JP5387598B2 - Evaluation method - Google Patents

Description

  The present invention relates to an evaluation method and an evaluation apparatus.

As a method of manufacturing a light emitting layer or the like of an organic EL device, a method of forming a functional film by forming a liquid material containing a functional material into droplets through a nozzle, discharging the liquid to a discharge target, and drying the liquid. Yes.
In order to obtain a functional film having a high uniformity of film thickness, it is important to align the relative discharge amount of the liquid material between the nozzles. For this purpose, it is important to calibrate the discharge amount by measuring the relative discharge amount of the liquid material discharged from the nozzle.
As a method for measuring the discharge amount of the liquid material, if the liquid material is colored, such as a color filter, it is possible to use a method of measuring the solute contained in the liquid material by drying the liquid material. it can.
In addition, as a method for measuring the discharge amount of the liquid material, for example, a large number of liquid materials are discharged and applied to the discharge target body via the nozzle, and the weight of the discharge target body before application and the weight of the discharge target body after application There are known a method for obtaining the correlation between the weight of the liquid material and the coating area based on the difference between them, and a method for directly measuring the volume by measuring the dots of the liquid material three-dimensionally.
Further, for example, as in Patent Document 1, after a liquid material discharged from a nozzle is received on a recording medium having a petri dish form, the liquid material is deformed into a cylindrical shape by covering with a top plate, and the area is measured. There is known a method for measuring the discharge amount.

JP 2000-153603 A

However, when an almost transparent material that forms a light emitting layer used in an organic EL device, for example, is used as the liquid material, the contrast between the region where the liquid material is applied and the other region cannot be obtained. There was a problem that the coated region could not be observed, and therefore it was extremely difficult to measure the area and the like.
Further, in the method shown in Patent Document 1, since it takes a long time to measure one point, it is practically difficult to measure at a practical measuring time for measuring about multiple points (for example, 180 points). There was a problem.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] An evaluation method according to this application example is an evaluation method for observing a region in which a functional liquid containing a solute in a solvent or a transparent liquid containing only the solvent is permeated. A coating step of discharging droplets of the liquid material to the receiving layer side of a transparent substrate having a layer to form a coating region in which the liquid material is permeated into the receiving layer; and the solvent in the liquid material. And an observing step of irradiating the substrate with light from one side of the substrate, transmitting the substrate, and observing the application region from the other side.

According to this, it is possible to observe the application region where the liquid material is applied in a state where the solvent remains. In the reflection type observation method in which light is reflected and observed, it is difficult to observe the coated area of the transparent liquid material, but light is irradiated from one side of the substrate and transmitted through the other side of the substrate. The application area can be observed by using a method of measuring the light distribution.
In this case, it is difficult to observe the application region unless the solvent remains, and it has been empirically confirmed that the application region can be observed if the solvent remains.
In addition, since the coating area can be observed only with a solvent, when using a functional liquid with a high dilution ratio with a solvent, such as an organic EL device, a certain amount of conditions can be set with only the solvent without using an expensive sample. Development costs can be reduced.
In addition, “transparent” in Ojizumi is described as “the object passes light well. When light passes through the substance, the degree of absorption is small”. That is, “transparent” is not limited to the case where the light reflectance and light absorption are zero. In the above description, “transparent” includes “small degree of absorption”.

  Application Example 2 In the evaluation method according to the application example described above, after discharging the droplet, at least the application region on the receiving layer side is covered with a transparent member that does not react with the liquid material, and the observation step is performed. It is characterized by performing.

  According to the application example described above, evaporation of the solvent is suppressed because the application region is covered with the transparent member. Therefore, an observation process for observing the application region more accurately can be performed. In addition, since the evaporation of the solvent due to the elapsed time between the discharge process and the observation process can be suppressed, the application region can be observed in a more stable state.

