CN107475671A - Metal film electrode preparation method based on MPTMS modification ITO heating plates - Google Patents

Abstract

The invention discloses a metal film electrode manufacturing method based on MPTMS modified ITO heating sheet. First, the ITO substrate is ultrasonically cleaned and dried; then the ITO substrate is treated with ultraviolet light; In the solution, the surface of the ITO substrate is modified by MPTMS self-assembly, so that a layer of self-assembled film is formed on the surface of the ITO substrate; finally, a metal film electrode is fabricated on the ITO substrate modified by MPTMS. In the present invention, a layer of self-assembled film is formed between the ITO substrate and the metal film electrode, and the two ends of the molecular chain of the self-assembled film are connected to the ITO substrate and the metal film electrode through bonding, so that the prepared metal film electrode is more uniform and compact , stronger adhesion and lower impedance. Therefore, the present invention effectively solves the problems of non-uniform impedance distribution and poor electrode adhesion existing in the preparation of ITO heater sheet electrodes using traditional techniques.

Description

Fabrication method of metal film electrode based on MPTMS modified ITO heating sheet

technical field

The invention relates to the field of preparation methods of ITO substrate electrodes, in particular to a method for manufacturing metal film electrodes based on MPTMS modified ITO heating sheets.

Background technique

At present, in the display field, ITO substrates are mostly used as heating devices, and the electrodes are mainly produced by coating conductive silver paste and vacuum evaporation, but there are two main problems in the electrodes produced by these methods. One is that the internal impedance of the electrodes is inconsistent, which makes the current distribution in the ITO heating sheet uneven, resulting in serious local heating. The second is that the adhesion of the electrode is too low. If the ITO heater works for a long time, it will cause the electrode to age and fall off, which will affect the reliability of the device. Therefore, it is necessary to optimize the preparation process of the electrode to improve the impedance uniformity of the electrode and the adhesion performance with the ITO surface.

SUMMARY OF THE INVENTION Aiming at the problems existing in the above-mentioned background technology, the present invention provides a metal film electrode manufacturing method based on MPTMS modified ITO heating plate, in order to solve the problem of uneven electrode impedance distribution and Problems with low adhesion.

In order to achieve the above object, the technical scheme adopted in the present invention is:

The method for manufacturing a metal film electrode based on MPTMS modified ITO heating sheet is characterized in that: firstly use organic silane material to self-assemble and modify the ITO substrate, and then make a metal film electrode on it, which specifically includes the following steps:

(1) Cleaning of ITO substrate:

Use ultrasonic cleaning to clean the ITO substrate, and dry the ITO substrate after cleaning;

(2), UV treatment:

Use an ultraviolet cleaning machine to treat the ITO substrate after step (1) to remove organic residues on the surface of the ITO substrate and increase the number of hydroxyl groups on the surface of the ITO substrate;

(3), MPTMS 3-mercaptopropyltrimethoxysilane modification of ITO substrate:

Place the ITO substrate treated in step (2) in a mixed solution of MPTMS 3-mercaptopropyltrimethoxysilane and toluene for self-assembly modification. Toluene is used as the solvent in the mixed solution, and the ITO substrate is rinsed with toluene after modification To remove excess MPTMS 3-mercaptopropyltrimethoxysilane, and finally dry the ITO substrate;

(4) Prepare a metal film electrode on the ITO substrate modified in step (3).

The method for manufacturing a metal film electrode based on MPTMS modified ITO heating sheet is characterized in that: in the step (2), the time length for processing the ITO substrate with an ultraviolet cleaning machine is 25-35 minutes.

The method for manufacturing a metal film electrode based on MPTMS modified ITO heating sheet is characterized in that: in the mixed solution of step (3), the volume ratio of MPTMS to toluene is 0.5-1.5:40; at room temperature, The ITO substrate is placed in the mixed solution for self-assembly modification, and the modification time is 3-8h.

The method for manufacturing a metal film electrode based on MPTMS-modified ITO heating sheet is characterized in that in the step (3), in addition to MPTMS, other organosilane materials can be used to modify the ITO substrate.

The method for manufacturing a metal film electrode based on MPTMS modified ITO heating sheet is characterized in that in the step (4), the metal film is preferably prepared on the ITO substrate modified in step (3) by vacuum evaporation electrode.

Principle of the present invention is:

In the step (2) of the present invention, an ultraviolet cleaning machine is used to process the ITO substrate. Ultraviolet light can decompose the organic residues on the surface of the ITO substrate; at the same time, the oxygen in the air generates ozone under the catalysis of ultraviolet light, and the ozone can further decompose the organic residues on the ITO surface, and the ozone reacts with the water molecules remaining on the ITO surface to generate redox reactions. Hydroxyl (-OH). The ultraviolet light treatment makes the surface of the ITO substrate cleaner, and at the same time increases the number of hydroxyl groups on the surface of the ITO substrate, which is beneficial to subsequent processing.

