Indium tin oxide conductive film rewritable laser processing micro-nano manufacturing system and method based on electrochemical reaction

Abstract

The invention belongs to the related technical field of micro-nano optical manufacturing, and discloses an indium tin oxide (ITO) conductive film rewritable laser processing micro-nano manufacturing system and method based on electrochemical reaction, and the method comprises the steps: 1, arranging two ITO conductive films at two opposite ends of a cylindrical body respectively to form a containing cavity, deionized water is added into the containing cavity; and step 2, applying an external voltage to the two ITO conductive films to start electrochemical reaction so as to realize modification of the ITO conductive films, and then performing low-power continuous laser direct writing processing on the ITO conductive films so as to realize manufacturing of the patterned micro-nano structure of the ITO conductive films. According to the invention, the ITO conductive film can be directly written and processed by low-power continuous laser, the dependence on an ultrafast high-energy pulse laser is reduced, and the cost is effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field related to micro-nano optical manufacturing, and more specifically, relates to a rewritable laser processing micro-nano manufacturing system and method of indium tin oxide conductive film based on electrochemical reaction. Background Art

[0002] ITO (Indium Tin Oxide) is an important optoelectronic material, mainly composed of indium oxide and tin oxide (mass ratio is 9:1). Vacuum magnetron sputtering coating technology is the main processing method for ITO conductive glass. This method uses sodium calcium base or silicon boron base as the glass processing original sheet, and uses vacuum magnetron sputtering technology to coat a layer of ITO (Indium Tin Oxide) film on the glass surface. It has the characteristics of high transmittance, high conductivity, high mechanical strength and excellent anti-corrosion performance, and is widely used in liquid crystal displays, solar panels and other fields.

[0003] In order to meet diverse needs, it is often necessary to pattern the surface of the ITO film to produce various functional structural patterns to achieve specific applications, such as manufacturing touch screens, OLED glass panels, transparent microelectrodes, transparent gas flow meters, etc. As the most classic micro-nano processing and manufacturing method, photolithography can be used to achieve patterned manufacturing of ITO conductive films. However, the purchase and maintenance costs of photolithography equipment are very high. At the same time, the cost of photoresist, mask and other materials in the production process cannot be ignored, which increases the cost of the entire manufacturing process. On the other hand, the photolithography process requires multiple steps, including coating, pre-baking, exposure, development, hardening, etching and degumming, etc. The complexity of the process flow increases the difficulty and time cost of manufacturing.

[0004] Laser direct writing is a technology that uses a laser beam to directly perform micro-machining on the surface of a material. It has the advantages of high precision, flexibility, no need for plate making, wide material adaptability, three-dimensional processing capability, non-contact processing, and high efficiency and environmental protection. Therefore, it is widely used in the field of ITO conductive film patterning micro-nano processing and manufacturing. However, due to the high light transmittance and high melting point of ITO conductive film, it is difficult to perform thermal ablation direct writing processing by continuous laser, and high-energy pulsed ultrafast lasers such as nanosecond, femtosecond, and picosecond lasers must be used as light sources for processing. At present, there are two main laser processing methods that are widely studied, including ultrafast laser direct ablation processing and pulsed laser radiation material modification combined with chemical wet etching post-processing. The latter can effectively reduce the dependence on high-power laser energy, reduce the cost of laser equipment, and avoid the pollution of thermal ablation debris residues, so this method is used more. However, if the introduction of chemical etchants is not handled properly, it may have a certain impact on the environment and cannot improve the reusability of ITO conductive films. Summary of the invention

[0005] In response to the above defects or improvement needs of the prior art, the present invention provides a rewritable laser processing micro-nano manufacturing system and method for indium tin oxide conductive film based on electrochemical reaction, which aims to solve the problem that the existing ITO conductive film micro-nano manufacturing process is prone to pollution and has low reusability.

[0006] To achieve the above object, according to one aspect of the present invention, a rewritable laser processing micro-nano manufacturing method of indium tin oxide conductive film based on electrochemical reaction is provided, and the method comprises the following steps:

[0007] Step 1: two ITO conductive films are respectively arranged at two opposite ends of the cylindrical body to form a receiving cavity, and then deionized water is added into the receiving cavity;

[0008] Step 2: Apply an external voltage to the two ITO conductive films to start an electrochemical reaction, thereby modifying the ITO conductive films, and then performing low-power continuous laser direct writing processing on the ITO conductive films to achieve the manufacture of patterned micro-nano structures of the ITO conductive films.

