Method for forming conductive film pattern, electro- optical device and electronic apparatus

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a method for forming a conductive film pattern used for wiring of an electronic circuit or an integrated circuit, an electro-optical device manufactured by using the method for forming the conductive film pattern, and an electronic device provided with the electro-optical device. It is a thing.

【0002】

[Conventional technology]

The conductive film pattern used in conventional wiring is formed by forming a metal thin film on the entire surface of the substrate by sputtering or vapor deposition, and then etching unnecessary parts by a photolithography method to form the required conductive film pattern. The most common. However, in this method, the process is complicated and it is necessary to use an expensive vacuum device, and the material usage efficiency is about several percent, and most of them are discarded. Therefore, a simpler and cheaper method has been sought.

【0003】

On the other hand, US Pat. No. 5,132248 proposes a method in which a liquid in which fine particles are dispersed is directly patterned on a substrate by an inkjet method, and then heat-treated or laser-irradiated to convert it into a conductive film pattern. This method eliminates the need for photolithography and greatly simplifies the process. However, such patterning by the inkjet method has an advantage that the process is simple and the amount of raw materials used can be small, but on the other hand, when the bank described later is not used, a structure having a size of about 100 μm is positioned at a position of about 30 μm. The limit is to form with accuracy. Therefore, in order to improve the processing accuracy by the inkjet method, a method of providing a bank on the substrate and controlling the position of the ejected droplets is usually used as disclosed in Japanese Patent Application Laid-Open No. 59-75205. .. When a bank is used, the droplets ejected on the substrate do not go out of the bank, and a pattern of about 30 μm can be formed with a position accuracy of about 1 μm. However, since such a bank needs to be formed by using photolithography, it leads to high cost.

【0004】

In recent years, a method of spin-coating a substrate with a liquid in which copper fine particles are dispersed in a solvent has been proposed for application to LSIs, etc. (Hirohiko Murakami et al., Proceedings of the 46th Annual Meeting of the Japan Society of Applied Physics in the Spring of 1999) Collection No.2, 29p-ZQ-15). In this case, a liquid is poured into the trenches and holes formed in the substrate in advance, and the copper thin film pattern is obtained by drying and heating. However, it is still necessary to use the photolithography method for forming the trenches and holes.

【0005】

As described above, a patterning means for obtaining a conductive film pattern from a liquid material by forming a film from a liquid material and performing patterning with an accuracy on the order of microns and in a simple process that does not use photolithography. Has never been.

【0006】

[Problems to be Solved by the Invention]

In the present invention, in the method of forming a conductive pattern by applying a pattern of a liquid containing fine particles on a substrate, the position of the liquid is not controlled by a bank or trench formed by photolithography as in the conventional case, but organic. By selectively applying the liquid material only to the parent liquid part of the substrate on which the pattern of the liquid repellent part and the parent liquid part is formed by the molecular film and then converting it into a conductive film pattern by the subsequent heat treatment, it is possible to accurately perform a simple process. The object of the present invention is to provide a method for forming a conductive film pattern.

【0007】

[Means for solving problems]

As a result of diligent research to achieve the above object, the present inventor uses an organic molecular film on the surface of the substrate to form a process of forming a parent liquid portion and a liquid repellent portion in a predetermined pattern, and conductive fine particles. A simple step is a method of forming a conductive film pattern, which comprises a step of selectively applying the contained liquid to the parent liquid portion on the substrate and a step of converting the coating film of the liquid into a conductive film by heat treatment. The present invention has been completed by finding that a conductive film pattern can be formed with high accuracy.

【0008】

As the substrate used in the present invention, various materials such as Si wafer, quartz glass, glass, plastic film, and metal plate can be used, and a semiconductor film, metal film, dielectric film, organic film, etc. are used on the surface of the substrate. There is no problem even if is formed as an underlayer.

【0009】

In the organic molecular film of the present invention, a functional group that can be bonded to a substrate and a functional group that modifies the surface property of the substrate (controls surface energy) such as a parent liquid group or a liquid repellent group on the opposite side thereof are used. It has a linear or partially branched carbon chain of carbon that connects functional groups, and binds to a substrate to self-assemble to form a molecular film, for example, a monomolecular film. Further, it is desirable that this organic molecular film is decomposed by ultraviolet irradiation and can be easily patterned by ultraviolet irradiation using a mask.

