JP2007152250A - Pattern forming method and liquid droplet ejection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern forming method with which the shape controllability of a pattern to be formed by irradiating ejected liquid droplets with a laser beam is improved and a liquid droplet ejection device. <P>SOLUTION: A head unit 30 mounted with a liquid droplet ejection head 32 is provided with a suction port 33 for sucking the "evaporation component Ev" from the liquid droplets Fb and a photosensor 35 for detecting the optical characteristics (light quantity) of the laser beam B (reflected diffuse light Br) from the landed liquid droplets Fb. The atmosphere of the liquid droplets Fb is subjected to the suction of a low suction speed suppressing the flow of gas until a light quantity detection signal detected by the photosensor 35 attains the drying end potential. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pattern forming method and a droplet discharge device.

  Conventionally, a display device such as a liquid crystal display device or an electroluminescence display device is provided with a substrate for displaying an image. On this type of substrate, an identification code (for example, a two-dimensional code) in which manufacturing information such as the manufacturer and product number is encoded is formed for the purpose of quality control and manufacturing control.

  Such an identification code manufacturing method includes a laser sputtering method in which a metal foil is irradiated with laser light to form a code pattern by sputtering, or a water jet that injects water containing an abrasive material onto a substrate or the like to imprint the code pattern. A method has been proposed (Patent Documents 1 and 2).

  However, in the above laser sputtering method, the gap between the metal foil and the substrate must be adjusted to several to several tens of micrometers in order to obtain a code pattern having a desired size. Therefore, very high flatness is required for the surface of the substrate and the metal foil, and the gap between them must be adjusted with an accuracy of the order of μm. As a result, there is a problem in that the target substrate for manufacturing the identification code is limited, and the versatility is impaired. Further, the water jet method has a problem of contaminating the target substrate because water, dust, abrasives, and the like are scattered when the substrate is engraved.

Therefore, in recent years, an inkjet method has attracted attention as a method for manufacturing an identification code that solves these problems. In the ink jet method, a code pattern is manufactured by discharging a droplet containing metal fine particles from a nozzle of a droplet discharge head and drying the droplet. Therefore, the range of the target substrate for manufacturing the identification code can be easily expanded, and the identification code can be manufactured without contaminating the target substrate.
Japanese Patent Laid-Open No. 11-77340 JP 2003-127537 A

  By the way, in the ink jet method described above, in order to improve the controllability of the shape of the code pattern, it is desired to irradiate laser light onto the landed droplet region and to instantaneously dry a droplet of a desired size. Yes.

  However, when laser light is irradiated onto the landed droplet region, there is a problem that the evaporation component from the droplet adheres to the optical system of the laser light, causing fluctuations in the amount of laser light and the irradiation position. It is considered that such a problem can be solved by providing a suction means for sucking the evaporated component from the droplet in the vicinity of the irradiation position where the laser beam is irradiated to avoid contamination of the optical system by the evaporated component. However, when the evaporated component is sucked in the vicinity of the irradiation position, the gas flow accompanying the suction causes the positional deviation and shape variation of the droplets, which may impair the code pattern shape controllability.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a pattern forming method and a droplet discharge method that improve the shape controllability of the pattern formed by irradiating the discharged droplets with laser light. Is to provide a device.

  The pattern forming method of the present invention is a pattern forming method in which a pattern including a pattern forming material landed on an object is irradiated with laser light to form a pattern on the object. Was sucked at a suction speed corresponding to the fluidity of the droplets.

  According to the pattern forming method of the present invention, when the evaporating component is sucked from the droplet, the flow of the gas accompanying the suction can correspond to the fluidity of the droplet. Therefore, it is possible to avoid the positional deviation and shape variation of the droplets due to the gas flow. As a result, the shape controllability of the pattern composed of droplets irradiated with laser light can be improved.

In this pattern forming method, the suction speed may be increased as the fluidity of the droplets decreases.
According to this pattern forming method, it is possible to apply suction at a low suction speed to droplets in a high fluidity state (immediately after landing), and to droplets in a low fluidity state (dry state). High suction speed can be applied. Therefore, it is possible to avoid the positional deviation and shape variation of the droplets irradiated with the laser light, and it is possible to improve the evaporating component suction efficiency.

In this pattern forming method, the suction speed may be controlled based on optical characteristics of laser light from the droplet region.
According to this pattern forming method, the fluidity of the droplet can be made to correspond to the optical characteristics of the laser light from the region of the droplet. Therefore, the suction corresponding to the fluidity of the droplet can be more reliably performed, and the positional deviation and shape variation of the droplet can be more reliably avoided.

  In this pattern forming method, the suction speed is controlled based on at least one of the light amount, wavelength, wavelength distribution, deflection state, polarization state, phase distribution, and intensity distribution of the laser light from the droplet region. It may be.

  According to this droplet discharge device, at least one of the light amount, wavelength, wavelength distribution, deflection state, polarization state, phase distribution, and intensity distribution of the laser light can be made to correspond to the suction speed. Therefore, the suction speed for sucking the evaporated component can be more accurately associated with the fluidity of the droplet, and the positional deviation and shape variation of the droplet irradiated with the laser light can be avoided more reliably.

In this pattern formation method, the suction speed may be controlled based on the evaporation component from the droplet region.
According to this pattern forming method, the fluidity of the droplet can be made to correspond to the evaporation component from the region of the droplet. Accordingly, the suction speed of the evaporation component can be more reliably associated with the fluidity of the droplet, and the positional deviation and shape variation of the droplet irradiated with the laser light can be more reliably avoided.

In this pattern forming method, the suction speed may be controlled based on at least one of the amount and type of the evaporation component from the droplet region.
According to this droplet discharge device, at least one of the amount and type of the evaporated component can be made to correspond to the suction speed, and the suction speed for sucking the evaporated component more accurately corresponds to the fluidity of the droplet. Can be made.

  A droplet discharge device according to the present invention includes a droplet discharge head that discharges a droplet toward an object, and a laser irradiation unit that irradiates a laser beam onto the region of the droplet that has landed on the object. In the droplet discharge device, a suction unit that sucks an evaporation component from the region of the droplet irradiated with the laser light, and the suction unit corresponding to the fluidity of the droplet irradiated with the laser light Suction speed control means for controlling the suction speed.

  According to the droplet discharge device of the present invention, the flow of gas by suction can correspond to the fluidity of the droplet. Therefore, it is possible to avoid positional deviation and shape variation caused by suction with respect to the droplet irradiated with the laser beam, and to improve the shape controllability of the pattern made of the droplet irradiated with the laser beam. it can.

  The droplet discharge device includes laser light detection means for detecting optical characteristics of laser light from the region of the droplet, and the suction speed control means is based on a detection signal detected by the laser light detection means. The suction speed of the suction means may be controlled.

  According to this droplet discharge device, the suction speed can be controlled based on the laser light from the droplet region. Therefore, the suction speed corresponding to the fluidity of the droplet can be more reliably applied. As a result, it is possible to more reliably avoid positional deviation and shape variation caused by suction with respect to the droplet irradiated with the laser beam.

  In this droplet discharge device, the suction speed control means determines whether or not the droplet has landed on the laser light region based on a detection signal detected by the laser light detection means, and the laser When the droplet has landed on the light region, the suction unit may be driven to start suction of the evaporation component.

  According to this droplet discharge device, suction can be started after the droplet has landed. Accordingly, it is possible to avoid suction of droplets that are being ejected or droplets that are in the middle of flight. As a result, it is possible to suppress the flow of the atmosphere with respect to the droplets that are being ejected or the droplets that are in the middle of flight, and it is possible to stabilize the droplet ejection operation and flight operation. As a result, it is possible to more reliably avoid the positional deviation and shape variation of the droplets caused by suction.

  In the liquid droplet ejection apparatus, the laser light detection means detects at least one of the light amount, wavelength, wavelength distribution, deflection state, polarization state, phase distribution, and intensity distribution of the laser light from the droplet region. You may make it do.

  According to this droplet discharge device, since at least one of the light amount, wavelength, wavelength distribution, deflection state, polarization state, phase distribution, and intensity distribution of the laser beam is detected, the fluidity of the droplet is more detailed. Can be detected.

  The droplet discharge device includes evaporation component detection means for detecting the evaporated component sucked by the suction means, and the suction speed control means is configured to detect the suction means based on a detection signal detected by the evaporation component detection means. The suction speed may be controlled.

