KR101279930B1 - Manufacturing Mothod of Curved Surface F-dopped Tin oxide film with Nonlinear In-line Lifting - Google Patents

Abstract

The present invention relates to a coating system for forming an FTO transparent conductive film on a transparent substrate having a complex shape such as a curved surface. In particular, the present invention provides a non-linear continuous transfer device up to a process of supplying and discharging a substrate, and the same 90 degree direction as that of the curved substrate. A non-linear structure in which raw material supply and exhaust nozzles are installed in the chamber, and raw materials are supplied in a direction of 90 degrees to the transfer direction of the curved substrate, and thus raw material gas is uniformly supplied to the curved substrate to coat a homogeneous thin film. It is characterized by performing a curved FTO transparent conductive film coating having a continuous feeder.

Description

Manufacturing Method of Curved Surface F-dopped Tin Oxide Film with Nonlinear In-line Lifting}

The present invention is to provide a method for forming an FTO transparent conductive film on a transparent substrate having a complicated shape by spray pyrolysis.

FTO (F-doped Tin Oxide) thin film material is a key electrode material for solar cells, automotive defrost glass windows and transparent heaters that require high temperature stability and is emerging as an important material in the display field.

Tin-doped Indium Oxide (ITO) thin film is a low-resistance material that can be deposited at low temperatures and has excellent etching characteristics, making it the most widely used material for display based on patterning. Due to the large deterioration of properties and lack of chemical stability, it is difficult to use in applications requiring thermal stability, chemical durability, mechanical durability, and the like.

Fluorine-containing tin oxide is a material in which tin oxide (SnO2) is doped with a small amount of fluorine, and fluorine (F) is substituted in the oxygen (O) site of tin oxide to increase the concentration of carrier electrons. It is known to change. In addition, the fluorine-containing tin oxide thin film material has an advantage of excellent heat resistance and chemical resistance compared to ITO due to the thermal, chemical, and mechanical stability of tin oxide (SnO 2).

FTO manufacturing process technology by spray pyrolysis method is based on ultrasonic spraying and liquid spray spraying method, which is a technique of incubating a liquid FTO precursor solution in a gaseous phase and sending it onto a heated substrate.

Although similar to conventional chemical vapor deposition (CVD) technology, it is very important to understand and equip the transport of very large droplets (or atomized precursor droplets) ranging in size from several hundreds of microns. This is evident in comparison to the diffusivity and cohesion of CVD precursors consisting of ordinary single molecules with micron droplets. The diffusivity means that the movement of the micron droplets is very slow and requires a separate carrier gas. On the flocculating surface, the micron droplets occur very seriously so that the droplets no longer grow in the weather or collision with the wall.

In addition, the solvent and the reaction gas are generated by the micron droplets as by-products during the reaction, and fine mist occurs on the surface of the substrate when the thin film is formed.

In addition, in the conventional technology, a method of spraying mist and placing a lower substrate in a 90 degree direction with a nozzle of an upper layer by using a linear transfer device is used. However, in order to form an FTO transparent conductive film on a transparent substrate having a complicated shape such as a curved surface, The uniformity of the film is significantly reduced.

FTO thin film manufacturing by spray pyrolysis is generally very difficult and is currently being produced in small quantities by a limited number of companies. Representative examples include solar cell manufacturing technology (silicon solar cell, dye-sensitized solar cell), sensor application technology, and touch panel technology.

On the other hand, instead of the FTO equipment system, a number of element technologies are known, and typically, an apparatus having a cylindrical hood between an upper nozzle and a lower substrate (JP 2004-167394A), a source apparatus for generating a precursor (JP 2006-236602A), An apparatus for moving and coating a plurality of nozzles (JP 2003-205235A), a substrate immobilization apparatus (JP 2006-184341A), and a substrate strain suppression system (JP 2006-19135A) when using a large substrate.

As a device for coating the transparent conductive film, the preheating chamber, the deposition chamber, and the slow cooling heat chamber are connected by a nonlinear transfer device, and the glass substrate is transferred to the preheating chamber, the deposition chamber, and the slow cooling heat chamber step by step, so that a thin film is formed on the curved substrate. To develop a system for manufacturing FTO (F-doped Tin Oxide) substrate with improved uniformity.

The preheating chamber is responsible for the surface treatment and preheating of the substrate, and performs the surface cleaning of the substrate, coating the barrier film, and the like to transport the surface-treated substrate to the deposition chamber.

The deposition chamber is provided with raw material supply and exhaust nozzles in the same 90 degree direction as the curved substrate, and atomized FTO precursor is sprayed from the nozzle to be deposited on the curved substrate, and reactant gas, carrier gas, unreacted material, and the like. Exits through the exhaust attached to the nozzle side. In this case, since the non-linear transfer means is used for the transferred curved substrate, a uniform thin film may be deposited on the curved substrate.

