JP2010139294A - Method for measuring volume of impact dot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a volume measuring method for an impact dot, which enables acquisition of high-reliability measurement results concerning the volume of an impact dot of a functional liquid drop discharged from each nozzle of a functional-liquid-drop head. <P>SOLUTION: The volume measuring method for an impact dot 10 is employed for measuring the volume of the impact dot 10 impacted on an inspection substrate by using an interferometer 99, by inspection discharge of the functional-liquid-drop discharge head 1. A plurality of kinds of inspection substrates 16 different in water repellence are prepared, and inspection discharge and measurement of the volume of the impact dot 10 are performed by using one inspection substrate 16 determined to accord to a measured humidity of the ambient atmosphere, based on humidity-water repellence data 20 representing the relation between the humidity of an ambient atmosphere and the plurality of kinds of inspection substrates 16 which make the impact dot 10 for measurement be in an appropriate dome shape. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a landing dot volume measuring method for measuring the volume of a landing dot of a functional droplet ejected from each nozzle of a functional droplet ejection head.

As a method for measuring the volume of this kind of landing dot, a method is known in which the shape of a landing dot, which is a functional liquid droplet that has landed on an inspection substrate, is measured by a form measuring device comprising an interferometer, and the volume is calculated from this shape. (See Patent Document 1). That is, in this volume measuring method, a large number of discharge nozzles of a functional liquid droplet ejection head are ejected one by one at time intervals while moving the functional liquid droplet ejection head relative to the inspection substrate in the main scanning direction. And a measuring step of measuring the shape of each of a large number of landing dots while moving the morphological measuring apparatus to the functional liquid droplet discharging head and relatively moving the same in the main scanning direction with respect to the inspection substrate. I have. With this method, the time from landing to measurement is constant for each landing dot, and measurement can be performed accurately and efficiently.
JP 2008-209218 A

However, since the landing dot is measured after a certain time has elapsed, the shape (volume) of the landing dot changes due to the evaporation of the solvent in each landing dot. Since the change in the shape of the landing dot is easily affected by the humidity of the surrounding atmosphere, there is a problem that the measurement error is large due to the seasonal change and the volume measurement cannot be performed accurately.
For example, in low-humidity environments, the landing dots are too prominent and the dot edges are jagged. There was a problem of not becoming. As a result, the surface shape of the landing dots cannot be appropriately acquired as interference fringes, and a large error has occurred in volume measurement.

  An object of the present invention is to provide a landing dot volume measuring method capable of accurately measuring the volume of a landing dot of a functional liquid droplet ejected from each nozzle of a functional liquid droplet ejection head.

  The landing dot volume measuring method of the present invention is a landing dot volume measuring method for measuring the volume of a landing dot that has landed on a test substrate by an inspection discharge of a functional liquid droplet discharge head using an interferometer. Based on humidity-water repellency data that shows the relationship between the humidity of the surrounding atmosphere and the multiple types of test boards that have a suitable dome shape for landing dots for measurement. The test discharge and the volume measurement of the landing dots are performed using one test substrate corresponding to the measured humidity of the ambient atmosphere.

  According to this configuration, regardless of the humidity of the surrounding atmosphere, the landing dot on the inspection substrate can be formed into an appropriate dome shape suitable for the measurement of the interferometer. For this reason, in the volume measurement by the interferometer, the surface shape can be appropriately acquired, and the volume measurement of the landing dot can be performed with high accuracy.

  In this case, it is preferable that a water repellent film is formed on the surface of each test substrate, and the plurality of types of test substrates are classified according to the length of time for forming the water repellent film.

  According to this configuration, a plurality of types of test substrates having different water repellency can be easily manufactured with good reproducibility.

  In this case, the landing dots are preferably formed by a plurality of shots of inspection ejection.

  According to this configuration, it is possible to reduce the influence of the volume variation in the functional liquid droplets in one shot, and thus it is possible to perform volume measurement more accurately.