  According to this droplet discharge device, the suction speed can be controlled based on the evaporation component from the droplet region. Therefore, the suction speed corresponding to the fluidity of the droplet can be more reliably applied to the region of the droplet. As a result, it is possible to more reliably avoid positional deviation and shape variation caused by suction with respect to the droplet irradiated with the laser beam.

In this droplet discharge device, the evaporation component detection means may detect at least one of the amount and type of the evaporation component from the droplet region.
According to this droplet discharge device, since at least one of the amount and type of the evaporation component is detected, the fluidity of the droplet can be detected in more detail.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. First, a liquid crystal display device 1 having an identification code formed using the pattern forming method of the present invention will be described with reference to FIG.

  In FIG. 1, a rectangular display unit 3 in which liquid crystal molecules are sealed is formed at a substantially central position on one side surface (surface 2 a) of a substrate 2, and a scanning line driving circuit is provided outside the display unit 3. 4 and a data line driving circuit 5 are formed. The liquid crystal display device 1 controls the alignment state of the liquid crystal molecules in the display unit 3 based on the scanning signal supplied from the scanning line driving circuit 4 and the data signal supplied from the data line driving circuit 5. ing. The liquid crystal display device 1 is configured to display a desired image in the area of the display unit 3 by modulating the plane light from the illumination device (not shown) according to the alignment state of the liquid crystal molecules.

  In the lower left corner of the surface 2a, a code area S made up of a square having a side of about 1 mm is defined, and in the code area S, 16 rows × 16 columns of data cells C are virtually divided. In the area of the selected data cell C in the code area S, dots D as patterns are formed, and the plurality of dots D constitute the identification code 10 of the liquid crystal display device 1. In this embodiment, the center position of the data cell C in which the dot D is formed is set as the target discharge position P, and the length of one side of each data cell C is referred to as “cell width W”.

  Each dot D is a hemispherical pattern whose outer diameter is formed by the length of one side of the data cell C (the “cell width W”). The dots D are formed by discharging droplets Fb of the liquid material F (see FIG. 5) to the data cells C, and drying and firing the droplets Fb that have landed on the data cells C. More specifically, the liquid F of the present embodiment is a liquid containing metal fine particles (for example, nickel fine particles and manganese fine particles) dispersed in a solvent with a dispersion medium, and the dots D are the same. The region of the droplet Fb is formed by sequentially irradiating (drying and firing) laser light B (drying laser B1 and firing laser B2: see FIG. 5). The identification code 10 reproduces the product number, lot number, and the like of the liquid crystal display device 1 depending on the presence or absence of the dot D in each data cell C. In the present embodiment, the longitudinal direction of the substrate 2 is referred to as the X arrow direction, and the direction orthogonal to the X arrow direction is referred to as the Y arrow direction.

  Next, a droplet discharge device 20 for forming the identification code 10 will be described with reference to FIG. In the present embodiment, a case will be described in which a plurality of identification codes 10 corresponding to each substrate 2 are formed on a mother substrate 2M as an object in which a plurality of the substrates 2 can be cut out.

  In FIG. 2, the droplet discharge device 20 is provided with a base 21 formed in a substantially rectangular parallelepiped shape, and a plurality of mother substrates 2M are arranged on one side (X arrow direction side) of the base 21. A substrate stocker 22 that can be accommodated is provided. The substrate stocker 22 moves in the vertical direction (Z arrow direction and anti-Z arrow direction) in FIG. 2 to carry out the respective mother substrates 2M to be accommodated onto the base 21 and the mother substrate 2M on the base 21. Are loaded into the corresponding slots.

  On the upper surface 21 a of the base 21, a traveling device 23 extending in the Y arrow direction is disposed on the substrate stocker 22 side (counter X arrow direction side). The traveling device 23 has a traveling motor MS (see FIG. 8) therein, and causes the transport device 24 that is drivingly connected to the output shaft of the traveling motor MS to travel in the Y arrow direction and the anti-Y arrow direction. It has become. The transport device 24 is a horizontal articulated robot having a transport arm 24a capable of attracting and gripping the back surface 2Mb of the mother board 2M, and is driven by an output shaft of a transport motor MT (see FIG. 8) disposed therein. The transport arm 24a to be connected is rotated in an extendable manner on the XY plane and moved in the vertical direction.

  On the upper surface 21a of the base 21 and on both sides in the Y arrow direction of the traveling device 23, a pair of mounting tables 25R and 25L for mounting the mother substrate 2M with the surface 2Ma of the mother substrate 2M on the upper side are provided. ing. The pair of mounting tables 25R and 25L each have a space (recessed portion 25a) that allows the transfer arm 24a to be extracted on the back surface 2Mb side of the mother substrate 2M to be mounted, and the transfer arm 24a in the recessed portion 25a. The mother board 2M can be transported and placed by moving the board up and down.

  When a signal for transporting the mother substrate 2M is supplied to the travel motor MS and the transport motor MT, the travel device 23 and the transport device 24 unload each mother substrate 2M in the substrate stocker 22 and carry it out. The substrate 2M is placed on one of the placement tables 25R and 25L. Further, the traveling device 23 and the transport device 24 are configured to carry the mother substrate 2M placed on the placement tables 25R and 25L into a predetermined slot in the substrate stocker 22 and collect it.

  In the present embodiment, as shown in FIG. 3, the code region S of the mother board 2M placed on the placement tables 25R and 25L, and the first row code region S1 in order from the X arrow direction side. The second line code area S2,..., The fifth line code area S5.

  In FIG. 2, an articulated robot (hereinafter simply referred to as a SCARA robot) 26 as a relative movement means is disposed on the upper surface 21a of the base 21 between the pair of mounting bases 25R and 25L. The SCARA robot 26 includes a main shaft 27 that is fixed to the upper surface 21a of the base 21 and extends upward (in the Z arrow direction).

  A first arm 28a that is drivingly connected to an output shaft of a first motor M1 (see FIG. 8) installed on the main shaft 27 is connected to an upper end of the main shaft 27 so as to be rotatable in a horizontal direction (XY plane direction). Yes. A second arm 28b that is drivingly connected to an output shaft of a second motor M2 (see FIG. 8) installed on the first arm 28a is connected to the tip of the first arm 28a so as to be rotatable in the horizontal direction. . At the tip of the second arm 28b, a cylindrical third arm 28c that is drivingly connected to the output shaft of the third motor M3 (see FIG. 8) installed on the second arm 28b is an axis along the Z arrow direction. It is connected so as to be rotatable about the center of rotation.

  A head unit 30 is disposed at the tip (lower end) of the third arm 28c, and the head unit 30 is provided with a case 31 formed in a box shape. Below the case 31, a droplet discharge head (hereinafter simply referred to as a discharge head) 32 and a suction port 33 constituting a suction means are disposed. In addition, a laser head 34 constituting laser irradiation means is disposed on one side surface of the case 31, and a photo sensor 35 constituting laser light detection means is disposed on the other side surface opposite to the laser head 34. It is installed.

  Then, when a signal for scanning the head unit 30 is supplied to the first, second, and third motors M1, M2, and M3, the SCARA robot 26 corresponds to the first, second, and third arms 28a, 28b, The head unit 30 is scanned within a predetermined region on the upper surface 21a by rotating 28c.

More specifically, as shown in FIG. 3, the SCARA robot 26 generates a smooth ninety-fold “target locus” generated based on the position coordinates of each target discharge position P (teaching coordinates Tp: see FIG. 8). The head unit 30 is scanned along “R”. That is, the SCARA robot 26 first rotates the first, second, and third arms 28a, 28b, and 28c as indicated by the arrows on the mounting table 25L, and the head unit 30 (the tip of the third arm 28c). Is made to be opposed to a position on the side opposite to the Y arrow in the first line code area S1 (hereinafter simply referred to as a starting point SP). Then, when the head unit 30 is made to be relative to the start point SP, the SCARA robot 26 moves the head unit 30 located at the start point SP along the direction of the arrow Y with the ejection head 32 in front.

  When the head unit 30 is scanned along the Y arrow direction, the SCARA robot 26 rotates the first, second, and third arms 28a, 28b, and 28c to move the head on the outer side of the mother substrate 2M in the Y arrow direction. The unit 30 is rotated counterclockwise by 180 degrees and rotated to the Y arrow direction side of the second line code area S2. When the head unit 30 is arranged on the second-line code area S2, the SCARA robot 26 causes the laser head 34 to precede and scans the head unit 30 along the anti-Y arrow direction. Yes.

