JP2006061841A - Method and apparatus for coating liquid material, electro-optical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of coating a liquid material ensuring precision of the height and giving sharp columns of a fine diameter. <P>SOLUTION: A liquid material L is discharged from a nozzle 25 of a discharging head 1 in columnar form and applied onto a substrate P. The method has a process of imparting light energy to the coated liquid material L. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid material coating method, a liquid material coating device, an electro-optical device, and an electronic apparatus.

In recent years, as a coating technique used in the manufacturing process of an electronic device, the use of a liquid ejection method tends to expand. In general, the coating technique using the liquid ejection method ejects a liquid as droplets from a plurality of nozzles provided in the liquid ejection head while relatively moving the substrate and the liquid ejection head, and the droplets are ejected onto the substrate. Compared to conventional coating techniques such as spin coating, there is less waste in the consumption of liquid material, and any pattern can be applied directly without using means such as photolithography. It has the advantage that it can be done.
In addition, as a method of discharging a liquid and applying it to a substrate, the liquid is discharged in a columnar shape to improve the accuracy of the adhesion position on the substrate (for example, see Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 4-129746 JP-A-9-101411

However, the following problems exist in the conventional technology as described above.
For example, it is conceivable to use the columnar body as a gap material for determining a cell gap in a liquid crystal display device. In this case, the diameter of the columnar body is fine and the accuracy of the height is also required. This coating method does not form a columnar body on the substrate by simply discharging the liquid in a columnar shape and adhering it to the substrate. Therefore, as described above, the fine diameter and height accuracy required for the columnar body are ensured. It is extremely difficult to do. In particular, when the liquid is ejected in a columnar shape, the height and diameter become unstable due to the spread of wetting, which makes it difficult to control and makes it difficult to form a sharp columnar body.

  The present invention has been made in consideration of the above points. The liquid coating method, the liquid coating apparatus, and the coating method that can secure the height accuracy and obtain a sharp columnar body with a fine diameter are provided. It is an object to provide a manufactured electro-optical device and electronic apparatus.

In order to achieve the above object, the present invention employs the following configuration.
The liquid material application method of the present invention is a liquid material application method in which a liquid material is discharged in a columnar shape from a nozzle of an ejection head and applied to a substrate, and includes a step of applying light energy to the applied liquid material. It is a feature.

  Therefore, in the liquid material coating method of the present invention, by applying light energy to the applied liquid material, the liquid material can be fixed by drying or baking without spreading. Therefore, it is possible to make the columnar body a columnar body having a fine diameter, and by controlling the gap between the nozzle and the substrate, the wettability (surface energy) of the substrate, the surface tension and elasticity of the liquid material, It becomes possible to ensure height accuracy and diameter.

For the liquid material applied to the substrate, a procedure of applying the light energy while separating the discharge head and the substrate can be suitably employed.
Thereby, since the front-end | tip of a columnar body is pulled and becomes thin, a sharp columnar body can be obtained as a result.

The time from application of the liquid material to application of the light energy is based on the surface energy of the discharged liquid material, more specifically, the surface of the liquid material at the landing site (application position). It is preferable that the time is set so that the light energy can be applied before spreading according to energy.
In this case, the liquid material is fixed while the diameter is small, and a columnar body having a fine diameter can be easily obtained.
Even when the coating position is lyophilic, the liquid material is fixed while the diameter is small, so it is possible to form a columnar body having a fine diameter without depending on the surface energy at the coating position. In particular, the adhesion between the substrate or the like and the columnar body can be enhanced by applying the liquid material to the lyophilic application position having a large surface energy.

Moreover, in this invention, it is suitable to set the application amount of the said light energy according to the material of the application position of the said liquid.
In this case, for example, the reflectance of light differs between the case where the application position of the liquid material is the substrate and the case where it is another member (for example, wiring or electronic element) provided on the substrate, and light is irradiated with the same amount of energy. Even if the amount of light energy applied to the liquid is different, the amount of energy actually applied to the liquid can be made constant by setting the amount of light energy applied according to the material at the application position. Is possible.

Moreover, in this invention, the procedure which has the process of detecting the diameter of the apply | coated liquid substance, and the process of adjusting the application position of the said light energy based on the detected said diameter is employable suitably.
Thereby, when the liquid material is applied, light energy can be applied at an appropriate position corresponding to the desired height, and the height accuracy with respect to the columnar body can be further improved. As a method of detecting the diameter of the liquid material, a method of installing a photodetector, a method of detecting the spread of reflected light, a method of detecting the distribution of diffracted light, and the like can be used.