  In this case, it is preferable to perform the test ejection and the volume measurement of the landing dots for each nozzle row in the functional liquid droplet ejection head.

  According to this configuration, the time from each ejection to each imaging is the same, the amount of the solvent vaporized from the functional droplets can be made uniform, and the measurement accuracy can be improved.

  Hereinafter, a method for measuring the volume of a landing dot according to an embodiment of the present invention will be described with reference to the accompanying drawings. The landing dot volume measurement refers to the measurement of the functional liquid droplet ejection amount that is performed in the ejection inspection of each nozzle in the functional liquid droplet ejection head inspection system. This inspection system performs performance inspection on individual functional liquid droplet ejection heads. First, a functional liquid droplet ejection head to be inspected will be described.

  As shown in FIG. 1, the functional liquid droplet ejection head 1 is a so-called dual type, and includes a functional liquid introduction unit 2 having two series of connecting needles 7 and two series connected to the side of the functional liquid introduction unit 2. The head substrate 3 having the connector 4, the two pump parts (not shown) connected to the functional liquid introduction part 2, and the nozzle plate 5 connected to the pump part are provided. The pump unit and the nozzle plate 5 constitute a square head main body 6.

  Two nozzle rows 12 and 12 are arranged in parallel to each other on the nozzle surface 11 of the nozzle plate 5, and each nozzle row 12 and 12 is composed of 180 discharge nozzles 13 arranged at an equal pitch. Has been. Of the 180 discharge nozzles 13, each of the ten discharge nozzles 13 disposed at both ends is an end invalid nozzle that is not used in the actual drawing process. In other words, the discharge nozzles 13 (160 nozzles from the 11th nozzle to the 170th nozzle counted from the end) sandwiched between the end invalid nozzles are effective nozzles.

  Next, the above-described inspection system for the functional liquid droplet ejection head 1 will be described with reference to FIGS. In this inspection system, a glass substrate 16 and a functional droplet discharge head 1 are set, a discharge inspection apparatus 31 (FIG. 2) for inspecting and discharging functional droplets on the glass substrate 16, and a function that has landed on the glass substrate 16. A landing dot imaging device 18 (FIG. 3) for imaging and inspecting and measuring droplets is provided. The user performs various discharge inspections and measurements of the functional liquid droplet discharge head 1 on the discharge inspection device 31 (flight bending inspection, drive voltage measurement, flight speed measurement of functional liquid droplets, etc.) and the glass substrate 16. After that, the glass substrate 16 is set on the landing dot imaging device 18, and the landing dots 10 on the glass substrate 16 are imaged and inspected (strictly, volume measurement). Thereby, the performance of the functional liquid droplet ejection head 1 is inspected.

  The ejection inspection device 31 is mounted on the machine base 32 and the head inspection device 33 that is placed on the machine base 32 and inspects the ejection performance of the functional liquid droplet ejection head 1. And a maintenance device 34 for maintaining and recovering the function of the droplet discharge head 1 and accommodated in a chamber 35. In addition, a control device 26 is provided outside the chamber 35, and controls the functional liquid droplet ejection head 1, the head inspection device 33, and the maintenance device 34 in an integrated manner. In order to inspect the functional liquid droplet ejection heads 1 one by one, the ejection inspection device 31 ejects the functional liquid from the head inspection device 33 while maintaining and recovering the function of the functional liquid droplet ejection head 1 by the maintenance device 34. The ejection performance of the functional liquid droplet ejection head 1 is inspected.

  The maintenance device 34 is disposed so as to be aligned with the suction device 36 and the suction device 36 for eliminating the discharge failure due to thickening or clogging of the functional liquid in the discharge nozzle 13, and the nozzle surface 11 of the functional liquid droplet discharge head 1 is arranged. And a wiping device 37 for wiping.