  Thereafter, in the same manner, the SCARA robot 26 moves the head unit 30 in the Y arrow direction (or reverse) in the order of the third, fourth, fifth line code areas S3, S4, S5 with the discharge head 32 in front. Scanning is performed along the Y arrow direction) and is made to be relative to the Y arrow direction side position (end point EP) of the fifth line code area S5. In the present embodiment, the scanning direction of the head unit 30 is referred to as a scanning direction RA.

  Next, the head unit 30 will be described with reference to FIGS. 4 and 5 are schematic side views for explaining the head unit 30, and FIG. 6 is a schematic plan view of the head unit 30 as viewed from the surface 2Ma of the mother substrate 2M. FIG. 7 is a timing chart for explaining a droplet detection process, a drying process, and a baking process by the head unit 30.

  In FIG. 4, a liquid tank 36 is disposed inside the case 31 so that the liquid F can be drawn out, and the liquid F to be stored is placed on the discharge head 32 disposed below the liquid tank. It comes to supply.

  In FIG. 5, a nozzle plate 37 is provided below the ejection head 32, and the lower surface (nozzle formation surface 37a) of the nozzle plate 37 is along the normal direction (Z arrow direction) of the mother substrate 2M. A plurality of circular holes (nozzles N) are formed through.

  In FIG. 6, the nozzles N are arranged and formed along a direction orthogonal to the scanning direction RA of the ejection head 32 (head unit 30), and the formation pitch is equal to the formation pitch of the data cells C (cell width W). It is formed with the same pitch. In the present embodiment, the positions on the mother substrate 2M that are opposed to the nozzles N to be scanned are the landing positions PF, and each of the scanned landing positions PF corresponds to the corresponding target discharge position. It passes through P.

  In FIG. 5, cavities 38 communicating with the liquid material tanks 36 are formed above the nozzles N, and the liquid materials F derived from the liquid material tanks 36 are supplied into the corresponding nozzles N, respectively. ing. A vibration plate 39 that can vibrate in the vertical direction is attached to the upper side of each cavity 38 so that the volume in the cavity 38 is enlarged or reduced. A plurality of piezoelectric elements PZ corresponding to the respective nozzles N are disposed on the upper side of the vibration plate 39, and receive signals (piezoelectric element driving voltage COM: see FIGS. 7 and 8) for discharging the droplets Fb. It contracts and expands in the vertical direction.

Then, when the landing position PF (nozzle N) is opposed to the target discharge position P (center position of the data cell C), the piezoelectric element driving voltage COM is supplied to the corresponding piezoelectric element PZ. Then, the corresponding piezoelectric element PZ contracts and expands, and the interface of the liquid material F in the nozzle N corresponding to the piezoelectric element PZ vibrates in the vertical direction. As a result, a droplet Fb having a size corresponding to the piezoelectric element driving voltage COM is ejected from the corresponding nozzle N. The discharged droplet Fb flies along the direction of the anti-Z arrow and lands on the opposite target discharge position P. The droplet Fb that has landed on the target discharge position P wets and spreads along the surface 2Ma, and eventually becomes a size that is dried and fired (the outer diameter becomes the cell width W).

  In this embodiment, from the start of the discharge operation of the droplet Fb (discharge operation start time T0: refer to FIG. 7), the outer diameter of the discharged droplet Fb becomes the cell width W (irradiation start time T1: FIG. 7). The time until (see) is referred to as irradiation standby time Dt0 (see FIG. 7). Further, the head unit 30 of the present embodiment is scanned for a predetermined distance (irradiation standby distance Lw) during the irradiation standby time Dt0. The irradiation standby distance Lw is set to a distance equal to the cell width W.

  On the upper side of FIG. 6, a plurality of semiconductor lasers LD corresponding to the respective nozzles N are arranged in the laser head 34 along the arrangement direction of the nozzles N. A reflection mirror M formed along the arrangement direction of the nozzles N is provided on the mother substrate 2M side of each semiconductor laser LD. Each semiconductor laser LD receives a signal (laser driving voltage Vz: see FIG. 7) for driving and controlling the semiconductor laser LD, and reflects the laser beam B in the wavelength region corresponding to the absorption wavelength of the droplet Fb to the reflecting mirror M. The light is emitted toward.

  More specifically, the semiconductor laser LD receives a low-potential laser drive voltage Vz (droplet detection laser drive voltage Vz0: see FIG. 7), can suppress the wetting and spreading of the droplet Fb, and A laser beam B (droplet detection laser B0) having an intensity capable of determining the presence or absence is emitted. The droplet detection laser B0 is used in a droplet detection process for detecting whether or not the droplet Fb has landed at the target discharge position P.

  The semiconductor laser LD receives a laser drive voltage Vz having an intermediate potential (dry laser drive voltage Vz1: see FIG. 7), is a laser beam B having energy higher than that of the droplet detection laser B0, and is a liquid. The laser beam B (referred to as dry laser B1) having an intensity that allows evaporation of the solvent of the droplet Fb as the “evaporation component Ev” is emitted. The drying laser B1 is used in a process (drying process) of evaporating the solvent of the droplet Fb and drying the droplet Fb.

  Further, the semiconductor laser LD receives the laser drive voltage Vz having a high potential (firing laser drive voltage Vz2: see FIG. 7), is a laser beam B having a higher energy than the dry laser B1, and the droplet Fb A laser beam B having an intensity for firing the metal fine particles by evaporating the dispersion medium as “evaporation component Ev” (referred to as firing laser B2) is emitted. The firing laser B2 is used in a process (firing process) of firing the metal fine particles of the droplet Fb.

  The reflection mirror M totally reflects the laser beam B (droplet detection laser B0, drying laser B1, firing laser B2) from each semiconductor laser LD, and is a position opposite to the scanning direction RA of the corresponding target ejection position P. It is guided to (irradiation position PT). The laser beam B guided to the irradiation position PT is reflected and scattered by the droplet Fb or the surface 2Ma located at the irradiation position PT, and most of the reflected light is reflected and scattered as the reflected scattered light Br on the scanning direction RA side (photosensor 35 side). It is supposed to let you.

In this embodiment, as shown in FIG. 5, the distance between the landing position PF where the droplet Fb lands and the irradiation position PT irradiated with the laser beam B is set to the irradiation standby distance Lw. Yes. That is, the laser beam B is emitted from the semiconductor laser LD at a timing when the irradiation standby time Dt0 has elapsed from the discharge operation start time T0 (the irradiation start time T1). Then, the droplet Fb that has landed at the landing position PF relatively moves to the corresponding irradiation position PT, and the laser beam B from the semiconductor laser LD relatively moves to the irradiation position PT, thereby reducing the outer diameter of the cell width W. The region of the droplets Fb that it has is irradiated.

  In FIG. 6, in the photosensor 35, a plurality of light receiving elements PD corresponding to the semiconductor laser LD are arranged along the arrangement direction of the semiconductor laser LD (nozzle N). Each light receiving element PD is an element formed of a photodiode or the like, and receives the reflected scattered light Br from the corresponding irradiation position PT (droplet Fb) and detects the optical characteristics of the received reflected scattered light Br. A signal (light quantity detection signal Vp) is output. The light receiving element PD of the present embodiment outputs a signal relative to the light quantity of the reflected scattered light Br as the optical characteristic of the reflected scattered light Br. However, the present invention is not limited to this. For example, the light receiving element PD The configuration may be such that the wavelength of the reflected scattered light Br, the distribution of the light quantity with respect to the wavelength, the deflection state, the polarization state, the phase distribution, the intensity distribution, etc. of the reflected scattered light Br are output as optical characteristics.

  Then, as shown in FIG. 7, at the timing of the irradiation start time T1, the droplet detection laser drive voltage Vz0 is supplied to the semiconductor laser LD for a predetermined time (droplet detection time Dt1) (drying start time T2). Until the droplet detection process is executed). Then, the semiconductor laser LD irradiates the corresponding irradiation position PT with the droplet detection laser B0 having the intensity corresponding to the droplet detection laser drive voltage Vz0.

  The droplet detection laser B0 irradiated to the irradiation position PT increases or decreases the amount of the reflected scattered light Br depending on whether or not the droplet Fb has landed on the irradiation position PT. That is, when the droplet Fb has landed at the irradiation position PT, a part of the droplet detection laser B0 irradiated to the irradiation position PT is absorbed by the droplet Fb and suppresses the wetting and spreading of the droplet Fb. At the same time, the amount of the reflected scattered light Br is reduced. On the other hand, when the droplet Fb has not landed at the irradiation position PT, the droplet detection laser B0 irradiated to the irradiation position PT is reflected by the mother substrate 2M and reflected with a light amount substantially equal to that of the droplet detection laser B0. The scattered light Br is reflected and scattered.