  Application Example 3 The evaluation apparatus according to this application example discharges a functional liquid containing a solute in a solvent or a transparent liquid containing only the solvent onto a transparent substrate having a receiving layer from a nozzle of the discharge head. An evaluation apparatus for observing the application region of the liquid material formed by permeating the receptor layer, the light source emitting light in a first direction, and the light emitting direction of the light source. And an imaging unit that observes light output from the first direction through the transparent substrate.

  According to this, in a state where the solvent remains, it is possible to observe the application region where the liquid material is applied. In the reflection type observation method in which light is reflected and observed, it is difficult to observe the coated area of the transparent liquid material, but light is irradiated from one side of the substrate and transmitted through the other side of the substrate. The application area can be observed by measuring the light distribution. In this case, it is difficult to observe the application region unless the solvent remains, and the application region can be observed if the solvent remains.

  Application Example 4 In the evaluation apparatus according to the application example, the transparent substrate is disposed between the light source and the imaging unit, and a positional relationship in which the light source and the imaging unit face each other is maintained. The apparatus further includes a moving mechanism that moves the positions of the light source and the imaging unit relative to the transparent substrate with respect to a planar direction of the transparent substrate.

  According to the application example described above, since the moving mechanism that moves relative to the transparent substrate with respect to the planar direction of the transparent substrate is provided, for example, even when there are a plurality of application regions, each application region It is possible to observe the image by moving it to this position, and even if there are a plurality of ejection holes of the ejection head, each can be observed.

(A) is sectional drawing which shows the state which discharges a transparent liquid material from a discharge device, (b) is sectional drawing which shows the state with which the liquid material was apply | coated to the receiving layer, (c) is a liquid material application | coating The schematic diagram which shows the state which is observing the area of the area | region made. (A) is a plan view of a droplet discharge evaluation apparatus that discharges and evaluates transparent ink from a plurality of nozzles, (b) is a cross-sectional view of the droplet discharge evaluation apparatus, and (c) shows the structure of the discharge head. A top view and (d) are sectional views showing the structure of a medium. (A), (b) is a top view which shows the evaluation procedure of the discharge amount using a droplet discharge evaluation apparatus. (A), (b) is a top view which shows the evaluation procedure of the discharge amount using a droplet discharge evaluation apparatus. (A), (b) is a top view which shows the evaluation procedure of the discharge amount using a droplet discharge evaluation apparatus.

  Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

(First Embodiment: Evaluation Method)
FIG. 1A is a cross-sectional view showing a state in which a transparent liquid material (hereinafter also referred to as transparent ink) is discharged from a discharger, and FIG. 1B shows a state in which the liquid material penetrates into the receiving layer. Sectional drawing which shows the apply | coated state, FIG.1 (c) is a schematic diagram which shows the state which is measuring (observing) the area of the area | region where the liquid body was apply | coated. As the transparent liquid, a functional liquid containing a solute in a solvent or a liquid containing only a solvent can be used.

The medium 100 as a transparent substrate includes a receiving layer 101 and a support film 102. The receiving layer 101 is a transparent film containing, for example, ceramic having a thickness of about 45 μm or a lyophilic resin. The receiving layer 101 is supported as a support film 102 by a PET (polyethylene terephthalate) resin having a thickness of about 150 μm, for example.
Note that “transparent” is defined as “the object passes light well. When light passes through a substance, the degree of absorption is small”. It is assumed that “the degree of being performed is small”.

  The transparent ink 140 is accommodated in the discharger 120, and for example, a solution obtained by dissolving / dispersing polyvinylcarbazole as a solute as a solute in cyclohexylbenzene (boiling point 240 ° C.) as a solvent is used. The boiling point of cyclohexylbenzene is 240 ° C., and when it is discharged from the discharger 120, it is difficult to dry even after being discharged onto the medium 100, and when it is dried under reduced pressure by heating, it has a property of drying quickly. Polyvinylcarbazole is a substance that functions as a light emitting layer or a hole transport layer of an organic EL element. In addition, as a solute, Alq3 and other things can be used properly according to the objective. As the solvent, butyl carbitol acetate (boiling point 247 ° C.) or the like may be used.

