CN115862960B

CN115862960B - Preparation method of metal grid conductive film, metal grid conductive film and touch screen

Info

Publication number: CN115862960B
Application number: CN202211727046.4A
Authority: CN
Inventors: 王钧; 冯旭平; 李阳; 石家乐; 江建国
Original assignee: Flextouch Technologies Co Ltd
Current assignee: Flextouch Technologies Co Ltd
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2024-03-12
Anticipated expiration: 2042-12-30
Also published as: CN115862960A

Abstract

The disclosure provides a preparation method of a metal grid conductive film, the metal grid conductive film and a touch screen. The preparation method comprises the following steps: providing a photoinitiator and presetting an exposure band of the photoinitiator, wherein the photoinitiator is selected from oxime ester photoinitiators, and the mass ratio range c of the photoinitiator in the photoresist composition is obtained; providing a photoresist composition according to the obtained mass ratio range; coating a photoresist composition on a substrate, and removing a solvent in the photoresist composition to form a photoresist layer; forming a catalyst layer on the photoresist layer; exposing and developing the photoresist layer to form a patterning layer between the photoresist layer and the catalyst layer; and placing the substrate in the electroless plating solution, and preparing a metal grid pattern on the pattern layer. In the preparation method, the swelling rate of the formed photoresist layer in the electroless plating solution can be reduced, and the amount of the metal lines growing to two sides along the photoresist layer is small, so that the line width increment of the metal lines can be obviously reduced.

Description

Preparation method of metal grid conductive film, metal grid conductive film and touch screen

Technical Field

The invention relates to the technical field of metal grids, in particular to a preparation method of a metal grid conductive film, the metal grid conductive film and a touch screen.

Background

With the rapid development of the internet and semiconductor technology, the variety of electronic devices is more and more, and the functions are more and more abundant. Touch screens are an important medium for human interaction with electronic devices, and thus, their applications have also been widely popularized, particularly in mobile phones, watches, notebook computers, and vehicle-mounted devices.

The externally hung touch control component based on the metal grid is widely focused and researched due to wide matching property, simple preparation process and low price. The current common manner of preparing the metal mesh comprises the following steps: a photoresist layer is coated on a flexible substrate, a catalyst layer is coated on the photoresist layer, patterning treatment is carried out on the photoresist layer, partial photoresist layer for depositing metal wires is reserved, and metal such as copper is plated under the action of the catalyst layer, so that a metal grid can be formed. After metal plating, the line width of the metal grid is usually in the range of 3.5-4 μm, and defects such as channel marks, moire patterns, grid visibility and the like may exist, so that the display effect of the display screen is affected. Especially for OLED display screens with denser pixel arrangements, it is often necessary to match finer metal grids, which requires the line widths of the metal grids to be below 2.5 μm.

Since the metal grid is prepared on the patterned photoresist layer, the line width of the metal grid is related to the line width of the photoresist layer. During the step of coating the catalyst layer, a portion of the catalyst may penetrate into the photoresist layer. In the step of plating metal, the plating solution permeates into the photoresist layer, so that metal is not only formed directly above the photoresist layer, but also grows along the top of the photoresist layer to both sides. Thus, a more obvious line width increment of the line width of the metal line can occur relative to the line width of the photoresist layer. For example, assuming that the design line width of the mask used in forming the trench pattern is 2 μm, the line width increment of the final metal line can reach 1.2 to 1.8 μm. Meanwhile, the line width increment mainly comes from the increment of the top end of the metal line, and in consideration of the adhesive force of the metal line, finer metal grids cannot be prepared simply by reducing the design line width. This hampers the preparation of finer metal grids.

Disclosure of Invention

Based on this, in order to reduce the line width increment generated in the manufacturing process of the metal grid, it is necessary to provide a manufacturing method of the metal grid.