  Note that the droplet discharge device 20 of the present embodiment has a subsequent irradiation process (drying process and laser beam B) according to each light quantity detection signal Vp based on the reflected scattered light Br received by the light receiving element PD in the droplet detection process. It is determined whether or not to perform the firing step.

  More specifically, the droplet discharge device 20 responds when the light amount detection signal Vp from the light receiving element PD at the droplet detection time Dt1 is maintained below a predetermined potential (droplet detection potential Vp0: see FIG. 7). It is determined that the droplet Fb has landed at the irradiation position PT to be irradiated, and the drying laser B1 is emitted to the corresponding semiconductor laser LD. In contrast, in the droplet discharge device 20, when the light amount detection signal Vp from the light receiving element PD at the droplet detection time Dt1 becomes higher than the droplet detection potential Vp0, the droplet Fb does not land at the irradiation position PT. Therefore, the emission of the laser beam B is stopped with respect to the corresponding semiconductor laser LD.

  Then, as shown in FIG. 7, when the light amount detection signal Vp from the light receiving element PD in the droplet detection step (droplet detection time Dt1) is maintained below the droplet detection potential Vp0, the corresponding semiconductor laser LD is The drying laser drive voltage Vz1 is supplied (the drying process is started at the start of drying T2). Then, the corresponding semiconductor laser LD irradiates the drying laser B1 toward the corresponding irradiation position PT (region of the droplet Fb subjected to the droplet detection step).

The drying laser B1 irradiated to the droplet Fb gradually evaporates the solvent of the droplet Fb positioned at the irradiation position PT as “evaporation component Ev”, and gradually improves the fluidity of the droplet Fb positioned at the irradiation position PT. Reduced, i.e. dried. Further, the drying laser B1 irradiated to the droplet Fb increases or decreases the amount of the reflected scattered light Br according to the fluidity of the droplet Fb. That is, when the solvent in the droplet Fb gradually decreases and the fluidity of the droplet Fb decreases, the dry laser B1 irradiated to the droplet Fb is equivalent to the amount of evaporation of the solvent in the droplet Fb. The light amount absorbed by the droplet Fb is decreased, and the light amount of the reflected scattered light Br from the droplet Fb is increased.

  The droplet discharge device 20 according to the present embodiment makes it possible to determine the timing of the subsequent irradiation process (firing process) of the laser beam B based on the light quantity detection signal Vp from the light receiving element PD in the drying process. ing.

  More specifically, in the droplet discharge device 20, the droplet Fb is dried while the light amount detection signal Vp from the light receiving element PD in the drying process is lower than a predetermined potential (drying end potential Vp1: see FIG. 7). It is determined that there is no (fluidity of the droplet Fb is high), and the emission of the drying laser B1 is continued in the corresponding semiconductor laser LD. On the contrary, in the droplet discharge device 20, when the light amount detection signal Vp in the drying process becomes higher than the drying end potential Vp1), the corresponding droplet Fb is dried (the fluidity of the droplet Fb is low). Therefore, the firing laser B2 is emitted to the corresponding semiconductor laser LD.

  Then, as shown in FIG. 7, the light amount detection signal Vp in the drying process (after the drying start time T2) becomes higher than the drying end potential Vp1 (becomes at the firing start time T3). Then, the firing laser drive voltage Vz2 is supplied to the corresponding semiconductor laser LD for a predetermined time (firing time Dt2) (the firing process is executed until the firing end time T4). When the firing laser drive voltage Vz2 is supplied, the corresponding semiconductor laser LD irradiates the corresponding irradiation position PT (region of the droplet Fb after the drying process) with the firing laser B2.

  The firing laser B2 irradiated to the droplet Fb evaporates the dispersion medium of the droplet Fb positioned at the irradiation position PT as “evaporation component Ev”, and the flow of the droplet Fb (metal fine particles) positioned at the irradiation position PT. It is made to adhere to the mother board | substrate 2M, ie, to fire, by reducing property.

  In FIG. 4, the suction port 33 is formed in a box shape having an opening at the bottom, and the inside thereof is connected to a suction tube T disposed in the case 31. The suction tube T is drawn around the third arm 28 c, the second arm 28 b, the first arm 28 a and the main shaft 27, and is connected to a suction pump PM disposed in the base 21.

  The suction pump PM receives a drive signal (suction start signal TP1: refer to FIG. 8) for starting suction, and starts suction from the suction port 33 via the suction tube T. In addition, the suction pump PM receives a drive signal (suction end signal TP2: see FIG. 8) for ending suction, and ends suction from the suction port 33 via the suction tube T.

  In the middle of the suction tube T, a switching valve 40 constituting a suction speed control means is connected. The switching valve 40 has a plurality of piezo valves, and switches the flow path resistance between the suction port 33 and the suction pump PM based on on / off of each piezo valve. The switching valve 40 receives a signal (switching signal Vc: refer to FIG. 7) for switching the flow path resistance between the suction port 33 and the suction pump PM, and receives the signal between the suction port 33 and the suction pump PM. While switching the flow path resistance, the suction speed from the suction port 33 is increased or decreased in correspondence with the switching signal Vc.

  More specifically, the switching valve 40 receives the switching signal Vc (blocking voltage Vc0: see FIG. 7) for blocking the flow path between the suction port 33 and the suction pump PM, and then receives the switching signal Vc and the suction pump PM. The flow path between and is cut off.

The switching valve 40 receives a switching signal Vc (low speed switching voltage Vc1: refer to FIG. 7) for increasing the flow path resistance between the suction port 33 and the suction pump PM, and receives the switching signal Vc. Is set to a predetermined flow path resistance (first flow path resistance). The first flow path resistance is set in advance based on a test or the like, and the droplet Fb (fluidity of fluidity) immediately after landing is determined by suction at a suction speed (low suction speed) corresponding to the first flow path resistance. The resistance value is set so that the position and shape of the high droplet Fb) do not vary.

  Further, the switching valve 40 receives the switching signal Vc (high-speed switching voltage Vc2: see FIG. 7) for lowering the flow path resistance between the suction port 33 and the suction pump PM, and receives the switching signal Vc. Is set to a predetermined flow path resistance (second flow path resistance) lower than the first flow path resistance. The second flow path resistance is set in advance based on a test or the like, and is dried by the suction of a suction speed (high suction speed) corresponding to the second flow path resistance (low fluidity). The resistance value is set so that the position and shape of the droplet Fb) do not vary.

  Then, as shown in FIG. 7, at the timing when the light amount detection signal Vp in the droplet detection step (droplet detection time Dt1) is maintained below the droplet detection potential Vp0 (starts the drying step), The low-speed switching voltage Vc1 is supplied. Then, the flow path resistance between the suction port 33 and the suction pump PM is switched to the first flow path resistance, and suction at a low suction speed corresponding to the first flow path resistance is started. That is, the “evaporated component Ev” generated in the drying process is sucked by suction at a low suction speed from the suction port 33.

  At this time, the position and shape of the droplet Fb before drying can be maintained in order to perform suction at a low suction speed with suppressed gas flow to the atmosphere of the highly fluid droplet Fb. Therefore, it is possible to avoid contamination of the optical system (for example, the reflection mirror M) due to the “evaporation component Ev”, and it is possible to avoid positional deviation and shape variation of the landed droplet Fb.

  Then, as shown in FIG. 7, at the timing when each light amount detection signal Vp becomes higher than the drying end potential Vp <b> 1 (starts the baking process), the switching valve 40 is given a predetermined time (baking time Dt <b> 2 and preliminary suction time Dt <b> 3). The high-speed switching voltage Vc2 is supplied only for the time obtained by adding Then, the flow path resistance between the suction port 33 and the suction pump PM is switched to the second flow path resistance, and the “evaporation component generated in the baking process by the suction at a high suction speed corresponding to the second flow path resistance. “Ev” is aspirated.

  At this time, in order to perform suction at a high suction speed without suppressing the flow of gas to the atmosphere of the low-fluidity droplet Fb, in a state where the position and shape of the droplet Fb before firing are maintained, “Evaporation component Ev” can be sucked in a short time. In addition, the remaining “evaporated component Ev” is sucked at the end of the suction (at the end of suction T5) in order to be continuously sucked by the preliminary suction time Dt3 after the end of the firing process (from the end of firing T4). By the time, it can be surely exhausted.