The liquid material preferably contains a photothermal conversion material.
With this configuration, the applied light energy can be effectively converted into heat energy, and the liquid can be efficiently dried or fired. A known material can be used as the photothermal conversion material, and it is not particularly limited as long as it is a material that can efficiently convert light into heat. For example, a metal layer made of aluminum, its oxide and / or its sulfide, And an organic layer made of a polymer to which carbon black, graphite, an infrared absorbing dye, or the like is added. Examples of the infrared absorbing dye include anthraquinone series, dithiol nickel complex series, cyanine series, azocobalt complex series, diimmonium series, squarilium series, phthalocyanine series, and naphthalocyanine series. Alternatively, a synthetic resin such as an epoxy resin may be used as a binder, and the photothermal conversion material may be dissolved or dispersed in the binder resin.

On the other hand, the electro-optical device of the present invention is an electro-optical device that is manufactured using a columnar body with an electro-optical layer sandwiched between a pair of substrates, and the columnar body is formed by the above-described liquid material coating method. It is characterized by forming.
Therefore, according to the present invention, an electro-optical device having a columnar body having a fine diameter and a desired height accuracy can be obtained.

  As the columnar body, a gap is formed between the pair of substrates and a mask portion for forming a conductive portion provided on the substrate and electrically connecting the first conductive portion and the second conductive portion sandwiching the insulating portion. It can be at least one of a spacer and a partition wall provided around the pixel portion. Thereby, in this invention, it becomes possible to form the mask part, spacer, and partition which have a desired height accuracy with a fine diameter.

In addition, the columnar body may have a pair of electrodes and a protrusion that is provided on one of the electrodes and emits electrons.
Accordingly, in the present invention, it is possible to form a protrusion (for example, a cathode of a field emission device (FED)) having a fine diameter and a desired height accuracy.

The electronic apparatus according to the present invention includes the above-described electro-optical device as a display unit.
Thereby, in this invention, it becomes possible to obtain the electronic device excellent in display quality.

Hereinafter, embodiments of a liquid material coating method, a liquid material coating apparatus, an electro-optical device, and an electronic apparatus according to the present invention will be described with reference to FIGS.
(First embodiment)
First, the liquid material coating apparatus according to the present invention will be described.
As this liquid material coating device, a liquid material ejection device (inkjet device) that ejects a liquid material (droplet) from a ejection head and applies the material to a substrate is used.

FIG. 1 is a perspective view showing a schematic configuration of the droplet discharge device IJ.
A droplet discharge device (droplet application device) IJ includes an discharge head 1, an X-axis direction drive shaft 4, a Y-axis direction guide shaft 5, a control device CONT, a stage 7, a cleaning mechanism 8, and a base. 9 and a heater 15.
The stage 7 supports the substrate P on which ink (liquid material) is provided by the droplet discharge device IJ, and includes a fixing mechanism (not shown) that fixes the substrate P at a reference position.

  The discharge head 1 is a multi-nozzle type discharge head having a plurality of discharge nozzles, and the longitudinal direction and the Y-axis direction are matched. The plurality of discharge nozzles are provided on the lower surface of the discharge head 1 along the Y-axis direction at regular intervals. Ink is ejected from the ejection nozzles of the ejection head 1 onto the substrate P supported by the stage 7. In addition, the ejection head 1 is configured to move in the direction of separating and approaching the substrate P, that is, the vertical direction under the control of the control device CONT.

An X-axis direction drive motor 2 is connected to the X-axis direction drive shaft 4. The X-axis direction drive motor 2 is a stepping motor or the like, and rotates the X-axis direction drive shaft 4 when a drive signal in the X-axis direction is supplied from the control device CONT. When the X-axis direction drive shaft 4 rotates, the ejection head 1 moves in the X-axis direction.
The Y-axis direction guide shaft 5 is fixed so as not to move with respect to the base 9. The stage 7 includes a Y-axis direction drive motor 3. The Y-axis direction drive motor 3 is a stepping motor or the like, and moves the stage 7 in the Y-axis direction when a drive signal in the Y-axis direction is supplied from the control device CONT.

The control device CONT supplies the discharge head 1 with a voltage for controlling droplet discharge. Further, a drive pulse signal for controlling the movement of the ejection head 1 in the X-axis direction is supplied to the X-axis direction drive motor 2, and a drive pulse signal for controlling the movement of the stage 7 in the Y-axis direction is supplied to the Y-axis direction drive motor 3. .
The cleaning mechanism 8 cleans the ejection head 1. The cleaning mechanism 8 is provided with a Y-axis direction drive motor (not shown). By driving the drive motor in the Y-axis direction, the cleaning mechanism moves along the Y-axis direction guide shaft 5. The movement of the cleaning mechanism 8 is also controlled by the control device CONT.
Here, the heater 15 is a means for heat-treating the substrate P by lamp annealing, and performs evaporation and drying of the solvent contained in the liquid material applied on the substrate P. The heater 15 is also turned on and off by the control device CONT.