[0009] The present invention also provides an indium tin oxide conductive film rewritable laser processing micro-nano manufacturing system based on electrochemical reaction, the system includes a laser direct writing processing optical path and an ITO electrochemical reaction sample cell, the ITO electrochemical reaction sample cell includes a cylindrical cavity formed by a gasket, the two ends of the cylindrical cavity are encapsulated with ITO conductive film to form a receiving cavity, the receiving cavity is used to receive deionized water; the two ITO conductive films are used to connect an external voltage to start an electrochemical reaction to achieve modification of the ITO conductive film; the laser direct writing processing optical path is used to perform low-power continuous laser direct writing processing on the modified ITO conductive film to achieve the manufacture of patterned micro-nano structures of the ITO conductive film.

[0010] Furthermore, the system also includes a measuring optical path, which is used to process the LED illumination light irradiated on the sample and then use a camera to collect imaging results in real time, and feed back to a computer to observe the processing process and preparation results.

[0011] Furthermore, the measuring optical path includes an LED lighting source, a processed sample, a focusing objective lens, a beam splitter cube, a third reflector, a tube lens and a camera; the light emitted by the LED lighting source carries sample processing information after passing through the processed sample, is amplified by the focusing objective lens, transmits through the beam splitter cube, changes the direction of the imaging optical path through the third reflector, and is imaged on the camera through the tube lens for observation.

[0012] Furthermore, the laser direct writing processing optical path includes a laser, an optical shutter, a first reflector, a second reflector, a first lens, a filter pinhole, a second lens, a beam splitter cube, a focusing objective lens and a processing sample; the laser is used to output a laser of predetermined power, and the switch of the laser is controlled by the optical shutter. After the incident direction is changed by the first reflector and the second reflector, it reaches the collimating beam expansion filter module composed of the first lens, the filter pinhole and the second lens, and then enters the focusing objective lens through reflection by the beam splitter cube. The laser is focused on the surface of the processing sample for ITO micro-nano processing.

[0013] Furthermore, the system also includes a voltage control module, which is used to apply a corresponding voltage according to the height of the receiving cavity to cause an electrochemical reaction on the surface of the ITO conductive film to modify the ITO conductive film.

[0014] Furthermore, the system also includes a translation stage and a controller. The translation stage is used to place the processed sample and can move up and down and horizontally; the controller is used to jointly and collaboratively control the up and down movement and / or horizontal movement of the translation stage and the opening and closing of the optical shutter under the control of a computer.

[0015] Furthermore, the light field collected by the camera in real time is post-processed by a computer to obtain the three-dimensional morphology of the sample in real time, and the position to be processed on the sample surface at the next moment is obtained based on the obtained three-dimensional morphology, and the sample is controlled to move up and down so that the position to be processed of the sample is aligned with the focal plane of the laser emitted by the objective lens in real time.

[0016] In general, compared with the prior art, the above technical solutions conceived by the present invention mainly have the following beneficial effects in comparison with the prior art:

[0017] 1. The present invention modifies the surface of the ITO conductive film through an electrochemical reaction, improves the absorption rate of the ITO conductive film to laser and reduces the melting point, so that the ITO conductive film can be processed by low-power continuous laser direct writing, reducing the dependence on ultrafast high-energy pulse lasers and effectively reducing costs. At the same time, the use of low-power continuous laser direct writing can realize the processing and manufacturing of any complex pattern on the ITO conductive film, without the need for chemical reagent post-treatment, and has the advantages of being environmentally friendly and pollution-free.

[0018] 2. By utilizing the properties of the modified ITO conductive film, the processed pattern can be erased and rewritten, which has the advantages of flexibility, efficiency and versatility.

[0019] 3. The present invention is based on the principle of electrochemical reaction and only requires the use of low-power continuous laser to process any micro-nanostructure pattern on the ITO surface. It has the advantages of low cost, no pollution, erasable and rewritable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction provided by the present invention;

[0021] Figure 2 Schematic diagram of the composition structure of the electrochemical reaction sample cell in an embodiment of the present invention;

[0022] Figure 3 Schematic diagram of electrochemically assisted laser direct writing micro-nano processing in an embodiment of the present invention;

[0023] Figure 4 It is a schematic diagram of the principle of laser direct writing processing on the surface of ITO conductive film under positive bias;

[0024] Figure 5 It is a schematic diagram of the principle of laser direct writing processing on the surface of ITO conductive film under negative bias;

[0025] Figure 6 This is a scanning electron microscope image of the laser direct writing structure of ITO conductive film under positive bias;

[0026] Figure 7 It is an optical micrograph of the structure of ITO conductive film laser direct writing under negative bias;

[0027] Figure 8 This is a schematic diagram of the processing, erasing, and reprocessing results of laser direct writing of rewritable ITO conductive film.