The boiling point of the solvent may be about 200 ° C. or higher, and ethylene glycol (boiling point 197.3 ° C.) or the like may be used. And if it is 230 degreeC or more, it is suitable and it becomes possible to raise observation precision more.
Such transparent ink 140 is ejected by the ejector 120 toward the receiving layer 101 of the medium 100 as the transparent ink 140 as droplets 141. The discharge amount is electrically controlled by a control device (not shown), and the discharge amount can be changed according to the purpose. The medium 100 receives the transparent ink 140 as droplets 141. When the droplet 141 of the transparent ink 140 lands, it penetrates into the receiving layer 101 of the medium 100 and forms an application region 100a to which the transparent ink 140 is applied (application process).

  After the application region 100a is formed, the medium 100 is conveyed to the measuring device 160. Then, the application region 100a is observed (observation process). FIG. 1C is a cross-sectional view of a measurement apparatus that irradiates and passes light from a light source from one surface of a medium and captures a projection of an application region by an imaging device provided on the other surface. The measurement device 160 includes a light source 161, an optical system 162, an imaging unit 163, an information processing unit 164, and a monitor 165.

  The light source 161 emits light that passes through the medium 100. The optical system 162 shapes the light emitted from the light source 161 and emits and transmits this light to the analysis target (in this case, the medium 100). The imaging unit 163 images light that has passed through the analysis target (in this case, the medium 100). The information processing unit 164 processes the light distribution information obtained by the imaging unit 163 and extracts, for example, the area of the application region 100a. For example, the monitor 165 copies the application area 100 a formed on the medium 100. By taking such a configuration, it is possible to observe the application region 100a with the transparent ink 140, which has been difficult to measure conventionally.

In this case, after the droplet 141 of the transparent ink 140 (liquid material) has permeated the medium 100, the coating region 100a (receiving layer 101 side) is covered with a transparent member that does not react with the transparent ink 140, such as a glass plate. Thus, since the evaporation of the solvent during the observation can be prevented, the observation can be continued for a long time. This method is particularly effective when a solvent having a boiling point of less than 200 ° C. is used. For example, even when dimethyl sulfoxide (boiling point 189 ° C.) or the like is used as a solvent, the coating region 100a can be observed. Become.
Further, the discharge amount of the transparent ink 140 from the discharger 120 may be changed stepwise and discharged to a plurality of locations (for example, separated by about 100 μm). In this case, the correlation between the ejection amount of the transparent ink 140 and the control signal applied to the ejector 120 can be known.

  The measurement method described above has the following effects.

  The application region 100a formed by discharging the transparent ink 140 from the discharger 120, which has been difficult in the past, can be observed. Therefore, for example, from the observation result, the discharge amount of the transparent ink 140 from the discharger 120 can be estimated qualitatively from the area of the application region 100a.

It becomes possible to observe the area change of the application region when the discharge amount of the transparent ink 140 from the discharger 120 is changed. In this case, for example, after the ejector 120 is moved so as to leave an interval of about 100 μm, the amount of ejection from the ejector 120 is changed (for example, the voltage for driving the ejector 120 is increased) to form the application region. Thereafter, the application region is also observed, and the ratio of the discharge amount can be obtained from the discharge amount and the area difference between the application region 100a and the application region.
As described above, even if ejection is performed from the ejector 120 with the same ejection amount, the surface state of the medium 100 is distributed, and the area of the application region 100a is the same even with the same ejection amount due to changes over time due to temperature, humidity, and the like. fluctuate. Therefore, it is difficult to estimate the discharge amount from the discharger 120 only with the area of the application region 100a.
On the other hand, when discharging is performed by changing the discharge amount using the same discharger 120 at adjacent positions, the surface state of the medium 100 can be handled as almost the same condition, and further, the temperature, humidity, etc. can be handled as almost the same condition. The correlation between the application region 100a, the area of the application region, and the discharge conditions can be grasped, and the relationship between the discharge conditions and the discharge amount of the dispenser 120 can be grasped.