In the step (3), based on the principle of molecular self-assembly, the ITO substrate treated in the step (2) is soaked in the mixed solution of MPTMS and toluene at room temperature, and the head group (-Si- OCH3) undergoes a hydrolysis reaction to generate -Si-OH, and then -Si-OH polymerizes with the -OH on the ITO surface to generate -Si-O-, thereby immobilizing MPTMS molecules on the surface of the ITO substrate, and finally on the surface of the ITO substrate A self-assembled film is formed. The sulfhydryl group (-SH) on the MPTMS molecular chain in the self-assembled film is exposed to the outside, and it is very easy to form a strong covalent bond with the metal, so that the metal can be fixed on the surface of the ITO substrate, making the prepared electrode more uniform, dense, and stable. Stronger adhesion. In the present invention, MPTMS self-assembly is used to modify the ITO substrate firstly, and then metal film electrodes are evaporated on the modified ITO substrate as heating plate electrodes. Due to the effect of the self-assembled thin film formed after MPTMS modification, the metal film electrode is more uniformly, densely and firmly bonded on the ITO substrate.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

The invention adopts MPTMS to modify the ITO substrate, and prepares the metal film electrode by vacuum evaporation on the ITO substrate. Compared with the traditional process, the electrode produced by the invention is more uniform and compact, has stronger adhesion and lower impedance. To a certain extent, it can improve the potential distribution of the heating plate electrode, improve the heating uniformity of the ITO heating plate, and alleviate the aging and falling off of the electrode, so that the reliability of the device is higher.

Description of drawings

Figure 1 is a schematic diagram of MPTMS self-assembly modified ITO substrate.

Fig. 2 is a schematic structural diagram of an ITO heating chip in a specific embodiment of the present invention.

Fig. 3 is the atomic force image of the ITO thin film modified by MPTMS and the Ag electrode made thereon in the specific embodiment of the present invention.

Fig. 4 is a schematic diagram of the cross-sectional structure of an Ag electrode fabricated on an ITO film modified by MPTMS in the present invention.

detailed description

The embodiments of the present invention will be described in detail below. Based on the technical solution of the present invention, this embodiment provides detailed implementation and specific operation process. The protection scope of the present invention includes but not limited to the following examples.

As shown in Figure 1 and Figure 2, the metal film electrode manufacturing method based on MPTMS modified ITO heating sheet includes the following steps:

(1) Cleaning of ITO substrate:

First, the ITO substrate was placed in acetone, absolute ethanol, and deionized water for 20 min, respectively, to ultrasonically clean the ITO substrate. The concentrations of acetone and ethanol were 99.5%. After ultrasonic cleaning, blow dry the ITO substrate with nitrogen.

(2) Ultraviolet light treatment:

Place the ITO substrate treated in step (1) in an ultraviolet cleaning machine for 30 minutes, wherein the working wavelength of the ultraviolet cleaning machine is 185nm and 254nm.

Ultraviolet light treatment can effectively decompose the organic residues on the ITO surface, make the ITO substrate surface cleaner, and increase the number of hydroxyl groups for subsequent MPTMS modification.

(3) 3-Mercaptopropyltrimethoxysilane (MPTMS for short) modification of ITO substrate:

Based on the principle of molecular self-assembly, the ITO substrate treated in step (2) was placed in a mixed solution of MPTMS and toluene for self-assembly modification, and toluene in the mixed solution was used as a solvent. After modification, rinse the ITO substrate with toluene to remove excess MPTMS, and then dry the ITO substrate with nitrogen.

In the mixed solution, the volume ratio of MPTMS to toluene is 0.5-1.5:40; the modification time is 3-8h. It is known from experiments that the volume ratio of MPTMS to toluene and the length of self-assembly modification will affect the effect of self-assembly. When the volume ratio of MPTMS to toluene is 1:40 and the modification time is 6h, the effect of self-assembly modification is the most ideal.

In the present invention, in addition to using MPTMS to self-assemble and modify the ITO substrate, other organosilane materials can also be used to modify the ITO substrate.

(4) Prepare a metal film electrode on the ITO substrate modified in step (3) by vacuum evaporation.

In the present invention, in addition to vacuum evaporation, other methods can also be used to prepare metal film electrodes, such as magnetron sputtering, electrostatic spraying and electrochemical deposition. However, compared with other methods, the vacuum evaporation method is easier to operate, has better repeatability and produces a more uniform and smooth metal film. Therefore, in this embodiment, the vacuum evaporation method is preferred to fabricate the metal film electrode.