[0028] In all the drawings, the same reference numerals are used to represent the same elements or structures, wherein: 1-laser, 2-light shutter, 3-first reflector, 4-second reflector, 5-first lens, 6-filter pinhole, 7-second lens, 8-beam splitter cube, 9-focusing objective lens, 10-processed sample, 11-LED illumination light source, 12-third reflector, 13-tube lens, 14-camera. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] The present invention provides a rewritable laser processing micro-nano manufacturing method for indium tin oxide conductive film based on electrochemical reaction, which modifies the ITO conductive film through electrochemical reaction, improves its absorption rate of laser and reduces the melting point, so that the ITO film can be processed by low-power continuous laser direct writing, thereby realizing patterned micro-nano structure manufacturing of the ITO conductive film, and based on the surface properties of the modified ITO conductive film, the processed pattern is erased and rewritten again, thereby solving the technical problems of complex process flow of existing ITO film micro-nano manufacturing, high cost of instruments and equipment, and inability to modify the structure pattern after a single processing.

[0031] The method mainly comprises the following steps:

[0032] Step 1: arrange two ITO conductive films at opposite ends of the cylindrical body to form a receiving cavity, and then add deionized water into the receiving cavity.

[0033] Step 2: Apply an external voltage to the two ITO conductive films to start an electrochemical reaction, thereby modifying the ITO conductive films, and then performing low-power continuous laser direct writing processing on the ITO conductive films to achieve the manufacture of patterned micro-nano structures of the ITO conductive films.

[0034] The method uses low-power continuous laser as the processing light source to effectively reduce the cost of high-performance pulse lasers. Deionized pure water is used as the electrolyte without chemical pollution, and rewritable processing of ITO thin films can be achieved. It has the advantages of low cost, no pollution, and rewritability.

[0035] The present invention also provides an indium tin oxide conductive film rewritable laser processing micro-nano manufacturing system based on electrochemical reaction, the system includes a laser direct writing processing optical path and an ITO electrochemical reaction sample cell, the ITO electrochemical reaction sample cell includes a cylindrical cavity formed by a gasket, the two ends of the cylindrical cavity are encapsulated with ITO conductive film to form a receiving cavity, the receiving cavity is used to receive deionized water; the two ITO conductive films are used to connect an external voltage to start an electrochemical reaction to achieve modification of the ITO conductive film; the laser direct writing processing optical path is used to perform low-power continuous laser direct writing processing on the modified ITO conductive film to achieve the manufacture of patterned micro-nano structures of the ITO conductive film.

[0036] The system also includes a measuring optical path, which is used to observe the manufacturing status of the patterned micro-nano structure of the ITO conductive film.

[0037] The present invention is further described in detail below with reference to specific embodiments.

[0038] Example 1

[0039] See also Figure 1 and Figure 2 Embodiment 1 of the present invention provides a rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction, and the system includes a laser direct writing processing optical path, a measurement optical path and an ITO electrochemical reaction sample cell.

[0040] The laser direct writing processing optical path includes a laser 1, an optical shutter 2, a first reflector 3, a second reflector 4, a first lens 5, a filter pinhole 6, a second lens 7, a beam splitter cube 8, a focusing objective lens 9 and a processing sample 10. The output laser power of the laser 1 is adjusted to a suitable size, the switch of the laser is controlled by the optical shutter 2, and the incident direction is changed by the first reflector and the second reflector 4 to reach the collimating beam expansion filter module composed of the first lens 5, the filter pinhole 6, and the second lens 7, and then reflected by the beam splitter cube 8 into the focusing objective lens 9, and the laser is focused on the surface of the processing sample 10 to perform ITO micro-nano processing and prepare the desired pattern.

[0041] The measuring optical path is used to process the LED illumination light irradiated on the sample and then use the camera 14 to collect the imaging results in real time, and feed it back to the computer for observation of the processing process and preparation results. The measuring optical path includes an LED illumination light source 11, a processed sample 10, a focusing objective lens 9, a beam splitter cube, a third reflector 12, a tube lens 13 and a camera 14. The light emitted by the LED illumination light source 11 carries the sample processing information after passing through the processed sample, is amplified by the focusing objective lens, transmits through the beam splitter cube, changes the direction of the imaging light path through the third reflector 12, and is imaged on the camera through the tube lens 13 for observation.

[0042] The ITO electrochemical reaction sample cell is composed of two ITO glass conductive surfaces placed facing each other, separated by a gasket to form a cavity, deionized water is added into the formed cavity, and a voltage is applied to the ITO glass conductive surface to form a sample to be processed.

