of the following: hydrogen atom, C 1-10 straight-chain alkyl, C 1-10 Branched alkyl, C 1-10 Alkyl groups containing heteroatoms, C 1-10 Aryl groups containing heteroatoms.

[0012] Optionally, the acrylate includes at least one selected from methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and ethyl dimethacrylate.

[0013] Optionally, the acrylate includes at least one of methyl methacrylate and methyl acrylate.

[0014] The epoxy diluent accounts for 1.5-5 wt% of the raw materials used in the preparation.

[0015] Optionally, the epoxy diluent accounts for 2-4 wt% of the raw materials used in the preparation.

[0016] The epoxy diluent is selected from at least one of the following: ethylene glycol glycidyl ether, 1,4-butanediol glycidyl ether, propylene glycol glycidyl ether, neopentyl glycol diglycidyl ether, hexanediol diglycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, glycerol triglycidyl ether, and trimethylolpropane triglycidyl ether.

[0017] The initiator is selected from at least one of tert-butyl peroxide, benzoyl peroxide, azobisisobutyronitrile, tert-butylhydroperoxide, azobisisoheptanenitrile, tert-butanol peroxide, and benzoic acid hydroperoxide.

[0018] Optionally, the initiator is selected from azobisisobutyronitrile (AIBN).

[0019] The solvent is selected from at least one of toluene, acetone, butanone, dichloromethane, dichloroethane, trichloroethane, chloroform, dioxane, methanol, water, and diethyl ether.

[0020] Optionally, the solvent is selected from toluene and methanol.

[0021] The second aspect of the present invention provides a method for preparing a photosensitive ink resin, comprising the following steps: heating and mixing an initiator comprising 30-60 wt% of the total initiator, acrylic acid or methacrylic acid comprising 25-40 wt% of the total acrylic acid or methacrylic acid, acrylamide analog comprising 20-40 wt% of the total acrylamide analog, acrylate comprising 3-15 wt% of the total acrylate, a solvent and an epoxy diluent to obtain a mixture; adding the remaining amount dropwise to the mixture, and reacting after the addition is complete to obtain a photosensitive ink resin.

[0022] Optionally, the preparation method of the photosensitive ink resin includes the following steps: heating and mixing an initiator accounting for 40-60 wt% of the total initiator, an acrylic acid or methacrylic acid accounting for 30-40 wt% of the total acrylic acid or methacrylic acid, an acrylamide analog accounting for 20-30 wt% of the total acrylamide analog, an acrylate accounting for 3-10 wt% of the total acrylate, a solvent, and an epoxy diluent to obtain a mixture; adding the remaining amount dropwise to the mixture, and reacting after the addition is complete to obtain the photosensitive ink resin.

[0023] Optionally, the preparation method of the photosensitive ink resin includes the following steps: heating and mixing an initiator accounting for 45-55 wt% of the total initiator, an acrylic acid or methacrylic acid accounting for 35-40 wt% of the total acrylic acid or methacrylic acid, an acrylamide analog accounting for 20-25 wt% of the total acrylamide analog, an acrylate accounting for 5-10 wt% of the total acrylate, a solvent, and an epoxy diluent to obtain a mixture; adding the remaining amount dropwise to the mixture, and reacting after the addition is complete to obtain the photosensitive ink resin.

[0024] Optionally, the heating temperature is 80-95℃.

[0025] Optionally, the heating temperature is 85-95°C.

[0026] Optionally, the dripping time is 3-4 hours, and the temperature during the dripping process does not exceed 120°C.

[0027] Optionally, the temperature during the dropping process is 80-110℃.

[0028] Optionally, the reaction time is 3-4 hours.

[0029] The photosensitive ink resin has a weight-average molecular weight of 30,000-40,000, a solid content of 40-70 wt%, a viscosity (25℃) of 25,000-38,000 cp, and an acid value of 60-85 mg KOH / g.

[0030] Optionally, the photosensitive ink resin has a weight-average molecular weight of 30,000-35,000, a solid content of 45-60 wt%, a viscosity (25°C) of 30,000-35,000 cp, and an acid value of 65-75 mg KOH / g.