According to some embodiments of the present disclosure, there is provided a method of manufacturing a metal mesh conductive film, including the steps of:

providing a photoinitiator and presetting an exposure wave band of the photoinitiator, wherein the photoinitiator is selected from oxime ester photoinitiators, and the mass ratio c of the photoinitiator in the photoresist composition is obtained according to the following formula: c=d·n/N _x Wherein, the value range of D is 1 to 5 per mill, N is the total light absorption amount of the photoinitiator, N _x Light absorption of the photoinitiator in the exposure wave band;

providing the photoresist composition, wherein the photoresist composition comprises a photosensitive prepolymer, a monomer and the photoinitiator, the mass ratio of the photoinitiator in the photoresist composition is c, the mass ratio of the photosensitive prepolymer is 10-30%, and the mass ratio of the monomer is 5-20%;

coating the photoresist composition on a substrate, and removing a solvent in the photoresist composition to form a photoresist layer;

forming a catalyst layer on the photoresist layer;

exposing and developing the photoresist layer with the exposure wave band to form a patterning layer between the photoresist layer and the catalyst layer;

and placing the substrate in an electroless plating solution, and preparing a metal grid pattern on the pattern layer.

In some embodiments of the present disclosure, the oxime ester photoinitiator is a ketoxime ester photoinitiator and/or a carbazole oxime ester photoinitiator.

In some embodiments of the present disclosure, the photoinitiator mass fraction c is no greater than 5% maximum and no less than 0.15% minimum.

In some embodiments of the present disclosure, the solids content in the photoresist composition is 20% to 30%.

In some embodiments of the present disclosure, the photosensitive prepolymer in the photoresist composition includes 55% to 65% by mass of an acrylic oligomer whose main chain contains an aromatic ring structure, and the mass ratio of the photosensitive prepolymer to the monomer in the photoresist composition is (2 to 2.4): 1.

In some embodiments of the present disclosure, in the acrylic oligomer, the aromatic ring structure is selected from one or more of fluorenyl and its derivatives and phenanthryl and its derivatives.

In some embodiments of the present disclosure, the catalyst layer comprises palladium catalytic particles having a particle size of < 5nm.

In some embodiments of the present disclosure, the photoresist composition further comprises a leveling agent.

In some embodiments of the present disclosure, the photoresist layer has a thickness of 200nm to 900nm.

In some embodiments of the present disclosure, after preparing the metal mesh pattern on the pattern layer, further comprising: and a step of blackening the metal mesh pattern and preparing an insulating layer on the conductive film.

According to still further embodiments of the present disclosure, there is also provided a metal mesh conductive film prepared by the preparation method described in any one of the above embodiments.

According to still further embodiments of the present disclosure, there is also provided a touch screen including the metal mesh conductive film of any one of the above embodiments.

In the preparation method of the metal mesh conductive film provided by the disclosure, an oxime ester photoinitiator is adopted, and the mass ratio c=D.N/N of the photoinitiator in the photoresist composition is further limited _x . Photoinitiators have an absorption spectrum over a broad range of wavelength bands, and those skilled in the art will generally not be concerned with the specific exposure band of the photoinitiator. Through the research of the disclosure, the oxime ester photoinitiator is adopted, and the mass ratio range of the photoinitiator is determined based on the light absorption amount of the oxime ester photoinitiator in an exposure wave band and the light absorption amount of the oxime ester photoinitiator in a total wave band, so that the curing rate of the photoresist composition during exposure can be effectively improved. The solidification rate of the photoresist layer is improved, the swelling rate of the formed photoresist layer in the electroless plating solution is reduced, and the amount of metal lines growing to two sides along the photoresist layer is small, so that the line width increment of the metal lines can be obviously reduced.

Drawings

FIG. 1 is an absorbance curve of the photoinitiator used in example 1, wherein the abscissa is wavelength and the ordinate is absorbance.

Detailed Description

The present invention will be described more fully hereinafter in order to facilitate an understanding of the present invention. Preferred embodiments of this invention are presented herein. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items. As used herein, "multiple" includes two and more items. As used herein, "above a certain number" should be understood to mean a certain number and a range of numbers greater than a certain number.

