JP2006272085A - Droplet discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a droplet discharge device capable of accurately irradiating a droplet containing a functional material discharged from a discharge port with laser light and performing efficient drying and baking.
A semiconductor laser L is mounted on a carriage on which a nozzle plate 31 is mounted on the lower surface of a droplet discharge head. A semi-transparent mirror 39 is disposed below the semiconductor laser L. The semi-transparent mirror 39 reflects part of the laser light (first laser light) on its surface and transmits the remaining laser light (second laser light). The first laser beam is irradiated in the vicinity of the landing position of the droplet Fb to dry the droplet, and the second laser beam is irradiated directly under the semiconductor laser L to sinter the droplet Fb.
[Selection] Figure 7

Description

  The present invention relates to a droplet discharge device.

  2. Description of the Related Art Conventionally, an electro-optical device such as a liquid crystal display device or an organic electroluminescence display device (organic EL display device) is provided with a transparent glass substrate (hereinafter simply referred to as 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 includes a code pattern (for example, a colored thin film or a concave portion) in a part of a large number of arranged pattern formation regions (data cells), and encodes manufacturing information depending on the presence or absence of the code pattern.

  This identification code can be formed by laser sputtering that irradiates a metal foil with laser light to form a code pattern by sputtering, or water jet that engraves a code pattern by spraying water containing an abrasive onto a substrate or the like. A method has been proposed (Patent Documents 1 and 2).

  However, in the laser sputtering method, in order to obtain a code pattern having a desired size, the gap between the metal foil and the substrate must be adjusted to several to several tens of μm. In other words, 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, the target substrate on which the identification code can be formed is limited, causing a problem that the versatility is impaired. Further, the water jet method has a problem of contaminating the substrate because water, dust, abrasives, etc. are scattered when the substrate is engraved.

In recent years, an inkjet method has attracted attention as a method for forming an identification code that solves such production problems. The ink jet method forms a code pattern by discharging fine droplets containing metal fine particles from a droplet discharge device and drying the droplets. For this reason, the range of the target substrate can be expanded, and the identification code can be formed while avoiding contamination of the substrate.
Japanese Patent Laid-Open No. 11-77340 JP 2003-127537 A

  By the way, in the ink jet method, the droplet landed on the substrate is dried, and the functional material is baked to adhere to the substrate. That is, the droplet shape is fixed by a drying process, and the functional material is hardened by a baking process. Since such a drying / firing step is a step necessary for forming an appropriate shape, efficient drying / firing has been desired in the ink jet method.

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to irradiate liquid droplets containing a functional material discharged from a discharge port with high accuracy and to perform efficient drying and baking. It is an object of the present invention to provide a droplet discharge device that can perform the above.

The droplet discharge apparatus of the present invention supplies a liquid material containing a functional material as droplets from a discharge port, and supplies laser light to the droplets discharged from the discharge port and landed on a substrate. A first laser beam for branching the laser beam from the laser irradiation unit and drying the droplets ejected from the droplet ejection unit; and Branching means for generating a second laser beam for firing the droplets.

  According to this droplet discharge device, the laser beam from the laser irradiation unit is branched to generate the first laser beam for drying and the second laser beam for firing. For this reason, the process of drying and baking can be implemented using one laser irradiation means. Since the purpose of implementation is different between drying and firing, irradiation can be performed under conditions according to each purpose. Further, since the first laser beam and the second laser beam are irradiated to the droplets at different timings, the laser beam can be irradiated to the droplets for a longer time even if the speed of the substrate to be moved is increased. Can do. Therefore, the droplets can be dried and fired more efficiently.

  In this droplet discharge device, the branching unit generates the first laser beam and the second laser beam so that the intensity of the second laser beam is larger than the intensity of the first laser beam.

  According to this droplet apparatus, the second laser light for firing is made stronger than the first laser light to be dried. Usually, more energy is required for firing compared to drying. Accordingly, since the second laser beam having higher energy is irradiated for firing, the droplets can be fired more efficiently. The term “half mirror” as used herein refers to an “optical member that distributes incident light into a transmissive component and a reflective component”, and in order to distribute the transmitted component into a transmissive component and a reflective component, some processing is applied to the surface or inside of the transparent member. It is not limited to such a member, but also includes a member such as untreated glass.

  In this droplet discharge apparatus, the branching unit may be a half mirror, a beam splitter, or a diffraction element. According to this droplet discharge device, the first laser beam and the second laser beam can be generated using a half mirror, a beam splitter, or a diffraction element.

  In this droplet discharge device, a follower is provided for causing the second laser light to follow the droplet landed on the substrate. According to this droplet discharge device, the second laser light can be made to follow the droplet landed on the substrate, so that the second laser beam can be irradiated to the droplet for a longer time. Therefore, the droplets can be fired more efficiently.

  In the liquid droplet ejection apparatus, the branching unit is provided on the optical axis of the laser beam emitted from the laser irradiation unit, and the follower unit moves the branching unit to move the branched second laser beam. It was made possible to irradiate following the landed droplets. According to this droplet discharge device, the second laser beam can be made to follow the droplet by moving the branching means.

(First embodiment)
A first embodiment of the present invention will be described below with reference to FIGS.
First, a display module of a liquid crystal display device having an identification code formed using the droplet discharge device of the present invention will be described. 1 is a front view of a liquid crystal display module of the liquid crystal display device, FIG. 2 is a front view of an identification code formed on the back surface of the liquid crystal display module, and FIG. 3 is a side view of the identification code formed on the back surface of the liquid crystal display module. is there.