  Therefore, the contamination of the optical system (for example, the reflection mirror M) due to the “evaporation component Ev” can be surely avoided, and the positional deviation and shape variation of the landed droplet Fb can be avoided.

Next, the electrical configuration of the droplet discharge device 20 configured as described above will be described with reference to FIG.
In FIG. 8, the droplet discharge device 20 is provided with a control device 51 composed of a CPU or the like. The control device 51 drives and controls the travel device 23, the transport device 24, and the SCARA robot 26 based on the current position of the tip of the third arm 28c (discharge head 32) and various control programs, and also discharge head 32, laser head. 34 and the switching valve 40 are driven and controlled.

  The control device 51 is provided with a storage unit 51 </ b> A and stores various data and various programs for manufacturing the identification code 10. For example, the storage unit 51A stores bitmap data BMD, the teaching coordinates Tp for creating the target locus R, information about the droplet detection potential Vp0 (droplet detection information FI), and information about the drying end potential Vp1. Various data such as (drying completion information EI) is stored.

  The bitmap data BMD is data indicating whether or not the droplet Fb is ejected to each position obtained by virtually dividing the drawing plane (the surface 2Ma of the mother substrate 2M) in the orthogonal coordinate system, and each bit value (0 or 0). This is data for defining whether or not each piezoelectric element PZ is driven according to 1). That is, the bitmap data BMD is data for defining whether or not the droplets Fb are ejected from each nozzle N when the ejection head 32 is scanned over each row code area S1 to S5.

  The control device 51 is provided with an interpolation calculation unit 51B, and forms a target locus R by performing interpolation processing (for example, linear interpolation, circular interpolation, etc.) at a predetermined interpolation cycle in a space between successive teaching coordinates Tp. The position coordinates (interpolated coordinates) of a plurality of interpolation points to be calculated are sequentially calculated. Then, the interpolation calculation unit 51B generates information (trajectory information TaI) including a corresponding teaching coordinate Tp and a plurality of interpolation coordinates for interpolating the space up to the teaching coordinate Tp, and converts the trajectory information TaI into an inverse conversion unit. The data is sequentially output to 51C.

  Based on the trajectory information TaI from the interpolation calculation unit 51B, the inverse conversion unit 51C makes the posture of the SCARA robot 26 (each motor M1) to make the tip position of the third arm 28c relative to the teaching coordinates Tp and the interpolation coordinates. , M2 and M3, etc.). That is, the inverse conversion unit 51C sequentially generates information on the posture of the SCARA robot 26 (arm rotation information θI) for causing the head unit 30 to scan along the target locus R. Then, the inverse conversion unit 51C outputs the generated arm rotation information θI to the SCARA robot drive circuit 55.

  The control device 51 includes an input unit 52, a travel device drive circuit 53, a transport device drive circuit 54, a SCARA robot drive circuit 55, a photo sensor drive circuit 56, a discharge head drive circuit 57, a laser head drive circuit 58, and a suction pump drive circuit. 59 and a switching valve drive circuit 60 are connected.

  The input unit 52 has operation switches such as a start switch and a stop switch, and inputs information related to the identification code 10 to the control device 51 as drawing data Ia in a predetermined format. Then, the control device 51 generates a bitmap data BMD by performing a predetermined development process on the drawing data Ia from the input unit 52, and based on the bitmap data BMD, an orthogonal coordinate system of each target discharge position P. The position coordinates at (the teaching coordinates Tp) are generated. Further, the control device 51 performs development processing different from the bitmap data BMD on the drawing data Ia, and the piezoelectric element drive voltage COM and the laser drive voltage Vz (droplet detection laser drive voltage Vz0, dry laser drive voltage). Vz1, firing laser drive voltage Vz2) are generated.

  A travel motor MS and a travel motor rotation detector MSE are connected to the travel device drive circuit 53, and the travel motor MS is rotated forward or reverse in response to a drive control signal from the control device 51, and the travel motor rotation is detected. Based on the detection signal from the container MSE, the moving direction and the moving amount of the transport device 24 are calculated.

A transport motor MT and a transport motor rotation detector MTE are connected to the transport device drive circuit 54, and the transport motor MT is rotated forward or reverse in response to a drive control signal from the control device 51, and the transport motor rotation is detected. Based on the detection signal from the device MTE, the moving direction and the moving amount of the transfer arm 24a are calculated.

  A first motor M1, a second motor M2, and a third motor M3 are connected to the SCARA robot drive circuit 55, and in response to arm rotation information θI from the control device 51, the first, second, and third motors. The motors M1, M2 and M3 are rotated forward or reverse. The SCARA robot drive circuit 55 is connected to a first motor rotation detector M1E, a second motor rotation detector M2E, and a third motor rotation detector M3E, and the first, second, and third motor rotation detectors. Based on the detection signals from M1E, M2E, and M3E, the moving direction and the moving amount of the tip (ejection head 32) of the third arm 28c are calculated. Then, the control device 51 scans the head unit 30 in a ninety-nine fold shape along the target locus R via the SCARA robot drive circuit 55, and the calculation result (discharge head 32) from the SCARA robot drive circuit 55. Various control signals are output based on the current position.

  More specifically, the control device 51 discharges the piezoelectric element drive voltage COM and the laser drive voltage Vz before each nozzle N (landing position PF) is opposed to each target discharge position P on the mother substrate 2M. It outputs to the head drive circuit 57 and the laser head drive circuit 58. Further, the control device 51 generates bitmap data BMD corresponding to each nozzle N as an ejection control signal SI synchronized with a predetermined clock signal, and serially transfers the ejection control signal SI to the ejection head drive circuit 57 sequentially. It is supposed to be.

  Further, the control device 51 generates a signal (discharge timing signal LP) for discharging the droplet Fb at a timing when each nozzle N (landing position PF) is opposed to each target discharge position P on the mother substrate 2M. At the same time, the generated ejection timing signal LP is output to the ejection head drive circuit 57.

  Further, the control device 51 generates the suction start signal TP1 and the suction end signal TP2 at the timing when the ejection head 32 is arranged at the start point SP and the end point EP, and generates the suction start signal TP1 and the suction end signal TP2. These are output to the suction pump drive circuit 59, respectively.

  A photo sensor 35 (the plurality of light receiving elements PD) is connected to the photo sensor driving circuit 56, and the light amount detection signal Vp corresponding to the reflected scattered light Br received by each light receiving element PD is synchronized with a predetermined clock signal. And sequentially output to the control device 51. And the control apparatus 51 outputs various control signals based on each light quantity detection signal Vp from the photosensor drive circuit 56. FIG.

  More specifically, the control device 51 dries the semiconductor laser LD corresponding to the light amount detection signal Vp when the light amount detection signal Vp corresponding to the droplet detection time Dt1 is maintained below the droplet detection potential Vp0. A dry laser selection signal KI for supplying the laser driving voltage Vz1 is generated. The control device 51 outputs the generated dry laser selection signal KI to the laser head drive circuit 58. Further, at this time, the control device 51 generates a low speed selection signal LI for supplying the low speed switching voltage Vc1 to the switching valve 40, and outputs the generated low speed selection signal LI to the switching valve drive circuit 60. ing.

The control device 51 supplies the firing laser drive voltage Vz2 to the corresponding semiconductor laser LD each time the light amount detection signal Vp from each light receiving element PD in the drying process becomes higher than the drying end potential Vp1. The firing laser selection signal MI is sequentially generated. Then, the control device 51 sequentially outputs the generated firing laser selection signal MI to the laser head driving circuit 58. Further, at this time, the control device 51 generates a high-speed selection signal HI for supplying the high-speed switching voltage Vc2 to the switching valve 40 at the timing of supplying the firing laser driving voltage Vz2 to all the corresponding semiconductor lasers LD. The generated high-speed selection signal HI is output to the switching valve drive circuit 60.

  The ejection head drive circuit 57 receives the ejection control signal SI from the control device 51, and serially / parallel converts the ejection control signal SI in correspondence with each piezoelectric element PZ. Upon receiving the ejection timing signal LP from the control device 51, the ejection head drive circuit 57 supplies the piezoelectric element drive voltage COM to each piezoelectric element PZ selected based on the serial / parallel converted ejection control signal SI. It is supposed to let you. When the ejection head drive circuit 57 receives the ejection timing signal LP from the control device 51, the ejection head drive circuit 57 outputs a serial / parallel converted ejection control signal SI to the laser head drive circuit 58.

