JP4396414B2 - Film pattern forming method and film pattern forming apparatus - Google Patents

Description

  The present invention relates to a film pattern forming method and a film pattern forming apparatus for forming a film pattern by applying a functional liquid as droplets to a substrate.

  A film pattern forming method for forming a film pattern by applying a functional liquid as droplets to a substrate is a method of forming a functional film pattern by ejecting a liquid containing a functional component onto a substrate by inkjet. A step of applying a liquid by inkjet onto a substrate having a film forming surface having a contact angle with respect to the liquid of 30 [deg] or more and 60 [deg] or less, and a step of converting the applied liquid into a functional film by heat treatment Has been disclosed (Patent Document 1).

  Furthermore, there is provided a film pattern forming method for forming a film pattern by discharging a droplet made of a liquid containing a film forming component to a predetermined film forming region on a substrate. Are ejected at a pitch larger than the diameter of the droplets after landing on the substrate over the entire wiring formation region. In the second ejection step, droplets are ejected at the same pitch as in the first ejection step at a position different from the ejection position in the first ejection step in the entire wiring formation region. In the third discharge step, droplets are discharged over the entire wiring formation region at a pitch smaller than the pitch in the first discharge step. A method is disclosed in which the substrate is processed in advance so that the contact angle with the droplet is 60 [deg] or more (Patent Document 2).

  As a study on the control of ejected microdroplets, “electrostatic conveyance of microdroplets” (Non-Patent Document 1) in the Higuchi Laboratory, Graduate School of Engineering, the University of Tokyo can be cited as a known document.

JP 2003-80694 A Japanese Patent Laid-Open No. 2003-136991 The 4th Chemistry and Microsystem Workshop Preliminary Proceedings Page 61

  In the conventional film pattern forming method as described above, when a film pattern is formed with a narrower width than a droplet landing diameter and a long distance, a plurality of droplets are landed over a necessary length. In other words, functional fluid is likely to be wasted.

  In addition, partition walls (banks) are formed so as to surround the film formation region so that droplets protruding outside the film formation region can be accommodated in the region, and lyophilic processing (reducing the contact angle with respect to the liquid) is performed on the bank bottom surface. Or a method of performing liquid repellency treatment (increasing the contact angle with respect to the liquid) on the upper surface of the bank and the outer peripheral portion. However, when the width between the banks surrounding the film formation region is extremely narrow, for example, 10 μm or less, it is difficult to optimize the surface treatment state of the bank bottom surface and the bank top surface, and the liquid is not sufficiently spread due to uneven processing. May occur.

  The present invention has been made in consideration of the above-described problems, and a film pattern forming method capable of forming a finer film pattern by applying a functional liquid as droplets and film pattern formation using the same An object is to provide an apparatus.

  The film pattern forming method of the present invention is a film pattern forming method in which a functional liquid is applied onto a substrate to form a predetermined film pattern, and the applied droplet is guided according to the shape of the film pattern. A pattern region forming step for forming a film forming region having a path, a coating step for applying a functional liquid in a film forming region other than the guide path, and a guiding step for guiding the functional liquid along the guide path and spreading it out. It is characterized by that.

  According to this configuration, in the pattern region forming step, a film forming region having a guide path through which the functional liquid is guided and guided is formed, and in the applying step, the functional liquid is applied in the film forming region other than the guide path. In the guiding process, the applied functional liquid is guided along the guide path and spreads, so even if the guide path is an extremely narrow flow path where it is difficult to apply the functional liquid, the guide liquid is not applied to the guide path. The functional liquid can be spread over the film forming region including the path. In addition, since it is not necessary to apply the functional liquid to the guide path, it is possible to eliminate the waste of the functional liquid. That is, a fine film pattern can be formed by applying the functional liquid to the film forming region without waste.

  In this case, it is preferable that the guide region is formed in a concave shape or a groove shape in the pattern region forming step.

  According to this configuration, since the guide path is formed in a concave shape or a groove shape, it is possible to prevent the applied functional liquid from spreading along the concave or groove-shaped inner wall surface and spreading out of the guide path. .

  In this case, the pattern region forming step includes a lyophilic processing step for processing the inside of the film forming region to be lyophilic and a lyophobic processing step for processing the outside of the film forming region to have lyophobic properties. It is preferable to provide.

  According to this configuration, in the lyophilic processing step, the inside of the film forming region is processed to be lyophilic, and in the lyophobic processing step, the outside of the film forming region is processed to be lyophobic. The functional liquid is more likely to spread and wet, and even if the functional liquid is applied outside the film forming area, the outside of the film forming area is treated to be liquid repellent, so that the functional liquid can be efficiently contained in the film forming area. it can. Therefore, it is possible to further reduce the waste of the applied functional liquid.

  Further, in this case, the coating step is characterized in that the functional liquid is discharged as droplets from the droplet discharge head into a film formation region other than the guide path.

  According to this configuration, since the functional liquid is ejected as droplets from the droplet ejection head in the coating process, an appropriate amount of the functional liquid necessary for forming the film pattern is deposited as droplets in the film formation region. Can be applied.

  Further, in this case, the guiding step is characterized in that the functional liquid is guided along the guide path and spreads wet by applying an electrostatic force to the applied functional liquid in a direction in which the guide path is formed.

  According to this configuration, an electrostatic force is applied to the functional liquid to generate a propulsive force that spreads the functional liquid. Therefore, in the guiding step, the functional liquid can be spread along the guide path by applying an electrostatic force to the functional liquid applied in the film formation region other than the guide path in the direction toward the guide path. .

  In this case, the guiding step may be such that the substrate is charged before or after applying the functional liquid in the applying step, and the applied functional liquid is wet spread along the guide path.

  According to this configuration, in the guiding step, the substrate can be charged before or after the functional liquid is applied to the substrate, and the functional liquid can be spread along the guide path by the electrostatic force of the charged substrate.