In FIG. 1, a liquid crystal display module 1 includes a transparent glass substrate (hereinafter simply referred to as a substrate 2) as a light transmissive display substrate. A rectangular display unit 3 enclosing liquid crystal molecules is formed at a substantially central position of the surface 2 a of the substrate 2, and a scanning line driving circuit 4 and a data line driving circuit 5 are formed outside the display unit 3. ing. The liquid crystal display module 1 controls the orientation state of the liquid crystal molecules 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, and is a plane irradiated from an illumination device (not shown). A desired image is displayed on the display unit 3 by modulating the light according to the alignment state of the liquid crystal molecules.

  In the right corner of the back surface 2b of the substrate 2, an identification code 10 of the liquid crystal display module 1 composed of dots D as a pattern is formed. As shown in FIG. 2, the identification code 10 is composed of a plurality of dots D formed in the pattern formation region Z1.

  A predetermined blank area Z2 is formed on the outer periphery of the pattern formation area Z1. The identification code 10 formed in the pattern formation region Z1 is a two-dimensional code in the present embodiment and can be read by a two-dimensional code reader. The blank area Z2 is an area in which the dot D is not formed, and the two-dimensional code reader identifies the pattern formation area Z1 and prevents erroneous detection of the identification code 10 in the pattern formation area Z1. .

  The pattern formation area Z1 is a square area of 1 to 2 mm square, and is virtually divided into 256 cells C of 16 rows × 16 columns as shown in FIG. Then, dots D are selectively formed for each cell C of 16 rows × 16 columns, and an identification code 10 for identifying the product number and lot number of the liquid crystal display module 1 constituted by each dot D is formed. Is done.

  In the present embodiment, the divided cell C, in which the cell C in which the dot D is formed in the cell C is the black cell C1, and the cell C in which the dot D is not formed in the cell C is the white cell C0 (non- Forming region). Further, in FIG. 4, from the upper side, the first row of cells C, the second row of cells C,..., The 16th row of cells C. In FIG. The cell C of the eye, ..., cell C of the 16th column.

  The dots D formed in the black cell C1 (dot region) are formed in close contact with the substrate 2 in a hemispherical shape as shown in FIGS. In the present embodiment, the dots D are formed by an ink jet method. More specifically, the dot D is a cell C (black cell C1) that is a droplet Fb of a liquid material Fa (see FIG. 8) containing a pattern forming material (for example, manganese fine particles) from a nozzle N of a droplet discharge device 20 described later. ). Next, the droplet Fb landed on the black cell C1 is dried, and the manganese fine particles contained in the droplet Fb are fired, so that hemispherical dots D made of manganese adhered to the substrate 2 are formed. The drying / firing is performed by irradiating the droplet Fb landed on the substrate 2 (black cell C1) with laser light.

Next, the droplet discharge device 20 used for forming the identification code 10 on the back surface 2b of the substrate 2 will be described. FIG. 5 is a perspective view showing the configuration of the droplet discharge device 20.
As shown in FIG. 5, the droplet discharge device 20 includes a base 21 formed in a rectangular parallelepiped shape. In the present embodiment, the longitudinal direction of the base 21 is the Y arrow direction, and the direction orthogonal to the Y arrow direction is the X arrow direction.

  A pair of guide grooves 22 extending in the Y arrow direction are formed on the upper surface 21a of the base 21 over the entire width in the Y arrow direction. A substrate stage 23 provided with a linear motion mechanism (not shown) corresponding to the pair of guide grooves 22 is attached to the upper side of the base 21. The linear movement mechanism of the substrate stage 23 is, for example, a screw type linear movement mechanism including a screw shaft (drive shaft) extending along the guide groove 22 and a ball nut screwed to the screw shaft. Is connected to a Y-axis motor MY (see FIG. 9) formed of a step motor. When a drive signal corresponding to a predetermined number of steps is input to the Y-axis motor MY, the Y-axis motor MY rotates forward or backward, and the substrate stage 23 corresponds to the same number of steps in the direction of the Y arrow. Are moved forward or backward (moved in the Y direction) at a predetermined speed.

In the present embodiment, the position at which the substrate stage 23 is disposed, and the position at which the substrate stage 23 is disposed closest to the base 21, as shown in FIG.
A placement surface 24 is formed on the upper surface of the substrate stage 23, and a suction-type substrate chuck mechanism (not shown) is provided on the placement surface 24. When the substrate 2 is placed on the placement surface 24 with the back surface 2b facing upward, the substrate 2 is positioned and fixed at a predetermined position on the placement surface 24 by the substrate chuck. At this time, the pattern formation region Z1 is set such that the column direction of each cell C is set along the Y arrow direction, and the cell C in the first row is closest to the Y arrow direction side.

  A pair of support bases 25a and 25b are erected on both sides of the base 21 in the X arrow direction, and a guide member 26 extending in the X arrow direction is installed on the pair of support bases 25a and 25b. The guide member 26 is formed such that the longitudinal width thereof is longer than the X arrow direction of the substrate stage 23, and one end of the guide member 26 projects to the support base 25 a side.

  A storage tank 27 is disposed on the upper side of the guide member 26. In the storage tank 27, a liquid Fa in which manganese fine particles are dispersed in a dispersion medium is stored in a detachable manner. On the other hand, on the lower side of the guide member 26, a pair of upper and lower guide rails 28 extending in the X arrow direction are provided so as to protrude over the entire width in the X arrow direction. A carriage 29 having a linear motion mechanism (not shown) corresponding to the guide rail 28 is attached to the guide rail 28. The linear movement mechanism of the carriage 29 is, for example, a screw type linear movement mechanism including a screw shaft (drive shaft) extending in the X arrow direction along the guide rail 28 and a ball nut screwed to the screw shaft. The drive shaft is connected to an X-axis motor MX (see FIG. 9) that receives a predetermined pulse signal and rotates forward and backward in steps. When a drive signal corresponding to a predetermined number of steps is input to the X-axis motor MX, the X-axis motor rotates forward or reverse, and the carriage 29 moves forward along the X arrow direction by the amount corresponding to the same number of steps. Or return.

