JP5078160B2 - Pattern forming method and pattern forming apparatus - Google Patents

Description

  The present invention relates to a pattern forming method and a pattern forming apparatus, and more particularly to a pattern forming method and a pattern forming apparatus for forming a linear pattern on the surface of a substrate using an ink jet recording head.

  In Patent Document 1, in a method of forming a functional film pattern by ejecting a liquid containing a functional component onto a substrate by inkjet, a contact angle with respect to the liquid is 30 [deg] or more and 60 [deg] or less. It is disclosed that a conductive film wiring is formed by discharging the liquid on a substrate having a film formation surface so that an overlap of 1% to 10% of the diameter occurs when applied on the substrate. Yes.

  Patent Document 2 discloses a dot matrix printing method in which printing is performed while a print head arranged at an angle of 45 ° with respect to the XY direction is moved relative to the X or Y direction.

Patent Document 3 discloses an on-demand coding device in which coating liquids ejected from a plurality of ejection ports are deposited on the same area of a medium so as to overlap each other.
JP 2003-80694 A JP-A-3-218837 Japanese Patent Laid-Open No. 11-123817

  When wiring drawing is performed by inkjet, a bump-like bulge (bulge) may be formed in a part of the wiring, or a jagged (jaggy) may be formed without forming a smooth outline (straight line) of the wiring. When wiring drawing is performed, it is necessary to prevent the occurrence of the bulge and jaggy described above. As a method for preventing the occurrence of jaggies, for example, a method of reducing the center-to-center distance (dot pitch) of droplets that have landed on the substrate is considered to be smaller than a predetermined value.

  By the way, when drawing a wiring having a narrow width, it is necessary to discharge a fine droplet having a small volume. When discharging fine droplets, the nozzle diameter is reduced or the meniscus surface is precisely controlled. However, when the nozzle diameter is reduced or the meniscus surface is precisely controlled, the ejection frequency (number of times of liquid ejection per second) of the ink jet recording head decreases.

  Patent Documents 1 to 3 do not simultaneously increase the discharge frequency and shorten the dot pitch.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a pattern forming method and a pattern forming apparatus capable of simultaneously increasing the ejection frequency and shortening the dot pitch.

In order to solve the above-described problem, a pattern forming method according to a first aspect of the present invention includes a plurality of nozzles that discharge droplets containing a functional component to the surface of a substrate that does not penetrate the droplets. A pattern forming method for forming a linear pattern by sequentially discharging the droplets in one direction on a surface of the substrate from an inkjet recording head having the plurality of nozzles arranged in a line at intervals l The angle formed by the linear pattern and the nozzle row is φ, the relative velocity between the inkjet recording head and the substrate in the direction parallel to the linear pattern is u, and the liquid adjacent to the surface of the substrate The time interval between droplets is t, the diameter of the droplet before landing on the surface of the substrate is d, the diameter of the droplet is d, and the contact angle of the droplet with respect to the substrate is θ. If

  The inkjet recording head is controlled so as to satisfy the above condition.

According to the first aspect, when the linear pattern L is formed using a plurality of nozzles arranged at the nozzle pitch l [μm], the condition of the above formula [Equation 1] is satisfied. , Angle φ [°], relative velocity u [mm / s], droplet ejection time interval t [ms], droplet diameter d [μm] and contact angle θ [ rad ] are controlled. Therefore, the occurrence of bulge can be prevented.

  In the pattern forming method according to the second aspect of the present invention, in the first aspect, when p = lcosφ-ut, the volume ratio of the volatile solvent contained in the droplets is

  That's it.

  According to the said 2nd aspect, generation | occurrence | production of a bulge can be effectively prevented by making the ratio of the volume of the volatile solvent in a liquid more than the value represented by said Formula [Equation 2]. .

  In the pattern forming method according to the third aspect of the present invention, in the first or second aspect, the relative velocity between the ink jet recording head and the substrate in a direction perpendicular to the linear pattern is v. In addition,

  The ink jet recording head is controlled so as to satisfy the above condition.