  The laser head driving circuit 58 receives the ejection control signal SI from the ejection head driving circuit 57 at the time T0 when the ejection operation starts. Further, after waiting for the irradiation standby time Dt0 (irradiation start time T1), the laser head driving circuit 58 applies the droplet detection laser driving voltage Vz0 to the semiconductor laser LD selected based on the ejection control signal SI. It comes to supply. The laser head driving circuit 58 emits a droplet detection laser B0 from the semiconductor laser LD corresponding to the nozzle N that ejected the droplet Fb.

  Further, the laser head driving circuit 58 is adapted to receive a drying laser selection signal KI from the control device 51 at the start of drying T2. The laser head drive circuit 58 supplies the dry laser drive voltage Vz1 to the semiconductor laser LD selected based on the dry laser selection signal KI. The laser head driving circuit 58 emits the drying laser B1 from the semiconductor laser LD corresponding to the irradiation position PT where the droplet Fb has landed.

  Further, the laser head drive circuit 58 receives the firing laser selection signal MI from the control device 51 at the start of firing T3. The laser head drive circuit 58 sequentially supplies the firing laser drive voltage Vz2 to the semiconductor laser LD selected based on the firing laser selection signal MI. The laser head driving circuit 58 emits the firing laser B2 in order from the semiconductor laser LD corresponding to the droplet Fb after the drying process.

  The suction pump drive circuit 59 is connected to the suction pump PM, and starts and ends the suction of the suction pump PM in response to the suction start signal TP1 and the suction end signal TP2 from the control device 51. Yes. Then, while the head unit 30 is scanned along the target locus R, the control device 51 drives the suction pump PM to continue the suction from the suction port 33.

  The switching valve drive circuit 60 receives the low speed selection signal LI from the control device 51 at the start of drying T2 and supplies the low speed switching voltage Vc1 to the switching valve 40. The switching valve drive circuit 60 starts suction at a low suction speed from the suction port 33 at the timing when the drying process of the droplet Fb is started.

The switching valve drive circuit 60 receives the high-speed selection signal HI from the control device 51 at the timing when the drying process of all the droplets Fb is completed, and supplies the high-speed switching voltage Vc2 to the switching valve 40. It has become. The switching valve drive circuit 60 starts suction at a high suction speed from the suction port 33 at the timing when the drying process of all the droplets Fb is completed.

Next, a method for forming the identification code 10 using the droplet discharge device 20 will be described.
First, the input unit 52 is operated to input the drawing data Ia to the control device 51. Then, the control device 51 drives and controls the traveling device 23 and the transfer device 24 to carry out the mother substrate 2M of the substrate stocker 22, and place the mother substrate 2M that has been carried out on the mounting table 25R (or the mounting table 25L). In addition, the control device 51 performs predetermined development processing on the drawing data Ia from the input unit 52 to generate bitmap data BMD, teaching coordinates Tp, the piezoelectric element driving voltage COM, and the laser driving voltage Vz (droplet detection laser). Drive voltage Vz0, dry laser drive voltage Vz1, and firing laser drive voltage Vz2).

  Then, when various data based on the drawing data Ia is generated, the control device 51 stores the generated bitmap data BMD and the teaching coordinates Tp in the storage unit 51A, and the third arm via the SCARA robot driving circuit 55. The tip of 28c is moved to the starting point SP.

  During this time, the control device 51 sequentially obtains a plurality of interpolated coordinates for interpolating from the teaching coordinate Tp located on the start point SP side of the first line code area S1 to the subsequent teaching coordinate Tp via the interpolation calculation unit 51B. The trajectory information TaI including a plurality of interpolation coordinates and subsequent teaching coordinates Tp is sequentially generated and sequentially output to the inverse conversion unit 51C. When the trajectory information TaI is output to the inverse conversion unit 51C, the control device 51 sequentially generates the arm rotation information θI corresponding to each of the plurality of interpolation coordinates and the subsequent teaching coordinate Tp via the inverse conversion unit 51C.

  When the tip of the third arm 28c (the ejection head 32) is disposed at the start point SP, the control device 51 sequentially outputs the generated arm rotation information θI to the SCARA robot drive circuit 55, so that the head unit 30 While starting scanning, the suction start signal TP1 is output to the suction pump drive circuit 59 to drive the suction pump PM.

  During this time, the control device 51 outputs the piezoelectric element drive voltage COM and the laser drive voltage Vz to the ejection head drive circuit 57 and the laser head drive circuit 58, respectively. Based on the calculation result from the SCARA robot drive circuit 55, the control device 51 sets the target position PF that moves together with the scanning of the head unit 30 to the most anti-Y arrow direction side of the first line code area S1. It is determined whether or not the discharge position P has been reached.

  Here, when the landing position PF reaches the target discharge position P located on the most anti-Y arrow side of the first line code area S1, the control device 51 outputs the discharge timing signal LP to the discharge head drive circuit 57, A piezoelectric element drive voltage COM is supplied to each piezoelectric element PZ selected based on the ejection control signal SI. Then, the droplets Fb are simultaneously discharged from the selected nozzles N, and each discharged droplet Fb is landed on the corresponding landing position PF (target discharge position P). The highly fluid droplet Fb that has landed on the target discharge position P wets and spreads in the area of the corresponding target discharge position P (in the data cell C), and when “irradiation standby time Dt0” elapses from the start of the discharge operation, The outer diameter is the cell width W.

  Further, when the landing position PF reaches the target discharge position P located on the most anti-Y arrow side of the first line code area S1, the control device 51 performs serial / parallel converted discharge control via the discharge head drive circuit 57. The signal SI is output to the laser head drive circuit 58. Then, the control device 51 scans the head unit 30 for the “irradiation standby time Dt0” via the SCARA robot drive circuit 55, and makes each irradiation position PT relative to the corresponding target discharge position P to move the head unit 30. Keep it stationary.

When each irradiation position PT is made to be relative to the corresponding target discharge position P, the control device 51 starts the droplet detection process.
That is, the control device 51 supplies the droplet detection laser drive voltage Vz0 to each semiconductor laser LD selected based on the ejection control signal SI through the laser head drive circuit 58 for the droplet detection time Dt1. . Then, the droplet detection laser B0 from the selected semiconductor laser LD is emitted all at once, and the emitted droplet detection laser B0 is irradiated to the corresponding irradiation position PT. The droplet detection laser B0 irradiated to each irradiation position PT increases or decreases the light amount detection signal Vp of the corresponding reflected scattered light Br depending on whether or not the droplet Fb has landed at the corresponding irradiation position PT.

  Then, when the droplet detection time Dt1 has elapsed, the control device 51 determines whether or not the droplet Fb has landed at each irradiation position PT based on the light amount detection signal Vp from the photosensor drive circuit 56. That is, the control device 51 determines whether or not each light amount detection signal Vp is equal to or lower than the droplet detection potential Vp0, and the semiconductor laser corresponding to the light receiving element PD whose light amount detection signal Vp is equal to or lower than the droplet detection potential Vp0. A dry laser selection signal KI is generated for supplying the dry laser drive voltage Vz1 to the LD.

When the drying laser selection signal KI is generated, the control device 51 starts a drying process for drying the landed droplet Fb.
That is, the control device 51 supplies the generated dry laser selection signal KI to the laser head drive circuit 58, and applies the dry laser B1 from the selected semiconductor laser LD to the corresponding irradiation position PT, that is, the droplet detection process. The irradiated droplet Fb region is irradiated. Further, at this time, the control device 51 generates the low speed selection signal LI and outputs the generated low speed selection signal LI to the switching valve drive circuit 60 to start suction at a low suction speed from the suction port 33. .

  Then, the region of the corresponding droplet Fb is irradiated with the drying laser B1 from the selected semiconductor laser LD, and the solvent of the droplet Fb located at the irradiation position PT gradually evaporates as “evaporation component Ev”. The evaporated “evaporated component Ev” is gradually sucked without adhering to the optical system of the laser beam B by the suction of the suction port 33 at a low suction speed. As a result, contamination of the optical system (for example, the reflection mirror M) due to the “evaporation component Ev” can be avoided, and positional displacement and shape variation of the highly fluid droplet Fb can be avoided.

  During this time, the control device 51 determines whether or not each droplet Fb has been dried based on each light amount detection signal Vp from the photosensor drive circuit 56. That is, the control device 51 determines whether or not the light amount detection signal Vp from the light receiving element PD corresponding to each droplet Fb is higher than the drying end potential Vp1.