  The carriage 29 is integrally provided with a droplet discharge head 30 as droplet discharge means. FIG. 6 is a perspective view when the lower surface (surface on the substrate stage 23 side) of the droplet discharge head 30 is directed upward. FIG. 7 shows a side view of the droplet discharge head 30. The droplet discharge head 30 is provided with a nozzle plate 31 on its lower surface, and in this embodiment, 16 nozzles N as discharge ports for forming the identification code 10 are arranged in a row in the X arrow direction. It is formed to penetrate at equal intervals.

  FIG. 8 is a cross-sectional view of a main part for explaining the structure of the droplet discharge head 30. As shown in FIG. 8, a cavity 32 is formed at a position above the nozzle plate 31 and facing the nozzle N. The cavities 32 communicate with the storage tanks 27 so that the liquid Fa in the storage tanks 27 can be supplied into the corresponding cavities 32. Above the cavity 32, a vibration plate 33 that vibrates in the vertical direction and expands and contracts the volume in the cavity 32, and a piezoelectric element 34 that includes a piezoelectric element that expands and contracts in the vertical direction and vibrates the vibration plate 33 is arranged. It is installed.

  When the droplet discharge head 30 receives a nozzle drive signal for controlling the drive of the piezoelectric element 34, the piezoelectric element 34 expands and contracts to enlarge or reduce the volume in the cavity 32 and reduce from the corresponding nozzle N. The liquid Fa containing a volume of manganese fine particles is discharged to the substrate 2 as droplets Fb.

As shown in FIG. 6, a laser irradiation device 38 is provided on the lower surface of the droplet discharge head 30 and on one side of the nozzle plate 31. In the laser irradiation device 38, semiconductor lasers L as 16 laser irradiation means provided corresponding to the 16 nozzles N are arranged in parallel at equal intervals in the X arrow direction. A laser array composed of these 16 semiconductor lasers L is 1
It is provided with a nozzle row composed of six nozzles N, and the intervals between the corresponding semiconductor lasers L and nozzles N are formed to be the same.

  As shown in FIG. 7, a semi-transparent mirror 39 as a branching unit is disposed below the semiconductor laser L. The semi-transparent mirror 39 is installed corresponding to the entire 16 nozzles N. The semi-transparent mirror 39 reflects a part of the laser light (first laser light) on its surface and transmits the remaining laser light (second laser light). Here, the first laser beam dries the landed droplet Fb, and the second laser beam burns the dried droplet Fb. In the present embodiment, the second laser light is irradiated from the landed droplets Fb to the cells located in the predetermined column so that the first laser light is irradiated in the vicinity of the position where the droplets Fb land on the substrate 2. Further, the mounting position of the semi-transparent mirror 39 is adjusted.

Next, the electrical configuration of the droplet discharge device 20 configured as described above will be described with reference to FIG.
9, the control device 40 includes an I / F unit 42 that receives various data from an input device 41 such as an external computer, a control unit 43 that includes a CPU and the like, a RAM 44 that includes DRAM and SRAM, and stores various data. A ROM 45 for storing various control programs is provided. The control device 40 also includes a drive waveform generation circuit 46, an oscillation circuit 47 that generates a clock signal CLK for synchronizing various drive signals, and a power supply circuit 48 that generates a laser drive voltage VDL for driving the semiconductor laser L. In addition, an I / F unit 49 for transmitting various drive signals is provided. In the control device 40, the I / F unit 42, the control unit 43, the RAM 44, the ROM 45, the drive waveform generation circuit 46, the oscillation circuit 47, the power supply circuit 48, and the I / F unit 49 are connected via the bus 50. ing.

  More specifically, the I / F unit 42 draws an image of the identification code 10 obtained by two-dimensionally coding the identification data such as the product number and lot number of the substrate 2 from the input device 41 by a known method, and draws the data in a predetermined format. Received as Ia. The control unit 43 executes an identification code creation processing operation based on the drawing data Ia received by the I / F unit 42. That is, the control unit 43 uses the RAM 44 or the like as a processing area, moves the substrate stage 23 according to a control program (for example, an identification code creation program) stored in the ROM 45 or the like, and carries out the transfer processing operation of the substrate 2. Each piezoelectric element 34 of the ejection head 30 is driven to perform a droplet ejection processing operation. In addition, the control unit 43 performs a drying processing operation for driving each semiconductor laser L and drying the droplets Fb in accordance with the identification code creating program.

  More specifically, the control unit 43 performs predetermined development processing on the drawing data Ia received by the I / F unit 42, and discharges the droplets Fb to each cell C on the two-dimensional drawing plane (pattern formation region Z1). Bitmap data BMD indicating whether or not to be generated is generated and stored in the RAM 44. The bitmap data BMD is serial data having a bit length of 16 × 16 bits corresponding to the piezoelectric element 34, and the piezoelectric element 34 is turned on or off according to the value (0 or 1) of each bit. It prescribes.