  According to the third aspect, the angle φ [°] formed by the nozzle line and the linear pattern so as to satisfy the above formula [Equation 3], and the relative velocity v [perpendicular to the linear pattern v [ [mm / s] is adjusted so that the ejection frequency is equal to or higher than a predetermined value (the time interval of droplet ejection is 1 millisecond or less), and the occurrence of bulges can be suppressed.

The pattern forming method according to a fourth aspect of the present invention is the pattern forming method according to any one of the first to third aspects, wherein the liquid droplets are ejected from the nozzle to a predetermined region other than the substrate before discharging the droplet onto the surface of the substrate. The droplets are preliminarily ejected, and the formation of the linear pattern is started within 1 second after the preliminary ejection.

  According to the said 4th aspect, generation | occurrence | production of jaggy and a bulge can be more effectively prevented by performing preliminary discharge in addition to said process.

In the pattern forming apparatus according to the fifth aspect of the present invention, a plurality of nozzles that discharge droplets containing a functional component to the surface of a substrate that is not soaked with the droplets are arranged in a line at an interval l. When forming a linear pattern by sequentially ejecting the droplets in one direction from the substrate to the surface of the substrate with an inkjet recording head, an angle formed by the linear pattern and the row of the nozzles is φ, before landing the relative speed between the substrate and parallel to the direction of the ink jet recording head in the linear pattern u, the time interval of jetting of droplets adjacent the surface of the substrate t, the surface of the substrate When the diameter of the droplet is a true sphere, the diameter of the droplet is d, and the contact angle of the droplet with respect to the substrate is θ,

  Control means for controlling the ink jet recording head so as to satisfy the above condition.

  In the pattern forming apparatus according to the sixth aspect of the present invention, when p = lcosφ-ut in the fifth aspect, the volume ratio of the volatile solvent contained in the droplets is

  That's it.

  The pattern forming apparatus according to a seventh aspect of the present invention is the pattern forming apparatus according to the fifth or sixth aspect, wherein the control means has a relative speed between the inkjet recording head and the substrate in a direction perpendicular to the linear pattern. Where v is

  The ink jet recording head is controlled so as to satisfy the above condition.

A pattern forming apparatus according to an eighth aspect of the present invention is the support plate for supporting the substrate according to the fifth to seventh aspects, and is disposed on the support plate or on a different surface from the support plate, A preliminary discharge area disposed around a surface of the support plate on which the substrate is placed, and the control means discharges the liquid droplets from the nozzle onto the surface of the substrate. The droplets are preliminarily ejected in the preliminary ejection region, and the formation of the linear pattern is started within 1 second after the preliminary ejection.

According to the present invention, when the linear pattern L is formed using a plurality of nozzles arranged at a nozzle pitch l [μm], the angle φ is set so as to satisfy the condition of the above equation [Equation 1]. By controlling at least one of [°], relative velocity u [mm / s], droplet ejection time interval t [ms], droplet diameter d [μm] and contact angle θ [ rad ], The occurrence of jaggy can be prevented. Further, the angle φ [°] formed by the nozzle line and the linear pattern and the relative velocity v [mm / s] in the direction perpendicular to the linear pattern are adjusted so as to satisfy the above formula [Equation 3]. By setting the ejection frequency to a predetermined value or more (the time interval between droplet ejections is set to 1 millisecond or less), the occurrence of bulges can be suppressed. Furthermore, according to the present embodiment, it is possible to more effectively prevent the occurrence of bulges by setting the volume ratio of the volatile solvent in the liquid to be equal to or greater than the value represented by the above formula [Equation 2]. it can.

  Preferred embodiments of a pattern forming method and a pattern forming apparatus according to the present invention will be described below with reference to the accompanying drawings.

  As methods for preventing the occurrence of bulge and jaggy, the following methods <1> to <3> are conceivable.

  <1> Increasing the number of discharges of liquid per unit time, the liquid on the substrate (substrate through which liquid does not permeate) becomes one large mass and is in an equilibrium state (the liquid is wet and spreads and the contour of the liquid is stable). A method to suppress the generation of periodic small bulges.

  <2> A method of preventing the occurrence of jaggy by setting the dot pitch to a certain value or less.