The process of preparing metal film electrodes on the modified ITO substrate in step (3) by vacuum evaporation is as follows:

(a) Attaching the mask plate:

The ITO substrate modified by MPTMS is bonded to the mask plate. The mask plate covers the part of the ITO substrate that does not need to prepare metal film electrodes, and only exposes the part that needs to make electrodes, that is, the shaded part in Figure 2.

(b), transfer mask:

Move the ITO substrate together with the attached mask plate to the substrate frame in the chamber of the vacuum coating machine. The ITO substrate, mask plate and substrate frame are fixed as a whole. When the substrate frame rotates, the ITO substrate is driven to rotate.

(c), Evaporated metal film electrode:

Vacuum until the vacuum degree is lower than 2x10 ^-7 Torr and start evaporation. When the evaporation rate is stable at 20Å/s, open the baffle to allow metal molecules to evaporate onto the ITO substrate. In order to ensure the uniformity of the metal film, the substrate holder rotates at a constant speed at 20 r/min.

Table 1 Table of film thickness and surface resistance value

serial number #1 #2 #3 #4 Film thickness (Å) 28312 28192 28251 28135 Surface resistance value (Ω/□) 0.26 0.26 0.26 0.26

The metal film electrode prepared by the above method was tested, the electrode film was divided into the same four sections, and the film thickness and surface resistance value of each section were measured with a step meter and a surface resistance meter respectively. The data are shown in Table 1. The metal film electrode The thickness is uniform, and the resistance value is relatively stable.

As shown in Figure 3, the atomic force image of the MPTMS-modified ITO thin film (left picture) obtained by the method of the present invention and the Ag electrode (right picture) fabricated on it, the scanning range is 5 μm * 5 μm. Its surface roughness is only 1 nm, indicating that the Ag electrode prepared on MPTMS-modified ITO is relatively smooth.

FIG. 4 is a schematic diagram of the cross-sectional structure of the heating chip electrode produced by the present invention. The MPTMS molecule is bonded, and the two ends of the molecule are respectively combined with ITO and Ag, thereby immobilizing Ag on the surface of ITO. The film layer formed by MPTMS self-assembly process tightly connects Ag and ITO, thereby enhancing the adhesion of Ag, making the formed Ag electrode film more uniform and dense, reducing the film thickness difference of the electrode, and improving the uniformity of the electrode. .

Claims (5)

1. The method for manufacturing a metal film electrode based on MPTMS modified ITO heating plate is characterized in that: first use organic silane material to self-assemble and modify the ITO substrate, and then make a metal film electrode on it, specifically including the following steps: (1) Cleaning of ITO substrate: Use ultrasonic cleaning to clean the ITO substrate, and dry the ITO substrate after cleaning; (2), UV treatment: Use an ultraviolet cleaning machine to treat the ITO substrate after step (1) to remove organic residues on the surface of the ITO substrate and increase the number of hydroxyl groups on the surface of the ITO substrate; (3), MPTMS 3-mercaptopropyltrimethoxysilane modification of ITO substrate: Place the ITO substrate treated in step (2) in a mixed solution of MPTMS 3-mercaptopropyltrimethoxysilane and toluene for self-assembly modification. Toluene is used as the solvent in the mixed solution, and the ITO substrate is rinsed with toluene after modification To remove excess MPTMS 3-mercaptopropyltrimethoxysilane, and finally dry the ITO substrate; (4) Prepare a metal film electrode on the ITO substrate modified in step (3). 2. The method for manufacturing a metal film electrode based on MPTMS modified ITO heating sheet according to claim 1, characterized in that: in the step (2), the time for processing the ITO substrate with an ultraviolet cleaning machine is 25-35 minutes. 3. The method for manufacturing a metal film electrode based on MPTMS modified ITO heating sheet according to claim 1, characterized in that: in the mixed solution of step (3), the volume ratio of MPTMS to toluene is 0.5-1.5:40 ; At room temperature, place the ITO substrate in a mixed solution for self-assembly modification, and the modification time is 3-8h. 4. The method for manufacturing a metal film electrode based on MPTMS-modified ITO heating sheet according to claim 1, characterized in that in the step (3), other organosilane materials can be used to modify the ITO substrate besides MPTMS. 5. The method for manufacturing a metal film electrode based on MPTMS modified ITO heating sheet according to claim 1, characterized in that: in the step (4), vacuum evaporation is preferably used after modification in step (3) Metal film electrodes were fabricated on ITO substrates.