  Further, the control unit 43 performs a development process different from the development process of the bitmap data BMD on the drawing data Ia, generates waveform data of the piezoelectric element drive voltage VDP applied to the piezoelectric element 34, and sends it to the drive waveform generation circuit 46. It is designed to output. The drive waveform generation circuit 46 includes a waveform memory 46a that stores the waveform data generated by the control unit 43, a D / A conversion unit 46b that digitally / analog converts the waveform data and outputs it as an analog signal, and a D / A And a signal amplifying unit 46c for amplifying an analog waveform signal output from the conversion unit. The drive waveform generation circuit 46 digital / analog converts the waveform data stored in the waveform memory 46a by the D / A converter 46b, amplifies the waveform signal of the analog signal by the signal amplifier 46c, and outputs the piezoelectric element drive voltage VDP. Is generated.

  Then, the control unit 43 sends the bitmap data BMD via the I / F unit 49 as a discharge control signal SI synchronized with the clock signal CLK generated by the oscillation circuit 47, which will be described later. 56) are serially transferred sequentially. Further, the control unit 43 outputs a latch signal LAT for latching the transferred ejection control signal SI to the head drive circuit 51. Further, the control unit 43 outputs the piezoelectric element drive voltage VDP to the head drive circuit 51 (switch elements Sa1 to Sa16) in synchronization with the clock signal CLK generated by the oscillation circuit 47.

  A head drive circuit 51, a laser drive circuit 52, a substrate detection device 53, an X-axis motor drive circuit 54 and a Y-axis motor drive circuit 55 are connected to the control device 40 via an I / F unit 49.

  The head drive circuit 51 includes a shift register 56, a latch circuit 57, a level shifter 58, and a switch circuit 59. The shift register 56 performs serial / parallel conversion on the ejection control signal SI transferred from the control device 40 (control unit 43) in synchronization with the clock signal CLK in association with the 16 piezoelectric elements 34. The latch circuit 57 latches the 16-bit ejection control signal SI converted in parallel from the shift register 56 in synchronization with the latch signal LAT input from the control device 40 (control unit 43), and the latched ejection control signal SI is latched. Output to the level shifter 58 and the laser drive circuit 52. The level shifter 58 boosts the ejection control signal SI latched by the latch circuit 57 to a voltage driven by the switch circuit 59, and generates an open / close signal GS1 corresponding to each of the 16 piezoelectric elements 34. The switch circuit 59 includes switch elements Sa1 to Sa16 corresponding to the piezoelectric elements 34, respectively, and a common piezoelectric element drive voltage VDP is input to the input side of each switch element Sa1 to Sa16, and the output side thereof. The corresponding piezoelectric elements 34 are connected. Each switch element Sa1 to Sa16 receives a corresponding open / close signal GS1 from the level shifter 58, and controls whether or not to supply the piezoelectric element drive voltage VDP to the piezoelectric element 34 in accordance with the open / close signal GS1. It has become.

  That is, the droplet discharge device 20 of the present embodiment applies the piezoelectric element drive voltage VDP generated by the drive waveform generation circuit 46 in common to the corresponding piezoelectric elements 34 via the switch elements Sa1 to Sa16. The droplet discharge device 20 controls the opening and closing of the switch elements Sa1 to Sa16 by a discharge control signal SI (open / close signal GS1) output from the control device 40 (control unit 43). When the switch elements Sa1 to Sa16 are closed, the piezoelectric element drive voltage VDP is supplied to the piezoelectric elements 34 corresponding to the switch elements Sa1 to Sa16, and the droplet Fb is discharged from the nozzle N corresponding to the piezoelectric element 34. The

  FIG. 10 shows the pulse waveforms of the latch signal LAT, the discharge control signal SI, and the opening / closing signal GS1 of FIG. 10, and the waveform of the piezoelectric element driving voltage VDP applied to the piezoelectric element 34 in response to the opening / closing signal GS1.

  As shown in FIG. 10, when the latch signal LAT output from the controller 43 to the head drive circuit 51 falls, the opening / closing signal GS1 is generated based on the 16-bit ejection control signal SI. Then, the piezoelectric element drive voltage VDP is supplied to the piezoelectric element 34 corresponding to the open / close signal GS1 that rises among the 16 open / close signals GS1. As the piezoelectric element drive voltage VDP rises, the piezoelectric element 34 contracts and the liquid Fa is drawn into the cavity 32, and as the piezoelectric element drive voltage VDP falls, the piezoelectric element 34 expands and the inside of the cavity 32 extends. The liquid material Fa is pushed out, and the droplet Fb is discharged. When the droplet Fb is ejected, the voltage value of the piezoelectric element driving voltage VDP returns to the initial voltage, and the ejection operation of the droplet Fb by driving the piezoelectric element 34 is completed.

  As shown in FIG. 9, the laser drive circuit 52 includes a delay pulse generation circuit 61 and a switch circuit 62. As shown in FIG. 10, the delay pulse generation circuit 61 receives the ejection control signal SI latched by the latch circuit 57 in response to the falling of the latch signal LAT for a predetermined time T (specifically, waiting times T1, T2 ) To generate a pulse signal (open / close signal GS2) that is delayed by a), and output the open / close signal GS2 to the switch circuit 62. Here, the waiting time T1 is the time required for the droplet Fb to land at the irradiation position of the first laser beam of the semiconductor laser L corresponding to the piezoelectric element 34 (nozzle N). The waiting time T2 is the time required for the landed droplet Fb to pass through the irradiation position of the second laser beam of the semiconductor laser L corresponding to the piezoelectric element 34 (nozzle N). The standby times T1 and T2 are based on the drive timing of the piezoelectric element 34 (falling timing of the latch signal LAT) (reference time Tk), and the standby times T1 and T2 are set based on tests or the like in advance. It was time. In the present embodiment, since the second laser beam is set to be irradiated from the cell at the irradiation position of the first laser beam to the cell in the predetermined column, the waiting time T2 is the cell corresponding to the predetermined column in the substrate 2. The waiting time is longer than the waiting time T1. When the delay pulse generation circuit 61 generates a pulse when the standby times T1 and T2 have elapsed, the delay pulse generation circuit 61 outputs an open / close signal GS2 to the switch circuit 62.