  <3> Since a large bulge that occurs randomly (non-periodically) in the length direction of the wiring occurs on a time scale in seconds, the liquid is discharged before a predetermined time (several seconds) elapses after the liquid has landed. A method of suppressing the generation of random bulges by solidifying the liquid or volatilizing the solvent using a volatile solvent so that the liquid does not wet and spread.

  However, as described above, when a wiring having a narrow width is drawn, the discharge frequency (number of times of liquid discharge per second) of the ink jet recording head is lowered because fine droplets are discharged.

  In this embodiment, in order to simultaneously increase the ejection frequency and shorten the dot pitch, the inkjet recording head having a plurality of nozzles is inclined with respect to the scanning direction (printing direction). By ejecting the liquid while scanning, the ejection frequency is increased and the nozzle pitch in the direction perpendicular to the scanning direction is shortened in a pseudo manner.

[Configuration of pattern forming apparatus]
FIG. 1 is a perspective view showing a pattern forming apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, a pattern forming apparatus (inkjet recording apparatus) 10 according to the present embodiment includes an inkjet recording head (hereinafter referred to as a recording head) 12 and a support plate 14.

  The recording head 12 is a line type recording head in which a plurality of nozzles 22 are arranged in a straight line.

  On the support plate 14, a substrate 16 that is a target for discharging liquid by the recording head 12 is placed. The support plate 14 is supported so that the clearance with the recording head 12 is constant, and can be scanned in the main scanning direction (x direction in FIG. 1).

  By discharging droplets from the recording head 12 while scanning the support plate 14 in the x direction, it is possible to discharge liquid over the entire drawing region of the substrate 16.

  FIG. 2 is a plan view showing a surface on which the nozzles of the recording head 12 are formed.

  As shown in FIG. 2, the recording head 12 has a structure in which ejection elements 20 (see FIG. 3) including nozzles 22 and pressure chambers 24 are linearly arranged at substantially equal intervals.

  The nozzle diameter of the recording head 12 is φ35 μm, for example, and the distance (nozzle pitch) between the centers of adjacent droplets on the substrate 16 is 254 μm (100 npi), for example. The recording head 12 can continuously eject droplets at a droplet ejection period of 1 kHz and a head scanning speed of 0.1 m / s.

  FIG. 3 is a cross-sectional view showing the ejection element 20.

  The pressure chamber 24 provided corresponding to the nozzle 22 has a substantially square planar shape. An outlet to the nozzle 22 is provided at one of the diagonal corners of the pressure chamber 24, and a liquid supply port 26 to the pressure chamber 24 is provided at the other. The planar shape of the pressure chamber 24 may have various forms other than the above-described square, such as a quadrangle (diamond, rectangle), a pentagon, a hexagon, other polygons, a circle, and an ellipse.

  As shown in FIG. 3, the pressure chamber 24 of the ejection element 20 communicates with the common flow path 28 via the supply port 26. The common flow path 28 communicates with a tank (not shown) as a liquid supply source, and the liquid supplied from the tank is distributed and supplied to each pressure chamber 24 via the common flow path 28.

  A piezoelectric element 34 having individual electrodes 32 is joined to a pressure plate (vibrating plate that also serves as a common electrode) 30 constituting a part of the pressure chamber 24 (the top surface in FIG. 3). In addition, as a material of the piezoelectric element 34, for example, a piezoelectric body such as lead zirconate titanate (PZT) or barium titanate can be used.

  When a drive signal is applied between the individual electrode 32 and the common electrode, the piezoelectric element 34 is deformed and the volume of the pressure chamber 24 changes. As a result, the pressure in the pressure chamber 24 changes, whereby droplets are ejected from the nozzle 22. Then, when the displacement of the piezoelectric element 34 is restored after the liquid is discharged, the pressure chamber 24 is refilled with the new liquid from the common flow path 28 through the supply port 26.

  In the present embodiment, a method of pressurizing ink by deformation of the piezoelectric element 34 is employed, but an actuator of a method other than the above (for example, a thermal method) may be applied.

  FIG. 4 is a block diagram showing a control system of the pattern forming apparatus 10.

  The pattern forming apparatus 10 includes a communication interface 40, a system controller 42, a memory 46, a motor driver 48, a heater driver 52, a droplet ejection control unit 56, a buffer memory 58, and a head driver 60.

