Pretreatment method in semi-addition process

Abstract

The invention relates to the technical field of metal grids, in particular to a pretreatment method in a semi-additive process, which comprises the following steps: S1, cleaning a substrate; s2, preparing materials; s3, appearance inspection; s4, carrying out whole-surface plasma pretreatment; s5, performing targeted plasma treatment; and S6, line groove post-inspection is carried out. According to the pretreatment method in the semi-addition process, the semi-addition process and plasma pretreatment are combined, a new metal grid preparation process is achieved, the product defects such as line breakage caused by dry film residues in the semi-addition process are overcome, the problem of dry film residues is more efficiently solved through a two-step method, and the product quality is improved. A feasible scheme is provided for improving the yield of the semi-additive process, and a larger space is created for development of metal grid transparent electrode materials.

Description

Technical Field

[0001] The present invention relates to the technical field of metal meshes, and specifically to a pretreatment method in a semi-additive process. Background Art

[0002] In touch screen technology, metal mesh materials play a very important role. Compared with the earlier developed ITO and nano silver, metal meshes have very excellent performance and stability, and have attracted much attention in the applications of large-size and high-end products. However, limited by the limitations of subtractive processes, convex circuits usually have defects such as relatively large nodes and easy oxidation. The semi-additive method will provide a new solution for optimizing metal mesh technology.

[0003] The semi-additive method (SAP) is commonly used in the field of PCB substrates. By the same principle, the semi-additive method can be applied to the preparation of metal mesh transparent conductive materials. In order to ensure that the dry film at the grooves is completely removed during the development process and to improve the adhesion of the coating or adhesive to the metal surface, the pretreatment process before electroplating is very important. Therefore, there is an urgent need for a pretreatment method for technical mesh substrates. Summary of the Invention

[0004] The purpose of the present invention is to provide a pretreatment method in a semi-additive process to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A pretreatment method in a semi-additive process, including the following steps:

[0006] S1: Substrate cleaning. To improve the adhesion of the coating or adhesive to the metal surface, the mesh board substrate is cleaned.

[0007] S2: Material preparation. The cleaned substrate is subjected to surface hot pressing of dry film or coating of photoresist, and then after exposure and development through a patterned photomask, a patterned circuit groove is obtained. In the subsequent steps, we will electroplate copper at the circuit groove. To ensure that the electroplated copper circuit has no defects and at the same time ensure good adhesion of the electroplated copper circuit to the underlying thin copper film, it is necessary to ensure that the dry film or photoresist at the circuit groove is completely removed. This is the necessity of doing the pretreatment before electroplating.

[0008] S3: Appearance inspection. After the circuit groove is developed, only a very small number of areas with obvious dry film residues will be present. First, these areas are found and marked through an optical microscope for targeted plasma cleaning.

[0009] S4: Whole-surface plasma pretreatment. Since during the development process, some of the dry film or photoresist remaining in the circuit groove cannot be observed through an optical microscope, the whole surface needs to be subjected to plasma pretreatment first.

[0010] S5: Targeted plasma treatment. For the sites marked in S2, due to the large remaining amount, they cannot be completely removed in S3. Therefore, in this step, key plasma treatment needs to be carried out for such areas.

[0011] S6: Inspection after circuit grooves. After the treatment in the previous steps, a second inspection is carried out on the overall area, especially a targeted inspection of the marked positions, to ensure that there is no dry film residue in the grooves.

[0012] Preferably, a cleaning mechanism is required for the substrate cleaning. The cleaning mechanism includes a cleaning pool, and a set of sliding limit frames are symmetrically installed in the cleaning pool. An installation frame is slidably arranged between the sliding limit frames. The installation frame is used to install the substrate, and several groups of cleaning components are arranged on the front and back sides of the installation frame respectively.

[0013] Preferably, the installation frame includes an outer frame, and several fixing brackets are arranged at the center of the outer frame. A positioning component is arranged on the outer frame.