The disclosure provides a method for preparing a metal mesh conductive film, which comprises the following steps:

providing a photoinitiator and presetting an exposure band of the photoinitiator, wherein the photoinitiator is selected from oxime ester photoinitiators, and the mass ratio c of the photoinitiator in the photoresist composition is obtained according to the following formula: c=d·n/N _x Wherein, the value range of D is 1 to 5 per mill, N is the total light absorption amount of the photoinitiator, N _x The light absorption amount of the photoinitiator in an exposure wave band;

providing a photoresist composition, wherein the photoresist composition comprises a photosensitive prepolymer, a monomer and a photoinitiator, the mass ratio of the photoinitiator in the photoresist composition is c, the mass ratio of the photosensitive prepolymer is 10-30%, and the mass ratio of the monomer is 5-20%;

coating a photoresist composition on a substrate, and removing a solvent in the photoresist composition to form a photoresist layer;

forming a catalyst layer on the photoresist layer;

exposing and developing the photoresist layer in an exposure wave band to form a patterning layer between the photoresist layer and the catalyst layer;

and placing the substrate in the electroless plating solution, and preparing a metal grid pattern on the pattern layer.

It has been found that in electroless plating solutions, the catalyst layer is mixed into the resist layer near the surface layer in addition to being located on the resist layer. Because the photoresist layer swells to a certain extent in the plating solution and expands to both sides, the catalyst therein expands to both sides along with the photoresist layer. In general, to reduce swelling, one skilled in the art may choose to increase the exposure energy to increase the degree of curing of the photoresist. However, the higher exposure energy promotes the reaction of the photo-curing material in the lateral direction, resulting in lateral expansion of the photoresist layer, so that the line width after development is significantly increased, and the curing rate of the photoresist layer at the lateral edge is still lower, so that the photoresist layer is easier to grow to two sides in the copper plating process. The manner in which the exposure energy is increased is not effective in reducing the line width increment.

In the preparation method of the metal mesh conductive film provided by the disclosure, an oxime ester photoinitiator is adopted, and the mass ratio c=D.N/N of the photoinitiator in the photoresist composition is further limited _x . Photoinitiators have an absorption spectrum over a broad range of wavelength bands, and those skilled in the art will generally not be concerned with the specific exposure band of the photoinitiator. According to the research of the disclosure, the mass ratio range of the photoinitiator in the photoresist composition is determined based on the light absorption amount of the oxime ester photoinitiator in an exposure wave band and the light absorption amount of the oxime ester photoinitiator in a total wave band, so that the line width increase generated in the subsequent preparation of metal grids can be effectively reduced, and the method is likely to be mainly beneficial to improving the curing rate of photosensitive prepolymer and monomer in the photoresist during exposure. The curing rate of the photosensitive prepolymer and the monomer of the photoresist layer is improved, so that the swelling rate of the formed photoresist layer in the electroless plating solution is reduced, the amount of metal lines growing to two sides along the photoresist layer is reduced, and the line width increment of the metal lines can be obviously reduced.

Wherein, the photoinitiator can absorb ultraviolet energy in a certain ultraviolet light wave band range, and the absorption amount of the photoinitiator in different ultraviolet light wave bands is different. N represents the total light absorption amount of the photoinitiator in the full ultraviolet band, N _x The amount of light absorbed by the photoinitiator in the exposure band used is indicated. The light absorption amount is determined by testing the change of absorbance of the photoinitiator with wavelength, and establishing the photoinitiator with wavelength as horizontal axis and absorbance as vertical axisThe absorbance curve of (2) can be obtained by calculating the integral of absorbance on the horizontal axis. The integral of the absorbance curve in the total wave band is the total absorbance N, and the integral in the exposure wave band is the absorbance N _x . For example, if N _x And the weight ratio of the photoinitiator in the photoresist composition is 0.33-1.67 percent when the value of N is 30 percent. When the photoresist composition is subsequently provided, the photoresist composition should be such that the oxime ester photoinitiator is used as a photoinitiator and the mass ratio of the oxime ester photoinitiator is within the obtained mass ratio range.

In some examples of this embodiment, N _x The value of N is 10% -90% so as to obtain lower line width increase. In the actual operation process, the ultraviolet light with a desired wave band can be obtained by using a filter with a specific wave band, or the ultraviolet light emitting the wavelength with the customized frequency is selected to realize N _x and/N.

Further, most photoinitiators absorb ultraviolet light in the predominantly 250nm to 400nm range. Therefore, in calculating the total light absorption amount N, 250nm to 400nm can be used as the total wavelength band.