  The object being observed here is not a solute, and most of the part will observe the nature of the solvent. Therefore, if the above-mentioned observation is performed using only the solvent, for example, the production conditions can be determined to some extent while suppressing the consumption of the expensive organic EL solid material. That is, the cost for the experiment can be reduced.

  After the transparent ink 140 is discharged from the ejector 120 to the medium 100 and the application region 100a is formed, the application region 100a is covered with a transparent member that does not react with the transparent ink 140, such as a glass plate, for example. Therefore, observation can be continued for a long time. This method is effective when the solvent has a boiling point of less than 200 ° C.

(Second Embodiment: Evaluation Device)
2A is a plan view of a droplet discharge amount evaluation apparatus as an evaluation apparatus for discharging and evaluating transparent ink from a plurality of nozzles, FIG. 2B is a cross-sectional view thereof, and FIG. FIG. 2D is a cross-sectional view showing the structure of the medium, and FIG. 2D is a plan view showing the structure of the ejection head.
The droplet discharge amount evaluation apparatus 200 includes a stage 201, a light source 202, an imaging unit 203, an ejection head fixing base 204, an ejection head rail 205, an imaging unit first rail 206, an imaging unit second rail 207, a media supply unit 208, A media collection unit 209, a comprehensive control device 210, a light source first rail 211, and a light source second rail 212 are provided.
In the plan view shown in FIG. 2A, the ejection head RGB 260 is originally hidden, but the positional relationship of the ejection head RGB 260 is an important position in the present embodiment.

The stage 201 is provided using, for example, hard glass and has a function of supporting the medium 250.
The light source 202 emits light toward the stage 201 and transmits the light flux to the imaging unit 203 via the stage 201 and the medium 250.
The imaging unit 203 detects and observes the application region 250a (see FIG. 3) formed on the medium 250.
The discharge head fixing base 204 fixes the discharge head RGB260.
The ejection head rail 205 is a rail for changing the position of the ejection head fixing base 204. For example, the ejection head fixing base 204 is moved so as to cover the stage 201 or moved away from the stage 201. Control.
The imaging unit first rail 206 is a rail for changing the position of the imaging unit 203, and controls the imaging unit 203 to move, for example, so as to cover the stage 201 or to move to a position away from the stage 201.
The imaging unit second rail 207 is a rail for changing the position of the imaging unit 203 in a direction intersecting with the imaging unit first rail 206 (in this case, an orthogonal direction). The position of the imaging unit 203 is changed to, for example, the media supply unit 208. Control to move to the media collection unit 209 side.
The light source first rail 211 is a rail for changing the position of the light source 202, and controls the light source 202 to move, for example, to cover the stage 201 or to move to a position away from the stage 201.
The light source second rail 212 is a rail for changing the position of the light source 202 in a direction crossing the light source first rail 211 (in this case, the orthogonal direction), and moves the position of the light source 202 to the media supply unit 208 side, for example. Or moving to the media collection unit 209 side. Here, it is assumed that both the light source 202 and the imaging unit 203 are moved relatively synchronously.
The media supply unit 208 has a function of supplying the media 250 to the stage 201.
The media collection unit 209 has a function of collecting the processed media 250 from the stage 201.
The overall controller 210 controls the stage 201 (for example, suction ON / OFF of the medium 250), supply / collection operation of the medium 250, position control of the discharge head fixing base 204, position control of the light source 202 and the imaging unit 203, and discharge. It has a function for performing overall control such as ejection amount control of the head RGB 260 and analysis of an image captured by the imaging unit 203.