  In this case, in the induction step, the electrostatic force applied to the functional liquid or the amount of charge of the substrate charged before or after the functional liquid is applied is determined by measuring the amount of the substrate measured using a surface potentiometer. It is 3000 (V) or more in terms of potential.

  According to this configuration, the electrostatic force applied to the functional liquid or the charged amount of the substrate charged before or after the functional liquid is applied is set to 3000 (V) or more to ensure the functional liquid. It can be spread along the guide path by applying electrostatic force to it.

  In this case, the functional liquid is a dispersion solution in which fine particles of a functional material are dispersed in a liquid medium.

  According to this configuration, since the functional liquid is a dispersion solution in which fine particles of the functional material are dispersed in the liquid medium, a propulsive force is generated by applying an electrostatic force to the functional liquid in the induction process. Therefore, a film pattern made of a functional material can be formed by applying this functional liquid in the film forming region and applying an electrostatic force to the functional liquid to spread it in the guide path.

  In this case, the functional material is a conductive material, and a wiring pattern made of this conductive material is formed as a film pattern. The functional material is a fluorescent material or a dye, and an element pattern made of the fluorescent material or the dye may be formed as a film pattern.

  According to this configuration, a conductive wiring pattern can be formed by using a dispersion solution in which fine particles of a conductive material are dispersed as a functional liquid. If a fluorescent material or a dye is used, an element pattern made of the fluorescent material or the dye can be formed. For example, when an organic EL material is used as the fluorescent material, an organic EL light emitting element can be formed. If a color filter material is used as the pigment, a color filter element can be formed.

  The film pattern forming apparatus of the present invention is a film pattern forming apparatus that forms a film pattern by applying a functional liquid onto a substrate, and the functional liquid is formed in a film forming region having a guide path that becomes a film pattern formed on the substrate. A droplet discharge unit that discharges as a droplet, a substrate on which a substrate is mounted, and a mounting table having electrodes arranged in a matrix at intervals, and a voltage generation unit that generates a high voltage, The voltage generation unit discharges between electrodes that are positioned corresponding to the film formation region of the substrate mounted on the mounting table.

  According to this configuration, the droplet discharge unit discharges the functional liquid as droplets to the film forming region that becomes the film pattern of the substrate mounted on the mounting table. The voltage generator discharges between the electrodes of the mounting table positioned corresponding to the film formation region of the substrate. As a result, the functional liquid applied in the film formation region is given an electrostatic force in the direction of the guide path of the film formation region and spreads wet along the guide path. Therefore, it is possible to form a film pattern made of a functional liquid without discharging droplets over the entire film formation region.

  Another film pattern forming apparatus of the present invention is a film pattern forming apparatus that forms a film pattern by applying a functional liquid onto a substrate, and is provided in a film forming region having a guide path to be a film pattern formed on the substrate. A droplet discharge unit that discharges the functional liquid as droplets, a mounting table on which the substrate is mounted, and a static electricity generation unit that charges the substrate mounted on the mounting table are provided.

  According to this configuration, the static electricity generation unit is mounted on the mounting table before or after the functional liquid is discharged as droplets to the film formation region having a guide path that is a film pattern formed on the substrate from the droplet discharge unit. If the placed substrate is charged, the droplet receives an electrostatic force from the charged substrate and spreads wet along the guide path. Therefore, it is possible to form a film pattern made of a functional liquid without discharging droplets over the entire film formation region.

  Hereinafter, an embodiment of a film pattern forming method and a film pattern forming apparatus of the present invention will be described with reference to the drawings. In this embodiment, a wiring pattern (film pattern) forming ink (functional liquid) containing conductive fine particles is ejected in droplet form from a discharge nozzle of a droplet discharge head by a droplet discharge method, and a glass substrate (hereinafter referred to as a substrate). An example in the case of forming a wiring pattern formed of a conductive film on the conductive film will be described.

(First embodiment)
First, a film pattern forming apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic perspective view showing the structure of a film pattern forming apparatus. The film pattern forming apparatus 100 is a film pattern forming apparatus that forms a film pattern by applying a functional liquid as droplets onto a substrate W. Then, a head unit 1 having a plurality of droplet discharge heads 20 (see FIG. 2) as droplet discharge portions that discharge functional liquid as droplets to a film formation region having a guide path that becomes a film pattern formed on the substrate W. And a mounting table 4 having floating island electrodes 40 (see FIG. 3) as electrodes placed on the substrate W and arranged in a matrix at intervals, and a voltage generator 9 for generating a high voltage It has.

  The film pattern forming apparatus 100 also includes an X-direction guide shaft 2 for driving the head unit 1 in the sub-scanning direction (X direction) and an X-direction drive motor 3 for rotating the X-direction guide shaft 2. Further, a Y direction guide shaft 5 for driving the mounting table 4 in the main scanning direction (Y direction) and a Y direction drive motor 6 for rotating the Y direction guide shaft 5 are provided. The X-direction guide shaft 2 and the Y-direction guide shaft 5 are provided with a base 7 disposed at the upper portion, and a control device 8 and a voltage generator 9 are provided at the lower portion of the base 7.

  Furthermore, a cleaning mechanism unit 14 for cleaning the head unit 1 and a heater 15 for heating the discharged functional liquid and evaporating and drying the solvent are provided.

  The head unit 1 includes a plurality of liquid droplet ejection heads 20 (see FIG. 2) that eject functional liquid from nozzles (ejection ports) and apply them to the substrate W. The plurality of droplet discharge heads 20 can individually discharge the functional liquid according to the discharge voltage supplied from the control device 8. The droplet discharge head 20 will be described later.

  The X direction drive motor 3 is not limited to this, but is a stepping motor, for example. When a drive pulse signal in the X axis direction is supplied from the control device 8, the X direction guide shaft 2 is rotated, The head unit 1 engaged with the direction guide shaft 2 is moved in the X direction.

