Solvent photosensitive dry film acrylic resin for PCB and preparation method thereof

Abstract

The application relates to a solvent photosensitive dry film acrylic resin for PCB and a preparation method thereof, and belongs to the technical field of photosensitive dry films. The solvent photosensitive dry film acrylic resin for PCB comprises the following components: modified acrylic resin, modified white carbon black, reaction monomer, photoinitiator, antioxidant, defoaming agent and deionized water; the solvent photosensitive dry film acrylic resin for PCB prepared by the application introduces an organic group with stronger thermal stability by modifying the white carbon black, and meanwhile, the dispersity and compatibility of the white carbon black in the system are improved by using a compatibilizer, so that the mechanical strength and high-temperature resistance of the film material are significantly enhanced.

Description

Technical Field

[0001] This invention belongs to the technical field of photosensitive dry film, and relates to a solvent-sensitive photosensitive dry film acrylic resin for PCB and its preparation method. Background Technology

[0002] Photosensitive dry film plays a crucial role in the production of printed circuit boards (PCBs), serving as a key raw material. To meet the special requirements of PCBs operating under prolonged high temperatures, photosensitive dry film must exhibit excellent high-temperature resistance and strong adhesion. To achieve these requirements, specific high-temperature resistant fillers, such as silica, silicon nitride, alumina, and zirconium oxide, are typically added to the coating of the photosensitive dry film. Furthermore, epoxy resin prepolymers with excellent adhesion properties are selected, and their performance is further enhanced through photocuring. However, in the application of acrylic resins, excessive use of epoxy groups can negatively impact the material's resistance to high-temperature yellowing and aging. To overcome this problem, fillers have been added to compensate for the defects. However, these fillers often exhibit poor flowability in acrylic resins, easily agglomerating and resulting in difficulty in uniform dispersion. This poor dispersibility ultimately limits further improvement in high-temperature resistance, thus affecting the overall performance and reliability of the PCB. Summary of the Invention

[0003] The purpose of this invention is to provide a solvent-sensitive photosensitive dry film acrylic resin for PCBs and its preparation method. The solvent-sensitive photosensitive dry film acrylic resin for PCBs prepared by this invention modifies silica and introduces organic groups with stronger thermal stability. At the same time, a compatibilizer is used to improve the dispersion and compatibility of silica in the system, thereby significantly enhancing the mechanical strength and high temperature resistance of the film material.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A solvent-sensitive photosensitive dry film acrylic resin for PCBs comprises the following components by weight: 62-70 parts modified acrylic resin, 9-10 parts modified silica, 21-24 parts reactive monomer, 0.4-0.6 parts photoinitiator, 0.2-0.3 parts antioxidant, 0.4-0.6 parts defoamer, and 7-10 parts deionized water;

[0006] As a preferred embodiment of the present invention, the reactive monomer is a mixture of triethylene glycol diacrylate and tetrahydrofuran methacrylate in a mass ratio of 1.5:1; the photoinitiator is photoinitiator 1173; the antioxidant is hindered phenolic antioxidant AO-80; and the defoamer is fatty alcohol polyoxyethylene ether.

[0007] This invention discloses a method for preparing the modified silica, comprising the following steps:

[0008] Step S1: Stir and mix silica, anhydrous ethanol and silane coupling agent, filter to obtain solid, wash with anhydrous ethanol 3 times, and dry to obtain silane modified silica.

[0009] Step S2: Under a nitrogen atmosphere, anhydrous ethanol, coniferaldehyde and initiator are added to silane-modified silica and mixed. The mixture is stirred at a constant temperature, centrifuged, washed three times with anhydrous ethanol, and then placed in an oven for vacuum drying to obtain pre-made silica.

[0010] Step S3: Mix the anisidine and anhydrous ethanol, add the pre-made silica, heat and stir, filter out the solid, wash it three times with anhydrous ethanol, vacuum dry it, add compatibilizer, melt extrude it, and granulate it to obtain modified silica.

[0011] As a preferred technical solution of the present invention, in step S1, the stirring and mixing is carried out at a speed of 500-600 r / min for 30-40 min; the drying is carried out under vacuum at 80°C until constant weight.