Here, the medium 250 as a transparent substrate includes a receiving layer 251 and a support film 252 as shown in FIG. The receiving layer 251 is a transparent film containing, for example, ceramic having a thickness of about 45 μm or a lyophilic resin. The receiving layer 251 is supported as a support film 252 by, for example, a PET (polyethylene terephthalate) resin having a thickness of about 150 μm.
The ejection head RGB260 is a group of three primary colors, for example, red, green, and blue. Each of the configurations of the ejection head RGB260 is ejected from a nozzle 261 provided in the ejection head RGB260 (all the red, green, and blue colors have the same configuration). An array of the nozzles 261 is referred to as a nozzle row 261a.
Moreover, as the transparent ink 140, as described above, a functional liquid containing a solute in a solvent or an ink containing only a solvent can be used. As an example, for example, a solvent obtained by dissolving / dispersing polyvinylcarbazole as a solute as a solute in cyclohexylbenzene (boiling point 240 ° C.) as a solvent, or cyclohexylbenzene alone can be mentioned.

(How to use the droplet discharge volume evaluation device)
Next, how to use the droplet discharge amount evaluation apparatus 200 as an evaluation apparatus will be described. 3 to 6 are plan views showing how to use the droplet discharge evaluation apparatus.
First, the overall control device 210 outputs an instruction signal to the stage 201 to attract the medium 250. Based on this instruction signal, the stage 201 sucks the medium 250.

  Next, as shown in FIG. 3A, as shown in FIG. 3A, the integrated control device 210 instructs the discharge head fixing base 204 to move to a fixed position side of the light source 202 of the stage 201 along the discharge head rail 205. Output a signal. Based on this instruction signal, the ejection head fixing base 204 moves.

  Next, as procedure 2, as shown in FIG. 3B, the overall control device 210 outputs a scanning signal for scanning the ejection head fixing base 204 along the ejection head rail 205. Then, in a state where the ejection head fixing base 204 is scanned, the general control device 210 outputs an instruction signal to the ejection heads RGB 260 to eject the transparent ink 140 all at once. Based on this instruction signal, the ejection heads RGB 260 eject the transparent ink 140 all at once. By performing this procedure, the transparent ink 140 permeates the receiving layer 251. Here, it is more preferable that the signal for controlling the discharge amount is shaken at several levels because the correlation between the discharge energy and the discharge amount can be obtained.

  Next, as procedure 3, as shown in FIG. 4A, the general control device 210 stops the discharge of the transparent ink 140 when the predetermined number of discharges is reached, and moves the discharge head fixing base 204 to a fixed position. .

  Next, as procedure 4, as shown in FIG. 4 (b), the comprehensive control device 210 detects each application region 250a formed on the medium 250, and each point or about 2 to 5 points at a time. An instruction signal is output for observation. Upon receiving this instruction signal, the light source 202 is scanned in a direction along the light source first rail 211 and the light source second rail 212. Then, the image capturing unit 203 is synchronized with the light source 202 along the image capturing unit first rail 206 and the image capturing unit second rail 207 (with the positional relationship between the light source 202 and the image capturing unit 203 being maintained). Each application region 250a is observed while moving in the plane direction, and the data is transferred to the comprehensive control device 210. The integrated control device 210 receives this data and calculates and stores the area of each application region 250a, for example. The area calculation may be performed by the imaging unit 203.

Next, as procedure 5, as shown in FIG. 5, the integrated control device 210 outputs an instruction signal for returning the light source 202 and the imaging unit 203 to their original positions (fixed positions). Based on this instruction signal, the light source 202 is moved along the light source first rail 211 and the light source second rail 212 to return to the original position (fixed position). Then, the imaging unit 203 is moved along the imaging unit first rail 206 and the imaging unit second rail 207 to return to the original position.
By following this procedure, the evaluation of the discharge amount can be observed using the droplet discharge amount evaluation apparatus 200.

  The above-described evaluation apparatus has the following effects in addition to the effects of the embodiment described above.

The surface state of the medium 250 has substantially uniform characteristics in a narrow region (for example, within a distance range of several centimeters), but the surface state shows different characteristics when viewed in a wide region. Therefore, even if the coating region 250a is observed using a wide region, it is difficult to observe precisely due to the influence of the surface state difference of the medium 250.
In this droplet discharge evaluation apparatus, the transparent ink 140 is discharged using the nozzle row 261a in which the nozzles 261 are arranged at adjacent positions to form the application region 250a. Therefore, a large number of application regions 250a are formed in a narrow region of the medium 250 (for example, About 180). For this reason, the surface state of the medium 250 has substantially uniform characteristics, and the factors that fluctuate the area of the application region 250a are reduced. Therefore, the transparent ink 140 of the same discharge amount spreads in substantially the same area. Have. Therefore, the area ratio is almost equal to the volume ratio, and the volume can be calibrated almost accurately with only the area information.