  Similarly, the Y-direction drive motors 6 and 16 are not limited to this, but are, for example, stepping motors or the like. When a drive pulse signal in the Y-axis direction is supplied from the control device 8, the Y-direction guide shaft 5 is moved. The table 4 and the cleaning mechanism unit 14 that are rotated and engaged with the Y-direction guide shaft 5 are moved in the Y-axis direction.

  When cleaning the head unit 1, the cleaning mechanism unit 14 moves to a position facing the head unit 1, closes the nozzle surface of the droplet discharge head 20, and sucks unnecessary functional liquid. A wiping operation is performed to wipe off the nozzle surface to which has adhered. Details of the cleaning mechanism are omitted.

  Although not limited to this, the heater 15 is, for example, a means for heat-treating the substrate W by lamp annealing, for evaporating and drying the functional liquid discharged on the substrate W and converting it into a film. Heat treatment is performed. The control device 8 also controls the turning on and off of the heater 15.

  In the coating operation of the film pattern forming apparatus 100, a predetermined drive pulse signal is sent from the control device 8 to the X direction drive motor 3 and the Y direction drive motor 6, and the head unit 1 is placed in the sub-scanning direction (X direction). 4 is relatively moved in the main scanning direction (Y direction). During this relative movement, a discharge voltage is supplied from the control device 8, and the functional liquid is discharged as droplets from the head unit 1 into the film formation region of the film pattern of the substrate W to perform coating.

  The discharge amount of the droplets discharged from the head unit 1 can be adjusted by the magnitude of the discharge voltage supplied from the control device 8.

  FIG. 2 is a schematic cross-sectional view showing the main structure of the droplet discharge head. The droplet discharge head 20 pressurizes the functional liquid filled in the pressure chamber 24 via the pressure chamber 24 communicating with the nozzle 21, the vibration plate portion 25 constituting one surface of the pressure chamber 24, and the vibration plate portion 25. A piezoelectric element (piezo) 30 is included. The actual droplet discharge head 20 includes a plurality of nozzles 21 formed on the nozzle plate 22, a pressure chamber 24 corresponding to the nozzles 21, a vibration plate portion 25, and a piezoelectric element 30. Further, a common cavity (not shown) communicating with each pressure chamber 24 of the pressure chamber substrate 23 is provided, and the functional liquid can be filled into the pressure chamber 24 by supplying the functional liquid to the common cavity from the outside. It has a structure that can be done.

  As shown in FIG. 2, the diaphragm portion 25 is configured by stacking an insulating film 27 and a lower electrode 26, and the piezoelectric element 30 is configured by stacking a piezoelectric layer 32 and an upper electrode 31. The lower electrode 26, the piezoelectric layer 32, and the upper electrode 31 can function as the piezoelectric element 30.

  When the pressure chamber 24 of the piezo-type droplet discharge head 20 is filled with the functional liquid and the pressure chamber 24 is pressurized by the piezoelectric element 30, the functional liquid is dropped from the nozzle 21 communicating with the pressure chamber 24. Can be discharged. Further, the droplet discharge by the piezo method has an advantage that the material composition is hardly affected because the material is not heated.

  3 shows the structure of the mounting table, FIG. 3A is a schematic sectional view showing the structure of the mounting table, and FIG. 3B is a schematic plan view showing the arrangement of floating island electrodes arranged on the mounting table. FIG.

  As shown in FIG. 3A, the mounting table 4 on which the substrate W is mounted has a plurality of floating island electrodes 40 disposed on the upper surface thereof. As shown in FIG. 3B, the floating island electrodes 40 are arranged in a matrix, and each electrode is given an X coordinate starting with x1 and a Y coordinate starting with y1. In this case, the floating island electrodes 40 are arranged at intervals of several μm to several hundred μm (for example, 10 μm). In addition, in the film pattern described later, the design of the film formation region of the film pattern is considered so as to correspond to the arrangement interval of the floating island electrodes 40. May be.

  FIG. 4 is a schematic diagram showing the electrical configuration of the floating island electrode. Each floating island electrode 40 has an electrode terminal 41. Each electrode terminal 41 is grounded to GND by a switching means 42.

  The voltage generation unit 9 generates a high voltage and discharges between the floating island electrode 40 grounded to the GND via the discharge terminal 43. As a result, electrostatic force (charge) can be applied to the functional liquid applied in the vicinity of the floating island electrode 40. The discharge terminal 43 is attached to the X-direction guide shaft 2 so as to be movable in the X direction (not shown).

  Next, the film pattern forming method of the present invention will be described with reference to FIGS. The film pattern forming method of the present embodiment is a film pattern forming method for forming a predetermined film pattern 50 by applying a functional liquid onto the substrate W using the above-described film pattern forming apparatus 100, and the applied function A pattern region forming step of forming a film forming region 51 having a liquid flow path 53 as a guide path through which the liquid is guided according to the shape of the film pattern 50, and a mechanism liquid in the film forming region 51 other than the liquid flow path 53 And an induction process for inducing and spreading the applied functional liquid along the liquid flow path 53.

FIG. 5 is a schematic view showing the shape of the film pattern. FIG. 5A is a schematic plan view showing one embodiment of the film pattern. FIG.5 (b) is the schematic sectional drawing cut by AA of Fig.5 (a).
FIG. 5C is a schematic plan view showing another embodiment of the film pattern.

  In the pattern region forming step, for example, the film forming region 51 of FIG. The film forming region 51 includes a liquid receiving portion 52 that receives the applied functional liquid, and a liquid flow path 53 as a guide path connected to the liquid receiving portion 52.

  In this case, the film forming region 51 is surrounded by a partition wall (hereinafter referred to as a bank 54) having a height of about 1 to 3 μm. Therefore, the liquid flow path 53 is formed in a concave shape or a groove shape.