  The droplet discharge device IJ discharges droplets onto the substrate P while relatively scanning the discharge head 1 and the stage 7 that supports the substrate P. Here, in the following description, the Y-axis direction is a scanning direction, and the X-axis direction orthogonal to the Y-axis direction is a non-scanning direction. Accordingly, the discharge nozzles of the discharge head 1 are provided side by side at regular intervals in the X-axis direction, which is the non-scanning direction. In FIG. 1, the ejection head 1 is disposed at a right angle to the traveling direction of the substrate P. However, the angle of the ejection head 1 may be adjusted so as to intersect the traveling direction of the substrate P. . In this way, the pitch between the nozzles can be adjusted by adjusting the angle of the ejection head 1. Further, the distance between the substrate P and the nozzle surface may be arbitrarily adjusted.

Examples of the discharge technique of the droplet discharge method include a charge control method, a pressure vibration method, an electromechanical conversion method, an electrothermal conversion method, and an electrostatic suction method. In the charge control method, a charge is applied to a material by a charging electrode, and the flight direction of the material is controlled by a deflection electrode and discharged from a nozzle. In addition, the pressure vibration method is a method in which a high pressure of about 3 × 10 ⁵ Pa is applied to the material and the material is discharged to the nozzle tip side. When no control voltage is applied, the material goes straight and is discharged from the nozzle. When a control voltage is applied, electrostatic repulsion occurs between the materials, and the materials are scattered and are not discharged from the nozzle. The electromechanical conversion method utilizes the property that a piezoelectric element (piezoelectric element) is deformed by receiving a pulse-like electric signal. The piezoelectric element is deformed through a flexible substance in a space where material is stored. Pressure is applied, and the material is extruded from this space and discharged from the nozzle.

FIG. 2 is a diagram for explaining the principle of discharging a liquid material by a piezo method.
In FIG. 2, a piezo element 22 is installed adjacent to a liquid chamber 21 that stores a liquid material (functional liquid). The liquid material is supplied to the liquid chamber 21 via a liquid material supply system 23 including a material tank that stores the liquid material. The piezo element 22 is connected to a drive circuit 24, and a voltage is applied to the piezo element 22 via the drive circuit 24 to deform the piezo element 22, whereby the liquid chamber 21 is deformed and the liquid material is discharged from the nozzle 25. Is discharged. In this case, the amount of distortion of the piezo element 22 is controlled by changing the value of the applied voltage with a predetermined drive waveform. Further, the strain rate of the piezo element 22 is controlled by changing the frequency of the applied voltage.
As a droplet discharge method, a bubble (thermal) method in which a liquid material is discharged by bubbles generated by heating the liquid material can be adopted. However, droplet discharge by the piezo method applies heat to the material. Therefore, there is an advantage that the composition of the material is hardly affected.

Further, in the present embodiment, as shown in FIG. 3A, the photodetector 11 is provided on one side of the ejection head 1 in the scanning direction, and is located on the other side of the ejection head 1 in the scanning direction. A laser light source 12 is provided for each of a plurality of nozzles. The photodetector 11 detects the diameter of the liquid material (columnar body) applied in a liquid column shape by irradiating the detection light directly below the ejection head 1 and detecting the reflected light. The detection result is output to the control device CONT.
As a method for detecting the diameter of the columnar body, a method for examining the spread of reflected light, a method for examining the distribution of diffracted light, or the like may be used.

  The laser light source 12 irradiates laser light with oblique incidence toward the lower side of the ejection head 1 under the control of the control device CONT, and an optical element (not shown) for condensing the laser light is provided inside. Is provided. The control device CONT is configured to be able to adjust the focal position of the laser beam, that is, the optical energy application position by the laser beam, by adjusting the position of the optical element. In this embodiment, in order to effectively apply light energy to a droplet having a small diameter, a beam profile in which the light intensity at the center of the beam is increased as shown in FIG.

Next, a method for applying a liquid material to a substrate using the liquid material applying apparatus IJ will be described.
In the liquid material coating method of this embodiment, first, after the substrate P is moved and positioned to the position where the columnar body is to be formed with respect to the ejection head 1, the liquid material is ejected from the ejection head 1 of the coating apparatus IJ in a liquid column shape. Then, it is applied to the substrate P and immediately irradiated with laser light from the laser light source 12.