  The switch circuit 62 includes switch elements Sb1 to Sb16 corresponding to the respective semiconductor lasers L. The common laser drive voltage VDL generated by the power supply circuit 48 is input to the input side of each switch element Sb1 to Sb16, and the corresponding semiconductor laser L is connected to the output side. Each switch element Sb1 to Sb16 receives a corresponding open / close signal GS2 from the delay pulse generation circuit 61, and controls whether or not to supply the laser drive voltage VDL to the semiconductor laser L in accordance with the open / close signal GS2. It is like that.

  That is, the droplet discharge device 20 of the present embodiment applies the laser drive voltage VDL generated by the power supply circuit 48 to the corresponding semiconductor lasers L in common via the switch elements Sb1 to Sb16. The droplet discharge device 20 controls the opening and closing of the switch elements Sb1 to Sb16 by a discharge control signal SI (open / close signal GS2) supplied by the control device 40 (control unit 43). When the switch elements Sb1 to Sb16 are closed, the laser drive voltage VDL is supplied to the semiconductor laser L corresponding to the switch elements Sb1 to Sb16, and laser light is emitted from the corresponding semiconductor laser L.

  That is, as shown in FIG. 10, when the latch signal LAT is input to the head drive circuit 51, the opening / closing signal GS2 is generated immediately, and the opening / closing signal GS2 is generated after the standby times T1 and T2. Then, when the open / close signal GS2 rises, the laser drive voltage VDL is applied to the corresponding semiconductor laser L, and the droplet Fb that has landed on the substrate 2 (black cell C1) that has just passed the irradiation position of the semiconductor laser L, Laser light is emitted from the semiconductor laser L. Then, the open / close signal GS2 falls, the supply of the laser drive voltage VDL is cut off, and the drying processing operation by the semiconductor laser L is completed.

  A substrate detection device 53 is connected to the control device 40 via an I / F unit 49. The substrate detection device 53 is used when the edge of the substrate 2 is detected and the position of the substrate 2 passing directly under the droplet discharge head 30 (nozzle N) is calculated by the control device 40.

  An X-axis motor drive circuit 54 is connected to the control device 40 via an I / F unit 49, and an X-axis motor drive control signal is output to the X-axis motor drive circuit 54. In response to the X-axis motor drive control signal from the control device 40, the X-axis motor drive circuit 54 rotates the X-axis motor MX that moves the carriage 29 back and forth. For example, when the X-axis motor MX is rotated forward, the carriage 29 moves in the X arrow direction, and when it is rotated reversely, the carriage 29 moves in the counter X arrow direction.

  An X-axis motor rotation detector 54a is connected to the control device 40 via the X-axis motor drive circuit 54, and a detection signal is input from the X-axis motor rotation detector 54a. Based on this detection signal, the control device 40 detects the rotation direction and rotation amount of the X-axis motor MX, and calculates the movement amount and the movement direction of the droplet discharge head 30 (carriage 29) in the X arrow direction. It is like that.

  A Y-axis motor drive circuit 55 is connected to the control device 40 via an I / F unit 49, and a Y-axis motor drive control signal is output to the Y-axis motor drive circuit 55. In response to the Y-axis motor drive control signal from the control device 40, the Y-axis motor drive circuit 55 rotates the Y-axis motor MY that reciprocates the substrate stage 23 in the normal direction or the reverse direction, and sets the substrate stage 23 in advance. It is designed to move at speed. For example, when the Y-axis motor MY is rotated forward, the substrate stage 23 (substrate 2) moves in the direction of the arrow Y at a predetermined speed, and when reversed, the substrate stage 23 (substrate 2) is reacted at a predetermined speed. Move in the direction of the Y arrow.

  A Y-axis motor rotation detector 55a is connected to the control device 40 via a Y-axis motor drive circuit 55, and a detection signal is input from the Y-axis motor rotation detector 55a. The control device 40 detects the rotation direction and the rotation amount of the Y-axis motor MY based on the detection signal from the Y-axis motor rotation detector 55a, and moves the substrate 2 with respect to the droplet discharge head 30 in the Y-arrow direction. Calculate the amount of movement.

Next, a method for forming the identification code 10 on the back surface 2b of the substrate 2 using the droplet discharge device 20 will be described.
First, as shown in FIG. 5, the substrate 2 is placed and fixed on the substrate stage 23 positioned at the forward movement position so that the back surface 2b is on the upper side. At this time, the side on the Y arrow direction side of the substrate 2 is disposed on the side opposite to the Y arrow direction from the guide member 26. The carriage 29 (droplet discharge head 30) is set at a position where the position (pattern formation region Z1) for forming the identification code 10 passes immediately below the substrate 2 when the substrate 2 moves in the direction of the arrow Y. .

  From this state, the control device 40 drives and controls the Y-axis motor MY, and transports the substrate 2 in the Y arrow direction at a predetermined speed via the substrate stage 23. Eventually, when the substrate detection device 53 detects the edge of the substrate 2 on the Y arrow side, the control device 40, based on the detection signal from the Y-axis motor rotation detector 55a, a horizontal row of cells C (black cells C1). Is calculated to have been conveyed to just below the nozzle N.