  The suction device 36 is in close contact with the nozzle surface 11 of the functional liquid droplet ejection head 1 and is connected to the three caps 41 corresponding to the R, G, and B colors and the three caps 41 via a suction tube (not shown). And an ejector (not shown). The suction device 36 closes each cap 41 to the nozzle surface 11 of the functional liquid droplet ejection head 1 and performs suction with an ejector, thereby eliminating ejection failure due to clogging of the ejection nozzle 13 or the like.

  The wiping device 37 includes a wiping sheet 42 that contacts the nozzle surface 11 and a sheet feeding mechanism (not shown) that feeds and winds the wiping sheet 42. The wiping device 37 presses the wiping sheet 42 against the nozzle surface 11 of the discharge nozzle 13, and moves the discharge nozzle 13 back and forth in the Y-axis direction by the XY table 52, whereby the nozzle surface of the functional liquid droplet discharge head 1 after the suction processing. 11 is wiped off.

  The head inspection apparatus 33 includes a head holder 51 on which one functional liquid droplet ejection head 1 is set without a tool, and moves the functional liquid droplet ejection head 1 in the X-axis direction and the Y-axis direction. A functional liquid supply unit 53 that supplies a functional liquid to the functional liquid droplet ejection head 1 via a supply tube (not shown), a flight inspection unit 54 that inspects the flight bend and flight speed of the discharged functional liquid, A discharge amount measuring unit 55 that measures the discharge weight of the discharged functional liquid, a target stage 56 on which the glass substrate 16 is placed, and a temporary placement stage 44 on which the glass substrate 16 is temporarily placed are provided. The functional liquid supply unit 53 is attached to the XY table 52, and the flight inspection unit 54, the discharge amount measuring unit 55, and the target stage 56 are moved along the X axis direction by the XY table 52 in the movement locus of the functional liquid droplet discharge head 1. They are arranged side by side on the machine base 32 so as to face downward.

  When the ejection performance of the functional liquid droplet ejection head 1 is inspected by the head inspection device 33, the functional liquid ejection head 1 is fed by the XY table 52 while the functional liquid is supplied from the functional liquid supply unit 53 to the functional liquid droplet ejection head 1. Are moved in the X-axis direction and the Y-axis direction so as to face the flight inspection unit 54, the discharge amount measuring unit 55, and the target stage 56, respectively.

  The functional liquid supply unit 53 has three functional liquid tanks 61 for storing R, G, and B color functional liquids, respectively, and each functional liquid tank 61 is disposed above the functional liquid droplet ejection head 1. Then, it is selectively used according to the set functional liquid droplet ejection head 1. Therefore, the functional liquid is supplied from each functional liquid tank 61 to the functional liquid droplet ejection head 1 via each supply tube.

  The discharge amount measuring unit 55 includes a container 62 that receives the functional liquid discharged from the functional liquid droplet discharge head 1, and an electronic balance 63 that measures the weight of the functional liquid in the container 62. When the discharge amount (discharge weight) of the functional liquid is measured by the discharge amount measuring unit 55, tens of thousands of functional liquids are discharged in units of the nozzle row 12 and the discharge weight of the functional liquid is measured by the electronic balance 63. When the discharge weight of the functional liquid is measured, the discharge amount (discharge weight) per discharge nozzle 13 is calculated from the measured discharge weight by dividing the number of discharges by the number of discharge nozzles 13 used for discharge. . The measurement of the discharge weight is performed for each nozzle row 12 (nozzle row 12 unit) in the two nozzle rows 12 of the functional liquid droplet discharge head 1.

  The target stage 56 mounts the glass substrate 16 for volume measurement, and droplets are ejected onto the glass substrate 16 by the functional droplet ejection head 1. As will be described later, the glass substrate 16 is naturally dried and then transferred to a separate landing dot imaging device 18 to measure the individual discharge amount (volume) of the landed droplet. The

  The flight inspection unit 54 is ejected from the illumination unit 65 having a pulse laser that is a pulse light source, a microscope camera 66 that is disposed opposite to the illumination unit 65 and receives pulsed light from the pulse laser, and the functional liquid droplet ejection head 1. A functional liquid receiving portion 67 for receiving the functional liquid. When inspecting the flight curve or missing dots, the functional liquid is discharged while the illumination unit 65 and the microscope camera 66 are driven. The discharged functional liquid is blocked by the pulse laser between the illumination unit 65 and the microscope camera 66 and landed on the functional liquid receiver 67. Then, the flight speed is measured based on the result of the high-speed shooting by the flight inspection unit 54, and it is checked whether there is a flight bend and whether there is a discharge omission.