As laser light, YAG laser (YAG fundamental wave; wavelength 1064 nm), YAG laser (YAG double wave; wavelength 532 nm), semiconductor laser (wavelength 808 nm), He—Cd laser (wavelength 442 nm), He—Cd laser (Wavelength 325 nm), YVO ₄ laser (wavelength 266 nm), or the like can be used. Here, a YAG laser (Gaussian beam having a beam diameter of about 20 μm) is used. The substrate P is given lyophilicity (high surface energy) in advance by ultraviolet irradiation treatment, O ₂ plasma treatment or the like in order to improve the adhesion with the ink.
Here, it is assumed that a plurality of nozzles 25 are arranged in a direction perpendicular to the paper surface of FIG. 3 according to the position of the columnar body to be formed.

Hereinafter, the case where the drive voltage of the waveform W1 shown in FIG. 5 is applied to the piezo element 22 from the drive circuit 24 will be described.
First, when the drive voltage is a positive gradient portion a1, the piezoelectric element 22 contracts to increase the volume of the liquid chamber 21, and the liquid material flows into the liquid chamber 21 from the liquid material supply system 23.

Next, in the negative gradient portion a <b> 2, the piezo element 22 expands to reduce the volume of the liquid chamber 21, and the pressurized liquid material is discharged from the nozzle 25.
Here, if the liquid is, for example, a UV curable resin, a monomer / oligomer mixed solution is used. By adding a polymer such as polyethylene glycol, polystyrene, or polydimethylacrylamide (PDMAA) to this liquid, its elastic modulus is used. Adjust. As a result, the length of the liquid column becomes longer, so the concentration and the molecular weight of the polymer are adjusted in advance so that the desired length is obtained. In this embodiment, about 0.7% by weight of PDMAA having a molecular weight of about 380,000 was added. Thereby, as shown in FIG. 6, the liquid L discharged from the nozzle 25 is discharged in the form of a liquid column without tearing in the middle.

Further, when the conductive columnar body is formed from a liquid, for example, an Ag aqueous dispersion ink or an Ag organic dispersion ink can be used.
In this embodiment, ink droplets containing a photothermal conversion material are ejected. Examples of the photothermal conversion material include a metal layer made of aluminum, an oxide thereof and / or a sulfide thereof, and an organic layer made of a polymer to which carbon black, graphite or an infrared absorbing dye is added. Examples of the infrared absorbing dye include anthraquinone series, dithiol nickel complex series, cyanine series, azocobalt complex series, diimmonium series, squarilium series, phthalocyanine series, and naphthalocyanine series. Alternatively, a synthetic resin such as an epoxy resin may be used as a binder, and the photothermal conversion material may be dissolved or dispersed in the binder resin.

The liquid columnar liquid ejected from the nozzle 25 reaches the surface of the substrate P at the tip. Here, since the surface of the substrate P is made lyophilic, the liquid L (the tip portion thereof) is after a certain time or a time corresponding to the surface energy of the liquid (for example, about 20 microseconds) has elapsed. It begins to spread and spreads over several tens of milliseconds until it reaches a contact angle corresponding to the surface energy of the substrate P and the surface energy of the liquid material. Since this time is known, before the liquid material L wets and spreads on the surface of the substrate P, the control device CONT applies laser light (for example, 1.0 W / mm) from the laser light source 12 as shown in FIG. ² is irradiated for 1 millisecond). The liquid L to which light energy is applied by laser light irradiation is dried or fired. In particular, since the liquid L contains a photothermal conversion material, the applied energy is efficiently converted into heat, so that the liquid L can be effectively applied with heat and dried or fired. it can.
When forming a columnar body with a liquid material, if a desired strength is required for the columnar body, laser light irradiation is performed until the tip of the liquid material L (the base portion of the columnar body) reaches a predetermined size. May be delayed.

  Thereafter, in the positive gradient portion a3 of the drive voltage, the piezoelectric element 22 contracts and the volume of the liquid chamber 21 increases. As a result, the liquid columnar liquid discharged from the nozzle 25 is drawn into the liquid chamber 21. At this time, the control device CONT raises the ejection head 1 and separates it from the substrate P. As a result, the supply amount of the liquid material to the substrate P is reduced, and the lower end portion of the liquid material L is dried and baked and fixed, so that the upper end portion of the liquid material L becomes thin and torn. As shown in b), a columnar body T having a sharp upper end is formed.

  At this time, since the position (condensing position) where the laser beam should be irradiated becomes higher along the liquid L, the controller CONT uses the laser light source 12 based on the diameter of the liquid L detected by the photodetector 11. The focal position of the laser beam (light energy application position) is moved upward along the liquid L. As a result, the entire liquid L can be irradiated with laser light, and a fixed columnar body T can be formed.

  Further, when controlling the size (relationship between the height and the diameter) of the columnar body T, the laser beam may be irradiated when the diameter at the height detected by the photodetector 11 reaches a predetermined value. . Thereby, the columnar body T having a desired cross-sectional shape can be formed.