  The pattern region forming step of the present embodiment includes a bank forming step for forming the bank 54, a lyophilic processing step for processing the inside of the film forming region 51 so as to have lyophilicity, and a portion other than the film forming region 51 on the substrate W. A liquid repellent treatment step for treating the region so as to have liquid repellency.

(Bank formation process)
The bank 54 is a member that functions as a partition member, and the bank 54 can be formed by an arbitrary method such as a lithography method or a printing method. For example, when the lithography method is used, an organic photosensitive material is applied on the substrate W according to the height of the bank 54 by a predetermined method such as spin coating, spray coating, roll coating, die coating, dip coating, or the like. Then, a mask is applied according to the bank shape (film pattern shape), and the resist is exposed and developed to leave the resist according to the bank shape.

  As a result, as shown in FIG. 5A, for example, a bank 54 having a height of 1 to 3 μm and a width of 10 μm is provided so as to surround the periphery of the film formation region 51 where the film pattern 50 is to be formed.

When the width of the liquid flow path 53 is 10 μm or less, when the droplet 60 is ejected from the droplet ejection head 20, the droplet diameter varies depending on the volume of the ejected droplet and the surface treatment state on the landing side. Is approximately 20 to 30 μm, and it is difficult to discharge and store the droplet 60 in the liquid flow path 53. The substrate W is subjected to HMDS treatment (a method of applying (CH ₃ ) ₃ SiNHSi (CH ₃ ) ₃ in a vapor state) as a surface modification treatment before applying the organic photosensitive material. Although not shown in FIG.

  The organic photosensitive material for forming the bank 54 may be a material that exhibits liquid repellency with respect to a liquid material, and can be made liquid repellent (Teflon (registered trademark)) by plasma treatment as described later. An insulating organic photosensitive material that has good adhesion to the base plate and is easily patterned by photolithography may be used. For example, a polymer material such as an acrylic resin, a polyimide resin, an olefin resin, or a melamine resin can be used.

(Liquid treatment process)
Next, in the lyophilic treatment step, an ultraviolet (UV) irradiation treatment that imparts lyophilicity by irradiating the substrate W on which the bank 54 is formed with an ultraviolet ray, or an O 2 plasma treatment that uses oxygen as a treatment gas in the atmosphere Here, O2 plasma treatment is performed. Moreover, the resist (organic substance) residue at the time of bank formation between banks can also be removed by this O2 plasma treatment.

  Specifically, this is performed by irradiating the substrate W with plasma oxygen from the plasma discharge electrode. As conditions for the O 2 plasma treatment, for example, the plasma power is 50 to 1000 W, the oxygen gas flow rate is 50 to 100 ml / min, the substrate transport speed of the substrate W with respect to the plasma discharge electrode is 0.5 to 10 mm / sec, and the substrate temperature is 70 to 90 ° C. When the substrate W is a glass substrate, the surface thereof is lyophilic with respect to the film pattern forming material. However, the film can be obtained by performing O2 plasma treatment or ultraviolet irradiation treatment as in the present embodiment. The lyophilicity in the formation region 51 can be enhanced.

(Liquid repellent treatment process)
Subsequently, the bank 54 is subjected to a liquid repellency treatment to impart liquid repellency to the surface thereof. As the liquid repellent treatment, for example, a plasma treatment method (CF4 plasma treatment method) using tetrafluoromethane as a treatment gas in an air atmosphere can be employed. The conditions of the CF4 plasma treatment are, for example, a plasma power of 50 to 1000 kW, a tetrafluoromethane gas flow rate of 50 to 100 ml / min, a substrate transfer speed of 0.5 to 20 mm / sec with respect to the plasma discharge electrode, and a substrate temperature of 70 to 90 ° C. It is said. The processing gas is not limited to tetrafluoromethane (carbon tetrafluoride), and other fluorocarbon gases can also be used.

  By performing such a liquid repellency treatment, a fluorine group is introduced into the resin constituting the bank 54, and high liquid repellency is imparted to the surface of the bank 54. The O2 plasma treatment as the lyophilic treatment described above may be performed before the bank 54 is formed. However, acrylic resin, polyimide resin, and the like are more fluorinated (liquid repellent) when pretreated with O2 plasma. ), It is preferable to perform O 2 plasma treatment after the bank 54 is formed. Although the lyophobic treatment for the bank 54 has some influence on the surface of the substrate W that has been previously lyophilicized, particularly when the substrate W is made of glass or the like, introduction of fluorine groups due to the lyophobic treatment occurs. Therefore, the lyophilicity, that is, the wettability of the substrate W is not substantially impaired. Further, the bank 54 may be formed of a material having liquid repellency (for example, a resin material having a fluorine group), so that the liquid repellency treatment may be omitted.

  As another embodiment of the film formation region 51 of the film pattern 50 formed through the above-described steps, the liquid receiving portions 52 are arranged at intervals as shown in FIG. 5C. It is good also as a shape which connected between the liquid receiving parts 52 with the liquid flow path 53 as a guide path. If the size of the liquid receiving portion 52 corresponding to the amount of the functional liquid that spreads in the liquid flow path 53 is determined and arranged in advance, the liquid receiving portion 52 does not become larger than necessary, and the predetermined length is fine. A film pattern 50 including the film forming region 51 having the film forming area 51 can be formed.

(Coating process)
The application process of the present embodiment is a process of discharging the functional liquid as droplets 60 from the droplet discharge head 20 into the film forming region 51 other than the liquid flow path 53 as a guide path. In this case, the droplet 60 is discharged to the liquid receiving portion 52. The discharged functional liquid will be described later. In the present embodiment, the shape of the liquid receiving portion 52 is a quadrangle. However, the shape is not limited to this, and the shape may be a shape connected by an arc according to the shape of the droplet 60 to land.

(Guidance process)
In the guiding process of the present embodiment, the functional liquid is guided along the liquid flow path 53 by applying an electrostatic force (charge) to the applied functional liquid in the direction in which the liquid flow path 53 as a guide path is formed. It spreads wet.