  The communication interface 40 is an interface unit that receives droplet ejection data sent from the host computer 80. As the communication interface 40, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. Note that a buffer memory for speeding up communication may be mounted in this portion.

  The system controller 42 includes a central processing unit (CPU) and its peripheral circuits, and is a control unit that controls each part of the pattern forming apparatus 10. The system controller 42 performs communication control with the host computer 80, read / write control of the memory 46, and the like, and generates control signals for controlling the motor 50 and the heater 54 of the transport drive system.

  The program storage unit 44 stores a control program for the pattern forming apparatus 10. The system controller 42 appropriately reads out various control programs stored in the program storage unit 44 and executes the control programs.

  The memory 46 is storage means used as a temporary storage area for data and a work area when the system controller 42 performs various calculations. As the memory 46, a magnetic medium such as a hard disk can be used in addition to a memory made of a semiconductor element.

  The motor 50 is a motor that drives at least one of the recording head 12 and the support plate 14 in FIG. 1 to drive a drive mechanism for relatively scanning the recording head 12 and the support plate 14. The motor driver 48 drives the motor 50 in accordance with a control signal from the system controller 42.

  The heater driver 52 drives the heater 54 in accordance with a control signal from the system controller 42. The heater 54 includes a temperature adjusting heater provided in each part of the pattern forming apparatus 10.

  The droplet ejection data sent from the host computer 80 is taken into the pattern forming apparatus 10 via the communication interface 40 and temporarily stored in the memory 46.

  The droplet ejection control unit 56 has a signal processing function for performing various processing and correction processing for generating a discharge control signal from the droplet ejection data in the memory 46 according to the control of the system controller 42. A control unit that supplies a discharge control signal (discharge data) to the head driver 60. The droplet ejection control unit 56 performs necessary signal processing, and controls the liquid ejection amount and ejection timing of the recording head 12 via the head driver 60 based on the droplet ejection data.

  The head driver 60 drives the piezoelectric element 34 of the recording head 12 based on the ejection data given from the droplet ejection control unit 56. The head driver 60 may include a feedback control system for keeping the head driving conditions constant.

  The droplet ejection control unit 56 includes a buffer memory 58, and droplet ejection data, parameters, and other data are temporarily stored in the buffer memory 58 when droplet ejection data is processed by the droplet ejection control unit 56.

  The buffer memory 58 can also be used as the memory 46. Further, a mode in which the droplet ejection control unit 56 and the system controller 42 are integrated and configured by one processor is also possible.

  Although not shown, the pattern forming apparatus 10 includes a supply system for supplying liquid to the recording head 12 and a maintenance unit that performs maintenance of the recording head 12.

[Liquid discharge conditions]
FIG. 5 is a diagram schematically illustrating a scanning control procedure when the pattern L is drawn by relatively scanning the recording head 12 and the substrate 16 in the x direction. In the following description, the direction in which the recording head 12 and the substrate 16 are relatively scanned (main scanning direction) is the x direction, the direction parallel to the substrate 16 and perpendicular to the x direction (sub-scanning direction) is the y direction, The direction perpendicular to the xy plane is the z direction, the direction in which the linear pattern L is formed (pattern formation direction, printing direction) is the U direction, the direction parallel to the substrate 16 and perpendicular to the U direction is the V direction.

  As shown in FIG. 5, at least two or more nozzles 22 are used when one linear pattern L is formed.

  As shown in FIG. 5, in the recording head 12, the angle formed by the straight line (nozzle line NL) connecting the centers of the nozzles 22 with respect to the printing direction (U direction) is φ [°] (0 ° <φ <90 °). To be held. The recording head 12 and the substrate 16 are relatively scanned in the main scanning direction (x direction) while the angle between the nozzle line NL and the U axis is maintained at φ [°], and the linear shape extends in the U direction. (For example, a straight line) pattern L is drawn.

[Liquid ejection condition 1 (dot pitch p)]
Here, if the interval (dot pitch p) between the droplets D ejected onto the substrate 16 is large, jaggies are likely to occur. Hereinafter, the condition of the dot pitch p for preventing the occurrence of jaggy will be described.

  FIG. 6 is a diagram (cross-sectional view and plan view) schematically showing the change over time of the droplets deposited on the surface of the substrate 16.