[0014] The positioning component includes two inner movable columns movably arranged inside the outer frame. Several movable pressing frames are arranged between the two inner movable columns. The movable pressing frames correspond to the fixing brackets one by one, and mounting grooves for placing the substrate are opened on the opposite surfaces of the movable pressing frames and the fixing brackets. Threaded holes are opened at the tops of the inner movable columns, and an adjusting torsion column is rotated on each side at the top of the installation frame. Threads are opened at the bottom ends of the adjusting torsion columns and are in threaded connection with the threaded holes.

[0015] Preferably, the cleaning component includes a mounting plate. Two C-shaped frames are rotatably installed on one side of the mounting plate. A cleaning roller is installed in the C-shaped frames. A cleaning motor is arranged at one end of the C-shaped frame, and the output end of the cleaning motor is connected to the cleaning roller. An adjusting motor is arranged on the other side of the mounting plate, and the output end of the adjusting motor is connected to the C-shaped frame. A support column is fixedly connected at the middle position of the mounting plate, and the support column is connected to an adjusting seat. The adjusting seat is used to adjust the position of the cleaning component.

[0016] Preferably, the plasma energy in S3 is 1 - 5 kw. If the energy is too small, it cannot play a role in surface cleaning. If the energy is too large, the dry film or photoresist outside the circuit grooves cannot be smoothly removed in the subsequent film stripping step.

[0017] Ar gas is selected as the gas source in S3 to prevent the oxidation of the underlying thin copper while ensuring the removal of the dry film or photoresist.

[0018] In S3, the plasma emission source is 5 - 20 cm away from the sample surface, and the treatment time is 10 - 30 s.

[0019] Preferably, in S4, the gas source is Ar and CF4, and the content of CF4 is 3%-10%;

[0020] In S4, for targeted treatment and to narrow the plasma treatment area, the emission source is 3-5 cm away from the sample surface;

[0021] In S4, the treatment time is 10-30 s.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] A pretreatment method in a semi-additive process proposed by the present invention, by first cleaning the substrate to remove dirt and impurities, avoiding affecting the effects of subsequent process steps and improving the adhesion of the coating or adhesive to the metal surface, and the clean metal surface is not prone to corrosion, which is crucial for extending the service life of the metal grid; and the present invention combines the semi-additive process with plasma pretreatment to achieve a new metal grid preparation process, solving product defects such as wire breakage caused by dry film residue in the semi-additive process. The present invention more efficiently processes the dry film residue problem through a two-step method, providing a feasible solution for improving the yield of the semi-additive process and creating a greater space for the development of metal grid transparent electrode materials. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the cleaning mechanism of the present invention.

[0025] Figure 2 It is a schematic structural diagram of the mounting rack of the present invention.

[0026] Figure 3 It is a schematic structural diagram of the positioning component of the present invention.

[0027] Figure 4 It is a schematic structural diagram of the cleaning component of the present invention.

[0028] In the figure: mounting rack 1, sliding limit rack 2, fixed bracket 3, inner movable column 4, movable pressure frame 5, threaded hole 6, adjusting torsion column 7, mounting plate 8, C-shaped frame 9, cleaning roller 10, cleaning motor 11, adjusting motor 12, support column 13. Detailed Embodiments

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figures 1 to 4, the present invention provides a technical solution: a pretreatment method in a semi-additive process, comprising the following steps:

[0031] S1: Substrate cleaning. To improve the adhesion between the coating or adhesive and the metal surface, the grid board substrate is cleaned.

[0032] S2: Material preparation. The cleaned substrate is subjected to surface hot pressing of dry film or coating of photoresist, and then after exposure through a patterned photomask and development, a patterned circuit groove is obtained. In subsequent steps, copper is plated in the circuit groove. To ensure that the plated copper circuit has no defects and at the same time ensure good adhesion of the plated copper circuit to the underlying thin copper film, it is necessary to ensure that the dry film or photoresist at the circuit groove is completely removed, which is the necessity of performing pretreatment before electroplating.

[0033] S3: Appearance inspection. After the circuit groove is developed, only in a very small number of areas will the dry film residue be relatively obvious. First, such areas are found and marked through an optical microscope for targeted plasma cleaning.

[0034] S4: Whole-surface plasma pretreatment. Since during the development process, some of the dry film or photoresist remaining in the circuit groove cannot be observed through an optical microscope, the whole surface needs to be subjected to plasma pretreatment first.