  During this time, the control device 40 outputs the ejection control signal SI based on the bitmap data BMD stored in the RAM 44 and the piezoelectric element drive voltage VDP generated by the drive waveform generation circuit 46 to the head drive circuit 51 according to the identification code creation program. . Further, the control device 40 outputs the laser drive voltage VDL generated by the power supply circuit 48 to the laser drive circuit 52. Then, the control device 40 waits for the timing to output the latch signal LAT.

  When the cell C (black cell C1) in the first row is transported to the position immediately below the nozzle N (landing position), the control device 40 outputs a latch signal LAT to the head drive circuit 51. When the head drive circuit 51 receives the latch signal LAT from the control device 40, the head drive circuit 51 generates an open / close signal GS1 based on the ejection control signal SI and outputs the open / close signal GS1 to the switch circuit 59. Then, the piezoelectric element drive voltage VDP is supplied to the piezoelectric elements 34 corresponding to the switch elements Sa1 to Sa16 in the closed state, and the droplets Fb corresponding to the piezoelectric element drive voltage VDP are simultaneously discharged from the corresponding nozzles N. To do.

On the other hand, when the latch signal LAT is input to the head drive circuit 51, the laser drive circuit 52 (delay pulse generation circuit 61) receives the ejection control signal SI latched by the latch circuit 57 and starts generating the opening / closing signal GS2. When the standby time T1 elapses, the generated opening / closing signal GS2 is output to the switch circuit 62. Then, the laser drive circuit 52 outputs the open / close signal GS2 generated by the delay pulse generation circuit 61 to the switch circuit 62, and supplies the laser drive voltage VDL to the semiconductor lasers L corresponding to the closed switch elements Sb1 to Sb16. To do. Thereby, a laser beam is irradiated from each semiconductor laser L. Then, this laser beam is branched into a first laser beam and a second laser beam by the half mirror 39. Among these, the first laser light is irradiated to the droplets Fb landed in the horizontal rows of black cells C1, the dispersion medium of the landed droplets Fb is evaporated by the energy of each first laser light, and the droplets Fb is dried.

  Thereafter, when the substrate 2 moves in the Y direction and the standby time T2 has elapsed, the laser drive circuit 52 (delay pulse generation circuit 61) receives the ejection control signal SI latched by the latch circuit 57 and generates the opening / closing signal GS2. The generated open / close signal GS2 is output to the switch circuit 62. Then, the laser drive circuit 52 outputs the open / close signal GS2 generated by the delay pulse generation circuit 61 to the switch circuit 62, and supplies the laser drive voltage VDL to the semiconductor lasers L corresponding to the closed switch elements Sb1 to Sb16. To do. Thereby, a laser beam is irradiated from each semiconductor laser L. Then, this laser beam is branched into a first laser beam and a second laser beam by a half mirror 39. Among these, the second laser light is irradiated to the droplet Fb landed in the horizontal row of black cells C1 reaching the irradiation position of the second laser light, and is contained in the droplet Fb by the energy of the second laser light. The fine manganese particles are baked and adhered to the substrate 2. Thereby, hemispherical dots D made of manganese are formed on the substrate 2. The first laser beam branched by the semi-transparent mirror 39 irradiates the irradiation position of the first laser beam, that is, the cell in the predetermined column from the horizontal row, and dries the droplet Fb landed on the cell.

  Thereafter, each time the droplets Fb ejected from the nozzles N are landed on the substrate 2, the droplets Fb are dried by receiving the irradiation of the first laser light of the corresponding semiconductor laser L, and the irradiation position of the second laser light. Each time it is conveyed, the semiconductor laser L is irradiated with the second laser light and baked. Then, hemispherical dots D constituting the identification code 10 are formed for each horizontal row.

  After that, when all the dots D of the identification code 10 formed in the pattern formation region Z1 are formed, the control device 40 controls the Y-axis motor MY to leave the substrate 2 from the position below the droplet discharge head 30. Let

Next, effects of the present embodiment configured as described above will be described below.
(1) According to the present embodiment, the semi-transparent mirror 39 is disposed below the semiconductor laser L. The semi-transparent mirror 39 reflects part of the laser light (first laser light) on its surface and transmits the remaining laser light (second laser light). The first laser beam is irradiated in the vicinity of the landing position of the droplet Fb to dry the droplet, and the second laser beam is irradiated directly under the semiconductor laser L to sinter the droplet Fb. Therefore, by using one semiconductor laser L corresponding to each nozzle N, it is possible to irradiate drying and firing with different purposes under conditions according to each purpose. Furthermore, since the first laser beam and the second laser beam are irradiated to the droplet at different timings, the laser beam can be irradiated to the droplet for a longer time. Accordingly, the droplet Fb can be efficiently dried and fired.

  (2) According to the present embodiment, the 16 semiconductor lasers L are driven only by the semiconductor lasers L corresponding to the driven piezoelectric elements 34. For this reason, in the area | region which does not need drying and baking, the laser irradiation by the semiconductor laser L can be suppressed and power consumption can be suppressed.

(Second Embodiment)
Next, a second embodiment embodying the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the part similar to 1st Embodiment, and the detailed description is abbreviate | omitted.

As shown in FIG. 11, in the present embodiment, the semiconductor laser L of the first embodiment is attached so as to be irradiated obliquely with respect to the substrate 2.
On the optical axis of the laser beam from the semiconductor laser L, a semi-transparent mirror 39 is disposed. The semi-transparent mirror 39 of the present embodiment uses the laser beam partially transmitted through the semi-transparent mirror 39 as the first laser beam for drying the droplet Fb, and uses the remaining laser beam reflected on the surface thereof. And used as a second laser beam for firing the droplet Fb. Also in the present embodiment, similarly to the first embodiment, the first laser beam is disposed near the position where the droplet Fb lands on the substrate 2.