【0010】

In the present invention, the self-assembled monolayer formed on the surface of the substrate is composed of a binding functional group capable of reacting with constituent atoms of a base layer such as a substrate and other linear molecules, and the interaction of the linear molecules. It is a film formed by orienting a compound having extremely high orientation. Unlike a resin film such as a photoresist material, the self-assembled film is formed by orienting a single molecule, so that the film thickness can be extremely thin, and the film becomes uniform at the molecular level. That is, since the same molecule is located on the surface of the film, it is possible to impart uniform and excellent liquid repellency and liquid friendship to the surface of the film, which is particularly useful for fine patterning.

【0011】

For example, when fluoroalkylsilane, which will be described later, is used as the compound having high orientation, each compound is oriented so that a fluoroalkyl group is located on the surface of the film to form a self-assembled film. Therefore, uniform liquid repellency is imparted to the surface of the film.

【0012】

Compounds that form such a self-assembling film include heptadecafluoro-1,1,2,2 tetrahydrodecyltriethoxysilane, heptadecafluoro-1,1,2,2 tetrahydrodecyltrimethoxysilane, and heptadeca. Fluoro-1,1,2,2 tetrahydrodecyltrichlorosilane, tridecafluoro-1,1,2,2 tetrahydrooctyltriethoxysilane, tridecafluoro-1,1,2,2 tetrahydrooctyltrimethoxysilane, trideca Fluoroalkylsilanes (hereinafter referred to as "FAS") such as fluoro-1,1,2,2 tetrahydrooctyltrichlorosilane and trifluoropropyltrimethoxysilane can be mentioned. In use, it is preferable to use one compound alone, but even if two or more compounds are used in combination, there is no limitation as long as the intended purpose of the present invention is not impaired. Further, in the present invention, it is preferable to use the FAS as the compound forming the self-assembled monolayer in order to impart adhesion to the substrate and good liquid repellency. By patterning the FAS, a pattern of the parent liquid part and the liquid repellent part can be made. The part where FAS exists becomes the liquid-repellent part.

【0013】

The FAS used here is generally structural formula R._nSiX_(4-n)It is represented by. Here, n represents an integer of 1 or more and 3 or less, and X is a hydrolyzing group such as a methoxy group, an ethoxy group, or a halogen atom. R is a fluoroalkyl group, and (CF₃) (CF₂)_x(CH₂)_y(Here, x represents an integer from 0 to 10 and y represents an integer from 0 to 4), and if multiple R or X are connected to Si, then R or X is They may all be the same or different. The hydrolyzing group represented by X forms silanol by hydrolysis, reacts with the hydroxyl group of the substrate (glass, silicon) or the like, and bonds to the substrate by a siloxane bond. On the other hand, R is on the surface (CF₃) Etc., so the underlying surface of the substrate or the like is modified to a non-wetting surface (low surface energy).

【0014】

Next, the parent fluid part will be described. Hydroxy groups are present on the surface of the region from which the self-assembled monolayer has been removed by ultraviolet light or the like, which will be described later. Therefore, it shows a property that it is very easy to get wet compared to the FAS region. Therefore, if the FAS in a part of the region is removed after the FAS is formed on the entire surface of the substrate, the region exhibits a liquid-like property, and a pattern of the parent-liquid portion and the liquid-repellent portion is formed.

【0015】

Furthermore, it is also possible to form a second self-assembled monolayer in the area where FAS has been removed as described above. Similar to FAS, the compound that forms the second self-assembled monolayer also has a binding functional group and a functional group that modifies the surface, and the binding functional group binds to the hydroxyl group on the substrate surface to form a self-assembled monolayer. Form. As the functional group that modifies the surface of the second self-assembled monolayer, a group that exhibits more positivity unlike FAS, or a group that has a strong binding force with fine particles, such as an amino group and a thiol group, is used. Is desirable. This enables more stable patterning and improves the adhesion of the finally obtained conductive film pattern to the substrate. Examples of the compound forming such a second self-assembling film include 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-aminopropyltrimethoxysilane. can give.

【0016】

The self-assembled monolayer is disclosed in detail in, for example,'An Introduction to ULTRATHIN ORGANIC FILMS: Ulman, ACADEMIC PRESS'.

【0017】

In the present invention, after forming the parent liquid portion and the liquid repellent portion in a predetermined pattern on the substrate by using the organic molecular film as described above, a liquid containing fine particles is selected as the parent liquid portion on the substrate. The coating film is converted into a conductive film by the subsequent heat treatment.