As shown in FIG. _6A , the droplets D1 _eqm ejected from the recording head 12 and landed on the surface of the substrate 16 are substantially circular at the beginning of landing and are in contact with adjacent droplets. Then, as shown in FIG. 6B, each droplet D wets and spreads to form a pattern L. Here, as a liquid (ink), what was produced | generated by mixing a functional component (for example, silver nanoparticle) with a volatile solvent (for example, water or tetradecane) can be used.

Here, it is assumed that the substrate 16 is a medium in which the droplet D does not permeate (does not penetrate), and the volume of the droplet is preserved before and after landing on the substrate 16. In addition, it is assumed that the contact angle θ [ rad ] of the droplet D with respect to the substrate 16 is constant.

At this time, the ratio (spreading ratio) β _eqm of the diameter d _eqm [μm] of the droplet D1 _eqm when landing on the substrate 16 to the diameter d [μm] of the droplet D before landing is expressed by the following equation (1). It is represented by Here, the diameter d is a diameter when the droplet D before landing is converted into a true sphere.

When the width of the pattern L is w [μm], the cross-sectional area S1 [μm ² ] when the liquid D2 _eqm in FIG. 6B is cut through the center of the liquid D2 _eqm and parallel to the zy plane is It is expressed by equation (2).

Accordingly, when the distance (nozzle pitch) between the centers of adjacent droplets on the substrate 16 is p [μm], the volume Va [μm ³ ] of the liquid D2 _eqm is expressed by the following equation (3).

On the other hand, since the diameter of the droplet before landing is d, the volume Vb [μm ³ ] of the droplet D before landing is expressed by the following equation (4).

  According to assumption 1, the volume of the droplet D is unchanged before and after landing. When Va = Vb is solved for the line width w, the following equation (5) is obtained.

Here, since w ≧ d _eqm = β _eqm d, when the equation (5) is solved with the dot pitch p as a variable, the conditional equation (6) of the dot pitch p is obtained.

  Here, if the distance (nozzle pitch) between the nozzle centers of the recording head 12 is 1 [μm], then p = 1 × cosφ. Substituting this into the above equation (6) yields the following equation (7).

  The above equation (7) is a conditional equation when the relative speed in the printing direction (the U direction in FIG. 5) between the recording head 12 and the substrate 16 is zero.

  The relative velocity in the printing direction (U direction) between the recording head 12 and the substrate 16 is u [mm / s] (when the recording head 12 moves in the printing direction (+ U direction) with respect to the substrate 16, u> 0. If the time interval of droplet ejection between adjacent dots on the substrate 16 is t [ms], the dot pitch between adjacent dots is shortened by ut [μm]. Is obtained.

The angle φ [°], the relative velocity u [mm / s], the droplet ejection time interval t [ms], the droplet diameter d [μm], and the contact angle θ so as to satisfy the condition of the above equation (8). By controlling at least one of [ rad ], it is possible to prevent the contour of the pattern L from being jagged (jaggy).

[Liquid ejection condition 2 (time interval of droplet ejection)]
Next, the condition of the time interval of droplet ejection for preventing the occurrence of bulge will be described.

Table 1 shows that the droplet diameter d = 26.0 [μm], d _eqm = 55.5 [μm], and the contact angle θ = 30 [°] (that is, the above-described conditional expression (6) is satisfied) This shows the stability of the line width w when a line is drawn by changing the number of times droplets D are printed per second (printing frequency) and the dot pitch (under conditions).

  In Table 1, when the line width w of the drawn line is stable (for example, the fluctuation amount of the line width w (for example, the difference between the maximum value and the minimum value of the line width per unit length) is less than a predetermined value. ) Is “◯” and the fluctuation amount of the line width w is equal to or greater than the predetermined value, but the fluctuation amount is not larger than the case of “×”, “△”, the maximum fluctuation amount when “△” A case where the fluctuation amount of the line width w is larger than that is represented by “x”. According to the experimental results shown in Table 1, when the printing frequency was set to 1000 Hz or more, the line width w was stabilized and bulges and jaggies were not generated.