The curved FTO-coated substrates transported to the slow cooling chamber result in various FTO substrates through natural cooling or functional cooling (FTO surface property conversion, tempered glass production, etc.).

As a substrate for coating the transparent conductive film, polyimide (PI), Teflon resin (PTFE), polynorbornin (PNB) resin, soda lime glass, low iron glass (Low-Fe glass), which are heat-resistant polymer films ), Etc. Further, the curved transparent conductive film coating material is not limited to FTO, ITO, AZO, ZnO, SnO2, IZO, GZO, TiO2, SiO2 and the like.

The present invention includes a non-linear continuous transfer device until the substrate is supplied and discharged, and the raw material supply and exhaust nozzles are installed in the same 90 degree direction as the curved substrate to supply the raw materials. Accordingly, since the raw material gas is uniformly supplied on the transparent substrate having a complicated shape such as a curved surface to form an FTO transparent conductive film, the FTO substrate having a complicated shape can be mass-produced.

Figure 1. Prior art (where a linear feeder is installed).
Figure 2. Schematic diagram of a curved FTO transparent conductive film production apparatus having a non-linear continuous feeder of the present invention.
3. Digital photo of curved FTO transparent conductive film.
Figure 4. SEM image of a curved FTO substrate showing the electrical properties of 7.3 ohms prepared in the present invention.
FIG. 5. SEM image of curved FTO substrate showing 5.2 ohm electrical characteristics prepared in the present invention.
6. Light transmittance of the curved FTO substrate prepared in the present invention.

FIG. 1 shows a film uniformity that is too uneven to coat a transparent substrate having a complex shape such as a curved surface as a FTO coating system using a conventional linear transfer device. However, in FIG. 2, the curved FTO coating system having the nonlinear continuous transfer device of the present invention can form a uniform thin film by reaching a predetermined distance from the mist coated on the curved substrate due to the tensioning device of the nonlinear transfer device. To make it possible.

The substrate introduced into the preheating unit 2 can be surface treated and heated. The plasma surface treatment machine (not shown) turns the substrate surface into an active state while simultaneously injecting a reactive gas to form new functional groups using ion energy on the substrate surface. In the case of heating, a separate heater (not shown: plate heater or hot wall heater) is provided. The preheated substrate is then transported to the deposition chamber 1. At this time, through the shutter or the air curtain (4) provided between the chamber between the chamber is closed and closed. The deposition unit may have a separate heating system (not shown: plate heater or hot wall heater) or may include a rotating heater. When the heater is activated, the substrate tray rotates so that the substrates on the tray rotate together. This makes the FTO coating film uniform.

The deposition unit 1 includes a nozzle in a 90 degree direction with the substrate, and the precursor supplied from the outside enters the deposition unit 1 through the nozzle. At this time, the flow of the precursor reaches the substrate by the exhaust part 10 provided on the side part, and forms a thin film, but other reaction product gases, unreacted gas, carrier gas, and the like exit from the exhaust part.

The FTO coated substrate prepared in the deposition unit 1 is transferred to the slow cooling unit 3. The slow cooling unit 3 may be separately provided with a device of a heater (not shown in the drawing: a plate heater or a hot wall heater), a cooling device, a quenching device (such as tempered glass or FTO substrate surface morphology change).

The substrate of the present invention mainly means a glass substrate, but includes a material having corrosion resistance to hydrofluoric acid (this reaction generates hydrofluoric acid). In addition, the substrate of the present invention may include a state in which a barrier film is coated on a glass substrate.

The substrate of the present invention includes a state in which a multilayer film is coated on a glass substrate in advance through an optical design.

Accordingly, the present invention provides an equipment and a process technology for coating the FTO on a substrate having a complex shape such as a curved surface having the nonlinear transfer device.

The formation process of FTO thin film is Pyro-sol principle. Or it is easily explained by the principle of chemical vapor deposition (CVD).

FTO precursor solution was prepared by dissolving SnCl 4 · 5H20 in tertiary distilled water to 0.68 M and dissolving NH 4 F in ethanol as an F dopant to 1.2 M, then mixing and stirring the two solutions and filtering.

It is also possible to use only pure water as the solvent. It is also possible to use other alcohols.

In addition, in this study, alcohols and ethylene glycol may be additionally added in addition to the above solution composition to prepare various FTO membranes.

In order to control the amount of F doping, the amount of NH 4 F may be changed from 0.1 to 3 M, or 0-2 M of hydrofluoric acid (HF) may be added. Therefore, the precursor solution for preparing the FTO membrane is not limited to the composition shown above.