[0031] In the process of optimizing photosensitive ink resin, this invention discovered that by using acrylic acid or methacrylic acid, methacrylamide, and methyl methacrylate or methyl acrylate as raw materials and introducing epoxy diluent for grafting, the photosensitive ink resin prepared based on the optimized initiator addition amount and synthesis method has very good film-forming properties. It not only retains the original resolution and adhesion, but also further improves its development speed.

[0032] Further research revealed that the specific batch addition method of the raw materials in this invention, combined with specific temperature and dropwise addition methods, enables the photosensitive dry film obtained by compounding photosensitive ink resins to achieve a linewidth or line spacing of 25 / 25. The resolution and adhesion can support the requirements of 3D packaging and advanced semiconductor processes. Furthermore, the development speed is significantly improved, and the preparation method of the film-forming resin is simple and convenient to use, effectively increasing production capacity and laying the foundation for the mass production of high-resolution photosensitive dry films. It is possible that by controlling the monomer formulation, the amount of initiator added, and the synthesis method, the resolution of the photoresist can be effectively avoided due to excessively large molecular weight of the photosensitive ink resin and molecular chain entanglement.

[0033] A third aspect of the present invention provides an application of a photosensitive ink resin in the preparation of a photosensitive dry film.

[0034] The raw materials for preparing the photosensitive dry film include photosensitive ink resin and diluent, and the content of the photosensitive ink resin in the photosensitive dry film is 20-40 wt%.

[0035] Optionally, the content of the photosensitive ink resin in the photosensitive dry film is 25-35 wt%.

[0036] The raw materials for preparing the photosensitive dry film also include photoinitiators, sensitizers, and organic solvents.

[0037] Optionally, by weight, the raw materials for preparing the photosensitive dry film include 120-140 parts of photosensitive ink resin, 250-350 parts of diluent, 1-3 parts of photoinitiator, 0.1-0.5 parts of sensitizer, and 30-70 parts of organic solvent.

[0038] Optionally, by weight, the raw materials for preparing the photosensitive dry film include 130 parts of photosensitive ink resin, 250-350 parts of diluent, 1-3 parts of photoinitiator, 0.1-0.5 parts of sensitizer, and 30-70 parts of organic solvent.

[0039] The raw materials for preparing the photosensitive dry film also include photoinitiators, sensitizers, and organic solvents.

[0040] Optionally, the diluent includes at least one of ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol hexaacrylate.

[0041] The photoinitiator is selected from at least one of 1-hydroxycyclohexylphenyl ketone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2,4-diethylthioxanthone, isopropyl-9H-thioxanthone, 2-methyl-2-(4-morpholino)-4'-(methylthio)phenylacetone, hydroxy-2-methylphenylacetone, 2-benzyl-2-(dimethylamino)-4'-morpholinophenylbutanone, benzoin dimethyl ether, benzophenone, and 3-methyl-4,phenylbenzophenone.

[0042] Optionally, the initiator is photoinitiator 184 (1-hydroxycyclohexylphenyl ketone).

[0043] The organic solvent is selected from at least one of toluene, acetone, butanone, dichloromethane, dichloroethane, trichloroethane, chloroform, dioxane, methyl ethyl ketone, methanol, water, and diethyl ether.

[0044] Optionally, the organic solvent is selected from toluene and methanol.

[0045] The sensitizer is selected from at least one of 2,4-diethylthioxanthanone (DETX), isopropylthioxanthanone (ITX), 4,4'-bis(diethylamino)benzophenone (michidone, MK), 2-chlorothioxanthanone (CTX), N-phenylglycine (NPG), and 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole (BCIM).

[0046] Beneficial effects

[0047] 1. The specific raw materials and the introduction of epoxy diluent of this invention can improve the film-forming properties of the prepared photosensitive ink resin, not only retaining the original resolution and adhesion, but also further improving its development speed.

[0048] 2. The specific method of adding raw materials in batches according to the present invention, combined with a specific temperature and dropping method, enables the photosensitive dry film obtained by compounding photosensitive ink resin to achieve a line width or line spacing of 25 / 25.