Further, since the liquid material L is applied in contact with only the front end portion on the substrate P, the reflectance at the laser irradiation point differs between the front end portion and the upper portion (portion other than the front end) due to the difference in the base. Therefore, if light energy equivalent to that of the tip portion is applied to the liquid L in the upper portion, there is a possibility that the heat applied to the upper portion is large and evaporates. Therefore, the control device CONT applies a smaller light energy (for example, 0.5 W / mm ² for 1 millisecond) to the liquid material in the upper portion than the tip portion. The amount of light energy applied is set according to the material.
In this way, the sharp columnar body T can be erected on the substrate P by applying light energy to the liquid L and drying or baking.

As described above, in the present embodiment, since light energy is applied to the applied liquid L and immediately fixed, the height accuracy is ensured and the sharp columnar body T can be easily formed. In particular, in the present embodiment, since the laser beam is irradiated while pulling up the ejection head 1, the tip of the columnar body T can be easily sharpened.
Further, since the thickness (diameter) of the columnar body T is a diameter of a droplet discharge method capable of managing the liquid L to be discharged with high accuracy, it is possible to easily form the columnar body T having a fine diameter. . In addition, in this embodiment, since the liquid L is fixed by irradiating the laser beam based on the diameter of the liquid L detected by the photodetector 11, the diameter of the columnar body T is also controlled with high accuracy. Is possible.

  Further, in the present embodiment, the time from application of the liquid L to application of light energy is based on the surface energy of the landing site (application position) of the liquid L before the liquid L spreads out. Since it is set, the columnar body T having a fine diameter can be formed even if the application position is lyophilic. Therefore, it is possible to form the columnar body T having high adhesion to the substrate P.

  Moreover, in this embodiment, the amount of light energy applied is adjusted according to the material at the application position of the droplet L, so that the applied liquid L does not cause inconveniences and the desired shape is not produced. The columnar body T can be formed stably. Furthermore, in this embodiment, since the light-to-heat conversion material is contained in the droplet L, it is possible to effectively convert light energy into heat energy, and efficiently fix the applied droplet. Can do.

(Second Embodiment)
Subsequently, a liquid crystal display device (electro-optical device) manufactured by the liquid material coating method will be described.
First, a schematic configuration of the liquid crystal display device will be described with reference to FIGS. FIG. 7 is an exploded perspective view of the liquid crystal display device, and FIG. 8 is a side sectional view taken along line AA of FIG. As shown in FIG. 8, a liquid crystal display device (electro-optical device) 101 is configured by sandwiching a liquid crystal layer (electro-optical layer) 102 between a lower substrate (counter substrate) 70 and an upper substrate (element substrate) 80. . A nematic liquid crystal or the like is employed for the liquid crystal layer 102, and a twisted nematic (TN) mode is employed as an operation mode of the liquid crystal display device 101. Note that liquid crystal materials other than those described above can be employed, and operation modes other than those described above can be employed. Hereinafter, an active matrix liquid crystal display device using a TFD element as a switching element will be described as an example. However, the present invention is applied to other active matrix liquid crystal display devices and passive matrix liquid crystal display devices. It is also possible to apply.

As shown in FIG. 7, in the liquid crystal display device 101, a lower substrate 70 and an upper substrate 80 made of a transparent material such as glass are disposed to face each other. A plurality of scanning lines 81 are formed inside the upper substrate 80. A plurality of pixel electrodes 82 made of a transparent conductive material such as ITO are arranged in a matrix on the side of the scanning line 81. The pixel electrode 82 is connected to each scanning line 81 via the TFD element 83. The TFD element 83 includes a first conductive film mainly composed of Ta formed on the surface of the substrate, an insulating film mainly composed of Ta ₂ O ₃ formed on the surface of the first conductive film, and an insulation thereof. A second conductive film mainly composed of Cr formed on the surface of the film (so-called MIM structure). The first conductive film is connected to the scanning line 81, and the second conductive film is connected to the pixel electrode 82. Accordingly, the TFD element 83 functions as a switching element that controls energization to the pixel electrode 82.

  On the other hand, a plurality of counter electrodes 72 made of a transparent conductive material such as ITO are formed inside the lower substrate 70. The counter electrode 72 is formed in a stripe shape orthogonal to the scanning line 81. When a scanning signal is supplied to the scanning line 81 and a data signal is supplied to the counter electrode 72, an electric field is applied to the liquid crystal layer by the opposing pixel electrode 82 and counter electrode 72. Therefore, a pixel region is constituted by the formation region of each pixel electrode 82.

  A light shielding film 77 called a black matrix is formed on the inner side of the lower substrate 70 in order to prevent light leakage from adjacent pixel regions. The light shielding film 77 is made of black metal chrome having light absorptivity. The light-shielding film 77 includes a plurality of openings 78 corresponding to the respective pixel areas. The openings 78 enable light source light to enter the image area or emit image light from the image area. Yes. A transparent insulating film 79 shown in FIG. 7 is formed so as to cover the light shielding film 77. Further, the counter electrode 72 described above is formed inside the insulating film 79.