In general glass used as a substrate, when heated to 400-600 degrees, impurities such as Na and K diffuse onto the substrate, damaging the surface of the glass substrate. This results in a decrease in film adhesion and film quality even when the FTO film is coated. Therefore, a barrier layer coating must be applied between the glass substrate and the FTO film to block impurities from entering.

Generally, ceramic films such as SiO2 and TiO2 are used a lot, but in this study, SiO2 barrier films are typically formed by using dip coating and spray coating at about 50-100 nm. In the case of a small substrate, a dip coating method is used, and in the case of a large substrate and a curved surface, a SiO 2 barrier film is formed using a spray coating method.

In the dip coating method, a silica sol [ethanol (95%): Tetraethyl silicate: Nitric acid = 90: 11: 0.5 (volume ratio)] was prepared, dip coated at a speed of 150 mm / min, and then heat-treated at 300-400 degrees for 5 minutes. SiO 2 barrier film is formed. Spray coating is performed on large area substrates or curved glass substrates. Silane reagents (SiH 4, SiH 2 Cl 2, Si (OC 2 H 5) 2, etc.) can be easily formed on a glass substrate heated to 400-600 degrees in air or in an oxygen atmosphere using the CVD principle (spray). When using high quality glass, that is, when using glass substrates with few impurities, such as Na and K (for example, borosilicate glass), it is not necessary to form a barrier film.

It is preferable to use the curved glass which coat | covered the substrate temperature 400-600 degree | times and 50-100 nm of SiO2 barrier film. The sheet resistance of the FTO film thus prepared is about 5-8 ohms.

3 is a real digital photograph of a curved FTO transparent conductive film like the complex shape of the present invention.

Figure 4 is an SEM image of a curved FTO substrate showing the electrical properties of 7.3 ohms prepared in the present invention. A thin film thickness of 540 nm is shown, and the thickness of the SiO 2 barrier film is about 50 nm. In addition, the light transmittance of the thin film is 80%, haze is 10%. (See Table 1)

FIG. 5 is an SEM image of a curved FTO substrate exhibiting electrical characteristics of 5.2 ohms prepared in the present invention. FIG. A thin film thickness of 700 nm is shown, and the thickness of the SiO 2 barrier film is about 50 nm. In addition, the light transmittance of the thin film is 78%, the haze is 14%. (See Table 1)

Figure 6 shows the light transmittance of the curved FTO substrate produced in the present invention. # 1 and # 2 show 78 ~ 80% optical properties. (See Table 1)

Accordingly, it can be seen that a variety of commercially available FTO substrates can be manufactured using the FTO transparent conductive film coating apparatus having the nonlinear continuous transfer device of the present invention.

Sample Thickness (nm) Grain Size (nm) Seet Resistence (Ohm / □) Transmission (%) Haze (%) #One 540 nm 100-150 nm 7.3 (/) 80% 10% #2 700 nm 200-250 nm 5.2 (/) 78% 14%

Claims (7)

In the method of manufacturing a curved FTO transparent conductive film,
Connecting the preheating unit, the deposition unit, and the slow cooling unit chamber to the nonlinear transfer apparatus;
A nozzle part attached to the substrate having a complex shape (curved surface) at a 90 degree position and an exhaust part provided at the nozzle side part;
The substrate is surface treated and heated in the preheating section and moved to the deposition section;
Spraying an FTO precursor through the nozzle of the deposition unit and simultaneously reaching the substrate through the exhaust unit to form a uniform curved FTO film;
The method of manufacturing a curved FTO transparent conductive film having a non-linear continuous conveying device, characterized in that the step of moving the FTO coated curved substrate to a slow cooling unit to quench and cool. The method of claim 1, wherein in the preheating unit, the substrate is heated to 400-600 degrees to move to the deposition unit. The curved FTO transparent conductive film manufacturing method according to claim 1, wherein, in the preheating unit, the substrate is plasma-treated to move to the deposition unit. The method of manufacturing a curved FTO transparent conductive film according to claim 1, wherein in the preheating unit, a barrier film is coated on the curved substrate and moved to the deposition unit. The curved FTO transparent conductive film manufacturing method of claim 1, wherein the deposition unit coats the FTO film at a substrate temperature of 400-600 degrees. The curved FTO transparent conductive film manufacturing method according to claim 1, wherein the substrate tray is rotated in the deposition unit. The method of manufacturing a curved FTO transparent conductive film according to claim 1, wherein the FTO precursor is produced by any one of a spray coating method, an ultrasonic spray coating method, and an ultrasonic spray spraying method.

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