  When the light amount detection signal Vp from the light receiving element PD becomes higher than the drying end potential Vp1, the control device 51 selects the firing laser for supplying the firing laser drive voltage Vz2 to the semiconductor laser LD corresponding to the light receiving element PD. The signal MI is generated, and the generated firing laser selection signal MI is sequentially output to the laser head driving circuit 58. Further, when all the light amount detection signals Vp corresponding to the respective droplets Fb become higher than the drying end potential Vp1, the control device 51 generates a high-speed selection signal HI for supplying the high-speed switching voltage Vc2 to the switching valve 40. The generated high-speed selection signal HI is output to the switching valve drive circuit 60.

  Then, the firing laser B2 from the semiconductor laser LD corresponding to the firing laser selection signal MI is irradiated to the region of the corresponding droplet Fb, and the dispersion medium of the droplet Fb located at the irradiation position PT is “evaporation component Ev. Evaporate. As a result, the droplets Fb (metal fine particles) are fired and are in close contact with the mother substrate 2M, that is, dots D are formed.

  Furthermore, at the timing when all the corresponding firing lasers B2 are irradiated, the flow path resistance between the suction port 33 and the suction pump PM is switched to the second flow path resistance, and the high flow rate corresponding to the second flow path resistance is set. The suction at the suction speed is performed from the firing start time T3 to the suction end time T5. As a result, it is possible to apply suction at a high suction speed to the atmosphere of the low-fluidity droplet Fb, and it is possible to suck “evaporated component Ev” in a short time. Therefore, it is possible to avoid contamination of the optical system of the laser beam B due to the “evaporation component Ev” during the formation of the dot D, and to avoid positional deviation and shape variation of the droplet Fb (dot D). Can do.

  Thereafter, similarly, the control device 51 causes the landing position PF to sequentially be made to be relative to the target discharge position P and discharge the droplet Fb from the selected nozzle N. Subsequently, at the timing when the landed droplet Fb reaches the cell width W, the region of the droplet Fb is sequentially irradiated with the droplet detection laser B0, the drying laser B1, and the firing laser B2. Then, suction with a low suction speed is performed when the drying laser B1 is irradiated, and suction with a high suction speed is performed when the drying process of all the droplets Fb is completed. As a result, the control device 51 can avoid contamination of the optical system due to the “evaporation component Ev” during the formation of each identification code 10, and avoid positional deviations and shape variations of all the dots D. be able to.

  When all the dots D are formed and the head unit 30 is scanned to the end point EP, the control device 51 outputs the suction end signal TP2 to the suction pump drive circuit 59, and the suction port 33 from the suction port PM by the suction pump PM. End aspiration. When the suction from the suction port 33 is finished, the control device 51 drives and controls the travel device 23 and the transport device 24 to carry the mother substrate 2M on which the dots D are formed into the substrate stocker 22, and the identification code 10 The forming operation is terminated.

Next, effects of the present embodiment configured as described above will be described below.
(1) According to the above embodiment, the suction port 33 that sucks the “evaporated component Ev” from the droplet Fb into the head unit 30 on which the droplet discharge head 32 is mounted, and the laser beam from the landed droplet Fb. And a photosensor 35 that detects an optical characteristic (amount of light) of B (reflected scattered light Br). The flow path resistance between the suction port 33 and the suction pump PM is maintained at the first flow path resistance until each light quantity detection signal Vp detected by the photosensor 35 reaches the drying end potential Vp1, and the droplet Fb In the vicinity (atmosphere), suction at a low suction speed with suppressed gas flow was performed.

Therefore, it is possible to perform suction at a low suction speed while suppressing the flow of gas to the highly fluid droplet Fb. As a result, it is possible to avoid contamination of the optical system due to the “evaporation component Ev”, and it is possible to avoid positional deviation and shape variation of the droplet Fb due to the suction operation. Therefore, the shape controllability of the dots D made of the droplets Fb can be improved.
(2) According to the above embodiment, suction at a high suction speed is performed at a timing when all the light amount detection signals Vp become higher than the drying end potential Vp1.

Therefore, suction at a high suction speed can be performed on the dried atmosphere of the droplet Fb having low fluidity. As a result, the “evaporation component Ev” can be sucked in a short time, and the suction efficiency of the “evaporation component Ev” can be improved.
(3) According to the above embodiment, the droplet detection laser B0 is irradiated to each irradiation position PT before the drying step. Then, the drying process and the baking process are performed on the irradiation position PT where the light amount detection signal Vp is maintained at the droplet detection potential Vp0 or lower.

Therefore, it is possible to avoid excessive laser irradiation to the region where the droplet Fb has not landed.
(4) According to the above embodiment, the droplet detection laser B0 is irradiated to each irradiation position PT before performing suction at a low suction speed. Only when the light amount detection signal Vp is maintained below the droplet detection potential Vp0, suction at a low suction speed is started.

Therefore, the suction during the ejection of the droplet Fb or the flight can be reliably stopped. As a result, the discharge operation and the flight operation of the droplet Fb can be stabilized, and the positional deviation and shape variation of the droplet Fb can be avoided more reliably. As a result, the shape controllability of the dots D made of the droplets Fb can be improved.
(5) According to the above embodiment, before the drying process is performed, the droplet Fb at the irradiation position PT is irradiated with the droplet detection laser B0 to suppress the wetting and spreading of the droplet Fb. . Then, the suction operation is stopped only during the droplet detection time Dt1 during which the droplet detection step is performed.

Accordingly, the suction operation can be delayed until the wetting and spreading of the droplet Fb is suppressed. As a result, it is possible to more reliably avoid positional deviation and shape variation of the droplet Fb.
(6) According to the above embodiment, the droplet detection laser B0, the drying laser B1, and the firing laser B2 are configured to emit from the same semiconductor laser LD. Therefore, the light source used in the droplet detection process, the drying process, and the firing process can be configured more simply.

In addition, you may change the said embodiment as follows.
In the above embodiment, the suction speed from the suction port 33 is controlled based on the reflected scattered light Br from the droplet Fb. For example, the suction speed from the suction port 33 may be controlled based on the laser beam B that has passed through the droplet Fb. That is, any configuration may be used as long as the suction speed is controlled based on the laser beam B from the region of the droplet Fb.
In the above embodiment, the suction speed from the suction port 33 is controlled based on the amount of reflected / scattered light Br. For example, the suction speed may be controlled based on at least one of the light quantity, wavelength, wavelength distribution, deflection state, polarization state, phase distribution, and intensity distribution of the reflected scattered light Br. .

According to this, on the basis of at least one of the light amount, wavelength, wavelength distribution, deflection state, polarization state, phase distribution, and intensity distribution, the size, surface shape, component, density, etc. of the droplet Fb Various parameters corresponding to the fluidity of Fb can be detected. Therefore, the fluidity of the droplet Fb can be detected more accurately, and suction corresponding to the fluidity of the droplet Fb can be more reliably performed.
In the above embodiment, the droplet detection process is executed to detect whether or not the droplet Fb has landed on each target discharge position P. However, the present invention is not limited to this, and a drying process may be performed immediately after the droplet discharge operation.
In the above embodiment, the suction from the suction port 33 is switched from the suction at the low suction speed to the suction at the high suction speed at the timing when all the light amount detection signals Vp become the drying end potential Vp1.

  For example, the suction at a low suction speed may be started at the timing when the light amount detection signal Vp becomes higher than a predetermined potential (the wetting and spreading of the droplet Fb is suppressed). According to this, suction can be started corresponding to the fluidity of the droplet Fb, and the shape controllability of the pattern made of the droplet Fb can be further improved.

Alternatively, at the timing when the light amount detection signal Vp becomes lower than a predetermined potential (the amount of reflected scattered light Br decreases due to regular reflection by the fired metal part particles), suction at a high suction speed is stopped. Also good. According to this, excessive suction can be suppressed, and the productivity of the pattern composed of the droplets Fb can be improved.
In the above embodiment, the head unit 30 is stationary during the droplet detection process, the drying process, and the firing process. Not limited to this, for example, each laser beam B (droplet detection laser B0, drying laser B1, and firing laser B2) to be irradiated can be scanned, and the head unit 30 is scanned while the droplet detection step, the drying step, You may make it the structure which performs a baking process. According to this, the productivity of the pattern made of the droplets Fb can be improved.
In the above embodiment, the suction unit is embodied in the suction port 33 common to each nozzle N. For example, as shown in FIG. 9, the suction means is arranged at a position corresponding to each nozzle N (each irradiation position PT) to a plurality of suction nozzles 33 </ b> N each capable of sucking “evaporation component Ev”. It may be embodied. At this time, a switching valve 40 corresponding to each suction nozzle 33N is provided between each suction nozzle 33N and the suction pump PM, and each switching valve 40 is based on the light amount detection signal Vp from each droplet Fb. A configuration for controlling the switching operation is preferable.