  Therefore, the interval from the printing of the nth drop to the printing of the (n + 1) th drop is set to 1 millisecond or less. By doing so, on the substrate 16 during printing, a portion in an equilibrium state (a state where the droplet D wets and spreads and the shape of the droplet D becomes stable) and a non-equilibrium state (the droplet D wets and spreads) are printed. It is possible to prevent the portion of the liquid droplet D in the middle of being in a state before the shape is stabilized) from being mixed. As a result, the liquid droplets D in a non-equilibrium state are largely agglomerated, and the pattern L is brought into an equilibrium state without being thickened, so that line drawing with a uniform width is possible.

  Here, when the relative speed in the direction (V direction) perpendicular to the printing direction (U direction) is v [mm / s], the interval from the printing of the nth drop to the printing of the (n + 1) th drop Conditional expression (9) is obtained for setting the value to 1 ms or less.

  By adjusting the angle φ [°] formed by the nozzle line NL and the U axis and the relative velocity v [mm / s] in the V direction so as to satisfy the above formula (9), the occurrence of bulges can be suppressed. .

[Liquid discharge condition 3 (Condition of ratio of solvent (volatile component) in liquid)]
Next, since the bulge is likely to be generated when the ratio of the volatile solvent contained in the liquid is large, the condition of the ratio of the solvent in the liquid for preventing the generation of the bulge will be described. Here, the liquid discharged onto the substrate 16 is, for example, a liquid (ink) in which silver nanoparticles are dispersed in a solvent of water or tetradecane (both are volatile).

As described above, when the pattern L is drawn by discharging the liquid onto the substrate 16, a bulge is likely to occur if the amount of the solvent (liquid component) on the pattern L is too large with respect to the line width w. In order to prevent the occurrence of bulges, when the solvent is volatilized (evaporated) after the droplets D have landed on the substrate 16, the amount of the solvent on the substrate 16 should be reduced to such an extent that bulges do not occur. . Specifically, the diameter d _eqm [μm] of the droplet D after the solvent is volatilized by spreading on the substrate 16 is made equal to the line width w [μm]. When w = d _eqm , the volume V ₁ [μm ³ ] of the droplet D2 _eqm after wetting and spreading and the solvent volatilizes is expressed by the following equation (10).

  Here, p = l cos φ−ut.

On the other hand, since the diameter of the droplet before landing is d, the volume V ₂ [μm ³ ] of the droplet D before landing is expressed by the following formula (11).

Therefore, the ratio (volume ratio) {(V ₂ −V ₁ ) / V ₂ × 100 [%]} of the volatile solvent contained in the liquid is represented by the following formula (12).

  By setting the volume ratio of the volatile solvent in the liquid to be equal to or greater than the value represented by the above formula (12), the occurrence of bulge can be prevented.

[Liquid discharge condition 4 (preliminary discharge)]
Next, preliminary ejection before starting printing will be described.

  In the ink jet type pattern forming apparatus, when a state where ink is not ejected continues for a predetermined time or longer, the ink solvent adhering to the vicinity of the nozzle 22 of the recording head 12 volatilizes (evaporates), and the silver nanoparticles of the ink The concentration of the resin becomes higher and the viscosity becomes higher. Then, when the piezoelectric element 34 (see FIG. 3) is operated, liquid ejection failure or non-ejection occurs.

  Therefore, in the present embodiment, the ink is adhered to the vicinity of the nozzle 22 by performing preliminary discharge (“empty discharge”, “purge”, “spitting”) that discharges ink to a predetermined preliminary discharge area before starting printing. Remove ink with high viscosity. In addition, after the nozzle surface is cleaned by a wiper (not shown) of a cleaning blade provided as a nozzle surface cleaning means, preliminary discharge is performed, and foreign matter is mixed into the nozzle by the wiper rubbing operation. To prevent.

  When the preliminary ejection is performed, it is preferable to start printing within 1 second after the preliminary ejection. This makes it possible to draw a line with a stable and uniform width.

  Preliminary ejection on the substrate 16 may give a serious problem to the product. Therefore, it is desirable to provide a preliminary ejection area in the pattern forming apparatus 10. In order to shorten the time from the start of preliminary discharge to the start of printing, it is desirable to install the preliminary discharge area around the substrate 16 or the entire print start position ST.