【0018】

As the fine particles used here, in addition to metal fine particles containing any one of gold, silver, copper, palladium, and nickel, conductive polymers and fine particles of superconductors are used. In the present invention, a liquid in which these fine particles are dispersed in a solvent is used. In order to disperse the fine particles, the surface of the fine particles may be coated with an organic substance or the like. Further, when applied to the substrate, the particle size of the fine particles is preferably about 50 nm or more and about 0.1 μm from the viewpoint of easy dispersion in a solvent and application of the inkjet method.

【0019】

In the present invention, the liquid in which the above fine particles are dispersed in a solvent is selectively applied only to the parent liquid portion on the substrate. The solvent used here preferably has a vapor pressure of 0.001 to 200 mmHg at room temperature. This is because when the vapor pressure is higher than 200 mmHg, the solvent evaporates first when the coating film is formed, and it becomes difficult to form a good coating film. On the other hand, when the vapor pressure at room temperature is lower than 0.001 mmHg, the drying becomes slow and the solvent tends to remain in the coating film, and it is difficult to obtain a good quality conductive film after the heat and / or light treatment in the subsequent step. When the above solution is applied by an inkjet device described later, the vapor pressure of the solvent is preferably 0.001 to 50 mmHg. This is because when the vapor pressure is higher than 50 mmHg, the nozzle is likely to be clogged due to drying when the droplets are ejected by the inkjet device, and stable ejection becomes difficult. On the other hand, when the vapor pressure is lower than 0.001 mmHg, the ejected ink dries slowly and the solvent tends to remain in the conductive film, making it difficult to obtain a good quality conductive film even after the heat treatment in the subsequent step. The solvent used in the present invention is not particularly limited as long as it can disperse the above fine particles and does not cause aggregation, but in addition to water, alcohols such as methanol, ethanol, propanol and butanol, n- Hydrocarbon solvents such as heptane, n-octane, decane, toluene, xylene, simen, durene, inden, dipentene, tetrahydronaphthalene, decahydronaphthalene, cyclohexylbenzene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol. Methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, 1, Ether-based solutions such as 2-dimethoxyethane, bis (2-methoxyethyl) ether, and p-dioxane, as well as polar solvents such as propylene carbonate, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, and cyclohexanone. Can be mentioned. Of these, water, alcohols, hydrocarbon solvents, and ether solvents are preferable, and more preferable solvents are, in terms of the dispersibility of fine particles, the stability of the dispersion, and the ease of application to the inkjet method. Examples include water and hydrocarbon solvents. These solvents can be used alone or as a mixture of two or more.

【0020】

The solute concentration when the fine particles are dispersed in a solvent is about 1 to 80% by weight, and can be adjusted according to the desired film thickness of the conductive film. If it exceeds 80% by weight, agglutination is likely to occur, and a uniform coating film cannot be obtained.

【0021】

The fine particle dispersion used in the present invention can be added with a small amount of a surface tension adjusting material such as fluorine-based, silicone-based, or nonionic-based, if necessary, as long as the desired function is not impaired. This nonionic surface tension adjusting material improves the wettability of the solution to the object to be applied, improves the leveling property of the applied film, and helps prevent the occurrence of lumps and yuzu skin of the coating film. It is a thing.

【0022】

The viscosity of the fine particle dispersion thus prepared is preferably 1 to 50 mPa · s. When applying a liquid with an inkjet device described later, if the viscosity is less than 1 mPa · s, the peripheral part of the nozzle is likely to be contaminated by the outflow of ink, and if the viscosity is larger than 50 mPa · s, the eyes at the nozzle hole. This is because the clogging frequency becomes high and it becomes difficult to smoothly eject the droplets.

【0023】

Further, it is desirable that the surface tension of the fine particle dispersion thus prepared is in the range of 20 to 70 dyn / cm. When applying a liquid with an inkjet device described later, if the surface tension is less than 20 dyn / cm, the wettability of the ink composition to the nozzle surface increases and flight bending is likely to occur, and if it exceeds 70 dyn / cm, the nozzle This is because the shape of the meniscus at the tip is not stable, which makes it difficult to control the ejection amount and ejection timing of the ink composition.