  Since the nozzles 261 are arranged side by side, even when the transparent ink 140 is used, the area of a large number of droplets (for example, about 180 points per color of the ejection head RGB 260) can be measured (observed) in a narrow region. . Therefore, for example, it is possible to statistically analyze a manufacturing problem of the ejection head RGB 260 such as a standard deviation. For example, when there are two peaks in the area distribution, it can be estimated that the discharge head RGB 260 has two types of manufacturing problems. Further, it is possible to extract the difference between the central nozzle 261 and the peripheral nozzle 261 of the ejection head RGB 260.

  In step 2, instead of causing the ejection heads RGB 260 to eject the transparent ink 140 all at once, for example, by ejecting the transparent ink 140 from the nozzles 261 every other nozzle, even when the transparent ink 140 is used, Crosstalk between adjacent nozzles 261 can be examined. In this case, by causing the transparent ink 140 to be ejected from the nozzle 261 in a narrow area and forming the application area 250a, the factor of changing the area of the application area 250a is reduced, and the same discharge amount of the transparent ink 140 is the same. Has a spread in area. Therefore, it is possible to quantitatively capture crosstalk.

  If the above-mentioned observation is performed in step 2 using only the solvent instead of the transparent ink 140, for example, the production conditions can be determined to some extent while suppressing the consumption of the expensive organic EL solid material. That is, the cost for the experiment can be reduced.

Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification is shown below.
[Modification 1]
After performing step 3, the coating region 250a is covered with a transparent member that does not react with the transparent ink 140, such as a glass plate, so that evaporation of the solvent during observation can be prevented. It is possible to continue.
[Modification 2]
In the second embodiment, the collar that moves the light source 202 and the imaging unit 203 to observe the application region 250a has been described. However, a configuration in which the medium 250 is moved for observation may be used.

  DESCRIPTION OF SYMBOLS 100 ... Medium, 100a ... Application | coating area | region, 100b ... Application | coating area | region, 101 ... Receptor layer, 102 ... Supporting film, 120 ... Discharger, 140 ... Transparent ink, 141 ... Droplet, 160 ... Measuring apparatus, 161 ... Light source, 162 ... Optical system 163 ... Imaging unit, 164 ... Information processing unit, 165 ... Monitor, 200 ... Droplet discharge amount evaluation device, 201 ... Stage, 202 ... Light source, 203 ... Imaging unit, 204 ... Discharge head fixing base, 205 ... Discharge Rail for head, 206 ... Imaging unit first rail, 207 ... Imaging unit second rail, 208 ... Media supply unit, 209 ... Media recovery unit, 210 ... Total controller, 211 ... Light source first rail, 212 ... Light source second Rail, 250 ... Media, 250a ... Coating region, 251 ... Receptive layer, 252 ... Support film, 260 ... Discharge head RGB, 261 ... Nozzle, 261a ... No Le column.

Claims (2)

A transparent liquid containing a functional liquid containing a solute in a solvent, or an evaluation method for observing a region infiltrated with a transparent liquid containing only the solvent,
A coating step of discharging droplets of the liquid material to the receiving layer side of a transparent substrate having a receiving layer, and forming a coating region in which the liquid material is infiltrated into the receiving layer;
An observation step of irradiating the substrate with light from one surface of the substrate while allowing the solvent in the liquid to remain, transmitting the substrate, and observing the coating region from the other surface side of the substrate. The evaluation method characterized by including these.   2. The evaluation method according to claim 1, wherein after the droplets are ejected, at least the application region on the receiving layer side is covered with a transparent member that does not react with the liquid material, and the observation step is performed. Evaluation method.

Images