Wherein, the photoresist composition also comprises photosensitive prepolymer, monomer and solvent. The photoinitiator is capable of initiating polymerization of the photosensitive prepolymer and monomer upon irradiation of ultraviolet light, thereby allowing the photoresist composition to be cured as a whole.

In some examples of this embodiment, the solids content in the photoresist composition is 20% to 30%. Wherein the solid content means the content of components other than the solvent in the photoresist composition. For example, if the solid content is 20%, the mass ratio of the solvent in the photoresist composition is 80%.

In some examples of this embodiment, the solvent in the photoresist composition may be selected from one or more of ethanol, isopropanol, toluene, ethyl lactate, butyl acetate, butanone, acetone, and propylene glycol methyl ether acetate.

In some examples of this embodiment, the oxime ester photoinitiator is a ketoxime ester photoinitiator and/or a carbazole oxime ester photoinitiator. Wherein the ketoxime ester photoinitiator refers to an oxime ester photoinitiator with a ketonic carbonyl group in a molecular structure, and the carbazole oxime ester photoinitiator refers to an oxime ester photoinitiator with a carbazole group in a molecular structure. The free radical generated by the ketoxime ester photoinitiator and the carbazole oxime ester photoinitiator under ultraviolet irradiation has higher reactivity, and the curing rate of the photosensitive prepolymer can be further improved. Optionally, the ketoxime ester photoinitiator may further contain one or more of diphenyl sulfide groups, derivative structures thereof, carbazole groups and derivative structures thereof.

For example, the ketoxime ester photoinitiator may be 1- (6-o-methylbenzoyl-9-ethylcarbazole) -1-cyclopentylacetonoxime having the following structural formula:

or the ketoxime ester photoinitiator may be 1- (6-o-methylbenzoyl-9-ethylcarbazole) -1-cyclopentylacetone oxime benzyl ester having the following structural formula:

or ketoxime lipid photoinitiators may also have the following structural formula:

further, the oxime ester photoinitiator may also be a carbazole oxime ester photoinitiator. Alternatively, the carbazole oxime ester photoinitiator may have the following structural formula:

wherein R is ₁ ～R ₅ Represents a substituent atom or substituent, R ₁ ～R ₅ Can be independently selected from one of hydrogen atom and saturated hydrocarbon group, R ₄ And R is ₅ Any other non-linking members being able to be bound to benzene ringsAttached to a carbon atom of the substituent.

Optionally, the carbazole oxime ester photoinitiator may also be 1-nitro-3- (1-oxime acetate) propyl-6- (1-oxime acetate-3-cyclohexyl) propyl-9-ethyl-carbazole, having the following structural formula:

the oxime ester photoinitiators exemplified above contain conjugated groups. The oxime ester compound is introduced with a conjugated group, and the group has a larger conjugated system and a stronger intramolecular electron transfer characteristic, so that the stability and the photosensitivity of the oxime ester compound can be greatly improved, and the curing degree of photoresist during exposure can be improved.

In some examples of this embodiment, the photoinitiator mass ratio range obtained in the photoresist composition is not higher than 5% at the maximum and not lower than 0.15% at the minimum to maintain adhesion between the prepared metal grid and the base layer while ensuring effective reduction of line width growth.

In some examples of this embodiment, the photosensitive prepolymer in the photoresist composition can include an acrylic oligomer and a solvent. Optionally, the acrylic oligomer is selected from one or more of aromatic acrylic specialty oligomer, polyester acrylate oligomer, epoxy acrylate oligomer, silicone modified acrylate oligomer, and urethane acrylate oligomer. Optionally, the mass content of the acrylic acid oligomer in the photosensitive prepolymer is 55% -65%.

In some examples of this embodiment, the monomer in the photoresist composition is selected from acrylic monomers. Optionally, the monomer in the photoresist composition is selected from one or more of alkoxylated bisphenol a di (methacrylate), vinyl ether acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

Experiments prove that the line width increment of the finally prepared metal line can be controlled within 0.8 mu m under the condition that the designed line width is 2 mu m through the selection of the type and the content of the photoinitiator in the photoresist composition. If the oxime ester photoinitiator is not adopted or the mass ratio of the photoinitiator is not in the determined range, the line width increment of the metal line can reach 1.2-1.8 mu m.