【0024】

Further, the electro-optical device of the present invention is characterized by having a conductive film pattern formed by the method for forming a conductive film pattern of the present invention.

【0025】

Further, the electronic device of the present invention is characterized by including the above-mentioned electro-optical device of the present invention.

【0026】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a typical method for forming the conductive film pattern of the present invention will be described with reference to the drawings. The step of forming the conductive pattern is carried out in the following steps. A pattern forming step in which the self-assembling film 12 is formed on the entire surface of the substrate 11, the self-assembling film 12 is partially removed, and the parent liquid portion 11a and the liquid repellent portion 11b are formed in a predetermined pattern, a spin coating method. A step of selectively applying the fine particle dispersion liquid 14 to the parent liquid portion 11a by a method such as or an inkjet method, and a step of converting the applied fine particle dispersion liquid into a conductive film 16 by heat treatment.

【0027】

Liquid repellent part, parent liquid part pattern forming process First, as shown in FIG. 1, a self-assembled monolayer 12 made of the above-mentioned FAS or the like is formed on the surface of the substrate 11. In the self-assembled monolayer 12, the above-mentioned raw material compound (for example, heptadecafluoro-1,1,2,2 tetrahydrodecyltriethoxysilane) and the substrate are placed in the same closed container, and the temperature is 2 at room temperature. It is formed on the substrate when left for about 3 days. Further, by holding the entire closed container at about 100 ° C, it is formed on the substrate in about 3 hours. The above is the method of forming from the gas phase, but the self-assembled monolayer can also be formed from the liquid phase. For example, a self-assembled monolayer can be obtained on a substrate by immersing the substrate in a solvent containing a raw material compound, washing and drying the substrate.

【0028】

Then, as shown in FIG. 2, the self-assembled monolayer 12 is patterned according to the pattern of the conductive film to be formed later. The portion where the surface of the substrate is exposed becomes the parent liquid portion 11a which has wettability with respect to the liquid material, and the portion where the self-assembled monolayer 12 remains is the liquid repellent portion 11b which does not have wettability with respect to the liquid material. It becomes.

【0029】

As a method for patterning the self-assembled monolayer, an ultraviolet irradiation method, an electron beam irradiation method, an X-ray irradiation method, a scanning probe microscope (SPM) method and the like can be applied. In the present invention, the ultraviolet irradiation method is preferably used. In the ultraviolet irradiation method, as shown in FIG. 3, the self-assembled monolayer 12 is irradiated with ultraviolet light having a predetermined wavelength through a photomask 13 in which an opening for forming a pattern of the conductive film is formed. It is done by. By irradiating with ultraviolet light in this way, the molecules forming the self-assembled monolayer 12 are decomposed and removed, and patterning is performed. Therefore, in the ultraviolet irradiation method, the patterns of the parent liquid portion and the liquid repellent portion can be formed according to the patterns formed on the respective photomasks.

【0030】

The wavelength and irradiation time of the ultraviolet light adopted at this time are appropriately determined according to the raw material compound of the self-assembling film, but in the case of FAS, it is preferable to use ultraviolet rays having a wavelength of 310 nm or less, and a wavelength of 200 nm or less. It is more preferable to use the ultraviolet light of.

【0031】

Further, before the self-assembled monolayer is first formed on the entire surface of the substrate, it is desirable to perform pretreatment by irradiating the surface of the substrate with ultraviolet light or cleaning with a solvent.

【0032】

Further, if necessary, a second self-assembled film is formed only on the parent liquid portion of the substrate having the pattern of the parent liquid portion and the liquid repellent portion formed as described above to further enhance the liquidity property. Alternatively, it is possible to increase the adhesion between the substrate and the fine particles. To form the second self-assembled monolayer, for example, the substrate having the above-mentioned parent liquid part and liquid repellent part patterns is immersed in a 2% ethanol solution of 3-mercaptopropyltriethoxysilane for 5 minutes. In this way, a second self-assembled monolayer having a thiol group on the surface is formed only in the parent liquid portion.

【0033】

Selective coating process of fine particle dispersion Next, the fine particle dispersion liquid is selectively applied only to the parent liquid portion 11a of the substrate on which the self-assembled monolayer is patterned. As a coating method, a spin coating method, a roll coating method, a curtain coating method, a dip coating method, a spray method, an inkjet method, or the like can be used. When the spin coating method is used, the rotation speed of the spinner is determined by the required film thickness of the conductive film, the solid content concentration and viscosity of the fine particle dispersion, but is generally 100 rpm to 5000 rpm, preferably 300 rpm to 3000 rpm.