  The control device 26 includes a drive unit (not shown) having various drivers and a control unit (not shown) that is connected to each unit and controls the entire ejection inspection device 31. The control unit inputs various data from each unit and outputs the result of processing according to the program stored in the hard disk to each unit via the drive unit. Thereby, the whole discharge inspection apparatus 31 is controlled, and various processes are performed.

Next, the landing dot imaging device 18 will be described with reference to FIG. Specifically, this apparatus is a non-contact three-dimensional surface shape roughness measuring machine, and measures the volume of the landing dot 10 by a scanning white light interference method.
The landing dot imaging device 18 includes an installation table 95, a set table 96 that fixes the glass substrate 16, an imaging XY table 97 that is disposed on the installation table 95 and supports the set table 96 movably in the XY directions, An imaging frame 98 disposed on the installation table 95 so as to straddle the set table 96, and a white interferometer (image recognition means) 99 disposed above the set table 96 (glass substrate 16) by the imaging frame 98 It is equipped with. The glass substrate 16 is moved in the XY direction by the imaging XY table 97, and the landing dots 10 landed on the glass substrate 16 are made to face the white interferometer 99 one by one, and the shape of all the landing dots 10 is measured.

  As shown in FIG. 4, the white interferometer 99 includes a white LED 101 serving as a light source that emits white light, and an interference filter (bandpass filter) 102 that is provided downstream of the irradiation direction of the white LED 101 and filters white. The reflection mirror 103 is provided downstream of the interference filter 102 and reflects white light at a right angle. The reflection mirror 103 is provided downstream of the reflection mirror 103 and emits white light toward an interference objective lens (Mirau type) 104 described later. A beam splitter 105 that transmits the reflected light reflected from the imaging object (landing dots 10) while reflecting at a right angle, an interference objective lens 104 provided on the downstream side of the beam splitter 105, and an interference objective lens 104 are provided. A piezo Z-axis table 106 that slightly vibrates in the Z-axis direction and reflected light reflected from the landing dot 10 are transmitted through an interference objective lens 104. Through the fine beam splitter 105 includes an imaging camera (CCD camera) 107 for imaging, a.

  The white interferometer 99 acquires the surface shape of the object imagewise as interference fringes. The shape measurement result by the white interferometer 99 (the imaging result by the imaging camera 107) is transmitted to the control device 26 and image recognition is performed. Based on this image recognition, the volume of each landing dot 10, and more specifically, the functional droplet The discharge amount of each discharge nozzle 13 of the discharge head 1 is inspected.

  Next, a method for measuring the volume of the landing dots 10 in the present embodiment will be described. First, the relationship between the humidity of the surrounding atmosphere and the water repellency of the glass substrate 16 will be described prior to measuring the volume of the landing dots 10.

  As described above, the functional droplet landed on the glass substrate 16 does not form an appropriate dome shape (FIG. 5A) due to excessive expansion of the droplet when the humidity is high. Specifically, the contact angle θ of the functional droplet on the glass substrate 16 becomes extremely small (FIG. 5B). On the other hand, when the humidity is low, an appropriate dome shape is not formed due to excessive rise of droplets, and flare (jagged shape) tends to occur at the edge of the landing dot 10. Specifically, the contact angle θ of the functional droplet on the glass substrate 16 becomes extremely large (FIG. 5C). As described above, when the droplet does not have an appropriate dome shape, the image of the surface shape cannot be properly recognized, and the measurement accuracy by the white interferometer 99 is lowered.