In the face of smaller design line widths, the choice of the type and content of the photoinitiator in the photoresist composition can still reduce the line width increment, but the adhesion is often disqualified. In the prior art, the adhesion of the metal grid on the photoresist layer is difficult to achieve enough strength under the condition of small design line width (for example, the design line width is lower than 2 μm).

In some examples of this embodiment, the photosensitive prepolymer includes 55% to 65% by mass of an acrylic oligomer having an aromatic ring structure in the main chain, and the mass ratio of the photosensitive prepolymer to the monomers in the photoresist composition is (2 to 2.4): 1. Wherein, the acrylic resin containing aromatic ring structure is selected, and the photosensitive prepolymer is used as a rigid framework in the crosslinked polymer, the monomer and the rigid framework form an interlocking structure when crosslinking, and meanwhile pi-pi action exists between molecules of the photosensitive prepolymer, so that the acting force between molecular chains can be further enhanced. The method enhances the plating solution resistance of the crosslinked polymer formed after curing, and avoids the problem of poor adhesive force of the metal grid caused by the corrosion of the pattern layer by the plating solution. In addition, the lateral growth of the metal grid lines can be further limited, also because the plating resistance of the crosslinked polymer is enhanced. Through verification, the photosensitive prepolymer and the monomer with corresponding content are adopted, and the adhesive force of F0 of the metal conductive grid can be ensured under the condition that the design line width is lower than 2 mu m. In some examples of this embodiment, the photosensitive prepolymer has a mass ratio of 10% to 30% and the monomer has a mass ratio of 5% to 20%.

In some examples of this embodiment, the catalyst layer comprises palladium catalytic particles having a particle size of < 5nm. In the embodiment, the curing rate of the photoresist layer can be improved and the photoresist layer is prevented from being excessively swelled by selecting the exposure wave band and the mass ratio of the oxime ester photoinitiator. Based on the photoresist layer, palladium catalytic particles with lower particle size are selected, so that the crystal grains of the grown metal particles can be reduced, and the effect of reducing the line width growth is achieved.

In addition, when the palladium catalyst particles are coated on the photoresist layer, more palladium catalyst particles can permeate into the photoresist layer, and the photoresist layer can cover more palladium catalyst particles when exposed and cured. And combining the selection of the type of the photosensitive prepolymer and the selection of the ratio of the type of the photosensitive prepolymer to the monomer consumption, wherein part of metal formed in the photoresist layer is entangled by acting force polymer chains among molecular chains, and macroscopic appearance is improved. This allows the adhesion of the metal grid to remain at a higher level while the design linewidth is further reduced.

In some examples of this embodiment, the photoresist composition further comprises one or more of a leveling agent and a polymerization inhibitor. Wherein the leveling agent can be selected from one or more of polyether modified organic silicon surfactant, acrylic leveling agent and fluorocarbon leveling agent. The mass ratio of the leveling agent in the photoresist composition may be 0.1% to 0.5%. Wherein the polymerization inhibitor can be selected from one or more of phenols, quinones, arylamines, aromatic nitro compounds and tris (N-nitroso-N-phenylhydroxylamine) aluminum salts. The mass ratio of the polymerization inhibitor in the photoresist composition may be 0.01% to 1%. The leveling agent is used for improving the fluidity of the whole photoresist composition, and the polymerization inhibitor has the functions of preventing the photoresist composition from losing efficacy caused by a small amount of free radicals generated by thermal initiation and prolonging the shelf life of the photoresist composition.

In some examples of this embodiment, in the step of removing the solvent in the photoresist composition, the solvent is removed by drying at a temperature of 60 to 90 ℃.

In some examples of this embodiment, the photoresist layer is formed to a thickness of 200nm to 900nm after the solvent is removed.

In some examples of this embodiment, in the step of forming the catalyst layer, a solution containing catalyst particles is coated on the photoresist layer, and a solvent in the solution is removed. The solvent in the solution can be removed by drying at 60-90 ℃.

In some examples of this embodiment, the electroless plating solution may be an electroless copper plating solution. The electroless copper plating solution may include copper salts, complexing agents, pH adjusting agents, reducing agents, and stabilizers, and the specific components may be appropriately selected with reference to the related art. The substrate is placed in the electroless plating solution for 0.5 min-15 min, and the temperature in the reaction process can be 30-45 ℃.