  7 to 9 are plan views showing examples of the arrangement of the preliminary ejection regions.

  In the example shown in FIG. 7, the recording head 12 is movable in the xy direction, and the preliminary ejection area 100 is provided in the area surrounding the substrate 16 on the surface of the support plate 14 on which the substrate 16 is placed.

  When preliminary ejection is performed, the shortest length L1 is selected from the perpendicular lines extending from the printing start position (point) ST of the substrate 16 to the inner periphery of the preliminary ejection area 100. Then, preliminary discharge is performed at a point (preliminary discharge position) PR on a line obtained by extending the most drooping pattern L1 to the preliminary discharge region 100 side. For example, the preliminary ejection position PR is set to a position where the distance between the preliminary ejection position PR and the substrate 16 is longer than the predicted value of the radius of the droplet when the preliminary ejected liquid has landed on the preliminary ejection area 100. Is done. Then, after the preliminary ejection is completed, the recording head 12 is moved to the print start position ST along the vertical pattern L1. Thereby, the time from the end of preliminary discharge to the start of printing at the print start position ST can be shortened.

  In the example shown in FIGS. 8 and 9, the preliminary discharge region 100 </ b> A is provided on both sides of the substrate 16. In the example shown in FIG. 8, the recording head 12 is movable in the ± y direction, and the substrate 16 is movable in the ± x direction. In the example shown in FIG. 9, the recording head 12 can move in the xy direction, and the substrate 16 can move in the + x direction.

  Also in the examples shown in FIGS. 8 and 9, by setting the preliminary discharge position as in FIG. 7, the time from the end of the preliminary discharge to the start of printing at the print start position ST can be shortened.

  It has been confirmed that the phenomenon in which part of the line swells greatly occurs on a time scale of 2 to 8 seconds. For this reason, it is also possible to prevent the occurrence of bulges by controlling the heater 54 and the like to solidify the droplets D on the substrate 16 within one second after landing.

[Pattern formation procedure]
Next, the pattern formation procedure will be described with reference to the flowchart of FIG.

  First, the system controller 42 obtains the coordinates of the print start position ST on the substrate 16 and calculates the coordinates of the preliminary discharge possible point (preliminary discharge position PR) closest to the print start position ST in the preliminary discharge area 100. . Then, the system controller 42 outputs a control signal to the head driver 60, and moves the recording head 12 to the preliminary ejection position PR (step S10).

  Next, preliminary ejection is performed (step S12), the recording head 12 is moved to the print start position ST (step S14), and printing is started (step S16). Then, at a dot pitch that satisfies the condition of the above expression (6), the angle φ [°] formed by the nozzle line NL and the U axis and the relative velocity v [mm] in the V direction so as to satisfy the condition of the above expression (9). / S] is adjusted (that is, the pattern L is drawn so that the droplet ejection interval is 1 millisecond or less) (step S18).

  Here, the system controller 42 controls the recording head 12 and the support plate 14 so that the processes from steps S12 to S16 are completed within one second.

According to the present embodiment, when the linear pattern L is formed using a plurality of nozzles arranged at a nozzle pitch l [μm], the angle φ is set so as to satisfy the condition of the above formula (6). By controlling at least one of [°], relative velocity u [mm / s], droplet ejection time interval t [ms], droplet diameter d [μm] and contact angle θ [ rad ], In addition to preventing the occurrence, the angle φ [°] formed by the nozzle line NL and the U axis and the relative velocity v [mm / s] in the V direction are adjusted so as to satisfy the above formula (9). By setting it to a value greater than or equal to (the time interval between droplet ejections is set to 1 millisecond or less), the occurrence of bulge and jaggy can be suppressed. Furthermore, by making the volume ratio of the volatile solvent in the liquid equal to or greater than the value represented by the above formula (12), the occurrence of bulge can be more effectively prevented.

  In the present embodiment, the line head in which the nozzles 22 are arranged in a line on the same straight line is used. However, for example, a recording head in which the nozzles are arranged in a matrix may be used.