【0034】

Further, it is particularly preferable to use the inkjet method as the method for applying the fine particle dispersion liquid of the present invention. This is because the required amount can be applied only to the parent liquid portion 11a. As a result, unlike the case of the spin coating method, the film thickness can be easily controlled by controlling the discharge amount, and a film composed of fine particles of different film thickness or different material is formed in different places on the substrate. It becomes possible to do. In addition, since it is applied only to the required place, there is an advantage that the amount of material used can be reduced. In addition, the patterns of the parent liquid part and the liquid repellent part on the substrate have the same effect as the bank formed by photolithography, and the droplets ejected to the parent liquid part by the inkjet method do not come out from the parent liquid part. However, the position will be controlled precisely.

【0035】

The inkjet type droplet ejection device used in the present invention may have any mechanism as long as it can eject a certain amount of arbitrary droplets, and particularly uses a piezoelectric element capable of forming and ejecting droplets of about several tens of ng. It does not matter which method is used, such as the inkjet method that has been used, or the bubble jet (registered trademark) method that uses the heat energy of the heater to generate bubbles. Further, if necessary, general coating methods such as the above spin coating, dip coating, spray coating, roll coating, and curtain coating can be combined.

【0036】

The process of converting the coating film into a conductive film by heat treatment The substrate to which the fine particle dispersion liquid is selectively applied is subjected to heat treatment in order to remove the solvent and improve the electrical contact between the fine particles. The heat treatment is usually carried out in the atmosphere, but if necessary, it can also be carried out in an atmosphere of an inert gas such as nitrogen, argon or helium. The treatment temperature of the above heat treatment may be appropriately determined depending on the boiling point (vapor pressure) of the solvent, the pressure and the thermal behavior of the fine particles, and is not particularly limited, but is preferably performed at room temperature or higher and 300 ° C or lower. In particular, in terms of being able to use a wide range of substrates such as plastic, it is particularly desirable to carry out the test at room temperature to 100 ° C or lower.

【0037】

Further, the heat treatment can be performed by lamp annealing in addition to the treatment in a normal hot plate, electric furnace, or the like. The light source of light used for lamp annealing is not particularly limited, but is limited to infrared lamps, xenon lamps, YAG lasers, argon lasers, carbon dioxide lasers, XeF, XeCl, XeBr, KrF, KrCl, ArF, ArCl and other excimer lasers. Can be used as a light source. Generally, these light sources have an output of 10 to 5000 W, but 100 to 1000 W is usually sufficient.

【0038】

FIG. 7 is a plan view showing a part of a matrix type display device, which is an example of an electro-optic device having a conductive film pattern obtained by using the method for forming a conductive film pattern of the present embodiment.

【0039】

In FIG. 7, reference numeral 131 is a scanning line, 142 is a first thin film transistor, and 143 is a second thin film transistor. The first thin film transistor 142 transmits the potential of the signal line 132 to the second thin film transistor 143 according to the potential of the scanning line 131, and the second thin film transistor 143 conducts the common line 133 and the pixel electrode 141. Control.

【0040】

In the example of this matrix type display device, wiring patterns such as scanning lines 131, signal lines 132, and common lines 133 are formed by using the method for forming a conductive film pattern of the above embodiment. That is, the pattern of the parent liquid portion 11a in the above embodiment is formed according to the pattern shape of the scanning line 131, the signal line 132, the common line 133, and the like, and these wirings are formed in the portion of the parent liquid portion 11a.

【0041】

<Electronic Equipment> Next, as an example of the above-mentioned electro-optical device, some examples of using a matrix type display device for a specific electronic device will be described.

【0042】

<Part 1: Mobile Computer> First, an example in which the matrix type display device according to this embodiment is applied to a mobile personal computer will be described. FIG. 8 is a perspective view showing the configuration of this personal computer. In the figure, the personal computer 1100 is composed of a main body 1104 having a keyboard 1102 and a matrix type display unit 1106. The matrix type display unit 1106 has a matrix type display panel 100.

【0043】

<Part 2: Mobile phone> Next, an example in which the matrix type display device is applied to the display unit of the mobile phone will be described. FIG. 9 is a perspective view showing the configuration of this mobile phone. In the figure, the mobile phone 1200 includes the above-mentioned matrix type display panel 100 together with the earpiece 1204 and the mouthpiece 1206 in addition to the plurality of operation buttons 1202.