[0035] S5: Targeted plasma treatment of the obvious dry film / photoresist residue positions. For the sites marked in S2, due to the large residue amount and being unable to be completely removed in S3, in this step, targeted plasma treatment needs to be carried out on such areas.

[0036] S6: Post-inspection of the circuit groove. After being processed through the previous steps, a second inspection is carried out on the overall area, especially a targeted inspection of the marked positions, to ensure that there is no dry film residue in the groove.

[0037] Substrate cleaning requires the use of a cleaning mechanism. The cleaning mechanism includes a cleaning tank, in which a set of sliding limit frames 2 are symmetrically installed. An installation frame 1 is slidably arranged between the sliding limit frames 2. A clamping member is provided on the sliding limit frames 2 to fix the installation frame 1. The installation frame 1 is used to install the substrate, and several groups of cleaning components are arranged on the front and rear sides of the installation frame 1 respectively. The installation frame 1 includes an outer frame, and several fixing brackets 3 are arranged at the center of the outer frame. A positioning component is provided on the outer frame; the positioning component includes two inner movable columns 4 movably arranged inside the outer frame. Several movable pressing frames 5 are arranged between the two inner movable columns 4. The movable pressing frames 5 correspond to the fixing brackets 3 one by one, and installation grooves for placing the substrate are opened on the opposite surfaces of the movable pressing frames 5 and the fixing brackets 3. Threaded holes 6 are opened at the tops of the inner movable columns 4. One adjusting torsion column 7 is rotated on each side of the top of the installation frame 1. Threads are opened at the bottom ends of the adjusting torsion columns 7 and are in threaded connection with the threaded holes 6. During cleaning, the installation frame 1 is pulled out through the handle at the top of the installation frame 1, and then the substrate is placed in the installation groove between the fixing bracket 3 and the movable pressing frame 5. The adjusting torsion column 7 is rotated to make the inner movable column 4 drive the movable pressing frame 5 to descend, so that the substrate can be fixedly installed. Then the installation frame 1 is pushed down into the cleaning tank, and the cleaning components can clean the substrate.

[0038] The cleaning components include an installation plate 8. Two U-shaped frames 9 are rotatably installed on one side of the installation plate 8. A cleaning roller 10 is installed in the U-shaped frames 9. A cleaning motor 11 is arranged at one end of the U-shaped frame 9. The output end of the cleaning motor 11 is connected to the cleaning roller 10. An adjusting motor 12 is arranged on the other side of the installation plate 8. The output end of the adjusting motor 12 is connected to the U-shaped frame 9. By controlling the start of the adjusting motor 12 to drive the U-shaped frame 9 to rotate, the angle of the cleaning roller 10 can be changed to improve the cleaning effect. A support column 13 is fixedly connected to the middle position of the installation plate 8. The support column 13 is connected to an adjusting seat, and the adjusting seat is used to adjust the position of the cleaning components, and the cleaning components can be moved in six axial directions of up, down, left, right, front and back, so as to clean all positions of the substrate. During cleaning, the cleaning components approach the substrate installed between the fixing bracket 3 and the movable pressing frame 5. The cleaning motor 11 is started to drive the cleaning roller 10 to wipe the surface of the substrate. The surface of the cleaning roller 10 is made of soft material and will not scratch the substrate. The rotation directions of the cleaning rollers 10 on both sides of the substrate need to be opposite.

[0039] In S3, the plasma energy is 1-5 kw. If the energy is too small, it cannot play the role of surface cleaning. If the energy is too large, the dry film or photoresist outside the circuit grooves cannot be smoothly removed in the subsequent film stripping step;

[0040] In S3, Ar gas is selected as the gas source to prevent the oxidation of the underlying thin copper while ensuring the removal of the dry film or photoresist;

[0041] In S3, the plasma emission source is 5 - 20 cm away from the sample surface, and the treatment time is 10 - 30 s.

[0042] In S4, the gas source is Ar and CF4, and the content of CF4 is 3% - 10%;

[0043] In S4, for targeted treatment and to narrow the plasma treatment area, the emission source is 3 - 5 cm away from the sample surface;

[0044] In S4, the treatment time is 10 - 30 s.