  In addition, alignment films 74 and 84 are formed so as to cover the pixel electrode 82 and the counter electrode 72. The alignment films 74 and 84 control the alignment state of the liquid crystal molecules when no electric field is applied, and are made of an organic polymer material such as polyimide, and the surface thereof is rubbed. As a result, when no electric field is applied, the liquid crystal molecules in the vicinity of the surfaces of the alignment films 74 and 84 are aligned substantially parallel to the alignment films 74 and 84 with the major axis direction coinciding with the rubbing treatment direction. . The alignment films 74 and 84 are rubbed so that the alignment direction of the liquid crystal molecules near the surface of the alignment film 74 and the alignment direction of the liquid crystal molecules near the surface of the alignment film 84 are shifted by a predetermined angle. It has been subjected. As a result, the liquid crystal molecules constituting the liquid crystal layer 102 are spirally stacked along the thickness direction of the liquid crystal layer 102.

  Further, the peripheral portions of the substrates 70 and 80 are joined by a sealing material 103 made of an adhesive such as a thermosetting type or an ultraviolet curable type. The liquid crystal layer 102 is sealed in a space surrounded by the substrates 70 and 80 and the sealing material 103. The thickness (cell gap, gap) of the liquid crystal layer 102 is regulated by the spacer 105 disposed between the substrates 70 and 80. Here, the spacer 105 is made of UV curable resin and has a height of about 5 μm on the light shielding film 77 using the above-described liquid material coating method.

On the other hand, a polarizing plate (not shown) is disposed outside the lower substrate 70 and the upper substrate 80.
Each polarizing plate is arranged in a state in which the mutual polarization axes (transmission axes) are shifted by a predetermined angle. Further, a backlight (not shown) is disposed outside the incident side polarizing plate.
The light emitted from the backlight is converted into linearly polarized light along the polarization axis of the incident-side polarizing plate and enters the liquid crystal layer 102 from the lower substrate 70. This linearly polarized light is rotated by a predetermined angle along the twist direction of the liquid crystal molecules in the process of passing through the liquid crystal layer 102 without application of an electric field, and is transmitted through the output side polarizing plate. Thereby, white display is performed when no electric field is applied (normally white mode). On the other hand, when an electric field is applied to the liquid crystal layer 102, the liquid crystal molecules are reoriented perpendicularly to the alignment films 74 and 84 along the electric field direction. In this case, since the linearly polarized light incident on the liquid crystal layer 102 does not rotate, it does not pass through the output side polarizing plate. Thereby, black display is performed when no electric field is applied. Note that gradation display can also be performed depending on the strength of an applied electric field.
The liquid crystal display device 101 is configured as described above.

In the present embodiment, the above-described spacer 105 is applied to the surface of the light shielding film 77 of the lower substrate (hereinafter simply referred to as the substrate) 70 by a liquid material application method. As the laser light source of the present embodiment, ultraviolet laser light (He-Cd laser (wavelength 442 nm), He-Cd laser (wavelength 325 nm), YVO ₄ laser (wavelength 266 nm), etc.) can be used.

In the present embodiment, in order to ensure the strength as the spacer, after the droplets are spread and spread, ultraviolet light is irradiated to give light energy.
Specifically, a liquid material having a diameter of about 15 μm was applied on the light shielding film 77, and ultraviolet light was irradiated after 1 ms had elapsed after the liquid material landed. In this case, once the curing reaction is initiated by UV irradiation, the reaction proceeds to the end, so that it is not necessary to cure later. Then, as shown in FIG. 9, a columnar body T as a spacer 105 having a height of about 5 μm and ensuring accuracy can be formed on the light shielding film 77 of the lower substrate 70.
Thereafter, liquid crystal is applied by a droplet discharge method, and bonded to the upper substrate 80 as shown in FIG. 8, whereby the liquid crystal display device 101 having an accurate gap can be manufactured.

In the liquid crystal display device, in addition to the spacer 105, the present invention can also be applied as a light shielding mask (mask portion) or a partition wall for discharging droplets.
This light-shielding mask is electrically connected to the interlayer insulating film when the upper and lower wiring patterns as the first and second conductive portions provided on the substrate and disposed via the interlayer insulating film (insulating portion) are electrically connected. It is used when forming a contact hole for embedding a plug of material.
Specifically, a lower wiring layer is formed on the substrate by etching or the like, and a columnar body as a mask portion is formed by a droplet applying method described above at a position corresponding to the contact hole on the lower wiring layer, and then the lower wiring is formed. An interlayer insulating film is formed on the layer. Then, by removing the columnar body by etching or the like, a contact hole can be formed in the interlayer insulating film.
Then, after forming the contact hole in this way, a conductive material is buried in the contact hole to form a plug, and further, an upper wiring layer is formed on the interlayer insulating film so as to be in contact with the plug, The lower wiring layer and the upper wiring layer can be electrically connected through the plug in the contact hole.