The volume measurement of the landed functional liquid droplet (landing dot 10) is performed after drying and stabilizing for a certain period of time. Here, the fixed time is a time until the landing dot 10 is in a dry stable state in which the evaporation of the solvent becomes a small amount, and the transition to the dry stable state is due to natural drying. A structure having a heating device and drying the landing dots 10 by heat drying to accelerate the transition to the dry stable state may be used. However, rapid drying by heating or the like does not stabilize the transpiration even if the dry stable state is reached. . That is, by drying the landing dots 10 by natural drying, transpiration is stabilized and more accurate volume measurement can be performed. At this time, the evaporation rate of the solvent varies depending on the atmospheric humidity.
Therefore, the influence of the atmospheric humidity on the measurement accuracy of the landing dot 10 is great. Therefore, several types of glass substrates 16 exhibiting different water repellency by surface modification treatment (plasma treatment) are prepared, and functional droplets landed on each glass substrate 16 are constant at room temperature under a plurality of different humidity conditions. After naturally drying for a while, the shape of the landing dot 10 was observed.

First, the glass substrate 16 was subjected to water repellency treatment to prepare a plurality of types of glass substrates 16 having different water repellency. The water repellent treatment is a fluorinated plasma treatment using, for example, fluorinated methane as a treatment gas. Here, a plurality of types of glass substrates 16 (Table speeds 10 mm / s, 15 mm / s, 20 mm / s, 25 mm / s, 30 mm / s, 35 mm / s). Here, the Table speed is set to the glass level, and the lower the glass level, the longer the water repellent treatment time (high water repellency).
Subsequently, the functional liquid droplets (landing dots 10) landed on the glass substrate 16 were naturally dried and stabilized for about 30 minutes, and then the shape was observed using a microscope (with a lens magnification of 3000 times, using LED illumination). . With respect to this result, the dome shape suitable for image recognition was evaluated as ◯, Δ when a slight jagged shape (flare) occurred at the edge of the landing dot 10, and x when a jagged shape occurred (FIG. 6). . Further, when adjacent landing dots 10 are connected or deviated from the field of view, the shape cannot be recognized.

According to the results shown in FIG. 6 (humidity-water repellency data 20), the landing dots 10 are formed on the glass substrate 16 having a high water repellency (glass level 10, 15) when the ambient atmosphere has a high humidity (80%). When used, it showed a dome shape suitable for imaging. Further, when the humidity of the ambient atmosphere was low (10%, 30%), the landing dot 10 showed an appropriate dome shape by using the glass substrate 16 having low water repellency (glass level 30, 35).
From the above results, it was found that by selecting the glass substrate 16 having water repellency suitable for the atmospheric humidity, the landing dots 10 always have an appropriate dome shape regardless of the atmospheric humidity.

Next, the volume measurement of the landing dot 10 will be described.
When starting the volume measurement of the landing dot 10, the operator selects a glass substrate (inspection substrate) 16 having water repellency suitable for the atmospheric humidity from the plurality of glass substrates 16 and sets it on the set table 96. Regarding the selection of the glass substrate 16, a control table relating to atmospheric humidity and water repellency is prepared in the control device 26 based on the above-described results. The control device 26 measures the atmospheric humidity and informs the operator of the glass substrate 16 having appropriate water repellency following this control table.
As shown in FIG. 7A, inspection discharge is performed with the functional liquid droplet discharge head 1 facing the glass substrate 16 set on the set table 96. Specifically, a plurality of shots of the functional liquid are continuously ejected from the effective nozzles excluding the ineffective nozzles of all the ejection nozzles 13 to the same position and slid in the Y axis direction. To discharge. Since FIG. 7B is a schematic diagram, the number of landing dots 10 is different from the actual number.
In the present embodiment, the landing dots 10 are formed with a plurality of shots of functional droplets in order to reduce the influence of volume variation in the functional droplets in one shot.