[0045] The method of the present invention first cleans the substrate to remove dirt and impurities, avoiding affecting the effects of subsequent process steps and improving the adhesion of the coating or adhesive to the metal surface. Moreover, the clean metal surface is not easily corroded, which is crucial for extending the service life of the metal grid; and the present invention combines the semi - additive process with plasma pretreatment to achieve a new process for preparing metal grids, solving product defects such as broken lines caused by dry film residues in the semi - additive process. The present invention more efficiently treats the problem of dry film residues through a two - step method, providing a feasible solution for improving the yield of the semi - additive process and creating more space for the development of metal grid transparent electrode materials.

[0046] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pretreatment method in a semi-additive process, characterized in that: The following steps are included: S1: Substrate cleaning: in order to improve the adhesion of the coating or adhesive to the metal surface, the grid plate substrate is cleaned; S2: Material preparation, hot pressing a dry film or coating a photoresist on the surface of the cleaned substrate, and then exposing and developing it through a patterned mask to obtain a patterned circuit groove; S3: Appearance inspection: After developing the circuit grooves, only a few areas of dry film residue will be obvious. First, use an optical microscope to find and mark such areas so that plasma cleaning can be used in a targeted manner. S4: Whole-surface plasma pretreatment. During the development process, some dry film or photoresist remaining in the circuit groove cannot be observed through an optical microscope, so the whole surface needs to be pretreated with plasma. S5: Targeted plasma treatment. For the sites marked in S2, the residue is large and cannot be completely removed in S3. Therefore, in this step, it is necessary to carry out targeted plasma treatment on such areas. S6: Post-inspection of circuit grooves. After the previous steps, the overall area is inspected for the second time, especially the targeted inspection of the marking position to ensure that there is no dry film residue in the groove.

2. The pretreatment method in a semi-additive process according to claim 1, characterized in that: The substrate cleaning requires the use of a cleaning mechanism, which includes a cleaning pool, in which a group of sliding limit frames are symmetrically installed, and a mounting frame is slidably arranged between the sliding limit frames. The mounting frame is used to install the substrate, and an array of cleaning components is respectively arranged on the front and rear sides of the mounting frame.

3. The pretreatment method in a semi-additive process according to claim 2, characterized in that: The mounting frame includes an external frame, a plurality of fixing brackets are arranged at the center of the external frame, and a positioning assembly is arranged on the external frame; The positioning assembly includes two inner movable columns movably arranged inside the external frame, a plurality of movable pressure frames are arranged between the two inner movable columns, the movable pressure frames correspond to the fixed brackets one by one, and mounting grooves for placing the substrate are provided on the opposite surfaces of the movable pressure frames and the fixed brackets, threaded holes are provided on the tops of the inner movable columns, and an adjusting twist column is rotatably arranged on both sides of the top end of the mounting frame, and the bottom ends of the adjusting twist columns are provided with threads and are matched and connected with the threaded holes.

4. The pretreatment method in a semi-additive process according to claim 2, characterized in that: The cleaning component includes a mounting plate, on one side of which two shaped frames are rotatably mounted, a cleaning roller is mounted in the shaped frame, a cleaning motor is arranged at one end of the shaped frame, the output end of the cleaning motor is connected to the cleaning roller, an adjusting motor is arranged on the other side of the mounting plate, the output end of the adjusting motor is connected to the shaped frame, a supporting column is fixedly connected at the middle position of the mounting plate, the supporting column is connected to the adjusting seat, and the adjusting seat is used to adjust the position of the cleaning component.

5. The pre-treatment method in a semi-additive process according to claim 1, characterized in that: The plasma energy in S3 is 1-5kw; Ar gas is selected as the gas source in S3; The plasma emission source in S3 is 5-20 cm away from the sample surface, and the processing time is 10-30 s.

6. The pre-treatment method in a semi-additive process according to claim 1, characterized in that: The gas sources in the S4 are Ar and CF4, and the content of CF4 is 3%-10%; In S4, in order to carry out targeted treatment and reduce the plasma treatment area, the emission source is 3-5 cm away from the sample surface; The processing time in S4 is 10-30s.

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