[0049] 3. The photosensitive dry film obtained by compounding the photosensitive ink resin of the present invention has excellent resolution and adhesion, and can support...

[0050] 3D packaging and advanced semiconductor manufacturing processes are in demand.

[0051] 4. The preparation method of the photosensitive ink resin of the present invention is simple and convenient to use, and is easy to realize large-scale industrial production and application.

[0052] 5. The photosensitive dry film obtained by the photosensitive ink resin compound of the present invention has a development speed of ≥4m / min, which not only improves production efficiency and yield, but also fully ensures the integrity of high-precision circuits, reduces copper surface oxidation and chemical contamination, and can meet the needs of high-density packaging technology. Detailed Implementation

[0053] Example 1

[0054] A photosensitive ink resin, by weight, comprises the following raw materials: 65 parts of acrylamide analog, 14 parts of acrylic acid, 110 parts of acrylate, 3 parts of initiator, 150 parts of solvent, and 10 parts of epoxy diluent.

[0055] The acrylamide analogue is methacrylamide; the acrylic acid is acrylic acid; the acrylate is methyl acrylate; the initiator is azobisisobutyronitrile; the solvent is toluene; and the epoxy diluent is ethylene glycol glycidyl ether.

[0056] A method for preparing a photosensitive ink resin includes the following steps:

[0057] (1) By weight, add 1.5 parts of initiator, 5 parts of acrylic acid, 15 parts of acrylamide analog, 8.5 parts of acrylate, solvent and 3 parts of epoxy diluent to a container and heat and stir (single paddle stirrer).

[0058] (2) The remaining initiator, acrylic acid, acrylamide analog and acrylate are added dropwise through a dropper (constant rate drop method, using a peristaltic pump) to the container in step (1) for reaction. After the drop is finished, the reaction continues to obtain the photosensitive ink resin.

[0059] The heating and stirring temperature in step (1) is 85℃; the reaction temperature is controlled at 80-110℃ during the dropwise addition process in step (2), the dropwise addition time is 3.5h, and the reaction continues for 3.5h.

[0060] The photosensitive ink resin has a weight-average molecular weight of 32,420 and a solid content of 57 wt%.

[0061] The solid content test method is as follows: Weigh 2±0.3g of resin with aluminum foil, bake it in an oven at 120℃ for 2h, take it out and weigh it again. The calculation method is Equation 1: (m1-m0) / m2, where m0 is the mass of the empty tray, m1 is the mass of the sample, and m3 is the mass of (sample + empty tray) after baking.

[0062] The acid value test method is as follows: Take 1 ± 0.05 g of sample, add 10 g of anhydrous ethanol and 40 g of butanone, stir until completely dissolved, then add 4 drops of phenolphthalein and titrate with KOH standard solution. The acid value is calculated using the following formula:

[0063] =C KOH *V KOH *56.1 / m 样品质量 .

[0064] An application of a photosensitive ink resin in the preparation of a photosensitive dry film, wherein the raw materials for preparing the photosensitive dry film are, by weight: 130 parts of photosensitive ink resin, 290 parts of diluent (dipentaerythritol hexaacrylate), 2 parts of photoinitiator (1-hydroxycyclohexylphenyl ketone), 0.25 parts of sensitizer (2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole), and 50 parts of organic solvent (toluene).

[0065] The preparation method of the photosensitive dry film is as follows: organic solvent and photosensitive ink resin are stirred and mixed, then photoinitiator and sensitizer are added, stirred and mixed, filtered and left to stand overnight to obtain coating liquid, the coating liquid is coated on the surface of a 19μm thick PET substrate at a coating speed of 3.0m / min and a coating thickness of 20μm, and then dried in an oven at 100℃ to obtain photosensitive dry film.

[0066] Example 2

[0067] The specific implementation method is the same as in Example 1, except that the methyl acrylate is replaced with methyl methacrylate, and the weight-average molecular weight of the photosensitive ink resin is 33,100, with a solid content of 58 wt%.