  Further, in the present embodiment, the semi-transparent mirror 39 is provided on the carriage 29 via a minute movement stage. This minute movement stage is provided with a half mirror driving mechanism (not shown) for minutely moving the half mirror 39 in the Y arrow direction. This semi-transparent drive mechanism is, for example, a screw type linear motion mechanism including a screw shaft (drive shaft) extending in the Y arrow direction along a guide rail extending in the Y arrow direction, and a ball nut screwed to the screw shaft. is there. Further, the drive shaft of the semi-transparent drive mechanism is connected to a moving motor MA (see FIG. 12) that receives a predetermined pulse signal and rotates forward and backward in steps. When a driving signal corresponding to a predetermined number of steps is input to the moving motor MA, the moving motor rotates forward or reverse, and the half mirror 39 moves in the direction of the Y arrow by an amount corresponding to the same number of steps. Move or return. Therefore, the second laser beam is driven in a state where the irradiation position of the first laser beam is substantially fixed in the vicinity of the landing position of the droplet Fb by driving the half mirror driving mechanism and moving the half mirror 39 in the Y arrow direction. Can be moved along the movement of the substrate 2 in the Y-axis direction so that the position shown in the upper diagram of FIG. Accordingly, the second laser beam can be moved following the movement of the droplet Fb landed on the substrate 2.

  As shown in FIG. 12, the control device 40 of the present embodiment is connected to a semi-transparent movement drive circuit 65 via an I / F unit 49, and outputs a drive control signal thereto. In addition, the pulse signal generated by the delay pulse generation circuit 61 of the laser drive circuit 52 is supplied to the half mirror movement drive circuit 65, and the movement motor MA for moving the half mirror 39 is rotated forward or reverse. At this time, the semi-transparent movement drive circuit 65 is used for movement in the case where the laser beam is irradiated based on the pulse signal (opening / closing signal GS2) delayed by the waiting time T2, that is, in the firing process. The motor MA is driven. Specifically, as the substrate 2 moves, the semi-transparent mirror 39 is moved in the direction of the arrow Y so as to follow the droplet Fb landed with the branched laser beam.

According to the present embodiment, in addition to the same effects as in the first embodiment, the following effects can be obtained.
(3) According to the present embodiment, the irradiation position of the second laser light is changed, and the semi-transparent mirror 39 is moved in the Y arrow direction so that the irradiation position of the second laser light can be changed in accordance with the movement of the substrate 2. A semi-transparent drive mechanism is provided. Usually, more energy is required for firing compared to drying. Accordingly, the relative speed difference between the movement of the irradiation position of the second laser beam and the movement of the substrate 2 is reduced, and the irradiation time of the second laser beam is increased for the droplet Fb that has landed on the substrate 2, thereby firing. Can be promoted. Therefore, the movement of the substrate stage 23 can be accelerated in order to increase the drawing speed, the irradiation time of the semiconductor laser L for firing can be ensured, and firing can be performed.

(4) According to this embodiment, the light that passes through the semi-transparent mirror 39 is the first laser light, and the light that reflects the semi-transparent mirror 39 is the second laser light. The irradiation position of the light transmitted through the semi-transparent mirror 39 does not move greatly even if the semi-transparent mirror 39 is moved up and down and translated. For this reason, even if the semi-transparent mirror 39 is moved so that the second laser light follows the droplet Fb, the irradiation position of the first laser light can be substantially fixed. Therefore, drying can be performed as soon as the droplet Fb lands on the substrate 2, and the droplet Fb can be efficiently baked by irradiating Fb with the second laser light for a long time.

In addition, you may change each said embodiment as follows.
In the second embodiment, the second laser beam is caused to follow the droplet Fb landed on the substrate 2 by moving the semi-transparent mirror 39 in the Y arrow direction. The tracking method of the second laser light is not limited to this. For example, the semi-transparent mirror 39 may be installed at an angle, and the semi-transparent mirror 39 may be moved as in the second embodiment. In this case, the position of the reflection point in the semi-transparent mirror 39 moves and the irradiation position can be changed. Further, the irradiation position can be changed by rotating the semi-transparent mirror 39. When the semi-transparent mirror 39 is rotated, the movement amount of the irradiation position of the first laser light is smaller than the movement amount of the irradiation position of the second laser light to be reflected. Even if the droplet Fb is followed, the first laser beam can be irradiated to substantially the same position.

  In the second embodiment, the semi-transparent mirror 39 is moved in the Y arrow direction, the first laser beam is irradiated in the vicinity of the landing position of the droplet Fb, and the second laser beam is made to follow the droplet Fb. It is not always necessary to split the first laser beam and the second laser beam. For example, when the drying and firing of the droplet Fb are not performed at the same timing, the semi-transparent mirror 39 may be moved or rotated so that only the first laser beam or the second laser beam is irradiated. For example, when the second laser beam is not irradiated, the semi-transparent mirror 39 may be retracted from the laser irradiation line and irradiated with only the first laser beam. Further, when the first laser beam is not irradiated, the semi-transparent mirror 39 may be rotated so that the laser beam is totally reflected so that only the second laser beam is irradiated.