In some examples of this embodiment, after preparing the metal mesh pattern on the pattern layer, further comprising: and a step of blackening the substrate on which the metal mesh pattern is prepared and preparing an insulating layer on the substrate.

Alternatively, the blackening may be performed in a blackening liquid. The blackening liquid may include an aqueous palladium catalyst solution, an alkylene polyamine, and a pH adjuster. Wherein the palladium catalyst may be prepared from a palladium salt, optionally at least one selected from the group consisting of palladium nitrate, palladium acetate, palladium oxide, palladium chloride, palladium sulfate, palladium iodide and palladium bromide. Alternatively, the alkylene polyamine is selected from one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and iminodipropylamine. The blackening function is to form a blackening layer on the surface of the metal grid pattern so as to reduce the reflectivity of the surface of the metal grid pattern.

Alternatively, in the step of preparing the insulating layer, a transparent insulating polymer material may be coated on the metal mesh pattern. The polymer material may be one or more selected from acrylic and polyester type polymer materials.

The disclosure also provides a metal mesh conductive film prepared by the preparation method.

In order that the invention may be more readily understood and put into practical effect, the following more particular examples and comparative examples are provided as reference. The various embodiments of the present invention and their advantages will also be apparent from the following description of specific examples and comparative examples and performance results.

The raw materials used in the examples below are all commercially available, unless otherwise specified.

Among them, in the photoresist compositions used in each of the examples and comparative examples, the leveling agent was: BYK33 (organosilicon surface aid BYK-2952 provided by Pick chemical), ethyl lactate as solvent, pentaerythritol tetraacrylate as monomer, and polyethylene terephthalate resin PET substrate as substrate.

Example 1.1

1-nitro-3- (1-oxime acetate) propyl-6- (1-oxime acetate-3-cyclohexyl) propyl-9-ethyl-carbazole was chosen as photoinitiator.

The absorbance curve of the photoinitiator is shown in FIG. 1, the area B is selected as the exposure wave band, and N is calculated at the moment _x N/N is 30%, N/N _x The value of (2) is 3.33.

Providing a photoresist composition comprising 20% by mass of a photosensitive prepolymer, 8.65% by mass of a monomer, 0.34% by mass of a photoinitiator, 0.5% by mass of a leveling agent, and the balance being a solvent, wherein the photosensitive prepolymer comprises 60% by mass of a fluorenyl-containing acrylic oligomer, the fluorenyl-containing acrylic oligomer has a molecular weight of 5000-7000 and is formed by polymerizing the following monomers:

coating the photoresist composition on a substrate, and drying at 80 ℃ to remove the solvent in the photoresist composition to form a photoresist layer with the thickness of 400 nm;

coating a catalyst solution containing palladium nano particles on the photoresist layer, and drying at 80 ℃ to form a catalyst layer, wherein the particle size of the palladium nano particles is 5-10 nm;

coating a water-oxygen barrier coating on the catalyst layer;

in the mask plateUnder the shielding of (2), exposing the photoresist layer under the preset exposure wave band with the exposure energy of 3mJ/cm ² The design line width of the mask is 1-2 mu m, the exposed part is crosslinked and solidified, and then development treatment is carried out by adopting developing solution to remove the unexposed area, so as to form a pattern layer;

placing the substrate in a copper plating chemical plating solution, and plating a copper metal layer with a thickness of about 400nm to form a metal grid pattern;

placing the substrate in blackening liquid for blackening treatment;

and coating a transparent high polymer material polymethyl methacrylate (PMMA) on the substrate to form an insulating layer.

Example 1.2

Example 1.2 is largely identical to the preparation procedure of example 1.1, except that the photoinitiator of example 1.2 has a mass ratio of 0.47% and the other parameters are identical.

Example 1.3

Example 1.3 is largely identical to the preparation procedure of example 1.1, except that the photoinitiator of example 1.3 has a mass ratio of 0.63% and the other parameters are identical.

Example 1.4

Example 1.4 the preparation procedure of example 1.1 was largely identical, except that the design linewidth in example 1.4 was 1.5 μm.