  FIG. 6 is a schematic diagram showing the induction process. FIG. 6A is a schematic sectional view showing the arrangement of the droplet discharge head, the discharge terminal, and the substrate in the induction process. FIG. 6B is a schematic plan view showing the positional relationship between the film pattern and the floating island electrode.

  As shown in FIGS. 6A and 6B, in the preceding application process, the functional liquid is ejected as droplets 60 to the liquid receiving portion 52 in the film formation region 51. Since the discharged functional liquid is processed so that the film forming region 51 becomes lyophilic in the lyophilic processing step described above, it tends to wet and spread in the film forming region 51. However, when the lyophilic process is not optimal or the lyophilic process becomes uneven on a large substrate or the like, the functional liquid slightly gets wet and spreads in the liquid flow path 53 that is the guide path by capillary action. May end up.

  In the induction process of the present embodiment, a high voltage is generated by the voltage generator 9, and discharge is performed between the floating island electrode 40 grounded to GND. Thus, an electrostatic force is applied to the discharged (applied) functional liquid, and the liquid is wet and spread along the liquid flow path 53. When a potential difference is generated between the functional liquid and the floating island electrode 40, an electrostatic attractive force acts between the anion in the functional liquid and the floating island electrode 40 in a region where the potential of the floating island electrode 40 is positive. In the region where the potential of the floating island electrode 40 is negative, an electrostatic attractive force acts between the cation in the functional liquid and the floating island electrode 40. Such a phenomenon is called an electrocapillary phenomenon. As one action of this electrocapillary phenomenon, it is conceivable that the interfacial tension of the functional liquid (surface tension in the case of liquid droplets) is lowered and the surface having lyophilicity is more easily spread.

  For example, as shown in FIG. 6B, the liquid receiving part 52 of the film forming region 51 is located at the position of the floating island electrode 40 having the coordinates x1y2. When the functional liquid discharged to the liquid receiving portion 52 as the droplet 60 is to be spread in the liquid flow path 53 in the direction of the arrow in the figure, the floating island electrode 40 in the direction of the arrow is sequentially turned to GND by the switching means 42. The electric charge is discharged from the discharge terminal 43 by grounding.

  FIG. 7 is a time chart illustrating an example of a voltage generation pattern of the voltage generation unit. When trying to spread the functional liquid in the direction of the arrow, first the floating island electrode 40 at the coordinate x1y2 is grounded to GND, the voltage Vp is set to 3000 V, the pulse width Pw is set to about 2 μsec, and the discharge terminal 43 is discharged. The distance between the discharge terminal 43 and the substrate W is about 0.5 to 1 mm depending on the surrounding environment.

  Subsequently, the floating island electrode 40 at the coordinate x2y2 is grounded to the GND by the switching means 42 at an interval of about 100 msec, and similarly discharged. As a result, the functional liquid applied to the liquid receiving portion 52 is guided in the direction of the coordinate x2y2. Thereafter, discharge is sequentially performed between the floating island electrode 40 positioned along the arrow direction.

  FIG. 8 is a schematic cross-sectional view showing a state in which the liquid droplet of the functional liquid has landed and spreads in the liquid flow path. FIG. 8A is a schematic cross-sectional view showing a droplet of the functional liquid that has landed on the liquid receiving portion 52. FIG. 8B is a schematic cross-sectional view showing a state in which wetting and spreading start along the liquid flow path by the induction process. FIG. 8C is a schematic cross-sectional view showing a state in which the functional liquid is wet and spread in the liquid flow path by the induction process. By repeating the discharge as described above, the functional liquid ejected as the droplet 60 as shown in FIG. 8 is guided along the liquid flow path 53 (bank 54) to spread and form the functional liquid film 61. it can.

  FIG. 9 is a schematic plan view showing another film pattern forming method. If the above induction method is used, even if the liquid flow path 53 is bent as shown in FIG. 9, discharge is performed between the floating island electrode 40 positioned corresponding to the shape of the liquid flow path 53. As a result, the film formation region 51 having a bent shape can be formed, and the film pattern 50 made of the functional liquid can be formed.

  In this film pattern forming method, in order to accurately discharge the functional liquid from the droplet discharge head 20 to the liquid receiving unit 52 and to apply electrostatic force to the discharged functional liquid, the substrate W placed on the mounting table 4 is used. While moving in the main scanning direction (Y direction), the droplet discharge head 20 is moved in the sub-scanning direction (X direction) to discharge the droplet 60 at a position facing the liquid receiving portion 52. Then, the floating island electrode 40 positioned corresponding to the liquid flow part 53 is discharged from the discharge terminal 43.

  In the film pattern forming method of the present embodiment, a high voltage is generated by the voltage generator 9, and electrostatic discharge is applied to the functional liquid by discharging between the floating island electrode 40 grounded to GND. As another method for applying an electrostatic force to the functional liquid, it is located corresponding to the film formation region 51 on the substrate W, and is appropriately between adjacent floating island electrodes 40 in the film formation region 51 or in the film formation region 51. A method of applying a high voltage (3000 V or more) generated by the voltage generating unit 9 between the floating island electrodes 40 positioned at a distance of is conceivable. According to this method, it is considered that the electrostatic force generated by discharging between the two floating island electrodes 40 is applied to the functional liquid, so that it can be spread along the liquid flow path 53.

  Note that the above-described induction process may not be performed for all the film formation regions 51. For example, when the functional liquid discharged to the liquid receiving unit 52 by lyophilic processing spreads to the liquid flow unit 53 and the lyophilic processing is not optimally processed as described above, It is conceivable that insufficient liquid spreading occurs in some liquid flow parts 53. In such a case, the induction process may be introduced to select the defective film formation region 51 and spread the functional liquid.

  As described above, the substrate W on which the functional liquid has been distributed in the film forming region 51 completes the film pattern 50 made of the functional material contained in the functional liquid through the intermediate drying process, the baking process, and the bank removing process. .