[0068] Example 3

[0069] The specific implementation method is the same as in Example 1, except that the acrylic acid is replaced with methacrylic acid, and the weight-average molecular weight of the photosensitive ink resin is 32,700, with a solid content of 60 wt%.

[0070] Comparative Example 1

[0071] The specific implementation method is the same as in Example 1, except that no epoxy diluent is added, and the amount of other raw materials remains unchanged; the weight-average molecular weight of the photosensitive ink resin is 33465, and the solid content is 59wt%.

[0072] Performance testing methods and data

[0073] The photosensitive dry films prepared in the examples and comparative examples were subjected to performance tests, and the test data are listed in Table 2. The test method was as follows: the photosensitive dry film was laminated onto a copper-clad laminate using a laminator, and the circuit board was prepared through processes such as exposure, development, and stripping. The specific process conditions are shown in Table 1.

[0074] Table 1

[0075] Table 2

[0076]

[0077] Table 2 shows that, based on the test results of Examples 1-4, although the resolution and adhesion of the photosensitive dry film compounded with the photosensitive ink resin without the introduction of epoxy diluent in Example 4 can reach 20 / 25, the development speed is only 2m / min. The photosensitive dry film made with the photosensitive ink resin with the introduction of epoxy diluent can maintain the resolution and adhesion at 20-25μm, and significantly improve its development speed (≥4m / min). At the same time, it improves production efficiency and yield, and can fully ensure the integrity of high-precision circuits. It can also reduce copper surface oxidation and chemical contamination, and can meet the needs of high-density packaging technology.

Claims

1. A photosensitive ink resin, characterized in that, The raw materials for preparation, by weight, include: 60-80 parts of acrylamide analog, 10-20 parts of acrylic acid or methacrylic acid, 100-120 parts of acrylate, 1-5 parts of initiator, 100-200 parts of solvent, and 5-20 parts of epoxy diluent.

2. The photosensitive ink resin according to claim 1, characterized in that, The acrylamide analog has the structure shown in Formula 1: Both R and R1 are selected from one of the following: hydrogen atom, C. 1-10 straight-chain alkyl, C 1-10 Branched alkyl, C 1-10 Alkyl groups containing heteroatoms, C 1-10 Aryl groups containing heteroatoms.

3. The photosensitive ink resin according to claim 1, characterized in that, The acrylate has the structure shown in Formula 2: R2 and R3 are both selected from one of the following: hydrogen atom, C 1-10 straight-chain alkyl, C 1-10 Branched alkyl, C 1-10 Alkyl groups containing heteroatoms, C 1-10 Aryl groups containing heteroatoms.

4. The photosensitive ink resin according to claim 2 or 3, characterized in that, The epoxy diluent accounts for 1.5-5 wt% of the raw materials used in the preparation.

5. A method for preparing a photosensitive ink resin according to any one of claims 1-4, characterized in that, Includes the following steps: The initiator (30-60 wt% of the total initiator), acrylic acid or methacrylic acid (25-40 wt% of the total acrylic acid or methacrylic acid), acrylamide analog (20-40 wt% of the total acrylamide analog), acrylate (3-15 wt% of the total acrylate), solvent, and epoxy diluent are heated and mixed evenly to obtain a mixture; the remaining amount is added dropwise to the mixture, and after the addition is complete, the reaction is completed to obtain a photosensitive ink resin.

6. The method for preparing the photosensitive ink resin according to claim 5, characterized in that, The heating temperature is 80-95℃.

7. The method for preparing the photosensitive ink resin according to claim 6, characterized in that, The dripping time is 3-4 hours, and the temperature during the dripping process is 80-110℃.

8. The method for preparing the photosensitive ink resin according to claim 7, characterized in that, The reaction time is 3-4 hours.

9. An application of the photosensitive ink resin according to any one of claims 1-4, characterized in that, It is used in the preparation of photosensitive dry films.

10. The application of the photosensitive ink resin according to claim 9, characterized in that, The raw materials for preparing the photosensitive dry film include the photosensitive ink resin and a diluent, wherein the content of the photosensitive ink resin in the photosensitive dry film is 20-40 wt%.

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