[0043] The system also includes a voltage control module, which is used to apply a suitable voltage according to the height of the reaction sample pool cavity to cause an electrochemical reaction on the surface of the ITO conductive film to modify the ITO conductive film while avoiding the electrolysis of water to generate bubbles.

[0044] The system also includes a translation stage and a controller. The translation stage is used to place the processing sample and can move up and down and horizontally. The up and down movement is used to align the position of the ITO conductive film to be processed on the sample surface with the focus of the focusing objective lens in real time. The horizontal movement is used to move the sample surface position and realize laser direct writing micro-nano processing of complex patterns in combination with the switching of the optical shutter; the controller is used to jointly and collaboratively control the up and down movement and / or horizontal movement of the translation stage and the switching of the optical shutter under the control of a computer.

[0045] The sample needs to be pre-cleaned. The cleaning steps are as follows:

[0046] (S1) using toluene solvent to ultrasonically clean the glass surface for 10 min to 20 min to remove grease and dust;

[0047] (S2) ultrasonically cleaning with acetone solvent for 10 min to 15 min to remove residual grease on the glass surface and dissolve toluene;

[0048] (S3) ultrasonically cleaning with ethanol solvent for 10 min to 20 min to remove residual acetone on the glass surface;

[0049] (S4) Ultrasonic cleaning with deionized water for 20 min to 30 min to remove residual ethanol on the glass surface, and then drying with a nitrogen gun.

[0050] Use a computer to turn on each component in sequence according to a predetermined timing step, adjust the translation stage to focus the light source on the sample surface, and perform direct writing processing according to the processing steps.

[0051] For details, please refer to Figure 3 , Figure 4 and Figure 5 , the timing processing steps are as follows:

[0052] Step 1: Prepare an ITO electrochemical reaction sample cell.

[0053] Step 2: Align the instrument horizontally.

[0054] Step 3: Place the sample on the translation stage, and move the translation stage up and down to focus.

[0055] Step 4: Apply voltage to the upper and lower surfaces of the sample to start the electrochemical reaction, and at the same time control the opening and closing of the optical shutter to achieve the processing and manufacturing of a specific pattern.

[0056] Step 5: Focus the camera, take pictures, and measure the surface morphology of the samples.

[0057] Step 6: Determine whether the processing result meets the requirements. If not, repeat the processing process; if it meets the requirements, stop processing.

[0058] The laser power emitted by the laser is adjusted to an appropriate size, the optical shutter is opened, and the incident direction is changed through the first and second reflectors to reach the collimating beam expansion filter module composed of the first lens, the filter pinhole, and the second lens. It enters the focusing objective lens through the beam splitting cube reflection, and the laser is focused on the surface of the ITO conductive film of the processing sample. A voltage is applied to the sample surface to start laser direct writing processing. The controller jointly and cooperatively controls the movement of the translation stage and the opening and closing of the optical shutter to achieve the processing and preparation of complex patterns.

[0059] The LED illumination light irradiated on the sample is processed by measuring the optical path, and the imaging results are collected in real time using a camera, and fed back to the computer for real-time observation of the processing process and preparation results.

[0060] The light field collected by the camera in real time is post-processed by a computer to obtain the three-dimensional morphology of the sample in real time. The position to be processed on the sample surface at the next moment is obtained based on the obtained three-dimensional morphology, and the sample is controlled to move up and down so that the position to be processed of the sample is aligned with the focal plane of the laser emitted by the objective lens in real time.

[0061] In the measurement optical path, the light emitted by the LED illumination light source 11 passes through the processed sample and carries the sample surface processing information. After being magnified by the focusing objective lens, it is transmitted through the beam splitter cube, and the direction of the imaging optical path is changed by the third reflector. The image is formed on the camera through the tube lens, and the camera collects the light field in real time and feeds it back to the computer.

[0062] The reaction principle during the processing is as follows:

[0063] 1. During the electrochemical reaction, an oxidation reaction occurs on the surface of the ITO conductive film under positive electrode bias. Since the components of ITO, indium oxide and tin oxide, have reached the highest chemical reaction oxidation state, the only element that can lose electrons is oxygen, so the indium-oxygen bond and the tin-oxygen bond break to form In 3+ , O 2- With Sn 4+ ,In 3+ Entering the solution, O 2- Lose electrons to generate oxygen, Sn 4+ With OH - The tin hydroxide generated by the reaction adheres to the surface of ITO.