(Intermediate drying process)
After the droplet 60 is discharged onto the substrate W, a drying process is performed as necessary to remove the dispersion medium in the functional liquid and to secure the film thickness. The drying process can be performed by lamp annealing in addition to a process using a normal hot plate, an electric furnace, or the like that heats the substrate W, for example. The heater 15 of the film pattern forming apparatus 100 of this embodiment employs lamp annealing. The light source used for lamp annealing is not particularly limited, but excimer laser such as infrared lamp, xenon lamp, YAG laser, argon laser, carbon dioxide laser, XeF, XeCl, XeBr, KrF, KrCl, ArF, ArCl, etc. Can be used as a light source. In general, these light sources have an output in the range of 10 W to 5000 W, but in the present embodiment, a range of 100 W to 1000 W is sufficient.

  By repeatedly performing the intermediate drying step, the coating step, and the induction step, the film pattern 50 has a non-projecting state with respect to the surface of the substrate W (preferably substantially as shown in FIG. 8C). To be flush with each other.

(Baking process)
In the dry film after the intermediate drying step, when a functional liquid in which conductive fine particles as a metal material are dispersed is used, it is necessary to completely remove the dispersion medium in order to improve electrical contact between the fine particles. In addition, when the surface of the conductive fine particles is coated with a coating agent such as an organic substance in order to improve dispersibility, it is also necessary to remove this coating agent. Therefore, the substrate after the intermediate drying process is subjected to heat treatment and / or light treatment.

  The heat treatment and / or light treatment is usually performed in the air, but can also be performed in an inert gas atmosphere such as nitrogen, argon, helium, etc., if necessary. The treatment temperature of the heat treatment and / or the light treatment depends on the boiling point (vapor pressure) of the dispersion medium, the type and pressure of the atmospheric gas, the thermal behavior such as the dispersibility and oxidation of the fine particles, the presence and amount of the coating agent, It is determined appropriately in consideration of the heat resistant temperature. For example, in order to remove the coating agent made of organic matter, it is necessary to bake at about 300 ° C. In the case where a substrate such as plastic is used, it is preferably performed at room temperature or higher and 100 ° C. or lower. Through the above steps, the dry film after the intermediate drying process is converted into a conductive film while ensuring electrical contact between the fine particles.

(Bank removal process)
In this step, the bank 54 existing around the film formation region 51 is removed by an ashing peeling process. As the ashing treatment, plasma ashing, ozone ashing, or the like can be employed. In the plasma ashing, a gas such as oxygen gas converted into plasma reacts with the bank 54 (resist), and the bank 54 is vaporized to be peeled off and removed. The bank 54 is a solid substance composed of carbon, oxygen, and hydrogen. When the bank 54 chemically reacts with oxygen plasma, it becomes CO ₂ , H ₂ O, O ₂ , and all can be separated as a gas.

On the other hand, the basic principle of ozone ashing is the same as that of plasma ashing. O ₃ (ozone) is decomposed and converted to reactive gas O ⁺ (oxygen radical), and this O ⁺ reacts with the bank 54. The bank 54 that has reacted with O ⁺ becomes CO ₂ , H ₂ O, and O ₂ , and all are separated as a gas. The bank 54 is removed from the substrate W by performing an ashing peeling process on the substrate W.

  Next, a wiring pattern (film pattern) formed by the above film pattern forming method using a functional liquid in which silver as conductive fine particles is dispersed in diethylene glycol ethyl ether as a solvent (dispersion medium) will be described with reference to FIG. .

  FIG. 10 is a schematic view showing a wiring pattern formed by the film pattern forming method of the first embodiment. FIG. 10A is a table showing the relationship between the charge amount of the substrate and the length of the wiring pattern. FIG. 10B is a schematic cross-sectional view showing a wiring pattern. Specifically, an experiment in which a functional liquid containing silver fine particles is discharged as a droplet 60 onto the liquid receiving unit 52 on the substrate W on which the film forming region 51 is formed, and spreads along the bank 54 (liquid flow path 53). It is the result of having gone. At this time, the volume ratio of the silver fine particles to the solvent is about 1:10, and the discharge amount of the droplet 60 is about 30 ng. The width of the liquid flow path 53 is approximately 10 μm.

  As can be seen from the table of FIG. 10 (a) and the schematic cross-sectional view of FIG. 10 (b), under the conditions of the experiment, when the charge amount of the substrate W is measured with a surface potentiometer, the droplet 60 is less than 3000V. Was about 10 μm wet spread due to capillary phenomenon, but at 3000 V or higher, the length L of the functional liquid film 61 spread to about 400 μm. Further, the functional liquid film 61 was subjected to the above-described intermediate drying process and baking process, and a wiring pattern having a thickness of approximately 0.6 μm was obtained.