  Specifically, when the irradiation is performed based only on the pulse generated by the delay pulse generation circuit 61 at the standby time T1, the semi-transparent mirror 39 is moved so as to generate the first laser beam by totally transmitting the laser beam. Alternatively, the rotation is controlled. When irradiation is performed based only on the pulse generated by the delay pulse generation circuit 61 at the standby time T2, the semi-transparent mirror 39 is moved or rotated so as to generate the second laser beam by totally reflecting the laser beam. To control. Further, when irradiation is performed based on the pulses generated by the delay pulse generation circuit 61 during the waiting times T1 and T2, the half mirror 39 is moved up and down so as to generate the first laser beam and the second laser beam. Control the rotation. Therefore, when the irradiation with the first laser beam or the irradiation with the second laser beam is unnecessary, the unnecessary irradiation is not performed, and the energy without the irradiation can be irradiated as the necessary laser beam.

  In each of the above embodiments, the semi-transparent mirror 39 is used as a branching unit that separates the first laser beam and the second laser beam. The branching means is not limited to this, and for example, a beam splitter or a diffraction element may be used.

  In each of the above embodiments, the semiconductor laser L is used for drying the droplet Fb, and the semiconductor laser L is used for firing the droplet Fb. Other lasers may be used for the laser for drying the droplet Fb or the laser for firing the droplet Fb.

  In each of the above embodiments, the laser irradiation position of the laser light emitted from the semiconductor laser L is substantially coincident with the landing position of the droplet Fb, but the laser irradiation position may be different from the landing position of the droplet. Good.

  In each of the above embodiments, the hemispherical dot D is embodied, but the shape is not limited. For example, the planar shape is an elliptical dot or a bar constituting a barcode. It may be linear.

  In each of the above embodiments, the pattern is a two-dimensional code identification code. However, the pattern is not limited to this, and may be a barcode, for example. Further, the pattern may be letters, numbers, symbols, and the like.

In each of the above embodiments, the identification code 10 is formed on the substrate 2 as a display substrate, but it may be a silicon wafer, a resin film, a metal plate, or the like.
In each of the above embodiments, the droplet Fb is ejected by the expansion and contraction of the piezoelectric element 34. However, the cavity 32 may be formed by a method other than the piezoelectric element 34 (for example, a method of generating and bursting bubbles in the cavity 32). The inside may be pressurized to discharge the droplet Fb.

  In each of the above embodiments, the delay pulse generation circuit 61 of the laser drive circuit 52 outputs the open / close signal GS2 when the standby times T1 and T2 have elapsed. The control device 40 measures the standby times T1 and T2, respectively, and outputs a control signal to the laser drive circuit 52 when the standby times T1 and T2 have elapsed. Then, the laser driving circuit 52 may output an opening / closing signal GS2 generated based on the ejection control signal SI input from the latch circuit 57 of the head driving circuit 51 in response to the control signal.

  In each of the above embodiments, the droplet discharge device 20 for forming the dots D constituting the identification code 10 is embodied. For example, the present invention may be applied to a droplet discharge device that discharges droplets containing a wiring material as a functional material onto a substrate to form a metal wiring on the substrate or form an insulating film. . Also in this case, drying and baking can be performed efficiently with the droplet discharge device.

  In each of the above embodiments, the liquid crystal display module 1 is embodied. For example, a display module of an organic electroluminescence display device may be used, or a field effect device (including a planar electron-emitting device and using light emission of a fluorescent material by electrons emitted from the device) ( A display module including an FED, an SED, or the like may be used. The substrate 2 on which the identification code 10 is formed may be used not only for these display devices but also for other electronic devices.

The front view of the liquid crystal display module of a liquid crystal display device. The front view of the dot pattern formed in the back surface of a liquid crystal display module. The side view of the dot pattern formed in the back surface of a liquid crystal display module. Explanatory drawing for demonstrating the structure of a dot pattern. FIG. 3 is a perspective view of a main part of the droplet discharge device according to the embodiment. The perspective view for demonstrating a droplet discharge head. The side view for demonstrating a droplet discharge head. FIG. 3 is a cross-sectional view of a main part for explaining a droplet discharge head. The electric block circuit diagram for demonstrating the electrical structure of a droplet discharge apparatus. The timing chart for demonstrating the drive timing of a piezoelectric element and a semiconductor laser. FIG. 3 is a cross-sectional view of a main part for explaining a droplet discharge head. The electric block circuit diagram for demonstrating the electrical structure of a droplet discharge apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS Fa ... Liquid body, Fb ... Droplet, L ... Semiconductor laser as laser irradiation means, N ... Nozzle as discharge port, 2 ... Glass substrate as substrate, 20 ... Droplet discharge device, 29 ... Carriage, 30 ... Liquid Droplet discharge head as droplet discharge means, 39... Semi-transparent mirror as branch means.

Claims (5)

A liquid having droplet discharge means for discharging a liquid material containing a functional material as droplets from the discharge port, and laser irradiation means for supplying laser light to the droplet discharged from the discharge port and landed on the substrate In the droplet ejection device,
The laser beam from the laser irradiation unit is branched to generate a first laser beam for drying the droplets ejected from the droplet ejection unit and a second laser beam for firing the droplets And a branching means for performing the operation. The droplet discharge device according to claim 1,
The branching unit generates the first laser beam and the second laser beam so that the intensity of the second laser beam is larger than the intensity of the first laser beam. apparatus. The liquid droplet ejection apparatus according to claim 1 or 2,
The droplet ejecting apparatus according to claim 1, wherein the branching unit is a half mirror, a beam splitter, or a diffraction element. In the liquid droplet ejection apparatus according to any one of claims 1 to 3,
A droplet discharge apparatus, comprising: a follower that causes the second laser beam to follow the droplet landed on the substrate. The droplet discharge device according to claim 4,
The branching unit is provided on the optical axis of the laser beam irradiated from the laser irradiation unit,
The droplet ejecting apparatus according to claim 1, wherein the tracking unit moves the branching unit to irradiate the branched second laser beam following the landed droplet.

Images