Example 1.5

Example 1.5 the preparation procedure was largely identical to that of example 1.4, except that the design linewidth in example 1.5 was 1 μm.

Comparative example 1

Comparative example 1 the preparation procedure was largely identical to that of example 1.1, except that the photoinitiator of comparative example 1 was present in a 1.72% mass ratio, with the other parameters being identical.

Example 2.1

Example 2.1 the procedure of example 1.1 was followed, except that: selecting the area C as an exposure wave band, and calculating N at the moment _x N/N is 5%, N/N _x The photoinitiator according to example 2.1 was present in an amount of 3.15% by mass, with a value of 20;

example 2.2

Example 2.2 is largely identical to the preparation procedure of example 2.1, except that the photoinitiator of example 2.2 has a mass ratio of 4.41% and the other parameters are identical;

comparative example 2

Comparative example 2 is largely identical to the preparation procedure of example 2.1, except that the photoinitiator of comparative example 2 has a mass ratio of 5.17% and the other parameters are identical;

example 3.1

Example 3.1 the procedure of example 1.1 was followed, except that area A was selected as the exposure band, at which time N was calculated _x N/N is 60%, N/N _x The photoinitiator according to example 3.1 has a value of 1.67 and a mass ratio of 0.19%;

example 3.2

Example 3.2 is largely identical to the preparation procedure of example 3.1, except that the photoinitiator of example 3.2 has a mass ratio of 0.13% and the other parameters are identical;

comparative example 3

Comparative example 3 is largely identical to the preparation procedure of example 3.1, except that the photoinitiator of comparative example 3 has a mass ratio of 0.91% and the other parameters are identical;

example 4

Example 4 the procedure was largely identical to that of example 1.1, except that example 4 used a special E6604 NS acrylate from the Serratemam group as the photosensitive prepolymer, which had no aromatic ring structure in its main chain.

Example 5

Example 5 is largely identical to the preparation procedure of example 1.1, except that the monomer content in example 5 is 12%.

Example 6.1

Example 6.1 the preparation procedure is largely identical to that of example 1.1, except that the monomer content in example 6.1 is 7%.

Example 6.2

Example 6.2 is largely identical to the preparation procedure of example 6.1, except that the design linewidth in example 6.2 is 1.5 μm.

Example 7

Example 7 is largely identical to the preparation step of example 1.1, except that the particle size of the palladium catalyst particles in example 7 is below 5nm.

Example 8

Example 8 the procedure is largely identical to that of example 1.1, except that the photoinitiator used in example 8 is benzyl 1- (6-o-methylbenzoyl-9-ethylcarbazole) -1-cyclopentylacetone.

Comparative example 4

Comparative example 4 the preparation procedure is largely identical to that of example 1.1, except that an alpha-aminoalkylbenzophenone photoinitiator is used as the photoinitiator in comparative example 4.

And (3) testing: linewidth CD of resist patterns after exposure of examples 1.1 to 7 and comparative examples 1 to 4 were measured _d Line width CD of metal grid _p The line width increase Δcd and adhesion rating, the results are shown in table 1. The test mode of the line width growth is as follows: the line width of the prepared metal grid is observed by a scanning electron microscope, and the difference between the line width and the design line width is the line width increase. The adhesion test method is as follows: the metal grid lines are stuck by using a 3M 610 adhesive tape, wherein 5B represents no falling off at all, 4B represents falling off within 5 percent, and 3B represents falling off within 15 percent, so that the metal grid lines are not qualified.

Table 1: linewidth growth and adhesion performance test of metal grids

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Referring to examples 1.1 to 1.5 and comparative example 1, it is understood that the line width growth of examples 1.1 to 1.5 can be controlled within 0.51, whereas the line width growth of comparative example 1 reaches 0.91. Similar situation is also true with reference to examples 2.1-2.2 and comparative example 2, examples 3.1-3.2 and comparative example 3. From this, it can be seen that when an oxime ester photoinitiator is used, the content of the photoinitiator is determined with reference to the method provided by the present disclosure, and the line width growth of the metal grid can be significantly reduced by using the photoinitiator within the content range. In the embodiment 8, another oxime ester compound is adopted as a photoinitiator, so that the line width growth of the metal grid can be effectively reduced. Also referring to comparative example 4, it is clear that the photoinitiator other than oxime esters does not have a similar effect of reducing the design linewidth.