The effects of the first embodiment are as follows.
(1) The film pattern forming method using the film pattern forming apparatus 100 is located in the film forming region 51 in which a high voltage is generated by the voltage generator 9 and sequentially grounded to GND by the switching means 42 in the induction process. By discharging from the discharge terminal 43 to the floating island electrode 40, an electrostatic force is applied to the functional liquid applied to the liquid receiving portion 52 in the application process, and the functional liquid is applied along the liquid flow path 53 as a guide path. Can spread wet. Therefore, even if the liquid flow path 53 is an extremely narrow flow path where it is difficult to apply the functional liquid, the functional liquid is spread over the film forming region 51 including the liquid flow path 53 without applying the functional liquid to the liquid flow path 53. be able to. Moreover, since it is not necessary to apply the functional liquid to the liquid flow path 53, it is possible to eliminate the waste of the functional liquid. That is, a fine film pattern can be formed by applying the functional liquid in the film forming region 51 without waste.
(2) Since the pattern region forming step includes a bank forming step of forming the bank 54 so as to surround the film forming region 51, the liquid flow path 53 as the guide path is formed in a concave shape or a groove shape and applied. The functional liquid can be prevented from spreading out along the concave or groove-like inner wall surface and out of the liquid flow path 53.
(3) The pattern region forming step includes a lyophilic processing step for processing the film forming region 51 so as to have lyophilic properties, and a processing other than the film forming region 51 on the substrate W so as to have liquid repellency. And a liquid repellent treatment step. Therefore, the functional liquid applied in the film forming region 51 is more likely to spread and wet, and even if the functional liquid is applied to a portion other than the film forming region 51, the portion other than the film forming region 51 is treated to be liquid repellent. The functional liquid can be efficiently stored in the film forming region 51.
(4) Since the electrostatic force (charge) applied to the functional liquid is 3000 V or more in terms of the potential of the substrate W measured with a surface potentiometer, the functional liquid is wetted along the liquid flow path 53 by electrocapillarity. Can be spread.
(5) In the film pattern forming method of the present embodiment, when a functional liquid in which silver fine particles are dispersed in ethylene glycol ethyl ether as a solvent (dispersion medium) is used as the functional material, the functional liquid is supplied to the liquid flow path 53. Even without application, a wiring pattern (film pattern) made of silver which is a functional material can be formed. Therefore, a fine wiring pattern having a liquid flow path 53 (10 μm) narrower than the landing diameter (approximately 20 to 30 μm) of the functional liquid can be formed.

(Second Embodiment)
Another film pattern forming method and film pattern forming apparatus will be described with reference to FIG. FIG. 11 is a schematic view showing another film pattern forming method and film pattern forming apparatus.

  As shown in FIG. 11, the film pattern forming apparatus 200 is a droplet that discharges a functional liquid as a droplet 60 to a film forming region 51 having a liquid flow path 53 as a guide path that becomes the film pattern 50 formed on the substrate W. The apparatus includes a droplet discharge head 20 serving as a discharge unit, a mounting table 70 on which the substrate W is mounted, and a static electricity generating unit 10 that charges the substrate W mounted on the mounting table 70. That is, the configuration of the mounting table 4 and the voltage generator 9 of the film pattern forming apparatus 100 is changed. The mounting table 70 is formed of a conductor.

  In the film pattern forming method in this case, the pattern region forming process for forming the film forming region 51 corresponding to the film pattern 50 on the substrate W is the same as described above. First, the substrate W on which the film formation region 51 is formed is placed on the placement table 70. Next, static electricity is generated from the static electricity generation unit 10 and electric charges are applied to the substrate W from the discharge terminals 43 to form a charged state. The charge amount of the substrate W at this time is 3000 V or more in terms of the potential of the substrate W measured using a surface potentiometer. Then, the functional liquid is ejected and applied as droplets 60 to the liquid receiving portion 52 constituting the film forming region 51 surrounded by the bank 54 of the substrate W charged in the coating process. The functional liquid that has landed on the substrate W is given an electric charge from the charged substrate W, and instantly wets and spreads along the liquid flow path 53 by the electric capillary phenomenon due to the electrostatic force.

  In this case, the timing at which the substrate W is charged may be after the functional liquid is applied.

The effects of the second embodiment are as follows.
(1) In the film pattern forming method using the film pattern forming apparatus 200, in the induction process, static electricity is generated by the static electricity generation unit 10, and electric charges are discharged from the discharge terminals 43 to the substrate W to make the substrate W charged. Later, the functional liquid is applied to the liquid receiving portion 52 in the application step. Then, the applied functional liquid can be wet spread along the liquid flow path 53 connected to the liquid receiving portion 52 by the electrocapillarity when electrostatic force is applied from the substrate W. Therefore, even if the liquid flow path 53 is an extremely narrow flow path where it is difficult to apply the functional liquid, the functional liquid is spread over the film forming region 51 including the liquid flow path 53 without applying the functional liquid to the liquid flow path 53. be able to. Moreover, since it is not necessary to apply the functional liquid to the liquid flow path 53, it is possible to eliminate the waste of the functional liquid. That is, a fine film pattern can be formed by applying the functional liquid in the film forming region 51 without waste.
(2) Since the charged amount of the substrate W in a charged state is 3000 V or more in terms of the potential of the substrate W measured with a surface potentiometer, the functional liquid is wet spread along the liquid flow path 53 by electrocapillarity. be able to.

Modifications other than the first embodiment and the second embodiment are as follows.
(Modification 1) The pattern region forming step is not limited to the method of surrounding the film forming region 51 with the bank 54. It has a functional group capable of binding to the substrate W on one end side, and a functional group that modifies the surface property of the substrate W to liquid repellency (controls the surface energy) on the other end side. A film forming region 51 is formed using an organic molecular film that has a straight chain or a partially branched carbon chain of carbons to be bonded and is bonded to the substrate W and self-assembles to form a molecular film, for example, a monomolecular film. Also good. According to this, since the organic molecular film has a functional group that makes the surface of the substrate W liquid-repellent on the other end side, even if a functional liquid is applied outside the film forming region 51, the organic molecular film is formed into a film. It can be accommodated in the formation region 51.
(Modification 2) The droplet discharge head 20 is not limited to the piezo method. An electrostatic droplet discharge head that pressurizes the pressure chamber 24 filled with the functional liquid with an electrostatic actuator may be used. According to this, as in the piezo method, the functional liquid can be ejected as droplets without applying heat.
(Modification 3) The functional liquid is not limited to a dispersion solution in which silver conductive fine particles are dispersed. What is necessary is just to disperse the fine particles of the functional material in the liquid medium. For example, if a fluorescent inorganic or organic compound is used as fine particles, an inorganic or organic EL light emitting layer can be formed. Furthermore, a color filter element can be formed by using a pigment exhibiting R (red), G (green), and B (blue).
(Modification 4) The substrate W is not limited to glass. Various substrates such as glass, quartz glass, Si wafer, plastic film, metal plate and ceramic can be used as the substrate W on which the film pattern is formed. In addition, a substrate in which a semiconductor film, a metal film, a dielectric film, an organic film, an insulating film, or the like is formed as a base layer on the surface of these various material substrates is also included.