[0012] As a preferred embodiment of the present invention, in step S1, the mass ratio of the silica, anhydrous ethanol and silane coupling agent is 15-16:50-60:6.5-7.3; the silane coupling agent is mercaptopropylmethyldimethoxysilane.

[0013] As a preferred technical solution of the present invention, in step S2, the constant temperature stirring is carried out at a temperature of 40-45℃ for 5-6 hours; the vacuum drying is carried out at a temperature of 80℃ to constant weight.

[0014] As a preferred embodiment of the present invention, in step S2, the mass ratio of the silane-modified silica, anhydrous ethanol, coniferaldehyde and the initiator is 22-24:70-80:5.2-6.0:0.22-0.24; the initiator is cerium ammonium nitrate.

[0015] As a preferred technical solution of the present invention, in step S3, the heating and stirring is carried out at a temperature of 50-60°C for 6-7 hours; the temperature of the melt extrusion is 190-200°C.

[0016] As a preferred embodiment of the present invention, in step S3, the mass ratio of the anisidine, anhydrous ethanol, pre-made silica and compatibilizer is 1.6-1.8:30-40:11-12:20-22; the compatibilizer is a styrene-methyl methacrylate-glycidyl methacrylate terpolymer.

[0017] This invention discloses a method for preparing the modified acrylic resin, comprising mixing acrylic acid, butyl methacrylate, methacrylic acid, sodium dodecyl sulfate, silane coupling agent NQ-62 and deionized water at a speed of 900-1000 r / min for 60-80 min, adding initiator VA-044 and stirring at a constant temperature of 82-86℃ for 2-3 h to obtain the modified acrylic resin.

[0018] As a preferred embodiment of the present invention, the mass ratio of acrylic acid, butyl methacrylate, methacrylic acid, silane coupling agent NQ-62, initiator VA-044, sodium dodecyl sulfate, and deionized water is 11-13:12-15:25-29:4.4-4.6:0.6-0.8:1.2-1.5:50-60.

[0019] This invention discloses a method for preparing solvent-sensitive photosensitive dry film acrylic resin for PCBs as described above, comprising the following steps: mixing modified acrylic resin, modified silica, reactive monomer, photoinitiator, antioxidant, defoamer and deionized water, and curing to obtain the final product.

[0020] The beneficial effects of this invention are:

[0021] The solvent-sensitive photosensitive dry film acrylic resin for PCBs prepared in this invention significantly enhances the mechanical strength and high-temperature resistance of the film material by modifying silica and introducing organic groups with stronger thermal stability, while using compatibilizers to improve the dispersion and compatibility of silica in the system. Detailed Implementation

[0022] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0023] Example 1

[0024] A solvent-sensitive photosensitive dry film acrylic resin for PCBs comprises the following components by weight: 62 parts modified acrylic resin, 9 parts modified silica, 21 parts reactive monomer, 0.4 parts photoinitiator, 0.2 parts antioxidant, 0.4 parts defoamer, and 7 parts deionized water; the reactive monomer is a mixture of triethylene glycol diacrylate and tetrahydrofuran methacrylate in a mass ratio of 1.5:1; the photoinitiator is photoinitiator 1173; the antioxidant is hindered phenolic antioxidant AO-80; and the defoamer is fatty alcohol polyoxyethylene ether.

[0025] The method for preparing the modified acrylic resin includes mixing acrylic acid, butyl methacrylate, methacrylic acid, sodium dodecyl sulfate, silane coupling agent NQ-62, and deionized water at 900 r / min for 60 min, adding initiator VA-044, and stirring at 82℃ for 2 h to obtain the modified acrylic resin; wherein the mass ratio of acrylic acid, butyl methacrylate, methacrylic acid, silane coupling agent NQ-62, initiator VA-044, sodium dodecyl sulfate, and deionized water is 11:12:25:4.4:0.6:1.2:50.