The perspective view which shows the pattern formation apparatus which concerns on the 1st Embodiment of this invention. The top view which shows the surface in which the nozzle of the recording head 12 was formed. Sectional view showing the ejection element 20 Block diagram showing a control system of the pattern forming apparatus 10 The figure which shows typically the procedure of the scanning control when drawing the pattern L by scanning the recording head 12 and the board | substrate 16 relatively to a x direction. The figure which shows typically the time-dependent change of the droplet hit | damaged on the surface of the board | substrate 16 (sectional drawing and top view) Plan view showing an example of the arrangement of the preliminary ejection regions Plan view showing an example of the arrangement of the preliminary ejection regions Plan view showing an example of the arrangement of the preliminary ejection regions Flow chart showing pattern formation procedure

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Pattern formation apparatus, 12 ... Recording head, 14 ... Support plate, 16 ... Substrate, 20 ... Discharge element, 22 ... Nozzle, 24 ... Pressure chamber, 26 ... Supply port, 28 ... Common flow path, 30 ... Pressure plate, 32 ... Individual electrode, 34 ... Piezoelectric element, 40 ... Communication interface, 42 ... System controller, 44 ... Program storage, 46 ... Memory, 48 ... Motor driver, 50 ... Motor, 52 ... Heater driver, 54 ... Heater, 56 ... Droplet ejection control unit, 58 ... Buffer memory, 60 ... Head driver, 80 ... Host computer

Claims (8)

From the inkjet recording head having a plurality of nozzles that discharge droplets containing a functional component to the surface of the substrate that does not penetrate the droplets, the droplets are sequentially discharged onto the surface of the substrate in one direction. A pattern forming method for forming a linear pattern,
The plurality of nozzles are arranged in a line at an interval l,
The angle between rows of the nozzle and the linear pattern phi, the relative speed between the substrate and parallel to the direction of the ink jet recording head in the linear pattern u, the droplets adjacent the surface of the substrate The time interval between droplets is t, the diameter of the droplet before landing on the surface of the substrate is d, the diameter of the droplet is d, and the contact angle of the droplet with respect to the substrate is θ. In case,

A pattern forming method of controlling the ink jet recording head so as to satisfy the above condition. When p = lcosφ-ut, the volume ratio of the volatile solvent contained in the droplet is

The pattern forming method according to claim 1, which is as described above. When the relative velocity between the inkjet recording head and the substrate in the direction perpendicular to the linear pattern is v,

The pattern forming method according to claim 1, wherein the inkjet recording head is controlled so as to satisfy the following condition. Before discharging the droplets from the nozzle to the surface of the substrate, the droplets are pre-discharged to a predetermined region other than the substrate,
The pattern formation method according to claim 1, wherein the formation of the linear pattern is started within 1 second after the preliminary ejection. An ink jet recording head in which a plurality of nozzles that discharge droplets containing a functional component to a surface of a substrate into which the droplets do not permeate are arranged in a line at intervals l;
When forming a linear pattern by sequentially discharging the droplets from the substrate onto the surface of the substrate in one direction, an angle formed by the linear pattern and the row of nozzles is φ, and the linear pattern The relative velocity between the inkjet recording head and the substrate in the direction parallel to the surface is u, the time interval between droplets adjacent to the surface of the substrate is t, and the droplets before landing on the surface of the substrate When the diameter of the droplet when the shape is a true sphere is d and the contact angle of the droplet with respect to the substrate is θ,

Control means for controlling the inkjet recording head so as to satisfy the following condition:
A pattern forming apparatus comprising: When p = lcosφ-ut, the volume ratio of the volatile solvent contained in the droplet is

The pattern forming apparatus according to claim 5, which is the above. When the relative speed between the inkjet recording head and the substrate in the direction perpendicular to the linear pattern is v,

The pattern forming apparatus according to claim 5, wherein the inkjet recording head is controlled so as to satisfy the following condition. A support plate for supporting the substrate;
A preliminary ejection region disposed on the support plate or on a surface different from the support plate, and disposed around a surface of the support plate on which the substrate is placed;
The control means preliminarily discharges the droplets to the preliminary discharge region other than the substrate before discharging the droplets from the nozzle to the surface of the substrate, and the linear shape within one second after the preliminary discharge. The pattern forming apparatus according to claim 5, wherein the formation of the pattern is started.

Images