  When functional droplets are inspected and discharged on the glass substrate 16, the glass substrate 16 is placed on the temporary placement stage 44 and waits for a predetermined time. As described above, the certain time is the time until the landing dot 10 is in a dry stable state in which the evaporation of the solvent is reduced to a small amount. This time is stored by the control device 26. When it is determined that, for example, 60 minutes have elapsed from the time when the impact was discharged by the time measuring mechanism (time measuring means) incorporated in the control device 26, the standby is ended. Although it is described that the standby is ended, this means that the user is notified of the end of the standby time by an alarm or the like. Thus, the user knows the end of the waiting time and performs the following operation.

Next, the glass substrate 16 is set on the set table 96 of the landing dot imaging device 18, and the volume of each landing dot 10 is measured (FIG. 3). The shape of each landing dot 10 is recognized by the white interferometer 99 described above, and the volume of each landing dot 10 is measured based on the image recognition. From the volume of each landing dot 10, the discharge amount at each discharge nozzle 13 is calculated. The volume measurement by the landing dot imaging device 18 continuously measures the volume of the landing dots 10 in units of the nozzle row 12 in the functional liquid droplet ejection head 1.
The landing dot 10 has a dome shape suitable for image recognition by using a glass substrate 16 having appropriate water repellency according to the atmospheric humidity. Accordingly, measurement errors can be suppressed as much as possible, so that the volume of each landing dot 10 is strongly reflected in the discharge amount of each discharge nozzle 13.

  According to the above configuration, a plurality of types of glass substrates 16 having different water repellency are prepared, and the relationship between the humidity of the surrounding atmosphere and the plurality of types of glass substrates 16 in which the landing dots 10 for measurement have an appropriate dome shape. Based on the expressed humidity-water repellency data 20, the volume of the surrounding atmosphere is measured by performing volumetric inspection discharge and landing dot 10 using one glass substrate 16 corresponding to the measured humidity of the surrounding atmosphere. The measurement error of the impacted dot 10 volume due to the influence can be suppressed as much as possible.

It is the external appearance perspective view which showed the functional droplet discharge head. It is the top view which showed typically the discharge inspection apparatus. It is the side view which showed the landing dot imaging device typically. It is sectional drawing which showed the white interferometer typically. It is a schematic diagram showing a state where the landing dots on the glass substrate form a substantially hemisphere with (a) a proper dome shape, (b) a contact angle of 90 ° or less, and (c) a contact angle of 90 ° or more. . It is a table | surface which shows the humidity-water repellency relationship between atmospheric humidity and a glass substrate. It is explanatory drawing for demonstrating test | inspection discharge in a discharge inspection apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Functional droplet discharge head 10 ... Landing dot 12 ... Nozzle row 13 ... Discharge nozzle 16 ... Glass substrate 20 ... Humidity-water repellency data 26 ... Control apparatus 99 ... White interferometer

Claims (4)

A method for measuring the volume of a landed dot by using an interferometer to measure the volume of a landed dot that has landed on a test substrate by test ejection of a functional liquid droplet ejection head,
Prepare multiple types of test substrates with different water repellency,
Based on the humidity-water repellency data representing the relationship between the humidity of the ambient atmosphere and a plurality of types of the test substrates in which the landing dots for measurement have an appropriate dome shape,
A method for measuring a volume of a landing dot, wherein the inspection discharge and the volume measurement of the landing dot are performed using the one inspection substrate corresponding to the humidity of the measured ambient atmosphere. A water repellent film is formed on the surface of each inspection substrate,
The landing dot volume measuring method according to claim 1, wherein the plurality of types of inspection substrates are classified according to the length of time for forming the water-repellent film.   The landing dot volume measuring method according to claim 1, wherein the landing dots are formed by a plurality of shots of the inspection discharge.   The landing dot volume measuring method according to claim 1, wherein the volume of the inspection discharge and the landing dot is measured for each nozzle row in the functional droplet discharge head.

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