The technical idea grasped from this embodiment and the modification is as follows.
(1) A film pattern forming method for applying a functional liquid on a substrate to form a film pattern having a film forming region composed of a liquid receiving portion and a liquid flow path connected to the liquid receiving portion, on the substrate A pattern region forming step for forming the film forming region; a droplet discharging step for discharging the functional liquid as droplets to the liquid receiving portion; a charge supplying step for applying a charge to the discharged functional liquid; and a liquid flow A film pattern forming method comprising: a discharging step of discharging the charge in a path forming direction.
(2) A film pattern forming method for applying a functional liquid on a substrate to form a film pattern having a film forming region composed of a liquid receiving portion and a liquid flow path connected to the liquid receiving portion. A pattern region forming step for forming the film forming region; a charging step for charging the substrate on which the film forming region is formed; and a step of forming the substrate before or after the substrate is charged. A film pattern forming method comprising: a droplet discharge step of discharging the functional liquid as droplets to the liquid receiving portion.
(3) A film pattern forming apparatus for forming a film pattern having a film forming region including a liquid receiving part and a liquid flow path connected to the liquid receiving part by applying a functional liquid on the substrate, A liquid droplet ejection unit that applies the functional liquid as liquid droplets to the liquid receiving unit; a substrate on which the substrate is mounted; a mounting table having electrodes arranged in a matrix at intervals; and a liquid flow path A voltage application unit that applies a voltage between at least two electrodes positioned correspondingly to discharge the voltage, and applies an electrostatic force to the functional liquid applied to the liquid receiving unit by the discharge between the two electrodes. Film pattern forming device to give.

The schematic perspective view which shows the structure of the film | membrane pattern formation apparatus of 1st Embodiment. FIG. 3 is a schematic cross-sectional view showing the main structure of a droplet discharge head. Schematic which shows the structure of a mounting base. Schematic which shows the electrical structure of a floating island electrode. Schematic which shows the shape of a film | membrane pattern. Schematic which shows a guidance process. The time chart which shows an example of the voltage generation pattern of a voltage generation part. The schematic sectional drawing which showed a mode that the droplet of a functional liquid landed and spread in the liquid flow path. The schematic plan view which shows the other film pattern formation method. Schematic which shows the wiring pattern formed with the film | membrane pattern formation method of 1st Embodiment. Schematic which shows the other film pattern formation method and film pattern formation apparatus of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 4 ... Mounting stand, 9 ... Voltage generation part, 10 ... Static electricity generation part, 20 ... Droplet discharge head as a droplet discharge part, 40 ... Floating island electrode as an electrode, 50 ... Film pattern, 51 ... Film formation area, 53 A liquid flow path as a guide path, 60, a droplet, 70, a mounting table according to the second embodiment, 100, a film pattern forming apparatus, and 200, a film pattern forming apparatus according to the second embodiment.

Claims (12)

A film pattern forming method for applying a functional liquid onto a substrate to form a predetermined film pattern,
A pattern region forming step for forming a guide path according to the shape of the film pattern;
An application step of applying the functional liquid to a liquid receiving portion connected to the guide path and receiving the applied functional liquid;
A guiding step of guiding and spreading the functional liquid applied to the liquid receiving portion along the guide path ;
In the inducing step, the functional liquid is induced by applying an electrostatic force .   The film pattern forming method according to claim 1, wherein in the pattern region forming step, the guide path is formed in a concave shape or a groove shape. The pattern region forming step includes a lyophilic treatment step in which the guide path and the liquid receiving portion are treated so as to have lyophilic properties, and a region other than the guide path and the liquid receiving portion in the substrate has liquid repellency. The film pattern forming method according to claim 1, further comprising: a liquid repellent treatment step of treating so as to have. 4. The film pattern forming method according to claim 1, wherein in the coating step, the functional liquid is ejected as droplets from a droplet ejection head to the liquid receiving portion . 5. The induction process, the film pattern forming method according to any one of claims 1 to 4, characterized that you induce the functional liquid by applying an electrostatic force in a direction in which the guide passage is formed . The induction process, the film pattern forming method according to any one of claims 1 to 5, wherein to Rukoto the substrate charged state before or after applying coating the functional liquid in the coating step . The film pattern formation according to claim 6 , wherein, in the inducing step, the charge amount of the substrate is 3000 (V) or more in terms of the potential of the substrate measured using a surface potentiometer. Method.   The film pattern forming method according to claim 1, wherein the functional liquid is a dispersion solution in which fine particles of a functional material are dispersed in a liquid medium.   9. The film pattern forming method according to claim 8, wherein the functional material is a conductive material, and a wiring pattern made of the conductive material is formed as the film pattern.   9. The film pattern forming method according to claim 8, wherein the functional material is a fluorescent material or a dye, and an element pattern made of the fluorescent material or the dye is formed as the film pattern. A film pattern forming apparatus that forms a film pattern by applying a functional liquid onto a substrate and inducing the functional liquid by applying an electrostatic force ,
A droplet discharge section for discharging the functional liquid as droplets;
The substrate is mounted, and a mounting table having electrodes arranged in a matrix at intervals,
A voltage generator for generating a high voltage,
The film pattern forming apparatus, wherein the voltage generator discharges between the electrode positioned corresponding to the film pattern formed on the substrate placed on the mounting table. A film pattern forming apparatus that forms a film pattern by applying a functional liquid onto a substrate and inducing the functional liquid by applying an electrostatic force ,
A droplet discharge section for discharging the functional liquid as droplets;
A mounting table on which the substrate is mounted;
A film pattern forming apparatus comprising: a static electricity generating unit that charges the substrate placed on the mounting table.

Images