[0026] The method for preparing the modified silica includes the following steps:

[0027] Step S1: Stir and mix silica, anhydrous ethanol, and silane coupling agent, filter to obtain the solid, wash three times with anhydrous ethanol, and dry to obtain silane-modified silica; wherein, the stirring and mixing is performed; the drying is performed by vacuum drying at 80°C to constant weight; the mass ratio of silica, anhydrous ethanol, and silane coupling agent is 15:50:6.5; the silane coupling agent is mercaptopropylmethyldimethoxysilane;

[0028] Step S2: Under a nitrogen atmosphere, anhydrous ethanol, coniferaldehyde, and an initiator are added to silane-modified silica and mixed. The mixture is then stirred at a constant temperature, centrifuged, washed three times with anhydrous ethanol, and placed in an oven for vacuum drying to obtain pre-prepared silica. The constant temperature stirring is performed at 40°C for 5 hours; the vacuum drying is performed at 80°C until constant weight is achieved. The mass ratio of silane-modified silica, anhydrous ethanol, coniferaldehyde, and initiator is 22:70:5.2:0.22; the initiator is cerium ammonium nitrate.

[0029] Step S3: After mixing bi-anisidine and anhydrous ethanol, add pre-made silica and heat and stir. After filtering, take the solid and wash it three times with anhydrous ethanol. Vacuum dry, add compatibilizer and melt extrude, then granulate to obtain modified silica. The heating and stirring are carried out at 50°C for 6 hours. The melt extrusion temperature is 190°C. The mass ratio of bi-anisidine, anhydrous ethanol, pre-made silica and compatibilizer is 1.6:30:11:20. The compatibilizer is a styrene-methyl methacrylate-glycidyl methacrylate terpolymer.

[0030] A method for preparing a solvent-sensitive photosensitive dry film acrylic resin for PCBs includes the following steps: mixing modified acrylic resin, modified silica, reactive monomer, photoinitiator, antioxidant, defoamer and deionized water, and curing to obtain the final product.

[0031] Example 2

[0032] A solvent-sensitive photosensitive dry film acrylic resin for PCBs comprises the following components by weight: 66 parts modified acrylic resin, 9.5 parts modified silica, 22 parts reactive monomer, 0.5 parts photoinitiator, 0.25 parts antioxidant, 0.5 parts defoamer, and 8 parts deionized water; the reactive monomer is a mixture of triethylene glycol diacrylate and tetrahydrofuran methacrylate in a mass ratio of 1.5:1; the photoinitiator is photoinitiator 1173; the antioxidant is hindered phenolic antioxidant AO-80; and the defoamer is fatty alcohol polyoxyethylene ether.

[0033] The method for preparing the modified acrylic resin includes mixing acrylic acid, butyl methacrylate, methacrylic acid, sodium dodecyl sulfate, silane coupling agent NQ-62, and deionized water at 950 r / min for 70 min, adding initiator VA-044, and stirring at 84℃ for 2.5 h to obtain the modified acrylic resin; wherein the mass ratio of acrylic acid, butyl methacrylate, methacrylic acid, silane coupling agent NQ-62, initiator VA-044, sodium dodecyl sulfate, and deionized water is 12:14:27:4.5:0.7:1.4:55.

[0034] The method for preparing the modified silica includes the following steps:

[0035] Step S1: Stir and mix silica, anhydrous ethanol, and silane coupling agent, filter to obtain the solid, wash three times with anhydrous ethanol, and dry to obtain silane-modified silica; wherein, the stirring and mixing is performed; the drying is performed by vacuum drying at 80°C to constant weight; the mass ratio of silica, anhydrous ethanol, and silane coupling agent is 15.5:55:6.9; the silane coupling agent is mercaptopropylmethyldimethoxysilane;

[0036] Step S2: Under a nitrogen atmosphere, anhydrous ethanol, coniferaldehyde, and an initiator are added to silane-modified silica and mixed. The mixture is then stirred at a constant temperature, centrifuged, washed three times with anhydrous ethanol, and placed in an oven for vacuum drying to obtain pre-prepared silica. The constant temperature stirring is performed at 42°C for 5.5 hours; the vacuum drying is performed at 80°C until constant weight is achieved. The mass ratio of silane-modified silica, anhydrous ethanol, coniferaldehyde, and initiator is 23:75:5.6:0.23; the initiator is cerium ammonium nitrate.