  In addition to this, when manufacturing a color filter used in a liquid crystal display device, a partition called a bank is used to prevent color mixing when applying a droplet containing a coloring material to a region corresponding to the pixel. The partition wall can also be formed by the droplet applying method. In addition to the liquid crystal display device, the present invention can also be applied to a partition wall used when forming a light emitting layer by a droplet discharge method when manufacturing an organic EL device.

(Third embodiment)
Next, a field emission display (hereinafter referred to as FED) which is an electro-optical device provided with a field emission element (electric emission element) manufactured by the above liquid material coating method will be described.
10A and 10B are diagrams for explaining the FED. FIG. 10A is a schematic configuration diagram showing the arrangement of the cathode substrate and the anode substrate constituting the FED, and FIG. 10B is a cathode substrate of the FED. It is a schematic diagram of the drive circuit which comprises.

  As shown in FIG. 10A, an FED (electro-optical device) 200 has a configuration in which a cathode substrate 200a and an anode substrate 200b are arranged to face each other. As shown in FIG. 10B, the cathode substrate 200a includes a gate line 201, an emitter line 202, and a field emission device 203 connected to the gate line 201 and the emitter line 202. This is a so-called simple matrix driving circuit. The gate signal 201 is supplied with gate signals V1, V2,..., Vm, and the emitter line 202 is supplied with emitter signals W1, W2,. The anode substrate 200b includes a phosphor made of RGB, and the phosphor has a property of emitting light when hit by electrons.

  As shown in FIG. 11, the field emission device 203 includes an emitter electrode 203 a connected to the emitter line 202 and a gate electrode 203 b connected to the gate line 201. Furthermore, the emitter electrode 203a includes a protrusion called an emitter tip 205 that decreases in diameter from the emitter electrode 203a side toward the gate electrode 203b. A hole 204 is formed in the gate electrode 203b at a position corresponding to the emitter tip 205. The tip of the emitter tip 205 is disposed in the hole 204.

  In such an FED 200, by controlling the gate signals V1, V2,..., Vm of the gate line 201 and the emitter signals W1, W2,..., Wn of the emitter line 202, the emitter electrode 203a and the gate electrode 203b are controlled. A voltage is supplied between them, and electrons 210 move from the emitter tip 205 toward the hole 204 by the action of electrolysis, and electrons 210 are emitted from the tip of the emitter tip 205. Here, since the light is emitted when the electrons 210 and the phosphor 206 of the anode substrate 200b hit each other, the FED 200 can be driven as desired.

  In the FED configured as described above, an emitter tip 205 as a cathode is formed by the above-described liquid material coating method. As the ink to be ejected, a material having a low work function (K, Ca, ITO, Ag—O—Cs, InGa / As, etc.) dispersed in a fine particle state can be used. Further, it is possible to employ a method in which metal is ionized and discharged in an aqueous solution state and oxidized with a laser during drying (Ag and Cs, In and Sn, etc.). Furthermore, it is possible to employ a method in which carbon nanotubes are dissolved in an organic solvent and applied. Then, for example, by adding about 1% by weight of PDMAA (polydimethylacrylamide) to these inks, it becomes possible to discharge in a liquid column shape.

  In any of the methods, the columnar body is formed and fixed by the liquid material coating method of the present invention, and a cathode with a narrow tip (emitter tip 205) is formed, so that electrons can be easily emitted. In addition, since the droplet discharge amount can be controlled by the droplet discharge method, there is no variation between pixels, and the cathode can be formed with high accuracy. In particular, the polymer added to the ink is preferable because it prevents the occurrence of cracks in the columnar body T after drying and baking, and also serves as a base material for maintaining the columnar shape.