Referring to examples 1.1, 1.4, 4, 5 and 6.2 of the present disclosure, it is known that the line width of the latter three increases less, but the adhesion level is lower. In particular, as shown in example 6.2, the adhesion level was reduced more significantly when the design linewidth was further reduced, as compared to example 6.1. Whereas examples 1.1 and 1.4 still achieved the 5B requirement for the adhesion rating of the metal grids produced, due to the specific resin type used and the resin and monomer content in the appropriate range.

As is clear from examples 1.1 and 7, example 7 uses a palladium catalyst having a particle diameter of 5nm or less, and can further significantly reduce the line width growth of the metal grid.

Note that the above embodiments are for illustrative purposes only and are not meant to limit the present application.

It should be understood that the steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least a portion of the steps of a step may include a plurality of sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, nor does the order in which the sub-steps or stages are performed necessarily occur in sequence, but may be performed alternately or alternately with at least a portion of the sub-steps or stages of other steps or other steps.

In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described by differences from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

Claims

1. The preparation method of the metal grid conductive film is characterized by comprising the following steps of:

providing a photoinitiator and presetting an exposure wave band of the photoinitiator, wherein the photoinitiator is selected from oxime ester photoinitiators, and the mass ratio c of the photoinitiator is obtained according to the following formula:wherein the value range of D is 1-5%o, N is the total light absorption amount of the photoinitiator, and the total light absorption amount is%>For the light absorption amount of the photoinitiator in the exposure wave band, the mass ratio c of the photoinitiator is not higher than 5% at the maximum value and not lower than 0.15% at the minimum value;

providing a photoresist composition, wherein the photoresist composition comprises a photosensitive prepolymer, a monomer and a photoinitiator, wherein the mass ratio of the photoinitiator in the photoresist composition is c, the mass ratio of the photosensitive prepolymer is 10% -30%, and the mass ratio of the monomer is 5% -20%;

forming a catalyst layer on the photoresist layer;

exposing and developing the photoresist layer by using the exposure wave band to form a pattern layer between the photoresist layer and the catalyst layer;

2. The method for preparing a metal mesh conductive film according to claim 1, wherein the oxime ester photoinitiator is a ketoxime ester photoinitiator and/or a carbazole oxime ester photoinitiator.

3. The method for producing a metal mesh conductive film according to claim 1, whereinThe value of (2) is 10% -90%.

4. The method of producing a metal mesh conductive film according to claim 1, wherein the solid content in the photoresist composition is 20% to 30%.

5. The method of producing a metal mesh conductive film according to any one of claims 1 to 4, wherein the photosensitive prepolymer in the photoresist composition comprises 55 to 65 mass% of an acrylic oligomer, the main chain of the acrylic oligomer has an aromatic ring structure, and the mass ratio of the photosensitive prepolymer to the monomer in the photoresist composition is (2 to 2.4): 1.

6. The method for producing a metal mesh conductive film according to claim 5, wherein in the acrylic oligomer, the aromatic ring structure is selected from one or more of a fluorenyl group and a derivative thereof and a phenanthryl group and a derivative thereof.

7. The method for producing a metal mesh conductive film according to any one of claims 1 to 4 and 6, wherein the catalyst layer comprises palladium catalytic particles having a particle diameter of < 5nm.

8. The method for producing a metal mesh conductive film according to any one of claims 1 to 4 and 6, wherein the photoresist composition further comprises a leveling agent.

9. The method for producing a metal mesh conductive film according to any one of claims 1 to 4 and 6, wherein the thickness of the photoresist layer is 200nm to 900nm.

10. The method for producing a metal mesh conductive film according to any one of claims 1 to 4 and 6, characterized by further comprising, after the metal mesh pattern is produced on the pattern layer: and a step of blackening the metal mesh pattern and preparing an insulating layer on the conductive film.

11. A metal mesh conductive film prepared by the preparation method of any one of claims 1 to 10.

12. A touch screen comprising the metal mesh conductive film of claim 11.