[0037] Step S3: After mixing bifenthrin and anhydrous ethanol, add pre-made silica and heat and stir. After filtering, take the solid and wash it three times with anhydrous ethanol. Vacuum dry, add compatibilizer and melt extrude, then granulate to obtain modified silica. The heating and stirring are carried out at 55°C for 6.5 hours. The melt extrusion temperature is 195°C. The mass ratio of bifenthrin, anhydrous ethanol, pre-made silica and compatibilizer is 1.7:35:11.5:21. The compatibilizer is a styrene-methyl methacrylate-glycidyl methacrylate terpolymer.

[0038] A method for preparing a solvent-sensitive photosensitive dry film acrylic resin for PCBs includes the following steps: mixing modified acrylic resin, modified silica, reactive monomer, photoinitiator, antioxidant, defoamer and deionized water, and curing to obtain the final product.

[0039] Example 3

[0040] A solvent-sensitive photosensitive dry film acrylic resin for PCBs comprises the following components by weight: 70 parts modified acrylic resin, 10 parts modified silica, 24 parts reactive monomer, 0.6 parts photoinitiator, 0.3 parts antioxidant, 0.6 parts defoamer, and 10 parts deionized water; the reactive monomer is a mixture of triethylene glycol diacrylate and tetrahydrofuran methacrylate in a mass ratio of 1.5:1; the photoinitiator is photoinitiator 1173; the antioxidant is hindered phenolic antioxidant AO-80; and the defoamer is fatty alcohol polyoxyethylene ether.

[0041] The method for preparing the modified acrylic resin includes mixing acrylic acid, butyl methacrylate, methacrylic acid, sodium dodecyl sulfate, silane coupling agent NQ-62, and deionized water at 1000 r / min for 80 min, adding initiator VA-044, and stirring at 86℃ for 3 h to obtain the modified acrylic resin; wherein the mass ratio of acrylic acid, butyl methacrylate, methacrylic acid, silane coupling agent NQ-62, initiator VA-044, sodium dodecyl sulfate, and deionized water is 13:15:29:4.6:0.8:1.5:60.

[0042] The method for preparing the modified silica includes the following steps:

[0043] Step S1: Stir and mix silica, anhydrous ethanol, and silane coupling agent, filter to obtain the solid, wash three times with anhydrous ethanol, and dry to obtain silane-modified silica; wherein, the stirring and mixing is performed; the drying is performed by vacuum drying at 80°C to constant weight; the mass ratio of silica, anhydrous ethanol, and silane coupling agent is 16:60:7.3; the silane coupling agent is mercaptopropylmethyldimethoxysilane;

[0044] Step S2: Under a nitrogen atmosphere, anhydrous ethanol, coniferaldehyde, and an initiator are added to silane-modified silica and mixed. The mixture is then stirred at a constant temperature, centrifuged, washed three times with anhydrous ethanol, and placed in an oven for vacuum drying to obtain pre-prepared silica. The constant temperature stirring is performed at 45°C for 6 hours; the vacuum drying is performed at 80°C until constant weight is achieved. The mass ratio of silane-modified silica, anhydrous ethanol, coniferaldehyde, and initiator is 24:80:6.0:0.24; the initiator is cerium ammonium nitrate.

[0045] Step S3: After mixing bifenthrin and anhydrous ethanol, add pre-made silica and heat and stir. After filtering, take the solid and wash it three times with anhydrous ethanol. Vacuum dry, add compatibilizer and melt extrude. Pelletize to obtain modified silica. The heating and stirring are carried out at 60°C for 7 hours. The melt extrusion temperature is 200°C. The mass ratio of bifenthrin, anhydrous ethanol, pre-made silica and compatibilizer is 1.8:40:12:22. The compatibilizer is a styrene-methyl methacrylate-glycidyl methacrylate terpolymer.

[0046] A method for preparing a solvent-sensitive photosensitive dry film acrylic resin for PCBs includes the following steps: mixing modified acrylic resin, modified silica, reactive monomer, photoinitiator, antioxidant, defoamer and deionized water, and curing to obtain the final product.