[0064] 2. A reduction reaction occurs on the surface of the ITO conductive film under negative bias, and indium oxide is reduced to generate metallic indium attached to the ITO surface.

[0065] 3. Since the light absorption rate of tin hydroxide and metallic indium is much greater than that of ITO film, and the melting point is much lower than that of indium oxide and tin oxide, they can be processed by low-power continuous laser direct writing.

[0066] 4. By utilizing the low melting point of metal indium, the processed pattern can be erased by heating and melting it. After melting, the above method can be used again to process the micro-nano structure pattern.

[0067] The results of ITO laser direct writing processing under positive bias are as follows Figure 6 As shown in the figure, the processing of the "HUST" logo is realized. The results of ITO laser direct writing processing under negative bias are shown in the figure. Figure 7 As shown in Figure 1, the processing of the grating structure is realized. The processing result can be rewritten as Figure 8As shown, the “+” symbol was first processed on the ITO film, then erased, and then processed again on the same area.

[0068] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rewritable laser processing micro-nano manufacturing method of indium tin oxide conductive film based on electrochemical reaction, characterized in that: The method comprises the following steps: Step 1: two ITO conductive films are respectively arranged at two opposite ends of the cylindrical body to form a receiving cavity, and then deionized water is added into the receiving cavity; Step 2: Apply an external voltage to the two ITO conductive films to start an electrochemical reaction, thereby modifying the ITO conductive films, and then performing low-power continuous laser direct writing processing on the ITO conductive films to achieve the manufacture of patterned micro-nano structures of the ITO conductive films.

2. A rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction, characterized in that: The system includes a laser direct writing processing optical path and an ITO electrochemical reaction sample cell. The ITO electrochemical reaction sample cell includes a cylindrical cavity formed by a gasket. Both ends of the cylindrical cavity are encapsulated with an ITO conductive film to form a receiving cavity, and the receiving cavity is used to receive deionized water. The two ITO conductive films are used to connect an external voltage to start an electrochemical reaction to achieve modification of the ITO conductive film. The laser direct writing processing optical path is used to perform low-power continuous laser direct writing processing on the modified ITO conductive film to achieve the manufacture of patterned micro-nano structures of the ITO conductive film.

3. The rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction as claimed in claim 2, characterized in that: The system also includes a measuring optical path, which is used to process the LED illumination light irradiated on the sample and then use a camera to collect imaging results in real time, and feed back to a computer for observation of the processing process and preparation results.

4. The rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction as claimed in claim 3, characterized in that: The measuring optical path includes an LED lighting source, a processed sample, a focusing objective lens, a beam splitter cube, a third reflector, a tube lens and a camera; the light emitted by the LED lighting source carries sample processing information after passing through the processed sample, is amplified by the focusing objective lens and then transmitted through the beam splitter cube, changes the direction of the imaging optical path through the third reflector, and is imaged on the camera through the tube lens for observation.

5. The rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction as claimed in claim 2, characterized in that: The laser direct writing processing optical path comprises a laser, an optical shutter, a first reflector, a second reflector, a first lens, a filtering pinhole, a second lens, a beam splitter cube, a focusing objective lens and a processing sample; the laser is used to output laser light of a predetermined power, the switch of the laser light is controlled by the optical shutter, and the incident direction is changed by the first reflector and the second reflector to reach a collimating beam expansion filtering module composed of a first lens, a filtering pinhole and a second lens, and then the laser light is reflected by the beam splitter cube to enter the focusing objective lens, and the laser light is focused on the surface of the processing sample to perform ITO micro-nano processing.

6. The rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction as claimed in claim 5, characterized in that: The system also includes a voltage control module, which is used to apply a corresponding voltage according to the height of the receiving cavity, so that an electrochemical reaction occurs on the surface of the ITO conductive film to modify the ITO conductive film.

7. The rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction as claimed in claim 5, characterized in that: The system also includes a translation stage and a controller. The translation stage is used to place the processed sample and can move up and down and horizontally. The controller is used to jointly and collaboratively control the up and down movement and / or horizontal movement of the translation stage and the opening and closing of the optical shutter under the control of a computer.

8. The rewritable laser processing micro-nano manufacturing system of indium tin oxide conductive film based on electrochemical reaction as claimed in claim 7, characterized in that: The light field collected by the camera in real time is post-processed by a computer to obtain the three-dimensional morphology of the sample in real time. The position to be processed on the sample surface at the next moment is obtained based on the obtained three-dimensional morphology, and the sample is controlled to move up and down so that the position to be processed of the sample is aligned with the focal plane of the laser emitted by the objective lens in real time.

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