According to this, suction corresponding to the fluidity can be performed for each of the landed droplets Fb. As a result, excessive suction can be avoided, and the shape controllability of the pattern composed of the droplets Fb can be further improved.
In the above embodiment, the suction speed is controlled based on the laser beam B (reflected scattered light Br) from the region of the droplet Fb. For example, as shown in FIG. 9, a gas sensor 35 </ b> S is provided in the middle of the suction tube T as an evaporating component detection unit that can detect the total amount or type of the sucked “evaporating component Ev”. The suction speed may be controlled based on the detection signal detected by 35S.

That is, a configuration may be adopted in which suction is performed at a high suction speed at a timing at which the total amount of “evaporated component Ev” sucked is greater than a predetermined amount based on the detection signal detected by the gas sensor 35S. Or based on the detection signal which gas sensor 35S detects, you may make it the structure which performs the suction of a high suction speed at the timing when the classification of the "evaporation component Ev" sucked switches from a solvent to a dispersion medium. According to this, the fluidity of the droplet Fb can be made to correspond to the “evaporation component Ev” from the droplet Fb. Therefore, the suction speed for sucking the “evaporated component Ev” can be made to correspond to the fluidity of the droplet Fb.
In the above embodiment, the suction speed is controlled based on the laser beam B (reflected scattered light Br) from the region of the droplet Fb. Not limited to this, the suction speed may be controlled based on the elapsed time from the discharge start time T0. According to this, it is possible to avoid contamination of the optical system due to the “evaporated component Ev” with a simpler configuration without requiring the photosensor 35 and the gas sensor 35S, and the droplet Fb caused by the suction operation can be avoided. Misalignment and shape variation can be avoided.
In the above embodiment, the droplet detection laser B0, the drying laser B1, and the firing laser B2 are configured to be emitted from the same semiconductor laser LD. For example, a light source (or optical system) for the droplet detection laser B0 may be provided separately, and light from the light source (or optical system) may be irradiated onto the droplet Fb. Furthermore, a configuration may be provided in which a photosensor for detecting a droplet that detects scattered light, reflected light, transmitted light, and the like from the droplet Fb as the light amount detection signal Vp is separately provided. And you may make it the structure which starts a drying process based on the detected light quantity detection signal Vp.

Accordingly, the droplet detection laser B0 corresponding to the droplet Fb can be irradiated in the droplet detection step regardless of the optical characteristics of the laser light necessary for drying or firing the droplet Fb. Furthermore, regardless of the detection capability of the photosensor 35, the droplet detection laser B0 via the droplet Fb can be detected. Therefore, the configuration range of the detectable liquid F can be expanded. In addition, the detection accuracy of the droplet Fb can be improved.
In the above embodiment, the head unit 30 is mounted on the SCARA robot 26 and moved in the two-dimensional direction on the mother board 2M. For example, the head unit 30 may be fixed and the mounting board of the mother substrate 2M may be moved, or the head unit 30 may be mounted on a carriage and moved in a one-dimensional direction on the mother substrate 2M. You may make it the structure to make.
In the above embodiment, the presence or absence of the droplet Fb is detected by the laser beam B irradiated to the irradiation position PT, and the droplet Fb is dried and fired. For example, the configuration may be such that the droplet Fb flows in a desired direction by the energy of the laser beam B to be irradiated. Alternatively, the configuration may be such that only the outer edge of the droplet Fb is irradiated with the laser beam B and the droplet Fb is pinned. In other words, any configuration may be used as long as the pattern formed of the droplets Fb is formed by the laser beam B applied to the region of the droplets Fb.
In the above embodiment, the hemispherical dots D are formed by the droplets Fb. However, the present invention is not limited to this. For example, an oval dot or a linear pattern may be formed.
In the above embodiment, the pattern is embodied as the dot D. For example, the pattern may be embodied in various thin films, metal wirings, color filters, and the like provided in the liquid crystal display device 1, and further an electric field including a planar electron-emitting device that emits a fluorescent material. The present invention may be embodied in various thin films and metal wirings provided in various display devices such as effect type devices (FED, SED, etc.). That is, any pattern may be used as long as it is composed of the droplet Fb irradiated with the laser beam B.
In the above embodiment, the object is embodied in the mother substrate 2M, but is not limited thereto, and may be a silicon substrate, a flexible substrate, a metal substrate, or the like, and the pattern is formed by the landed droplets Fb. Any object can be used.

The top view which shows the liquid crystal display device in this embodiment. Similarly, the schematic perspective view which shows a droplet discharge device. Similarly, the schematic plan view which shows a liquid suitable discharge apparatus. Similarly, the schematic side view explaining a head unit. Similarly, the schematic side view explaining a droplet discharge head. Similarly, explanatory drawing explaining a head unit. Similarly, the timing chart explaining a droplet detection process, a drying process, and a baking process. Similarly, the electric block circuit diagram which shows the electric constitution of a droplet discharge apparatus. The schematic side view explaining the droplet discharge head in the example of a change.

Explanation of symbols

2M ... Mother board as object, 20 ... Droplet discharge device, 32 ... Droplet discharge head, 33 ... Suction port constituting suction means, 34 ... Laser head as laser irradiation means, 35 ... Laser light detection means 40 ... a switching valve constituting suction speed control means, 51 ... a control device constituting suction speed control means, B ... laser light, Ev ... evaporation component, Fb ... droplet, Vp ... light quantity as detection signal Detection signal.

Claims (12)

In the pattern forming method in which a pattern is formed on the object by irradiating a laser beam onto a region of a droplet including the pattern forming material landed on the object,
A pattern forming method, wherein an evaporation component from the droplet is sucked at a suction speed corresponding to the fluidity of the droplet. In the pattern formation method of Claim 1,
The pattern forming method characterized in that the suction speed is increased as the fluidity of the droplets decreases. In the pattern formation method of Claim 1 or 2,
The pattern forming method, wherein the suction speed is controlled based on optical characteristics of laser light from the droplet region. In the pattern formation method of Claim 3,
The suction speed is controlled on the basis of at least one of a light amount, a wavelength, a wavelength distribution, a deflection state, a polarization state, a phase distribution, and an intensity distribution of laser light from the droplet region. Pattern forming method. In the pattern formation method of Claim 1 or 2,
The pattern forming method, wherein the suction speed is controlled based on the evaporation component from the droplet region. In the pattern formation method of Claim 5,
The pattern forming method, wherein the suction speed is controlled based on at least one of the amount and type of the evaporation component from the droplet region. In a liquid droplet ejection apparatus comprising: a liquid droplet ejection head that ejects liquid droplets toward an object; and a laser irradiation unit that irradiates laser light onto a region of the liquid droplets that have landed on the object.
Suction means for sucking an evaporated component from the region of the droplet irradiated with the laser light;
A suction speed control means for controlling the suction speed of the suction means in accordance with the fluidity of the droplet irradiated with the laser beam;
A droplet discharge apparatus comprising: In the droplet discharge device according to claim 7,
Comprising laser light detecting means for detecting optical characteristics of laser light from the region of the droplet,
The liquid droplet ejection apparatus, wherein the suction speed control means controls a suction speed of the suction means based on a detection signal detected by the laser light detection means. The liquid droplet ejection apparatus according to claim 8,
The suction speed control means determines whether or not the droplet has landed on the laser light area based on a detection signal detected by the laser light detection means, and the droplet is placed on the laser light area. A droplet discharge device characterized in that, when the ink is landed, the suction means is driven to start suction of the evaporated component. In the droplet discharge device according to claim 8 or 9,
The laser light detecting means detects at least one of a light amount, a wavelength, a wavelength distribution, a deflection state, a polarization state, a phase distribution, and an intensity distribution of the laser light from the droplet region. Drop ejection device. In the droplet discharge device according to claim 7,
Evaporation component detection means for detecting the evaporation component sucked by the suction means,
The liquid droplet ejection apparatus, wherein the suction speed control means controls a suction speed of the suction means based on a detection signal detected by the evaporation component detection means. The droplet discharge device according to claim 11,
The pattern forming method, wherein the evaporation component detection means detects at least one of the amount and type of the evaporation component from the droplet region.

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