[0047] Comparative Example 1

[0048] Compared with Example 3, Comparative Example 1 differs in that mercaptopropylmethyldimethoxysilane is not used in step S1, while the remaining components, preparation steps and parameters are the same.

[0049] Comparative Example 2

[0050] Compared with Example 3, Comparative Example 2 differs in that step S2 does not use coniferaldehyde, while the other components, preparation steps and parameters are the same.

[0051] Comparative Example 3

[0052] Compared with Example 3, Comparative Example 3 differs in that aniline is used instead of bifenisamine in step S3, while the other components, preparation steps and parameters are the same.

[0053] Comparative Example 4

[0054] Compared with Example 3, Comparative Example 4 differs in that step S3 does not use anisidine, while the remaining components, preparation steps and parameters are the same.

[0055] Comparative Example 5

[0056] Compared with Example 3, Comparative Example 5 differs in that step S3 does not use the styrene-methyl methacrylate-glycidyl methacrylate terpolymer, while the remaining components, preparation steps and parameters are the same.

[0057] Comparative Example 6

[0058] Compared with Example 3, Comparative Example 6 differs in that it does not use silane coupling agent NQ-62, while the other components, preparation steps and parameters are the same.

[0059] The photosensitive dry film acrylic resins prepared in Examples 1-3 and Comparative Examples 1-6 were tested as follows, and the test results are shown in Table 1.

[0060] Tensile strength test: The tensile properties of the photosensitive dry film cured with acrylic resin were determined using a UTM5000 electronic universal testing machine. Samples with dimensions of 20mm×10mm×0.5mm were used, and the crosshead speed was set to 10mm / min. Each sample was measured three times, and the average value was calculated as the final result.

[0061] High temperature resistance test: Bake at 260℃ for 60 minutes and test the change rate of tensile strength.

[0062] Table 1

[0063] Tensile strength (MPa) Tensile strength (MPa) after baking Example 1 30.6 30.3 Example 2 30.8 30.6 Example 3 30.9 30.7 Comparative Example 1 25.6 21.4 Comparative Example 2 26.4 21.7 Comparative Example 3 25.2 21.1 Comparative Example 4 24.5 18.4 Comparative Example 5 24.8 17.6 Comparative Example 6 25.6 20.2

[0064] As shown in Table 1, the mechanical strength and thermal stability of the photosensitive dry film acrylic resin prepared in this invention are significantly better than those in Comparative Examples 1-6 compared to Examples 1-6. This invention modifies the surface of silica with mercaptopropylmethyldimethoxysilane to make it hydrophobic and introduces high-temperature resistant active functional groups (thiol groups). These thiol groups form covalent bonds with coniferaldehyde through a click reaction. The oxygen-containing functional groups on the coniferaldehyde form physical crosslinks with the silane-modified silica through hydrogen bonding and electrostatic interactions. At the other end, high-strength and high-temperature resistant biphenyl and Schiff base structures are introduced through the interaction between the aldehyde group and the amino group of bifenthrinamine. The epoxy groups of the styrene-methyl methacrylate-glycidyl methacrylate terpolymer can react with the hydroxyl groups of the pre-prepared silica to form chemical structures. The styrene phase exhibits good physical compatibility with pre-formed silica, further increasing the bonding force of modified silica in the acrylic resin system and forming a denser structure. In addition, the methyl methacrylate phase and glycidyl methacrylate phase have good compatibility with acrylic resin. The silane coupling agent NQ-62 in the modified acrylic resin not only participates in the polymerization reaction of acrylic resin, but the amino groups it introduces also have good compatibility with the excess aldehyde groups and Schiff base structure of pre-formed silica, effectively promoting the dispersion and compatibility of modified silica in the system, thereby significantly improving the mechanical properties and high-temperature resistance of the film material.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A solvent photosensitive dry film acrylic resin for PCB, characterized by, By weight parts including the following components: modified acrylic resin 62-70 parts, modified white carbon black 9-10 parts, reaction monomer 21-24 parts, photoinitiator 0.4-0.6 parts, antioxidant 0.2-0.3 parts, defoaming agent 0.4-0.6 parts and deionized water 7-10 parts;Wherein, the preparation method of the modified acrylic resin comprises mixing acrylic acid, butyl methacrylate, methacrylic acid, sodium dodecyl sulfate, silane coupling agent NQ-62 and deionized water under the stirring speed of 900-1000r / min for 60-80min, adding initiator VA-044, constant temperature stirring at 82-86℃ for 2-3h, to obtain the modified acrylic resin; The preparation method of the modified white carbon black comprises the following steps: Step S1, the white carbon black, anhydrous ethanol and silane coupling agent are stirred and mixed, the solid is filtered, washed with anhydrous ethanol for 3 times, dried to obtain silane modified white carbon black; Step S2, under the nitrogen atmosphere, the silane modified white carbon black is added with anhydrous ethanol, coniferyl aldehyde and initiator, then mixed and constant temperature stirring, centrifugation, washed with anhydrous ethanol for 3 times, vacuum drying in the oven, to obtain the pre-prepared white carbon black; Step S3, the anisole is mixed with anhydrous ethanol, then the pre-prepared white carbon black is added and heated and stirred, the solid is filtered out, washed with anhydrous ethanol for 3 times, vacuum drying, adding compatibilizer, melt extrusion, granulation, to obtain the modified white carbon black; The silane coupling agent is mercaptopropyl methyl dimethoxysilane;The compatibilizer is styrene-methyl methacrylate-glycidyl methacrylate terpolymer.