(Fourth embodiment)
Subsequently, an electronic apparatus including the electro-optical device according to the embodiment will be described.
12A to 12C show an embodiment of an electronic apparatus according to the present invention.
The electronic apparatus of this example includes an electro-optical device (liquid crystal display device, organic EL device, FED) manufactured by the droplet coating method according to the present invention as display means.
FIG. 12A is a perspective view showing an example of a mobile phone. In FIG. 12A, reference numeral 1000 denotes a mobile phone body (electronic device), and reference numeral 1001 denotes a display unit using the electro-optical device.
FIG. 12B is a perspective view showing an example of a wristwatch type electronic device. In FIG. 12B, reference numeral 1100 indicates a watch body (electronic device), and reference numeral 1101 indicates a display unit using the above electro-optical device.
FIG. 12C is a perspective view illustrating an example of a portable information processing apparatus such as a word processor or a personal computer. In FIG. 11C, reference numeral 1200 denotes an information processing apparatus (electronic device), reference numeral 1202 denotes an input unit such as a keyboard, reference numeral 1204 denotes an information processing apparatus body, and reference numeral 1206 denotes a display unit using the above electro-optical device. ing.
Each of the electronic devices shown in FIGS. 12A to 12C includes the electro-optical device according to the present invention as a display unit, and thus has a protrusion having a fine diameter and a desired height accuracy, and has a high quality. An electronic device having the display characteristics can be obtained.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, as an electro-optical device manufactured by the droplet coating method according to the present invention, in addition to the above, for example, a microlens provided for adjusting the focal length on a surface emitting laser is formed into a columnar shape by the droplet coating method according to the present invention. The protrusion of the finder screen that is formed on the body to reduce the light emission angle or is used for adjusting the focus of the camera can be manufactured by the droplet applying method according to the present invention. In addition, it can also be applied to projector screens and micromachines.

1 is a schematic perspective view of a droplet discharge device according to the present invention. It is a figure for demonstrating the discharge principle of the liquid material by a piezo method. FIG. 6 is a diagram in which a photodetector and a laser light source are arranged in the vicinity of the ejection head. It is a figure which shows the relationship between the position in a laser beam, and light intensity. It is a figure which shows the waveform of the drive voltage applied to a piezoelectric element. It is a figure which shows the liquid body discharged in a liquid column shape. It is a disassembled perspective view of a liquid crystal display device. It is side surface sectional drawing in the AA of FIG. It is a figure which shows the procedure which bonds an upper board | substrate and a lower board | substrate, and manufactures a liquid crystal display device. (A) is a schematic block diagram which showed arrangement | positioning of the cathode substrate and anode substrate which comprise FED, (b) is a schematic diagram of the drive circuit with which a cathode substrate is equipped among FED. It is a figure which shows schematic structure of FED. It is a figure which shows the example of the electronic device of this invention.

Explanation of symbols

IJ: droplet ejection device (droplet coating device), L, L1 to L3: droplet, P ... substrate, 1 ... ejection head, 25 ... nozzle, 70 ... lower substrate (substrate), 80 ... upper substrate (substrate) 101 ... Liquid crystal display device (electro-optical device), 102 ... Liquid crystal layer (electro-optical layer), 200 ... Field emission display (FED, electro-optical device), 205 ... Emitter tip (protrusion), 1000 ... Mobile phone body ( Electronic device), 1100 ... Clock body (electronic device), 1200 ... Information processing device (electronic device)

Claims (12)

A liquid material application method in which a liquid material is discharged in a columnar shape from a nozzle of an ejection head and applied to a substrate,
A method for applying a liquid material, comprising the step of applying light energy to the applied liquid material. In the liquid substance coating method according to claim 1,
A liquid coating method, wherein the light energy is applied while separating the ejection head and the substrate. In the liquid substance coating method according to claim 1 or 2,
The method for applying a liquid material, wherein a time period from application of the liquid material to application of the light energy is set based on surface energy of the discharged liquid material. In the liquid substance coating method according to claim 3,
The liquid material applying method, wherein the light energy is applied before the liquid material wets and spreads according to the surface energy. In the liquid substance coating method according to any one of claims 1 to 4,
A method of applying a liquid material, wherein the amount of light energy applied is set according to the material at the application position of the liquid material. In the liquid substance coating method according to any one of claims 1 to 5,
Detecting the diameter of the applied liquid,
And a step of adjusting the application position of the light energy based on the detected diameter. In the liquid substance coating method according to any one of claims 1 to 6,
The liquid material contains a photothermal conversion material, and is a liquid material coating method.   A liquid material coating apparatus for applying a liquid material to the substrate by the liquid material coating method according to claim 1. An electro-optical device that is manufactured using a columnar body, the electro-optical layer being sandwiched between a pair of substrates,
An electro-optical device, wherein the columnar body is formed by the liquid material coating method according to claim 1. The electro-optical device according to claim 9.
The columnar body is a spacer that is provided on the substrate and forms a gap between the mask portion for forming a conductive portion that electrically connects the first conductive portion and the second conductive portion sandwiching the insulating portion, and a gap between the pair of substrates And at least one of partition walls provided around the periphery of the pixel portion. The electro-optical device according to claim 9.
Having a pair of electrodes,
The electro-optical device, wherein the columnar body is a projection provided on one of the electrodes to emit electrons. An electronic apparatus comprising the electro-optical device according to claim 9 as a display unit.

Images