【0044】

<Part 3: Digital Still Camera> Further, a digital still camera using a matrix type display device as a finder will be described. FIG. 10 is a perspective view showing the configuration of this digital still camera, but also briefly shows the connection with an external device.

【0045】

While a normal camera exposes the film to the light image of the subject, the digital still camera 1300 generates an image pickup signal by photoelectrically converting the light image of the subject with an image sensor such as a CCD (Charge Coupled Device). Is. Here, the display panel 100 described above is provided on the back surface of the case 1302 in the digital still camera 1300, and the display is performed based on the image pickup signal by the CCD. Therefore, the display panel 100 functions as a finder for displaying the subject. Further, on the observation side (back side in the figure) of the case 1302, a light receiving unit 1304 including an optical lens, a CCD, and the like is provided.

【0046】

Here, when the photographer confirms the subject image displayed on the display panel 100 and presses the shutter button 1306, the image pickup signal of the CCD at that time is transferred and stored in the memory of the circuit board 1308. Further, in this digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. Then, as shown in the figure, a TV monitor 1430 is connected to the video signal output terminal 1312 of the former, and a personal computer 1430 is connected to the input / output terminal 1314 for data communication of the latter, respectively, as needed. .. Further, the imaging signal stored in the memory of the circuit board 1308 is output to the television monitor 1430 and the personal computer 1440 by a predetermined operation.

【0047】

In addition to the personal computer shown in FIG. 8, the mobile phone shown in FIG. 9, and the digital still camera shown in FIG. 10, the electronic devices include an LCD TV, a viewfinder type, a monitor direct view type video tape recorder, and a car navigation device. , Pagers, electronic organizers, calculators, word processors, workstations, videophones, POS terminals, devices equipped with touch panels, etc. Needless to say, the above-mentioned display device can be applied as a display unit of these various electronic devices.

【0048】

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

【0049】

[Example]

Hereinafter, the present invention will be specifically described with reference to Examples.

【0050】

(Example 1) The glass substrate was cleaned by irradiating the glass substrate with ultraviolet light having a wavelength of 172 nm at 10 mW for 10 minutes as a pretreatment. Next, in order to form a liquid-repellent self-assembled monolayer on the entire surface of the substrate, the glass substrate and 0.5 ml of tridecafluoro-1,1,2,2 tetrahydrooctylliethoxysilane are placed in the same closed container. A self-assembled monolayer having a fluoroalkyl group on its surface was formed on the glass substrate by placing it in a glass substrate and leaving it at room temperature for 48 hours. Then, ultraviolet light having a wavelength of 172 nm is irradiated with ultraviolet light having a wavelength of 10 mW for 10 minutes through a photomask having a predetermined pattern to selectively remove only the self-assembled film in the unmasked portion. , A parent liquid portion and a liquid repellent portion were formed.

【0051】

Here, the details of the photomask used are as follows. The substrate is made of quartz and transmits about 60% of ultraviolet light having a wavelength of 172 nm. It is a linear pattern called line and space, with a line width of 30 μm and a line spacing of 20 μm. The pattern is made of a chrome film, and ultraviolet light is blocked by the chrome film. In addition, four alignment marks are provided around the photomask for alignment in the case of droplet coating by the inkjet method described later.

【0052】

Next, in order to form a second self-assembled monolayer having a thiol group on the surface in the portion where the liquid-repellent self-assembled monolayer was removed and became pro-liquid, 3-mercaptopropyltriethoxysilane was added. The above substrate was immersed in a 2% ethanol solution for 5 minutes and then washed with ethanol. As a result, a self-assembled monolayer having a thiol group on the surface was formed only in the parent liquid portion.

【0053】

Next, a liquid (manufactured by Vacuum Metallurgical Co., Ltd., trade name "Perfect Gold") in which fine gold particles having a particle size of 10 nm are dispersed in α-terpineol is spun on a substrate in which the above-mentioned parent liquid part and liquid repellent part are patterned. When coated, the liquid remained only in the parent liquid portion, and no liquid remained in the liquid repellent portion. When this substrate was fired in the air at 300 ° C. for 15 minutes, the liquid applied to the parent liquid part became a gold thin film, and a line pattern of a gold thin film with a width of 30 μm was formed according to the pattern of the photomask. Was done. The film thickness of this gold thin film is 0.5 μm, and the specific resistance is 2 × 10.^-5It was Ωcm.