2. The solvent photosensitive dry film acrylic resin for PCB according to claim 1, characterized in that: The reaction monomer is mixed by triethylene glycol diacrylate and methyl methacrylate tetrahydrofurfuryl ester according to the mass ratio of 1.5:

1. 3.The solvent photosensitive dry film acrylic resin for PCB according to claim 1, characterized in that: The photoinitiator is photoinitiator 1173;The antioxidant is hindered phenol antioxidant AO-80;The defoaming agent is fatty alcohol polyoxyethylene ether.

4. The solvent photosensitive dry film acrylic resin for PCB according to claim 1, characterized in that: In step S1, the stirring speed is 500-600r / min for 30-40min;The drying is vacuum drying at 80℃ until constant weight;The mass ratio of the white carbon black, anhydrous ethanol and silane coupling agent is 15-16:50-60:6.5-7.3;The silane coupling agent is mercaptopropyl methyl dimethoxysilane.

5. The solvent photosensitive dry film acrylic resin for PCB according to claim 1, characterized in that: In step S2, the constant temperature stirring is at 40-45℃ for 5-6h;The vacuum drying is at 80℃ until constant weight;The mass ratio of the silane modified white carbon black, anhydrous ethanol, coniferyl aldehyde and initiator is 22-24:70-80:5.2-6.0:0.22-0.24;The initiator is cerium ammonium nitrate.

6. The solvent photosensitive dry film acrylic resin for PCB according to claim 1, characterized in that: In step S3, the heating and stirring is at 50-60℃ for 6-7h;The melt extrusion temperature is 190-200℃;The mass ratio of the anisole, anhydrous ethanol, pre-prepared white carbon black and compatibilizer is 1.6-1.8:30-40:11-12:20-22;The compatibilizer is styrene-methyl methacrylate-glycidyl methacrylate terpolymer.

7. The solvent photosensitive dry film acrylic resin for PCB according to claim 1, characterized in that: In the preparation of the modified acrylic resin, the mass ratio of the acrylic acid, butyl methacrylate, methacrylate, silane coupling agent NQ-62, initiator VA-044, sodium dodecyl sulfate and deionized water is 11-13:12-15:25-29:4.4-4.6:0.6-0.8:1.2-1.5:50-60.

8. A method for preparing a solvent photosensitive dry film acrylic resin for a PCB according to any one of claims 1 to 7, characterized by, The preparation method comprises the following steps: uniformly mixing the modified acrylic resin, modified white carbon black, reaction monomer, photoinitiator, antioxidant, defoaming agent and deionized water, and after curing, the product is obtained.