【0054】

(Example 2) Heptadecafluoro-1,1,2,2 tetrahydro as a material for forming a liquid-repellent self-assembled monolayer after cleaning the glass substrate in the same process as in Example 1. Using decyltriethoxysilane, a liquid-repellent self-assembled monolayer having a fluoroalkyl group on the surface was formed on the entire surface of the substrate in the same process as in Example 1. Then, the same ultraviolet irradiation was performed through the same photomask as in Example 1 to form a pattern of a liquid-repellent part and a parent-liquid part.

【0055】

Next, the above substrate was immersed in a 2% ethanol solution of 3-aminopropyltriethoxysilane for 5 minutes in order to form a second self-assembled monolayer having an amino group on the surface of the parent solution. Then, it was washed with ethanol. As a result, a self-assembled monolayer having an amino group on the surface was formed only in the parent liquid portion.

【0056】

The silver fine particle dispersion liquid to be applied to the parent liquid portion of the substrate thus formed was adjusted as follows. First, 90 mg of silver nitrate was dissolved in 500 ml of water, heated to 100 ° C., 10 ml of a 1% aqueous sodium citrate solution was added while stirring, and the mixture was boiled for 80 minutes. As a result, a liquid in which silver colloid covered with citric acid for preventing aggregation was dispersed in an aqueous solution was obtained. The average particle size of this silver colloid was 30 nm. After concentrating this liquid by centrifugation, water and a surface tension adjuster were added again to make ink, and the viscosity and surface tension were adjusted so that the ink jet head could eject the liquid.

【0057】

The above-inked fine particle dispersion was drawn along the line of the parent liquid formed on the substrate using a commercially available printer (trade name MJ930C) head as an inkjet head. At that time, the position accuracy of discharge is about 30 μm, and there are droplets that are discharged so as to protrude from the line of the parent liquid part with a width of 30 μm, but the part off the line is liquid-repellent, so it is liquid-repellent. All the droplets protruding from the part moved to the original parent liquid part, and the liquid could be selectively applied only on the line of the parent liquid part. When this was dried at room temperature for 1 hour, a solid silver colloid was precipitated only on the line of the parent liquid part, but the surface of the silver colloid was covered with organic matter and had a copper luster, and most of the electrical conduction was There wasn't.

【0058】

Furthermore, when this substrate was irradiated with a 500 W xenon lamp for 60 seconds, organic substances on the surface of the silver colloid were removed, and a silver-glossy conductive pattern was formed. The film thickness is about 0.1 μm and the resistivity is about 5 × 10.^-4It was Ωcm.

【0059】

[Effect of the invention]

As described above, according to the present invention, it is possible to provide a conductive film patterning technique having micron-order accuracy by a simple process without the need for photolithography and etching steps such as development and rinsing.

[Simple explanation of drawings]

[Figure 1]

Sectional drawing of the self-assembled monolayer formed on the substrate.

[Figure 2]

The cross-sectional view which shows the process of the patterning of the self-assembled monolayer.

[Fig. 3]

A cross-sectional view showing a state in which the self-assembled monolayer is patterned.

[Fig. 4]

The cross-sectional view which shows the state which the fine particle dispersion liquid was applied only to the parent liquid part of a substrate.

[Fig. 5]

The cross-sectional view of the coating film formed in the parent liquid part after the solution was dried.

[Fig. 6]

FIG. 3 is a cross-sectional view of a conductive film formed by heat-treating a coating film of a fine particle dispersion liquid.

[Fig. 7]

It is a top view of the matrix type display device obtained by using the method of forming a conductive film pattern of this invention.

[Fig. 8]

It is a perspective view which shows the structure of the personal computer which is an example of the electronic device of this invention.

[Fig. 9]

It is a perspective view which shows the structure of the mobile phone which is an example of the electronic device.

[Fig. 10]

It is a perspective view which shows the structure of the back side of the digital still camera which is an example of the electronic device.

[Explanation of symbols]

11 board 11a Parent fluid part 11b Liquid repellent part 12 Self-assembled monolayer 13 photomask 14 Fine particle dispersion 15 Coating film of fine particle dispersion 16 Conductive 17 UV light